WO2025009393A1 - Display device - Google Patents

Abstract

[Problem] To achieve an increase in definition of a displayed image easily and at a low cost while ensuring a wide angle of view. [Solution] A display device 1 according to an embodiment comprises: an optical system 10 that includes an ocular lens 11; a first display panel 21 that has a first display region 21A in which a plurality of pixels are arranged and that causes the first display panel 21 to face the optical system 10; and a second display panel 22 that has, at a position in the periphery of the first display region 21A in a view of the first display region 21A from the optical system 10, a second display region 22A in which a plurality of pixels are arranged.

Description

Display device

This disclosure relates to a display device.

Display devices known as head-mounted displays, electronic binoculars, and electronic viewfinders are conventionally known. These types of display devices typically include an optical system that includes an eyepiece, and a display panel that emits light into the optical system. Such display devices are used with the user's eyes close to the eyepiece. In this state of use, when the display panel emits light to form an image, this light is guided through the eyepiece to the user's eyes. This allows the user to view the image through the eyepiece in front of their eyes.

Among the display devices mentioned above, head mounted displays, for example, can be broadly categorized into VST (Video See-through) type and OST (Optical See-through) type. From the standpoint of ease of use and visibility, VST type head mounted displays are generally required to display images with a wide angle of view as well as satisfy desirable conditions regarding eye relief and eye box size. Eye relief is the distance from the eyeball surface to the eyepiece. Eye box is the range of eye positions in front of the eyepiece where the user can properly view an image through the eyepiece.

For example, if the eye relief of the optical system is set short, a large angle of view can be ensured even when a small display panel is used. In this case, however, ease of use may be compromised if the eyebox becomes excessively small due to the eye relief dimensions, for example. For these reasons, it is currently said that a display panel size of about 2 inches is desirable for head-mounted displays. In this case, it becomes easier to ensure a wide angle of view, for example 100° or more, while still satisfying the desired conditions regarding the desired eye relief, desired eyebox size, etc.

Furthermore, from the standpoint of ease of use, head mounted displays are generally required to be small and lightweight. In response to this demand, there is a trend in recent head mounted displays to switch from the Fresnel lens that has traditionally been widely used as the optical system to an optical system known as a pancake lens type. When a Fresnel lens is used, the distance between the Fresnel lens and the display panel becomes relatively large, and as a result, the thickness of the head mounted display in the optical axis direction can become relatively large. On the other hand, with the pancake lens type, the light emitted by the display panel for forming an image is folded back by the optical system and guided to the eyes. This shortens the distance between the optical system and the display panel, and makes it possible to reduce the thickness of the head mounted display in the optical axis direction.

As mentioned above, it is said that the size of the display panel used in a head mounted display is currently preferably about 2 inches. Liquid crystal panels are mass-produced in large sizes with relatively high pixel density, and liquid crystal panels with a size of about 2 inches can be obtained at low cost with a relatively high pixel density. Therefore, from the perspective of reducing costs, liquid crystal panels are useful as display panels for head mounted displays.

However, although the pixel density of LCD panels is becoming relatively high, it cannot be said to be sufficient for the high definition that is currently required, and is expected to be required in the future, for head-mounted displays.

To be more specific, in the field of head mounted displays, high angular resolution has recently been attracting attention as an indicator of high definition. Specifically, it is said that it is desirable for head mounted displays to have an angular resolution of about 60 PPD (Pixels Per Degree). Here, the pixel density that achieves 60 PPD is 4000 PPI (Pixels Per Inch) or more. When an angular resolution of about 60 PPD is ensured, for example, users will be able to read text and other images displayed in VR space without stress. In contrast, the pixel density of LCD panels is currently about 1000 to 1600 PPI, which is considered high definition. It is thought that a considerable amount of development time and development costs will be required to achieve a high pixel density corresponding to 60 PPD in LCD panels.

Meanwhile, in the field of organic electroluminescence, devices with a higher pixel density than LCD panels have already been put to practical use. Specifically, MOLEDs (Micro Organic Light Emitting Diodes) with a pixel density of around 4000 PPI have already been realized. However, it is currently difficult to enlarge MOLEDs to the desired size of around 2 inches for use in the head-mounted displays mentioned above. Furthermore, it is thought that a considerable amount of development time and development costs will be required to enlarge them to the desired size.

As described above, achieving both high image resolution and a wide angle of view poses manufacturing difficulties. For example, various technologies related to head-mounted displays have been proposed, but no technology is known that effectively solves the problems described above.

Japanese Patent Application Publication No. 6-3641 International Publication No. 2018/100237 International Publication No. 2021/181303

This disclosure has been made in consideration of the above circumstances, and provides a display device that can easily and inexpensively achieve high-definition images while ensuring a wide angle of view.

The display device disclosed herein comprises an optical system including an eyepiece lens, a first display panel having a first display area in which a plurality of pixels are arranged and facing the first display area to the optical system, and a second display panel having a second display area in which a plurality of pixels are arranged, positioned to surround the first display area when the first display area is viewed from the optical system.

FIG. 1 is a diagram illustrating a schematic configuration of a head mounted display as a display device according to an embodiment. FIG. 2 is an exploded perspective view of the head mounted display shown in FIG. 1 . FIG. 3 is a cross-sectional view of the head mounted display taken along line III-III in FIG. 2 is a front view of a first display panel and a second display panel that constitute the head mounted display shown in FIG. 1 . 5 is a cross-sectional view taken along line VV in FIG. 4, showing the first display panel, the second display panel, and the optical members that constitute the head mounted display. 6A to 6C are diagrams for explaining the function of the optical member shown in FIG. 5 . 6A to 6C are diagrams for explaining the function of the optical member shown in FIG. 5 . 6 is a diagram for explaining specific characteristics of the optical member shown in FIG. 5 . FIG. 2 is a diagram for explaining a first modified example of the embodiment shown in FIG. 1 . FIG. 4 is a diagram for explaining a second modified example of the embodiment shown in FIG. 1 . FIG. 11 is a diagram for explaining a third modified example of the embodiment shown in FIG. FIG. 13 is a diagram for explaining a fourth modified example of the embodiment shown in FIG. FIG. 13 is a diagram for explaining a fifth modified example of the embodiment shown in FIG. FIG. 13 is a diagram for explaining a sixth modified example of the embodiment shown in FIG. FIG. 13 is a diagram for explaining a seventh modification of the embodiment shown in FIG. FIG. 13 is a diagram for explaining an eighth modified example of the embodiment shown in FIG. FIG. 13 is a diagram for explaining a ninth modification of the embodiment shown in FIG. FIG. 23 is a diagram for explaining a tenth modification of the embodiment shown in FIG. 1 . FIG. 13 is a diagram for explaining an eleventh modification of the embodiment shown in FIG. 1 .

Below, one embodiment of the present disclosure will be described with reference to the drawings.

<General configuration of head mounted display>
Fig. 1 shows a schematic configuration of a head mounted display 1 as a display device according to one embodiment. Hereinafter, the head mounted display 1 is abbreviated as HMD 1. Fig. 2 is an exploded perspective view of the HMD 1, and Fig. 3 is a cross-sectional view of the HMD 1 taken along line III-III in Fig. 1.

The HMD 1 shown in FIG. 1 includes a lens assembly 13 including an optical system 10, a display panel unit 20, a housing box 30, a band 31, and a display control system 40.

