WO2009084556A1

WO2009084556A1 - Image display device

Info

Publication number: WO2009084556A1
Application number: PCT/JP2008/073510
Authority: WO
Inventors: Makoto Kondo
Original assignee: Suncorporation
Priority date: 2007-12-28
Filing date: 2008-12-25
Publication date: 2009-07-09

Abstract

It is possible to easily display an image such as characters and graphics on a transparent display panel. An image is formed on a surface of a transparent display panel by using a transparent ink and light is applied from an end face into an interior of the display panel. The light introduced propagates inside the panel while being reflected by the surface of the display panel. When the light reaches the image formed by the transparent ink, the light is scattered by microparticles contained in the ink to display the image. Since an image is formed by a transparent ink, it is possible to easily form and display an image. Moreover, the image formed on a surface of a transparent display panel by using a transparent ink is not noticed unless light is applied to the image. Accordingly, the image comes up simultaneously with the light and can give a deep impression to a viewer.

Description

Image display device

The present invention relates to a technique for displaying images such as characters and figures on a transparent display board.

Various technologies have been proposed for forming characters and figures on a transparent display board and displaying these images using light. Many of them are techniques for displaying characters and figures formed on a display board by irradiating light from the back side of the display board.

On the other hand, by drawing a figure by digging a groove with a substantially triangular cross section on the surface of a transparent display board and introducing light into the display board from the side of the display board, characters and figures are raised and displayed A technique to be attempted has also been proposed (Patent Document 1).

According to such a proposed technique, in order to introduce light from the side surface of the transparent display plate, it is possible to make the display portion thinner as compared with a method of irradiating light from the back side. Characters, figures, images, etc. can be displayed much more easily than the method using a liquid crystal screen.

Japanese Patent No. 3864342

However, in the proposed technique, it is necessary to dig a groove on the surface of the display board and draw a figure, and there is a problem that it is not so easy to draw such a figure.

The present invention has been made in response to the above-mentioned problems in the prior art, and an object thereof is to provide a technique capable of easily displaying images such as characters and figures on a transparent display board.

In order to solve at least a part of the problems described above, the image display apparatus of the present invention employs the following configuration. That is,
An image display device for displaying a predetermined image,
A display plate, which is a transparent plate-like member having the image formed on the surface thereof, using transparent ink containing fine particles that scatter light;
And a light incident portion for entering light from the end face of the display plate toward the inside of the display plate.

In such an image display device of the present invention, an image to be displayed is formed on the surface of a transparent display plate with transparent ink, and light is incident from the end face of the display plate toward the inside. Then, the light incident on the inside of the display panel propagates through the inside while being reflected by the surface of the display board. Then, the light that reaches the portion where the image is formed by the transparent ink is scattered around by the fine particles, and as a result, the image is illuminated and displayed.

If an image is formed with transparent ink on the surface of the display board, it can be performed much more easily than when an image is formed by digging a groove on the surface. For example, if the image to be displayed is a simple character or graphic, it can be easily drawn by handwriting, and even a complex graphic image can be easily printed by using a printing apparatus. it can. For this reason, images such as characters and figures can be easily displayed on a transparent display board. Further, since the image to be displayed is formed on the surface of the transparent display board using transparent ink, the image is formed on the surface of the display board to a consistent degree before the image is lit. It is hard to notice that Even if light is incident from the end face of the display panel to shine an image, the light propagating through the inside of the display board is not visible, and it is difficult to notice that the light is incident from the end face. As a result, the image can be displayed in a very impressive manner such that the image emerges with light from an empty place.

In this specification, “transparent ink” refers to ink applied to reflect light on the ink surface (for example, paint, correction liquid, various printing inks, etc., hereinafter referred to as reflective ink). Is called an ink applied on the assumption that light passes through the ink layer. For example, an ink obtained by diluting a commercially available so-called reflective ink to about half by using a commercially available so-called clear ink cannot sufficiently transmit light through the ink layer. Not applicable. In contrast, if the commercially available clear ink is used and the commercially available reflective ink is diluted to a quarter or less, the light can be sufficiently transmitted through the ink layer. Corresponds to “transparent ink”. Here, the ratio between the clear ink and the reflective ink is defined by the volume ratio excluding the volatile component in each ink. For example, “diluting reflective ink in half using clear ink” means that when the diluted ink is dried (or solidified), the component derived from the clear ink and the component derived from the reflective ink Say that the same volume is included.

In addition, when the ink layer is formed with transparent ink, most of the light can pass through the ink layer, but when the ink layer is formed with reflective ink, much light is blocked by the ink layer. Therefore, when a continuous ink layer of a certain area or more is formed on an acrylic plate or the like and light is illuminated from the back side, the light transmitted through the portion where the ink layer is formed is attenuated to 70% or less. Ink (ink that blocks 30% or more of the light that attempts to pass through the ink layer) does not fall under “transparent ink” in this specification. On the other hand, if the ink allows more than 70% of the light to pass through the ink layer, it corresponds to “transparent ink” in the present specification.

Even when an image is printed with transparent ink, it may appear whitish depending on light. This is because the formation of the ink layer creates fine irregularities on the surface of the display plate, and as a result of the irregular reflection of the light, the image appears whitish even though the ink layer itself is transparent. This is because there is a case where it ends up. However, even in this case, if the irregular reflection due to the unevenness is suppressed, the image becomes transparent. Therefore, even if the image looks whitish, if the image becomes transparent by applying a transparent acrylic lacquer from above, the image is formed using the “transparent ink” referred to in this specification. Can be said. This is because in such a case, although the ink layer is transparent (transmits most of the light), it can be determined that the image looked whitish because light was irregularly reflected by the surface irregularities. is there. In other words, even if an acrylic lacquer is applied, it does not correspond to an image formed with “transparent ink” as used in the present specification as long as it does not show through.

In the image display device of the present invention described above, a plurality of display plates on which images of transparent ink are formed are stacked, and light is incident from the end face of each display plate, whereby images on each display plate are displayed. It may be displayed. At this time, the display panels are laminated so that a gap is secured between the surfaces.

Even if multiple display panels are stacked, if there is a gap between the surfaces, it is certain that light incident on one display panel will enter the next display panel and shine an image on the next display panel. Can be avoided. For this reason, for example, when light of a different color is incident on each display board, it is possible to display images formed on the display boards with different colors. In addition, when light is incident at different timings for each display panel, it is possible to display only the image of the display panel on which the light is incident.

Further, in the image display device of the present invention in which a plurality of display plates are stacked, red light is incident on the first display plate stacked with a gap between them, and the second display plate is green. Light may be incident and blue light may be incident on the third display panel.

Since a gap is secured between each display board, an image formed on the surface of each display board can be illuminated with the color of light incident on the display board. If red light, green light, and blue light are superimposed, various colors can be expressed. Accordingly, among the laminated display panels, if red light, green light, and blue light are respectively incident on the first display panel, the second display panel, and the third display panel, various color images are displayed. It becomes possible.

Further, in the image display device of the present invention in which a plurality of display plates are laminated, the following may be performed. First, at least one of the plurality of display boards is an additional image display board, and an image (additional image) to be displayed in addition to the image of another display board is formed on the surface of the display board. . Further, the additional light incident part that makes light incident from the end face of the additional image display board makes light incident on the additional image display board while the other light incident part is incident on the inside of the display board. And a state in which no light is incident may be switched.

In this way, with the image formed on the display board other than the additional image display board being displayed, the additional image display board can be displayed or displayed by making light incident on the additional image display board or stopping the incidence. The added image can be deleted. Moreover, since the additional image is also printed with transparent ink, it is difficult to notice the presence of the additional image unless light is incident. In addition, since an image that is not an additional image is displayed brightly, it is even more difficult to notice that an additional image is formed. In such a state, when light is incident from the end face of the additional image display board, an impression is given as if the additional image has been lifted from nothing. Further, when the incidence of light is stopped, it is possible to give an impression that only the additional image is scraped off while the original image remains unchanged. If the additional image can be displayed or the display can be stopped in the state where the image is displayed as described above, the image can be displayed in a manner that makes it easier to attract the eyes.

Alternatively, in the image display device of the present invention in which a plurality of display plates are stacked, a plurality of convex portions may be provided at intervals on at least one of the surfaces of the plurality of display plates facing each other. And it is good also as laminating | stacking a some display board in the state which ensured the clearance gap between the surfaces of the display board with the convex part.

In this way, when a plurality of display panels are stacked, the adjacent display panels can be reliably separated by the convex portions formed on the surface, so that the gap between the display panels can be made extremely thin. . In addition, even if the display panel is bent, there is no possibility of coming into contact with the adjacent display panel, so that the thickness of each display panel can be reduced. As a result, for the person who sees the image display device, an impression as if it is one display board is given rather than a plurality of display boards being laminated, and from among the one display board, For example, it is possible to display an image in an impressive manner such as images of various colors appearing or different images appearing one after another.

In order to secure a gap between the display plates, when providing a plurality of projections on the surface, it is desirable to provide projections at least at the four corner positions of the display plate. When the area of the display board is small, the figure to be displayed is also small, so it will be observed relatively close, but when observed from near, the convex part formed on the surface of the display board will be easily noticed . However, since the positions of the four corners of the display panel are relatively unnoticeable, the convex portions can be formed with almost no notice at the four corner positions of the display panel. In addition, when the area of the display panel is small, the deflection of the display panel itself is also small. Therefore, if protrusions are provided at least at the four corners, a gap can be secured between the display panels.

In addition, by providing a plurality of convex portions on the surface, when a plurality of display plates are stacked in a state where a gap is ensured, the side surface formed by stacking the plurality of display plates is covered with a cover member. It is desirable to keep it. When the display panels having a plurality of projections are stacked, the gaps formed between the display panels are narrow, so that it becomes difficult to remove foreign substances such as dust and moisture from the side surfaces. Thus, if the side surface on which the display bodies are stacked is covered with a cover member, it is possible to avoid foreign matter from entering between the display plates. At this time, the inner surface of the cover member, that is, the surface facing the side surface of the stacked display body may be configured to reflect light. A part of the light incident from the end face of the display panel is emitted from the other end face to the outside of the display board without causing the transparent ink image to shine. However, if the inner surface side of the cover member reflects light, the light emitted from the end face of the display panel can be returned to the inside of the display panel again. As a result, it is possible to make an image brighter with less light.

In the image display device of the present invention described above, the light scattering ratio at each location of the image takes into account not only the target luminance at that location but also the distribution of the light scattering rate from the end face of the display board to that location. The image may be printed so that the light scattering ratio determined as described above is obtained.

When an image is printed on the surface of the display board with transparent ink, and light is incident from the end face of the display board and shines, the light incident from the end face travels inside while shining the image printed on the surface. become. For this reason, the intensity of light is insufficient on the downstream side, and it may be difficult to shine an image with sufficient brightness. However, considering not only the target brightness at that location, but also the distribution of the light scattering rate from the end surface on the light incident side to that location, if you set the light scattering rate at each location of the image, Even if the light intensity is insufficient, it can be compensated by the light scattering ratio. As a result, all areas of the image can be illuminated with appropriate brightness, and the image can be displayed appropriately.

Further, in the above-described image display device of the present invention, the surface of the display plate is evenly divided into a plurality of pixels, and an image is printed by forming an ink layer of transparent ink in each pixel. good. And it is good also as changing the light-scattering ratio in each location of an image by varying the area of the ink layer formed in each pixel.

According to such a method, an image can be printed using a general printing technique such as ink jet printing or screen printing, so that an image using transparent ink is appropriately and easily formed on the surface of the display board. It becomes possible.

Further, the area of the ink layer formed in the pixel may be determined as follows. First, an index value proportional to the area of the ink layer formed in the pixel is determined for the pixel on the most upstream side when viewed from the direction in which light enters. This index value may be determined in accordance with the target luminance (target luminance) for which the pixel is to be illuminated. Next, for the downstream pixel, the index value is determined based on the target luminance at the pixel position and the index value already obtained for each pixel upstream of the pixel. After determining the index value for each pixel in this manner, the index value for each pixel is then read so that the largest index value (maximum index value) among the index values obtained for each pixel is a predetermined area. Thus, the area of the ink layer formed in each pixel may be determined.

In this way, each pixel of the image can be illuminated with appropriate brightness according to the target luminance regardless of whether it is upstream or downstream along the light traveling direction in the display panel. It becomes possible. Further, if the set value of the area for rereading the maximum index value is set to an appropriate value, the contrast when the image is illuminated can be set to an appropriate contrast. Therefore, it is possible to display an image with sufficient contrast without increasing the intensity of incident light.

Further, in the image display device of the present invention described above, a color image may be displayed as follows. First, an R component display plate having an R light incident portion that receives red light at an end portion, a G component display plate having a G light incident portion that receives green light at an end portion, and blue light incident A display panel is formed by stacking together three B component display plates each having a B light incident portion provided at the end (the R component display plate, the G component display plate, and the B component display plate are combined. , RGB component display panels). In addition, an image of transparent ink is printed on the surface of each RGB component display board. Here, for each image, the light scattering ratio at each pixel position is determined as follows. First, the index value of each pixel is determined for each RGB component display board. The index value of each pixel can be determined based on the above-described method, that is, based on the target luminance that is intended to illuminate the pixel and the index value that has already been obtained for the pixel upstream of the pixel. Subsequently, after extracting the maximum index value from all the index values obtained for each RGB component display board, the index values obtained for each pixel of each RGB component display board are re-read, The area of the ink layer to be formed is determined. When the index value is read as the area of the ink layer, it is read at a ratio such that the maximum index value becomes a predetermined area. According to the area determined in this way, an image for each component of RGB may be printed by forming an ink layer on each pixel.

In order to display a color image with an appropriate color, it is necessary to mix R light, G light, and B light at an appropriate ratio. Therefore, in order to display a color image appropriately by superimposing display boards for RGB components, the following is important. First, in the display board for each of the RGB components, it is important that all the image areas from the upstream side to the downstream side are illuminated with appropriate brightness along the light traveling direction. In addition, when an image of each component of RGB is illuminated, it is important that the brightness ratio between the components is also an appropriate ratio according to the color to be displayed. In the image display device of the present invention described above, the image of each RGB component display board is printed by replacing the index value obtained for each pixel with the area of the ink layer. It is possible to make it shine. Further, when the index value obtained for each pixel is read as the area of the ink layer, it is not read separately for each RGB component display board, but among all the index values obtained for each RGB component display board. The maximum index value is extracted, and the index values of the RGB component display panels are read so that the maximum index value has a predetermined area. For this reason, the image of each RGB component display board can be made to shine so that the brightness between each RGB component becomes an appropriate ratio. As a result, it is possible to appropriately display a color image.

Instead of using the maximum index value obtained in each pixel, the index value of each pixel is read so that the average value of the index values obtained in each pixel becomes a predetermined reference area, thereby The area may be determined. At this time, it is desirable that the reference area for rereading the average value of the index values is set to an area smaller than the predetermined area for rereading the maximum index value.

When calculating the index value for each pixel, a large index value may be obtained for only a few pixels. In such a case, if the index values of all the other pixels are read so that the maximum index value obtained with the few pixels becomes a predetermined area, the whole area is read as a small area, which is sufficient. There may be a case where the brightness cannot be secured. In such a case, if the average value of the index values obtained for each pixel is read so as to have a predetermined reference area, even if only a small number of pixels have a large index value, It is possible to replace the index value of the pixel with an appropriate area.

Of course, when displaying a color image, the average value of the index values obtained for each component of RGB may be read so as to be a predetermined reference area. In this way, it is possible to appropriately display a color image by shining the image of each RGB component display board while maintaining the brightness between the RGB components at an appropriate ratio.

Further, in the image display apparatus of the present invention which can display a color image by superimposing three R component display boards, G component display boards, and B component display boards, each of these RGB components is displayed. By providing a plurality of convex portions at intervals on at least one surface where the plates face each other, the RGB component display plates may be stacked with a gap therebetween.

In this way, even if the gaps between the RGB component display boards are made thin, or even if the thickness of each component display board is made thin and the display board is easily bent, the RGB formed by the convex portions formed on the surface. These component display boards can be reliably separated from each other. For this reason, the display board which laminated | stacked each RGB component display board 3 sheets can be made thin to such an extent that it is not conscious of having laminated | stacked the several display board. If the display board can be made thin in this way, even if the image is observed from an oblique direction, the positional deviation between the RGB components becomes inconspicuous. It is possible to display.

Even when a plurality of protrusions are formed on the surface of the display board in order to display a color image, it is desirable that the plurality of protrusions be provided at least at the four corner positions of the display board. Since the four corners of the display panel are relatively unnoticeable, convex portions can be formed with little notice. In addition, when a plurality of display plates are stacked in a state where a gap is secured by the convex portion, the side surface is covered with a cover member so that foreign matter such as dust and moisture does not enter from the side surface where the plurality of display plates are stacked. It is desirable. At this time, if the inner surface side of the cover member, that is, the surface facing the side surface of the laminated display body is configured to reflect light, the light emitted from the end surface of the display plate is again transmitted to the inside of the display plate. Therefore, the color image can be displayed brightly.

Further, in the image display device of the present invention described above, an image made of transparent ink may be formed as follows instead of directly forming on the surface of the display plate. That is, as an image is formed on the surface of the display plate by forming an image with transparent ink on the surface of the transparent sheet and pasting the transparent sheet on the surface of the display plate in a replaceable manner. Also good.

Since the transparent sheet does not contain fine particles that scatter light, when light is incident from the end face of the display panel, only the image formed on the transparent sheet can be illuminated. For this reason, it becomes possible to display an image in an impressive manner as if the image emerged with light from an empty place. In addition, since the transparent sheet is pasted on the surface of the display board in a manner that can be pasted, the display content can be easily changed by pasting the transparent sheet.

It should be noted that such a transparent sheet may be provided on one surface with an adhesive layer made of a transparent and fluid resin material and attached to the surface of the display plate by the adhesive layer. When the transparent sheet is attached to the display board, it is important that the transparent sheet is closely attached so that there is no gap between the transparent sheet and the display board. Therefore, if the transparent sheet is pasted by the adhesive layer, even if fine irregularities exist on the surface of the display board, the transparent sheet can be adhered to the surface of the display board by filling the irregularities with the adhesive layer. it can. In addition, even when dust in the air is sandwiched when the transparent sheet is pasted, if the dust is small, it is embedded in the adhesive layer, so that the transparent sheet can be brought into close contact with the surface of the display board.

Further, in the image display device of the present invention described above, the following may be performed. First, a specific information storage unit that stores predetermined specific information corresponding to an image formed on the surface of the display board in a readable manner is provided on the display board. And specific information is read from a display board, and you may make it make light inject into the inside of a display board in the aspect according to the specific information.

Since the image displayed on the display board shines by reflecting the light incident from the end face, the manner in which the image is displayed differs depending on the manner in which the light is incident. For example, changing the intensity of incident light changes the brightness of the displayed image, and changing the incident light color changes the color of the displayed image. An appropriate mode for displaying an image is considered to be different depending on an image to be displayed. Therefore, specific information corresponding to the image formed on the display board is stored in advance on the display board in a readable manner. For example, a storage medium such as an IC chip in which specific information is stored may be embedded in the display board, or the specific information may be described in a form such as a barcode at a predetermined location on the display board. When an image is displayed, specific information is read from the display board by an electromagnetic or optical technique, and light is incident on the inside of the display board in a manner determined according to the specific information. At this time, for example, if the content of the specific information is data (or a parameter describing the incident mode) describing the mode in which light is incident on the inside of the display board, the light can be incident in the mode described in the specific information. That's fine. On the other hand, when the content of the specific information is data specifying an incident mode to be used from among a plurality of preset incident modes, the plurality of incident modes stored in advance are selected. What is necessary is just to read the incident mode specified by specific information and to inject the light in that mode. If it carries out like this, it will become possible to display the image printed on the display board in the suitable mode according to the image.

