JP2009122440A - Prism member and optical member - Google Patents

Abstract

[PROBLEMS] To provide a prism member having good scratch resistance and capable of maintaining high luminance even when bonded to another sheet or film or colored.
A light diffusing plate 100A includes a prism plate 200A in which a plurality of linear prisms 210 are arranged on one surface, a diffusion sheet 300 laminated on the side of the prism plate 200A on which the prism 210 is formed, Consists of. The prism 210 formed on the prism plate 200 </ b> A includes two roof-shaped slope portions 211 and 212 and a top surface portion 213 provided between the slope portions 211 and 212. The slope portion 211, the slope portion 212, and the top surface portion 213 are formed in a substantially trapezoidal cross section.
[Selection] Figure 1

Description

  The present invention relates to a prism member and an optical member in which a large number of prisms are arranged.

Conventionally, surface light source devices used for liquid crystal backlights and the like have been required to have high luminance in the normal direction relative to the light emitting surface in addition to good visual characteristics. Therefore, a prism member having protrusions formed on the surface is used, and light rays passing through the slopes of the protrusions are refracted or reflected so that the light rays are directed in the normal direction with respect to the light emitting surface.
For example, Patent Document 1 describes a prism member in which the tip of a protrusion is formed into a curved surface.

Japanese Patent Laid-Open No. 7-20305

In recent years, sheets and films such as prism members have been used in a wide range of fields such as liquid crystal backlight units and rear transmission projectors, and these sheets and films can be combined to combine functions. It is desired.
When the prism member is bonded to another sheet or film, the projection of the prism member is likely to be scraped, and there is a high possibility that the light transmittance will change. Even if the tip of the protrusion is formed into a curved surface as in Patent Document 1, the apex is a single point, and thus the surface is easily scratched. Then, when a sheet or film is bonded to a protrusion having a sharp tip or a curved surface, the thickness of the adhesive becomes unstable and the bonding area changes. That is, there is a problem that the light transmittance changes.

  In addition, when adjusting the amount of light or coloring, it is difficult to apply paint only to the tops of the protrusions of the prism member. Since the slope portion of the protrusion is an optically important portion, there is a problem that if paint adheres to the slope portion, the light transmittance is affected and the luminance is lowered.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a prism member and an optical member that have good scratch resistance and can maintain high luminance even when bonded to another sheet or film or colored.

  The prism member of the present invention is a plate-like prism member in which a large number of prisms are arranged, and the prism includes two planar slopes inclined with respect to the thickness direction of the prism member, And a planar top surface portion formed between the two slope portions and parallel to the surface direction of the prism member.

In this invention, the prism member is a flat transparent plate, a transparent sheet, a transparent film, or the like. In this prism member, a large number of prisms each having a substantially trapezoidal cross section are arranged with two inclined surface portions inclined with respect to the thickness direction and a planar top surface portion formed between the inclined surface portions.
The inclination angle of the two slope portions is not particularly limited. The two slope portions may be inclined at the same angle or may be inclined at different angles, but are preferably the same angle from the viewpoint that high luminance can be obtained. In addition, in order to obtain an effect of reflecting light that enters a substantially right angle to the flat prism member, the inclination angle of the two slope portions is preferably 45 degrees with respect to the surface direction of the prism member.

  Thus, since the top surface portion of the prism is flat, the prism is hardly damaged. That is, since the prism shape can be maintained, there is no change in light transmittance. Therefore, high luminance can be maintained.

In addition, since the flat top surface portion is provided in parallel to the surface direction of the prism member, an adhesive or the like can be uniformly applied to the top surface portion when another sheet or film is bonded to the prism member. The thickness of the adhesive and the bonding area can be made constant. Therefore, the bonded portion can be kept beautiful and can be bonded to a sheet or film having another function while maintaining high luminance, so that the functions can be combined.
Similarly, when the prism member is colored, the thickness of the paint and the paint area can be made constant, so that a regular pattern can be colored. Therefore, it is possible to provide a prism member having characteristic optical characteristics due to the colored pattern.

