JPS6046541A - Position controller for optical image projection lens - Google Patents

Abstract

PURPOSE:To secure the safety of a lens unit by driving the lens unit to where it is gripped even if the position of the lens unit is unknown when a power source is turned on again while the lens unit stops away from a specific position. CONSTITUTION:A positioning control means 60 refers to the detection signals of detecting means right after the device is powered on, and drives an optical image projection lens 10 at a low speed in one direction unless none of them detects the lens 10 there. When one of the detecting means 17-30 detects the arrival of the optical image projection lens 10 at the specific position, the position of the optical image projection lens 10 based upon the detection signal of the detecting means is compared with a target position corresponding to specified magnification, and the optical image projection lens 10 is driven and position at the target position by the positioning means 60 according to a specific high low speed pattern.

Description

Detailed Description of the Invention [Technical Field] The present invention relates to a position control device for positioning a lens that projects a light image onto a photoreceptor drum or an imaging device in order to set the light image projection magnification. The present invention relates to a position control device that drives a lens with a drive system including the lens, detects the lens position with a plurality of detection means, compares the detected position with a target position, and drives the lens to the target position.

■Prior Art For example, in a copying machine, in order to set various copying magnifications, a plurality of image projection lenses with different copying magnifications are arranged in a direction perpendicular to the image projection axis and fixed on a single carriage. , a position control device that drives a carriage to place an image projection lens that provides the specified magnification on the image projection axis according to the specified magnification, or a position control device that drives the carriage so that the image projection lens that provides the specified magnification is placed on the image projection axis, or a master lens that is placed on the image projection axis and moved in a direction along the axis. A position control device is used that is driven to set the position corresponding to the designated magnification.

In either case, a plurality of detection means detect the lens position, and the lens detection position based on the detection signal of the detection means is compared with a target position corresponding to the indicated magnification to move the lens to the target position at a predetermined high or low speed. Positioning control means that performs bias control driven by a pattern is used.

Normally, the lens remains stationary at a position that provides a predetermined magnification.
Drives only when the specified magnification is changed.

However, the device power may be turned off while the lens is being driven in response to a change in the specified magnification, and in this case, the lens may be at a position that does not correspond to the specified magnification, that is, the position cannot be detected by any of the detection means. Stop at a position. Then, the next time the power is turned on, since the positioning control means does not know the lens position, it drives the lens in a predetermined direction until one of the detection means detects that the lens has arrived at a predetermined position.

Conventionally, lenses are driven at low speed.

However, recently, the lens driving speed is sometimes increased in order to speed up the magnification change, and especially when the lens movement distance is relatively large, the speed is gradually increased from the start of lens driving (and then the speed increases). Therefore, there is an increasing need for high-speed driving, such as high-speed and low-speed pattern driving, in which the speed is kept constant, the speed is decelerated before the target position, and the target position is stopped quietly.

However, when driving at high speed, when the power is turned on while the lens is stopped between the detection means and the lens is driven toward a predetermined position, the lens position at the start of driving is unknown. Even if the motor energization is stopped after detecting lens unit 1~ with the limit switch, the carriage and lens unit collide with the end of the moving shaft at high speed, causing damage to lens unit 1~.

This causes deformation, defocus, etc.

(1) Purpose The purpose of the present invention is to prevent impact to the lens unit when driving the lens immediately after power is turned on.

■Structure In order to achieve the above object, in the present invention, the positioning control means refers to the detection signal of the detection means immediately after turning on the device power, and both of them detect that the optical image projection lens is there. If not, the light image projection lens is biased to be driven in one direction at a low speed, and when the detection means detects that the light image projection lens has arrived at a predetermined position, the light image projection lens is driven based on the detection signal of the detection means. The position is compared with the target position corresponding to the specified magnification, and biasing control is performed to drive the optical image projection lens to the target position in a predetermined high and low speed pattern.

