JP5167800B2 - Prism sheet - Google Patents

Description

  The present invention relates to a prism sheet.

A prism sheet in which a plurality of convex prism portions extending over the entire length between two opposing edges of the sheet-like member are formed in parallel with each other on one surface of the transparent sheet-like member is, for example, a liquid crystal display element It is used as an optical element for making incident light from a surface light source arranged on the side opposite to the observation side incident on the liquid crystal display element in a predetermined direction (see Patent Document 1).
JP 2003-100126 A

  The prism sheet is mounted between the liquid crystal display element and the surface light source, for example, with the edge of the prism sheet supported by a prism sheet support, and a liquid material adheres to the prism sheet support. The liquid enters the valley portion between the adjacent prism portions from the open end, and further flows along the valley portion, so that the light emitted from the prism portion becomes non-uniform. There was a problem.

  The present invention can prevent the flow of liquid material that enters the valley-shaped portion between the plurality of prism portions from its open end along the valley-shaped portion, and maintains the uniformity of the light emitted from the prism portion. An object of the present invention is to provide a prism sheet that can be used.

In the prism sheet according to claim 1 of the present invention, a plurality of convex prism portions extending over the entire length between two opposing edges of the sheet-like member are arranged on at least one surface of the transparent sheet-like member. The prism portions adjacent to the two edge regions on both end sides of the plurality of prism portions, of the edge regions having a predetermined width along the periphery of the sheet-like member, are formed in parallel. A flow stop portion is formed to prevent the flow of liquid material entering the valley portion between the open ends along the valley portion, and the flow stop portion crosses the plurality of prism portions. characterized isosamples consist deeply formed antirunning groove than trough portion along.

According to a second aspect of the present invention, in the prism sheet according to the first aspect of the present invention, protrusions supported by the prism sheet support portion are formed on the two end edges of the plurality of prism portions, respectively. cage, said flow preventing portion is characterized in that it is formed in a portion corresponding to at least the protruding portion.

According to a third aspect of the present invention, in the prism sheet according to the first or second aspect , the flow stop portion is formed over substantially the entire length of two edge regions on both end sides of the plurality of prism portions. It is characterized by that.

According to a fourth aspect of the present invention, in the prism sheet according to the first or third aspect of the present invention, receiving portions for the liquid material that has flowed along the flow stop groove are formed at both ends of the flow stop groove, respectively. It is characterized by being.

Invention according to claim 5, in the prism sheet according to claim 5, wherein the flow stop groove is formed over substantially the entire length of the two edge regions of the both ends of the plurality of prism portions, wherein The liquid material receiving portion is connected to the other two edge regions in parallel to the length direction of the plurality of prism portions, and both ends thereof are communicated with the flow stop grooves on both ends of the plurality of prism portions, respectively. It is characterized by comprising a liquid material receiving groove formed.

The invention according to claim 6 is the prism sheet according to any one of claims 1 to 3, wherein the flow stop portion is provided in the two edge regions on both end sides of the plurality of prism portions. The prisms are formed in a plurality of stages at intervals in the length direction.

  According to the prism sheet of the present invention, it is possible to prevent the flow of the liquid material entering the valley-shaped portion between the plurality of prism portions from the open end along the valley-shaped portion, and uniformity of the light emitted from the prism portion Can be maintained.

(First embodiment)
1 to 5 show a first embodiment of the present invention, and FIG. 1 is a sectional view of a liquid crystal display module provided with a prism sheet.

  The liquid crystal display module includes a housing 1, a liquid crystal display element 6 disposed in the housing 1, and a surface of the housing 1 opposite to the observation side (upper side in FIG. 1) of the liquid crystal display element 6. A surface light source 15 that is disposed so as to irradiate illumination light toward the liquid crystal display element 6 and for irradiating the light emitted from the surface light source 15 to the liquid crystal display element 6 in a predetermined direction. And two prism sheets 22 and 25 disposed to overlap each other between the surface light source 15 and the liquid crystal display element 6.

  The housing 1 includes a rectangular frame-shaped housing main body 2 made of a resin molded product, and a bottom plate 5 made of a metal plate that closes an opening surface on the opposite side of the observation side of the housing main body 2. A shelf-like display element support 3 for supporting the peripheral edge of the liquid crystal display element 6 from the opposite side to the observation side, and the two prism sheets 22 and 25 on the inner peripheral surface of the housing body 2. A groove-shaped prism sheet support portion 4 for supporting the peripheral edge portion is formed.

