JP2017037304A - VIDEO UNIT FOR HEAD-UP DISPLAY, HEAD-UP DISPLAY, AND METHOD FOR GENERATING CONVERSION IMAGE FOR STEREOVISION USING VIDEO UNIT - Google Patents

Abstract

The present invention provides a video unit for a head-up display. A video unit includes a display unit having a first display area and a second display area arranged outside the first display area, and a first light field. Illuminates the first display area 102 from behind, and the second light field 112 illuminates the second display area 104 from behind, the first display area 102 and the second display area 102. A beam splitter 118 disposed between the display region 104 and deflecting the first light field 110 toward the side of the beam splitter 118 not facing the second display region 104, The beam splitter 11 configured to transmit the second light field 112 to the side not facing the second display area 104. And, equipped with a. [Selection] Figure 1

Description

  The present invention relates to an apparatus or a method according to the preamble of the independent claim. Furthermore, the subject of the present invention is a computer program.

  International Patent Publication No. 20030126666 describes a display device that generates a virtual image using a projector and at least a partially reflecting surface. The projector has an optical element that guides light in an autostereoscopic manner. The display device is a display device for an automobile, and the driver is a virtual image outside the vehicle in front of the window glass, and is suitable for the display device for the automobile in which the virtual image reflected by the mirror is viewed. .

  From such a background, a video unit for a head-up display (Head-Up-Display, HUD), a head-up display, and a pair of images for stereoscopic viewing using the video unit (see FIG. A method for generating (Halbbuilder), a control device using the method, and finally a corresponding computer program according to the independent claims are introduced. The measures described in the dependent claims allow advantageous developments and modifications of the device indicated in the independent claims.

A video unit for a head-up display, the video unit having the following characteristics:
A display unit having a first display area and a second display area disposed outside the first display area;
At least one light source unit for illuminating the first display area from behind with a first light field and illuminating the second display area from behind with a second light field;
A beam splitter disposed on a side of the display unit facing the at least one light source unit, the beam splitter configured to deflect a first light field and transmit a second light field;
The video unit is introduced.

  A video unit may be understood as a unit that generates an autostereoscopic image, ie an image that can be perceived in three dimensions. The video unit can be realized as a projector for displaying a virtual image. A display unit may be understood as a display, in particular a liquid crystal display (LCD), for example. The display unit is divided into two display areas. A display area is a part of the active plane of the display unit and can be understood as the above part useful for displaying image content by illuminating the display area from behind with light rays. In particular, the display areas have approximately the same size and can have the same format, for example, a square format. The display areas can be arranged adjacent to each other or spaced apart from each other. Each of the first light field and the second light field can display a stereoscopic image. A light source unit can be understood as, for example, a configuration comprising a photodiode, a laser diode, an organic light emitting diode, or a plurality of such light emitting elements. A beam splitter can be understood as an optical element for dividing a light field into two partial light fields, i.e., for example, a reflective light field and a transmissive light field. For example, the beam splitter can be realized as a polarizing beam splitter or as a prism. The beam splitter can be mounted, for example, at a height between the first display area and the second display area, in particular on the side of the display unit facing the light source. The beam splitter may be configured or arranged to output or emit the deflected first light field component and the transmitted second light field component on the same side of the beam splitter. The beam splitter is further adjacent to the display unit and the first display area and / or the second display area, or is in contact with the display unit and the first display area and / or the second display area. sell. For example, the beam splitter can be arranged at a height between the first display area and the second display area, particularly on the side not facing the light source unit.

  The approach presented here is based on the recognition that by using a display unit in combination with a beam splitter, a paired image can be generated with an autostereoscopic head-up display. By using only a display unit such as a liquid crystal display for generating an image for autostereoscopic driving, the manufacturing cost of the video device corresponding to the head-up display is almost halved. This not only reduces the cost of the video device, but also reduces the installation space due to the lack of additional electronic circuitry for controlling additional display units. This is because the two partial planes of the display unit, each generating one of the paired images, can be arranged very compactly. This further reduces the position deviation. This is because only the display unit needs to be correctly aligned.

  For example, one liquid crystal display can be used as a display unit for simultaneously generating two different image contents in time to realize autostereoscopic display. For this purpose, the liquid crystal display is divided into two partial areas, each partial area being capable of generating image content for each eye. Thereafter, the two partial images are superimposed by a suitable beam splitter. In doing so, the head-up display may have imaging optics that are specially adapted to this type of imaging device configuration. By using only one liquid crystal display with a suitable backlight, a compact and inexpensive configuration can be realized.