  In the prism member of the present invention, it is preferable that a concave recess is formed in the top surface portion.

An adhesive or a paint is applied to the recess formed in the concave shape on the top surface portion.
One recess may be formed over the entire top surface portion, or a plurality of indentations may be formed on the top surface portion.
The shape of the recess is not particularly limited, and examples thereof include a substantially arc-shaped section, a substantially V-shaped section, and a substantially trapezoidal section. The depth of the indentation is not particularly limited, but is preferably 0.001 to 0.3 times the prism height. If the depth of the dent is less than 0.001 times the height of the prism, the adhesive or paint cannot be applied sufficiently. On the other hand, if it is larger than 0.3 times, it is necessary to apply an adhesive or paint more than necessary, and the material cost is increased.

  In this way, since the adhesive can be applied to the recess formed in the top surface portion, when another sheet or film is bonded to the prism member, the adhesive surface can be kept beautiful without the adhesive protruding. . In addition, since the paint can be applied to the recess, the paint does not adhere to the slope portion of the prism. Therefore, since there is no possibility of affecting the light transmittance, high luminance can be maintained and unevenness can be suppressed.

  In the prism member of the present invention, it is preferable that the pitch of the prism is 10 μm or more and 500 μm or less, and the height of the prism is 5 μm or more and 250 μm or less.

When the prism pitch is less than 10 μm, the prism becomes too dense, and when it exceeds 500 μm, the prism becomes too sparse. Therefore, since the incident light beam is less likely to be directed in the normal direction with respect to the light emitting surface, the luminance may be reduced. Further, when the height of the prism is less than 5 μm or more than 250 μm, the incident light beam is less likely to be directed in the normal direction with respect to the light emitting surface, so that the luminance may be lowered.
Therefore, by setting the prism pitch to 10 μm or more and 500 μm or less and the prism height to 5 μm or more and 250 μm or less, the incident light can be directed in the normal direction with respect to the light emitting surface, so that the brightness is high. be able to.

In the prism member according to the present invention, it is preferable that an angle formed by the two slope portions is 90 degrees.
According to the present invention, since the two inclined surfaces forming the prism are formed at an angle of 90 degrees, the light incident on these two inclined surfaces is refracted or reflected, and in the normal direction to the light emitting surface. Can collect rays. Therefore, high luminance can be achieved.

In the prism member of the present invention, it is preferable that the prisms are linearly arranged on at least one surface of the prism member.
Generally, in a backlight, a plurality of cold cathode fluorescent lamps (lights) are arranged in a straight line. By arranging the prisms in a straight line in parallel with the cold cathode tubes, the light of the light can be made uniform.

In the prism member of the present invention, it is preferable that the prisms are two-dimensionally arranged on at least one surface of the prism member.
In recent years, LEDs have been used in backlight units, but in order to diffuse the light of each of a plurality of point light sources of this LED, a conical or pyramidal tip is recessed on a flat surface. It is effective to arrange prisms having
In the present invention, the plurality of prisms arranged two-dimensionally can suppress the transmission of light immediately above the light, thereby making it possible to make the light uniform.

In the prism member of the present invention, it is preferable that a low prism having a lower height than the prism is provided between the plurality of prisms.
In particular, the low prism preferably has a pointed tip, for example, a substantially triangular cross section. According to this invention, it is excellent in optical characteristics (diffusibility, reflectivity), and can be bonded to a sheet having another function by a prism having a flat top surface portion.

The prism member of the present invention preferably contains a diffusing agent.
As the diffusing agent, one or more kinds selected from crosslinked PMMA resin particles, silicone resin particles, polyorganosilsesquioxane particles, silica particles, quartz particles, silica fibers, quartz fibers, and glass fibers. The combination of is mentioned.
According to the present invention, since predetermined particles or the like are added as a diffusing agent, a prism member having good diffusibility and sufficiently high luminance can be obtained.

