JP2010044291A - Display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact, low-cost display device capable of imaging a display image having depth feel through the use of a half mirror. <P>SOLUTION: A display plate 15 having a three-layer structure is constituted by depositing first and second half mirror layers 17, 18 on the front and rear sides of a visible light-transmissive substrate 16. A printing paper 19 with outline-characters written thereon is disposed behind the display plate 15, and the paper is sandwiched between the display plate 15 and a pressure plate 20, and then, they are fixed to a holder frame 12. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention forms a display image with a sense of depth that can be widely used for display screens of electronic devices such as name plates, advertisement displays, information plates, bulletin boards or mobile phones, PDAs (Personal Digital Assistants), and radios. The present invention relates to a display device that can be made to operate.

It is possible to add a decoration to a character or a figure as a painting technique to express it as if it is deep, and it has been widely used for example in poster characters. However, nameplates and advertising displays created using such flat prints with characters that have a sense of depth as a painting technique can actually provide a complex three-dimensional effect with holograms and liquid crystal displays. In the current situation, it is felt that there is no sense of luxury.
For example, Patent Literature 1 and Patent Literature 2 are cited as techniques for realizing display with a sense of depth by using a hologram or liquid crystal display. Further, as a technique for realizing display with a sense of depth using a half mirror, for example, Patent Document 3 is cited.
JP-A-6-67591 JP-A-10-340060 JP 2004-151034 A

However, each of the above-mentioned prior arts has to construct an electrically and mechanically complicated mechanism, and actually has many applications such as name plates, advertising displays, information plates, bulletin boards or mobile phones, PDAs, etc. In order to use widely for display screens of electronic devices or radios, there are problems in terms of space limitations and cost. Therefore, a display device that has a simple structure, is not bulky, and can be provided at low cost has been demanded.
The present invention has been made paying attention to such problems existing in the prior art. The object is to provide a display device capable of forming a display image using a half mirror having a sense of depth at low cost without being bulky.

  As a first means for solving the above-mentioned problem, the background is behind a plate-shaped body having a three-layer structure in which first and second half mirror layers are respectively formed on the front and back of a base material that transmits visible light. On the other hand, the gist is that a pattern surface constituted by an image pattern with relatively high brightness or an image pattern with relatively low brightness with respect to the background is arranged.

An example of the structure of the display device is shown for ease of explanation. As shown in FIG. 6, the visible light reaching the first half mirror layer is partially reflected, but is transmitted and further passes through the base material to reach the second half mirror layer. A part of the visible light reaching the second half mirror layer is also reflected but reaches the pattern surface. The pattern surface is visually recognized through the second half mirror layer and the first half mirror layer and is recognized as an image pattern having a high brightness relative to the background or an image pattern having a relatively low brightness relative to the background. Become. Here, the image pattern is a kind of symbol that is composed of characters, figures and the like for the purpose of communication of the user. The image visually observed at this time is defined as a normal image A.
On the other hand, the pattern surface image is partially reflected by the first and second half mirror layers. Among these, as shown by a broken line in FIG. 6, the image pattern reflected by the first half mirror layer is further reflected by the second half mirror layer to display a virtual image B. The optical path length of the virtual image B reciprocates between the substrates as shown in the figure and becomes a distance that is twice the thickness of the substrate, so that the virtual image B appears to be deeper than the actual pattern surface. The virtual image B is also reflected in the same manner, and a secondary virtual image is projected at the back position. That is, the virtual image B is multiplexed and projected. When the amount of light is greatly attenuated, the secondary virtual image is not clearly seen. Multiplexing can be changed by adjusting the reflectance of the half mirror layer. For example, if there is a sufficient amount of light and the reflectance is large, a large number of virtual images B can be projected.
As shown in FIG. 6, in such an optical system, an observer who views the display device from the first half mirror layer side views two image patterns of a normal image A and a virtual image B. Since the normal image A is not attenuated so much, the brightness is large, and since there is also light that is transmitted when reflected by the first and second half mirror layers, the attenuation is large and the brightness is relatively small. For this reason, the virtual image B having a lower brightness than that of the normal image A is visually observed so as to snuggle up, and the presence of the virtual image B makes it feel as if the image pattern has a depth. As the base material becomes thicker, the normal image A and the virtual image B are separated from each other and the depth is increased.

