JPS6298342A - Copying machine - Google Patents

Abstract

PURPOSE:To enable a copying machine to recover an abnormal state in a short time by detecting the abnormal movement of an original scanning unit and performing a different restarting process according to the current position of the scanning unit. CONSTITUTION:An original 22 is placed on the original platen 21 of a digital color copying machine and the original 22 is scanned by an original scanning body 18. Further, reflected light from the original 22 is converged on a readout sensor 15 through a rod array 14 to detect the abnormal moving speed of the original scanning body 18 and the position of the unit device when the abnormality occurs. Then, if the scanning body 18 detects the abnormality during its original scan, an unnecessary image is formed possibly on a form 64 by a transfer drum 9, so the image formation is made ineffective and the form is discharged automatically. If abnormality is detected before the front end of the original is passes, the form 64 is discharged only this time. If abnormality is detected after the rear end of the original is passed, it is considered that the operation is completed normally. Thus, the function is recovered automatically in a short time from the detection of the abnormality of the scanning body.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a copying machine, and particularly to a copying machine having processing means for recovering from an abnormal state of movement of a document scanning unit for scanning a document.

[Conventional technology]

In general, the document scanning unit of a copying machine that reads documents is accelerated during a predetermined run-up period from the scanning start position to the leading edge of the document, reaches a target movement speed at the leading edge of the document, and moves at a constant speed while reading the document until it reaches the trailing edge of the document. After passing the trailing edge of the document, it decelerates and stops after a predetermined deceleration period. Then, it is reversed and returns to the original scanning start position. Therefore, speed control such as target movement speed, scanning start position, document trailing edge position, etc.

It is necessary to control the position of the trailing edge of the document, etc.

In addition, it is necessary to adjust the timing between the image reading device (hereinafter referred to as "reader J") and the image forming apparatus (hereinafter referred to as "printer"), for example, the timing of starting scanning, feeding 2 images, writing 9 images, etc. Unit time control is required.

An example of such control is a method of feeding back signals from a device that detects position or speed and controlling a drive source (DC motor, stamping motor, etc.) to a target speed and desired position.

[The problem that the invention is trying to solve]

However, when a change in the environment such as load or friction occurs, the controlled object (velocity or position) changes from the target value, and it often deviates from the allowable range of the change, resulting in the formation of an undesired image. In particular, in the case of a stepping motor, the motor may no longer follow the drive pulse and may lose synchronization.

Although the above-mentioned drawbacks can be reduced by a hydraulic device that can widen the tolerance range, there is a problem that the wider the tolerance range, the more complicated and expensive the device becomes.

[Means for solving problems]

The present invention has been made in view of the above points, and an object of the present invention is to provide a copying machine that can recover from an abnormality in a short time and resume image forming operations even if an abnormality occurs.

A further object of the present invention is to provide an inexpensive copying machine having an abnormality detection function and a function of recovering from an abnormal state in a short time.

Therefore, it has an abnormality detection means for detecting whether the movement of the original scanning unit is normal or not, and a position detection means for detecting the position of the original scanning unit, and the abnormality detection means detects whether the movement of the original scanning unit is normal or not. If a movement abnormality is detected, different restart processing is performed depending on the position of the scanning unit before it reaches the leading edge of the original, during scanning of the original, and after the trailing edge of the original. The aim is to solve these problems by doing so.

〔Example〕

Hereinafter, a digital color copying machine will be described as an embodiment of the present invention with reference to FIGS. 1 to 4.

Figure 2 is a schematic configuration diagram of this digital color copying machine, where 1 is a color league, 2 is a color printer, and 3 is a combination of both.
, 2, 4 is a laser scanning unit having a laser emitting device and an optical section for scanning laser light,
5 is a rotating mirror, 6 is a mirror that changes the optical path of the laser beam,
7 is a photosensitive drum in electrophotography, 8-1 to 4 are developing units for developing toners of different colors, 9 is a transfer drum, 10 is a pulse width modulation board based on the signal from the color league, and 11 is a laser. A laser driver board for controlling driving, 12 an irradiation lamp as a light source, 13 a reflection mirror, and 14 a document 22 placed on a document table glass 21.
This is a rod lens array that focuses reflected light from the sensor onto the reading sensor 15. 18 is the irradiation lamp 121
Reflection mirror 13. Rod lens array 14. This is a scanning body equipped with a reading sensor 15 and an A/D conversion circuit board 17 that A/D converts a signal coming from the sensor 15 via a signal line 16.These mounted objects 12 to 17 are connected to a scanning body 18. It becomes a document scanning unit and performs the same linear movement. 20 is a processing control circuit board that stores, performs calculations on, and outputs signals coming from the A/D conversion circuit board 17 via the signal line 19.