The specific information may be stored on the display board in a rewritable manner, and the specific information stored on the display board may be rewritten using a specific information reading unit for reading the specific information from the display board. good. If the specific information on the display board can be rewritten, the image display mode can be changed to a more preferable mode. At this time, if a function for rewriting specific information is added to the specific information reading unit for reading the specific information, the specific information can be easily rewritten.

Further, in the above-described image display device of the present invention, the outermost surface of the display plate is smoothed by providing a clear layer made of a transparent resin not containing fine particles that scatter light on an image formed of transparent ink. It may be formed.

Since the image by the transparent ink is formed on the display board, when viewed microscopically, it is raised from the surface of the display board. For this reason, even if it is formed of transparent ink, it may be noticed that an image is formed due to a difference in reflection (or gloss) of light on the surface. Furthermore, since the ink layer made of transparent ink is formed so as to rise from the surface of the display plate, light may escape to the outside from the end portion of the ink layer. As a result, depending on the direction in which the image is observed, the edge of the transparent ink may shine strongly, and the image may appear glare. Therefore, if the outermost surface of the display panel is formed smoothly by providing a transparent clear layer on the image formed by the transparent ink, it is possible to avoid such problems and display the image appropriately. Is possible.

Further, in the image display device of the present invention described above, the following may be performed. A light radiating portion that radiates light propagating through the inside of the display panel may be provided on an end surface of the display panel, but different from an end surface on which light is incident. Here, the light radiating unit may be one in which the light propagating through the display panel can be radiated to the outside by simply opening the end face of the display panel, or the propagated light is diffused to the surroundings. For example, a member that diffuses light may be attached to the end face of the display panel.

Although the detailed mechanism will be described later, the light incident from the end face of the display board propagates through the inside of the display board with almost no loss to the end face on the other end side except that it is used for displaying an image with transparent ink. To reach. Therefore, if the light reaching the end face on the other end side is emitted outside, the light that could not be used for image display can be used as indirect illumination light. In addition, since the image is displayed using light scattering by the fine particles in the transparent ink, no light loss due to absorption occurs when the image is displayed. Therefore, all the light used to display the image is finally used as indirect illumination light after the image is lit. As a result, it is possible to realize indirect illumination with extremely high efficiency using almost all the light incident from the end face of the display panel while displaying an image in an impressive manner. Furthermore, if a member for diffusing the light propagating through the inside of the display panel is provided, the light emitted from the end face of the display panel can be diffused to the surroundings to easily realize indirect illumination.

In the above-described image display device of the present invention, the image is formed on the surface of the transparent plate member with the transparent ink containing fine particles that scatter light. However, as will be described later, even when an image is formed using a transparent ink that does not contain fine particles, the image can be displayed with light. Therefore, the image display apparatus of the present invention can be grasped in the following manner. That is, such an image display device as another aspect is
An image display device for displaying a predetermined image,
A display board on which the image is formed with transparent ink on the surface of a transparent plate-like member;
And a light incident portion for entering light from the end face of the display plate toward the inside of the display plate.

Also in the image display device of the present invention grasped in such another aspect, the image formed with the transparent ink is made to shine on the surface of the display plate by entering light from the end face of the display plate toward the inside. Can be displayed. As a result, it is possible to display an image in a very impressive manner such that the image emerges with light from an empty place, and easily.

It is explanatory drawing which illustrates the image display apparatus of 1st Example integrated in the glass window of the wristwatch. It is explanatory drawing which showed the principle by which the image printed with the transparent ink is displayed on the surface of a transparent display board. It is explanatory drawing which illustrated the image display apparatus of the modification of 1st Example integrated in the pendant top. It is explanatory drawing which showed the rough structure of the image display apparatus of 2nd Example. It is explanatory drawing which showed a mode that the display board of 2nd Example was mounted | worn to a base part. It is sectional drawing which showed notionally the positional relationship of the display board with which the groove | channel of the base part was mounted | worn, and LED provided in the groove | channel. It is explanatory drawing which showed a mode that the ink layer was formed in a pixel with the area according to the luminance data for every pixel. It is explanatory drawing which illustrated the image data of the image which it is going to display. It is explanatory drawing which illustrated a mode that the luminance data for 1 row of pixels of image data was converted into the area of an ink layer. It is explanatory drawing which showed the fundamental view at the time of converting image data into the area of an ink layer in the image display apparatus of 2nd Example. It is explanatory drawing which showed a mode that the area of an ink layer was determined for every pixel in the image display apparatus of 2nd Example. It is a disassembled assembly figure which shows the structure of the display board of 3rd Example which can display a color image. It is explanatory drawing which showed a mode that the display board was mounted | worn in the groove | channel of the base part in the image display apparatus of 3rd Example. In the image display apparatus of the third embodiment, it is an explanatory diagram showing how the areas of the R component ink layer, the G component ink layer, and the B component ink layer are determined. It is explanatory drawing which illustrated a mode that the full-color color image was displayed in the image display apparatus of 3rd Example. It is explanatory drawing which showed the display board of the modification of 3rd Example which covered the side surface on which the display board of each component of RGB was laminated | stacked with the cover member. It is explanatory drawing which showed the display board of the other modification of 3rd Example laminated | stacked on both sides of the display board of each component of RGB, and having laminated | stacked the frame member. It is explanatory drawing which showed the rough structure of the display board used with the image display apparatus of 4th Example. It is explanatory drawing which showed a mode that the display board of 4th Example was mounted | worn in the groove | channel of the base part. It is explanatory drawing which showed notionally the mode that the additional image of the character "Merry! Xmas!" Was displayed or deleted in the state which displayed the image of the Christmas tree. It is explanatory drawing which illustrated the image display apparatus of the 4th Example which laminated | stacked the several display board as an additional display board. It is explanatory drawing which showed the structure of the base part in the image display apparatus of 5th Example. It is the block diagram which showed notionally the function of the base part used with the image display apparatus of 5th Example. It is explanatory drawing which showed the structure of the tag affixed on the surface of the display board. It is explanatory drawing which illustrated the drive pattern memorize | stored in memory of the control part. It is explanatory drawing which showed the structure of the image display apparatus of the modification of 5th Example. In the image display apparatus of 6th Example, it is explanatory drawing which showed the principle which can shine and display the image of the transparent sheet affixed on the surface of the display board. It is explanatory drawing which showed a mode that the transparent sheet in which the image was formed is replaced in the image display apparatus of 6th Example. In the image display apparatus of 7th Example, it is explanatory drawing which shows a mode that the clear layer was provided on the ink layer and the outermost surface was formed smoothly. It is explanatory drawing which expanded and showed the ink layer formed with the transparent ink on the surface of the display board. It is explanatory drawing which showed notionally the part corresponded to the part corresponding to a top surface part, and the part corresponding to an edge part about the ink layer from which a magnitude | size differs. It is explanatory drawing which showed notionally the mode that a part of image printed with the transparent ink on the surface of the display board was expanded. It is explanatory drawing about the effect acquired by forming a clear layer from on an ink layer. It is explanatory drawing which illustrated the image display apparatus of the 8th Example used as an indirect illumination apparatus. It is explanatory drawing which illustrated the image display apparatus of the 1st modification of 8th Example. It is explanatory drawing which illustrated the image display apparatus of the 2nd modification of 8th Example. In the image display apparatus of the 2nd modification of 8th Example, it is explanatory drawing which illustrated a mode that the end surface shape at the side which radiate | emits light was varied for every display board. It is explanatory drawing which illustrated the image display apparatus of the 3rd modification of 8th Example. It is explanatory drawing which shows the reason which can make the ink layer 114 light, without using the light-scattering fine particle 114p.

Hereinafter, in order to clarify the contents of the present invention described above, examples will be described in the following order.
A. First embodiment:
A-1. Apparatus configuration of the first embodiment:
A-2. Image display principle:
A-3. Modification of the first embodiment:
B. Second embodiment:
B-1. Apparatus configuration of the second embodiment:
B-2. How to print an image:
C. Third embodiment:
C-1. Apparatus configuration of the third embodiment:
C-2. How to print an image:
C-3. Modification of the third embodiment:
D. Fourth embodiment:
E. Example 5:
F. Example 6:
G. Example 7:
H. Example 8:
H-1. First modification of the eighth embodiment:
H-2. Second modification of the eighth embodiment:
H-3. Third modification of the eighth embodiment:
I. Variation:
I-1. First modification:
I-2. Second modification:

A. First Example:
A-1. Device configuration :
FIG. 1 is an explanatory view showing an image display device 100 of the first embodiment incorporated in a glass window of a wristwatch 10. FIG. 1A shows a state in which the wristwatch 10 incorporating the image display device 100 is viewed from the front as viewed from the front of the wristwatch 10. FIG. 1B shows a cross section of a portion where the image display device 100 is incorporated as viewed from the side of the wristwatch 10. As shown in FIG. 1, the image display device 100 of the first embodiment is incorporated in a display plate 110 formed by diverting a glass window of a wristwatch 10 and a window frame portion in which the glass window is fitted. The light emitting diode (hereinafter referred to as LED 126) and the operation button 122 provided on the side of the case of the wristwatch 10 are configured. Also, an image 112 in which characters are designed with transparent ink containing fine particles is drawn on the back side (the dial side) of the glass window. Since the image 112 is drawn with a transparent ink on a transparent glass window, as shown in FIG. 1A, the image 112 is not immediately noticed when it is slightly seen.

The image display apparatus 100 of the first embodiment illustrated in FIG. 1 displays an image as follows. First, when the operation button 122 provided on the case side surface of the wristwatch 10 is pressed, the LED 126 incorporated in the window frame is turned on. As shown in FIG. 1B, the LED 126 is provided at a position facing the end face of the glass window (that is, the display panel 110) of the wristwatch 10, and the light emitted from the LED 126 is transmitted from the end face to the glass window. Incident inside. The light incident on the inside propagates through the inside of the display board 110 and shines the image 112 drawn on the back side of the display board 110. FIG. 1C shows a state in which an image formed of transparent ink is displayed on the glass window (display plate 110) of the wristwatch 10 in a shining manner. The mechanism by which light is incident from the end face of the glass window (display plate 110) and the image by the transparent ink is shined and displayed will be described in detail later.

The wristwatch 10 incorporating the image display device 100 of the first embodiment is not different from a normal wristwatch as shown in FIG. 1 (a) as long as it is viewed without displaying an image. However, when the operation button 122 is pressed and the LED 126 is turned on, as shown in FIG. 1C, the image 112 is displayed on the glass window. Here, since the LED 126 is incorporated in the window frame of the glass window, as long as the wristwatch 10 is normally viewed, the LED 126 is not noticed. In addition, even if the light from the LED 126 propagates through the inside of the glass window (display panel 110), it is not known, so even if the image 112 is lit and displayed, it seems that it is illuminated from somewhere. can not see. As a result, it becomes possible for the observer of the wristwatch 10 to display the image 112 in a very impressive manner as if the image 112 had floated with light from the empty glass window.

Of course, even if an image is drawn by digging a groove in the glass window of the wristwatch 10 or an image is drawn with fine scratches, it is possible to light up these images by turning on the LED 126. . However, it is clear that an image drawn by digging a groove or an image drawn with fine scratches is drawn there before the LED 126 is turned on. For this reason, even if the LED 126 is turned on to shine the image, it is impossible to display the image in an impressive manner as described above. In addition, in order to draw an image by digging a groove or drawing an image with fine scratches, skilled techniques and special devices are required, so an image is drawn on the surface of the display board 110. Is never easy.

On the other hand, in the image display device 100 of the first embodiment, it is only necessary to form an image with transparent ink, so that an image to be displayed can be easily formed without skilled or special devices. . Moreover, since the image is formed with the transparent ink, it can be difficult to notice that the image is formed at first glance. As a result, as described above, the image is very impressive. Can be displayed. Hereinafter, the principle of displaying an image drawn with transparent ink on the surface of the glass window (display plate 110) by entering light from the end face of the wristwatch 10 will be described.

A-2. Image display principle:
FIG. 2 is an explanatory diagram showing the principle of displaying an image 112 printed with transparent ink on the surface of the transparent display board 110 by turning on the LED 126. As described above, the LED 126 is provided at a position facing the end face of the display panel 110. For this reason, when the LED 126 is turned on, the light emitted from the LED 126 enters from the end face of the display panel 110 and travels into the display panel 110. FIG. 2A shows a state in which light from the LED 126 is incident from the end face of the display panel 110 and travels inside the display panel 110. Thus, most of the light incident from the end face intersects the surface of the display panel 110 at a shallow angle. The light reaching the surface of the display panel 110 at such a shallow angle is not transmitted from the surface to the outside of the display panel 110, but all of the light is reflected by the surface, and the reflected light again travels inside the display panel 110. proceed. Then, it intersects the surface on the opposite side at a shallow angle, all the light is reflected, and travels inside the display panel 110 again. Most of the light emitted from the LED 126 propagates inside the display panel 110 while being repeatedly reflected on the surface of the display panel 110 in this way. Such a phenomenon is a phenomenon that appears as an aspect of light refraction, and is sometimes referred to as “complete reflection”. In the image display apparatus 100 according to the present embodiment, light is propagated inside the transparent display plate 110 using the phenomenon called complete reflection, and the image 112 printed with the transparent ink is raised. Therefore, a phenomenon called complete reflection will be briefly described.

FIG. 2B is an explanatory diagram conceptually showing how light is refracted. The refraction of light is a phenomenon that occurs when light tries to pass through the boundary surface between two media having different refractive indexes, and is summarized as “Snell's law”. Here, the refractive index is a physical property value related to the ease of passage of light in the medium. According to Snell's law, when light traveling in a medium with a certain refractive index reaches the boundary with a medium with a different refractive index, some of the light is reflected at the boundary and the rest of the light is It passes through the boundary surface and travels through a medium having a different refractive index. At this time, the light reflected at the boundary surface is reflected in a direction in which the angle at which the light is incident on the boundary surface (incident angle θi) and the angle at which the light is reflected from the boundary surface (reflection angle θr) are equal. Here, the incident angle θi is usually expressed by an angle between a normal line from the boundary surface and the traveling direction of light (incident light) incident on the boundary surface, and the reflection angle θr is the boundary angle It is represented by an angle formed by the normal of the surface and the traveling direction of the light reflected by the boundary surface (reflected light).

The traveling direction of light (transmitted light) traveling through a medium having a different refractive index travels through the downstream medium, where n1 is the refractive index of the upstream medium and n2 is the refractive index of the downstream medium. If the angle of the transmitted light (transmission angle θt), in the downstream medium,
n1 · sinθi = n2 · sinθt
It proceeds in the direction of the transmission angle θt that satisfies the above. Here, the transmission angle θt is represented by an angle between the normal line of the boundary surface between the media having different refractive indexes and the traveling direction of the transmitted light. FIG. 2B conceptually shows a state in which a part of the incident light is reflected and the remaining light travels through different media as transmitted light according to Snell's law. For example, when light traveling through an acrylic resin plate reaches the surface of the plate, the light travels in the air after the traveling direction is bent at the surface portion according to Snell's law. Here, the refractive index of acrylic resin is about 1.5, and the refractive index of air is about 1.0, which corresponds to the case of entering from a medium with a high refractive index into a low medium. The light travels in the air with its traveling direction being bent in a direction approaching the boundary surface (that is, the surface of the acrylic resin). Conversely, when the light traveling in the air enters the acrylic resin from the low refractive index medium, the light traveling direction is bent away from the boundary surface. Will be.

From the above Snell's law, when light traveling in a medium with a high refractive index reaches the boundary with a medium with a low refractive index, there is a special condition that all light is reflected. I understand that. That is, as described above, when light travels from a medium having a high refractive index to a medium having a low refractive index, the light traveling in the downstream medium travels slightly toward the boundary surface with respect to the incident direction. The direction is bent. Therefore, when the angle of light incident on the boundary surface is gradually laid down (incident angle θi is increased), the direction of light transmitted downstream of the boundary surface is bent in a direction approaching the boundary surface by Snell's law. Therefore, when the incident angle θi 光 is reached, the traveling direction of the transmitted light becomes parallel to the boundary surface. Such a state is a state where light cannot enter the downstream medium. Furthermore, when light is incident on the boundary surface more than the incident angle θi (at a large angle incident angle θi), it means that all the light is reflected on the boundary surface. FIG. 2C conceptually shows such a state. Further, the incident angle θi in which such a state (the traveling direction of transmitted light is parallel to the boundary surface) is called a critical angle θc.

On the other hand, when light is going to travel from a medium having a low refractive index to a medium having a high refractive index, the light transmitted through the boundary surface is bent in a direction away from the boundary surface by Snell's law. For this reason, a state where the traveling direction of the transmitted light is parallel to the boundary surface cannot occur, and there is no critical angle θc.

As described above, the critical angle θc can be considered when light is to be emitted from a medium having a high refractive index into a medium having a low refractive index. When light is incident on the boundary surface at an angle larger than the critical angle θc (that is, laid on the boundary surface), all the light is reflected by the boundary surface, and enters the medium having a low refractive index. I can't get out. In this specification, such a condition is referred to as a “complete reflection condition”. By the way, when light is going to be emitted from the acrylic resin (refractive index is about 1.5) into the air (refractive index is about 1.0), the critical angle θc is about 42 degrees.

In the image display apparatus 100 according to the present embodiment, the light from the LED 126 is efficiently guided to the portion where the image 112 is printed on the surface of the display board 110 by using the above-described complete reflection condition. The ink layer 114 is illuminated. That is, the display panel 110 is formed of a transparent material such as acrylic resin or glass, and these materials are all media having a refractive index larger than that of air. When light is incident from the end face of the thin display panel 110, most of the incident light travels at a shallow angle (at a large incident angle) with respect to the surface of the display panel 110. Eventually, of the light incident from the end face, the light incident at an incident angle larger than the critical angle θc with respect to the surface of the display panel 110 is satisfied, and as a result, much of the light incident from the end face is satisfied. In this case, the light travels inside the display panel 110 while being repeatedly reflected on the surface of the display panel 110.

In FIG. 2A, a state in which light incident from the end face of the transparent display panel 110 travels through the surface while being repeatedly reflected on the surface of the display panel 110 is represented by a thick broken line or a thick dashed line arrow. ing. In the vicinity of the end face, there is also light incident on the surface of the display panel 110 at an angle smaller than the critical angle θc (that is, from a direction perpendicular to the surface). An arrow indicated by a thin two-dot chain line in FIG. 2A illustrates light incident on the surface of the display panel 110 at an angle smaller than the critical angle θc 角. For such light, since the condition of complete reflection does not hold, a part of the light passes through the surface of the display panel 110 and travels into the air, and the remaining light is reflected inside the display panel 110. The reflected light passes through the inside of the display panel 110 and reaches the surface on the opposite side, but since the condition for complete reflection is not satisfied even on the surface on the opposite side, a part of the light also travels in the air on this surface, The remaining light is reflected and passes through the display panel 110 again. Light that does not satisfy the conditions for complete reflection is attenuated by repeating this process, so that it almost disappears until it slightly travels from the end face. In the area beyond that, only light that satisfies the condition of complete reflection travels inside the display panel 110.

Note that, in the range from the incident light from the end face of the display panel 110 until the light that does not satisfy the complete reflection condition disappears, a part of the light is transmitted to the outside, so that the display panel 110 shines lightly. May be visible. As shown in FIG. 1B, in the wristwatch 10 incorporating the image display device 100 of this embodiment, a glass window (display plate 110) is provided at least in the vicinity of the LED 126 so that such a portion can be hidden. ) Is covered with a window frame. In this way, when the image 112 printed on the display board 110 is lit and displayed, it is possible to make it harder to understand the location where the light is supplied. It is possible to give a stronger impression as if it was raised.

