JP4886295B2 - LCD device - Google Patents

Description

  The present invention relates to a liquid crystal display device.

  In general, a liquid crystal display device called LCOS (Liquid Crystal On Silicon) is bonded to a silicon substrate having a pixel electrode formed on the surface thereof and a glass substrate having a counter electrode formed on the surface in a predetermined positional relationship. A liquid crystal display panel in which liquid crystal is injected between the substrates is mounted on a circuit substrate or a base, a potential difference is applied between the pixel electrode and the counter electrode, and various displays are obtained by controlling the alignment of the liquid crystal.

  12A and 12B are diagrams showing a liquid crystal display device according to the prior art, in which FIG. 12A is a front view, and FIG. A liquid crystal display panel 11 having a liquid crystal sandwiched between two electrode substrates is fixed to the center of the base 12. The liquid crystal display panel 11 and the base 12 are fixed to each other via a double-sided tape 13, and the double-sided tape 13 is provided corresponding to the entire fixing surface of the liquid crystal display panel 11.

  Reference numeral 14 denotes a flexible wiring board which is connected to one side of the liquid crystal display panel 11 and is drawn out of the base 12.

  The above-mentioned liquid crystal display device is mainly used by being incorporated in a liquid crystal projector, and is required to guarantee operation in a high temperature environment. For this reason, in the liquid crystal display device having the above-described configuration, the base 12 is made of a metal plate, and the heat generated in the liquid crystal display panel 11 can be quickly generated by using the double-sided tape 13 having high thermal conductivity for the double-sided tape 13. A structure for radiating heat to a metal plate has been proposed. (For example, refer to Patent Document 1.)

JP 2005-62726 A

  According to the above-described conventional technology, in order to quickly dissipate the heat accumulated in the liquid crystal display panel 11 to the base 12, a high thermal conductive double-sided tape is used for fixing the liquid crystal display panel 11 and the base 12. Furthermore, in order to obtain the heat dissipation effect to the maximum, it is necessary to provide a high thermal conductive double-sided tape used for fixing the liquid crystal display panel 11 and the base 12 corresponding to the entire surface of the liquid crystal display panel 11.

  However, when the entire surface of the liquid crystal display panel 11 is fixed to the base 12, the liquid crystal display panel 11 is constituted by unevenness when the double-sided tape 13 is fixed to the entire surface of the liquid crystal display panel 11 and contraction / extension stress due to heat. As a result, the uniformity of the gap between the respective electrode substrates is impaired, and as a result, color unevenness occurs partially on the display surface, and the original characteristics of the liquid crystal display device such as uniform display cannot be satisfied.

  The color unevenness of the liquid crystal display panel reacts sensitively to the gap unevenness of the liquid crystal display panel. In particular, since this color unevenness can be detected remarkably in gradation display, the color unevenness in the panel plane can be evaluated by looking at the distribution of the effective voltage applied between the panels at a certain gradation.

  FIG. 13 shows a state of occurrence of color unevenness in the liquid crystal display panel surface of the liquid crystal display device according to the prior art in which the liquid crystal display panel and the base are fixed with a double-sided tape corresponding to the entire fixing surface of the liquid crystal display panel. FIG. This is the result of measuring the voltage unevenness of the liquid crystal display panel by measuring the voltage at 50% of the maximum luminance at 3000 points in the liquid crystal display panel surface.

  From FIG. 13, when the entire surface of the liquid crystal display panel is fixed to the base, unevenness when the double-sided tape is fixed to the base, mixing of bubbles or foreign matters, stress of the double-sided tape after bonding, etc. Thus, it can be seen that color unevenness locally occurs in the liquid crystal display panel. This uneven color is caused by a change in the gap (desired gap) of the liquid crystal display panel at the time of fixing, and as a result, there is a difference in voltage value as shown in FIG. In FIG. 13, the X and Y axes indicate the vertical and horizontal directions of the liquid crystal display panel, and the Z axis indicates the voltage value at each point. From FIG. 13, the voltage value changes greatly in a portion far from the peripheral seal portion of the liquid crystal display panel forming the desired gap of the liquid crystal display panel, for example, in the central portion of the liquid crystal display panel. It can be seen that unevenness occurs.

