JPS5953526B2 - Copy machine magnification device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a variable magnification device for a copying machine that changes copying magnification by moving a lens of an exposure optical system along an optical path of the exposure optical system.

Generally, copying machines used to make copies of the same size as originals, but recently it has become increasingly desirable to make reduced copies of drawings, newspapers, and other documents that need to be kept. Ta.

Among them, conversion copying of A column and B column size, area magnification 1
/2 (linear magnification, bow:) copying is particularly desired. Conventionally,
Various types of copying machines with variable magnification functions have been devised and put into practical use, but most of them are full-exposure type copying machines, and their control circuits are extremely complex. There were many copying machines that limited the types of copying magnification to two types, including equal magnification, or that increased the user's operation ratio. This is because when trying to obtain three or more magnification settings, it becomes extremely difficult to set a predetermined magnification in the middle, and for example, if the power is turned off for some reason, it becomes impossible to judge the position of the lens. It is. It is an object of the present invention to provide a variable magnification device of the type mentioned at the beginning, which can extremely easily achieve setting of three or more magnifications without limiting the copying magnification to two types. Regardless of how the power is turned off, and therefore, regardless of the position of the lens, simply by operating the magnification selection means, the lens can be accurately and reliably positioned at each selected magnification position. It has characteristics such as being able to be positioned.

The present invention can be applied to any variable magnification copying machine, regardless of whether it uses a full exposure method or a slit exposure method, as long as the lens moves in the direction of the exposure optical path. The present invention will be described with reference to an illustrated embodiment based on a copying machine.

FIG. 1 shows the optical system of a slit exposure type copying machine, and the slit illumination device consists of a light source 1, a reflector 2, and a first mirror 3.

The slit illumination device may be of either mobile or fixed type. The one shown in this figure is a mobile type.
The illumination device reciprocates between a standby position A and an exposure end position B. At this time, the second mirror 4 moves at approximately 1/2 the speed of the illumination device in synchronization with the illumination device to keep the optical path length up to the lens 5 constant. The light that has passed through the lens 5 is directed to the third mirror 6
The light is reflected by the fourth mirror 7 and forms an image on a photoreceptor, for example, a drum-shaped or flat photoreceptor 8. In this case, the light D incident on the photoreceptor 8 is at an angle θ to the normal to the photoreceptor surface.
(Figure 2). In other words, the optical axis is inclined with respect to the imaging plane. In order to correct this inclination, the optical axis of the lens 5 is tilted by θ with respect to the principal ray, and the reflected light from the document is tilted by θ with respect to the normal line of the contact glass. When the slit illumination device is of a fixed type, the illumination device is fixed at an arbitrary position between A and B, and an image is formed on the photoreceptor 8 by moving the document using, for example, a movable document table or a document transfer device. Become. The lens 5, the third mirror 6, and the fourth mirror 7 constitute a variable magnification device, and when changing the copying magnification, these move in a certain relationship to the position shown by the broken line in Fig. 1. This is done by changing the optical path length from the lens 5 to the original and to the surface of the photoreceptor.

At this time, the scanning speed is changed in a moving type slit exposure device according to a change in copying magnification, and the moving speed of the document is changed in a fixed type slit exposure device. Further, if possible, the magnification can be changed by changing the circumferential speed of the photoreceptor drum. In FIGS. 2 and 3, the lens 5 is fixed to a lens stand 10 attached to a lens bracket 9. In FIGS.

The lens bracket 9 is guided by a guide 11 provided on the machine frame 12'' and a guide rod 13 fixed to the machine frame 2 so that it can move parallel to the chief ray, and is rotatably supported. The drive screw 14 is screwed onto a drive screw 14, and is driven by the rotation of the drive screw 14 to move the lens 5 parallel to the chief ray.
The pulley 15 is drivingly connected to a pulley 17 attached to a variable power drive motor 16 by a belt 18. Therefore, the lens 5 is moved by the variable power drive motor 16.
is moved. The third mirror 6 and the fourth mirror 7 are fixed to a mirror bracket 19, and the mirror bracket 19 is slidably guided by a guide lens 20 fixed to the machine frame 12, and is tilted at a certain angle with respect to the direction of lens movement. It is now movable in direction R.

