JPS59112372A - Display device of image - Google Patents

Abstract

PURPOSE:To protect secrets and to remove bad influences to the succeeding display image by turning an image carrier in the positive direction and displaying a non-image surface when the time displaying the same image has passed a prescribed period. CONSTITUTION:When a reverse half rotation switch SW3 on an operation board 3 is depressed, a belt-like photosensitive body 9 is reversely turned by a half of rotation to display the image of the just preceeding page formed on the photosensitive body 9 again, and after setting up a prescribed time in a memory, the clear start of a timer is executed. When the clocking of the timer exceeds the time set up in the memory, the photosensitive body 9 is turned by a half of rotation in the normal direction to display a non-image surface. In addition, the approach of the time-up of the timer is informed to the operator by light or sound immediately before the time set up in the memory.

Description

Detailed Description of the Invention Technical Field The present invention relates to an image display device that forms an image on an image bearing member such as a photoreceptor belt or an insulating drum. A terminal display or league device that reproduces and displays signalized image information or image information stored as a soft copy on a magnetic tape or the like as a visible image, or an office automation device such as a copying machine;
This is an improved image display device suitable as an image monitor device in other image-related equipment.

2. Description of the Related Art CRT (cathode ray V) display devices and liquid crystal display devices have been put into practical use as image devices that visually display image information converted into electrical signals.

Among these, CRT display devices are the most commonly used and highly reliable devices, but they can be used to display fine-sized characters such as those used in newspapers and magazines, especially fine-grained characters with a large number of strokes such as kanji. Displaying characters in their original size has nothing to do with resolution. Although the text is enlarged to make it easier to read, the number of characters that can be displayed on the screen decreases in inverse proportion to the enlargement rate, resulting in a decrease in the amount of information per screen. 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 are also difficult to manufacture with large screens.
There is also a problem that it becomes expensive.

Therefore, as a third image display device that does not have the above-mentioned drawbacks, the present applicant previously proposed an image display device using electrophotography (Japanese Patent Application No. 1137410-1977).
No. 413). This display device reproduces and displays image information as a toner image, and has excellent resolution and easy-to-see images.
A device with a large screen can be manufactured at a relatively low cost and is a highly reliable device.

However, an image display device using electrophotography forms an image by attaching toner to a belt-shaped photoreceptor and displays it, and an electric image display method such as a CRT etc. Therefore, even if the displayed image is no longer needed, it 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 protecting the sparrow. In addition, since the device is constructed so that the toner image is visually observed by shining external light onto the photoreceptor on which the toner image has been formed, the parts of the photoreceptor that are shaded by 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 unevenness of the image will occur during the next image formation.

The object of the present invention is to eliminate the above-mentioned drawbacks, and to protect the secret by allowing the image to be redisplayed at any time within a certain period of time, and to prevent any adverse effects on the next displayed image. An object of the present invention is to provide an image display device that eliminates the above problems.

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 l is a vertical device exterior, and 2 is an exterior housing 1.
Display image peephole formed with a large opening on the front panel surface, 3
4 is a control panel arranged on the upper surface of the front panel with its lower part projected forward; 4 is a display window glass placed in the window hole 2; 5. f
l,? and 8 are 2 each at the top and bottom inside the exterior case.
Four wooden endless belt-shaped photoconductor suspension instruction rollers are arranged parallel to each other with their axes in the left-right direction of the exterior casing, and individually rotatably supported on bearings; 9 denotes the four wooden rollers 5 to 5;
This is an endless belt-shaped photoreceptor that is suspended and supported by 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 to the surface of the metal-deposited surface, a layer of photosensitive material such as CdS (
It is entirely flexible and consists of a photoconductive layer (photoconductive layer) formed thereon, and is suspended and supported by two four-wooden rollers with the photosensitive material layer on the outside.

Among the four rollers 5 to 8, roller 5 is used as a driving roller to transmit the rotational force of a motor M (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 8. Therefore, the drive roller 5
When the belt 8 is rotated counterclockwise in FIG. 2 by the motor, the suspension belt 8 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.