The lens assembly 13, the display panel unit 20, and the display control system 40 are housed in a housing box 30. The band 31 is connected to the housing box 30. The optical system 10 in the lens assembly 13 includes an eyepiece 11 through which the user looks. The optical system 10 is held in the housing box 30 with the eyepiece 11 exposed to the outside from the housing box 30. The display panel unit 20 is positioned so as to face the optical system 10 within the housing box 30. The display panel unit 20 emits light to form an image toward the optical system 10.

The user can fasten the band 31 around the head with the housing box 30 positioned in front of the eyes. This allows the user to wear the HMD 1 with the eyes e (left eye eL, right eye eR) close to the eyepiece lens 11. When the display panel unit 20 emits light for forming an image in this wearing state, this light is guided to the user's eyes e through the eyepiece lens 11. This causes an image to be displayed in front of the user's eyes e. Note that the image that the HMD 1 displays to the user may be a three-dimensional image or a two-dimensional image. Each part of the HMD 1 will be described in detail below.

(Lens assembly)
The HMD 1 includes a lens assembly 13 for the left eye eL and a lens assembly 13 for the right eye eR. Each lens assembly 13 has an optical system 10 and a lens housing 13H that holds the optical system 10. Each optical system 10 is configured as a pancake lens assembly including, for example, the above-mentioned eyepiece lens 11 and an objective lens 12 that is disposed closer to the display panel unit 20 than the eyepiece lens 11. The left and right lens assemblies 13 have the same configuration, and the left and right optical systems 10 also have the same configuration.

Needless to say, the left optical system 10 including the left eyepiece 11 and the left objective lens 12 is used to display an image to the left eye eL, and the right optical system 10 including the right eyepiece 11 and the right objective lens 12 is used to display an image to the right eye eR. In the following explanation, when simply describing the optical system 10, simply the eyepiece 11, simply the objective lens 12, etc., matters common to both the left and right are explained.

As will be described later, the HMD 1 includes a display panel unit 20 for the left eye eL and a display panel unit 20 for the right eye eR. The display panel unit 20 for the left eye eL faces the optical system 10 of the lens assembly 13 for the left eye eL, and the display panel unit 20 for the right eye eR faces the optical system 10 of the lens assembly 13 for the right eye eR. The optical system 10, configured as a pancake lens assembly, reflects light that is incident from the corresponding display panel unit 20 and taken into the optical system 10, and then reflects this reflected light again in a direction away from the display panel unit 20 before being emitted to the outside of the optical system 10. The light emitted to the outside of the optical system 10 reaches the user's eye e. In the pancake lens assembly, even if the distance between the optical system 10 and the display panel unit 20 (more specifically, the first display area 21A of the first display panel 21 and the second display area 22A of the second display panel 22 described below) is shortened, the user's eye e can be focused on the image, and an appropriate image can be displayed to the user. This makes it possible to suppress an increase in the thickness of the HMD 1 in the optical axis direction.

The eyepiece lens 11 has an eyepiece entrance surface 11i facing the display panel unit 20, and an eyepiece exit surface 11e located opposite the eyepiece entrance surface 11i. The objective lens 12 has an objective entrance surface 12i facing the display panel unit 20, and an objective exit surface 12e located opposite the objective entrance surface 12i. More specifically, the eyepiece entrance surface 11i and the objective exit surface 12e face each other between the eyepiece lens 11 and the objective lens 12.

FIG. 3 shows a cross section of the right eyepiece 11 and right objective lens 12 of the optical system 10, and illustrates how light is folded back in the pancake lens assembly in this embodiment. When an image is displayed in front of the user's eyes, as shown in FIG. 3, light from the display panel unit 20 that is incident on the eyepiece entrance surface 11i of the eyepiece 11 via the objective lens 12 is reflected by the eyepiece exit surface 11e of the eyepiece 11. The light reflected by the eyepiece exit surface 11e is then reflected by the eyepiece entrance surface 11i. The light reflected by the eyepiece entrance surface 11i is then emitted outside the optical system 10 and reaches the eye e. The same light behavior as on the right side occurs in the left eyepiece 11 and left objective lens 12.

Pancake lens assemblies are well known and may be constructed using wave plates, reflective films, polarization control elements, etc. The drawings accompanying this specification omit illustration of these optical elements. In this embodiment, the pancake lens assembly is constructed such that light is reflected twice within the eyepiece 11, but it may also be constructed such that light is reflected twice by the objective lens 12, that is, the first reflection is made at the objective exit surface 12e of the objective lens 12, and the second reflection is made at the objective entrance surface 12i. It may also be constructed such that light is reflected twice between the eyepiece 11 and the objective lens 12, that is, the first reflection is made at the eyepiece entrance surface 11i of the eyepiece 11, and the second reflection is made at the objective exit surface 12e.

Note that the optical system 10 may be of a type other than a pancake lens assembly. For example, the optical system 10 may be an optical system that uses a Fresnel lens or a multi-lens array, or an optical system that stacks three or more lenses in the optical axis direction.

(Display panel unit)
As shown in Fig. 1, the HMD 1 includes a display panel unit 20 for the left eye eL and a display panel unit 20 for the right eye eR. The display panel unit 20 for the left eye eL is disposed so as to face the optical system 10 of the lens assembly 13 for the left eye eL, and the display panel unit 20 for the right eye eR is disposed so as to face the optical system 10 of the lens assembly 13 for the right eye eR. Each display panel unit 20 includes a first display panel 21, a second display panel 22, and an optical member 23. In this embodiment, the first display panel 21 and the second display panel 22 are separate display panels, and the HMD 1 includes four separate display panels, but the pair of first display panels 21 and the pair of second display panels 22, a total of four display panels, cooperate to display one image to the user. In detail, the two first display panels 21 emit light that forms a central viewing portion within the angle of view of the image to be displayed, and the two second display panels 22 emit light that forms a peripheral viewing portion of the image, thereby displaying one image to the user.

The left and right display panel units 20 have the same configuration, and the left and right first display panels 21, the left and right second display panels 22, and the left and right optical members 23 also have the same configuration. In the following description, when simply describing the display panel unit 20, simply the first display panel 21, simply the second display panel 22, simply the optical member 23, etc., matters that are common to the left and right are described.

FIG. 4 is a front view of the first display panel 21 and the second display panel 22. FIG. 5 is a cross-sectional view taken along line V-V in FIG. 4, and shows a schematic cross-section of the first display panel 21, the second display panel 22, and the optical member 23 in the thickness direction (for ease of explanation, no hatching has been applied).

As shown in Figures 4 and 5, the first display panel 21 has a plate-shaped first substrate 21S and a first display area 21A formed on the surface of the first substrate 21S. The first display area 21A is configured by arranging a plurality of first pixels 21P on the surface of the first substrate 21S. The first display panel 21 faces the first display area 21A to the corresponding optical system 10. More specifically, the first display panel 21 faces the first display area 21A to the objective entrance surface 12i of the objective lens 12 of the corresponding optical system 10. In Figure 4, dots are added to the range indicating the first display area 21A.

The first display panel 21 may be an OLED (Organic Light Emitting Diode) panel or an LCD (Liquid Crystal Display) panel. However, in this embodiment, as described above, the first display panel 21 is the part that emits light that forms the central visual field of the image, so it is desirable to configure it so that it can display high-definition images. Therefore, in this embodiment, the first display panel 21 uses an OLED, which has the advantage over LCD in terms of achieving high definition. In order to display high-definition images, the pixel density of the first display panel 21 is preferably 2500 ppi or more, more preferably 3000 ppi or more, and even more preferably 4000 ppi or more.

