JP4886296B2 - 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.

  6A and 6B are diagrams showing a liquid crystal display device according to the prior art, where FIG. 6A is a front view and FIG. 6B is a cross-sectional view taken along line AA. 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 is caused by unevenness of the double-sided tape when it is fixed to the entire surface of the liquid crystal display panel 11 and the base 12, and contraction / extension stress due to heat. As a result, the uniformity of the gap between the electrode substrates constituting 11 is impaired, resulting in partial color unevenness 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. 8 shows the 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. 8, when the entire surface of the liquid crystal display panel is fixed to the base, non-uniformity when the double-sided tape is fixed to the liquid crystal display panel and the base, mixing of bubbles or foreign matter, and both surfaces after bonding It can be seen that uneven color locally occurs in the liquid crystal display panel due to the stress of the tape and the like. 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. 8, 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. According to FIG. 8, since the voltage value is greatly changed 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 panel bonded by a member;
A liquid crystal display panel mounting substrate having an opening at a portion facing the liquid crystal display panel, and arranging and fixing the liquid crystal display panel via an adhesive means provided at a peripheral edge of the opening;
A circuit board having an opening corresponding to the liquid crystal display panel, disposed on the liquid crystal display panel mounting substrate and making electrical connection with the liquid crystal display panel;
The liquid crystal display panel mounting substrate, the liquid crystal display panel placed on the liquid crystal display panel mounting substrate, and a case member for storing the circuit board;
A heat conducting member provided at a facing portion between the liquid crystal panel and the case member facing each other through the opening of the circuit board and the opening of the liquid crystal panel mounting substrate;
A liquid crystal display device comprising:
The bonding means provided at the peripheral edge of the opening of the liquid crystal display panel mounting substrate has an adhesive surface having substantially the same shape as that of the sealing member of the liquid crystal display panel, and is interposed at a position facing the sealing member. A liquid crystal display device.

  The bonding means is a liquid crystal display device provided with at least one non-bonded surface.

  The bonding means is a liquid crystal display device that is an epoxy resin adhesive.

  The bonding means is a liquid crystal display device that is an adhesive double-sided tape.

  The heat conducting member is a liquid crystal display device made of a silicon gel material.

  The case member is a liquid crystal display device made of aluminum.

  The case member is a liquid crystal display device provided with fin-like heat dissipation means.

  According to the present invention, since the heat conducting member is provided at the facing portion between the liquid crystal panel and the case member facing each other through the opening of the circuit board and the opening of the liquid crystal panel mounting substrate, a quick heat dissipation effect is provided. Can be obtained. Further, the bonding means used for fixing the liquid crystal display panel to the circuit board or the liquid crystal display panel mounting board has an adhesive surface having substantially the same shape as the planar surface of the sealing member, and is provided only at a position facing the sealing member. Therefore, 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 the 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.

  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 pasted together with a shifted positional relationship. 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 configured to be disposed and fixed on a liquid crystal display panel mounting substrate 7 (hereinafter simply referred to as a mounting substrate) located below the circuit board 3. The circuit board 3 is provided with an opening 3a, and the liquid crystal display panel 1 is arranged and fixed at a predetermined position of the mounting board 7 through the opening 3a. Further, the mounting substrate 7 to which the liquid crystal display panel 1 is fixed is arranged and fixed to the case member 8.

  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. Accordingly, if the bonding means 6 has 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, the mounting substrate 7 of the liquid crystal display panel 1 is provided. Even if the adhesive means 6 adheres to the entire surface of the liquid crystal display panel 1 or is subjected to external stress due to heat shrinkage or expansion, the display quality such as color unevenness of the liquid crystal display panel 1 is improved. There is no loss.

  FIG. 7 is a diagram showing a voltage that is 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. 7, it can be confirmed that no color unevenness occurs in the display of the liquid crystal display device by using the bonding means of this 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 adhesive means 6 is not provided in a continuous frame shape, but is provided with a non-continuous portion 6a and having a non-adhesive surface in a fixed state between the liquid crystal display panel 1 and the mounting substrate 7. It is.

