JPH08123332A - Image display device - Google Patents

Abstract

PURPOSE: To provide an image display device capable of displaying a color image repeatedly by toner of single color. CONSTITUTION: The toner 18 on a toner carrying roller 16 in a toner image forming device 10 is flown and stacked from a string of plural opening parts 12 in an electrode array 1 in accordance with image data on each color filter as moving an endless display belt 3 equipped with color filters of plural colors at every picture element. The rear face of the display belt 3 is irradiated with white light from a back light device 5. Consequently, the transmission of light is blocked by a grain, and the light permeability of each color filter is modulated. Since one picture element consists of a pair of plural color filters, a filter color is added and mixed corresponding to the light permeability, which enables an image of color in accordance with the image data to be reproduced and displayed. The image can be displayed repeatedly on the same display belt 3 by eliminating a toner image after display by a cleaning blade 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image display device capable of displaying high resolution and large capacity information such as a color image.

[0002]

2. Description of the Related Art Conventionally, as an image display device of this type, as proposed in Japanese Patent Application Laid-Open No. 58-98746,
A photoconductor belt having a photoconductive layer on a transparent conductive sheet, and a toner carrier disposed adjacent to the photoconductor belt. The toner on the toner carrier is provided on the photoconductor surface side of the photoconductor belt. While contacting and applying a voltage between the conductive sheet and the toner on the photoreceptor belt,
There is a structure in which a toner image is obtained on the photoconductor surface of the photoconductor belt by exposing while exposing the conductive sheet surface while sweeping laser light according to the image.

Further, the applicant of the present invention has previously disclosed the Japanese Patent Laid-Open No. 6-155.
In Japanese Patent Laid-Open No. 798, 798, an electrode array having a plurality of openings arranged in a line controls the passage of charged toner through the openings and is positioned on the opposite side of the conductive toner carrying roller with the electrode array sandwiched therebetween. In an image forming apparatus for forming an image on an image recording medium, an electrically insulating sheet of the electrode array is arranged so as to face the peripheral surface of the toner carrying roller, and one side of the electrode array faces the image recording medium. On the side, a control electrode is arranged separately for each opening, and the toner extracted from the opening is ejected toward the front surface of the image recording medium by electrostatic force. The back electrode body is arranged so as to be in contact with the back electrode body, and a voltage of a predetermined polarity is applied to the back electrode body. Further, the toner adhered as pixels on the surface of the image recording medium is fixed by the fixing device provided on the downstream side of the conveyance.
Proposed fixing the image.

[0004]

However, in order to obtain a color image with the above-mentioned conventional structure, different color toners are required, and an image forming apparatus is required for each color toner. Was extremely complicated. Further, in the image forming apparatus of the type in which the toner image is fixed on the image recording medium, there is a problem that the image recording medium is used only once and the same image recording medium cannot be used repeatedly. .

The present invention has been made to solve these problems, and an object of the present invention is to provide an image display device which can display a color image only with charged particles of one color, has a simple mechanism, and is inexpensive. Is.

[0006]

In order to achieve the above object, the image display device according to the invention of claim 1 is an image recording medium having a plurality of color filters for each pixel, and an image recording medium on the surface of the image recording medium. A particle image forming apparatus for forming an image of charged particles according to an image signal.

According to a second aspect of the present invention, in the image display apparatus according to the first aspect, a backlight device for illuminating the image recording medium from the back side is provided. According to a third aspect of the present invention, in the image display apparatus according to the first or second aspect, the image recording medium is formed in an endless belt shape, and the image recording medium is synchronized with an image forming operation by the particle image forming apparatus. And a cleaning means for removing charged particles from the image recording medium after display is completed.

[0008]

Next, an embodiment of the present invention will be described. FIG. 1 shows an outline of an image display device according to the present invention, which is a main body case 50 having a rectangular display portion 51 having a vertically long length such as a transparent glass window and having a width substantially equal to the width of the display belt 3. Inside, a toner image forming apparatus 10 as a particle image forming apparatus and an endless display belt 3 as an image recording medium for supporting the particle image (toner image) on the surface are arranged. This endless display belt 3
Is wound around the back electrode roller 2 arranged close to the upper surface of the toner image forming apparatus 10 and the driving roller 4 arranged in the upper part of the main body case 50, and the driving roller 4 is rotated by a driving motor (not shown), One of the outer peripheral surfaces (wide surfaces) of the display belt 3 is arranged so as to move in the direction of arrow A in FIG.