Figure 3 below is a schematic diagram of the color league, with 23
is a stepping motor 24 which is a driving source of the scanning body 18;
25 is a belt that transmits the rotational motion of the motor 23 to a pulley 26 that is fixed to the shaft 27; 28 is a pair of drive pulleys that are fixed to both ends of the shaft 27; , 29 is the surface of the scanning body 1
8 is a pair of sliding rails, 30 is a pair of drive wires, and the mounting bracket 3 is connected via the drive pulley 28 and the idle pulley 33.
1 and member 32 are respectively fixed to both side surfaces of the scanning body 18, and the pair of idle pulleys 33 are each biased by a coil spring 34 in a direction that applies tension to the drive wire 30. 35 is a motor control board that includes a motor driver circuit that generates a signal to drive the stepping motor 23 based on the signal 36 from the processing control circuit board 20, and a pulse control circuit that generates a pulse for timing the drive signal; It is connected to the stepping motor 23 by a line 37.

With the above configuration, the rotational movement of the motor 23 is caused by the motor pulley 24. Belt 25. Pulley 26. Shaft 27, drive pulley 28. Drive wire 30. This is converted into a linear motion of the scanning body 18 on the rail 29 via the mounting bracket 31 and the member 32. The direction of linear movement of the scanning body 18 at this time is controlled by forward and reverse rotation of the stepping motor 23.

In addition, the rotation speed n8 of the stepping motor 23 and the scanning body 1
8 is given by the radius of the drive pulley 28. Therefore, by making the rotation speed ng of the stepping motor 23 variable, the moving speed V of the scanning body 18 is can be made variable.

Image reading of the original is performed by an image reading unit (irradiation lamp 129 and degree mirror 1s) integrated with the scanning body 18.

Rod lens array 14. The reading sensor 15) reads the document 2.
2 by scanning at a certain speed.

The read image signal obtained in this way is sequentially transmitted to the color printer 2 in real time via the signal line 3, converted into a pattern signal for all lasers 0N10FF by the pulse width modulation board 10, and sent to the laser driver board 11. becomes a current signal that drives the laser, and the laser light is ON10.
An image pattern is sequentially applied to the photosensitive drum 7 in real time via the mirror 6 using a laser beam based on the read image signal that forms the pattern of FF, and the image pattern is developed by attaching toner by the developing unit 8 and transferred. The image is transferred to paper 63 supported on drum 9.

By repeating this operation for each color, a color image is formed.

Next, FIG. 4 shows a schematic diagram of the drive circuit of the stepping motor 23.

40 is a CP that controls the driving of the stepping motor 23;
U, 42 is a ROM that stores a control program and pulse generation data, and 43 is a ROM that stores variable data.
AM, 44 is a timer, 45 is a pulse generation circuit, 46 is an I10 board, 47 is a driver, 48 is a motor driver circuit that generates several pulses 56 for driving the motor;
41 is an operation display circuit board.

The CPU 40 receives the scanning start signal and the scanning specification signal 50 or 51 from the operation display circuit board 41 or the processing control circuit board 20, and the CPU 40 stores the ROM 42 or the RAM 4.
3 sends frequency data 52 of the generated pulses to the pulse generation circuit 45 via the CPU 40, and the circuit 45 outputs pulses 54 via the driver 47-1 to the motor driver circuit 48 using a signal 53 based on the data 52. .

On the other hand, the rotation direction of the stepping motor 23 and the ON state of the current
A signal 55 for controlling the 10FF etc. is sent to the motor driver circuit 4 via the I10 host 46 and driver 47-1.
8. The circuit 48 receives a signal 55 and a pulse 54.
Based on the edge, a motor drive pulse 56 suitable for driving the motor 23 is supplied to the motor 23 to rotate or stop the motor 23.

This stepping motor 23 is designed to rotate by a certain angle in response to one pulse 54, and as mentioned above, the rotational movement of the motor 23 cannot correspond to the linear movement of the scanning body in one day. be. Therefore, by controlling the number and frequency of pulses 54, the movement ratio, that is, the position and movement speed V, of scanning body 18 is controlled. Further, the relationship between the number of pulses 54 and the frequency can be uniformly controlled electrically to determine the position and moving speed V of the scanning body 18.
The relationship between the two is also electrically controlled.

Next, an overview of the copying operation of this color copying machine will be explained based on the flowchart shown in FIG. 1 and the relation diagram between the movement of the scanning body 18 of the color reader 1 and the flow of paper 63 of the color printer 2 shown in FIG. do. Note that 81 to S25 represent each step of the flowchart.

