JP2003035897A - Liquid crystal display module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal display module capable of reducing manufacturing man hours of a liquid crystal display device under suitable functioning of a panel heater without necessitating any special outside mechanism to monitor the temperature of a liquid crystal display panel by monitoring the temperature of the liquid crystal display panel using a function of a built-in temperature compensation circuit of an LCD(liquid crystal display) driver of the liquid crystal display panel. SOLUTION: The LCD driver 23 contains the built-in temperature compensation circuit 24 adjusting a voltage value of a liquid crystal driving voltage corresponding to the temperature of the liquid crystal display panel 8. A monitoring means 26 is constructed so as to monitor the temperature of the liquid crystal display panel 8 based on the liquid crystal driving voltage adjusted with the built-in temperature compensation circuit 24.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display module, and more particularly, to properly maintain the response speed of liquid crystal at low temperature by heating the liquid crystal display panel by applying voltage while monitoring the temperature of the liquid crystal display panel. The present invention relates to a liquid crystal display module suitable for

[0002]

2. Description of the Related Art Conventionally, a liquid crystal display device has a liquid crystal display module provided with a panel heater for heating a liquid crystal display panel by applying a voltage, from the viewpoint of appropriately maintaining the response speed of the liquid crystal at a low temperature. Was there.

FIG. 3 shows an example of a liquid crystal display module 2 equipped with such a panel heater 1.
The liquid crystal display module 2 has a liquid crystal display panel 8 in which a liquid crystal 6 is sealed between a pair of transparent substrates 4 and 5 which are attached to each other via a frame-shaped seal 3. Of the pair of transparent substrates 4 and 5, the lower transparent substrate 5 in FIG. 3 is formed to have a larger dimension in the left-right direction than the upper transparent substrate 4 facing it.

A pair of transparent conductive films 9 and 10 patterned into a predetermined shape are formed on inner surfaces of the transparent substrates 4 and 5 which face each other, and the pair of transparent conductive films 9 and 10 are formed. , Are electrically connected to each other by a conductive material or the like arranged in the seal 3.

An LCD driver 12 as an external drive circuit is connected to the lower transparent conductive film 10.

By applying a liquid crystal driving voltage between the transparent conductive films 9 and 10 by the LCD driver 12, the orientation of the liquid crystal 6 between the transparent conductive films 9 and 10 can be changed. ing. Therefore, it is possible to display various liquid crystal images by utilizing the change in the light shielding due to the change in the orientation of the liquid crystal 6.

On the other hand, as shown in FIG. 4, the transparent substrate 5
A heater electrode is formed on the entire outer surface of the
A pair of heater electrode terminals 14 are formed at predetermined intervals in the vertical direction in FIG. The pair of heater electrode terminals 14 are electrically connected to the heater control unit 16 of the liquid crystal display device. Then, the heater control unit 16
By applying a voltage between both heater electrode terminals 14 of the transparent substrate 5, the transparent substrate 5 can be heated.

Further, as shown in FIG. 5, the transparent substrate 5
Is provided with a temperature detector 17 such as a thermistor as a monitoring means for monitoring the temperature of the liquid crystal display panel 8.
The temperature detector 17 is connected to the heater control unit 16 via a wiring 19.

Therefore, the temperature of the liquid crystal display panel 8 can be monitored through the temperature detector 17, and the temperature detector 17 indicates the temperature of the liquid crystal display panel 8 below the reference temperature (for example, 0 ° C.). In this case, the panel heater 1 can be driven appropriately.

An LCD driver 12 for driving the liquid crystal of the liquid crystal display panel 8 is mounted on the transparent substrate 5.

[0011]

However, in the conventional liquid crystal display module 2, a temperature detector 17 such as a thermistor externally attached to the transparent substrate 5 is used as a monitoring means for monitoring the temperature of the liquid crystal display panel 8. Because it was adopted,
When manufacturing the liquid crystal display module 2, it was necessary to dispose the temperature detector 17 and the wiring 19 for outputting a detection signal from the temperature detector 17 to the control unit on the liquid crystal display panel. .

For this reason, conventionally, since the number of manufacturing steps is required for disposing the monitoring means, there has been a problem that the liquid crystal display module 2 cannot be manufactured simply and quickly.

The present invention has been made in view of the above problems, and monitors the temperature of the liquid crystal display panel by utilizing the function of a temperature compensation circuit built in the LCD driver of the liquid crystal display panel. An object of the present invention is to provide a liquid crystal display module capable of reducing the number of manufacturing steps of the liquid crystal display device while properly operating the panel heater without requiring a special external mechanism for monitoring the temperature of the display panel. Is.

