Liquid crystal display device

Abstract

To provide a liquid crystal display device with which, although a liquid crystal display element in which connecting terminals are formed at two opposing side edges of a pixel electrode substrate, it is possible to reduce the device size.SOLUTION: A first flexible printed board 2A is valley-folded twice along a first side end surface of a heat sink 3 and mountain-folded in a 45-degree direction. A first tip 2A2 protrudes to the outside of the heat sink 3 from a third side end surface side sandwiched by a first side end surface and a second side end surface facing the first side end surface. A second flexible printed board 2B valley-folded twice along a second side end surface of the heat sink 3 and mountain-folded in a 45-degree direction. A second tip 2B2 protrudes to the outside of the heat sink 3 from the third side end surface side.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a liquid crystal display device. [Background technology]

[0002] Liquid crystal display devices include a liquid crystal display element that modulates illumination light in accordance with the image to be projected. In recent years, the number of pixels in images projected by liquid crystal display devices has been increasing. Liquid crystal display elements with a larger number of pixels, or so-called 8K, have appeared, with a horizontal pixel count of 7680 pixels and a vertical pixel count of 4320 pixels, than liquid crystal display elements with a horizontal pixel count of 3840 pixels and a vertical pixel count of 2160 pixels, or so-called 4K. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2022-139939 Summary of the Invention [Problem to be solved by the invention]

[0004] The number of connection terminals connected to each pixel electrode in a liquid crystal display element with 8K pixels is four times the number of connection terminals connected to each pixel electrode in a liquid crystal display element with 4K pixels. Therefore, it is difficult to form connection terminals for a liquid crystal display element with 8K pixels on only one side edge of the pixel electrode substrate. Therefore, as described in Patent Document 1, in a liquid crystal display element with 8K pixels, it is necessary to form connection terminals on two opposing side edges of the pixel electrode substrate.

[0005] When connection terminals are formed on two opposing side edges of the pixel electrode substrate, two drive substrates are required to drive the liquid crystal display element: a first drive substrate connected to the connection terminals formed on one side edge, and a second drive substrate connected to the connection terminals formed on the other side edge. Furthermore, the two drive substrates are positioned apart from each other across the liquid crystal display element, which results in an increased size of the liquid crystal display device. Even for liquid crystal display devices equipped with liquid crystal display elements with a large number of pixels, such as 8K, miniaturization of the liquid crystal display device is desired.

[0006] An object of the present invention is to provide a liquid crystal display device that can be made smaller while incorporating a liquid crystal display element having connection terminals formed on two opposing side edges of a pixel electrode substrate. [Means for solving the problem]

[0007] The present invention provides a reflective liquid crystal display element having first and second side edges facing each other, on which connection terminals for connection with pixel electrodes in a plurality of pixels are formed; first and second flexible printed circuit boards connected to the connection terminals formed on the first and second side edges and extending in opposite directions to each other, perpendicular to the end faces of the first and second side edges; and a heat sink to which the reflective liquid crystal display element is fixed with its light incident surface facing outward, and which dissipates heat generated by the reflective liquid crystal display element, wherein the first flexible printed circuit board is folded twice in a valley along a first side edge face of the heat sink on the side of the first side edge, and a first tip end of the first flexible printed circuit board is attached to the heat sink on the back side of the heat sink, the first tip end facing the first side edge face. the second flexible printed circuit board is folded twice in a valley along the second side end face on the second side end side, so that a second tip of the second flexible printed circuit board is directed toward the first side end face on the back side of the heat sink, and is further folded in a mountain direction at 45 degrees with the first tip facing the second side end face, so that the first tip protrudes outside the heat sink from a third side end face side that is sandwiched between the first side end face and the second side end face; the second flexible printed circuit board is folded twice in a valley along the second side end face on the second side end side, so that a second tip of the second flexible printed circuit board is directed toward the first side end face on the back side of the heat sink, and is further folded in a mountain direction at 45 degrees with the second tip facing the first side end face, so that the second tip protrudes outside the heat sink from the third side end face side. [Effects of the Invention]

