JPH02134676A - Picture display device - Google Patents

Abstract

PURPOSE:To obtain a high picture resolution and to save electric power for illumination by using a second back sheet whose surface is transparent or white, or which has light diffusivity for a monotone picture when a monotone picture is displayed. CONSTITUTION:Display sheet function is divided into two; one is a recording sheet 21 which has light transmission and electrical conductivity, and the other is a first back sheet 22 which has a stripe filter face for a color picture. The first back sheet 22 and the second back sheet 25 for a monotone picture are continuously provided and turned by two rollers 26 and 27, whereby either the first back sheet 22 or the second back sheet 25 can be selectively confronted with the recording sheet 21. Thereby, a high picture resolution for a monotone picture can be obtained and electric power for illumination is saved.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention involves attaching magnetic conductive toner to a recording sheet having translucency and conductivity according to an image signal, and attaching a stripe filter for color images to the back surface of the recording sheet. The present invention relates to an image display device that displays a color image by overlapping the images and further illuminating from the back.

(Prior Art) A conventional example of an image display device having the above structure is shown in FIGS. 3 and 4. FIG. 3 is a side view of the entire device, and FIG. 4 is a partially enlarged view of FIG. 3. A transparent face plate 2 is provided on the front side of a housing 1 of the image display device to form a display surface. Also, this housing
Three rollers 3, 4.5 are provided inside, and a display sheet 6 is wound around these rollers 3, 4.5 so as to be rotatable. This display sheet 6 has fine color stripes 7R, 7 in the width direction (direction perpendicular to the rotation direction).
G and 7B are provided. The color stripe is red (R
), green (G), and blue (B) are alternately arranged in large numbers and cover the entire surface of the display sheet 6. Further, a light-transmitting conductive layer is provided on the surface of the display sheet 6.

An image forming means 8 attaches magnetic conductive toner 9 to the rotating display sheet 6 in accordance with the applied image signal to form an arbitrary image on the surface of the display sheet 6. The image forming means 8 has a non-magnetic sleeve 11 provided inside a case 10, and a rotating magnet 12 provided inside this non-magnetic sleeve 11. Further, the magnetic conductive toner 9 is placed around the non-magnetic sleeve 11 to block light.

A large number of recording electrodes 13 are provided between the non-magnetic sleeve 11 and the display sheet 6 in the width direction of the display sheet 6. These many recording electrodes 13 are connected to the control device 1, respectively.
4, the voltage of the voltage supply device 15 is controlled ON@OFF. The image is formed by this control, and when forming the image, red, green, and blue color stripes 7R,
It is determined which part of 7G and 7B is to be covered with the magnetic conductive toner. By covering any of the color stripes in this way, a color image can be formed with the required colors.

(Problem to be Solved by the Invention) However, in such an image forming apparatus, one pixel is formed by three color stripes;
There is a drawback that the decomposition performance when forming an image deteriorates. Furthermore, since the reflected light of the three-color stripe filter is darker than the white background, the entire image formed becomes a dark image. Therefore, when forming a color image, it is necessary to always illuminate from the back of the display sheet.

The above disadvantages are still unavoidable when displaying color images, but for example, when forming monotone characters to display character information, higher image resolution performance is desired, or when saving power. Therefore, even when it is desired to display a monotone image without illumination, the above-mentioned drawbacks similarly exist and are a problem.

This invention was made in view of the above problems, and an object of the present invention is to obtain an image display device that can exhibit high image resolution performance when displaying images in monotone and can save power for illumination. .

(Means for Solving the Problems) The present invention includes a recording sheet having a light-transmitting conductive layer, and an image forming means for depositing magnetic conductive toner on the recording sheet in accordance with an image signal to form an arbitrary image. , a first back sheet having a striped filter surface for color images and a second back sheet having a transparent or light-diffusing or white surface for monochrome images are selectively attached to the back surface of the recording sheet. This image display device includes movable back seats that can face each other and lighting means provided on the back of the facing back seats.

(Function) With the above configuration, the portion corresponding to the conventional display sheet is divided into a transparent conductive recording sheet and a first back sheet having a striped filter surface for color images, and this first back sheet is , it can be used selectively with the second back sheet for monotone, so if the back sheet of F52 for monotone is transparent, has light-diffusing properties, or has a white surface, when displaying a monotone image, The problems of the conventional striped filters can be avoided.

(Embodiment) An embodiment of the image display device of the present invention is shown in FIGS. 1 and 2. The functions of the conventional display sheet 6 are divided into two parts, one of which is a translucent and conductive recording sheet 21, and the other of which is a first back sheet 22 having a striped filter surface for color images.

