Liquid crystal display device

Abstract

The present invention effectively suppresses temperature increase of a liquid crystal panel. This liquid crystal display device comprises: a liquid crystal panel; a panel housing configured to be able to house the liquid crystal panel; a first transparent member disposed on the front surface side of the liquid crystal panel; and a frame member which holds the first transparent member and is configured to be attachable to the panel housing, the frame member defining an interval between the liquid crystal panel and the first transparent member, and forming a gap through which a cooling liquid is able to flow along the front surface of the liquid crystal panel between the liquid crystal panel and the first transparent member. The panel housing has an inlet flow path of the cooling liquid which is formed in a first portion of the panel housing, and an outlet flow path of the cooling liquid which is formed in a second portion other than the first portion of the panel housing. The frame member has an introduction hole which connects with the inlet flow path at one end and causes the inlet flow path to communicate with the gap, and a discharge hole which connects with the outlet flow path at one end and causes the outlet flow path to communicate with the gap.

Description

[Technical Field]

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

[0002] When attempting to increase the brightness and resolution of a liquid crystal display device, temperature rise in the liquid crystal panel can become a problem. In a liquid crystal display device, the liquid crystal panel functions as a light modulation device. Patent Document 1 describes a technology related to liquid cooling of a liquid crystal panel. Specifically, the liquid crystal panel and a transparent dustproof glass provided on the front side thereof are joined together with a sealant with a predetermined gap between them, and through-holes are formed in part of the sealant to allow the flow of cooling liquid. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 3815382 Summary of the Invention

[0004] This technology aims to liquid-cool the LCD panel by introducing and circulating a cooling liquid through a through-hole in the sealant, i.e., a missing portion of the sealant, into the gap formed between the LCD panel and the dustproof glass. However, since a portion of the sealant that should be present is missing, there are concerns about the impact on sealing. Furthermore, to ensure sufficient sealing with such a configuration, the structure would have to be large, making it impossible to incorporate into conventional LCD displays.

[0005] An object of the present disclosure is to provide a liquid crystal display device that can effectively suppress a rise in temperature of a liquid crystal panel.

[0006] A liquid crystal display device according to one embodiment of the present disclosure includes a liquid crystal panel, a panel housing configured to accommodate the liquid crystal panel, a first transparent member disposed on the front side of the liquid crystal panel, and a frame member configured to hold the first transparent member and be attachable to the panel housing. In this embodiment, the frame member determines the distance between the liquid crystal panel and the first transparent member and forms a gap between the liquid crystal panel and the first transparent member through which a coolant can flow along the front surface of the liquid crystal panel. The panel housing has an inlet flow path for the coolant formed in a first portion of the panel housing and an outlet flow path for the coolant formed in a second portion of the panel housing excluding the first portion. The frame member has an inlet hole connected at one end to the inlet flow path and communicating the inlet flow path with the gap between the liquid crystal panel and the first transparent member, and an outlet hole connected at one end to the outlet flow path and communicating the outlet flow path with the gap. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic diagram showing a configuration of a liquid crystal display device according to an embodiment of the present disclosure. [Figure 2A] FIG. 2A is a schematic diagram showing an example of the overall configuration of a cooling system for the liquid crystal display device according to the embodiment. [Figure 2B] FIG. 2B is a schematic diagram showing the overall configuration of a cooling system for a liquid crystal display device according to a modified example of the embodiment. [Figure 3] FIG. 3 is a plan view of a liquid crystal panel module of the liquid crystal display device according to the embodiment. [Figure 4] FIG. 4 is a perspective view of a liquid crystal panel module of the liquid crystal display device according to the embodiment. [Figure 5] FIG. 5 is an exploded view of a liquid crystal panel module of the liquid crystal display device according to the embodiment, and also shows the flow of the cooling liquid. [Figure 6] FIG. 6 is an exploded view of the liquid crystal panel module of the liquid crystal display device according to the embodiment, showing the relative relationship between the frame members, front glass, and rear glass involved in liquid cooling of the liquid crystal panel. [Figure 7]FIG. 7 shows an exploded view of FIG. 6 as viewed from the rear side of the liquid crystal panel. [Figure 8] 8A is a cross-sectional view taken along line AA in FIG. 4, and FIG. 8B is an enlarged view of that portion (portion X). [Figure 9] FIG. 9 is an enlarged plan view of the heat exchanger of the liquid crystal panel module, and schematically shows the flow path of the cooling water in the heat exchanger. [Figure 10] FIG. 10 is an explanatory diagram showing, as a comparative example, a state in which the coolant flows into the gap from above and flows out again to the upper side. [Figure 11] FIG. 11 is an explanatory diagram showing, as a comparative example, a state in which the distance from the cooling liquid inlet to the liquid crystal panel is relatively short. [Figure 12] FIG. 12 is an exploded view of a liquid crystal panel module of a liquid crystal display device according to another embodiment of the present disclosure, showing the relative relationship between a frame member and a front glass relating to liquid cooling of the liquid crystal panel. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The embodiment described below is a specific example of the present disclosure, and is not intended to limit the technology of the present disclosure to the specific aspects described below. Furthermore, the arrangement, dimensions, and dimensional ratios of each component in the following embodiment are not limited to the examples shown in the drawings.

