JPH06250595A - Display device, and image forming device for forming image sheet used in display device - Google Patents

Abstract

PURPOSE:To easily form an image onto a light transmitting sheet at low cost by use of an electrophotographic image forming device, and provide a back light type display device capable of obtaining an image having a high image density and excellent gradation property even when an image sheet formed in this way is used. CONSTITUTION:A display device 200 has a casing 205 having one surface opened, and a lighting device 201 provided in the casing 205. A transparent support plate 202 is mounted on the opened surface of the casing 205. As an image sheet 203 used in the display device 200, a sheet in which a transparent sheet 203b having the same image as the image on a diffusion transmitting sheet 203a formed thereon is put on the sheet 203a is used. The images on both the sheets are formed by a full color copying machine. To the support plate 202, the image sheet 203 is pressed by an acrylate transparent cover 204 having a thickness of 2mm.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backlight type display device and an image forming apparatus for forming an image sheet for the display device.

[0002]

2. Description of the Related Art Currently, a backlight type display device is used for advertisement and the like. The backlight type display device illuminates an image on the translucent sheet by shining light from the back side of the translucent sheet on which an image is formed. FIG. 1 shows an example of such a display device.

As shown in FIG. 1, a display device 50.
Reference numeral 0 denotes a casing 505 whose one surface is open, a lighting device 501 provided inside the casing 505, and a translucent support plate 502 attached to the open surface of the casing 505.
It has and.

The supporting plate 502 is for transmitting the light emitted from the illuminating device 501 and for supporting the translucent sheet (image sheet) 503 on which an image is formed. The image sheet 503 is pressed onto the support plate 502 by the transparent cover 504.

In general, a diffuse translucent plate material such as frosted glass or a white resin plate is used for the support plate 502, or a diffuse translucent sheet is lined on the image sheet 503.
The light emitted by the lighting device 501 is uniformly diffused over the entire area of the image sheet 503.

The image displayed by such a display device has a strong effect on human vision because the image is illuminated from the inside and emerges.

Conventionally, as an image sheet used for such a display device, a sheet (a positive image sheet) on which an image is formed on a transparent sheet by a silver salt photographic method has been used. However, the production of a positive image sheet is expensive because a large printing apparatus is required.

Therefore, in recent years, instead of the positive sheet produced by the silver salt photographic method, for example, an electrophotographic copying machine on which a light-transmissive sheet is subjected to image formation has been used. By using such an electronic copying machine, an image can be formed on the translucent sheet easily and quickly, and the image sheet can be obtained at low cost.

[0009]

However, when an image sheet created by an electronic copying machine is set on the above-mentioned display device and an image is displayed, the displayed image has low density and gradation is low. It was inferior. One of the causes is an image displayed by internal lighting such as a backlight (display image), an image when light is reflected on an image on paper, or an image projected on a screen by an overhead projector (OHP). Differences in characteristics from (reflection image) can be mentioned.

Generally, when an image (toner image) formed on a copy sheet by using a toner by an electronic copying machine is viewed as a reflection image, light directed to the toner image once passes through the toner image, Looking at the copy paper behind the image and passing through the toner image again.

In addition, an image formed on a transparent sheet (OHP sheet) used for OHP by an electronic copying machine is OH
When the image is projected on the screen by P and the projected image is viewed, the light directed to the projected image once passes through the projected image, is reflected by the screen behind the projected image, and passes through the projected image again. Looking at. That is,
In the reflection image, light that has passed through the toner image or the projection image twice is recognized as an image.

On the other hand, in the display image by the above-described display device, light from the light source behind the image on the transparent sheet passes through the image on the transparent sheet and is obtained as visual information. That is, what is recognized as an image is light that has passed through the image on the transparent sheet only once.

As described above, in the display image, light passes through the toner image and the projection image less times before being recognized as an image than the image on the copy paper or the projection image by OHP. This seems to be one of the causes of the above problems.

