JPH0117304B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial 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 and displayed to make it easier to read, the problem is that the number of characters that can be displayed on the screen decreases in inverse proportion to the enlargement rate, and 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, your eyes will 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.
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.

[Problem to be solved by the invention]

However, image display devices using electrophotography form an image by adhering toner to a belt-shaped photoreceptor and display this.
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. In addition, since the device is configured to visually observe the toner image by shining external light onto the photoreceptor on which the toner image has been formed, the portions of the photoreceptor that are in the shadow of the toner are directly exposed to the external light. There is a physical difference between the two parts. Therefore, if this state continues for a long time, there is a risk that adverse effects such as occurrence of image unevenness may occur during the next image formation.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention provides an image carrier 9 for forming an image, moving means 71 and 72 for moving the image carrier, and a method using the moving means. Image forming means 10, 16 for forming an erasable image on a moving image carrier and erasing the image formed on the image carrier, and displaying the image formed on the image carrier. a display means 4; a timer 70 for measuring the time elapsed after the image carrier is stopped by the moving means in order to display an image on the display means; and a control for controlling the moving means and the image forming means. means 70, and the control means causes the moving means to move the image carrier and cause the image forming means to erase the image displayed on the display means when the timer measures a predetermined time. (Fig. 5 52
1) It is a thing.

[Operation] According to the present invention, with the above configuration, even if the operator forgets to erase the screen, the screen is automatically erased after a predetermined period of time, thereby protecting the confidentiality of the image, and displaying the next image. This makes it possible to eliminate any negative influence on the display.

[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, in which 1 is a vertical device exterior casing, and 2 is a display image viewing window formed with a large opening on the front plate surface of the exterior casing 1. 3 is an operation panel arranged on the upper surface of the front panel with the lower part of the front panel protruding forward; 4 is a display window glass installed in the window hole 2; 5, 6, 7, and 8 are the upper parts of the exterior housing 1; and four endless belt-shaped photoreceptor suspension instruction rollers, two each of which are disposed at the bottom, parallel to each other with their axes oriented in the left and right directions of the exterior casing, and individually supported with freely rotatable bearings; 9 indicates the four of them. It is an endless belt-shaped photoreceptor that is suspended and supported by rollers 5 to 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 conductivity while leaving the metal evaporated, a photosensitive material layer (photoconductive layer) such as CdS is formed on the metal-deposited side, and the entire structure is 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 suspension belt 9 rotates counterclockwise without waving, sagging, or slipping. Along with this rotation, the tension side outer surface of the belt 9 moves and passes through the display screen viewing hole 2 from the bottom to the top between the rollers 5 and 8.

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 and vertical movement caused by rotationally moving belt 9, and from 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 a display start command is input by key, the belt 9, which is a 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 bottom to top to the display image viewing window 2 part as the belt rotates and moves to the specified window hole range position, the belt 9 is rotated. 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 the developing brush 35. Immediately after this cleaning, the toner image is subjected to simultaneous exposure and development again. By receiving the toner image, 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 roller drive motor M ₁ that drives the endless belt-like photoreceptor (belt) 9, a driver (drive circuit) for 72;
73 is a driver for the developer motor 74 that drives the developing sleeve (developing brush) 35; 75 is +200V;
This is a developing bias circuit that outputs a developing bias voltage of ~+300V to the developing unit 16, and the operation of these drivers 71 and 73 and the developing bias circuit 75 is turned on and off (intermittent) by a control signal from the sequence controller 70. controlled.

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.
Make sure that the output is 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.
The LaserRDY signal is supplied to the sequence controller 70.

78 is an unblanking signal ANB used to emit laser light in a non-image area in the main scanning direction.
unblanking signal generation circuit that generates 79
detects the laser beam and outputs the laser beam detection signal BD
The unblanking signal generating circuit 78 outputs external equipment (not shown) such as an image reading device or an external storage device according to the detection signal BD from the beam detector 79. Generates a synchronization signal Hsync used to synchronize the video signals transmitted from the main scanning direction. Therefore, the above-mentioned unblanking signal ANB is supplied to the laser driver 77 via the OR gate 80 together with the video signal. Furthermore, the unblanking signal generation circuit 78 also performs detection operations such as detection of synchronization deviation of scanning in the main scanning direction based on the detection signal BD of the beam detector 79, and supplies the detection signal BDRDY 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. Set the flag F in the sequence controller 70 to “0”
(step 402). Home position signal HP generated according to the rotation of the belt photoreceptor 9
If the number of pulses is received (step 403), counting of the number of pulses of the belt clock signal BCLK is started (step 404). Next, turn on the image erase switch SW1 and the power cutoff switch Power on the operation panel 3.
- OFF is not pressed (step 405), the CPU waits until the count of the belt clock signal BCLK reaches a predetermined value n1 indicating the image writing reference position (step 406).

