JPH0558197B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to an image display device that forms an image on an image carrier, and particularly to an operation sequence thereof.

[Prior art]

2. Description of the Related Art Conventionally, display devices have been devised that form an image on an endless belt-like photoreceptor and display the image.

This conventional device will be explained using FIGS. 1 to 3.

1 is a vertical device housing outside the device; 2 is a display image viewing window hole formed in a large opening on the front panel surface of the exterior housing 1; 3
numeral numeral 4 has an operation panel arranged on the upper surface of the front panel with the lower part thereof protruding forward; numeral 4 indicates a display window glass pasted in the window hole 2; Four endless belt-like photoreceptor suspension support rollers are arranged parallel to each other with two axes extending in the left and right directions of the exterior casing, and individually rotatably supported by bearings; 9 indicates the four rollers 5; This is an endless belt-shaped photoreceptor that is suspended and supported by .

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. It is a flexible product made by forming a photosensitive material layer (photoconductive layer) such as CdS on the metal-deposited surface side by imparting conductivity while leaving the metal evaporated. It is suspended and supported by the four rollers mentioned above.

Reference numeral 10 denotes a laser beam scanning type image exposure device fixedly arranged in a space inside the hanging belt 9, which includes a semiconductor laser transmitter 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.

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 disposed with its lower surface slightly protruding downward from the common tangent below the rollers 7 and 8, and the belt 9
The plate 15 is in pressure contact with the inner surface of the plate 15.
The single surfaces 15 ₁ and 15 ₂ on the belt entry side and the belt exit side are chamfered and rounded so that the belt 9 can contact and move smoothly. The transparent plate 15 also supports the vertical movement of the rotating belt 9 and the development device 16.
This prevents vertical vibration of the belt 9 caused by contact with the magnetic developing brush 35, maintains the exposure position constant, and improves resolution.

39 is a chain stretched at a predetermined position on the side end of the belt 9 or near both side ends of the belt 9 and driven by the drive roller 5; 40 is a light shielding plate protruding from a predetermined position of the chain 39; An operation timing signal is generated when the light shielding plate 40 crosses the groove of a photo interrupter 41 disposed along the moving surface of the belt 9.

However, in this type of device, the stopping position of the belt is not constant due to inertia and may shift, and this shift may accumulate and the belt seam may extend beyond the image display surface, resulting in an unsightly image.

[Purpose] Therefore, an object of the present invention is to eliminate the above-mentioned drawbacks and obtain an easy-to-see image. That is, a belt-shaped recording medium having seams capable of forming image layers for at least two screens, a driving means for rotating the recording medium, an input means for inputting image data, and an input means for inputting image data by the input means. an image forming means for forming an image on the recording medium based on the image data;
An image display device comprising: a display section that displays an image formed on the recording medium; and an output means that outputs a request signal requesting input of image data; a first detecting means for detecting whether or not the recording medium has been moved; a second detecting means for detecting a moving distance of a predetermined portion of the recording medium from the predetermined position when the rotation of the recording medium has stopped; An object of the present invention is to provide an image display device including a control means for adjusting the output timing of the request signal for displaying the next image according to the moving distance detected by the second detection means.

〔Example〕

The present invention will be described in detail below with reference to the drawings.

FIG. 4 shows an example of the configuration of the image display device of the present invention, and common parts with the conventional example are designated by the same numbers. Here, 50 is a plate stay that connects the endless belt-like photoreceptor 9 and the two chains 39, and is attached at a position such as a joint 51 of the belt-like photoreceptor 9, for example.
Through this plate stay 50, the rotation of the drive roller 5 is transmitted to the photoreceptor 9 from a chain 39 that meshes with sprockets 52 attached to both ends of the roller 5, and the rotation of the drive roller 5 is transmitted to the photoreceptor 9. Ensure proper rotation. Also, the number of meshing parts (required number of links) N of the chain 39 is determined by the sprocket 5.
It is set to be a common multiple of the number of teeth Z of 2 and the number of pages P of images that can be displayed with one rotation of the photoreceptor 9. For example, when the number of teeth Z of the sprocket 52 is "25" and the number of pages P is "2", the number N of meshing parts of the chain 39 is set to "200". This results in
Position of teeth of sprocket 52 and belt-shaped photoreceptor 9
The position of the image and the page display position on the belt-shaped photoreceptor 9 can always be maintained in a constant correspondence relationship.