IO is a laser beam scanning type image exposure device fixedly arranged in the inner space of the hanging belt 9, and includes a semiconductor laser oscillator 11, a polygon mirror scanner 12, an fθ lens (imaging lens) 131, a reflecting mirror 14, and a transparent plate 15. and has. The transparent plate 15 is connected to the above-mentioned belt hanging support rollers 7 and 8.
It is a horizontally long transparent flat plate made of glass or plastic that is placed in pressure contact with the inner surface of the tension belt part between them with an appropriate amount of 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 directed from a semiconductor laser oscillator 11 at the front of the drawing toward a rotating polygon mirror scanner 12 at the back of the drawing. oscillates. The laser beam L incident on the scanner 12 is swung in the belt width direction, and is swung through the fθ lens 13. Reflector 1
4. Belt 8 between rollers 7 and 8 in the path of transparent plate 15
The laser beam enters the inside of the belt and is scanned in the width direction of the belt. As a result, this laser beam scanning is set as main scanning,
Image exposure is performed with a laser beam from inside the belt, using the rotational movement of the belt 8 as a sub-scan.

Reference numeral 16 denotes a toner developing device disposed on the outer surface side of the belt portion between rollers 7 and 8. The transparent plate 15 is arranged with its lower surface slightly protruding downward from the common tangent below the rollers 7 and 8, and is brought into pressure contact with the inner surface of the belt 9. The end surfaces 15□ and 152 on the side and exit sides are chamfered and rounded so that the belt 9 can come into contact with it smoothly. In addition, this transparent plate 15 prevents the belt 9 from waving during rotation, vertical movement of the belt 9 caused by downward movement, and contact with the magnetic developing brush 35 of the developing device 16, and prevents exposure. Improve resolution by keeping the position constant.

First, after setting the necessary 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 command is input manually, the belt 8, 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 toner in the developing device 16 acts on the outer surface of the belt, so 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 portion as the belt rotates and moves to the specified window hole range position, the belt 9
rotation is 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 8 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, and immediately after this cleaning, it is exposed to light. A new toner image is formed by undergoing simultaneous development. In this way, the image information is reproduced and displayed as a toner image, and the image is exposed using a very thin laser aperture, so it is possible to display fine text and other images clearly and easily. In addition to being able to display high-resolution images, it has an extremely simple configuration that does not require corona charging means or special cleaning means because it uses a simultaneous exposure toner application method, and large-screen products can be manufactured at a relatively low cost. A highly reliable display device with less deterioration of the photoreceptor and photoreceptor can be constructed.

FIG. 3 shows an example of the configuration of the control section of the apparatus shown in FIG. Based on this, the system recognizes the actions specified by the operator and controls and manages the predetermined actions. Also,
The operation panel 3 includes switches for setting conditions such as calling up image information and specifying the display position, as well as switches 5Wl-
There are 9W3' and switches for power on and power off. The switch SWI is a switch that supports erasing the image displayed on the photoreceptor 9, and the switch SW2 is a switch that notifies the sequence controller 70 that the operator is using the image displayed on the photoreceptor 8. The switch SW3 is a switch that supports rotating the belt-shaped photoreceptor 9 by half a rotation in the reverse direction, and the power-off switch Power-OFF is a switch that turns off the power through the sequence controller 70. 71
is a roller drive motor (M, ) that drives an endless belt-like photoreceptor (belt) 8; a driver (drive circuit) of 72;
3 is a driver for the developer motor 74 that drives the developing sleeve (developing brush) 35; 75 is +200v to +300v;
This is a developing bias circuit that outputs a developing bias voltage to the developing unit 16, and the on/off (intermittent) of the operation of these drivers 71 and 73 and the developing/halous circuit 75 is controlled by control signals from the sequence controller 70. be done.

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 8, respectively. , the sequence controller 70 receives these signals BCLK and HP, and controls each driving section 71 .
The drive timings of 73 and 75 are determined and appropriate sequence control is performed. The output signal HP at that time indicates the reference position 1, for example, the tip position of the display page portion of the photoreceptor 9. Therefore, for example, every time the belt-shaped photoreceptor 9 rotates, the sensor 63
If the light-shielding plate rotates once and it is possible to write two pages on the photoreceptor 8, the rear part of the light-shielding plate is provided at two equally spaced locations, so that the light-shielding plate rotates once. Make sure that the signal HP is output twice every time.

76 is a scanner driver 8 that drives the scanner 12 that scans the laser beam from the laser oscillator 11 in the main scanning direction, and also sends a signal 5CNRDY indicating whether or not the scanner 12 is rotating at a constant rate to the sequence controller 70. supply to. 77 is a laser driver that drives the laser oscillator 11, and a signal La5er indicating whether or not the laser oscillator 11 has an abnormality such as a temperature control abnormality.
The RDY signal is coupled to the sequence controller 70.

78 is an unblanking signal generation circuit that generates an unblanking signal AND used to emit a laser beam in a non-image area in the main scanning direction; 78 is an unblanking signal generation circuit that detects the laser beam and generates a laser beam detection signal BII. 78, and the beam detector 7 is supplied to the unblanking signal generating circuit 78.
External devices such as an image reading device and an external storage device according to the detection signal BD of No. 8.

