JPS62134639A - Driving device for optical system of copying machine - Google Patents

Abstract

PURPOSE:To simplify a driving mechanism and to reduce the variance of a driving load by calculating moving directions, the order of moving, and extents of movement of both a lens and a conjugate length correcting mirror in accordance with an already set copy magnification and another newly designated copy magnification to control the driving mechanism of both the lens and the mirror. CONSTITUTION:An original on an original platen 8 is scanned by a scanning mirror 2, a fixed mirror 3, a lens 4, and a conjugate length correcting mirror 5 to form an electrostatic latent image on a photosensitive drum 1, and the image is developed and transferred. When the magnification is changed from unmagnification, the lens 4 and the mirror 5 are moved to positions 4'' and 5'' respectively for the purpose of preventing the collision between the lens 4 and the mirror 5. After the start, the CPU 10 moves the lens 4 and the mirror 5 to unmagnification positions through motor drivers 12 and 13 and motors M1 and M2, and at this time, the lens 4 is moved more quickly than the mirror 5. In case of copying, the CPU 10 compares preceding and current copy magnification signals from a CPU 11 with each other to operate moving directions, the order of moving, and extents of movement of the lens 4 and the mirror 5, and the lens 4 and the mirror 5 are moved in accordance with operation results.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an optical system and drive device for copying (copying) that can change the magnification.1 [Prior Art] In the field of copying machines, a method for enlarging a document and making a copy. Copying machines that can change the magnification have become popular in order to meet the demand for reduced copying, but in recent years: - There has been a demand for an expansion of the range in which the magnification can be changed.

Expanding the magnification change range not only expands the movement range of the copying optical system such as the lens and the conjugate length correction mirror (the movement range of the lens and the movement range of the conjugate length correction mirror partially overlap) There will be cases.

FIG. 2 shows this, with the vertical axis showing the change range of the magnification factor, and the horizontal axis showing the positions of the lens and the mirror for conjugate length correction. The movement range of the lens falls within the movement range of the conjugate length correction mirror, and overlaps within the range A. Therefore, when a certain desired magnification is selected, if the lens is moved before moving the conjugate length correction mirror, the lens may collide with the conjugate length correction mirror.

[Problem that the invention seeks to solve]

In conventional copying machines, the range of magnification change is not so large, and even though there is some overlap in the movement range of the conjugate length correction mirror and lens, mechanical movement mechanisms such as cams are used. By designing the cam shape, the conjugate length correction mirror and lens could be moved to a predetermined magnification without colliding with each other. .

However, as the range of magnification changes expands, it becomes difficult to design the shape of the cam used in the movement mechanism, and the load when changing the magnification varies greatly depending on the shape of the cam. Since it is necessary to select according to the maximum and negative load, there are problems such as the overall size of the device.
There was a limit to the range in which the magnification of a copying machine could be changed.

[Means for solving problems]

The present invention aims to solve the above-mentioned problems, and includes: a drive mechanism that independently drives a lens and a conjugate length correction mirror that constitute a copying optical system; a means for specifying a copying magnification; The moving direction, moving speed, and moving amount of the lens and the conjugate length correction mirror are calculated from the already set copying magnification and the newly specified copying magnification, and the newly specified copying magnification is calculated based on this calculation multiplication. Copy magnification position]C
It is comprised of a control means for controlling the lens and the conjugate length correction mirror drive mechanism so as to set the lens and the conjugate length correction mirror.

To explain this with reference to FIG. 1 corresponding to the example, the first
The figure shows the basic configuration of the optical system and drive unit of a copying machine.
The original on the original platen 8 is mirror 2, fixed mirror 3, and lens 4.
, a photosensitive drum is formed by a copying optical system consisting of a mirror 5 for conjugate length correction.

In order to change the copying magnification, the lens 4 and the mirror 5 are driven by independent drive mechanisms, and the lens 4 is at position 4' when the magnification is increased, and at position 4'' when the magnification is decreased.
The mirror 5 moves to a position 5' when the magnification is increased and to a position 5'' when the magnification is decreased, and a microprocessor is used for the side legs of the drive mechanism.

[For production]

When copying, when a copy magnification is specified from the operation panel and input to the microprocessor, the microprocessor compares it with the copy magnification set during the previous copy and determines the direction and amount of movement of the lens and mirror. , a moving speed at which the lens and mirror do not collide during movement is calculated, and according to the result of this calculation, the driving mechanism for the lens and mirror is controlled, and the lens and mirror are set at a predetermined copying magnification position.