  In the optical member of the present invention, it is preferable that at least one surface of the prism member is covered with a functional layer.

The layer having functionality is a layer for imparting another function to the prism member, and can impart, for example, diffusibility, antistatic properties, and antireflection properties.
In this invention, since the above-mentioned prism member is covered with a layer having another function, the functions can be combined.

In the optical member of the present invention, it is preferable that the functional layer is a diffusion sheet, and the diffusion sheet is laminated on one surface of the prism member.
In this invention, it can be used as a light diffusing plate by laminating a diffusion sheet on the aforementioned prism member. Thereby, the light beam emitted from the prism member can be sufficiently diffused. Therefore, high luminance can be achieved.

In the optical member of the present invention, it is preferable that the diffusion sheet is laminated on a surface of the prism member on the side where the prism is formed.
In this invention, the light beam emitted from the surface of the prism member on which the prism is formed can be diffused. Therefore, uniform brightness can be ensured from any angle.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[First embodiment]
(Configuration of light diffusion plate)
FIG. 1 is a perspective view of a light diffusing plate according to an embodiment of the present invention, and FIG. 2 is a front view of FIG.
As shown in FIG. 1, a light diffusing plate 100A includes a prism plate 200A in which a plurality of linear prisms 210 are arranged on one surface, and a diffusion sheet laminated on the side of the prism plate 200A where the prisms 210 are formed. 300. In the present embodiment, the prism plate 200A is the prism member of the present invention.

(Configuration of prism plate 200A)
The prism 210 formed on the prism plate 200A includes two slope portions 211 and 212 that are inclined with respect to the thickness direction of the prism plate 200A, and a planar top surface portion 213 provided between the slope portions 211 and 212. And consist of The top surface portion 213 is provided in parallel to the surface direction of the prism plate 200A. That is, the inclined surface portion 211, the inclined surface portion 212, and the top surface portion 213 are formed in a substantially trapezoidal cross section as shown in FIG. In the present embodiment, the angle of the inclined surface portion 211 with respect to the surface direction of the prism plate 200A and the angle of the inclined surface portion 212 are 45 degrees.

The pitch of the prisms 210 is preferably in the range of 10 μm to 500 μm, and is 200 μm in this embodiment. The height of the prism 210 is preferably 5 μm or more and 250 μm or less, and is 100 μm in this embodiment.
The apex angle θ formed by the slope portion 211 and the slope portion 212 is formed to be 90 degrees.

  As the thermoplastic resin used for the prism plate 200A, a polycarbonate resin, a cyclopolyolefin resin, an acrylic resin, a polysulfone resin, a polyarylate resin, a polyethersulfone resin, or the like is preferably used.

  The thickness of the prism plate 200A is not particularly limited, but is 0.5 to 3 mm, preferably 0.6 to 2 mm, from the viewpoint that the luminance can be improved and the luminance distribution can be made uniform. When the thickness of the prism plate 200A is 0.5 mm or more, the rigidity is appropriate, and flatness is maintained without being bent by its own weight when incorporated in a direct type backlight. Further, when the thickness of the prism plate 200A is 3 mm or less, the optical characteristics are not deteriorated and the lightness is maintained.

In addition, a light diffusing agent can be mixed into the thermoplastic resin. Examples of the light diffusing agent include at least one selected from a crosslinked acrylic resin, a crosslinked polystyrene resin, a silicone resin, a fluorine resin, silica, quartz, titanium oxide, and zinc oxide. These light diffusing agents have an average particle diameter of 1 to 200 μm, preferably 3 to 100 μm, and / or fiber length / fiber diameter (L / D) of about 2 to 100. preferable.
When a polycarbonate resin is used as the thermoplastic resin, the light diffusing agent is particularly preferably a combination of thermoplastic acrylic resin particles, crosslinked acrylic resin particles, and quartz fibers.