When the belt clock signal BCLK is counted up to a predetermined value n1, a video signal output command is sent to an external device (step 407), and the received video signal is written to the page portion of the belt-shaped photoreceptor 9 (step 407).
408). Subsequently, counting of the belt clock signal BCLK and image writing are continued until the count number of the belt clock signal 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-described writing process to the belt-shaped photoreceptor 9 is completed.

Next, if switch SW1 or Power-OFF is not pressed (step 410), each motor 7
After stopping the rotation of 2 and 74 and stopping the application of the developing bias voltage (step 413), a write end signal is sent to the external device (step 414), and the process returns to the main routine shown in FIG. 6, which will be described later. Shift to operation. This completes the instruction image processing,
An image is displayed on the belt-shaped photoreceptor 9.

On the other hand, if the image deletion switch SW1 or the power cutoff switch Power-OFF is pressed, the above-mentioned step 405 will be affirmatively determined, so the step
The process jumps to step 409, and the process of step 408 is performed until the count number of the belt clock signal BCLK reaches n2. However, at this time, since the external device is not requested to output a video signal, the display image of one page of the belt-shaped photoreceptor 9 is erased by the writing process in step 408. Here, in this example, the number of possible display image pages is assumed to be 2, so
Further, the process proceeds from determination step 410 to step 411, where it is determined whether or not flag F is "1". If the determination is negative, it is determined that the display image erasure of the entire circumference of 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 that the belt-shaped photoreceptor 9 is
It is determined that the object has rotated, and the process proceeds to step 413.
After processing the next step 414, the sixth
The process returns to the main routine shown in the figure and moves on 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.

FIG. 5 shows the main routine of the operating procedure of the apparatus shown in FIG. First, after turning on the power, the device is set to the initial state (step 501), then steps 502 to 504 are performed to monitor input from the operation panel 3, and
Move to the main loop of 507. 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 SW2 is determined.
is on (step 504), whether the power cutoff switch Power-OFF is on (step 506), and whether timer T in the sequence controller 70 has exceeded the time set in memory M. These determination processes are performed sequentially, and if all the determinations are negative, the process returns to step 502, and the above-described determination process of the main loop is repeated until one of the steps is determined to be positive. Thereafter, when an instruction to display an image is received from the operation panel 3 (step 502), the subroutine shown in FIG. After setting the predetermined time T1 (step 512), the above-mentioned timer T is cleared to zero and time measurement is started (hereinafter referred to as clear start) (step 513), and the process returns to step 502 of the main loop again. In this state, the image remains displayed.

When the image deletion switch SW1 is pressed (step 503), step 403 of the subroutine shown in FIG.
The entire display screen of the photoconductor is erased during one rotation of the belt-shaped photoconductor 9 by repeating the processing steps from ~409 twice (step 521), and then, after stopping the timer T, ( Step 522), then return to step 502 of the main loop. 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 ( Step 531), the process returns to step 502 of the main loop and monitors key input.

When the power cutoff switch Power-OFF is pressed (step 506), the belt-like 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 522).

If timer T exceeds the time set in memory M (step 507), step 521 described above is executed.
, turn the belt-shaped photoreceptor 9 once to erase the display image surface, and then stop the timer T (step
522), 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.

[Effects of the Invention] As explained above, according to the present invention, an image can be displayed for a long time by automatically erasing the displayed image if the image carrier is not moved for a predetermined period of time after displaying the image. This eliminates the possibility of the display image being left unattended, thereby ensuring the confidentiality of the displayed image.
Also, it becomes possible to remove the adverse influence on the next image display.

[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 and 5 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 hole (display window), 3...Operation panel, 4...Display window glass, 5...Drive roller, 6...Belt tension roller, 7, 8...
Endless belt-shaped photoconductor suspension support roller, 9... Endless belt-shaped photoconductor (belt), 10... Laser beam scanning type image exposure device, 11... Semiconductor laser oscillator, 12... Polygon mirror scanner, 13... fθ lens image 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, 72
...Roller drive motor ( _M1 ), 73...Developer motor driver, 74...Developer motor ( _M2 ), 75...Developer bias circuit, 76...Scanner driver, 77
...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-rotation switch, Power-OFF...Power erase switch.

Claims (1)

[Scope of Claims] 1: an image carrier for forming an image; a moving means for moving the image carrier; and an image carrier for forming an erasable image on the image carrier moved by the moving means; an image forming means for erasing the image formed on the image carrier; a display means for displaying the image formed on the image carrier; and an image forming means for displaying the image on the display means by the moving means. It has a timer that measures the time since the carrier stops, and a control means that controls the moving means and the image forming means, and the control means controls the moving means when the timer measures a predetermined time. An image display device characterized in that the image carrier is moved to cause the image forming means to erase the image displayed on the display means.