As a result, the lens and mirror drive mechanism becomes simpler than a conventional drive mechanism using a cam or the like, and the drive load can be made less variable.

〔Example〕

Examples of the present invention will be described below.

FIG. 1 shows the basic configuration of the optical system and its drive unit of a copying machine according to the present invention. 1 is a photosensitive drum, 2 is a first mirror of the copying optical system that scans an original, and 3 is a first mirror. 2. 3rd
A fixed mirror consisting of a mirror, 4 is a lens, 1, 1' is the position when the magnification is enlarged, and 4'' is the position when the magnification is reduced. 5 is a conjugate length correction mirror (hereinafter simply a mirror). 5' is the position when the magnification is enlarged, and 5'' is the position when the magnification is reduced. 6 is the same-magnification position detection sensor of the mirror, and 7 is the same-magnification of the lens. A position detection sensor, 8 a document table, 9 a light source lamp, M1 a stepping motor for driving a lens, and M2 a stepping motor for driving a mirror.

Next, to explain its operation, the document on the document table 8 is scanned by the mirror 2, fixed mirror 3, lens 4, which constitutes the scanning optical system.
It is scanned by a mirror 5 to form an electrostatic a image on the photoreceptor drum 1. This static or clear image is developed, transferred and fixed onto copy paper.

Assume that lens 7↓ and mirror 5 are set to make a copy at the same magnification, and if you want to change the reduction to a certain magnification, set lens 4 to the 4" position and mirror 5 to 5". At this time, when the lens 4 is moved to the position 4, the mirror 5 remains at the same magnification copying position, so the two collide. Therefore, in this case moves the lens 41 to the lens 4'' position while moving the mirror 5 to the mirror 5'' position.

In addition, to move the lens and mirror from the reduced magnification state to the same magnification state as described above, move lens 4'' to lens 11.
The mirror 5'' is moved to the position of the mirror 5 while moving at a speed faster than the moving speed of the mirror 5 to the position of the mirror 5.

As described above, in order to move the lens 4 and mirror 5 to a position where the desired copying magnification can be obtained, a microprocessor is used to calculate the moving direction, moving speed, and moving amount, and a stepping motor for driving the lens and mirror is used. control.

FIG. 3 is a diagram showing an outline of the copying machine control circuit. In the figure, a first microprocessor (hereinafter referred to as CPU 1) 1
0 is used to control the copying optical system. Mita driver 12
A stepping motor M for driving a lens is connected via a motor driver 13, and a stepping motor M2 for driving a mirror is connected to an output port P4 of the CPU 1 via a motor driver 13.

In addition, 2111% of the total copying other than changing the copying magnification
For this purpose, a second microprocessor (hereinafter referred to as CPU 2) is required.
and (・5) 11 should be used.

CPU 1 and CPU 2 are connected by a signal line, and signals related to copying operations are transmitted and received.

For example, a signal related to the copying magnification input from the operation panel of a copying machine is processed by the CPU 2 and then sent to c P 1.
Based on this copy magnification signal, the CPU l controls the lenses and mirrors to move to desired positions.

Next, signal processing within CPU I will be explained. FIG. 4(a) is a flowchart of a copy magnification signal routine carried out within CPU I.

First, after starting, initial values are set in step S1. Furthermore, the lens 4 and mirror 5 are returned to the same magnification position.

At this time, the moving speed of the lens 4 is made faster than the moving speed of the mirror 5 to prevent the two from colliding. The lens and mirror magnification positions are detected by a sensor 6.7.

In step S2, the copy magnification signal input from the CPU 2 during the previous copying operation and the CP in the current copying operation are compared.
The copy magnification signal input from U2 is compared.

If there is no change in the cultivation rate, the magnification change process is not performed and step S4
Move to. If there is a change in magnification, proceed to step S3;
Move to the lens and mirror fixed subroutine for changing magnification. This will be explained later based on FIG. After this, the process moves to step S4.

In step S4, signal processing other than lens and mirror movement control is performed, but since it is not directly related to this invention, the explanation will be omitted.
In the interrupt processing routine in step S5, the copying machine 5 controls the entire copying machine, communicates with the CPU 2, and receives data regarding the copying magnification.

