JPH0117305B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to an image display device that forms and displays an erasable image on an image carrier. [Prior art] CRTs (cathode ray tubes) have traditionally been used as image devices that visually display image information converted into electrical signals.
Display devices and liquid crystal display devices have been put into practical use. Among these, CRT display devices are the most commonly used and highly reliable devices, but they are used to display fine-sized characters such as those used in newspapers and magazines, especially fine characters with a large number of strokes such as kanji. Displaying the image in its original size has nothing to do with resolution. Although the text is enlarged to make it easier to decipher, the number of characters that can be displayed on the screen decreases in inverse proportion to the enlargement rate, resulting in a problem in that the amount of information per screen decreases. Furthermore, if the same image is displayed continuously for a long time, the screen will be burned in and the display performance will deteriorate. Furthermore, if the screen flickers,
My eyes get tired. Next, liquid crystal display devices are display devices that have recently been put into practical use, but like CRT display devices, not only do they have insufficient resolution, but they also have the problem of being difficult to manufacture with large screens and being expensive. There is. Therefore, the present applicant previously proposed an image display device using electrophotography as a third image display device that does not have the above-mentioned drawbacks (Japanese Patent Application No. 1983-
197410-197413). This display device reproduces and displays image information as a toner image, has excellent resolution, makes the image easy to see, can be manufactured with a large screen at a relatively low cost, and is a highly reliable device. [Problems to be Solved by the Invention] However, image display devices using electrophotography form images by attaching toner to a belt-shaped photoreceptor and display the images.
Because it is not an electrical image display method like
Even if the displayed image is no longer needed, the image will remain displayed if you simply turn off the power. For this reason, there is a possibility that the residual image may be seen by a person other than the operator, which is a real inconvenience in terms of confidentiality. The displayed image may be erased, but it is often necessary to display the previously displayed image again. However, inputting the same image and displaying it again takes time, and using RAM to store the displayed images makes the device expensive. [Means for Solving the Problems] In order to solve the above problems, the present invention provides an image carrier 9 having a plurality of page areas for forming images, and a moving means 7 for moving the image carrier.
1, 72, image forming means 10, 16 for forming an erasable image on the image carrier moved by the moving means and erasing the image formed on the image carrier; It has a display means 4 for displaying an image formed on the body, and a control means 70 for controlling the moving means and the image forming means, and the control means moves the image carrier by the moving means. , a mode in which the non-image page area is displayed on the display means without erasing the formed image (FIG. 6, 561); and a mode in which the image carrier is moved in the opposite direction by the moving means, It has a mode (541 in FIG. 6) in which the image is redisplayed on the display means. [Function] According to the present invention, with the above configuration, an image erased from the display means can be quickly redisplayed with a simple configuration. [Example] Hereinafter, the present invention will be described in detail with reference to the drawings. 1 and 2 show an example of the configuration of the image display device of the present invention, where 1 is a vertical device exterior casing, and 2 is a display image viewing window hole formed in a large opening on the front panel of the exterior casing. , 3 is an operation panel disposed on the upper surface of the front panel with its lower part protruding forward; 4 is a display window glass placed in the window hole 2; 5, 6, 7, and 8.
Four endless belt-shaped photoreceptor suspension instruction rollers are disposed in the upper and lower parts of the exterior casing 1 in parallel with each other with their axes oriented in the left and right directions of the exterior casing, and individually rotatably supported on bearings. , 9 is an endless belt-shaped photoreceptor which is suspended and supported by the four rollers 5-8. The endless belt-shaped photoreceptor 9 (hereinafter simply referred to as a belt) has a base layer made of a transparent sheet such as a polyester sheet, and a very thin layer of metal is deposited on the outer surface of the sheet to substantially maintain transparency. By imparting electrical conductivity to the metal-deposited surface, a photosensitive material layer (photoconductive layer) such as CdS is formed on the metal-deposited side, making the entire structure flexible. It is suspended and supported by the four rollers mentioned above. Among the four rollers 5 to 8, roller 5 is used as a driving roller to transmit the rotational force of motor M ₁ (not shown). At least one of the other three rollers 6 to 8, for example roller 6, acts as a belt tension roller and applies tension to the suspended belt 9. Therefore, when the drive roller 5 is rotated counterclockwise in FIG. 2 by the motor M, the hanging belt 9 rotates counterclockwise without waving, sagging, or slipping. Along with this rotation, between the rollers 5 and 8, the tension side outer surface of the belt 9 moves past the display screen viewing hole 2 from the bottom to the top. Reference numeral 10 denotes a laser beam scanning type image exposure device that is fixedly arranged in a space inside the hanging belt 9, and includes a semiconductor laser oscillator 11 and a polygon mirror scanner 1.
