JP2012145739A - Screen and manufacturing method of mold for manufacturing screen - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a screen capable of widening a viewing angle and of suppressing reduction in contrast, and further to provide a manufacturing method of a mold for manufacturing the screen.SOLUTION: A plurality of concave portions 2 having concave surfaces 2A is arranged on an incident plane 11A, on which light forming an image is made incident, in a screen 1. The concave portions 2 is individually formed along a plurality of rows of substantially concentric circular shapes having reference points as centers that are set on a plane of either the incident plane 11A or an extended plane of the incident plane 11A. As viewed in a cross-sectional view at the concave portions 2 extending along a radiation direction from the reference points, each central angle θ of each concave surface 2A between two straight lines L formed by connecting a center point of a virtual circle having the each concave surface 2A as an arc thereof to both opening ends 21 of each concave portion 2 is decreased as each distance between each reference point and the each concave portion 2 is increased.

Description

  The present invention relates to a screen and a method for manufacturing a screen manufacturing mold.

Conventionally, as a screen for displaying an image projected from a projector, a screen in which a plurality of recesses are formed on an incident surface on which light forming the image is incident is known (see, for example, Patent Document 1).
In the screen described in Patent Document 1, a reflective film is formed on the surface of each recess according to the incident area of light from the projector. By these reflective films, light obliquely incident from below the front side of the screen is reflected to the front side of the screen, and an observer located on the front side can observe the image.

  By the way, such a screen uses, for example, a glass substrate in which a lens mold corresponding to the recess is formed by etching as a mother mold, and a resin mold is manufactured by injecting a resin or the like into the mother mold. It is manufactured by forming a recess in the screen base material. In addition, the screen is also manufactured, for example, by pressing a final mold manufactured by nickel electroforming from the resin mold against the screen base material to form a recess in the screen base material.

JP 2009-181096 A

  However, in the above-described method, when a resin mold having a convex portion is produced by injecting resin or the like into the mother mold, there is a possibility that bubbles may be generated between the mother mold and the resin. When peeling, the resin mold may be damaged. For this reason, since a resin mold cannot be manufactured satisfactorily, if a screen is manufactured using such a resin mold, a recess cannot be formed satisfactorily on the screen base material. This causes a problem that the viewing angle becomes narrow and the contrast of the image displayed on the screen decreases.

  An object of the present invention is to provide a screen capable of widening a viewing angle and suppressing a decrease in contrast, and a method for manufacturing a screen manufacturing mold.

  The screen of the present invention is a screen in which a plurality of concave portions having concave curved surfaces are arranged on an incident surface on which light forming an image is incident, and the concave portion is one of the incident surface and an extended surface of the incident surface. Each formed along a plurality of substantially concentric rows centered on a reference point set on the surface of the recess, and in the cross-sectional view of the recess along the radial direction from the reference point, the opening end of the recess and the A central angle of the concave curved surface, which is an angle formed by two straight lines connecting a virtual circle center point having a concave curved surface as an arc, decreases as the distance between the reference point and the concave portion increases. .

  According to the present invention, the central angle of the concave curved surface of the concave portion is formed so as to decrease as the distance between the reference point and the concave portion increases. According to this, in order to form such a concave portion, when a resin mold having a convex portion is produced by injecting resin or the like into the above-described mother die, bubbles are generated between the mother die and the resin. Can be prevented. Further, when the resin mold is peeled from the mother mold, the resin mold can be peeled well, and the resin mold can be prevented from being damaged. Thus, the resin mold can be formed satisfactorily and the recess can be formed satisfactorily on the screen base material. Therefore, the viewing angle can be widened, and the decrease in contrast of the image displayed on the screen can be suppressed.

In the screen of the present invention, it is preferable that the central angle is set in a range of 60 degrees or more and 160 degrees or less.
By the way, in the case where the central angle is formed to be less than 60 degrees, when forming the above-described resin mold, air bubbles are easily generated between the mother mold and the resin, and a good resin mold cannot be manufactured. Further, when the central angle is formed to be less than 60 degrees, the incident light to the concave portion enters the vicinity of the bottom surface of the concave portion, and much of the incident light is not appropriately reflected to the viewer side, resulting in glare.
On the other hand, when the central angle is formed to be larger than 160 degrees, the dimension from the opening end to the bottom of the recess is increased, and therefore, when the resin mold is peeled from the mother mold, it is difficult to peel the resin mold from the mother mold. The resin mold is easily damaged. For this reason, a good resin mold cannot be manufactured.

