JP2009048152A - Optical sheet, backlight unit using same, and display apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical sheet that can prevent itself from curving and peeling-off due to its thermal deformation even if a liquid crystal display device is continuously used for long period of time; a backlight unit using the same; and a display apparatus. <P>SOLUTION: The optical sheet for display includes: a light-diffusion layer that diffuses light emitted from the display; and at least one lens sheet that is provided on an emission surface side of the light-diffusion layer and that controls the light emitted from the display. The optical sheet for display has a support element for fixing the side face of the light-diffusion layer and lens sheet. The backlight unit using the optical sheet and the display apparatus are also provided. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention illuminates, from the back side, a liquid crystal panel in which a transmissive / non-transmissive lens sheet and a display optical sheet in pixel units or a display element in which a display pattern is defined according to a transparent state / scattering state is arranged. The present invention relates to a backlight unit and a display device.

  In recent years, liquid crystal display devices using TFT liquid crystal panels and STN liquid crystal panels have been commercialized mainly for color notebook PCs (personal computers) in the OA field.

  In such a liquid crystal display device, a so-called backlight method in which a light source is arranged on the back side (observer side) of the liquid crystal panel and the liquid crystal panel is illuminated with light from the light source is employed.

  As a backlight unit employed in this type of backlight system, a light source lamp such as a cold cathode fluorescent lamp (CCFT) is roughly divided into a flat light guide plate made of acrylic resin having excellent light transmittance. There are a “light guide plate light guide method” for reflecting (a so-called edge light method) and a “direct type method” that does not use a light guide plate.

  As a liquid crystal display device on which a light guide plate light guide type backlight unit is mounted, for example, the one shown in FIG. 30 is generally known.

  This is provided with a liquid crystal panel 72 sandwiched between polarizing plates 71 and 73 at the top, and a light guide plate 79 made of a transparent base material such as a substantially rectangular plate-like PMMA (polymethyl methacrylate) or acrylic on the lower surface side. Is installed, and a diffusion film (diffusion layer) 78 is provided on the upper surface (light emission side) of the light guide plate.

  Further, a scattering reflection pattern portion for efficiently scattering and reflecting the light introduced into the light guide plate 79 in the direction of the liquid crystal panel 72 is provided on the lower surface of the light guide plate 79 by printing or the like. A reflection film (reflection layer) 77 is provided below the scattering reflection pattern portion (not shown).

Further, the light guide plate 79 is provided with a light source lamp 76 at the side end, and further covers the back side of the light source lamp 76 so that the light from the light source lamp 76 can be efficiently incident on the light guide plate 79. Thus, a high-reflectance lamp reflector 81 is provided. The scattering reflection pattern portion is formed by printing, drying, and forming a mixture of white titanium dioxide (TiO ₂ ) powder in a solution such as a transparent adhesive in a predetermined pattern, for example, a dot pattern. The light incident on the light plate 79 is imparted with directivity and guided to the light exit surface side, which is a device for increasing the brightness.

  Furthermore, recently, in order to increase the light utilization efficiency and increase the brightness, as shown in FIG. 31, a prism film (prism layer) having a light condensing function between the diffusion film 78 and the liquid crystal panel 72 is provided. ) 74 and 75 are proposed. The prism films 74 and 75 are configured to collect light emitted from the light exit surface of the light guide plate 79 and diffused by the diffusion film 78 on the effective display area of the liquid crystal panel 72 with high efficiency.

However, in the apparatus illustrated in FIG. 30, the control of the viewing angle is left only to the diffusibility of the diffusion film 78, which is difficult to control, and the center in the front direction of the display is bright and becomes darker toward the periphery. This characteristic is inevitable. For this reason, when the liquid crystal screen is viewed from the side, the luminance is greatly reduced, and the light utilization efficiency is reduced.
Furthermore, in the apparatus using the prism film illustrated in FIG. 31, two prism films are required, which not only causes a large decrease in the amount of light due to the absorption of the film but also increases the cost due to the increase in the number of members. It was also.

  On the other hand, in the direct type, a display device such as a large liquid crystal TV in which the light guide plate is difficult to use is used.

  As a direct liquid crystal display device, a device illustrated in FIG. 32 is generally known. In this, a liquid crystal panel 72 sandwiched between polarizing plates 71 and 73 is provided on the upper side, and is emitted from a light source 51 made of a fluorescent tube or the like on the lower surface side thereof and diffused by an optical sheet such as a diffusion film 82. The light is condensed on the effective display area of the liquid crystal panel 72 with high efficiency. In order to efficiently use the light from the light source 51 as illumination light, a reflector 52 is disposed on the back surface of the light source 51.

  However, even in the apparatus illustrated in FIG. 32, the control of the viewing angle is left only to the diffusibility of the diffusing film 82, which is difficult to control, and the central portion in the front direction of the display is bright and becomes darker toward the peripheral portion. This characteristic is inevitable. For this reason, when the liquid crystal screen is viewed from the side, the luminance is greatly reduced, and the light utilization efficiency is reduced. Furthermore, in the case of using a prism film, since the number of prism films is two, not only the light amount is greatly decreased due to absorption of the film but also the cost is increased due to an increase in the number of members.

  If the distance between the light sources 51 is too wide, uneven brightness tends to occur on the screen, and the number of light sources 51 cannot be reduced, leading to an increase in power consumption and an increase in cost.

  By the way, in such a liquid crystal display device, light weight, low power consumption, high luminance, and thinning are strongly demanded as market needs, and accordingly, a backlight unit mounted on the liquid crystal display device is also light. In addition, low power consumption and high brightness are required.

  In particular, in a color liquid crystal display device that has recently made remarkable progress, the panel transmittance of the liquid crystal panel is remarkably lower than that of a monochrome-compatible liquid crystal panel. It is essential to obtain power consumption.

  However, as described above, it is difficult to say that the conventional apparatus sufficiently satisfies the demand for high luminance and low power consumption, and the user has low price, high luminance, high display quality, and low power consumption. The development of a backlight unit capable of realizing a power liquid crystal display device is awaited.

  In view of the above situation, for example, as disclosed in Patent Document 1, the present applicant includes a liquid crystal panel and light source means for illuminating light from the back side of the liquid crystal panel, and the light source means includes light from the light source. A liquid crystal display device has been proposed in which a lens layer for guiding the liquid crystal panel to the liquid crystal panel is provided and a light-shielding portion having an opening in the vicinity of the focal plane of the lens layer.

  In the above-mentioned Patent Document 1, as shown in FIGS. 1 to 3 of the same document, a configuration in which a lens sheet having a light-shielding portion is disposed between a liquid crystal panel and a backlight unit is disclosed. 1 to 3, the lens sheet has a concavo-convex shape constituting a lens portion on the liquid crystal panel side.

  The effect obtained by interposing the lens sheet described above has a concavo-convex shape that forms a lens portion on the liquid crystal panel side by modulating the diffusivity of light emitted from the light guide plate by the lens action.

  The effect obtained by interposing the lens sheet described above is that the diffusibility of the light emitted from the light guide plate is modulated into the lens action, and the liquid crystal panel can be emitted with the direction aligned. .

In addition, by forming an opening at a specific location, it is possible to selectively increase the amount of light incident on the pixels of the liquid crystal panel, improving the use efficiency of the backlight and controlling the shape of the opening. In this way, it is possible to control the visual field region of the display light.
JP 2000-284268 A JP 2006-106197 A

  By the way, a liquid crystal display device used for a liquid crystal TV or a personal computer monitor is used continuously for a long time compared to a mobile phone or a mobile terminal. In addition, recently, liquid crystal display devices used in mobile phones and mobile terminals are expected to be used continuously for a longer time than before due to the adoption of power saving design.

  As described above, when the liquid crystal display device is used continuously for a longer period of time, the temperature of the optical sheet used in the backlight unit rises due to the heat generated from the light source, and warpage or peeling due to thermal deformation occurs. In addition, there is a problem that the image quality displayed from the liquid crystal display device may be deteriorated due to the occurrence of bending or the deflection due to the low rigidity of the sheet.

  The present invention has been made in view of such circumstances, and by integrating a diffusion film, a lens sheet, and a light diffusion layer, it is thin and has sufficient strength, and warping and peeling due to thermal deformation may occur. It is an object of the present invention to provide an optical sheet satisfying optical characteristics, a backlight unit using the optical sheet, and a display device.

In order to achieve the above object, the present invention takes the following measures.
That is, the invention of claim 1 is an optical sheet for display,
A light diffusion layer for diffusing light from the light source of the display;
At least one lens sheet for controlling light from the light diffusing layer, on the light exit surface side of the light diffusing layer;
An optical sheet for display comprising a support element for fixing the light diffusion layer and the side surface of the lens sheet.
The invention of claim 2 is an optical sheet for display,
A light diffusion layer for diffusing light from the light source of the display;
At least one lens sheet for controlling light from the light diffusing layer, on the light exit surface side of the light diffusing layer;
An optical sheet for a display, comprising a support element that is fixed while maintaining a gap with the four sides of the light diffusion layer and the lens sheet.
The invention of claim 3 is an optical sheet for display,
A light diffusion layer for diffusing light from the light source of the display;
At least one lens sheet for controlling light from the light diffusing layer, on the light exit surface side of the light diffusing layer;
An optical sheet for display comprising a support element for fixing any one pair of opposite sides among the four sides of the side surfaces of the light diffusion layer and the lens sheet.
The invention according to claim 4 is characterized in that the support element is
A first projecting portion for fixing the light diffusion layer and the side surface of the lens sheet and the display outer region of the lens sheet from the side surface;
The display optical sheet according to claim 1, further comprising a second projecting portion that fixes the light diffusion layer from the side surface.
According to a fifth aspect of the present invention, the first overhanging portion includes:
The optical sheet for display according to any one of claims 1 to 3, wherein the optical sheet for display according to any one of claims 1 to 3, wherein the optical sheet for display is fixed by being engaged with unevenness of at least one unit lens of the lens portion of the lens sheet.
The invention according to claim 6 is the optical sheet for display according to any one of claims 1 to 3, wherein the support element is made of metal.
The invention according to claim 7 is the optical sheet for display according to any one of claims 1 to 3, wherein the support element is made of a resin.
The invention according to claim 8 is the optical sheet for display according to claims 1 to 3, wherein the support element has at least one hole.
The invention of claim 9 is an optical sheet for display,
A light diffusion layer for diffusing light from the light source of the display;
A light-emitting layer side of the light diffusion layer; a lens sheet that controls light from the light diffusion layer; and a light-emitting surface side of the lens sheet, and a diffusion film that diffuses light from the lens sheet,
The light diffusion layer and the lens sheet are integrated through a fixing element while maintaining a first gap,
Furthermore, the lens sheet and the diffusion film are integrated through an adhesive layer or an adhesive layer while maintaining the second gap,
4. The optical sheet for display according to claim 3, further comprising a support element that fixes a pair of opposite sides of the light diffusion layer, the lens sheet, and the diffusion film.
A tenth aspect of the invention is the optical sheet for display according to the ninth aspect, wherein the fixing element has an adhesive.
The invention according to claim 11 is the optical sheet for display according to claim 9, wherein the fixing element has an adhesive.
The invention according to claim 12 is the optical sheet for display according to claim 9, wherein when the fixing element is the adhesive or the adhesive, the adhesive and the adhesive contain fine particles. .
A thirteenth aspect of the present invention is the display optical sheet according to the ninth aspect, wherein the fixing element has a rib.
The invention according to claim 14 is the optical sheet for display according to claim 9, wherein the fixing element has a reflective surface.
The invention according to claim 15 is the optical sheet for display according to claim 9, wherein the ground contact area of the fixing element is 0.05% or more and 20% or less with respect to the area of the incident surface of the lens sheet. It is.
The invention according to claim 16 is the optical sheet for display according to claim 9, wherein the surface of the light diffusion layer has a fine uneven shape.
The invention according to claim 17 is the optical sheet for display according to claim 9, wherein the light diffusion layer has a fine particle layer on the surface thereof.
In the invention of claim 18, when the lens portion of the lens sheet is formed by arranging a plurality of unit triangular prisms or unit convex cylindrical lenses in parallel,
Of the two sets of facing end faces of the optical sheet for display, one set of the end faces parallel to the longitudinal direction of the unit triangular prism or unit convex cylindrical lens is fixed by a support element,
10. The optical sheet for display according to claim 9, wherein the first gap and the second gap of the other set of the end faces are opened.
According to a nineteenth aspect of the present invention, in the optical sheet for display according to the ninth aspect, an apex angle of the unit triangular prism is defined in a range of 70 ° ± 30 °.
According to a twentieth aspect of the invention, there is provided the optical sheet for display according to the first or ninth aspect, wherein the unit triangular prism is round in the vicinity of the valley and the apex thereof.
21. The display according to claim 9, wherein a relationship of 2T ≦ H is established between a thickness T of the adhesive or adhesive layer and a height H of the unit lens. It is an optical sheet.
The invention of claim 22 is an optical sheet for display,
A light diffusion layer for diffusing light from the light source of the display;
At least one lens sheet for controlling light from the light diffusing layer, on the light exit surface side of the light diffusing layer;
A support element for fixing a side surface of the light diffusion layer and the lens sheet;
The display optical sheet is characterized in that air leaks from between the light diffusion layer and the side surface of the lens sheet and the support element.
The invention of claim 23 is an optical sheet for display,
A light diffusion layer for diffusing light from the light source of the display;
At least one lens sheet for controlling light from the light diffusing layer, on the light exit surface side of the light diffusing layer;
A support element for fixing a side surface of the light diffusion layer and the lens sheet;
The display optical sheet further comprises a buffer material between the light diffusion layer and the side surface of the lens sheet and the support element.
According to a twenty-fourth aspect of the present invention, there is provided an optical sheet for display according to any one of the first to third aspects or the twenty-second to twenty-third aspects, and a liquid crystal panel on the back surface of the optical sheet for display from the non-viewing surface side of the liquid crystal panel. A backlight unit comprising a light source that emits light.
The invention of claim 25 includes the backlight unit;
A display device comprising the liquid crystal panel on a light exit surface side of the display optical sheet of the backlight.
The invention of claim 26 is characterized in that the backlight device and the display device each have a light source, and the light source is any one of a cold cathode fluorescent lamp, an LED, an EL, and a semiconductor laser. Item 20. The display device according to Item 19.