Reference numeral 53 denotes an extension shaft extending from the rotating shaft of the drive roller 5, and a series of gear trains 5 driven by the extension shaft 53.
7 to 60, a circular light shielding plate 61 is fixed to the shaft end of the output side gear 60, and a means for detecting the home position of each page is provided by this circular light shielding plate 61 and a photo interrupter 62 passing through the light shielding plate 61. A photo encoder 63 is configured to be used as a home position sensor. Therefore, the ratio of the number of teeth (gear ratio) of the above-mentioned gear train is such that the light shielding plate 6 is
Set so that 1 always rotates once. For example, number of teeth Z = 25, number of pages P = 2, number of chain meshing parts N =
200, if the tooth ratio G is set to 1/8, the light shielding plate 60 rotates once for each rotation of the belt 9, and the home position detection signal for each page is generated from the photo interrupter 62. I can do it.

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). This motor _M1 has a built-in pulse encoder and is used as a signal generating means (belt clock generating means) to obtain the operation timing for each page. At least one of the other three rollers 6 to 8, for example roller 6, acts as a belt tension roller, and the suspended belt 9
give tension to Therefore, when the drive roller 5 is driven to rotate counterclockwise in FIG. 2 by the motor _M1 , the suspension belt 9 rotates counterclockwise without slack or slip. With this rotation, the tension side outer surface of the belt 9 moves and passes through the display image viewing hole 2 from bottom to top between the rollers 5 and 8.

In the image exposure apparatus 10, an intermittent laser beam L corresponding to time-series electric pixel signals supplied from an electronic computer, an image reading device, etc. is transmitted from a semiconductor laser transmitter 11 at the front of the drawing to a rotating polygon mirror scanner at the back of the drawing. It is oscillated towards 12.
The laser beam L incident on the scanner 12 is swung in the belt width direction and passes through the fθ lens 13, the reflector 14, and the transparent plate 15, and then reaches the belt 9 between the rollers 7 and 8.
The laser beam enters the inner surface of the belt and is scanned in the width direction of the belt. Thereby, an image is exposed by the laser beam from the inner surface of the belt, with this laser beam scanning as a main scanning and the rotational movement of the belt 9 as a sub-scanning.

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 manipulation exposure of designated image information is then initiated on the inner side 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 designated window range position, once the belt 9 rotates. movement is stopped. As a result, an image is displayed in the two window holes,
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 image is displayed. After the image is displayed, the toner image on the outer surface of the belt reaches the toner developing unit 16 with the rotation of the belt, where it is cleaned and removed by a developing brush 35, and immediately after this cleaning, it is once again subjected to simultaneous exposure and development. As a result, a new toner image is formed.

In this way, the image information is reproduced and displayed as a toner image, and the image exposure is performed using a very narrow laser beam L, so it is possible to display high-resolution images that can clearly display fine text and other images. In addition to being able to display images, it has an extremely simple configuration that does not require corona charging means or special cleaning means because it uses a toner application method at the same time as exposure.
A display device with a large screen can be manufactured at a relatively low cost and has high reliability with less failure and photoreceptor deterioration.

Therefore, in this embodiment, the above endless belt-shaped image display device (hereinafter referred to as a soft display) is combined with an image reading device (not shown), and the image signal obtained by the image reading device is received by the soft display. This is visualized and displayed. FIG. 5 shows a block diagram of the sequence control section of the soft display. Figures 6 and 7
8 are detailed timing charts of this sequence control section.

The sequence control section shown in FIG. 5 mainly consists of a counting circuit A 106 and a counting circuit B 107, which count clocks A and B, respectively, and output a required signal at an appropriate timing. Clock selection circuit (SELA, SELB)
Each of the clocks 10 and 105 selects either the reference clock from the reference clock generator 102 using a well-known oscillator or the belt clock (BELTCLK) at an appropriate timing, and supplies them as clocks A and B to their respective counting circuits. This is what you input. BELTCLK is a clock output from a pulse encoder 113 built into the motor 112 that drives the belt.
The preset circuit 103 is a circuit that generates a preset value for the counting circuit A106. The count value of the counting circuit B107 that counts the clock B is input to the timing signal generation circuit 108, which outputs one of the VSYNC', MON, and MOFF signals (described later) according to the count value. MON, MOFF
The signal is input to a drive circuit 111 that drives each drive section of the soft display. This drive circuit 11
1 drives the belt drive motor, developer motor, and developing bias. The belt drive motor 112 is controlled in speed by feeding back a signal from a built-in pulse encoder 113 to the drive circuit 111, and rotates at a constant speed.

Reference numeral 110 is an RDY determination circuit that detects the usable state (hereinafter referred to as RDY state) of a semiconductor laser oscillator (11 in FIG. 4) and a polygon mirror scanner (12 in FIG. 4) used in the soft display. 100 is the home position (hereinafter
This circuit shapes the waveform of the HP signal detected by the HP sensor (42 in FIG. 4).
Reference numeral 101 denotes an HP counter, which is a circuit for counting HP signals, and this circuit detects an abnormality when the photosensitive belt 9 continues to be driven due to some abnormality. 109 is when the power is turned on or
This is a PON signal generator that is triggered by an abnormal operation signal of the photoreceptor belt detected by the HP counter 101 and outputs a PON signal. A pulse generator 114 is a one-shot multivibrator, which generates a pulse when a PON signal is input, and sets the R-S flip-flops 114 and 115.

