JPH03174566A - Electrophotographic copying device - Google Patents

Abstract

PURPOSE:To improve accuracy in a lens moving position and a reflection member moving position and to simplify an adjusting operation by providing a 1st driving means, a 2nd driving means and a control means. CONSTITUTION:The device is provided with the 1st driving means M1 for moving and positioning a single focusing lens 15, the 2nd driving means M2 for moving and positioning the reflection members 16 and 17, and the control means for respectively and independently actuating the 1st and the 2nd driving means M1 and M2 by arithmetically operating the moving quantites of the lens 15 and the reflection members 16 and 17. An error in the focal distance of the lens 15 is discriminated in advance and the moving quantities of the lens 15 and the reflection members 16 and 17 are arithmetically operated every magnification including the error in the focal distance. The lens 15 and the reflection members 16 and 17 are respectively and independently moved to the optimum positions in accordance with the copying magnification based on the arithmetically operated numerical value. Thus, the accuracy in the moving quantities of the lens 15 and the reflection members 16 and 17 at the time of changing the magnification is improved and the adjusting operation is simplified.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrophotographic copying apparatus, and particularly to a control mechanism for an optical system that projects an original image onto a photoreceptor.

Generally speaking, in an electrophotographic copying device, when changing the copying magnification of an optical system that uses a single focus lens as an image projection lens, one direction (lateral direction) perpendicular to the scanning direction is used. In order to adjust the magnification, it is necessary to move the lens to a predetermined position, and to correct the conjugate length, it is necessary to move the reflecting member (mirror) to a predetermined position. Conventionally, both have been moved using a common driving source (an ordinary stepping motor is used), and the amount of movement has been adjusted using a cam. That is, the lens is moved by controlling the rotation angle of one stepping motor according to a set copying magnification, and the reflecting member is moved by a cam plate connected to a part of the rotation transmission system from the stepping motor. The conjugate length is corrected.

However, as a practical matter, single-focal-length lenses have a certain degree of error in focal length due to variations in the characteristics of the lenses themselves, errors in assembly accuracy, and the like. For lenses that are directly driven by a stepping motor, it is possible to correct the focal length error for each lens, but for reflective members, it is necessary to design a cam plate with a shape that corresponds to the focal length error of the lens in advance. You need to be prepared. but,
The types of cam plates that can be designed and prepared in advance for the same model are limited due to the constraints of increasing costs due to the complexity of control data and increase in the number of parts.The conjugate length correction function based on the error in the focal length of the lens is limited. The current situation is that this is not enough. Further, when a cam plate and a cam floor are used, the torque loss of these becomes large, and the load on the drive motor becomes large.

Furthermore, there is another problem in that the mutual adjustment of focus and magnification becomes very complicated. In other words, if it is detected that the magnification is not accurate after adjusting the focus, if you try to correct it by moving the lens, the reflective member will also move, resulting in the focus being out of focus. Become. Therefore, it is necessary to adjust the focus again and repeat the above operations until the focus and magnification are accurately matched, which is extremely troublesome.

Therefore, an object of the present invention is to improve the accuracy of the magnification and focus when changing the magnification, in other words, the accuracy of the lens movement position and the reflection member movement position, in response to the error in the focal length of a single focus lens, and to simplify the adjustment work. An object of the present invention is to provide an electrophotographic copying apparatus equipped with an optical system.

Means and Effects for Solving the Problems In order to solve the above problems, the electrophotographic copying apparatus according to the present invention includes: (a) moving a single focus lens to focus according to a set copying magnification; a first driving means for positioning; (b) a second driving means for moving and positioning the reflecting member to correct the conjugate length according to a set copying magnification; and (c) a focal length of the lens. control means for calculating the amount of movement of the lens and the reflecting member with respect to the set copying magnification according to the error, and operating the first and second driving means independently. do.

In the above configuration, the error in the focal length of the single focus lens is determined in advance, and the amount of movement of the lens and the reflecting member is calculated for each magnification including the error in the focal length. Based on the numerical values calculated in this way, the lens and the reflecting member are each independently moved to the optimum position according to the copying magnification. In particular, the amount of movement of the reflecting member, which was conventionally dependent on the movement of the lens by the cam plate, is adjusted independently of the lens, and the accuracy of correcting the conjugate length is significantly improved.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of an electrophotographic copying apparatus according to the present invention will be described with reference to the accompanying drawings.

[First Example, Figures 1 to 12rl! J] FIG. 1 schematically shows a copying apparatus with a fixed document table and a moving optical system. The photosensitive drum (1) can be driven to rotate in the direction of the arrow (8), and around it are a charger (2), an inter-image/edge eraser lamp (3), and a magnetic brush type developing device (4a).
, (4b), transfer charger (5), sheet separation charger (6), residual toner cleaning device (7),
A residual charge eraser lamp (8) is arranged. The sheet is fed from the left side in Fig. 1, conveyed along the - dotted chain line (A>), and after the image is transferred, is ejected outside the machine via a fixing device (not shown). composition,
The operation is well known and its explanation will be omitted.

