JPS6027971B2 - Copy machine variable magnification optical device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a variable magnification optical device for a copying machine capable of variable magnification copying.

The optical device of a copying machine having a variable magnification function is generally configured by a combination of the following exposure methods [11 to [41] and variable magnification mechanisms {a-, [b--].

That is, as an exposure method (11 document platen scanning slit exposure,
'21 mirror scanning slit exposure, '3 lens scanning slit exposure, '4) full-scale exposure, and the variable magnification mechanism [a-moves the mirror to change the optical path length between the original and the imaging surface, and the imaging position during reduction. In order to correct this, the lens unit is moved to a predetermined position. There are some systems that move the lens to a predetermined position in order to change the focal length and correct the imaging position during reduction, and these are based on a combination of the above. In these combinations, the original platen scanning slit exposure of ``M'' and the mirror scanning slit exposure of ``21'' require a large scanning distance and are not suitable for high speed, and the full-scale exposure of ``4'' requires that the entire machine becomes very large. There are drawbacks. Further, in the variable power mechanism that changes the focal length of the lens unit 'b}, the mechanism of the lens unit becomes complicated, and there are problems such as making adjustment difficult and expensive. Therefore, the remaining combination, that is, an optical device that employs the lake lens scanning slit exposure as the exposure method and a variable magnification mechanism that moves the mirror 'a' to change the optical path length, is used in the copying machine. It will be done.

One of the known optical devices of this type is such that the entire lens unit moving mechanism for moving the lens unit to a predetermined variable magnification position also performs movement for scanning an original.

That is, a variable power motor is installed in a fixed part separately from the main motor,
The rotational force of this zooming motor is transmitted to the lens unit moving mechanism using a flexible intermediate section, so that the moving mechanism can be moved to a predetermined zooming position. The scanning movement is enabled by the main motor using wires or cams and bars, and in order to determine the optical path during reduction, it directly detects the parts of the optical elements such as the lens unit and mirror unit that need to be stopped. The utensils are arranged. However, in the above-mentioned apparatus, since the entire lens moving mechanism section scans, the scanning weight becomes large, and therefore a large driving force is required for movement, and the scanning speed cannot be increased.

In addition, since scanning is performed while the lens unit moving mechanism and the variable magnification motor are connected, the curved state of the flexible intermediate member that connects them changes with the scanning movement of the lens unit moving mechanism, and the lens unit It is difficult to perform stable scanning because the force applied to the object is unstable. Such flexible intermediate members have problems in terms of durability because one side of the flexible intermediate member does not move and the other side swings, and also requires a mechanism for correcting the curved state. Furthermore, in the above device, it is necessary to connect the movement mechanism of the optical element other than the Shinnzunit with a drive source and a clutch, etc., and adjustment is difficult because a detector is used for each stop position of the optical element. There is a drawback. As described above, the conventional optical device has a large number of parts, a complicated structure, and is therefore expensive.The object of the present invention is to provide a light scanning device with a light scanning weight and a stable scanning speed, which is suitable for a variable magnification high-speed copying machine. An object of the present invention is to provide a variable magnification optical device.

The present invention will be explained below with reference to the illustrated embodiments.

FIG. 1 schematically shows a copying machine capable of double-sided copying and variable magnification visual copying, and has a variable magnification optical section IA on the left side of the figure and a copying section IB on the right side. In the variable magnification optical section IA, a document battle plate 2 is fixed to the copying machine housing 1 above it, and illumination devices 3 and 3' are arranged below it on both sides of the document teaching table 2, respectively. .