  On the other hand, according to the present invention, the central angle is set in a range of 60 degrees to 160 degrees. According to this, when the resin mold is manufactured from the mother mold, it is possible to reliably prevent bubbles from being generated between the mother mold and the resin, and further, the resin mold can be easily detached from the mother mold. In addition, the resin mold can be reliably prevented from being damaged. Thereby, a favorable resin mold can be manufactured. In a screen manufactured using a good resin mold, glare of an image can be prevented.

  The method for manufacturing a screen manufacturing mold according to the present invention is a method for manufacturing a screen manufacturing mold used for manufacturing a screen in which a plurality of concave portions having concave curved surfaces are arranged on an incident surface on which light forming an image is incident. A mother die manufacturing process for producing a mother die by forming a concave lens die corresponding to the concave portion formed on the incident surface on one surface of the substrate, and using the formed mother die, the lens A resin mold manufacturing process for manufacturing a resin mold having a transferred mold as the screen manufacturing mold, and in the mother mold manufacturing process, set on one of the one surface and an extended surface of the surface As the distance between the reference point and the lens mold increases, the center point of a virtual circle having an arc at the opening end of the concave portion and the concave curved surface in a sectional view of the lens mold along the radial direction from the reference point Two straight lines connecting As the central angle is the angle becomes smaller, and wherein the forming a plurality of the lens mold along a substantially concentric multiple columns around the reference point.

According to the present invention, the central angle of the concave curved surface of the concave portion of the concave lens mold formed on the mother die is formed so as to decrease as the distance between the reference point and the concave portion increases. According to this, in order to form such a concave portion, when a resin mold having a convex portion is produced by injecting resin or the like into the above-described mother die, bubbles are generated between the mother die and the resin. Can be prevented. Further, when the resin mold is peeled from the mother mold, the resin mold can be peeled well, and the resin mold can be prevented from being damaged. Thus, the resin mold can be formed satisfactorily and the recess can be formed satisfactorily on the screen base material. Therefore, the viewing angle can be widened, and the decrease in contrast of the image displayed on the screen can be suppressed.
Further, for example, if the central angle of the concave curved surface of the concave portion is set in a range of 60 degrees or more and 160 degrees or less, as described above, when the resin mold is manufactured from the mother mold, there are bubbles between the mother mold and the resin. Can be reliably prevented, and the resin mold can be easily peeled from the mother mold, and the resin mold can be reliably prevented from being damaged. Thereby, since a favorable resin mold can be manufactured, a viewing angle can be widened and a decrease in contrast of an image displayed on the screen can be suppressed.

The front view which shows the screen which concerns on one Embodiment of this invention. The fragmentary sectional view which shows the screen in the said embodiment. The schematic diagram for demonstrating the central angle of the concave curved surface in the said embodiment. The graph which shows the relationship between the distance from the origin on the screen in the said embodiment, and the central angle of a concave curved surface. The figure which shows typically the mother die manufacturing process in the said embodiment, the resin mold manufacturing process, and the screen manufacturing process.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
[Overall screen configuration]
FIG. 1 is a front view showing a screen 1 according to the present embodiment.
The screen 1 according to this embodiment is configured to display an image obliquely incident from a projector (not shown) disposed below the front side of the screen 1 (downward on the front side when FIG. 1 is viewed). The image is mainly reflected on the front side and displayed. As shown in FIG. 1, the screen 1 includes a screen base 11 having a substantially rectangular shape when viewed from the front.

FIG. 2 is a partial cross-sectional view partially showing a cross-sectional view of the screen 1.
The incident surface 11A on the front side of the screen 1 is a surface that reflects light (light that forms an image) incident from the projector.
As shown in FIGS. 1 and 2, the incident surface 11A has a concave curved surface 2A having a predetermined curvature along a concentric circle centered on a reference point C set on the extended surface of the incident surface 11A. A plurality of recesses 2 (lens elements) having the above-described shape are formed, whereby a plurality of rows of recesses 2 are formed concentrically around the reference point C on the incident surface 11A. In addition to two or more “circles (true circles and perfect circles)” sharing a center, concentric circles may have shapes deformed with reference to “circles” (for example, two or more “ovals sharing a center” ”,“ Free curve ”, and combinations thereof). Furthermore, the combination of the curve (for example, circular arc) which comprises "ellipse" and "free curve", and a straight line is included.