The direction of R is preferably parallel to the bisector of the plane formed by the chief ray C toward the third mirror 6 and the chief ray D toward the fourth mirror 7. The mirror bracket 19 is pressed to the left in FIGS. 2 and 3 by a spring 21 attached to the guide rod 20, and the force of the spring causes the cam follower 22 attached to the mirror bracket 19 to move against the second cam of the mirror cam 23. It is pressed against the surface 23b. The mirror cam 23 is rotatably supported on the machine frame 12 by a pin 24, and the first cam surface 23a of the mirror cam 23 is supported by the spring 2.
1, it is pressed into contact with a roller 25 as a mirror driving member attached to the lens bracket 9. The first cam surface 23a of the mirror cam 23 is inclined with respect to the moving direction of the mirror drive member 25, and as the lens 5 moves, that is, the mirror drive member 25 moves, the mirror cam 23 moves toward the pin 24.
It is designed to rotate around the center. mirror cam 23
As the mirror cam rotates, the position of the cam follower 22 in contact with the second cam surface 23b of the mirror cam changes, and the mirror bracket 19 moves to the position shown by the broken line in FIG. By selecting the shapes of the first cam surface 23a and the second cam surface 23b of the mirror cam 23, the relationship between the amount of movement of the lens 5 and the amount of movement of the third and fourth mirrors 6 and 7 can be set in advance. Reference numerals 26, 27, and 28 shown in the upper part of FIG. 2 are micro switches as magnification positioning means, which are operated by an actuator 29 attached to the lens bracket 9 as the lens 5 moves.

As the magnification positioning means and the actuator 29, in addition to a contact-operated type such as a micro switch, a non-contact operated type such as a photocoupler, a magnetoelectric transducer, a reed switch, etc. can be used. In this example, the mital switch 28
is copy magnification 1:1, 27 is A row:B row, 26 is 1:1/
2 (area ratio). However, in order to set two or more types of arbitrary copying magnification, a different number of microswitches can be provided at desired positions. In the block diagram of FIG. 4, numeral 30 is a magnification selection means placed in the operation section of the copying machine, and is, for example, a switch that can be changed, such as a rotary switch or a push button switch.

Reference numeral 31 represents the magnification positioning means 26, 27, and 28 described above.

The judgment circuit 32 receives the selected magnification command SO from the magnification selection means 30 selected by the operator, the position detection signal S1 from the magnification positioning means 31 generated according to the position of the lens 5 at that time, and the holding circuit 33. Based on the tile holding signal S2, a signal is sent to the drive section 35 through the output circuit 34,
The variable power drive motor 16 is controlled to position the lens 5 to the selected magnification position. First, the case where the magnification of 1:1 is selected by the magnification selecting means 30, that is, the case where the micro switch 28 is specified as the lens positioning position will be explained.

If the actuator 29 attached to the lens bracket 9 is in the micro switch 28 (1:1 position), the judgment circuit 32 instructs it to remain stopped, but if the actuator 29 is not in that position and the micro When the switch 26 (1:1/2 position) or the micro switch 26 and 28 is present, the output circuit 34 is commanded to move to the micro switch 28 (1:1 position), resulting in a change. The double drive motor 16 is rotated to stop the lens 5 at a predetermined 1:1 magnification change position. The rotational direction of the variable power drive motor 16 at this time will be referred to as "reverse rotation" from now on. 1:1 with magnification selection means 30
The way the judgment circuit 32 issues an output command when a magnification of /2 is selected is the same as in the case of selecting a magnification of 1:1,
When there is an actuator 29 other than the micro' switch 26 (1:1/2 position), a command is given to move the lens 5 to the 1:1/2 magnification position.

