FR2626126A1 - IMAGE FORMING APPARATUS HAVING A FUNCTION WHICH ENABLES CONTROL OF THE START OF SCAN START - Google Patents

Abstract

In an apparatus offering several possible imaging magnifications, such as an electronic copying machine, the position of a first carriage carrying an exposure lamp 22 is detected by a sensor 72 belonging to a position sensor 150 of the image forming. engine. An operation start position is stored in a first subprocessor 142. The start positions corresponding to the maximum reduction magnification, 100% magnification and maximum magnification magnification, respectively, and the exposure start position are determined at from the number of pulses supplied by a device 146 for driving the stepper motor on the basis of the operation start position. When a button of the control panel 80 is actuated, the first carriage moves from the operation start position so that, over distances between the start positions and the exposure start position, it is accelerated based on the minimum reduction magnification, and then, after the exposure start position, it moves at a predetermined scanning speed.

Description

The present invention relates to an image forming apparatus and, more

  particularly, an image forming apparatus having a function for controlling the start position

  scanning according to the magnification of the image formation.

  As is well known, an image forming apparatus, for example an electronic copy machine, has a 100% magnification function that allows it to reproduce an original image on a sheet of paper the size of the original image , and another function allowing it to reproduce an original image in enlarged or reduced form. The image is formed by moving a scanning means of scanning along

of the document surface.

  In an electronic copy machine that is able to reproduce an original image at an enlarged size or at a reduced size, the exposure-scanning means moves to expose and scan the original. The speed of displacement.

  means of exposure-scanning differs between the modes of

  copy machine, enlargement mode and reduction mode. More specifically, the speed of the displacement of the exposure means is, for a reduction mode, set to a higher value than for the 100% magnification. In the magnification mode, the speed of movement is less than that of the

o100% magnification mode.

  In a similar conventional copy machine, the posi-

  starting point of the exposure-scanning means is the same for the

  100% magnification mode and for magnification or reduction mode

  tion. Thus, the starting position is set to that corresponding to the maximum reduction magnification, which requires the longest acceleration distance, for all copy modes, 100% magnification, magnification and reduction. In addition, the scanning means is accelerated for the magnification to the minimum reduction. Thus, in a 100% magnification mode, the exposure-scanning means reaches the necessary scanning speed

  for 100% magnification before the exposure start position.

  front end of the original. The time between the position where the required sweeping speed is reached and the

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  exposure start position is useless for the expo-

  light and sweep the original. This leads

  that, in a conventional copying machine, the means of

  scan travels an excessive distance during exposure and scanning and that, especially when the copy operation

  is performed repeatedly, it takes a lot of time for the opera-

  exposure and scanning of the original image.

  It is therefore an object of the invention to produce an image forming apparatus in which the magnification of the reproduced image is easily fixed and modified, and a reduction in the time taken by the exposure operation is realized. scanning an image

  original, especially during a repeat copy operation.

  tion. According to one aspect of the invention, there is provided an apparatus for forming an image on a training medium

  image, said apparatus comprising means for optimally scanning

  an original, a means for setting one of a plurality of magnifications for the scanned image of the original, a means for initializing the optical scanning means to an initial position, and a means for controlling the distance wherein the optical scanning means moves between an initial position and a start position where the optical scanning means begins to operate, depending on the image forming magnification set by the magnification fixing means, the means for

  optical scanning being accelerated from the initial position to the

  start and reaching the start position in an accelerated state. According to another aspect of the invention, it is proposed a

  scanning apparatus which includes means for optimally scanning

  an original, means for setting one of a plurality of magnifications for the scanned image of the original, means for initializing the optical scanning means at an initial position, means for photoelectrically converting the image. image into an electrical signal for the magnification considered among the different magnifications of the image, and a means for controlling the speed, which is selected from a plurality of speeds and at which the optical scanning means moves between the initial position and a position of beginning o the optical scanning means starts to operate, depending on a

  scanning magnification fixed by the magnifying attachment means

  the optical scanning means being accelerated from the initial position to the start position and reaching the start position

in an accelerated state.

  The following description, designed as an illustration of

  the invention aims to provide a better understanding of its features and benefits; it is based on the accompanying drawings, among which: - Figure 1 is a block diagram showing the control system of an electronic copy machine according to one embodiment of the invention; FIG. 2 is a perspective view showing the external appearance of the copy machine; - Figure 3 is a longitudinal sectional view showing the internal structure of the copy machine; FIG. 4 is a diagram showing the arrangement of the controls on the operating panel of the copy machine;

  FIG. 5 is a perspective view showing a diagram showing

  only a drive mechanism of the optical system of the copy machine;

  FIG. 6 is a perspective view showing a diagram showing

  the control mechanism of the optical system of the copying machine, the representation being made to explain the displacement of the optical system;

  FIG. 7 is a flowchart showing the operation of

  the copy machine; FIG. 8 is a graph showing the relationship between the traveling speed and the distance for a first carriage; Fig. 9 is a graph showing the relationship between travel speed and time for a first carriage; and

26 2 6 1 2 6

  FIG. 10 is a sectional view showing the structure

  of a scanning device, which constitutes another embodiment of

of the invention.

