JP3310023B2 - Optical display board - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display panel whose appearance changes depending on the viewing angle.

[0002]

2. Description of the Related Art Conventionally, display bodies such as signboards, nameplates, nameplates, decorative letters, and signs are made of glass, ceramics, metal, paper, wood, plastic, or a combination of these materials, depending on the purpose of use. I have. The display body is required to have an identification function of an own or another product or an own or other service, an information transmission function, or the like, depending on a character or a pattern displayed by the display.

[0003] Taking an advertisement medium as an example, these functions greatly affect the differentiation from other individualized product groups, and are very important. However, despite the fact that the first condition is that various conventional display objects are eye-catching, all of them have only similar effects and are not novel, so that they are inevitably obsolescent. Therefore, it is difficult to say that the above functions and effects are necessarily satisfied.

As a means for solving the above-mentioned problem, Japanese Utility Model Laid-Open No. 1-92678 discloses a transparent film plate obtained by curing an oligomer having a difference in refractive index and a monomer or a resin composition comprising monomers or oligomers. Disclosed is a display having a structure formed of a laminate attached to a surface or interposed between a plurality of transparent plates, and the display is such that a light control film appears transparent or opaque depending on a viewing angle. Or have the effect of However, it is not always satisfactory in that the production method and processing method are complicated and time-consuming, and that the materials used are often harmful to the human body, such as photopolymerizable monomers and oligomers.

[0005] In addition, since the opaque portion of the display is formed by diffusion and absorption of light, a satisfactory effect cannot always be obtained when the display is used for an internally illuminated signboard. In other words, if light is positively incident from the back side of the internally illuminated signboard, the opaque part will also slightly pass light,
The decorative effect as a signboard is difficult because it is difficult to clearly distinguish the light-transmitting part from the non-transmitting part, and the light-transmitting part absorbs light, which reduces the luminous efficiency of the signboard. There was a disadvantage that it faded.

[0006]

SUMMARY OF THE INVENTION Accordingly, the present invention is an optical display panel whose appearance changes depending on the viewing angle, which can be manufactured very easily with a material safe for the human body, and which is used as an internally illuminated signboard. An object of the present invention is to provide an optical display panel that can express a clear pattern or the like with high brightness even in such a case.

[0007]

In order to solve the above-mentioned problems, the present invention provides a prism-forming surface or a prism formed from a transparent sheet having a large number of parallel prisms formed on one surface. It has at least two optical sheets that totally reflect or transmit the incident light depending on the incident angle of the incident light incident on the surface opposite to the forming surface, and the at least two optical sheets are the prism forming surfaces. Characterized in that they are juxtaposed or layered facing each other in opposite directions, and a pattern to be displayed is formed by at least one of the at least two optical sheets. Provide a display board.

[0008]

Before describing the structure of the display panel of the present invention in detail, the principle of operation of the display panel of the present invention will be described. An optical sheet composed of a transparent sheet having a large number of parallel prism shapes formed on one surface, for example, a product name "S" manufactured by Minnesota Mining and Manufacturing Company, USA
In the case of "OLF" (refractive index: about 1.586, angle of the groove of the prism is about 90 degrees), light incident on the prism forming surface of the sheet is reflected at one incident angle and transmitted at another incident angle. I do.

FIG. 1 shows the optical paths of light incident on the optical sheet having a prism groove angle of about 90 degrees at angles of incidence of 0 °, 50 ° and 70 ° on the surface of the optical sheet opposite to the surface on which the prism is formed. Light incident at 0 ° is reflected, and
Light incident at ° and 70 ° is transmitted. On the other hand, FIG. 2 shows the same optical sheet as the optical sheet shown in FIG.
The optical path of incident light is shown in degrees, and light having an incident angle of 0 ° is transmitted, but light having an incident angle of 50 ° is reflected. A part of the light having an incident angle of 70 ° is transmitted, and the other part is reflected.

FIGS. 3 and 4 show the above phenomenon three-dimensionally. 3 shows the opposite side of the optical sheet from the prism forming surface, and FIG. 4 shows the prism forming surface side. In each of the drawings, light incident on a point on the sheet surface 0 passes through any point on the displayed hemisphere. In these figures, only the light that has entered through the hemispherical hatched surface is reflected and exits again through the hemispherical hatched region.