  The blending amount of the light diffusing agent may be selected by adjusting the light diffusing function along the optical characteristics of the shape of the prism 210 formed on the surface of the prism plate 200A. For example, with respect to 100 parts by mass of the thermoplastic resin, The light diffusing agent is 0.01 to 20 parts by mass, preferably 0.1 to 3 parts by mass.

(Configuration of diffusion sheet 300)
The diffusion sheet 300 is a sheet that diffuses light incident from the prism plate 200A. The diffusion sheet 300 is formed of a thermoplastic resin, and examples thereof include those obtained by applying various diffusion agents to the surface of a PET film by a coating method. As the diffusing agent, acrylic cross-linked beads or the like can be used.
The diffusion sheet 300 is attached to the prism plate 200 </ b> A via the adhesive 400. The adhesive 400 is applied smoothly on the top surface portion 213 of the prism 210, and the diffusion sheet 300 is laminated thereon. As the adhesive 400, an acrylic adhesive, a pressure-sensitive adhesive, a UV curable adhesive, a rubber adhesive, or the like can be used.

(Prism member manufacturing method)
In this embodiment, a polystyrene resin is used as the thermoplastic resin.
First, a resin material obtained by blending a polystyrene resin with a light diffusing agent is kneaded by a generally used method. For example, a ribbon blender, a Henschel mixer, a Banbury mixer, a drum tumbler, a single screw extruder, a twin screw extruder, a kneader, a multi screw extruder and the like can be mentioned.

  Next, the kneaded material is dried. The drying treatment is performed under conditions of 70 to 90 ° C. and 2 to 10 hours, and can be performed in an atmosphere such as heated air, dry air, or vacuum by a commonly used method. By this drying treatment, most of the volatile reaction byproducts generated when preparing the thermoplastic resin, the moisture contained in the light diffusing agent, and the transparent resin material can be removed.

Subsequently, the dried resin material is extruded with an extruder equipped with a devolatilizer, and formed into a sheet. A devolatilizer is required for an extrusion apparatus for forming a sheet. This devolatilizer can be decompressed to atmospheric pressure or lower in a molten state, and is normally decompressed to 8 kPa or less, preferably 4 kPa or less during extrusion. This vacuum devolatilization can remove moisture and volatile reaction byproducts remaining in the transparent resin material, and can also remove secondary volatile reaction byproducts generated by extrusion.
In addition, what is necessary is just to set the temperature at the time of sheet | seat shaping | molding suitably according to the material to be used.
If the devolatilization during the drying process and extrusion molding is insufficient, the foaming of the sheet or the rough surface occurs on the surface of the sheet, and the uniform diffusion of light in the sheet surface cannot be obtained.

Next, the prism 210 is formed on the surface of the obtained sheet.
The method of forming the prism 210 is not particularly limited, and examples thereof include a method of directly forming the prism 210 on the sheet and a method of forming the prism 210 by fusing a transparent resin sheet to the sheet. In addition to this, using a mold engraved with prisms, a method of providing the prism 210 by injection molding or press molding, or applying or injecting an acrylic transparent thermosetting resin to a mold engraved with prisms, etc. A diffusion plate is attached to the top, and then the curable resin is cured into a prism shape by irradiating it with electron beam, radiation, ultraviolet rays, etc. from the diffusion plate side, and then peeled off in a form adhered to the diffusion plate. Thus, there is a method for obtaining a prism member.

  In the prism plate 200 </ b> A thus obtained, the adhesive 400 is applied to the top surface portion 213 of the prism 210 with a uniform thickness, and the diffusion sheet 300 is bonded through the adhesive 400. In this way, the light diffusing plate 100A can be obtained.

