JPS6159316A - Temperature control method of liquid crystal panel - Google Patents

Abstract

PURPOSE:To improve display characteristics and extend the life of a liquid crystal penal by providing the liquid crystal panel with a layer where liquid for temperature control is passed separately from a layer of liquid crystal, and holding the liquid within some temperature range and circulating the liquid. CONSTITUTION:The liquid 4 is circulated by a circulating mechanism and passed through a glass plate 3 to control the temperature of the liquid crystal 2. Further, the glass plate 3, liquid 4, heat-ray absorption glass 5, and condenser lens 9 reduce heat rays with which the liquid crystal 2 is irradiated by a halogen lamp 10. Further, when the output of a light source is small, the heat-ray absorption glass 5 is replaceable with normal glass. Members 16 and 17 are provided as members as turbulent flow generation so as to supply the liquid 4 to the entire surface the liquid crystal panel equally and mix the liquid in the panel to uniform the heat distribution. Thus, display characteristics of the liquid crystal panel are improved and the life is prolonged.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is applicable to projection projectors that use liquid crystals and are capable of displaying graph ink, liquid crystal shunter arrays for printers, liquid crystal panels used in automobile instruments, etc. This invention relates to a method of controlling temperature within an operable range.

[Conventional technology]

Liquid crystal panels are temperature dependent, and the display density and drive voltage characteristics change, and response becomes slower at low temperatures. Furthermore, at high temperatures, the lifespan of liquid crystal materials is shortened.

Conventionally, as a measure against temperature, a method has been considered in which the temperature is detected and the voltage or pulse width applied to the liquid crystal is varied.

[Problems that non-invention attempts to solve]

However, in environments such as automobiles, where the temperature changes over a wide range from -60 degrees Celsius to +90 degrees Celsius, this measure alone was insufficient. In addition, 1i3 is used as a projection projector.
However, the liquid crystal panel is exposed to high temperatures of 100 degrees Celsius or more due to side radiation for a long time, causing the liquid crystal panel to work hard and shortening its lifespan.

[Means to try to solve problems]

In order to solve the above-mentioned problems, this invention provides a liquid crystal panel with a liquid crystal layer and a layer (separate from fi) that allows the liquid to pass through for temperature control, keeps the liquid within a certain temperature range, and circulates the liquid.
It is.

[Function] According to the above configuration, the liquid exchanges heat with the liquid crystal via the glass plate. In other words, when the temperature is low, heated liquid is circulated to provide heat to the liquid crystal and keep it warm. When the liquid crystal panel is overheated, the liquid that has radiated heat is circulated to remove the heat from the liquid crystal and cool it down. Therefore, the liquid crystal panel operates within a certain temperature range, and the display characteristics become stable. Furthermore, it will extend the life of the LCD panel.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 shows the relationship between a cross-sectional view of a liquid crystal panel and a light source according to the present invention, where 1 is a glass plate, 2 is a liquid crystal, 6 is a glass plate, and 4 is a liquid such as ash, oil, ethylene glycol, etc. Water containing . 5 is heat ray absorbing glass, 6
7 is a sealing material, 7 is a spacer, 8 is a copying agent, 9 is a condenser range, and 10 is a halogen lamp. Liquid 4 (l
It has a circulation mechanism and controls the temperature of the liquid crystal 2 through the glass plate 5f. Also, the glass plate 5, the liquid 4, the heat ray absorbing glass 5, and the condenser lens 9 work to reduce the heat rays irradiated to the liquid crystal 2. Similarly, when the output of the light source is small or when a fluorescent tube is used as the light source, it is possible to replace the heat ray absorbing glass 5 with ordinary glass, and this is also included in the invention.

2 and 6 are plan cross-sectional views of the liquid crystal panel shown in FIG. 1 taken from the spacer 7, in which 11 is the NESA electrode portion of the glass plate 1, 12 is the NESA electrode portion of the glass plate 5, and 13 is the NESA electrode portion of the glass plate 5. Spacers 14 and 15 are pipes that serve as inlets and outlets for the liquid 4. Reference numeral 1'4° 17 in FIG. 2 denotes a turbulent flow generating member provided in order to spread the liquid 4 over the entire surface of the liquid crystal panel.

This creates a thin layer that mixes the liquid within the panel and evens out the heat distribution. Same, spacer 15
, the pipes 14 and 15, and the members m6 and 17 for generating turbulent flow can be made by integral molding.

FIG. 3 shows another embodiment in which the shape of the member for generating turbulence in FIG. 2 is changed. 18.19°20.21 in FIG. 5 is an example of a member for generating turbulent flow.

FIG. 4 shows an example in which the invention is applied to a device for projecting an image on a liquid crystal panel, and is a block diagram illustrating the circulation of a coolant. FIG. 5 shows an embodiment in which the same system as in FIG. 4 is applied to an overhead projector.