[0009] The explanation will be given in the following order. 1. First embodiment 1.1. Schematic configuration of a liquid crystal display device 1.2. Overall configuration of the cooling system 1.3. LCD panel module configuration 1.4. Action and Effects 2. Second embodiment 3. Summary

[0010] 1. First Embodiment (1.1. Schematic configuration of a liquid crystal display device) FIG. 1 is a schematic diagram showing a configuration of a liquid crystal display device 1 according to a first embodiment of the present disclosure.

[0011] The liquid crystal display device 1 according to this embodiment is a transmissive liquid crystal display device, and more specifically, a transmissive projector that includes a liquid crystal panel 11 as a light modulation device. An example of an applicable liquid crystal panel 11 is an HTPS liquid crystal panel (high temperature polysilicon TFT liquid crystal panel).

[0012] The liquid crystal display device 1 is equipped with a light source (not shown), and light emitted from the light source is separated into three primary color lights Lr, Lg, and Lb (e.g., red, green, and blue). After passing through the liquid crystal panel 11, the lights are combined by a dichroic prism 12 and projected onto a screen Sc as image light Lout of a color image via a projection lens 13.

[0013] The emitted light can be separated by a dichroic mirror and a reflecting mirror (not shown). For example, this can be achieved by arranging a first dichroic mirror on the optical path of the emitted light from the light source, which reflects the green light Lg and the blue light Lb and transmits the red light Lr, and by arranging a second dichroic mirror on the optical path of the reflected light from the first dichroic mirror, which reflects the green light Lg and transmits the blue light Lb.

[0014] After being separated, the primary color lights Lr, Lg, and Lb are directed toward the liquid crystal panel 11 by a reflecting mirror or the like, and are optically modulated by the liquid crystal panel 11 in accordance with the image signals for each color before being incident on the dichroic prism 12. In the optical paths of the primary color lights Lr, Lg, and Lb, polarizing plates 14a and 14b are arranged before and after the liquid crystal panel 11.

[0015] The optically modulated primary color lights Lr, Lg, and Lb are combined by the dichroic prism 12. In this embodiment, the dichroic prism 12 is configured by combining four right-angle prisms, and has a cross-shaped dielectric multilayer film that reflects red light Lr and a dielectric multilayer film that reflects blue light Lb formed on its inner surface.

[0016] The light combined by the dichroic prism 12 is magnified by the projection lens 13 and projected onto the screen Sc as image light Lout, thereby displaying a color image on the screen Sc.

[0017] In this embodiment, a cooling system 101 capable of circulating a coolant is provided for the purpose of cooling the liquid crystal panel 11. The cooling system 101 includes, as its main element, a heat exchanger 111 that cools the liquid crystal panel 11 by heat exchange with the coolant. The coolant is a so-called antifreeze liquid, and maintains a viscosity sufficient to ensure sufficient fluidity throughout the entire operating temperature range of the liquid crystal display device 1. Here, in this embodiment, the heat exchanger 111 is disposed on the front side (light incident side) of the liquid crystal panel 11, but the location of the heat exchanger 11 is not limited thereto. The heat exchanger 11 can also be disposed on the rear side (light exit side) of the liquid crystal panel 11, or on both the front and rear sides. In this embodiment, the liquid crystal panel 11 and the heat exchanger 111 of the cooling system 101 are integrally coupled to form a liquid crystal panel module M, and the heat exchanger 111 is disposed between the liquid crystal panel 11 and a polarizing plate 14a provided on its front side.

[0018] (1.2. Overall configuration of the cooling system) FIG. 2A shows an example of the overall configuration of a cooling system 101 of a liquid crystal display device 1 according to this embodiment, and FIG. 2B shows the overall configuration of a cooling system 101 of a liquid crystal display device 1 according to a modified example of this embodiment.

[0019] The cooling system 101 basically includes a heat exchanger 111, a feed pump 112, a radiator 114, and a buffer tank 115. When the degassing filter 113 is included, the cooling system 101 also includes the degassing filter 113, a trap 116, and a vacuum pump 117.

[0020] When the cooling system 101 is in operation, the feed pump 112 is driven. The coolant stored in the buffer tank 115 is pumped up by the feed pump 112 and pressure-fed through the supply pipe toward the heat exchanger 111. If a degassing filter 113 is provided, the vacuum pump 117 is driven as needed. The coolant discharged from the feed pump 112 passes through the degassing filter 113 on its way to the heat exchanger 111, and air bubbles are removed by the degassing filter 113. An example of an applicable degassing filter 113 is the "SEPAREL" (registered trademark) degassing filter module manufactured by DIC Corporation. The degassing filter 113 includes a filter element made of multiple hollow fibers, which are arranged parallel or perpendicular to the flow direction of the coolant. By reducing the pressure inside the hollow fibers with the vacuum pump 117 and flowing the coolant around the hollow fibers, air bubbles contained in the coolant, such as oxygen and nitrogen, can be sucked into the hollow fibers and separated from the coolant. The separated air bubble components can be captured and collected by a trap 116 provided upstream of the vacuum pump 117. During operation of the cooling system 101, it is possible to monitor the air bubbles contained in the coolant, and stop the vacuum pump 117 when the number of bubbles has decreased sufficiently.