Specifically, in this embodiment, the first display panel 21 is configured as a MOLED (Micro Organic Light Emitting Diode) panel with a pixel density of approximately 4000 ppi. However, the specific configuration (format, pixel density, etc.) of the first display panel 21 is not particularly limited.

The arrangement pattern of the first pixels 21P in the first display area 21A may be, for example, a stripe arrangement, a pentile arrangement, a diamond arrangement, or the like. The arrangement pattern of the first pixels 21P in the first display area 21A is not particularly limited. Note that a pixel as used in this specification is a part that constitutes the smallest unit of an image, and means a range that includes a predetermined number of sub-pixels. Note that the optical system 10 described above is designed so that the object plane (focal plane) is aligned with the display surface (first display area 21A) of the first display panel 10 that forms the central visual field of the image.

The material of the first substrate 21S can be determined according to the type of panel. The first substrate 21S may be a glass substrate, a silicon substrate, or the like. The shape of the first substrate 21S is not particularly limited, but in this embodiment it is rectangular, and more specifically, it is a rectangular shape with its longitudinal direction extending in the left-right direction.

In this embodiment, the first display area 21A is formed on most of the surface of the first substrate 21S in a shape similar to that of the surface of the first substrate 21S. In detail, as shown in FIG. 5, an outer non-display area 21n is formed on the first display panel 21. The outer non-display area 21n means an area of the surface of the first substrate 21S on which the first display area 21A is formed where pixels are not arranged. In other words, the first display area 21A is formed in a range of the surface of the first substrate 21S other than the outer non-display area 21n. The outer non-display area 21n extends along the outer edge of the first display panel 21 while being adjacent to the first display area 21A. The outer edge of the first display panel 21 is formed by the outer edge of the first substrate 21S. In this embodiment, the outer non-display area 21n is a rectangular frame as a whole.

The size of the first display area 21A of the first display panel 21 may be 1.4 inches or less, or 1.3 inches or less, or 1.2 inches or less. In this case, even if the first display panel 21 is constructed of a MOLED with a pixel density of approximately 4000 ppi, it is easy to avoid excessive increases in manufacturing costs while ensuring the desired display performance. However, the size of the first display panel 21 is not particularly limited.

The second display panel 22 also has a plate-shaped second substrate 22S and a second display area 22A formed on the surface of the second substrate 22S. The second display area 22A is formed by arranging a plurality of second pixels 22P on the surface of the second substrate 22S. The second display panel 22 faces the second display area 22A to the corresponding optical system 10. More specifically, the second display panel 22 faces the second display area 22A to the objective entrance surface 12i of the objective lens 12 of the corresponding optical system 10. In FIG. 4, the range indicating the second display area 22A is marked with dots.

In this embodiment, as described above, the second display panel 22 emits light that constitutes the peripheral visual field of the image. Correspondingly, the second display area 22A is formed in a position that is the periphery of the first display area 21A when the first display area 21A is viewed from the optical system 10.

5, in this embodiment, the second display panel 22 has an opening 221 penetrating in the thickness direction. The opening 221 is formed in the second substrate 22S. The second display area 22A is provided around the opening 221 in the second display panel 22. The first display panel 21 is arranged such that, from the viewpoint shown in FIG. 4 (when viewed from the optical system 10), at least a part (in this example, the whole) of the first display area 21A is located inside the opening 221 and the outer peripheral part does not cover the second display area 22A from the optical system 10 side. As a result, in the display panel unit 20, the second display area 22A is positioned at a position that is the periphery of the first display area 21A when the first display area 21A is viewed from the optical system 10.

The second display panel 22 may be an OLED panel or an LCD panel. Here, as described above, the second display panel 22 emits light that constitutes the peripheral vision portion of the image. In this case, it is not strongly desired that the second display panel 22 display high-definition images. In detail, by realizing high-definition image display in the first display area 21A, the HMD 1 can realize an image display that is desirable for the user even if the second display panel 22 is not configured to realize high-definition image display. Therefore, in this embodiment, the second display panel 22 is configured as a display panel having a second display area 22A that has a pixel density smaller than the pixel density of the first display area 21A. This makes it possible to realize a desirable image display while particularly keeping costs down.

The inventors' knowledge is that in HMD applications, if the pixel density of the first display area 21A is ensured to be 4000 ppi or more and the first display area 21A can cover the user's main central visual field, desirable image display can be achieved even if the pixel density of the second display area 22A is, for example, 1/10 or less of the pixel density of the first display area 21A. Therefore, the second display panel 22 in this embodiment is, as an example, composed of an AMOLED (Active Matrix Organic Light Emitting Diode) panel in which the pixel density of the second display area 22A is 200 ppi or more and 800 ppi or less.

The HMD1 according to this embodiment aims to reduce the cost of the second display panel 22 in particular by not ensuring excessive pixel density in the second display panel 22, thereby suppressing overall costs and realizing desirable image display. Therefore, the second display panel 22 is composed of a display panel having a second display area 22A that has a pixel density lower than the pixel density of the first display area 21A.

However, the pixel density of the second display area 22A in the second display panel 22 is not particularly limited. For example, the pixel density of the first display area 21A and the pixel density of the second display area 22A may be the same. Even in this case, the first display panel 21 and the second display panel 22 may be manufactured separately, which may avoid the increase in cost due to the larger size. Also, a configuration in which the pixel density of the first display area 21A is partially greater than the pixel density of the second display area 22A may be adopted. Also, in this embodiment, the second display panel 22 is composed of AMOLEDs, but the specific configuration of the second display panel 22 is not particularly limited, and LEDs called micro LEDs or LEDs called Mini LEDs may be adopted. The arrangement pattern of the second pixels 22P in the second display area 22A may be, for example, a stripe arrangement, a pen tile arrangement, a diamond arrangement, or the like, but is not particularly limited.

The material of the second substrate 22S may be determined according to the type of panel. The second substrate 22S may be a glass substrate, a silicon substrate, or a flexible substrate such as polyimide. The shape of the second substrate 22S is not particularly limited, but the outer contour is rectangular. More specifically, the outer contour of the second substrate 22S is a rectangular shape extending longitudinally in the left-right direction. The opening 221 described above is rectangular, more specifically, a rectangular shape extending longitudinally in the left-right direction. By forming the rectangular opening 221 in the second substrate 22S, the surface of the second substrate 22S is formed in the shape of a rectangular frame. Note that the concept of a rectangle in this specification includes both a square and a rectangle. In other words, the first display panel 21 and the second display panel 22 described above may be square.

In this embodiment, the second display area 22A is formed in a shape similar to the shape of the surface of the second substrate 22S, i.e., in a frame shape, over most of the surface of the second substrate 22S. On the other hand, as shown in FIG. 4, the second display panel 22 is formed with an outer non-display area 22n and an inner non-display area 22m.

The outer non-display area 22n and the inner non-display area 22m refer to areas of the surface of the second substrate 22S on which the second display area 22A is formed, where the second pixels 22P are not arranged. The second display area 22A is formed in an area of the surface of the second substrate 22S other than the outer non-display area 22n and the inner non-display area 22m. The outer non-display area 22n extends along the outer edge of the second display panel 22 while adjacent to the second display area 22A. The outer edge of the second display panel 22 is formed by the outer edge of the second substrate 22S. In this embodiment, the outer non-display area 21n is generally rectangular frame-shaped. The inner non-display area 22m is generally rectangular frame-shaped, and extends along the periphery of the opening 221 while adjacent to the second display area 22A. In this embodiment, the inner non-display area 22m is also generally rectangular frame-shaped.