  As described above, the lens sheet according to the present invention, the optical sheet for display, and the backlight unit and display device using the same are thin and have sufficient strength as compared with the conventional configuration, and are due to thermal deformation. It is possible to provide an optical sheet, a backlight unit, and a display device that achieve desired luminance, light distribution range, uniformity, and the like without causing warpage or peeling.

The best mode for carrying out the present invention will be described below with reference to the drawings.
Fig.1 (a) is a side view which shows the structural example of the optical sheet 9 based on embodiment of this invention.
In the optical sheet 9, the light diffusion layer 7 and the lens sheet 5 are integrated with the fixing element 3 maintaining the first gap 6, and the diffusion film 1 is further adhered on the lens portion of the lens sheet 5. Alternatively, they are integrated while maintaining the second gap 4 via the adhesive layer 2.

  1A and 26, the optical sheet 9 includes the light diffusion layer 7 that scatters the light K from the incident surface 100 toward the exit surface 102 that is the non-incident surface.

  Here, the light diffusion layer 7 includes a transparent resin and transparent particles dispersed in the transparent resin, and the refractive index of the transparent resin and the refractive index of the transparent particles are different. There is a need. The difference between the refractive index of the transparent resin and the refractive index of the transparent particles is preferably 0.02 or more. If the difference in refractive index is smaller than this, sufficient light scattering performance cannot be obtained. Further, the refractive index difference may be 0.5 or less.

  The light diffusion layer 7 needs to transmit the light H incident on the light diffusion layer 7 while scattering the light H. For this reason, the average particle diameter of the transparent particles contained in the light diffusion layer 7 is desirably 0.5 to 10.0 μm. Preferably it is 1.0-5.0 micrometers. Alternatively, the light diffusion layer 7 has a structure having a fine cavity containing air in the transparent resin, and the diffusion performance may be obtained by the difference in refractive index between the transparent resin and air.

  Examples of the transparent resin include polycarbonate resin, acrylic resin, fluorine acrylic resin, silicone acrylic resin, epoxy acrylate resin, polystyrene resin, cycloolefin polymer, methylstyrene resin, fluorene resin, PET, polypropylene, and acrylonitrile styrene. A polymer etc. can be used.

Here, the linear expansion coefficients of polycarbonate, polystyrene, methylstyrene resin, and cycloolefin polymer are 6.7 × 10 ⁻⁵ (cm / cm / ° C.), 7 × 10 ⁻⁵ (cm / cm / ° C.), and 7 respectively. It is * 10 < ^-5 > (cm / cm / degreeC) and 6-7 * 10 < ^-5 > (cm / cm / degreeC). On the other hand, when the lens sheet 5 includes, for example, PET, the linear expansion coefficient of PET is 2.7 × 10 ⁻⁵ (cm / cm / ° C.), and the linear expansion coefficient of the light scattering layer is larger. Therefore, when the optical sheet 9 receives heat and deforms, warpage occurs on the light scattering layer 7 side.
However, in the embodiment of the present invention, considering that the linear expansion coefficient of the lens sheet 5 is small, the linear expansion coefficient of the light diffusion layer 7 is 7.0 × 10 ⁻⁵ (cm / cm / ° C.) or less. By doing so, the above-described deformation can be prevented.
In the case where the lens sheet 5 is manufactured by using polycarbonate as a material by the extrusion method, warpage does not occur because the linear expansion coefficient is almost the same as that of other transparent resins.

  Moreover, as transparent particles, transparent particles made of inorganic oxide or transparent particles made of resin can be used. For example, examples of the transparent particles made of an inorganic oxide include particles made of silica, alumina or the like. The transparent particles made of resin include acrylonitrile styrene copolymer particles, acrylic particles, styrene particles, styrene acrylic particles and cross-linked products thereof, melamine-formalin condensate particles, PTFE (polytetrafluoroethylene), PFA. (Perfluoroalkoxy resin), FEP (tetrafluoroethylene-hexafluoropropylene copolymer), PVDF (polyfluorovinylidene), ETFE (ethylene-tetrafluoroethylene copolymer) and other fluorine-containing polymer particles, silicone resin particles, etc. Can be mentioned. These transparent particles may be used as a mixture of two or more.

And the plate-shaped light-diffusion layer 7 can be manufactured by disperse | distributing transparent particles in these transparent resins, and extrusion-molding. The thickness is desirably 1 to 5 mm.
If the thickness is less than 1 mm, the light diffusing layer 7 has a drawback that it is bent because it is thin and free of strain. On the other hand, if it exceeds 5 mm, the light transmittance from the light source 15 is deteriorated.

  Furthermore, the light diffusion layer 7 may have fine unevenness on the surface, and the surface may have light diffusibility with the fine unevenness on the surface. In this case, the light diffusing layer 7 is formed by an extrusion method, a casting method, or a method using both the extrusion method and the casting method, which are well known in the art. Here, examples of the fine unevenness include a convex cylindrical shape, a lens shape, and a triangular prism shape, but are not limited thereto, and the light diffusion function of the light diffusion layer 7 gives a fine unevenness. If it is the thing of the uneven | corrugated shape improved compared with before being done, it will not restrict to said shape.

In addition, the formation of fine irregularities on the surface of the light diffusion layer 7 is not limited to the above-described light diffusion function, and a first gap 6 described later can be secured.
That is, when the light emitting surface 102 of the light diffusing layer 7 and the light incident surface 104 of the lens sheet 5 are joined, the first gap 6 is secured by the fine unevenness formed on the light emitting surface 102 of the light diffusing layer 7. It becomes possible. In this case, examples of the fine irregularities include those obtained by patterning irregularities on the light diffusion layer 7, ribs, and microlenses. However, the present invention is not limited thereto, and any irregular shape that can ensure the gap 6 may be used. .

  Furthermore, a fine particle layer may be attached to the surfaces of both surfaces of the light diffusion layer 7 in order to further improve the light diffusibility, and the fine particle layer may be attached to one surface instead of the both surfaces. The fine particle layer may be, for example, a transparent ink containing beads, spacers, etc., but the thickness of the fine particle layer, the type and size of the fine particles are not limited, and the light diffusion function of the light diffusion layer 7 is fine. What is necessary is just to improve compared with before giving a layer.

  In addition, when creating the light-diffusion layer 7 with the fine cavity which contains air in transparent resin as mentioned above, you may foam and produce the foaming agent previously contained in transparent resin. The transparent resin contains a resin that is incompatible with each other, and is produced by a method of stretching at least in a uniaxial direction.

  The optical sheet 9 is provided between the exit surface 102 side of the light diffusing layer 7 and the incident surface 104 of the lens sheet 5, and is fixed while holding the first gap 6 between the light diffusing layer 7 and the lens sheet 5. It has element 3.

  As the fixing element 3, a plurality of ribs that transmit light diffused by the light diffusion layer 7, an adhesive layer or an adhesive layer, or a plurality of reflective surfaces that reflect the light diffused by the light scattering layer 7 to the light diffusion layer 7 side. The rib which has or contains a reflecting material, the adhesion layer and the contact bonding layer containing a reflecting material are mentioned.

Here, the fixing element 3 does not cover all the non-incident surface 102 of the light diffusion layer 7 and the incident surface 104 of the lens sheet 5.
That is, the first gap 6 is provided between the light diffusion layer 7 and the lens sheet 5 of FIG. 1 and transmits the light diffused by the light diffusion layer 7 to the lens sheet 5 on the non-diffusion layer side. Can do. Light transmitted through the gap 4 can be collected and guided to the lens sheet 5. The first gap 6 is made of air. That is, the heat received by the optical sheet 9 from the light source 15 due to the air flowing through the first gap 6 can be released. This is effective in preventing warpage and peeling of the optical sheet 9.

  First, the case where an adhesive layer or an adhesive layer is used as the fixing element 3 will be described. The position where the adhesive layer or the adhesive layer is applied is at least partly outside the display area of the light diffusion layer 7 and the lens sheet 5 (which means an area other than that used for image display when the lens sheet 5 is incorporated in the display device). Jointly.

However, depending on the case, the adhesive layer or the adhesive layer may be in the display area as long as the image display quality of the display (for example, the fixing element 3 is visually recognized from the display) is not affected. In this case, the ground contact area of the fixing element 3 is preferably 0.05% to 20% with respect to the area of the entrance surface 104 of the lens sheet 5 or the exit surface 102 of the light diffusion layer 7.
If it is 0.05% or less, the adhesion between the lens sheet 5 and the light diffusion layer 7 is weak, and the lens sheet 5 is easily peeled off. Further, if it is 20% or more, the display quality is deteriorated such that the fixing element can be seen from the viewing surface side of the optical sheet.