  The liquid crystal display element 6 is disposed opposite to each other with a predetermined gap, and is connected to the observation side and the opposite side joined via a frame-shaped sealing material 9 surrounding a region corresponding to a screen area (not shown). A pair of transparent substrates 7 and 8, a liquid crystal layer 10 enclosed in a region surrounded by the sealing material 9 in a gap between the substrates 7 and 8, and an outer surface of the pair of substrates 7 and 8, respectively. And a pair of polarizing plates 11 and 12 on the opposite side.

  The liquid crystal display element 6 is an active matrix liquid crystal display element using, for example, a TFT (thin film transistor) as an active element. Although omitted in FIG. 1, one of inner surfaces of the pair of substrates 7 and 8 facing each other, for example, A plurality of transparent pixel electrodes arranged in a matrix form on the inner surface of the substrate 8 on the opposite side of the observation side, and arranged corresponding to these pixel electrodes, respectively, and connected to the corresponding pixel electrodes A plurality of TFTs, a plurality of scanning lines for supplying gate signals to the TFTs in each row, and a plurality of signal lines for supplying data signals to the TFTs in each column are provided. A single transparent electrode facing the pixel electrode array region is provided.

  Although not shown in the figure, the inner surface of the observation-side substrate 7 has red, green, blue corresponding to a plurality of pixels each having a region in which the plurality of pixel electrodes and the counter electrode face each other. These three color filters are provided, and the counter electrode is formed on the color filter. An alignment film is provided on the inner surfaces of the pair of substrates 7 and 8 so as to cover the electrodes, and the liquid crystal molecules of the liquid crystal layer 10 are interposed between the pair of substrates 7 and 8 by the alignment film. It is oriented in the defined orientation state.

  A driver mounting portion 7a is formed on the opposite substrate 8 so as to project outward from the observation side substrate 7. The plurality of scanning lines and signal lines are mounted on the driver mounting portion 7a. Connected to the display driver 13, the counter electrode is connected to the counter electrode via a cross connection portion (not shown) provided at a substrate bonding portion by the sealing material 9 and a counter electrode connection line (not shown) formed on the driver mounting portion 7 a. Connected to a potential source.

  The liquid crystal display element 6 is disposed in the housing 1 with the peripheral edge of the liquid crystal display element 6 placed on the display element support 3, and the peripheral edge of the liquid crystal display element 6 is viewed from the observation side. The pressing member 14 is fixed.

  The surface light source 15 is made of a rectangular plate-shaped transparent member having an area larger than the screen area of the liquid crystal display element 6, and an incident surface 17 through which light is incident is formed on one end surface thereof. The light exit surface 18 of the light incident from the incident surface 17 is formed on one of them, and the reflective film 19 that reflects the light incident from the incident surface 17 toward the light exit surface 18 is provided on the other plate surface. A plurality of light emitting elements 20 including LEDs (light emitting diodes) or the like that are arranged to face the incident surface 17 of the light guide plate 16 and emit light toward the incident surface 17 of the light guide plate 16; The diffusion layer 21 is formed on the emission surface 18 of the light guide plate 16.

  The surface light source 15 is disposed in the housing 1 with the light exit surface 18 of the light guide plate 16 facing the liquid crystal display element 6, and the opposite surface of the light guide plate 16 (the outer surface of the reflective film 19) is the housing. 1 is supported on the bottom plate 5.

  The surface light source 15 guides light emitted from the plurality of light emitting elements 20 by the light guide plate 16 and irradiates the light emitting surface 18 toward the liquid crystal display element 6. Light enters the light guide plate 16 from its incident surface 17, is guided through the light guide plate 16, is reflected by the reflection film 19, exits from the entire exit surface 18, and is diffused by the diffusion layer 21. The light is emitted to the liquid crystal display element 6 side.

  Each of the two prism sheets 22 and 25 is one of transparent sheet-like members 23 and 26 made of acrylic resin or the like formed in a rectangular plate shape having an area larger than the screen area of the liquid crystal display element 6. A plurality of ridge-shaped prism portions 24 and 27 are formed in parallel with each other at a pitch smaller than the arrangement pitch of the pixels of the liquid crystal display element 6 over the entire area. The plurality of prism portions 24 of the first prism sheet 22 arranged on the side facing the surface light source 15 among the light guide plates 22 and 25 are guided in the light guide direction of the light guide plate 16 of the surface light source (opposite side from the incident end surface 17). Of the second prism sheet 25 formed on the side facing the liquid crystal display element 6 and formed in a convex shape along a direction substantially perpendicular to the direction toward the end surface of the liquid crystal display element 6. The prism portion 27 of the light guide plate 16 extends along a direction substantially parallel to the light guide direction of the light guide plate 16 (a direction substantially perpendicular to the length direction of the plurality of prism portions 24 of the first prism sheet 22). It is formed in a ridge shape.