  According to one embodiment, the video unit has a first polarizing layer arranged in a first display area for polarizing the first light field in a first polarization direction, in addition or alternatively In particular, the second light field has a second polarizing layer disposed in the second display region for polarizing the second light field in a second polarization direction different from the first polarization direction. In particular, the first polarization direction and the second polarization direction can be substantially orthogonal to each other.

  The first polarizing layer and the second polarizing layer are to be understood as layers configured to polarize a light field that hits the first display area or the second display area into a linear or circular shape. The predetermined polarization directions of the two polarizing layers may be orthogonal to each other, for example. Such orientation of the two polarization directions is simply and at a relatively low cost by utilizing the corresponding polarizing layer.

  In the polarization-independent beam splitter, for example, the polarization directions of the two light fields do not need to be different. Depending on the embodiment, video units whose polarizations cross each other or video units whose polarizations are at least offset from each other can be realized.

  Furthermore, it is advantageous if the beam splitter is realized as a polarizing beam splitter and / or as a prism. According to this embodiment, it is possible to reflect or transmit two light beams very efficiently. This further reduces the double image.

  According to another embodiment, the main extension plane of the beam splitter is oriented substantially perpendicular to the main extension plane of the first display area and / or the second display area. For example, the beam splitter may be configured in a plate shape and fixed in the center of the display unit, thus obtaining a T-shaped configuration. Thereby, the beam splitter functions as an optical partition between the first display area and the second display area. Such a configuration is particularly realized in a simple manner and at a low cost, saving installation space.

  Further, the video unit is an optical element arranged in the optical path of the first light field and / or the second light field between the light source and the display unit, and the first light field and / or the second light unit. The optical element for deflecting the light field and / or collecting the first light field and / or the second light field. In particular, the optical element deflects the first light field in the first direction associated with the first eye of the viewer of the head-up display and is associated with the second eye of the viewer. It can be configured to deflect the second light field in the second direction. For example, an optical element can be used to direct two rays into the optical path to a so-called eyebox, i.e. directing the two rays into the area into which the viewer's eyes fall. Is possible. According to this embodiment, two light fields can be shaped according to a given spatial condition and imaging condition. By separating the two light fields into separate eyeboxes, a stereoscopic function is realized, which greatly improves the display quality of the image unit.

  Furthermore, it is advantageous if the optical element has at least one microlens array. Additionally or alternatively, the optical element may have at least one lens, mirror, or polarizing beam splitter, depending on the embodiment. The microlens array can be understood as a configuration including a plurality of lenses having a miniaturized shape, that is, for example, a cylindrical lens. According to this embodiment, even when only one light source is used, it is possible to radiate two light fields in various radiation directions by using means provided simply and at low cost.

  In that case, the lens may be realized as a Fresnel lens. A Fresnel lens can be understood as a step-like lens divided into annular zones. Thereby, it is possible to efficiently deflect the light beam to the display unit.

  According to another embodiment, the video unit deflects the second light field with a first lens arranged or positionable in the optical path of the first light field for deflecting the first light field. The second lens arranged in the optical path of the second light field and the light field deflected by the first lens and / or the second lens in the first light collecting direction. And a second microlens array for condensing the light field deflected by the first lens and / or the second lens in the second condensing direction. Can be provided. According to the present embodiment, the directivity angles of the two light fields spreading in a conical shape (hereinafter referred to as a conical beam) can be set separately from each other.

  Optionally, the video unit, additionally or alternatively, the light source may be rotatable about at least one axis. Thereby, the light beam can follow the movement of the viewer's head or eyes.

  Furthermore, the light source unit may have at least one light source. The light source unit may be configured to illuminate the first display area from behind with the first light beam. Correspondingly, the light source may be configured to illuminate the second display area from behind by the second light beam. In particular, the light source unit is arranged to emit the first light field in a first direction associated with the viewer's first eye, the light source corresponding to the viewer's second eye. It can be arranged to emit a second light field in the attached second direction. According to the present embodiment, the two display areas can be illuminated from behind without depending on each other.

  Furthermore, the approach described herein creates a head-up display with a video unit according to one of the previously described embodiments. A head-up display can be understood as a display system for projecting information onto the field of view of the driver of the vehicle. In particular, the head-up display is suitable for displaying a three-dimensional virtual image.

Further, according to the proposed approach, a method for generating a paired image for stereoscopic viewing using a video unit according to one of the embodiments described herein, comprising the following steps: That is,
By illuminating the first display area from behind with the first light field, an image for the first stereoscopic view is generated, and by illuminating the second display area from behind with the second light field. A method is created that includes controlling the display unit and / or the light source unit to generate an image for a second stereoscopic view.

  The method can be implemented, for example, in a controller, for example by software or hardware, or by a mixed form of software and hardware.