Examples of the adhesive layer or adhesive layer include acrylic, urethane, rubber, and silicone adhesives and adhesives. In either case, since it is used in a high-temperature backlight, it is desirable that the storage elastic modulus G ′ is 1.0E + 04 Pa or more at 100 ° C. If the value is lower than this, the light diffusion layer 7 and the lens sheet 5 may be misaligned during use. In order to secure the first gap 6 stably, transparent fine particles such as beads may be mixed in the adhesive layer or the adhesive layer.
The pressure-sensitive adhesive may be a double-sided tape or a single layer.

  Furthermore, when an adhesive layer or an adhesive layer is used in the display area, the light absorption must be within 1%. If it exceeds 1%, the integrated light quantity emitted from the optical sheet 9 decreases, and the front luminance decreases regardless of the shape of the lens sheet 5.

  As a method for applying the adhesive layer or the adhesive layer, various coating apparatuses such as a comma coater, a printing method, a method using a dispenser or a spray, or manual coating using a brush or the like may be used.

  Here, as a method of providing the first gap 6 described above with reference to FIG. 2, as shown in FIG. 2 (a), a method in which fine particles such as spacers are mixed and applied in an adhesive, or a light diffusion layer 7 is prepared. 2 and a lens sheet 5 coated with an adhesive layer or an adhesive layer or laminated, or a lens sheet 5 with irregularities fabricated as shown in FIG. There is also a method in which the diffusion layer 7 is produced by pasting and bonding an adhesive layer or an adhesive layer to the diffusion layer 7.

  A rib may be used as the fixing element 3. By the method using this rib, the first gap 6 can be fixed uniformly with a constant thickness, so that appearance characteristics such as display quality (optical adhesion, unevenness, Newton ring) can be improved. .

  Here, the rib is made of a transparent resin molded into a certain shape. Further, the transparent resin may contain other effects such as diffusion and coloring by containing inorganic and organic particles and bubbles.

  As a transparent resin for the rib material, for example, a polyester resin, an acrylic resin, an acrylonitrile styrene copolymer, a polycarbonate resin, a polystyrene resin, a methyl styrene resin, a polymethylpentene resin, a thermoplastic resin such as a cycloolefin polymer, or a polyester acrylate Transparent resins such as radiation curable resins composed of oligomers such as urethane acrylates and epoxy acrylates, or acrylates are generally used. However, in addition to the above materials, resins capable of producing rib characteristics can also be used.

  As particles dispersed in the transparent resin, inorganic substances such as silica, alumina, titanium oxide, carbon black, and glass beads, and organic substances such as various resin beads can be used. Various particles dispersed in the transparent rib can be locally disposed, for example, by giving the rib surface a reflection characteristic. Further, bubbles can be dispersed in the resin and used instead of the particles. These particles and bubbles dispersed in the transparent resin may be used in combination of a plurality of types or may not be used depending on the application to be used.

  As for the height of the rib, it is necessary to keep the first gap 6 between the lens sheet 5 and the light diffusion layer 7 at 200 nm or more in order to prevent optical adhesion due to distortion of the optical sheet 9. On the other hand, if the thickness of the first gap 6 exceeds 2 mm, it is not preferable because the visibility of the ribs is increased, unevenness is caused, and light leakage easily occurs from the side.

  The ground contact area of the rib to the non-incident surface 102 is the total ground contact area of the rib in contact with the non-incident surface 102 of the light diffusion layer 7 or the incident surface 104 of the lens sheet 5 in order to prevent a decrease in adhesive strength and a decrease in front luminance. Is preferably 0.01 to 60% with respect to the area of the non-incident surface 102 of the light diffusion layer 7 or the incident surface 104 of the lens sheet. Furthermore, in order to minimize the decrease in luminance, it is more preferable that the installation area of the rib light diffusion layer 7 on the non-incident surface 102 is 0.05% or more and 20% or less.

  Here, when the rib is used, it is not necessary to limit the installation position outside the display area as described above, and it can be installed on the entire incident surface 104 of the lens sheet 5 or the light emitting surface 102 of the light diffusion layer 7.

Further, the grounding size of one rib (or a group of ribs in some cases) to the non-incident surface 102 of the light diffusion layer 7 is a lenticular shape extending in one direction so that rib unevenness is not visible from the upper surface of the optical sheet 9. As for the structure such as the trapezoidal shape and the prism shape, it is preferable that the width of the rib of the grounded portion joined to the lens sheet 5 is 50 μm or less. Further, it is preferable that the area of the ground contact portion of a structure such as a cone (or a truncated cone, a truncated cone, or the like), a polygonal column, a cylinder, or the like, a rectangular parallelepiped, a sphere (or hemisphere), or an ellipsoid is 2500 μm ² or less.
In order to further improve visibility, it is more preferable that the width of the rib is 3 μm and the area is 900 μm ² or less.

Rib shape, lenticular shape, trapezoidal shape, prism shape, etc., polygonal cones, cones (or polygonal cones, truncated cones, etc.), polygonal columns, columnar cylinders, rectangular parallelepipeds, spherical shapes (or It may be a hemispherical structure or an ellipsoidal structure.
Depending on the rib manufacturing method, the shape of the side surface may be an unspecified shape as long as the height of the rib is constant. When the first gap 6 is secured with these ribs, the above-described one type of rib structure may be used as a whole, or a plurality of types of rib structures may be used in combination. The arrangement of these ribs may be periodic such as a stripe shape or a dotted line, or may be random, and is appropriately selected according to the design.

Regarding the hardness of the rib, it is preferable that the rib has an appropriate flexibility so that the warp between the lens sheet 5 and the light diffusion layer 7 can be minimized even at a high temperature during use of the backlight.
Regarding the height of the ribs, it is preferable that the ribs are uniformly arranged as a whole. However, the height of the base material of the lens sheet 5 varies according to the expansion and contraction due to rigidity, heat, water absorption, etc. Also good.

  Then, using these transparent resins and particles, ribs can be formed on the rib itself or the back surface of the lens sheet 5 and the surface of the light diffusion layer 7 at once by various methods such as radiation curing molding, extrusion molding, and hot press molding. Shapes can be made. Moreover, when bonding together, it can integrate so that the fixed gap | interval 4 may be provided between the lens sheet 5 and the light-diffusion layer 7 using an adhesive or an adhesive agent on the one or both surfaces of a rib. As another rib forming method, ribs with adhesive or adhesive can be prepared in advance by dispersing ribs in an adhesive or adhesive and applying them by various printing methods. The first gap 6 can be integrated.

  Next, the case where a rib having a plurality of reflective surfaces, an adhesive layer containing a reflective material, or an adhesive containing a reflective material is used as the fixing element 3 will be described.

The pressure-sensitive adhesive layer or adhesive layer containing a reflective material can be prepared by coating the light diffusion layer 7 with metal particles or high refractive index transparent particles dispersed in the above-mentioned adhesive / adhesive.
In the case of a rib having a reflective surface, it can be prepared by mixing metal particles or high refractive index transparent particles in a transparent resin forming the rib. It can also be formed by dry film formation such as vapor deposition or sputtering of a highly reflective metal such as silver, aluminum or nickel on the surface of the rib.

  Furthermore, it can also be created by applying an ink obtained by dispersing and mixing high refractive index transparent particles on the surface of a transparent rib, or an adhesive / adhesive layer obtained by dispersing and mixing high refractive index transparent particles. In addition to the above, as a method of creating the fixing element 37 having reflectivity, it can be formed by transferring a kneaded metal particle or high refractive index transparent particle in a binder, or by forming a white foil or a metal foil laminate. .

  Here, examples of the high refractive index transparent particles include titanium oxide, barium sulfate, magnesium carbonate, zinc oxide, clay, aluminum hydroxide, zinc sulfide, silica, and silicone. Examples of the metal particles or the metal foil include aluminum and silver. One kind of these high refractive index transparent particles, metal particles or metal foil may be used, or a plurality of kinds may be used in combination.

Furthermore, the light absorption by the fixing element 3 having the function of reflecting light must be within 1%. When it exceeds 1%, the integrated light quantity emitted from the optical sheet 37 decreases, and the on-axis luminance decreases regardless of the shape of the lens sheet 1.
In the case of the fixing element 3 having the above-described reflection function, the reflectance is required to be 70% or more, and more preferably 80% or more. If it is lower than 70%, the transmitted light increases too much, so that it may be visually recognized as a bright part in a low-luminance visual field. If it is 80% or more, it is not visually recognized even in a low-luminance visual field.

  The arrangement of the fixing elements 3 having a reflecting function is the same as that of the rib having no reflecting function.

  The lens sheet 5 described above is incident from the incident surface 104 on which the light transmitted from the light source 15 through the light diffusion layer 7 and the first gap 6 is incident from FIG. The light is emitted as light K having an optical gain of 1 or more.

Here, the optical gain is one of indexes indicating the diffusibility of the optical diffusing member, and is expressed as a ratio to the luminance of the light, assuming that the luminance of the diffuser that completely diffuses is 1. When the diffusivity of the diffusing member to be measured is biased depending on the direction, the diffusion characteristic of the diffusing member can be shown by obtaining the optical gain for each direction.
Also, complete diffusion refers to an ideal diffuser that has zero absorption and a constant intensity in any direction. That is, an optical gain of 1 or more indicates that there is an effect of collecting light in the measurement direction, and that the larger the value, the stronger the light collection effect.

Here, in FIG. 1B, the lens sheet 5 has a triangular prism shape, but is not limited to this, and may have a convex cylindrical shape or a parabolic shape. In the triangular prism, the left and right sides may be asymmetric, and the sides may be curved instead of straight.
Moreover, in the above-described triangular prism, the valley portion X and the top portion Y may be rounded.
Further, in consideration of fixing with the lens sheet 5 and the diffusion film 1 adhesive layer or the adhesive layer 6, the top of the triangular prism may be flat. In this case, the flat width at the top is preferably 0.5% to 30% with respect to the lens pitch P. That is, when it is 0.5% or less, the lens sheet 1 and the pressure-sensitive adhesive layer or the adhesive layer 6 are easily peeled, and when it is 30% or more, the visibility is deteriorated.

  This lens sheet 5 is well known in the technical field using PET (polyethylene terephthalate), PC (polycarbonate), PMMA (polymethyl methacrylate), acrylonitrile styrene copolymer, COP (cycloolefin polymer) and the like. It is formed by an extrusion molding method, an injection molding method, or a hot press molding method.

  Further, the lens sheet 5 may be molded using a UV or radiation curable resin (the type is not particularly limited as long as the resin includes a material curable by UV or radiation).

Here, when the lens sheet 5 is a cylindrical lens, the angle formed by the perpendicular line from the concave and convex valley X of the unit lens and the tangent line of the unit lens needs to be α (15 ° <α).
The reason for this is that if the angle 2α formed by the boundary (valley part X) between adjacent unit lenses is less than 30 °, the mold releasability after molding deteriorates, or the mold tip ends while repeating molding. This is because the mold life is often shortened by bending and making it impossible to release the molded product or damaging the tip of the mold when handling the mold.