In order to solve this problem, it is conceivable to increase the image density by increasing the amount of toner attached to the translucent sheet. In general, the toner adhesion amount and the image density are in a proportional relationship until the toner adhesion amount is a constant value.
However, when the toner adhesion amount exceeds a certain value, the image density tends to be saturated due to the proportional relationship. In particular, this tendency becomes remarkable in an electronic copying machine in which the laser generator for forming the electrostatic latent image modulates the emission intensity.

If the amount of toner adhered to the translucent sheet is too large, the load of the image on the fixing device is increased, resulting in defective fixing, image noise due to offset, back stain on the translucent sheet, and the like. The problem also arises. Therefore, the problem of image density cannot be solved only by increasing the toner adhesion amount.

Therefore, the first object of the present invention is, for example,
Even when an image is formed on a translucent sheet easily and inexpensively using an electrophotographic image forming apparatus such as an electronic copying machine and the image on the image sheet thus created is displayed, the toner adhesion amount is increased. It is an object of the present invention to provide a backlight type display device that can obtain an image having high image density and excellent gradation without causing problems that sometimes occur.

A second object of the present invention is to provide an electrophotographic apparatus which can easily produce an image sheet on which an image having a high image density and excellent gradation is displayed by a back light type display device. Method is provided.

[0018]

A display device according to the present invention comprises an image-forming sheet formed by forming an image on a light-transmitting sheet, and a diffusion light-transmitting means for transmitting and diffusing light from the back side of the image sheet. In the display device that irradiates light through the display to display, a plurality of translucent sheets on which substantially the same image is formed are stacked as the image sheet.

Further, the image forming apparatus according to the present invention is an electrophotographic image forming apparatus having a plurality of sheet feeding devices for feeding a transfer material to the main body of the image forming apparatus. It is characterized in that the apparatus is provided with a control means for feeding a translucent sheet from each of the devices and forming substantially the same image on each translucent sheet.

Further, in the electrophotographic image forming apparatus according to the present invention, a plurality of types of translucent sheets are stacked in a predetermined order as a unit sheet, and the unit sheets are sequentially stacked, and the translucent sheet is used. A sheet feeding device that feeds the property sheet to the main body of the image forming apparatus, and a control unit that forms substantially the same image on each translucent sheet of the unit sheet are provided.

[0021]

According to the display device of the present invention, for example,
The same toner image is formed on two translucent sheets by an electrophotographic image forming apparatus, and a sheet obtained by superposing these is used as an image sheet. Therefore, light that has passed through the toner image twice is recognized as an image. As a result, an image having high image density and excellent gradation can be obtained.

Further, according to the electrophotographic image forming apparatus of the present invention, since the same image can be formed on each of a plurality of translucent sheets, an image sheet used for a display device can be easily used. Can be created.

[0023]

Embodiment 1 An embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 2 is a schematic view of a display device which is an embodiment of the present invention. As shown in FIG. 2, the display device 200 includes a casing 205 whose one surface is open and a lighting device 201 provided inside the casing 205, as in the case shown in FIG. 1 above. A transparent support plate 202 is attached to the open surface of the casing 205.

Image sheet 20 set on support plate 202
3 uses a transparent sheet 203b in which the same image as the image on the diffuse translucent sheet 203a is formed at the same position on the diffuse translucent sheet 203a on which the image is formed. The diffuse translucent sheet 203a and the transparent sheet 203b have the same size, and the images on both sheets are formed by a full-color copying machine described later. The image sheet 203 is a 2 mm thick acrylic transparent cover 204.
Then, it is pressed down on the support plate 200.

In this embodiment, the diffuse translucent sheet 203a is used.
Copy paper is used for the transparent sheet 203b with a thickness of 0.3.
mm OHP sheet is used. Of course, these sheets are not limited to the copy paper and the OHP sheet, and may be a trancing paper or a white resin sheet.

The display device 200 having such a configuration
The gradation characteristics of the display image by are shown below. First,
The gradation characteristics of the reflected image will be described.