  FIG. 2 is a plan view of the first prism sheet 22, and a plurality of prism portions 24 of the prism sheet 22 are arranged on the surface opposite to the surface facing the surface light source 15 of the sheet-like member 23. 2 between the two edges facing each other in the direction substantially perpendicular to the light guide direction (left-right direction in FIG. 2) of the light guide plate 16 in the periphery of the shaped member 23, that is, the incident surface 17 of the light guide plate 16. It is formed over the entire length between two edges corresponding to the side and the opposite side.

  Further, the first prism sheet 22 has two other edges of the periphery of the sheet-like member 23, that is, a plurality of positions of two edges parallel to the length direction of the plurality of prism portions 24, For example, it has the protrusion part 23a formed in two places, respectively, The said some prism part 24 is formed in the said protrusion part 23a in parallel with the prism part 24 of another area | region.

  3 and 4 are a plan view of the second prism sheet 25 and an enlarged perspective view of a part thereof. The plurality of prism portions 27 of the prism sheet 25 are connected to the liquid crystal display element 6 of the sheet-like member 26. FIG. It is formed on the opposite surface over the entire length between two edges facing each other in the direction substantially parallel to the light guide direction (left and right direction in FIG. 3) of the light guide plate 16 in the periphery of the sheet-like member 26. ing.

  Further, the second prism sheet 25 is provided at a plurality of, for example, two locations on two end edges of the plurality of prism portions 27 in the periphery of the sheet-like member 26. Each of the prism portions 27 in the region corresponding to the protrusion portion 26a among the plurality of prism portions 27 is provided with the protrusion portion 26a. It is formed to extend to the end edge.

  Further, the second prism sheet 25 has an area outside the area corresponding to the screen area of the liquid crystal display element 6, that is, an edge area having a predetermined width along the periphery of the sheet-like member 26. Among the plurality of prism portions 27, the liquid-like valley portions 28 that enter the valley portions 28 between the adjacent prism portions 27, 27 from the open ends thereof, respectively. A flow stop portion 29 is formed to prevent the flow along.

  The flow stop portion 29 is formed of a flow stop groove formed deeper than the valley-shaped portion 28 along a direction crossing the plurality of prism portions 27, and this flow stop portion (hereinafter referred to as a flow stop groove). 29 is formed at least in a portion corresponding to the protruding portion 26a. In this embodiment, the flow stop groove 29 is formed over substantially the entire length of the two edge regions on both ends of the plurality of prism portions 27.

  Further, receiving portions 30 for the liquid material flowing along the flow stop groove 29 are formed at both ends of the flow stop groove 29, respectively. The liquid material receiving portion 30 is provided in the other two edge regions (edge regions orthogonal to the edge region where the flow stop grooves 29 are formed) in the length direction of the plurality of prism portions 27, respectively. The liquid material receiving grooves are formed in parallel with both ends communicating with the flow stop grooves 29 and 29 on both ends of the plurality of prism portions 27, respectively.

  The liquid material receiving portion (hereinafter referred to as a liquid material receiving groove) 30 is formed in the other two edge regions, respectively, at the same depth as or deeper than the flow stop groove 29, The flow stop grooves 29 and 29 on both ends of the plurality of prism portions 27 are respectively formed over the entire length between the liquid material receiving grooves 30 and 30 in the other two edge regions.

  The first and second prism sheets 22 and 25 are overlapped with each other as shown in FIG. 1, and the protruding portions 23 a and 26 a formed on the prism sheets 22 and 25 are arranged inside the housing body 2. By being inserted into a groove-like prism sheet support portion 4 formed on the peripheral surface, the prism sheet support portion 4 supports the prism sheet support portion 4.