[0021] After passing through heat exchanger 111, the coolant is pumped through a discharge pipe toward buffer tank 115 and collected in buffer tank 115 via radiator 114. Radiator 114 dissipates the heat received by the coolant through heat exchange with liquid crystal panel 11 by heat exchange with the air.

[0022] (1.3. LCD panel module configuration) FIG. 3 is a plan view of the liquid crystal panel module M of the liquid crystal display device 1 according to this embodiment, and FIG.

[0023] 5 to 7 are all exploded views of the liquid crystal panel module M, with Fig. 5 showing the flow of cooling liquid in the liquid crystal panel module M using dotted lines, and Fig. 6 showing the liquid crystal panel 11 housed in the panel housing 21 and illustrating the relative relationships of the main components involved in liquid cooling of the liquid crystal panel 11, specifically the front glass 215, rear glass 216, and frame member 217. Furthermore, Fig. 7 shows the exploded view of Fig. 6 as viewed from the rear side of the liquid crystal panel 11 (i.e., the light emission side).

[0024] FIG. 8(a) is a cross-sectional view taken along the line AA shown in FIG. 4, and FIG. 8(b) is an enlarged view of that portion (portion X).

[0025] FIG. 9 is an enlarged plan view of the heat exchanger 111 of the liquid crystal panel module M, and schematically shows the flow path of the cooling water in the heat exchanger 111. As shown in FIG.

[0026] The configuration and basic operation of the liquid crystal display device 1 will be described with reference to FIGS.

[0027] As shown in FIG. 5, the liquid crystal panel module M mainly comprises a liquid crystal panel 11, a panel housing 21, a printed wiring board 31, and various elements related to liquid cooling of the liquid crystal panel 11.

[0028] As already mentioned, the liquid crystal panel 11 functions as a light modulation device.

[0029] The panel housing 21 houses the liquid crystal panel 11 and serves as a frame when the liquid crystal panel 11 is installed in the liquid crystal display device 1. The panel housing 21 has a recessed portion 21a with an opening of a size that allows the primary color light Lr, Lg, and Lb to pass through after passing through the liquid crystal panel 11, in other words, after being modulated by the liquid crystal panel 11, and the liquid crystal panel 11 is housed in this recessed portion 21a. FIG. 6 shows a state in which the liquid crystal panel 11 is housed in the recessed portion 21a. The primary color light Lr, Lg, and Lb pass through the liquid crystal panel 11 from its front surface to its back surface and pass through the liquid crystal panel module M via the opening in the recessed portion 21a.

[0030] The printed wiring board 31 is connected to a terminal portion formed on the liquid crystal panel 11, and applies a liquid crystal operating voltage to the liquid crystal panel 11.

[0031] The liquid crystal panel 11 is cooled by a coolant circulating through the cooling system 101, and the liquid crystal panel module M includes a supply joint (sometimes called a supply manifold) 211 configured to be connectable to a supply-side pipe, and a discharge joint (sometimes called a discharge manifold) 212 configured to be connectable to a discharge-side or return-side pipe. The supply joint 211 includes a connection portion 211a to which a tubular member of the supply pipe is connected, and the discharge joint 212 includes a connection portion 212a to which a tubular member of the discharge pipe is connected. The supply joint 211 constitutes a "first joint" according to this embodiment, and the discharge joint 212 constitutes a "second joint" according to this embodiment.

[0032] Both the supply joint 211 and the discharge joint 212 are positioned away from the panel housing 21, and are connected to a coolant flow path formed in the panel housing 21 via a supply pipe 213 and a discharge pipe 214. The supply pipe 213 constitutes a "first connecting pipe" according to this embodiment, and the discharge pipe 214 constitutes a "second connecting pipe" according to this embodiment.

[0033] As described above, in this embodiment, the supply and discharge of the coolant to the heat exchanger 111 of the liquid crystal panel module M is achieved via the supply joint 211, the supply pipe 213, the discharge joint 212, and the discharge pipe 214. This configuration enables the panel housing 21 to be made thinner, and enables the heat exchanger 111 to be disposed between the polarizing plate 14a and the liquid crystal panel 11.

[0034] In contrast to the liquid crystal panel module main body formed by housing the liquid crystal panel 11 in the panel housing 21, the heat exchange section 111 of the liquid crystal panel module M is formed as an assembly of a front glass 215, a rear glass 216 and a frame member 217, and is arranged on the front side of the liquid crystal panel 11.

[0035] The front glass 215 and the rear glass 216 are both flat, thin, and rectangular, and have a transparency sufficient to sufficiently suppress optical loss when the primary color lights Lr, Lg, and Lb pass through. Fused silica is an example of a material that can be used for the front glass 215 and the rear glass 216. In addition to fused silica, synthetic quartz, glass, and quartz are also examples. Spinel and sapphire are also examples of materials that are expected to have higher thermal conductivity. Spinel and sapphire are particularly suitable materials for the rear glass 216 because they are excellent not only in transparency but also in thermal conductivity.

[0036] In this embodiment, the front glass 215 has an elongated shape with one side longer than the other side perpendicular to it, and the coolant flows in a direction parallel to the one side (i.e., the longitudinal direction). In contrast, the dimension of the rear glass 216 in a direction parallel to the longitudinal direction of the front glass 215 is smaller than the dimension of the front glass 215. The front glass 215 corresponds to a "first transparent member" in this embodiment, and the rear glass 216 corresponds to a "second transparent member" in this embodiment.