[0008] According to the liquid crystal display device of the present invention, it is possible to reduce the size of the device while mounting a liquid crystal display element in which connection terminals are formed on two opposing side edges of a pixel electrode substrate. [Brief explanation of the drawings]

[0009] [Figure 1A] FIG. 1A is a perspective view of a liquid crystal display element assembly included in a liquid crystal display device according to an embodiment, viewed from the front side. [Figure 1B]FIG. 1B is a perspective view of a liquid crystal display element assembly included in a liquid crystal display device according to an embodiment, viewed from the rear side. [Figure 2] FIG. 2 is an exploded perspective view of a liquid crystal display element assembly included in a liquid crystal display device according to an embodiment. [Figure 3] FIG. 3 is a plan view showing a schematic configuration of a reflective liquid crystal display element included in the liquid crystal display element assembly. [Figure 4] FIG. 4 is a plan view showing a state in which a reflective liquid crystal display element and a flexible printed circuit board are integrated together. [Figure 5] FIG. 5 is a perspective view of the heat sink provided in the liquid crystal display element assembly, as seen from behind. [Figure 6] FIG. 6 is a perspective view showing a bracket provided in the liquid crystal display element assembly. [Figure 7] FIG. 7 is a perspective view showing a state in which the bracket shown in FIG. 6 is fixed to a heat sink that fixes a reflective liquid crystal display element integrated with a flexible printed circuit board. [Figure 8A] FIG. 8A is a plan view showing a state in which a reflective liquid crystal display element integrated with a flexible printed circuit board is fixed to a heat sink, as viewed from the front. [Figure 8B] FIG. 8B is a plan view showing the state in which the reflective liquid crystal display element integrated with the flexible printed circuit board is fixed to the heat sink, as viewed from behind. [Figure 9A] FIG. 9A is a plan view showing a state corresponding to FIG. 8B before the flexible printed circuit board is folded. [Figure 9B] FIG. 9B is a plan view showing a state in which one of the flexible printed circuit boards has been folded twice in a valley shape from the state shown in FIG. 9A. [Figure 9C] FIG. 9C is a plan view showing a state in which one of the flexible printed circuit boards is bent at an angle of 45 degrees from the state shown in FIG. 9B. [Figure 9D] FIG. 9D is a plan view showing a state in which the other flexible printed circuit board is folded twice in a valley shape from the state shown in FIG. 9C. [Figure 9E]FIG. 9E is a plan view showing a state in which the other flexible printed circuit board is bent at an angle of 45 degrees from the state shown in FIG. 9D. [Figure 10A] FIG. 10A is a plan view showing a first preferred configuration example of a flexible printed circuit board. [Figure 10B] FIG. 10B is a plan view showing a second preferred configuration example of the flexible printed circuit board. [Figure 11] FIG. 11 is a perspective view showing a state in which the flexible printed circuit board is folded from the state shown in FIG. 7 as shown in FIGS. 9A to 9E. [Figure 12] 12 is a perspective view showing a state in which a pressing member for pressing the folded flexible printed circuit board is fixed to the heat sink in the state shown in FIG. [Figure 13] FIG. 13 is a perspective view showing the pressing member. [Figure 14] FIG. 14 is a perspective view showing a driving substrate provided in the liquid crystal display element assembly. [Figure 15] FIG. 15 is a perspective view showing a spacer provided in the liquid crystal display element assembly. [Figure 16] FIG. 16 is a perspective view showing a state in which a fan is arranged near a heat sink in a liquid crystal display element assembly. [Figure 17] FIG. 17 is a plan view showing the fan and liquid crystal display element assembly shown in FIG. 16 as seen from the side with the bracket and spacer removed. DETAILED DESCRIPTION OF THE INVENTION

[0010] A liquid crystal display device according to an embodiment will be described below with reference to the accompanying drawings. The liquid crystal display device according to an embodiment includes a liquid crystal display element assembly 100 shown in FIGS. 1A and 1B. FIG. 1A is a perspective view of the liquid crystal display element assembly 100 as seen from the front side, and FIG. 1B is a perspective view of the liquid crystal display element assembly 100 as seen from the rear side. The front side of the liquid crystal display element assembly 100 is the side on which a reflective liquid crystal display element (hereinafter referred to as a liquid crystal display element) 1 is located, and the rear side is the side opposite to the front side. If the liquid crystal display device includes three liquid crystal display elements 1 for red light, green light, and blue light, the liquid crystal display device includes three liquid crystal display element assemblies 100.