Here, the half mirror layer is a film layer having a plate-like area that can divide visible light into reflected light and transmitted light. Generally, reflection and transmission are 1: 1. The ratio is not limited. Moreover, not all incident light is divided into two, and the case where a part is absorbed may be sufficient. The reflectance of the half mirror layer may be in the range of 10 to 90%, and the transmittance may be in the range of 10 to 90%.
The half mirror layer is composed of metal, dielectric multilayer film, etc., and there is no particular limitation on the film formation method, but in general, the film is formed by vapor deposition or sputtering, and the film is smooth and adherent. It is preferable from the property.
The substrate on which the half mirror layer is formed is not necessarily a flat plate.
In addition, the image pattern on the pattern surface is a portion having a pattern with a higher brightness than the background or a pattern with a lower brightness than the background, for example, the background is typically black and the image pattern is white. It is possible to use a color other than white and a background other than black. In addition, a fluorescent color may be arranged along with the image pattern portion. The image pattern may be printed or pasted on the background.
The pattern surface may be attached to the plate-like body so as to be in close contact with the second half mirror layer, and is in close contact with or close to the second half mirror layer in a state of being attached to another base body separate from the plate-like body. You may make it make it.

In the second means, in addition to the first means, a light source is arranged behind the pattern surface so that light incident from the light source is transmitted from the image pattern to the plate-like body side on the pattern surface. This is the gist.
In such a configuration, light from a light source serving as a so-called backlight transmits light from the back side of the pattern surface to the plate-like body side from the image pattern position, increasing the brightness of the pattern surface and making the normal image clearer. And a virtual image can be visually recognized.

Further, the third means is characterized in that, in addition to the first or second means, the first or second half mirror layer has a non-flat reflection characteristic in the visible light region.
In other words, the reflection characteristic in the visible light region may be large at a certain wavelength or conversely small. This allows the normal and virtual images of the image pattern and the background color to be accompanied by a color rather than a simple silver reflection color.

In the fourth means, in addition to any of the first to third means, a protective layer is formed on the first half mirror layer formed on the surface side of the plate-like body. This is the gist.
This can prevent the deterioration of the first half mirror layer on the outside particularly when the display device is placed in a poor environment such as being installed outside.
The protective layer can be hardened with a hard coat, etc., and can be formed by spraying, dipping, sputtering, vacuum deposition, etc. with a combination of antifouling properties and slipperiness such as a water repellent coat. it can.

  In the inventions of the above claims, since the pattern surface is arranged behind the plate having a three-layer structure in which half mirror layers are formed on the front and back surfaces, the normal image of the image pattern on the pattern surface has a depth. In this way, the virtual image is visually observed, and a high-class stereoscopic pattern can be realized with a very simple configuration and a reduced thickness. Also, since the plate-like body and the pattern surface are separated, it is easy to replace the pattern surface, so it is ideal for applications where it is desired to replace the pattern surface and a display device with a wide range of applications. Can be provided.

Embodiments of a display device according to the present invention will be described below with reference to the drawings.
Example 1
FIG. 1 is an example of a guide plate using the display device 11. The display device 11 of Example 1 is held by a holder frame 12 having a rectangular outer shape. As shown in FIG. 2, the holder frame 12 can be divided into a front frame 12 a and a rear frame 12 b, and both are connected by screws 13. When the holder frame 12 is assembled, a groove 14 is formed in a channel shape on the inner periphery, and the display device 11 is fitted in the groove 14. The display device 11 includes a display plate 15 as a plate-like body. The display plate 15 includes a transparent rectangular substrate 16 made of acrylic, and first and second half mirror layers 17 and 18 made of a dielectric multilayer film formed by vapor deposition on the front and back of the substrate 16. . The first and second half mirror layers 17 and 18 in the first embodiment show reflectance characteristics as shown in FIG.
A printing paper 19 as a pattern surface is disposed on the back surface of the display plate 15. In the first embodiment, the printing paper 19 is described as “TOKAI OPTICAL” as an image pattern with a white background and a white background. That is, the image pattern portion is printed with the background color of the paper itself black.
A transparent rectangular holding plate 20 made of acrylic is disposed on the back surface of the printing paper 19. The printing paper 19 is sandwiched between the display plate 15 and the holding plate 20 in the assembled state of the holder frame 12.
In this embodiment, the thickness of the substrate 16 is 20 mm, and the thickness of the pressing plate 20 is 15 mm. The first and second half mirror layers 17 and 18 were 50 nm and the printing paper 19 was 200 μm. However, in the above drawings, these thicknesses are expressed differently from the actual thickness due to limitations in drawing.