2, an fθ lens (imaging lens) 13, a reflecting mirror 14, and a transparent plate 15. The transparent plate 15 is a horizontally long transparent flat plate made of glass or plastic, which is placed in pressure contact with the inner surface of the tensioned belt portion between the belt suspension support rollers 7 and 8 with an appropriate force. In this image exposure apparatus 10, an intermittent laser beam L corresponding to time-series electric pixel signals supplied from a computer, an image reading device, etc. is transmitted from a semiconductor laser oscillator 11 at the front of the drawing to a rotating polygon mirror scanner 12 at the back of the drawing. It is oscillated towards. The laser beam L incident on the scanner 12 is swung in the belt width direction, enters the inside of the belt 9 between the rollers 7 and 8 through a path of the fθ lens 13, the reflector 14, and the transparent plate 15, and is converted into a laser beam in the belt width direction. scanned. As a result, an image is exposed by a laser beam from inside the belt, with this laser beam scanning as a main scanning and the rotational movement of the belt 9 as a sub-scanning. Reference numeral 16 denotes a toner developing device disposed on the outer surface side of the belt portion between rollers 7 and 8. In addition, transparent plate 1
5 is disposed with its lower surface slightly protruding downward from the common tangent below the rollers 7 and 8, and is in pressure contact with the inner surface of the belt 9. The plate 15 has a belt entry side and an exit side. The end faces 15 ₁ and 15 ₂ of the belt 9 are chamfered and rounded so that the belt 9 can smoothly contact and move. Further, the transparent plate 15 prevents the belt 9 from waving, vertical movement, and vertical movement of the belt 9 caused by contact with the magnetic developing brush 35 of the developing device 16.
Improves resolution by keeping the exposure position constant. First, after setting the required conditions such as calling up the image information and specifying the image display position by operating the buttons on the operation panel 3, when the display start instruction is inputted, the belt 9, which is the photoreceptor, rotates at a predetermined speed. movement begins. Laser beam scanning exposure of designated image information is then started on the inner surface of belt 9 between rollers 7 and 8. At the same time as this exposure, the developer 16
Since the toner acts on the outer surface of the belt, the belt 9
Toner images corresponding to the exposed images are sequentially formed on the outer surface of the toner image. When the toner image formed on the outer surface of the belt rotates from the bottom to the top of the display image viewing window 2 as the belt rotates and moves to the designated window range position, the belt 9 stops rotating once. will be stopped. As a result, an image is displayed in the window hole 2, and the image is visually recognized through the display window glass 4. Next, when the belt 9 is rotated again by a belt re-rotation operation command, the next display image moves to the window hole range position, and the next screen is displayed. After the image is displayed, the toner image on the outer surface of the belt reaches the toner developing unit 16 as the belt rotates, where it is cleaned and removed by a developing brush 35, and immediately after this cleaning, it is subjected to simultaneous exposure and development again. As a result, a new toner image is formed. In this way, image information is reproduced and displayed as a toner image, and the image exposure is performed using a very narrow laser hole L.
This method allows for high-resolution image display that allows fine characters and other images to be displayed clearly and easily, and because it uses a simultaneous exposure toner application method, there is no need for corona charging means or special cleaning. With an extremely simple configuration that does not require any means, it is possible to configure a highly reliable display device that can be manufactured at a relatively low cost even with a large screen, and has less failure and photoreceptor deterioration. FIG. 3 shows an example of the configuration of the control section of the apparatus shown in FIG. 1, where 70 is a sequence controller that receives various input signals from the operation panel 3 for specifying the start of display operation, specifying the number of pages to be displayed, etc. Recognizes the action specified by the operator based on the
Control and manage predetermined operations. Also, the operation panel 3
In addition to switches for setting conditions such as calling up image information and specifying the display position, there are also switches SW1 to
There are SW3 and switches for power on and power off. The switch SW1 is a switch that supports erasing of the image displayed on the photoreceptor 9.
SW2 is a switch that notifies the sequence controller 70 that the operator is using the image displayed on the photoreceptor 9;
3 is a switch that supports rotating the belt-shaped photoreceptor 9 by half a rotation in the opposite direction, and the power cutoff switch Power-OFF is controlled by the sequence controller 70.