  Furthermore, the approach proposed herein creates a controller configured to perform, control, or implement the steps of the method variations proposed herein with corresponding devices. This variant of the method in the form of a control device solves the problem underlying the present invention quickly and effectively.

  As used herein, a control device can be understood as an electrical device that processes sensor signals and outputs control signals and / or data signals in accordance with the sensor signals. The control device may have a configurable interface based on hardware and / or software. In the case of a hardware-based configuration, the interface can be a component of a so-called system ASIC that includes various functions of the control device, for example. However, the interface may be a unique integrated circuit or may be at least partially composed of separate components. In the case of a software-based configuration, the interface can be a software module that resides with other software modules on the microcontroller, for example.

  One of the embodiments described above, which can be stored on a machine-readable carrier or storage medium, such as a semiconductor memory, hard disk, or optical memory, and especially when the program product or program is executed on a computer or apparatus Also advantageous are computer program products or computer programs having program code which are used to execute, implement and / or control the steps of the method described in.

  Embodiments of the invention are shown in the drawings and are explained in detail in the description of the following specification.

The schematic of the video unit which concerns on one Example is shown. The schematic diagram of the image unit provided with the optical element concerning one example is shown. The schematic diagram of the image unit provided with the optical element concerning one example is shown. The schematic diagram of the image unit provided with the optical element concerning one example is shown. The schematic diagram of the image unit provided with the optical element concerning one example is shown. 1 shows a schematic diagram of a head-up display according to one embodiment. FIG. Fig. 5 shows a glass showing the light output behind a display unit according to one embodiment. 1 shows a schematic diagram of a head-up display according to one embodiment. FIG. 1 shows a schematic diagram of a head-up display according to one embodiment. FIG. The schematic diagram of the image unit provided with the optical element concerning one example is shown. 1 shows a schematic diagram of a head-up display with a rotatable video unit according to one embodiment. FIG. The schematic diagram of the image unit provided with the optical element concerning one example is shown. Fig. 2 shows a flow diagram of a method according to an embodiment.

  In the following description of an advantageous embodiment of the present invention, the same or similar reference numerals are used for components that act in a similar manner as shown in the various figures, and a redundant description of the components is provided. Do not do.

  FIG. 1 is a schematic diagram of a video unit 100 according to an embodiment. The video unit 104 includes a display unit 106 divided into a first display area 102 and a second display area 104, that is, an LCD display, for example. In FIG. 1, the second display area 104 exists below the first display area 102, for example. The light source unit (here, in the form of the light source 108) illuminates the first display area 102 from behind by the first light field 110 and illuminates the second display area 104 from behind by the second light field 112. It is configured as follows. Two light fields 110, 112 are missing in the other polarization directions from the side of the display unit 106 not facing the light source 108.

  In order to realize the above-described effect, the first display region 102 includes the first polarizing layer 114, and the second display region 104 includes the second polarizing layer 116. The first polarizing layer 114 is configured to polarize the first light field 110 in the first polarization direction, and the second polarizing layer 116 is configured to polarize the second light field 112 in the second polarization direction. Composed. According to this embodiment, the two polarizing layers 114 and 116 are designed such that the corresponding polarization directions are orthogonal to each other.

  Further, the video unit 100 has a beam splitter 118, that is, a plate-shaped polarizing beam splitter in this case, and this polarizing beam splitter passes the first light field 110 that has escaped from the first display region 102 to the beam. It serves to reflect the splitter 118 towards the side not facing the second display area 104. In FIG. 1, the first light field 110 has, for example, an incident angle and an output angle of 45 degrees with respect to the beam splitter 118. Further, the beam splitter 118 serves to transmit the second light field 112 that has escaped from the second display area 104 to the side of the beam splitter 118 that does not face the second display area 104; At that time, the emission angle of the second light field 112 is also 45 degrees with respect to the beam splitter 118. In FIG. 1, two light fields 110 and 112 are guided in each direction by a beam splitter 118 to form a respective eyebox.

  According to the embodiment shown in FIG. 1, the beam splitter 118 is fixed at a location where the two display areas 102 and 104 of the display unit 106 are adjacent to each other. In FIG. 1, this place corresponds to the center of the display unit 106, for example. Here, the beam splitter 118 has an angle of 90 degrees with respect to the display unit 106, so that a T-shaped arrangement is obtained.

  The control device 120 is configured to prepare control signals for controlling the two light fields 110 and 112 and the display unit 106 and to output them to the light source 108 and the display unit 106. The light source 108 is configured to emit two light fields 110, 112 utilizing the control signal 122. The two light fields 110, 112 serve to illuminate from behind the two display areas 102, 104 when the two display areas 102, 104 are illuminated from behind by each light field passing through each display area. Control is performed by the control signal 122 so as to generate a paired image of the stereoscopic image. According to one embodiment, the control device 120 is configured to control the light source 108 for tracking at least one movable axis and for brightness control, in which case the control device in controlling the display unit 106. The substantial function of 120 is to generate a counter image.