Thus, the light traveling inside the display board 110 eventually reaches a portion where the image 112 is printed on the surface of the display board 110 (an area where the ink layer 114 of transparent ink is formed). Since the material of the ink layer 114 is different from the material of the display board 110, the refractive index does not completely match. However, compared to the difference between the display board 110 and air, the display board 110 and the ink layer 114 are different. The refractive index is not significantly different (in practice, it is slightly larger than the refractive index of the display plate 110. For example, if the display plate 110 is made of acrylic resin, the refractive index of acrylic is approximately 1). .5, it is desirable that the refractive index be as large as possible, typically about 1.6. For this reason, the light that reaches the boundary surface between the display panel 110 and the ink layer 114 passes through the boundary surface as it is without being bent in the traveling direction, and travels inside the ink layer 114.

Here, transparent ink in which fine particles that scatter light (light-scattering fine particles 114p) are dispersed is used for image printing, and the light-scattering fine particles are also applied to the ink layer 114 formed on the surface of the display panel 110. 114p is in a dispersed state. Therefore, a part of the light traveling in the ink layer 114 collides with the light scattering fine particles 114p and is scattered around. Since the light scattering particles 114p are uniformly dispersed in the ink layer 114, the entire image printed with the transparent ink is brightly displayed. In FIG. 2A, the state in which the light traveling in the ink layer 114 collides with the light scattering fine particles 114p and is scattered is displayed by a thick broken line arrow or a thick dashed line arrow.

On the other hand, the light that has not collided with the light scattering fine particles 114p travels as it is inside the ink layer 114 and reaches the surface of the ink layer 114. As described above, since the refractive index of the ink layer 114 and the refractive index of the display panel 110 are substantially the same, the condition of complete reflection is also established on the surface of the ink layer 114. For this reason, the light that has reached the surface of the ink layer 114 is completely reflected by the surface, travels inside the ink layer 114, and further returns into the display board 110. In FIG. 2A, a state in which light is completely reflected on the surface of the ink layer 114 and then returns to the display plate 110 is indicated by thin broken arrows.

The image display device 100 according to the present embodiment displays the image 112 by causing the light scattering fine particles 114p of the ink layer 114 formed on the surface of the transparent display plate 110 to shine. Even if the light radiated from the LED 126 propagates through the inside of the display panel 110, it is not known, so that it looks to the observer as if the image itself is emitting light. In addition, when the LED 126 is not turned on, the display board 110 can be seen only as a transparent board at first glance, so it is very impressive as if the image is shining from the transparent board. It is possible to display an image in a manner.

As is apparent from the above description, the image display device 100 of the first embodiment shines the image 112 by shining the light scattering fine particles 114p dispersed in the ink layer 114. Therefore, if the concentration of the light scattering fine particles 114p is increased, it is possible to make the image brighter and clearer. Thus, the fact that the image is displayed brightly and clearly is effective in displaying the image with a deep impression. However, on the other hand, as the concentration of the light scattering fine particles 114p increases, the ink layer 114 gradually approaches a cloudy state. As the white turbidity of the ink layer 114 progresses, it becomes easier to notice that the image is printed on the surface of the display plate 110 even when the image is not shining. From this point, the concentration of the light scattering fine particles 114p is too high. Increasing the height acts in a direction that hinders the display of an image with a deep impression. Therefore, the concentration of the light scattering fine particles 114p contained in the transparent ink is the most in consideration of the viewpoint of making the image bright and clear and the viewpoint of suppressing the white turbidity in order to make it difficult to notice that the image is formed. The density is set so that an image can be displayed impressively. The light scattering fine particles 114p are preferably white fine powder (for example, powder of metal oxide such as aluminum oxide or titanium oxide) from the viewpoint of scattering light as efficiently as possible.

In the image display device 100 of the first embodiment illustrated in FIG. 1, since the dial of the wristwatch 10 has a whitish color, the image 112 is formed on the glass window (display plate 110) even when the ink layer 114 is cloudy. It is difficult to notice what is being done. Correspondingly, the concentration of the light-scattering fine particles 114p of the transparent ink is set to a relatively high concentration. In addition, since the dial as a background is a whitish color when the image 112 is displayed, it is not so noticeable even if the image 112 is shined white. For this reason, an LED that emits light other than white (for example, red, green, and blue) is used as the LED 126. As a result, coupled with the light scattering fine particles 114p being set at a relatively high concentration, it is possible to display the image 112 clearly in red or the like with a whitish dial as a background. .

In this specification, the display board 110 and the transparent ink are both assumed to be colorless and transparent. However, if an image printed with the transparent ink is not conspicuous on the surface of the display board 110, the display board 110 is not necessarily transparent and colorless. Need not be. For example, when the display board 110 is slightly colored, an image printed using a transparent ink slightly colored with the same color is inconspicuous. Therefore, even if the transparent ink is slightly colored, if the color is the same color as that of the display panel 110, it can be suitably used as the transparent ink. Of course, as long as the transparent ink is colorless and transparent, it can be suitably used regardless of the color of the display board 110.

A-3. Modification of the first embodiment:
The case where the image display device 100 of the first embodiment is incorporated in the glass window of the wristwatch 10 has been described above. However, the image display device 100 of the first embodiment is a flat plate in a pure sense like the glass window of the wristwatch 10 as long as it has a certain thickness (for example, 2 mm) and has a transparent portion. Not limited to this, it can be incorporated into various objects. Hereinafter, a modification of the first embodiment in which the image display device 100 of the first embodiment is incorporated in an accessory such as a pendant top or a key holder will be described.

FIG. 3 is an explanatory view showing an image display device 100 according to a modification of the first embodiment incorporated in the pendant top 20. FIG. 3A shows the external shape of the pendant top 20. The illustrated pendant top 20 is formed of a transparent material such as acrylic resin or glass, and a base part that also serves as the display board 110 and a base that is assembled to the main body part and through which a chain for hanging on the neck is passed. Part 120. In addition, an operation button 122 is provided on the base unit 120, and when the operation button 122 is pressed, an image is displayed on the main body unit in a shining manner. FIG. 3B shows a state in which the image 112 is shined and displayed on the main body by pressing the operation button 122.

FIG. 3C shows the structure of the image display device 100 according to a modification of the first embodiment by taking a cross section of the pendant top 20. As shown in the figure, the main body of the pendant top 20 is formed by combining two transparent members, and one transparent member is the display board 110. An image 112 made of transparent ink containing fine particles is formed on the surface of the display panel 110 on the side that is combined with one transparent member. In addition, an LED 126 is provided inside the base portion 120 at a position facing the end face of the transparent member that also serves as the display plate 110. Therefore, when the operation button 122 is pressed to turn on the LED 126, light is incident from the end face of the display plate 110, and the image 112 made of transparent ink can be illuminated and displayed by the mechanism described above.

In the image display device 100 according to the modification of the first embodiment, the transparent member used as the display plate 110 is not a flat plate in a pure sense. However, if the condition of complete reflection is generally satisfied for the entire transparent member, it can be used as the display board 110 by forming an image with transparent ink on the surface. Also in the image display device 100 according to the modification of the first embodiment configured as described above, an image to be displayed may be formed with transparent ink, so that the image can be easily displayed. Moreover, since the image is formed with transparent ink on the surface of the transparent member, at first glance, it is not noticed that the image is formed. As a result, it is possible to display the image in a very impressive manner as if the image had been lifted with light from the place where there was nothing.

Of course, as illustrated in FIG. 3D, an image 112 made of transparent ink is formed on the surface of a transparent flat plate to form the display plate 110, and both sides of the display plate 110 are covered with a transparent cover member. The pendant top 20 may be configured. In such a configuration, even if the light from the LED 126 enters the inside of the cover member, the light does not satisfy the condition of complete reflection, so that the light is attenuated immediately, and almost no light propagates inside the cover member. Therefore, even if a fine flaw is attached to the surface of the cover member, it can be avoided that the flaw is shining and becomes conspicuous.

Further, when the flat display plate 110 is used, a plurality of display plates 110 may be stacked and light may be incident from the end face of each display plate 110. For example, as illustrated in FIG. 3E, an LED 126R that emits red light, an LED 126G that emits green light, and an LED 126B that emits blue light are provided, and the light of the LED 126R is for red. The LED 126G may enter from the end face of the display panel 110R, and the light of the LED 126G may enter from the end face of the green display board 110G, and the light of the LED 126B may enter from the end face of the blue display board 110B. If the surfaces of the display board 110R, the display board 110G, and the display board 110B are not in direct contact with each other, the light incident from the respective end faces propagates only inside the display board 110, and the other display boards 110 Will not propagate to.

Then, a red image 112R is formed on the surface of the display plate of the display plate 110R, a green image 112G is formed on the surface of the display plate of the display plate 110G, and a blue image is formed on the surface of the display plate of the display plate 110B. If the image 112B is formed, the image on each display board 110 can be displayed in each color. In addition, it is possible to display a color different from the color of incident light in a portion where images of different colors are displayed in an overlapping manner. For example, a yellow image can be displayed in a portion where a red image and a green image are displayed overlapping each other.

Of course, if the image 112 to be formed is made different without changing the color of light incident on the surface of each display plate 110, the displayed image 112 is switched by switching the display plate 110 on which light is incident. It is also possible.

Further, when the image display device 100 is incorporated into a small transparent member such as a pendant top or a key chain as illustrated in FIG. 3, a reflective member may be provided around a member corresponding to the display plate 110. When the display panel 110 is small, light incident from the end face immediately reaches the opposite end face, so that it is considered that most of the incident light passes through the display panel 110. Therefore, if a reflecting member that reflects light is provided around the display panel 110, the light passing through the display panel 110 can be reflected and returned to the inside of the display panel 110 again. Therefore, the image 112 can be brightly illuminated by effectively using the light from the LED 126.

B. Second embodiment:
In the first embodiment described above, it has been described that a relatively simple image such as a character or a line drawing figure is displayed on the small display board 110. However, it is also possible to display a complicated image such as a photograph on the larger display board 110. Below, the image display apparatus 100 of such 2nd Example is demonstrated.

B-1. Apparatus configuration of the second embodiment:
FIG. 4 is an explanatory diagram showing a rough configuration of the image display apparatus 100 according to the second embodiment. As shown in the figure, the image display device 100 according to the second embodiment includes a large display board 110 on which an image is displayed, and a base portion 120 on which the display board 110 is erected. The display board 110 is formed of a transparent plate member such as an acrylic board or a glass board, and an image 112 to be displayed is printed on the surface of the display board 110 with a transparent ink containing light scattering fine particles. ing. Therefore, similarly to the first embodiment described above, in the image display device 100 of the second embodiment, it is difficult to notice that the image 112 is printed on the surface of the display board 110 at first glance. . In the image display device 100 according to the second embodiment, such a display plate 110 is mounted in a groove provided on the upper surface of the base portion 120.

FIG. 5 is an explanatory view showing a state where the display board 110 of the second embodiment is mounted on the base part 120. In FIG. 5, in order to show the rough structure of the base portion 120, the base portion 120 is shown in a state where it is broken. As shown in the figure, a groove 124 in which the display panel 110 is mounted is formed in the approximate center of the top surface of the base portion 120, and a plurality of light emitting diodes (hereinafter referred to as LEDs 126) are formed at the bottom of the groove 124. Are provided in a row. The display board 110 is mounted in the groove 124 from above the base portion 120 as indicated by an arrow in the drawing.

In addition, although LED126 demonstrates as what is white LED which radiates | emits white light here, not only this but what kind of LED may be used. Or various LED which radiates | emits the light of a different color can also be mixed and used. Furthermore, you may use not only LED but other light-emitting bodies, such as a miniature light bulb.

FIG. 6 is a cross-sectional view conceptually showing the positional relationship between the display board 110 mounted in the groove 124 of the base portion 120 and the LEDs 126 provided in a row in the groove 124. As shown in the figure, when the display board 110 is mounted in the groove 124 of the base portion 120, the end face of the display board 110 faces the LEDs 126 arranged in a line. For this reason, when the LED 126 is turned on by operating the operation button 122 after the display board 110 is mounted on the base portion 120, the light emitted from the LED 126 enters the inside of the display board 110 from the end face. Then, after propagating through the display panel 110 by the mechanism described above with reference to FIG. 2, the image 112 printed with transparent ink is illuminated. As a result, before the LED 126 is turned on, the image 112 is displayed on the display board 110 that has been seen as a simple transparent board. FIG. 4 illustrates a state before the LED 126 is turned on (see FIG. 4A) and a state where the LED 126 is turned on and an image is displayed (see FIG. 4B).

As described above with reference to FIG. 2, in the image display device 100 of the second embodiment, the range from the incident light from the end face of the display plate 110 until the light that does not satisfy the complete reflection condition disappears. Then, since a part of the light is transmitted to the outside, the display board 110 appears to shine lightly. Therefore, in the image display device 100 according to the second embodiment, the depth of the groove 124 of the base portion 120 is set to a depth at which such a portion appearing near the end face of the display plate 110 can be hidden. For this reason, when the image 112 printed on the display board 110 is illuminated and displayed, the portion to which the light is supplied can be hidden, so that the image appears as if it has been lifted from the transparent board. It becomes possible to give stronger.

Here, as apparent from a comparison between the image display device 100 of the first embodiment illustrated in FIG. 1 or FIG. 3 and the image display device 100 of the second embodiment illustrated in FIG. 4, the second embodiment. The image display device 100 displays an image 112 on a relatively large display board 110. Along with this, the displayed image is not a simple figure such as a character but a more complicated image. In order to appropriately display such an image, a special device is required for the image 112 printed with the transparent ink. Hereinafter, this point will be described in detail.

B-2. How to print an image:
As described above, if the ink layer 114 made of transparent ink containing fine particles is formed on the surface of the transparent display plate 110 and light is incident from the end face of the display plate 110, the portion where the ink layer 114 is formed. It is possible to shine. Here, in order to display complex images such as photographs and natural images instead of simple images such as characters and figures, intermediate brightness can be displayed and the image can be displayed according to the location of the image. Therefore, a technique for shining with a desired brightness is required. First, a technique for shining an image printed with transparent ink on the surface of the display panel 110 with a desired brightness will be described. There are roughly two methods for shining an image of transparent ink with a desired brightness. The first method is to form a fine ink layer 114 on the surface of the display panel 110 and control the density of the ink layer 114 according to the brightness desired to be shined. If a so-called ink jet printer is used, a fine ink layer 114 can be formed on the surface of the display panel 110. The second method is a method of controlling the area of the ink layer 114 according to the brightness desired to shine. The second method using area modulation does not need to form a fine ink layer 114, and thus can be applied to screen printing and the like, and can be said to be a more versatile method. Therefore, in the following, a method of making an image of transparent ink shine with intermediate brightness using area modulation will be described.

The principle of shining an image printed with transparent ink with a desired brightness by using area modulation is as follows. First, the surface of the display panel 110 is divided into small grids. Then, an ink layer 114 corresponding to an area of 1/4 of the cell is formed on each cell in a certain area, and an area of 1/2 of the cell is formed on each cell in another area. Assume that the ink layer 114 is formed. Then, the area where the ink layer 114 having a half area of the square is formed is made to shine about twice as bright as the area where the ink layer 114 having a quarter area of the square is formed. be able to. Therefore, if the image to be displayed is divided into small squares and the area of the ink layer 114 formed on the squares is controlled according to the brightness at which the squares are desired to be illuminated, each square is desired. It is possible to shine with brightness. Since the image data is normally described by luminance data representing the luminance of each pixel, it is considered that the ink layer 114 may be formed so as to have an area corresponding to the luminance data.

FIG. 7 is an explanatory diagram showing a state in which the ink layer 114 is formed in the pixel with an area corresponding to the luminance data for each pixel. In the second embodiment, one pixel is divided into four small areas, two vertically and horizontally, and the ink layer 114 is formed in the number of small areas corresponding to the luminance data. Of course, the method is not limited to this, and the ink layer 114 may be formed in a number of small areas corresponding to the luminance data by dividing the pixels into a total of 16 small areas, for example, four vertically and horizontally. Furthermore, it may be divided into more small areas. The size of one pixel is determined by the number of pixels in the vertical and horizontal directions (that is, resolution) of the image data and the size of printing the image, but the resolution of the image data is too high, or If the size of one pixel becomes small because the size to be printed is too small, a large pixel is formed by combining a plurality of pixels, and then the large pixel is divided into a plurality of small regions. A similar process may be performed.

Considering the case where one pixel is divided into four small regions, one pixel has the following five states: “a state where no ink layer 114 is formed in the pixel”, “an ink layer only in one small region” "State to form 114", "State to form ink layer 114 in two small areas", "State to form ink layer 114 in three small areas", "State to form ink layer 114 in all small areas Can be in five states. Naturally, the state where the ink layer 114 is formed in all the small regions in the pixel is the brightest state, and the state where no ink layer 114 is formed in the pixel is the darkest state. Further, if the ink layer 114 is formed in half of the small area in the pixel, the brightness is just intermediate.

Therefore, assuming that the gradation value of the luminance data can be in the range of 0 to 255, as shown in FIG. 7A, the pixels with the gradation value of the luminance data of 0 to 63 are included in the pixel. Without forming the ink layer 114, the ink layer 114 may be formed only in one small region for pixels with luminance data gradation values of 64 to 127. In the drawing, the small area where the ink layer 114 is formed is displayed with hatching. In addition, the ink layer 114 is formed in two small areas for pixels with luminance data gradation values of 128 to 191 and the ink is formed in three small areas for pixels with luminance data gradation values of 192 to 254. The layer 114 may be formed. Then, for a pixel with a luminance data gradation value of 255, the ink layer 114 may be formed in all small regions within the pixel. In this way, it becomes possible to make the pixel shine brighter as the gradation value of the luminance data increases.

However, in the method shown in FIG. 7A, the luminance data changes in 256 levels from gradation value 0 to gradation value 255, whereas the brightness of the pixel is 5 including the state where no light is emitted. It can only be changed in stages. Therefore, in order to compensate for this, the following method is also used in combination in the second embodiment.

For example, as shown in FIG. 7B, the luminance data at a certain pixel has a gradation value of 16, and the gradation of the luminance data also applies to the right pixel, the lower pixel, and the lower right pixel of the pixel. Assume that the value was 16. Since the luminance data of any pixel has a gradation value of 16, according to the method of FIG. 7A, the ink layer 114 should not be formed for any pixel, and these four pixels are not illuminated at all. Become. However, actually, since the gradation value of the luminance data is “16”, it is in a state where only the gradation value of 16 is left. Since the unregistered gradation value 16 occurs in each pixel, it can be considered that the unregistered gradation value 64 (= 16 × 4) occurs when the four pixels are combined. The luminance data having the gradation value 64 can be expressed by forming the ink layer 114 in one small area.

If this is utilized, the ink layer 114 can be more appropriately formed according to the gradation value of the luminance data. That is, as shown in FIG. 7A, when the gradation value of the luminance data increases by “64”, if the small area forming the ink layer 114 is increased by one, the gradation value of the luminance data As long as is not a multiple of 64, the remaining gradation values that cannot be reflected in the area of the ink layer 114 are generated little by little in each pixel. Therefore, these accumulated tone values are collected and when the tone value reaches 64, only one small region is added to form the ink layer 114. In FIG. 7B, for the four pixels whose luminance data gradation value is “16”, the number of small regions for forming the ink layer 114 is determined in accordance with the gradation value, and the pixels are left unstacked at each pixel. The manner in which the ink layer 114 is additionally formed for one small region by collectively collecting the gradation values is conceptually shown.

FIG. 7C shows a state in which the number of small regions for forming the ink layer 114 is determined for each pixel in the same manner for four pixels whose luminance data gradation value is “80”. ing. That is, for a pixel with a gradation value of 80, the ink layer 114 is formed in one small region as shown in FIG. However, since one small area corresponds to the gradation value 64 of the luminance data, this causes an accumulation of gradation values 16 (= 80-64) per pixel. If the remaining gradation values of the four pixels are combined, the gradation value for one small area is reached. Therefore, by forming the additional ink layer 114 for only one small region, the remaining gradation value generated in the four pixels is eliminated.