Both illumination devices 3, 3' include light sources 4, 4', swinging mirrors 5, 5' that reflect light from the light sources to the manuscript calendar plate 2,
The reflection shade 6, 6' for directing the light from the light source to the swinging mirror, and the swinging mirror 5, 5' reciprocatingly rotate within a predetermined angular range, allow the light on the manuscript calendar board 2 to be reflected. It is comprised of a drive device (not shown) and a control device (not shown) for illuminating and scanning a document (not shown). The pivoting and rotational movements of the swinging mirrors 5 and 5' ensure that the irradiated lights from the illumination devices 3 and 3' are aligned with each other on the original teaching layer plate 2, and that state is maintained while the irradiated light is placed on the original document. It is controlled to run at a constant speed on the calendar board 2. By doing this, the document surface is irradiated and scanned without the amount of light decreasing near both sides of the document surface. A lens moving device 8 including a lens 7 is arranged in the middle of the variable magnification optical section IA. This lens moving device 8 includes a guide rod 12 that guides the lens 7 in the scanning direction (horizontal direction in FIG. 1) parallel to the document surface as shown by an arrow x in FIG. 1, as will be explained in detail later. A rod carrier (first carriage) 10 and this first carriage 10 are supported and guided so as to be movable in a direction perpendicular to the document surface (vertical direction 8 in FIG. 1) as shown by arrow Z in FIG. and a carrier bracket (second carriage) 20 that can move in the Y direction, that is, in a direction parallel to the document surface and perpendicular to the scanning direction (perpendicular to the plane of the paper in FIG. 1). When making a reduced copy, the first carriage 10 is guided by the second carriage 201 and lowered to a position a certain distance away from the document calendar plate 2, so that the lens 7 assumes the position indicated by the chain line in FIG. 1, for example. . Further, during this downward movement, the second carriage 20 moves in a direction perpendicular to the paper plane of FIG. 1, so that the position of the lens 7 is slightly shifted. The reason will be explained later. A mirror unit 9 having two mirrors 66 and 67 mutually oriented in a V-shape is arranged at the lower part of the variable magnification optical section IA, and is positioned as shown by the chain line in FIG. changes.

This is to change only the approximate length of the light while keeping the angle of incidence on the photosensitive drum 100 in the copying section IB unchanged. Therefore, the direction P in which the mihuunit 9 moves is a direction tilted by an arbitrary angle with respect to the optical axis of the lens 7. The image of the document irradiated by the illumination devices 3, 3' and scanned by the swinging mirrors 5, 5' and the lens 7 passes through the mirror unit 9, and then passes through the photoreceptor drum 1.
It is projected and imaged onto 00. The surface of the photoreceptor drum 10 is uniformly charged by a charging device 101 prior to this, so that an electrostatic latent image of the document is formed on the photoreceptor drum 100. This latent image is then visualized by the developing device 102. The developed image, that is, the toner image on the photoreceptor drum 100 is overlapped with the transfer paper sent at an appropriate timing from the paper feed bag layer 103 or 103', and is transferred onto the transfer paper by passing through the transfer device 104. transcribed into.
After passing through the transfer device 104 , the transfer paper on which the toner image has been transferred is separated from the photosensitive drum 100 by a separation and conveyance device 105 , and then sent to a fixing device 106 . The transfer paper on which the toner image has been fixed by the fixing device 106 is transferred to the drum paper tray 108 according to the switching position of the tray selection guide 107.
Alternatively, it is sent to the double-sided copying tray 109. still,
The tray selection guide 107 is moved to the side of the tray 108 or 109 by a control drive device (not shown) depending on the copy mode selected by the copy mode specifying means (not shown), that is, whether single-sided copying or double-sided copying. It is designed to switch. The transfer paper on the double-sided copy tray 109 is in the double-sided paper feed bag layer 1.
From the first river, the paper is sent out again to the common conveyance path with the above-mentioned paper feeders 103 and 103', and after undergoing the above-described copying operation, it is sent out to the paper discharge tray 108. After transfer, photoreceptor drum 1
00 is neutralized and cleaned by the cleaning device 111. The reduction ratio of the reduction copy of the above-mentioned copying machine cannot be selected steplessly, but one of several reduction ratios prepared in advance is selectively specified by a variable magnification mode means (not shown). It is now possible to do so.