FIG. 1 shows an outline of the structure of a mechanical section in an embodiment of the present invention. This example shows a variable magnification mechanism of a copying machine.

The master lens unit 10 is inserted into a part of an image projection axis that passes through a contact glass plate on which a document is placed, reflects light from several types of mirrors, further reflects the light from several types of mirrors, and projects it onto a photosensitive drum. , are driven leftward and rightward along the image projection axis (the thick arrow in FIG. 1 indicates the projection direction of the optical image on the projection axis). That is, the master lens unit IO is fixed to a carriage, a wire is coupled to the carriage, and a pulley for driving the wire is coupled to the rotating shaft of the servo motor 15 via a gear. It is driven to the right in forward rotation and to the left in reverse rotation.

A rotary encoder 16 is connected to the servo motor 15 and generates two sets of pulses having a frequency proportional to the rotational speed of the motor 15 and having different phases.

Four conversion lens units 11 to 14 are arranged so as to be able to advance toward and retreat from the optical image projection axis where the master lens unit 10 is placed. Conversion lens unit 11 is for 1.41x setting, 12
is for 1.0x setting, 13 is for 0.707x setting, and 14 is for 0.5x setting. The conversion lens units 11 to 13 are each fixed to a separate carriage, a wire is coupled to each carriage, and a pulley for driving the wire is selectively coupled to a rotating shaft rod by clutches 38 to 41. ing. The rotating shaft rod is coupled to a rotating shaft of a servo motor 36 via a gear.

A rotary encoder 37 is coupled to the servo motor 36 and generates two sets of pulses with frequencies proportional to the rotational speed of the servo motor 36 and different phases.

Limit switches 42 to 45 are closed when the conversion lens units 11 to 14 are respectively in the standby position.

17 to 30 are switches for detecting the positions of the master lens units 1 to 10, and each blank has the following meaning.

Switch 17 closed: Master lens unit 1-10 is at the left end limit position.

Switch 18 closed: The master lens unit 10 is at the deceleration start position (in the case of normal rotation drive) for stopping PL (1, 41x position).

Switch 19 closed: Master lens unit 10 is at PI (1,41x position).

Switch 20 closed: Master lens unit IO is at the deceleration start position (in case of reverse drive) for stopping PI (1, 41x position).

Switch 21 closed: Master lens unit 10 is at P2 (1,0x position)
It is at the deceleration start position for stopping (in the case of normal rotation drive).

Switch 22 closed: Master lens unit 10 is at P2 (1,0x position).

Switch 23 closed: The master lens unit 10 is at the deceleration start position (in the case of reverse drive) for stopping P2 (1,0x position).

Switch 24 closed: The master lens unit 10 is at the deceleration start position (in the case of normal rotation drive) for stopping at P3 (0,707 times position).

Switch 25 closed: Master lens unit 10 is at P3 (0,707x position).

Switch 26 closed: Master lens unit 10 P3 (0,707
double position) deceleration start position for stopping (in case of reverse drive)
It is in.

Switch 27 closed: The master lens unit 10 is at the deceleration start position (in the case of normal rotation drive) for stopping at P4 (0,5 times position).

Switch 28 closed: Master lens unit 10 is at P4' (0.5x position)
It is in.

Switch 29 closed: The master lens unit 10 is at the deceleration start position (in the case of reverse drive) for stopping P4 (0,5 times position).

Switch 30 closed: The master lens unit 10 is in the right mitt position.

When the magnification is 1.41x, 10x to master lens unit 1.
is placed in the P1 position, and the conversion lens unit 1-
11 is placed on the image projection axis.

When the magnification is 1.0, the master lens unit 10 is placed at the P2 position as shown, and the conversion lens unit 2 is placed on the image projection axis as shown by the solid line.

At 0.707x, the master lens unit IO
is placed in the P3 position, and the conversion lens unit 1
3 is placed on the image projection axis.

Also, when the magnification is 0.5x, the master lens unit]~1
0 is placed at the P4 position, and the conversion lens unit 14 is placed on the image projection axis.