[0011] 2 is an exploded perspective view of the liquid crystal display element assembly 100. The liquid crystal display element assembly 100 includes a liquid crystal display element 1 (shown in FIG. 1A) to which flexible printed circuit boards 2A and 2B (first and second flexible printed circuit boards) are attached, a heat sink 3, a heater 4 (shown in FIG. 5), a bracket 5, a pressing member 6, a drive substrate 7A (first drive substrate), a drive substrate 7B (second drive substrate), and a spacer 8.

[0012] As shown in FIG. 3, the liquid crystal display element 1 includes a pixel electrode substrate 11 disposed on the bottom side and a glass substrate 12 disposed above the pixel electrode substrate 11. The pixel electrode substrate 11 is a silicon substrate. A plurality of pixels (not shown), for example, 8K pixels, and pixel electrodes (not shown) corresponding to each pixel are formed on the pixel electrode substrate 11. A transparent electrode is formed on the glass substrate 12. A sealant 13 is provided between the pixel electrode substrate 11 and the glass substrate 12. A liquid crystal (not shown) is injected through an injection port 131 into the space surrounded by the sealant 13 between the pixel electrode substrate 11 and the glass substrate 12.

[0013] Side edges 11a and 11b (first and second side edges) on the long sides of the pixel electrode substrate 11 protrude beyond the side edge surfaces on the long sides of the glass substrate 12. Side edges 12a, 12b1, and 12b2 on the short sides of the glass substrate 12 protrude beyond the side edge surfaces on the short sides of the pixel electrode substrate 11. The side edges 12a, 12b1, and 12b2 are used to fix the liquid crystal display element 1 to the heat sink 3. A notch 12b3 between the side edges 12b1 and 12b2 is formed so that a sealant 132 can be injected into the injection port 131 using a dispenser nozzle (not shown). The injection port 131 is sealed with the sealant 132, and the liquid crystal is held in a space surrounded by the sealant 13 between the pixel electrode substrate 11 and the glass substrate 12.

[0014] Connection terminals 11t connected to each pixel electrode in a plurality of pixels are formed on the side edges 11a and 11b of the pixel electrode substrate 11. Because the connection terminals 11t are formed on both the side edges 11a and 11b, the liquid crystal display element 1 can be provided with connection terminals 11t corresponding to 8K pixels on the pixel electrode substrate 11. Both short-side edge portions of the pixel electrode substrate 11 may be protruded beyond both short-side end faces of the glass substrate 12, and the connection terminals 11t may be formed on both short-side edge portions. However, in a liquid crystal display element 1 having 8K or more pixels, it is preferable to form the connection terminals 11t on the long-side edge portions 11a and 11b.

[0015] The surface of the liquid crystal display element 1 facing the glass substrate 12 is a light incident surface 14 onto which illumination light is incident. The illumination light incident on the liquid crystal display element 1 is modulated by the liquid crystal in accordance with the image to be projected, reflected by the liquid crystal or the reflective electrode formed on the pixel electrode substrate 11 side, and emitted from the light incident surface 14.

[0016] As shown in Fig. 4, flexible printed circuit boards 2A and 2B are connected to connection terminals 11t on the side ends 11a and 11b, respectively. The liquid crystal display element 1 and the flexible printed circuit boards 2A and 2B are integrated. The flexible printed circuit boards 2A and 2B supply the drive voltages for each pixel electrode, which are supplied from the drive substrates 7A and 7B, respectively, to the connection terminals 11t.