[0037] The frame member 217 has an opening with a size that allows the primary color light Lr, Lg, and Lb to be optically modulated by the liquid crystal panel 11 (i.e., before modulation by the liquid crystal panel 11) to pass through, and a front glass 215 and a rear glass 216 are bonded to a frame portion that forms this opening. The front glass 215 is bonded to an end face of the frame portion of the frame member 217 that faces the front surface, and the rear glass 216 is bonded to an end face of the frame portion of the frame member 217 that faces the rear surface. Here, with respect to the frame member 217, the "front surface side" can be rephrased as the side distal to the liquid crystal panel 11, and the "rear surface side" can be rephrased as the side proximal to the liquid crystal panel 11. The frame member 217 corresponds to the "frame member" according to this embodiment. An example of a material that can be used for the frame member 217 is aluminum.

[0038] 6, when the front glass 215 and the rear glass 216 are joined to the frame member 217, a gap Sp is formed between the front glass 215 and the rear glass 216, the gap Sp having a depth corresponding to the thickness of the frame member 217, and this gap Sp forms a flow path for the cooling water in the heat exchanger 111. The cooling water flows through the flow path formed by the gap Sp in a direction parallel to the front surface of the liquid crystal panel 11 (FIG. 5).

[0039] The frame member 217 has an inlet hole h1 for introducing the coolant supplied via the supply joint 211 into the gap Sp, and a discharge hole h2 for discharging the coolant discharged via the discharge joint 212 from the gap Sp. The inlet hole h1 and the discharge hole h2 are both formed to penetrate the frame member 217 in its thickness direction, and form openings in the gap Sp that face in a direction perpendicular to the flow direction of the coolant in the gap Sp.

[0040] 6, frame member 217 has steps in the frame portion located before and after the opening in gap Sp in the direction of coolant flow, making these portions recessed and forming spaces before and after the opening. The spaces formed by the steps, together with the opening, form gap Sp, and form a flow path for the coolant in heat exchanger 111. Inlet hole h1 and outlet hole h2 penetrate the bottom of the steps in the thickness direction of frame member 217.

[0041] As shown in FIG. 9, the spaces before and after the opening formed by the step have an inverse tapered shape, widening from the inlet hole h1 toward the opening, i.e., the effective screen area of the liquid crystal panel 11, and a forward tapered shape, narrowing from the opening toward the outlet hole h2. This encourages the coolant introduced into the gap Sp from the inlet hole h1 to spread across the entire width of the gap Sp, thereby cooling the liquid crystal panel 11 across its entire effective screen area, and encourages the coolant that passes through the opening to flow toward the outlet hole h2, allowing it to be smoothly discharged from the gap Sp. FIG. 9 shows the inverse tapered widened portion t1 before the opening and the forward tapered narrowed portion t2 after the opening. The widened portion t1 corresponds to the "widened portion" in this embodiment.

[0042] The introduction and discharge of the coolant can be made smoother by changing not only the width but also the depth of the flow passages in the widened portion t1 and the narrowed portion t2. For example, the bottom surface of the widened portion t1 can be sloped downward in the flow direction, and the bottom surface of the narrowed portion t2 can be sloped upward in the flow direction.

[0043] The length L of the widened portion t1 can be, for example, a length L in the range of 1 / 3 to 1 / 2 of the width of the opening of the frame member 217, in other words, the width W of the effective screen area of the liquid crystal panel 11 perpendicular to the flow direction of the coolant in the gap Sp. When the length of the widened portion t1 is in this range, it is possible to ensure the distance necessary to encourage the coolant introduced into the gap Sp to spread across the entire width of the gap Sp.

[0044] Continuing to refer to FIG. 9 , in this embodiment, the panel housing 21 is formed with an inlet flow path p1 for the coolant and an outlet flow path p2 for the coolant. The interior of the supply joint 211 is connected to an inlet hole h1 of the frame member 217 via the inlet flow path p1, and the interior of the discharge joint 212 is connected to a discharge hole h2 of the frame member 217 via the outlet flow path p2. FIG. 9 schematically illustrates the positional relationship between the supply pipe 213, the inlet flow path p1, and the inlet hole h1, as well as the positional relationship between the discharge pipe 214, the outlet flow path p2, and the discharge hole h2. The inlet flow path p1 is connected to the interior of the supply joint 211 via the supply pipe 213 on one hand and to the inlet hole h1 on the other hand. The outlet flow path p2 is connected to the interior of the discharge joint 212 via the discharge pipe 214 on the other hand and to the discharge hole h2 on the other hand. The inlet flow path p1 and the outlet flow path p2 can be formed in the panel housing 21 in the form of holes, or can also be formed in the form of grooves.

