KR102630911B1 - Surface uneven sheets, screens, video display systems and transfer rolls - Google Patents

Abstract

A surface uneven sheet, a screen with a surface uneven sheet, and a video display system equipped with a screen that can produce a screen with high relative frontal luminance of the displayed image, low left/right 60° luminance ratio and 100° luminance difference ratio, and low chromatic aberration. , and a transfer roll for manufacturing a surface uneven sheet. The present invention is a surface uneven sheet having a plurality of convex stripes on at least one surface and concave stripes formed between two adjacent convex stripes, wherein the ratio of the average height of the convex stripes to the average spacing between the convex stripes (average height/average spacing) is 0.07 or more and 0.40 or less, the average roughness obtained from the roughness curve in the extending direction of the convex lines at the top of the convex lines is 0.10 ㎛ or more and 0.90 ㎛ or less, and the surface unevenness sheet is stretched in a direction orthogonal to the extending direction of the convex lines, and the surface When the frequency (T) of the slope angle calculated from the height data in the cross-sectional shape when the uneven sheet is cut in the thickness direction is calculated, and the frequency ratio (%) is calculated from the following equation (A), the frequency ratio (%) %) relates to a sheet with surface irregularities of 98% or more.

Description

Surface uneven sheets, screens, video display systems and transfer rolls

The present invention relates to a surface irregularity sheet, a screen with a surface irregularity sheet, an image display system with a screen, and a transfer roll for producing the surface irregularity sheet.

Reflective screens are required to be able to display images with high luminance (gain) and small luminance differences to all observers observing the screen. Conversely, in the direction where there is always no observer, the screen does not need to display a high-brightness image, or, to put it in the extreme, may not be able to display an image. To achieve this, it is necessary to suppress reflection and diffusion of image light in a direction where there is always no observer.

As a conventional reflective screen, it is known that a reflective layer is formed on the back side of a light diffusion sheet having a light diffusion layer in which particles are dispersed. However, because conventional screens reflect and diffuse image light in various directions, they always display images in directions away from the viewer. For this reason, in conventional screens, the luminance of the image displayed in the direction where the viewer is located decreases.

As a reflective screen that is believed to have a sufficient viewing angle and achieve high screen gain and luminance uniformity, a screen with a vertical diffusion angle smaller than the horizontal diffusion angle has been proposed (Patent Document 1). Additionally, Patent Document 2 discloses a reflective screen including a lens layer, a reflection layer, and a light control layer, wherein the light control layer has convex portions and concave portions alternately arranged in a substantially rectangular cross-sectional shape. An uneven structure is disclosed. Additionally, Patent Documents 3 and 4 disclose a projection screen or a reflection screen, in which a lenticular lens is used as a lens layer.

Japanese Patent Publication No. 2005-266264 Japanese Patent Publication No. 2012-226103 Japanese Patent Publication No. 2000-180967 Japanese Patent Publication No. 2013-171114

Reflective screens are required to have the following, for example:

·Suppress reflection and diffusion of image light in areas at almost all angles in the vertical direction of the screen and in areas exceeding ±50° in the horizontal direction of the screen, where it is assumed that there will be no observer at all times. Accordingly, the front luminance (relative front luminance) of the image displayed on the screen will be higher than the front luminance (standard front luminance) of the image displayed on the conventional screen.

·Suppress reflection and diffusion of image light in areas exceeding ±50° in the horizontal direction of the screen where it is assumed that there will be no observer at all times. That is, in the image displayed on the screen, the ratio of the average value of the luminance at +60° in the horizontal direction of the screen and the luminance at -60° in the horizontal direction of the screen to the frontal luminance (60° left and right luminance ratio) must be low. .

·The difference in luminance of the image in the area within ±50° of the horizontal direction of the screen where the observer is assumed to be must be small. That is, in an image displayed on a screen, the ratio of the luminance difference between the maximum and minimum luminance values in an area within ±50° of the horizontal direction of the screen to the frontal luminance (100° luminance difference ratio) is low. thing.

·There should be little chromatic aberration in the image displayed on the screen in the area where the observer is assumed to be.

However, in the screen described in Patent Document 1, as shown in FIG. 3 of Patent Document 1, the maximum value of the screen gain (brightness) in the area within ±50° of the horizontal direction of the screen (approximately at 0°) 3) The difference in luminance between the minimum value (approximately 0.5 at ±50°) is large. Specifically, the 100° luminance difference ratio obtained by (maximum value of luminance - minimum value of luminance)/front luminance x 100 is 80% or more. Also, in the screens described in Patent Documents 2 to 4, the difference in luminance in the horizontal direction of the screen is large. On such a screen, an image with high luminance and small luminance difference cannot be displayed to all observers looking at the screen.

The present invention provides a surface irregularity sheet, a screen with a surface irregularity sheet, and a screen capable of obtaining a screen with high relative frontal luminance of the displayed image, low left and right 60° luminance ratio and 100° luminance difference ratio, and low chromatic aberration. Provided is an image display system and a transfer roll for manufacturing a surface uneven sheet.

The present invention has the following aspects.

<1> A surface uneven sheet having a plurality of convex lines on at least one surface and concave lines formed between two adjacent convex lines,

The ratio of the average height of the convex lines and the average spacing of the convex lines (average height/average spacing) is 0.07 or more and 0.40 or less,

The average roughness at the top of the convex lines, obtained from the roughness curve in the extending direction of the convex lines, is 0.10 μm or more and 0.90 μm or less,

Calculate the frequency (T) of the slope angle calculated from the height data in the cross-sectional shape when the surface irregularity sheet is cut in a direction perpendicular to the extension direction of the convex lines and in the thickness direction of the surface irregularity sheet, , a surface uneven sheet with a frequency ratio (%) of 98% or more when the frequency ratio (%) is calculated from the following formula (A);

Formula (A): Frequency ratio (%) = Frequency (T) / Frequency (S) × 100

Here, the frequency (S) is the most frequent angle in the range of -2° to 89° in the frequency distribution chart of the slope angle calculated from a sine curve in which the average height of the convex lines and the average spacing between the convex lines are equal. It is the sum of the frequencies,

The frequency (T) is calculated by assuming that the most frequent angle in the sine curve is the angle (Mθs), and the surface irregularity sheet is cut in a direction perpendicular to the extension direction of the convex lines and in the thickness direction of the surface irregularity sheet. It is the sum of the frequencies in the range of angle (Mθs) -2° to 89° in the frequency distribution chart of the slope angle calculated from the height data in the cross-sectional shape at the time.

<2> The uneven surface sheet of <1> above, comprising a base material layer and at least one surface layer, and having the convex lines and the concave lines on the surface of the surface layer.

<3> The uneven surface sheet of <1> above, which is a single-layer sheet having the convex lines and the concave lines on at least one surface of the substrate.

<4> A screen including the uneven surface sheet of any of the above <1> to <3> and a reflective layer.

<5> A video display system including the screen of <4> above and a projector that projects video light onto the screen.

<6> A transfer roll having a plurality of concave lines on the surface and convex lines formed between two adjacent concave lines,

The ratio of the average depth of the concave structures and the average spacing of the concave structures (average depth/average spacing) is 0.07 or more and 0.40 or less,

The average roughness at the bottom of the concave structure obtained from the roughness curve in the extending direction of the concave structure is 0.10 μm or more and 0.90 μm or less,

The frequency (T) of the slope angle calculated from the depth data in the cross-sectional shape when the transfer roll is cut in a direction perpendicular to the extending direction of the concave line and in a direction perpendicular to the central axis of the transfer roll When calculating and calculating the frequency ratio (%) from the following formula (A), the transfer roll whose frequency ratio (%) is 98% or more;

Formula (A): Frequency ratio (%) = Frequency (T) / Frequency (S) × 100

Here, the frequency (S) is in the range of the most frequent angle -2° to 89° in the frequency distribution chart of the slope angle calculated from a sine curve in which the average depth of the above-mentioned concave lines and the average interval between the above-mentioned concave lines are equal. It is the sum of the frequencies,

The frequency (T) is calculated by assuming that the most frequent angle in the sine curve is the angle (Mθs), and the transfer roll is moved in a direction perpendicular to the extending direction of the concave pattern and in a direction perpendicular to the central axis of the transfer roll. It is the sum of the frequencies in the range of angle (Mθs) -2° to 89° in the frequency distribution chart of the slope angle calculated from depth data in the cross-sectional shape when cut.

According to the uneven surface sheet of the present invention, it is possible to obtain a screen in which the relative frontal luminance of the displayed image is high, the left and right 60° luminance ratios and 100° luminance difference ratios are low, and chromatic aberration is low. The screen of the present invention has high relative frontal luminance of the displayed image, low left and right 60° luminance ratio and 100° luminance difference ratio, and has little chromatic aberration.

According to the image display system of the present invention, an image with high luminance, little luminance difference, and little chromatic aberration can be displayed to all observers watching the screen.

According to the transfer roll of the present invention, the surface uneven surface sheet of the present invention can be manufactured.

1 is an enlarged perspective view schematically showing an example of a surface uneven sheet of the present invention.
Figure 2 is an enlarged perspective view schematically showing another example of the uneven surface sheet of the present invention.
Figure 3 is an example of a laser microscope image of the surface of the uneven surface sheet of the present invention.
Figure 4 is an example of a roughness curve in the direction in which the convex stripes extend at the top of the convex stripes obtained by measuring the surface of the uneven surface sheet of the present invention with a laser microscope.
Figure 5 is an enlarged perspective view for explaining a method of calculating the average height of the convex lines, the average spacing of the convex lines, and the average illuminance of the top of the convex lines.
Figure 6 is an enlarged perspective view for explaining a method of calculating the average illuminance of the top of a convex strip when the convex strip is meandering.
Figure 7 is an enlarged perspective view near the surface schematically showing an example of the transfer roll of the present invention.
Figure 8 is an enlarged perspective view for explaining a method of calculating the average depth of the concave grooves, the average spacing of the concave grooves, and the average roughness of the bottom of the concave grooves.
Figure 9 is an enlarged perspective view for explaining a method of calculating the average illuminance of the bottom of a concave structure when the structure is meandering.
Figure 10 is an enlarged perspective view schematically showing an example of the screen of the present invention.
Figure 11 is an enlarged perspective view schematically showing another example of the screen of the present invention.
Figure 12 is a schematic configuration diagram schematically showing an example of a video display system of the present invention.
Figure 13 is an enlarged perspective view schematically showing an example of a screen in the video display system of the present invention.
Fig. 14 is a top view showing the arrangement of the screen, projector, and measurement points when measuring front luminance.
Fig. 15 is a side view showing the arrangement of the screen, projector, and measurement points when measuring front luminance.
Fig. 16 is a top view showing the arrangement of the screen, projector, and measurement points when measuring luminance at +60° in the horizontal direction of the screen and -60° in the horizontal direction of the screen.
Fig. 17 is a top view showing the arrangement of the screen, projector, and measurement points when measuring luminance in an area within ±50° of the horizontal direction of the screen.
Figure 18 is a schematic diagram illustrating a method for calculating the frequency (T) of a surface uneven sheet.
Figure 19 shows some extracted data of the surface uneven height measurement data of the surface uneven sheet and is a schematic diagram explaining the slope angle.
Figure 20 is an example of a graph showing the relationship between slope angle and frequency in a surface uneven sheet or sine curve.
Fig. 21 is a schematic diagram explaining the structure of the surface uneven sheet in Comparative Example 5.
Figure 22 is a schematic diagram explaining the structure of the surface uneven sheet in Comparative Example 6.
Figure 23 is a schematic diagram explaining the structure of the surface uneven sheet in Comparative Example 7.
Figure 24 is a frequency distribution chart of slope angles in Examples 2 to 5.
Figure 25 is a frequency distribution chart of slope angles in Comparative Examples 1 to 7.

Each term in this specification and claims means the following.

“Front” refers to the side on which the image projected on the screen, etc. is observed by the observer.

The “front direction of the screen” refers to the normal direction to the front of the screen (x-axis direction in FIG. 13).

The “vertical direction of the screen” refers to the vertical direction of the screen (z-axis direction in FIG. 13) perpendicular to the front direction of the screen when the screen is installed.

The “horizontal direction of the screen” refers to the left and right direction of the screen (y-axis direction in FIG. 13) which is perpendicular to the front direction of the screen and orthogonal to the vertical direction of the screen when the screen is installed.

The “horizontal surface of the screen” refers to a surface horizontal to the ground and perpendicular to the front. The horizontal plane of the screen is parallel to the horizontal direction of the screen and is also parallel to the front direction of the screen.

The “horizontal angle” refers to the angle formed between the normal line (0°) of the center point of the front of the screen and a line starting from the center point inclined in the horizontal direction with respect to the normal line of the center point. For example, “+60° in the horizontal direction” means that the angle between the normal line of the center point in front of the screen and the line starting from the center point, tilted horizontally and to the right as seen by the viewer, with respect to the normal line of the center point, is 60°. This means that “-60° in the horizontal direction” means that the angle between the normal line of the center point in front of the screen and the line starting from the center point, tilted horizontally and to the left as seen by the observer, with respect to the normal line of the center point is 60°. It says that

The “vertical angle” refers to the angle formed between the normal line (0°) of the center point of the front of the screen and the line starting from the center point, inclined in the vertical direction with respect to the normal line of the center point.

