JP2004184498A - Liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display device in which common electrodes and segment electrodes are wired so as to avoid an air passage communicating with the outside air and provided successively to a hole part sealant for forming a through hole and are driven by the display data in the picture memory and in which display data are accurately written in or read out to or from a picture memory. <P>SOLUTION: When the total number of the common electrodes is represented by m and that of the segment electrodes is represented by n, the picture memory 30 has a data store part of a m×n bitmap type corresponding to respective intersections of the electrodes, wherein a portion of the data store part corresponding to imaginary pixels with no real intersections of the electrodes is made to be an invalid memory region 31 to which access is forbidden. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a liquid crystal display device having a through-hole through which a part of a mechanical means can be inserted in a display unit, and more particularly, to a wiring technology of a display electrode in a display unit and an image display technology. .
[0002]
[Prior art]
The liquid crystal display device is a type of digital display in which the position of each pixel is fixed, and predetermined information is displayed by lighting / non-lighting of each pixel. There is a practice that a through-hole is formed through which a pointer rotary shaft of a speedometer can be inserted and used together with an analog indicating instrument.
[0003]
In order to form a through hole in the display section, when two transparent electrode substrates are pressure-bonded via a peripheral sealing material, a hole sealing material is applied in advance to the through hole forming position in the display section, and both transparent electrode substrates are formed. Is pressed and the liquid crystal is sealed, and a hole penetrating through the hole sealing material is opened by a drill or a hydraulic cutter. The hole sealing material is applied, for example, in a solid shape or a donut shape (annular shape).
[0004]
When the hole sealing material is applied in a solid shape, the sealing material may be crushed at the time of press-bonding the substrate, which may cause a gap in the display portion around the through-hole and may make uniform display impossible. Further, when the application shape of the hole sealing material is a donut shape, the pressure in the ring increases when the substrate is pressed, and a puncture (burst) of the donut-shaped hole seal may occur.
[0005]
In order to reduce the occurrence of puncturing, a pressure bonding method in a vacuum is also being studied, but this is not a preferable method due to an increase in the size of the pressure bonding device, an increase in the cost of the device, and a decrease in productivity. The puncture occurrence rate of the donut-shaped hole seal is proportional to the hole diameter. For example, since a joystick, a seesaw switch, or the like is inserted into the through hole, a puncture easily occurs when the hole diameter is 10 mm or more.
[0006]
This puncture phenomenon occurs because the inside of the donut-shaped hole sealing material is in a closed state. Therefore, particularly for those having a large hole diameter, a part of the donut-shaped hole sealing material is pulled out to a predetermined side of the liquid crystal cell so as to form an air passage for communicating the inside of the donut-shaped hole sealing material with the outside air. I have.
[0007]
According to this, puncture of the hole sealing material can be prevented irrespective of the size of the hole diameter. On the other hand, since the inside of the air passage is always exposed to the outside air, the wiring passing through the air passage in the display electrode can be prevented. Another problem occurs in that the portion is corroded by the electrolytic corrosion phenomenon.
[0008]
Therefore, the present applicant has proposed that a common electrode and a segment electrode be wired around a liquid crystal cell having such an air passage while avoiding the air passage, and that the common electrode can be driven by one common driver. The following technology was filed as Patent Document 1 below.
[0009]
That is, in Patent Document 1, one common driver is provided by wiring the common electrode so as to be folded from one divided display portion side divided by the air passage to the other divided display portion side along the periphery of the through hole. It is possible to drive the common electrode in each divided display portion.
[0010]
[Patent Document 1]
Japanese Patent Application 2002-023617
[0011]
[Problems to be solved by the invention]
When the common electrode is wired as in Patent Document 1, the wiring of the segment electrode also changes accordingly, so if the bitmap format image memory used for ordinary full dot matrix display is used as it is, There is a possibility that writing and reading of display data may be performed to a data store portion having no electrode intersection, and an image to be displayed may be partially inverted depending on how the display data is inserted.
[0012]
Therefore, an object of the present invention is to wire the common electrode so as to be folded from one divided display portion side divided by the air passage to the other divided display portion side along the periphery of the through hole and to the common electrode. On the other hand, in the case where the segment electrodes are wired so as to be orthogonal to each other, it is an object of the present invention to enable accurate writing and reading of display data to and from an image memory and obtain an appropriate display.
