JP6787681B2 - Liquid crystal display device - Google Patents

Description

The present invention relates to a liquid crystal display device.

Liquid crystal display devices are widely used in various fields and are used in various environments. Looking at the temperature environment, it is used in a wide range of environments from a low temperature range (for example, -30 degrees) to a high temperature range (for example, 60 degrees), and it is required to operate normally within that temperature range.

The response speed of the liquid crystal is greatly affected by the operating temperature environment, and especially in a low temperature environment, the response speed of the liquid crystal becomes slow and the image quality may deteriorate. Therefore, especially when used in a low temperature environment, a so-called panel heater having a heat generating layer made of an ITO thin film or the like formed on the surface of a glass substrate or the like is attached to the liquid crystal display device in order to warm the liquid crystal. (See, for example, Patent Document 1)

Japanese Unexamined Patent Publication No. 2011-64756

When a panel heater is attached to heat the liquid crystal display device, problems such as an increase in size of the liquid crystal display device and an increase in power consumption occur.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a liquid crystal display device capable of heating a liquid crystal without using a panel heater.

Comprising a liquid crystal panel, and an infrared-absorbing member which generates heat by absorbing infrared rays, a liquid crystal display device to which the infrared absorption member by heat generated by absorbing infrared rays, the liquid crystal panel is configured to be warmed It is configured to include an infrared light source that mainly selectively emits infrared rays, and the infrared rays emitted from the infrared light source are absorbed by the infrared absorbing member, and the infrared absorbing member is not a non-liquid crystal panel. and it is configured as a light-shielding mask covering the display area, a liquid crystal display device.

An infrared reflecting member that reflects infrared rays emitted from the infrared light source toward the infrared absorbing member, and a reflective polarizing member that reflects visible light toward the liquid crystal panel and transmits visible light emitted from the liquid crystal panel. A liquid crystal display device having a plate and having the infrared reflecting member laminated on the reflective polarizing plate may be used.

According to the present invention, the liquid crystal can be heated without using a panel heater.

Schematic diagram showing an embodiment of a liquid crystal display device according to the present invention (Example 1) Schematic diagram showing an embodiment of a liquid crystal display device according to the present invention (Example 2) Schematic diagram showing an embodiment of a liquid crystal display device according to the present invention (Example 3)

FIG. 1 is a schematic view showing an embodiment of a liquid crystal display device according to the present invention. In this embodiment, the polarizing plates 2 are arranged on the upper and lower surfaces of the liquid crystal panel 1 configured as the transmissive liquid crystal panel, and the backlight unit 4 faces the liquid crystal panel 1 with the lower polarizing plate 2 sandwiched between them. Is arranged, and further, an infrared absorbing film 3 is arranged between the lower polarizing plate 2 and the backlight unit 4.

The infrared absorbing film 3 is arranged so as to cover both the display area where the image of the liquid crystal panel 1 is displayed and the non-display area where the image is not displayed, but is arranged so as to cover only the display area or only the non-display area. It may have been done. The infrared absorbing film 3 selectively absorbs infrared rays having a wavelength of about 780 nm to 1 mm at an absorption rate of about 50% or more to generate heat. In particular, here, the infrared ray absorbing film 3 has a wavelength of about 780 nm to 3 μm. It is supposed to absorb infrared rays with an absorption rate of about 50% or more. The infrared wavelength band to be absorbed by the infrared absorbing film 3 can be arbitrarily selected, but when the purpose is to locally heat the film in a short time, the infrared rays in the near infrared wavelength band are absorbed. Is preferable. However, the wavelength band of infrared rays absorbed by the infrared absorbing film 3 is not limited to this.

The liquid crystal panel 1, the upper polarizing plate 2, the lower polarizing plate 2, the infrared absorbing film 3, and the backlight unit 4 are arranged so that adjacent ones are close to each other or in contact with each other, and are bonded to each other as necessary. However, in order to facilitate heat transfer to the liquid crystal panel 1, in particular, the liquid crystal panel 1, the lower polarizing plate 2, the infrared absorbing film 3, and the backlight unit 4 are in contact with each other. It is preferable that they are arranged in such a manner.

The backlight unit 4 incorporates a light source such as an LED that mainly emits visible light, and the visible light emitted from the light source is an infrared absorbing film 3, a lower polarizing plate 2, a liquid crystal panel 1, and an upper polarized light. It passes through the plate 2 in sequence and is observed as an image above.

The infrared absorbing film 3 generates heat by selectively absorbing infrared rays contained in the light emitted from the backlight unit 4 and the light incident from the outside of the liquid crystal display device. The generated heat is transferred to the liquid crystal panel 1 via the lower polarizing plate 2, and the liquid crystal is warmed. Further, when heat is generated from the backlight unit 4 by driving the backlight unit 4, the heat is also transferred to the liquid crystal panel 1 via the infrared absorbing film 3 and the lower polarizing plate 2, and the liquid crystal is warmed.