When the reduction ratio is specified by this variable magnification mode means, the first
The carriage 10 is therefore moved to a position away from the original plate 2 by a corresponding distance in the Z direction, and the mirror unit 9 moves the photosensitive drum 100 in the P direction at an arbitrary angle with respect to the optical axis of the lens. and fixed to maintain optical relationship. Furthermore, the optical axis of the second carriage 20 and hence the lens 7 is slightly shifted in the Y direction.
The reason is that if the lens 7 is simply moved downward without shifting the position of the optical axis of the lens 7,
As shown in Fig. 2, the image forming position on the document surface 2a is as shown in 2b, and the image forming point at one end A of the document is shifted by an amount △ from the image forming point B at the same magnification, and becomes B'. be. Therefore, in order to ensure ease of handling of manuscripts for the copying machine user, in a copying machine that requires the manuscript to be aligned with one end of the manuscript board 2, that is, with A in FIG. It is important to correct the positional deviation of the copy image on the transfer paper caused by the deviation of this Δ amount. To make this correction, it is necessary to shift the position of the transfer paper relative to the toner image on the photosensitive drum 100, or to shift the position of the lens 7 in the Y direction in FIG. In the former case, possible means include sliding the transfer paper while it is being conveyed across the photosensitive drum 10, or changing the stock position of the transfer paper. However, configuring the copying machine in this manner is not appropriate as it increases the risk of problems such as paper jams. Therefore, in the optical device of this embodiment, the latter correction method of shifting the position of the lens 7 is adopted. However, this correction amount, that is, the amount of shift of the lens optical axis, does not necessarily have to make the image forming position B' at the time of reduction match the image forming position B' at the same magnification, but it is necessary to reduce the deviation △ between B and B by an arbitrary amount. By correction, it is also possible to create a binding margin with a width sufficient to increase the desired width, for example, punch holes, in the reduced 4 copy. FIG. 3 shows details of the above-mentioned soz moving device 8. In FIG. 3, the first carriage 10 is cantilevered so as to be movable up and down by a vertical support rod 21 provided on the second carriage 20'.

In order to prevent the first carriage 10 from rotating around the vertical support rod 21, the second carriage 20 is provided with an auxiliary rod 22 in parallel with the vertical support rod 21, while the first carriage 20' is this auxiliary rod 2
Guide rollers 15, 15' (
(Fig. 8) is provided. This assembly of both the first and second carriages includes the two side plates 41, 4 of the optical section IA.
It is located between the two. Hentai optical section IA side plate 4
Between 1 and 42, a guide rod 43 and a guide rod 44 pass through the upper part and the lower part in the above-mentioned Y direction, respectively, and are fixed to the side plates 41 and 42.

The second carriage 20 is slidably supported on this upper guide rod 44 by its two ears 23, 23'. In order to prevent rotation of the assembly about the guide rod 44, the second carriage 20 is provided with a guide roller 24 that runs opposite the lower guide rod 44 and rolls on this rod. As a result, the vertical support rod 21 of the second carriage is held vertically in the above-mentioned Z direction. The first carriage 10 is cantilever-supported and guided by the vertical support rod 21 of the second carriage 20 and extends from the rod 21, and has a substantially rectangular entrance 11 on the side closer to the side plate 42 thereof.

The carriage portion 10a forming this Sekiguchi 11 has two parallel guide rods 1 extending in the X direction inside the Sekiguchi 11.
2, 12' are fixed. This guide rod 12,1
A lens holder 13 to which a lens 7 is attached is slidably supported at 2'. That is, the guide rod 12 passes through one side of the lens holder 13, and the other side of the lens holder 13 is supported by guide rollers 14, 14' that run oppositely to the guide rod 12' from both sides in the diametrical direction. A so-called linear motor that functions as a scanner motor 80 is provided in a portion 10a of the first carriage lo on the side plate 41 side, so that the lens holder 13 and therefore the lens 7 can perform scanning motion in the X direction. . In FIG. 3, the second carriage 2 has a vertically long opening 25 in the portion where the vertical support rod 21 is located. A stop pin 16 fixed to the boss portion 10c of the first carriage 10 protrudes through this opening □25, and a shaft 2 is attached to the rear surface 20a of the second carriage 2 on the side where the first carriage does not exist.
A stop lever 2 hangs down so as to be rotatable around 6.
It is designed to be able to engage with the claw portions 27a and 27b of No.7. That is, the pin 16 of the first carriage engages with the uppermost claw part 27a during full-size copying, and engages with the lower claw part 27b in the first reduced copying position, and is held in that position by its own weight. There is. A stopper 28 whose height can be adjusted is provided at the lowest part of the second carriage 20, and the boss portion 10c of the first carriage comes into contact with this and stands still at the second reduced copying position. Stop lever 27
The spring 32 always causes the arm 3 to rotate in the direction of supporting the pin 16, but the solenoid 30 causes the arm 3 to
1 in a direction away from the pin 16. 29 is a limiter that determines the rotation range of the lever 27.