  An object of the present invention is to provide a liquid crystal display device which eliminates adverse effects on the liquid crystal display panel due to the stress of an adhesive used for fixing the liquid crystal display panel and a base and is excellent in heat dissipation.

at least,
A first electrode substrate having a plurality of pixel electrodes; and a second electrode substrate having a counter electrode facing the first electrode substrate, wherein the first electrode substrate and the second electrode substrate are sealed at a predetermined position and interval. A liquid crystal display device comprising: a liquid crystal display panel bonded by a member; and a circuit board that fixes and arranges the liquid crystal display panel via an adhesive unit and is electrically connected to the liquid crystal display panel, It said bonding means is configured to have a bonding surface of the sealing member in a plane substantially the same shape, and have a gap formed by the non-adhesive surface on at least one place, provided in a position opposed to the sealing member, the circuit board, a liquid crystal display device that having a opening in the opposing portion between the liquid crystal display panel except for said adhesive means interposed section.

At least a first electrode substrate having a plurality of pixel electrodes and a second electrode substrate having a counter electrode opposed to the first electrode substrate, wherein the first electrode substrate and the second electrode substrate have a predetermined position and interval in a liquid crystal display panel are bonded together by a sealing member, the liquid crystal display panel, a liquid crystal display panel mounting board arranged and fixed through adhesive means, a liquid crystal display device wherein the adhesive means, the seal thereby have a bonding surface of the member in plan view approximately the same shape, and have a gap formed by the non-adhesive surface on at least one place, provided in a position opposed to the sealing member, the liquid crystal display panel mounting board , a liquid crystal display device that having a opening in the opposing portion between the liquid crystal display panel except for said adhesive means interposed section.

The first electrode substrate is made of silicon, and the liquid crystal display panel mounting substrate is a liquid crystal display device made of 42 alloy .

  According to the present invention, the adhesive means used for adhering the liquid crystal display panel and the circuit board or the liquid crystal display panel mounting substrate has an adhesive surface having substantially the same shape as that of the seal member, and faces the seal member. Since the structure is provided only at the position, a high-quality liquid crystal display device can be provided without adversely affecting the uniformity of the gap of the liquid crystal display panel.

Embodiments of the present invention will be described below with reference to the drawings.
1 to 3 are views showing a liquid crystal display device according to a first embodiment of the present invention. FIG. 1 is a top view, FIG. 2 is a cross-sectional view taken along line AA in FIG. Reference numeral 1 denotes a liquid crystal display panel, in which a silicon substrate 1a and a glass substrate 1b are bonded to each other with a desired gap secured through a seal member 2. Liquid crystal is injected into the gap between the silicon substrate 1a and the glass substrate 1b to constitute the liquid crystal display panel 1. The liquid crystal display panel 1 is arranged and fixed at a predetermined position on the circuit board 3.

  A pixel electrode (not shown) is formed on the silicon substrate 1a, and a counter electrode (not shown) is formed on the glass substrate 1b. Each substrate supplies a potential to each electrode. They are stuck together in a shifted position. The supply of the potential to the pixel electrode is realized by connecting the silicon substrate 1a and the electrode pad on the circuit substrate 3 with the wire 4 and making them electrically conductive. On the other hand, the potential is supplied to the counter electrode by applying a thermosetting conductive resin 5, such as silver paste, between the glass substrate 1b and the circuit board 3, and the electrode pads on the counter electrode and the circuit board 3 (not fixed). This is realized by electrically conducting (shown). Different electric potentials are supplied to the pixel electrode and the counter electrode, respectively.

  The liquid crystal display panel 1 is arranged and fixed on the circuit board 3 by an adhesive means 6. The bonding means 6 has a bonding surface having substantially the same shape as that of the sealing member 2 and is provided at a position facing the sealing member 2 below the silicon substrate 1a. In the present embodiment, like the seal member 2 shown in FIG. 1, it is provided in a frame shape. The adhesive means 6 can be used by appropriately selecting one applied in a frame shape using an epoxy resin adhesive or one having a frame-like adhesive double-sided tape attached thereto.