The first embodiment described above has the following operational effects.
(1) Since the prism 210 has a substantially trapezoidal cross section, there is no protrusion at the tip of the prism 210, so that it is difficult to be damaged. That is, since there is no fear of the prism 210 being deformed, the light transmission is not affected. Therefore, good light transmittance and high luminance can be maintained.

(2) Since the top surface portion 213 is formed in a flat shape, the adhesive 400 can be uniformly applied to the top surface portion 213 when the diffusion sheet 300 is bonded to the prism plate 200A. That is, the thickness and adhesive area of the adhesive 400 can be made constant. Therefore, a beautiful flat surface with no unevenness can be formed on the surface of the bonded diffusion sheet 300.
Thereby, it can be bonded to a sheet or film having another function while maintaining high luminance, and the functions can be combined.

(3) In this embodiment, the pitch of the prisms 210 is 200 μm, the height is 100 μm, and the apex angle θ formed by the slope portions 211 and 212 is 90 degrees. The prism 210 formed in this way can collect light rays in the normal direction with respect to the light emitting surface by refraction or reflection of the light rays incident on the prism plate 200A by the inclined portions 211 and 212. Therefore, the brightness can be increased.

(4) In this embodiment, a diffusing agent is mixed with the material. Therefore, it is possible to provide a prism member that exhibits good diffusibility and sufficiently high brightness.

(5) In this embodiment, the diffusion sheet 300 is bonded to the prism plate 200A. With the diffusion sheet 300, the light incident from the prism 210 can be diffused. Therefore, a high-brightness light diffusing plate can be provided.

[Second Embodiment]
Since the second embodiment is the same as the first embodiment except that the recess 214 is formed in the top surface portion 213 of the first embodiment, the description thereof is omitted.
FIG. 3 shows a front view of the light diffusing plate according to the second embodiment of the present invention.
As shown in FIG. 3, the light diffusion plate 100 </ b> B includes a prism plate 200 </ b> B and a diffusion sheet 300. A concave recess 214 is formed on the top surface 213 of the prism plate 200B over the entire surface. The recess 214 is formed in a substantially arc shape in cross section, and its depth is about 10 μm at the deepest portion. This depth is preferably set to be 0.001 to 0.3 times the height of the prism 210.

In such a second embodiment, the same operational effects as described above and the following operational effects can be achieved.
(6) Since the concave recess 214 is formed in the top surface portion 213, the adhesive 400 can be easily applied to the recess 214. In addition, since the recess 214 has a certain depth, the adhesive 400 can be easily applied and the adhesive 400 does not protrude from the top surface portion 213. Therefore, when the diffusion sheet 300 is bonded, there is no possibility that the adhesive 400 protrudes, so that the light transmittance is not affected.
Moreover, since there is little possibility that the adhesive agent 400 will accidentally adhere to the slope portions 211 and 212, light transmittance can be maintained and high luminance can be achieved.

[Third embodiment]
The third embodiment is the same as the second embodiment except that the paint is applied to the top surface portion 213 instead of the adhesive 400 used in the second embodiment, and thus the description thereof is omitted.

Such a third embodiment has the following operational effects in addition to the operational effects described above.
(7) Since the prisms 210 are regularly arranged linearly, a regular color arrangement pattern can be formed on the surface of the light diffusing plate 100B by applying a paint to the top surface portion 213. The prism 210 has a substantially trapezoidal cross section, and a recess 214 is provided on the top surface portion 213 thereof. Since a paint can be applied to the recess 214, the paint does not protrude. Therefore, it is possible to provide a prism member that forms a beautiful color arrangement pattern and has characteristic optical characteristics due to the colored pattern.
In addition, since there is no possibility that the paint adheres to the slopes 211 and 212 which are important for exhibiting optical characteristics, it is possible to maintain good optical characteristics and achieve high luminance.

