JPH0356460B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a copying machine having a lens position control device for a copying machine having a variable magnification function.

Conventionally, a motor is used as a drive means to move the lens system in a copying machine with a variable magnification function, and the lens is moved to a position corresponding to the variable magnification ratio, and the lens is at the desired position according to the variable magnification ratio. It was customary to detect and control this using a lens position detector.

Furthermore, as described in Japanese Patent Application Laid-Open No. 55-7770 as a prior art, in addition to the same size copying, in a copying machine that is capable of variable size copying with one type of variable size ratio, for example, the same size key is used. Immediately after the variable magnification key was operated to start driving the lens etc. from the variable magnification position to the variable magnification position, there were some models that returned the lens etc. from the current position to the variable magnification position when the variable magnification key was operated again.

However, conventional copying machines that can specify many variable magnification ratios have not been capable of switching the movement of the lens midway when the specified magnification is changed while the lens is moving.

In other words, in a copier that can specify many variable magnifications, if the specified magnification is changed while the lens is moving, it is difficult to determine whether the specified magnification position after the change is in the direction of lens movement or in the opposite direction. Therefore, the moving direction of the lens may or may not be reversed. Therefore, in such a copying machine, the moving direction of the lens cannot be unconditionally reversed when the specified magnification is changed, unlike in the prior art in which there is only one type of magnification.

The present invention has been made in view of the above points, and
If the magnification is changed from the first magnification to the second magnification while the optical system lens is moving to the position corresponding to the specified first magnification, the position corresponding to the second magnification is To provide a copying apparatus capable of quickly and accurately setting an optical system lens to a position corresponding to a second magnification, whether in the moving direction or in the opposite direction.

That is, the present invention includes: an exposure means for exposing a document placed on a document table; an optical system lens for forming a variable magnification image of the document exposed by the exposure means on a photoreceptor; a recording means for recording a variable magnification image on the body on recording paper; a specifying means for specifying a desired magnification; and the optical system lens positioned at a position for forming a variable magnification image of the specified magnification on the photoreceptor. and a counting means for counting pulse signals synchronized with the movement of the optical system lens to grasp the position of the optical system lens being moved by the driving means, When the optical system lens is moved by the driving means to set the optical system lens at a position corresponding to the designated magnification ratio, and the counting means counts a count value set according to the specified magnification ratio. comprising a control means for stopping the movement of the optical system lens by the drive means, the control means:
Even when the counting means is counting while the optical system lens is moving to a position corresponding to the specified magnification, the designation means detects a change in the magnification, and the drive means detects the change in the magnification. When the specifying means detects that the magnification has been changed from the first magnification to the second magnification while moving the system lens to a position corresponding to the designated first magnification;
The moving direction of the optical system lens is determined and the count value to be counted by the counting means is changed according to the position of the optical system lens during movement and the position corresponding to the second magnification, and the determined movement direction is determined. The optical system lens is moved by the driving means, and when the counting means counts the changed count value, the movement of the optical system lens by the driving means is stopped, and the optical system lens is moved to the second magnification. The present invention provides a copying apparatus which is characterized in that it can be set at a position corresponding to a copying machine.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic diagram of an electrophotographic copying machine to which the present invention can be applied. Drum-shaped rotating photoreceptor 1
is pre-charged with charger 5, primary charged with 6, charged with corona discharger 7 at the same time as image exposure,
An electrostatic latent image corresponding to the original image is formed on the surface of the photoreceptor 1 by exposure from the original surface. After that, the entire surface is exposed as necessary. That is, an exposure lamp 4 is fixed on a horizontal plane below the contact glass 17 on which the original is placed, and the light from the exposure lamp 4 is reflected by the mirror 2 and projected onto the photoreceptor 1 through the lens 3. Ru. An electrostatic latent image corresponding to the original image is formed on the surface of the photoreceptor 1. This latent image is visualized by adhering a developer in the next developing section 8.