FIG. 3 shows gradation characteristics of a reflection image when an image is formed on a copy sheet by a copying machine which will be described later and light is applied to the image. Generally, in a full-color copying machine, in order to obtain color reproducibility and gradation characteristics that are true to the original,
As shown in FIG. 3, it is preferable that the relationship between the image density and the gradation level is substantially linear. Further, as shown in FIG. 3, the image density at the gradation level 255 is 1.4 to
It is desirable to obtain a value of 1.5.

FIG. 4 shows gradation characteristics of a display image by the display device 200. For comparison, FIG. 4 shows characteristics when the same image is formed on a transparent sheet and a diffuse translucent sheet, and those obtained by overlapping them are used as an image sheet (indicated by symbol A in the figure). And a characteristic (indicated by symbol B in the figure) when an image-formed transparent sheet backed by a non-image-formed diffuse translucent sheet is used as an image sheet. It is shown.

As indicated by the symbol A in FIG. 4, the gradation characteristics when a transparent sheet on which the same image is formed and a diffusion translucent sheet are overlapped are shown on the copy paper shown in FIG. Similar to the gradation characteristic as the image reflection image of No. 3, the image density at the gradation level 255 is 1.4 to
A sufficient value of 1.5 is obtained.

On the other hand, as shown by symbol B in FIG. 4, when the image-formed transparent sheet is lined with a non-image-diffusing translucent sheet, which gradation is used. Also in the level, only the image density lower than the gradation characteristic shown by the symbol A can be obtained. For example,
The image density at the gradation level 255 is about 0.9, which is lower than the image density of the gradation characteristic shown by the symbol A.

As described above, the display device 200 can obtain a display image having high image density and excellent gradation which cannot be obtained by the conventional display device shown in FIG. Moreover, the toner image obtained by using the electronic copying machine has a toner layer thickness that varies depending on each gradation. Therefore, the display image is recognized as having a different refraction or reflection state of light passing through the toner image, and an image with a depth and stereoscopic effect that cannot be obtained when a positive image sheet of the silver salt photographic method is used. Can be obtained.

Next, the diffuse translucent sheet 20 shown in FIG.
An image forming method on 3a and the transparent sheet 203b will be described. In this embodiment, an image is formed on these sheets by using an electrophotographic full-color copying machine.

FIG. 5 is a sectional view of the copying machine 1 used for producing the image sheet 203. The configuration and operation of the copying machine 1 will be described with reference to FIG.

When a print key provided on the operation panel, which will be described later, is pressed, the photosensitive drum 2 rotates in the direction indicated by arrow C in the figure, and the charging device 3 causes the photosensitive layer on the outer periphery of the photosensitive drum 2 to rotate. Are uniformly charged.

The exposure lamp 5 illuminates an original document (not shown) placed on the original table 4, and the reflected light is projected on the reading optical section 6 to produce an image signal of three colors of red, blue and green for each pixel. Read. The red, blue, and green image signals are converted into image data corresponding to four types of toner colors including yellow, magenta, cyan, and black by an image processing circuit (not shown), and then color adjustment / density adjustment・
After being subjected to processing such as magnification change, it is sent to the laser generator 7.

The laser generator 7 irradiates the charged area of the photoconductor 2 with a laser beam modulated based on the image data, and forms an electrostatic latent image according to the image data of each toner color.

The developing unit 8 includes a plurality of developing devices 8Y and 8Y containing developer containing different color toners.
M, 8C and 8B are provided, and one developing device selected by moving up and down as a whole faces the photoconductor 2 and reveals the electrostatic latent image with a developing device having toner of a corresponding color. Image.

On the other hand, the transfer material is conveyed to the transfer drum 10 from the cassette paper feeding device 9 provided at the lower portion of the copying machine 1 main body or the manual paper feeding device 15 provided at the side of the main body of the copying machine 1 to transfer the transfer drum 10. It is wrapped around the outer circumference and held. First, the yellow toner image developed by the developing device 8Y is transferred onto the transfer material by the discharge of the transfer device 11. Subsequently, while the developing device is moved and switched by the elevator type moving unit, the magenta, cyan, and black toner images formed in the same manner are sequentially superposed and transferred to form a full-color toner image.