  When an adhesive double-sided tape is selected as the adhesive means 6, the non-continuous portion 6a is provided in two places and divided into two, thereby facilitating the adhesive double-sided tape sticking operation.

  The mounting substrate 7 to which the liquid crystal display panel 1 is fixed is provided with an opening 7a, and the liquid crystal display panel 1 is opposed to the circuit board 3 through the opening 3a and the opening 7a of the mounting substrate 7. A heat conducting member 9 is disposed at a portion facing the case member 8. As the heat conducting member 9, for example, a silicon gel material that does not harden at room temperature is used. With this configuration, heat generated in the liquid crystal display panel 1 can be transferred to the case member 8 via the heat conducting member. At this time, if the case member is made of a material having high thermal conductivity, for example, aluminum, the heat dissipation effect is further improved. The heat conducting member 9 is attached to the surface of the liquid crystal display panel 1 and the case member 8 opposite to the surface. If a soft silicon gel material is used as the heat conducting member 9, the heat conducting member 9 is large. No load is applied.

  Further, in this case, it is preferable to select a member having high thermal conductivity for the bonding means 6 to the mounting substrate 7 of the liquid crystal display panel 1 as well. For example, “3M-8805” manufactured by 3M can be suitably selected as a high thermal conductive double-sided tape.

  FIG. 5 is a side view showing a liquid crystal display device according to another embodiment of the present invention, and is a side view seen from the direction of arrow B in FIG. As shown in the figure, the case member 8 is provided with a fin-like heat dissipation member 8a. With this configuration, heat dissipation can be further improved.

Further, if the mounting substrate 7 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, stress on the silicon substrate 1a due to the thermal expansion of the mounting substrate 7 can be relieved. Since the silicon substrate 1a of this embodiment has a linear expansion coefficient of 2.5 × 10 ⁻⁶ mm / ° C., the mounting substrate 7 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 7 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 side view which shows the liquid crystal display device of other embodiment of 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. The figure showing the color nonuniformity generation state in the liquid crystal display panel surface of the liquid crystal display device by this invention 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 3a Opening part 4 Wire 5 Conductive resin 6 Adhesive means 6a Discontinuous part 7 Liquid crystal display panel mounting substrate 7a Opening part 8 Case member 8a Heat dissipation member 9 Thermal conduction Member 11 Liquid crystal display panel 12 Base 13 Double-sided tape 14 Flexible wiring board

Claims (7)

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 having an opening at a portion facing the liquid crystal display panel, and arranging and fixing the liquid crystal display panel via an adhesive means provided at a peripheral edge of the opening;
A circuit board having an opening corresponding to the liquid crystal display panel, disposed on the liquid crystal display panel mounting substrate and making electrical connection with the liquid crystal display panel;
The liquid crystal display panel mounting substrate, the liquid crystal display panel placed on the liquid crystal display panel mounting substrate, and a case member for storing the circuit board;
A heat conducting member provided at a facing portion between the liquid crystal panel and the case member facing each other through the opening of the circuit board and the opening of the liquid crystal panel mounting substrate;
A liquid crystal display device comprising:
The bonding means provided at the peripheral edge of the opening of the liquid crystal display panel mounting substrate has an adhesive surface having substantially the same shape as that of the sealing member of the liquid crystal display panel, and is interposed at a position facing the sealing member. A liquid crystal display device characterized by:   The liquid crystal display device according to claim 1, wherein the adhesion unit is provided with at least one non-adhesion surface.   The liquid crystal display device according to claim 1, wherein the bonding means is an epoxy resin adhesive.   The liquid crystal display device according to claim 1, wherein the adhesive means is an adhesive double-sided tape.   The liquid crystal display device according to claim 1, wherein the heat conducting member is a silicon gel material.   The liquid crystal display device according to claim 1, wherein the case member is made of aluminum.   The liquid crystal display device according to claim 1, wherein the case member is provided with fin-like heat dissipation means.

Images