When the copy key is pressed and copying is enabled, copying begins. First, the number n of sheets to be continuously copied is set in the down counter CNT1, and the down counter C
The number m of document scanning based on the color designation of the output image (for example, 4 or 3 times for full color, 1 time for monochrome and monochrome) is set in NT2 (Sl). On the other hand, the paper 63 is fed from a cassette 64, passes through a paper transport path 65, and is temporarily stopped at a registration roller 60. The drive timing of the registration roller 60 is determined based on the rotation of the transfer drum 9, and the paper 63 is placed on the transfer drum 9. Grip in place (S
2). When the actuator plate 62 inside the transfer drum 9 passes the image leading edge sensor (LTOP sensor), the image leading edge (LT
OP), the motor 23 is driven, and the moving speed V of the scanning body 18 at the reference starting position I-LP is accelerated to a constant speed ft (see Fig. 5) (S4).
).

When it is detected that the scanning body 18 has reached the leading edge nTOP of the document (S5), the document is read, and a latent image is sequentially formed on the photosensitive drum γ. The image is transferred and image formation is performed in a predetermined color until it reaches the trailing edge of the document, END (S6). When the scanning body 18 is at the rear edge of the original,
When passing is detected (S7), the motor 23 is decelerated and stopped (S8), and when the movement of the scanning object 18 has stopped, the motor 23 is reversed and the scanning object 18 is moved in the opposite direction. When the standard starting position t) LP is detected (SIO), the motor 2
3 and stop the movement of the scanning body 18 (S11). Then, the down counter CNT2 is decremented by "1" (S12)
, 813, if the counter CNT2 is "0", S
Move to 3 and repeat up to 813 again. At this time, the color of the developing toner is sequentially changed to reproduce the specified color. If the down counter CNT2 is "0", the timing is determined from the rotation of the transfer drum 9, the grip on the paper 63 is released, the paper 63 is separated from the transfer drum 9 by the separation claw 61 (see FIG. 5), and the paper is The sheet is passed through the entire transport path 66, fixed by the fixing device 67, and discharged to the copy tray 68 (S14).

Note that the down counter CNTl is decremented by "1" (81
5) If the counter CNT1 reaches rOJ in S16, it is detected that the number n of sheets to be continuously copied has been completed, the copy operation routine is exited, and the process waits for the key to be manually operated.

However, if the counter CNTl is not "0",
The number m of document scanning is set in the down counter CNT2 (817), and steps S2 to S16 are repeated.

Next, the restart processing in this embodiment will be explained with reference to FIG.

The position of the scanning body 18 is detected (520), and it is determined whether the movement of the scanning body 18 is normal or abnormal by comparing and determining whether or not it is at the target position at that time (S21).

If it is determined that there is an abnormality, the GATE2 signal 53 is set to Hi, and the generation of the pulse 540 that controls the motor 23 is stopped.
The motor 23 is stopped (S22). The position where the abnormality occurred, the position where the abnormality was determined, and the position where the sudden stop occurred are considered to be almost the same if the abnormality is determined in real time and with a short sampling time, but in reality, the position where the abnormality occurred and the position where the abnormality occurred and the position where the sudden stop occurred are almost the same. There is a difference because processing time is required. In the present invention, the position of the scanning body 18 is constantly monitored, and the position judged to be abnormal, the position where it suddenly stopped, and the last normal position in terms of time are stored (820,
21, 22) and used to detect abnormal positions (S23).

First, the trailing edge of the manuscript, the path f・ζ that passed through END,
It is determined that an abnormality has occurred when the last normal position is the rear edge of the document and the document has passed END in forward motion.

After the original 1) When an abnormality occurs after passing through 7IIF IIE N D, the original f422 has been read normally and an image has been formed on the paper 63, so the image and processing are validated and the scanning body 18 is returned to the reference starting position P (39-11), and then the normal process (S12) is performed. Note that until the image has returned to the reference starting position (LP), the image tip 1. Even if the TOP signal comes, it is ignored and has no effect on the movement of the motor 23. This is common to all cases.

Next, it is determined that an abnormality has occurred before the leading edge of the document passes the TOP, which is the last normal position.

This is performed when the document has not reached or passed the leading edge of the document or the TOP at any of the positions judged to be abnormal or the positions where the sudden stop occurred. In this case, since the original 22 has not been read yet, no image has been formed on the paper 63 during the current scan, and there has been no change since the previous scan, only the current scan is invalidated. In order to do this, down counter CNT2
is incremented by "1" (524) and restarts from S9.

In addition, an abnormality exists while scanning the document, that is, while the scanning body 18 is moving forward from the leading edge of the document, from TOP to the trailing edge of the document, and from END, and while the document 22 is being read by the reading sensor 15, A determination that an abnormality has occurred in the movement of the scanning body 18 while the process is in progress is made when an abnormality occurs in cases other than the above two cases. It should be noted that the occurrence of an abnormality while the scanning body 18 is moving backwards is caused by the rear edge of the document, the EN
Needless to say, the process is the same as the abnormality occurrence after D. In this case, since an unnecessary image may have been formed on the paper 63, the down counter CNT2 is set to "1" in order to invalidate the current paper 63 and eject it. Increase by "1" 52
5) Restart from the previous process (S9).