  According to one embodiment, two regions functioning as display regions 102 and 104 of a display unit 106 such as a liquid crystal display are provided with two polarizing layers 114 and 116 whose polarizations are orthogonal to each other. . The beam splitter 118 in the form of a polarizing beam splitter has two display areas 102 such that the virtual image generated by the second display area 102 is present on the side of the beam splitter 118 facing the first display area 104. , 104 are stacked. At that time, the two display areas 102 and 104 are separately illuminated by the light source 108.

  When the two display areas 102 and 104 are separately illuminated from behind as described above, separate image information is generated for both eyes of the viewer of the head-up display having the video unit 100, and is generated by the beam splitter 119. Overlaid. At this time, for example, the first polarizing layer 114 is configured to transmit linearly polarized light at an angle of 45 degrees, and the second polarizing layer 116 is configured to transmit linearly polarized light at an angle of −45 degrees. At that time, the beam splitter 118 is attached to the display unit 106 perpendicularly to the display surface of the display unit 106.

  FIG. 2 is a schematic diagram of the video unit 100 including the optical element 200 according to an embodiment. The video unit 100 is related to, for example, the video unit described above with reference to FIG. According to this embodiment, the optical element 200 includes a first mirror 202, a second mirror 204, and a polarization-dependent beam disposed between the first mirror 202 and the display unit 106 in this example. And a splitter 206. Here, the two mirrors 202 and 204 are orthogonal to each other. However, other configurations are possible depending on the embodiment.

  The polarization-dependent beam splitter 206 divides light emitted from a light source not shown here into a first light field 110 and a second light field 112. Here, the first light field 110 directly hits the first display area 102. The second light field 112 is reflected by the second display area 104 via the two mirrors 202 and 204. According to the present embodiment, the two mirrors 202 and 204 are arranged such that the second light field 112 is deflected by a total of 180 degrees. As a result, the two display regions 102 and 104 are illuminated with polarized light beams orthogonal to each other. For this purpose, the optical element 200, also called a backlight unit, first divides the light emitted from the light source into two polarizations orthogonal to each other by the polarization-dependent beam splitter 206. Upon passing through the display unit 106, the two light beams 110 and 112 are again superimposed by the beam splitter 118.

  The advantage of using a polarization-dependent beam splitter as the beam splitter 118 is that the beam splitter 118 is correspondingly positioned and a corresponding polarizer is provided in the two display areas 102, 104, so that two As long as the polarization directions of the partial images cross each other in a cross shape, the entire light from the display unit 106 is transmitted or reflected.

  The window glass of a vehicle usually has a strong priority direction when it is reflected because light rays strike near the so-called Brewster angle. Therefore, in order to achieve the same possible reflection for the two partial images, the system described here is designed for +45 degrees and 45 degrees polarization on the glazing, thus The loss occurs in the window glass, but does not occur in the video unit 100. That is, less stray light is caused inside the video unit, thereby improving the contrast characteristics.

  When a polarization independent beam splitter is utilized, the system can be similarly designed to minimize light loss in the window glass. In this case, the two display areas 102 and 104 can be provided with the same polarizing layer.

  By utilizing a beam splitter to superimpose two partial images, undesired double images can occur due to interreflection within the beam splitter. This double image can be reduced, for example, by using a suitable beam splitter with anti-reflection processing on the back. Alternatively, it is possible to use a particularly thin beam splitter, in which case the double image is very close to the original image. If the misalignment between the two images is, for example, less than one pixel at the display unit 106, the double image is no longer perceived as an independent image. This type of beam splitter can be produced, for example, by depositing a particularly thin metal film, i.e. a glass film with a coating of, for example, a 4 nm thick aluminum coating or a dielectric film.

  By utilizing a polarization dependent beam splitter, double images can be reduced as well. This is because this kind of beam splitter has a very high reflection effect or transmission effect, for example, by using a wire-grid technology.

  The field of view for the left and right eyes, generated by special backlighting, should follow the driver's head movement. In order to determine the position of the driver's eyes, it is possible to use, for example, a head-tracking system based on one or more cameras.

  Corresponding eyeball position data is transferred to the video unit 100, and the video unit 100 is configured to rotate as a whole according to the eyeball position and adjust the field of view for each position of the driver's head. The rotation angle of the mechanical tracking of the video unit 100 is, for example, about 6 degrees. Alternatively, tracking of the light source present behind the display unit 106 may also be envisaged to change the angle of the conical beam at the display unit 106.