[0013]
[Means for Solving the Problems]
In order to achieve the above object, according to the present invention, a first transparent electrode substrate having a common electrode (scanning electrode) and a second transparent electrode substrate having a segment electrode (signal electrode) are pressure-bonded via a peripheral sealing material, A liquid crystal cell in which liquid crystal is sealed between the transparent electrode substrates; and a controller that reads display data from an image memory and drives the common electrode and the segment electrodes via a driver. A through-hole surrounded by a hole sealing material is formed in a substantially central portion of the liquid crystal cell, and a part of the hole sealing material is drawn out to a predetermined side of the liquid crystal cell as an air passage. In a liquid crystal display device in which a part of a display area of a liquid crystal cell is divided into two parts, the common electrode is formed from one of the divided display parts divided by the air passage. The segment electrodes are wired so as to be folded back to the other divided display portion side through the periphery of the through hole, and the segment electrodes are wired so as to be orthogonal to the common electrode from two sides adjacent to the predetermined side. The image memory has an m × n data store corresponding to each electrode intersection, where m is the total number of the common electrodes and n is the total number of the segment electrodes. The present invention is characterized in that the data store section at a predetermined non-existent address is an access prohibited area.
[0014]
According to this, it is possible to prevent the display data from being written into the data store where the electrode intersection does not actually exist or from being read out from the data store.
[0015]
According to a preferred aspect of the present invention, the common electrode is sequentially bent at a right angle in the same direction at three places around the through-hole, and extends from the one divided display portion side to the first bent portion. A first section, a section between the first bent section and the second bent section, a second section, a section between the second bent section and the third bent section, a third section, the third bent section. The area from to the front of the air passage is defined as a fourth section, and the data store section of the address corresponding to the portion where the respective sections change is defined as an access prohibited area.
[0016]
In addition, by writing display data from the first section side sequentially in the same direction by 90 ° in the respective data store sections at addresses corresponding to the first to fourth sections, a partial display is performed. Does not lie down or is inverted, and an appropriate display with uniform direction can be obtained.
[0017]
On the other hand, the inner diameter of the through hole is preferably 10 mm or more. According to this, switch means (for example, a joystick or a seesaw switch) capable of selecting at least four directions, up, down, left, and right, are incorporated in the through hole. Thus, a multi-function display capable of controlling the display of a specific display area in the liquid crystal cell display section by the switch means can be realized.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
First, the basic configuration of the liquid crystal cell 10 included in the liquid crystal display device of the present invention will be described with reference to a schematic plan view of FIG. 1 and a cross-sectional view of FIG.
[0019]
The liquid crystal cell 10 is formed by pressing a first transparent electrode substrate 11 and a second transparent electrode substrate 12 via a peripheral sealing material 13, and a hole seal for forming a through hole is formed in the cell. A material 14 is provided.
[0020]
In this case, the hole sealing material 14 is formed in a C-shape close to a circle, and both ends thereof are drawn out to predetermined sides of the liquid crystal cell 10, whereby an air passage 15 communicating the inside of the hole sealing material 14 with the outside air is formed. Is formed. The hole sealing material 14 is applied to one of the transparent electrode substrates 11 and 12 before the pressure bonding thereof, and is pressed together with the peripheral sealing material 13. It doesn't puncture because it's in communication.
[0021]
After the two transparent electrode substrates 11 and 12 are pressed, a predetermined liquid crystal is injected into the cell from an injection port 131 formed in the peripheral sealing material 13, and thereafter, the injection port 131 is filled with a sealing material such as an ultraviolet curable resin. Sealed at 132. Then, a through hole 16 that passes through the inside of the hole sealing material 14 is coaxially formed in both the transparent electrode substrates 11 and 12 by a drill or a hydraulic cutter (not shown). Alternatively, the liquid crystal may be injected into the cell after the through hole 16 is opened.
[0022]
Next, as a preferred embodiment of the present invention, a case will be described in which the liquid crystal cell 10 is used in combination with switch means capable of selecting at least four directions of up, down, left, and right. This type of switch means includes a joystick or a four-way seesaw switch, and any of them can be employed. In this example, the joystick 20 is employed as shown in FIG.
[0023]
That is, in this embodiment, the through-hole 16 is formed in the center of the liquid crystal cell 10 and the joystick 20 is disposed therein, and the display areas D1 and D2 are provided at two positions above and below the through-hole 16 as a center. In addition, the display areas D3 and D4 are respectively set in two islands at the left and right of the through hole 16 so that the display of each display area can be switched in accordance with the operation (tilt) of the joystick 20 up, down, left and right. I have. The inner diameter of the through hole 16 is preferably 10 mm or more in view of the size and operability of the joystick 20.