  In the case of a triangular prism, the apex angle is preferably 70 ° ± 30 °. That is, when the apex angle is smaller than 40 °, only the front luminance is high and the viewing angle is narrowed. Further, if the apex angle is larger than 100 °, the viewing angle becomes wide, but the front luminance is lowered and the display becomes dark.

  As shown in FIG. 1, the diffusion film 1 diffuses the light from the lens sheet 5 on the exit surface of the lens sheet 5 (the back surface of the incident surface 104), and the first gap 4 is interposed via the adhesive layer or the adhesive layer 2. And is integrated with the lens sheet 5.

As shown in FIG. 33, in the light emitted from the lens sheet 5, only the on-axis luminance is excessively improved in the front luminance distribution, the peak width of the luminance distribution curve is remarkably narrow, and the viewing area is extremely limited. Therefore, by providing the diffusion film 1 on the lens portion of the lens sheet 5 (the portion where the lens shape of the lens sheet 5 is formed), the peak width of the light emitted from the lens sheet 5 is appropriately expanded, Moreover, a side rope can be reduced.
Further, as another function of the diffusion film 1, when the lens sheet 5 is a triangular prism, it is possible to prevent the top from being scratched, or to reduce moire caused by the lens pitch P of the lens sheet 5 and the pixels of the display.

  Further, the sheet rigidity of the optical sheet 9 is improved with the sheet integrated with the diffusion film 1 as compared with the sheet integrated with only the light diffusion layer 7 and the lens sheet 5. Deflection is less likely to occur when 9 is incorporated in a display device.

  Here, the diffusion film 1 may be a PET base film provided with a layer in which a filler is dispersed in a binder on both sides or one side, or a polycarbonate surface with a mat shape. The film thickness is preferably 0.05 mm to 0.3 mm, and the haze is preferably 40% to 80%.

The diffusion film 1 and the lens sheet 5 are fixed by the adhesive layer or the adhesive layer 2. FIG. 3 shows a fixing method.
In FIG. 3A, the pressure-sensitive adhesive layer or the adhesive layer 2 is applied to the diffusion film 1 by various coating apparatuses such as a comma coater, a printing method, a method using a dispenser or a spray, or manual coating using a brush or the like. . Thus, the diffusion film 1 to which the adhesive layer 6 is adhered is adhered to the lens sheet 5 by lamination or the like.
FIG. 3B shows the lens sheet 5 and the diffusion film 1 bonded together using the pressure-sensitive adhesive layer or the adhesive layer 2 as in FIG. 3A. The top of the lens may be pierced into the diffusion film 1. In this case, it is desirable that the lens top of the lens sheet 1 is pierced into the diffusion film 1 before the adhesive layer or adhesive layer 2 is completely cured, and the adhesive layer or adhesive layer 2 is completely cured after piercing.
FIG. 3C shows an adhesive layer or adhesive layer 2 provided only on the top of the lens of the lens sheet 5 and adhered to the diffusion film 1.

  Examples of the adhesive layer or adhesive layer 2 include acrylic, urethane, rubber, and silicone adhesives and adhesives. In either case, since it is used in a high-temperature backlight, it is desirable that the storage elastic modulus G ′ is 1.0E + 04 Pa or more at 100 ° C. If the value is lower than this, the diffusion film 1 and the lens sheet 5 may be displaced during use. In order to secure the first gap 4 stably, transparent fine particles such as beads may be mixed in the adhesive or adhesive.

  Moreover, as a pressure-sensitive adhesive or an adhesive used for the pressure-sensitive adhesive layer or the adhesive layer 2, a white turbid and low-transparency material cannot be used, and the material needs to be a highly transparent material from the viewpoint of visibility. . Specifically, the total light transmittance (JIS K7361-112, pressure sensitive adhesive or adhesive thickness 10 μm) is required to be 80% or more with a spectrophotometer.

  Further, in order to keep the gap 4 when the lens sheet 5 and the diffusion film 1 are integrated with the pressure-sensitive adhesive layer or the adhesive layer 2, it is between the lens height H of the lens sheet 5 and the thickness T of the pressure-sensitive adhesive layer or the adhesive layer 2. 2T ≦ H needs to be satisfied. Thus, the first gap 4 can be reliably provided between the lens sheet 5 and the diffusion film 1. As a result, the air flows through the first gap 4, whereby the optical sheet 9 can be cooled, which is effective in preventing warpage and peeling of the optical sheet 9.

  The optical sheet 9 produced as described above is obtained by integrating the light diffusion layer 7, the lens sheet 5, and the diffusion film 1 with three types of components, and such components having different materials and thicknesses. For example, if the optical sheet 9 is incorporated into a liquid crystal display device and used continuously for a long time, the optical sheet 9 is likely to be peeled off or bent due to the influence of heat from the light source 15.

  Therefore, from FIG. 4, peeling, bending, and warping can be prevented by fixing the side surface of the optical sheet 9 with the support element 11. In particular, the support element 11 dramatically improves the sheet rigidity of the optical sheet 9. FIG. 4A shows a case where only the side surface of the optical sheet 9 is fixed. In this case, it is preferable that both ends of the optical sheet 9 are ends that are not the valley portions X of the unit lens of the lens sheet 5. That is, since the contact area between the support element 11 and the lens sheet 5 is large compared to the case of the valley X of the unit lens of the lens sheet 5, it can be firmly bonded to the support element 11.

  FIG. 4B shows not only the side surface of the optical sheet 9 but also the support elements 11 attached to the U and G areas outside the display area that are not displayed as a display when the optical sheet 9 is incorporated in the display device. Show. In this case, the optical sheet 9 can be fixed more firmly than in FIG.

  Further, FIG. 5 shows a case where the support element 11 is fixedly fitted to the unit lens of the lens sheet 5. In this case, in order to fix the optical sheet 9 more stably, the optical sheet 9 is fixed so as to mesh with the unevenness of the unit lens. In this case, at least one unit lens (one pitch or more) is required for meshing with the support element 11.

  Further, as shown in FIG. 6, the support element 11 needs to fix only one set of the two end faces facing each other among the four sides of the optical sheet 9. Thereby, since the end surface without the support element 11 remains open, the air flow F in the gap 4 is improved, so that the optical sheet 9 can be efficiently cooled. Therefore, even when the liquid crystal display device is used continuously for a long time, warpage or peeling due to thermal deformation of the optical sheet 9 is prevented, and the optical element 9 is prevented from being bent by the support element 11, thereby deteriorating image quality. Can be prevented.

  Considering the air flow F in the above-described case, when the lens portion of the lens sheet 5 is formed by arranging a plurality of unit triangular prisms or unit convex cylindrical lenses in parallel, two sets of end faces of the optical sheet 9 that face each other. Among them, one set of the end faces parallel to the longitudinal direction N of the unit triangular prism or unit convex cylindrical lens needs to be fixed by the support element 11. This is because if the opposite end face is fixed, air does not flow through the first gap 4.

  On the other hand, when the lens portion of the lens sheet 5 is formed by two-dimensionally arranging a plurality of unit convex lenses, any one of the two end faces facing the optical sheet 9 is fixed by the support element 11. It only has to be done. This is because air flows into the first gap 4 from any direction.

  From FIG. 7, when the air flow F is taken into consideration, when the optical sheet 9 is installed in the display device, the air flow F is compared to FIG. 7A and FIG. Since the air flow is good, the optical sheet 9 can be cooled more efficiently, which is preferable.

  Here, examples of the support element 11 include a pressure-sensitive adhesive, an adhesive, a welding method, a method using a fixing tool, and a method of irradiating an excimer to perform room temperature bonding.

  Examples of the pressure-sensitive adhesive and adhesive include acrylic-based, urethane-based, rubber-based, and silicone-based pressure-sensitive adhesives and adhesives. In either case, since it is used in a high-temperature backlight, it is desirable that the storage elastic modulus G ′ is 1.0E + 04 Pa or more at 100 ° C. If the value is lower than this, the support element 11 may be peeled off during use. The pressure-sensitive adhesive or adhesive may be a double-sided tape or a single layer.

  As a method of applying an adhesive or an adhesive, various coating apparatuses such as a comma coater, a printing method, a method using a dispenser or a spray, or manual coating using a brush or the like may be used.

  In the case of using a welding technique as the support element 11, for example, a method using heat, ultrasonic waves, or a laser can be used. These methods are easy to process and are suitable for joining outside the display area.

When a fixture is used as the support element 11, examples of the fixture include a resin, metal, metal stopper, staple, tape, rubber, clip, and the like molded into the shape of the support element 11 shown in FIGS. Can be mentioned. In consideration of environmental problems, biodegradable plastics and materials containing cellulose such as paper and wood may be used.
Further, the molded resin or metal stopper may be integrated with the backlight housing. These methods are easier to process than welding, and are suitable for joining outside the display area.

  In addition, when the optical sheet 9 is fixed using the support element 11, an opening for positioning is provided in advance in the diffusion film 1, the lens sheet 5, and the light diffusion layer 7 in consideration of improvement in work efficiency. The optical sheet 9 can be easily assembled by providing a pin that penetrates through the opening. When there are a plurality of pins on the support element 11, the positional accuracy is further improved.

  In the case of using a method in which excimer is irradiated and room temperature bonding is used as the support element 11, after irradiating one or both of the two materials to be bonded with 178 nm excimer UV, the two materials are laminated. Heat may be applied during lamination, or heat may be applied after lamination.

(Second Embodiment)
A second embodiment of the present invention will be described below.
In the case of the optical sheet 9 described above, a configuration in which there is one each of the diffusion film 1, the lens sheet 5, and the light diffusion layer 7 is shown. Here, by using the support element 11 described above, the following configuration of the optical sheet 9 is also possible.

FIG. 8 shows the lens sheet 5 in which two cylindrical lens sheets that are orthogonal to each other are stacked (laminated) (FIG. 9), and the side surface of the light diffusion layer 7 laminated thereon is fixed with a support element 11. Is.
In this way, by using the support element 11, the side surface of a plurality of sheets and films laminated, such as a configuration in which two lens sheets 5 are located under the diffusion film 1 and a light diffusion layer 7 is further provided thereunder. It is also possible to prevent warpage of the optical sheet 9 as shown in FIG. 8 by fixing and securing the air flow from the optical sheet 9 by the method described in detail below.

  In FIG. 9, two cylindrical lens sheets are laminated as the lens sheet 5 at right angles. However, the type of the lens sheet 5 is not limited to this, and may be a triangular prism, a convex cylindrical shape, a parabolic shape, or the like. The lens array may be a one-dimensional array, or the lens array such as a microlens may be a two-dimensional array.

  In the triangular prism, as shown in FIG. 21, the left and right sides may be asymmetric, and the sides may be curved instead of straight. Similarly, it is not limited to a curved lens having left and right sides that are symmetrical as in a convex cylindrical lens, but may also be asymmetrical to the left and right.

Furthermore, in the above-described triangular prism, the apex portion of the unit lens and the valley portion between the unit lenses may be rounded. Further, a trapezoidal prism as shown in FIG.
That is, if the second gap 4 is formed between the unit lenses of the lens sheet 5, air can be passed.

In consideration of stacking a plurality of lens sheets 5, the top of the lens sheet 5 may be substantially flat. In this case, the lens sheets 5 can be laminated more stably.
Further, in this case, as shown in FIG. 23, a light reflecting layer containing the above-described high refractive index transparent particles may be formed substantially flat on the top of the lens portion. This is because the light emitted from the lens sheet 5 can be controlled.