“The main component is resin” means that the base layer, adhesive layer, adhesive layer, surface layer, or base material contains 50% by mass or more of resin in terms of solid content, preferably 80% by mass or more, more preferably 90% by mass or more. says

Hereinafter, each aspect of the present invention will be described in detail while showing illustrative examples.

The dimensional ratios in FIGS. 1, 2, and 5 to 17 are different from the actual ones for convenience of explanation.

＜Surface uneven sheet＞

The surface uneven surface sheet of the present invention has a plurality of convex lines on at least one surface and concave lines formed between two adjacent convex lines. In other words, the surface uneven surface sheet of the present invention has a plurality of convex lines on at least one surface, and concave lines are formed between two adjacent convex lines.

1 is an enlarged perspective view schematically showing an example of a surface uneven sheet of the present invention.

The surface uneven sheet 10 is a laminated sheet including a base layer 14 and a surface layer 15 formed on one surface of the base layer 14, and a plurality of convex lines 12 on the surface of the surface layer 15. , it has a concave groove 13 formed between two adjacent convex grooves 12. In other words, the surface uneven surface sheet 10 of the present invention has a plurality of convex lines 12 on the surface of the surface layer 15, and concave lines 13 are formed between two adjacent convex lines 12. . Fine irregularities are formed on the surface of the convex lines 12, especially the top portion 12a, but illustration of the fine irregularities is omitted in Fig. 1. Hereinafter, when the uneven surface sheet of the present invention is a laminated sheet, it is also simply referred to as a laminated sheet with uneven surface.

Figure 2 is an enlarged perspective view schematically showing another example of the uneven surface sheet of the present invention.

The surface uneven sheet 11 is a single-layer sheet having a plurality of convex lines 12 on one surface of the substrate 16 and a concave line 13 formed between two adjacent convex lines 12. In other words, the surface uneven surface sheet 11 of the present invention has a plurality of convex lines 12 on one surface of the substrate 16 and a concave line 13 formed between two adjacent convex lines 12. there is. Fine irregularities are formed on the surface of the convex lines 12, especially the top portion 12a, but illustration of the fine irregularities is omitted in FIG. 2. Hereinafter, when the surface uneven sheet of the present invention is a laminated sheet, it is also simply referred to as a surface uneven single-layer sheet.

Figure 3 is an example of a laser microscope image of the surface of the uneven surface sheet of the present invention. Fig. 4 is an example of a roughness curve in the direction in which the convex lines extend at the top of one convex line obtained from a laser microscope image of the surface of the uneven surface sheet of the present invention.

As shown in the laser microscope image of the surface of the surface of the uneven surface sheet and the roughness curve of the top of the convex stripes, fine irregularities are formed on the surface of the convex stripes, especially the top portion.

The base material layer in the uneven surface laminated sheet preferably has light transparency when the uneven surface sheet is used as a member constituting a part of the screen.

It is preferable that the main component of the base material layer in the uneven surface laminated sheet is resin because it gives the screen flexibility. Types of resin include cured products of curable resins and thermoplastic resins, and thermoplastic resins are preferred because they provide flexibility to the screen. Examples of thermoplastic resins include polyethylene terephthalate (hereinafter also referred to as “PET”), polyethylene naphthalate, polycarbonate, polyether sulfone, and polyolefin. Resins can be used one type or in combination of two or more types.

The base material layer in the uneven surface laminated sheet may have a single-layer lamination structure or may have a lamination structure of multiple layers. When the base material layer in the uneven surface laminated sheet is comprised of multiple layers, a base layer (also referred to as an alternating laminate) formed by alternately laminating two types of transparent resin layers with different refractive indices may be used. Among these alternating laminates, when an alternating laminate having a function of reflecting visible light is used as a base layer, it is not necessary to form a reflecting layer, which will be described later, when producing a screen containing a surface concavo-convex laminated sheet.

It is preferable that the surface of the base layer in the uneven surface laminated sheet has no irregularities and the surface of the base layer (interface between the base layer and the surface layer) is smooth, for example, in order to obtain a more desirable relative front brightness.

When the main component of the base material layer in the uneven surface laminated sheet is resin, the thickness of the base layer is preferably 75 ㎛ or more and 2000 ㎛ or less, and 100 ㎛ or more and 1000 ㎛ or less from the viewpoint of obtaining a more preferable relative front brightness. More preferably, 150 ㎛ or more and 500 ㎛ or less is further preferable, and 200 ㎛ or more and 300 ㎛ or less is particularly preferable. When the base material layers in the uneven surface laminated sheet are alternately laminated, the thickness of the base layer is preferably 0.05 μm or more and 50 μm or less, and more preferably 0.1 μm or more and 30 μm or less from the viewpoint of reflectivity and cost.

In the uneven surface laminated sheet, an adhesive layer or an adhesive layer may be formed between the base layer and the surface layer, or between the base layer and the base layer. The adhesive layer or adhesive layer can preferably be used to adhere and secure the base layer and the surface layer. It is preferable that the main component of the adhesive layer or adhesive layer is resin. The type of resin is not particularly limited, and examples include acrylic resin.

The surface layer in the uneven surface laminated sheet preferably has light transparency when the uneven surface sheet is used as a member constituting a part of the screen.

Since the surface layer in the surface uneven surface laminated sheet tends to form convex and concave lines, it is preferable that the main component is resin. Types of resin include cured products of curable resins and thermoplastic resins, and cured products of curable resins are preferred because they easily form convex lines and concave lines. Examples of the curable resin include ionizing radiation-curable resin and thermosetting resin, and ionizing radiation-curable resin is preferable because it is easy to form convex lines and concave grooves. Examples of the ionizing radiation curable resin include photocurable resin (ultraviolet curable resin) and electron beam curable resin. It is preferable that the main component of the surface layer of the uneven surface laminated sheet is an ultraviolet curable resin. Examples of the ultraviolet curable resin include acrylic resin, urethane resin, vinyl ester resin, and polyester/alkyd resin, and among these, acrylic resin is preferable. Resins can be used one type or in combination of two or more types.

The thickness of the surface layer in the uneven surface laminated sheet is preferably 5 μm or more and 100 μm or less, more preferably 10 μm or more and 50 μm or less, and 15 μm or more and 30 μm or less from the viewpoint of obtaining a more desirable relative frontal brightness. is more preferable.

The base material in the surface uneven single-layer sheet preferably has light transparency when the surface uneven sheet is used as a member constituting a part of the screen.

It is preferable that the main component of the base material in the surface uneven single-layer sheet is resin because it gives the screen flexibility and easily forms convex lines and concave lines. Types of resin include cured products of curable resins and thermoplastic resins. Thermoplastic resins are preferred because they provide flexibility to the screen and facilitate the formation of convex and concave grooves. Resins can be used one type or in combination of two or more types.

The thickness of the base material in the surface uneven single-layer sheet is preferably 75 ㎛ or more and 2000 ㎛ or less, more preferably 100 ㎛ or more and 1000 ㎛ or less, and 150 ㎛ or more and 500 ㎛ or less from the viewpoint of obtaining a more desirable relative front brightness. is more preferable, and 200 ㎛ or more and 300 ㎛ or less is particularly preferable.

The average height of the convex lines is preferably 0.35 ㎛ or more and 40 ㎛ or less, more preferably 0.7 ㎛ or more and 30 ㎛ or less, more preferably 1 ㎛ or more and 24 ㎛ or less, even more preferably 3 ㎛ or more and 20 ㎛ or less, and 5 ㎛ or more. 12㎛ or less is particularly preferable. When the average height of the convex lines is within the above range, it is a preferable aspect because more preferable relative frontal luminance and chromatic aberration suppression are obtained.

The average height of the convex lines is obtained as follows.

Using a laser microscope, the surface irregularities of the surface irregularities sheet are measured under the conditions of a 50x objective lens and a measurement pitch of 0.1 μm. Subsequently, as shown in FIG. 5, the cross-sectional shape corresponding to the cross section when the surface uneven sheet is cut in the direction perpendicular to the extension direction of the convex lines 12 and in the thickness direction of the surface uneven sheet is measured. . The height H1 from the bottom 13a of one concave strip 13 adjacent to the convex strip 12 to the top 12a of the convex strip 12 is measured. Similarly, the height H2 from the bottom part 13a of the other concave strip 13 adjacent to the convex strip 12 to the top part 12a of the convex strip 12 is measured. The average value of the height H1 and H2 is taken as the height H of the convex lines 12. The height (H) is calculated for each of the five randomly selected convex lines (12). The average value of the heights (H) of the five convex lines 12 is obtained, and this is taken as the average height of the convex lines 12.

The average spacing of the convex lines is preferably 5 μm or more and 100 μm or less, more preferably 10 μm or more and 75 μm or less, more preferably 15 μm or more and 55 μm or less, and especially preferably 20 μm or more and 40 μm or less. When the average spacing of the convex lines is within each preferable range, this is a preferable aspect in that more preferable relative frontal luminance and chromatic aberration suppression can be obtained.

The average spacing of convex lines is obtained as follows.

Using a laser microscope, the surface irregularities of the surface irregularities sheet are measured under the conditions of a 50x objective lens and a measurement pitch of 0.1 μm. Subsequently, as shown in FIG. 5, the cross-sectional shape corresponding to the cross section when the surface uneven sheet is cut in the direction perpendicular to the extension direction of the convex lines 12 and in the thickness direction of the surface uneven sheet is measured. . The width (W ₅ ) from the top 12a of the randomly selected standard convex lines 12 to the tops 12a of the five adjacent convex lines 12 is obtained. The value obtained by dividing the width (W ₅ ) into 5 equal parts is taken as the average spacing of the convex lines 12.

The ratio of the average height of the convex lines and the average spacing of the convex lines (average height/average spacing), that is, the aspect ratio of the convex lines is 0.07 or more and 0.40 or less, preferably 0.09 or more and 0.40 or less, and more preferably 0.12 or more and 0.30 or less. Assuming that the average illuminance described later is 0.10 ㎛ or more to 0.90 ㎛, if the aspect ratio of the convex stripe is more than the lower limit of the above range, the 100° luminance difference ratio of the image displayed on the screen is lowered due to the synergistic effect with the average illuminance. As a result, images can be displayed without causing a large difference in luminance in an area within ±50° of the horizontal direction of the screen where the viewer is assumed to be. Assuming that the average illuminance described later is 0.10 ㎛ or more to 0.90 ㎛, if the aspect ratio of the convex lines is less than the upper limit of the above range, the 60° left and right luminance ratio of the image displayed on the screen is lowered due to the synergistic effect with the average illuminance. As a result, reflection and diffusion of image light in an area exceeding ±50° in the horizontal direction of the screen, where it is assumed that the observer is always absent, is suppressed, and the relative frontal luminance is improved accordingly.

The average roughness obtained from the roughness curve in the direction in which the convex lines extend at the top of the convex lines should be 0.10 μm or more, and is preferably 0.12 μm or more. In addition, the average roughness at the top of the convex stripes, obtained from the roughness curve in the direction in which the convex stripes extend, may be 0.90 ㎛ or less, preferably 0.70 ㎛ or less, more preferably 0.50 ㎛ or less, and even more preferably 0.40 ㎛ or less. , 0.30 μm or less is even more preferable, and 0.29 μm or less is particularly preferable. Assuming that the aspect ratio of the convex stripes is 0.07 or more and 0.40 or less, if the average illuminance of the top of the convex stripes is more than the lower limit of the above range, the chromatic aberration of the image displayed on the screen is small due to the synergistic effect with the aspect ratio of the convex stripes. As a result, color changes in images displayed on the screen are unlikely to occur for observers located in any direction in the horizontal direction of the screen. Assuming that the aspect ratio of the convex stripes is 0.07 or more and 0.40 or less, if the average illuminance of the top of the convex stripes is below the upper limit of the above range, the image light reflected and diffused in the vertical direction of the screen is suppressed due to the synergistic effect with the aspect ratio of the convex stripes. , the relative frontal luminance of the image displayed on the screen increases. As a result, the image displayed in front of the screen becomes brighter. On the other hand, the average roughness at the top of the convex stripes, obtained from the roughness curve in the direction in which the convex stripes extend, is thought to be due to fine irregularities formed on the surface of the convex stripes 12, especially the top portion 12a.

The average illuminance of the top of the convex lines is obtained as follows.

Using a laser microscope, the surface irregularities of the surface irregularities sheet are measured under the conditions of a 50x objective lens and a measurement pitch of 0.1 μm. Subsequently, as shown in FIG. 5, the surface unevenness sheet corresponds to the cross section CS (the portion surrounded by a broken line in the figure) when the surface unevenness sheet is cut in the thickness direction of the surface unevenness sheet along the ridge line of the convex lines 12. Measure the cross-sectional shape. From the cross-sectional shape corresponding to the cross-section CS, a roughness curve (reference length l: 200 μm) in the extending direction of the convex stripes 12 at the top 12a of the convex stripes 12 is obtained. From the roughness curve, the arithmetic mean roughness Ra is obtained according to a calculation formula based on JIS B 0601:1994. The arithmetic mean roughness Ra is obtained for each of the top portions 12a of the five randomly selected convex lines 12. The average value of the arithmetic mean illuminance Ra of the top portions 12a of the five convex lines 12 is obtained, and this is taken as the average illuminance of the top portions 12a of the convex lines 12.