Another vertically long entrance or notch 33 is provided on the side plate 41 side of the second carriage 20, and a carriage slide roller 17 fixed to the first carriage 10 projects through this notch 33. Further, a carriage slide cam plate 45 is attached to the side plate 41 at a position where it can be opposed to the rollers 17 so as to be adjustable later. and the second
A sliding spring 34 is provided between the carriage 20 and the side plate 41, and the roller 17 is constantly pressed against the cam plate 45 by the force of this spring. Therefore, when the first carriage 10 moves in the vertical direction along the vertical support rod 21 of the second carriage, the rollers 17 slide along the cam plate 45, which causes the second carriage 20 and therefore the lens 7 of the first carriage to Slide in the direction. The roller 17 is on the cam surface 45a at the same-size copying position, on the cam surface 45b at the first reduced copying position, and on the second cam surface 45a.
At the reduction copying position, it is placed on the cam surface 45c to correct the imaging position of the lens during reduction as explained in FIG. As mentioned above, when changing the copying magnification, the guide rod 12 for scanning,
12' is moved parallel to the document surface to change the scanning position of the lens.

Therefore, only the minimum number of objects, such as the lens 7 and lens holder 13, need to be moved for scanning, and it is possible to reduce the weight of the moving object and increase the scanning speed.
The vertical movement of the first carriage 10 relative to the second carriage 20' is controlled by a wire suspended in a U-shape from pulleys 35, 18, and 36, one end of which is fixed to the side plate 41 with a screw 46, and the other end is idling. This is done by a drive wire 39 fixed to a drive pulley 38 via a pulley 37.

The pulley 18 is a movable pulley attached to the boss portion 10c of the first carriage and located on the rear surface 20a side of the second carriage through the opening 25, that is, a pulley that moves up and down together with the first carriage 10. The pulleys 35 and 36 are fixed pulleys provided on both sides of the upper part of the opening 25 on the back surface 20a of the second carriage. The drive pulley 38 is connected to the side plate 42
The idler pulley 37 therefore functions to change the direction of the drive wire 39. The drive pulley 38 is rotationally driven by a variable power motor 40' attached to the side plate 42 via an L-shaped plate 46'. That is, as can be clearly seen from FIG.
7, the worm gear 48 and the worm wheel 49 fixed to the top of the same gear are rotated, and the drive pulley 38 is driven. With this warm mechanism, even if the power is turned off or other situations occur, the first carriage 20
The free fall of the material is prevented from occurring. FIG. 4 shows the principle of separating the vertical movement and lateral movement of the first carriage using the wire and pulley.

Now, try moving the second carriage 20 along the guide rod 43 while the drive pulley 38 is stationary. At this time, if the relative positional relationship of the pulleys 35, 18, and 36 does not change, even if the whole moves from the solid line position to the broken line position in FIG. 4, the height position of the working pulley 18 in the Z direction or the horizontal wire There is no change in the distance d from 39. In other words, the distance d is related only to the amount of winding of the drive pulley 38.
Therefore, the vertical movement and lateral movement of the first carriage 10 can be controlled separately and independently. Therefore, when performing vertical movement or lateral movement, there is no need to re-correct the other position, making the movement mechanism simple and easy to control. In FIG. 5, a shaft 5 is provided on the back surface 20a of the second carriage.
An inverted V-shaped lever 50 that can be rotated around 1 is provided, and the lever 51 is connected to a wire fixing screw 46 and a fixing pulley 35.
It is located at a higher position than the wire 39 stretched between.

A pulley 52 is attached to one arm of the lever 50.
The pulley 1' rests on a wire 39. The other arm of the lever 50 is subjected to a rotational behavior by a spring 54 in the direction in which the pulley 52 pushes down the wire 39. The lower end 55 of the other arm of the lever 50 functions as a feeler portion capable of shielding light between the light emitting and receiving elements of the variable magnification sensor 56. That is, the lever 50 is a feeler and a tension lever, and when the first carriage 10 is stopped at a predetermined position and the wire 39 is loosened, the lever 50 is rotated by the spring 54 from the dotted line position to the solid line position in FIG. The feeler section 55 of 50 enters the variable power sensor 56, and the variable power sensor 56
is set to turn on. In FIG. 6, the side plate 4
2, a drive sprocket 57 is fixed to a drive pulley 38 that is rotated by a variable power motor 40, and a sprocket 57 is attached below the drive sprocket 57.
8 and 59 are provided, and these sprockets 57, 5
A chain 60 is wound between 8 and 59.