  In addition, since a plurality of lens sheets 5 are laminated, optical contact (prevention of Newton's ring, etc.) is prevented, and in order to allow more air to pass, a fine uneven shape is formed on the back side of the lens sheet 5 on which the lens is formed. It may be given.

  In the above-described configuration, the case where at least two lens sheets 5 are used is defined, but naturally one lens sheet 5 may be used. The material and manufacturing method of the lens sheet are the same as those described above.

  Next, FIG. 10 shows a configuration in which the diffusion film 1 is laminated on the lens sheet 5. The reason for laminating the diffusion film 1 is the same as described above. When the lens sheet 5 is a triangular prism or the like, the top is prevented from being scratched, and the moire caused by the lens pitch P of the lens sheet 5 and the pixels of the display is reduced. And so on.

  As the diffusion film 1 used in this case, a PET base film provided with a layer in which a filler is dispersed on both sides or one side, or a polycarbonate surface with a mat shape can be used. In addition, considering the case where the support element 11 is partially fixed, wrinkles or the like due to the weight of the diffusion film 1 is less likely to occur when the rigidity of the diffusion film 1 is a certain degree. Therefore, the film thickness of the diffusion film 1 is 0.3 mm or more. More preferably. In this case, the haze of the diffusion film 1 is preferably 40% to 80%.

Next, the light diffusion layer 7 laminated under the lens sheet 5 is the same as the light diffusion layer 7 used in the configuration of FIG.
FIG. 11 shows an uneven surface formed on the surface of the light diffusion layer 7. In this case, the concavo-convex shape has a cylindrical shape. As a result, air flows through the gap between the projections and depressions of the lens sheet 5 and the light diffusing layer 7 and is effective in preventing warpage.

  Here, a plurality of lens sheets 5 are used, or, for example, at least one lens sheet 1 contains the transparent particles used in the light diffusing layer 7 described above, whereby a lamp image of the light source 15 (light source 15 The light diffusing layer 7 may not be used when there is almost no place where the light source 15 and the light source 15 appear dark.

  For example, FIG. 25 shows an optical sheet 9 in which two lens sheets 5 are laminated on a light diffusion layer 7 and fixed by a support element 11. Here, of the two lens sheets 5, the lens sheet 5 laminated thereon contains the transparent particles used in the above-described light diffusion layer 7. FIG. 25A shows a case where transparent particles are included in the entire lens sheet 5, and FIG. 25B shows that transparent particles are included in addition to the lens portion Y of the lens sheet 5. FIG. 25C shows a case where transparent particles are contained only in the lens portion Y of the lens sheet 5. In the case of FIG. 25, if there is almost no lamp image without the light diffusion layer 7 in FIG. 25, the light diffusion layer 7 may be omitted.

Next, as shown in FIG. 12A, the support element 11 is fixed to the pair of opposite sides of the optical sheet 9 by the support element 11 as in the configuration of FIG. As shown, there is a method of fixing all four sides of the optical sheet 9 with the support element 11. The type, material and manufacturing method of the support element 11 are the same as those described above.
In some cases, for example, one side of the optical sheet 9 may be partially fixed by the support element 11 without fixing all one side of the optical sheet 9 by the support element 11.
In any case, it is assumed that air flows between the optical sheets 9.

  First, a method of fixing the pair of opposite sides of the optical sheet 9 facing the support element 11 with the support element 11 is performed by the method shown in FIGS. 4 and 5 described above. Here, in the case where a plurality of lens sheets 5 are used orthogonally, the second gap 4 is formed between any of the laminated lens sheets 5 and thus is not fixed by the support element 11. Another pair of opposite sides is air.

Next, when all four sides of the optical sheet 9 are fixed with the support element 11, since all the side surfaces of the lens sheet 5 and the light diffusion layer 7 are fixed, the rigidity of the optical sheet 9 itself is dramatically improved, Further, since the optical sheet 9 is fixed from four sides, wrinkles are hardly generated.
In this case, in order to ensure the flow of air between the optical sheets 9, a gap T is provided between the lens sheet 5, the light diffusion layer 7, the diffusion film 1 and the support element 11 as shown in FIG. 13. Necessary. Here, the clearance gap T should just open at least one place among the optical sheet 4 sides. In consideration of the air flow, it is more preferable that there are two or more entrances and exits. That is, it is only necessary that air leaks between the side surface of the optical sheet 9 and the support element 11.

  Further, when all four sides of the optical sheet 9 are fixed by the support element 11, for example, a configuration in which at least one or more holes W are opened in the support element 11 itself may be employed. Here, the size, shape, position, and number of the holes W may be appropriately determined in consideration of more leakage of air between the side surface of the optical sheet 9 and the support element 11.

Further, for example, when the support element 11 is made of plastic, metal such as aluminum or stainless steel, the lens sheet 5 or the light diffusion layer 7 is formed by impact or expansion / contraction of the lens sheet 5 under a high temperature condition. A shock absorber such as rubber, sponge, or spring is preferably provided between the side surface of the optical sheet 9 and the support element 11 because it collides with the support element 11 and generates friction powder or other wear powder from the lens sheet 5 or the like. In this case, it is necessary for air to leak from the buffer material, or between the buffer material and the support element 11, or between the buffer material and the optical sheet 9.
Further, in order to further improve the air leakage, the cushioning material does not have to be on the entire surface of the support element 11, and the cushioning material may be attached at intervals. Such a cushioning material may be appropriately fixed with an adhesive, an adhesive, or the like when being fixed to the support element 11 or the side surface of the optical sheet 9.

Moreover, as shown in FIG. 14, the slide V may be formed in the support element 11 in the position where the diffusion film 1, the lens sheet 5, and the light-diffusion layer 7 are arrange | positioned. Thereby, the diffusion film 1 etc. can be arrange | positioned stably. In this case, not only four sides but only three sides may be fixed.
In the case of three sides, the lens sheet 5 and the like can be slid and inserted from the side where the support element 11 is not provided, so that the work efficiency is good.

Moreover, it is preferable that the surface side which contacts the optical sheet 9 of the support element 11 is a rough surface. This is because air easily flows between the optical sheet 9 and the support element 11. Further, in order to improve the brightness of the optical sheet, the light K incident from the light source 15 reflects the light leaked to the end of the optical sheet 9 and is reused in the optical sheet 9, so that it contacts the optical sheet 9 of the support element 11. A reflective layer containing the above high refractive index transparent particles may be formed on the surface side surface. Conversely, if the casing in which the optical sheet 9 is installed in the display device 13 is white and reflects light well, the support element 11 may be transparent.

When the four sides of the optical sheet 9 are fixed by the support element 11, the arrangement and configuration of the lens sheet 5, the diffusion film 1, and the light diffusion layer 7 in the optical sheet 9 may be any. This is because air leaks between the support element 11 and the optical sheet 9.
Furthermore, when fixing with the support element 11, since it fixes, maintaining the clearance gap T with the support element 11, the magnitude | size of the lens sheet 5, the diffusion film 1, and the light-diffusion layer 7 may differ a little.

A typical configuration example of the optical sheet 9 produced as described above is shown below.
FIG. 15 shows a structure in which a trapezoidal prism is used as the lens sheet 5 on the light diffusion layer 7. A reflective layer X containing high refractive index transparent particles is formed under the first gap 6 of the trapezoidal prism. In this case, more preferably, the support element 11 is fixed so that air flows from the first gap 6.

  FIG. 16 shows a lens sheet 5 having a cylindrical shape with a concave surface on the back surface of a lens portion Y, and a reflective layer X containing high refractive index transparent particles is formed on the bottom of the convex portion. . In this case, more preferably, the support element 11 may fix the air so that air flows from the first gap 6.

  FIG. 17 shows the optical sheet 9 of FIG. 16 in which the concave portion of the lens sheet 5 is a part of an ellipse and a curved surface. Also in this case, it is more preferable to fix the support element 11 so that air flows from the first gap 6.

FIG. 18 shows a lens sheet 5 having a cylindrical shape with an irregular surface on the back surface, and a reflective layer X containing high refractive index transparent particles is formed in the concave portion. In this case, it is preferable that air leaks from the gap T between the support element 11 and the optical sheet 9.
In this case, in order to increase air leakage, it is preferable to fix only two sides with the support element 11.

  FIG. 19 shows a lens sheet 5 in which fine irregularities are provided under a cylindrical lens portion Y. In this case, more preferably, the support element 11 may fix the air so that air flows from the first gap 6.

  FIG. 20 shows the lens sheet 5 having a different height of the lens portion Y. In this case, the support element 11 is different in the height of the support element 11 on the right and left, The support element 11 having a shape or the like is appropriately selected and fixed. In this case, it is preferable that air leaks from the gap T between the support element 11 and the optical sheet 9.

  FIG. 21 shows a case where triangular prisms having different left and right lens shapes are used as the lens sheet 5, and in this case, more preferably, the optical sheet is formed by the fixed element 11 so that air flows from the second gap 4. 9 is fixed.

  FIG. 22 shows the lens sheet 5 in which two cylindrical lens sheets are laminated in parallel. In this case, more preferably, the support element 11 may fix the air so that air flows from the first gap 6.

  In FIG. 23, as the lens sheet 5, the top part of the cylindrical lens sheet 5 is flat, the tops thereof having the reflective layer X formed thereon are arranged orthogonally, and the diffusion film 1 is further laminated thereon. Yes. In this case, more preferably, the support element is configured so that air flows from the first gap 6 or between the second gap 4 formed between the diffusion film 1 and the lens sheet 5 although not visible from FIG. 11 should be fixed.

  In FIG. 24, a cylindrical lens sheet is laminated as the lens sheet 5 with the lens portions facing in opposite directions. In this case, more preferably, the support element 11 may fix the air so that air flows from the first gap 6.

  The optical sheet 9 produced by the above description is not limited to the use for improving the luminance of the backlight, but also includes a viewing angle control film for a display such as LCD, EL, and PDP, a contrast enhancement film, a light control film for solar cells, It can be used for a projection screen.

FIG. 26 is a side view illustrating an example of a backlight unit and a display device using the optical sheet 9 according to the embodiment of the present invention.
In the backlight unit according to the embodiment of the present invention, a plurality of cylindrical light sources 15 housed in a lamp house (not shown) and light K from each light source 15 are sandwiched between polarizing plates 21. An optical sheet 9 to be supplied to the liquid crystal panel 19 is provided. In the figure, reference numeral 17 denotes a light reflecting plate disposed on the back side of the plurality of light sources 41.

  The display device according to the embodiment of the present invention is a device that includes the light source 15 and the optical sheet 9 described above, and further includes a liquid crystal panel 19 thereon. In this case, the display device is a liquid crystal display device, but is not limited to this, and is a display device that displays an image using light, such as a projection screen device, a plasma display, and an EL display, including the optical sheet 9 described above. There is no limitation on the type.

  The optical sheet 9 can be used not only in the case where the light source is a cold cathode fluorescent lamp, but also in a display device using LEDs, EL, semiconductor lasers, and the like that have recently attracted attention as light sources for displays.

  Here, when an LED is used as the light source of the display device, as shown in FIG. 29 (a), an array of red, green, and blue LEDs is used, and an array of red, green, and blue LEDs is guided by a light guide plate or the like. Light that is uniformly emitted as white light, or light from an array of red, green, and blue LEDs using a diffuser plate or the like as shown in FIG. It can be used also for what can be emitted.