[0045] In this embodiment, the panel housing 21 and the frame member 217, specifically, the front surface of the frame of the panel housing 21 and the back surface of the frame of the frame member 217, are joined together in a state where they are in contact with each other. After joining, the inlet hole h1 of the frame member 217 is arranged coaxially with the outlet opening of the inlet flow path p1, and the discharge hole h2 of the frame member 217 is arranged coaxially with the inlet opening of the outlet flow path p2. An annular groove is formed on the surface of the frame of the panel housing 21 so as to surround the outlet opening of the inlet flow path p1 all around, and an annular groove is formed so as to surround the inlet opening of the outlet flow path p2 all around, and O-rings 218 and 219 are installed in each groove (FIG. 5). By fastening the frame member 217 to the panel housing 21, the O-rings 218 and 219 are compressed between the frame member 217 and the panel housing 21, thereby liquid-tightly sealing the connection end between the inlet flow path p1 and the introduction hole h1 and liquid-tightly sealing the connection end between the outlet flow path p2 and the discharge hole h2. The frame member 217 is fastened to the panel housing 21 by a fixing member such as a screw, for example. The O-ring 218 provided on the introduction hole h1 side corresponds to the "first sealing member" according to this embodiment, and the O-ring 219 provided on the discharge hole h2 side corresponds to the "second sealing member" according to this embodiment.

[0046] As shown in Fig. 8, after the panel housing 21 and the frame member 217 are joined together, the entire back surface of the rear glass 216 contacts the front surface of the liquid crystal panel 11. Here, the back surface of the rear glass 216 may have an area smaller than that of the front surface of the liquid crystal panel 11, but it preferably has an area sufficient to surround the effective screen area of the front surface of the liquid crystal panel 11 in the planar direction. The effective screen area of the liquid crystal panel 11 refers to the area of the front surface of the liquid crystal panel 11 that substantially contributes to the optical modulation of incident light (in this embodiment, primary color light Lr, Lg, and Lb). The back surface of the rear glass 216 contacts the front surface of the liquid crystal panel 11, and the entire back surface is bonded with an adhesive.

[0047] In this embodiment, after bonding, the surface of the front glass 215, in other words, the distal surface of the front glass 215 facing the optical path, is positioned closer to the liquid crystal panel 11 than the end surface of the frame of the frame member 217 facing the optical path. This makes it possible to protect the front glass 215 from external contact. FIG. 8( b) shows the step between the surface of the front glass 215 and the end surface of the frame of the frame member 217 facing the optical path, as indicated by a dimension D1. On the other hand, the rear surface of the rear glass 216, in other words, the proximal surface of the rear glass 216 facing the opposite side of the optical path, i.e., the liquid crystal panel 11, is positioned closer to the liquid crystal panel 11 than the end surface of the frame of the frame member 217 facing the opposite side of the optical path. This makes it possible to improve adhesion between the rear glass 216 and the liquid crystal panel 11 and improve cooling efficiency when bonding the rear glass 216 and the liquid crystal panel 11. Furthermore, it is possible to suppress the excess adhesive remaining between the rear glass 216 and the liquid crystal panel 11, which not only reduces cooling efficiency but also affects light transmittance. FIG. 8(b) shows the step of the rear surface of the rear glass 216 relative to the end face of the frame member 217 on the opposite side to the optical path, as indicated by dimension D2. The end face of the frame member 217 facing the optical path corresponds to the "first end face" in this embodiment, and the end face facing the opposite side to the optical path corresponds to the "second end face" in this embodiment.

[0048] FIG. 8 also shows a schematic diagram of the terminal portion of the printed wiring board 31, in other words, the connection portion to the liquid crystal panel 11.

[0049] In this embodiment, the terminal portion of the printed wiring board 31 is provided between the inlet hole h1 and the outlet hole h2 in the flow direction of the coolant in the space Sp. The printed wiring board 31 is then drawn out from this terminal portion in a direction perpendicular to the flow direction of the coolant through the supply joint 211, the supply connection pipe 213, the discharge joint 212, and the discharge connection pipe 214. In this way, the drawing direction of the printed wiring board 31 from the terminal portion is perpendicular to the flow direction of the coolant in the space Sp.

[0050] (1.4. Actions and Effects) When attempting to increase the brightness and resolution of liquid crystal display devices, temperature rise in liquid crystal panels can be a problem. The aforementioned Patent Document 1 discloses a technology for liquid crystal panel liquid cooling, which describes bonding a liquid crystal panel and a transparent dustproof glass panel attached to its front side with a sealant while leaving a predetermined gap between them, and forming through-holes in the sealant through which a coolant can flow. However, this technology liquid cools the liquid crystal panel by introducing a coolant into the gap formed between the liquid crystal panel and the dustproof glass through the through-holes in the sealant, i.e., through missing portions of the sealant, and circulating the coolant through this gap. However, since this technology removes a portion of the sealant that should be present, there are concerns about the impact on sealing. Furthermore, ensuring sufficient sealing with such a configuration unavoidably requires an increased size of the structure, making it impossible to incorporate into conventional liquid crystal display devices.

[0051] In contrast, in this embodiment, a frame member 217 having an opening that exposes the effective screen area of the liquid crystal panel 11 is attached to the front side of the liquid crystal panel 11 to the panel housing 21 that houses the liquid crystal panel 11, and the frame member 217 holds the front glass 215 in a state where it covers the front of the liquid crystal panel 11 and is spaced a predetermined distance from the liquid crystal panel 11, forming a gap Sp between the liquid crystal panel 11 and the front glass 215, through which the coolant can flow along the front surface of the liquid crystal panel 11. Furthermore, an inlet path and an outlet path for the coolant are formed that penetrate the panel housing 21 and the frame member 217 and connect to the gap Sp, and the coolant is circulated in the gap Sp via the inlet path and the outlet path.