A striker that closes the switches 17 to 30 is fixed to the carriage of the master lens unit 10.
Further, a click groove lever 31 for accurately positioning the carriage at each position is fixed, and solenoid devices 32 to 35 having rollers that enter the groove of the click groove lever 31 are pivotally attached to the fixed part of the copying machine. is located,
This solenoid device provides accurate positioning and partial locking of the carriage of unit 10 at each position PI-P4. That is, when the master lens units 1 to 10 reach the predetermined positions P1 to P4, the switches 19+ 22+
When 25+28 are idle, motor 15
When the energization is stopped and the rollers of the solenoid devices 32 to 35 enter the groove of the click groove lever 31, the carriage stops and the position of the carriage is fixed.

The fixed part of the copying machine is equipped with a toggle mechanism that performs a reversal operation when the conversion lens units 11 to 14 are placed on the image projection axis, which also ensures that the conversion lens units 11 to 14 are accurately placed on the image projection axis. It is designed to perform positioning and temporary locking. That is, when the carriage of the lens units 1-11-14 reaches the image projection axis, the toggle mechanism is driven by the striker of the carriage and reversed to generate a force that forces the striker to a predetermined position.

FIG. 2 shows the configuration of an electric device that reads the switches of the above mechanism and controls the motor energization. A servo motor energization/control circuit 46 is connected to the six servo motors 15.
This circuit 46 is connected to a microcomputer (hereinafter C
A PU (referred to as PU) 60 gives momentum control instructions such as a forward rotation instruction, a reverse rotation instruction, a rising instruction, a constant speed instruction, a deceleration instruction, and a stop instruction.

Rotary encoder 1 coupled to servo motor 15
The two sets of generated pulses No. 6 are applied to interrupt terminals To and T1 of the CPU 60, respectively, and one set is applied to the F/V converter 47.

The servo motor energizing/control circuit 46 is a known one,
The energization, rotational speed, etc. of the motor 15 are controlled in accordance with instructions from the CPU 60 and in accordance with the output voltage (speed detection signal) of the F/V converter 47.

The CPU 60 determines the rotation direction of the motor 15 from the phase sequence of the two sets of pulses from the rotary encoder 16, sets the pulse count 1- to up count run 1- or down count, and counts one of the two sets of pulses. The amount of movement of the carriage of the master lens unit IO (the carriage position of the master lens unit 10) is grasped.

The servo motor 36 includes a servo motor energizing/control circuit 48
is connected to this circuit 46, and a microcomputer (hereinafter referred to as CPU) 60 gives energizing control instructions such as a forward rotation instruction, a reverse rotation instruction, a rising instruction, a constant speed instruction, a deceleration instruction, and a stop instruction.

Rotary encoder 3 coupled to servo motor 36
The two sets of generated pulses No. 7 are applied to interrupt terminals To and T1 of the CPU 60, respectively, and one set is applied to the F/V converter 49.

The servo motor energizing/control circuit 48 is a known one,
The energization, rotational speed, etc. of the motor 36 are controlled in accordance with instructions from the CPU 60 and in accordance with the output voltage (speed detection signal) of the F/V converter 49.

The CPU 60 determines the rotation direction of the motor 36 from the phase sequence of the two sets of pulses from the rotary encoder 37, sets the pulse count to up count 1 or down count, counts one of the two sets of pulses, and performs conversion. The amount of movement (carriage position) of the carriage of the lens unit (11 to 14) is grasped.

FIG. 3 shows the positioning control operation of CI) U 60. The control operation of the CPU 60 will be explained with reference to FIG.

When the power is turned on, the CPU 60 sets internal registers, counters, flags, etc. to their initial states, sets data indicating a multiplier of 1.0 in the magnification register, and sets the output boat to its initial state (motor stopped, solenoid The device is off, the clutch is off, and the magnification display is set to 1.0), and the input port is enabled for input.

Then read the input port signal.