It generates a synchronization signal Hsync used to synchronize the video signals transmitted from (not shown) in the main scanning direction. Therefore, the above-mentioned unblanking signal ANB is supplied to the laser driver 77 via the OR gate 8° together with the video signal. Further, the unblanking signal generation circuit 78 also performs detection operations such as detection of synchronization deviation in scanning in the main scanning direction based on the detection signal BD of the beam detector 78, and supplies the detection signal BIIRDY 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 image information from the operation panel 3, each motor 72 and 74 and the developing bias voltage are turned on (step 4).
01), a flag F in the sequence controller 70 used to distinguish between half a rotation and one rotation of the belt-shaped photoreceptor 8 is set to '0°'' (step 402). When 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). Next, press the image erase switch SWI and power cutoff switch Power on the operation panel 3.
- If none of OFF is pressed (step 40)
5) Wait until the count number of the belt clock signal BCLK reaches a predetermined value nl indicating the image writing reference position (step 40B).

When the belt clock signal BCLK is counted up to a predetermined value nl, a video signal output command is transmitted to an external device (step 407), and the received video signal is written in the page portion of the belt-shaped photoreceptor 8 (step 408). continue,
Counting of the belt clock signal BC:LK 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 in2 (step 409), the writing process to the belt-shaped photoreceptor 8 described in I- is completed.

Next, if the switch SWI 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. At step 414), 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 instruction image processing is completed, and an image is displayed on the belt-shaped photoreceptor 9.

On the other hand, if the image erasing switch SWI or the power cutoff switch Power-OFF is pressed, the double step 405 becomes an affirmative determination, so the process jumps to step 409 and waits until the count number of the belt clock signal BCLK reaches n2. , performs the process of step 408. However, in this case, we are not requesting the external device to output a video signal, so
By the writing process in step 408, the belt-shaped photoreceptor 8
The display image for one page of is erased. Here, in this example, it is assumed that the number of possible display image pages is 2, so proceeding to the determination step 410 to 411, it is determined whether the flag F is "l", and in the case of a negative determination, It is determined that erasure of the display image around the entire circumference of the belt-shaped photoreceptor 9 has not been completed, and after resetting the flag F to °°l°' in step 412, the process returns to step 4Q3.
Go back to ” and repeat the two steps. Then step 4
Since the flag F is determined to be "'1" in step 11, it is determined that the bell I-shaped photoreceptor 9 has rotated once, and the process proceeds to step 413, where the process of the next step 414 is performed. Then, the process returns to the main routine shown in FIG. 8, which will be described later, 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.

Further, as will be described later, when the timer setting time has elapsed, the process jumps from step 405 to step 408, and the process of step 408 is performed until the count number of the belt clock signal BCLK reaches 12, and the non-image for one page is processed. The surface is formed, and when the number n2 is reached, the process proceeds to step 410. Since it is not necessary to rotate the belt-shaped photoreceptor 8 once, a negative determination is made in step 410, and after processing steps 413 and 414, the process returns to the main routine shown in FIG. 6, which will be described later, and performs the next operation. to move to. This completes the belt half rotation 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 rotation instruction for rotating the belt-shaped photoreceptor by half a rotation in the opposite direction is given. First, if there is an instruction from the operation panel 3 to rotate the belt-shaped photoreceptor 8 half a rotation in the opposite direction, the roller drive motor 72 and the developer motor 74 are turned on and rotated in the opposite direction, and the developer bias power is turned on to the developer 1B. (step 421). Next, in step 422), the system waits until the home position signal HP is generated, and in response to the reception of the home position signal HP, the belt clock signal BCLK is activated.
starts counting the number of pulses (step 423).

A predetermined value n in which the count number of the belt clock signal BCLK indicates the reverse half-rotation position of the belt-shaped photoreceptor 9.
3 (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/heyas voltage are stopped (step 425), and as will be described later. The process returns to the main routine shown in FIG. 6 and moves on 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 following relationship exists between the count numbers n3 and n2 described above.

n3=n-n, where n indicates the number of pulses of the belt clock signal BCLK occurring between the generation of the first home position signal HP and the generation of the next 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) Next, the process moves to the main loop of steps 502 to 507 in which input from the operation panel 3 is monitored. That is, it is determined whether there is an instruction to call up the image information (step 502), and the image deletion switch SWI is
is on (step 503), judgment is made on whether the image use switch SW2 is on (step 504), and judgment is made on whether the reverse half rotation switch SW3 is on (step 5).
05), determine whether the power cut-off switch Power-OFF is on (step 506), and determine whether the timer T in the sequence controller 70 has exceeded the time set in the memory H. , if all of the determinations are negative, the process returns to step 502, and the above-described determination processing of the main loop is repeated until any step is determined to be affirmative. Thereafter, when an instruction to display an image is received from the operation panel 3 (step 502), the subroutine shown in FIG. After setting Tl for a predetermined time (step 512)
, clear the above-mentioned timer T to zero and start timing (hereinafter,
(referred to as clear start) (step 513), and the process returns to step 502 of the main loose. In this state, the image remains displayed.