As shown in FIG. 3, the display device 11 having such a configuration is visible light transmitted through the first and second half mirror layers 17 and 18 according to the above theory when viewed from the front side oblique direction of the display plate 15. As a result, the image pattern itself of the printing paper 19 is actually visually observed as a normal image 21 at the back position of the display plate 15. On the other hand, the virtual image 22 reflected on the first half mirror layer 17 and reflected on the second half mirror layer 18 is deviated from the normal image 21 and is further viewed deeper than the normal image 21. It will be. The distance between the normal image 21 and the virtual image 22 varies depending on the position viewed by the viewer. If the viewer's eyes are in a position facing the display plate 15, the virtual image 22 matches the normal image 21. The virtual image 22 is visually observed at a position away from the normal image 21 as the position deviates from the directly facing position. In FIG. 4, the normal image 21 is shown in black and the virtual image 22 is shown in white in the illustrated relationship.
Further, the second half mirror layer 18 has the following effects by adjusting the reflectance (transmittance) as appropriate. When the reflectance of the second half mirror layer 18 is increased, the reflected image by the multiple reflection becomes clear, and the resulting shadow changes from singular to plural and becomes a mirror image. Here, when there are many repeated shadows (virtual image B) and the readability of characters or the like is impaired, or a complicated impression is accompanied, it is possible to adjust by mainly controlling the reflectance of the second half mirror 18. is there.

With such a configuration, the following effects are achieved in the first embodiment.
(1) It is possible to form a screen having a depth like a hologram without using a hologram, and it is possible to supply a high-quality display device 11 at a low cost. (2) Since it can be configured very thin, it is not bulky. On the other hand, it is possible to give a feeling of depth twice as large as the transparent plate-like body that is the main body of the actual thickness.
(3) Since the positional relationship between the normal image 21 and the virtual image 22 changes depending on the viewing position, and it is felt that there is a depth than actual, a design effect is great.
(4) Since the printing paper 19 can be easily replaced, the image pattern to be displayed can be easily changed as desired.
(5) Since the reflectance characteristics of the first and second half mirror layers 17 and 18 are set so as to largely reflect in the blue wavelength band as shown in FIG. 5, it is possible to give a bluish color tone to the entire background. It has become.

(Example 2)
FIG. 4 is an example of an advertisement display using the display device 11. Constituent elements common to the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.
In the second embodiment, an LED light emitting substrate 25 on which a white LED 24 as a light source is mounted is disposed behind the display device 11. A reflector 26 is disposed between the LED light emitting substrate 25 and the display device 11 so as to surround the LED light emitting substrate 25. The reflector 26 is a cylindrical body made of an aluminum alloy that is expanded toward the display device 11 side.
By adopting such a configuration, in the second embodiment, in addition to the effects of the first embodiment, the image pattern of the printing paper 19 is illuminated by the white LED 24 (diffusely reflected) and becomes bright. The image pattern is displayed more clearly, and the image pattern can be viewed even when installed in a dark place. Moreover, it is possible to project a secondary virtual image more clearly in the back of the virtual image 22 in FIG. Further, by increasing the reflectance of the first half mirror layer 17, it is possible to obtain a solid mirror-like appearance in a state where normal outside light is strong. And it is possible to make a pattern emerge by illuminating from the back.

It should be noted that the present invention can be modified and embodied as follows.
In the above embodiment, the printing paper 19 is sandwiched between the display plate 15 and the pressing plate 20, but since the holder frame 12 as described above may not be provided, the printing paper 19 is pressed against the pressing plate. You may make it stick on a plate like 20.
For example, a hard coat layer may be formed as a protective layer on the front surface of the display plate 15, that is, on the first half mirror layer 17.
The outer shape of the display device 11 is an example, and other shapes can be freely adopted.
The setting of the optical characteristics of the first and second half mirror layers 17 and 18 is an example, and other characteristics may be used. The optical characteristics of the first and second half mirror layers 17 and 18 may be different.
The black and white pattern of the printing paper 19 may be reversed.
In addition, it is free to implement in a mode that does not depart from the spirit of the present invention.

4 is a partial cross-sectional view illustrating an application example of the display device of Embodiment 1. FIG. Explanatory drawing which decomposes | disassembles and demonstrates the structure of Example 1. FIG. The perspective view of the application example of the apparatus shown of an Example. 4 is a partial cross-sectional view illustrating an application example of the display device of Embodiment 1. FIG. The graph explaining the reflective and transmissive | pervious characteristic of a 1st and 2nd half mirror layer. Explanatory drawing explaining the theory of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Display apparatus, 16 ... Board | substrate as a base material, 17 ... 1st half mirror layer, 18 ... 2nd half mirror layer, 19 ... Printing paper as a pattern surface.

Claims (4)

An image pattern or background having a relatively high brightness behind the three-layered plate-like body in which the first and second half mirror layers are respectively formed on the front and back of the base material that transmits visible light. A display device comprising a pattern surface configured by an image pattern having relatively low brightness. The display device according to claim 1, wherein a light source is disposed behind the pattern surface, and light incident from the light source is transmitted from the image pattern to the plate-like body side on the pattern surface. . The display device according to claim 1, wherein the first or second half mirror layer has a non-flat reflection characteristic in a visible light region. The display device according to claim 1, wherein a protective layer is formed on an upper layer of the first half mirror layer formed on the surface side of the plate-like body.

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