Signals to the input capo 1 are read by reading the opening/closing of the magnification indicating switch 61 and by reading the switches 17 to 30 (more precisely, switches 17, 19, 22, 25, 28, and 3) shown in FIG.
0 only) and 42-45 open/close readings. When a magnification different from the magnification stored in the magnification register is designated by the 1 magnification instruction switch 61 during this reading, a code indicating the magnification designated in the magnification register is updated and stored in the magnification register.

Now, when reading the opening/closing of switches 17-30 and 42-45, if all switches 42-45 are closed, all of the conversion lens units 11-14 are in the standby position, so the next opening/closing of switches 17-30 is For reference, if any of the switches 42 to 45 is open, the conversion lens unit corresponding to the switch that is open is not in the standby position (this means that it is on the image projection axis or not). , or between the image projection axis and the standby position), the CPU 60 opens the open switch i (i=42 to 45).
Turn on clutch 1-4 (38-41) corresponding to
An instruction is issued to the motor energizing/control circuit 48 to energize the motor 36 in the reverse direction at a low speed (setting the instruction signal to be output). Then, the signal of switch i is monitored, and when it is closed (when the conversion lens unit returns to the standby position), an instruction signal to the motor energization/control circuit 48 is reset and an instruction is given to stop the clutch i-4. is off.

This can be repeated until all switches 42-45 are closed.

5 Normally, only one conversion lens unit is selectively placed on the image projection axis, so this waiting time ms
is performed for only one conversion lens unit.

Next, CPtJ60 switches 17 to 30 (to be exact, only switches 17, 19, 22, 25, 28 and 30)
Referring to the opening and closing of switches 19゜22.2!5 and 2
8 is closed (master lens unit 10
is in any of the positions P1 to P4), or
When the switch 17 or 30 is closed (when the master lens unit 10 is at the left limit position or the right limit position), the position of the master lens unit 10 is known and the motor energizing/control circuit 46 is used to stop the motor 15. 1 Proceed to normal magnification setting.

However, switches 17, 19, 22. ．． When all of 25, 28 and 30 are open, the master lens unit 1-
Since I don't know the position of 10, all solenoid devices 32~
35 is output to the solenoid drivers 53 to 56, and the low speed reverse bias of the motor 15 is activated.
Instructs the control circuit 46.

and switches 17, 19, 22, 25, 28 and 3
0 reading is repeated, and when one of the switches closes, the position is known, so the motor energizing/control circuit 46 is instructed to stop the motor 15 (resetting the low speed reverse energizing instruction), and the entire After receiving the energization instruction for the solenoid devices 32 to 35, proceed to normal magnification setting.

In normal magnification settings, the CPU 60 first switches 17,
19, 22, 25, 28, and 30 (7) open/close, read the position (current position) of master lens unit ■0, and select master lens unit 1 from the contents of the magnification register.
Determine the target position of 0 and compare the two. If they match, proceed to drive the conversion lens unit, but if they do not match, the motor 15 will rotate in the required rotation direction and start deceleration from the current position and target position. Detection switch (18)
, 20, 21, 23, 24, 26, 27° 29) and a detection switch (19, 22, 25
, 28).

Then, the energization (roller retraction) of all the solenoid devices 32 to 35 is indicated to the solenoid drivers 53 to 5G at 411, the rotation direction is instructed to the motor energization/control circuit 46, and the motor activation is instructed.

Thereafter, the state of the switch used to start deceleration is monitored while counting the number of pulses generated by the rotary encoder 16 using an interrupt, and when the value reaches a predetermined value, the motor energizing/control circuit 46 is instructed to run at a constant speed. . If the switch that refers to the start of deceleration is closed afterwards or before that,
Then, the driver is instructed to decelerate.

The motor energization/control circuit 46 starts up the motor speed toward high speed with a predetermined startup characteristic after receiving an instruction to start the motor, shifts to constant speed control when a constant speed instruction is given, and shifts to constant speed control when a deceleration instruction is given. Therefore, the motor speed is decelerated toward a stop using a predetermined falling characteristic.