The second display area 22A of the second display panel 22 is not particularly limited, but for HMD applications, it is preferably about 2 inches. If the size of the second display panel 22 is 2 inches, it becomes easier to realize an HMD that is easy for the user to use while ensuring a wide viewing angle. Note that the size of the second display panel 22 refers to the size of the outer contour of the second display panel 22, without taking into account the opening 221.

To describe the positional relationship between the first display panel 21 and the second display panel 22 in this embodiment in more detail, as shown in FIG. 5, the first display panel 21 and the second display panel 22 are each plate-shaped and are arranged with their thickness directions aligned. As described above, the first display panel 21 is arranged such that, from the viewpoint shown in FIG. 4 (when viewed from the optical system 10), at least a part (in this example, the whole) of the first display area 21A is located inside the opening 221 and the outer peripheral part does not cover the second display area 22A from the optical system 10 side. As a result, in the display panel unit 20, the second display area 22A is positioned at a position that is the periphery of the first display area 21A when the first display area 21A is viewed from the optical system 10.

In more detail, the first display panel 21 is disposed at a position farther away from the optical system 10 than the second display panel 22, and overlaps the rear surface of the second display panel 22 such that at least a portion (in this example, the entirety) of the first display area 21A is located inside the opening 221 when viewed from the viewpoint shown in FIG. 4. The first display panel 21 faces at least a portion (in this example, the entirety) of the first display area 21A to the optical system 10 through the opening 221.

Furthermore, as shown in FIG. 5, the first display panel 21 and the second display panel 22 are arranged such that their respective outer non-display areas 21n and inner non-display areas 22m overlap each other in the thickness direction. In this case, the outer non-display area 21n of the first display panel 21 is hidden by the inner non-display area 22m of the second display panel 22.

In this embodiment, the area occupied by the first display area 21A and the second display area 22A forms the entire display area of the display panel unit 20. Here, in each display panel, it is difficult to form a display area close to the outer edge or inner edge, and the outer non-display area 21n of the first display area 21A and/or the inner non-display area 22m of the second display area 22A are formed as areas where no pixels exist in the display area of the display panel unit 20 formed by the first display area 21A and the second display area 22A. At this time, the outer non-display area 21n of the first display panel 21 is hidden by the inner non-display area 22m of the second display panel 22, so that the range of the area where no pixels exist in the display area of the display panel unit 20 can be reduced. This makes it possible to suppress the influence of the area where no pixels exist on the image display. In this embodiment, in detail, the outer non-display area 21n of the first display panel 21 is completely hidden by the inner non-display area 22m of the second display panel 22. As a result, the only area in the entire display area (21A, 22A) where there are no pixels is the inner non-display area 22m of the second display panel 22.

The optical member 23 is disposed between the optical system 10 and the first display area 21A of the first display panel 21 and the second display area 22A of the second display panel 22, and faces the first display area 21A and the second display area 22A. The optical member 23 is sheet-like, and is disposed so that its in-plane direction (direction perpendicular to the thickness direction) is aligned with the first display area 21A of the first front panel 21 and the second display area 22A of the second display panel 22.

In this embodiment, when the display panel unit 20 is viewed from the optical system 10, as shown in FIG. 4, the inner non-display area 22m of the second display panel 22 appears as an area where no pixels exist. Here, the optical member 23 emits at least a portion (in this embodiment, all) of the light incident from the second display area 22A from an emission point shifted toward the first display area 21A from the incidence point in the in-plane direction along the surface facing the first display area 21A and the second display area 22A. In this way, the optical member 23 can improve the display quality of the image by making the area where no pixels exist difficult to see.

In this embodiment, the optical element 23 is configured to include a PB (Pancharatnam-Berry) phase element as an example. More specifically, as shown in FIG. 5, the optical element 23 includes a transparent substrate 23A, an incident side PB phase element 23i, and an exit side phase element 23e. The transparent substrate 23A is a plate material. The transparent substrate 23A can be formed of a glass plate or a resin plate material that is transparent to visible light. The material of the resin plate material may be, for example, acrylic, polycarbonate, etc.

The incident side PB phase element 23i and the exit side PB phase element 23e are each in the form of a film. The incident side PB phase element 23i is provided by being bonded to the surface of the transparent substrate 23A facing the first display panel 21 and the second display panel 22. The exit side PB phase element 23e is provided by being bonded to the surface of the transparent substrate 23A opposite to the surface on which the incident side PB phase element 23i is provided. The incident side PB phase element 23i and the exit side PB phase element 23e are formed by holding liquid crystal oriented in a predetermined direction in a film-like resin. The incident side PB phase element 23i and the exit side PB phase element 23e have the function of refracting the incident light by a predetermined angle and exiting it, regardless of the angle of incidence, by modulating the phase of the incident light.

In this embodiment, the incident side PB phase element 23i and the exit side PB phase element 23e are provided around the part including the central position of the transparent substrate 23A and facing the first display area 21A. The exit side PB phase element 23e extends further toward the central position of the transparent substrate 23A than the incident side PB phase element 23i. The incident side PB phase element 23i is positioned so as to cover the second display area 22A of the second display panel 22 but not the inner non-display area 22m. The exit side PB phase element 23e is positioned so as to cover both the second display area 22A and the inner non-display area 22m. In this embodiment, it is not intended to change the behavior of light from the second display area 22A by the incident side PB phase element 23i and the exit side PB phase element 23e, and to cause an optical change in the light from the first display area 21A. Therefore, the incident side PB phase element 23i and the exit side PB phase element 23e are partially provided on the transparent base material 23A. This can reduce manufacturing costs, for example, and can prevent the characteristics of the light from the first display region 21A from being affected.

In FIG. 5, the path of light incident from the second display area 22A and passing through the incident side PB element 23i, the transparent substrate 23A, and the exit side PB element 23e is indicated by the arrow α. As indicated by the arrow α, the light perpendicularly incident from the second display area 22A to the incident side PB phase element 23i is refracted by the incident side PB phase element 23i and travels through the transparent substrate 23A in a state tilted with respect to the initial incident direction at the incident point P1, for example. The light incident on the exit side PB phase element 23i is then refracted by the exit side PB phase element 23e and is emitted from the exit point P2 in a direction perpendicular to the exit side PB phase element 23e. In this embodiment, as an example, the incident side PB phase element 23i is configured to refract the incident light by a predetermined angle by modulating the phase of the incident light, for example, to the delayed side. In contrast, the output side PB phase element 23e is configured to modulate the phase of the incident light to the advanced side, thereby refracting the incident light by a predetermined angle in the direction opposite to the input side PB phase element 23i. This makes it possible to control the light as shown by the arrow α in Figure 5.

Referring to the arrow α in Figure 5, light incident from the edge or periphery of the edge of the first display area 21A side of the entrance side PB phase element 23i as the incident point is refracted by the entrance side PB phase element 23i and reaches a portion of the exit side PB phase element 23e that faces the inner edge or periphery of the inner edge of the inner non-display area 22m. Then, the light that reaches the exit side PB phase element 23e rises up and is emitted in a direction perpendicular to the exit side PB phase element 23e from the exit point in front of the inner non-display area 22m (on the optical system 10 side). On the other hand, most of the light that enters the optical element 23 from the first display area 21A transmits through the optical element 23 without passing through the entrance side PB phase element 23i and the exit side PB phase element 23e. In this case, when the first display area 21A and the second display area 22A emit light for image formation, a portion of the image is displayed on the inner non-display area 22m located between the first display area 21A and the second display area 22A, making the inner non-display area 22m difficult to see.