[0017] 5, a plurality of fins 31 are formed on the rear side of the heat sink 3 along the longitudinal direction of the rectangular heat sink 3. The heat sink 3 is made of, for example, aluminum. The plurality of fins 31 dissipate heat generated by the liquid crystal display element 1.

[0018] A heater housing section 32, where fins 31 are not formed, is formed in the center of the back side of the heat sink 3. A heater 4 serving as a heat source is housed in the heater housing section 32. A ceramic heater is preferably used as the heater 4. The heater 4 is held down by a retaining plate 40 fixed to the heat sink 3 by a pair of screws 41, and is fixed so as not to fall out of the heater housing section 32. The retaining plate 40 is formed, for example, by processing an aluminum plate. When the temperature of the liquid crystal display element 1 is low, the liquid crystal display element 1 is heated by the heater 4.

[0019] 5, the retainer plate 40 is actually fixed to the heat sink 3 by screws 41 with a fixing portion 51 of the bracket 5, which will be described later, positioned on the lower side. The retainer plate 40 has a pair of downward protruding pieces that elastically deform and press down on the heater 4.

[0020] As shown in FIG. 6, the bracket 5 has a fixing portion 51 for fixing to the heat sink 3 and a substrate mounting portion 52 for mounting the drive substrates 7A and 7B. The bracket 5 is integrally formed by processing, for example, an aluminum plate. As shown in FIG. 7, the bracket 5 is integrated with the heat sink 3 by fixing the fixing portion 51 to the rear surface of the heat sink 3 with four screws 53. The liquid crystal display element 1, to which the flexible printed circuit boards 2A and 2B are connected, is fixed to the heat sink 3. FIG. 7 shows that the pressing plate 40 is fixed to the heat sink 3 with screws 41 via the fixing portion 51 located on the underside.

[0021] The liquid crystal display element 1, to which the flexible printed circuit boards 2A and 2B are connected, is fixed to a heat sink 3 as shown in Figures 8A and 8B. The liquid crystal display element 1 is fixed to the front of the heat sink 3 with the light incident surface 14 facing outward. Figure 8A shows the heat sink 3 to which the liquid crystal display element 1 is fixed, as viewed from the front, and Figure 8B shows the heat sink 3 as viewed from the back.

[0022] When the flexible printed circuit boards 2A and 2B are not bent, they extend in opposite directions perpendicular to the end faces of the side ends 11a and 11b. The flexible printed circuit boards 2A and 2B each have straight portions 2A1 and 2B1 having parallel side ends, and tip portions 2A2 and 2B2 (first and second tip portions) that branch into two on the tip side of the straight portions 2A1 and 2B1. The flexible printed circuit boards 2A and 2B are bent multiple times as described below to reach the folded state shown in FIGS. 1A, 1B, and 2.

[0023] FIG. 9A corresponds to the state shown in FIG. 8B. In FIGS. 9A to 9E, the fins 31 of the heat sink 3 are omitted and only the outer shape is shown. The side end surface 33a (first side end surface) of the heat sink 3 is the side end surface on the side end portion 11a side of the pixel electrode substrate 11, and the side end surface 33b (second side end surface) opposite the side end surface 33a is the side end surface on the side end portion 11b side. The flexible printed circuit board 2A is folded twice at the bending points Fa1 and Fa2 shown in FIG. 9A, and is thereby folded along the side end surface 33a as shown in FIG. 9B, with the tip portion 2A2 on the back side of the heat sink 3 facing the side end surface 33b side. The side end surface 33a is covered by the flexible printed circuit board 2A.

[0024] 9B, the flexible printed circuit board 2A is bent at a bending point Fa3 at a 45-degree angle relative to the side edge of the flexible printed circuit board 2A, with the tip portion 2A2 facing the side edge face 33b. As a result, as shown in FIG. 9C, the tip portion 2A2 protrudes from the side edge face 33c (third side edge face) sandwiched between the side edge face 33a and the side edge face 33b to the outside of the heat sink 3.