In the example described above, since the ink layer 114 is formed in one small region for four pixels, the ink layer 114 is formed in one-fourth small region when converted to one pixel. Corresponding to Therefore, in the method shown in FIG. 7A, the area of the ink layer 114 per pixel can be changed only in five steps, whereas the method shown in FIGS. 7B and 7C is used. If the method is used, it is possible to change to 13 (= 4 × 3 + 1) stages. Furthermore, instead of grouping four pixels, it is possible to change in more stages by increasing the number of pixels to be grouped with 9 pixels each in vertical and horizontal directions or 16 pixels in vertical and horizontal directions. It is.

In FIG. 7B and FIG. 7C, even if the remaining gradation values generated in the four pixels are collected, if the gradation value does not reach 64, the remaining gradation value is temporarily stored. It will be canceled and not reflected in the number of small areas. However, if the sum of the remaining gradation values does not reach the gradation value 64, the accumulated value may be carried over to the next adjacent pixel until the total value reaches the gradation value 64. . In this way, in principle, the area of the ink layer 114 per pixel can be changed in 256 steps as in the luminance data.

Therefore, if the image data to be displayed on the display board 110 is acquired and the image is printed by replacing the area of the ink layer 114 by the above-described method based on the luminance data for each pixel, the image of the image data is It should be possible to display on the display board 110 as it is. However, when actually tested, it has been found that if the area of the ink layer 114 formed on each pixel is set to the area obtained by converting the luminance data of each pixel, the image cannot be properly illuminated. In order to display an image appropriately according to the image data, further devices as described below are required. Hereinafter, this point will be described in detail.

FIG. 8 is an explanatory diagram illustrating image data of an image to be displayed. The small squares shown in the figure represent pixels, and the numerical values displayed in the pixels represent the gradation values of the luminance data for the pixels. In the case of so-called black-and-white image data, luminance data is set for each pixel (that is, each cell). On the other hand, in the image data of a color image, luminance data of each color component of R component, G component, and B component is set for each pixel. In the following, in order to simplify the description, description will be made using image data of a black and white image, but substantially the same description holds for image data of a color image. The luminance data is so-called 8-bit data, and is expressed as data of 256 gradations that can take gradation values of 0 to 255.

FIG. 9 shows a state in which the luminance data for one column of image data is converted into the area of the ink layer 114 formed in the pixel. In FIG. 9, luminance data is converted into the area of the ink layer 114 for the image data for one column of pixels surrounded by a broken line in the image shown in FIG. 8 according to the method described above with reference to FIG. The result is displayed. The hatched portion in the drawing is a region where the ink layer 114 is formed. It is assumed that light propagates from the left side on the paper surface of FIG. 9 with respect to such an image for one column of pixels. As described above with reference to FIG. 2, when the light propagating through the display panel 110 reaches the ink layer 114, the light collides with the light scattering fine particles 114p included in the ink layer 114 and is scattered. In FIG. 9, the hatched portion of the ink layer 114 is brightly displayed.

However, when such an ink layer 114 is actually formed on the surface of the display panel 110 and light is incident from the end face to make the image shine, the darker the image becomes, the more downstream the light travels. Turned out to be. This is because the upstream ink layer 114 scatters the light that collides with the light scattering particles 114p, and as the ink layer 114 on the downstream side becomes smaller, the absolute amount of the supplied light becomes insufficient. it is conceivable that. Therefore, if the luminance data of each pixel of the image data is simply converted into the area of the ink layer 114 by the method shown in FIG. 7, the image cannot be illuminated appropriately. Therefore, in the image display apparatus 100 according to the second embodiment, it is possible to appropriately set the area of the ink layer 114 of each pixel in consideration of light being lost due to scattering in the upstream ink layer 114. The following method was developed.

FIG. 10 is an explanatory diagram showing a basic concept when the image data is converted into the area of the ink layer 114 in the image display apparatus 100 of the second embodiment. FIG. 10 (a) focuses on a certain pixel (the nth pixel from the upstream side along the light traveling direction), and the light amount I (n) of light propagating from the upstream side to the pixel position. , The area S (n) of the ink layer 114 formed in the pixel, the amount of light R (n) used to illuminate the ink layer 114 in the pixel, and the downstream from the pixel position. The relationship with the amount of light I (n + 1) is shown. Note that since the display board 110 on which the ink layer 114 is formed has a thickness, when referring to “a certain pixel position”, it is necessary to consider a depth corresponding to the thickness of the display board 110. Accordingly, the amount of light propagating from the upstream side to the pixel position represents the amount of all light incident on the pixel position, including the depth direction of the display panel 110.

In FIG. 10B, the light amount I (n) of light incident on the pixel of interest, the area S (n) of the ink layer 114 formed on the pixel, and the ink layer 114 are illuminated. A relationship is established between the amount of light R (n) used in the above and the amount of light I (n + 1) propagating to the adjacent pixel. As shown in the uppermost equation in FIG. 10B, the amount of light R (n) used to shine the ink layer 114 is considered to be proportional to the amount of light I (n) propagating from the upstream side. . The area S (n) of the ink layer 114 formed in the pixel is a proportional coefficient between the light amount I (n) propagating from the upstream side and the light amount R (n) for causing the ink layer 114 to shine. It is thought that it has decided. Correspondingly, in the uppermost expression in FIG. 10B, the proportionality coefficient between the light quantity I (n) and the light quantity R (n) is expressed as f (S ( n)).

Here, if the area S (n) of the ink layer 114 is doubled, the brightness is also doubled (that is, the amount of light used for making the light is doubled), so the light amount I (n) and the light amount R ( The proportional coefficient f (S (n)) with n) can be considered to be proportional to the area S (n) of the ink layer 114 in the simplest case. That is, as shown in FIG. 10C, f (S (n)) = k · S (n) can be obtained. Alternatively, as a human visual characteristic, the function form shown in FIG. 10D can be used in consideration of the fact that the brightness recognized as the area S (n) increases tends to be saturated. is there.

In the pixel of interest, after the light amount R (n) is used to shine the ink layer 114 out of the light amount I (n) propagated from the upstream side, the remaining light amount T (n) It propagates to the pixels. Such a relationship is shown in the second equation from the top in FIG. However, light also attenuates when propagating through the display panel 110. Therefore, taking this light attenuation into consideration, the light amount I (n + 1) propagating to the adjacent pixel is a value obtained by multiplying the remaining light amount T (n) by exp (−μL). Here, μ is a light attenuation coefficient and is a physical property value determined by the material of the display panel 110. L is the size of one pixel, and is a value determined by the resolution of the image data and the size of the image to be printed as described above. Accordingly, when image data for one column of pixels as shown in FIG. 9 is given, the amount of light I (n) propagating in the display panel 110 from the most upstream pixel using the relationship shown in FIG. ) In order, the area S (n) of the ink layer 114 is determined, and the area of the ink layer 114 for each pixel is determined so that brightness corresponding to the luminance data of each pixel can be obtained. It becomes possible to do.

FIG. 11 shows how the area of the ink layer 114 is determined for each pixel while considering the attenuation of light inside the display plate 110 and the loss of light caused by causing the ink layer 114 to shine on the surface of the display plate 110. It is explanatory drawing shown. In the illustrated example, human visual characteristics are considered as f (S) representing a coefficient between the amount of light I (n) incident on the pixel of interest and the amount of light R (n) for causing the pixel to shine. The function form of FIG. 10D was used, and the value of the constant K appearing in the function was 4.5. The value L corresponding to the pixel size is not the actual pixel size, but is considered per pixel, and the value of L is 1. This is because the actual pixel size can be changed in various ways depending on the size of the image to be displayed. Further, 0.004 was used as the light attenuation coefficient μ.

Strictly speaking, the constant K in f (S) is a value determined by various factors such as the surface state of the ink layer 114. However, these factors are not analyzed here, but values obtained from experience are used. Further, the light attenuation coefficient μ is a physical property value originally determined by the material of the display plate 110, but here, a value obtained from experience is used. This is due to the following reason. In the actual image display device 100, the light propagating through the inside of the display board 110 spreads away from the LED 126 as the light source, and the intensity of the light becomes weaker. Therefore, in the calculation formula described above with reference to FIG. 10, in order to avoid the complexity of the calculation, the phenomenon in which the light is weakened by the diffusion of the light is also treated as a kind of light attenuation. The influence of the above and the influence of the original light attenuation are collectively considered as one attenuation coefficient μ. Further, since the value L corresponding to the size of the pixel is considered per pixel, not the actual length, it is not very meaningful to determine an exact value. For these reasons, the calculation shown in FIG. 11 uses a value obtained from experience, not the attenuation coefficient μ determined by the physical properties of the display panel 110.

First, FIG. 11 (a) will be described. FIG. 11A shows a numerical table divided into an upper stage, a middle stage, a lower stage, and a third stage, but the upper number table represents input values for calculation. The number table in the middle row shows the progress of the calculation performed based on the input in the upper row, and the number table in the lower row shows the finally obtained calculation result. Hereinafter, each stage will be described in detail.

11A shows the pixel position and the image data (that is, the target luminance of the pixel) for the pixel. In the example shown in FIG. 11A, the gradation value of the image data changes greatly for each pixel except for two pixels from the edge of the image. However, since the actually used pixel has a side length of about 0.1 mm, the gradation value does not change so much between adjacent pixels. In the actual image data, the gradation value changes more slowly. However, since it is difficult to show the overall movement if the actual image data is used, virtually generated data is used in FIG. It has been.

As shown in FIG. 11A, for the pixel at the first pixel position at the left end, the target luminance to be lit is a gradation value of zero. That is, since it is not necessary to shine this pixel, the area S (1) of the ink layer 114 formed in the pixel may be zero. Further, in this pixel, the reflected light amount R (1) used to illuminate the pixel has a gradation value of 0, so the incident light amount I (1) is transmitted as it is. Since the incident light amount I (1) can be set relatively freely by setting the LED 126, it is assumed here that the incident light amount I (1) has a gradation value of 1000, assuming that a sufficient amount of light is incident. The transmitted light amount T (1) of this pixel has a gradation value of 1000.

However, the transmitted light amount T (1) does not directly become the incident light amount I (2) to the next pixel. As described above with reference to FIG. 10B, light attenuation by one pixel acts on the transmitted light amount T (1), and the result is the incident light amount I (2) of the next pixel. In FIG. 11A, the transmitted light amount T (1) at the pixel position 1 has a gradation value of 1000, but the light is attenuated before entering the adjacent pixel, and as a result, the adjacent pixel. It is shown that the incident light I (2) at (pixel position 2) decreases to a gradation value 996.

Since the target brightness of the pixel at the pixel position 2 is also the gradation value 2, the area S (2) of the ink layer 114 formed in the pixel is 0 as in the case of the pixel at the pixel position 1, and the incident light is incident. The light amount I (2) becomes the transmitted light amount T (2) as it is, and becomes the gradation value 996 of the transmitted light amount T (2). The light is attenuated by one pixel while the transmitted light T (2) is incident on the next pixel. As a result, the incident light I (3) to the next pixel has a gradation value 992. Decrease.

For the pixel at pixel position 3, the target luminance is set to a gradation value of 65. In addition, from the above-described calculation, the incident light amount I (3) to this pixel is the gradation value 992. Therefore, for this pixel, the pixel has to be illuminated with the brightness equivalent to the gradation value 65 with the incident light amount I (3) having the gradation value 992 (in other words, the reflected light amount R (3) of the pixel). Is the gradation value 65). Here, as shown in FIG. 10 (b), R (3) = f (S) between the light amount used to illuminate the pixel (reflected light amount R) and the incident light amount I to the pixel. ) · I (3). Since R (3) = 65 and I (3) = 992, f (S) = 65/992, so if the function form of f (S) is known, the area S (3) can be calculated. It becomes possible to decide. In the example shown in FIG. 11, the function form shown in FIG. 10D is used as the function form of f (S). Further, since the value of the constant K appearing in the function is empirically known to be 4.5, S (3) can be obtained.

The value of the area S (3) shown at the pixel position 3 in FIG. 11A is a value determined in this way. In other words, if the area S (3) of the pixel position 3 is set to such a value, the pixel is detected with the light amount of the gradation value 65 for the incident light amount I (3) of the gradation value 992. It is possible to shine. As a result, the transmitted light amount T (3) at the pixel position 3 becomes a gradation value 927 obtained by subtracting the reflected light amount R (3) from the incident light amount I (3). The meaning of the value of area S (3) will be described later.

For the pixel at pixel position 4, the target luminance is set to a gradation value of 75. Further, the incident light amount I (4) to the pixel has a gradation value 923 due to the attenuation acting on the transmitted light amount T (3) at the pixel position 3 described above. Therefore, since the incident light quantity I (4) and the reflected light quantity R (4) can also be known for this pixel, the area S (4) at that pixel can be determined in the same manner as in the case of the pixel position 3. . Thereafter, in exactly the same manner, for the pixel at the pixel position 5, the incident light amount I (5) has the gradation value 845 and the reflected light amount R (5) has the gradation value 130, so the area S (5) is 818.2. Further, for the pixel at pixel position 6, the incident light quantity I (6) has a gradation value 712 and the reflected light quantity R (6) has a gradation value 95, so the area S (6) is 692.8. Thus, the area S is calculated in order for all the pixels.

The value of the area S obtained for each pixel as described above is not actually meaningful for the value of each pixel, but is a value that is meaningful for the relative size between pixels. ing. For example, for the pixel at pixel position 3, a value of area S (3) = 315.5 is obtained with respect to the gradation value 65 of the target luminance. However, the amount of incident light can be changed by the setting of the LED 126. If the amount of incident light changes, the area S for realizing the target luminance also changes. Therefore, the value of the area S is merely an area for realizing the target luminance under a certain fictitious incident light quantity, and the value of the area S is large as long as the incident light quantity value is a fictitious value. There is no meaning. That is, the value of the area S obtained in the middle number table in FIG. 11A is meaningful only in the ratio between pixels.

Therefore, as an example, the value of the obtained area S is interpreted as follows. In the first place, the calculation shown in FIG. 11 was performed because the luminance data of the image was replaced with the area of the ink layer 114 by the simple method as shown in FIG. This is in order to solve the problem of dark images as it goes downstream. Therefore, for the time being, paying attention to the pixel at the pixel position 3 on the upstream side, regarding this pixel, it is considered that there is no problem even if the target luminance is simply replaced with the area of the ink layer 114 by the method shown in FIG. That is, the area S (3) = 315.5 obtained in FIG. In addition, the area S (4) = 397.8 is set so that the relative ratio between the area S (3) of the pixel position 3 and the area S (4) obtained for the pixel position 4 is maintained. Convert. As a result, the area S (4) = 397.8 is converted into the gradation value 82. Similarly for the following pixels, the area S (5) for the pixel position 5 is converted to a gradation value 168, and the area S (6) for the pixel position 6 is converted to a gradation value 143.

The numerical table in the lower part of FIG. 11A shows the gradation values (corrected areas) obtained by rereading the area S in this way. As is clear from comparison between the pixel position 3 surrounded by a broken line in the figure and the pixel position 5, the target luminance at the pixel position 5 is exactly twice that of the pixel position 3, The area of the ink layer 114 to be formed is twice or more. This is because the area was corrected in consideration of the effect of decreasing the amount of incident light I because it was used to illuminate the pixel upstream of the pixel position 5 or due to attenuation. Then, if the area of the ink layer 114 is determined by applying the method shown in FIG. 7 to the gradation value (corrected area) obtained in this way, it will be located downstream in the light traveling direction. Even if it becomes, it becomes possible to display a good image that does not become a dark image.

Although only one column of pixels has been described here, the pixels are two-dimensionally arranged in an actual image, and it is possible to determine the correction area by performing the same operation for all these pixels. Needless to say. That is, for each pixel, an area S corresponding to the target luminance is calculated, and the calculated area S value is converted into a corrected area by reading it at a certain ratio. Moreover, the ratio when the area S obtained for each pixel is read may be read at the same ratio for all the pixels constituting the image.

In the method of replacing the area S with the gradation value of the corrected area in the above-described procedure, that is, the method of replacing the value of the area S obtained in the upstream pixel with the target luminance in that pixel, FIG. As is clear from the lower number table, the corrected area that has been read out increases as it goes downstream. Therefore, there is a possibility that the correction area is pasted on the gradation value 255 even if the target luminance is a pixel that does not have a very large gradation value (for example, a pixel whose target luminance is about the gradation value 150). Therefore, it is desirable to replace the area S with the corrected area at a ratio such that the area S having the largest value obtained in the middle number table becomes the gradation value 255.

FIG. 11B shows the result of replacing the area S with the corrected area so that the largest value in the calculated area S is the gradation value 255 in this way. In the upper table of FIG. 11B, the target luminance (the amount of reflected light R) for each pixel and the area S calculated for the target luminance are collectively displayed for reference. . The corrected area obtained by rereading the area S is shown in the lower number table. As shown in the upper table of FIG. 11B, the value 818.2 obtained for the pixel position 5 has the largest area S calculated for the target luminance. . Therefore, when the area S in the upper number table is read so that the value 818.2 becomes the gradation value 255, the corrected area shown in the lower number table can be obtained.

In FIG. 11, only one column of pixels is shown, but the actual image has pixels arranged two-dimensionally. Therefore, in the actual image, the largest value is selected from the areas S obtained for all the pixels arranged two-dimensionally, and the area S is set so that this value becomes the gradation value 255. You just have to replace it. If the area of the ink layer 114 is determined by applying the method shown in FIG. 7 to the corrected area obtained in this way, a dark image will be obtained when it is downstream in the light traveling direction. Thus, it is possible to display a good image.

If the maximum value of the area S is read so as to be the gradation value 255, the pixel having the maximum area S is in a solid state (a state in which the ink layer 114 is formed in all four small regions in the pixel). ) So that the correction area can be set. Therefore, it is possible to display an image efficiently by making the most of the gradation range that can be expressed using the area of the ink layer 114 formed in the pixel, and the display panel 110 has good contrast. It is possible to display a simple image.

In the above description, the corrected area is set so that the pixel having the largest area S is in a solid state. However, for example, when only one pixel has a large area S, the correction area of other pixels may be reduced due to the influence of this pixel. In such a case, instead of the largest area S, the average value (or intermediate value, median value, etc.) of the area S obtained in each pixel may be read so as to be an appropriate correction area. In this way, even if very few pixels have a large area S, most of the pixels can be read as appropriate correction areas.

Further, the area S calculated from the target luminance is a value that is meaningful for the relative size between the pixels, not the absolute size for each pixel, and is meaningful for this relative size. Based on the area S, a corrected area that is meaningful in absolute size is determined. Further, as described above, the parameters such as the attenuation coefficient μ and the constant K used to calculate the area S are not numerical values that are uniquely determined by physical properties, shapes, or the like, but are determined empirically. Value is used. Further, the pixel size L must be a value having a dimension of length according to the calculation formula shown in FIG. 10, but when calculating the area S as described above, it is referred to as “per pixel”. It is calculated using a value that does not have a length dimension. This is possible because the area S is a meaningful value for the relative size between the pixels, not the absolute size for individual pixels.

Thus, if the area S is only meaningful in relative size and the area S is converted into a corrected area that is meaningful in absolute size, the area S is calculated. By adjusting various parameters (for example, attenuation coefficient μ, constant K, pixel size L) and the like to appropriate values, the corrected area can be calculated directly without going through the area S. Seems to be possible. However, as will be described later, it is actually impossible to calculate the corrected area directly without going through the area S. For this reason, as described above, it is extremely important to determine the correction area via the area S having a meaningful relative size in order to display an image appropriately. Further, instead of changing the area of the ink layer 114 in the pixel, each pixel is formed by, for example, forming the ink layer 114 by overcoating or changing the concentration of scattering particles in the ink layer 114. Even when changing the intensity of shining, it is important to determine the correction area via the area S in order to display an image appropriately. In the following, this point will be described with some supplementation.