FIGS. 6 and 7 are diagrams for explaining the function of the optical member 23. FIG. 6 shows an image formed by the light emitted from the first display area 21A and the second display area 22A without the optical member 23. In the image shown in FIG. 6, an inner non-display area 22m located between the first display area 21A and the second display area 22A is displayed.

Figure 7 shows an image formed by light emitted from the first display area 21A and the second display area 22A with the optical member 23 provided. In Figure 7, the optical member 23 causes light incident from the second display area 22A to exit from an exit point that is shifted toward the first display area 21A side from the light entrance point in the in-plane direction of the optical member 23. As a result, part of the image is displayed on the inner non-display area 22m, making it difficult to view the inner non-display area 22m.

FIG. 8 is a diagram for explaining the characteristics of the optical element 23 shown in FIG. 5, and shows an enlarged view of the entrance side PB phase element 23i, the exit side PB phase element 23e, the first display area 21A, and the second display area 22A.

8 indicates the thickness of the transparent substrate 23A in the optical member 23, and the symbol d indicates the frame length (bezel width) which is the distance in the in-plane direction (direction perpendicular to the thickness direction) from the first display area 21A to the second display area 22A. The symbol θ indicates the angle at which the optical member 23 refracts the light incident on the incident side PB phase element 23i and the exit side PB phase element 23e. The angle θ is the angle between the in-plane direction of the incident side PB phase element 23i and the direction of the light traveling inside the optical member 23 (transparent substrate 23A), or the angle between the in-plane direction of the exit side PB phase element 23e and the direction of the light emitted from the optical member 23. The frame length d means the width of the area where no pixels exist. In the example of FIG. 5, the frame length d corresponds to the width of the inner non-display area 22m in the second display panel 22. The optical element 23 may have an optical characteristic in which the refraction angle θ satisfies "tan θ = d/l."

As can be seen from the arrow α and other arrows parallel to it in FIG. 5, the optical element 23 in this embodiment is configured to refract incident light at a refraction angle θ regardless of the position of the light incident on the incident side PB phase element 23i. The exit side PB phase element 23e is configured to refract incident light at a refraction angle θ regardless of the position of the light incident on the exit side PB phase element 23e. However, the optical element 23 may be configured to change the degree to which light is refracted depending on the position of incidence.

In addition, when the first display area 21A and the second display area 22A emit light for forming an image, a part of the image is displayed on the inner non-display area 22m located between the first display area 21A and the second display area 22A by the optical member 23, and the central visual field of the image formed by the first display area 21A and the peripheral visual field of the image formed by the second display area 22A are displayed in an integrated manner. However, in this embodiment, the pixel density of the first display area 21A is higher than the pixel density of the second display area 22A. Therefore, there is a risk that the image will be distorted or a visual discomfort will occur at the boundary between the central visual field and the peripheral visual field and in the vicinity thereof. Therefore, image processing may be performed to adjust the distortion and resolution.

Specifically, for example, image processing may be performed in the peripheral portion of the first display area 21A adjacent to the second display area 22A such that the resolution gradually changes, specifically, gradually decreases, from the center toward the outer edge. Such image processing is performed under the control of the controller 50 described above.

In addition, in this embodiment, as shown in FIG. 1, the lens assembly 13 for the left eye eL and the display panel unit 20 for the left eye eL are integrally held by the housing 10H to form the left panel optical system module 8L. Similarly, the lens assembly 13 for the right eye eR and the display panel unit 20 for the right eye eR are integrally held by the housing 10H to form the right panel optical system module 8R. In this embodiment, the left and right panel optical system modules 8L and the panel optical system module 8R are separate. The left and right panel optical system modules 8L and the panel optical system module 8R can be moved closer to or farther apart in the left-right direction. This allows the lens position to be adjusted appropriately for each user. The lens assembly 13 and the display panel unit 20 do not have to be integrated.

(Other elements)
Returning to Fig. 1, the display control system 40 includes first to fourth panel drivers 41 to 44 and a controller 50. The first to fourth panel drivers 41 to 44 are electrically connected to the controller 50. The first panel driver 41 is connected to the first display panel 21 for the left eye, and the second panel driver 42 is connected to the second display panel 22 for the left eye. The third panel driver 43 is connected to the first display panel 21 for the right eye, and the fourth panel driver 44 is connected to the second display panel 22 for the right eye.

The controller 50 controls the driving of the first to fourth panel drivers 41 to 44 according to the image to be displayed. When the display panel is an LED, the first to fourth panel drivers 41 to 44 can express the gradation of the image by controlling the amount of light emitted by the sub-pixels. When the display panel is an LCD, the first to fourth panel drivers 41 to 44 can express the gradation of the image by controlling the orientation of the liquid crystal corresponding to the sub-pixels. As described above, a total of four panels, the pair of first display panels 21 and the pair of second display panels 22, work together to display one image to the user, and each panel is controlled by a separate panel driver. That is, in this embodiment, the display control system 40 constitutes a so-called multi-channel display system.

When performing image processing so that the resolution gradually decreases as described above, the controller 50 may apply a low-pass filter to the portion of the image where the resolution is to be decreased, and then generate a drive signal to be provided to the first panel driver 41 and the third panel driver 43.

(Action and Effects)
Next, the action and effect of the HMD 1 according to this embodiment will be described.

The user wears the HMD 1 with their eyes e (left eye eL, right eye eR) close to the eyepiece lens 11. In this wearing state, the HMD 1 guides the light for image formation emitted by the display panel unit 20 to the user's eyes e through the eyepiece lens 11. This causes an image to be displayed in front of the user's eyes e. The light for image formation described above is emitted by each of the first display area 21A and the second display area 22A.

In this embodiment, the pixel density of the first display area 21A is higher than that of the second display area 22A, so that a high-definition image is formed by the light emitted from the first display area 21A. Meanwhile, the second display area 22A is disposed at a position that is on the periphery of the first display area 21A. This allows the first display area 21A and the second display area 22A to ensure a wide overall display area in the HMD 1. This allows a wide angle of view of the displayed image to be ensured.

The central visual field of the image is formed by the light emitted by the first display area 21A, and the peripheral visual field of the image is formed by the light emitted by the second display panel 22. Normally, human vision has high visual resolution only at the center of the field of vision, and low visual resolution in the peripheral field. Therefore, even if the display quality of the peripheral visual field of the image formed by the second display area 22A is not high, there is no significant impact on the user's vision. Therefore, in the HMD 1 according to this embodiment, the central visual field of the image is formed in high resolution by the first display area 21A, so that a high-resolution image that is desirable for the user can be displayed without unnecessarily expanding the high-resolution image range. And by not unnecessarily expanding the high-resolution image range, the HMD 1 is extremely advantageous in terms of reducing manufacturing effort and costs.