  The concave curved surface 2A of these concave portions 2 absorbs the reflection film 11A1 (outlined portion in FIG. 2) that reflects incident light (for example, projection light) and incident light (for example, external light such as a fluorescent lamp). The light absorption film 11A2 (the black portion in FIG. 2) is formed. Among these, the reflective film 11A1 is formed on the distal end side in the radial direction from the reference point C in the concave portion 2, and the incident light is mainly reflected to the observer side within the formation range of the reflective film 11A1. An effective reflection area is included. On the other hand, the light absorption film 11A2 is formed on the base end side in the radial direction.

FIG. 3 is a schematic diagram illustrating a cross section of the concave portion 2 along the radial direction described above and explaining the central angle θ of the concave curved surface 2A of the concave portion 2.
As shown in FIG. 3, the central angle θ of the concave curved surface 2 </ b> A is formed along the incident surface 11 </ b> A and in the sectional view of the concave portion 2 in the direction along the radial direction from the reference point C. It is an angle formed by two straight lines L connecting a center point O of a virtual circle (a virtual circle derived from the radius of curvature of the arc) forming a 2A arc. Depending on the formation process of the concave curved surface 2A, a flat surface may be formed at the bottom of the concave curved surface 2A. However, the virtual circle is derived without considering the flat surface.

FIG. 4 is a graph showing the relationship between the distance from the origin SP on the screen 1 and the central angle θ of the concave curved surface 2A. As shown in FIG. 1, the origin SP is located on a virtual straight line SL passing through the reference point C and the center point of the incident surface 11A, and is the point closest to the reference point C on the incident surface 11A. In other words, it is the point closest to the projector on the incident surface 11A.
As shown in FIGS. 2 and 4, the recess 2 is formed so that the central angle θ decreases as the distance from the origin SP increases. Specifically, each concave portion 2 is formed such that the central angle θ is 160 degrees which is the largest at the origin SP and 60 degrees which is the smallest at the position farthest from the origin SP. The central angle θ is set to 60 degrees or more and 160 degrees or less.

[Screen manufacturing method]
Next, an example of a method for manufacturing the screen 1 will be described with reference to FIG.
The screen 1 is a process of manufacturing the matrix B by etching the glass substrate P (matrix manufacturing process), and a process of manufacturing a resin mold F having convex portions by injecting resin or the like into the manufactured matrix B ( Resin mold manufacturing process), a process of forming the recess 2 in the screen base 11 using the resin mold F (transfer process), and a process of forming the reflection film 11A1 and the light absorption film 11A2 described above in the recess 2 ( (Film forming step). If necessary, the screen 1 may be manufactured by manufacturing a final mold from the manufactured resin mold F by nickel electroforming and performing a transfer process and a film forming process using the final mold. Good.

First, a mother mold manufacturing process for manufacturing the mother mold B will be described.
As shown in FIG. 5A, a mask layer M, which is a metal film, is formed on one surface of the polished glass substrate P. Then, as shown in FIG. 5B, a hole H is formed in the mask layer M by laser irradiation or the like. The hole H is for forming a concave lens mold PC (see FIG. 5C) corresponding to the concave portion 2 (see FIG. 5F) by etching.
Next, an etching solution is injected into the hole H. As a result, as shown in FIG. 5C, the glass substrate P is eroded downward, and the glass substrate P is eroded so as to spread outwardly from the periphery of the hole H in a concave curved shape, so that the concave portion A lens mold PC corresponding to 2 is formed. At this time, the lens mold PC has a plurality of concentric rows centered on the reference point C set on the extended surface of the surface of the glass substrate P on which the lens mold PC is formed, like the concave portion 2 described above. And the central angle θ of the lens mold PC is set within a range of 60 degrees or more and 160 degrees or less so that the distance between the reference point C and the lens mold PC becomes smaller (see FIG. 3).
Then, as shown in FIG. 5D, by removing the mask layer M from the glass substrate P, the mother die B is manufactured.

Next, a resin mold manufacturing process for manufacturing the resin mold F from the manufactured mother mold B will be described.
Using the 2P method (Photo-polymerization method), a resin is injected into the manufactured matrix B, and the injected resin is irradiated with radiation to cure the resin. As the resin, silicone resin, epoxy resin, acrylic, or the like can be used.
Then, the resin mold F having the convex lens mold FC is manufactured by peeling the cured resin from the mother mold B.