The recording sheet 21 is a resin film made of polyethylene terephthalate or the like, provided with a transparent conductive layer of indium tin oxide or the like, and further provided with a thin film of butyral resin, acrylic resin, or the like as a recording layer. Therefore, this recording sheet 21 has a light-transmitting property, and at the same time, the magnetic conductive toner 9 is attached thereto. This recording sheet 21 is wound and rotated between two rollers 23 and 24.

An image forming means 8 is provided for attaching magnetic conductive toner 9 to the rotating recording sheet 21 in accordance with an applied image signal to form an arbitrary image. This image forming means 8 has a rotating magnet 12 at the center, a non-magnetic sleeve 11 is provided around it, a magnetic conductive toner 9 is placed around it, and a case 10 is placed on the outside.
It is surrounded by Further, between the non-magnetic sleeve 11 and the recording sheet 21, a large number of recording electrodes 13 are provided in the width direction of the recording sheet 21. These recording electrodes 13 are controlled by the control device 14 so that the voltage from the voltage supply device 15 is set to 0N-O.
FF controlled. Through this control, the magnetic conductive toner 9 adheres to the surface of the recording sheet 21 to form an arbitrary image.

The first back sheet 22 having a striped filter surface for color development is the second back sheet 2 for monotone development.
5 and are provided consecutively.

This second back sheet 25 for monotone has a transparent, light-diffusing, or white surface (0 screen surface sheet) 22,2
5 is wound and rotated between two rollers 26 and 27 between the wound recording sheets 21, thereby forming a movable back sheet 28. That is, by being rotated by the two rollers 26 and 27, the first back sheet 22 or the second back sheet 25 can be selectively opposed to the recording sheet 21.

The three color stripes of red (R), green CG) and blue (B) on the first back sheet 22 are 7R.

A large number of 7G and 7B are arranged in the width direction of the back sheet 22. However, as in the conventional example shown in FIG. 4, a large number of them may be arranged in the rotation direction.

Incidentally, a transparent face plate 2 is provided on the front surface of the housing 1 of the image display device, and constitutes a display surface. Further, a back support plate 29 is provided corresponding to this display surface, and supports the recording sheet 21 and the back sheet 22, 25 in a stacked state from the back side. This back support plate 2
9 is provided with a slight curvature so as to support the stacked recording sheet 21 and the back sheet 22, 25 in a suppressed state so that they do not separate. In addition, when the second back sheet 25 is made transparent, it is desirable that this back support plate 29 has a light diffusion function.

A plurality of illumination lamps 31 serving as illumination means are provided between the rolled movable back sheets 28 in the sheet extending direction. By this illumination lamp 31, the recording sheet 21
Illumination can be performed from the back of the first back sheet 22 or the second back sheet 25 facing the. Although lighting is necessary for the second back sheet 22, it is not necessarily necessary for the second back sheet 25. This is because when it is bright, such as during the day, it is possible to display a monotone image satisfactorily without illumination.

The rollers 23, 24, 26 and 27 around which the movable back sheet 28 or recording sheet 21 is wound are provided with ribs 32 at their respective ends as shown in FIG.
1, 22, and 25 are prevented from shifting in the axial direction of the roller. This misalignment prevention prevents the stripe filter surface of the first back sheet 22 and the image formed on the recording sheet 21 from misaligning, and prevents the colors of the image from becoming dull or distorted.

The operation of the above embodiment will be explained. When displaying a color image, the rollers 26.2 of the movable backsheet 28
7 to move the first back sheet 22 in a direction to face the back surface of the recording sheet h21. Then, based on the applied image signal, the control device 14 performs ON/OFF control of a large number of recording electrodes 13 that are present corresponding to each color stripe, and causes the magnetic conductive toner 9 to adhere to the surface of the recording sheet 21 to form an image. form. During this image formation, which of the three color stripes 7R, 7G, and 7B is to be covered with the magnetic conductive toner 9 is determined each time, and a color image is determined.

When displaying a monotone image, the rollers 26 and 27 are rotated to move the second back sheet 25 in the direction opposite to the back surface of the recording sheet 21 in the same manner as described above. Then, an image is formed using the magnetic conductive toner 9 by ON/OFF control of the recording electrode 13 in the same manner as described above, but in this image formation, there is no need to consider color stripes, and a color image is formed using the stripe filter surface. In the case of forming an image, three times the image resolution performance can be obtained. Further, since it is not a color image, bright illumination is not required and there is no need to turn on the illumination lamp 31. In addition, when the second back sheet 25 is transparent, the back support plate 29 is provided with a light diffusion function.