This is a switch that cuts off the power through the 71 is a driver (drive circuit) for a roller drive motor (M ₁ ) 72 that drives an endless belt-like photoreceptor (belt) 9; 73 is a driver for a developer motor 74 that drives a developing sleeve (developing brush) 35; +
Apply a developing bias voltage of 200V to +300V to the developing unit 16.
The drivers 71 and 73 and the developing bias circuit 75 are turned on/off (on/off) by control signals from the sequence controller 70. The output signal HP of a home position sensor 63, such as a photo encoder, which is directly attached to the drive shaft 53 of the drive roller 5 (see FIG. 2) is supplied to the sequence controller 70 as a position detection signal of the belt-shaped photoreceptor 9, respectively. Based on the reception of these signals BCLK and HP, the sequence controller 70 determines the drive timing of each drive section 71, 73, and 75, and performs appropriate sequence control. The output signal HP at this time indicates the reference position of the display page portion of the photoreceptor 9, for example, the tip position. Therefore, for example, if the light-shielding plate of the sensor 63 rotates once for each rotation of the belt-shaped photoreceptor 9, and it is possible to write two pages on the photoreceptor 9, the rear part of the light-shielding plate is Two locations are provided at intervals, so that the signal HP is 2 for each rotation of the light shielding plate.
Enable the output to be emitted. 76 is a scanner driver that drives the scanner 12 that scans the laser beam from the laser oscillator 11 in the main scanning direction;
A signal indicating whether or not 2 is rotating at a constant rate.
SCNRDY is supplied to the sequence controller 70. 77 is a laser driver that drives the laser oscillator 11, and a signal indicating whether or not the laser oscillator 11 has an abnormality such as a temperature control abnormality.
Supplies the LaserRDY signal to the sequence controller. 78 is an unblanking signal used to emit laser light in a non-image area in the main scanning direction
An unblanking signal generating circuit 79 that generates HANB is a beam detector that detects the laser beam and supplies a laser beam detection signal BD to the unblanking generating circuit 78. 7
In response to the detection signal BD of No. 9, a synchronization signal Hsync used for synchronizing video signals in the main scanning direction transmitted from an external device (not shown) such as an image reading device or an external storage device is generated. Therefore,
The above-mentioned unblanking signal ANB is supplied to the laser driver 77 via the OR gate 80 together with the video signal. In addition, the unblanking signal generation circuit 78 also performs detection operations such as detecting synchronization deviation of scanning in the main scanning direction based on the detection signal BD of the beam detector 79, and the detection signal
BDRDY is supplied to the sequence controller 70. Furthermore, the sequence controller 70 is also supplied with an interface signal for communication connection with an external device, and can exchange commands or data with the external device. FIG. 4 shows a subroutine of the operating procedure of the apparatus shown in FIG. 3 when image display is supported. first,
If there is an instruction to call up the image information from the operation panel 3, after turning on each motor 72 and 74 and the developing bias voltage (step 401), it is used to distinguish between a half rotation and a single rotation of the belt-shaped photoreceptor 9. Flag F in the sequence controller 70 is set to "0" (step 402). If the home position signal HP generated in response to the rotation of the belt-shaped photoreceptor 9 is received (step 403),
Counting of the number of pulses of the belt clock signal BCLK is started (step 404). Then,
If neither the image erase switch SW1 nor the power cut-off switch Power-OFF on the operation panel 3 is pressed (step 405), the count of the belt clock signal BCLK reaches a predetermined value n1 indicating the image writing reference position. Wait (step 406). When the belt clock signal BCLK is counted up to a predetermined value n1, a video signal output command is sent to the external device (step 407), and the belt-shaped photoreceptor 9
The received video signal is written in the page portion of the page (step 408). Next, the belt clock signal
Counting of the belt clock signal BCLK and image writing are continued until the count number of BCLK reaches a predetermined position n2 indicating the end position of image writing, and when the count number reaches the predetermined position n2 (step 409), the above-mentioned belt The writing process to the photoreceptor 9 is completed. Next, if switch SW1 or Power-OFF is not pressed (step 410), the rotation of each motor 72 and 74 is stopped, the application of the developing bias voltage is stopped (step 413), and a write end signal is transmitted to the external device. (Step 41)
4) Return to the main routine shown in FIG. 6, which will be described later, and proceed to the next operation. As a result, the instruction image processing is completed, and an image is displayed on the belt-shaped photoreceptor 9. On the other hand, if the image erase switch SW1 or the power cut-off switch Power-OFF is pressed, the above-mentioned step 405 becomes an affirmative determination, so the process jumps to step 409, and continues to step 408 until the count number of the belt clock signal BCLK reaches n2. Process. However, in this case, the external device is not requested to output a video signal, so step 408
By the writing process, one page of the displayed image on the belt-shaped photoreceptor 9 is erased. Here, in this example, since the number of possible display image pages is assumed to be 2, further steps 410 to 411 are performed.