When the convex lines are meandering, as shown in FIG. 6, straight lines (broken lines in the figure) connecting points formed at predetermined intervals (straight line distance 40 μm) are drawn along the ridge of the convex lines 12. For each straight line, the cross-sectional shape corresponding to the cross-section (CS1, CS2, CS3...) (portion surrounded by a broken line in the figure) is measured. From each of the cross-sectional shapes corresponding to the cross-sections (CS1, CS2, CS3...), a roughness curve in the extension direction of the convex stripes 12 at and near the top 12a of the convex stripes 12 is obtained, These roughness curves are connected to obtain the final roughness curve (standard length (l): 200 μm). Meanwhile, in FIG. 6, since the intention is to explain the meandering of the convex stripes 12 more easily, the illustration of fine irregularities existing in the extending direction of the convex stripes 12 as in FIG. 5 is omitted.

The average roughness of the tops of the convex lines of the surface uneven sheet depends on the average roughness of the bottoms of the concave lines of the transfer roll described later. The average roughness of the bottom of the groove of the transfer roll can be adjusted by appropriately setting the manufacturing conditions of the transfer roll, etc., which will be described later.

Calculate the frequency (T) of the slope angle calculated from the height data in the cross-sectional shape when the surface uneven surface sheet of the present invention is cut in the direction perpendicular to the extension direction of the convex lines and in the thickness direction of the surface uneven surface sheet, When the frequency ratio (%) is calculated from the following formula (A), the frequency ratio (%) is 98 or more, preferably 100% or more, more preferably 105% or more, and even more preferably 108% or more. On the other hand, the frequency ratio (%) is preferably 300% or less, and more preferably 200% or less.

Formula (A): Frequency ratio (%) = Frequency (T) / Frequency (S) × 100

Here, the frequency (S) is the frequency in the range of the most frequent angle -2° to 89° in the slope angle frequency distribution chart calculated from a sine curve with the average height of the convex lines and the average spacing between the convex lines being the same. It's the sum. In addition, the frequency (T) is calculated when the most frequent angle in the sine curve is set as the angle (Mθs), and the surface irregularity sheet is cut in the direction perpendicular to the direction of extension of the convex lines and in the thickness direction of the surface irregularity sheet. It is the sum of the frequencies in the range of angle (Mθs) -2° to 89° in the frequency distribution diagram of the slope angle calculated from height data in the cross-sectional shape.

More specifically, the frequency (T) is calculated as follows.

First, using a laser microscope (VK-8500, manufactured by Keyence), the measurement area M of the uneven surface sheet 10 was measured under the conditions of a 50x objective lens and a measurement pitch in the height direction of 0.05 μm (FIG. 18(a)). Acquire height data (reference). At this time, the measurement interval is the direction perpendicular to the extending direction of the convex lines 12 of the uneven surface sheet 10 (corresponding to the y direction in Fig. 18(a)) and the convex lines 12 of the uneven surface sheet 10. In the extension direction (corresponding to the z direction in Fig. 18(a)), each is set to 0.2913 μm. On the other hand, the measurement area M is 295.0869 ㎛ (for 1014 pieces of data) in the direction perpendicular to the extending direction of the convex lines 12 of the surface uneven sheet 10 (corresponding to the y direction in Fig. 18(a)), and , The area is 215.8533 ㎛ (742 pieces of data) in the direction in which the convex lines 12 of the uneven surface sheet 10 extend (corresponding to the z direction in Fig. 18(a)). Here, Figure 18 (b) shows the measurement position of the measurement data of the height of the surface irregularities of the obtained surface uneven sheet 10 in the direction orthogonal to the extending direction of the convex lines 12 of the surface uneven sheet 10 (y direction). ), is an image diagram expressed as coordinates (y, z), with the direction in which the convex lines 12 of the uneven surface sheet 10 are extended (z direction) as the coordinate axes, respectively.

Next, in the measurement data of the height of the surface unevenness of the surface unevenness sheet 10 obtained by the above-described measurement method, for example, positional data of the coordinates 1014 (β) are extracted from the coordinates (1, β). As shown in FIG. 18(c), the extracted measurement data is obtained by moving the surface uneven sheet 10 in the direction (y direction) perpendicular to the extending direction of the convex lines 12 at the position of the β value on the z-axis. This is measurement data of the height of the surface irregularities of the surface irregularities sheet 10, where the cross-section when the sheet 10 is cut in the thickness direction (x direction) is measured at intervals of 0.2913 μm. In order to correct the error in the measurement data on each coordinate axis, for the measurement data from coordinates (1, β) to coordinates (1005, β), the correction value of the data at coordinates (n, β) is set to ( Correction is made by setting the average value of 10 points from n, β) to (n + 9, β).

Next, the slope angle is determined from the measurement data obtained as described above. Figure 19(a) shows a series of convex lines 12 with respect to the correction value of the extracted data of the coordinates (1005, β) from the coordinates (1, β) of the measurement data of the height of the surface irregularities of the surface unevenness sheet 10. A portion is shown by plotting the direction perpendicular to the direction (y-direction) as the horizontal axis and the thickness direction (x-direction) of the uneven surface sheet 10 as the vertical axis. At this time, correction of the data in (n, β) of the correction value of the data of the coordinates (1004, β) extracted from the coordinates (1, β) of the measurement data of the height of the surface irregularities of the surface unevenness sheet 10 The line connecting the two points of the value Av(n, β) and the correction value Av(n+1, β) of the data at (n+1, β) is L(n, β), and the angle formed by the y-axis is the slope angle. When θs(n, β) is used, the slope angle θs(n, β) can be obtained from the following equation (10).

Equation (10): Slope angle (n, β) = arctan (h / 0.2913)

Here, h is the absolute value of the difference in height between the two points Av(n, β) and Av(n+1, β) (the unit of the length of h is μm). Additionally, the slope angle (n, β) is taken as an absolute value. That is, the slope angle θs(n, β) in Fig. 19(a) and the slope angle θs(n+1, β) in Fig. 19(b) are both positive values. For example, if the surface uneven sheet of Example 1 is measured by the above method and graphed with the slope angle on the horizontal axis and the frequency on the vertical axis, a frequency distribution chart as shown in Fig. 20(a) is obtained.

On the other hand, the frequency (S) is the most frequent angle of -2° to 89 in the slope angle frequency distribution chart calculated from a sine curve in which the average height of the convex lines and the average spacing between the convex lines of the surface uneven sheet to be measured are equal to each other. It is the sum of frequencies in the range of °. Here, all the convex lines in the sine curve have the same height as the average height of the convex lines of the surface uneven sheet, the spacing of the convex lines in the sine curve is constant, and all spacings are the same as the average spacing of the convex lines of the surface uneven surface sheet. am. For example, since the average height of the convex lines of the surface uneven surface sheet of Example 1 is 7.1 μm and the average spacing between the convex lines is 36 μm, the frequency distribution of the slope angle calculated from a sine curve in which the average height of the convex lines and the average spacing between the convex lines are the same (Theoretical value) is as shown in Figure 20(b). Here, in the frequency distribution chart of the slope angle calculated from a sine curve where the average height of the convex lines and the average spacing between the convex lines are the same, the most frequent slope angle (hereinafter also referred to as the most frequent angle) is 31°, so the most frequent An angle of -2° becomes 29°. For this reason, in Example 1 (FIG. 20(b)), the frequency S is the sum of the frequencies in the range of 29° to 89°, and the total actual frequency value is 215922. On the other hand, the frequency (T) in the surface uneven sheet to be measured is the sum of the frequencies in the range of 29° to 89°, and the total actual frequency value is 249387. As a result, the frequency ratio (%) calculated from equation (A) is 115%.

In this specification, a frequency ratio (%) of 98% or more means that many frequencies of high slope angles except 90° are observed. In screens and diffusion sheets, sheets with concave-convex shapes with a high frequency of slope angles tend to perform better in terms of light diffusion than sheets with concave-convex shapes with a high frequency of low slope angles. In addition, when the surface uneven surface sheet of the present invention has a fine uneven shape at the top of the convex stripes in the extending direction of the convex stripes, the light diffusion property is further increased, so that the average height of the convex stripes and the average spacing between the convex stripes are adjusted. Compared to the frequency distribution in the same sine curve, more frequencies are observed on the side with a higher slope angle. In this way, the present invention has discovered a new index called frequency ratio (%) when evaluating light diffusivity, and has also found that good light diffusivity is achieved when the frequency ratio (%) above a predetermined value is satisfied. will be.

As described above, the uneven surface sheet of the present invention is useful as a light diffusion sheet. Additionally, the uneven surface sheet of the present invention can also be used for screen purposes, lighting purposes, etc. The uneven surface sheet of the present invention is particularly useful as a member constituting the screen of the present invention described later.

On the other hand, the surface uneven surface sheet of the present invention may have a plurality of convex lines on at least one surface, and the aspect ratio of the convex lines and the average roughness of the top of the convex lines may be within a specific range, and is not limited to the example shown.

For example, the uneven surface sheet of the present invention may have convex lines and concave lines on both surfaces.

The convex lines may be continuous in a straight line or may be continuous in a meandering manner.

The convex lines may be continuous in one direction parallel to each other, or may have portions that are not parallel to other convex lines.

A convex line may branch along the way. The concave structure may branch midway.

The shape formed by the surfaces of the convex and concave lines in the cross section when the surface uneven sheet is cut in the direction perpendicular to the direction of continuation of the convex lines and in the thickness direction of the surface uneven sheet is easy to exhibit the effect of the present invention. In this regard, a waveform (wave shape) as shown in the illustrated example is preferable.

In addition, the surface uneven surface sheet of the present invention does not have a lenticular structure, but a curve forming a convex portion in a cross section when the surface uneven surface sheet is cut in a direction perpendicular to the extending direction of the convex lines and in the thickness direction of the surface uneven surface sheet. The curves that form the concave and concave sections are alternate and continuous, making them continuous. For this reason, in the curve that constitutes the cross section when the surface unevenness sheet is cut in the direction perpendicular to the direction of extension of the convex lines and in the thickness direction of the surface unevenness sheet, there is no point where the change rate of the slope of the tangent line is extremely large. No.

＜Manufacturing method of surface uneven sheet＞

The method for producing a surface uneven surface sheet of the present invention includes a step of coating a resin and a step of forming a surface layer having a predetermined uneven shape while curing the resin. Here, the resin is preferably coated on a substrate, and the substrate may be a member constituting a surface uneven sheet or may be removed from the surface layer.

The resin used in the method for producing the uneven surface sheet of the present invention is not particularly limited, but examples include ionizing radiation hardening type resin, thermosetting type resin, and thermoplastic type resin. Since it is easy to form convex lines and concave lines, it is preferable to use an ionizing radiation-curing type resin. Examples of the ionizing radiation-curing type resin include photocuring resin (ultraviolet curing type resin) and electron beam curing type resin. Among these, it is preferable that the main component of the resin forming the surface layer is an ultraviolet curable resin. Examples of the ultraviolet curable resin include acrylic resin, urethane resin, vinyl ester resin, and polyester/alkyd resin, and among these, acrylic resin is preferable. Resins can be used one type or in combination of two or more types.

When coating resin, a solvent may be used to improve coating properties. Examples of solvents include hydrocarbons such as hexane, heptane, octane, toluene, xylene, ethylbenzene, cyclohexane, and methylcyclohexane; Halogenated hydrocarbons such as dichloromethane, trichloroethane, trichlorethylene, tetrachloroethylene, and dichloropropane; Alcohols such as methanol, ethanol, propanol, isopropyl alcohol, butanol, isobutyl alcohol, and diacetone alcohol; ethers such as diethyl ether, diisopropyl ether, dioxane, and tetrahydrofuran; Ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, isophorone, and cyclohexanone; esters such as methyl acetate, ethyl acetate, butyl acetate, isobutyl acetate, amyl acetate, and ethyl butyrate; Polyols such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, propylene glycol monoethyl ether, and propylene glycol monomethyl ether acetate can be mentioned.

The coating liquid used when coating the resin may contain a polymerization initiator. For example, when the resin used in the production method of the present invention is ultraviolet curable, it is preferable to add a photopolymerization initiator such as acetophenone or benzophenone to the coating liquid.

A cured product of a curable resin or a thermoplastic resin can be used as the substrate used in the method for producing the uneven surface sheet of the present invention. In order to give the screen flexibility, it is preferable to use a thermoplastic resin. Examples of the thermoplastic resin include polyethylene terephthalate (hereinafter also referred to as “PET”), polyethylene naphthalate, polycarbonate, polyethersulfone, polyolefin, etc. can be mentioned. Resins can be used one type or in combination of two or more types. On the other hand, the thickness of the substrate is preferably 5 ㎛ or more and 2000 ㎛ or less, more preferably 100 ㎛ or more and 1000 ㎛ or less, more preferably 150 ㎛ or more and 500 ㎛ or less, and especially preferably 200 ㎛ or more and 300 ㎛ or less.