  FIG. 3 is a schematic diagram of the video unit 100 including the optical element 200 according to an embodiment. Unlike FIG. 2, the optical element 200 shown in FIG. 3 includes a lens 300 in the form of a Fresnel lens, and a microlens array 302 disposed between the lens 300 and the display unit 106.

  Here, possible backlighting to the display unit 106 for the formation of a defined conical beam with a specific width in a specific direction on the display unit 106 is shown. A conical beam is generated, for example, based on a scattering surface that is emitted with a narrow solid angle. Instead of a scattering surface, such a backlighting concept can be realized by the microlens array 302 behind the display unit 106. In order to determine the direction of the central radiation of the conical beam, the light emitted from the light source 108 is deflected by the Fresnel lens 300. The microlens array 302 connected to the rear stage of the lens 300 collects light on the plane of the display unit 106. According to the size of the opening of the microlens and the focal length, such a conical beam with a defined width that illuminates the display unit 106 is generated.

  According to an embodiment, the two parts of the display unit 106 may also have a unique backlight that generates the directivity on the display unit 106 that is necessary for stereo vision driving of the autostereoscopic head up display. Good.

  FIG. 4 is a schematic diagram of the video unit 100 including the optical element 200 according to one embodiment. Unlike the display unit shown in FIG. 3, the video unit 100 according to FIG. 4 includes a first lens 400 arranged in the first display region 102 of the display unit 106 and a second display of the display unit 106. And the second lens 402 disposed in the region 104, in which case the first lens 400 deflects the first light field 110 to the first display region 102 and the second lens 402. Is configured to deflect the second light field 112 to the second display area 104. For example, the display unit 106 and the two lenses 400 and 402 form a stacked structure together with the microlens array 302, and the microlens array 302 converges the two light beams 110 and 112. For this purpose, it is a layer that exists between the display unit 106 and the two lenses 400 and 402.

  A further difference from FIG. 3 is that the video unit 100 has in addition to the light source 108 a further further light source 404 configured to emit the second light field 112. The two light sources 108, 404 are oriented in different directions. Strictly speaking, the light source 108 is arranged to guide the first light field 110 to the optical path to the viewer's right eye, indicated by the alphabet R. The second light source 404 is oriented so that the second light field 112 is directed into the light path to the viewer's left eye, indicated by the alphabet L. This is because the first auxiliary lens 406 disposed in the optical path of the first light beam 110 between the first lens 400 and the light source 108, and between the second lens 402 and the further another light source 404. This is performed using a second auxiliary lens 408 disposed in the optical path of the second light beam 112.

  FIG. 4 shows a basic principle for superimposing two partial images, that is, a basic principle for dividing the two partial images into a left partial image L and a right partial image R. At that time, the two partial images L and R are emitted in slightly different directions, that is, for example, in directions different by 5 degrees to 10 degrees, for example. This causes the two light fields 110, 112 to reach two fields of view for the left and right eyes (eyebox in English). The different radiation directions are realized by corresponding positioning of the backlight elements in the form of two light sources 108, 404, for example realized as LEDs. Depending on the embodiment, the division of the two partial images L, R can be performed such that the two partial images L, R differ in the vertical or horizontal direction depending on the subsequent optical elements.

  FIG. 5 shows a schematic diagram of a video unit 100 including an optical element 200 according to an embodiment. The video unit 100 substantially corresponds to the video unit described with reference to FIG. 4, but differs in that the beam splitter 118 according to FIG. 5 is realized as a prism. By means of a beam splitter 118 in the form of a prism shown in diagonal lines in FIG. 5, the two display partial surfaces 102, 104 can be superimposed so that the formation of a double image is effectively prevented. Such a beam splitter prism in the form of a glass body can be optically coupled to an LCD module as the display unit 106, for example. In doing so, the glass surface through which each of the two light fields 110, 112 exits the beam splitter 118 can be adjusted for each radiation direction.

  FIG. 6 shows a schematic diagram of a head-up display 600 according to an embodiment. The head-up display 600 shown in the side view and the perspective view is an imaging optical system including, for example, the video unit 100 described above with reference to FIGS. 1 to 5 and two display mirrors. And the imaging optical system configured to guide the light beam emitted by the unit 100 to the driver's visual field 606 through the windshield 604. In the perspective view, two partial images for the driver's left eye and right eye can be seen, where the upper part of the display unit 106 contributes for the left eye and the lower part of the display unit 106 for the right eye. Contribute.

  The head-up display 600 is realized as an autostereoscopic head-up display including an LCD display as the display unit 106, for example. The beam splitter 118 superimposes the light beams of the two parts of the display unit 106.