On the other hand, the optical system (10) is installed below the document table glass (9), and includes an exposure lamp (11), a first mirror <12>,
2nd mirror (13), 3rd mirror (14), single focus lens (15>, 4th mirror (16), 5th mirror (17)
, and a sixth mirror (18). The original placed on the original table glass (9) is irradiated with light from the exposure lamp (11), and the reflected light is reflected by the mirror (12), (1
3), (14), lens (15), mirror (15),
(17) and from the mirror (18) to the photoreceptor drum (1).
) is imaged on. Exposure lamp (11) and first mirror (
12) are integrated into one unit, and the second mirror (1
3> and the third mirror (14) are integrated as another unit, and these units scan the document image in the direction of the arrow (b).
) direction. At this time, the exposure lamp (11) and the first mirror (12) are set at v/m
(v: circumferential speed of the photosensitive drum (1), m: copying magnification), and the second and third mirrors (13), (14
> moves at a speed of V/2m. The speed ratio of both is 2
:1, the distance from the document surface to the lens (15>) is kept constant during document scanning.

Figure 1 shows the arrangement of the lens (15) and the fourth and fifth mirrors (16) and (17) when copying at the same magnification, but when copying at variable magnification, the lens (15) and the fourth and fifth mirrors are arranged. It is necessary for mirrors (16) and (17) to move in the (X) or (X゛〉 direction.If the copying magnification is m (>O) and the focal length of the lens is f, then the lens front distance Ll (document surface The distance from the document surface to the lens) and the conjugate length L2 (the distance from the document surface to the photoreceptor surface) are expressed by the following equations (1) and (2).

Ll-(1+-)Xr...
(1) L2= (2+ m + -) X f'
- (2) As is clear from the above equations (1) and (2), if the focal length f of the lens differs, the front lens distance L1 and conjugate length L2 will differ, so the lens ( 15> and the fourth and fifth mirrors (16), (1
7) It is necessary to change the amount of movement. Conventionally, the f-value of the lens is divided into groups in advance by predetermined ranges, and the distance of movement of the lens and the shape of the mirror cam plate are changed to correspond to the set magnification for each group. In this example,
As shown in FIG. 2, the lens (15) was independently driven by a stepping motor (Ml), and the mirrors (16) and (17) were independently driven by a stepping motor (Ml).

Specifically, the lens (15> is installed so as to be movable in the arrow (X) and (X') directions on the guide rail (22>) via the frame (20). The output gear (23> of 28) is fixed on the frame (20).

Further, in order to detect the reference position of the lens (15>), a reference position detection sensor (SEI) is installed which is turned on and off by a protrusion (21) attached to the frame (20>. ), (17) is the frame (30>
Arrow (X>, (X″) on guide rail (32〉) through
It is installed so that it can be moved in the > direction. Mirror drive stepping motor (Ml), output gear (33), gear (3)
4>, the drive system of the pulleys (35), (36), (37), and the wire (38>) is constructed in the same way as the drive system of the lens (15), and the reference position detection sensor (SE2) is connected to the frame (
30〉 protrusion (on at 31〉).

It will be turned off.

FIG. 3 is a block diagram of a microcomputer (60) for controlling the optical system (10) constructed as described above. The microcomputer (60) receives signals from a mask microcomputer (not shown) that controls the operation panel, image forming element, and paper feed conveyance system of the copying machine other than the optical system (10), and controls the lens (15) and mirror (16). ,
(17) Control the movement of.

The microcomputer (60) is an input board (61),
ROM (62), RAM and registers (63), CP
Consists of U (64), an oscillation circuit (65) for generating a clock signal r CLK, a timer unit (66), and an output port (67).Input port (61)
The set magnification MAG inputted by the operator as a signal from the mask microcomputer, and the optical system (
10> scan start request SCAM, focal length f of the lens (15), lens reference position correction data, and mirror reference position correction data are input, and furthermore, the lens reference sensor (SE
The output signal LHOME from I) and the output signal MHOME from the mirror reference sensor (SE2) are input.

From the output boat (67), output signals φO1φ1.φ2.φ3 for driving lens and mirror drive stepping motors (Ml>, (Ml), lens motor selection signal, mirror motor selection signal, optical system (10) A scanning system output signal for controlling image scanning, a lens (15>) and a mirror (16) when changing magnification and when turning on the power.

A signal READY is output to inform the master microcomputer that the movement (17) has been completed.

FIG. 4 shows a drive circuit for the stepping motors (Ml) and (M2). Transistor (QIE), (Q2E
) (7) Input stage is output boat (67) (7) Boat 0
Connected to UrO, 0UTI, the boat 0UTO, 0U
When Tl is 'L', each motor (Ml) from DC type fiE
, (M2) are supplied with current. So, for example, 0U
When TO is “Lt+”, output signals φ0°φ1.φ2.
By sequentially changing the excitation phase of φ3, the lens driving stepping motor (Ml) rotates.

Next, the lens (15〉) and mirror (15〉) at a certain magnification
6), Figure 5a regarding the method of calculating the position of (17),
This will be explained with reference to FIG. 5b.