A fan-shaped feeler 61 is attached to the sprocket 58, and two magnification sensors 62 and 63, each consisting of a photo interrupter that detects the feeler and turns on, are installed around the feeler 61. placed apart. Sprocket 59 is attached to a rod 65' having a millilift cam 64. Third
In the figures and FIG. 6, two mirrors 66 and 67 of the mirror unit 9 are fixed to a mirror bracket 68 in a V-shape. This mirror bracket 68 needs to move diagonally up and down along the P direction in FIG. For this purpose, four mirror guides 69 (side plates 41 and 42) are provided on side plates 41 and 42.
(the sides are not shown) are attached along the P direction in FIG. 1, that is, along a line extending at an arbitrary angle with respect to the Z direction. These mirror guides 69 have guide grooves 70 inside. The mirror bracket 69 is provided with a guide roller (not shown) that protrudes through a hole (not shown) in the side plate, and this guide roller is movably inserted into the guide groove 70 of the mirror guide. are doing. Therefore, the mirror bracket 68 is slidably guided at a predetermined angle by the guide rod O and the guide groove 70, and is held by its own weight on the mirror lift cam 64 by the mirror lift rollers 65 fixed to the mirror bracket 68. . The mirror lift cam 64 rotates in conjunction with the drive pulley 38 via the chain 60 in accordance with the amount of vertical movement of the first carriage 10, and moves the mirror bracket 68 to a predetermined position. Next, the operation when changing the actual copy magnification will be explained with reference to FIGS. 5 to 7.

When the main switch (not shown) is turned on, the variable magnification position of the first carriage 10 is detected by the variable magnification sensors 56, 62, and 63, and if the variable magnification position of the first carriage 10 is not at the same magnification position as shown in FIG. (not shown) returns the first carriage to the same magnification position.
0 is assumed to be at the same magnification position.

Now, when the reduction ratio is designated by the magnification designation means (not shown), the variable power motor 40 temporarily rotates in the direction to wind up the drive wire 39 (hereinafter referred to as "normal rotation").

As a result, the lever 50 changes to the dotted line and calendar shown in FIG. 5, and the variable power sensor 56 turns OFF. The first carriage 10 rises and the stop pin 16 of the first carriage separates from the claw portion 27a of the stop lever 27 of the second carriage. On the other hand, the fan-shaped feeler 61, which is linked to the variable power motor via the chain 60, also rotates in the direction of the arrow E in FIG. The fan-shaped feeler 61 is located at the position shown in FIG. 6 at the same magnification, and the variable magnification sensor 6
2 and the feeler tip 61A is very small.
Therefore, the variable power sensor 62 is turned on as soon as the pin 16 is separated from the claw portion 27a of the stop lever by one or two distances. When the variable power sensor 62 is turned ON, the solenoid 30 is turned ON, the stop lever 27 is rotated counterclockwise in FIG. 5 via the arm 31, and at the same time, the variable power motor 40 is reversed.

That is, the four-way motor rotates in a direction that loosens the wire 39, and the moving pulley 18 and therefore the first carriage 10 descend. The instantaneous position of the descending first carriage 10 is determined by the amount of rotation of the drive pulley 38, that is, the feeler 61.
It is detected by a combination of the on/off states of the metamorphosis sensors 62 and 63 depending on the position of.

For example, when both the variable magnification sensors 62 and 63 are turned OFF, it is the timing to turn off the solenoid 30 when you want to move the first carriage 10 to the first reduction position, and the variable magnification sensor 63 is OFF and only 62 is ON. When the second
The timing at which the solenoid 30 should be turned off is determined regarding the contracted position. The rotation of the feeler 61 and the rotation amount of the drive pulley 38, that is, the position of the first carriage 10, are detected by the variable magnification sensors 62 and 63, and the specified stripe 4.
Solenoid 30 is turned off at each timing according to the rate.
F is given.