  According to one embodiment, the light beam is superimposed by a beam splitter 118 and then guided by imaging optics having one or more mirrors, depending on the embodiment, and finally through the window glass 604. To reach. In the system shown in FIG. 6, the display unit 106 is inclined, for example, 45 degrees with respect to the optical axis of the LED backlight. By illuminating the display unit 106 obliquely, the luminance emitted by the display unit in the direction of the optical axis is lowered.

  FIG. 7 shows a glass representing the light output behind the display unit according to one embodiment. The graph shown in FIG. 7 relates to the display unit described above with reference to FIG. 6, for example. Here, the measurement result of the transmitted light output of a display unit in the form of an LCD display with an LED collimated backlight according to the inclination of the display unit relative to the optical axis of the backlight is shown. Thereby, the normalized light output is shown as a function of the tilt angle, in which case the corresponding detector is in line with the optical axis of the LED backlight. The vertical axis shows the light output as a percentage, and the horizontal axis shows the slope as an angle. When the inclination is 45 degrees, the light output in the optical axis direction is lowered to a value of about 70 percent. This can be corrected, for example, by using a stronger backlight. Since the autostereoscopic head-up display has a relatively small field of view for the left eye and the right eye, depending on the situation, a smaller luminous flux is required as compared with a conventional head-up display.

  FIG. 8 shows a schematic diagram of the head-up display 600 of FIG. 6 according to one embodiment. Unlike FIG. 6, the imaging optical system of the head-up display 600 shown in FIG. 8 has three display mirrors instead of two display mirrors. Here, a side view (left) and an enlarged view (right) of the head-up display 600 are shown.

  According to this embodiment, the required angle of the chief ray of the conical beam at the center of the LCD half area of the display unit 106 is 25 degrees with respect to the surface normal of the display unit 106. Overall, light rays are emitted at an angle of less than 47 degrees for each position within the entire eyebox range provided, for example, by 140 mm × 50 mm, and for all points of the display unit 106. That is, the required tilted angle of the backlight is 47 degrees. A smaller radiation angle compared to FIG. 6 increases the contrast value and efficiency of the display system. The conical beam at the central display point requires a directivity angle of 2 degrees in the horizontal direction and 3 degrees in the vertical direction, for example.

  FIG. 9 shows a schematic diagram of a head-up display 600 according to an embodiment. Unlike the head-up display previously described with reference to FIGS. 6 and 8, the two display areas 102, 104 of the display unit 106 according to FIG. The light source 404 is separately illuminated from behind.

  In addition, immediately behind the display unit 106, there are additional microlenses and lenses as light shaping elements, as will be described in detail below using FIG. Two partial images radiated from the display areas 102 and 104 via the beam splitter 118 are overlaid so that a virtual image of the first display area 102 exists at the location of the second display area 104. The display areas 102 and 104 overlapped in this way are imaged through a head-up display mirror optical system including one or more HUD mirrors 602 and a window glass 604. The light of the two partial images is provided to the eyes that are within the full eyebox 606 range. Inside the full eyebox 606, the rays of each partial image form a smaller eyebox in which each eye of the driver is present. The two display areas 102 and 104 are virtually imaged through the head-up display optical system and the window glass 604.

  From the distance data to the virtual screen, the field of view, and the overall size of the eyebox, the invariant of the system's Lagrange-Helmholtz is calculated, thereby the expected cone width of the cone beam at the display unit 106. Is determined. Thus, the pointing half angle of the conical beam is 9 degrees in the horizontal direction and 2.9 degrees in the vertical direction. The maximum angle of the ray relative to the surface normal that occurs on the display is calculated using the half angle of the cone beam and the tilt of the display relative to the optical axis. Thus, according to Lagrantz-Helmholtz invariants, the maximum vertical angle is 32.9 degrees in the vertical direction and 9 degrees in the horizontal direction. The maximum vertical angle generated according to the optical simulation is, for example, 36.9 degrees. According to the simulation, the maximum angle of the ray with respect to the surface normal is 41.6 degrees, for example. In that case, the incident angle of the light ray with respect to the surface normal has a horizontal component and a vertical component.