The position Assuming that the data is 0, it is expressed by the following equation (3).

Therefore, the position data of the lens (15) is o, soo~
In order to express it as a positive value at all magnifications of 2,000, the lens position LPO5I at the minimum magnification of 0.500 is set to O, and the amount of lens movement per pulse of the stepping motor (Ml) is determined by the amount sent from the 31 mask microcomputer. When the set magnification MAG is set to m=MAGX O,001, the lens position data LPO5I at the magnification MAG is expressed by the following equation (4).

The position X of the mirror <16), (17) is expressed by the following equation (5), where O is the position data at the same magnification.

Therefore, as with the lens (15), we set the setting magnification MAG sent from the mask microcomputer to m”MAGX.
0,001, the mirror position data MPO5I at the magnification MAG is expressed by the following equation (6>).

(6) In this embodiment, the lens position data LPO5I and the mirror position data MPO5I corresponding to the focal length f regarding the set magnification MAG are calculated based on the above equations (4) and (5), and the stepping motor ( Ml) and (M2) are driven independently, and the lens (15> and mirror (16)
), (17) to a predetermined position. in this case,
When moving in the direction of magnification (increasing magnification), the lens (
The movement of step 15) is executed before the movement of mirrors (16) and (17). Conversely, when moving in the reduction direction (magnification decreases), the lens (15) is moved by the mirror (16).

Execute after the movement in (17). This is to avoid collision between the lens unit and the mirror unit when they move. Regarding mirrors (16) and (17), the current mirror position is stored in RAM (63), and the difference between the mirror position at the newly set magnification and the stored current mirror position is calculated. Then, the mirror position at the rent ratio is directly moved to the mirror position at the newly set magnification without going through the same magnification position. In this case, mirror (16), (17)
is in (d) instead of (c) in Figure 6! ! The goal is to travel the shortest distance in the shortest amount of time.

Next, the above control will be explained in more detail according to the flowcharts shown in FIGS. 7 to 12.

FIG. 7 shows the main routine of the microcomputer (60).

When the power is turned on and the program starts, the output port (67) and RAM (63) are initialized in step (S1), and an internal timer is set in step (S2). This internal timer is used to determine the processing time per main routine, and is connected to the oscillation circuit (65).
The clock signal r CLK output from the timer unit (66) is counted.Subsequently, step (S3)
In step (S4), a subroutine for controlling the lens/mirror position is called, and in step (S4), a subroutine for controlling image scanning by the optical system (10) is called. Step (S3
This subroutine is related to the present invention and will be described in detail below.

When it is confirmed in step (S5) that the internal timer has finished counting, the process returns to step (S2) and step (53
), (54) are repeatedly processed.

8a, 8b, 8c, and 8d show a subroutine for controlling the lens/mirror position executed in step (S3) of the main routine. In this subroutine, first, in step (50>) the state counter SCL is
Check M, and perform the following processing in sequence based on the current name.

When the count value of SCLM is 0 (initial state), it is determined in step (501) whether the signal MHOME from the mirror reference position sensor (SEA) is "L". Sensor (
SE2) is "L" when the protrusion (31) enters the optical axis.
” and outputs “H” when it leaves the optical axis. MH
If OME is "L II" and mirrors (16) and (17) are located at the reference position, MP indicating the excitation phase of the mirror drive stepping motor (Ml) is set in step (502).
Store the initial excitation phase 0011B (CB means binary number) in RASH. Next, step (50
3), stepper motor (Ml), LMSTEP representing the number of moving steps of (Ml), a mirror (16),
(17) Predetermined maximum number of movement steps MAXM
Store SIEP. Note that the step (503) executed here is as shown in FIG.
When detecting the reference positions of mirrors (16) and (17) using one sensor (SE3), first detect the reference positions of mirrors (16) and (17).
) in the magnification changing direction (X) so that the protrusion (31>) does not block light from the reference position sensor (SE3).
Move the lens (15) in the enlargement direction (X'>) and remove the protrusion (
21>, the mirrors (16) and (17) are moved in the magnification direction (X) by the maximum number of movement steps MAXMSTEP in order to make the reference sensor position (SE3') unblocked. Next is Miller (16).

Call subroutine MMOVEI in step (504) to move (17) by a predetermined number of steps in the scaling direction (X), then increment (set to 1) SCLM in step (506), and return to the main routine. .

On the other hand, the signal MH from the mirror reference position sensor (SE2)
If OME is "H" (No in step (SQL)) and mirrors (16) and (17) are away from the reference position, SCLM is set to 2 in step (505) and the process returns to the main routine.

When the count value of SCLM is 1, step (511
) and whether I'JOBLM is 0 or not, that is, mirror (16)
, (17) determines whether the movement of the number of steps set in the step (503) has been completed. N
If o, return to the main routine and step (511)
) is repeated, and when TJOBLM becomes O, step (S
Increment (set to 2) SCLM in OB).

