JPS6084566A - Image display device - Google Patents

Abstract

PURPOSE:To position a window and an image correctly and obtain an easy-to- see image by counting a specific number of pulses generated synchronizing with the movement of a belt and stopping the belt. CONSTITUTION:While the transparent belt 9 obtained by forming a photoconductive layer on a polyester sheet after vapor-depositing metal is exposed with the beam of a laser 11 which is modulated by an image signal, a developing device 16 including a magnetic brush impressed with a developing bias is put in operation to form a toner image. Simultaneously, the belt 9 is driven by a driving roller 5 to rotate at a constant speed. Pulses from the rotary encoder of the motor as a driving source are counted to know the movement extent of the belt 9, and the motor is stopped when the belt moves by the display extent of the image to be displayed in the window 4 to stop the belt 9.

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;
In particular, it concerns its operation sequence.

[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 exterior cylinder, 2 is a display image viewing window formed with a thick (opening) on the front plate surface of the exterior cylinder 1, and 3 is arranged on the upper surface of the front plate with the lower part thereof protruding forward. An operation panel 4 has a display window glass pasted in the window hole 2; 5, 6, 7, and 8 have two axes each in the upper and lower parts of the outer cylinder 1, parallel to each other with their axes in the left and right directions of the outer cylinder; Four endless belt-shaped photoreceptor suspension support rollers are individually disposed with freely rotatable bearings, and reference numeral 9 designates an endless belt'-shaped photoreceptor that is suspended and supported by the four 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 to the surface while the metal is deposited, a photosensitive material layer (photoconductive layer) such as K CdS is formed on the metal vapor-deposited surface, making the entire structure flexible, with the photosensitive material layer side facing outward. It is suspended and supported by the four rollers mentioned above.

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 transmitter 11, a polygon mirror scanner 2° fθ lens (imaging lens) 13, a reflecting mirror 14, and a transparent It has a plate 15. 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.

Reference numeral 16 denotes a toner developing device disposed on the outer surface side of the belt portion between rollers 7 and 8. Note that the transparent plate 15 is
The lower surface of the plate 15 is arranged so as to project slightly downward from the common tangent line on the lower side of the plate 15, and is in pressure contact with the inner surface of the belt 9.
and 152 are chamfered and rounded so that the belt 9 can contact and move smoothly. Further, the transparent plate 15 prevents vertical vibration of the belt 9 caused by the vertical movement of the rotating belt 9 and contact with the magnetic developing brush 35 of the developing device 16, and keeps the exposure position constant. to improve resolution.

Reference numeral 39 denotes a chain that is stretched at a predetermined position on the side end of the belt 9 or near both side ends of the belt 9 and is driven by the drive roller 5. Reference numeral 40 denotes 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 the photointerrupter 41 arranged along the moving surface of the belt 9.

-1 However, in this type of device, when displaying an image, the display position of the image information may shift, and it may not be possible to display all the image information for one page.

(Objective) Therefore, the present invention aims to eliminate the above-mentioned drawbacks and obtain an easy-to-see image without shifting the display position. That is, in an image display device having a rotating image carrier and displaying an image on the image carrier, there is provided a means for generating a signal synchronized with the rotation of the image carrier, and a counting means for counting the synchronization signal. The apparatus is characterized in that the rotation of the image carrier is stopped after counting the synchronization signal a predetermined number of times.

(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, 5
A plate stay 0 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.

The rotation of the drive roller 5 is transmitted to the photoreceptor 9 via the plate stay 50 from the 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 reliable rotation.

