JP3750134B2 - Display device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a display device that performs display using transmitted light from a light source.
[0002]
[Prior art]
Conventionally, there is a liquid crystal display device using a liquid crystal cell as a display device. This liquid crystal cell is configured by sealing liquid crystal between both electrode substrates, and performs display under the drive of a drive device.
[0003]
Further, in the liquid crystal display device, when the temperature of the liquid crystal is not within an appropriate operating temperature range, the operation of the liquid crystal is deteriorated. For this reason, it is difficult to perform good display using the liquid crystal display device. In particular, when the temperature of the liquid crystal becomes lower than a temperature within an appropriate operating temperature range, the response of the liquid crystal is drastically lowered due to the increase in the viscosity of the liquid crystal.
[0004]
Therefore, for example, as disclosed in Japanese Patent Application Laid-Open No. 11-38391, there is known one that controls the temperature of the liquid crystal to be within an appropriate operating temperature range. Such a display device uses a panel heater, a cooling fan, or the like to control the temperature so that the liquid crystal is within an appropriate operating temperature range in order to perform a good display immediately after the power switch is turned on. Is what you do.
[0005]
[Problems to be solved by the invention]
However, when used in a harsh environment, such as when mounted on a vehicle, the proper operating temperature range of the liquid crystal and the actual temperature of the liquid crystal may differ greatly. It was necessary to control the temperature.
[0006]
In particular, in these temperature controls, when the temperature of the liquid crystal is raised to an appropriate operating temperature range using the panel heater, it takes time to conduct heat from the panel heater to the liquid crystal. In addition, the temperature of the liquid crystal is increased to within the appropriate temperature range for liquid crystal in a very low temperature state because the temperature is gradually increased at a heat generation temperature that takes into account the heat-resistant temperature of various parts in contact with the heat generating part of the panel heater. It took a long time to make it happen. Therefore, during this period, it has been a problem because good display by the liquid crystal display device has been difficult.
[0007]
Therefore, the present invention has been made paying attention to the above-described problems, and an object thereof is to provide a display device capable of performing more rapid temperature control.
[0008]
[Means for Solving the Problems]
As described in claim 1, the display device of the present invention includes a first polarizing member, a liquid crystal cell in which the first polarizing member is provided on one surface side, and the other surface side of the liquid crystal cell. A panel heater provided with a translucent substrate on which a translucent heat generating layer is formed on a surface facing the liquid crystal cell, and a surface of the translucent substrate opposite to the surface on which the translucent heat generating layer is formed. And a second polarizing member formed by wearing the second polarizing member.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings, taking as an example a display device provided in a vehicle head-up display that displays vehicle speed, engine speed, and the like.
[0010]
FIG. 1 shows a vehicle head-up display mounted on a vehicle, and a display image projected by a head-up display C provided on the dashboard B of the vehicle A is directed to an observer E by a windshield D. It has a structure that is reflected by. The observer E can observe the display image as a virtual image F superimposed on the landscape.
[0011]
The head-up display C according to the embodiment of the present invention includes a concave mirror 2, a liquid crystal display 3 and the like in a housing 1 provided so as to be embedded in the upper part of the dashboard B. 2 will be described.
[0012]
The housing 1 is made of a light-shielding synthetic resin material, and includes a first opening 1A that opens an upper portion (front glass D side) where the concave mirror 2 is disposed, and a second opening 1B that protrudes a heat sink described later. Is provided in the housing 1 with a light shielding wall 1C for preventing the sunlight from entering the liquid crystal display 3 and making the virtual image F difficult to see (wash out). 1 is formed integrally. In addition, a translucent cover 1D made of a translucent synthetic resin material (for example, acrylic) is provided on the upper portion of the housing 1, and is disposed so as to close the first opening 1A.
[0013]
The concave mirror 2 is provided in the housing 1 and reflects the display image projected from the liquid crystal display 3 to the windshield D side. The concave mirror 2 is provided so that the angle can be adjusted so that the observer E can easily view the display image.
[0014]
Hereinafter, the liquid crystal display 3 will be described with reference to FIGS.
[0015]