[0014]

To achieve the above object, the liquid crystal display module according to claim 1 of the present invention has the following characteristics.
The LCD driver has a built-in temperature compensation circuit that adjusts the voltage value of the liquid crystal drive voltage according to the temperature of the liquid crystal display panel, and the monitoring unit controls the liquid crystal drive adjusted by the built-in temperature compensation circuit. It is formed to monitor the temperature of the liquid crystal display panel based on the voltage.

By adopting such a configuration, it is possible to appropriately drive the panel heater while monitoring the temperature of the liquid crystal display panel based on the liquid crystal drive voltage adjusted by the built-in temperature compensation circuit. Therefore, an external temperature detecting means for monitoring the temperature of the liquid crystal display panel is not required, and the number of manufacturing steps and the number of parts of the liquid crystal display device can be reduced.

A feature of the liquid crystal display module according to claim 2 is that the monitoring means corresponds to the liquid crystal drive voltage adjusted by the built-in temperature compensation circuit and the liquid crystal drive voltage of the liquid crystal display panel at the reference temperature. The heater control unit has a voltage comparison unit for comparing with a reference voltage, and the heater control unit turns on a voltage applied to the panel heater based on a comparison result of the liquid crystal drive voltage by the voltage comparison unit and the reference voltage. The point is to control the on / off.

By adopting such a configuration, it becomes possible to monitor the temperature of the liquid crystal display panel with a simpler configuration.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a liquid crystal display module according to the present invention will be described below with reference to FIGS.

The same reference numerals will be used for parts having the same or similar basic structure as the conventional liquid crystal display module 2.

The liquid crystal display module according to the present embodiment has the same basic structure as the conventional one, such as a liquid crystal display panel and a panel heater.

However, the liquid crystal display module according to the present embodiment does not have the external temperature detector 17 as in the prior art as a monitoring means for monitoring the temperature of the liquid crystal display panel 8, and the LCD driver 23 has The temperature of the liquid crystal display panel 8 is monitored based on the liquid crystal drive voltage.

That is, as shown in FIG. 1, the liquid crystal display module in this embodiment has a built-in temperature compensation circuit 24 in the LCD driver 23.

In general, the built-in temperature compensating circuit 24 detects the temperature of the liquid crystal display panel 8 by the temperature detecting means in view of the fact that the optimum driving voltage of the liquid crystal display panel 8 has a correlation with the temperature. It is built in the LCD driver 23 in order to automatically adjust the liquid crystal drive voltage supplied to the liquid crystal display panel based on the temperature.

Therefore, as shown in FIG. 2, the liquid crystal drive voltage adjusted by the built-in temperature compensation circuit 24 is
The liquid crystal display panel 8 has a characteristic that the temperature drops substantially in proportion to the temperature of the liquid crystal display panel 8. Therefore, the temperature of the liquid crystal display panel 8 can be easily monitored based on the liquid crystal drive voltage adjusted by the built-in temperature compensation circuit 24.

The LCD driver 23 has a signal line 25.
A voltage comparison circuit 26 as a voltage comparison means which constitutes the monitoring means in the present embodiment is connected via
The voltage comparison circuit 26 includes the built-in temperature compensation circuit 24.
The liquid crystal drive voltage adjusted by, that is, the liquid crystal drive voltage according to the temperature of the liquid crystal display panel 8 is input. A reference voltage is input to the voltage comparison circuit 26 via a signal line 25 from a host device (not shown). The reference voltage is a voltage corresponding to the liquid crystal drive voltage output by the LCD driver 23 according to the temperature characteristics shown in FIG. 2, for example, at the reference temperature of the liquid crystal display panel 8 (for example, 0 ° C.).

The voltage comparison circuit 26 compares the reference voltage and the liquid crystal drive voltage with each other, and outputs the comparison result to the heater controller 16.

The heater control section 16 controls the on / off of the panel heater 1 according to the comparison result output from the voltage comparison circuit 26.

Therefore, the temperature of the liquid crystal display panel 8 can be easily and properly monitored by utilizing the function of the built-in temperature compensation circuit 24. Therefore, it is not necessary to provide a special external mechanism such as the temperature detector 17 for monitoring on the liquid crystal display panel 8 as in the conventional case, and the number of manufacturing steps of the liquid crystal display device can be reduced.

Next, the operation of this embodiment will be described.

Liquid crystal display module 2 in this embodiment
When driving 2, the liquid crystal drive voltage is first applied between the transparent conductive films 9 and 10 of both transparent substrates 4 and 5 by the LCD driver 23 to change the orientation of the liquid crystal 6 between both transparent substrates 4 and 5. .

At this time, the built-in temperature compensating circuit 24 built in the LCD driver 23 adjusts the liquid crystal driving voltage according to the temperature of the liquid crystal display panel 8. That is, as shown in the characteristics of FIG. 2, the liquid crystal driving voltage is adjusted to be lower as the temperature of the liquid crystal display panel 8 is higher.