Also, the number of meshing parts of the chain 39 (required number of links)
It is set to be a common multiple of the number of teeth Z of the Nt-sprocket 52 and the number of pages P of images that can be displayed in one rotation of the photoreceptor 9. For example, the number of teeth Z of the sprocket 52 is l'251
', if the number of pages P is @21a, chain 3
The number N of meshing portions of No. 9 is set to "200". Due to this, the position of the teeth of the sprocket 52, the position of the belt-shaped photoreceptor 9, 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 5 extending from the rotation shaft of the drive roller 5.
A series of gear trains 57 to 60 are provided, each of which is driven by a gear train 57 to 60, and a circular light shielding plate 61 is fixed to the shaft end of the output gear 60. A photo encoder 63 is configured to be used as home position detection means (home position sensor) for each page. Therefore, the tooth ratio (gear ratio) of the gear train described above is 1 rotation of the belt-shaped photoreceptor 901 or 1 rotation of the belt-shaped photoreceptor
The light shielding plate 61 is set so that it always rotates once per page display cycle. For example, number of teeth Z-25, number of pages P,
= 2, number of chain meshing parts N = 200,
If the tooth ratio Q'lt 1 /8 K is set, the belt 901
The light shielding plate 60 rotates once each time it rotates, and the photointerrupter 62 can generate a home position detection signal for each page.

Roller 5 of the four rollers 5 to 8 is used as a driving roller to transmit the rotational force of a motor M1 (not shown). This motor MI K has a built-in pulse encoder.
It is used as a signal generating means (belt clock generating means) for obtaining the operation timing for each page. Fewer of the other three rollers 6 to 8 (both one, e.g. 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 Ml,
The hanging belt 9 rotates counterclockwise without slack or slip. With this rotation, the tensioned surface of the belt 9 moves between the rollers 5 and 8 from below the display image viewing hole 2 to -L.

Further, in the image exposure apparatus 10, an intermittent laser beam L corresponding to a time-series electric pixel signal supplied from an electronic computer, an image reading device, etc. is transmitted to a semiconductor laser transmitter 11 in the front of the drawing.
The laser beam is oscillated toward the rotating polygon mirror scanner 12 at the rear of the drawing.

The laser beam L incident on the scanner 12 is swung in the belt width direction, enters the inner surface 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 emitted as a laser beam in the belt width direction. Beam scanned. As a result, 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 90 as a sub-scanning.

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 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 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 the bottom to the top of the two display image viewing holes as the belt rotates and moves to the designated window hole range position, the belt rotates 90 times. will be stopped.

As a result, an image is displayed in the window hole 2, and the 70-panel image can be 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, and then reaches the developing brush 3.
Immediately after this cleaning, the toner image is exposed and simultaneously developed again to form a new toner image.

In this step 5, the image information is reproduced and displayed as a toner image,
In addition, since the image exposure is performed using a very narrow laser beam, it is possible to display high-resolution images that are easy to see even small characters and other images (clearly displayed), and the toner application method at the same time as exposure is possible. Because of this, it has an extremely simple configuration that does not require corona charging means or special leaning means, and can be manufactured at a relatively low cost even with large screens.It is a highly reliable display device with less failure and photoreceptor deterioration. obtain.

Therefore, in this embodiment, the above-mentioned 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. I try to visualize and display it. FIG. 5 shows a block diagram of the sequence control section of the soft display. Figure 6,
FIGS. 7 and 8 are detailed timing charts of this sequence control section.

The sequence control section shown in FIG. 5 consists of a counting circuit A106 and a counting circuit B107, each of which counts clocks A1 and B, thereby outputting a required signal at an appropriate timing. Each of the clock selection circuits (SBLA, 5ELB) 104 and 105 receives the reference clock or belt clock (B
FiLTCLK) and clock A.
.

It is input as clock B to each counting circuit. BELTCLK is the motor 1 that drives the belt.
This is the clock output from the pulse encoder 113 built in the 12. Preset circuit 03 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, and according to this count value, one of the VSYNC' MON and MOFF signals (described later) is output. The MON and MOFF signals are sent to the drive circuit 1 that drives each drive section of the soft display.
11. This drive circuit 111 drives a belt drive motor, a developer motor, and a developing bias. The belt drive motor 112 has a built-in pulse encoder 113
The speed is controlled by feeding back a signal from the drive circuit 111 to the drive circuit 111, and the motor 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 a home position (hereinafter referred to as HP) sensor (42 in Fig. 4)
) is a circuit that shapes the waveform of the HP signal detected by the HP signal.

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. 1
Reference numeral 09 denotes a PON signal generator that is triggered when the power is turned on or by an abnormal operation signal of the photoreceptor belt detected by the HP counter 101, and outputs a PON signal. 1
14 is a pulse generator using a one-shot multivibrator, which generates a pulse when the PON signal is input manually, and R
-8 flip-flops 114, 115Y are set.