If the calculation result illustrated in FIG. 11 is obtained, it is possible to directly calculate the value shown in the corrected area instead of the value shown as the area S. For example, in the simplest case, a new proportionality coefficient A is brought into the calculation formula for the area S, and a value obtained by multiplying the value of the conventional area S by the proportionality coefficient A may be used as the new area S. In the example shown in FIG. 11B, the conventional area S value 818.2 only needs to be the gradation value 255. Therefore, if the value of the proportionality coefficient A is set to 255 / 818.2, the correction is made. It is possible to directly calculate the gradation value of the area as the value of the area S.

However, this is possible only for the same image data, and the proportionality coefficient A set for one image data cannot be applied to another image data. For example, in the example shown in FIG. 11B, the amount of incident light I (5) to the pixel position 5 is reduced along with the change in the target luminance at the pixel position 3 to the gradation value 70. The value of area S (5) must also be increased from 818.2. Along with this, the value of the proportional coefficient A also changes. Alternatively, even if the target luminance from the pixel position 1 to the pixel position 5 is the same, considering a case where, for example, a pixel having the gradation value 130 of the target luminance is added to the downstream pixel position 7, the pixel Since the value of the area S (7) with respect to is maximized, the value of the proportionality coefficient A is completely different. Furthermore, even if a pixel having the same target luminance as that of the pixel position 1 is added upstream of the pixel position 1, the amount of attenuation of light on the upstream side changes. Strictly speaking, the value of the proportional coefficient A is It will not be the same.

In this way, even if a new proportionality coefficient A is introduced, the value of the proportionality coefficient A differs for each image data, so that in order to obtain the value, only the relative size is meaningful in the end. The area S must be calculated once. Therefore, in order to display an image appropriately, it can be said that it is extremely important to determine the correction area via the area S having a meaningful relative size.

On the display board 110 used in the image display apparatus 100 of the second embodiment, an ink layer 114 of transparent ink is formed as described above based on the image data of the image to be displayed. For this reason, even when the display board 110 becomes large or when a relatively complicated image such as a photographic image or a natural image is displayed, it is possible to display the image appropriately by shining it. .

C. Third embodiment:
In the image display apparatus 100 according to the second embodiment described above, the image displayed on the display board 110 has been described as a single-color image expressed using only the brightness of pixels. However, as described above, the color image can be appropriately displayed by calculating the area S from the target luminance and determining the correction area based on the obtained area S. Below, the image display apparatus 100 of 3rd Example which can display a color image is demonstrated.

C-1. Apparatus configuration of the third embodiment:
FIG. 12 is an exploded view illustrating a configuration of a display plate 110 that can display a color image mounted on the image display apparatus 100 according to the third embodiment. As is well known, color image data for displaying a color image is composed of luminance data of each component of RGB, and in response to this, a color image is displayed by the image display device 100 of the third embodiment. In order to display, one display board 110 is configured by superimposing the display panel 110R for R component, the display board 110G for G component, and the display board 110B for B component. Further, a small protrusion 118 is formed on the surface of the display plate 110 so that the surfaces of the

display plates

110R, 110G, and 110B of the respective color components are not in contact with each other. The protrusion 118 may be formed by printing transparent ink, or may be formed by adhering a small member to the surface of the display panel 110. In the third embodiment, the projections 118 are formed by printing on the surface of the display panel 110 using a transparent UV ink that is cured by ultraviolet rays. By doing so, it is possible to easily form the protrusion 118 having an accurate height at an accurate position. In addition, when an image using a transparent ink is printed using a transparent UV ink that is cured by ultraviolet rays, the image 112 and the protrusion 118 can be formed simultaneously.

In addition, instead of forming the small protrusion 118, the following may be simply performed. That is, fine display particles (typically having a particle size of about several tens of micrometers) may be sprayed on the surface of the display panel 110 to stack the display panel 110 in that state. By doing so, a gap can be secured between the display panels 110 by the fine particles sprayed on the surface. Moreover, if the particles are fine particles, there is no possibility that the observer of the image display apparatus 100 will notice.

In this way, the display plate 110 configured by overlapping the three

display plates

110R, 110G, and 110B is mounted in a groove provided on the upper surface of the base portion 120. FIG. 13 is an explanatory diagram showing a state in which the display plate 110 is mounted in the groove of the base portion 120 used in the image display device 100 of the third embodiment. FIG. 13 shows the base 120 viewed from the side (direction along the surface of the display plate 110). As illustrated, in the base portion 120 of the third embodiment, a red LED 126R that emits red light, a green LED 126G that emits green light, and a blue LED 126B that emits blue light are formed at the bottom of the groove 124. , Provided in a row. When the display board 110 is mounted, the end face of the R component display board 110R faces the red LED 126R, the end face of the G component display board 110G faces the green LED 126G, and the blue LED 126B. Is configured so that the end faces of the display panel 110B for the B component face each other. Therefore, if the red LED 126R is turned on, red light is incident on the inside of the R component display board 110R, and the image printed with the transparent ink on the surface of the display board 110R is made red. Similarly, if the green LED 126G is turned on, the G image printed on the G component display board 110G is displayed in green, and if the blue LED 126B is turned on, the B image printed on the B component display board 110B is displayed. The image is displayed in blue. As a result, the R image, the G image, and the B image are combined and a color image is displayed on the transparent display board 110.

Here, since the color of the color image is determined by the ratio of the amounts of light of red light, green light, and blue light, in order to display a color image of an appropriate color, R printed on the R component display board 110R. It is important to shine the image, the G image printed on the G component display board 110G, and the B image printed on the B component display board 110B with appropriate brightness. In the image display apparatus 100 according to the third embodiment, as described above with reference to FIG. 11, the ink layer 114 made of transparent ink is formed on the surfaces of the

display plates

110R, 110G, and 110B for each component in consideration of light attenuation. Can be formed in an appropriate area. As a result, it is possible to display an image of each component of RGB with appropriate brightness and display a color image with appropriate colors. Hereinafter, a method for printing an image using transparent ink so that the ink layer 114 of each component of RGB has an appropriate area will be described.

C-2. How to print an image:
FIG. 14 is an explanatory diagram showing how the area of the ink layer 114 is determined for each of the RGB components in order to appropriately print an image on the surface of the

display plate

110R, 110G, 110B for each of the RGB components. When displaying a color image, first, image data of the color image to be displayed is acquired. The color image data is usually expressed by R component luminance data, G component luminance data, and B component luminance data. Therefore, the acquired color image data is separated into luminance data for these RGB components.

Next, the area SR for the R component is calculated based on the luminance data of the R component. Here, as described above with reference to FIG. 11, the area SR is a value that is meaningful for the relative size between pixels. The area SR can be calculated in the same manner by simply replacing the “target luminance” portion with the luminance data of the R component in the numerical table shown in FIG. Similarly, for other components, the area SG for the G component is calculated from the luminance data for the G component, and the area SB for the B component is calculated from the luminance data for the B component. As a result, the R component area SR, the G component area SG, and the B component area SB are obtained for all the pixels constituting the color image. Therefore, the largest area Smax is extracted from all the areas SR, SG, and SB including all the pixels. The R component area SR, the G component area SG, and the B component area SB are set so that the extracted maximum area Smax has a certain gradation value (typically, gradation value 255). By converting, the R component correction area, the G component correction area, and the B component correction area are calculated.

The operation of extracting the maximum area Smax and converting the area SR of the R component, the area SG of the G component, and the area SB of the B component into a corrected area for each component is described above with reference to FIG. The operation is almost the same. That is, in FIG. 11B, when the target luminance is given for each pixel constituting the image, the area S is calculated based on the target luminance of each pixel, and the largest value among all the areas S is calculated. Is converted into a corrected area by rereading the area S so that the gradation value becomes 255. On the other hand, when displaying a color image, since luminance data of R component, G component, and B component is given for each pixel, areas SR, SG, and SB are calculated for each component. That is, three types of areas SR, SG, and SB are calculated for one pixel. Then, the area Smax that is the largest value is extracted from all the areas SR, SG, and SB obtained for each of the three pixels constituting the image, and the area Smax has a gradation value of 255 (or a predetermined value). The areas SR, SG, and SB are converted into corrected areas for the respective components so as to be (gradation value).

Next, the areas of the ink layers 114R, 114G, and 114B formed in each pixel are determined based on the correction area of each component obtained for each pixel in this way. When determining the areas of the ink layers 114R, 114G, and 114B in the pixel based on the corrected area, the method described above with reference to FIG. 7 may be applied. Finally, an R component ink layer 114R is formed on the R component display board 110R, and a G component ink layer 114G is formed on the G component display board 110G. A B component ink layer 114B is formed on the display panel 110B.

As described above, the

display plates

110R, 110G, and 110B for each component are formed of a transparent material, and the ink layers 114R, 114G, and 114B of each component are also formed of a transparent ink. For this reason, in a state where the red LED 126R, the green LED 126G, and the blue LED 126B are not lit, it is difficult to notice that an image with transparent ink is printed. Accordingly, the red LED 126R is turned on to cause the ink layer 114R of the display board 110R to glow red, the green LED 126G is turned on to cause the ink layer 114G of the display board 110G to glow green, and the blue LED 126B is turned on to turn on the ink layer 114B of the display board 110B. If the light is shined blue, it is possible to display an image in a very impressive manner as if a color image has floated with light from the transparent display plate 110.

Further, as illustrated in FIG. 12, small protrusions 118 are provided on the surface of the display panel for G component 110G and the surface of the display panel for B component 110B, respectively. The surfaces of 110G and display board 110B are not in contact with each other. For this reason, it is avoided that the light propagating through the inside of a certain display board 110 enters the inside of the adjacent display board 110 and shines the adjacent image. For example, when R-color light propagating through the R-component display board 110R enters the adjacent G-component display board 110G, the G image that should originally be emitted in the G color is emitted in the R color. As a result, the color image cannot be displayed in the original color. The same applies to light of G color and light of B color. In this respect, in the image display device 100 of the third embodiment, since the gaps are secured among the display plate 110R, the display plate 110G, and the display plate 110B by the small protrusions 118, such a problem does not occur. . As a result, it is possible to display a color image appropriately. FIG. 15 illustrates a state in which a full-color color image is displayed on the image display device 100 of the third embodiment.

In addition, in order to display an appropriate color, it is necessary to mix light of R color, light of G color, and light of B color at an appropriate ratio, so that a color image of an appropriate color is displayed. In order to do this, it is necessary that the intensity of light of each color of RGB is an appropriate ratio in each pixel. This means that the following two things are important for properly displaying a color image. First, if the image becomes darker from the upstream side to the downstream side along the light traveling direction, the ratio of each component of RGB is destroyed, so a color image is displayed with an appropriate color. It is virtually impossible to do. Second, even if the image can be displayed so that it does not become dark even if it is downstream in each component, if the balance of brightness is lost among the components, a color image is displayed with an appropriate color. I can't do it. That is, in order to display a color image appropriately, it is not necessary to simply display the RGB three-color images in a superimposed manner, and it is necessary to satisfy the two conditions described above. From this point of view, displaying a color image by the above-described method is an extremely rational and excellent method. This point will be described below.

First, as described above with reference to FIG. 14, the areas SR, SG, and SB are calculated based on the luminance data for all of the R component, G component, and B component. The areas SR, SG, and SB are meaningful values for the relative sizes between the pixels, and light loss caused by illuminating the pixels on the upstream side or light when propagating from the upstream side. In consideration of the influence of attenuation of the pixel, it is a value that indicates what ratio should be used to illuminate each pixel with brightness according to the luminance data. Then, after converting the areas SR, SG, and SB obtained in this way into corrected areas of the ink layers 114R, 114G, and 114B formed for each pixel, the R component is used by the method described above with reference to FIG. Ink image, G component ink image, and B component ink image are printed. For this reason, the first condition described above, that is, the condition that the image does not become darker from the upstream side to the downstream side in the light traveling direction is the same for any RGB component image. Can be satisfied.

Further, both the operation for calculating the areas SR, SG, and SB from the luminance data of each component and the operation for converting the areas SR, SG, and SB into the corrected areas of the respective components form an image with ink according to the obtained corrected areas. The operation is basically performed for each component. However, only when determining the ratio of replacing the areas SR, SG, and SB of each component with the corrected area, the RGB components are handled as a whole and replaced. The ratio is determined. That is, as shown in FIG. 14, the area Smax, which is the largest value, is extracted from the total areas SR, SG, and SB obtained for each of the three components for all pixels constituting the image, and the area Smax is the floor. The areas SR, SG, and SB are converted into corrected areas for each component so that the tone value is 255 (or a predetermined gradation value). For this reason, the second condition described above, that is, the condition that the balance of the brightness of the R image, the G image, and the B image is maintained at the balance of the RGB components indicated in the color image data can be satisfied. it can.

Eventually, in the image display device 100 of the third embodiment, the first condition and the second condition described above can be satisfied at the same time by displaying a color image by the method shown in FIG. As a result, as illustrated in FIG. 15, for example, a star decoration attached to the tip of a Christmas tree is displayed in gold, a leaf portion is displayed in deep green, and a trunk portion is brown. It is possible to display a color image in a very impressive manner.

As described in the first embodiment, also in the image display apparatus 100 of the third embodiment, if the concentration of the light scattering fine particles 114p is increased, the R image, the G image, and the B image can be clearly emitted. As a result, a color image can be clearly displayed. However, on the other hand, when the concentration of the light scattering fine particles 114p increases, the ink layer 114 gradually becomes cloudy, so that even when the image is not illuminated, it is easy to notice that the image is printed on the surface of the display plate 110. . Therefore, also in the image display device 100 of the third embodiment, the density of the light scattering fine particles 114p included in the transparent ink is the most impressive in consideration of the viewpoint of clearly displaying the color image and the viewpoint of suppressing the cloudiness. The density is set so that a color image can be displayed. However, in the third embodiment, when the image is not illuminated, the R image, the G image, and the B image due to the cloudy ink layer 114 appear to overlap, so that it is understood that something is printed as it is, It is difficult to understand what is printed. Therefore, when displaying a plurality of images in a superimposed manner, such as when displaying a color image using an R image, a G image, and a B image, the light scattering particles are smaller than when displaying without overlapping images. Even if the density of 114p is set in a direction in which white turbidity further advances, an impressive display can be performed.

C-3. Modification of the third embodiment:
In the image display device 100 according to the third embodiment described above, the

display plates

110R, 110G, and 110B for each component of RGB are laminated to form one display plate 110, and the display plate 110R for each component. , 110G, 110B, a small protrusion 118 provided on the surface provides a gap corresponding to the height of the protrusion 118. If foreign matter such as dust or moisture enters the gap, it may be difficult to display an image clearly. Moreover, in order to make the display board 110 thin and to make the positional deviation of the image of each component inconspicuous when the display board 110 is viewed from an oblique direction, the gap is usually set very narrowly, Once a foreign object enters, it is difficult to remove it. Therefore, in order to avoid the occurrence of such a problem, the display panel 110 may be configured as follows.

FIG. 16 is an explanatory view showing a display board 110 according to a modification of the third embodiment in which the side face on which the

display boards

110R, 110G, and 110B of RGB components are stacked is covered with a cover member 110S. Thus, if the side surface on which the plurality of display panels 110 are stacked is covered with the cover member 110S, it is possible to avoid the entry of foreign substances into the narrow gaps between the display panels 110.

In addition, it is desirable that the cover member 110S has a surface on the side facing the display plate 110 so as to reflect light. As described above with reference to FIG. 2, the light incident from the end face of the display panel 110 travels through the inside while repeating the complete reflection on the surface of the display board 110, and eventually reaches the outside from the opposite or side end face. To be emitted. Thus, the light radiated from the end face does not shine the image formed on the surface of the display panel 110, and is, in other words, light that is wasted. Therefore, if the surface of the cover member 110S is a surface that reflects light, such as a mirror, for example, the light that is thrown away from the end face of the display board 110 is returned to the inside of the display board 110 again, and an image is displayed. Can shine. As a result, it is possible to brighten the image on the display panel 110 without making the light incident from the end face unnecessarily strong.

Further, in the third embodiment described above, it has been described that the small projections 118 are provided on the surface of the display plate 110 to avoid contact between the surfaces of the display plates 110. However, the display panel 110 may be configured by stacking the thin frame members 110W between the

RGB display panels

110R, 110G, and 110B.

FIG. 17 is an explanatory view showing a display board 110 of another modification of the third embodiment in which the frame member 110W is sandwiched between the

display boards

110R, 110G, and 110B of each component. As illustrated, the frame member 110 </ b> W has a frame shape by cutting out a portion where an image is displayed. For this reason, it is possible to avoid contact between the surfaces of the display boards 110 by laminating the

display boards

110R, 110G, and 110B of RGB components with such a frame member 110W interposed therebetween. In addition, since the gap between the display panel 110 and the display panel 110 is blocked by the frame member 110W on the side surface of the display panel 110 formed by stacking, there is no possibility that foreign matters such as dust are mixed. .

In addition, if the frame member 110W is formed of a transparent material, the entire display board 110 in which the

display boards

110R, 110G, and 110B of RGB components are laminated can be kept transparent. However, in this case, the light (light of other colors) of the adjacent display board 110 enters through the portion of the frame member 110W. Therefore, in order to suppress this influence, it is desirable that the frame member 110W has a shape as thin as possible (the width of the contact portion with the display plate 110 is narrow). On the other hand, if the frame member 110W is made of an opaque material, the outer peripheral portion of the display board 110 cannot be transparent, but the light of the adjacent display board 110 enters through the frame member 110W. Can be avoided.

D. Fourth embodiment:
In each of the above-described embodiments, an image can be displayed in a very impressive manner in which an image is lifted and displayed together with light from the transparent display plate 110. However, once the image is displayed, it is difficult to change the display contents, and therefore it is not easy to keep the eye on the eyes forever. In view of this, it is possible to add another image to be displayed or display the added image while the image is displayed. Hereinafter, the image display apparatus 100 according to the fourth embodiment will be described.

FIG. 18 is an explanatory diagram showing a rough structure of the display board 110 used in the image display device 100 of the fourth embodiment. As shown in the drawing, the display board 110 of the fourth embodiment is an additional display board on the display board 110 of the third embodiment (the display board 110 in which each of

RGB components

110R, 110G, and 110B is laminated). 110E is laminated. In addition, a gap is secured by the protrusion 118 between the additional display panel 110E and the R component display panel 110R. An image to be additionally displayed (additional image) is formed on the surface of the additional display board 110E with transparent ink. In the example shown in FIG. 18, images of a Christmas tree are formed on the

display plates

110R, 110G, and 110B for each of RGB components, as in the third embodiment. An additional image 112E representing the characters “Merry! Xmas!” Is formed on the surface of the additional display board 110E. Since this additional image 112E is also formed on the surface of the transparent display board 110 using transparent ink, it is difficult to notice that the additional image 112E is formed at a glance.

FIG. 19 is an explanatory view showing a state where the display board 110 of the fourth embodiment is mounted in the groove 124 of the base portion 120. As described above with reference to FIG. 18, the display board 110 of the fourth embodiment is composed of four display boards. Corresponding to this, the base portion 120 of the fourth embodiment is provided with four rows of LEDs at the bottom of the groove 124 as shown in FIG. Among these, a row of red LEDs 126R is provided at a position facing the end face of the display panel 110R for the R component. Similarly, a row of green LEDs 126G is provided at a position facing the end face of the G component display board 110G, and a row of blue LEDs 126B is provided at a position facing the end face of the B component display board 110B. ing. A row of white LEDs 126E that emit white light is provided at a position facing the end face of the additional display board 110E. In addition, about LED of the position facing the additional display board 110E, you may use LED which emits not only white light but what kind of light.

As described above, if the red LED 126R, the green LED 126G, and the blue LED 126B are turned on in a state where the display plate 110 of the fourth embodiment is mounted on the base portion 120, it is exactly the same as the image display device 100 of the third embodiment described above. Color images can be displayed. In this state, if the white LED 126E is turned on, an additional image 112E (for example, an image of “Merry! Xmas!” As illustrated in FIG. 19) formed on the additional display board 110E is lit and displayed. Or turn off the display.