A backlight device 5 is arranged on the inner peripheral side of the endless display belt 3. In the backlight device 5, the display portions 51 are arranged so as to face each other, and a transparent light guide body 6 such as a transparent resin material or transparent glass having substantially the same width dimension as the display belt 3 and the transparent light guide body 6 are provided. It is composed of a light source lamp 7 such as a fluorescent lamp arranged along the end face, and by this light source lamp 7, one surface of the transparent light guide 6 (a wide surface facing the display section 51) becomes white almost uniformly as a whole, The display belt 3 is configured to be illuminated with white light from the inner surface side.

Next, the structure of the display belt 3 will be described. As shown in FIGS. 2 and 3, the display belt 3 has a fine structure that transmits red (R), green (G) and blue (B) light. One side of the film-shaped endless base body 35 made of a transparent resin material (such as the outer peripheral surface side of the endless display belt).
Is printed on almost the entire surface of. As shown in the enlarged view of FIG. 3, the red filter 36, the green filter 37, and the blue filter 38 are arranged in a delta arrangement at intervals of 60 μm in both the width direction and the vertical direction. That is, the red filter 36, the green filter 37, and the blue filter 38 arranged at the respective vertex positions of the triangle 39 shown by the broken line in FIG. As shown in FIG. 3, when a so-called black matrix in which the outer circumference of each color filter is surrounded by a black frame is formed, an image with good contrast can be obtained.

Further, as shown in FIG. 2, a timing mark 40 for synchronization for moving the display belt 3 in synchronization with the position of each pixel is printed on one side edge of the endless base body 35. ing. Next, the structure of the toner image forming apparatus 10 as the particle image forming apparatus will be described. In this apparatus, a film-like electrode array 1 as a toner flow control means arranged on the upper surface of a toner case 9 containing toner 18 is arranged so as to face the back electrode roller 2, and the back electrode roller 2 The surface of the display belt 3 located on the lower peripheral surface and the surface of the electrode array 1 are about 0.5 mm to 1 mm.
The display belt 3 as an image recording medium can be moved with an interval of mm.

The toner 18 contained in the toner case 9, the supply roller 15, the conductive toner carrying roller 16 made of a metal cylinder such as copper or aluminum, and the toner 18 in the toner reservoir are agitated. While supplying the agitator 17 toward the supply roller 15, the toner carrying roller 1
A regulation blade 19 for rubbing the toner 18 with a constant layer thickness is disposed on the peripheral surface of the roller 6.

Further, the cleaning blade 14 connected to the recovery port on one side of the upper surface of the toner case 9 is provided with a display unit 41.
It slides in contact with the outer peripheral surface of the display belt 3 on the opposite side, and serves as a cleaning unit for removing and collecting the toner 18 adhering to the surface of the display belt 3. A toner carrying roller 16, a supply roller 15, and an agitator 17 having a rotation axis parallel to the rotation axis of the back electrode roller 2.
Have a length substantially the same as the width of the display belt 3, and are rotated in the directions of the arrows in FIG. 1 by a rotation driving device (not shown).

Part of the outer peripheral surface of the toner carrying roller 16 is
It is arranged so as to face the back surface of the insulating sheet 11 so as to come into contact with the vicinity of the opening 12 row of the electrode array 1 described later. The base end of a regulation blade 19 for regulating the thickness of the toner layer, which is in pressure contact with the peripheral surface on the upstream side of the rotation of the toner carrying roller 16, is fixed to the toner case 9, and the toner supplied from the agitator 17 via the supply roller 15 is supplied. The wide blade 18 of the regulation blade 19 slidably contacts the outer peripheral surface of the toner carrying roller 16 to regulate the layer thickness of the toner 18 to a predetermined uniform thickness and to charge the toner 18.

The electrode array 1, as shown in FIG.
A polyimide insulating sheet 11 as an electrically insulating base material having a thickness of 5 μm is provided with a plurality of openings 12 having a diameter of about 40 μm at intervals of 60 μm in a direction orthogonal to the moving direction of the display belt 3 as the image recording medium. The control electrodes 13 are formed in a two-row zigzag arrangement, and control electrodes 13 are formed on the side facing the display belt 3 and divided into the openings 12.

As shown in FIG. 4, for each opening 12 such as a round hole formed through the insulating sheet 11, a ring shape is formed on the upper side of the insulating sheet 11 along the circumferential edge of each opening 12. The control electrode 13 including the electrode portion 13a and the lead portion 13b for connecting each electrode portion 13a to the control voltage applying circuit 21 is formed of a metal such as copper or gold having a thickness of about 1 μm. .