When SCLM's karantoi direct is 2, step (52
1) The signal L from the lens reference position sensor (SEI)
Determine whether HOME is "L". LHOME is L
”, if the lens (15) is located at the reference position, the lens driving stepping motor (M
Initial excitation phase 001 in LP) IAsE indicating the excitation phase of l)
Store 1B 6 Next, call subroutine LMOVEI in step (523) to move the lens (15> in the enlargement direction X゛>, and in step (506) SCL
M is incremented (set to 3), while the signal LHOME from the lens reference position sensor (SEI) is “H”.
” (No in step (521)) If the lens (15) is far from the reference position, SCLM is performed in step (524).
is set to 4 and returns to the main routine.

When the count value of SCLM is 3, step (531
) is the output signal LH of the lens reference position sensor (SEI).
It is determined whether OME is "H", that is, whether the lens (15) has moved in the enlargement direction (X゛), and if NO, immediately returns to the main routine, repeats step (531), and returns LHOME. When becomes "H", subroutine LMSIOP of step (532) is called to stop the movement of lens <15> and mirrors (16) and (17). Thereafter, in step (SOS) SCLM is incremented (set to 4) and the process returns to the main routine.

When SCLM's karantoi direct is 4, mirror (16)
.

Step (5) of moving (17) in the equal debt direction (X゛〉
After calling the subroutine MMOVE2 of 41), the process moves to step (506) and SCLM is incremented (set to 5).

When SCLM's karantoi direct is 5, step (55
1) The output signal MH of the mirror reference position sensor (SE2)
OME becomes “L”, that is, mirror (16),
When it is confirmed that the mirror (17) has reached the reference position, the subroutine f'y LMSIOP similar to the step (532) in step (S52) is called, and the mirror (17) is moved to the reference position.
6), (17) is stopped.

Furthermore, in this embodiment, the mirror reference position correction data is stored in LMSTOP in step (553).
Lens (15) and mirror (16), (1) when power is turned on
Set the initial position of 7) to the position of magnification 2.000, and move the mirror (16), (1
Stepping motor (M2) required to move 7)
The number of steps is input from the operation unit, and this is sent from the mask microcomputer to the optical system control microcomputer (60) as mirror reference position correction data, and based on this data, the initial stage of the mirrors (16) and (17) is Determine the position. Note that similar control is possible even when a magnification other than 2.000 is used as the initial position.

Next, the step of moving the mirrors (16) and (17) by a predetermined number of steps in the magnification change direction (X) (after calling the sub-run MMOVE3 of S50, the step (
506) and increments SCLM (sets it to 6).

When the count value of SCLM is 6, step (561
), whether τJOBLM is O or not, that is, mirror < 16),
(17) determines whether the movement has been completed by the number of steps set in step (553). If NO, repeat this step (561) and
If becomes 0, the focal length f of the lens (15) is input in step (562). The focal length f is used to calculate position data of the lens (15) and mirrors (16) and (17). Next, in step (563) MAG
2.000 indicating the magnification of the initial position is stored in , and in step (564) mirror position data MPO5I of 2.000 times is calculated according to the equation (6). Furthermore, in order to compare with the next mirror position data when there is the next magnification change request by the operator, the MPO5
The mirror position data MPO51 is stored in 2. This completes the setting of the reference positions of the mirrors (16) and (17) and the calculation of the reference position data. Next, in order to set the reference position of the lens (15), subroutine LMOVE2 of the step (566) for moving the lens (15) in the reduction direction (X) is called, and the subroutine LMOVE2 of the step (506) is called.
and increments SCLM (sets it to 7).

When the count value of SCLM is 7, step (571
”), the output signal LH of the lens reference position sensor (SEl)
When it is confirmed that OME has become "L", that is, that the lens (15) has reached the reference position, step <57
Call the subroutine LMSTOP similar to steps (532) and (552) in 2), and set the lens (15).
to stop.

Furthermore, in step (573), lens reference position correction data is stored in LMSTEP. Here, the lens reference position correction data means that the optimum focal point is determined from the detection point of the reference position sensor (SEI) at a magnification of 2.000. This is the number of steps of the stepping motor (Ml) necessary for the lens (15) to move to the obtained position, and has the same characteristics as the mirror reference position correction data stored in step (553). Subsequently, a step (
After calling the subroutine LMOVE3 of 574),
The process moves to step (506) and SCLM is incremented (set to 8).

When SCLM's karantoi direct is 8, step (58
In step 1), it is determined whether TJOBLM is O or not, that is, whether the lens (15) has completed the movement of the number of steps set in the step (573).If No, this step (581) is determined. Repeat, if TJOBLM becomes 0, step (582) performs 2. according to equation (4).
000x lens position data LPO5I is calculated. Furthermore, step (583
) stores the lens position data LPO5I in the LPO52. Next, in step (584), the current magnification data MAG (2000) is stored in MAGI, in step (585), the signal READY is set to "L", and in step (506), SCLM is incremented (set to 9). ).The signal READY is set to "L" when the lens (15) and mirrors (16) and (17) are not being moved, and is set to "H" otherwise. In the step (585), the lens (15) and the mirror (
16) and (17) are the initial reference positions at a magnification of 2.00.
This indicates that it has been set to the 0 position, and now 2.
Copying operation at a magnification of 0,000 times becomes possible. Therefore, READ
In the state of Y="L", if the scan start request 5CAN from the mask microcomputer becomes "L", the optical system (1
0) controls the scanning of the image.