Therefore, the stop lever 27 returns to its original position due to the balance between the spring 32 and the stop lever itself. The first carriage continues to descend to the river, and its stop pin 16 hits the lower claw part 27b of the stop lever 27, which has returned to its original position.
Or, it will hit the stopper 28 of the lowest layer.

However, the variable magnification mode 40 continues to reverse, and as a result,
The drive wire 39 begins to loosen, and the V-shaped lever 50 is rotated counterclockwise in FIG. 5 by the spring 54, turning on the variable power sensor 56. The variable power motor is turned off at this point. To do this, the first carriage 1
By loosening the drive wire 39 even after the carriage 10 is at the predetermined contracted position, the first carriage 10 can be stably set at the predetermined position by its own weight, and the influence of overrun etc. on the predetermined position due to acceleration during movement can be avoided. This is to eliminate it. Also, the cam surface 45 of the cam 45 for the first carriage slide
A to 45c are formed as flat portions to eliminate the above-mentioned error. As the first carriage 10 moves from the same magnification position to the first or second reduced position, the sliding roller 17
The cam surface 45a of the sliding cam plate 45 also shifts to 45b or 45c.

Therefore, both the first and second carriages 10, 20 are connected to the spring 34.
5 to the left in FIG. 5, and the image forming position of the lens 7 described in FIG. 2 is corrected. Further, the mirror lift cam 64 is rotated by the chain 60 in accordance with the amount of descent of the first carriage 10, and the mirror bracket 68 is moved to a predetermined contracted position. The mirror lift cam 64 also has a flat cam surface at a predetermined reduced position to eliminate overrun errors. In other words, the amount of overrun is preset in the mirror lift cam 64 in anticipation of the amount of overrun. The change from the first reduced position to the second small position is the same as above, and after the perverted motor 40 slightly raises the first carriage 10 and separates the stop pin 16 from the claw portion 27b, the solenoid 30 is Then, the variable power motor 40 is reversed. Thereby, the first carriage is brought to a predetermined lower position from one river above, and when the variable power sensor 56 is turned on, the transformation motor 40 is turned off and fixed at a predetermined position. The first carriage 10 and the mirror bracket 68 return to the same magnification position after a certain period of time has elapsed after the end of reduction copying, when the same magnification is specified, or after the main switch is turned on.

In this case, the variable magnification motor 40' rotates forward and the feeler 6
1 is the position where the variable power sensor 62 is turned on, that is, the stop pin 1
6 is the upper part 1 of the uppermost claw part 27a of the stop lever 27
It continues to rotate in the normal direction until it reaches the position of ~2 skin, and then rotates in the reverse direction and stops when the variable power sensor 56 turns on. As mentioned above, drive pulley 38 and mirror soft cam 64 are connected by chain 60 and configured to maintain optical position relative to each other.

Therefore, the positions of the first carriage 10 and the mirrors 66, 67 are simply determined by the feeler 6 which is interlocked with the drive pulley 38.
It is only necessary to detect the rotation angle position of 1. Therefore, controlling the lens moving device 8 and the mirror unit 9 is very simple. Changes in the magnification positions of the lens moving device 8 and the mirror unit 9 are performed under program control using a microcomputer including a central processing unit CPU.

In FIG. 7, reference numeral 71 denotes a program control unit that performs magnification variable drive control during normal operation, and this program control unit 71
and the forward rotation output section 72 and the reverse rotation output section 7 of the variable power motor.
3, there is a program control section 7 due to noise etc.
In order to prevent runaway of 1, a safety circuit 7 consisting of a logic circuit is installed.
4 are provided. In this example, the safety circuit 74 is composed of a register consisting of inverters 75 and 76 and NOR gates 77 and 78. Normally, variable power drive control is performed by controlling the inverters 75 and 75 based on commands from the program control section 71.
or 76 is missed, the register is set or reset, and the forward or reverse rotation output sections 72 and 73 are turned on and off, but when the variable magnification sensor 62 is turned on, the forward rotation output section 72 is turned off,
Also, when the variable power sensor 56 turns ON, the reverse rotation output section 73 key O
FF. In this way, by providing the safety circuit 74 that functions according to the output state of the variable magnification sensors 56 and 62, it is possible to prevent the program control unit from running out of control, thereby providing redundancy and performing safer and more reliable control. can.