In this case, the rotation direction of the variable power drive motor 16 is 1:1 as described above.
Since this is the opposite of when selecting the magnification, it will be referred to as "normal rotation" from now on. A
Row: Variable magnification drive motor 1 when selecting the magnification position of row B
6 operates a little differently from the above two types of magnification.

That is, if the actuator 29 is in the microswitch 27 (A row: B row position), the judgment circuit 32 is similarly instructed to remain stopped. However, the actuator 2 is placed between micro switches 27 and 28 (1:1 position with A row and B row) or between micro switch 28 (1:1 position).
If 9 is present, the determination circuit 32 immediately issues a normal rotation command and moves the lens 5 to a predetermined magnification position (position of A row: B row). Conversely, if the actuator 29 is between the micro switches 26 and 27 (1:1/2 and A row: B row positions),
The judgment circuit 32 first issues a command for normal rotation and rotates the lens 5 to 1:
1:1/2 positioning means 26 toward the 1/2 position.
When the actuator 29 presses , the holding circuit 33 works to issue a reverse command to move the lens 5 to the positions of the A row and the B row. When the actuator 29 is in the 1:1/2 micro switch 26, the holding circuit 33 controls the A
Row: Issue a reverse command to move to the position of row B. As a result, the variable power drive motor 16 is reversely rotated, and when the lens 5 comes to the position of the A row and the B row, the holding circuit 33 is released and the motor 16 is stopped. The above is the operation of the control circuit, but when selecting the copy magnification of column A: column B, contrary to the above, 1
It is also possible to make the holding circuit 33 work in the :1 position.

FIG. 5 shows an embodiment of the above control circuit, in which the thyristor Ql
．． Transistor Q2 and inverter Q3 constitute the above-mentioned holding circuit 33.

When the magnification is selected to be 1:1, when the magnification selection means 30 is switched to ``1:r'', the 1:1 indicator (light emitting diode) LEDl lights up and the terminal a of the resistor R1 becomes H level.

If the actuator 29 turns on the 1:1 micro switch 28, the terminal d of the resistor R5 becomes L level. Therefore, the output of AND gate Q5, which has two inputs as the levels of both terminals A and d, is at L level. Also, the resistors R belonging to the A and B rows and the 1:1/2 switching contacts that are not selected at this time
2, terminals B and C of R3 are at L level, therefore terminal b
The outputs of AND gates Q6 and Q7, which have terminal C as one input, and AND gate Q8, which has terminal C as one input, are at L level. Therefore transistor Qll and relay RA
1, and a forward rotation output circuit 3 consisting of a transistor Ql2 and a relay RA2.
4B do not operate, and as a result, the variable power drive motor 16 in the drive section 35 is also stopped. That is, the selected copy magnification 1
If the lens 5 is already located at :1, it is maintained at that position. When the lens 5 is at a position other than the copying magnification of 1:1, the micro switch 28 is OFF, so the resistor R
Terminal d of Q5 becomes H level, and therefore AND gate Q5
Since the two inputs of both become H level, AND gate Q5
The output becomes H level.

Therefore, the transistor Qll of the reversing output circuit 34A is turned ON via the 0R gate Q9, and the relay RAl is activated.
The contact RAl-1 in the drive unit 35 closes and the motor 1
6 is reversed. When the lens 5 reaches the 1:1 copying magnification position, the micro switch 28 is turned ON by the actuator 29, so that the terminal d becomes L level, and the AND
The gate Q5 becomes L level and the motor 16 stops.
When the magnification is selected to be 1:1/2, when the magnification selection means 30 is switched to n:1/2'', the indicator LED 3 lights up and the terminal C of the resistor R3 becomes H level.

If the lens 5 is at the 1:1/2 magnification position and the microswitch 26 is ON, the terminal e of the resistor R6 is at the L level, so the output of the AND gate Q8 is at the L level.