When the count value of SCLM is 9, step (591
) to set the copy magnification MAG (set by the operator and sent from the master microcomputer).
2 Hesdoor. Next, in step (592) MAG
Contents of 2 and MAGI (magnification at which lens (15) and mirrors (16) and (17) are currently positioned)
If they are equal, return to the main routine immediately, and if they are not equal, the lens (15> and mirror (16)
.

(17) is moving, step (5
93), set READY to “H” and proceed to step (5).
06) increments SCLM (sets it to 10).

When the count value of SCLM is 10, step (51
01) with lens (15) and mirror (16), (17)
MAG the magnification MAG2 which is the target to be moved from now on.
Next, in step (5102), lens position data LPO5I is calculated using equation (4) as in step (582), and in step (5103), as in step (564), equation ( 6) to calculate mirror position data MPO5I. Then step (50
6) increment SCLM (set it to 11);
Return to main routine.

When the SCLM count value is 11, the step (Si
ll) compares the new magnification MAG2 and the previous magnification MAGI. If MAG2>MAGI, SCLM is incremented (set to 12) in step (506), and steps 13 and 14 of SCLM true are executed. If MAG2 > MAGI, enlarge direction (X)
To prevent collision between the lens unit and mirror unit, first move the lens (15), then move the mirrors (1a) and (17), and then move the MAG
If 2 < MAGI, SC in step (5112)
Set LM to 14 and execute step SCLM=14 first. If MAG2 < MAGI, the movement is in the reduction direction (X), so in order to prevent collision between them, the mirrors (16) and (17) are moved first, and then the lens (15) is moved.

When the count value of SCLM is 12, step (51
21), subtract the previous lens position data LPO52 from the new lens position data LPO5I, and use the result as LM.
Store in STEP. Next, the lens movement direction and movement amount are determined based on the value of LMSIEP, and the lens (15
) subroutine L of step (5122) for moving
Call MOVE4 and step (506)
Increment M (set to 13).

When the count value of SCLM is 13, step (51
31), whether τJOBLM is 0 or not, that is, the lens (15>
It is determined whether the movement of is completed, and if YES, MAG2 and MAGI are compared again in step (5132), and MAG2>MAGl (movement in the enlargement direction (X゛))
If so, SCLM is incremented (set to 14) in step (506). If MAG2<MAGI (movement in the reduction direction (X)), in this case, the mirror (
16) and (17) have already finished moving in the direction of magnification (X), so in step (5133) SCLM is
6 and return to the main routine.

When the count value of 5CLM is 14, step (51
41), subtract the previous mirror position data MPO52 from the new mirror position data MPO5I, and use the result as LM.
Store in STEP. Next, the mirror movement direction and movement amount are determined based on the value of LMSrEP, and the mirror (16
), move (17) subrune f MMOVE4 of step (5142), step (5
06) - Increment (set to 15) rscLM. Regarding the movement of the mirrors (16) and (17), if m in the above formula (5) is 1/m, then the mirror (16) and (17)
The position X in 6) and (17) has the same value both during enlargement and reduction. Therefore, when the mirrors (16) and (17) move from a certain magnification m to a different magnification m', m'-1/m
If so, mirror (16).

(17) does not need to be moved. The same thing can be said when the magnification changes between the same magnification. For example, when changing from a certain magnification m (m > 1) to the next magnification m (m'< 1), the mirror < 16), (17) is moved by an amount that corrects the change in the conjugate length of m and m. All you have to do is
(See (d) in the figure). Therefore, by storing previous mirror position data in memory, the mirror can be moved over the shortest distance.

When the count value of SCLM is 15, step (51
51), whether TJOBLM is O or not, that is, mirror (16)
, Determine whether the movement in (17) is completed, and select YES.
If so, MAG2 and MAG again in step (5152)
The direction of movement is determined by comparing with l. If the movement is in the reduction direction, SCLM is set to 12 in step (5153), and the movement of the lens (15) is subsequently processed. If the movement is in the enlargement direction, the movement of the lens (15) has been completed, so SCLM is incremented (set to 16) in step (506).

When the count value of SCLM is 16, step (51
61), set READY to "L" and attach the lens (15).
) and mirrors (16) and (17) are displayed, and in steps (5162) and (5163), the current magnification MAG2 is stored in MAGI for the next variable magnification operation, and the position data LPO5I, MPO5I to LPO
52, store in MPO52.

Thereafter, in step (5164), SCLM is set to 9, and the next copying magnification set by the operator is awaited.

FIG. 9 shows a subroutine for starting lens movement. Here, each step in the lens/mirror position control subroutine (513), (566), (574)
.

(5122). LMOVEI moves Lz/z (15) to the enlargement side, LMOVE2 moves the lens (15) to the reduction side, so LMOVE3
In order to move the lens (15) to the enlargement side by the lens reference position correction data, LMOVE4 is a subroutine to relatively move the lens (15) by a predetermined number of steps.