The coating amount of resin is preferably 1 g/m 2 or more, more preferably 2 g/m 2 or more, and even more preferably 3 g/m 2 or more. In addition, it is preferable that the coating amount of resin is 50 g/m 2 or less. In addition, the thickness of the formed surface layer is preferably 5 μm or more and 100 μm or less, more preferably 10 μm or more and 50 μm or less, and even more preferably 15 μm or more and 30 μm or less. As a coating method, a general resin coating device can be used. Examples of coating devices include a blade coater, air knife coater, roll coater, bar coater, gravure coater, micro gravure coater, rod blade coater, lip coater, Die coaters, curtain coaters, etc. can be mentioned.

In the method for producing an uneven surface sheet of the present invention, a step of forming an adhesive layer or an adhesive layer between the base layer and the surface layer or between the base layer and the base layer may be included, if necessary. In this case, it is preferable to apply the composition for forming an adhesive layer or a composition for forming an adhesive layer on the base layer and further form a surface layer thereon. Examples of the composition for forming an adhesive layer or a composition for forming an adhesive layer include resins such as acrylic resin, styrene resin, epoxy resin, silicone resin, polyester resin, and polyurethane resin. These may be used alone, or two or more types may be mixed or copolymerized. In addition, the composition for forming an adhesive layer or the composition for forming an adhesive layer contains additives such as crosslinking agents, antioxidants, metal corrosion inhibitors, tackifiers, silane coupling agents, ultraviolet absorbers, hindered amine compounds, light stabilizers, fillers, and ionic compounds. Liquid, etc. may be included.

In the process of forming a predetermined uneven shape in the resin, for example, it is preferable to employ an imprint method using a stamper having concave and convex lines on the surface corresponding to the convex and concave lines on the surface of the surface uneven sheet. do.

Examples of the imprint method include the ionizing radiation imprint method and the thermal imprint method. The ionizing radiation imprint method is also called the optical imprint method, and a stamper is pressed against a resin composition containing ionizing radiation-curable resin as a main ingredient applied to the surface of a substrate (base layer), and ionizing radiation (ultraviolet rays, electron beams, etc.) is irradiated to form the resin composition. This is a method of transferring the surface irregularities of the stamper to the surface of a layer containing ionizing radiation-curable resin applied to the surface of the base layer by curing the ionizing radiation-curable resin in the stamper. The thermal imprint method is a method of transferring the surface irregularities of the stamper to the surface of a substrate by pressing a stamper on the surface of a heated substrate and then cooling it. As an imprint method, the ionizing radiation imprint method (optical imprint method) is preferable because the productivity of the surface uneven sheet is good.

As a stamper, a transfer roll having a plurality of concave lines on the surface and a convex line formed between two adjacent concave lines is preferable because the productivity of the surface uneven sheet is good. Here, the transfer roll means a roll for transferring (shaping) a plurality of concave lines and a plurality of convex lines to a sheet-shaped object in contact with the transfer roll. The concave lines of the transfer roll have a shape corresponding to the convex lines of the surface uneven surface sheet, and the convex lines of the transfer roll have a shape corresponding to the concave lines of the surface uneven surface sheet.

The grooves in the transfer roll may be extended in the circumferential direction of the surface of the transfer roll, or may be extended perpendicular to the circumferential direction of the transfer roll. In particular, when the uneven surface sheet is used for screen applications or lighting purposes, the horizontal direction of the screen, etc. is often the long side, and it is desirable for light to diffuse in the horizontal direction of the screen, etc., so the transfer roll It is preferable that the concave lines extend perpendicularly to the circumferential direction of the transfer roll. The material of the surface of the transfer roll may be metal or resin. When the surface material of the transfer roll is resin, a resin roll may be used as the transfer roll, and a plurality of concave lines and a plurality of convex lines may be formed on a roll other than the resin (e.g., a metal roll). A roll obtained by winding a resin sheet may be used as a transfer roll. When the surface material of the transfer roll is metal, the transfer roll may be called a metal transfer roll or a transfer metal roll.

When curing the ionizing radiation curable resin in the resin composition using ultraviolet rays by the ionizing radiation imprint method (optical imprint method), a metal halide lamp can be used. In this case, in order to sufficiently cure the ionizing radiation-curable resin without deforming the substrate, the irradiation intensity of ultraviolet rays is preferably 300 mJ/cm 2 or more and 1000 mJ/cm 2 or less.

Figure 7 is an enlarged perspective view near the surface schematically showing an example of the transfer roll of the present invention.

The transfer roll 100 has a plurality of concave lines 102 on one surface of the roll body 101 and a convex line 103 formed between two adjacent concave lines 102. In other words, the transfer roll 100 of the present invention has a plurality of concave lines 102 on one surface of the roll body 101 and a convex line 103 formed between two adjacent concave lines 102. there is. Although fine irregularities are formed on the surface of the concave structure 102, especially the bottom portion 102a, the illustration of fine irregularities is omitted in FIG. 7 .

The average depth of the concave structure is preferably 0.35 ㎛ or more and 40 ㎛ or less, more preferably 0.7 ㎛ or more and 30 ㎛ or less, more preferably 1 ㎛ or more and 24 ㎛ or less, even more preferably 3 ㎛ or more and 20 ㎛ or less, and 5 ㎛ More than 12㎛ or less is particularly preferable. When the average depth of the concave grooves is within each preferable range, this is a preferable mode because more preferable relative frontal luminance and chromatic aberration suppression can be obtained.

The average depth of the concave structure is obtained as follows.

Using a laser microscope, the surface irregularities of the transfer roll are measured under the conditions of a 50x objective lens and a measurement pitch of 0.1 μm. Subsequently, as shown in FIG. 8, a cross-sectional shape corresponding to the cross-section when the vicinity of the surface of the transfer roll is cut in the direction perpendicular to the extending direction of the concave strip 102 and in the direction toward the center of the transfer roll. Make measurements. The depth D1 from the top part 103a of one convex strip 103 adjacent to the concave strip 102 to the bottom part 102a of the concave strip 102 is measured. Similarly, the depth D2 from the top part 103a of the other convex strip 103 adjacent to the concave strip 102 to the bottom part 102a of the concave strip 102 is measured. The average value of the depth D1 and the depth D2 is taken as the depth D of the concave structure 102. The depth (D) is calculated for each of the five randomly selected concave structures 102. The average value of the depth (D) of the five concave structures 102 is obtained, and this is taken as the average depth of the concave structures 102.

The average spacing of the concave lines is preferably 5 μm or more and 100 μm or less, more preferably 10 μm or more and 75 μm or less, more preferably 15 μm or more and 55 μm or less, and especially preferably 20 μm or more and 40 μm or less. When the average spacing of the concave lines is within the respective preferred ranges, this is a preferable mode in that more preferable relative frontal luminance and chromatic aberration suppression can be obtained.

The average spacing of the concave structures is obtained as follows.

Using a laser microscope, the surface irregularities of the transfer roll are measured under the conditions of a 50x objective lens and a measurement pitch of 0.1 μm. Subsequently, as shown in FIG. 8, a cross-sectional shape corresponding to the cross-section when the vicinity of the surface of the transfer roll is cut in the direction perpendicular to the extending direction of the concave strip 102 and in the direction toward the center of the transfer roll. Make measurements. Obtain the width (W ₅ ) from the bottom part (102a) of the randomly selected standard concave structure (102) to the bottom part (102a) of the five adjacent concave structures (102). The value of dividing the width (W ₅ ) into 5 equal parts is taken as the average spacing of the concave structure 102.

The ratio of the average depth of the concave structure and the average spacing of the concave structure (average depth/average interval), that is, the aspect ratio of the concave structure, is 0.07 or more and 0.40 or less, preferably 0.09 or more and 0.40 or less, and more preferably 0.12 or more and 0.30 or less. If the aspect ratio of the concave lines is within the above range, an uneven surface sheet having an aspect ratio of the convex lines within the above range can be suitably manufactured.

The average roughness at the bottom of the concave structure obtained from the roughness curve in the direction in which the concave structure extends should just be 0.10 μm or more, and is preferably 0.12 μm or more. In addition, the average roughness at the bottom of the concave structure obtained from the roughness curve in the direction in which the concave structure extends may be 0.90 ㎛ or less, preferably 0.70 ㎛ or less, more preferably 0.50 ㎛ or less, even more preferably 0.40 ㎛ or less, 0.30 μm or less is even more preferable, and 0.29 μm or less is particularly preferable. If the average roughness of the bottom of the concave lines is within the above range, a surface uneven surface sheet having the average roughness of the top of the convex lines is within the above range can be suitably manufactured. On the other hand, the average roughness at the bottom of the concave strip obtained from the roughness curve in the extending direction of the concave strip is thought to be due to fine irregularities formed on the surface of the concave strip 102, especially the bottom portion 102a.

The average illuminance of the bottom part of the concave structure is obtained as follows.

Using a laser microscope, the surface irregularities of the transfer roll are measured under the conditions of a 50x objective lens and a measurement pitch of 0.1 μm. Subsequently, as shown in FIG. 8, a cross section CS (broken line in the figure) when the vicinity of the surface of the transfer roll is cut in the direction toward the center of the transfer roll along the curve of the concave line 102. Measure the cross-sectional shape corresponding to the portion surrounded by ). From the cross-sectional shape corresponding to the cross-section CS, the roughness curve (reference length l: 200 μm) in the extending direction of the concave structure 102 at the bottom 102a of the concave structure 102 is obtained. . From the roughness curve, the arithmetic mean roughness Ra is obtained according to a calculation formula based on JIS B 0601:1994. The arithmetic mean illuminance Ra is obtained for each of the bottom portions 102a of the concave structures 102 at five randomly selected locations. The average value of the arithmetic mean roughness Ra of the bottom part 102a of the five concave lines 102 is obtained, and this is taken as the average roughness of the bottom parts 102a of the concave lines 102.

When the concave structure is meandering, as shown in FIG. 9, a straight line (broken line in the figure) connecting points formed at predetermined intervals (straight line distance 40 μm) along the curve of the concave structure 102. Draw a line. For each straight line, the cross-sectional shape corresponding to the cross-section (CS1, CS2, CS3...) (portion surrounded by a broken line in the figure) is measured. From each of the cross-sectional shapes corresponding to the cross-sections (CS1, CS2, CS3...), a roughness curve in the extension direction of the concave structure 102 at the bottom 102a of the concave structure 102 and its vicinity is obtained, These roughness curves are connected to obtain the final roughness curve (standard length (l): 200 μm). Meanwhile, in FIG. 9, since the intention is to explain the meandering of the concave lines 102 more easily, the illustration of fine irregularities existing in the extending direction of the concave lines 102 as in FIG. 8 is omitted.

The frequency (T) of the slope angle calculated from the depth data in the cross-sectional shape when the transfer roll is cut in a direction perpendicular to the direction of continuation of the concave pattern and perpendicular to the central axis of the transfer roll is calculated, When the frequency ratio (%) is calculated from the following formula (A), the frequency ratio (%) is 98% or more, preferably 100% or more, more preferably 105% or more, and even more preferably 108% or more. Additionally, the frequency ratio (%) is preferably 300% or less, and more preferably 200% or less. Meanwhile, assuming that the transfer roll has a planar shape, the frequency T is calculated.

Formula (A): Frequency ratio (%) = Frequency (T) / Frequency (S) × 100

Here, the frequency (S) is the frequency in the range of the most frequent angle -2° to 98° in the slope angle frequency distribution chart calculated from a sine curve in which the average depth of the concave structures and the average spacing between the concave structures are equal. It's the sum. In addition, the frequency (T) is calculated by assuming that the most frequent angle in the sine curve is the angle (Mθs), and the transfer roll is cut in a direction perpendicular to the continuous direction of the concave pattern and in a direction perpendicular to the central axis of the transfer roll. It is the sum of the frequencies in the range of angle (Mθs) -2° to 98° in the frequency distribution chart of the slope angle calculated from depth data in the cross-sectional shape at the time.

Here, all the concavities in the sine curve have the same depth as the average depth of the concavities in the transfer roll, the spacing of the concavities in the sine curve is constant, and all spacings are the same as the average spacing of the concavities in the transfer roll.

Meanwhile, the frequency (T) and frequency (S) of the transfer roll are calculated in the same manner as the frequency (T) and frequency (S) of the uneven surface sheet.

Additionally, “/” in equation (A) is “÷” and means division.

The transfer roll can be manufactured, for example, by engraving a plurality of grooves on the surface of the roll body using a laser engraving device.

Examples of the laser engraving device include a laser device that generates laser light and an optical system. Laser devices include carbon dioxide gas lasers, YAG lasers, semiconductor lasers, and ytterbium fiber lasers. The optical system includes a combination of various lenses such as a collimator lens and an objective lens. Laser engraving devices include Japanese Patent Application Laid-Open No. 2010-181862, Japanese Patent Application Publication No. 5-24172, Japanese Patent Application Publication No. 8-28441, Japanese Patent Application Publication No. 8-293134, and Japanese Patent Application Publication No. 2011. Known laser engraving devices described in -20407 and the like can be mentioned.

The conditions of laser engraving (beam diameter of laser light, laser power, laser pulse length, roll peripheral speed, etc.) are the material of the laser engraving target, the average depth of the grooves of the surface irregularities of the transfer roll, the average spacing of the grooves, and the average roughness of the bottom of the grooves. It is set appropriately according to etc. For example, when the beam diameter of the laser light is increased, the average illuminance of the bottom of the concave groove tends to decrease, and the average depth of the concave groove tends to become shallow. When the laser output is increased, the average illuminance of the bottom of the concave structure tends to increase, and the average depth of the concave structure tends to become deeper. When the laser pulse length is lengthened, the average illuminance of the bottom of the concave groove tends to increase and the average depth of the concave groove tends to become deeper. When the roll peripheral speed is increased, the average roughness of the bottom of the concave groove tends to decrease, and the average depth of the concave groove tends to become shallow.