[0025] Similarly, the flexible printed circuit board 2B is folded twice at bending points Fb1 and Fb2 shown in Fig. 9C, and is thereby folded along the side end surface 33b as shown in Fig. 9D, with the tip portion 2B2 facing the side end surface 33a on the rear surface side of the heat sink 3. The side end surface 33b is covered with the flexible printed circuit board 2B.

[0026] In Fig. 9D, the flexible printed circuit board 2B is bent at a bending point Fb3 at a 45-degree angle relative to the side edge of the flexible printed circuit board 2B, with the leading end portion 2B2 facing the side end face 33a. As a result, as shown in Fig. 9E, the leading end portion 2B2 protrudes from the side end face 33c to the outside of the heat sink 3. The flexible printed circuit boards 2A and 2B are overlapped over most of their surfaces. The leading end portions 2A2 and 2B2 protrude to the outside of the heat sink 3 at approximately the same position in the direction of the surface along the back surface of the heat sink 3, but are offset in the direction perpendicular to the back surface.

[0027] In the example shown in FIGS. 9A to 9E, flexible printed circuit board 2A is folded first, and then flexible printed circuit board 2B is folded, but flexible printed circuit board 2B may be folded first, and then flexible printed circuit board 2A may be folded.

[0028] Incidentally, flexible printed circuit boards 2A and 2B are coated with a shielding material to form a shielded structure, except for some areas such as connection terminals, which will be described later. The application of the shielding material can make it difficult to bend at bending points Fa1 to Fa3 and Fb1 to Fb3. To make it easier to bend flexible printed circuit boards 2A and 2B, flexible printed circuit boards 2A and 2B may be configured as shown in FIG. 10A or 10B.

[0029] 10A, bending grooves Ga1 and Ga2, where the shielding material is thin or no shielding material is applied, are provided on the back surface of flexible printed circuit board 2A at locations corresponding to bending locations Fa1 and Fa2.Bending groove Ga3, where the shielding material is thin or no shielding material is applied, is provided on the front surface of flexible printed circuit board 2A at a location corresponding to bending location Fa3.Bending grooves Ga1, Ga2, and Ga3 may have a predetermined width.

[0030] The rear surface of the flexible printed circuit board 2B has bending grooves Gb1 and Gb2 where the shielding material is thin or no shielding material is applied at locations corresponding to the bending locations Fb1 and Fb2. The front surface of the flexible printed circuit board 2B has bending groove Gb3 where the shielding material is thin or no shielding material is applied at a location corresponding to the bending location Fb3. The bending grooves Gb1, Gb2, and Gb3 may have a predetermined width.

[0031] When the flexible printed circuit boards 2A and 2B are bent at the bending points Fa1 and Fa2, and Fb1 and Fb2, the flexible printed circuit boards 2A and 2B are bent at approximately 90 degrees at the bending points Fa1 and Fa2, and Fb1 and Fb2. When the flexible printed circuit boards 2A and 2B are bent at the bending points Fa3 and Fb3, the flexible printed circuit boards 2A and 2B are bent at approximately 180 degrees. Therefore, the flexible printed circuit boards 2A and 2B coated with a shielding material are more difficult to bend when the flexible printed circuit boards 2A and 2B are bent at the bending points Fa3 and Fb3.

[0032] Therefore, only the bending grooves Ga3 and Gb3 may be provided on the front surfaces of the flexible printed circuit boards 2A and 2B.

[0033] 10B, rectangular bending regions Ha3 and Hb3, which have a thin shielding material or are not coated with a shielding material, may be provided on the front surface of flexible printed circuit boards 2A and 2B so as to include bending points Fa3 and Fb3. Bending grooves Ga1, Ga2, Gb1, and Gb2 shown in FIG. 10A may or may not be provided on the rear surface of flexible printed circuit boards 2A and 2B.