It is determined whether the flag F is "1" or not, and if the determination is negative, it is determined that the erasure of the displayed image around the entire circumference of the belt-shaped photoreceptor 9 has not been completed.
After the flag F is reset to "1" in step 412, the process returns to step 403 and the above-described process is repeated. After that, in step 411, it is determined that the flag F is "1", so it is determined that the belt-shaped photoreceptor 9 has rotated once, and the process proceeds to step 413, and the process proceeds to the next step 41.
After performing the process in step 4, the process returns to the main routine shown in FIG. 6, which will be described later, and proceeds to the next operation. As a result, the belt-one-rotation screen erasing process is completed, and all display images written on the belt-like photoreceptor 9 are erased. Further, as will be described later, when the timer has elapsed for a set time, the process jumps from step 405 to step 409, and the process of step 408 is performed until the count number of the belt clock signal BCLK reaches n2 to form one page of non-image area. is performed, and when the count reaches n2, the process advances to step 410. Since it is not necessary to rotate the belt-shaped photoreceptor 9 once, a negative determination is made in step 410, and after performing the processing in steps 413 and 414, the process returns to the main routine shown in FIG. 6, which will be described later, and moves on to the next operation. do. This completes the belt half-turn non-screen display process, and the non-screen portion of the belt-shaped photoreceptor 9 is displayed. FIG. 5 shows a subroutine of the operating procedure of the apparatus shown in FIG. 3 when a reverse half-rotation instruction for rotating the belt-shaped photoreceptor in the opposite direction is given. First, if there is an instruction from the operation panel 3 to rotate the belt-shaped photoreceptor 9 by half a rotation in the opposite direction, the roller drive motor 72 and developer motor 74 are turned on and rotated in the opposite direction, and the developer bias power is turned on to the developer 16. (step 421). Next, the system waits until the home position signal HP is generated (step 422).
Belt clock signal depending on the reception of that signal HP
Start counting the number of BCLK pulses (step 423). When the count number of the belt clock signal BCLK reaches a predetermined value n3 indicating the reverse half-rotation position of the belt-shaped photoreceptor 9 (step 424),
It is determined that the belt-shaped photoreceptor 9 has rotated half a rotation in the opposite direction, and the rotation of each motor 72 and 74 and the application of the developing bias voltage are stopped (step 425).
The process returns to the main routine shown in FIG. 6, which will be described later, and proceeds to the next operation. This completes the belt reverse half-rotation image display process, which will be described later, and the original screen is displayed on the display window 2 as it is. Note that the above count number n
The following relationship exists between 3 and n2. n3=n-n2 where n is the first home position signal HP
indicates the number of pulses of the belt clock signal BCLK that occur between the generation of the home position signal HP and the next generation of the home position signal HP. FIG. 6 shows the main routine of the operating procedure of the apparatus shown in FIG. First, after turning on the power, set the device to its initial state (step 501), and then turn on the operation panel 3.
Steps 502 to 507 for monitoring input from
Move to the main loop. That is, it is determined whether there is an instruction to call up the image information (step 502), whether the image deletion switch SW1 is on or not (step 503), and the image use switch is
Determining whether SW2 is on (step 504),
Determine whether reverse half-rotation switch SW3 is on or not (step 505), power cutoff switch Power-OFF
is on (step 506), and whether or not the timer T in the sequence controller 70 has exceeded the time set in the memory M are sequentially performed.
Returning to step 02, the above-described main loop determination process is repeated until one of the steps becomes an affirmative determination. Thereafter, when an instruction to display an image is received from the operation panel 3 (step 502), the subroutine shown in FIG. 4 is executed to display the instruction image (step 511).
Next, after setting a predetermined time T1 in the memory M in the sequence controller 70 (step 512), the above-mentioned timer T is cleared to zero and time measurement is started (hereinafter referred to as clear start) (step 513). ), the process returns to step 502 of the main loop. In this state, the image remains displayed. When the image erasing switch SW1 is pressed (step 503), the entire photoconductor shape is erased during one rotation of the belt-shaped photoconductor 9 by repeating the processing procedure of steps 403 to 409 of the subroutine shown in FIG. 4 twice. Clear the display screen (step 52)
1), then after stopping the timer T (step 522), the main loop returns to step 50.