The backlight unit is becoming thinner and thinner, and the distance between the light source and the optical sheet is shortened accordingly. However, if the optical sheet 9 of the present invention is used, a direct type or side edge type backlight is used. Even in the unit, there is no influence of visibility such as a dark spot generated between the light source lamps, and the unit can be used sufficiently.
Furthermore, the size of the optical sheet 39 is also increasing along with the increase in the size of the display device, but the optical sheet 39 of the present invention is thin and strong, and further has excellent display quality. It can be sufficiently used for such a large display device.

  FIG. 26 shows an embodiment in which the optical sheet 9 according to the present invention is used in a direct backlight unit and a display device using the backlight unit.

  FIG. 27 shows an embodiment in which the optical sheet 9 according to the present invention is used for the side-edge type light guide plate 23.

  FIG. 28 shows an example in which the EL light source 25 is used as the light source of the display using the optical sheet 9 according to the present invention.

(Production method of optical sheet)
Example 1
A polycarbonate resin, which is a thermoplastic resin, is heated to about 300 ° C., formed into a 0.3 mm thick film while being stretched along a roll, and then heated using a cylinder mold with a microlens shape cut. The film was cooled while being pressurized (cylinder mold itself was 80 ° C.) to reduce the viscosity of the thermoplastic resin and to be completely cured. The lens sheet 5 produced by this method is a microlens group having a lens diameter of 50 μm and a height H of 25 μm. Next, an acrylic fine particle adhesive having a particle size of 50 μm was uniformly applied by spraying to the entire emission surface 102 side of the light diffusion layer 7 so that the adhesion area was 5%. And it compressed in the state which accumulated the back surface of the light-diffusion layer 7 which is an application surface of this fine particle adhesive, and the entrance plane 104 side of the lens sheet 5. As shown in FIG. Next, an acrylic adhesive was applied to one surface of the diffusion film 1 and compressed in a state where the lens portions of the lens sheet 5 were overlapped. Thus, the optical sheet 9 was produced. Furthermore, a set of end faces of the optical sheet 9 was fixed 5 mm from the end by a plastic siding plate (supporting element 11).
When the optical sheet 9 thus prepared was measured with an easy contrast (viewing angle measuring device), a front luminance distribution without side lobes could be obtained as shown in the graph with the diffusion film 1 in FIG.
Further, the optical sheet 9 produced as described above was placed at 80 ° C. for 24 hours. This condition assumes the temperature when the backlight is lit.
As a result, the light diffusion layer 7, the lens sheet 5, and the diffusion film 1 were not peeled off or warped, and no bubbles were generated from the adhesive.
In addition, in order to test the vibration state due to transportation, a lamp unit containing the prepared optical sheet 9 and a cold cathode lamp was assembled in a housing to produce a backlight unit, and a liquid crystal panel was installed on the backlight unit. The periphery of the backlight unit and the liquid crystal panel was fixed with a fastener and placed in a housing to produce a liquid crystal display device.
In addition, in order to test the vibration state due to transportation, the liquid crystal display device manufactured as described above has a frequency of 5 to 50 Hz, an acceleration of 1.0 G, 70 minutes in the Z direction, 20 minutes in the X direction, and 20 minutes in the Y direction. For 20 minutes. As a result, the optical sheet 9 was not peeled off or warped.

(Production method of optical sheet)
(Example 2)
A polycarbonate resin, which is a thermoplastic resin, is heated to about 300 ° C., formed into a 0.3 mm thick film while being stretched along a roll, and then heated using a cylinder mold in which the shape of a triangular prism is cut. The formed film was cooled while being pressurized (cylinder mold itself was 80 ° C.) to reduce the viscosity of the thermoplastic resin and to be completely cured. The lens sheet 5 produced by this method is a triangular prism group having a lens pitch P of 50 μm and a height H of 25 μm. Next, an acrylic fine particle adhesive having a particle size of 50 μm was uniformly applied by spraying to the entire emission surface 102 side of the light diffusion layer 7 so that the adhesion area was 5%. And it compressed in the state which accumulated the back surface of the light-diffusion layer 7 which is an application surface of this fine particle adhesive, and the entrance plane 104 side of the lens sheet 5. As shown in FIG. Next, an acrylic adhesive was applied on one surface of the diffusion film, and the lens portion of the lens sheet 5 was compressed in a superposed state. In this way, the optical sheet 9 was further fixed with a plastic siding plate (supporting element 11) 5 mm from the end of the set of end faces parallel to the longitudinal direction N of the triangular prism among the set of end faces of the optical sheet 9 ( Optical sheet A).
Similarly, the optical sheet 9 manufactured as described above is a plastic siding plate (supporting element 11) having a pair of end faces perpendicular to the longitudinal direction N of the triangular prism among the pair of end faces of the optical sheet 9 and 5 mm from the end. ) (Optical sheet B).
Similarly, the optical sheet 9 manufactured as described above was further fixed with a plastic siding plate (supporting element 11) 5 mm from the end of all four sides of the optical sheet 9 (optical sheet C).
When the optical sheets A, B, and C produced in this way were each measured with an easy contrast (viewing angle measuring device), a front luminance distribution without side lobes was obtained as shown in the graph with the diffusion film 1 in FIG. I was able to.
Furthermore, optical sheets A, B, and C produced as described above were placed at 80 ° C. for 24 hours. This condition assumes the temperature when the backlight is lit.
As a result, the optical sheet A peeled off the light diffusion layer, the lens sheet, and the diffusion film, and no warpage occurred, and no bubbles were generated from the adhesive, but the optical sheets B and C were peeled off or warped. .
In addition, in order to test the vibration state due to transportation, the produced optical sheets A, B, and C are each assembled with a lamp house containing a cold cathode lamp in a housing to produce a backlight unit, and further on the backlight unit. A liquid crystal panel was installed, and the periphery of the backlight unit and the liquid crystal panel was fixed with a fastener and placed in a housing to produce a liquid crystal display device.
In addition, in order to test the vibration state due to transportation, the liquid crystal display device manufactured as described above has a frequency of 5 to 50 Hz, an acceleration of 1.0 G, 70 minutes in the Z direction, 20 minutes in the X direction, and 20 minutes in the Y direction. For 20 minutes. As a result, the optical sheets A, B, and C were not peeled off or warped.

(Production method of optical sheet)
(Example 3)
A polycarbonate resin, which is a thermoplastic resin, is heated to about 300 ° C., formed into a 0.3 mm thick film while being stretched along a roll, and then heated using a cylinder mold in which the shape of a triangular prism is cut. The formed film was cooled while being pressurized (cylinder mold itself was 80 ° C.) to reduce the viscosity of the thermoplastic resin and to be completely cured. The lens sheet 5 produced by this method is a triangular prism group having a lens pitch P of 50 μm and a height H of 25 μm. Next, an acrylic fine particle adhesive having a particle diameter of 50 μm was uniformly applied by a bar coater to the entire light exit surface 102 side of the light diffusion layer 7 so that the adhesion area was 5%. And it compressed in the state which accumulated the back surface of the light-diffusion layer 7 which is an application surface of this fine particle adhesive, and the entrance plane 104 side of the lens sheet 5. As shown in FIG. Next, an acrylic adhesive was applied on one surface of the diffusion film, and the lens portion of the lens sheet 5 was compressed in a superposed state. In this way, the optical sheet 9 was further fixed with a plastic siding plate (supporting element 11) 5 mm from the end of the set of end faces parallel to the longitudinal direction N of the triangular prism among the set of end faces of the optical sheet 9 ( Optical sheet D).
In the optical sheet manufactured as described above, an acrylic fine particle adhesive having a particle size of 50 μm is uniformly applied to the entire light exit surface 102 side of the light diffusion layer 7 with a bar coater so that the adhesion area is 0.03%. (Optical sheet E).
Moreover, in the optical sheet produced as described above, an acrylic fine particle adhesive having a particle diameter of 50 μm was uniformly applied by a bar coater to the entire emission surface 102 side of the light diffusion layer 7 so that the adhesion area was 30%. (Optical sheet F).
When the optical sheets D and E thus produced were measured with an easy contrast (viewing angle measuring device), a front luminance distribution without side lobes can be obtained as shown in the graph with the diffusion film 1 in FIG. did it. However, in the optical sheet F, uneven adhesion was confirmed from the viewing surface side.
Furthermore, the optical sheets D, E, and F produced as described above were placed at 80 ° C. for 24 hours. This condition assumes the temperature when the backlight is lit.
As a result, the optical sheets D and F were not peeled off or warped, and no bubbles were generated from the adhesive, but the optical sheet E was peeled off.

(Production method of optical sheet)
Example 4
A polycarbonate resin, which is a thermoplastic resin, is heated to about 300 ° C., formed into a 0.3 mm thick film while being stretched along a roll, and then heated using a cylinder mold in which the shape of a triangular prism is cut. The formed film was cooled while being pressurized (cylinder mold itself was 80 ° C.) to reduce the viscosity of the thermoplastic resin and to be completely cured. The lens sheet 5 produced by this method is a triangular prism group having a lens pitch P of 50 μm and a height H of 25 μm. Next, an acrylic fine particle adhesive having a particle size of 50 μm was uniformly applied by spraying to the entire emission surface 102 side of the light diffusion layer 7 so that the adhesion area was 5%. And it compressed in the state which accumulated the back surface of the light-diffusion layer 7 which is an application surface of this fine particle adhesive, and the entrance plane 104 side of the lens sheet 5. As shown in FIG. Next, an acrylic adhesive was applied to the entire surface of the diffusion film with a film thickness T of 5 μm, and the lens part of the lens sheet 5 was compressed in a superposed state. In this way, the optical sheet 9 was further fixed with a plastic siding plate (supporting element 11) 5 mm from the end of the set of end faces parallel to the longitudinal direction N of the triangular prism among the set of end faces of the optical sheet 9 ( Optical sheet G).
In the optical sheet produced as described above, an acrylic adhesive was applied to the entire surface of the diffusion film with a film thickness T of 12 μm, and the lens portion of the lens sheet 5 was compressed in a superposed state. (Optical sheet H).
Moreover, in the optical sheet produced as described above, an acrylic adhesive was applied to the entire surface of one side of the diffusion film with a film thickness T of 30 μm, and the lens portion of the lens sheet 5 was compressed in a superposed state. . (Optical sheet I).
The optical sheets G, H, and I produced as described above were placed at 80 ° C. for 24 hours. This condition assumes the temperature when the backlight is lit.
As a result, the optical sheets G and H did not warp and no bubbles were generated from the adhesive, but the optical sheet I warped. Further, when the end faces of the optical sheets G, H, and I were observed with a stereomicroscope, the first gap 6 was confirmed in the optical sheets G and H, but in the optical sheet I, the first gap 6 was filled with an adhesive. I found out.