  FIG. 10 is a schematic diagram of the video unit 100 including the optical element 200 according to an embodiment. For example, the video unit 100 is related to a video unit based on an enlarged view described with reference to FIG. It can be seen that a light shaping optical element in the form of two lenses 400, 402 exists immediately behind the display unit 106. The light comes from the two light sources 108, 402, passes through one of the two lenses and is deflected so that the correct radiation direction of the central beam of the cone beam at the display unit 106 is generated. For this reason, the two light sources 108 and 404 are positioned relatively corresponding to the two lenses 400 and 402. In order to shape the conical beam at the display unit 106, it is focused by a microlens array 302 including two partial arrays 1000, 1002 according to this embodiment. The partial arrays 1000 and 1002 are realized as cylindrical lens arrays, for example, such that the first partial array 1000 acts only in the horizontal direction and the second partial array 1002 acts only in the vertical direction. Depending on the curvature radius of each microlens, the directivity angles of the conical beams on the display unit 106 can be set separately from each other. After the directivity in the two display areas 102 and 104 is formed, the obtained partial images are superimposed by the beam splitter 118.

  FIG. 11 shows a schematic diagram of a head-up display 600 including a rotatable video unit 100 according to an embodiment. For example, the head-up display 600 includes the video unit 100 described with reference to FIG. A rotation axis around which the video unit 100 can rotate is indicated by a dotted line. For example, when the video unit 100 set is rotated around the rotation axis, the eye box for each eye in the entire eye box 606 is also shifted. Thereby, the light rays incident on all the eye boxes 606 follow the movement of the driver's head.

  Alternatively or additionally, the two light sources 108, 404 can be rotated about an axis of rotation. For example, the two light sources 108 and 404 can be rotated without the video unit 100 set moving together. It can also be envisaged that the light shaping elements behind the display unit 106 partially rotate together.

  FIG. 12 is a schematic diagram of the video unit 100 including the optical element 200 according to an embodiment. The video unit 100 corresponds to, for example, a combination of the embodiments described above with reference to FIGS. 2, 4, and 10. According to this, the two display areas 102 and 104 are joined together by the light source 108. Illuminated from behind.

  At that time, for example, the two display regions 102 and 104 are provided with deflection layers whose polarizations are orthogonal to each other. In this case, a polarizing beam splitter 118 existing on the display unit 106 overlaps the display areas 102 and 104 that are illuminated with polarized light that form an angle of 90 degrees with each other. At that time, the optical element 200 first splits the light into two polarized light beams orthogonal to each other by the polarization beam splitter 206. After passing through the display unit 106, the light is again superimposed by the beam splitter 119. In that case, the virtual image of the second display area 104 exists in the first display area 102.

  According to the embodiment shown in FIG. 12, the two display areas 102 and 104 use the light of the same light source 108. For this purpose, the light is first divided into two polarization directions orthogonal to each other by the polarization-dependent beam splitter 206. At this time, the light of one polarization direction illuminates the first display area 102 from behind. To do. The light, which is polarized orthogonally to the light of one polarization direction and whose direction is changed by the beam splitter 206, passes through the two mirror optical systems 202 and 204 arranged opposite to each other here. It is deflected to the second display area 104. Each of the polarizing layers transmits light polarized orthogonally to each other, so that the light polarized similarly orthogonally to each other passes through the two display regions 102 and 104. Due to the orthogonal polarization, the light is efficiently superimposed by the polarization dependent beam splitter 118. According to other embodiments, a 50:50 beam splitter or a beam splitter with a different branching ratio may be used as the beam splitter 118.

  FIG. 13 shows a flow diagram of a method 1300 for generating an optical counter image using a video unit according to one embodiment. The method 1300 may be performed, for example, in connection with the video unit described above with reference to FIGS. The method includes step 1310, where an image for a first stereoscopic view is generated by illuminating the first display area from behind by the first light field, and by the second light field. One or more light sources of the display unit or the video unit are controlled such that an image for the second stereoscopic view is generated by illuminating the second display area from behind.

  In doing so, the light source, for example a photodiode, substantially serves for backlighting. The image content is first applied by the display unit. The light source is controlled for dimming and tracking. In effect, the control of the image content is almost via the display unit.

Where an example includes an “and / or” connection between a first feature and a second feature, the example according to one embodiment includes the first feature and the second feature. It should be understood that examples according to other embodiments have only the first feature or only the second feature.

According to one embodiment, two regions functioning as display regions 102 and 104 of a display unit 106 such as a liquid crystal display are provided with two polarizing layers 114 and 116 whose polarizations are orthogonal to each other. . Beam splitter 118 in the form of a polarizing beam splitter, on the side facing the first display region 102 of the beam splitter 118, as a virtual image generated by the second display area 104 is present, two display areas 102 , 104 are stacked. At that time, the two display areas 102 and 104 are separately illuminated by the light source 108.