In addition, when performing laser engraving, the laser light may engrave a concave pattern by continuous irradiation or may engrave a concave pattern by intermittent irradiation. Additionally, the concave lines may be serially spread in the CD direction (direction perpendicular to the circumferential direction of the transfer roll). In addition, it is also possible to make adjustments, such as deepening the average depth of the concave pattern, by irradiating the laser once to irradiate the laser multiple times to the point where the concave pattern was carved.

When performing laser engraving, the material of the object of engraving (the object of the engraving is a plate roll) is preferably metal, ceramics, etc. because it is easy to form fine irregularities on the surface of the concave structure, especially at the bottom. Among metals, copper is preferable.

In the present invention, after carving a plurality of grooves on the surface of the roll body, water washing, acid washing, and/or plating treatment may be performed on the surface of the roll body as needed.

Types of water cleaning include immersion cleaning, ultrasonic cleaning, and spray cleaning. Among water cleaning, ultrasonic cleaning is preferable because the surface irregularities of the transfer roll can be treated in a relatively short time. The frequency of ultrasonic waves is not particularly limited, but is often used in the range of 25 kHz to 50 kHz. Additionally, during water washing, a known surfactant may be added as needed. When water washing is performed with the addition of a surfactant, it is preferable to perform water washing again for the purpose of removing the surfactant.

When the object of laser engraving is metal (for example, copper), it is possible to adjust the average depth of the concave lines and the average roughness of the bottom of the concave lines by pickling. When the cleaning time of pickling is long, the average depth of the concave tank tends to become shallow, and the average roughness of the bottom of the concave tank tends to become small. Examples of acidic solutions used for acid washing include hydrochloric acid and sulfuric acid.

When the object of laser engraving is a metal (e.g., copper), it is preferable to perform water cleaning only, or water cleaning and acid cleaning. Additionally, for the purpose of improving the wear durability of the transfer roll for long-term use, It is preferable to perform plating treatment such as hard chrome plating, nickel plating, or nickel-phosphorus plating on the outermost surface of the roll body. The plating may be electrolytic plating or electroless plating. The plating treatment allows adjustment of the average depth of the concave structure and the average roughness of the bottom of the concave structure. In the case of electrolytic plating, the higher the current density, the shallower the average depth of the grooves tend to be, and the smaller the average roughness of the bottom of the grooves becomes. In addition, in both electrolytic plating and electroless plating, the longer the plating time, the shorter the average depth of the grooves tend to be, and the average roughness of the bottom of the grooves tends to be smaller.

The size of the transfer roll of the present invention is not particularly limited. For example, the width of the transfer roll is preferably 0.1 m to 50 m, and the diameter of the transfer roll is preferably 0.1 m to 10 m.

On the other hand, the transfer roll of the present invention can have a plurality of grooves on at least one surface, and the aspect ratio of the grooves and the average roughness of the bottom of the grooves are in a specific range, and it is not limited to the example shown.

For example, the concave structures may be series in a straight line or may be series in a meandering manner. The concave structures may be serially arranged in one direction parallel to each other, or may have portions that are not parallel to other concave structures.

The concave structure may branch midway. A convex line may branch along the way.

The shape formed by the surfaces of the concave and convex lines in a cross section when the vicinity of the surface of the transfer roll is cut in a direction perpendicular to the extension direction of the concave lines and in the direction toward the center of the transfer roll shows the effect of the present invention. Since it is easy to exert, a waveform as shown in the illustrated example is preferable.

＜Screen＞

The screen of the present invention is a reflective screen provided with the uneven surface sheet of the present invention and a reflective layer.

Figure 10 is an enlarged perspective view schematically showing an example of the screen of the present invention.

The screen 20 includes an uneven surface sheet 10 and a reflective layer 22 formed on the opposite side of the surface of the uneven surface sheet 10 having the convex lines 12 and concave lines 13. Fine irregularities are formed on the surface of the convex lines 12, especially the top portion 12a, but illustration of the fine irregularities is omitted in FIG. 10 .

Figure 11 is an enlarged perspective view schematically showing another example of the screen of the present invention.

The screen 21 includes an uneven surface sheet 11 and a reflective layer 22 formed on the opposite side of the surface of the uneven surface sheet 10 having the convex lines 12 and concave lines 13. Fine irregularities are formed on the surface of the convex stripes 12, especially the top portion 12a, but illustration of the fine irregularities is omitted in FIG. 11 .

The form of the reflective layer may be any layer that efficiently reflects visible light. Examples of such reflective layers include vapor-deposited metal films, metal foils, metal plates, dielectric multilayer films, and coating films. The form of the reflective layer is preferably a vapor-deposited film, a dielectric multilayer film, or a coating film because it is easy to form the reflective layer and gives the screen flexibility.

Metals of the vapor deposition film include aluminum, silver, nickel, tin, stainless steel, rhodium, and platinum. As a metal for the deposited film, aluminum or silver is preferable because it has a high reflectance in the visible light region. Vapor deposition methods include vacuum deposition and sputtering. From the viewpoint of reflectivity, the thickness of the deposited film is preferably 10 nm or more and 500 nm or less, more preferably 30 nm or more and 300 nm or less, and even more preferably 100 nm or more and 300 nm or less.

A dielectric multilayer film is a multilayer reflective film in which high refractive index dielectric thin films and low refractive index dielectric thin films are alternately overlapped in multiple layers, and is a film that can control the reflectance of visible light by adjusting the refractive index of the high refractive index film, the refractive index of the low refractive index film, and the optical film thickness. am. The reflectance of the dielectric multilayer film is preferably 95% or more. Materials that form the high refractive index film include TiO ₂ , Nb ₂ O ₅ , Ta ₂ O ₅ , and ZrO ₂ . Materials that form the low refractive index film include MgF ₂ , SiO ₂ , Al ₂ O ₃ , etc. High refractive index films and low refractive index films can be formed by physical vapor deposition (vacuum deposition, sputtering, ion plating, etc.), chemical vapor deposition (CVD) (thermal CVD, plasma CVD, optical CVD, etc.) methods.

When using a coating film as a reflective layer, it is preferable that it is a coating film (coating film) coated with metallic ink. The coating film to which the metallic ink is applied is, for example, applied by applying a metallic ink containing thin aluminum flakes (e.g., Toyo Aluminum Co., Ltd., Riping Alpaste) to the base material layer (base material) by screen printing. obtained. In this case, the applied aluminum flakes are arranged parallel to the film, thereby achieving a mirror-like reflective function.

The relative frontal luminance of the image displayed on the screen is preferably 150% or more and 500% or less, more preferably 160% or more and 480% or less, and even more preferably 170% or more and 450% or less. If the relative front luminance is more than the lower limit of the above range, the image displayed on the front of the screen becomes sufficiently bright. If the relative front luminance is below the upper limit of the above range, the image displayed on the front of the screen does not become excessively bright. Relative frontal luminance is measured by the method described in the Examples.

The left and right 60° luminance ratio of the image displayed on the screen is preferably 30% or less, more preferably 28% or less, and even more preferably 25% or less. If the left-right 60° luminance ratio is below the upper limit of the above range, reflection and diffusion of image light in the area exceeding ±50° in the horizontal direction of the screen, where the viewer is always assumed to be absent, is sufficiently suppressed, and the relative frontal luminance is sufficiently improved accordingly. The lower the left and right 60° luminance ratio, the more desirable it is, and the lower limit is 0%, 1%, etc. The left and right 60° luminance ratio is measured by the method described in the examples.

The 100° luminance difference ratio of the image displayed on the screen is preferably 60% or less, more preferably 55% or less, and even more preferably 50% or less. If the 100° luminance difference ratio is below the upper limit of the above range, an image with a sufficiently small luminance difference can be displayed in an area within ±50° of the horizontal direction of the screen where the viewer is assumed to be. The lower the 100° luminance difference ratio, the more desirable it is, and the lower limit is 0%, 1%, etc. The 100° luminance difference ratio is measured by the method described in the examples.

The chromatic aberration of the image displayed on the screen is preferably 2.0 or less, more preferably 1.9 or less, and even more preferably 1.8 or less. If the chromatic aberration is below the upper limit of the above range, it is difficult for the color change of the image displayed on the screen to sufficiently occur for an observer located in any direction of the horizontal direction of the screen. The lower the chromatic aberration, the more desirable it is, and the lower limit is 0, 0.1, etc. Chromatic aberration is measured by the method described in the Examples.

Meanwhile, the screen of the present invention can be any one provided with the surface uneven sheet and the reflective layer of the present invention, and is not limited to the example shown.

For example, a reflective layer may be formed on the side of the surface having the convex lines 12 and the concave lines 13 of the uneven surface sheet.

As the surface uneven sheet, one having convex lines and concave lines on both sides may be used.

A reflective layer may be formed between two sheets of surface unevenness.

Another layer (adhesive layer, adhesive layer, ultraviolet absorbing layer, etc.) may be formed between the uneven surface sheet and the reflective layer.

Another layer (hard coat layer, self-repairing layer, etc.) may be formed on the surface of the uneven surface sheet opposite to the reflective layer.

＜Video display system＞

The video display system of the present invention includes the screen of the present invention and a projector that projects video light onto the screen.

Figure 12 is a schematic configuration diagram schematically showing an example of a video display system of the present invention.

The image display system 30 is disposed away from the screen 20 and has a reflective layer (not shown) on the opposite side of the screen 20, i.e., convex (not shown) and concave (not shown) surfaces. It is provided with a projector 40 that projects the image light L on the front side (not shown). In the drawing, the x-axis, y-axis, and z-axis are spatial coordinates of the location where the screen 20 is installed, the z-axis represents the vertical direction, and the x-axis is the same as the front direction of the screen 20 among the directions perpendicular to the z-axis. It represents the direction, and the y-axis represents the direction perpendicular to the z-axis and the x-axis.

In the screen of the present invention, the image light is widely reflected and diffused in a direction intersecting the direction in which the convex lines are extended, and the reflection and diffusion of the image light in the direction in which the convex lines are extended is suppressed. Therefore, in the video display system of the present invention, as shown in Fig. 13, the screen 20 is arranged so that the direction in which the convex lines 12 extend is along the z-axis.

Projectors include liquid crystal projectors, DLP projectors, LCOS projectors, CRT projectors, and overhead projectors.

Meanwhile, the video display system of the present invention can be provided with the screen and projector of the present invention, and is not limited to the example shown.

For example, a control device for controlling a projector, an audio device, a lighting device, etc. may be additionally provided.

Instead of the screen 20, another screen of the present invention, such as the screen 21, may be provided.

Example

Hereinafter, the present invention will be described in detail through examples, but the present invention is not limited to these.

(Average depth of concavity of transfer roll)

The average depth of the grooves of the transfer roll was determined as follows.

The surface irregularities of the transfer roll were measured using a laser microscope (VK-8500, manufactured by Keyence) under the conditions of a 50x objective lens and a measurement pitch of 0.1 μm. Subsequently, as shown in FIG. 8, a cross-sectional shape corresponding to the cross-section when the vicinity of the surface of the transfer roll is cut in the direction perpendicular to the extending direction of the concave strip 102 and in the direction toward the center of the transfer roll. Measurements were made. The depth D1 from the top 103a of the convex strip 103 adjacent to the concave strip 102 to the bottom 102a of the concave strip 102 was measured. Similarly, the depth D2 from the top 103a of the other convex strip 103 adjacent to the concave strip 102 to the bottom 102a of the concave strip 102 was measured. The average value of depth (D1) and depth (D2) was taken as the depth (D) of the concave structure 102. The depth (D) was calculated for each of the five randomly selected concave structures (102). The average value of the depth (D) of the five concave structures was obtained, and this was taken as the average depth of the concave structures (102).

(Average spacing of concave lines of transfer roll)

The average spacing between the grooves of the transfer roll was determined as follows.

The surface irregularities of the transfer roll were measured using a laser microscope (VK-8500, manufactured by Keyence) under the conditions of a 50x objective lens and a measurement pitch of 0.1 μm. Subsequently, as shown in FIG. 8, a cross-sectional shape corresponding to the cross-section when the vicinity of the surface of the transfer roll is cut in the direction perpendicular to the extending direction of the concave strip 102 and in the direction toward the center of the transfer roll. Measurements were made. The width (W ₅ ) from the bottom part 102a of the randomly selected standard concave structure 102 to the bottom part 102a of the five adjacent concave structures 102 was obtained. The randomly selected standard concave line 102 is one of the five selected concave lines when the average depth of the concave lines of the transfer roll is calculated, and has a depth closest to the average depth value of the concave line 102. It was made of wood (102). Next, the value obtained by dividing the width (W ₅ ) into 5 equal parts was taken as the average interval of the concave lines 102. That is, the width (W ₅ ) divided by 5 was taken as the average spacing of the concave structures (102).

(Concave aspect ratio of transfer roll)

The aspect ratio of the concave grooves of the transfer roll was obtained by dividing the average depth of the concave grooves by the average spacing of the concave grooves.