The specific operation of the sequence control unit is explained in Section 6. This will be explained below using the timing charts shown in FIGS. 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 turned on, the photoconductor belt rotates forward (photoconductor belt)! Stop at a designated position.

Then, when the laser and scanner enter the RDY state after the previous rotation is completed, 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 is stabilized due to the delay effect of RC in FIG. 5, and then the PON signal generator 10
When a signal is input to 9, a PON signal is output. Counting circuit B is activated by the rising edge of this PON signal.
107 starts counting clock B. At this time, the clock B is set in the R-8 flip-flop 116 by the action of the PON signal, and becomes the reference clock by selection of the 8ELB 105. When the counting circuit B107 counts PC clocks Bi, the timing signal generator 57 outputs a 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. With this operation, rotation of the photoreceptor belt, ie, forward rotation, begins.

Thereafter, when the photoreceptor belt rotates a certain distance, the HP detection circuit 100 detects the HP signal, and in synchronization with it, the preset value is transferred from the preset circuit 102 to the counting circuit A 106, and the counting circuit 106 starts counting operation. At this time, clock A becomes the reference clock due to the action of the PON signal. When Pa clocks A (Pa is equal to the preset value) are counted, a DR]13Q signal is output,
This DREQ' signal causes the counting circuit B107 to start counting.

At this time, clock B is the reference clock as in the previous state. After counting Pa clocks B, the counting circuit B107 outputs V8 from the timing signal generator 108.
Outputs YNC' signal. When the PON signal is valid (that is, when the power is turned on), the V8YNC' signal is
It is used as a counting operation start signal for the counting circuit B107. At the same time, clock B is converted from the reference clock to the belt clock (BBLTCL) by the V 8 Y N C' multiplied signal.
K). Therefore, the counting circuit B107 is
After outputting the signal multiplied by V 8 Y N C', counting of the belt clock (BELTCLK) is started again. At this point, the photoreceptor belt is being rotated at a constant speed from the start. The counting operation of the counting circuit B107 is performed when the belt clock (BELTCLK) is Pe.
When the number of BP3LTCLK reaches Pe, a MOFF' signal is output from the timing signal generator 108, and the driving of the photosensitive belt is stopped. Also, M.O.
The FF signal enters the PON signal generator and stops outputting the PON signal. Since the soft display is configured such that the HP multiplication signal is detected immediately before the photosensitive belt stops, the HP multiplication signal is input to the HP multiplication signal counting circuit A106 immediately before the MOFF signal is output. The counting circuit A106 executes loading of a preset value by the HP multiplication signal and starts counting operation. Furthermore, clock A is changed from the reference clock to the belt clock (B Fi L 'I' C
L K ), and the counting circuit Al 06
will count the belt clock (BELTCLK). This counting operation is interrupted because the belt clock (BELT(,'LK)) cannot be obtained due to the drive stop of the photosensitive belt. This corresponds to the moving distance of the belt.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 signal DO sent from the image reading device
This is uniquely generated within the T and V8YNCv sequence control unit to execute the pre-rotation operation. That is, P
ON signal is DOT compensation signal 2, V 8 YNC' signal 1)
Corresponds to #uV S Y N Cm. During the pre-rotation operation, the RDY signal indicating that the software display is available for use in 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 is inverted by the inverter.
When the ON signal disappears and the laser and scanner enter the RDY state, the RDY signal is valid.

Next, the normal operation sequence will be explained with reference to FIG.

First, the signal D8 instructs the soft display to start operating.
T is input to the software display from an image reading device (not shown). In the soft display, the counting circuit A106 and the counting circuit B108 simultaneously start counting operations in response to the D8T signal.