[0034] The rear surface of the flexible printed circuit board 2A may be provided with a rectangular bending region including bending points Fa1 and Fa2, where the shielding material is thin or no shielding material is applied.The rear surface of the flexible printed circuit board 2A may be provided with a rectangular bending region including bending points Fb1 and Fb2, where the shielding material is thin or no shielding material is applied.

[0035] In this way, by applying a thinner shielding material to the valley fold or mountain fold areas on the back or front of the flexible printed circuit boards 2A and 2B than to other areas, or by applying no shielding material at all, the flexible printed circuit boards 2A and 2B can be easily folded.

[0036] When the flexible printed circuit boards 2A and 2B are folded as described above, the flexible printed circuit boards 2A and 2B change from the state shown in Fig. 7 to the state shown in Fig. 11. In Fig. 11, the flexible printed circuit boards 2A and 2B are shown folded back at approximately 180 degrees by two valley folds at approximately right angles and one mountain fold, but in reality, the flexible printed circuit boards 2A and 2B are folded gently so as not to damage them.

[0037] 12, a presser member 6 is fixed to the heat sink 3 so as to cover the folded flexible printed circuit boards 2A and 2B. Because the flexible printed circuit boards 2A and 2B are gently bent as described above, if the flexible printed circuit boards 2A and 2B are not covered by the presser member 6, the flexible printed circuit boards 2A and 2B will bulge away from the rear surface of the heat sink 3. Covering the flexible printed circuit boards 2A and 2B with the presser member 6 can prevent the flexible printed circuit boards 2A and 2B from bulging and interfering with other components.

[0038] It is preferable that the pressing member 6 gently presses down on the flexible printed circuit boards 2A and 2B. In order for the pressing member 6 to gently press down on the flexible printed circuit boards 2A and 2B, the pressing member 6 is configured as shown in FIG. 13. The pressing member 6 has a pair of pressing pieces 61 in the longitudinal direction of the heat sink 3, and an inclined pressing piece 62 that is connected to the middle of the pair of pressing pieces 61 and protrudes outward. The inclined pressing piece 62 is inclined so that its tip approaches the heat sink 3. The pressing member 6 is formed, for example, by processing an aluminum plate.

[0039] 13, there is a predetermined space between the pressing piece 61 and the tip of the inclined pressing piece 62 in a direction perpendicular to the back surface of the heat sink 3. Therefore, the pressing member 6 can gently press the flexible printed circuit boards 2A and 2B.

[0040] The pressing member 6 has a rectangular opening 63a at one end, and a locking piece 63 is formed on the distal side of the opening 63a. The pressing member 6 also has a connecting piece 64 at the other end that connects the pair of pressing pieces 61, with both ends of the connecting piece 64 being bent and having locking claws 641 formed at the ends. As shown in FIG. 12 , the locking piece 63 is locked to the end of the pressing plate 40 that presses down the heater 4. The locking claws 641 at both ends of the connecting piece 64 are locked to both side end surfaces of the fixing portion 51 of the bracket 5. In this way, the pressing member 6 is positioned with respect to the heat sink 3 and the bracket 5 by the locking piece 63 and the pair of locking claws 641, and presses down the flexible printed circuit boards 2A and 2B.

[0041] As shown in Fig. 14, the drive substrates 7A and 7B are provided with a pair of connectors 71 for connecting connection terminals provided at the very tip of the tip portion 2A2 or 2B2. The connectors 71 are provided at the ends of the drive substrates 7A and 7B. Four slot-shaped openings 72 are formed at both side ends of the drive substrates 7A and 7B. The surface of the drive substrates 7A and 7B shown in Fig. 13 is the front surface.

[0042] 15 shows a spacer 8 disposed between drive substrate 7A and drive substrate 7B. Spacer 8 has protrusions 81 on both sides of one end. Spacer 8 is formed by processing an aluminum plate, for example.