Each step (5201), (5202), (520
3), (5205).

(5206)-t' sets or resets the flag FLARGE to al" or "0". This flag FLARGE
E is "1" when moving the lens (15) to the magnification side.
When moving to the reduction side, it is reset to "0" and is used to determine the rotational direction of the stepping motor (Ml), that is, the manner in which the excitation phase changes.

In step (5204), the movement direction is checked in advance, and if LMSTEP is 0 or more, the flag FLARGE is set to 1" in step (5205) as an increase in lens position data. If it is smaller than 0, step (520)
In step 6), the flag FLARGE is reset to '0', and in step (5207), LMSIEP is subtracted from 0 and stored, and the number of moving steps is expressed as an integer.

In step (5208), TJOBLM is reset to 0.

This is the reference position switch (
This is because the determination is made based on whether SEI') is on or off.

Also, in step (5209), LMS is sent to TJOBLM.
Store TEP. This is because the amount of movement of the lens (15) is determined by counting the number of steps.

Next, in step (5210), LPHASE is set to φO1φ1... to output the initial lens excitation phase. φ2. φ3
Output to. In step (5211'), the lens motor selection signal is set to "L" in order to supply current to the lens driving stepping motor (Ml).
5212), the stepping motor (Ml) is driven by the timer interrupt of the internal timer in the timer unit <66>, so the driving frequency of the lens (15>, mirror (16), and (17) is set in the timer (2). Specified value TM
Set PPS. In this embodiment, the lens (15) and mirrors (16) and (17) are both moved at a constant speed at the same frequency. For example, set the clock f' CLK to 5
MHz, to move at a speed of 200 pps (200 pulses per second), TMPPS must be 250
If it is set to 00, 200 interruptions will occur per second, and the stepping motor (Ml) will rotate at 200 pps.

Next, in step (5213), interrupt processing by the timer <T2> is permitted, in step (5214), counting of the timer (T2> is started, and in step (S3)
Return to the Nosu routine.

FIG. 10 shows a subroutine for starting mirror movement. Here, each step (504), (541), (554) in the lens/mirror position control subroutine will be explained.
).

(5142). MMOVEI is a mirror (1
In order to move mirrors (16) and (17) by the maximum movement step in the magnification direction (X), MMOVE2 moves mirrors (16) and (1
7) in the equal-borrow direction (X'), M'MOV
E3 moves mirrors (16) and (17) in the direction of magnification by the mirror reference position correction data, so MMOVE4
is a subroutine for relatively moving mirrors (16) and (17) by a predetermined number of steps.

Each step (5301), (5302), (530
3), (5305).

The flag FLARGE, which is set and reset to “1” or MO” in (5306), has a height of “1” in the magnification direction (X
), and when it is “0”, it indicates movement in the direction (X′〉).Sten Bu (5304), (5307)
is the same as steps (5204) and (5207) described above, and the mirror position data at the same magnification position is O, and the mirror position data changes by an integer when changing the magnification, so LMSI'EP is set in step (5304). If it is determined that it is smaller than 0, step (5307
) to subtract LMSTEP from 0 and store it.

Steps (5308) and (5309) are steps (
5208).

Similarly to (5209), it is determined whether the end of lens movement is determined by the reference position switch or by counting the number of steps. Next, step (5)
310), MP is used to output the initial mirror excitation phase.
) IASE is output to φ0, 1.2.3. Step (
5311), the mirror drive stepping motor (Ml
> In order to supply current to
”. After that, go to step 5212 in Figure 9.
), (5213), and (5214) and drive the stepping motor (Ml) using a timer interrupt.

Figure 11 shows a subroutine that processes interrupts of the timer (1M2). This subroutine only processes when the timer (1M2) has finished counting while the interrupts of the timer (1M2) are enabled (see step (5213)). Let's do it.

First, in step (5401), output port 0UIO is set to “
If the output boat ouTo is set to 'L', the lens motor (Ml) is driven and the lens (15) is moving, and the output boat 0UTO is set to 'H'. If so, output port 0UTI is “L”
The mirror motor (Ml) is driven by the mirror (16),
(17> is being moved. Therefore, step (540
If YES in step 1) (the lens is moving), step (5
In step 402), it is determined whether FLARGE is "0".

If YES, the movement is in the reduction direction (X), so shift LPHASE to the right by 1 bit in step (5403) 0 For example, if the current LPHASE is 0OIIB, 0011B → l001B → l100B → 0IIO
Change the motor excitation phase sequentially like B Pass 0011B, then in step (5405) change the motor excitation phase to φo, t, z,
a is output, and the process moves to step (S41Q). Also,
If NO in step (5402), the movement is in the enlargement direction (X'), so in step (5404) L is
Shift PHASE one bit to the left. For example, if the current LPHASE is 0OIIB, 0OIIB → 01
Change them sequentially like 10B → 1100B → 100IB → 0OIIB. Subsequently, the process moves to step (5410) via the step (5405).