In other words, the HMD1 realizes high-definition image display in a manner desirable for the user without unnecessarily expanding the high-definition image range by separating the first display panel 21 having the first display area 21A from the second display panel 22 having the second display area 22A. In contrast, when a single display panel having a display area with the same pixel density as the first display area 21A is manufactured within a range of the display area occupied by the first display area 21A and the second display area 22A, and high-definition image display is realized, the high pixel density combined with the large area may significantly reduce the yield, for example, compared to the case of manufacturing the first display panel 21 and the second display panel 22 in this embodiment. Therefore, the cost may increase significantly. Although the size of the second display panel 22 in the HMD1 may be large, a high pixel density is not required, so the decrease in yield may be suppressed. Therefore, the HMD1 is extremely advantageous in terms of reducing manufacturing effort and costs while achieving both high definition and a wide angle of view.

Therefore, the HMD 1 according to this embodiment can easily and inexpensively display high-definition images while ensuring a wide angle of view.

In addition, in this embodiment, the first display panel 21 and the second display panel are arranged with their respective non-display areas (21n, 22m) overlapping each other. In this case, the range of the area where no pixels exist in the entire display area formed by the first display area 21A and the second display area 22A can be reduced, and the effect that the area where no pixels exist has on the image display can be suppressed.

The HMD 1 also includes an optical member 23 that is disposed between the optical system 10 and the first display area 21A of the first display panel 21 and the second display area 22A of the second display panel 22, and faces the first display area 21A and the second display area 22A. The optical member 23 emits at least a portion of the light incident from the second display area 22A from an emission point that is shifted toward the first display area 21A from the incidence point in the in-plane direction. In this case, the display quality of the image can be improved by making it difficult to view the areas in the entire display area formed by the first display area 21A and the second display area 22A where the above-mentioned pixels do not exist.

The optical member 23 also includes PB phase elements (23i, 23e). The PB phase elements are usually formed of a film. Therefore, the increase in size of the HMD 1 due to the addition of the optical member 23 can be suppressed. The optical system 10 is also a pancake lens assembly. With a pancake lens assembly, an appropriate image can be displayed to the user even if the distance between the optical system 10 and the first display area 21A is shortened. This makes it possible to suppress an increase in the thickness of the HMD 1 in the optical axis direction.

<Modification>
In the following, several modified examples of the above-described embodiment will be described. The same reference numerals will be used to designate the same parts in each modified example as those in the above-described embodiment, and duplicated descriptions will be omitted.

(First Modification)
9 shows a first modified example, in which the configuration of the optical member 23 is different from that of the above-described embodiment.

The optical member 23 according to the first modified example emits at least a portion of the light incident from the second display area 22A from an emission point shifted toward the first display area 21A from the incidence point in the in-plane direction of the optical member 23. This function is common to the above-mentioned embodiment. Meanwhile, the optical member 23 according to the first modified example is configured to change the distance from the incidence point of the light from the second display area 22A to the emission point shifted in the in-plane direction of the optical member 23 depending on the position of the incidence point of the light. As mentioned above, the in-plane direction is the direction along the surface facing the first display area 21A and the second display area 22A.

In more detail, the closer the incident point of light entering from the second display area 22A is to the first display area 21A, the greater the distance that the optical element 23 shifts from the incident point to the exit point. In FIG. 9, arrows are used to show multiple paths of light that enters from the second display area 22A and passes through the incident side PB phase element 23i, the transparent substrate 23A, and the exit side PB phase element 23e. As is clear from the arrows, the amount that the light is shifted changes depending on the incidence of the light, and the closer the incident point is to the first display area 21A, the greater the shift of the light.

More specifically, the symbol △(x1) in FIG. 9 indicates the distance (shift amount) from the incident point of light incident on the optical member 23 to the exit point, with the incident point being the periphery of the end of the incident-side PB phase element 23i on the first display area 21A side. The symbol △(x2) indicates the distance from the incident point of light incident on the optical member 23 to the exit point, with the incident point being a position farther from the first display area 21A than the incident point of light shifted by the distance △(x1). In the first modified example, the relationship distance △(x1)>distance △(x2) holds.

In addition, the angle θ (x1) in FIG. 9 indicates the refraction angle when light whose shift from the incident point to the exit point is the above-mentioned distance Δ (x1) is refracted by the incident-side PB phase element 23i. The angle θ (x2) indicates the refraction angle when light whose shift from the incident point to the exit point is the above-mentioned distance Δ (x2) is refracted by the incident-side PB phase element 23i. The refraction angle here is the angle between the in-plane direction of the incident-side PB phase element 23i and the direction of the light traveling inside the optical member 23 (transparent base material 23A). In the first modified example, the relationship of angle θ (x1) < angle θ (x2) holds. In other words, it can be said that the optical member 23 in the first modified example has the function of refracting the incident light to a greater extent the closer the incident point of the light incident from the second display area 22A is to the first display area 21A.

According to the first modified example described above, as in the above embodiment, it is possible to improve the display quality of the image by making it difficult to see areas without pixels in the entire display area formed by the first display area 21A and the second display area 22A. Also, by changing the distance from the incident point to the shifted exit point depending on the position where the light is incident, it is possible to avoid, for example, a situation in which the overall direction of light is excessively changed, thereby improving the display quality of the image.

(Second Modification)
10 shows a second modified example, in which the configuration of the optical member 23 is different from that of the above-described embodiment.

The optical member 23 according to the second modified example emits at least a portion of the light incident from the second display area 22A from an emission point shifted toward the first display area 21A from the incident point in the in-plane direction of the optical member 23. This function is common to the above-mentioned embodiment. Meanwhile, in the optical member 23 according to the second modified example, the thickness of the portion of the optical member 23 facing the first display area 21A is smaller than the thickness of the portion facing the second display area 22A.

The optical element 23 refracts the light incident from the second display area 22A and emits it from an emission point shifted from the incident point. In this case, the optical path length of the light is longer than when the light incident from the second display area 22A is transmitted without being refracted. Light incident on the optical element 23 from the first display area 21A basically transmits through the optical element 23 without being refracted. Although the first display area 21A is positioned farther away from the optical element 23 than the second display area 22A, a difference may occur between the optical path length of the light transmitting through the optical element 23 from the first display area 21A and the optical path length of the light transmitting through the optical element 23 from the second display area 22A. When a difference in the optical path length occurs, a so-called blur occurs in the displayed image. Therefore, in this modified example, the thickness of the portion facing the first display area 21A is made different from the thickness of the portion facing the second display area 22A, thereby reducing or eliminating the difference between the optical path length of the light passing through the optical member 23 from the first display area 21A and the optical path length of the light passing through the optical member 23 from the second display area 22A.

10, reference symbol l1 indicates the thickness of a portion of the optical member 23 facing the second display region 22A, reference symbol l2 indicates the thickness of a portion of the optical member 23 facing the first display region 21A, and reference symbol Δt indicates the thickness of the second base material 22S of the second display panel 22. Specifically, in this modification, the following relational expression (1) holds when the refractive index of the transparent base material 23A of the optical member 23 is n.
△t+(l1-l2)+n×l2=n×l1...(1)

When the above-mentioned relationship is satisfied, the difference between the optical path length of the light passing through the optical member 23 from the first display region 21A and the optical path length of the light passing through the optical member 23 from the second display region 22A becomes small or disappears, and blurring of the image is less likely to occur. Note that, since blurring of the image is less likely to occur if the difference in the optical path lengths is small, the display panel unit 20 may be designed to satisfy, for example, the following relationship (2).
0.95×(△t+(l1-l2)+n×l2)≦n×l1≦1.05×(△t+(l1-l2)+n×l2)...(2)

Furthermore, if the difference between the optical path length of the light passing through the optical member 23 from the first display region 21A and the optical path length of the light passing through the optical member 23 from the second display region 22A is smaller than 0.1 mm, blurring of the image is unlikely to occur. Therefore, for example, the display panel unit 20 may be designed to satisfy the following relational expression (3).
|△t+(l1-l2)+n×l2-n×l1|<0.1...(3)
In addition, the units of Δt, l1, and l2 in the relational expression (3) are mm (millimeters).