From the distance data to the virtual screen, the field of view, and the overall size of the eye box, the invariant of the system's Lagrange-Helmholtz is calculated, thereby the expected cone width of the cone beam at the display unit 106. Is determined. Thus, the pointing half angle of the conical beam is 9 degrees in the horizontal direction and 2.9 degrees in the vertical direction. The maximum angle of the ray relative to the surface normal that occurs on the display is calculated using the half angle of the cone beam and the tilt of the display relative to the optical axis. Therefore, according to the invariant raglan Tsuju Helmholtz, the uppermost large angle, 32.9 ° in the vertical direction, is 9 degrees in the horizontal direction. The maximum vertical angle generated according to the optical simulation is, for example, 36.9 degrees. According to the simulation, the maximum angle of the ray with respect to the surface normal is 41.6 degrees, for example. In that case, the incident angle of the light ray with respect to the surface normal has a horizontal component and a vertical component.

Claims (15)

A video unit (100) for a head-up display (600), the video unit (100) comprising the following features:
A display unit (106) having a first display area (102) and a second display area (104) disposed outside the first display area (102);
At least for illuminating the first display area (102) from behind by a first light field (110) and illuminating the second display area (104) from behind by a second light field (112). One light source unit (108, 404);
A beam splitter (118) disposed on a side of the display unit (106) facing the at least one light source unit (108, 404), deflecting the first light field (110); The beam splitter (118) configured to transmit a second light field (112);
A video unit (100).   The video unit (100) includes a first polarizing layer (114) disposed in the first display region (102) for polarizing the first light field (110) in a first polarization direction. And / or a second light field (112) disposed in the second display region (104) for polarizing the second light field (112) in a second polarization direction different from the first polarization direction. The video unit (100) according to claim 1, characterized in that it comprises two polarizing layers (116), in particular, the first polarization direction and the second polarization direction being substantially orthogonal to each other. ).   Video unit (100) according to claim 1 or 2, characterized in that the beam splitter (118) is realized as a polarizing beam splitter and / or as a prism.   The main extension plane of the beam splitter (118) is oriented substantially perpendicular to the main extension plane of the first display area (102) and / or the second display area (104). Video unit (100) according to any one of the preceding claims, characterized in that.   The video unit (100) is disposed in the optical path of the first light field (110) and / or the second light field (112) between the light source (108) and the display unit (106). Optical element (200) for deflecting the first light field (110) and / or the second light field (112) and / or the first light beam (110) and / or Comprising the optical element (200) for condensing a second light beam (112), in particular the optical element (200) associated with the first eye of the viewer of the head-up display (600); The first light field (110) is deflected in the first direction, and the second light field (110) is moved in the second direction associated with the second eye of the viewer. Rudo (112), characterized in that it is configured so as to deflect the video unit according to any one of claims 1-4 (100).   Said optical element (200) comprises at least one microlens array (302; 1000, 1002) and / or lens (300; 400, 402, 406, 408) and / or mirror (202, 204) and / or polarized beam. Video unit (100) according to claim 5, characterized in that it comprises a splitter (206).   Video unit (100) according to claim 6, characterized in that the lens (300) is realized as a Fresnel lens. The video unit (100)
A first lens (400) disposed or positionable in the optical path of the first light field (110) for deflecting the first light field (110);
A second lens (402) disposed in the optical path of the second light field (112) for deflecting the second light field (112);
A first microlens array (1000) for condensing the light field deflected by the first lens (400) in a first condensing direction;
A second microlens array (1002) for condensing the light field deflected by the second lens (402) in a second condensing direction;
The video unit (100) according to any one of claims 5 to 7, characterized by comprising:   9. The video unit (100) and / or the light source unit (108, 404) can be rotated about at least one axis, according to any one of the preceding claims. Video unit (100). The light source unit (108, 404) has at least one light source (404), and the light source unit (108) is behind the first display area (102) by the first light field (110). Configured to illuminate from
The light source (404) is configured to illuminate the second display area (104) from behind by the second light field (112), in particular, the light source unit (108) Arranged to radiate the first light field (110) in the first direction associated with a first eye, the light source (404) being located in the second eye of the viewer Video unit (1) according to any one of the preceding claims, characterized in that it is arranged to radiate the second light field (112) in the associated second direction. 100).   A head-up display (600) comprising the video unit (100) according to any one of claims 1 to 10. A method (1300) for generating a counter image for stereoscopic viewing using the video unit (100) according to any one of claims 1 to 10, comprising:
Said method (1300) comprises the following steps:
An image for the first stereoscopic view is generated by illuminating the first display area (102) from behind by the first light field (110), and the second light field (112) Controlling (1310) the display unit (106) and / or the light source unit (108, 404) to generate an image for a second stereoscopic view by illuminating the display area (104) from behind.
A method (1300) comprising:   A controller (120) configured to perform and / or control a method (1300) according to claim 12.   A computer program configured to execute and / or control a method (1300) according to claim 12. A machine-readable storage medium storing the computer program according to claim 14.

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