  A substance for forming a desired gap called a spacer (not shown) is mixed in the seal member 2. For this reason, in the liquid crystal display panel 1, the vicinity of the interposed portion of the seal member 2 is a portion strong against external stress. Therefore, if the bonding means 6 has substantially the same shape as the sealing member 2 in a plan view and is provided at a position facing the sealing member 2 below the silicon substrate 1a, the circuit substrate 3 of the liquid crystal display panel 1 is provided. In the fixing to the liquid crystal display panel 1, even when the adhesive means 6 is unevenly fixed to the liquid crystal display panel 1 or external stress due to shrinkage / extension stress due to heat after the fixing occurs, the color unevenness of the liquid crystal display panel 1, etc. There is no loss of display quality.

  FIG. 11 is a diagram showing a voltage that becomes 50% of the maximum luminance of the liquid crystal display panel of the liquid crystal display device according to the present embodiment, and shows the difference in voltage at 3000 points in the surface of the liquid crystal display panel element. From FIG. 11, it can be confirmed that no color unevenness occurs in the display of the liquid crystal display device by using the bonding means of the present embodiment. That is, it can be seen that the uniformity of the gap (desired gap) is not lost.

  FIG. 4 is a perspective view showing another form of the bonding means used in the liquid crystal display device of the present invention. In this configuration, the adhering means 6 is not provided in a continuous frame shape, but is provided with a discontinuous portion 6a and having a non-adhesive surface when the liquid crystal display panel 1 and the circuit board 3 are fixed. It is.

  According to the said structure, the clearance gap formed by the said non-bonding surface can be utilized as the discharge | release port to the outward of the heat which accumulates in the lower surface part enclosed by the adhesion means 6 of the said liquid crystal display panel 1. FIG.

  When an adhesive double-sided tape is selected as the adhesive means 6, the non-continuous portion 6a is provided at two locations and divided into two parts, so that the adhesive double-sided tape can be easily attached.

  5 to 7 are views showing a liquid crystal display device according to a second embodiment of the present invention. FIG. 5 is a top view, FIG. 6 is a cross-sectional view taken along the line AA in FIG. Since the configuration of the liquid crystal display panel 1 and the means for supplying potential to each electrode of the liquid crystal display panel 1 are the same as those in the first embodiment, the description thereof is omitted. The same reference numerals are used for the same members as those shown in the first embodiment.

  In the present embodiment, the liquid crystal display panel 1 is arranged and fixed to the circuit board 7 via the adhesive means 6. The bonding means 6 has a bonding surface having substantially the same shape as that of the sealing member 2, and is provided at a position facing the sealing member 2 below the silicon substrate 1a. Like the sealing member 2 shown, it is provided in a frame shape. The adhesive means 6 can be used by appropriately selecting one applied in a frame shape using an epoxy resin adhesive or one having a frame-like adhesive double-sided tape attached thereto.

  The circuit board 7 is provided with an opening 7 a at a portion facing the display area 1 c of the liquid crystal display panel 1. According to this configuration, it is possible to release the heat accumulated in the lower surface portion surrounded by the bonding means 6 of the liquid crystal display panel 1 from the opening 7a to the outside.

  In addition to the above configuration, the bonding means 6 is not formed into a continuous frame shape as shown in FIG. 4, but is provided with a non-continuous portion 6a and has a non-bonded surface in a fixed state between the liquid crystal display panel 1 and the circuit board 7. If so, a further heat dissipation effect can be obtained.

  Moreover, when an adhesive double-sided tape is selected as the bonding means 6, the non-continuous portion 6a is provided at two locations and divided into two, thereby facilitating the adhesive double-sided tape sticking operation. .