Return to 2. At this time, no image is formed on the belt-shaped photoreceptor 9. When the image use switch SW2 is pressed (step 504), if the timer T is in operation, it is cleared to zero, and time measurement starts again. If the timer T is stopped, it is cleared to zero, and remains stopped ( At step 531), the process returns to step 502 of the main loop to monitor key input. When the reverse half-rotation switch SW3 is pressed (step 505), the belt-shaped photoreceptor 9 is rotated in the reverse half by executing the subroutine shown in FIG. 5, and the previous page formed on the photoreceptor 9 is After displaying the image again (step 541) and setting a predetermined time T1 in the memory M, (step 541)
42), the timer T is cleared and started (step 543), and the process returns to step 502 of the main loop. When the power cutoff switch Power-OFF is pressed (step 506), the belt-shaped photoreceptor 9 is rotated once to erase the image by executing the subroutine shown in FIG. 4 (step 551), and then the power is turned off (step 551). Step 552). If the timer T exceeds the time set in the memory M (step 507), the belt-shaped photoreceptor 9 is removed by executing the subroutine shown in FIG.
to display the non-image plane (step 56).
1) If the contents of memory M at this time are T1 (step 562), after changing the contents of memory M to T2 (step 563), clearing and starting timer T (step 564), and starting the main loop. Return to step 502. On the other hand, the contents of memory M are T
If not 1, after stopping timer T (step 565), the process returns to step 502 of the main loop. At this time, just before the timer T reaches the time set in the memory M, the operator is informed by light or sound that the time is almost up (not shown). At this time, if the switch SW2 is pressed, the timer T starts counting again from the beginning. In this embodiment, two pages of images can be displayed per belt rotation, but it is of course possible to display images of a larger number of pages. In this case, "belt half rotation" in the description of this embodiment may be changed to "belt rotation 1/number of pages" (see steps 541 and 561). [Effects of the Invention] As explained above, according to the present invention, the non-image page area is displayed on the display means without erasing the formed image, and the displayed image is displayed by moving the image carrier in the opposite direction. It becomes possible to easily protect the confidentiality of images and redisplay images.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an example of the external appearance of the image display device of the present invention, FIG. 2 is a sectional view showing an example of the internal configuration of the device shown in FIG. 1, and FIG. 3 is a configuration of the control section of the device shown in FIG. 1. FIGS. 4 to 6 are flowcharts showing examples of the operation of the control section shown in FIG. 3, respectively. DESCRIPTION OF SYMBOLS 1...Device exterior casing, 2...Display image viewing port (display window), 3...Operation panel, 4...Display window glass, 5...Drive roller, 6...Belt tension roller, 7, 8
...Endless belt-like photoreceptor suspension support roller, 9...Endless belt-like photoreceptor (belt), 10...Laser beam scanning type image exposure device, 11...Semiconductor laser oscillator, 12...Polygon mirror scanner, 13...Fθ lens ( (imaging lens), 14...reflector, 15...transparent plate, 16...toner developer, 35...magnetic developing brush, 56...belt clock sensor, 63...
Home position sensor, 70... Sequence controller, 71... Roller drive motor driver, 7
2...Roller drive motor ( _M1 ), 73...Developer motor driver, 74...Developer motor ( _M2 ), 75...
Developing bias circuit, 76...Scanner driver, 7
7... Laser driver, 78... Unblanking signal generation circuit, 79... Beam detector (horizontal synchronization signal generation circuit), 80... OR gate, HP... Home position signal, BD... Beam detector signal, SCNRDY... Scanner rotation detection signal , Laser
RDY...Laser status signal, Hsync...Synchronization signal,
ANB...Unblanking signal, SW1...Image erase switch, SW2...Image use switch, SW3
...Reverse half-turn switch, Power-OFF...Power erase switch.

Claims (1)

[Claims] 1. An image carrier having a plurality of page areas for forming images, a moving means for moving the image carrier, and an image that can be erased on the image carrier moved by the moving means. an image forming means for forming an image and erasing the image formed on the image carrier; a display means for displaying the image formed on the image carrier; and a moving means and an image forming means. a mode in which the control means moves the image carrier by the moving means to display a non-image page area on the display means without erasing the formed image; An image display apparatus characterized by having a mode in which the image carrier is moved in the opposite direction by the moving means and the formed image is redisplayed on the display means.