[Fourth embodiment]
Since the fourth embodiment is the same as the second embodiment except that the shape of the prism plate is different, the description thereof is omitted.
(Configuration of prism member)
FIG. 4 is a front view of the light diffusing plate according to the fourth embodiment.
As shown in FIG. 4, the light diffusing plate 100 </ b> C includes a prism plate 200 </ b> C and a diffusing sheet 300. On the prism plate 200C, linear prisms 210 and low prisms 220 having a height lower than that of the prisms 210 are alternately arranged on one surface.

The prism 210 has the same shape as in the first embodiment.
The low prism 220 is formed in a substantially triangular cross section by two inclined surface portions 221 and 222 inclined with respect to the thickness direction of the prism plate 200 </ b> C, and is lower in height than the prism 210. And it forms so that the angle which the slope part 221 and the slope part 222 make may be 90 degree | times.

  The heights of the prism 210 and the low prism 220 can be appropriately set within a range of 5 μm to 250 μm. For example, when the height of the prism 210 is 100 μm, the height of the low prism 220 is 80 μm. Further, according to the set height, the pitch of the prism 210 and the low prism 220 can also be set as appropriate within a range of 10 μm to 500 μm.

In the fourth embodiment, the following functions and effects are provided in addition to the functions and effects described above.
(8) In the fourth embodiment, since a low prism having a substantially triangular cross section is disposed, optical characteristics (diffusibility, reflectivity, etc.) are excellent, and a diffusion sheet is bonded to a prism whose top surface is a flat surface. Can do.

It should be noted that the present invention is not limited to the above-described embodiments, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the present invention.
For example, in the above embodiment, the diffusion sheet is laminated on the prism member. However, in addition to the diffusion sheet, a functional sheet such as a sheet containing an antistatic agent, a film having a prism shape, or a polarizing reflection sheet may be bonded. it can.

  Moreover, in the said embodiment, although only one hollow was formed in the top surface part, several hollows may be formed.

  EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated more concretely, this invention is not limited to the content, such as an Example, at all.

[Example 1]
First, desired surface protrusions are formed on a copper plate. This surface protrusion is a portion that becomes a prism when transferred to the PS sheet.
In Example 1, a plurality of convex portions having a substantially trapezoidal cross section with an apex angle of 90 degrees, a pitch of 150 μm, and a height of 40 μm were linearly cut using a diamond bit on the surface of a copper plate to produce a mold. In addition, a lathe was used for cutting, and a cylindrical plate was created.
Next, the mold formed on the copper plate was transferred to a nickel alloy plate by electroforming to form a nickel plate.
Then, this nickel plate and PS sheet (manufactured by PS Japan Co., Ltd., product name “GPPS grade 680”) are stacked, and a pressure of 5 MPa and a temperature of 160 are used by using a general hydraulic press device including a hydraulic cylinder and a heating plate. Pressed at ° C. Then, after cooling to 50 degreeC, PS sheet | seat was peeled from the nickel plate and PS sheet (prism member) in which the prism was formed was obtained.
Next, a film with an adhesive (manufactured by Nichiban Co., Ltd., product name “CT405AP-18”) was bonded to the PS sheet.

[Example 2]
On the surface including the short side of the substantially trapezoidal cross section of the convex portion formed on the surface of the copper plate in Example 1, a recess of 5 μm was provided. Then, a nickel plate was produced in the same manner as in Example 1 and pressed with the PS sheet to produce a PS sheet (prism member) on which a prism was formed.
Then, the paint was transferred by bringing the top surface of the prism of the PS sheet into contact with a white paint (manufactured by Pentel Co., Ltd., product name “Pentel White 100WM”) thinly applied on paper.

[Comparative Example 1]
The surface of the copper plate is cut into a plurality of convex portions having an apex angle of 90 degrees, a pitch of 150 μm, and a height of 40 μm and a substantially triangular cross section. As a result, a PS sheet having a prism having a substantially triangular cross section was produced.
And the film (Nichiban Co., Ltd. product name "CT405AP-18") with an adhesive was bonded together to this PS sheet.