  8 to 10 are views showing a liquid crystal display device according to a third embodiment of the present invention. FIG. 8 is a top view, FIG. 9 is a cross-sectional view taken along line AA in FIG. 8, and FIG. The same members as those shown in the first embodiment and the second embodiment will be described using the same reference numerals. Reference numeral 1 denotes a liquid crystal display panel, which has the same configuration as that shown in the first embodiment and the second embodiment. However, in the present embodiment, the liquid crystal display panel 1 is arranged and fixed on a liquid crystal display panel mounting substrate 9 (hereinafter simply referred to as a mounting substrate) located below the circuit board 8. The circuit board 8 is provided with an opening 8a, and the liquid crystal display panel 1 is arranged and fixed at a predetermined position of the mounting board 9 through the opening 8a.

  A pixel electrode (not shown) is formed on the silicon substrate 1a, and a counter electrode (not shown) is formed on the glass substrate 1b. Each substrate supplies a potential to each electrode. They are stuck together in a shifted position. The supply of the potential to the pixel electrode is realized by connecting the silicon substrate 1a and the electrode pad on the circuit substrate 8 with the wire 4 and making them electrically conductive. On the other hand, the potential is supplied to the counter electrode by applying a thermosetting conductive resin 5 such as a silver paste between the glass substrate 1b and the circuit board 8, and the electrode pad on the counter electrode and the circuit board 8 (not fixed). This is realized by electrically conducting (shown). Different electric potentials are supplied to the pixel electrode and the counter electrode, respectively.

  The placement and fixing of the liquid crystal display panel 1 to the mounting substrate 9 is performed by an adhesive means 6. The bonding means 6 has a bonding surface having substantially the same shape as that of the sealing member 2 and is provided at a position facing the sealing member 2 below the silicon substrate 1a. In the present embodiment, like the seal member 2 shown in FIG. 8, it is provided in a frame shape. The adhesive means 6 can be used by appropriately selecting one applied in a frame shape using an epoxy resin adhesive or one attached with a frame-like adhesive double-sided tape.

  A substance for forming a desired gap called a spacer (not shown) is mixed in the seal member 2. For this reason, in the liquid crystal display panel 1, the vicinity of the interposed portion of the seal member 2 is a portion strong against external stress. Therefore, if the bonding means 6 has substantially the same shape as the sealing member 2 in a plan view and is provided at a position facing the sealing member 2 below the silicon substrate 1a, the mounting substrate 9 of the liquid crystal display panel 1 is provided. Even when the adhesive means 6 adheres to the liquid crystal display panel 1 or is subjected to external stress due to shrinkage or expansion due to heat after the fixing, display of color unevenness or the like of the liquid crystal display panel 1 is displayed. There is no loss of quality.

  As shown in FIG. 4, the bonding means 6 is not formed into a continuous frame shape, but is provided with a discontinuous portion 6 a and has a non-bonded surface in a fixed state between the liquid crystal display panel 1 and the mounting substrate 9. The gap formed by the non-adhesive surface can be used as an outward discharge port for heat trapped in the lower surface portion surrounded by the adhesive means 6 of the liquid crystal display panel 1.

  Moreover, when an adhesive double-sided tape is selected as the bonding means 6, the non-continuous portion 6a is provided at two locations and divided into two, thereby facilitating the adhesive double-sided tape sticking operation. .

  Further, if the mounting substrate 9 is provided with an opening 9a at a portion facing the display area 1c of the liquid crystal display panel 1, the heat accumulated in the lower surface portion surrounded by the bonding means 6 of the liquid crystal display panel 1 is generated. It is possible to discharge outward from the opening 9a.

  In addition, if the mounting substrate 9 is made of a material having high thermal conductivity, it is possible to further enhance the heat dissipation effect of the heat generated in the liquid crystal display panel 1 to the outside. Aluminum is suitable as the member having high thermal conductivity. In this case, the bonding means 6 to the mounting substrate 9 of the liquid crystal display panel 1 may be similarly selected from members having high thermal conductivity. For example, “3M-8805” manufactured by 3M can be suitably selected as a highly heat-conductive adhesive double-sided tape.