As a modification of this embodiment, for example, an infrared light source such as an LED that selectively emits infrared rays (particularly near infrared rays) is arranged around the liquid crystal panel 1, and the infrared rays emitted from the infrared rays are emitted from the infrared absorbing film 3. It is also possible to increase the amount of heat generated by absorbing infrared rays. Further, in that case, if the infrared light source is incorporated into the backlight unit 4 to form a unit, the configuration can be simplified. Further, the infrared light source may be configured to emit infrared rays only when the liquid crystal panel 1 has a low temperature and to stop emitting infrared rays when the liquid crystal panel 1 has a high temperature.

The infrared absorbing film 3 is not limited to between the lower polarizing plate 2 and the backlight unit 4, but is arranged, for example, between the upper polarizing plate 2 or the lower polarizing plate 2 and the liquid crystal panel 1. In this case, since the infrared absorbing film 3 approaches the liquid crystal panel 1, the heat from the infrared absorbing film 3 is easily transferred to the liquid crystal panel 1.

FIG. 2 is a schematic view showing an embodiment of a liquid crystal display device according to the present invention. In this embodiment, the polarizing plate 2 is arranged on the upper surface side of the liquid crystal panel 1 configured as the reflective liquid crystal panel, the front light unit 11 is arranged above the polarizing plate 2, and the front light unit 11 and the polarizing plate 2 are further arranged. An infrared absorbing film 3 is arranged between them.

The infrared absorbing film 3 is arranged so as to cover both the display area where the image of the liquid crystal panel 1 is displayed and the non-display area where the image is not displayed, but is arranged so as to cover only the display area or only the non-display area. It may have been done.

The liquid crystal panel 1, the polarizing plate 2, the infrared absorbing film 3, and the front light unit 11 are arranged so that adjacent ones are close to each other or in contact with each other, and are adhered to each other as necessary, but heat is applied to the liquid crystal panel 1. It is preferable that adjacent objects are arranged so as to be in contact with each other in order to facilitate transmission.

A light source such as an LED that mainly emits visible light is incorporated in the front light unit 11, and the visible light emitted from the light source passes through the infrared absorbing film 3 and the polarizing plate 2 in this order and is incident on the liquid crystal panel 1. , Reflected by the liquid crystal panel 1, passes through the polarizing plate 2 and the infrared absorbing film 3 in that order, and is observed as an image above.

The infrared absorbing film 3 generates heat by selectively absorbing infrared rays contained in the light emitted from the front light unit 11 and the light incident from the outside of the liquid crystal display device. The generated heat is transferred to the liquid crystal panel 1 via the polarizing plate 2, and the liquid crystal is warmed. When heat is generated from the front light unit 11 by driving the front light unit 11, the heat is also transferred to the liquid crystal panel 1 via the infrared absorbing film 3 and the polarizing plate 2, and the liquid crystal is warmed.

As a modification of this embodiment, for example, an infrared light source such as an LED that selectively emits infrared rays (particularly near infrared rays) is arranged around the liquid crystal panel 1, and the infrared rays emitted from the infrared rays are transmitted to the infrared absorbing film 3. It is also possible to increase the amount of heat generated by absorbing it. Further, in that case, if the infrared light source is incorporated into the front light unit 11 to form a unit, the configuration can be simplified. Further, the infrared light source may be configured to emit infrared rays only when the liquid crystal panel 1 has a low temperature and to stop emitting infrared rays when the liquid crystal panel 1 has a high temperature.

The infrared absorbing film 3 is not limited to between the polarizing plate 2 and the front light unit 11, but may be arranged, for example, between the polarizing plate 2 and the liquid crystal panel 1. In this case, the infrared absorbing film 3 may be arranged. Is closer to the liquid crystal panel 1, so that the heat from the infrared absorbing film 3 is easily transferred to the liquid crystal panel 1.

FIG. 3 is a schematic view showing an embodiment of the liquid crystal display device according to the present invention. In this embodiment, a liquid crystal panel 1 configured as a reflective liquid crystal panel and a light source 8 such as an LED having a light emitting surface facing upward are installed on a circuit board 9, and a reflecting plate 10 is placed above the light source 8. The diffuser plate 7 and the polarizing plate 2 are arranged diagonally so as to face the reflector 10, and the reflective polarizing plate 5 such as a wire grid film is arranged diagonally so as to face the polarizing plate 2. An infrared reflective film 6 is arranged on the lower surface thereof, and an infrared absorbing film 3 is arranged on the upper surface of the liquid crystal panel 1 facing the infrared reflective film 6. In this configuration, the front light unit is composed of a light source 8, a reflector 10, a diffuser 7, a polarizing plate 2, and a reflective polarizing plate 5.

The infrared absorbing film 3 is arranged so as to cover the display area where the image of the liquid crystal panel 1 is displayed and the non-display area where the image is not displayed, but is arranged so as to cover only the display area or only the non-display area. You may. The infrared absorbing film 3 is arranged so as to be close to or in contact with the liquid crystal panel 1 and is adhered to the liquid crystal panel 1 as needed. However, in the sense that heat is easily transferred to the liquid crystal panel 1, the liquid crystal panel 1 It is preferably arranged so as to come into contact with.