The transfer paper 10 is fed to the photoconductor 1 side by the paper feed roller 9 through the registration roller 11, and the developer attached to the photoconductor 1 is transferred to the transfer paper 10 by the transfer charger 12 to form a normal image. It is formed.

Thereafter, the transfer paper 10 is separated from the photoreceptor 1, transported by the transport section 13 to the fixing device 14, fixed by the fixing device 14, and discharged onto the tray 16.

When changing the magnification of a copied image, the position of the lens 3 installed in the exposure path is changed along its optical axis, and the ratio between the scanning speed of the original and the rotational speed of the photoreceptor 1 is adjusted according to the magnification. It is necessary to change it constantly.

The structure and operation of the electrophotographic copying machine described above are well known, and further detailed explanation will be omitted.

Next, lens movement in the system for changing the magnification of a copied image will be explained.

FIG. 2 is a schematic diagram of the lens drive. The lens 3 is fixed to a support member 37, and this support member 3
7 is slidably supported by a pair of guide bars 38 extending parallel to the moving direction of the lens.
Reference numeral 39 denotes a wire, and both ends of the wire are supported by support members 33 that are rotatably fixed.
The drive motor 32 rotates the pulley 40 and moves the lens 3 via the wire 39. A pulse generating means 31 is connected to the drive motor 32 . This pulse generating means 31 consists of a slit disk 3 in which a large number of slits are formed at equal intervals in the circumferential direction.
1-1, a photo interrupter 31-2 consisting of a light-emitting element and a light-receiving element arranged oppositely through the slit disk 31-1, and a photo interrupter 3.
It is constituted by a support stand 30 that supports 1-2. Drive motor 32 by pulse generating means 31
Since the serial pulse signal can be generated in association with the operation of the pulse generating means 31, the moving distance of the lens 3 per one pulse of the pulse generating means 31 can be determined in advance.

In this embodiment, the reference position of the lens is detected by the sensor 36, and the reference position sensor 36 can be installed at the same magnification position. Further, detectors 34 and 35 are arranged at the maximum magnification ratio position or a stroke position higher than that and the minimum magnification ratio position or a stroke position lower than that, one of which is used as the reference position, and the other is a stopper position where the lens is stopped or reversed. It is also possible to do this. In this example, the detector 34,
35 are both at the stopper position.

Next, lens control when the reference position sensor 36 is installed at the same magnification position will be explained with reference to FIG. 3.

When a same-size copy command is input to the controller 53 from the operation unit 41 of the copying machine, it is determined whether the reference position sensor 36 has detected the lens 3,
When the lens 3 is not at the reference position, the controller 53 outputs a drive signal for the drive motor 32, and the drive motor 32 is driven via the driver 54 to move the lens 3 in one direction to search for the reference position. That is, in addition to driving the motor, the pulse generating means 3
1 is input to the controller 53 via the waveform shaping circuit 51, and if more pulse signals are input to the controller 53 than a preset number of pulses N, the motor is reversely rotated and the lens is rotated in the opposite direction. change the direction of movement. In this case, the predetermined pulse N corresponds to the distance greater than or equal to the distance between the maximum and minimum lens positions, or the maximum and minimum distances from the reference position. Furthermore, if the reference position sensor 36 detects the lens 3 before reaching the preset number of pulses N, or if the lens 3 is detected after the direction change, the drive motor 32
Stops driving. This allows the lens to be set in advance at the reference position.

The operation in this case can also be executed in response to an on signal when the operator turns on a power switch that supplies power to each part of the copying machine. Then, after the power is turned on, the lens can be set at the same magnification position without inputting the same magnification command.

Incidentally, when setting the lens at the reference position, the direction of movement of the lens can also be changed using the stroke detectors 34 and 35.