[0052] This makes it possible to effectively suppress the temperature rise of the liquid crystal panel 11 through liquid cooling, and to maintain the liquid crystal panel 11 at a temperature below its operating limit temperature, thereby achieving even higher brightness and resolution for the liquid crystal panel 11 and the liquid crystal display device 1, and enabling the formation of brighter, more precise images.

[0053] In this embodiment, the inlet path for the coolant is formed by the inlet flow path p1 of the panel housing 21 and the inlet hole h1 of the frame member 217, and the outlet path for the coolant is formed by the outlet flow path p2 of the panel housing 21 and the outlet hole h2 of the frame member 217. This makes it possible to circulate the coolant in the liquid crystal panel module M without using flow path members such as pipes. This allows the heat exchanger 111 to be configured thin and compact, reducing the volume required for installing the heat exchanger 111 and making it possible to incorporate the heat exchanger 111 into the relatively narrow space between the liquid crystal panel 11 and the polarizing plate 14a, which has little room to spare. This contributes to making the entire liquid crystal panel module M thinner and more compact.

[0054] Furthermore, by adopting a rear glass 216 in addition to the front glass 215 and forming a gap Sp between the front glass 215 and the rear glass 216, which serves as a flow path for the coolant, it is possible to easily ensure the liquid-tightness of the heat exchanger 111, thereby increasing the reliability of the heat exchanger 111 or the liquid crystal panel module M and reducing the introduction cost.

[0055] 9, in this embodiment, the open ends of the inlet hole h1 and the outlet hole h2 are each oriented perpendicular to the direction of coolant flow in the gap Sp, and the flow path from the inlet hole h1 through the opening to the outlet hole h2 is formed linearly along the longitudinal direction of the front glass 215. This allows the coolant to flow smoothly throughout the entire gap Sp and prevents the coolant flow from stagnating. This makes it possible to prevent temperature unevenness and the like from occurring in the coolant flowing through the gap Sp, which could result in deterioration of the image on the screen Sc (for example, uneven brightness in the image).

[0056] In this embodiment, the widened portion t1 and the narrowed portion t2 are formed before and after the opening in the flow direction of the coolant, which allows the flow of the coolant introduced into the gap Sp to be smoothly widened and then smoothly narrowed after passing through the opening. This allows the coolant to be introduced into and discharged from the gap Sp more smoothly and more effectively prevents the coolant flow from stagnating.

[0057] FIG. 10 is an explanatory diagram showing a state in which the coolant flows into the gap Sp1 (liquid crystal panel 11) from above and flows out to the upper side, as a first comparative example of this embodiment.

[0058] In the first comparative example, the flow direction of the coolant from the inlet hole h11 toward the opening and the flow direction from the opening toward the outlet hole h2 are both perpendicular to the flow direction of the coolant at the opening, i.e., the effective flow direction in the gap Sp1. The flow path from the inlet hole h11 through the opening to the outlet hole h21 is not linear. This causes the flow of the coolant in the gap Sp to become uneven around the opening, which tends to cause the flow to stagnate in the region R1 near the bottom edge. Flow stagnation not only causes temperature unevenness but also causes air bubbles in the coolant to concentrate and stagnate, significantly affecting image quality.

[0059] In this embodiment, a widened portion t1 is formed following the opening, and the length L of this widened portion t1 is set to a length L in the range of 1 / 3 to 1 / 2 of the width W of the opening of the frame member 217, thereby ensuring the distance necessary for the flow of cooling liquid to expand from the introduction hole h1 to the opening, and making it possible to more effectively prevent stagnation of the flow of cooling liquid.

[0060] FIG. 11 is an explanatory diagram showing a state in which the distance from the introduction hole h12 to the opening is relatively short, as a second comparative example for this embodiment.

[0061] In the second comparative example, the distance from the introduction hole h1 to the opening is short, and the flow of coolant reaches the opening before it has sufficiently expanded, so the flow of coolant tends to stagnate in the region R2 near the boundary between the widened portion t11 and the opening.

[0062] 2. Second Embodiment FIG. 12 is an exploded view of a liquid crystal panel module M' of a liquid crystal display device 1 according to a second embodiment of the present disclosure, showing the relative relationship between a front glass 215 and a frame member 217 for liquid cooling of the liquid crystal panel 11.

[0063] In the first embodiment described above, in addition to the front glass 215, a rear glass 216 is used as a member for closing the opening of the frame member 217, and the opening of the frame member 217 is closed from both the front side or the optical path side and the opposite side, thereby forming a gap Sp.

[0064] In contrast, in this embodiment, of the two front and rear glass sheets 215, 216, the rear glass sheet 216 is removed, and a gap that serves as a flow path for the coolant is formed between the liquid crystal panel 11 and the front glass sheet 215. The opening of the frame member 217 is then blocked from the front side by the front glass sheet 215, while on the opposite rear side, the opening of the frame member 217 is blocked from the rear side by the liquid crystal panel 11.

[0065] According to this embodiment, by eliminating the rear glass 216, it is possible to realize the liquid crystal panel module M' and its heat exchanger with fewer parts, which is advantageous mainly in terms of introduction cost. Furthermore, by eliminating the rear glass 216, thermal resistance is reduced, and the cooling capacity of the liquid crystal panel 11 is also improved.