FIG. 20 conceptually shows how the additional image 112E of the characters “Merry! Xmas!” Formed on the additional display board 110E is displayed or deleted while the Christmas tree image 112 is displayed. FIG. FIG. 20A shows a state where the additional image 112E is not displayed. Since the additional image 112E is formed of a transparent ink on the transparent display board 110E, unless the image of the additional image 112E is illuminated, the display board 110E is provided at first glance, or the display board It is difficult to notice that the additional image 112E is formed on 110E. When the white LED 126E is turned on from this state to light up the additional image 112E (see FIG. 20B), the additional image 112E (the image of “Merry! Xmas!” In FIG. 20) emerges from anywhere. Can give an impression as if Then, when the white LED 126E is turned off again, the additional image 112E can be erased as if it was erased. In this way, the image display apparatus 100 of the second embodiment can not only display an image (here, an image of a Christmas tree) but also display the additional image 112E in a floating manner or erase it. Therefore, it is possible to display an image in a manner that is very easy to catch the eye.

In the above description, it is assumed that the additional display board 110E on which the additional image 112E is formed is one sheet. However, a plurality of display panels 110 can be stacked as additional display panels. FIG. 21 is an explanatory view illustrating the image display device 100 of the fourth embodiment in which a plurality of display plates 110 are stacked as an additional display plate 110E. In the image display device 100 according to the fourth embodiment illustrated in FIG. 21, an image of the characters “Merry! Xmas!” Is formed of transparent ink as an additional image 112E on one of the additional display plates 110E. On the other additional display board 110E, an image showing snow as an additional image 112F is formed with transparent ink. Then, a white LED 126E and a white LED 126F (not shown) are provided facing the end faces of these additional display boards 110E, and when the white LED 126E is turned on, as shown in FIG. 21B, “Merry! Xmas! "Can be displayed superimposed on the Christmas tree, and if the white LED 126F is turned on, an image as if snow is falling on the Christmas tree is displayed as shown in FIG. Can do. Further, when the white LED 126E and the white LED 126F are turned on, as shown in FIG. 21 (d), an image of the letter “Merry! Xmas!” Is displayed over the image such as snowing on the Christmas tree. Is possible.

In the image display device 100 of the fourth embodiment described above, the white LED 126E (or the white LED 126F) is turned on or off to display the additional image 112E (or the additional image 112F) or to turn off the display. Can be performed manually by pressing an operation button 122 provided on the base 120. Of course, a timer may be built in the base unit 120, and the white LED 126E (white LED 126F) may be turned on or off at a predetermined timing or randomly according to a program stored in advance.

Further, in the above-described fourth embodiment, it has been described that the additional display board 110E on which the additional image 112E is formed is laminated on the display board 110 of the third embodiment capable of displaying a color image. However, as described in the first embodiment or the second embodiment, the display plate 110E may be stacked on the display plate 110 capable of displaying a monochrome image.

E. Fifth embodiment:
In each of the above-described embodiments, it has been described that the base unit 120 simply allows light to enter the display panel 110 to which the base unit 120 is attached to shine an image. However, the information stored in the display board 110 may be read out, and light may be incident in a manner corresponding to the information to make the image glow. Hereinafter, the image display apparatus 100 according to the fifth embodiment will be described.

FIG. 22 is an explanatory diagram showing the structure of the base unit 120 in the image display device 100 of the fifth embodiment. FIG. 22 also shows a part of the display board 110 attached to the base portion 120. Similar to the base portion 120 of the various embodiments described above, also in the fifth embodiment, the upper surface of the base portion 120 is provided with a groove 124 on which the display plate 110 is mounted, and a plurality of grooves are provided at the bottom of the groove. LEDs 126 are provided in a row. FIG. 22 shows a state in which the LED substrate 127 on which the plurality of LEDs 126 are mounted is provided at the bottom of the groove 124.

Also, a control unit 128 that controls the light emission operation of the LED 126 is provided inside the base unit 120, and this control unit 128 is connected to a data reading unit 132 provided on the side wall of the groove. Further, as shown in FIG. 22, in the fifth embodiment, a tag 130 is attached to a predetermined position on the surface of the display board 110, and the data reading unit 132 of the base unit 120 uses the display board 110 as a base part. It is provided at a position so as to face the tag 130 of the display board 110 when mounted in the 120 groove 124. As will be described in detail later, the tag 130 of the display board 110 stores predetermined data (specific information) corresponding to an image printed on the surface of the display board 110. The specific information stored in 130 can be read using the data reading unit 132.

FIG. 23 is a block diagram conceptually showing the function of the base unit 120 used in the image display device 100 of the fifth embodiment. The control unit 128 of the base unit 120 includes an LED driver 128d that is connected to the LED board 127 and drives each LED 126, a memory 128m that stores a plurality of types of drive patterns that drive each LED 126, and the like. In the illustrated example, six types of drive patterns of pattern A1, pattern A2, pattern B1, pattern B2, pattern C, and pattern D are stored. In addition, when the display board 110 is mounted on the base section 120, the data reading section 132 of the base section 120 reads data from the tag 130 attached to the surface of the display board 110 and inputs the data to the control section 128.

FIG. 24 is an explanatory diagram showing the structure of the tag 130 attached to the surface of the display board 110. As shown in the figure, the tag 130 has a two-layer structure in which a tag sheet 130a formed by embedding an IC chip or an antenna in a resin sheet and a resin-made reflective sheet 130b vapor-deposited on aluminum are bonded together by an adhesive layer. It has a structure. Such a tag 130 is attached to a predetermined position of the display board 110 (a position surrounded by a thin broken-line rectangle in the drawing) via an adhesive layer. When the display board 110 is attached to the base part 120, the tag 130 attached to the display board 110 and the data reading part 132 provided on the base part 120 are in a position facing each other. As a result, the data reading unit 132 of the base unit 120 can read the data stored in the IC chip of the tag 130 in a non-contact manner via the antenna.

Here, in the image display apparatus 100 of the fifth embodiment, the tag 130 having a two-layer structure covered with the reflection sheet 130b from the top of the tag sheet 130a is used for the following reason. As described above with reference to FIG. 2, the light incident from the LED 126 propagates inside the display panel 110 while being completely reflected by the surface. Here, since the tag 130 is affixed with an adhesive layer, depending on the refractive index of the adhesive layer, the above-described complete reflection condition is difficult to be satisfied. Further, the refractive index of the resin sheet constituting the tag sheet is also different from the refractive index of the display plate 110, and the condition of complete reflection is difficult to be satisfied depending on the refractive index of the resin sheet. In addition, since an IC chip, an antenna, or the like is embedded in the resin sheet, light that collides with the IC chip, the antenna, or the like is scattered around. For this reason, the light incident from the end face of the display panel 110 may be attenuated at the location where the tag 130 is attached, and the downstream image may become darker. In consideration of this point, the image display apparatus 100 according to the fifth embodiment employs a tag 130 having a two-layer structure in which a tag sheet 130a is covered with a reflection sheet 130b. By doing this, even if the condition of complete reflection is lost at the place where the tag 130 is attached, all the light that penetrates the tag sheet 130a and exits from the surface is reflected by the

reflective sheet

130b, 110 can be returned. As a result, it is possible to prevent light from being attenuated at the position of the tag 130.

Here, the tag 130 is described as a tag in which an IC chip and an antenna are formed in a seal shape and configured to be able to read data stored in the IC chip in a non-contact manner. The embodiment of the present invention is not limited to such an embodiment, and tags of various embodiments can be used. For example, a tag configured such that an IC chip and an electrode are formed in a seal shape and data in the IC chip can be read by contacting terminals can be used. Alternatively, instead of storing data by an electromagnetic method, it is possible to use a tag that stores data by a bar code or a combination of small irregularities.

FIG. 25 is an explanatory diagram illustrating drive patterns stored in the memory 128m of the control unit 128. Each drive pattern is given a pattern number, and the drive pattern can be specified by the pattern number. For example, in the driving pattern (pattern A1) specified by the pattern number A1, the light emission intensity of the LED 126 increases as time passes, and when the light intensity reaches a certain light intensity, the light intensity decreases slowly after being kept for a while. Then, the pattern is set to repeat turning off at the end. In addition, the drive pattern (pattern A2) specified by the pattern number A2 is set to a pattern whose light intensity is generally weaker than that of the pattern A1. Alternatively, the drive pattern (pattern B1) specified by the pattern number B1 is set to a pattern in which the light intensity slowly increases with time and turns off suddenly when reaching a certain light intensity. . Furthermore, the light intensity of all the LEDs 126 is not changed at the same time, but for example, by turning on the LEDs little by little from the LED 126 on one end side and turning off the light after a predetermined time has passed, It is also possible to set a pattern in which the light band moves toward the side. Thus, a plurality of types of drive patterns are stored in the memory 128m of the control unit 128, and these drive patterns can be specified by pattern numbers.

As described above with reference to FIG. 23, a pattern number for specifying a drive pattern is stored in the IC chip of the tag 130. When the display board 110 is attached to the base unit 120, the pattern number stored in the IC chip of the tag 130 is read by the data reading unit 132 of the base unit 120 and input to the control unit 128. Then, a drive pattern corresponding to the pattern number is specified from the drive patterns stored in the memory 128m in the control unit 128, and the LED driver 128d drives the LED board 126 according to the specified drive pattern. Light is emitted from each LED 126 according to the drive pattern.

As a result, in the image display apparatus 100 of the fifth embodiment, the LED 126 is driven with a drive pattern corresponding to the pattern number in the tag 130 attached to the display board 110, and the image on the display board 110 can be illuminated. Accordingly, by storing an appropriate pattern number in the tag 130 according to an image printed on the surface of the display board 110 with transparent ink, the display board 110 can be appropriately attached only to the base unit 120. It is possible to display the image on the display board 110 by causing the LED 126 to shine with a pattern. If the display board 110 on which a different image is printed is replaced, a new pattern number is read from the tag 130 of the newly attached display board 110, and a new drive pattern corresponding to the read pattern number. Accordingly, the LED 126 is driven. As described above, in the image display device 100 of the fifth embodiment, the pattern of the LED 126 emitting light is switched simply by replacing the display plate 110, and the image is appropriately displayed by being printed with the transparent ink on the surface of the display plate 110. It becomes possible.

In the above-described image display device 100, a drive pattern corresponding to the pattern number read from the tag 130 may not be stored in the memory 128m of the control unit 128. Therefore, a standard drive pattern is determined in advance among a plurality of drive patterns stored in the memory 128m, and a drive pattern corresponding to the pattern number read from the tag 130 is not stored in the memory 128m. In this case, the LED 126 may be caused to emit light using a standard driving pattern.

Alternatively, the memory 128m may be configured by a memory capable of rewriting stored data, and a new drive pattern may be stored in the memory 128m using the data writing unit 129 provided in the base unit 120. The new drive pattern may be created, for example, using the operation switch 122 provided on the front surface of the base unit 120, or a new drive pattern may be acquired from an external computer or a mobile phone. Furthermore, as the tag 130, a tag into which data can be written from the outside may be adopted so that the pattern number stored in the tag 130 can be changed. At this time, as indicated by a broken line arrow in FIG. 23, the pattern number stored in the IC chip of the tag 130 may be rewritten from the data writing unit 129 via the data reading unit 132. . Since the data reading unit 132 is configured to be able to access the IC chip in the tag 130 and read out the stored data, the data reading unit 132 also passes through the data reading unit 132 when rewriting the data in the tag 130. The data in the tag 130 can be easily rewritten without adding any special equipment.

In the fifth embodiment described above, the tag 130 of the display board 110 has been described as being stored with only one pattern number. However, a plurality of pattern numbers may be stored in the tag 130, and the LED 126 may be caused to emit light using a plurality of drive patterns corresponding to the pattern numbers in order. Or you may make it switch the pattern which actually drives LED126 among these several drive patterns using the operation switch 122 of the base part 120. FIG.

In the fifth embodiment described above, a plurality of driving patterns for actually driving the LED 126 are stored on the base 120 side, and the tag 130 on the display board 110 side has a plurality of driving patterns. In the above description, only the pattern number for specifying one pattern is stored. However, the drive pattern itself for driving the LED 126 may be stored in the tag 130 of the display panel 110.

FIG. 26 shows a rough configuration of the image display apparatus 100 according to such a modification. As shown in FIG. 26A, in the image display device 100 according to the modified example, a drive pattern (in the illustrated example, the pattern A1) is stored in the tag 130 attached to the display board 110. . When such a display panel 110 is mounted on the base unit 120, a drive pattern is read from the tag 130, supplied to the base unit 120 via the data reading unit 132, and an LED driver according to the supplied drive pattern. 128d drives each LED 126. Even with such a configuration, by storing an appropriate driving pattern in the tag 130 according to the image printed on the surface of the display board 110, the LED 126 emits light with an appropriate pattern according to the image, An image can be displayed appropriately. Of course, if the display board 110 is replaced, a new drive pattern corresponding to the image of the replaced display board 110 is read out. Therefore, the light emission pattern of the LED 126 can be appropriately changed according to the image simply by replacing the display board 110. It becomes possible to change to.

In addition, in the image display apparatus 100 of such a modification, it is not necessary to store a plurality of drive patterns in the control unit 128 in the base unit 120, and thus the configuration of the base unit 120 may be simplified. it can. On the other hand, in the image display device 100 of the fifth embodiment described above, only the pattern number needs to be stored in the tag 130 of the display board 110. Therefore, it is possible to use a simple tag 130 such as a barcode.

Alternatively, the tag 130 may be configured by a memory that can rewrite data from the outside, such as an IC chip, and the drive pattern stored in the tag 130 may be rewritten from the outside. At this time, as shown in FIG. 26B, a data writing unit 129 is provided in the base unit 120, and the IC chip of the tag 130 is inserted through the data reading unit 132 that reads the driving pattern from the tag 130. The stored pattern number may be rewritten. A broken arrow shown in FIG. 26B represents a state in which the drive pattern in the tag 130 is rewritten from the data writing unit 129 through the data reading unit 132. Since the data reading unit 132 is configured to be able to access the IC chip in the tag 130 and read out the stored data, the data reading unit 132 also passes through the data reading unit 132 when rewriting the data in the tag 130. The data in the tag 130 can be easily rewritten.

F. Sixth embodiment:
In the various embodiments described above, it has been described that an image is directly formed on the surface of the display plate 110 using transparent ink. However, instead of directly forming an image on the surface of the display board 110, an image made of transparent ink is formed on the surface of the transparent sheet, and the transparent sheet is pasted to form an image made of transparent ink on the surface of the display board 110. It may be formed. Even in this case, it is possible to shine and display the image formed on the surface of the transparent sheet by making light incident from the end face of the display plate 110. Then, if the transparent sheet is pasted on the display board 110 in a replaceable manner, the displayed image can be changed by pasting the transparent sheet.

FIG. 27 is an explanatory diagram showing the principle that allows the image of the transparent sheet 111 attached to the surface of the display plate 110 to be displayed by shining light from the end face of the display plate 110. As described above with reference to FIG. 2, the light incident from the end face of the display panel 110 travels inside the display panel 110 while being completely reflected on the surface of the display panel 110. Here, the refractive index of the transparent sheet 111 is not significantly different from the refractive index of the display panel 110. For this reason, when the light traveling inside the display plate 110 reaches a position where the transparent sheet 111 is attached to the surface, the light travels directly into the transparent sheet 111 without being reflected by the surface of the display plate 110. To do. The surface of the transparent sheet 111 (the surface in contact with the air) is substantially parallel to the surface of the display panel 110 to which the transparent sheet 111 is attached. Then, it returns to the inside of the display board 110 again. That is, since the refractive index of the display plate 110 and the transparent sheet 111 are not significantly different, there is no significant difference between the transparent sheet 111 and the display plate 110 for the light traveling inside the display plate 110. For this reason, the inside of the display plate 110 or the transparent sheet 111 advances while being completely reflected repeatedly.

When such light reaches the ink layer 114, it enters the ink layer 114, collides with the light scattering fine particles 114p in the ink layer 114, and is scattered around. As a result, even when the ink layer 114 is formed on the surface of the transparent sheet 111, the light is displayed by being incident from the end face of the display plate 110, similarly to the case where it is formed on the surface of the display plate 110. It becomes possible to do. In the image display device 100 of the sixth embodiment, a transparent sheet 111 having a thickness of about 100 microns to 1 millimeter is used.

Further, an adhesive layer made of a resin material having substantially the same refractive index as that of the transparent sheet or the display plate 110 is provided on one surface of the transparent sheet 111, and the display can be performed in a manner that can be replaced by the adhesive layer. Affixed to the plate 110. For this reason, the transparent sheet 111 can be easily replaced. In addition, since the image of the transparent sheet 111 is formed of transparent ink, the transparent sheet 111 with a different image can be easily created. Therefore, in the image display device 100 according to the sixth embodiment, it is possible to easily change the displayed image by replacing the transparent sheet 111. FIG. 28 shows how the transparent sheet 111 on which the image 112 made of transparent ink is formed is pasted.

Note that the adhesive layer provided on the transparent sheet 111 is preferably formed of a resin material having fluidity (for example, a gel material). If there is an air gap between the attached transparent sheet 111 and the display plate 110, light is reflected on the surface of the display plate 110 at that portion. For this reason, light does not reach the transparent sheet 111, and the ink layer 114 in that portion cannot be illuminated. However, if the adhesive layer of the transparent sheet 111 is formed of a resin material having fluidity, even if fine irregularities exist on the surface of the display plate 110, the irregularities are filled with the adhesive layer, and no gap is formed. Thus, the transparent sheet can be brought into close contact with the surface of the display board. In addition, even when dust in the air is caught when sticking the transparent sheet, if the dust is small, it will be embedded in the adhesive layer, so the transparent sheet can be brought into close contact with the surface of the display board. Become.

Further, as is clear from the above description, the thickness of the adhesive layer of the transparent sheet 111 is deformed with respect to the irregularities on the surface of the display panel 110, so that dust can be embedded even when dust in the air is sandwiched. It is desirable to have a thickness of several microns to several tens of microns so that it can be achieved. In addition, the adhesive layer does not necessarily require strong adhesive force, but it is desirable that the adhesive layer has fluidity that can be deformed and adhered to fine irregularities. By providing such an adhesive layer on one surface of the transparent sheet 111 (preferably, the surface on which the image is not formed), the transparent sheet 111 can be easily replaced, The transparent sheet 111 can be appropriately pasted so that there is no air gap between them. As a result, it is possible to easily change the image to be displayed by pasting the transparent sheet 111.

G. Seventh embodiment:
Further, in the various embodiments described above, it has been described that the image using the transparent ink is merely formed on the display board 110 (or the transparent sheet 111). Accordingly, the portion where the ink layer 114 made of transparent ink is formed is in a state of being slightly raised from the surface of the display panel 110 (or the transparent sheet 111). However, the outermost surface of the display board 110 including the ink layer 114 may be formed smoothly by forming a clear layer made of a transparent resin that does not include light-scattering fine particles on an image using transparent ink. . Hereinafter, the image display apparatus 100 according to the seventh embodiment will be described.

FIG. 29 is an explanatory diagram showing a state in which a clear layer 116 made of a transparent resin is provided on the ink layer 114 and the outermost surface is formed smoothly. As shown in the figure, in the image display device 100 of the seventh embodiment, a clear layer 116 made of a transparent resin not containing the light scattering fine particles 114p is formed on the ink layer 114 formed on the display plate 110. The outermost surface of the display panel 110 (therefore, the boundary surface between the clear layer 116 and the air) is substantially smooth. In the image display device 100 according to the seventh embodiment, the display plate 110 having such a configuration makes it possible to make an image made of transparent ink more difficult to see, and when the image is shined, the image is more beautiful. Can be displayed. The reason why such an effect can be obtained will be described below.