[0024]
Each of the display modes of the display areas D1 to D4 is a dot matrix display in which a common electrode (scanning electrode) and a segment electrode (signal electrode) intersect at right angles, and the wiring on the common electrode C side is shown in FIG. FIG. 4 shows a wiring state on the segment electrode S side. In this example, the common electrode C is formed on the side of the second transparent electrode substrate 12 and the segment electrode S is formed on the side of the first transparent electrode substrate 11, but the arrangement may be reversed.
[0025]
Regarding the electrode wiring, first, it is important in the present invention that, as apparent from FIGS. 3 and 4, the common electrode C and the segment electrode S are formed with holes to prevent electrolytic corrosion due to exposure to the outside air. That is, wiring is performed while avoiding a portion of the air passage 15 extending from the sealing material 14 to the outside of the cell.
[0026]
By the way, when the electrodes are not provided in the air passage 15, a part of the liquid crystal cell 10 in the display section is divided. In the illustrated example, since the air passage 15 is drawn out from the hole sealing material 14 at the center of the liquid crystal cell 10 to the right side 10R side of the liquid crystal cell 10, the display portion of the liquid crystal cell 10 has With the air passage 15 as a boundary, the upper display portion DU and the lower second display portion DL are separated from each other. In this example, the display regions D1, D3, and D4 are inside the first display portion DU. And the display area D2 is included in the second display section DL.
[0027]
Therefore, if the common electrode C is wired so as to be parallel to the air passage 15, for example, the common electrode wired to the first display unit DU and the common electrode wired to the second display unit DL respectively. Although another common driver is required, in the present invention, the common electrode of the first display unit DU and the common electrode of the second display unit DL can be driven by one common driver as follows. And
[0028]
That is, the common driver 18 is mounted, for example, on the second display unit DL side among the terminal units on the right side 10R side of the liquid crystal cell 10 as shown in FIG. Then, each common electrode C is pulled out from the connection portion with the common driver 18, passed through the second display unit DL, and detoured around the through-hole 16 into the first display unit DU. The wiring is extended to the display area D4 side.
[0029]
In this manner, each common electrode C is wired in series from the common driver 18 → the display area D2 → the display area D3 → the display area D1 → the display area D4. Can be controlled. Further, since the common electrode C can be formed near the through hole 16, the display regions D1 to D4 can be effectively disposed.
[0030]
As for the segment electrode S, as shown in FIG. 4, the segment drivers 19a and 19b are mounted on the terminal unit on the first display unit DU side and the terminal unit on the second display unit DL side, respectively. The segment electrodes S are wired from one segment driver 19a toward the display regions D1 and D4, and the segment electrodes S are wired from the other segment driver 19b toward the display regions D2 and D3.
[0031]
In this case, in order to make the display electrodes D3 and D4 orthogonal to the common electrode C in each of the display areas D1 to D4, the segment electrodes S are bent at substantially right angles at predetermined portions, and the display electrodes D3 and D4 are laterally bent. Derive from
[0032]
The number of the common electrodes C and the segment electrodes S is selected in accordance with the number of display dots in each of the display areas D1 to D4. In a certain display area, the common electrode C is wired in the vertical direction in FIG. In this example, the display areas D3 and D4 correspond thereto.
[0033]
Assuming that the number of display dots is represented by the common side × the segment side, for example, if the number of display dots in the display areas D1 and D2 is 32 × 150 and the number of display dots in the display areas D3 and D4 is 32 × 100, In the regions D1 and D2, there are 32 common electrodes C extending in the horizontal direction and arranged in parallel with each other in the vertical direction, and 150 segment electrodes S extending in the vertical direction and arranged in parallel with each other in the left and right direction. Will be passed.
[0034]
On the other hand, in the display areas D3 and D4, 100 segment electrodes S extending in the horizontal direction and arranged in parallel with each other in the vertical direction, and the segment electrodes S extending in the vertical direction and arranged in parallel with each other in the left and right direction. The 32 common electrodes C are passed through.
[0035]
As an example of the application, when the joystick 20 is mounted on a vehicle, the display areas D1 to D4 are assigned to mode displays such as “air conditioner”, “audio”, “switching in the vehicle”, and “air clean”. Each mode can be selected by operation.
[0036]
Next, an example of a display drive system according to the present invention will be described with reference to FIGS. As shown in FIG. 5, this display drive system includes, in addition to one common driver 18 and two segment drivers 19a and 19b, a controller 20 for controlling them, and an image memory 30 for storing display data. ing.
[0037]
As in the above-described embodiment, the common driver 18 is mounted on, for example, the second display unit DL among the terminals on the right side 10R of the liquid crystal cell 10. Further, one segment driver 19a is mounted on a terminal on the first display unit DU side, and the other segment driver 19b is mounted on a terminal unit on the second display unit DL side. A microcomputer is used for the controller 20.