  The first and second prism sheets 22 and 25 have a predetermined direction, for example, light emitted from the surface light source 15 (light emitted from the emission surface 18 of the light guide plate 16 and diffused by the diffusion layer 21). The first prism sheet 22 is arranged to enter the liquid crystal display element 6 in a front direction (a direction near the normal line of the liquid crystal display element 6). Irradiation light directed in a direction parallel to the light guide direction of the light guide plate 16, that is, in a direction perpendicular to the length direction of the plurality of prism portions 24 of the first prism sheet 22 is the front direction. The second prism sheet 25 is refracted and emitted, and the second prism sheet 25 is a direction orthogonal to the light guide direction of the light guide plate 16 in the irradiation light from the surface light source 15, that is, the second prism sheet 25. Multiple processes The irradiation light directed in a direction along the direction perpendicular to the length direction of the prism portion 27 is refracted into the front direction and emitted.

  By the way, the plurality of prism portions 27 of the second prism sheet 25 of the first and second prism sheets 22 and 25 are two in which protrusions 26a supported by the prism sheet support portion 4 are formed. Each of the prism portions 27 in the region corresponding to the protruding portion 26a of these prism portions 27 is extended to the end edge of the protruding portion 26a. If a liquid material such as oil such as a mold release agent applied to the molding die of the housing body 2 or a residue such as moisture at the time of cleaning adheres to the prism sheet support portion 4, for example, An object enters from the open end into the valley portion 28 between the prism portions 27 and 27 adjacent to each other in the region corresponding to the protruding portion 26a.

  However, since the second prism sheet 25 is formed with flow stop grooves 29 in two edge regions on both ends of the plurality of prism portions 27, a valley between the adjacent prism portions 27 and 27 is formed. It is possible to prevent the liquid material that has entered the shape portion 28 from its open end from flowing along the valley portion 28 and maintain the refractive characteristics and transmittance of the prism portion 27.

  FIG. 5 is an enlarged plan view of a portion of the second prism sheet 25 supported by the prism sheet support 4, and FIG. 6 shows the prism sheet support of the prism sheet 25 ′ of the comparative example that does not have the flow stop groove 29. FIG. 6 is an enlarged plan view of a portion supported by part 4.

  As shown in FIG. 6, in the prism sheet 25 ′ of the comparative example, when the liquid material 32 is adhered in the prism sheet support portion 4 of the housing body 2, the liquid material 32 is adjacent to the prism portions 27 and 27. It enters the valley portion 28 between the open ends, and further flows along the valley portion 28 to enter the region corresponding to the screen area of the liquid crystal display element 6, and the refraction of the prism portion 27 in that region. Affects properties and transmittance.

  Therefore, in the display module including the prism sheet 25 ′ according to the comparative example, the intensity of the emitted light in the portion corresponding to the area where the liquid material 32 of the prism sheet 25 ′ enters the screen area of the liquid crystal display element 6 is changed. Unlike other parts, it becomes non-uniform and a display defect occurs.

  On the other hand, as shown in FIG. 5, the second prism sheet 25 of the embodiment has a valley-like portion between the prism portions 27 and 27 extended to the protruding portion 26a supported by the prism sheet support portion 4. Even if the liquid material 32 enters the opening 28 from the open end, the liquid material 32 is prevented from further flowing along the valley-shaped portion 28 by the flow stop groove 29, Since it flows along the length direction, it is possible to maintain the refractive characteristics and transmittance of the inner portion of the prism portion 27 with respect to the flow stop groove 29.

  In addition, since the second prism sheet 25 has the flow stop groove 29 formed over substantially the entire length of the two edge regions on both ends of the plurality of prism portions 27, the prism portions 27, 27 are formed. Most of the liquid material 32 that has entered the valley portion 28 between the open ends flows in the length direction of the flow-preventing groove 29, and the liquid material 32 overflows from the flow-preventing groove 29 and flows into the flow-preventing groove. It is possible to prevent entry into the valley 28 inside 29.

  Further, since the second prism sheet 25 has receiving grooves 30 for the liquid material flowing along the flow stop grooves 29 at both ends of the flow stop grooves 29, the flow stop grooves 29 are formed. It is possible to more effectively prevent the liquid material 32 from overflowing.

  Further, the second prism sheet 25 includes the plurality of prism portions 27 in the liquid material receiving groove 30 in two edge regions orthogonal to the edge region where the flow stop groove 29 is formed. The both ends of the plurality of prism portions 27 are connected to the flow stop grooves 29, 29 in parallel with each other in the longitudinal direction of the plurality of prism portions 27. However, even if the amount of the liquid material 32 is large, the liquid material 32 can be received with a margin.