Note that, as a matter of course, the magnification change drive is not performed while the copying machine is in the print cycle. Next, the lens scanning section in the first carriage will be explained.

In FIG. 8, the scanner motor 80 includes a partial piece 81a having a concave portion of a slot 82 fixed to the leg portion 10b of the side plate 41 of the first carriage 10, and a square bar-shaped partial piece 81.
b, a yoke 81 that can be divided into two parts, a plate-shaped permanent magnet 83 attached to the upper yoke piece 81a within the slot 82 of this yoke 81, and a bobbin with a coil wound thereon, and a slot below the magnet 83. 82 and a scanner motor bobbin portion 84 positioned around the lower yoke portion 81b with an appropriate clearance.

The scanner motor bobbin portion 84 is connected to the above-mentioned lens holder 13 via a bracket 85 located below the yoke portion 81b. The scanner motor bobbin section 84 is placed in the gap of the magnetic path including the magnet 83 and the yoke 81. Therefore, by passing a current through the bobbin section 84, the bobbin section 84 moves along the x direction in FIG. The lens holder 13 is moved through the bracket 85 by receiving thrust in the direction shown in FIG. The opening 11 provided in the first carriage must be shielded from light so that light does not enter through the lens 7, no matter which position the lens holder 13 moves to.

Therefore, on the lower surface of the first carriage 10, shield curtains 86 extend from both sides of the lens holder 13 when viewed in the moving direction of the lens holder 13, and the ends of these shield curtains are located near the green ends of the Sekiguchi 11 at both ends. It is wound around shield drums 87, 87' which are rotatably held in shield holders 88, 88' provided in the shield drums 87, 87'. Therefore, the area of Sekiguchi 11 other than the lens holder 13 is covered by this shield curtain 86. Also shield drum 87
, 87' are each provided with a toothed pulley 89, and a timing belt 90 whose both ends are fixed to the lens holder 13 is stretched around the both toothed pulleys 89. When the lens holder 13 moves, this timing belt 90
The shield drums 87, 87' rotate synchronously,
The shield drum on one side operates the shield curtain and the shield drum on the other side winds up the shield curtain. Therefore,
During the scanning movement, the force applied from the shield curtain 86 to the lens holder 13 is approximately constant, the scanning speed is stable, and high scanning accuracy is obtained. Like the subordinate, the shield drum 87,
In the case where the 87' itself has a mainspring or the like and then always applies a force in the winding direction to the shield curtain 86 using female force, the force applied to the lens holder 13 varies depending on the scanning position of the lens holder 13, and the scanning accuracy is affected. It is inconvenient to increase the In order to detect instantaneous scanning misalignment of the scanner motor bobbin section 84, a rotor IJ encoder 91 is attached to the side surface 81' of the yoke 81 opposite to the side plate 41. The scanner motor bobbin section 84 is rotated according to the amount of movement thereof.

That is, the wire 92 is stretched between pulleys 93 and 94 located near both ends of the slot 82 on the side surface 81' of the yoke 81, and a pulley (not shown) of the encoder 91, and is connected to the bracket 85. There is. Although the pulley 93 is fixed, a pulley 94 is attached to one end of a lever 95 that is pivotally connected to the yoke side surface 81', and a spring 96 provided between the lever 95 and the yoke side surface 81' applies a constant tension to the wire. It is given to 92 people. In FIG. 9, lens position and speed detection means 91', which is comprised of a lens position signal from an encoder 91 and a circuit that processes the position signal and generates a speed signal, rotates as the lens 7 scans and generates a corresponding signal. and sends it to the lens scanning control section 97.

The control section 97 sends this signal to the photosensitive drum speed detection means 98.
control the output current to the bobbin section 84 of the scanner motor 80 so as to maintain the rotation of the photosensitive drum 100 at a predetermined speed corresponding to each specified magnification given from the lens speed specifying means 99; Therefore, lens 7
The scanning speed is controlled, and the scanning distance predetermined by each magnification is also controlled by the lens position signal. The lens holder 13 is designed to return to a predetermined position except when the machine is executing a print cycle, and a sensor (not shown) is provided on the first carriage 10' to detect this position. be. As mentioned above, the fact that the lens holder 13, which is the lens scanning means, is directly connected to the scanner motor 80, which is the driving means, makes it easy to control the lens scanning speed, and it is also extremely easy to change the lens scanning speed when changing the magnification. make it easier. In the variable magnification optical device of the present invention, a scanner motor 80 serving as a lens driving means is mounted on the first carriage 101. Therefore, when changing the magnification, the scanner motor 80 and the guide rods 12, 1 for lens scanning are mounted on the first carriage 101.
Since the lenses 2' are integrated and move together, the drive mechanism for lens scanning is greatly simplified.