(Production method of optical sheet)
(Example 5)
A polycarbonate resin, which is a thermoplastic resin, is heated to about 300 ° C., formed into a 0.3 mm thick film while being stretched along a roll, and then heated using a cylinder mold with a microlens shape cut. The film was cooled while being pressurized (cylinder mold itself was 80 ° C.) to reduce the viscosity of the thermoplastic resin and to be completely cured. The lens sheet 5 produced by this method is a microlens group having a lens diameter of 50 μm, a height H of 25 μm, and an apex angle θ of 90 °. Next, an acrylic fine particle adhesive having a particle size of 50 μm was uniformly applied by spraying to the entire emission surface 102 side of the light diffusion layer 7 so that the adhesion area was 5%. And it compressed in the state which accumulated the back surface of the light-diffusion layer 7 which is an application surface of this fine particle adhesive, and the entrance plane 104 side of the lens sheet 5. As shown in FIG. Next, an acrylic adhesive was applied to one surface of the diffusion film 1 and compressed in a state where the lens portions of the lens sheet 5 were overlapped. Thus, the optical sheet 9 was produced. Furthermore, a set of end faces of the optical sheet 9 was fixed 5 mm from the end by a plastic siding plate (supporting element 11) (optical sheet J).
In the optical sheet manufactured as described above, the lens sheet 5 having a lens diameter of 50 μm, a height H of 25 μm, and an apex angle θ of 55 ° was manufactured (optical sheet K).
Further, in the optical sheet manufactured as described above, the lens sheet 5 was manufactured as a microlens group having a lens diameter of 50 μm, a height H of 25 μm, and an apex angle θ of 130 ° (optical sheet L).
When the optical sheets J, K, and L thus produced were measured with an easy contrast (viewing angle measuring device), the optical sheet J had a front luminance without side lobes as shown in the graph with the diffusion film 1 in FIG. Distribution could be obtained. Further, the optical sheets K and L were shaped like a graph with a diffusion film in FIG. 33, but the front luminance was low and the optical characteristics were poor as an optical sheet for display.

(Production method of optical sheet)
(Example 6)
A polycarbonate resin, which is a thermoplastic resin, is heated to about 300 ° C., formed into a 0.3 mm thick film while being stretched along a roll, and then heated using a cylinder mold in which the shape of a triangular prism is cut. The formed film was cooled while being pressurized (cylinder mold itself was 80 ° C.) to reduce the viscosity of the thermoplastic resin and to be completely cured. The lens sheet 5 produced by this method is a triangular prism group having a lens pitch P of 50 μm and a height H of 25 μm. Next, an acrylic fine particle adhesive having a particle size of 50 μm was uniformly applied by spraying to the entire emission surface 102 side of the light diffusion layer 7 so that the adhesion area was 5%. And it compressed in the state which accumulated the back surface of the light-diffusion layer 7 which is an application surface of this fine particle adhesive, and the entrance plane 104 side of the lens sheet 5. As shown in FIG. Next, an acrylic adhesive was applied on one surface of the diffusion film, and the lens portion of the lens sheet 5 was compressed in a superposed state. In this way, the optical sheet 9 was further fixed with a plastic siding plate (supporting element 11) 5 mm from the end of the set of end faces parallel to the longitudinal direction N of the triangular prism among the set of end faces of the optical sheet 9 ( Optical sheet A).
Similarly, the optical sheet 9 manufactured as described above is a plastic having a shape shown in FIG. 5 with a set of end faces orthogonal to the longitudinal direction N of the triangular prism among the set of end faces of the optical sheet 9 being 5 mm from the end. Only one pitch of the unit lens of the lens sheet 1 was fixed with the siding plate (supporting element 11) (optical sheet M).
Similarly, in the optical sheet produced as described above, a set of end faces perpendicular to the longitudinal direction N of the triangular prism among the set of end faces of the optical sheet 9 is a plastic having a shape shown in FIG. The two pitches of the unit lenses of the lens sheet 1 were fixed with the siding plate (supporting element 11) (optical sheet N).
In order to test the vibration state due to transportation of the optical sheets M and N produced in this way, the optical sheets M and N are assembled in a housing together with a lamp house containing a cold cathode lamp, and a backlight unit is produced. A liquid crystal panel was installed on the backlight unit, the periphery of the backlight unit and the liquid crystal panel was fixed with a fastener, and the liquid crystal display device was manufactured by placing it in a housing.
In order to test the vibration state due to transportation, the liquid crystal display device manufactured as described above has a vibration frequency of 5 to 50 Hz, an acceleration of 1.0 G, 70 minutes in the Z direction, 20 minutes in the X direction, and 20 minutes in the Y direction. Minute test. As a result, no peeling or warping occurred in the optical sheet N, but in the scholarly sheet M, the support element 11 was peeled off and the optical sheet was peeled off.

(Production method of optical sheet)
(Example 7)
The resin of acrylonitrile styrene copolymer is heated to about 300 ° C, formed into a 0.3mm thick film while being stretched along a roll, and then heated using a cylinder mold with a cylindrical shape cut. The formed film was cooled while being pressurized (cylinder mold itself was 80 ° C.) to reduce the viscosity of the thermoplastic resin and to be completely cured. By this method, two cylindrical lens sheets were produced. This is a cylindrical lens group having a lens pitch P of 60 μm and a height H of 30 μm. Next, the light diffusion layer 7 was prepared by using a transparent resin as an acrylonitrile styrene copolymer and dispersing and blending acrylic particles therein.
Next, a cylindrical lens sheet was orthogonally crossed on the light diffusion layer 7 produced as described above.
Next, a pair of opposite sides of the optical sheet 9 facing each other are fitted to the side surfaces of the lens sheet 5 and the light diffusing layer 7 laminated in this manner with a support element 11 made of aluminum and having the shape shown in FIG. Fixed.
When the optical sheets 9 thus produced were each measured with an easy contrast (viewing angle measuring device), a front luminance distribution without side lobes was obtained as shown in the graph with the diffusion film 1 in FIG. .
Further, the optical sheet 9 produced as described above was placed at 80 ° C. for 24 hours. This condition assumes the temperature when the backlight is lit.
As a result, the optical sheet A was hardly warped in the light diffusion layer, the lens sheet, and the diffusion film.
In addition, in order to test the vibration state of the produced optical sheet 9 due to transportation, the optical sheet 9 is assembled in a housing together with a lamp house containing a cold cathode lamp to produce a backlight unit, and a liquid crystal is further formed on the backlight unit. A panel was installed, and the periphery of the backlight unit and the liquid crystal panel was fixed with a fastener and placed in a housing to produce a liquid crystal display device.
In order to test the vibration state due to transportation, the liquid crystal display device manufactured as described above has a vibration frequency of 5 to 50 Hz, an acceleration of 1.0 G, 70 minutes in the Z direction, 20 minutes in the X direction, and 20 minutes in the Y direction. Minute test. As a result, no warpage occurred in the optical sheet 9, and no peeling occurred between the support element 11 and the optical sheet 9.

(Production method of optical sheet)
(Example 8)
A polycarbonate resin is heated to about 300 ° C., formed into a 0.3 mm thick film while being stretched along a roll, and then the heated film is pressurized using a cylinder mold with a cylindrical shape cut. While cooling (the cylinder mold itself was 80 ° C.), the viscosity of the thermoplastic resin was lowered and completely cured. By this method, two cylindrical lens sheets were produced. This is a cylindrical lens group having a lens pitch P of 60 μm and a height H of 30 μm. Next, the light diffusing layer 7 was prepared by using transparent resin as polycarbonate resin and dispersing and blending acrylic particles therein.
Next, a cylindrical lens sheet was orthogonally crossed on the light diffusion layer 7 produced as described above. Here, the size of the cylindrical lens sheet or the light diffusion layer 5 used this time is 37 inches.
Next, all four sides of the side surfaces of the lens sheet 5 and the light diffusing layer 7 thus laminated were fitted and fixed with the support elements 11 made of aluminum and having the shape shown in FIG. Here, holes with a diameter of 5 mm were opened at equal intervals by 5 centimeters in the support element 11 corresponding to each side. Here, since the support element 11 is strong when it is made of metal, the work efficiency is good in that only the support element 11 can be held by hand during work. In this case, if the support element 11 is provided with a handle for pressing with the hand, the working efficiency is further improved.
In order to test the vibration state due to transportation of the optical sheet 9 produced in this way, the optical sheet 9 is assembled in a housing together with a lamp house containing a cold cathode lamp, and a backlight unit is further manufactured. A liquid crystal panel was installed on the top, and the periphery of the backlight unit and the liquid crystal panel was fixed with a fastener and placed in a housing to produce a liquid crystal display device.
Further, the optical sheet 9 produced as described above was placed at 80 ° C. for 24 hours. This condition assumes the temperature when the backlight is lit.
As a result, the optical sheet A was hardly warped in the light diffusion layer, the lens sheet, and the diffusion film.
In addition, in order to test the vibration state of the produced optical sheet 9 due to transportation, the optical sheet 9 is assembled in a housing together with a lamp house containing a cold cathode lamp to produce a backlight unit, and a liquid crystal is further formed on the backlight unit. A panel was installed, and the periphery of the backlight unit and the liquid crystal panel was fixed with a fastener and placed in a housing to produce a liquid crystal display device.
In order to test the vibration state due to transportation, the liquid crystal display device manufactured as described above has a vibration frequency of 5 to 50 Hz, an acceleration of 1.0 G, 70 minutes in the Z direction, 20 minutes in the X direction, and 20 minutes in the Y direction. Minute test. As a result, no warpage occurred in the optical sheet 9, and no peeling occurred between the support element 11 and the optical sheet 9.

(Production method of optical sheet)
Example 9
A polycarbonate resin is heated to about 300 ° C., formed into a 0.3 mm thick film while being stretched along a roll, and then the heated film is pressurized using a cylinder mold with a cylindrical shape cut. While cooling (the cylinder mold itself was 80 ° C.), the viscosity of the thermoplastic resin was lowered and completely cured. By this method, two cylindrical lens sheets were produced. This is a cylindrical lens group having a lens pitch P of 60 μm and a height H of 30 μm. Next, the light diffusing layer 7 was prepared by using transparent resin as polycarbonate resin and dispersing and blending acrylic particles therein.
Next, a cylindrical lens sheet was orthogonally crossed on the light diffusion layer 7 produced as described above. Here, the size of the cylindrical lens sheet or the light diffusion layer 5 used this time is 37 inches.
Next, all four sides of the side surfaces of the lens sheet 5 and the light diffusion layer 7 thus laminated were laminated using polycarbonate and the support element 11 produced by injection molding into the shape shown in FIG. 4B. A 10 mm thick sponge was sandwiched between the lens sheet 5 and the side surface of the light diffusion layer 7 and the support element 11 and fixed.
In order to test the vibration state due to transportation of the optical sheet 9 produced in this way, the optical sheet 9 is assembled in a housing together with a lamp house containing a cold cathode lamp, and a backlight unit is further manufactured. A liquid crystal panel was installed on the top, and the periphery of the backlight unit and the liquid crystal panel was fixed with a fastener and placed in a housing to produce a liquid crystal display device.
Further, the optical sheet 9 produced as described above was placed at 80 ° C. for 24 hours. This condition assumes the temperature when the backlight is lit.
As a result, the optical sheet A was hardly warped in the light diffusion layer, the lens sheet, and the diffusion film.
In addition, in order to test the vibration state of the produced optical sheet 9 due to transportation, the optical sheet 9 is assembled in a housing together with a lamp house containing a cold cathode lamp to produce a backlight unit, and a liquid crystal is further formed on the backlight unit. A panel was installed, and the periphery of the backlight unit and the liquid crystal panel was fixed with a fastener and placed in a housing to produce a liquid crystal display device.
In order to test the vibration state due to transportation, the liquid crystal display device manufactured as described above has a vibration frequency of 5 to 50 Hz, an acceleration of 1.0 G, 70 minutes in the Z direction, 20 minutes in the X direction, and 20 minutes in the Y direction. Minute test. As a result, wrinkles, warpage, and abrasion powder from the lens sheet 5 and the like were not generated on the optical sheet 9.