At this time, the other terminals a and b not selected by the magnification selection means 30 are at L level, so the remaining AND gates Q5, Q6, and Q7 are all closed. Therefore, the output circuits 34A and 34B do not move, and the lens 5 remains at the 1:1/2 magnification position. If the lens 5 is at a magnification position other than 1:1/2, the 1:1/2 magnification positioning means 26 is OFF, so the terminal e of the resistor R6 is at H level.

Therefore, the two inputs of AND gate Q8 are both at H level, and when the output of AND gate Q8 is at H level, 0R
Transistor Ql2 of forward rotation output circuit 34B is turned ON through gate QlO, and relay RA2 is activated. As a result, the contact RA2-1 in the drive unit 35 closes, the motor 16 rotates normally, and the lens 5 is moved to the 1:1/2 magnification position. The lens 5 stops at a predetermined magnification position of 1:1/2 where the actuator 29 turns the micro switch 26 ON. When the magnification is selected for column A: column B, when the magnification selection means 30 is switched to column A: column B 7, the indicator LED 2 lights up, the terminal b of the resistor R2 goes to the high level, and the AND gate Q
6 and the first input terminal of Q7.

Since the terminals A and c of the resistors Rl and R3 belonging to the other magnification selection positions "1:r" and ":1/2" are at L level, A
ND gates Q5 and Q8 are closed and do not participate in the operation at this time. If the lens 5 is at the magnification position of the A row: B row and the micro switch 27 is 0N, the terminal g of the resistor Rl3 becomes L level, and is input to the second input terminal of the AND gates Q6 and Q7. .

Therefore, the output of AND gates Q6 and Q7 becomes L level regardless of the input level of the third input terminal, and as a result, the motor 16 remains stopped. That is, the lens 5 remains at the desired magnification position of the A-row:B-row. When the lens 5 is not at the magnification position of the A row:B row, that is, the micro switch 2
7 is 0FF, the terminal g of the resistor Rl3 is high.
level and is applied to the second input terminals of AND gates Q6 and Q7.

Therefore, AND gates Q6 and Q7 connect elements Ql, Q2
, Q3, which generates an H-level output regardless of the output signal of the holding circuit 33. When the lens 5 is in the 1:1 magnification position, that is, the micro switch 2
8 is 0N and micro switches 26 and 27 are 0FF.
In this case, the terminal g of the resistor Rl3 is at H level.

Further, the thyristor Q1 is turned off because its gate circuit is separated from the power supply bus by the micro switch 26, and the base circuit of the transistor Q2 connected in parallel to the thyristor Q1 is connected to the mital switch 27.
The anode terminal f of thyristor Q1 is OFF because it is disconnected from the power bus by
Be at the level. Therefore, the output of the AND gate Q7 whose third input terminal is directly connected to the terminal f becomes H level, and the forward rotation output circuit 34B is activated via the 0R gate QlO, causing the motor 16 to rotate forward. When the lens 5 comes to the magnification position of row A: row B, the micro switch 27 is turned on, the terminal g becomes L level, and the AND gates Q6 and Q7 are closed. Therefore, the motor 16 is stopped, and the lens 5 is positioned at the magnification position of the A row:B row. When the lens 5 is at the 1:1/2 magnification position, that is, the micro switch 26 is 0N.
, and when the micro switches 27 and 28 are OFF, the gate circuit of the thyristor Q1 is connected to the power supply bus line by the ON state of the mital switch 26, and the thyristor Q1 is fired.