When the desired first magnification ratio is commanded from the operation unit 41, the lens 3 is moved from the same magnification position to the position A according to the magnification ratio. For example, when the number of pulses of the pulse generating means 31 is 100 pulses and the magnification changes by 0.1 times, when driving the lens 3 to a lens position where the magnification changes to 0.66 times, the controller 53 drives the drive motor 32. A signal is output to drive the drive motor 32 via the driver 54, and the drive motor 32 is driven until the pulse signal generated from the pulse generating means 31 is inputted to the controller 53 for 340 pulses (from the same magnification position to the first magnification position). . Drive motor 3 when 340 pulses are input
By stopping 2, the lens can be set at a desired position.

After setting, the brake of the motor 32 is locked so that it does not move. The lock is released in synchronization with the start of motor rotation. Therefore, the lens is stopped and fixed at the first magnification position. This is the same when setting the reference position of equal magnification and when setting other magnifications.

Next, when setting from the first magnification to the second magnification,
Rotate the motor 32 and use the previous 340 pulses as a reference
When the pulse count reaches the number n corresponding to the second magnification (from the same magnification), the motor 32 is stopped and the lens is set at the second position B as described above. In this case, the lens is moved to the right from position A in FIG. 2, and when the lens reaches the detector 35, it is reversed and moved to the left until it reaches point n, and then stopped at point B.
This is the memory RAM of the controller 53 unless the controller 53 is powered off after the first magnification is set.
This can be achieved by storing the previous 340 pulse signals in (random access memory).

If the detector 35 is not provided, it is also possible to count the number of pulses corresponding to the position of the detector 35 and execute the reversal to move toward B. This is 53 memory
36 to 3 in ROM (read only memory)
If you remember the number of pulses that reach 5, that RAM
It can be executed from the number of memories.

The above lens setting operation may be performed according to a manual command for the desired magnification, but if the command information is stored in RAM and executed for the first time with a copy start command, the machine may be moved unnecessarily by changing key inputs, etc. Never. This RAM information can be canceled using the clear key that cancels the desired number of copies data.

In this embodiment, the controller 53 can be a well-known one-chip microcomputer such as μPD7801G manufactured by NEC Corporation.

4-A and 4-B are examples of control flowcharts according to the embodiment of the present invention, which are programmed and stored in the memory ROM of the controller 53. The flowcharts shown in FIGS. 4-A and 4-B will be explained below.

After the power is turned on, in step 1, the reference position sensor 36 determines whether the lens 3 is at the reference position. If the lens 3 is not at the reference position, it is determined in step 2 whether the detector 34 is detecting the lens 3 or not. Detector 34 in step 2
If the lens 3 is detected, the drive motor 32 is driven clockwise in step 3. When the reference position sensor 36 detects the lens 3 in step 4, it is determined that the lens 3 has moved to the reference position, and the drive motor 32 is stopped. Also, in step 2, detector 3
If the sensor 4 does not detect the lens 3, the process moves to step 5, where it is determined whether the sensor 35 detects the lens 3 or not. If the detector 35 detects the lens 3 in step 5, the drive motor 3 is activated in step 6.
2 to rotate counterclockwise. Then, the process moves to step 4, and when the reference position sensor 36 detects the lens 3, the drive motor 32 is stopped. If the lens 3 is not detected by the detector 35 in step 5, the number of pulses N is set in the counter _T1 in the controller 53 in step 7, the drive motor 32 is driven clockwise, and the process moves to step 8. In steps 8 and 9, the number of pulses generated by the pulse generating means 31 is counted and the content of the counter _T1 is subtracted. Further, if the reference position sensor 36 detects the lens 3 while counting the number of pulses, the drive motor 32 is stopped. When the contents of the counter _T1 become 0 in step 9, the process moves to step 10.
In step 10, the drive motor 32 is stopped and then driven counterclockwise. In step 11,
The reference position sensor 36 continues to detect the lens 3,
When detected, the drive motor 32 is stopped and the process moves to step 12. In step 12, a lens desired position flag is set to check that the lens 3 has arrived at the desired position.