(Second Embodiment)
7 and 8 are a plan view of a second prism sheet showing a second embodiment of the present invention and an enlarged perspective view of a part thereof.

  This prism sheet 25 a is formed by forming flow stop portions in a plurality of stages at intervals in the length direction of the plurality of prism portions 27 in two edge regions on both ends of the plurality of prism portions 27. In this embodiment, two flow stop portions 29a and 29b are formed in two edge regions at intervals in the length direction of the plurality of prism portions 27, and the other two edge regions. Two liquid material receiving grooves 30a and 30b respectively communicating with the two flow stop portions 29a and 29b are formed therein.

  This prism sheet 25a forms flow stop portions 29a and 29b in a plurality of stages at intervals in the length direction of the plurality of prism portions 27 in two edge regions on both ends of the plurality of prism portions 27. Therefore, the valley-shaped portion 28 of the liquid material 32 entering from the open end into the valley-shaped portion 28 between the prism portions 27, 27 extended to the protruding portion 26 a supported by the prism sheet support portion 4. Can be more effectively prevented.

(Third embodiment)
FIG. 9 is an enlarged perspective view of a part of a second prism sheet showing a third embodiment of the present invention. This prism sheet 25b is located in two edge regions on both end sides of the plurality of prism portions 27. FIG. In each of the edge regions, a flow stop portion 31 made of a dam that closes the valley portion 28 is formed over substantially the entire length, and the other configuration is the same as that of the prism sheet 25 of the first embodiment. It is.

  In the prism sheet 25b of this embodiment, the flow stop portion 31 (hereinafter referred to as a flow stop dike) 31 made of the dam has two ends perpendicular to the edge region where the flow stop groove 29 is formed. Each of the edge portions is formed to have a length located at the center portion in the width direction, and to a height at which the top portion of the flow blocking levee 31 is flush with the top portions of the plurality of prism portions 27.

  In the prism sheet 25b, the flow barrier 31 is formed in each of the two edge regions on both ends of the plurality of prism portions 27. Therefore, the prism sheet 25b is formed in the valley portion 28 between the adjacent prism portions 27 and 27. The liquid material that has entered from the open end can be prevented from flowing along the valley portion 28, and the refractive characteristics and transmittance of the prism portion 27 can be maintained.

  In the prism sheet 25b of this embodiment, the flow breaker 31 may be formed over the entire length of the edge region in which the flow stop groove 29 is formed. May be formed at a height protruding from the top of the plurality of prism portions 27.

  Further, in the prism sheet 25b of this embodiment, the flow barrier 31 is spaced in the length direction of the plurality of prism portions 27 in the two edge regions on both ends of the plurality of prism portions 27. It may be formed in a plurality of stages. By doing so, it is possible to more effectively prevent the flow of liquid 32 entering the valley 28 from the open end thereof along the valley 28. it can.

(Other embodiments)
The prism sheets 25, 25 a, 25 b of the above-described embodiments are configured so that the flow stop grooves 29, 29 a, 29 b or the flow stop ridges 31 are respectively in two edge regions on both ends of the plurality of prism portions 27. The flow stop grooves 29, 29a, 29b or the flow stop bank 31 are portions corresponding to the protrusions 26a formed on the two end edges, respectively. In addition, the protrusion 26a may be formed to have a length longer than the width of the protrusion 26a.

  The prism sheets 25, 25 a, 25 b of the above embodiments are formed by forming protrusions 26 a that are supported by the prism sheet support 4 at the two end edges on both ends of the plurality of prisms 27. However, the protruding portion 26a may be omitted, and the two edge portions on both ends of the plurality of prism portions 27 may be supported by groove-like or trapezoidal prism sheet support portions, respectively. The flow stop grooves 29, 29a, 29b or the flow stop dike 31 may be formed in the two edge regions on both ends of the plurality of prism portions 27 over substantially the entire length of these edge regions.

  Further, each of the prism sheets 25, 25a, 25b in each of the above embodiments has a plurality of prism portions 27 formed on one surface of the transparent sheet-like member 26. The present invention can also be applied to a prism sheet in which a plurality of convex prism portions are formed on both surfaces.