The transfer material on which the full-color toner image is formed is separated from the transfer drum 10 and is conveyed to the fixing device 13 by the conveying device 12, where the toner image is heat-fixed on the transfer material and is ejected to the paper ejection tray 14. It

A diffusive and permeable sheet is housed in the cassette sheet feeding device 9. The transparent sheet is a manual paper feeder 15
Insert from. Each paper feeding device can feed a transfer material up to A3 size. In the vicinity of the manual sheet feeding device 15, a manual sheet feeding switch 16 that is turned on only when a transfer material is set in the manual sheet feeding device 15 is provided.

FIG. 6 is a schematic view of the operation panel 100 provided on the upper part of the copying machine 1. As shown in FIG. 6, an LCD display unit 103 is provided on the operation panel 100. The LCD display unit 103 displays various messages, various copy modes of the copying machine 1, displays a plurality of copy conditions, and allows the user to select an arbitrary copy condition. A plurality of mode selection keys 10 provided on the operation panel 100 are used to select a copy condition and a copy mode.
5, the plurality of function keys 106 and the cursor movement key 107 are used, but the details are omitted.

On the operation panel 100, a numeral key 102 for setting the number of copies, a clear key 108 for clearing the number of copies set by the numeral key 102, and a stop key for stopping copying. 109, a print key 101 for starting copying, and an image sheet 2
An Andon mode key 104 for selecting an Andon mode for creating 03 is provided.

When creating the image sheet 203, first, the Andon mode key 104 is pressed to select the Andon mode. Next, a transparent sheet is set in the manual paper feeding device 15. When the print key 101 is pressed, an image is formed on the transparent sheet set in the manual sheet feeding device 15, and subsequently, an image is formed on the diffusion translucent sheet set in the cassette sheet feeding device 9. . If the Andon mode key 104 is not pressed, the manual paper feeding device 15
Or, for the transfer material set in the cassette paper feeding device 9,
Image formation is performed under the specified copying conditions.

FIG. 7 is a block diagram showing the configuration of a control circuit for controlling each part of the copying machine 1. As shown in FIG.
The central processing unit (CPU) 400 includes a manual feed switch 16, a print key 101, and an Andon mode key 1.
A signal is inputted from 04 and the other input 401. Further, the CPU 400 receives the cassette paper feeding device 9 and the manual paper feeding device 15 according to these inputs.
A control signal is sent to the LCD display unit 103, the image forming unit 402 for forming an image, and the other output 403.

FIG. 8 is a flowchart of the image forming control of the CPU 400.

When the program of the CPU 400 of the full color copying machine 1 is started, the CPU 400 executes the step S1.
Manual feed flag F1 and Andon mode flag F
Each value of 2 is set to 0. The manual paper feed flag F1 indicates whether or not there is a transfer material in the manual paper feed device 15. When the transfer material is set in the manual paper feed device 15 and the manual paper feed switch 16 is turned on, the value of the flag is set. 1
Is set to. The Andon mode flag F2 indicates whether or not the Andon mode is selected. When the Andon mode key 104 is pressed to select the Andon mode, the flag value is set to 1.

In the following step S2, the value of the Andon mode flag F2 is determined. If the value of the flag F2 is 1, the process proceeds to step S5. If the value of the flag F2 is not 1, the process proceeds to step S3. Naturally step S when starting the program
Go to 3.

In step S3, the Andon mode key 1
It is determined whether 04 has been pressed. If the mode key 104 has not been pressed, the process proceeds to step S5. If the Andon mode has been pressed, the value of the Andon mode flag F2 is set to 1 in step S4, and after the message that the Andon mode is selected is displayed on the LCD display unit 103,
Go to step S5.

In step S5, the value of the manual paper feed flag F1 is determined. If the value of the flag F1 is 1, step S
Proceed to 9. If the value of the flag F1 is not 1, step S6
Proceed to.