Therefore, the terminal f goes to the L level, and the third input terminal of the AND gate Q6 connected to the terminal f via the inverter Q3 goes to the H level. Therefore, the output of the AND gate Q6 becomes H level, and the reverse rotation output circuit 34A is activated via the 0R gate Q9, causing the motor 16 to reverse. lens 5
comes to the desired position of row A: row B, the switch 27 is set to 0.
Therefore, the transistor Q2 becomes 0N. Therefore, the thyristor Q1 cannot maintain the holding current and is turned off. Therefore, the terminal f becomes L level, and the AND
The output of gate Q6 becomes L level, and the lens is in the A row:
It stops at the magnification position in row B. In addition, at this time, switch 27
0N, terminal g becomes L level and AND gate Q6
and Q7 to prevent malfunction (normal rotation) of the motor 16. If the lens 5 is located at an intermediate position other than the above, that is, all mital switches 26, 27, and 28 are set to 0FF.
If so, the terminal f becomes H level and the motor 16 rotates normally.

When the lens 5 is located between the A and B rows and the 1:1 magnification position, its movement is the same as when it is at the 1:1 magnification position. Also, lenses 5 are in A row: B row and 1:
When the magnification is between 1/2 and 1/2, the motor 16 is 1:
It continues to rotate in the normal direction until the 1/2 magnification positioning means 26 is set to 0N, and when the terminal f changes to the L level due to the 0N of the switch 26, the rotation is reversed, and the lens 5 is rotated at the desired magnification position of A row: B row. make it stop. In this way, three types of magnification positioning are performed. Incidentally, when the magnification selection means 30 is switched, one of the exposure time adjustment circuits 36, 37, 38 connected to each terminal A, b, c is selected as shown in the lower part of FIG. Electromagnetic clutch MC belonging to magnification
], MC2, and MC3 operate to change the optical path length and scanning speed, thereby making it possible to perform complete variable-magnification copying. FIG. 6 shows another embodiment of the control circuit, in which the holding circuit 33 comprised of the thyristor Q1, transistor Q2, and inverter Q3 in FIG. 5 is replaced with a flip-flop Q16.

That is, the terminal h of the resistor 9 connected to the ℃N'' contact of the microswitch 26 is connected to the set terminal of the flip-flop Ql6, and the terminal i of the resistor 20 connected to the ``ON'' contact of the microswitch 27 is connected to the flip-flop Ql6. is connected to the set terminal, and the same flip-flop Ql
The Q and Q terminals of 6 are connected to the third input terminals of AND gates Q6 and Q7, respectively. When the magnification of row A: row B is selected, if there is no lens 5 in the corresponding position and the micro switch 27 is OFF, then 1
: If the lens 5 is at the 1/2 magnification position, the flip-flop Ql6 is set and the motor 16 is reversed, and 1:
If lens 5 is at the magnification position of 1, flip-flop Q]
6 is set and the motor 16 rotates normally.

When the desired magnification position of the A row and B row is reached, the terminal g becomes L level and the motor is stopped. This control circuit has the advantage of being simple and inexpensive. The circuits shown in FIGS. 5 and 6 can be further developed to perform more types of magnification positioning control.

As an example, FIG. 7 shows a circuit which is an extension of the circuit shown in FIG. 6 and which performs four types of magnification positioning control. In FIG. 7, the magnification selection means 30 is
: A 1/5'' switching contact is added, and a corresponding micro switch 39 as magnification positioning means is provided at a predetermined position.
The terminal k of the resistor R22 belonging to the ON'' contact is connected to the flip-flop Q through the 0R gate Ql7 in the same way as the terminal h.
It is input to the set input terminal of 16. Therefore, for example, A
Column: 1:1/2 or 1: if the magnification of column B is selected
When the lens 5 is at the 1/5 magnification position, the flip-flop Ql6 is set and the motor 16 is rotated in reverse. In addition, since a new magnification position of 1:1/5 has been provided, the second flip-flop Ql8 and AND gates Ql9 and 20 is provided, and the output of both AND gates is sent to the output circuit 34A through the 0R gate Q9'' or QlO''.
, 34B. In this case, as in the case of column A:B, the first input terminals of the AND gates Ql9 and 20 are connected to the terminal C belonging to the intermediate 1:1/2 magnification selection, and the second input terminal is connected to the terminal L of the resistor R23 associated with the 0FF contact of the 1:1/5 magnification positioning means 39 located at the outermost end. Therefore, for example, if a magnification of 1:1/2 is selected, the lens 5
When is at the 1:1/5 magnification position, flip-flop Q18 is set and motor 16 is rotated in reverse. As described above, according to the present invention, variable-magnification copying is possible using a simple control circuit and mechanism, and if the circuit input is cut off during magnification selection, that is, while the drive motor is rotating, it will be possible to make copies using a simple control circuit and mechanism. The motor automatically rotates and positions the lens to the selected magnification position without the need to detect the lens position.