In FIGS. 4 and 5, the light from the halogen lamp 1G passes through the condenser lens 9 and the liquid crystal panel 22. The liquid crystal panel 22, which has a low light transmittance, absorbs a lot of light energy and generates heat. When the temperature is low, turning on the halogen lamp 10 heats the liquid crystal and improves the response of the liquid crystal. If the operation continues for a while, the liquid crystal panel 22 will become overheated.

The liquid crystal panel 22 has the structure shown in FIG. 1, and circulates the liquid 4 for temperature control. Then, the liquid 4 cools the liquid crystal panel 22 and the temperature of the liquid 4 increases, but the heat is radiated by the radiator 26 and becomes equal to the outside temperature. The liquid 4 is pumped out by the pump 24 and cools the liquid crystal panel 22 again via the regulator 25. The pump 25, like a diaphragm pump, gives vibration to the liquid crystal panel 22 when the pressure changes periodically. This causes fluctuations in the image projected on the screen 41, which is magnified by the lens. To prevent this, the regulator 25 is useful. The fan 26 air-cools the radiator 25 and the halogen lamp 10. Same, 27.28,2
9.50 is a lens, and 51.32 is a mirror. 3 in Figure 6
6 is an ORIP sheet, which is combined with the image on the liquid crystal panel 22 and projected onto the screen 41. Further, the rotation axis of the fan 26 and the axis of the halogen lamp 100 are arranged so as not to be parallel to each other, so that the flow of air is not obstructed by the condenser lens 9 or reflective steel (not shown).

4 and 5, the liquid 4 is forcibly pumped by the pump 24.
However, when the output of the halogen lamp 10 is low, even if the pump 24 is omitted, it will still be circulated by convection. The liquid 4 heated by the knob and the liquid crystal panel 22 rises, and the liquid 4 cooled by the radiator 25 falls. Therefore, the present invention also includes a system that allows natural circulation and does not include the pump 24. Although not shown, the present invention also includes application to a so-called liquid crystal shunter type printer in which a photosensitive paper or the like is placed in place of the screen 41.

FIG. 6 shows an example in which the present invention is fully applied to a liquid crystal panel for an automobile instrument. The liquid crystal panel 64 is illuminated by a lamp 55. A temperature sensor 36 is connected to the controller 37 and drives the heater 38 when the liquid crystal panel 54 is at a low temperature, and drives the fan 59 when the liquid crystal panel 54 is at a high temperature to radiate heat from the radiator 40.

The liquid 4 is brought to an appropriate temperature and circulated by the pump 24 to control the temperature of the liquid crystal panel 34.

〔Effect of the invention〕

According to the present invention, all of the display characteristics such as temperature circulation, response speed, crosstalk, etc., which allow the liquid crystal panel to operate stably, can be brought to the best possible state. In addition, even when used for projection, the liquid crystal does not deteriorate due to heat, so it can be used for projectors with high brightness screens,
This has the effect of realizing a high-speed liquid crystal printer.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a liquid crystal panel according to the present invention, FIGS. 2 and 6 are plan cross-sectional views of a liquid crystal panel according to the invention, and FIG. 4 is an embodiment of a device for projecting an image of a liquid crystal panel. FIG. 5 shows an embodiment in an overhead browser, and FIG. 6 shows an embodiment in an automobile instrument panel. 1.5...Glass plate 4...Liquid for temperature/counterfeit control 5...Heat ray absorbing glass 7...
Spacer 22...Liquid crystal panel 25...Radiator 24...Pump 25...Regulator 5
6... OHP sheet 56... Temperature sensor and beyond
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Claims (5)

[Claims] (1) three or more glass plates stacked with a gap greater than a certain size; two or more gaps formed by the glass plates; a liquid crystal filled in one of the gaps; A liquid crystal panel comprising a temperature control liquid filled in one or more remaining layers of the gap, and a temperature control means including a means for circulating the liquid, a heat radiation means or a heating means for the liquid, A temperature control method for a liquid crystal panel characterized by keeping the liquid level of the panel within a specific range. (2) The temperature control method for a liquid crystal panel according to claim 1, characterized in that the liquid crystal panel is provided with a member for generating turbulent flow near the inlet/outlet of the liquid. (3) The temperature control method for a liquid crystal panel according to claim 1, characterized in that one or more of the glass plates of the liquid crystal panel is made of heat ray absorbing glass. (4) A liquid crystal panel according to claim 1, characterized in that the same fan motor is used to cool a light bulb for a light source installed near the liquid crystal panel and to cool a radiator section of the heat dissipation means. temperature control method. (5) The temperature control method for a liquid crystal panel according to claim 1, wherein the means for circulating the liquid includes a regulator that also keeps the pump delivery pressure constant.