[0038]
As shown in FIG. 6, the common electrode C is substantially spirally wired on the second transparent electrode substrate 12. That is, the common driver 18 passes through the second display unit DL, bypasses the periphery of the through hole 16 to reach the first display unit DU, and extends therefrom toward the right side 10R side of the liquid crystal cell 10, the tip of which is extended. The wiring is further arranged so as to be bent toward the air passage 15 side.
[0039]
In the illustrated example, five common electrodes C1 to C5 are connected to the common driver 18 for convenience of explanation. The common electrodes C1 to C5 are sequentially bent at right angles in the same direction (clockwise in this example) at three places A, B, and C around the through hole 16.
[0040]
Here, a first section P1 extends from the right end of the second display section DL to the first bent section A, and a second section P2 extends from the first bent section A to the second bent section B. The third section P3 between the bent section B and the third bent section C and the fourth section P4 between the third bent section C and the front of the air passage 15 are referred to as a fourth section P4. D1 is included in the third section P3, display area D2 is included in the first section P1, display area D3 is included in the second section P2, and display area D4 is included in the fourth section P4.
[0041]
Next, as shown in FIG. 7, the segment electrode S is formed on the first transparent electrode substrate 11 side, but in the illustrated example, for convenience of explanation, the segment electrode S is disposed on the second display unit DL side. Eleven segment electrodes S1 to S11 are extracted from the driver 19b, and 14 segment electrodes S12 to S25 are extracted from the segment driver 19a arranged on the first display unit DU side. Shall be. Therefore, the total number of the segment electrodes S is 25.
[0042]
FIG. 8 shows an intersection state between the common electrodes C1 to C5 and the segment electrodes S1 to S25. In FIG. 8, □ indicates an effective pixel portion where an electrode intersection actually exists, and X indicates a virtual pixel where an electrode intersection does not exist.
[0043]
Of the eleven segment electrodes S included on the segment driver 19b side, the segment electrodes S1 to S7 are wired so as to be orthogonal to the common electrode C in the first section P1, and the remaining segment electrodes S8 to S11 are In the two sections P2, wiring is performed so as to be orthogonal to the common electrode C.
[0044]
Among the segment electrodes S1 to S7 wired in the first section P1, the segment electrodes S1 to S4 cross the five common electrodes C1 to C5, respectively, but the segment electrode S5 has four common electrodes C2 to C5. Crosses C5. The segment electrode S6 intersects with three common electrodes C3 to C5, and the segment electrode S7 intersects with two common electrodes C4 to C5.
[0045]
Among the segment electrodes S8 to S11 wired in the second section P2, the segment electrode S8 intersects with the two common electrodes C4 to C5, the segment electrode S9 intersects with the three common electrodes C3 to C5, and The electrode S10 intersects with four common electrodes C2 to C5, and the segment electrode S11 intersects with five common electrodes C1 to C5. As described above, the number of the electrode intersections decreases as the segment electrode S approaches the portion where the section changes, that is, the closer to the bent portions A, B, and C of the common electrode C.
[0046]
Of the 14 segment electrodes S included in the segment driver 19a, the segment electrodes S12 to S14 are wired so as to be orthogonal to the common electrode C in the second section P2, and the segment electrodes S15 to S21 are The third segment P3 is wired so as to be orthogonal to the common electrode C, and the remaining segment electrodes S22 to S25 are wired so as to be orthogonal to the common electrode C in the fourth segment P4.
[0047]
As for the 14 segment electrodes S included in the segment driver 19a, as shown in FIG. 8, the closer to the part where the section changes (the bent parts A, B, and C of the common electrode C), the closer the electrode intersection is. The number is low.
[0048]
The image memory 30 is of a bitmap type, and has an m × n data store corresponding to each electrode intersection, where the total number of common electrodes C is m and the total number of segment electrodes S is n. In this example, since the total number of the common electrodes C is 5 and the total number of the segment electrodes S is 25, a 5 × 25 data store shown in FIG. 9 is provided.
[0049]
As can be seen in comparison with FIG. 8, in the 5 × 25 data store section, the hatched portion is the data store section corresponding to the imaginary pixel having no electrode intersection, and in the present invention, the hatched portion is shown in FIG. Is prohibited from being accessed as the invalid memory area 31.
[0050]
That is, display data cannot be written to or read from the invalid memory area 31. Display data can be written and read only in the effective memory area 32 of the data store corresponding to the effective pixel where the actual electrode intersection exists. Therefore, the display data can be accurately written in the image memory 30.