[0043] The drive board 7A, spacer 8, and drive board 7B are mounted in this order on the board mounting portion 52 of the bracket 5 shown in Fig. 12. When the drive boards 7A and 7B are mounted on the board mounting portion 52, the surfaces of the drive boards 7A and 7B are parallel to the light incident surface 14. In Fig. 12, the drive board 7A is mounted with the end where the connector 71 is provided facing the heat sink 3 and the front surface facing downward. The drive board 7B is mounted with the end where the connector 71 is provided facing the heat sink 3 and the front surface facing upward. The connection terminals provided at the foremost ends of the tip portions 2A2 and 2B2 are connected to the connector 71.

[0044] When the drive substrate 7A, spacer 8, and drive substrate 7B mounted on the substrate mounting portion 52 are fastened with four screws 73 (shown in FIG. 2) inserted into the four openings 72, the liquid crystal display element assembly 100 shown in FIGS. 1A and 1B is formed. As shown in FIG. 1B, the pair of protrusions 81 come into contact with the tip surface 521 of the substrate mounting portion 52, so that the position of the spacer 8 in the direction toward the heat sink 3 is restricted.

[0045] If the drive substrates 7A and 7B are movable in directions toward or away from the heat sink 3, it is easy to connect the connection terminals to the connector 71. Because the opening 42 is shaped like an elongated hole, before the drive substrate 7A, spacer 8, and drive substrate 7B are fixed to the substrate mounting portion 52 with the screws 73, the drive substrates 7A and 7B can be moved a predetermined distance toward or away from the heat sink 3. This makes it easy to connect the connection terminals to the connector 71. After the connection terminals are connected to the connector 71, the drive substrate 7A, spacer 8, and drive substrate 7B are completely fixed to the substrate mounting portion 52 with the screws 73.

[0046] In this manner, the liquid crystal display element assembly 100 shown in FIGS. 1A and 1B is constructed. The heat sink 3 to which the liquid crystal display element 1 is fixed is accurately positioned and fixed at a predetermined location within the housing of the liquid crystal display device. The liquid crystal display device may also include a main drive substrate other than the drive substrates 7A and 7B. The main drive substrate and the drive substrates 7A and 7B are connected to each other by a connecting cable. When the liquid crystal display device includes a main drive substrate, the main drive substrate drives the liquid crystal display element 1 via the drive substrates 7A and 7B. The drive substrates 7A and 7B function as relay substrates that drive the liquid crystal display element 1.

[0047] 16, a fan 9 that blows air between the fins 31 of the heat sink 3 is disposed at a position a predetermined distance away from a side end face 33d (fourth side end face) that faces the side end face 33c of the heat sink 3 in the liquid crystal display element assembly 100. When the fan 9 is rotated, the air generated by the fan 9 flows between the fins 31 and cools the heat sink 3. The air flowing between the fins 31 exits from the side end face 33c to the outside of the heat sink 3 and flows in the direction of the drive substrates 7A and 7B.

[0048] By folding the flexible printed circuit boards 2A and 2B as described above, the side end faces 33a and 33b of the heat sink 3 are covered by the flexible printed circuit boards 2A and 2B, respectively. Furthermore, the tip ends 2A2 and 2B2 of the flexible printed circuit boards 2A and 2B protrude from the side end face 33c toward the outside of the heat sink 3. The heat sink 3 has a plurality of fins 31 formed in a direction along the side end faces 33a and 33b, enabling efficient cooling of the heat sink 3 (liquid crystal display element 1). By setting the relationship between the folding method of the flexible printed circuit boards 2A and 2B and the direction of the fins 31 of the heat sink 3 in this manner, it is possible to achieve not only a compact device but also efficient cooling of the liquid crystal display element 1.

[0049] Figure 17 shows the fan 9 and liquid crystal display element assembly 100 shown in Figure 16, viewed from the side, with the bracket 5 and spacer 8 removed. As shown in Figure 7, the fixing portion 51 of the bracket 5 is fixed to the rear surface of the heat sink 3, and the substrate mounting portion 52 is positioned displaced toward the rear surface. Therefore, as shown in Figure 17, the end face of the driving substrate 7B, of the driving substrates 7A and 7B, does not face the side end face 33c. The driving substrate 7B is disposed at a position spaced apart from the heat sink 3 in a direction perpendicular to the light incident surface 14.