After instructing deceleration, CPU 6.0 reads the state of the detection switch (a switch that detects arrival at the target position, one of 19, 22, 25, or 28) that is used to stop the motor, and determines whether it is closed. Then all solenoid devices 32-35
Reset the energization instruction (roller advance) and set the motor energization.
Instructs the control circuit 4G to stop the motor.

The above is the step FL2 of driving the master lens unit 10 to the set magnification position shown in FIG.

Next, the CPU 60 proceeds to step F]-3 where the conversion lens corresponding to the set magnification is set 11m.

In this case, the conversion lens unit specified by the contents of the magnification register (11 for magnification 11.'ll, 127 for magnification 1.0, 13 for magnification 0.707, and 0 for magnification
．． Clutches (38 to 41) assigned to 5 and 14)
An on instruction is outputted to the solenoid drivers (49 to 52), and the motor energizing/control circuit 48 is instructed to rotate forward and start the motor. Then, the interrupt starts counting up the pulses generated by the rotary encoder 36, and when the count value reaches a predetermined value, a constant speed instruction is issued to the motor energization/control circuit 48, and the count up continues until the count value reaches the next value. When the predetermined value is reached, a deceleration instruction is issued to the motor energizing/control circuit 48, and the count up continues, and when the count value reaches the next predetermined value, the solenoid driver (49
52 to turn off the clutch, and the motor energizing/control circuit 48 to stop the motor.

When the motor energization/control circuit 48 receives a motor start instruction, it starts energizing the motor to increase the speed at high speed with a predetermined rise characteristic in a specified rotation direction, and when it receives a constant speed instruction, it starts constant speed control. When a deceleration instruction is received, the motor starts energizing to decelerate toward a stop with a predetermined falling characteristic.
When a stop instruction is given, the motor's energization is stopped.

As a result of the above, the master lens unit 10 is set at a position corresponding to the designated magnification, and the conversion lens unit that provides that magnification is positioned on the image projection axis.

Thereafter, the CPU 60 only reads the magnification designation switch 61 and waits for another magnification to be designated by the switch 61.

When another magnification is specified, the CPU 60 stores the contents of the magnification register in the previous magnification register, updates the data indicating the currently specified magnification in the magnification register, and waits for the conversion lens at the set position. The process advances to step FL4, where it is driven to the position.

In this standby position drive step FL4, the CPU 60 first specifies the clutches (38 to 41) to be energized for standby drive based on the contents of the register M and the solenoid drivers (49 to 52). It instructs the clutch to be turned on, and instructs the motor energizing/control circuit 48 to reverse rotation and start. Then, the countdown of the pulses generated by the o-IJ-encoder 37 is started using an interrupt. Then, when the count value reaches a predetermined value, the CPtJ 60 instructs the motor energization/control circuit 48 to maintain a constant speed, and further continues the countdown, and when the count value falls below the next predetermined value, the motor energization/control circuit 48; After instructing deceleration, the value from 1 to 0 becomes zero, and the standby position l of the conversion lens unit that is driven b); a certain switch (11
- 14) are closed. When one of σ) is established, the motor energizing/control circuit 48 is instructed to stop the EL, and the solenoid drino (49 to 52) is instructed to turn off the clutch. As a result of the above, the conversion lens was placed on the image projection axis in order to obtain the previous magnification, and the conversion lens was retracted to the standby position.

Next, the CPU 60 proceeds to step FL2, sets the master lens 22 1-10 to the position corresponding to the contents of the magnification register in the same manner as described above, and further sets the conversion lens corresponding to the contents of the magnification register in the next step FL3. Set the unit on the image projection axis. As a result, the master lens unit 10 is set at a position corresponding to the currently designated magnification, and the conversion lens required to obtain that magnification is also set on the image projection axis.