(A) It is explanatory drawing which shows sectional drawing of the optical sheet which concerns on embodiment of this invention. (B) It is explanatory drawing which shows the perspective view of the lens sheet which concerns on embodiment of this invention. (A) It is explanatory drawing which shows sectional drawing of the optical sheet which concerns on embodiment of this invention. (B) It is explanatory drawing which shows the perspective view of the optical sheet which concerns on embodiment of this invention. (C) It is explanatory drawing which shows the perspective view of the optical sheet which concerns on embodiment of this invention. (A) It is explanatory drawing which shows the method of integration of the lens sheet and adhesive layer or contact bonding layer which concern on embodiment of this invention. (B) It is explanatory drawing which shows the method of integration of the lens sheet and adhesive layer or contact bonding layer which concern on embodiment of this invention. (C) It is explanatory drawing which shows the method of integration of the lens sheet and adhesive layer or contact bonding layer which concern on embodiment of this invention. (A) It is explanatory drawing which shows sectional drawing of the optical sheet which concerns on embodiment of this invention. (B) It is explanatory drawing which shows sectional drawing of the optical sheet which concerns on embodiment of this invention. (C) It is explanatory drawing which shows sectional drawing of the optical sheet which concerns on embodiment of this invention. It is explanatory drawing which shows sectional drawing of the optical sheet which concerns on embodiment of this invention. It is explanatory drawing which shows that air passes along the optical sheet which concerns on embodiment of this invention. (A) It is explanatory drawing which shows the flow of air when the optical sheet which concerns on embodiment of this invention is integrated in a display apparatus. (B) It is explanatory drawing which shows the flow of air when the optical sheet which concerns on embodiment of this invention is integrated in a display apparatus. It is explanatory drawing which shows sectional drawing of the optical sheet which concerns on embodiment of this invention. It is explanatory drawing which shows the perspective view of the lens sheet which concerns on embodiment of this invention. It is explanatory drawing which shows sectional drawing of the optical sheet which concerns on embodiment of this invention. It is explanatory drawing which shows sectional drawing of the optical sheet which concerns on embodiment of this invention. (A) It is explanatory drawing which shows the top view of the optical sheet which concerns on embodiment of this invention. (B) It is explanatory drawing which shows the top view of the optical sheet which concerns on embodiment of this invention. It is explanatory drawing which shows sectional drawing of the optical sheet which concerns on embodiment of this invention. It is explanatory drawing which shows sectional drawing which shows the optical sheet structural example which concerns on embodiment of this invention. It is explanatory drawing which shows sectional drawing which shows the optical sheet structural example which concerns on embodiment of this invention. It is explanatory drawing which shows sectional drawing which shows the optical sheet structural example which concerns on embodiment of this invention. It is explanatory drawing which shows sectional drawing which shows the optical sheet structural example which concerns on embodiment of this invention. It is explanatory drawing which shows sectional drawing which shows the optical sheet structural example which concerns on embodiment of this invention. It is explanatory drawing which shows sectional drawing which shows the optical sheet structural example which concerns on embodiment of this invention. It is explanatory drawing which shows sectional drawing which shows the optical sheet structural example which concerns on embodiment of this invention. It is explanatory drawing which shows sectional drawing which shows the optical sheet structural example which concerns on embodiment of this invention. It is explanatory drawing which shows sectional drawing which shows the optical sheet structural example which concerns on embodiment of this invention. It is explanatory drawing which shows sectional drawing which shows the optical sheet structural example which concerns on embodiment of this invention. It is explanatory drawing which shows sectional drawing which shows the optical sheet structural example which concerns on embodiment of this invention. (A) It is explanatory drawing which shows sectional drawing which shows the optical sheet structural example which concerns on embodiment of this invention. (B) It is explanatory drawing which shows sectional drawing which shows the optical sheet structural example which concerns on embodiment of this invention. (C) It is explanatory drawing which shows sectional drawing which shows the optical sheet structural example which concerns on embodiment of this invention. It is explanatory drawing which shows sectional drawing of the display apparatus which concerns on embodiment of this invention. It is explanatory drawing which shows sectional drawing of the display apparatus which concerns on embodiment of this invention. It is explanatory drawing which shows sectional drawing of the display apparatus which concerns on embodiment of this invention. (A) It is explanatory drawing which shows sectional drawing of the display apparatus which concerns on embodiment of this invention. (B) It is explanatory drawing which shows sectional drawing of the display apparatus which concerns on embodiment of this invention. It is explanatory drawing which shows the structural example of the liquid crystal display device by a prior art. It is explanatory drawing which shows the structural example of the liquid crystal display device by a prior art. It is explanatory drawing which shows the structural example of the liquid crystal display device by a prior art. It is explanatory drawing which shows the light intensity distribution radiate | emitted from the optical sheet using BEF.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Diffusion film, 2 ... Adhesive layer or adhesive layer, 3 ... Fixed element, 4 ... 2nd gap | interval, 5 ... Lens sheet, 6 ... 1st gap | interval, 7 ... Light diffusion layer, 9 ... Optical sheet, 11 ... Support element, 13 ... display device, 15 ... light source, 17 ... reflector, 19 ... liquid crystal layer, 21 ... polarizing plate, 23 ... light guide plate, 25 ... EL, 27, 29 ... LED, 100 ... incident surface of light diffusion layer DESCRIPTION OF SYMBOLS 102 ... Outgoing surface of light diffusing layer, 104 ... Incident surface of lens sheet, X ... Valley of unit lens, Y ... Top of unit lens, N ... Longitudinal direction of unit lens, T ... Film of adhesive layer or adhesive layer Thickness, H: height of unit lens, P: lens pitch of unit lens, G: first overhanging portion, U: second overhanging portion, F: flow of air flowing through first gap or second gap , K: Light source, S: Display viewing direction, α: Uneven valley X of unit lens Angle tangent forms of al the perpendicular line and the unit lens, the apex angle of theta ... unit lens, T ... clearance, V ... slide, W ... hole, X ... reflective layer, Y ... lens unit

Claims (26)

An optical sheet for a display,
A light diffusion layer for diffusing light from the light source of the display;
At least one lens sheet for controlling light from the light diffusing layer, on the light exit surface side of the light diffusing layer;
An optical sheet for display, comprising a support element for fixing the light diffusion layer and a side surface of the lens sheet. An optical sheet for a display,
A light diffusion layer for diffusing light from the light source of the display;
At least one lens sheet for controlling light from the light diffusing layer, on the light exit surface side of the light diffusing layer;
An optical sheet for a display, comprising: a support element that holds the light diffusion layer and the four side surfaces of the lens sheet while maintaining a gap. An optical sheet for a display,
A light diffusion layer for diffusing light from the light source of the display;
At least one lens sheet for controlling light from the light diffusing layer, on the light exit surface side of the light diffusing layer;
An optical sheet for display, comprising a support element for fixing any one pair of opposite sides among the four sides of the side surfaces of the light diffusion layer and the lens sheet. The support element is
A first projecting portion for fixing the light diffusion layer and the side surface of the lens sheet and the display outer region of the lens sheet from the side surface;
4. The optical sheet for display according to claim 1, further comprising a second projecting portion that fixes the light diffusion layer from the side surface. 5. The first overhang portion is
The optical sheet for display according to any one of claims 1 to 3, wherein the optical sheet for display according to any one of claims 1 to 3, wherein the optical sheet for display is engaged with and fixed to the unevenness of at least one unit lens of the lens portion of the lens sheet.   The optical sheet for display according to claim 1, wherein the support element is made of metal.   The optical sheet for display according to claim 1, wherein the support element is made of a resin.   4. The display optical sheet according to claim 1, wherein the support element has at least one hole. An optical sheet for a display,
A light diffusion layer for diffusing light from the light source of the display;
A light-emitting layer side of the light diffusion layer; a lens sheet that controls light from the light diffusion layer; and a light-emitting surface side of the lens sheet, and a diffusion film that diffuses light from the lens sheet,
The light diffusion layer and the lens sheet are integrated through a fixing element while maintaining a first gap,
Furthermore, the lens sheet and the diffusion film are integrated through an adhesive layer or an adhesive layer while maintaining the second gap,
4. The display optical sheet according to claim 3, further comprising a support element that fixes a pair of opposite sides of the light diffusion layer, the lens sheet, and the diffusion film.   The optical sheet for display according to claim 9, wherein the fixing element has an adhesive.   The optical sheet for display according to claim 9, wherein the fixing element has an adhesive.   The optical sheet for display according to claim 9, wherein when the fixing element is the adhesive or the pressure-sensitive adhesive, the adhesive and the pressure-sensitive adhesive contain fine particles.   The optical sheet for display according to claim 9, wherein the fixing element has a rib.   The optical sheet for display according to claim 9, wherein the fixing element has a reflective surface.   The optical sheet for display according to claim 9, wherein a ground contact area of the fixing element is 0.05% or more and 20% or less with respect to an area of an incident surface of the lens sheet. The optical sheet for display according to claim 9, wherein the surface of the light diffusion layer has a fine uneven shape. The optical sheet for display according to claim 9, wherein a fine particle layer is provided on a surface of the light diffusion layer. When the lens portion of the lens sheet is formed by arranging a plurality of unit triangular prisms or unit convex cylindrical lenses in parallel,
Of the two sets of facing end faces of the optical sheet for display, one set of the end faces parallel to the longitudinal direction of the unit triangular prism or unit convex cylindrical lens is fixed by a support element,
10. The optical sheet for display according to claim 9, wherein the first gap and the second gap of the other set of the end faces are opened.   The optical sheet for display according to claim 9, wherein an apex angle of the unit triangular prism is defined in a range of 70 ° ± 30 °.   10. The optical sheet for display according to claim 1, wherein the vicinity of the valley and the apex of the unit triangular prism are rounded. The optical sheet for display according to claim 9, wherein a relationship of 2T ≦ H is established between a thickness T of the adhesive or adhesive layer and a height H of the unit lens. An optical sheet for a display,
A light diffusion layer for diffusing light from the light source of the display;
At least one lens sheet for controlling light from the light diffusing layer, on the light exit surface side of the light diffusing layer;
A support element for fixing a side surface of the light diffusion layer and the lens sheet;
An optical sheet for display, wherein air leaks from between the light diffusion layer and the side surface of the lens sheet and the support element. An optical sheet for a display,
A light diffusion layer for diffusing light from the light source of the display;
At least one lens sheet for controlling light from the light diffusing layer, on the light exit surface side of the light diffusing layer;
A support element for fixing a side surface of the light diffusion layer and the lens sheet;
An optical sheet for display having a buffer material between the light diffusion layer and the side surface of the lens sheet and the support element. An optical sheet for display according to any one of claims 1 to 3 or claim 22 to claim 23, and a light source for irradiating light from a non-viewing surface side of the liquid crystal panel on a back surface of the optical sheet for display. Backlight unit characterized by that. The backlight unit;
A display device comprising the liquid crystal panel on a light emission surface side of the display optical sheet of the backlight.   20. The display device according to claim 19, wherein each of the backlight device and the display device has a light source, and the light source is any one of a cold cathode fluorescent lamp, an LED, an EL, and a semiconductor laser.