Here, paying attention to the vicinity of the vertex of the hemisphere, it can be seen that the transmission and reflection of the incident light are reversed in FIGS. That is, light incident at a certain angle, for example, from near the apex is reflected when incident on the surface on the reflection side with respect to the prism surface (FIG. 3), and transmitted when incident on the prism surface (FIG. 4). On the other hand, light incident at other angles is the opposite.

Therefore, as shown in FIG. 5, for example, when two optical sheets A and B are juxtaposed with their prism surfaces facing in opposite directions, light incident at a certain incident angle passes through one of the sheets, It will be reflected by the other sheet. For light incident at another angle of incidence, the relationship between transmission and reflection is reversed. Therefore, the transmission and reflection of light in the pattern formed by the sheets A and B are reversed depending on the viewing angle.

On the other hand, as shown in FIG. 6, when an optical sheet D is overlaid on an optical sheet C such that the prism surfaces are in contact with each other,
Since the overlapping portion is geometrically symmetric, the light transmitted through the sheet D also transmits through the sheet C. Therefore, FIG.
The portion consisting of only sheet C and the portion where C and D overlap exhibit the same behavior with respect to the reflection and transmission of light as those of sheet A and sheet B shown in FIG.

In FIG. 7, sheets E and F are in contact with the surface opposite to the prism surface, and light transmitted through sheet F also passes through sheet E. 6A and 6B show the same behavior with respect to reflection and transmission of light as in the case of sheets A and B in FIG. 6 and 7, a pattern to be marked is formed by the shapes of the sheets D and F, respectively. As described above, the product name “SOLF” manufactured by 3M USA has been described as an example, but the present invention is not limited to this.

[0015]

Next, the structure of the optical display panel of the present invention will be described in detail. FIG. 8 is a diagram showing the components of the optical display panel of the present invention separated from each other. Reference numerals 1 and 2 denote optical sheets each having a prism shape on one surface, such as “SOLF” as described above. Is commercially available from Minnesota Mining and Manufacturing Company, USA. In the embodiment shown in FIG. 8, the optical sheets 1 and 2 are arranged so that the prism faces face each other (FIG. 6).
), But may be arranged such that the surface opposite to the prism surface faces (corresponding to FIG. 7).

In FIG. 7, an optical sheet 2 not forming a pattern is overlaid with an optical sheet 1 forming a pattern, but a portion of the sheet 2 corresponding to a portion formed by the sheet 1 is cut out and the sheet 1 is cut out. And 2 may be arranged so as to be present on one plane (corresponding to FIG. 5). Further, the optical sheets 1 and 2 may be formed in different shapes from each other, and a complicated optical pattern may be formed by layering. In this case, the number of optical sheets may be three or more.

For the convenience of handling as a display panel and from the viewpoint of protecting the surface of the optical sheet, it is preferable that the above-mentioned optical sheets 1 and 2 are sandwiched between support plates 3 and 4. In this case, these support plates must be light-transmissive. Here, the light transmittance means transparent or translucent. As the light transmitting support plate, for example, a transparent or translucent acrylic resin plate can be used.

In FIG. 8, a coloring film 5 is inserted between the optical sheet 2 and the support plate 4 as an optional member. Such a colored film may be provided between the optical sheets 1 and 2 and between the optical sheet 1 and the support plate 3 or between the optical sheets 1 and 2 and between the sheet 1 and the support plate 3. And at any two or more places between the sheet 2 and the support plate 4.

[0019]

Next, the present invention will be described more specifically with reference to examples. 360mm long x 485 wide as light transmitting support plate
An optical sheet (SOLF) having the same size as two transparent acrylic plates having a thickness of 2 mm, and an optical sheet (SOLF) cut into desired characters (3M) were prepared. These were superposed as shown in FIG. 8 to form one flat plate. Thus, the transparent portion and the reflective portion were reversed depending on the viewing angle, and a display panel having an excellent decorative effect was obtained.

Further, the size is 360 mm long × 485 mm wide,
By installing the display panel on a light box of relatively uniform brightness using two 10W straight tube fluorescent lamps made of a milky white acrylic plate (Mitsubishi Rayon 432) with a light-emitting surface of 290 mm in length × 360 mm in width. An internally illuminated display with a more novel effect is obtained, in which the part that shines depending on the angle is reversed between the character part and the part other than the character part.

