JPH10239652A - Liquid crystal display module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal display module which has a high productivity and is low-cost and electrically detects destruction of a liquid crystal display panel. SOLUTION: The destruction detection output from an electrode for display which is arranged on at least one of transparent substrates 21 and 22 of the liquid crystal display panel and is used as an electrode for destruction detection also is used to detect the destruction by comparison with an arbitrary DC voltage value where an electrode resistance value variance can be ignored. Since the electrode for display can be pulled out to external connection terminals in two or more directions to make intervals of external connection terminals wider, the productivity and the cost power are improved. Further, the detection output is improved because of no influence of a destruction detection output voltage variance.

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 capable of confirming breakage of a liquid crystal display panel by means other than visual observation.

[0002]

2. Description of the Related Art In recent years, a new product using a liquid crystal display module has been produced due to its thinness, low voltage, and low power, and the liquid crystal display module has been used in many electronic devices as a display device. .

The configuration of a conventional liquid crystal display module will be described below. FIG. 4 shows a configuration of a conventional liquid crystal display module. In FIG. 4, a plurality of horizontal and vertical transparent electrodes 1 and 2 are arranged side by side, and transparent substrates 5 and 6 having alignment films 3 and 4 formed on their surfaces are opposed to each other with a slight gap therebetween. As described above, the liquid crystal material 8 is filled between the substrates with the sealing material 7 and the liquid crystal material 8 is filled between the substrates, and the polarizing plate 9 is bonded to the outside of the transparent substrates 5 and 6 to constitute the liquid crystal display panel. . A liquid crystal display module is formed by electrically connecting the external connection terminals 10 provided at the ends of the transparent substrate 5 or 6 and the circuit board 11 with the conductive member 12. If conductive rubber is used for the conductive member, press the connection part from the outside with a metal frame or the like.If a conductive film is used, connect with a conductive film adhesive or another adhesive. ing.

The operation of the liquid crystal display module configured as described above will be described below. First, a scanning voltage is supplied from the circuit board 11 to one of the transparent electrodes 1 and 2 and a signal voltage is supplied to the other, and an AC voltage is applied between the electrodes at the intersection of the transparent electrodes 1 and 2 to perform liquid crystal display. .

When the above-described liquid crystal display module is used in a public telephone, a vending machine, or the like, the transparent substrate is formed of glass or the like due to an impact caused by an earthquake, an accident, or the like. And maintenance was complicated, such as the necessity of patrol inspection. In order to simplify maintenance, it has become necessary to detect destruction by a method other than visual inspection.

As a method for detecting that the display capability has been impaired due to the destruction of the transparent electrode of such a liquid crystal display module by visual inspection, an electrode for destruction detection is provided in addition to the display electrode to detect the destruction electrically. Methods are known.

[0007]

However, in the above structure, as shown in FIG. 5, the destruction of the transparent substrate is caused by cracks 13 extending over any two sides of at least one of the transparent substrates. Detection electrode 14
In order to electrically detect the destruction by disconnection, the destruction detection electrode 14 must be disposed on at least one of the transparent substrates so as to surround the periphery of the display electrode 15 with almost no space in the vertical and horizontal directions of the transparent substrate. Must. Therefore, when the display electrode 15 is routed, the external connection terminal 1
6 can be pulled out only in one direction on the opposite side where the destruction detection electrode 14 is disposed, the interval between external connection terminals becomes very narrow, the connection member electrically connected to the circuit board becomes expensive, There is a problem in that the productivity of assembly in positioning the electrodes of the display panel and the circuit board is poor, and that the strength of the liquid crystal display panel is reduced when the destruction detection electrodes are provided below the seal material.

The present invention has been made in view of the above-mentioned problems, and has as its object to realize detection of breakage of a liquid crystal display panel with an inexpensive and highly productive configuration.

[0009]

In order to achieve this object, a liquid crystal display module according to the present invention uses a part of a plurality of transparent electrodes provided on a transparent substrate for display as a destruction detection electrode. It is configured.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In a liquid crystal display panel, the present invention relates to a structure for detecting the destruction of a transparent substrate by comparing an electric waveform output from a liquid crystal display panel through a display electrode with an arbitrary DC voltage. Have.

According to this configuration, since the display electrode also serves as the destruction detection electrode, the degree of freedom in routing the display electrode is improved, and the external connection terminal can be drawn out in at least one transparent substrate in two or more directions. The distance between the external connection terminals can be widened, the connection member for electrically connecting to the circuit board can be reduced in cost, and the productivity of the assembly in aligning the electrodes of the liquid crystal display panel and the circuit board can be improved. Further, since no breakage detection electrode is provided below the sealing material, the strength of the liquid crystal panel is not reduced. Further, by setting the DC voltage value to an intermediate voltage value between the normal voltage value and the destruction voltage value of the output waveform, it is possible to eliminate the influence of the output voltage value variation due to the electrode resistance value variation.

FIG. 1 shows an embodiment of the present invention.
This will be described with reference to FIGS.