That is, for example, the second back sheet 25 is made semitransparent,
When the illumination lamp 31 is turned on, the image can be displayed brightly, and even when it is not turned on, the inside of the device can be exposed and hidden from view. Furthermore, if the design is such that no illumination lamp is used when displaying a monotone image, the second back sheet 25 can be made white.

In the above embodiment, ribs 32 are provided to prevent the back sheet 22° 25 and the recording sheet 21 from shifting in the width direction.
However, in other embodiments, this deviation may be automatically detected and automatically corrected. For example, if a red image is formed on a trial basis, or green and blue color stripes are 7G and 7B), a red sensor that detects only red is provided on the display surface, and the light emitted from the illumination lamp 31 passes through the first back sheet 22 and the recording sheet 21. The relative positions of the recording sheet 21 and the back sheet 22 in the width direction are adjusted so that the maximum amount of red light is detected when it comes to the display surface. For this adjustment, it is necessary to provide a drive device to the rollers 23, 24, 26, 27, etc. and drive them in the axial direction of the rollers.

In the above embodiment, the recording sheet 21 is the two rollers 2.
3.24 and rotated, but in other embodiments it may be in the form of a sheet or a flat plate that does not rotate.

In such a case, it is conceivable that the image forming means 8 moves to form the image.

Although the movable back sheet 28 in which the first back sheet 22 and the second back sheet 25 are successively provided and can be rotated by being wound around two rollers 26 and 27 has been described, other embodiments For example, it is also possible to construct a movable back sheet such that the back sheet is made up of a large number of slice pieces, such as a blind hung on a window, and each slice piece can be rotated by 90 degrees.

Further, the 2
The two rollers 26 and 27 are the rollers 23 and 27 of the recording sheet 21.
．． 24, but in other embodiments it is provided on an axis perpendicular to the recording sheet 21 and the back sheet 2.
It is also possible to rotate 2.25 in the right angle direction.

In the above embodiment, color stripes 7R and 7G are provided corresponding to each recording electrode 13.

Although the present invention is configured to provide 7B, the present invention is not limited to this. For example, the width of the color stripe per - color may be doubled so that the color changes every two electrodes 13. When such a configuration is adopted, the resolution decreases when displaying a color image, but since the pitch of the color stripes becomes rougher, it is possible to easily prevent the displacement of jFt between the color stripes and the recording sheet 21. Note that when displaying an image in a single color, it can be displayed at the same resolution as in the above embodiment.

Further, when displaying an image using the above-described device, by changing the stopping position of the back sheet 28, it is also possible to partially display the image in color and display the rest in monochrome. For example, the upper one-third of the display image can be displayed in color using large characters such as headings, and the lower two-thirds can be used to display a large amount of information in high-resolution monochrome.

Further, the means for forming an image is not limited to one using toner as in the above embodiment, but may be any other means as long as it changes the transmittance or scattering rate of light with respect to the recording sheet h21, such as thermal recording. It is also possible to use non-printable, thin image display means such as electronic devices, electrochromic displays, liquid crystal display panels, and the like.

(Effects of the Invention) As explained above, according to the image display device of the present invention, when displaying a color image, the first back sheet having a stripe filter surface for color images is used, and a monotone image is displayed. When displaying a monochrome image, a second back sheet with a transparent or light-diffusing or white surface can be used, which eliminates the problems of conventional striped filters when displaying a monochrome image. It is therefore possible to obtain high image resolution performance and save power for illumination.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional side view showing an embodiment of the image display device of the present invention, FIG. 2 is an enlarged perspective view of the main part of FIG. 1, and FIG. 3 is a schematic cross-sectional side view showing a conventional image display device. , FIG. 4 is a perspective view of the main part of FIG. 3. Symbol l...Housing 3.4.5...Roller 8...Image forming means 10...Case description 2...Face plate 6...Display sheet 9...Magnetic conductive toner 11 ...Nonmagnetic sleeve 2...Rotating magnet 3...Recording electrode 1 5...Voltage supply device 2 2...First back sheet 5...Second back sheet 8...Movement Type back sheet...Illumination lamp (illumination means) 4...Control device l...Record sheet

Claims (1)

[Claims] A recording sheet having a light-transmitting conductive layer, an image forming means for forming an arbitrary image by attaching magnetic conductive toner to the recording sheet in accordance with an image signal, and a stripe filter for color images on the back side of the recording sheet. A movable back sheet in which a first back sheet having a surface and a second back sheet having a monotone transparent, light-diffusing, or white surface can selectively face the recording sheet, and the opposing back sheet An image display device comprising: illumination means provided on the back of the image display device.