In step S6, it is determined whether the manual feed switch 16 is ON. If the manual feed switch 16 is ON, the value of the manual feed flag F1 is set to 1 in step S7, and then the process proceeds to step S9. If the manual feed switch 16 is not ON, the process proceeds to step S8.

In step S8, the Andon mode flag F is set.
Determine the value of 2. If the value of the flag F2 is 1, the process returns to step S6, and the flow during this period is repeated until the manual feed switch 16 is turned on. If the value of the flag F2 is not 1, the process proceeds to step S9.

In step S9, it is determined whether the print key 101 has been pressed. If the print key 101 is pressed, the process proceeds to step S10. Print key 10
If 1 is not pressed, the process returns to step S2, and the process during this period is repeated.

In step S10, the manual paper feed flag F
Judge the value of 1. If the value of the flag F1 is 1, the value of the flag F1 is set to 0 in step S11, the manual sheet feeding device 15 is operated in step S12, and the transparent sheet set in the manual sheet feeding device 15 is fed. After that, the process proceeds to step S14. If the value of the flag F1 is not 1, the cassette sheet feeding device 9 is operated in step S13 to feed the diffuse translucent sheet set in the cassette sheet feeding device 9, and then the process proceeds to step S14.

In step S14, an image forming process is performed on the fed transfer material, and the process proceeds to step S15.

In step S15, the value of the Andon mode flag F2 is determined. If the value of the flag F2 is 1, the value of the flag F2 is set to 0 in step S16, and then the process returns to step S13. If the value of the flag F2 is not 1, the process ends.

The following functions are provided to prevent troubles when the Andon mode is selected.
May be added to.

When the Andon mode is selected, the cassette paper feeder 9 in which the transfer material of the same size as the transfer material set in the manual paper feeder 15 is set is automatically selected.

If the transfer material of the same size as the transfer material set in the manual paper feeding device 15 is not set in the cassette paper feeding device 9 when the Andon mode is selected, the LCD display unit 103 indicates that fact. To display.

When the Andon mode is selected, if the transfer material having the same size as the transfer material set in the manual paper feeding device 15 is not set in the cassette paper feeding device 9, the manual paper feeding can be performed again. To do. Then, the transfer material of the same size as the one set before is again fed to the manual paper feeding device 1
When set to 5, this transfer material is fed.

Further, the transparent sheet after passing through the fixing device 13 and the diffuse translucent sheet have different expansion and contraction states. Therefore, the image signal when forming an image on each sheet may be corrected in consideration of this difference.

[0062]

[Embodiment 2] In this embodiment, a display device in which the same image is formed on two transparent sheets and the two are superposed on each other will be described.

FIG. 9 is a schematic view of the display device of this embodiment. As shown in FIG. 9, a display device 300
Is provided with a diffuse translucent supporting plate 302 on the opening surface of a casing 305 provided with a lighting device 301.
02, two transparent sheets 3 on which the same image is formed
An image sheet 303, which is a stack of 03a and 303b, is held by a transparent cover 304.

With the above-mentioned structure, it is easy to set the number of copies to 2 in a well-known electronic copying machine and set the two transparent sheets in the manual feeding device of the copying machine for copying. You can create an image sheet in. Then, by using this image sheet, it is possible to obtain a display image having high image density and excellent gradation as in the first embodiment.

A display device A using various image sheets based on the configuration of the display device of the second embodiment.
~ H was constructed and the beauty of the image was evaluated. The beauty of the image was evaluated by observing color unevenness, contrast, closeness, glossiness, and depth of hue. The results are shown in Tables 1 and 2.

[0066]

[Table 1]

[0067]

[Table 2]

In (A), one image-formed transparent sheet is used as an image sheet and is placed in front of a diffuse translucent support plate. No transparent cover is used. In this case, the beauty of the image is inferior to any of the cases (A ′) to (H) described later.