As mentioned above, in this embodiment, the master lens unit 1
Although the desired magnification is obtained by selectively setting the master lens unit IO and the conversion lens units 11 to 14 at predetermined positions, the present invention is applicable to driving both the master lens unit IO and the conversion lens units 11 to 14. Immediately after turning on the power, and if the detection switch has not detected the position of the lens unit, move the lens unit in a predetermined direction (direction toward the left limit position L1 in the master lens unit 10, direction toward the left limit position L1 in the case of the master lens unit 10, 1 to 11 to 14, the lens unit is driven at low speed in the direction toward the standby position), and when the lens unit is detected by the detection switch, the normal magnification setting control is performed there. It will not collide with the limit end at high speed, and will not cause shocks due to being forced to stop suddenly at high speed, and will not cause deformation of the lens unit, defocusing, damage to the lens drive system, deformation 2 position shift, etc. No rattling etc. will occur.

■Effects As described above, according to the present invention, if the copying machine power is turned off while the lens drive system 1- is being driven, the lens drive system 1- stops at a position deviated from the predetermined position. Even if you do not know the position of the lens unit when the power is turned on again, the lens unit will be stably driven to a position that can be grasped, so there is no possibility of sudden stop control due to high-speed drive and causing shock. There is no problem with this, and the safety of the lens unit is ensured.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an outline of a mechanical section of an embodiment of the present invention. FIG. 2 is a block diagram showing the configuration of an electric device that reads the opening and closing of switches arranged in the mechanism and controls the power of motors, solenoids, etc., and FIG. It is a flow chart showing control operation. 10: Master lens unit (light image projection lens) 11
~14: Conversion lens unit (light image projection lens) 15.367 Serpo motor (electric motor) 16.37
: Rotary encoder 17.19, 22, 25, 28, 30 : Switch (detection means) 18. 20, 21, 23, 24, 26, 27,
29: Switch 31: Click groove lever 32-35: Solenoid device 38-41: Clutch 42-45: Switch (detection means) 60: Microcomputer (positioning control means) 61
: Magnification indicator switch 63 : Setting magnification indicator 33 Procedural amendment (voluntary) Commissioner of the Japan Patent Office Wakasugi Wainu 1, Indication of the case Patent Application No. 154688 of 1982 2
, Title of the invention Position control device 3 for an optical image projection lens, Relationship to the case of the person making the correction Patent applicant address 1-3ti6 Nakamagome, Ota-ku, Tokyo Name (6
74) Ricoh Co., Ltd. Representative Hama 1) Hiro 4, Agent 103 Phone 03 864-6052
Address: 2-27-6-5, Higashi-Nihonbashi, Chuo-ku, Tokyo, subject of amendment 6, contents of amendment No. 2121 attached.'' Please make the corrections as shown in the attached sheet. 7. Inventory drawing of attached documents (Figure 2)...-leaf

Claims (1)

[Scope of Claims] A lens drive mechanism that includes an electric motor and drives an optical image projection lens, an energizing circuit that energizes the electric motor, and an optical image projecting lens located at one of a plurality of predetermined positions. a plurality of detection means for detecting this, and a detection position of the light image projection lens based on the detection signal of the detection means and a target position corresponding to a specified magnification are compared, and the light image projection lens is moved to the target position; In a positioning control device for an optical image projection lens, the positioning control device includes a positioning control device that performs energizing control driven in a predetermined high and low speed pattern: The positioning control device refers to the detection signal of the detection device immediately after the device is powered on. However, when none of them detects that the light image projection lens is there, the light image projection lens is biased to be driven in one direction at a low speed, and the detection means detects the presence of the light image projection lens. When arrival at a predetermined position is detected, the position of the light image projection lens based on the detection signal of the detection means is compared with a target position corresponding to a specified magnification, and the light image projection lens is moved to the target position in a predetermined high and low speed pattern. 1. A position control device for an optical image projection lens, characterized in that the position control means performs biasing control driven by a.