The liquid crystal drive voltage adjusted by the built-in temperature compensation circuit 24 is input to the voltage comparison circuit 26 as a monitoring means via the signal line 25.

When the LCD driver 23 is driven, a reference temperature (for example, 0
A reference voltage corresponding to the liquid crystal drive voltage of the LCD driver 23 at (° C.) is applied.

The voltage comparison circuit 26, to which the liquid crystal drive voltage and the reference voltage are input, compares the voltage values of both. When the liquid crystal drive voltage is higher than the reference voltage, the voltage comparison circuit 26 determines that the temperature of the liquid crystal display panel 8 is lower than the reference temperature, and outputs the determination result to the heater controller 16. To do. On the other hand, when the liquid crystal drive voltage is lower than the reference voltage, it is determined that the temperature of the liquid crystal display panel 8 is higher than the reference temperature, and the determination result is output to the heater controller 16.

When the liquid crystal driving voltage is higher than the reference voltage, the heater control section 16 receives the judgment result of the voltage comparison circuit 26, and raises the temperature of the liquid crystal display panel 8 to the reference temperature. A voltage is applied to the panel heater 1. On the other hand, when the liquid crystal drive voltage is lower than the reference voltage, the panel heater 1 is not driven.

As a result, the liquid crystal display panel 8 is driven only when the temperature of the liquid crystal display panel 8 is lower than the reference temperature, and when the liquid crystal display panel 8 does not require heating, the panel heater is driven. 1 can be stopped.

Therefore, according to the present embodiment, the function of the built-in temperature compensating circuit 24 can be utilized for the liquid crystal display panel 8 without providing a special external mechanism for monitoring the temperature of the liquid crystal display panel 8. Since the temperature can be monitored,
The panel heater 1 can be efficiently driven, and the number of manufacturing steps of the liquid crystal display device can be reduced.

The present invention is not limited to the above-mentioned embodiment, but various modifications can be made as necessary.

For example, the conditions such as the duty of the voltage applied to the panel heater and the voltage value may be appropriately changed according to the voltage difference between the reference voltage and the liquid crystal drive voltage.

The reference temperature and the reference voltage corresponding thereto can be selected from various values according to the design concept or the temperature characteristics of the liquid crystal drive voltage.

[0041]

As described above, according to the liquid crystal display module of the first aspect of the present invention, the number of manufacturing steps and the number of parts of the liquid crystal display device can be reduced and the productivity can be improved.

According to the liquid crystal display module of the second aspect, in addition to the drop of the liquid crystal display module of the first aspect, the temperature of the liquid crystal display panel can be more easily monitored. It is possible to further reduce the number of manufacturing steps of the liquid crystal display device.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a liquid crystal display module according to the present invention.

FIG. 2 is a graph showing a temperature characteristic of a liquid crystal drive voltage of an LCD driver having a built-in temperature compensation circuit in an embodiment of a liquid crystal display module according to the present invention.

FIG. 3 is a side sectional view showing an example of a liquid crystal display panel which constitutes a conventionally used liquid crystal display module.

FIG. 4 is a plan view showing a panel heater mounted on a conventionally used liquid crystal display module.

FIG. 5 is a perspective view showing temperature monitoring means of a liquid crystal display panel mounted on a conventional liquid crystal display module.

[Explanation of symbols]

1 panel heater 8 Liquid crystal display panel 16 Heater controller 23 LCD driver 24 Built-in temperature compensation circuit 26 Voltage comparison circuit

Claims (2)

[Claims] 1. A liquid crystal display panel, a panel heater for heating the liquid crystal display panel by applying a voltage, monitoring means for monitoring the temperature of the liquid crystal display panel, and the monitoring means for monitoring the temperature of the liquid crystal display panel below a reference temperature. In the case shown, a heater controller that drives the panel heater, and an LC that drives the liquid crystal display panel by applying a liquid crystal drive voltage.
In the liquid crystal display module provided with a D driver, the LCD driver has a built-in temperature compensation circuit that adjusts the voltage value of the liquid crystal drive voltage according to the temperature of the liquid crystal display panel, and the monitoring means includes: A liquid crystal display module, which is formed so as to monitor the temperature of the liquid crystal display panel based on the liquid crystal driving voltage adjusted by the built-in temperature compensation circuit. 2. The monitoring means includes voltage comparison means for comparing the liquid crystal drive voltage adjusted by the built-in temperature compensation circuit with a reference voltage corresponding to the liquid crystal drive voltage of the liquid crystal display panel at the reference temperature. The heater control unit controls ON / OFF of a voltage applied to the panel heater based on a comparison result of the liquid crystal drive voltage and the reference voltage by the voltage comparison unit. The liquid crystal display module according to claim 1.