In the process shown in FIG. 1, the scanning body 18 is at the reference starting position H,
Although the paper 63 is ejected after returning to P, it is also possible to control the paper ejection and the motor 23 independently.

Reference starting position fKP, document leading edge, TOP position.

Trailing edge of document, END position 2 Image leading edge 1. To detect the TOPO position, an actuator plate is attached to the moving body (scanning body 18 and transfer drum 9), a sensor such as a photo interrupter is provided at a predetermined position within the range of movement of the actuator plate, and the actuator plate is detected by the sensor. To do this. Note that this attachment can also be reversed.

The above embodiment is a digital color copying machine in which paper is gripped on a transfer drum, but it is applicable to copying machines (both digital and analog) that do not use a transfer drum.
However, similar abnormality detection and processing can be performed as shown in the flowchart shown in FIG.

Further, although the above-mentioned copying machine does not have an image memory, in a copying machine having an image memory, it is possible to apply abnormality detection and processing to the case where the document is being scanned among the above three categories. . Particularly in the case of the type that scans everything before outputting it, the scan is repeated many times until all the scanned images are correct. However, during this time, no unnecessary images are formed on the paper.

In the embodiment of the present invention, if an abnormality occurs during document scanning, there is a method for stopping the transmission of unnecessary images from the color reader 1 to the color printer 2, and a method for stopping the transmission of unnecessary images from the color reader 1 to the color printer 2. By using a method of exposing the image to light, a method of cleaning unnecessary images visualized on the photosensitive drum 7 before transfer, etc., unnecessary images can be removed from the paper 6.
3, a part of the normal image is formed on the paper 63, and the continuation or the first image is formed in the next scan. In this case as well, it is necessary to detect the position where the abnormality occurs.

In addition, in the embodiment, a stepping motor 2 is used as the motor.
3 was used, but it is also possible to use a linear motor, DC motor, AC motor, etc. However, with a motor that follows pulses, the method of abnormality detection is to compare the position of the scanning object 18 with the target position that should be once a certain number of pulses have been output. It is also possible to perform this depending on whether or not the movement of the motor is being followed.

〔Effect of the invention〕

As explained above, the present invention easily detects when the movement of the scanning object deviates from a certain tolerance range from the original target control (e.g. position, speed), and automatically restores the function within a short period of time. This has the effect that a copying machine that can form the required original image can be provided at a low cost.

In particular, when a transfer drum is used to repeatedly scan several times to obtain a full-color image, ejecting paper on which an unnecessary image has been formed is particularly important when overwriting a single sheet of paper by scanning several times. This has the advantage of reducing the probability that

Further, if an abnormality is detected, by suddenly stopping the scanning body, it is possible to protect the scanning body from vibrations, collisions, etc., and also to prevent unpleasant vibration noise.

[Brief explanation of drawings]

FIG. 1 is a flowchart showing normal copying operations and abnormality detection processing operations in a color copying machine according to an embodiment of the present invention, FIG. 2 is a schematic configuration diagram of the same color copying machine, and FIG.
Figure 4 is a schematic diagram of the color reader; Figure 4 is a schematic diagram of the stepping motor drive circuit; Figure 5 is a diagram showing the relationship between the movement of the league scanning body and the flow of paper in the printer; FIG. 6 is a flowchart showing the hubby operation and abnormality processing of a copying machine that does not use a transfer drum. 1...Color league 2...Color printer 7...Photosensitive drum 9...Transfer drum 14.・・・・・・Rod lens array 15...
...Reading sensor 18...Scanning body 20...Processing control circuit board 23...
...Stepping motor 35...
Motor control board 40...CPU 41...Operation display circuit board 48...
...Motor driver circuit 63...
Paper, TOP... Leading edge of the document, END... Back edge of the document Figure 2 Color league AHEAD & END Figure 3 Figure 5 Figure 6

Claims (2)

[Claims] (1) The abnormality detection means detects whether the movement of the original scanning unit is normal or not, and the position detection means detects the position of the original scanning unit, and the abnormality detection means detects whether the movement of the original scanning unit is abnormal. 1. A copying machine characterized in that the copying machine is configured to perform different restart processing depending on the position of the document scanning unit when the document scanning unit is detected. (2) The copying machine according to claim 1, wherein the position of the document scanning unit is classified into before reaching the leading edge of the document, while scanning the document, and after the trailing edge of the document.