FIG. 30 is an explanatory diagram showing an enlarged ink layer 114 formed of transparent ink on the surface of the display board 110. As shown in the drawing, the ink layer 114 is formed so as to rise from the surface of the display panel 110. Further, immediately after the transparent ink is applied to the display plate 110, the end surface of the ink has a curved shape due to the surface tension of the transparent ink. For this reason, the end portion of the ink layer 114 after the transparent ink is hardened also has a curved shape. Of course, as long as the ink layer 114 is not so small, there is a portion that can be regarded as a substantially flat surface near the center of the ink layer 114. Therefore, as shown in FIG. 30, the actual ink layer 114 has a shape in which a curved portion (end portion) is formed around a portion (top surface portion) that can be regarded as a substantially flat surface. .

It is considered that the image formed on the surface of the display board 110 (or the transparent sheet 111) is formed by gathering such ink layers 114. The portion of the display board 110 (or the transparent sheet 111) where the image is not formed is substantially in a mirror-like state, whereas the portion where the ink layer 114 is formed (particularly at the end portion). Since the way the light is reflected (in part), it may be noticed that an image of transparent ink is formed there.

Alternatively, when the light is incident on the inside of the display panel 110 to light the ink layer 114, the ink layer 114 may not be appropriately lighted at the end of the ink layer 114 for the following reason. First, as shown in FIG. 30, the actual ink layer 114 can be roughly divided into a top surface portion that can be regarded as a substantially flat surface, and an end portion having a curved shape. For this reason, light that has entered the ink layer 114 from the inside of the display panel 110 is roughly classified into three types. That is, the light that collides with the light scattering fine particles 114p in the ink layer 114 and scatters to the surroundings, the light that travels through the ink layer 114 without colliding with the light scattering fine particles 114p and reaches the surface of the top surface portion, and the same ink There are three types of light that travel through the layer 114 and reach the surface of the edge. In FIG. 30, light that collides with the light-scattering fine particles 114p is represented by a thick solid arrow, light that reaches the top surface is represented by a thin broken arrow, and light that reaches the end surface is represented by a thick dashed line arrow. Is represented by.

The light reaching the ink layer 114 is light that has traveled while being completely reflected on the surface of the display plate 110, and the top surface portion of the ink layer 114 can be considered to be substantially parallel to the surface of the display plate 110. Nearly perfect reflection conditions are met at the top surface. Accordingly, the top surface portion of the ink layer 114 is completely reflected as indicated by the thin broken arrow in FIG. 30, proceeds inside the ink layer 114, and returns to the display plate 110 again.

On the other hand, at the end of the ink layer 114, the surface of the ink layer 114 is greatly inclined with respect to the surface of the display plate 110, so that the condition of complete reflection is not satisfied. Therefore, a part of the light reaching the end of the ink layer 114 is reflected, and the remaining light is refracted on the surface of the end as shown by the thick dashed line arrow in FIG. After changing, go straight in the air. Unlike the light scattered around by the light scattering fine particles 114p (light indicated by a thick broken line in the figure), such light travels straight in the air in a certain direction determined by the angle refracted at the surface of the end. , It will feel dazzling when it enters the eyes of the observer. For this reason, when the image displayed on the display board 110 is observed from a certain angle, the light from the end of each ink layer 114 enters the eyes and feels dazzling. In some cases, the images appear to be glaring. It may end up.

FIG. 31 is an explanatory diagram conceptually showing a portion corresponding to the top surface portion and a portion corresponding to the end portion of the ink layers 114 having different sizes. From FIG. 31A to FIG. 31B and FIG. 31C, as the area of the ink layer 114 gradually increases, the ratio of the end portion to the entire area of the ink layer 114 increases. In general, when printing a high-quality image, it is usual to increase the resolution of the image, and the size of each ink layer 114 is reduced accordingly. As a result, the ratio of the end portion of the entire ink layer 114 to the whole becomes high, and it becomes easy to notice that an image is formed, or glare of the image is likely to occur. In particular, if a printer that prints images by ejecting fine ink droplets (a so-called inkjet printer) is used, it is possible to print an image as high in quality as a photograph, but ejecting fine ink droplets. For this reason, since the area of the ink layer 114 is also reduced, such problems are likely to occur. FIG. 32 is an explanatory diagram conceptually showing a state in which a part of an image printed with transparent ink on the surface of the display board 110 is enlarged. Small rectangles indicated by broken lines in the figure represent pixels. Among these pixels, an image is printed by generating pixels in which an ink layer 114 of transparent ink is formed with an appropriate distribution. In the image printed by forming such a small ink layer 114, the ratio of the end portions of the ink layer 114 is increased as described above with reference to FIG.

On the other hand, in the image display device 100 of the seventh embodiment, as shown in FIG. 29, by providing a transparent clear layer 116 on the ink layer 114, the outermost surface of the display board 110 (clear layer 116 and The boundary surface with air is formed almost smoothly. For this reason, it is possible to avoid the occurrence of such a problem. Hereinafter, this reason will be described.

FIG. 33 is an explanatory diagram showing the reason why it is possible to avoid the notice of the image made of the transparent ink or the feeling of the image becoming glaring by forming the clear layer 116 on the ink layer 114. is there. First, by providing the clear layer 116 from above the ink layer 114, the outermost surface of the display panel 110 (the boundary surface between the clear layer 116 and air) can be formed almost smoothly. For this reason, the portion where the image is formed with the transparent ink is also almost in the state of a mirror like the portion where the image is not elaborated, so that the image is formed due to the difference in light reflection. It can be difficult to notice.

In addition, it is possible to avoid that the image looks glaring when light is incident from the end face of the display plate 110 for the following reason. First, when the light that has entered from the end face of the display panel 110 and propagated through the inside reaches the portion where the ink layer 114 is formed, it proceeds directly into the ink layer 114. And when it collides with the light-scattering fine particles 114p dispersed in the ink layer 114, it scatters to the surroundings and makes that portion shine. In FIG. 33, light that has propagated through the inside of the display panel 110 and then is scattered around by the light scattering fine particles 114 p in the ink layer 114 is represented by dashed arrows.

On the other hand, since the refractive index of the ink layer 114 and the clear layer 116 is not so different, the light that has passed through the ink layer 114 without colliding with the light scattering fine particles 114p almost reaches the boundary surface with the clear layer 116. It passes through the boundary surface without being reflected, and reaches the boundary surface between the clear layer 116 and the air. The refractive index of the clear layer 116 and that of air are greatly different, and the upper surface of the clear layer 116 is formed smoothly, so that almost perfect reflection conditions are satisfied. As a result, the light is completely reflected on the surface of the clear layer 116 and returns to the display panel 110 again. In FIG. 33, light that has propagated through the display panel 110 and then passes through the ink layer 114 and is reflected by the upper surface of the clear layer 116 is represented by an alternate long and short dash line arrow. In this way, even if light escapes from the end of the ink layer 114, it can be completely reflected at the boundary surface between the clear layer 116 and air, so that the light does not enter the viewer's eyes, As a result, it can be avoided that the image looks glaring.

It should be noted that when forming the clear layer 116, it is desirable to use the same material as the transparent ink for forming the ink layer 114, but using a transparent ink that does not include the light scattering fine particles 114p. For example, after printing an image using a transparent ink containing the light scattering fine particles 114p, the clear layer 116 is formed by printing using a transparent ink not containing the light scattering fine particles 114p, or by applying from the top of the image by spraying or the like. What is necessary is just to form. In this way, it is possible to completely eliminate a slight light loss due to a part of light reflected at the boundary surface between the ink layer 114 and the clear layer 116 due to a difference in refractive index.

Further, when the ink layer 114 of transparent ink is formed on the surface of the display panel 110 with a certain density or more, the clear layer 116 can be substantially formed by the following method. That is, a transparent ink (hereinafter referred to as UV ink) having a property of being cured by irradiation with ultraviolet rays or the like is used as the transparent ink, and an image of the UV ink including the light scattering fine particles 114p is displayed on the surface of the display plate 110. In the case where the ink layer 114 is formed by irradiating ultraviolet rays or the like after printing, the ultraviolet ray or the like is irradiated after a certain amount of time has elapsed after printing the image with the UV ink. Also good. In this way, the UV ink before curing is combined with the adjacent UV ink by the surface tension, and as a result, the edge is reduced. Then, when the end portion is reduced to some extent, the UV ink is cured by irradiating ultraviolet rays or the like. This makes it possible to print an image with a low proportion of the edge portion of the ink layer 114. Therefore, when the image with the transparent ink is noticed due to the difference in the reflection of light, or when the image is shining, It is possible to avoid the appearance of an image.

Alternatively, in the case where an image is printed using a transparent ink of a type that is cured by volatilization of the solvent, the viscosity of the transparent ink may be slightly decreased to such an extent that it can be combined with the adjacent ink. By doing so, before the transparent ink applied to the surface of the display panel 110 is cured, the edge is reduced by combining with the adjacent transparent ink, so an image with a low ratio of the edge of the ink layer 114 is printed. be able to. As a result, it is possible to avoid the fact that an image made of transparent ink is noticed due to the difference in the reflection of light or that the image appears to be glaring when the image is lit.

H. Eighth embodiment:
Moreover, indirect illumination can be performed very efficiently by using the image display devices 100 of the above-described embodiments. Below, the image display apparatus 100 of the 8th Example used as an indirect illumination apparatus is demonstrated.

FIG. 34 is an explanatory diagram illustrating the image display device 100 of the eighth embodiment used as an indirect illumination device. In the illustrated example, a state in which an image is displayed by entering light from the end surface on the lower end side of the display plate 110 in a state where the image display device 100 is installed in the room is shown. When the image is displayed in this manner, the light reaching the upper end of the display board 110 without emitting the image is emitted toward the ceiling, so that not only the image can be displayed but also indirect illumination can be performed. It becomes possible.

For example, if you try to perform indirect lighting using a lighting fixture that can display an image using light, such as stained glass, the light utilization efficiency will be very low, and it will be sufficient unless a very strong light source is used. Usually, a sufficient amount of light cannot be secured. However, the image display apparatus 100 of the eighth embodiment as shown in FIG. 34 has an extremely high light utilization efficiency while displaying an image, and as a result, it is indirect while ensuring a sufficient amount of light even with a relatively weak light source. Illumination can be performed. Hereinafter, this reason will be described.

A lighting device capable of performing indirect illumination while displaying an image using light, such as stained glass, displays an image based on the following principle. That is, a part of the lighting device is configured by a panel or sheet formed of a translucent material, and an image is drawn on the panel or sheet. Then, by illuminating the back of the sheet or panel with a light source, an image is displayed and at the same time indirect illumination is performed. If the image is printed with colored transparent ink, etc., the colored image will be displayed shining like a stained glass, and if it is printed with an opaque material, the image will be displayed like a shadow picture. The In such a lighting device, the light use efficiency is reduced for the following reasons because the image is displayed by irradiating light from the back side of the panel (or sheet) formed of an opaque material. It is inevitable.

First, when an image is printed with an opaque material (or a material that does not easily transmit light) and the image is displayed like a shadow picture, light blocked by the image can hardly be used for illumination. In addition, even when an image is displayed using a colored transparent ink or when a colored transparent member such as a stained glass is fitted into the panel, the colored transparent ink or the colored transparent member is displayed. Much of the light is absorbed when passing through. For example, red transparent ink (or a red transparent member) has a property of absorbing a blue light component or a green light component and transmitting a red light component. For this reason, when a portion drawn with red transparent ink is illuminated with white light from the back side, the portion appears to glow red. Conversely, when an image is displayed using red transparent ink (or a red transparent member), the blue light component and the green light component are absorbed, so the amount of light that can be used for illumination is It will decrease to less than half (roughly 1/3). The situation is the same for colored transparent inks other than red (or colored transparent members), and most of the light components are absorbed by the colored transparent ink (or colored transparent members), and the amount of light that can be used for illumination. The ratio will be negligible.

Furthermore, since conventional lighting equipment that can also perform indirect illumination while displaying an image displays an image by irradiating light from the back side of the panel or sheet, the panel (or sheet) is necessarily an opaque material. It is necessary to form with. This is because if a panel or sheet is made of a transparent material such as acrylic resin or glass, the light for displaying the image will pass through the panel (or sheet) and illuminate the room, so indirect lighting It is because it does not become. When a panel or sheet is made of an opaque material, a considerable proportion of light is absorbed when passing through the panel (or sheet).

In the conventional lighting equipment that can also perform indirect illumination while displaying an image, for the various reasons described above, the light use efficiency has to be low, and it is difficult to ensure a sufficient amount of light. .

On the other hand, in the image display apparatus 100 of the eighth embodiment, the image printed on the display board 110 with the transparent ink is not illuminated from the back side, but light is emitted from the end face of the display board 110 to the inside of the display board 110. Incident. As described above with reference to FIG. 2, the incident light propagates toward the end face on the other end side while repeating complete reflection inside the display panel 110. As long as the condition of complete reflection is satisfied, light does not pass through the surface of the display plate 110 and exit to the outside. Therefore, even if the display plate 110 is formed using a transparent material such as acrylic resin. , It will not be directly lighting. In addition, the fact that the display panel 110 is formed of a transparent material and that light loss due to reflection does not occur in principle in the case of complete reflection, the light incident from the end face is greatly reduced. It is possible to efficiently lead to the end surface on the other end side.

The light emitted from the LED 126 is not incident on the end face of the display plate 110 as it is, but once it is converged by a lens or the like and then incident, light that does not satisfy the condition of complete reflection near the end face of the 110 is obtained. Can be reduced. As a result, the utilization efficiency of light emitted from the LED 126 can be further increased. Alternatively, it is needless to say that the light utilization efficiency can be improved not by converging the light from the LED 126 but also by using the light leaking outside in the vicinity of the end face of the display panel 110 as illumination light. .

Further, the principle of displaying an image by the image display apparatus 100 of the eighth embodiment is that light is scattered by the light scattering fine particles 114p dispersed in the transparent ink as described above with reference to FIG. Is. The light that collides with the light-scattering fine particles 114p scatters to the surroundings and brightens the image, so that eventually this light is also used as a kind of illumination, and almost no loss of light is caused by displaying the image. Absent. Even when light passes through the light scattering fine particles 114p and reaches the surface of the ink layer 114 without colliding with the light scattering fine particles 114p, the light is completely reflected on the surface and the ink layer 114 and the display plate 110 are reflected. In this case, no light loss occurs. In addition, as described above, as the transparent ink, a colorless ink or a slightly colored ink is used, so that the ink layer 114 of the transparent ink hardly absorbs light.

Eventually, in the image display apparatus 100 of the eighth embodiment, is almost all the light incident on the inside of the display plate 110 from the end face emitted from the end face on the other end side and used for indirect illumination? Alternatively, since it is used to shine an image of transparent ink printed on the display panel 110, light loss is hardly caused and extremely high light utilization efficiency can be realized. For this reason, even when a general light source such as an LED 126 or a fluorescent lamp is used instead of an unnecessarily powerful light source, indirect illumination can be realized while securing a sufficient amount of light.

Of course, the image displayed simultaneously with the indirect illumination can be displayed in a very impressive manner as if the image has emerged from the transparent display board 110 with light.

In the above description, the light incident from the end face is described as being emitted upward from the opposite end face. However, as a matter of course, some light may be emitted to the outside from the end surface on the side surface side. Needless to say, the light emitted from the end face on the side surface side can be used as indirect illumination light, similarly to the light emitted from the end face on the upper end side. Further, a reflection plate such as a reflection tape may be provided on the end surface on the side surface so that light that is about to be emitted to the outside from the end surface on the side surface side may be reflected and returned to the inside of the display plate 110. In this way, it is possible to emit light from the end face on the side surface side to the outside from the end face on the upper end side without causing any loss of light.

Further, instead of directly forming an image with transparent ink on the surface of the display plate 110, a transparent sheet 111 on which an image 112 with transparent ink is formed as in the sixth embodiment described above with reference to FIGS. Alternatively, it may be attached to the surface of the display board 110. In this way, for example, by changing the transparent sheet 111 depending on the season, it is possible to change the displayed image and perform indirect illumination more appropriately.

There are various modifications of the image display apparatus 100 of the eighth embodiment that performs indirect illumination. Hereinafter, each of these modified examples will be briefly described.

H-1. First modification of the eighth embodiment:
In the image display apparatus 100 of the eighth embodiment described above, light is emitted from the end surface opposite to the end surface on which light is incident on the display plate 110 toward the outside (the ceiling in the example shown in FIG. 34). In the above description, the indirect illumination is performed. However, a special member for diffusing light may be provided on the end face from which light is emitted to the outside.

FIG. 35 is an explanatory view illustrating an image display device 100 of a first modification of the eighth embodiment provided with a light diffusing unit 150 on the upper end side. FIG. 35A shows a state in which the light diffusing unit 150 is mounted on the upper end side (the side opposite to the base unit 120) of the display panel 110. FIG. The light diffusion part 150 shown in FIG. 35 has a substantially rectangular parallelepiped shape, and a rectangular recess is formed on the lower surface side. Then, the light diffusing portion 150 is mounted by fitting the concave portion to the upper end of the display plate 110. The light diffusing unit 150 is made of a transparent material such as an acrylic resin, and light scattering particles 150p are dispersed therein. The light diffusing portion 150 itself is made of a transparent material, but is slightly cloudy because the light scattering fine particles 150p are dispersed at a high density.

FIG. 35B shows a cross-sectional view of the internal state when light is incident on the display plate 110 with the light diffusing unit 150 attached. A thin broken line or a thin one-dot chain line arrow shown in the figure represents a state in which light propagates while completely reflecting inside the display panel 110. In this way, when the light propagating through the inside of the display panel 110 reaches the end face, the light enters the light diffusion portion 150 from the end face. As described above, since the light scattering fine particles 150p are dispersed at a high density in the light diffusing portion 150, the light collides with the light scattering fine particles 150p, is scattered to the surroundings, and the entire light diffusing portion 150 is lit. become. The light emitted from the light diffusing unit 150 in this way is not light that travels with directionality like light generated from the light source (in this case, the LED 126), but soft light that is scattered by the light scattering fine particles 150p. Therefore, the same effect as indirect illumination can be obtained.

Further, the mechanism for causing the light diffusing unit 150 to shine is light scattering by the light scattering fine particles 150p when viewed microscopically, and no light loss occurs. For this reason, although the obtained light is soft light, it is possible to realize indirect illumination with very high light utilization efficiency with almost no loss of light.

H-2. Second modification of the eighth embodiment:
In the above-described eighth embodiment or the first modification of the eighth embodiment, it has been described as displaying a monochromatic image. However, a color image can be displayed in the same manner as in the third embodiment described above with reference to FIGS. Also in this case, it is possible to appropriately perform indirect illumination while ensuring extremely high light use efficiency. That is, as described above, a color image is displayed by superimposing an R image, a G image, and a B image, but these images do not exhibit their respective colors due to light absorption. For example, the R image is not red by absorbing green light components and blue light components, but the incident light is red and only shines red as a result of reflecting that light. It is. The situation is exactly the same for the G image and B image, and no light is absorbed when a color image is displayed. In addition, since the light incident from the end face of the display panel 110 propagates to the ink layer 114 while repeating complete reflection, the light can be guided with almost no light loss. For this reason, it is possible to perform indirect illumination with extremely high light utilization efficiency while displaying a color image.

In the image display device 100 of the second modification described above, red light is radiated upward from the upper end of the display plate 110R (the R component display plate 110R) that displays the R image. Green light is emitted from the upper end of the display plate 110G (G component display plate 110R) for displaying an image, and blue light is emitted from the upper end of the display plate 110B (R component display plate 110R) for displaying a B image. Radiated upward. Even if red, green, and blue light are separately emitted in this way, the light is applied to almost the same part and mixed there to give almost white color, so indirect illumination can be performed as usual. It is. In addition, in the end portion of the region irradiated with light, the intensity of light of each color varies, and as a result, the color is exhibited, so that a unique lighting effect can be obtained.