On the other hand, if No in the step (5401) (mirror is moving), FLARGE is "
If YES, step (540
Step 7) shifts MPHASE to the right by 1 bit, and if NO, shifts MPHASE to the left by 1 bit in step (5408). These are the steps (5403), (
5404), in step (5409) the motor excitation phase is output to φ0,1°2.3, and in step (54
10).

Next, in step (5410), it is determined whether TJOBLM is 0 or not, and if it is 0, the stepping motor (Ml >
, (Ml) is stopped by the reference position sensor (SEI),
Since this is performed by turning on and off (SE2), this subroutine is ended and the process returns to the lens/mirror position control subroutine. In the step (5410), τJOBL
If it is determined that M is not 0, in step (5411) T
Subtract 1 from JOBLM and check I'JOBLM again at step (5412).

If TJOBLM is not 0, this subroutine is immediately terminated, the lens/mirror position control subroutine is returned, and the movement process is continued. Also, if I'JOBLM is O, the motor (l'It), (
Since M2) has been driven, the subroutine LMSTOP of step (5413) is called to stop the movement of the lens (15) and mirrors (16) and (17), and the interrupt processing is ended.

Figure 12 shows each step (532), (552), (
572) and (5413) to stop the movement of the lens and mirror.

First, in step (5501), the timer (T2) is stopped counting, and in step (5502), the timer (τ2) is stopped.
Disable interrupt processing by Furthermore, step (55
03) sets the output port 0UT1.0UI2 to "H", cuts off the current to the stepping motors (Ml) and (M2), and returns to the main routine.

[Other Embodiments, Figures 13 to 19] Figure 13 shows a second embodiment of the present invention, in which the lens (15)
One sensor (SE3) is used to detect the reference position of the mirror (16) and mirror (C17).
21) and (31) can move forward and backward toward the optical axis of the sensor (SE3), respectively.

FIG. 14 shows a third embodiment of the present invention, in which the lens (15)
and mirrors (16) and (17) are driven by a single steering motor (M3).In other words, the gear (24) transmits rotational force to the wires (28) and (38). .

(34) meshes with an output gear (not shown) of the stepping motor (M3), and an electromagnetic clutch is attached to the gears (24) and (34). To move the lens (15), turn on the electromagnetic clutch of the gear (24), and to move the mirrors (16) and (17), turn on the gear (34).
Just turn on the electromagnetic clutch. In circuit terms, the stepping motor (M3) is configured to be constantly supplied with power, and the motor selection signal output port 0UT shown in Figure 3 is used.
This can be easily realized by changing I and 0UT2 to ON/OFF signals for the electromagnetic clutch.

In addition, if the above configuration is adopted, the lens (15), mirror (16), (1
7) may move due to vibration, etc. Therefore, some means is required to prevent vibration when the drive is turned off, and it is preferable to provide a brake means inside the electromagnetic clutch to prevent slippage when the drive is turned off.

In addition to the electronic clutch, as a drive switching means,
Gear (24) using a combination of solenoid and lever mechanism or kick spring method.

(34) may be brought into contact with and separated from the output gear of the stepping motor (M3).

15 and 16 show a fourth embodiment of the present invention, in which a stepping motor (Ml) is provided on a base plate (40> that holds a lens (15). The three rollers (41), (41), and (41) are in pressure contact with a guide rail (49) fixed within the copying machine body, thereby making it possible to move in the directions of arrows (X) and (X'). The output gear (23) of the stepping motor (Ml) meshes with the gear (46) rotatably mounted on the base plate (40>), and the pulley (47> fixed coaxially with the gear (46>) and the base plate (40) Idle pulley (48) rotatably attached to
A wire (44) with both ends fixed is stretched between the stepping motor (Ml) and the stepping motor (Ml).A current is supplied to the stepping motor (Ml) from a flexible power supply cord (42). Due to the forward and reverse rotation of Ml), the gear (46> and pulley (47) rotate forward and backward inside each other, and the tension of the wire (44>) and the wire (44> and pulley (47)
Due to the frictional force between the plywood (40) and the guide rail (47), the plywood (40)
9) and the arrow (X) along with the lens (15>),
Move in the (X') direction.

FIG. 17 shows a fifth embodiment of the present invention, in which a rack (50) fixed within the main body of a copying machine is meshed with a binion (52) fixed coaxially with a gear (51>).

The gear (51> is rotatably mounted on the base plate (40>) and meshes with the output gear (23) of the stepping motor <Ml> provided on the base plate (40>. Pitching <53> and guide roller (54) rotatably mounted coaxially with gear (51) and binion (52),
(54) is movable in the directions of arrows (X) and (X') by coming into pressure contact with the rail portion (50a) of the rack (50). Due to forward and reverse rotation of the stepping motor (Ml), the gear (51) and the binion (52) are rotated in the forward and reverse directions, and the binion (52) is transferred along the rack (50), so that the base plate (40) is rotated in the forward and reverse directions. > is the rail part (50
a) Guided by the lens (15〉 along with the arrow (X),
Move in the (X') direction.