(Average roughness of the bottom of the concave structure of the transfer roll)

The average roughness of the bottom of the concave structure of the transfer roll was determined as follows.

The surface irregularities of the transfer roll were measured using a laser microscope (VK-8500, manufactured by Keyence) under the conditions of a 50x objective lens and a measurement pitch of 0.1 μm. Subsequently, as shown in FIG. 8, a cross section CS (broken line in the figure) when the vicinity of the surface of the transfer roll is cut in the direction toward the center of the transfer roll along the curve of the concave line 102. The cross-sectional shape corresponding to the portion surrounded by ) was measured. From the cross-sectional shape corresponding to the cross-section CS, the roughness curve (reference length l: 200 μm) in the extension direction of the concave strip 102 at the bottom 102a of the concave strip 102 was obtained. From the roughness curve, the arithmetic average roughness Ra was obtained according to a calculation formula based on JIS B 0601:1994. The arithmetic mean roughness Ra was obtained for each of the bottom portions 102a of the concave structures 102 at five randomly selected locations. The five randomly selected grooves 102 were selected when the average depth of the grooves of the transfer roll was determined. The average value of the arithmetic mean roughness Ra of the bottom part 102a of the five concave structures 102 was obtained, and this was set as the average roughness of the bottom parts 102a of the concave structures 102.

(Average height of convex lines of surface uneven sheet)

The average height of the convex lines of the surface uneven sheet was determined as follows.

The surface irregularities of the surface irregularities sheet were measured using a laser microscope (VK-8500, manufactured by Keyence) under the conditions of a 50x objective lens and a measurement pitch of 0.1 μm. Subsequently, as shown in FIG. 5, the cross-sectional shape corresponding to the cross section when the surface uneven sheet was cut in the direction perpendicular to the extension direction of the convex lines 12 and in the thickness direction of the surface uneven sheet was measured. . The height H1 was measured from the bottom part 13a of the concave strip 13 on one side adjacent to the convex strip 12 to the top part 12a of the convex strip 12. Similarly, the height H2 from the bottom part 13a of the other concave strip 13 adjacent to the convex strip 12 to the top part 12a of the convex strip 12 was measured. The average value of the height (H1) and the height (H2) was taken as the height (H) of the convex lines 12. The height (H) was obtained for each of the five randomly selected convex lines (12). The average value of the heights (H) of the five convex lines 12 was obtained, and this was taken as the average height of the convex lines 12.

(Average spacing of convex lines of surface uneven sheet)

The average spacing between the convex lines of the surface uneven sheet was determined as follows.

The surface irregularities of the surface irregularities sheet were measured using a laser microscope (VK-8500, manufactured by Keyence) under the conditions of a 50x objective lens and a measurement pitch of 0.1 μm. Subsequently, as shown in FIG. 5, the cross-sectional shape corresponding to the cross section when the surface uneven sheet was cut in the direction perpendicular to the extension direction of the convex lines 12 and in the thickness direction of the surface uneven sheet was measured. . The width (W ₅ ) from the top (12a) of the randomly selected reference convex stripes (12) to the tops (12a) of the five adjacent convex stripes (12) was obtained. The randomly selected standard convex stripe 12 is one of the five convex stripes selected when the average height of the convex stripes of the surface uneven sheet is obtained, and has a depth closest to the average depth value of the convex stripes 12. It was made into convex lines (12). Next, the value obtained by dividing the width (W ₅ ) into 5 equal parts was taken as the average spacing of the convex lines 12. That is, the width (W ₅ ) divided by 5 was taken as the average spacing of the convex lines 12.

(Aspect ratio of convex lines of surface uneven sheet)

The aspect ratio of the convex stripes of the surface uneven sheet was obtained by dividing the average height of the convex stripes by the average spacing of the convex stripes.

(Average roughness of the top of the convex lines of the surface uneven sheet)

The average roughness of the top portion of the convex lines of the surface uneven sheet was determined as follows. Subsequently, as shown in FIG. 5, the surface unevenness sheet corresponds to the cross section CS (the portion surrounded by a broken line in the figure) when the surface unevenness sheet is cut in the thickness direction of the surface unevenness sheet along the ridge line of the convex lines 12. The cross-sectional shape was measured. From the cross-sectional shape corresponding to the cross-section CS, a roughness curve (reference length l: 200 μm) in the extending direction of the convex stripes 12 at the top 12a of the convex stripes 12 was obtained. From the roughness curve, the arithmetic average roughness Ra was obtained according to a calculation formula based on JIS B 0601:1994. The arithmetic mean roughness Ra was obtained for each of the top portions 12a of the five randomly selected convex lines 12. The five convex lines 12 selected at random were used as concave lines at five places selected when the average depth of the convex lines of the surface uneven sheet was determined. The average value of the arithmetic mean roughness Ra of the top portions 12a of the five convex lines 12 was obtained, and this was taken as the average roughness of the top portions 12a of the convex lines 12.

(Relative frontal luminance)

A screen 20, a projector 40 (LCD projector, LV-X420, manufactured by Canon), and a spectroradiometer (SR-3, manufactured by Topcon Techno House) were installed as shown in Figs. 14 and 15. Meanwhile, for convenience of explanation, the screen 20 is installed in the drawing, but when evaluating a screen other than the screen 20, a screen 20 may be used as a substitute screen (e.g., screen 21, a reference screen). etc.) can be installed.

The screen 20 was arranged so that the direction in which the convex lines were extended was along the z-axis in the drawing, and the surface direction of the screen 20 was parallel to the yz-plane consisting of the y-axis and z-axis in the drawing.

The projector 40 was placed on the side opposite to the side having the reflective layer of the screen 20, that is, on the side having the convex and concave lines (front side).

The meanings of the symbols in the drawings are as follows.

SH: vertical length of the screen 20,

SW: horizontal length of the screen 20,

O: Center point of the front of the screen 20,

P: Center point of the light emitting lens surface of the projector 40,

S: measuring point in the spectroradiometer,

SFH: Height from the floor to the bottom of the screen 20,

PFH: Height from the floor to the center point (P) of the light emitting lens surface of the projector 40,

SCFH: Height from the floor to the center point (O) of the front of the screen 20 (height from the floor to the measuring point (S) in the spectroradiometer),

SPL: Horizontal distance from the center point (O) of the front of the screen (20) to the center point (P) of the light emitting lens surface of the projector (40).

White image light L was projected from the projector 40, and the front luminance at the front center point O of the screen 20 was measured using a spectroradiometer at the measurement point S.

The front luminance of the reference screen (the front luminance of the reference screen is also referred to as standard front luminance) was measured in the same manner, except that a reference screen described later was installed instead of the screen 20. The relative frontal luminance was obtained using the formula below.

Relative front luminance = front luminance / standard front luminance × 100

Here, front luminance refers to the front luminance of each example or comparative example.

(60° brightness ratio left and right)

The screen 20, projector 40, and spectroradiometer were installed in the same manner as when measuring relative frontal luminance. Meanwhile, for convenience of explanation, the screen 20 is installed in the drawing, but when evaluating a screen other than the screen 20, a substitute screen (for example, screen 21, etc.) of the screen 20 is installed. It's okay too.

As shown in FIG. 16, the spectroradiometer was moved from the measurement point S to the measurement point RGT60 60° to the right of the y-axis direction with the x-axis including the measurement point S and the center point O as the main axis. White image light L was projected from the projector 40, and the luminance at the front center point O of the screen 20 was measured using a spectroradiometer at the measurement point RGT60. Here, the luminance with RGT60 as the measurement point is called the right 60° luminance. Additionally, the spectroradiometer was moved from the measurement point (S) to the measurement point (LFT60) 60° to the left of the y-axis direction with the x-axis including the measurement point (S) and the center point (O) as the main axis. White image light L was projected from the projector 40, and the luminance at the front center point O of the screen 20 was measured using a spectroradiometer at the measurement point LFT60. Here, the luminance with LFT60 as the measurement point is called left 60° luminance. Next, the left and right 60° luminance ratio was obtained using the equation below.

Left and right 60° luminance ratio = l (60° luminance on the right + 60° luminance on the left) / 2 l / Front luminance × 100

(100° luminance difference ratio)

The screen 20, projector 40, and spectroradiometer were installed in the same way as when measuring relative frontal luminance. Meanwhile, for convenience of explanation, the screen 20 is installed in the drawing, but when evaluating screens other than the screen 20, a substitute screen (for example, screen 21, etc.) of the screen 20 is installed. It's okay too.

As shown in FIG. 17, the spectroradiometer was moved from the measurement point S to the measurement point RGT10 10° to the right of the y-axis direction with the x-axis including the measurement point S and the center point O as the main axis. White image light L was projected from the projector 40, and the luminance at the front center point O of the screen 20 was measured using a spectroradiometer at the measurement point RGT10. Here, the luminance with RGT10 as the measurement point is referred to as the right 10° luminance, and similarly, the luminance with RGTn as the measurement point is referred to as the right n° luminance (n is a positive integer). Next, 20° luminance to the right, 30° luminance to the right, 40° luminance to the right, and 50° luminance to the right at the front center point (O) of the screen 20 are measured from the spectroradiometer at the measurement points (RGT20, RGT30, RGT40, and RGT50). was measured.

Additionally, the spectroradiometer was moved from the measurement point (S) to the measurement point (LFT10) 10° to the left of the y-axis direction with the x-axis including the measurement point (S) and the center point (O) as the main axis. White image light L was projected from the projector 40, and the luminance at the front center point O of the screen 20 was measured using a spectroradiometer at the measurement point LFT10. Here, the luminance with LFT10 as the measurement point is referred to as the left 10° luminance, and similarly, the luminance with LFTn as the measurement point is referred to as the left n° luminance (n is a positive integer). Next, from the spectroradiometer at the measurement points (LFT20, LFT30, LFT40, LFT50), 20° luminance to the left, 30° luminance to the left, 40° luminance to the left, and 50° luminance to the left at the center point O in front of the screen 20 are measured. was measured.

Next, among the luminances measured at 10 locations as described above (luminance at RGT10, RGT20, RGT30, RGT40, RGT50, LFT10, LFT20, LFT30, LFT40, LFT50), the maximum value and minimum value of luminance are determined, The 100° luminance difference ratio was obtained from the difference between the maximum value and the minimum value using the formula below.

100° luminance difference ratio = (maximum luminance value - minimum luminance value) / front luminance × 100

(chromatic aberration)

The screen 20, projector 40, and color luminance meter are installed in the same manner as when measuring relative frontal luminance, except that a color luminance meter (CS-200, manufactured by Konica Minolta) is installed instead of a spectroradiometer. did. Meanwhile, for convenience of explanation, the screen 20 is installed in the drawing, but when evaluating a screen other than the screen 20, a substitute screen (for example, screen 21, etc.) of the screen 20 is installed. It's okay too.

White image light L was projected from the projector 40, and the chromaticities u' and v' at the front center point O of the screen 20 were measured using a color luminance meter at the measurement point S.

The chromaticities u" and v" were measured in the same manner, except that a reference screen described later was installed instead of the screen 20.

The difference Δu' (=u'-u") between the chromaticity u' measured on the screen 20 and the chromaticity u" measured on the reference screen, and the chromaticity v' measured on the screen 20 and the chromaticity u" measured on the reference screen. The chromatic aberration (ΔJND) was obtained from the difference Δv' (=v'-v") of chromaticity v" using the formula below.

ΔJND=(Δu' ² ＋Δv' ² ) ^2/1 ／0.004

[Production Example 1]

(Coating liquid for light diffusion sheet for reference)

A coating liquid for a reference light diffusion sheet of the following composition was prepared.

Acrylic resin (100% non-volatile component, glass transition temperature 105°C, weight average molecular weight 600,000): 8 parts by mass,

Cross-linked polystyrene particles (SBX-6, manufactured by Sekisui Chemical Industries, Ltd., average particle diameter 6.4 μm, no glass transition temperature): 13.2 parts by mass,

Cross-linked polystyrene particles (SBX-12, manufactured by Sekisui Chemical Industries, Ltd., average particle diameter 11.7 μm, no glass transition temperature): 9.6 parts by mass,

Cross-linked polystyrene particles (SBX-17, manufactured by Sekisui Chemical Industries, Ltd., average particle diameter 16.1 μm, no glass transition temperature): 1.2 parts by mass,

Toluene: 68 parts by mass.

(Light diffusion sheet for reference)

Apply the coating liquid for the reference light diffusion sheet to one side of the base material (transparent PET film, A4300, thickness 250㎛, manufactured by Toyobo Corporation) using a bar coater so that the coating amount of the light diffusion layer after drying is 8g/㎡, and dry. I ordered it. As a result, a reference light diffusion sheet provided with a base material layer and a light diffusion layer was obtained.

(screen for reference)

Aluminum was deposited to a thickness of 200 nm on the surface opposite to the light diffusion layer of the reference light diffusion sheet. As a result, a reference screen equipped with a light diffusion sheet and a reflective layer was obtained. In the reference screen, a light diffusion layer with surface irregularities is formed on one side of a base layer made of transparent PET film, and a reflection layer is formed on the other side of the base layer.