The specific operation of the sequence control section will be explained below with reference to timing charts shown in FIGS. 6, 7, and 8.

Sequence control operations can be roughly divided into two: when the power is turned on and during normal operation, that is, when receiving an image signal from the reading device. FIG. 6 is a timing chart when the power is turned on. When the soft display is powered on, the photoreceptor belt is rotated forward and the photoreceptor belt is stopped at a predetermined position.
After the previous rotation, the laser and scanner are RDY.
When the state is reached, an RDY signal indicating that the soft display can be used is output to the image reading device. In FIG. 6, Vcc indicates the power supply voltage. When Vcc is turned on, the power supply voltage stabilizes due to the delay effect of RC in Figure 5, and then PON
By inputting a signal to the signal generator 109,
PON signal is output. The counting circuit B107 starts counting the clock B in response to the rising edge of the PON signal. At this time, clock B is set in the R-S flip-flop 116 by the action of the PON signal, and becomes the reference clock by the selection of SELB 105. Counting circuit B107 is Pc
After counting the number of clocks B, the timing signal generator 57 outputs the MON signal to the drive circuit 111 to start driving the belt drive motor. At this point, the counting operation of counting circuit B stops. This operation starts the rotation of the photoreceptor belt, that is, the forward rotation. After that, when the photoreceptor belt rotates a certain distance,
The HP detection circuit 100 detects the HP signal, and in synchronization with it, a preset value is transferred from the preset circuit 102 to the counting circuit A106, and the counting circuit A106 starts counting operation. At this time, clock A is PON
It becomes a reference clock by the action of the signal.
Pa clocks A (Pa equals the preset value)
is counted, the DREQ′ signal is output, and this
The DREQ' signal starts the counting operation of the counting circuit B107. At this time, clock B is the reference clock as in the previous state. And counting circuit B10
After counting Pd clocks B, the timing signal generator 108 outputs a VSYNC' signal. When the PON signal is valid (that is, when the power is turned on), the VSYNC' signal is
107 is used as a counting operation start signal. At the same time, clock B is switched from the reference clock to the belt clock (BELTCLK) by the VSYNC' signal.
can be switched to Therefore, counting circuit B107
starts counting the belt clock (BELTCLK) again after outputting the VSYNC' signal. At this point, the rotation of the photoreceptor belt is being driven in a state where the rotation has changed from the start-up to rotation at a constant speed. The counting operation of the counting circuit B107 continues until the belt clock (BELTCLK) reaches Pe pieces.
When Pe counts of BELTCLK, an MOFF signal is output from the timing signal generator 108, and the driving of the photosensitive belt is stopped. Also, the MOFF signal is
Enters the PON signal generator and stops outputting the PON signal. The soft display is configured so that the HP signal is detected just before the photosensitive belt stops, so the HP signal is detected just before the MOFF signal is output.
The signal is input to counting circuit A106. In response to the HP signal, the counting circuit A106 loads a preset value and starts counting. Furthermore, clock A is switched from the reference clock to the belt clock (BELTCLK) by the HP signal.
The counting circuit A106 counts the belt clock (BELTCLK). This counting operation is interrupted because the belt clock (BELTCLK) cannot be obtained due to the drive stop of the photosensitive belt. Therefore, the count value of the counting circuit corresponds to the moving distance of the photosensitive belt after the HP signal is input. The above operation is almost the same as the normal operation when displaying image information, and the difference from the normal operation is that the signals DST and VSYNC sent from the image reading device are generated independently within the sequence control unit. This is because a forward rotation operation is executed. That is, the PON signal
The VSYNC′ signal corresponds to the DST signal. During the pre-rotation operation, the RDY signal indicating that the soft display is ready for use on the image reading device is forcibly disabled by the PON signal inverted by the inverter, and after the pre-rotation is completed, the PON signal disappears and the laser is turned off. The RDY signal is enabled when the scanner is in the RDY state.