FIG. 5 is a flowchart of the lens and mirror 4 movement subroutine. First, in step S6, the copying magnification at the previous copying operation and the currently specified copying magnification are compared.

If the previous copying magnification is larger, the process moves to step S7, and the direction of movement is determined to reduce the copying magnification.

Moving on to step S8, the moving speed of the mirror 5 and the lens 4 are determined.
The respective stepping rates are determined so that the moving speeds of are the same speed V(.Next, the process moves to step S9,
The number of movement steps of the lens and mirror is calculated as the number of pulses.

Also, if the previous copy magnification is smaller, step S
Moving to IO, the object to be moved in the direction of enlarging the copy magnification and the direction of movement are determined.

Proceeding to step Sll, respective stepping rates are determined so that the moving speed of the mirror 5 is set to {circle around (2)} and the moving speed of the lens 4 is set to 2V, which is twice the moving speed of the mirror. Next, the process moves to step S12, and the number of movement steps of the lens and mirror is calculated as the number of pulses. This calculation can also be performed by storing a table calculated in advance from the copying magnifications before and after the movement of the lens and mirror in the memory of the CPU 1, and calculating from this table.

Once the moving direction of the lens and mirror and the number of moving pulses are obtained, the motor driver 12.13 is activated based on this and pulses are sent to the motors hi, , M2, but every time a pulse is output (step 514). Then, the pulses are counted (step 515), and it is determined whether a predetermined number of pulses have been output (step 513), and the process is repeated until a predetermined number of pulses are output.

When a predetermined number of pulses have been output, the lens and mirror have moved to a predetermined position, so the output of pulses is stopped and the process ends.

The embodiments of the optical system drive device for changing the copying magnification of the present invention have been described above.
The direction of the inequality sign in step S6 for determining the driving order of the lenses and mirrors shown in the figure may change from that shown in this figure if the conjugate length correction mirror changes.

In addition, in the example, a stepping motor driven by pulses was used to drive the lenses and mirrors, but a DC motor was used to measure the number of rotations or the amount of movement of the lenses and mirrors using pulses, etc. However, it is possible to realize it.

Furthermore, in the embodiment, the moving speed of the lens is changed depending on the moving direction; 1. In order to shorten drive time, sensors are installed at positions where there is a risk of collision between the lens and mirror.
When it is determined from the sensor detection signal that there is no risk of collision, the lens may be moved faster than the mirror. In this case, the sensor can also be used as a lens and mirror initial position detection sensor.

In addition, the absolute positions of the lenses and mirrors are determined from the number of pulses supplied to the driving stepping motor, and the CPU
If it is stored in 1, the position detection sensor for the lens and mirror can be omitted.

〔Effect of the invention〕

As explained above, according to the present invention, when changing the copying magnification, the lenses and mirrors constituting the copying optical system are driven by independent drive mechanisms, and the direction in which the lenses and mirrors move as the copying magnification changes Since the system calculates the speed and amount of movement and uses the output to control the drive mechanism, it is not only possible to change the copying magnification over a wide range without being subject to mechanical design constraints.
The copying magnification changing mechanism can be simplified 1. Furthermore, since the lens and mirror can be moved simultaneously, the copying magnification can be changed quickly.

[Brief explanation of drawings]

Fig. 1 is a basic configuration diagram of the optical system and its drive unit of the copying machine of the present invention, Fig. 2 is a diagram showing the range of change in copying magnification and the positional relationship of lenses and mirrors, and Fig. 3 is a diagram of the copying machine control circuit. 4 is a flowchart of a copying magnification changing routine, and FIG. 5 is a flowchart of a lens and mirror driving routine. 1: Photosensitive drum, 2: Scanning mirror, 3: Fixed mirror,
4: Lens, 5: Mirror for conjugate length correction, 6: Mirror 1x position detection sensor, 7: Lens 1x position detection sensor,
M, , pigeon varnish chipping motor. i3 diagram

Claims (1)

[Claims] A drive mechanism for independently driving a lens and a conjugate length correction mirror constituting a copying optical system, a means for specifying a copy magnification, and a means for specifying an already set copy magnification and a newly specified copy magnification. The direction, speed, and amount of movement of the lens and the mirror for conjugate length correction are calculated from the above, and the lens and the mirror for conjugate length correction are set to a newly specified copying magnification position according to the calculation results. An optical system drive device for a copying machine, comprising: a mirror for conjugate length correction; and a control means for controlling a drive mechanism.