In step 13, if a magnification change command is input to the controller 53 from the operation unit 41, step 14
The desired lens position flag is reset in step 15, and the process moves to step 15. In step 15, it is determined whether the command magnification input to the controller 53 is smaller than the magnification corresponding to the current lens position. If the commanded magnification is smaller than the magnification corresponding to the current lens position, proceed to step 16 and multiply the commanded magnification from the magnification corresponding to the current lens position by 1000 to determine the number of pulses to be set in counter _T1. decide. Thereafter, the drive motor 32 is driven clockwise to set the lens 3 at the commanded magnification position.
If the commanded magnification is greater than the magnification corresponding to the current lens position in step 15, the process proceeds to step 17, where the commanded magnification minus the magnification corresponding to the current lens position is multiplied by 1000 and set in counter _T1 . Determine the number of pulses. Thereafter, the drive motor 32 is driven to rotate counterclockwise. In steps 18 and 19, the number of pulses generated by the pulse generating means 31 is counted and the content of the counter _T1 is subtracted.
When the content of the counter _T1 becomes 0 in step 19, the process moves to step 20, and the drive motor 32 is stopped, assuming that the lens 3 is set at the commanded magnification position. Thereafter, the process moves to step 12 to set the desired lens position flag. Further, if a change in the command magnification is input from an operation unit (not shown) while the lens 3 is being moved by the drive motor 32 to set the position of the command magnification, it is determined in step 21,
Move to step 15. After step 15, as described above, the number of pulses to be set in the counter _T1 is determined and the direction of rotation of the drive motor is determined.
That is, in step 21, the commanded magnification can be changed even while the current lens 3 is moving to the commanded magnification position. Then, the rotational direction of the motor and the moving distance of the lens can be determined immediately.

In order to improve the accuracy of the lens setting operation described above, it is necessary to take into account the extra number of pulses generated due to the inertia of the motor after the motor drive signal is stopped when counting the number of pulses.

As detailed above, according to the present invention, when the magnification is changed from the first magnification to the second magnification while the optical system lens is moving to the position corresponding to the specified first magnification, Whether the position corresponding to the second magnification is in the moving direction of the optical system lens or in the opposite direction,
The optical system lens can be quickly and accurately set at a position corresponding to the second magnification.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram of a copying machine to which the present invention can be applied, FIG. 2 is an example of a schematic configuration diagram of the main lens drive of the present invention, and FIG. 3 is an example of a block diagram for lens drive control according to the present invention. , Figure 4-A, 4th
-B is an example of a control flowchart according to the present invention. Here, 1 is a photoreceptor, 3 is a lens, 31 is a pulse generating means, 32 is a drive motor, 34 and 35 are detectors, 36 is a reference position sensor, 41 is an operating section, and 53
is a controller, and 54 is a driver.

Claims (1)

[Scope of Claims] 1. An exposure means for exposing a document placed on a document table; an optical system lens for forming a variable magnification image of the document exposed by the exposure means on a photoreceptor; recording means for recording the variable magnification image on the photoreceptor on recording paper; designation means for specifying a desired magnification; a driving means for moving the optical system lens; and a counting means for counting pulse signals synchronized with the movement of the optical system lens in order to grasp the position of the optical system lens being moved by the driving means. , the optical system lens is moved by the driving means to set the optical system lens at a position corresponding to the designated magnification ratio, and the counting means calculates the count value set according to the designated magnification ratio. control means for stopping the movement of the optical system lens by the driving means when counted, the control means controlling the pulses caused by the counting means while the optical system lens is moving to a position according to a specified magnification ratio; Detecting a change in magnification by the specifying means even while counting signals, and detecting a change in magnification by the specifying means while the driving means is moving the optical system lens to a position corresponding to the specified first magnification. When it is detected that the magnification has been changed from the first magnification to the second magnification, the optical system lens is moved according to the position of the optical system lens during movement and the position corresponding to the second magnification. After determining the direction and changing the count value to be counted by the counting means, moving the optical system lens by the driving means in the determined moving direction, and counting the changed count value by the counting means, the driving means By stopping the movement of the optical system lens by
A copying device characterized in that the copying device is set at a position corresponding to the magnification of the copying device.