Next, a screen manufacturing process (transfer process and film forming process) for manufacturing the screen 1 from the manufactured resin mold F will be described.
As shown in FIG. 5 (F), the manufactured resin mold F is pressed against the screen base material 11 to transfer the lens mold FC of the resin mold F, thereby forming the recess 2 in the screen base material 11. To do.
In the film forming step, as shown in FIG. 5G, a reflective film 11A1 and a light absorbing film 11A2 are formed in the recess 2 by vapor deposition or the like, and a protective film is formed on these films 11A1 and 11A2 as necessary.
Thus, the screen 1 having the recess 2 is manufactured.

〔Example〕
Table 1 below shows the results of mold formation in Examples and Comparative Examples 1 and 2, respectively.

In the example, a resin mold for manufacturing a screen in which the central angle θ of the concave curved surface 2A of the concave portion 2 is 60 degrees or more and 160 degrees or less is manufactured.
In Comparative Example 1, a resin mold for manufacturing a screen in which the central angle θ of the concave curved surface of the concave portion is 40 degrees or more and less than 60 degrees was manufactured.
In Comparative Example 2, a resin mold for manufacturing a screen in which the central angle θ of the concave curved surface of the concave portion is larger than 160 degrees and equal to or smaller than 180 degrees was manufactured.
In Examples and Comparative Examples 1 and 2, the resin is injected into the mother die from a position corresponding to the reference point, and when the resin die is peeled from the mother die, the resin is peeled from the side having the smaller central angle θ. ing.

In the examples, when the resin mold was produced from the above-described mother mold, no bubbles were generated between the mother mold and the resin. Further, when the resin mold was peeled from the mother mold, the resin mold was not damaged.
In Comparative Example 1, it was found that when a resin mold was produced from the above-described mother mold, bubbles were generated between the mother mold and the resin, resulting in a transfer failure. Moreover, it turned out that the peelability at the time of peeling a resin mold from a mother mold is bad.
In Comparative Example 2, it was found that when the resin mold was peeled from the mother mold, the resin mold was damaged.

  As described above, when the central angle θ is 60 degrees or more and 160 degrees or less, the resin mold can be satisfactorily formed from the matrix, and the central angle θ is 40 degrees or more and less than 60 degrees, and larger than 160 degrees, 180 degrees. It has been found that the resin mold cannot be formed satisfactorily when the temperature is less than 1 degree.

According to this embodiment described above, there are the following effects.
The central angle θ of the concave curved surface 2A of the concave portion 2 is formed so as to decrease as the distance between the reference point C and the concave portion 2 increases. According to this, in order to form such a concave portion 2, when a resin mold having a convex portion is manufactured by injecting resin or the like into the above-described mother die, bubbles are generated between the mother die and the resin. Can be prevented. Further, when the resin mold is peeled from the mother mold, the resin mold can be peeled well, and the resin mold can be prevented from being damaged. Thus, the resin mold can be formed satisfactorily, and the recess 2 can be formed satisfactorily on the screen base material 11. Accordingly, the viewing angle can be widened, and the decrease in contrast of the image displayed on the screen 1 can be suppressed.

  Further, the center angle θ is set in a range of 60 degrees to 160 degrees. According to this, when the resin mold is manufactured from the mother mold, it is possible to reliably prevent bubbles from being generated between the mother mold and the resin, and further, the resin mold can be easily detached from the mother mold. In addition, the resin mold can be reliably prevented from being damaged. Thereby, a favorable resin mold can be manufactured. The screen 1 manufactured using a good resin mold can prevent image glare.

[Modification of Embodiment]
The present invention is not limited to the above-described embodiment, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the present invention.
In the above-described embodiment, the screen 1 reflects light obliquely incident from a projector located below the front side and displays an image formed by the light. However, the present invention is not limited to this. That is, the position of the projector may be located on the front side upper side. In such a case, if the reference point C and the origin SP are set above the screen 1, and the recess 2 is formed so that the central angle θ of the concave curved surface 2A decreases as the distance from the reference point C and the origin SP increases. Good.