In the electrode array 1, the sheet 11 is bent in two rows about the row of the openings 12 with respect to the toner carrying roller 16 by bending the sheet 11 at the upstream side and the downstream side in the moving direction of the display belt 3 at substantially the same angle. -Shaped openings 12 are in uniform pressure contact with the outer peripheral surface of the toner carrying roller 16, and the toner carrying roller 1
6 is stretched so that the contact area with the outer peripheral surface of 6 is large.

A DC power source 20 is connected between the back electrode body 2 and the toner carrying roller 16, and the back electrode body 2
Is applied with a high voltage of about +500 V, a control voltage application circuit 21 is connected between the toner carrying roller 16 and the control electrode 13, and based on the image forming signal,
A pulse voltage of -20V or + 20V is applied to the control electrode 13.

The agitator 17, toner supply roller 15, and regulation blade 19 are grounded at 0V. The toner 18 in this embodiment is a black insulating toner having an electric insulating property, and is supplied to the surface of the toner carrying roller 16 by the supply roller 15. The surface of the conductive toner carrying roller 16 and the toner 18 attached thereto also have the same potential as a whole.

Next, the recording / displaying operation of the image display device thus constructed will be described. First, the toner carrying roller 16 and the toner supplying roller 15 and the agitator 17 having substantially the same length as the toner carrying roller 16 rotate in the direction of the arrow shown in FIG. Insulating toner 18 sent
Are rubbed against the surface of the toner carrying roller 16. Then, the toner 1 is adjusted by the blade 19 for controlling the toner layer thickness.
The toner 18 having the layer thickness of No. 8 thinned to a predetermined value and negatively charged is carried on the surface of the toner carrying roller 16. The toner 18 conveyed toward the electrode array 1 by the rotation of the toner carrying roller 16 is
It is supplied under the opening 12 while being rubbed against the insulating sheet 11.

On the other hand, in response to the image display command, the sensor 41 shown in FIG.
0 is read, and the display belt 3 is conveyed one pixel at a time into the gap between the back electrode roller 2 and the electrode array 1. Here, when there is an image, the amount of toner deposited on the color filter of each color of each pixel in the image is calculated by a control device (central processing unit) (not shown) of the image display device based on the color image signal. Control voltage application circuit 21
Therefore, a drive voltage of + 20V or -20V having a pulse width corresponding to the toner amount is applied to the control electrode 13 of the opening 12 corresponding to the color filter portion.

As a result, the control electrode 1 corresponding to the image portion
When a voltage of +20 V is applied to 3, the potential difference between the control electrode 13 and the conductive toner carrying roller 16 is generated in the vicinity of the opening 12 corresponding to the color filter portion of each color in each image in the image. Annular control electrode portion 13a
More lines of electric force are formed toward the toner carrying roller 16. The strength of the line of electric force at this time is proportional to the potential difference and inversely proportional to the distance between the control electrode 13 and the surface of the toner carrying roller 16.

Then, the negatively charged toner 18
Is subjected to an electrostatic force in the direction of higher potential by the line of electric force from the control electrode 13 toward the toner carrying roller 16, and is drawn out so as to pass through the opening 12. The toner 18 thus extracted is further applied to the display belt 3 by the voltage (+ 500V) applied to the back electrode body 2.
The toner 18 flies toward the display belt 3 due to the electric field formed between the electrode array 1 and the electrode array 1, and the toner 18 is deposited on the surface of the display belt 3.

At the position of the opening 12 where the voltage of -20 V is applied to the control electrode 13, the toner carrying roller 16 is provided.
The electric potential line between the toner carrying roller 16 and the control electrode 13 is formed by the potential difference between the control electrode 13 and the control electrode 13,
The negatively charged toner 18 receives an electrostatic force in the direction of a high electric potential, that is, an electrostatic force pressed on the toner carrying roller 16, so that the toner is opened.
Do not pass through.

Therefore, a toner amount proportional to the pulse width of the applied voltage is deposited on the surface of each color filter. Then, on the surface of the display belt 3, one line of the toner 18 is formed by the 12 rows of openings.
While the pixels for the rows are formed, the display belt 3 is conveyed by one pixel in the direction perpendicular to the rows of the openings 12 (direction of arrow A in FIG. 1). The movement of the display belt 3 (operation of the drive roller 4) and the timing of applying the pulse voltage are performed in synchronization with the signal detected by the sensor 41 on the timing mark 40 on the surface of the display belt 4.