[Comparative Example 2]
A paint was applied to the PS sheet produced in Comparative Example 1 in the same manner as in Example 2.

<Evaluation>
Cross-sectional photographs of the PS sheets prepared in Example 1 and Comparative Example 1 were taken. Photographing was performed using a digital microscope (manufactured by Keyence Corporation, product name “VHX-600”) and irradiating light from the upper surface. FIG. 5 is a cross-sectional photograph according to Example 1, and FIG. 6 is a cross-sectional photograph according to Comparative Example 1.

In FIG. 5, since the top surface portion is flat, the adhesive surface with the film with the pressure-sensitive adhesive is smooth, and the surface of the film is also formed smoothly. The white portion in the figure is transmitting light. This shows that the light transmittance is also stable.
On the other hand, in FIG. 6, since the top of the prism has a sharp shape, the adhesive surface of the film is not stable. Therefore, the surface of the film is not smooth and the light transmission is not stable.

  Next, planar photographs of the PS sheets prepared in Example 2 and Comparative Example 2 were taken. Photographing was performed in the same manner as in Example 1 and Comparative Example 1. 7 is a plan photograph according to Example 2, and FIG. 8 is a plan photograph according to Comparative Example 2.

In FIG. 7, since the bonded portions and the non-bonded portions are arranged alternately and neatly, a regular coloring pattern is formed. Light transmittance is also good.
On the other hand, in FIG. 8, a regular coloring pattern is not formed because the paint protrudes.

  The present invention can be used for, for example, a liquid crystal backlight device having a light source such as a fluorescent tube, an LED, and an EL, an illumination device such as a backlight projector, and a fluorescent lamp.

The perspective view which shows the light diffusing plate concerning 1st embodiment of this invention. The front view of FIG. The front view which shows the light diffusing plate concerning 2nd embodiment of this invention. The front view which shows the light diffusing plate concerning 4th embodiment of this invention. 2 is a cross-sectional photograph according to Example 1. FIG. Sectional photograph concerning the comparative example 1. FIG. The plane photograph concerning Example 2. FIG. The plane photograph concerning the comparative example 2.

Explanation of symbols

100A, 100B, 100C Light diffusion plates 200A, 200B, 200C Prism plate 210 Prism 211, 212 Slope portion 213 Top surface portion 214 Indentation 300 Diffusion sheet 400 Adhesive

Claims (11)

A plate-shaped prism member in which a large number of prisms are arranged,
The prism is
Two planar slopes inclined with respect to the thickness direction of the prism member;
A prism member, comprising: a flat top surface portion formed between the two slope portions and parallel to the surface direction of the prism member. The prism member according to claim 1,
A concave member is formed in the top surface portion. A prism member, wherein: In the prism member according to claim 1 or 2,
The pitch of the prism is 10 μm or more and 500 μm or less, and
The prism member, wherein a height of the prism is 5 μm or more and 250 μm or less. In the prism member according to any one of claims 1 to 3,
The prism member characterized in that an angle formed by the two slope portions is 90 degrees. In the prism member according to any one of claims 1 to 4,
The prism is characterized in that the prism is linearly arranged on at least one surface of the prism member. In the prism member according to any one of claims 1 to 5,
The prism is characterized in that the prism is two-dimensionally arranged on at least one surface of the prism member. The prism member according to any one of claims 1 to 6,
A prism member characterized in that a low prism having a lower height than the prism is provided between the plurality of prisms. In the prism member according to any one of claims 1 to 7,
A prism member characterized by containing a diffusing agent. An optical member, wherein at least one surface of the prism member according to any one of claims 1 to 8 is covered with a functional layer. The optical member according to claim 9,
The functional layer is a diffusion sheet,
The optical member, wherein the diffusion sheet is laminated on one surface of the prism member. The optical member according to claim 10,
The optical member, wherein the diffusion sheet is laminated on a surface of the prism member on which the prism is formed.