Further, if the mounting substrate 9 is made of a material having a linear expansion coefficient that is as close as possible to the linear expansion coefficient of the silicon substrate 1a, the stress on the silicon substrate 1a due to the thermal expansion of the mounting substrate 9 can be reduced. Since the silicon substrate 1a of this embodiment has a linear expansion coefficient of 2.5 × 10 ⁻⁶ mm / ° C., the mounting substrate 9 is a 42 alloy having a linear expansion coefficient of 4.5 × 10 ⁻⁶ mm / ° C. It is good to compose with. As other materials, for example, glass having a linear expansion coefficient of 3.76 × 10 ⁻⁶ mm / ° C., invar material having a linear expansion coefficient of 1.7 × 10 ⁻⁶ mm / ° C., and the like can be selected. It is. In the present embodiment, a silicon substrate is taken as an example as the first electrode substrate constituting the liquid crystal display panel. However, when the substrate is composed of another member, it is mounted on the mounting substrate 9 in accordance with the linear expansion coefficient of the member. What is necessary is just to select the material to be used suitably.

The top view which shows the liquid crystal display device of 1st embodiment of this invention AA sectional view of FIG. The disassembled perspective view which shows the liquid crystal display device of 1st embodiment of this invention. The perspective view which shows another form of the adhesive means used for a liquid crystal display device The top view which shows the liquid crystal display device of 2nd embodiment of this invention. AA sectional view of FIG. The disassembled perspective view which shows the liquid crystal display device of 2nd embodiment of this invention. The top view which shows the liquid crystal display device of 3rd embodiment of this invention. AA sectional view of FIG. The disassembled perspective view which shows the liquid crystal display device of 3rd embodiment of this invention. The figure showing the color nonuniformity generation state in the liquid crystal display panel surface of the liquid crystal display device by this invention It is a figure which shows the liquid crystal display device by a prior art, (a) is a front view, (b) is AA sectional drawing. A diagram showing the occurrence of color unevenness in the liquid crystal display panel of a conventional liquid crystal display device

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Liquid crystal display panel 1a Silicon substrate 1b Glass substrate 2 Sealing member 3 Circuit board 4 Wire 5 Conductive resin 6 Adhesive means 6a Discontinuous part 7 Circuit board 7a Opening part 8 Circuit board 8a Opening part 9 Liquid crystal display panel mounting board 9a Opening part 11 Liquid crystal display panel 12 Base 13 Double-sided tape 14 Flexible wiring board

Claims (3)

at least,
A first electrode substrate having a plurality of pixel electrodes; and a second electrode substrate having a counter electrode facing the first electrode substrate, wherein the first electrode substrate and the second electrode substrate are sealed at a predetermined position and interval. A liquid crystal display panel bonded by a member;
A circuit board that fixes and arranges the liquid crystal display panel via an adhesive means and is electrically connected to the liquid crystal display panel;
A liquid crystal display device comprising:
It said bonding means is configured to have a bonding surface of the sealing member in a plane substantially the same shape, and have a gap formed by the non-adhesive surface on at least one place, provided in a position opposed to the sealing member,
The circuit board, a liquid crystal display device according to claim Rukoto that having a opening in the opposing portion between the liquid crystal display panel except for the intermediate portion of the adhesive means. at least,
A first electrode substrate having a plurality of pixel electrodes; and a second electrode substrate having a counter electrode facing the first electrode substrate, wherein the first electrode substrate and the second electrode substrate are sealed at a predetermined position and interval. A liquid crystal display panel bonded by a member;
A liquid crystal display panel mounting substrate on which the liquid crystal display panel is arranged and fixed via an adhesive means;
A liquid crystal display device comprising:
The adhesive means has an adhesive surface having substantially the same shape as the seal member in a plane, and has a gap formed by a non-adhesive surface in at least one place, and is provided at a position facing the seal member.
The liquid crystal display panel mounting substrate has an opening at a portion facing the liquid crystal display panel excluding the bonding means intervening portion. The first electrode substrate is made of silicon,
The liquid crystal display device according to claim 2, wherein the liquid crystal display panel mounting substrate is made of 42 alloy.

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