Counting circuit Al06 (clock A is the reference clock due to the HP multiplication signal) has a count value of 1, as explained in the operation sequence at power-on. The value corresponds to the position of the belt. The preset value is Ppre, the value counted from the time the HP multiplication signal is detected until the photosensitive belt stops is 1kPB.The total count number of the counting circuit A106 is 7P.
When set to full, the DOT signal is input and the counting circuit A1
The count number re until 06 outputs the DREQ signal is Pe = Pfull - (Ppre + Pn). Therefore, when the count value FB becomes large, the count value P
The relationship is such that e becomes small, and conversely, when FB is small, Pe becomes large. This may cause variations in the stop position due to the inertia of the photoreceptor belt, or the DRF that instructs the image reading device to output an image signal.
It is possible to absorb variations in the time from the IQ signal until the V8YNC signal indicating the leading edge of the image signal is manually input to the soft display. In other words, if the stop position of the photosensitive belt is short based on the HP multiplication signal indicating the absolute position on the photosensitive belt, D
By delaying the output timing of the DREQ signal from the 8T signal, and in the reverse case, advancing the output timing of the DREQ signal, the cumulative error of the stop position shift of the photoreceptor belt is eliminated, and the seam of the photoreceptor belt is always located outside the effective image area. It is located in

The counting circuit B107 counts the reference clock whose clock B is selected by the DOT signal, and when the counted value reaches Ph, the timing signal generator 108 outputs the MON signal and starts driving the photoreceptor belt. Then DRII! i
V8 sent from the image reading device in response to the Q signal
In response to the YNC signal, the counting circuit B107 starts the counting operation again. Clock B at this time is BELTCLK due to the V8YNC signal. After the counting circuit B107 finishes counting the number of BELTCLK corresponding to the effective image area, the timing signal generating circuit 108 generates a MOFF signal to stop the photosensitive belt.

This operation ensures that the image display position always has a constant positional relationship with respect to the display screen. Counting circuit A106
loads the preset value and counts BELTCLK based on the HP multiplication signal detected immediately before the photoreceptor belt stops, and as mentioned above, when the photoreceptor belt stops, the photoreceptor belt is It maintains a count value corresponding to the distance traveled. Next, HP counter 1
The abnormal operation detection means and processing of the photoreceptor belt according to No. 01 will be described below. A timing chart of this abnormal operation is shown in FIG. 8 regarding the detection and processing means when the photosensitive belt continues to be driven due to noise or other causes.

The HP counter 101 is cleared by the rising edge of the D8T signal transmitted from the image reading and stacking device (8th
(■ in the figure). After this clearing operation, the detected HP multiplied 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 (■ in FIG. 8). When this abnormality is detected, the HP counter 101 outputs an output to the ACNTCN PON signal generator 109. At the same time, the I'LDY signal output to the image reading device is invalidated to notify that the soft display is in an unusable state. Here, the PON signal generator 109 is ACNT
By receiving the data on the CN, sequence control is performed which performs the same processing as that at the time of power-on described above, that is, the pre-rotation processing (■ in FIG. 8). In other words, by performing the pre-rotation process when the power is turned on, an operation is executed to stop the rotation of the photosensitive belt due to an abnormal operation at an appropriate position.

After executing the above process, as soon as the PON signal is released,
The ACN'l' signal is also released and the RDY signal becomes valid. Note that ■ indicates normal operation.

(Effect) As described above, according to the present invention, the rotation of the image carrier is stopped after counting a predetermined number of signals synchronized with the rotation of the image carrier. Image information is displayed without missing, resulting in an easy-to-view image.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an example of the external appearance of a conventional device, FIG. 2 is a sectional view showing an example of the internal configuration of the device shown in FIG.
FIG. 4 is a perspective view showing an example of the configuration of an image display device according to the present invention with a part 0-1 cut away, and FIG. 5 is a perspective view showing the control section of the device shown in FIG. FIGS. 6, 7, and 8 are time charts showing the operation of the control section shown in FIG. 5. FIGS. 0-2 Akira 1 Figure

Claims (1)

[Scope of Claims] 1) In an image display device having a rotating image carrier and displaying an image on the image carrier, means for generating a signal synchronized with the rotation of the image carrier, and the synchronizing signal and counting means for counting the synchronization signals, and stops rotation of the image carrier after counting the synchronization signals by a predetermined number. (2) The image display device according to item 1, wherein the counting means counts the synchronization signal based on a signal indicating the leading edge of image information.