Next, the normal operation sequence will be explained with reference to FIG. First, a signal DST instructing the start of operation of the soft display is input to the soft display from an image reading device (not shown). The soft display is controlled by the counting circuit A106 by the DST signal.
Counting circuit B108 starts counting operation at the same time.
Counting circuit A106 (clock A serves as a reference clock based on the HP signal) has its count value stopped from the HP signal detection position in the previous operation, as explained in the operation sequence at power-on. The value corresponds to the position of the photosensitive belt. If the preset value is Ppre, the value counted from the time the HP signal is detected until the photosensitive belt stops is P _B , and the total number of counts of the counting circuit A106 is Pfull.
When the DST signal is input, the counting circuit A106
The count number Pe until the DREQ′ signal is output is Pe
=Pfull−(Ppre+P _B ). Therefore, the count value
When P _B becomes larger, the count value Pe becomes smaller,
Conversely, when P _B is small, Pe becomes large. This may cause variations in the stop position due to the inertia of the photoreceptor belt, or DREQ, which instructs the image reading device to output an image signal.
Variations in the time from the signal until the VSYNC signal indicating the leading edge of the image signal is input to the soft display can be absorbed. In other words, if the stop position of the photoreceptor belt is short from the HP signal indicating the absolute position on the photoreceptor belt, the timing of outputting the DREQ signal from the DST signal will be delayed, and vice versa.
By advancing the output timing of the DREQ signal, the cumulative error of the stop position deviation of the photoreceptor belt is eliminated, and the seam of the photoreceptor belt is always located outside the effective image area.

The counting circuit B107 counts the reference clock whose clock B is selected by the DST signal, and when the count value reaches Ph, the timing signal generator 108 outputs the MON signal and starts driving the photoreceptor belt. Thereafter, in response to the DREQ signal, the counting circuit B107 starts counting again in response to the VSYNC signal sent from the image reading device. At this time, clock B is set to BELTCLK by the VSYNC signal.
It is becoming. After the counting circuit B107 finishes counting the number of BELTCLK corresponding to the effective image area,
A timing signal generation circuit 108 generates an MOFF signal to stop the photoreceptor belt. This operation ensures that the image display position always has a constant positional relationship with respect to the display screen. Counting circuit A106
The preset value is loaded and the BELTCLK is activated by the HP signal detected just before the photosensitive belt stops.
As described above, when the photoreceptor belt is stopped, a count value corresponding to the traveling distance of the photoreceptor belt from the time the HP signal is detected until the photoreceptor belt stops is held. Next, the abnormal operation detection means and processing of the photosensitive belt by the HP counter 101 will be described. This abnormal operation may be caused by noise, etc.
FIG. 8 shows a timing chart regarding the detection and processing means when the photosensitive belt continues to be driven.

The HP counter 101 is cleared by the rising edge of the DST signal transmitted from the image reading device (see FIG. 8). After this clearing operation, the detected HP signal is counted, and in this embodiment, when the counted value reaches 3 pulses, it is detected as an abnormal operation of the photosensitive belt (as shown in FIG. 8). If this abnormality is detected, the HP counter 101 will be ACNT
The signal is output to the PON signal generator 109. At the same time, the RDY signal output to the image reading device is invalidated to notify that the soft display is in an unusable state. Here, PON signal generator 10
By receiving the ACNT signal, numeral 9 performs sequence control for performing the same process as that at the time of power-on described above, that is, pre-rotation process (in FIG. 8). In other words, by performing the pre-rotation process when the power is turned on, the rotation of the photosensitive belt due to abnormal operation is stopped at an appropriate position.
After the above processing is executed, the PON signal is canceled, the ACNT signal is also canceled, and the RDY signal becomes valid. Note that indicates normal operation.

〔effect〕

As described above, according to the present invention, by shifting the output timing of the image information request signal according to the stop position of the image carrier in the previous image display, the seam of the image carrier is displayed on the image display section. First, the image can be displayed at an appropriate position on the image carrier, resulting in an easily viewable image.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an example of the appearance of a conventional device;
2 is a sectional view showing an example of the internal configuration of the device shown in FIG. 1, FIG. 3 is a perspective view showing a main part of FIG. 5 is a partially cutaway perspective view, FIG. 5 is a block diagram showing an example of the configuration of the control section of the device shown in FIG. 4, and FIG.
7 and 8 are time charts showing the operation of the control section in FIG. 5.

Claims (1)

[Scope of Claims] 1. A belt-shaped recording medium having a seam and capable of forming an image for at least two screens; a driving means for rotating the recording medium; an input means for inputting image data; In an image display device, the image display device includes an image forming unit that forms an image on the recording medium based on image data input by the input unit, and a display unit that displays the image formed on the recording medium, requesting input of image data. output means for outputting a request signal to perform the rotation; first detection means for detecting whether or not the predetermined portion of the recording medium has rotated to a predetermined position; a second detection means for detecting the movement distance of the predetermined portion of the recording medium from the recording medium; and adjusting the output timing of the request signal for displaying the next image according to the movement distance detected by the second detection means. An image display device comprising: a control means for controlling;