  In that case, in the case where the plurality of prism portions on both sides are formed in the shape of ridges parallel to each other along the direction between the two edges on the side supported by the prism sheet support portion, the sheet-like member 26 When the flow-preventing grooves 29, 29a, 29b or the flow-preventing dam 31 are formed on both surfaces of each of the two surfaces, and the plurality of prism portions on the both surfaces are formed in a convex shape in a direction perpendicular to each other, they are supported by the prism sheet support portion. The flow stop grooves 29, 29a, 29b or the flow stop bank 31 may be formed on the surface on which the prism portion is formed along the direction between the two edges on the side to be formed.

  Further, in the display module shown in FIG. 1, the plurality of prism portions 24 of the first prism sheet 22 are arranged between two end edges orthogonal to the edge portion supported by the prism sheet support portion 4 of the housing body 2. The plurality of prism portions 27 of the second prism sheet 25 are formed over the entire length between the two end edges supported by the prism sheet support portion 4, but on the contrary, The plurality of prism portions 24 of the first prism sheet 22 are formed over the entire length between two edges supported by the prism sheet support portion 4, and the plurality of prism portions 27 of the second prism sheet 25 are formed. The first prism sheet 2 may be formed over the entire length between two edges orthogonal to the edge supported by the prism sheet support 4. Each of the plurality of prism portions 24 is transmitted along the valley-shaped portion of the liquid material that has entered the valley-shaped portion between the adjacent prism portions 24, 24 from the open end thereof into the two edge regions on both ends. What is necessary is just to form the flow stop part (flow stop groove | channel or flow stop bank) for blocking a flow.

  Furthermore, the present invention can be applied not only to the prism sheet mounted on the display module but also to a prism sheet mounted on another optical device.

1 is a cross-sectional view of a liquid crystal display module provided with a prism sheet showing a first embodiment of the invention. The top view of the 1st prism sheet mounted in the said liquid crystal display module. The top view of the 2nd prism sheet mounted in the said liquid crystal display module. The expansion perspective view of a part of said 2nd prism sheet. The enlarged plan view of the part supported by the prism sheet support part of the said 2nd prism sheet. The enlarged plan view of the part supported by the prism sheet support part of the prism sheet of the comparative example which does not have a flow stop part. The top view of the 2nd prism sheet which shows the 2nd Example of this invention. The expansion perspective view of a part of 2nd prism sheet of the 2nd example. The expansion perspective view of a part of 2nd prism sheet which shows the 3rd Example of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Display module housing, 4 ... Prism sheet support part, 6 ... Liquid crystal display element, 15 ... Surface light source, 22 ... 1st prism sheet, 25, 25a, 25b ... 2nd prism sheet, 26 ... Sheet-like member 26a ... projecting portion, 27 ... prism portion, 28 ... valley-like portion, 29, 29a, 29b ... flow stop groove, 30, 30a, 30b ... liquid material receiving groove, 31 ... flow stop embankment, 23 ... liquid material.

Claims (6)

On at least one surface of the transparent sheet-like member, a plurality of prism-shaped prism portions extending over the entire length between two opposing edges of the sheet-like member are formed in parallel to each other, and the periphery of the sheet-like member The liquid material that enters the valley portions between the adjacent prism portions from the open ends thereof into the two edge regions on both ends of the plurality of prism portions in the edge region having a predetermined width along A flow stop portion is formed to prevent the flow along the valley portion of the
The said flow stop part consists of the flow stop groove | channel formed deeply rather than the trough part along the direction which crosses a some prism part, The prism sheet characterized by the above-mentioned. Each of the two edges of both ends of the plurality of prism portions, projecting portion supported is formed on the prism sheet supporting portion, said flow preventing portion is formed at a portion corresponding to at least the projecting portion The prism sheet according to claim 1. 3. The prism sheet according to claim 1, wherein the flow stop portion is formed over substantially the entire length of two edge regions on both ends of the plurality of prism portions. 4. The prism sheet according to claim 1 or 3, characterized in that each end of the flow stopper groove, the receiving portion of the liquid material having flowed down along along said flow stopper groove is formed. The flow stop groove is formed over substantially the entire length of two edge regions on both ends of the plurality of prism portions, and the liquid material receiving portion is provided in each of the other two edge regions. of the parallel longitudinal, and wherein the ends to claim 4, characterized in that it consists of both ends the flow stopper groove to liquid material receiving groove formed by respectively communicated to said plurality of prism portions Prism sheet. 2. The flow stop portion is formed in a plurality of stages at intervals in the length direction of the plurality of prisms in two edge regions on both ends of the plurality of prism portions. The prism sheet in any one of -3.

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