(A ') has a transparent cover with a thickness of 2 mm adhered to the front surface of (A). In this case, the glossiness of the image can be improved. Therefore, it can be seen that the transparent cover improves the gloss level.

(B) is an image sheet in which a transparent sheet on which an image is formed and a transparent sheet on which a mirror image of the image on the transparent sheet is formed are superposed on each other to form an image sheet, which is placed in front of a diffuse translucent support plate. It is a thing. No transparent cover is used. In this case, since the two transparent sheets are superposed, the color unevenness can be made inconspicuous and the contrast can be emphasized. However, due to the image shift due to the mismatch between the normal image and the mirror image, the degree of immediacy can be improved. Cannot be improved.

In (B '), a transparent cover having a thickness of 2 mm is closely attached to the front surface of (B). In this case, the degree of closeness cannot be further improved, but the degree of gloss and the depth of hue can be improved.

In (C), an image sheet is obtained by sandwiching a transparent sheet having a thickness of 0.3 mm between two transparent sheets on which the same image is formed, and is placed in front of the diffuse translucent support plate. It is a thing. No transparent cover is used. in this case,
Since two transparent sheets are stacked, color unevenness can be made inconspicuous and contrast can be emphasized, but a transparent sheet with no image formed is sandwiched between the two transparent sheets. As a result, the transparency is lowered, the white part of the display image is yellowed, and the degree of imminence cannot be improved.

(C ') has a transparent cover with a thickness of 2 mm adhered to the front surface of (C). In this case, it is not possible to further improve the closeness, but it is possible to improve the glossiness and the depth of hue.

In (D), two transparent sheets on which the same image is formed are laminated to form an image sheet, which is placed in front of the diffuse translucent support plate. No transparent cover is used. In this case, since the two transparent sheets are stacked, it is possible to make the color unevenness inconspicuous and enhance the contrast. Also, the degree of imminence can be improved. However, since a transparent cover is not used, the degree of gloss and the depth of color are not good.

In (E), a transparent cover having a thickness of 1 mm is closely attached to the front surface of (D). In this case, since the two transparent sheets are stacked, it is possible to make the color unevenness inconspicuous and to emphasize the contrast and the degree of imminence. Further, since the transparent cover is brought into close contact with the front side surface of the image sheet, the degree of gloss and the depth of hue can be improved. However, the thickness of the transparent cover is 1 mm
The image looks a little thin.

(F) shows a transparent cover having a thickness of 2 mm adhered to the front surface of (D), which is shown in FIG. In this case, the degree of gloss can be further improved.

In (G), a transparent cover having a thickness of 3 mm is closely attached to the front surface of (D). In this case, since the transparent cover and the image appear to be separated, the degree of imminence is (F).
Lower than. By comparing (E), (F), and (G), it is found that it is effective to select the thickness of the transparent cover in accordance with the type of image sheet in order to obtain a desired good-looking image.

In (H), three transparent sheets having the same image formed thereon are superposed, and a transparent cover having a thickness of 2 mm is closely attached to the front surface thereof. In this case, since the three transparent sheets are stacked, the evaluation of the contrast and the degree of realism is low because the light transmittance is lowered and the dark portion is crushed.

However, depending on the degree of the toner adhesion amount on the image sheet, the evaluation of the color unevenness, the contrast, the degree of closeness, etc. may be higher in the three-sheet stack than in the two-sheet stack. Therefore, the number of transparent sheets to be overlapped may be three or more depending on the degree of toner adhesion.

[0080]

Third Embodiment In the present invention, since the image sheet used for the display device is prepared by using, for example, an electronic copying machine, it is possible to easily prepare an image sheet in which additional information such as characters and symbols are superimposed on the image. Is possible. Therefore, in this embodiment, an example in which an image sheet to which additional information is added is created using a well-known electronic copying machine will be described.