When the image deletion switch SWl is pressed (step 503
), steps 403 to 408 of the subroutine shown in FIG.
By repeating the processing procedure twice, the entire display screen of the photoconductor is erased during one rotation of the belt-shaped photoconductor 9 (step 521), and then, after stopping the timer T, (step 522) , the process returns to the main loose step 502 again. In this state, the belt-shaped photoreceptor 8-]
In the second, no image is formed.

When the image use switch SW2 is pressed (step 504), if the timer T is operating, it is cleared to zero, and if the timer T is stopped, it is cleared to zero, and if the timer T is stopped, it is cleared to zero, and the timer T remains stopped. Yes (step 531), the process returns to main loose step 502 and key manual monitoring is performed.

If the reverse half-rotation switch SW3 is pressed (step 505
), by executing the subroutine shown in FIG. 5, the belt-shaped photoreceptor 9 is rotated in the reverse half rotation to display the image of the previous page formed on the photoreceptor 9 again (step 541).
), then after setting TI in memory for a predetermined time, (
Step 542), clear start the timer T (
Step 543), return to step 502 of the main loose.

When the power-off 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 55
2).

If the timer T exceeds the time set in the memory (step 50?), the belt-shaped photoreceptor 9 is rotated by half a rotation to display the non-image surface by executing the subroutine shown in FIG. 4 (step 5θl). ), □If the content of the memory at this time is TI (step 562), after changing the content of the memory to T2 (step 583), clearing and starting the timer T (step 564),
Return to step 502 of the main loose.

On the other hand, if the contents of memory X are not T1, timer T
After stopping (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 H, the operator is notified 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 time again from the beginning.

In this embodiment, it is assumed that two pages of images can be displayed for every l-1 rotation of the bell, but it is of course possible to display images of a larger number of pages. In this case, in the description of this embodiment, ``belt half rotation'' may be replaced with ``belt 1 rotation''.
/page number rotation'° (see steps 541 and 581).

Effects As explained above, according to the present invention, in an image display device that forms and displays an image on an image carrier, if the time for displaying the same image has elapsed over a predetermined time, the image carrier is rotated. When the non-image surface is displayed and the non-image surface is displayed, the image remains on the image carrier, and if a certain period of time has passed since the non-image surface was displayed, the image on the image carrier is Since the image is deleted, the image does not remain displayed for a long time, the secret is protected and the negative influence on the next image is removed, and the image can be displayed again at any time within a certain period of time. The effect is obtained.

[Brief explanation of the drawing]

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 in FIG. 3, respectively. DESCRIPTION OF SYMBOLS 1... Equipment exterior casing, 2... Display image viewing hole (display window), 3... Operation panel, 4... Display window glass, 5... Drive roller, 6... Belt tension roller, ? , 8... Endless belt-shaped photoreceptor suspension support roller, 8...
... Endless belt-shaped photoreceptor (belt), lO ... 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... Magnet I-manufactured developing brush, 58... Belt clock sensor, 83... Home position sensor, 70...Sequence controller, 71...Roller single motion motor driver, 72...Roller drive motor (Ml), 73...Developer motor driver. 74...Developer motor (M2), 75...Developer bias circuit, 76...Scanner dry/to, 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, 5CNRDY...scanner rotation detection signal, aser
RDY...Laser status signal, Hsync...Synchronization signal, ANB...Unblanking signal, SWI...Image erase switch, SW2...Image use switch, SW3...Reverse hand rotation switch, Power-OFF ...Power erase switch. Patent applicant: Canon Co., Ltd. Figure 5■ Next operation

Claims (1)

[Scope of Claims] 1) In an image display device that forms an image on an image carrier and displays the image, when the time for displaying the same image has elapsed, the image carrier is rotated in the forward direction and turned off. An image display device characterized by comprising means for displaying an image plane. 2. The apparatus according to claim 1, further comprising means for erasing the image on the image carrier when a predetermined period of time has elapsed since the non-image surface was displayed by the means. image display device.