The liquid crystal display 3 projects a display image of the transmissive display element onto the windshield D through the concave mirror 2, and includes a liquid crystal display element (display device) 4, a wiring board 5, and a heat dissipation member 6. ing. The liquid crystal display element 4 includes a calculation circuit that measures the vehicle speed and the engine speed based on output signals from a vehicle speed sensor and an ignition coil provided in the vehicle A, and a liquid crystal drive circuit that drives liquid crystal based on the calculation result. This is for representing the measured values of the speed A and the engine speed as numerical values. The wiring board 5 is formed by mounting a light emitting diode 5B serving as a light source on a hard wiring board 5A made of an insulating glass cloth base epoxy resin material so as to face the liquid crystal display element 4. The heat dissipating member 6 is made of a heat sink, is provided on the back side of the wiring board 5 and is provided so as to face the second opening 1B.
[0016]
With the above configuration, the illumination light of the light-emitting diode 5B can project a display indicating the vehicle state by transmitting and illuminating the display image formed by the liquid crystal display element 4, and the front can be projected via the concave mirror 2. A virtual image F can be displayed on the glass D.
[0017]
Further, the liquid crystal display element 4 which is a main part of the present invention will be described in detail with reference to FIG.
[0018]
As shown in FIG. 3, the liquid crystal display element 4 includes a liquid crystal cell 4A, a first polarizing member 4B, a panel heater 4C, and a second polarizing member 4D. The liquid crystal cell 4A is formed by adhering two transparent substrates at regular intervals so that they are parallel to each other, and a liquid crystal is sandwiched between the two transparent substrates. Pixel electrodes are provided in a matrix on the opposing surfaces of the two transparent substrates. On one transparent substrate, a TFT (thin film transistor) for switching the pixel electrodes and a voltage applied to the pixel electrodes are provided. An auxiliary capacity for holding is provided. The first polarizing member 4B is adhered to the front side (the display image exit side) of the liquid crystal cell 4A. The panel heater 4C is provided at a predetermined interval on the back surface side (illumination light incident side) of the liquid crystal cell 4A, and ITO (Indium Tin Oxide) is formed on the surface of the translucent substrate 4E (on the surface facing the liquid crystal cell 4A). ) Is formed. The second polarizing member 4D is attached on the back surface (the incident side surface of the illumination light from the light emitting diode 5B) of the transparent substrate 4E.
[0019]
The liquid crystal display element 4 includes a first polarizing member 4B, a liquid crystal cell 4A provided with the first polarizing member 4B on one surface side, and a heating surface so as to face the other surface side of the liquid crystal cell 4A. The translucent panel heater 4C having the above and the second polarizing member 4D provided on the surface opposite to the heat generating surface of the panel heater 4C are provided, so that the light transmitting member serving as the heat generating element of the panel heater 4C is provided. Since the heat generating layer 4F and the liquid crystal cell 4A having a liquid crystal can be disposed close to each other, the liquid crystal cell can be efficiently warmed without an extra member. Therefore, a display device capable of performing more rapid temperature control on the liquid crystal is obtained.
[0020]
Moreover, since the translucent heat generating layer 4F does not abut against other components (for example, the polarizing members 4B and 4D) other than the translucent substrate 4E, the heat-resistant temperature of the other components is not taken into consideration, so that the temperature becomes higher. Since heat can be generated, a large amount of heat can be transmitted to the liquid crystal in a short time. Therefore, a display device capable of performing more rapid temperature control on the liquid crystal is obtained.
[0021]
In the embodiment of the present invention, the heating surface of the panel heater 4C and the surface of the liquid crystal cell 4A are provided so as to be adjacent to each other at a predetermined interval. However, the present invention is not limited to this. In addition, the heating surface of the panel heater 4C and the surface of the liquid crystal cell 4A can be provided in contact with each other, and a greater effect can be expected.
[0022]
In the embodiment of the present invention, the TFT type liquid crystal cell 4A having a thin film transistor has been described as an example. However, the present invention is not limited to this, for example, a STN (Super Twisted Nematic) type. A liquid crystal cell may be used, and the same effect as the above-described embodiment can be obtained.
[0023]
【The invention's effect】
The display device of the present invention relates to a display device that performs display using transmitted light from a light source, and can perform more rapid temperature control.
[Brief description of the drawings]
FIG. 1 is a side view of a vehicle showing an embodiment of the present invention.
FIG. 2 is a cross-sectional view of a head-up display showing the embodiment.
FIG. 3 is a side view of an essential part showing a part in a cross section showing the embodiment.
[Explanation of symbols]
4A Liquid crystal cell 4B First polarizing member 4C Panel heater 4D Second polarizing member

Claims (1)

A first polarizing member, and a liquid crystal cell provided with the first polarizing member on one surface side;
A panel heater provided with a translucent substrate in which a translucent heat generating layer is formed on a surface facing the liquid crystal cell on the other surface side of the liquid crystal cell;
And a second polarizing member bonded to the surface of the light-transmitting substrate opposite to the surface on which the light-transmitting heat generating layer is formed .

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