[Example 1]

(Warrior Roll)

A ytterbium fiber laser (manufactured by IPG Photonics, Inc.) attached to the laser engraving device is used on the surface of the roll body whose surface material is copper, with a laser light beam diameter of 2.8㎛, laser power of 200W, laser pulse length of 120ns, and roll peripheral speed of 45cm/. Under the conditions of s, a plurality of concave structures extending in the circumferential direction of the roll body were carved.

The roll body on which the plurality of concave structures were carved was washed with water (pure water, ultrasonic cleaning at 25 kHz) for 5 minutes. Next, pickling was performed for 12 minutes at 50°C with an acidic solution (sulfuric acid aqueous solution with a concentration of 10% (v/v)), and then electrolyte solution (600 g/liter of nickel sulfamate, 5 g/liter of nickel chloride, 40 g/liter of boric acid, naphthalene) was applied. Electrolytic plating was performed with 0.5 g/liter sodium sulfonate and 1 g/liter sodium lauryl sulfate) for 22 minutes under the conditions of a liquid temperature of 50°C and a current density of 1.5 A/dm2. As a result, a transfer roll having surface irregularities as shown in FIG. 7 was obtained. Table 1 shows the average depth of the concave lines of the transfer roll, the average interval between the concave lines, the aspect ratio of the concave lines, and the average roughness of the bottom of the concave lines.

(surface uneven sheet)

A liquid ultraviolet curable resin (acrylic resin, viscosity 50 cPs) was applied to one side of a base material (transparent PET film, A4300, manufactured by Toyobo Co., Ltd., thickness 250 ㎛) to a thickness of 20 ㎛, to obtain a base material with a resin coating film. The base material with the resin coating film was brought into contact with the transfer roll so that the resin coating film was pressed against the surface of the transfer roll. Ultraviolet rays were irradiated to the base material with the resin coating film in contact with the transfer roll so that the amount of ultraviolet irradiation from the metal halide lamp was 700 mJ/cm2, and the ultraviolet curable resin in the resin coating film was cured. The base material with the cured resin coating film was peeled from the transfer roll. As a result, a surface uneven sheet having a surface layer containing a cured product of ultraviolet curable resin as a main component was obtained on the surface of a base material layer made of a transparent PET film. Surface irregularities as shown in Fig. 1, where the surface irregularities of the transfer roll were reversed, were transferred to the surface of the surface layer of the surface irregularities sheet. Additionally, the surface irregularities of the transfer roll were not transferred to the base material layer formed on the back side of the surface layer, and the interface between the base layer and the surface layer was smooth. Table 1 shows the average height of the convex stripes, the average spacing between the convex stripes, the aspect ratio of the convex stripes, and the average roughness of the top of the convex stripes of the uneven surface sheet.

(screen)

Aluminum was deposited to a thickness of 200 nm on the surface opposite to the surface layer of the uneven surface sheet. As a result, a reflective screen including a surface uneven sheet and a reflective layer was obtained. In the screen, a surface layer having surface irregularities as shown in FIG. 10 is formed on one side of a base layer made of transparent PET film, and a reflective layer is formed on the other side of the base layer. Table 1 shows the relative frontal luminance, left and right 60° luminance ratio, 100° luminance difference ratio, and chromatic aberration of the image displayed on the screen.

[Example 2]

A transfer roll was obtained in the same manner as in Example 1, except that the laser output was changed to 180 W and the pickling time was changed to 11 minutes. Table 1 shows the average depth of the concave lines of the transfer roll, the average interval between the concave lines, the aspect ratio of the concave lines, and the average roughness of the bottom of the concave lines.

A surface uneven sheet was obtained in the same manner as in Example 1, except that the transfer roll of Example 2 was used. Table 1 shows the average height of the convex stripes, the average spacing between the convex stripes, the aspect ratio of the convex stripes, and the average roughness of the top of the convex stripes of the uneven surface sheet.

A screen was obtained in the same manner as in Example 1, except that the surface uneven sheet of Example 2 was used. Table 1 shows the relative frontal luminance, left and right 60° luminance ratio, 100° luminance difference ratio, and chromatic aberration of the image displayed on the screen.

[Example 3]

A transfer roll was obtained in the same manner as in Example 1, except that the laser output was changed to 240 W, acid washing was not performed, and electrolytic plating was changed to 25 minutes. Table 1 shows the average depth of the concave lines of the transfer roll, the average interval between the concave lines, the aspect ratio of the concave lines, and the average roughness of the bottom of the concave lines.

A surface uneven sheet was obtained in the same manner as in Example 1, except that the transfer roll of Example 3 was used. Table 1 shows the average height of the convex stripes, the average spacing between the convex stripes, the aspect ratio of the convex stripes, and the average roughness of the top of the convex stripes of the uneven surface sheet.

A screen was obtained in the same manner as in Example 1, except that the surface uneven sheet of Example 3 was used. Table 1 shows the relative frontal luminance, left and right 60° luminance ratio, 100° luminance difference ratio, and chromatic aberration of the image displayed on the screen.

[Example 4]

A transfer roll was obtained in the same manner as in Example 1, except that the beam diameter of the laser light was changed to 1.8 μm, the laser power was changed to 164 W, the acid washing was changed to 38 minutes, and the electrolytic plating was changed to 18 minutes. . Table 1 shows the average depth of the concave lines of the transfer roll, the average interval between the concave lines, the aspect ratio of the concave lines, and the average roughness of the bottom of the concave lines.

A surface uneven sheet was obtained in the same manner as in Example 1, except that the transfer roll of Example 4 was used. Table 1 shows the average height of the convex stripes, the average spacing between the convex stripes, the aspect ratio of the convex stripes, and the average roughness of the top of the convex stripes of the uneven surface sheet.

A screen was obtained in the same manner as in Example 1, except that the surface uneven sheet of Example 4 was used. Table 1 shows the relative frontal luminance, left and right 60° luminance ratio, 100° luminance difference ratio, and chromatic aberration of the image displayed on the screen.

[Example 5]

A transfer roll was obtained in the same manner as in Example 1, except that the laser output was changed to 190 W, the pickling time was changed to 4 minutes, and the electrolytic plating time was changed to 21 minutes. Table 1 shows the average depth of the concave lines of the transfer roll, the average interval between the concave lines, the aspect ratio of the concave lines, and the average roughness of the bottom of the concave lines.

A surface uneven sheet was obtained in the same manner as in Example 1, except that the transfer roll of Example 5 was used. Table 1 shows the average height of the convex stripes, the average spacing between the convex stripes, the aspect ratio of the convex stripes, and the average roughness of the top of the convex stripes of the uneven surface sheet.

A screen was obtained in the same manner as in Example 1, except that the surface uneven sheet of Example 5 was used. Table 1 shows the relative frontal luminance, left and right 60° luminance ratio, 100° luminance difference ratio, and chromatic aberration of the image displayed on the screen.

[Comparative Example 1]

A transfer roll was obtained in the same manner as in Example 1, except that the beam diameter of the laser light was changed to 1.8 μm, the laser output was changed to 340 W, the acid washing was changed to 32 minutes, and the electrolytic plating was changed to 30 minutes. . The average depth of the concave lines of the transfer roll, the average spacing between the concave lines, the aspect ratio of the concave lines, and the average roughness of the bottom of the concave lines are shown in Table 2.

A surface uneven sheet was obtained in the same manner as in Example 1, except that the transfer roll of Comparative Example 1 was used. Table 2 shows the average height of the convex lines, the average spacing between the convex lines, the aspect ratio of the convex lines, and the average roughness of the top of the convex lines of the surface uneven sheet.

A screen was obtained in the same manner as in Example 1, except that the surface uneven sheet of Comparative Example 1 was used. Table 2 shows the relative frontal luminance, left and right 60° luminance ratio, 100° luminance difference ratio, and chromatic aberration of the image displayed on the screen.

[Comparative Example 2]

A transfer roll was obtained in the same manner as in Example 1, except that the laser output was changed to 132 W, acid cleaning was not performed, and electrolytic plating was changed to 25 minutes. The average depth of the concave lines of the transfer roll, the average spacing between the concave lines, the aspect ratio of the concave lines, and the average roughness of the bottom of the concave lines are shown in Table 2.

A surface uneven sheet was obtained in the same manner as in Example 1, except that the transfer roll of Comparative Example 2 was used. Table 2 shows the average height of the convex lines, the average spacing between the convex lines, the aspect ratio of the convex lines, and the average roughness of the top of the convex lines of the surface uneven sheet.

A screen was obtained in the same manner as in Example 1, except that the uneven surface sheet of Comparative Example 2 was used. Table 2 shows the relative frontal luminance, left and right 60° luminance ratio, 100° luminance difference ratio, and chromatic aberration of the image displayed on the screen.

[Comparative Example 3]

Example except that the laser output was changed to 400W, the laser pulse length was changed to 200ns, the roll peripheral speed was changed to 30cm/s, the pickling was changed to 125 minutes, and the electrolytic plating was changed to 35 minutes. A transfer roll was obtained in the same manner as in 1. The average depth of the concave lines of the transfer roll, the average spacing between the concave lines, the aspect ratio of the concave lines, and the average roughness of the bottom of the concave lines are shown in Table 2.

A surface uneven sheet was obtained in the same manner as in Example 1, except that the transfer roll of Comparative Example 3 was used. Table 2 shows the average height of the convex lines, the average spacing between the convex lines, the aspect ratio of the convex lines, and the average roughness of the top of the convex lines of the surface uneven sheet.

A screen was obtained in the same manner as in Example 1, except that the surface uneven sheet of Comparative Example 3 was used. Table 2 shows the relative frontal luminance, left and right 60° luminance ratio, 100° luminance difference ratio, and chromatic aberration of the image displayed on the screen.

[Comparative Example 4]

A transfer roll was obtained in the same manner as in Example 1, except that the laser output was changed to 240 W, the roll peripheral speed was changed to 38 cm/s, the acid washing was changed to 95 minutes, and the electrolytic plating was changed to 10 minutes. . The average depth of the concave lines of the transfer roll, the average spacing between the concave lines, the aspect ratio of the concave lines, and the average roughness of the bottom of the concave lines are shown in Table 2.

A surface uneven sheet was obtained in the same manner as in Example 1, except that the transfer roll of Comparative Example 4 was used. Table 2 shows the average height of the convex lines, the average spacing between the convex lines, the aspect ratio of the convex lines, and the average roughness of the top of the convex lines of the surface uneven sheet.

A screen was obtained in the same manner as in Example 1, except that the surface uneven sheet of Comparative Example 4 was used. Table 2 shows the relative frontal luminance, left and right 60° luminance ratio, 100° luminance difference ratio, and chromatic aberration of the image displayed on the screen.

In the screens of Examples 1 to 5, the aspect ratio of the convex lines of the surface uneven sheet is 0.07 to 0.40, and the average illuminance of the top of the convex lines is 0.10 μm to 0.90 μm, so the relative frontal luminance of the image displayed on the screen is high, The left and right 60° luminance ratio and 100° luminance difference ratio were low, and chromatic aberration was small.

In the screen of Comparative Example 1, the aspect ratio of the convex lines of the surface uneven sheet exceeded 0.40, so the left and right 60° luminance ratio of the image displayed on the screen was high.

In the screen of Comparative Example 2, the aspect ratio of the convex lines of the uneven surface sheet was less than 0.07, so the 100° luminance difference ratio of the image displayed on the screen was high.

In the screen of Comparative Example 3, the average illuminance of the top of the convex lines of the surface uneven sheet exceeded 0.90 μm, so the relative frontal luminance of the image displayed on the screen was low.

In the screen of Comparative Example 4, the average illuminance of the top of the convex lines of the surface uneven sheet was less than 0.10 μm, so the chromatic aberration of the image displayed on the screen was large.

[Comparative Example 5]

(Warrior Roll)

After performing ultra-precision cutting using a bite (cutting tool) in the circumferential direction of the surface of the roll body whose surface material is nickel-phosphorus, the front surface of the convex lines and the surface of the concave lines were roughened by sandblasting. The roll body on which the plurality of grooves were carved was washed with water (pure water, ultrasonic cleaning at 25 kHz) for 5 minutes to obtain a transfer roll.

(surface uneven sheet)

Using the transfer roll of Comparative Example 5, the uneven surface sheet of FIG. 21 was obtained in the same manner as in Example 1. The average height (H) of the convex stripes 141 of the surface uneven sheet is 20㎛, the average spacing (P) of the convex stripes 141 is 100㎛, the aspect ratio of the convex stripes 141 is 0.20, and the convex stripes 141 have an aspect ratio of 0.20. The average roughness of the top portion 141a and the bottom portion 142a of the concave structure 142 was 0.80 μm.

On the other hand, the concave lines of the transfer roll of Comparative Example 5 correspond to the convex lines 141 of the surface uneven surface sheet in FIG. 21, and the convex lines of the transfer roll correspond to the concave lines 142 of the surface uneven surface sheet of FIG. 21, Comparative Example The transfer roll and the uneven surface sheet in Fig. 5 were of an inverted shape.

In addition, fine unevenness is formed in the top part 141a of the convex line 141 and the bottom part 142a of the concave line 142 in FIG. 21, but illustration of the fine unevenness is omitted in FIG.

(screen)

A screen was obtained in the same manner as in Example 1, except that the surface uneven sheet of Comparative Example 5 was used. Visual evaluation of the screen revealed that the front side was too bright and was clearly unsuitable as a screen. For this reason, evaluation of relative frontal luminance, left and right 60° luminance ratio, 100° luminance difference ratio, and chromatic aberration was not performed.