FIG. 10 is a schematic view of an original set on the copying machine. As shown in FIG. 10, the characters and symbols to be added are copied on the transparent sheet 601 in advance by using an electronic copying machine. In this case, for example, white toner can be used. Next, the transparent sheet 601 on which the characters and symbols are drawn is placed on the original image 600 and set in a well-known electronic copying machine, and when the image is formed on the translucent sheet, the characters and symbols are added. It is possible to create a customized image sheet.

Of course, data of a desired symbol may be added to the image data on the microcomputer terminal, and an image may be formed on the translucent sheet by a well-known electrophotographic laser printer based on this data.

[0083]

Fourth Embodiment Another embodiment of the electronic copying machine to which the present invention is applied will be described.

FIG. 11 shows a transfer material bundle used in the copying machine of this embodiment. As shown in FIG. 11, this transfer material bundle 20
Is a sheet in which diffused translucent sheets 21 and transparent sheets 22 are alternately stacked one by one.

In the copying machine of the present embodiment, such a transfer material bundle 20 is set in one of the cassette paper feeding devices, and when the Andon mode is selected, paper is fed from this cassette paper feeding device and spread. The same image is subsequently formed on the translucent sheet and the transparent sheet. Therefore, the image sheet used for the display device can be easily created. The detailed structure of the copying machine is omitted.

[0086]

As described above, the display device according to the present invention is inexpensive and can easily form an image sheet. Using this image sheet, high image density and excellent gradation can be obtained. In addition, it is possible to display an image with depth and stereoscopic effect, which is not obtained with a positive image sheet of the silver salt photographic method.

According to the electrophotographic image forming apparatus of the present invention, the same image can be formed on each of a plurality of translucent sheets, so that the image sheet can be easily used in a display device. Can be created.

[Brief description of drawings]

FIG. 1 is a schematic view of a conventional display device.

FIG. 2 is a schematic view of a display device to which the present invention is applied.

FIG. 3 is a gradation characteristic as a reflection image of an image on copy paper.

4 is a gradation characteristic of a display image by the display device 200. FIG.

5 is a sectional view of a full-color copying machine 1 for making the image sheet of FIG.

FIG. 6 is a schematic view of an operation panel of the copying machine 1.

FIG. 7 is a circuit block diagram of the copying machine 1.

FIG. 8 is a flowchart of the CPU of FIG.

FIG. 9 is a schematic view of a display device according to a second embodiment of the present invention.

FIG. 10 is a diagram showing a method of creating an image sheet according to a third embodiment of the present invention.

FIG. 11 is a diagram showing a transfer material bundle used in a copying machine according to a fourth embodiment of the present invention.

[Explanation of symbols]

 200 display device 201 lighting device 202 support plate 203 image sheet 203a diffuse translucent sheet 203b transparent sheet

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shuzo Yamaguchi 2-3-3 Azuchi-cho, Chuo-ku, Osaka Osaka International Building Minolta Camera Co., Ltd.

Claims (6)

[Claims] 1. A display device for displaying by forming an image on a translucent sheet to form an image sheet, and irradiating light from the back side of the image sheet through a diffusion translucent means for transmitting and diffusing light. In the display device, a plurality of translucent sheets on which substantially the same image is formed are stacked as the image sheet. 2. The display device according to claim 1, wherein the translucent sheet is a transparent sheet. 3. The display device according to claim 1, wherein the diffuse translucent means is a translucent sheet on which the image is formed. 4. The display device according to claim 1, wherein the image on the translucent sheet is formed by using an electrophotographic image forming apparatus. 5. An electrophotographic image forming apparatus comprising a plurality of sheet feeding devices for feeding a transfer material to an image forming apparatus main body, wherein a translucent sheet is fed from each of the plurality of sheet feeding devices. An image forming apparatus comprising a sheet of paper and a control means for forming substantially the same image on each of the translucent sheets. 6. A paper feed for stacking a plurality of types of translucent sheets in a predetermined order as a unit sheet, stacking the unit sheets in order, and feeding the translucent sheet to an image forming apparatus main body. An electrophotographic image forming apparatus, comprising: an apparatus; and a control means for forming substantially the same image on each of the translucent sheets of the unit sheet.