  In the embodiment, the central angle θ is formed so as to be in a range of 60 degrees or more and 160 degrees or less. However, the center angle θ may be formed in the range, and the central angle θ is, for example, 70 degrees or more and 150 degrees or less. You may form in. Furthermore, although the central angle θ of the concave portion 2 near the origin SP is 160 degrees and the central angle θ of the concave portion 2 having the longest distance from the reference point C is 60 degrees, the present invention is not limited to this. That is, it is only necessary to form each recess 2 so that the central angle θ decreases in the range of 60 degrees or more and 160 degrees or less as the distance from the origin SP increases, and the central angle θ decreases in a range narrower than the range. Each recess 2 may be formed.

  In the above-described embodiment, the recesses 2 are formed along a row that forms part of a concentric circle centered on the reference point C on the incident surface 11A, but the present invention is not limited to this. That is, in addition to two or more “circles (true circles and perfect circles) sharing a center”, the concentric circle includes a shape deformed based on the “circle” (for example, two or more “circles sharing a center” In addition, a combination of a curve (for example, an arc) and a straight line constituting “ellipse” and “free curve” is also included.

Further, the distance between the columns of the adjacent recesses 2 may be set to increase as the distance from the reference point C increases, for example, and a virtual straight line passing through the center of the recess 2 and the reference point C, and a virtual straight line As the angle with the SL increases, the distance between the rows of the recesses 2 may be increased.
Further, the distance between two adjacent recesses 2 on the same row may be set so as to increase as the row moves away from the reference point C. Furthermore, the distance between the two concave portions 2 may be set to be maximum when the angle between the virtual straight line and the virtual straight line SL is 45 degrees, and to be decreased as the angle increases or decreases from 45 degrees.
In such a case, the concave portion 2 can be formed small while ensuring a reflection region (effective reflection region) for reflecting incident projection light to the front side, thereby increasing the brightness of the screen 1. it can.

  In the above-described embodiment, the reflective film 11A1 and the light absorption film 11A2 are formed in all the concave portions 2, but the present invention is not limited to this. For example, the light absorption film 11A2 may not be formed. Further, another recess for allowing the projection light to enter the recess 2 located in the radial direction from the reference point C may be formed between the rows of the arc-shaped recesses 2 centered on the reference point C. If such a concave portion is formed, in the concave portion 2 formed at a position where the incident angle of the projection light with respect to the normal line of the incident surface 11A is large, the incident light can be efficiently reflected to the front side. The projection light can be appropriately incident.

  The present invention can be used as a screen for displaying an image projected from a projector or the like.

  DESCRIPTION OF SYMBOLS 1 ... Screen, 2 ... Concave, 2A ... Concave curved surface, 11A ... Incident surface, 21 ... Open end, B ... Master mold, C ... Reference point, F ... Resin mold, FC, PC ... Lens mold, L ... Straight line, O ... center, SL ... virtual straight line.

Claims (3)

A screen in which a plurality of concave portions having concave curved surfaces are arranged on an incident surface on which light forming an image is incident,
The recesses are respectively formed along a plurality of substantially concentric rows centered on a reference point set on any of the incident surface and an extended surface of the incident surface,
In the cross-sectional view of the concave portion along the radial direction from the reference point, the center of the concave curved surface is an angle formed by two straight lines connecting the opening end of the concave portion and the center point of a virtual circle having the concave curved surface as an arc. The corner decreases as the distance between the reference point and the recess increases. The screen of claim 1,
The center angle is set in a range of 60 degrees to 160 degrees. A method for manufacturing a screen manufacturing mold used for manufacturing a screen in which a plurality of concave portions having concave curved surfaces are arranged on an incident surface on which light forming an image is incident,
A master mold manufacturing process for manufacturing a master mold by forming a concave lens mold corresponding to the concave portion formed on the incident surface on one surface of the substrate;
A resin mold production process for producing a resin mold to which the lens mold is transferred as the mold for producing the screen using the formed mother mold;
In the mother die manufacturing process, along the radial direction from the reference point as the distance between the reference point set on one of the one surface and the extended surface of the surface and the lens mold increases. Centering the reference point so that a central angle, which is an angle formed by two straight lines connecting the opening end of the concave portion in a cross-sectional view of the lens mold and the central point of a virtual circle having the concave curved surface as an arc, is reduced. A plurality of lens molds are formed along a plurality of substantially concentric rows. A method for manufacturing a screen manufacturing mold.

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