That is, the operator only needs to operate the magnification selection means. Further, even when the number of types of copying magnifications is increased, the circuit can perform positioning control by adding components such as flip-flops. Further, since the magnification positioning means only requires arranging an element such as a micro lens, it is possible to easily determine the movement relationship between the lens and the mirror when changing the magnification. Although the embodiments have been described with reference to a variable magnification device in a slit exposure type copying machine, it is clear that the present invention is applicable not only to a slit exposure type copying machine but also to a full exposure type copying machine.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a copying machine to which the variable magnification device of the present invention is applied;
Fig. 2 is a partial sectional view of the variable magnification device, Fig. 3 is a partially cutaway plan view, Fig. 4 is a block diagram of the control circuit,
FIG. 5 shows an embodiment of the control circuit, FIG. 6 shows another embodiment of the control circuit, and FIG. 7 shows an embodiment of the control circuit capable of four types of variable magnification positioning. 5...Luns, 6,7...Mirror, 16
...Magnification variable drive motor, 30...Magnification selection means, 31...Magnification positioning means, 32...
... Judgment circuit, 33 ... Holding circuit, 34.
...Output circuit, 35...Drive section.

Claims (1)

[Claims] 1. A copying machine that has a lens of an exposure optical system that moves along the optical path of the exposure optical system and a variable power drive motor that can move the lens in forward and reverse directions, and that changes the copying magnification by changing the position of the lens. A variable magnification device includes: an actuator that moves according to movement of a lens; a plurality of magnification positioning means arranged at predetermined magnification positions along a movement path of the actuator and actuated by the actuator; and a magnification selection means. , a control circuit that receives a selected magnification command signal from the magnification selection means and a detection signal from the magnification positioning means, compares and calculates both signals, and generates an output signal for driving and controlling the variable magnification drive motor. and when a selected magnification command signal regarding a magnification corresponding to one of the two magnification positioning means provided at both ends of the movement range of the lens is input from the magnification selection means, the magnification positioning means corresponding to the magnification is activated. If there is no position detection signal indicating that the lens has been actuated by the lens, a drive control signal is issued to drive the variable magnification drive motor in normal rotation in order to move the lens toward that magnification position, and when corresponding to the other positioning means. If there is no detection signal from the magnification positioning means corresponding to the magnification of the lens, it outputs a drive control signal that drives the variable magnification drive motor in reverse in order to move the lens toward that position. When the selected magnification command signal regarding the magnification corresponding to the positioning means is input from the magnification selection means, if there is no position detection signal indicating that the magnification positioning means corresponding to the magnification has been operated by the actuator, the magnification is correct. Outputs a signal to drive and control the variable power drive motor in a predetermined direction between rotation and reverse rotation,
A stop signal is issued in response to a detection signal from a predetermined magnification positioning means, and if a detection signal from one of the two ends of the magnification positioning means is input before reaching a predetermined magnification position, an inversion drive control signal is issued, and the A control circuit including two systems of logic circuits for forward rotation and reverse rotation is selected so as to issue an inversion drive control signal from the beginning when it is in the inversion position, and the detection signal from the magnification positioning means and the magnification A variable magnification device for a copying machine, characterized in that a variable magnification drive motor is kept stopped when a signal from a selection means indicates the same magnification.