However, also in the second modification that displays a color image, a member that diffuses light may be provided at the upper end of the display plate 110. If it carries out like this, light of each component of RGB can be mixed at the same time it diffuses light with this member, and it can be set as substantially white light.

FIG. 36 is an explanatory view exemplifying an image display device 100 of a second modification of the eighth embodiment provided with the light mixing and diffusing unit 160 at the upper end. FIG. 36A shows a state where the light mixing and diffusing unit 160 is mounted on the upper end side (the side opposite to the base unit 120) of the display plate 110. FIG. The light mixing and diffusing portion 160 has a substantially rectangular parallelepiped shape, similar to the light diffusing portion 150 described above, and a recess is formed on the lower surface side. Then, the concave portion is attached by fitting the concave portion to the upper end of the display plate 110. The light mixing and diffusing unit 160 is also formed of a transparent material such as an acrylic resin similarly to the light diffusing unit 150 described above, and light scattering fine particles 160p similar to the light scattering fine particles 150p are dispersed therein at a high density. Thus, the entire light mixing and diffusing unit 160 is slightly cloudy.

FIG. 36B is a cross-sectional view showing a state in which red light is emitted from the R component display plate 110R in a state where the light mixing diffusion unit 160 is mounted on the display plate 110. As shown in the figure, the light mixing and diffusing unit 160 of the first modified example is different from the light diffusing unit 150 described above in that a gap is provided between the upper end of the display panel 110 and the light mixing and diffusing unit 160. Yes. Therefore, the red light emitted from the R component display panel 110R spreads in the gap and irradiates the entire top of the light mixing and diffusing unit 160.

As shown in FIG. 36 (b), light is prevented from being transmitted from the side surface to the outside in the side surface portion of the gap provided between the upper end of the display panel 110 and the light mixing and diffusing portion 160. A shielding member 162 may be provided. By doing so, it is possible to avoid that the side surface of the light mixing and diffusing unit 160 on the R component display plate 110R side is lit red by red light from the upper end of the R component display plate 110R. Further, as the shielding member 162, a reflecting member that reflects light may be used instead of a simple shielding member. In this way, it is possible to guide all the red light emitted from the upper end of the R component display panel 110R to the top of the light mixing diffusion unit 160.

FIG. 36 (c) shows a state in which the green light emitted from the G component display plate 110G irradiates the entire top of the light mixing and diffusing unit 160. Further, FIG. 36 (d) shows a state in which the blue light from the B component display plate 110 </ b> G irradiates the entire top of the light mixing and diffusing unit 160. As shown in FIG. 36B, if a shielding member 162 is provided between the upper end of the display plate 110 and the light mixing and diffusing portion 160, the light is emitted from the G component display plate 110G or the B component display plate 110B. The emitted green light and blue light can be prevented from leaking from the side surface of the light mixing and diffusing unit 160.

In the image display device 100 according to the second modification of the eighth embodiment, the red light from the R component display plate 110R, the green light from the G component display plate 110G, and the B component display plate 110B are processed as described above. Is irradiated on the entire top of the light mixing and diffusing unit 160. As described above, since the light mixing diffusion unit 160 is formed of a transparent material such as acrylic resin, red light, green light, and blue light respectively enter the light mixing diffusion unit 160, It collides with the light scattering fine particles 160p dispersed inside the light mixing and diffusing unit 160 and is scattered around. As a result, red light, green light, and blue light are mixed in the light mixing and diffusing unit 160 and diffused to the surroundings, so that it is possible to realize indirect illumination similar to the case where white light is used. Become. In the light mixing and diffusing unit 160, since the light scattering fine particles 160p are dispersed at a high density, almost all light is scattered by the light scattering fine particles 160p while traveling in the light mixing and diffusing unit 160. The For this reason, it becomes possible to mix and diffuse all the light emitted from the R component display board 110R, the G component display board 110G, and the B component display board 110B.

Also in the image display device 100 of the second modified example provided with the light mixing and diffusing unit 160 described above, the light mixing and diffusing unit 160 merely scatters light, and no light loss occurs. . Therefore, it is possible to realize a very high light utilization efficiency while causing the color image to be displayed on the display panel 110 and the light mixing and diffusing unit 160 to perform indirect illumination with soft white light.

In the image display device 100 of the second modified example including the light mixing and diffusing unit 160 described above, the end surface shapes on the light emission side are the R component display plate 110R, the G component display plate 110G, and the B component display plate 110B. Both of them are described as being the same. However, as shown in FIGS. 36 (b) to 36 (d), the light can reach the entire top portion depending on the positional relationship between the

display panels

110R, 110G, and 110B and the top portion of the light mixing and diffusing portion 160. There are display panels that are easy to display and display panels that are difficult to allow light to reach the entire top. Therefore, the end face shape on the light emitting side may be optimized for each of the

display plates

110R, 110G, and 110B.

FIG. 37 is an explanatory view exemplifying a state in which the end face shape on the light emitting side is changed for each of the R component display board 110R, the G component display board 110G, and the B component display board 110B. In this way, if the end face shape is appropriate for each display panel, the gap between the upper end of the display panel 110 and the top of the light mixing and diffusing unit 160 is reduced, and the top is brought closer to the upper end of the display panel 110. Therefore, the light mixing and diffusing unit 160 can be made compact. Further, if the end face shape on the light emitting side is optimized for each display plate so that the light emitted from each display plate is evenly applied to the top surface of the light mixing and diffusing unit 160, each display It is also possible to mix light emitted from the end face of the plate more uniformly.

H-3. Third modification of the eighth embodiment:
In the image display device 100 according to the second modification of the eighth embodiment described above, it has been described that the intensity of each light emitted by the red LED 126R, the green LED 126G, and the blue LED 126B is fixed. However, the overall light intensity can be changed, and the ratio of the light intensity between the colors can be changed.

FIG. 38 is an explanatory view illustrating an image display device 100 of a third modified example in which the overall light intensity and the ratio of the light intensity between colors can be changed. In FIG. 38A, an operation switch 122a for changing the overall light intensity and an operation switch 122b for changing the ratio of the light intensity between colors are provided on the base portion 120. It is shown. When the operation switch 122a is rotated, the overall light intensity can be increased or decreased without changing the intensity ratio of red light, green light, and blue light. It is also possible to turn off the illumination by turning the operation switch 122a fully counterclockwise. Such a function inserts a variable resistor into a circuit that supplies power from a power source built in the base unit 120 to a red LED 126R that emits red light, a green LED 126G that emits green light, and a blue LED 126B that emits blue light. This can be easily realized. FIG. 38B conceptually shows that the entire light intensity can be changed by operating the operation switch 122a.

When the operation switch 122b shown in FIG. 38A is rotated, it is possible to change the ratio of the light intensity of red light (R light), green light (G light), and blue light (B light). is there. For example, when the operation switch 122b is set at a position where “standard” is displayed, the light intensities of red light (R light), green light (G light), and blue light (B light) are set to the same ratio. Further, when the operation switch 122b is rotated counterclockwise, the ratio of red light (R light) is decreased and the ratio of green light (G light) is slightly decreased. As a result, the color image displayed on the display board 110 can be changed to a cool color tone that is bluish as a whole, and at the same time, by mixing these lights, the light of a cool color tone that is bluish as a whole is obtained. Indirect lighting can be performed.

Conversely, when the operation switch 122b is rotated clockwise, the ratio of blue light (B light) is decreased and the ratio of green light (G light) is slightly decreased. As a result, the color image displayed on the display board 110 can be changed to a warm reddish color tone as a whole, and at the same time, by mixing these lights, an overall reddish warm color tone is obtained. Indirect illumination can be performed with light. FIG. 38C conceptually shows how the ratio of red light (R light), green light (G light), and blue light (B light) changes as the operation switch 122b is operated. Yes. Changing the ratio of red light (R light), green light (G light), and blue light (B light) in accordance with the operation of the operation switch 122b in this way is based on the power supply built in the base unit 120. This can be easily realized by inserting a dedicated control circuit between the red LED 126R, the green LED 126G, and the blue LED 126B. Then, if the ratio of the light intensity of each color is changed in this way by operating the operation switch 122b, the color of the image displayed on the display board 110 and the indirect illumination is changed from a range from a cool color tone to a warm color tone. It can be set freely.

As described above, in the image display device 100 according to the third modified example of the eighth embodiment, the brightness for displaying an image and the intensity of indirect illumination can be adjusted by operating the operation switch 122a. In addition, by operating the operation switch 122b, the displayed image and the color tone of the indirect illumination can be adjusted. As a result, it is possible to display an image with an appropriate color tone and perform indirect illumination according to the season and situation.

I. Modified example:
The following modifications can be further considered for the various image display devices 100 described above. Hereinafter, these modified examples will be briefly described.

I-1. First modification:
In the various embodiments described above, the light scattering fine particles 114p are dispersed in the ink layer 114, and the ink layer 114 is made to shine by scattering light with the light scattering fine particles 114p. However, in order to make the ink layer 114 shine, it is not always necessary to disperse the light scattering fine particles 114p, and the following method can also be adopted.

FIG. 39 is an explanatory diagram showing the reason why the ink layer 114 can be illuminated without using the light scattering fine particles 114p in the image display device 100 according to the first modification. Also in the image display device 100 of the first modified example, when the LED 126 is turned on and light is incident on the inside of the display plate 110 from the end face, the incident light is reflected on the display plate 110 according to the principle described above with reference to FIG. It progresses inside while repeating perfect reflection on the surface. In FIG. 39, a state in which light incident from the end face of the display panel 110 travels through the inside while repeating complete reflection on the surface is represented by a broken line or a one-dot chain line arrow. Then, the light traveling inside the display panel 110 eventually reaches the ink layer 114 formed on the surface with transparent ink. As described above, since the refractive index of the ink layer 114 is relatively close to the refractive index of the display plate 110, the light reaching the boundary surface between the display plate 110 and the ink layer 114 is hardly bent in the traveling direction. After passing through the boundary surface as it is and proceeding inside the ink layer 114, the boundary surface between the ink layer 114 and air (the surface of the ink layer 114) is reached.

However, the surface of the ink layer 114 is not as flat as the surface of the display panel 110, and unevenness is formed on the surface. For this reason, on the surface of the ink layer 114, a portion where the condition of complete reflection is not satisfied is generated at a constant rate and almost uniformly. From such a portion, according to the Snell's law described above, A certain ratio of light is transmitted to the outside. As a result, the ink layer 114 appears to shine.

Further, such a mechanism appears more prominently when the image 112 on the surface of the display board 110 is printed using a so-called inkjet printer. As is well known, an inkjet printer prints an image by ejecting fine ink droplets. Therefore, an image 112 printed on the surface of the display board 110 using an ink jet printer is formed by collecting fine (small area) ink layers 114 (see FIG. 32). In addition, when the area of the ink layer 114 is small, the surface of the ink layer 114 (boundary surface with air) is formed into a curved surface as illustrated in FIG. 32 by the action of the surface tension of the ink. For this reason, in the image 112 printed using the ink jet printer, the ratio of the light transmitted to the outside without satisfying the condition of complete reflection in the light reaching the ink layer 114 is increased. Even when it is not included, the image 112 can be illuminated with sufficiently practical brightness.

As described above, if the image 112 is formed using the transparent ink not including the light scattering fine particles 114p, the image 112 formed on the surface of the display panel 110 can be made more inconspicuous. . As a result, by turning on the LED 126 and causing the image 112 to shine, it is possible to display the image in a very impressive manner as if the image floated from the transparent plate. Here, an ink jet printer has been described as an example. However, if a fine (small area) ink layer 114 is formed as in an ink jet printer, the image 112 may be printed by a method other than the ink jet printer. The above-mentioned matters apply in exactly the same way.

I-2. Second modification:
In the above-described various embodiments and modifications, the visible light incident from the end face of the display plate 110 is scattered by the light scattering fine particles 114p in the ink layer 114 or transmitted through the surface of the ink layer 114. It was explained as something that shines. In this case, if red light is incident, the image is displayed in red, and if white light is incident, the image is displayed in white. The image 112 shines with the color of light incident from the end face. On the other hand, the image 112 may be formed using a transparent ink containing a fluorescent material. “Fluorescence” means that when it is irradiated with visible light, ultraviolet light, infrared light, electromagnetic waves, etc., it is temporarily excited, and is irradiated when returning from the excited state to a more stable state. This is a phenomenon in which light having a wavelength different from that of light is emitted. In addition, light emitted by the fluorescence phenomenon may be simply referred to as “fluorescence”. Different fluorescent materials can emit light of different wavelengths and shine in different colors even when irradiated with the same light. Therefore, if such a fluorescent material is used, an image can be displayed as follows.

First, a plurality of types of transparent inks containing fluorescent materials that shine in different colors are prepared. These transparent inks emit different colors of fluorescence depending on the type of fluorescent material contained. As such a transparent ink, for example, a paint containing a fluorescent material is commercially available from Shinroihi Co., Ltd. under the trade name “Leuhi Marker” or “Magic Lumino Paint”. These products are transparent under normal conditions, but have the property of emitting fluorescence when irradiated with ultraviolet light. The fluorescent color is also red paint, green paint, blue paint, etc. Various fluorescent products are commercially available. Therefore, an image 112 is formed on the surface of one display board 110 using these fluorescent colored transparent inks, and an LED 126 that generates ultraviolet light is provided facing the end face of the display board 110. deep. If the LED 126 is turned on and ultraviolet light is incident from the end face, it is possible to display the image 112 with each fluorescent color.

In the image display device 100 according to the second modified example, it is possible to print the image 112 using a transparent ink under normal light, and it is not necessary to disperse the light scattering fine particles 114p. For this reason, in a state where the LED 126 is not lit, it is possible to make the image 112 formed on the display board 110 more inconspicuous. In addition, since it is not necessary to form the surface of the ink layer 114 with unevenness or to form the image 112 with the fine (small area) ink layer 114, the surface of the display board 110 may be changed depending on how light is reflected. It is also possible to avoid the fact that the image 112 has been formed. As a result, it is possible to display the image in a very impressive manner as if the image was shining from the transparent plate.

Of course, in the image display device 100 of the second modification, the image 112 may be formed on the surface of the plurality of display plates 110. For example, as in the image display device 100 of the third embodiment described above, an image 112 is formed on the surface of a certain display board 110 using transparent ink having a red fluorescent color, and the other display board 110 has a green color. The image 112 may be formed using fluorescent transparent ink, and the image 112 may be formed on another display plate 110 using blue fluorescent transparent ink, and the images 112 may be used in a superimposed manner. In this way, since the image 112 can be formed by being shared by the plurality of display boards 110, it is possible to form a finer image 112 than when the image 112 is formed on one display board 110. Become.

While various embodiments of the present invention have been described above, the present invention is not limited thereto, and is not limited to the wording of each claim unless it departs from the scope described in each claim. Improvements based on the knowledge that a person skilled in the art normally has can also be added as appropriate to the extent that those skilled in the art can easily replace them.

An image can be displayed on a transparent display board in an extremely attractive and impressive manner. For this reason, advertising, decoration, transmission of various information, indirect lighting, etc. can be performed extremely effectively.

Claims

An image display device for displaying a predetermined image,
A display plate, which is a transparent plate-like member having the image formed on the surface thereof, using transparent ink containing fine particles that scatter light;
An image display device comprising: a light incident portion that makes light incident from an end face of the display plate toward the inside of the display plate.
The image display device according to claim 1,
A plurality of the display boards;
A plurality of light incident portions that are provided for each of the display plates and receive light from an end surface of the display plate;
The plurality of display panels are image display devices in which different images are formed of the transparent ink and are stacked in a state where a gap is secured between the surfaces of the display boards.
The image display device according to claim 2,
The plurality of display boards include a first display board, a second display board, and a third display board,
The light incident portion includes an R light incident portion that receives red light from an end surface of the first display plate, a G light incident portion that receives green light from an end surface of the second display plate, and the third light incident portion. An image display device comprising: a B light incident portion that injects blue light from an end face of the display plate.
The image display device according to claim 2,
Among the plurality of display boards, an additional image display board in which an additional image displayed in addition to an image of another display board is formed on the surface is included,
Among the plurality of light incident portions, an additional light incident portion that enters light from the end face of the additional image display plate toward the inside of the additional image display plate is included,
The additional light incident part is in a state in which light is incident on the additional image display plate while the other light incident part is incident on the inside of the display plate. An image display device, which is an incident portion configured to be switchable between a state where no image is present.
The image display device according to claim 2,
The plurality of display plates are provided with a plurality of convex portions provided at intervals on at least one of the surfaces facing each other, and the display plates are stacked in a state where a gap is secured between the surfaces by the convex portions. An image display device.
The image display device according to claim 1,
The image has a target luminance at which each part of the image scatters the light reaching the part from the inside of the display board, the target luminance to shine the part, and the display board An image display device, which is an image printed so as to have a light scattering ratio determined based on the distribution of the light scattering ratio from the end surface to the location.
The image display device according to claim 6,
The image is
In the plurality of pixels obtained by equally dividing the surface of the display panel, the ink layer is formed by the transparent ink, and
An image display device, which is an image printed with different areas of the ink layer formed in each pixel so that the light scattering ratio at each pixel position of the image becomes the desired light scattering ratio.
The image display device according to claim 7,
In determining the area of the ink layer formed in the pixel,
For the pixel on the most upstream side when viewed from the direction in which light enters, an index value proportional to the area of the ink layer formed in the pixel is determined according to the target luminance for the pixel,
For the pixel downstream of the most upstream pixel, the index value of the pixel is determined based on the target luminance for the pixel and the index value obtained for each pixel upstream of the pixel. To determine the index value for each pixel on the downstream side,
An image for determining the area of the ink layer formed in each pixel by rereading the index value of each pixel so that the largest maximum index value among the index values obtained for each pixel becomes a predetermined area Display device.
The image display device according to claim 8,
The display panel includes an R component display plate provided with an R light incident portion at an end thereof that receives red light, a G component display plate provided with an G light incident portion that receives green light at an end portion thereof, and a blue color. A B-component display panel having a B-light incident portion at the end thereof, which is incident on the end, is overlapped in three pieces, and each of the RGB component display panels has an image formed by the transparent ink. Is a printed display board,
Each of the images formed on the RGB component display boards is
Determining the index value for each of the pixels for each RGB component display board;
Extracting the maximum index value from all the index values obtained for the RGB component display board,
By rereading the index value obtained for each pixel of the RGB component display board so that the maximum index value becomes a predetermined area, the area of the ink layer formed in each pixel is determined,
An image display device which is an image printed by forming the ink layer of a determined area in each of the pixels.
The image display device according to claim 9,
The display panel includes a plurality of protrusions provided at intervals on at least one surface of the surface of the R component display panel, the surface of the G component display panel, and the surface of the B component display panel. An image display device, which is a laminated display panel in a state where a gap is formed between the R component display panel, the G component display panel, and the B component display panel.
The image display device according to claim 1,
The image is formed on the surface of the display board by sticking a transparent sheet on the surface of which the image of the transparent ink is formed in a manner that can be pasted on the surface of the display board. An image display device which is a display board.
The image display device according to claim 1,
Predetermined specific information corresponding to the image formed on the surface of the display board is stored in a readable manner, and a specific information storage unit provided on the display board;
A specific information reading unit that reads the specific information from the display board,
The image display device, wherein the light incident part is a light incident part that enters light into the display board in a mode corresponding to the specific information read from the display board.
The image display device according to claim 1,
The display board is a display board in which a clear layer made of a transparent resin not containing fine particles that scatter the light is provided on the image formed by the transparent ink so that the outermost surface is formed smoothly. Image display device.
The image display device according to claim 1,
The display panel is an image display device comprising a light emitting portion that radiates light propagating through the inside of the display plate to the other end side of the end face on which light from the light incident portion is incident.