The infrared reflective film 6 is called, for example, a near-infrared band gap interference reflective film, and selectively directs light in the near-infrared wavelength band included in the light emitted from the light source 8 toward the infrared absorbing film 3. It is configured to reflect. The infrared reflective film 6 is arranged so as to be close to or in contact with the reflective polarizing plate 5, but is arranged so as to be in close contact with the reflective polarizing plate 5 in the sense of preventing diffused reflection of light on the surfaces between them. In addition, in terms of simplifying the configuration, it is preferable that the polarizing plate 5 is laminated and integrated. The infrared reflective film 6 may be arranged on the surface of the reflector 10 facing the light source 8, and in the sense that the infrared absorbing film 3 efficiently absorbs the infrared rays emitted from the light source 8, the reflective polarizing plate 5 is used. It is preferably arranged on both the surface and the surface of the reflector 10. However, the infrared reflective film 6 is not essential and can be omitted. The infrared reflective film 6 can also be used in Examples 2 and 3.

The visible light emitted from the light source 8 passes through the reflecting plate 10, the diffusing plate 7, the polarizing plate 2, the infrared reflecting film 6, the reflective polarizing plate 5, the infrared reflecting film 6, and the infrared absorbing film 3 in that order, and the liquid crystal panel 1 After that, it is reflected by the liquid crystal panel 1 and passes through the infrared absorbing film 3, the infrared reflecting film 6, and the reflective polarizing plate 5 in this order, and is observed as an image above.

The infrared rays contained in the light emitted from the light source 8 enter the infrared reflective film 6 via the reflector 10, the diffuser 7, and the polarizing plate 2, and are then reflected by the infrared reflective film 6 to be reflected by the infrared absorbing film 6. It is incident on 3 and absorbed there.

The infrared absorbing film 3 generates heat by selectively absorbing infrared rays contained in the light emitted from the light source 8 and the light incident from the outside of the liquid crystal display device. The generated heat is transferred to the liquid crystal panel 1 to warm the liquid crystal. Further, when heat is generated from the circuit board 9 by driving the circuit board 9, the heat is also transferred to the liquid crystal panel 1 to warm the liquid crystal.

As a modification of this embodiment, for example, an infrared light source such as an LED that selectively emits infrared rays (particularly near infrared rays) is arranged around the liquid crystal panel 1, and the infrared rays emitted from the infrared rays are emitted from the infrared absorbing film 3. It is also possible to increase the amount of heat generated by absorbing infrared rays. Further, in that case, if the infrared light source is incorporated into the light source 8 or the like to form a unit, the configuration can be simplified. Further, the infrared light source may be configured to emit infrared rays only when the liquid crystal panel 1 has a low temperature and to stop emitting infrared rays when the liquid crystal panel 1 has a high temperature.

In the above Examples 1 to 3, when the infrared absorbing film 3 is arranged in the non-display area of the liquid crystal panel 1, the infrared absorbing film 3 is configured as a light-shielding mask (parting off) covering the non-display area of the liquid crystal panel 1. It is also possible. Specifically, for example, the infrared absorbing film 3 is a black film, and an opening for exposing the display area of the liquid crystal panel 1 is provided therein to form a light-shielding mask. In this configuration, the number of parts can be reduced as compared with the case where the infrared absorbing film 3 and the light-shielding mask are arranged as separate members.

The infrared absorbing film 3 may be a plate-like film having lower flexibility than the film, and is formed as a thin film on the surface of the member to be contacted, particularly when it is arranged in contact with the liquid crystal panel 1 or the like. In this case, the number of parts can be reduced as compared with the case where the infrared absorbing film 3 is arranged as a separate member.

1 Liquid crystal panel 2 Polarizing plate 3 Infrared absorbing film 4 Backlight unit 5 Reflective polarizing plate 6 Infrared reflecting film 7 Diffusing plate 8 Light source 9 Circuit board 10 Reflecting plate 11 Front light unit

Claims (2)

A liquid crystal display device including a liquid crystal panel and an infrared absorbing member that generates heat by absorbing infrared rays, so that the liquid crystal panel is warmed by the heat generated by the infrared absorbing member absorbing infrared rays. And
It is provided with an infrared light source that mainly emits infrared rays selectively, and is configured so that the infrared rays emitted from the infrared light source are absorbed by the infrared absorbing member.
The infrared absorbing member is configured as a light-shielding mask that covers a non-display area of the liquid crystal panel.
A liquid crystal display device characterized by this. An infrared reflecting member that reflects infrared rays emitted from the infrared light source toward the infrared absorbing member, and a reflective polarizing member that reflects visible light toward the liquid crystal panel and transmits visible light emitted from the liquid crystal panel. a plate, a liquid crystal display device according to claim 1, wherein the infrared reflecting member in the reflective polarizer is characterized in that it is laminated.

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