[0066] <3. Summary> The embodiments of the present disclosure have been described above in detail with reference to the drawings. According to the embodiments of the present disclosure, it is possible to effectively suppress a rise in temperature of a liquid crystal panel, achieve even higher brightness and resolution in the liquid crystal panel and the liquid crystal display device, and form brighter and more precise images.

[0067] The technology of the present disclosure is not limited to the above specific embodiments, and various modifications are possible, and combinations of the modifications are also possible.

[0068] Furthermore, not all of the configurations and operations described in each embodiment are necessarily essential to the configurations and operations of the present disclosure. For example, among the components in each embodiment, any component that is not recited in an independent claim that represents the highest concept of the present disclosure is understood to be an optional component.

[0069] Terms used throughout this specification and the appended claims should be interpreted as "open-ended" terms. For example, the terms "including" or "including" should be interpreted as "limited to the aspects described as including," and the term "having" should be interpreted as "limited to the aspects described as having."

[0070] The terms used in this specification are used merely for the convenience of description and are not intended to limit the configuration, operation, etc. For example, terms such as "right," "left," "upper," and "lower" merely indicate directions in the drawings to which reference should be made. Furthermore, terms such as "inner" and "outer" indicate directions toward and away from the center of a focused element, respectively. The same applies to terms similar to or having the same meaning as these terms.

[0071] The technology of the present disclosure may have the following configuration. According to the technology of the present disclosure having the following configuration, it is possible to effectively suppress temperature rise in the liquid crystal panel, achieve even higher brightness and resolution in the display device, and form brighter, more precise images. It is also possible to achieve an effect of extending the life of the liquid crystal panel. The effects achieved by the technology of the present disclosure are not necessarily limited to these, and may be any of the effects described in this specification. (1) A liquid crystal display device comprising: a liquid crystal panel; a panel housing configured to accommodate the liquid crystal panel; a first transparent member arranged on the front side of the liquid crystal panel; and a frame member that holds the first transparent member and is configured to be attachable to the panel housing, the frame member determining the distance between the liquid crystal panel and the first transparent member and forming a gap between the liquid crystal panel and the first transparent member through which a coolant can flow along the front side of the liquid crystal panel; the panel housing having an inlet flow path for the coolant formed in a first part of the panel housing and an outlet flow path for the coolant formed in a second part of the panel housing excluding the first part; and the frame member having an introduction hole connected at one end to the inlet flow path and connecting the inlet flow path to the gap, and an exhaust hole connected at one end to the outlet flow path and connecting the outlet flow path to the gap. (2) The liquid crystal display device of (1) above further comprises a second transparent member disposed between the liquid crystal panel and the first transparent member, and the frame member is configured to be able to hold the first transparent member and the second transparent member spaced apart from each other, forming a gap between the first and second transparent members. (3) The liquid crystal display device according to (2) above, wherein the second transparent member and the liquid crystal panel are bonded together over the entire rear surface of the second transparent member. (4) The liquid crystal display device of (2) or (3) above, wherein the first transparent member has a dimension in the direction of flow of the cooling liquid in the gap that is larger than that of the second transparent member. (5) The first transparent member has a surface facing the same direction as the front surface of the liquid crystal panel and a back surface on the opposite side, and the surface of the first transparent member is connected to the first transparent member of the frame member facing the same direction as the surface of the first transparent member. The liquid crystal display device is any one of the above (2) to (4), which is provided at a position closer to the liquid crystal panel than the end face. (6) The liquid crystal display device of any one of (2) to (5) above, wherein the second transparent member has a surface facing the same direction as the front surface of the liquid crystal panel and a back surface on the opposite side, and the surface of the second transparent member is located closer to the liquid crystal panel than the second end face of the frame member facing the same direction as the surface of the second transparent member. (7) The liquid crystal display device according to any one of (1) to (6) above, wherein the introduction hole has an open end closer to the gap oriented in a direction perpendicular to the flow direction of the cooling liquid in the gap. (8) The liquid crystal display device according to any one of (1) to (7) above, wherein the discharge hole has an open end closer to the gap oriented in a direction perpendicular to the direction of flow of the cooling liquid in the gap. (9) A liquid crystal display device according to any one of (1) to (8) above, wherein the panel housing and the frame member are joined together in a state in which the inlet flow path and the introduction hole are directly connected and the discharge hole and the outlet flow path are directly connected, and further comprising a first sealing member that surrounds the connection end between the inlet flow path and the introduction hole all around, and a second sealing member that surrounds the connection end between the discharge hole and the outlet flow path all around. (10) A liquid crystal display device according to any one of (1) to (9) above, having a widening portion formed between the open end of the introduction hole and a first edge of the liquid crystal panel that is closest to the open end in the flow direction of the cooling liquid in the gap, so as to gradually widen the width of the flow path of the cooling liquid. (11) The liquid crystal display device of (10) above, wherein the length of the widened portion in the direction of flow of the coolant is 1 / 3 to 1 / 2 of the width of the front surface of the liquid crystal panel perpendicular to the direction of flow. (12) A liquid crystal display device according to any one of (1) to (11) above, further comprising a first joint, a second joint, a first connecting pipe connected between the first joint and the panel housing and connecting the inside of the first joint to the inlet flow path, and a second connecting pipe connected between the second joint and the panel housing and connecting the inside of the second joint to the outlet flow path, wherein the first and second joints are each positioned away from the panel housing. (13) The liquid crystal display device according to any one of (1) to (12) above, further comprising a degassing filter configured to be able to remove air bubbles contained in the cooling liquid. (14) A liquid crystal display device according to any one of (1) to (13) above, wherein the liquid crystal panel is a transmissive type, the front surface of the liquid crystal panel faces the incident side of light from the light source, and an air gap is disposed between the light source and the liquid crystal panel in the optical path from the light source.