FIGS. 1 and 2 are diagrams showing the arrangement of electrodes on a liquid crystal display panel and a transparent substrate. Reference numeral 21 denotes a transparent substrate on which transparent scanning electrodes and destruction detection electrodes are disposed. Reference numeral 22 denotes a transparent substrate on which transparent signal electrodes and destruction detection electrodes are disposed. As described above, an alignment film is provided on each of the transparent electrodes. The liquid crystal display panel is formed by forming the liquid crystal display panel 23 and facing each other with a gap therebetween by a sealing material 24, filling the gap with a liquid crystal material 25, and further attaching a deflection plate 26 on the outer surface. Make up.

Reference numeral 27 denotes an external connection terminal provided at an end of the transparent substrate 22. Reference numeral 28 denotes a display scanning electrode provided on the transparent substrate 21, and reference numeral 29 denotes a display scanning electrode which is also provided on the transparent substrate 21 and serves also as a destruction detection electrode. 30
Is a display signal electrode provided on the transparent substrate 22, and 31 is a display signal electrode which is also provided on the transparent substrate 22 and serves also as a destruction detection electrode. Reference numeral 32 denotes an intermediate connection line provided on the external connection terminal 27 for routing the display scanning electrode 29. Note that the configuration in FIGS. 1 and 2 has a two-terminal structure because the scanning electrode and the signal electrode are led out to the same external connection terminal portion. However, a three-terminal structure may be provided by providing another terminal as the scanning electrode.

FIG. 3 is an electric circuit configuration diagram of a liquid crystal display module using the liquid crystal panel having the above configuration. 33
Is a liquid crystal drive circuit. Reference numeral 34 denotes a liquid crystal display panel having the configuration shown in FIG. A destruction detection waveform is output from one of the electrode wirings of the electrodes 29 and 31. In this case, a liquid crystal driving waveform is input from one of the electrode wires to the electrodes 29 and 31, and a destruction detection waveform is output from the other. When the transparent substrate is normal without destruction, the input liquid crystal driving waveform is output. When the transparent substrate is broken due to cracks or the like, a destructive waveform due to electrode disconnection is output. 35 is a voltage buffer circuit,
36 is an AC-DC converter for converting the breakdown detection output into a DC voltage value, and 37 generates a DC voltage intermediate between the normal voltage value and the breakdown voltage value of the breakdown detection output from the AC-DC conversion circuit 36. The DC voltage circuit 38 includes a breakdown detection output output from the AC-DC conversion circuit 36 and the DC voltage circuit 3.
7 is a voltage comparison circuit for detecting a breakdown by comparing the DC voltage from the power supply 7.

According to the above configuration, cracks on any two sides of the transparent substrate can be detected. Further, by also using the destruction detection electrode as a display electrode, the degree of freedom in routing the display electrode of the liquid crystal display panel is improved, and in at least one of the transparent substrates, the external connection terminal portion can be drawn out in two or more directions, Since the space between the external connection terminals can be widened, a low-priced product can be used for a connection member that is electrically connected to the circuit board. Further, the productivity of the assembly in the alignment of the electrodes with the circuit board is improved. Further, since the electrode pattern is not provided on the sealing material as in the conventional method, there is no problem in the strength of the liquid crystal display panel. Also,
By setting the comparison DC voltage value to an intermediate voltage value between the normal voltage value and the breakdown voltage value of the destruction detection output, it is possible to eliminate the influence of the output voltage value variation due to the electrode resistance value variation. It has excellent output.

[0017]

As described above, according to the present invention, the display electrode of at least one of the transparent substrates also serves as a destruction detection electrode, and the display function of the liquid crystal display panel is impaired. Has the function of electrically detecting the destruction of the liquid crystal display panel by a method other than visual inspection by detecting by comparing with an arbitrary DC voltage using the destruction detection output from Thus, a liquid crystal display module having excellent detection output can be realized.

[Brief description of the drawings]

FIG. 1 is a sectional view of a liquid crystal display panel according to an embodiment of the present invention.

FIG. 2 is a plan view showing electrode wiring of the panel.

FIG. 3 is an electric circuit diagram of the liquid crystal display module according to the present invention.

FIGS. 4A and 4B are a plan view and a cross-sectional view of a conventional liquid crystal display panel.

FIG. 5 is a plan view showing a state where cracks have occurred in a transparent substrate in the panel.

[Explanation of symbols]

 21, 22 Transparent substrate 24 Sealing material 25 Liquid crystal material 28, 29 Display scanning electrode 30, 31 Display signal electrode

Claims (1)

[Claims] 1. A first transparent substrate in which a plurality of display electrodes are juxtaposed in a vertical direction, and a plurality of display electrodes in a lateral direction opposing the first transparent substrate with a liquid crystal material interposed therebetween. And a second transparent substrate having a plurality of display electrodes arranged side by side, wherein the display electrode disposed on at least one of the first and second transparent substrates is an electrode for detecting breakage of the transparent substrate. Liquid crystal display module that also serves as