[0050] The end face of the drive substrate 7A faces the side end face 33c. The substrate mounting portion 52 may be configured so that the end face of the drive substrate 7A does not face the side end face 33c. It is preferable that the end face of at least one of the drive substrates 7A and 7B does not face the side end face 33c and is positioned away from the heat sink 3 in a direction perpendicular to the light incident surface 14.

[0051] Since neither of the drive substrates 7A nor 7B faces the side end surface 33c, the air generated by the fan 9 and passing from the side end surface 33c to the outside of the heat sink 3 flows almost unobstructed by the drive substrates 7A and 7B, thereby enabling efficient cooling of the heat sink 3 (liquid crystal display element 1).

[0052] The present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the gist of the present invention. [Explanation of symbols]

[0053] 1 Reflective LCD display element 2A Flexible Printed Circuit Board (First Flexible Printed Circuit Board) 2B Flexible Printed Circuit Board (Second Flexible Printed Circuit Board) 2A1,2B1 Straight section 2A2 Tip (first tip) 2B2 Tip (second tip) 3 Heatsink 4 heater 5 Bracket 6. Retaining member 7A Drive board (first drive board) 7B drive substrate (second drive substrate) 8 spacers 9 Fans 11a,11b side ends 11t connection terminal 14 Light entrance surface 31 Finn 33a side end surface (first side end surface) 33b side end surface (second side end surface) 33c side end face (third side end face) 33d Side end face (fourth side end face) 51 Fixed part 52 Circuit board mounting section 71 Connector 100 Liquid crystal display element assembly

Claims

1. a reflective liquid crystal display element having connection terminals for connecting to pixel electrodes of a plurality of pixels formed on first and second side edges facing each other; first and second flexible printed circuit boards connected to connection terminals formed on the first and second side ends and extending in opposite directions perpendicular to the end faces of the first and second side ends, respectively; a heat sink to which the reflective liquid crystal display element is fixed with its light incident surface facing outward, the heat sink dissipating heat generated by the reflective liquid crystal display element; Equipped with The first flexible printed circuit board includes: the first flexible printed circuit board is folded twice along a first side end surface of the heat sink on the side of the first side end portion, and a first tip end portion of the first flexible printed circuit board is directed toward a second side end surface of the heat sink that faces the first side end surface on the back side of the heat sink, Furthermore, the first tip portion is bent at a 45-degree angle with the first tip portion facing the second side end surface, and the first tip portion protrudes from a third side end surface between the first side end surface and the second side end surface to the outside of the heat sink, The second flexible printed circuit board includes: a second end portion of the second flexible printed circuit board facing the first side end surface on the rear surface side of the heat sink; Furthermore, the second tip portion is bent at a 45-degree angle with the second tip portion facing the first side end surface, and the second tip portion protrudes from the third side end surface to the outside of the heat sink. LCD display device.

2. the reflective liquid crystal display element has a rectangular shape, and the first and second side edges are side edges on the long sides of the reflective liquid crystal display element; The heat sink has a rectangular shape, and the third side end surface is a side end surface on a short side of the heat sink. The liquid crystal display device according to claim 1 .

3. 3. A liquid crystal display device according to claim 1, wherein the areas on the back or front of the first and second flexible printed circuit boards that are to be valley-folded or mountain-folded are coated with a thinner shielding material than other areas or are not coated with any shielding material.

4. 3. The liquid crystal display device according to claim 1, wherein the first and second flexible printed circuit boards are superimposed on each other, and further comprising a pressing member for pressing the first and second flexible printed circuit boards.

5. the first and second drive substrates are disposed outside the third side end surface and parallel to the light incident surface; Connection terminals provided at the most distal ends of the first and second tip portions are connected to connectors provided on the first and second drive substrates, respectively.

3. The liquid crystal display device according to claim 1.

Images