FIGS. 9 and 10 show the results of measuring the luminance of the display panel by changing the viewing direction (the angle from the line perpendicular to the display panel) of the character portion and the portion other than the character portion. FIG.
Indicates the luminance of the character portion, and FIG. 10 indicates the luminance of the other portions. Points not connected by a line indicate the brightness of the light box itself. In the character portion, the luminance is extremely low in the direction perpendicular to the display surface, while in other portions, the luminance is extremely high and the contrast is remarkable. 40 for vertical
At an angle of ５０50 °, the brightness of the character portion is high and the brightness of the other portions is close to 0, and the contrast is also remarkable.

On the other hand, FIG. 11 and FIG. 12 show the results of calculating the luminance of the character portion and the luminance of the character portion of the display device described in Japanese Utility Model Laid-Open No. 1-92678 from the haze data. The calculation was based on the following equation. _{T p = T t -T d T} t: total light transmittance _{H = T d / T t T} d: diffuse transmittance T _p: parallel ray transmittance H: haze

As can be seen from this figure, in the prior art device, the luminance is substantially retained even at an angle where the character portion or other portion must appear dark, and the contrast is low.

[0024]

According to the display panel having the structure of the present invention, characters and patterns formed in an arbitrary shape become transparent or a reflective film depending on an angle at which the display panel is viewed, so that an excellent decorative effect can be obtained. Bring. By installing a colored film, for example, a product of 3M Corporation (“Scotchcal” film) under (or above or below) the superposed optical sheets, when the display body is viewed at different angles, the film color and Inversion (or color change) of the silver color of the reflection occurs.

Further, by installing a relatively uniform surface light emitter (a very common light emitter such as a light box) thereunder, the light emitting portion is inverted depending on the angle.
Further, an internally illuminated display body with a novel effect becomes possible. Also,
The display panel of the present invention has a very simple structure, can be manufactured easily and at low cost, and does not need to use materials harmful to the human body in manufacturing.

[Brief description of the drawings]

FIG. 1 shows a relationship between an incident angle of light incident on an optical sheet used in the present invention from a surface opposite to a prism forming surface and reflection or transmission.

FIG. 2 shows the relationship between the incident angle of light incident on the optical sheet used in the present invention from the prism forming surface and reflection or transmission.

FIG. 3 is a perspective view three-dimensionally showing the relationship between the incident angle and light reflection or transmission shown in FIG. 1, and light reaching a point C through a hatched area of a virtual hemisphere is reflected. The light incident at other angles of incidence is transmitted.

FIG. 4 is a perspective view three-dimensionally showing a relationship between an incident angle and light reflection or transmission shown in FIG. 2, and has the same meaning as in FIG.

FIG. 5 shows an example of an arrangement of two optical sheets for forming a pattern to be displayed.

FIG. 6 shows an example of an arrangement of two optical sheets.

FIG. 7 shows an example of an arrangement of two optical sheets.

FIG. 8 schematically shows the structure of the display panel of the present invention, in which each layer is actually laminated in close contact.

FIG. 9 is a diagram showing the luminance in the character portion of the internally illuminated display device manufactured using the display panel of the present invention manufactured as shown in FIG. 8 in the embodiment, and the viewing direction (from the line perpendicular to the display panel). FIG.

FIG. 10 is a diagram showing the luminance and the viewing direction (perpendicular to the display panel) of the portion of the internally illuminated display device manufactured using the display panel of the present invention as shown in FIG. (Angle from a line).

FIG. 11 is a graph obtained by calculating the relationship between the angle and the luminance for the device of the related art, similarly to FIG.

FIG. 12 is a graph obtained by calculating the relationship between the angle and the luminance for the device of the related art, similarly to FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Optical sheet which comprises a pattern 2: Optical sheet 3, 4 ... Light transmissive support plate 5 ... Colored film

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G09F 13/16

Claims (2)

(57) [Claims] 1. An incident angle of incident light incident on a prism-forming surface or a surface opposite to the prism-forming surface, which is formed of a transparent sheet having a large number of parallel prism shapes formed on one surface. At least two optical sheets that totally reflect or transmit the incident light depending on the at least two optical sheets, the at least two optical sheets being juxtaposed or layered with their prism-forming surfaces facing in opposite directions to each other, and An optical display plate, wherein a pattern to be displayed is formed by at least one of the at least two optical sheets. 2. The optical display panel according to claim 1, wherein said at least two pieces of optical sheets are sandwiched between two light-transmissive support plates.