As described above, according to the second modified example, as in the above embodiment, it is possible to improve the display quality of the image by making it difficult to see areas in which there are no pixels in the entire display area formed by the first display area 21A and the second display area 22A. In addition, it is possible to suppress blurring of the image.

(Third Modification)
11 shows a third modified example, in which the configuration of the optical member 23 is different from that of the above-described embodiment.

The optical member 23 in the third modified example emits at least a portion of the light incident from the second display area 22A from an emission point shifted toward the first display area 21A from the incident point in the in-plane direction of the optical member 23. This function is common to the above-mentioned embodiment.

On the other hand, while in the above embodiment the incident side PB phase element 23i and the exit side PB phase element 23e are partially provided on the transparent substrate 23A, in this modified example the incident side PB phase element 23i and the exit side PB phase element 23e are provided on the entire front and back surfaces of the transparent substrate 23A. However, the portions of the incident side PB phase element 23i and the exit side PB phase element 23e that face the first display region 21A do not refract the incident light.

According to the third modified example described above, the process of bonding the incident side PB phase element 23i and the exit side PB phase element 23e to the transparent substrate 23A can be facilitated.

(Fourth Modification)
12 shows a fourth modified example, in which the configuration of the optical member 23 is different from that of the above-described embodiment.

The optical member 23 in the fourth modified example emits at least a portion (specifically, a part) of the light incident from the first display area 21A from an emission point shifted toward the second display area 22A from the incident point in the in-plane direction of the optical member 23.

In detail, the optical member 23 changes the distance from the incident point of the light from the first display area 21A to the exit point shifted in the in-plane direction of the optical member 23 according to the position of the incident point of the light from the first display area 21A. More specifically, the closer the incident point of the light from the first display area 21A is to the second display area 22A, the greater the distance from the incident point to the exit point shifted by the optical member 23. In FIG. 12, multiple arrows indicate multiple paths of light that enters from the first display area 21A and passes through the entrance side PB phase element 23i, the transparent substrate 23A, and the exit side PB phase element 23e. As is clear from the multiple arrows, the amount of shift of the light changes according to the incidence of the light, and the closer the incident point is to the second display area 22A, the greater the shift of the light. In this example, the optical member 23 transmits light from the center and its periphery of the first display area 21A without refracting it.

The incident side PB phase element 23i and the exit side PB phase element 23e are provided in a portion of the transparent substrate 23A facing the first display region 21A. The exit side PB phase element 23e extends further toward the outer edge of the transparent substrate 23A than the incident side PB phase element 23i. The incident side PB phase element 23i and the exit side PB phase element 23e may be provided on the entire front and back surfaces of the transparent substrate 23A.

As described above, according to the fourth modified example, as in the above-described embodiment, the areas in the entire display area formed by the first display area 21A and the second display area 22A where there are no pixels are made difficult to see, thereby improving the display quality of the image.

(Fifth Modification)
13 shows a fifth modified example, in which the configuration of the optical member 23 is different from that of the above-described embodiment.

The optical member 23 according to the fifth modified example includes a light-transmitting portion 23C including a portion facing the first display region 21A and a peripheral portion 23P including a portion facing the second display region 22A, and the peripheral portion 23P includes an optic plate. The optical member 23 causes at least a portion of the light incident from the second display region 22A to exit from an exit point shifted toward the first display region 21A side from the entrance point in the in-plane direction of the optical member 23 by the optic plate of the peripheral portion 23P. The light-transmitting portion 23C and the peripheral portion 23P are adjacent to each other to form a roughly sheet-like shape. The in-plane direction means the in-plane direction of the roughly sheet-like shape formed by the light-transmitting portion 23C and the peripheral portion 23P or the direction in which the light-transmitting portion 23C and the peripheral portion 23P are adjacent to each other.

As described above, according to the fifth modified example, as in the above-described embodiment, the areas in the entire display area formed by the first display area 21A and the second display area 22A where there are no pixels are made difficult to see, thereby improving the display quality of the image.

(Sixth Modification)
14 shows a sixth modified example. In the sixth modified example, the configuration of the optical member 23 is different from that of the above-described embodiment.

The optical member 23 according to the sixth modified example includes, as in the fifth modified example, a light-transmitting portion 23C including a portion facing the first display area 21A, and a peripheral portion 23P including a portion facing the second display area 22A. However, it differs from the fifth modified example in that the peripheral portion 23P includes a magnifying lens. The magnifying lens in the peripheral portion 23P of the optical member 23 causes at least a portion of the light incident from the second display area 22A to exit from an exit point shifted toward the first display area 21A side from the entrance point in the in-plane direction of the optical member 23. The sixth modified example provides the same effect as the above-mentioned embodiment.

(Seventh Modification)
15 shows a seventh modified example. In the seventh modified example, the configuration of the optical member 23 is different from that of the above-described embodiment.

The optical member 23 in the seventh modification includes a light-transmitting portion 23C including a portion facing the first display area 21A, and a peripheral portion 23P including a portion facing the second display area 22A, similar to the fifth modification. However, it differs from the fifth modification in that the peripheral portion 23P includes a flat transparent plate. The flat transparent plate in the peripheral portion 23P is disposed at an angle relative to the second display area 22A.

The optical member 23 causes at least a portion of the light incident from the second display area 22A to exit from an exit point shifted toward the first display area 21A side from the entrance point in the in-plane direction of the optical member 23 due to the refraction effect of the flat transparent plate of the peripheral portion 23P. The light-transmitting portion 23C and the peripheral portion 23P are adjacent to each other to form a roughly sheet-like shape. The in-plane direction refers to the in-plane direction of the roughly sheet-like shape formed by the light-transmitting portion 23C and the peripheral portion 23P or the direction in which the light-transmitting portion 23C and the peripheral portion 23P are adjacent to each other.

(Eighth Modification)
16 shows an eighth modified example. In the eighth modified example, the configuration of the optical member 23 is different from that of the above-described embodiment.

The optical member 23 in the eighth modified example diffuses and emits light incident from the second display area 22A. The optical member 23 has a diffusion area 23D in a portion facing the second display panel 22. The diffusion area 23D can be formed, for example, by roughening the surface.

In the eighth modified example, as in the above-described embodiment, the areas without pixels in the entire display area formed by the first display area 21A and the second display area 22A are made less visible, thereby improving the display quality of the image.

(Ninth Modification)
17 shows a ninth modified example. In the ninth modified example, the layout of the first display panel 21 and the second display panel 22 is different from that of the above-described embodiment.

In the ninth modified example, the first display panel 21 is disposed closer to the optical system 10 (see also FIG. 1) than the second display panel 22. At least a portion (in this example, the entirety) of the first display area 21A of the first display panel 21 covers the opening 221 in the second display panel 22 from the optical system 10 side.

(Tenth Modification)
18 shows a tenth modified example. In the tenth modified example, the first display panel 21 is disposed at a position closer to the optical system 10 (see also FIG. 1 ) than the second display panel 22. On the other hand, the second display panel 22 does not have the opening 221 described in the above embodiment.