By repeating such an operation, a predetermined image is formed by the toner 18 on the surface of the display belt 3. After that, when the portion of the toner 18 accumulated on the display belt 3 is conveyed to the position of the display portion 51, the following color image is seen by the white light from the backlight device 5. That is, the black toner 18 deposited on each of the color filter portions absorbs the white light according to the deposition amount, and modulates the white light emitted from the back surface of the display belt 3. For example, when one pixel is made up of a set of fine three-color transmission filters that transmit red (R), green (G), and blue (B) light, black toner is placed at the red filter 36 and the green filter 37. 18 is deposited in a sufficient amount, and black toner 18 is deposited on the blue filter 38.
When there is no accumulation, only the blue (B) light is transmitted and the blue image portion is visible to the human eyes outside the display portion 51. Similarly, when the black toner 18 is sufficiently deposited on the blue filter 38 and the black toner 18 is not deposited on the red filter 36 and the green filter 37 at all, the yellow light is an additive mixture of red light and green light. The light passing through the three-pixel color filter for one pixel is subjected to additive color mixing in accordance with the modulation amount, and color display is performed for each pixel, and a still color image is displayed on the entire surface of the display unit 51. can do.

After the display of the still color image for one screen is completed, the driving roller 4 is driven to move the display belt 3 so that the color image display portion is removed at the cleaning blade 14. The toner 18 scraped off by the cleaning blade 14 and the toner case 9 are again collected, and then agitated by the agitator 17 for reuse.

With the above process, the display and rewriting of the still color image can be repeated. In the above-described embodiment, the backlight device 5 may use a white base plate instead of the transparent light guide 6 and the light source lamp 7. in this case,
The light (for example, sunlight) from the outside of the image display device uses the light reflected from the white base plate after passing through the surface of the display belt 3 from the display unit 51, so the color reproduction range is narrowed.
This has the effect of simplifying the configuration.

In the embodiment shown in FIG. 5, a backlight device is not used, and white toner is used on the back surface of the display belt 3. The image display device of FIG. 5 has a rectangular display part 51 that is vertically long and has a width substantially equal to the width of the display belt 3 such as a transparent glass window. A toner image forming apparatus 10 as an image forming apparatus and an endless display belt 3 as an image recording medium for supporting the particle image (toner image) on the surface are arranged.

The endless display belt 3 is wound around a drive roller 52 driven by a drive motor (not shown) and two driven rollers 53 and 54, and a color image on the display belt 3 is provided inside the display section 51. Is rotated so as to move in the direction of arrow A. The toner image forming apparatus 10 is arranged on the inner peripheral side of the endless display belt 3, and the plate-shaped back electrode body 55 is arranged vertically on the outer peripheral side of the display belt 3.
The toner image forming apparatus 10 is arranged so as to face an electrode array (not shown), and the toner carrying roller 16 is arranged on the back side of this electrode array. The other construction of the toner image forming apparatus 10 is almost the same as that of the embodiment shown in FIG. 1, so a detailed description thereof will be omitted, but the white toner 18 is deposited on the back surface side of the display belt 3 based on the image data. To be made. Further, a cleaning blade 56, which is on the upper side of the display portion 51 and is in sliding contact with the inner peripheral surface of the display belt 3, is provided, and the collected toner is returned to the toner case 9 via the conduit 57.

In this embodiment, the color filter 1 for three colors is used.
When viewed from the surface of the display belt 3 having one pixel as a set, the color of the color filter appears in the color filter portion where the white toner 18 is deposited, and the portion where the white toner is not deposited appears black. This allows the still color image to be repeatedly displayed. Even in this implementation,
Although the color reproduction range is narrowed, the structure is simple.

A brush or a brush roller may be used in place of the cleaning blade in each of the above-described embodiments, and as a cleaning device, a voltage having a polarity opposite to a predetermined toner polarity may be applied to be attracted by electrostatic force or high voltage. The toner accumulated by air may be blown off. In the toner image forming apparatus configured as described above, if the insulating toner 18 is used, the conductive toner carrying roller 1
The electrical insulation between 6 and the control electrode 13 in the electrode array 1 is maintained.

According to the above process, the control electric field in the electrode array 1 is formed between the control electrode 13 and the surface of the toner carrying roller 16 as one electrode facing the opening 12. The electric field for control can be directly applied to the toner 18 conveyed by the toner carrying roller 16 to the vicinity of the opening 12, and the toner control efficiency is excellent.