[Comparative Example 6]

(Warrior Roll)

After performing ultra-precision cutting using a bite (cutting tool) in the circumferential direction of the surface of the roll body whose surface material is nickel-phosphorus, the cut surface was roughened by sandblasting. The roll body on which the plurality of grooves were carved was washed with water (pure water, ultrasonic cleaning at 25 kHz) for 5 minutes to obtain a transfer roll.

(surface uneven sheet)

Using the transfer roll of Comparative Example 6, a surface uneven sheet was obtained in the same manner as in Example 1. The average height (H1) of the convex stripes of the surface uneven sheet is 50㎛, the average spacing (P1) of the convex stripes is 140㎛, the aspect ratio of the convex stripes is 0.36, and the average roughness of the top 151a of the convex stripes 151 is 0.50㎛. It was.

On the other hand, the concave lines of the transfer roll of Comparative Example 6 corresponded to the convex lines of the surface uneven surface sheet in Fig. 22, and the transfer roll and surface uneven surface sheet of Comparative Example 6 were inverted.

In addition, fine irregularities are formed in the top portion 151a of the convex lines 151 in FIG. 22, but illustration of fine irregularities is omitted in FIG. 22.

(screen)

A screen was obtained in the same manner as in Example 1, except that the surface uneven sheet of Comparative Example 6 was used. As a result of visual evaluation of the screen, there was uneven brightness and darkness in the horizontal direction, making it clearly unsuitable as a screen. For this reason, evaluation of relative frontal luminance, left and right 60° luminance ratio, 100° luminance difference ratio, and chromatic aberration was not performed.

[Comparative Example 7]

(Warrior Roll)

Ultra-precision cutting was performed using a bite (cutting tool) in the circumferential direction of the surface of the roll body whose surface material was nickel-phosphorus. The roll body on which the plurality of grooves were carved was washed with water (pure water, ultrasonic cleaning at 25 kHz) for 5 minutes to obtain a transfer roll.

(surface uneven sheet)

Using the transfer roll of Comparative Example 7, a surface uneven sheet was obtained in the same manner as in Example 1. The average height (H2) of the convex stripes of the surface uneven sheet is 40㎛, the average spacing (P2) of the convex stripes is 140㎛, the aspect ratio of the convex stripes is 0.29, and the average roughness of the top 161a of the convex stripes 161 is 0.03㎛. It was. Additionally, the uneven shape of Comparative Example 7 is a shape that combines two types of lenticular shapes: convex lines 161 and concave lines 162. h2 of the convex lines 161 is 20 μm and W2 is 95 μm, and h3 of the concave lines 162 is 20 μm and W3 is 45 μm.

On the other hand, the concave lines of the transfer roll of Comparative Example 7 correspond to the convex lines 161 of the surface uneven surface sheet in FIG. 23, and the convex lines of the transfer roll correspond to the concave lines 162 of the surface uneven surface sheet of FIG. 23, Comparative Example The transfer roll and the uneven surface sheet in Fig. 7 were of inverted shapes.

In addition, fine irregularities are formed in the top portion 161a of the convex lines 161 in FIG. 23, but illustration of fine irregularities is omitted in FIG. 23.

(screen)

A screen was obtained in the same manner as in Example 1, except that the surface uneven sheet of Comparative Example 7 was used. As a result of visual evaluation of the screen, there was uneven brightness and darkness in the horizontal direction, making it clearly unsuitable as a screen. For this reason, evaluation of relative frontal luminance, left and right 60° luminance ratio, 100° luminance difference ratio, and chromatic aberration was not performed.

Table 3 shows the frequency ratio (%) of the uneven surface sheets of Examples 1 to 5 and Comparative Examples 1 to 7. The frequency ratio is a value calculated by the following formula (A), and was specifically calculated by the method described later.

Formula (A): Frequency ratio (%) = Frequency (T) / Frequency (S) × 100

Here, the frequency (S) is the frequency in the range of the most frequent angle -2° to 89° in the slope angle frequency distribution chart calculated from a sine curve with the average height of the convex lines and the average spacing between the convex lines being the same. It's the sum. In addition, the frequency (T) is calculated when the most frequent angle in the sine curve is set as the angle (Mθs), and the surface irregularity sheet is cut in the direction perpendicular to the direction of extension of the convex lines and in the thickness direction of the surface irregularity sheet. It is the sum of the frequencies in the range of angle (Mθs) -2° to 89° in the frequency distribution diagram of the slope angle calculated from height data in the cross-sectional shape.

Here, the frequency (T) was calculated as follows.

First, using a laser microscope (VK-8500, manufactured by Keyence), the measurement area (M) of the uneven surface sheet obtained in the examples and comparative examples was measured under conditions of a 50x objective lens and a measurement pitch in the height direction of 0.05 μm (Figure Height data (see 18(a)) was acquired. At this time, the measurement interval is the direction perpendicular to the extending direction of the convex lines 12 of the uneven surface sheet 10 (corresponding to the y direction in Fig. 18(a)) and the convex lines 12 of the uneven surface sheet 10. In the extension direction (corresponding to the z direction in Fig. 18(a)), each was set to 0.2913 μm. On the other hand, the measurement area M is 295.0869 (1014 pieces of data) in the direction orthogonal to the extending direction of the convex lines 12 of the surface uneven sheet 10 (corresponding to the y direction in Fig. 18(a)), and the surface The area was 215.8533 ㎛ (equivalent to 742 pieces of data) in the direction in which the convex lines 12 of the uneven sheet 10 extend (corresponding to the z-direction in Fig. 18(a)).

Next, the correction value of the data at the coordinates (n, β) is set as the 10-point average value of (n, β) to (n + 9, β), and the surface irregularities of the surface irregularity sheet 10 obtained by the measurement method described above are calculated. Correction of the height measurement data was performed. If the position data of the coordinates (1014, β) is extracted from the coordinates (1, β), as shown in FIG. 18(c), the surface uneven sheet 10 is placed at the position of the β value on the z-axis, and the convex lines 12 ) of the uneven surface sheet 10, whose cross-section was measured at intervals of 0.2913 μm when cut in the direction perpendicular to the extension direction (y direction) and in the thickness direction (x direction) of the uneven surface sheet 10. Measurement data of the height of the surface irregularities are obtained. In order to correct the error in the measurement data on each coordinate axis, for the measurement data from coordinates (1, β) to coordinates (1005, β), the correction value of the data at coordinates (n, β) is set to ( Correction was performed by setting the average value of 10 points from n, β) to (n + 9, β).

Next, from the measurement data obtained as described above, the slope angle was calculated from the coordinates (1, β) to the correction values of the coordinates (1004, β). The slope angle θs(n, β) was obtained from the following equation (10).

Equation (10): Slope angle (n, β) = arctan (h / 0.2913)

Here, h is the absolute value of the height difference between the two points Av(n, β) and Av(n+1, β) (the unit of the length of h is ㎛). Additionally, the slope angle (n, β) is taken as an absolute value. That is, the slope angle θs(n, β) in Fig. 19(a) and the slope angle θs(n+1, β) in Fig. 19(b) are both positive values. For example, when the surface uneven sheet of Example 1 was measured by the above method and graphed with the slope angle on the horizontal axis and the frequency on the vertical axis, a frequency distribution diagram as shown in Fig. 20(a) was obtained.

On the other hand, the frequency (S) is the most frequent angle of -2° to 89 in the slope angle frequency distribution chart calculated from a sine curve in which the average height of the convex lines and the average spacing between the convex lines of the surface uneven sheet to be measured are equal to each other. It is the sum of frequencies in the range of °. Since the average height of the convex lines of the surface uneven surface sheet of Example 1 is 7.1 ㎛ and the average spacing between the convex lines is 36 ㎛, the frequency distribution of the slope angle calculated from a sine curve where the average height of the convex lines and the average spacing between the convex lines are the same (theoretical value) is as shown in Figure 20(b). Here, in the frequency distribution chart of the slope angle calculated from a sine curve where the average height of the convex lines and the average spacing between the convex lines are the same, the most frequent slope angle (hereinafter also referred to as the most frequent angle) was 31°, so the most frequent An angle of -2° was 29°. For this reason, in Example 1 (FIG. 20(b)), the frequency S was the sum of the frequencies in the range of 29° to 89°, and the total actual frequency value was calculated to be 215,922. On the other hand, the frequency (T) of the uneven surface sheet to be measured is the sum of the frequencies in the range of 29° to 89°, and the total actual frequency was calculated to be 249387. As a result, the frequency ratio (%) calculated from equation (A) was 115%. In the same manner as above, frequency ratios (%) were also calculated for Examples 2 to 5 and Comparative Examples 1 to 7. Meanwhile, the frequency distribution chart of Examples 2 to 5 is shown in Figure 24, and the frequency distribution chart of Comparative Examples 1 to 7 is shown in Figure 25.

Meanwhile, Table 4 shows the results of theoretical calculations of lenticular shapes with various average heights of convex lines and average spacing between convex lines. In this way, the frequency ratios of the lenticular lenses were all below 98.

The uneven surface sheet of the present invention is useful as a member constituting a reflective screen.

10 surface uneven sheet, 11 surface uneven sheet, 12 convex lines, 12a top part, 13 concave structure, 13a bottom part, 14 base material layer, 15 surface layer, 16 base material, 20 screen, 21 screen, 22 reflection layer, 30 video display system, 40 Projector, 100 transfer roll, 101 roll body, 102 concave section, 102a bottom section, 103 convex section, 103a top section, CS cross section, CS1 cross section, CS2 cross section, CS3 cross section, D depth, D1 depth, D2 depth, H height , H1 height, H2 height, L video light, W ₅ width, 141 Convex line, 141a Top of convex line, 142 Concave line, 142a Bottom of concave line, 151 Convex line, 151a Top of convex line, 161 Convex line, 161a Top of convex ridge, 162 Concave ridge

Claims (6)

A surface uneven sheet having a plurality of convex lines on at least one surface and concave lines formed between two adjacent convex lines,
The ratio of the average height of the convex lines and the average spacing of the convex lines (average height/average spacing) is 0.07 or more and 0.40 or less,
The average roughness at the top of the convex lines, obtained from the roughness curve in the extending direction of the convex lines, is 0.10 μm or more and 0.90 μm or less,
Calculate the frequency (T) of the slope angle calculated from the height data in the cross-sectional shape when the surface irregularity sheet is cut in a direction perpendicular to the extension direction of the convex lines and in the thickness direction of the surface irregularity sheet, , a surface uneven sheet with a frequency ratio (%) of 98% or more when the frequency ratio (%) is calculated from the following formula (A);
Formula (A): Frequency ratio (%) = Frequency (T) / Frequency (S) × 100
Here, the frequency (S) is the most frequent angle in the range of -2° to 89° in the frequency distribution chart of the slope angle calculated from a sine curve in which the average height of the convex lines and the average spacing between the convex lines are equal. It is the sum of the frequencies,
The frequency (T) is calculated by assuming that the most frequent angle in the sine curve is the angle (Mθs), and the surface irregularity sheet is cut in a direction perpendicular to the extension direction of the convex lines and in the thickness direction of the surface irregularity sheet. It is the sum of the frequencies in the range of angle (Mθs) -2° to 89° in the frequency distribution chart of the slope angle calculated from the height data in the cross-sectional shape at the time. According to claim 1,
A surface uneven surface sheet that is a single-layer sheet having the convex lines and the concave lines on at least one surface of a substrate. According to claim 1,
It has a base layer and at least one surface layer,
A surface uneven surface sheet having the convex lines and the concave lines on the surface of the surface layer. A screen comprising the uneven surface sheet according to any one of claims 1 to 3 and a reflective layer. An image display system comprising the screen of claim 4 and a projector that projects image light onto the screen. A transfer roll having a plurality of concave lines on the surface and convex lines formed between two adjacent concave lines,
The ratio of the average depth of the concave structures and the average spacing of the concave structures (average depth/average spacing) is 0.07 or more and 0.40 or less,
The average roughness at the bottom of the concave structure obtained from the roughness curve in the extending direction of the concave structure is 0.10 μm or more and 0.90 μm or less,
The frequency (T) of the slope angle calculated from the depth data in the cross-sectional shape when the transfer roll is cut in a direction perpendicular to the extending direction of the concave line and in a direction perpendicular to the central axis of the transfer roll When calculating and calculating the frequency ratio (%) from the following formula (A), the transfer roll whose frequency ratio (%) is 98% or more;
Formula (A): Frequency ratio (%) = Frequency (T) / Frequency (S) × 100
Here, the frequency (S) is in the range of the most frequent angle -2° to 89° in the frequency distribution chart of the slope angle calculated from a sine curve in which the average depth of the above-mentioned concave lines and the average interval between the above-mentioned concave lines are equal. It is the sum of the frequencies,
The frequency (T) is calculated by assuming that the most frequent angle in the sine curve is the angle (Mθs), and the transfer roll is moved in a direction perpendicular to the extending direction of the concave pattern and in a direction perpendicular to the central axis of the transfer roll. It is the sum of the frequencies in the range of angle (Mθs) -2° to 89° in the frequency distribution chart of the slope angle calculated from depth data in the cross-sectional shape when cut.

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