[0051]
Further, when the common electrode C is circling around the through hole 16, for example, when the character “E” is displayed at several places on the screen, as shown in FIG. By writing character data for displaying the character "E" sequentially in the effective memory areas 32a to 32d of the image memory 30 corresponding to the section P4 so as to be rotated by 90 [deg.], As shown in FIG. The character "E" can be displayed correctly with the characters "E" aligned vertically.
[0052]
In the above-described display driving system, one common driver 18 and two segment drivers 19a and 19b are used. As shown in FIG. 12, instead of one segment driver 19b, a common driver section and a common driver are used. It is also possible to use a control driver 21 integrally provided with a segment driver unit.
[0053]
【The invention's effect】
As described above, according to the present invention, the common electrode is divided by the air passage in the liquid crystal display device in which the hole sealing material for forming the through hole is provided with the air passage communicating with the outside air through the display unit. The wiring is arranged so as to be folded back from one divided display portion side to the other divided display portion side along the periphery of the through hole, and the segment electrode is wired so as to be orthogonal to the common electrode. When reading the display data and driving the common electrode and the segment electrode, it is possible to accurately write and read the display data to and from the image memory, and obtain an appropriate display.
[Brief description of the drawings]
FIG. 1 is a schematic plan view illustrating a basic configuration of a liquid crystal cell included in a liquid crystal display device of the present invention.
FIG. 2 is a cross-sectional view of the liquid crystal cell.
FIG. 3 is a schematic plan view showing a wiring state of a common electrode of the liquid crystal cell.
FIG. 4 is a schematic plan view showing a wiring state of a segment electrode of the liquid crystal cell.
FIG. 5 is a schematic diagram showing a display drive system of the liquid crystal cell.
FIG. 6 is a schematic wiring diagram of a common electrode for explaining the display drive system.
FIG. 7 is a schematic wiring diagram of segment electrodes for explaining the display drive system.
FIG. 8 is a developed view showing an intersection state between the common electrode in FIG. 6 and the segment electrodes in FIG. 7;
FIG. 9 is a schematic diagram showing a configuration of an image memory used in the display drive system.
FIG. 10 is a schematic diagram showing a preferred mode of writing display data to the image memory.
FIG. 11 is a schematic diagram showing a display example on a screen in a preferable writing mode of the display data.
FIG. 12 is a schematic view showing a modification of the display drive system.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Liquid crystal cell 11, 12 Transparent electrode substrate 13 Peripheral sealing material 14 Hole sealing material 15 Air passage 16 Through hole 18 Common driver 19a, 19b Segment driver 20 Controller 30 Image memory 31 Invalid memory area 32 Effective memory area D1-D4 Display area DU First display section DL Second display section C Common electrode S Segment electrode P1 to P4 Section

Claims (3)

A liquid crystal cell in which a first transparent electrode substrate having a common electrode and a second transparent electrode substrate having a segment electrode are pressure-bonded via a peripheral sealing material, and a liquid crystal is sealed between the transparent electrode substrates; A controller for reading the display data and driving the common electrode and the segment electrode via a driver, and a through-hole surrounded by a hole sealing material is formed at a substantially central portion in the display area of the liquid crystal cell. In the liquid crystal display device, a part of the hole sealing material is drawn out to a predetermined side of the liquid crystal cell as an air passage, and a part of a display area of the liquid crystal cell is divided into two by the air passage.
The common electrode is wired so as to be folded back from one divided display part side divided by the air passage to the other divided display part side through the periphery of the through hole and the segment electrode is connected to the predetermined divided display part. It is wired so as to be orthogonal to the common electrode from two sides adjacent to the side,
The image memory has m × n data stores corresponding to the respective electrode intersections, where the total number of the common electrodes is m and the total number of the segment electrodes is n, and the electrode intersection does not actually exist. A liquid crystal display device, wherein the data store section at a predetermined address is an access prohibited area. The common electrode is sequentially bent at right angles in the same direction at three places around the through hole, and a first section and a first fold are formed from the one divided display portion side to the first bent portion. The second section is from the bent section to the second bent section, the third section is from the second bent section to the third bent section, and the section from the third bent section to the air passage. 2. The liquid crystal display device according to claim 1, wherein the fourth section is defined as a fourth section, and the data store section at an address corresponding to a portion at which each section changes is an access prohibited area. 3. The liquid crystal according to claim 2, wherein display data is sequentially written from the first partition side in the same direction by 90 ° in the respective data store units at addresses corresponding to the first to fourth partitions. Display device.

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