This effect is the same even when a DC servo motor, step motor, or other device is used as the lens driving means. However, especially when using a linear motor, the bobbin section 8
4 and the lens holder 13 can be directly connected, so there is no time lag between the motor operation and the lens operation, unlike when gears, wires, etc. are used in the middle, and stable scanning control is possible. is obtained.

[Brief explanation of the drawing]

Fig. 1 is a schematic cross-sectional view of a copying machine equipped with the variable magnification optical device of the present invention, Fig. 2 is an explanatory diagram of correction of the lens position with respect to the imaging position during reduction, and Fig. 3 shows the entire variable magnification optical device from the rear. This is a perspective view as seen from the side with a part cut away. Figure 4 is an explanatory diagram of the separation principle of lateral movement and vertical movement of the first carriage using wires and pulleys. Figure 5 is a variable magnification optical system. 6 is an enlarged view of the side plate of FIG. 3, FIG. 7 is a block diagram of the variable power drive control device, and FIG. 8 is a partially cutaway view of the device. FIG. 9 is a perspective view showing a portion of the carriage, and a block diagram of the Shins scan control device. IA...Variable magnification optical section, IB...Copying section, 2...Manuscript Hagi calendar board, 3,3'...
...Illuminating device, 7...Lens, 8...Lens moving device, 9...Mifunite, 10...First carriage, 12, 12'...Guide rod, 13...Lens holder , 16... Stop pin, 17... Slide roller, 18... Pulley, 20... Second carriage, 21
... Vertical support rod, 25 ... Closed,
27... Stop lever, 27a...
Claw portion, 27b... Claw portion, 28... Stopper, 30... Solenoid, 33...
Section, 34...Sliding spring, 35,
36...F. -IJ, 38... Drive pulley, 39.
...drive wire, 40...variable magnification mode
Evening, 41, 42... Side plate, 43, 44... ．．・
．． ．． Guide lock, 45...Slide cam plate, 48.
... Worm gear, 49 ... Worm wheel, 50
...V-shaped lever, 52, 53...F. -Re, 54... Spring, 55... Feeler portion, 56... Variable power sensor, 57... Drive sprocket, 58... Filler sprocket, 59
...Mirror lift sprocket, 60...Chain, 6
1... Feeler, 62, 63... Variable power sensor,
64...Mirror lift force, 65...Mirror lift control, 66, 67"""kofu, 69"""mirror guide, 71...Program control section, 72...・
...Forward rotation output section, 73...Reverse rotation output section, 74.
... Safety circuit, 80 ... Scanner motor, 81 ... Yoke, 82 ... Slot, 83 ...
・Permanent magnet, 84...Scanner motor bobbin part, 85...Bracket, 91...Rotary encoder,
97...Lens scanning control unit, 98...Drum speed detection means, 99...Lens speed designation means, 1
00...Photosensitive drum. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 9 Figure 8

Claims (1)

[Claims] 1. A variable magnification optical device for a copying machine that forms an original image via a lens and a mirror on a photoreceptor that is driven by a drive motor, and the lens is fixed in a plane parallel to the original surface. a first carriage having a guide rod that guides the first carriage so as to be linearly reciprocated in the direction of the document; a second carriage movable in a direction, a lens driving means for moving the lens along the guide rod, and a lens scanning control device for controlling the lens driving means to cause the lens to scan at a predetermined speed; When changing the copy magnification, the first and second
A magnification motor for moving both carriages and the mirror to a predetermined position, and a means for controlling the magnification motor, wherein a dedicated scanner motor is mounted on the first carriage as the lens driving means, and a copying apparatus is provided. A variable magnification optical device characterized in that the scanner motor moves together with the first carriage when changing magnification.