(Eleventh Modification)
19 shows an eleventh modified example. In the eleventh modified example, the first display panel 21 is arranged side by side with the second display panel 22. More specifically, the first display panel 21 is arranged inside an opening 221 in the second display panel 22.

The above-described embodiment shows one example for realizing the present disclosure, and the present disclosure can be implemented in various other forms. For example, various modifications, substitutions, omissions, or combinations thereof are possible without departing from the gist of the present disclosure. Forms in which such modifications, substitutions, omissions, etc. have been made are also included in the scope of the invention and its equivalents as set forth in the claims, just as they are included in the scope of the present disclosure.

For example, in the above embodiment, an example in which the present disclosure is applied to an HMD is described, but the present disclosure can also be applied to electronic binoculars, electronic viewfinders, etc.

Furthermore, the effects of the present disclosure described in this specification are merely examples, and other effects may also be present.

The present disclosure can also be configured as follows.
[Item 1]
an optical system including an eyepiece;
a first display panel having a first display area in which a plurality of pixels are arranged, the first display area being opposed to the optical system;
A display device comprising: a second display panel having a second display area in which a plurality of pixels are arranged, the second display area being positioned around the first display area when the first display area is viewed from the optical system.
[Item 2]
2. The display device of claim 1, wherein a pixel density of the first display area is at least partially greater than a pixel density of the second display area.
[Item 3]
the second display panel has an opening penetrating in a thickness direction,
the second display region is provided around the opening in the second display panel,
3. The display device according to item 1 or 2, wherein when the first display region and the second display region are viewed from the optical system, at least a portion of the first display region is located inside the opening.
[Item 4]
the first display panel is disposed at a position farther from the optical system than the second display panel;
4. The display device according to item 3, wherein at least a portion of the first display area faces the optical system through the opening.
[Item 5]
the first display panel is disposed closer to the optical system than the second display panel;
4. The display device according to item 3, wherein at least a portion of the first display region covers the opening from the optical system side.
[Item 6]
the first display panel has a non-display area adjacent to the first display area and extending along an outer edge of the first display panel;
the second display panel has a non-display area adjacent to the second display area and extending along a periphery of the opening,
6. The display device according to item 4 or 5, wherein the first display panel and the second display panel are arranged with their respective non-display areas overlapping each other.
[Item 7]
an optical member disposed between the optical system and the first display area and the second display area and facing the first display area and the second display area;
The display device according to any one of items 1 to 6, wherein the optical member causes at least a portion of the light incident from the first display region to exit from an exit point shifted toward the second display region from the entrance point in an in-plane direction along a surface facing the first display region and the second display region, or causes at least a portion of the light incident from the second display region to exit from an exit point shifted toward the first display region from the entrance point in the in-plane direction.
[Item 8]
8. The display device according to item 7, wherein the optical member changes a distance from the incident point to the exit point, which is shifted in the in-plane direction, depending on a position of the incident point on the optical member.
[Item 9]
9. The display device according to item 8, wherein the optical member increases the distance from the incident point to the exit point shifted in the in-plane direction as the incident point of the light incident from the first display region is closer to the second display region, or as the incident point of the light incident from the second display region is closer to the first display region.
[Item 10]
10. The display device according to any one of items 7 to 9, wherein the optical member includes a PB phase element.
[Item 11]
11. The display device according to any one of items 1 to 10, further comprising an optical member that diffuses and emits light incident from the second display region.
[Item 12]
the optical system is a pancake lens assembly including the eyepiece and an objective lens disposed at a position closer to the first display area and the second display area than the eyepiece;
12. The display device according to any one of items 1 to 11, wherein the optical system reflects light that enters the optical system from the first display region and the second display region, reflects the reflected light again in a direction away from the first display region and the second display region, and then emits the reflected light to the outside of the optical system.

1...Head mounted display 8L, 8R...Panel optical system module 10...Optical system 11...Eyepiece lens 11i...Eyepiece entrance surface 11e...Eyepiece exit surface 12...Objective lens 12i...Objective entrance surface 12e...Objective exit surface 13...Lens assembly 13H...Lens housing 20...Display panel unit 21...First display panel 21S...First substrate 21A...First display area 21P...First pixel 21n...Outer non-display area 22...Second display panel 22S...Second substrate 22A... Second display area 22P...Second pixel 22n...Outer non-display area 22m...Inner non-display area 221...Opening 23...Optical member 23A...Transparent substrate 23i...Incoming side PB phase element 23e...Outgoing side PB phase element 23C...Light transmitting portion 23P...Peripheral portion 23D...Diffusion area 30...Housing box 31...Band 40...Display control system 41...First panel driver 42...Second panel driver 43...Third panel driver 44...Fourth panel driver 50...Controller e...Eye

Claims (13)

an optical system including an eyepiece;
a first display panel having a first display area in which a plurality of pixels are arranged, the first display area being opposed to the optical system;
A display device comprising: a second display panel having a second display area in which a plurality of pixels are arranged, the second display area being positioned around the first display area when the first display area is viewed from the optical system. The display device of claim 1, wherein the pixel density of the first display area is at least partially greater than the pixel density of the second display area. the second display panel has an opening penetrating in a thickness direction,
the second display region is provided around the opening in the second display panel,
The display device according to claim 1 , wherein when the first display region and the second display region are viewed through the optical system, at least a portion of the first display region is located inside the opening. the first display panel is disposed at a position farther from the optical system than the second display panel;
The display device according to claim 3 , wherein at least a portion of the first display area faces the optical system through the opening. the first display panel is disposed closer to the optical system than the second display panel;
The display device according to claim 3 , wherein at least a portion of the first display region covers the opening from the optical system side. the first display panel has a non-display area adjacent to the first display area and extending along an outer edge of the first display panel;
the second display panel has a non-display area adjacent to the second display area and extending along a periphery of the opening,
The display device according to claim 4 , wherein the first display panel and the second display panel are arranged such that the non-display areas of the first display panel and the second display panel overlap each other. an optical member disposed between the optical system and the first display area and the second display area and facing the first display area and the second display area;
2. The display device of claim 1, wherein the optical element causes at least a portion of the light incident from the first display region to exit from an exit point shifted toward the second display region from the entrance point in an in-plane direction along a surface facing the first display region and the second display region, or causes at least a portion of the light incident from the second display region to exit from an exit point shifted toward the first display region from the entrance point in the in-plane direction. The display device according to claim 7, wherein the optical member changes the distance from the incident point to the exit point, which is shifted in the in-plane direction, depending on the position of the incident point on the optical member. The display device according to claim 8, wherein the optical member increases the distance from the incident point of the light incident from the first display region to the exit point shifted in the in-plane direction as the incident point of the light incident from the second display region is closer to the second display region, or the incident point of the light incident from the second display region is closer to the first display region. The display device according to claim 7, wherein the optical element includes a PB phase element. The display device according to claim 1, further comprising an optical member that diffuses and emits light incident from the second display region. the optical system is a pancake lens assembly including the eyepiece and an objective lens disposed at a position closer to the first display area and the second display area than the eyepiece;
2. The display device of claim 1, wherein the optical system reflects light that enters the optical system from the first display area and the second display area, reflects the reflected light again in a direction away from the first display area and the second display area, and then emits the reflected light to the outside of the optical system. the display device includes a pair of the optical systems, a pair of the first display panels, and a pair of the second display panels;
The display device according to claim 1 , further comprising separate panel drivers for driving the pair of first display panels and the pair of second display panels, respectively.