[0072] This application claims priority based on Japanese Patent Application No. 2020-145696, filed on August 31, 2020, in the Japan Patent Office, the entire contents of which are incorporated herein by reference.

[0073] Those skilled in the art will recognize that various modifications, combinations, subcombinations, and variations may occur depending on design requirements and other factors, and are intended to be within the scope of the appended claims and their equivalents.

Claims

1. An LCD panel, a panel housing configured to accommodate the liquid crystal panel; a first transparent member disposed on the front side of the liquid crystal panel; a frame member that holds the first transparent member and is configured to be attachable to the panel housing, that determines a distance between the liquid crystal panel and the first transparent member, and that forms a gap between the liquid crystal panel and the first transparent member through which a coolant can flow along the front surface of the liquid crystal panel; Equipped with The panel housing includes: an inlet flow passage for the cooling liquid formed in a first portion of the panel housing; an outlet flow path for the cooling liquid formed in a second portion of the panel housing excluding the first portion; and The frame member is an introduction hole connected at one end to the inlet flow path and communicating the inlet flow path with the gap; a discharge hole connected at one end to the outlet flow path and communicating the outlet flow path with the gap; and an open end of the introduction hole that is closer to the gap faces a direction perpendicular to a flow direction of the cooling liquid in the gap; LCD display device.

2. A liquid crystal panel; a panel housing configured to accommodate the liquid crystal panel; a first transparent member disposed on the front side of the liquid crystal panel; a frame member that holds the first transparent member and is configured to be attachable to the panel housing, that determines a distance between the liquid crystal panel and the first transparent member, and that forms a gap between the liquid crystal panel and the first transparent member through which a coolant can flow along the front surface of the liquid crystal panel; Equipped with The panel housing includes: an inlet flow passage for the cooling liquid formed in a first portion of the panel housing; an outlet flow path for the cooling liquid formed in a second portion of the panel housing excluding the first portion; and The frame member is an introduction hole connected at one end to the inlet flow path and communicating the inlet flow path with the gap; a discharge hole connected at one end to the outlet flow path and communicating the outlet flow path with the gap; and The discharge hole has an open end close to the gap oriented in a direction perpendicular to the flow direction of the cooling liquid in the gap. LCD display device.

3. a second transparent member disposed between the liquid crystal panel and the first transparent member; the frame member holds the first transparent member and the second transparent member spaced apart from each other to form the gap between the first and second transparent members; 3. The liquid crystal display device according to claim 1.

4. the second transparent member and the liquid crystal panel are bonded to each other over the entire back surface of the second transparent member; The liquid crystal display device according to claim 3 .

5. the first transparent member has a larger dimension in the flow direction of the cooling liquid in the gap than the second transparent member; The liquid crystal display device according to claim 3 .

6. the first transparent member has a front surface facing the same direction as the front surface of the liquid crystal panel and a back surface on the opposite side; a surface of the first transparent member is provided at a position closer to the liquid crystal panel than a first end face of the frame member that faces the same direction as the surface; The liquid crystal display device according to claim 3 .

7. the second transparent member has a front surface facing the same direction as the front surface of the liquid crystal panel and a back surface on the opposite side; a surface of the second transparent member is provided at a position closer to the liquid crystal panel than a second end face of the frame member that faces the same direction as the surface; The liquid crystal display device according to claim 3 .

8. the panel housing and the frame member are joined to each other in a state in which the inlet flow path and the introduction hole are directly connected and the discharge hole and the outlet flow path are directly connected, a first sealing member that surrounds the entire periphery of a connection end between the inlet flow channel and the introduction hole; a second sealing member surrounding the entire periphery of the connection end between the discharge hole and the outlet flow path, 3. The liquid crystal display device according to claim 1.

9. a widening portion formed between an open end of the introduction hole and a first edge of the liquid crystal panel that is close to the open end in a flow direction of the cooling liquid in the gap so as to gradually widen a width of the flow path of the cooling liquid; 3. The liquid crystal display device according to claim 1.

10. a length of the widened portion in the flow direction of the cooling liquid is 1 / 3 to 1 / 2 of a width of a front surface of the liquid crystal panel perpendicular to the flow direction; The liquid crystal display device according to claim 9 .

11. A first joint; A second joint; and a first connecting pipe connected between the first joint and the panel housing, and connecting the inside of the first joint to the inlet flow path; a second connecting pipe connected between the second joint and the panel housing, and connecting the inside of the second joint to the outlet flow path; Furthermore, the first and second joints are each positioned away from the panel housing; 3. The liquid crystal display device according to claim 1.

12. The cooling system further includes a degassing filter configured to remove air bubbles contained in the cooling liquid.

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

13. the liquid crystal panel is a transmissive type, the front surface of the liquid crystal panel faces the side on which light from a light source is incident, the gap is disposed between the light source and the liquid crystal panel in a light path from the light source; 3. The liquid crystal display device according to claim 1.

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