FIG. 18 shows a sixth embodiment of the present invention, in which a drive roller (57) and guide rollers (58), (58) are pressed from both sides to a guide rail (55) fixed inside the main body of the copying machine. be. The guide rollers (58), (58) are rotatably mounted on the plywood (40), and the drive roller (57)
is coaxially fixed to a gear (56) rotatably attached to the base plate (40).The gear (56) is made of plywood (4o
) The output gear (2) of the stepping motor (Ml) installed in
3) meshes with each other. The reference position is the guide rail (55)
A motor with a high coefficient of friction is used, and the stepping motor (Ml) rotates forward and reverse in the forward and reverse directions integrally with the gear (56), and by rolling along the guide rail (55), The base plate (4o) is the guide rail (55)
is guided by the arrows (X) and (X) together with the lens (15).
') move in the direction. In this case, the guide roller (58)
, (58) also preferably have a high coefficient of friction, and are preferably brought into pressure contact with the guide rail (55) by a spring member (not shown).

FIG. 19 shows a seventh embodiment of the present invention, in which a mesh-like rope (6o) is used as the driving force transmission means. Both ends of the rope (6o) are fixed inside the copying machine. Drive pulley (62) fixed coaxially with gear (61)
and idler pulleys (63), (63) rotatably mounted on plywood (40). In addition, the gear (61) is rotatably mounted on the plywood (40), and the gear (61) is rotatably mounted on the plywood (40).
It meshes with the output gear <23> of the stepping motor (Ml) installed at The plywood (40>) can be moved together with the lens (15) in the arrow (X) and (X') directions.

A similar form to this seventh embodiment is a rope (60).
In place of the drive pulley (62), a chain, a timing belt, and a sprocket wheel can be used.Also, in the fourth embodiment shown in FIGS. 15 and 16, the wire (44) If sufficient tension is applied, it is also possible to omit the guide rail (49>).

Note that various driving forms other than those described above can be adopted, and it goes without saying that the same driving form can be adopted for the mirror as well.

As is clear from the above explanation, according to the present invention, the amount of movement of the lens and reflective member regarding the set copying magnification is calculated according to the error in the focal length of the single focus lens, and the lens Since the driving means for the reflecting member and the driving means for the reflecting member are operated independently, it is possible to use many different types of cam plates compared to the conventional method in which the reflecting member is positioned while correcting errors in the focal length of the lens using a cam plate. Not only is there no need to prepare in advance, but the accuracy of the amount of movement of the lens and reflecting member when changing the magnification is improved, and the adjustment work is also simple.

[Brief explanation of the drawing]

1 to 12 show the first embodiment, FIG. 1 is a schematic configuration diagram of a copying machine, FIG. 2 is a perspective view showing driving means for lenses and mirrors, and FIG. 3 is a control of the optical system. Circuit block diagram, Figure 4 is a stepping motor drive circuit diagram, Figure 5a.
5b is an explanatory diagram showing the moving state of the lens and mirror, FIG. 6 is an explanatory diagram showing the moving state of the mirror, and FIG. 7 is a flowchart showing the main routine of the microcomputer that controls the optical system. Figure 8a, Figure 8b, Figure 8
Figures c and 8d show that the lens/
FIG. 9 is a flowchart showing a subroutine for controlling the position of the mirror; FIG. 9 is a flowchart showing a subroutine for controlling the movement of the lens in the subroutines shown in FIGS. 8a to 8d; FIG. 11 is a flowchart showing a subroutine that controls the movement of the mirror in the subroutine of FIGS. 8a to 8d. FIG. 12 is a flowchart showing a subroutine that controls timer interrupt processing in the subroutine of FIGS. 8a to 8d. - FIG. 8d is a flowchart showing a subroutine for controlling movement stop of the lens and mirror in the subroutines of FIG. 11; FIG. 13 is a perspective view showing lens and mirror driving means in the second embodiment, and FIG. 14 is a perspective view showing lens and mirror driving means in the third embodiment. 15th
The figure is a perspective view showing the lens driving means in the fourth embodiment;
FIG. 16 is a back view of FIG. 15. FIG. 17 is a back view showing the lens driving means in the fifth embodiment, and FIG. 18 is a back view showing the lens driving means in the sixth embodiment.
FIG. 9 is a back view showing the lens driving means in the seventh embodiment. (10>...Optical system, (15)...Lens, (16)
), (17)...Mirror, (60)...Microcomputer, (Ml), (M2). (M3)...Stepping motor, (SEI),
(SE2), (SE3)...Reference position detection sensor.

Claims (1)

[Claims] 1. In an electrophotographic copying apparatus using a single focus lens in an optical system for projecting an original image onto a photoreceptor, the lens is moved to focus according to a set copying magnification. a first driving means for positioning the reflecting member according to a set copying magnification, a second driving means for moving and positioning the reflecting member to correct the conjugate length according to a set copying magnification, and a second driving means for positioning the reflecting member according to an error in focal length of the lens. , a control means for calculating the amount of movement of the lens and the reflecting member with respect to a set copying magnification, and operating the first and second driving means independently, respectively. . 2. The device according to claim 1, wherein the means for detecting that the lens is at the reference position and the means for detecting that the reflecting member is at the reference position are shared by one switch. Electrophotocopying equipment.