Since the toner carrying roller 16 which is one of the electrodes and the electrode array 1 having the control electrode 13 are extremely close to each other with the conveyed toner 18 therebetween, the applied voltage for control is lowered. However, since the electric field strength can be increased and the flight force of the toner 18 can be increased,
As the control voltage applying circuit 21 for driving the control electrode 13, a low voltage one can be used, and the manufacturing cost of the toner image forming apparatus becomes low.

Electrically insulating sheet 11 in the electrode array 1
When the toner is carried on the outer peripheral surface of the toner carrying roller 16 as one electrode, there is no electrical short circuit even if the toner 18 is not carried on the toner carrying roller 16. In the present invention, the color filter formed on the display belt 3 as the image recording medium may have any two colors. In that case, it goes without saying that some colors cannot be reproduced due to the law of additive color mixing.

Although the display belt 3 as the image recording medium is moved in the above embodiment, the display belt is kept stationary and the toner image forming apparatus is arranged on the display unit 51 along one side of the display belt. The toner image may be formed while moving from one to the other.

[0037]

As described above, claim 1
The image display device according to the invention described in 1), an image recording medium having a plurality of color filters for each pixel, and a particle image forming device for forming an image of charged particles on the surface of the image recording medium according to an image signal. It is equipped with and.

According to this structure, for each pixel, particles such as toner of one color are deposited on the color filter of each color on the image recording medium by the particle image forming apparatus according to the image data. As a result, the transmission of light is blocked by the particles, and the light transmittance of each color filter is modulated. Since one pixel is composed of a set of a plurality of color filters, additive colors are mixed according to the modulated light transmittance of the filter colors, and colors corresponding to the image data can be reproduced.

Therefore, according to the present invention, as compared with the conventional apparatus, only one type of color of particles such as toner is used, and accordingly, only one particle image forming apparatus is required. It is possible to provide an image display device that is easy to operate. According to a second aspect of the present invention, in the image display apparatus according to the first aspect, a backlight device for illuminating the image recording medium from the back side is provided. As described above, when the image recording medium is illuminated from the back side by the backlight device, the light transmittance in which the filter color is modulated in the portion where the particles are deposited and the portion where the particles are not deposited on the color filter of the image recording medium. The color reproduction range of additive color mixture increases in accordance with the above.

Therefore, according to the present invention, in addition to the function and effect of the invention described in claim 1, it is possible to obtain a color image of high quality and high resolution. Claim 3
In the image display apparatus according to claim 1 or 2, the invention described in claim 1 forms the image recording medium in an endless belt shape, and moves the image recording medium in synchronization with an image forming operation by the particle image forming apparatus. The cleaning means for removing the charged particles after the display is configured is provided.

Therefore, if the color image displayed by temporarily depositing particles on the image recording medium becomes unnecessary, the toner deposited on one surface of the image recording medium can be easily removed by the cleaning means. As a result, in addition to the action and effect of the invention described in claim 1 or 2, the effect that the image rewriting can be easily executed to repeatedly display different color images on one image recording medium is exhibited.

[Brief description of drawings]

FIG. 1 is a schematic side sectional view of an image display device according to a first embodiment.

FIG. 2 is a partial front view of a display belt.

FIG. 3 is an enlarged view of a main part of a part of the surface of the display belt.

FIG. 4 is a partially cutaway enlarged perspective view of an electrode array.

FIG. 5 is a schematic side sectional view of an image display device according to a second embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electrode array 2 Back electrode roller 3 Display belt as an image recording medium 4,52 Driving roller 5 Backlight device 9 Toner case 10 Toner image forming device 11 Insulating sheet 12 Opening 13 Control electrode 14,56 Cleaning blade 16 Toner carrying roller 20 DC power supply 21 Control voltage application circuit 35 Endless base body 36 Red filter 37 Green filter 38 Blue filter 40 Timing mark 55 Rear electrode body

Claims (3)

[Claims] 1. An image recording medium provided with a plurality of color filters for each pixel, and a particle image forming apparatus for forming an image of charged particles on the surface of the image recording medium according to an image signal. Image display device featuring. 2. The image display device according to claim 1, further comprising a backlight device that illuminates the image recording medium from the back side. 3. The image recording medium is formed in an endless belt shape,
2. A cleaning unit configured to move the image recording medium in synchronism with the image forming operation of the particle image forming apparatus, and having a cleaning unit for removing charged particles from the image recording medium after the end of display. The image display device according to claim 2.