  In Figures 1 to 5 is schematically shown the assembly of an image forming apparatus, for example a copy machine, according to the invention. A document table (transparent glass plate) 14 for supporting an original 0 is attached to the central portion of the top panel 12 on the upper face of the main body 10 of a copy machine. The table 14 has a fixed scale 16 serving as reference when positioning an original 0 on the table 14. In addition, a cover 18, which can be opened and closed, and a work table 20 are placed near the table 14. The original 0 placed on the table 14 is exposed to light and is scanned when an optical system containing an exposure lamp 22 and mirrors 24, 26 and 28 makes a go movement and back along the lower surface of the table 14 according to the directions of the arrow "a". In this case, to maintain the optical path, the mirrors 26 and 28 move at half speed of the mirror 24. The reflected light from the original 0 during the scanning operation by the optical system, namely the light reflected by the original which comes from the illumination by the lamp 22, is reflected by the mirrors 24, 26 and 28, passes into an optical objective at variable magnification 30, is reflected again by

  the mirror 32, and is brought to a photoconductive drum 34.

  In this way, the image of the original 0 is formed on the surface of the

drum 34.

  The drum 34 can rotate in the direction of the arrow "b" as shown in FIG. 3. In the copy operation, the

  main charger 36 first charges the surface of the drum 34.

  Then, the reflected light containing an image of the original is applied via a slot on the surface of the drum 34, so that

  an electrostatic latent image forms on the surface of the drum.

  The developing device 38 applies an inking agent, or toner, to the latent image on the surface of the drum,

to visualize this image.

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  Sheet paper on which an image is to be reproduced is placed in an upper feed cassette 401 and a lower feed cassette 402 These cassettes 401 and 402 removably insert into the lower portion of the right side of the main body 10. The paper P is taken one sheet at a time from one or the other of the cassettes 401 and 402 by a sampling cylinder 421 or 422. The withdrawn paper P is guided via the paper guide path 441 or 442 until to a pair of matching cylinders 46. The pair of rolls 46 further guides the paper to the transfer unit

  48. This cassette 401 or 402 is manually selected

  an associated key on the operating panel.

  80 which will be described below. Cassette size detecting switches 501 and 502 are for selecting the cassette size of the cassette 401 or 402, which depends on the size of the paper P placed in the cassettes. These switches 501 and 502 each include several microswitches that close and open at the time of insertion of the cassettes.

different sizes.

  Paper P transported to the transfer unit 48

  is brought into close contact with the surface of the Dhotoconduc-

  3L in the portion of a charge transfer device 52, so that the toner image on the surface of the drum 34 is transferred onto the paper P by the transfer charging device 52. The paper P carrying the transferred toner image is electrostatically separated from the surface of the drum 34 by a

  separating load device 54. The separated paper is

  carried to a pair of fixing cylinders 58 acting as

  fixing means which is placed downstream of a transport means 56.

  The paper P coming from the pair of fixing rolls is discharged on a receiving plate 62 by a pair of rolls of

exit 60.

  As a result of the image transfer, the photoconductive drum

  34 is discharged by a charging device 64 discharging, and then the residual toner on the surface of the drum is removed by a cleaning unit 66. The drum 34 is moved below a discharge lamp 68 by means of which a recurring image on the surface of the drum is removed, so that the drum is returned to the initial state. Reference numeral 70 designates a cooling fan for preventing excessive temperature rise within the main body 10. Reference numeral 72 designates a sensor for measuring the initial position of a first carriage 100,

  as will be explained below.

  Fig. 4 shows an operation panel 80 installed on the upper surface of the main body 10. Reference numeral 82 denotes a reproduction key for controlling the start of a copy operation; 84 denotes number keys for indicating the number of reproductions; 86 denotes an indicator section for indicating various operating states of the necessary parts of the copy machine

  as well as a paper jam; 88 designates selection keys

  cassette arrangement for selecting an upper feed cassette 401 or lower 402; 90 denotes indicators each serving to indicate the selected cassette; 92 designates magnification adjustment keys for setting degrees

  enlargements of reduction and enlargement according to a

  predetermined 94 denotes keys of continuous variation

  used to continuously adjust magnification magnifications

  waste and reduction; 96 denotes a display window for displaying the fixed magnification; and 98 denotes a density adjustment section for setting the density of the reproduced image. Fig. 5 shows a drive mechanism for moving the optical system back and forth. As shown, the exposure lamp 22 and the mirror 24 are carried by a first carriage 100, and the mirrors 26 and 28 are carried by a second carriage 102. These first and second carriages 100 and 102 are both respectively guided by guide rails 104 and 106, and these carriages, arranged in parallel, can move in both directions, as indicated by the arrow "a". A scale 108, which will be described

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  hereinafter is attached to the upper surface of the first carriage 100.

  A scanning motor 110 (a quadriphase stepper motor) drives a pulley 112. A timing belt 116 passes over the pulley 112 and onto an idler pulley 114 spaced from this first pulley. One end of the first carriage 100 carrying the mirror 24 is attached to this belt 116. Two pulleys 120 and 122 are rotatably mounted at the two end portions of a guide member 118 of the second carriage 102 carrying the mirrors 26 and 28, which extends along the guide rail 106. A wire 124 passes over the pulleys 120 and 122. One end of the yoke 124 is attached to an L-shaped member 126, while its other end is fixed.

  to this same element via a coil spring 128.

  One end of the first carriage 100 is fixed at a suitable position of the wire 124. With this arrangement, when the scanning motor 110 is energized, the belt 116 rotates so that

  move the first carriage 100 as well as the second carriage 1 ..

  During this operation, these pulleys 120 and 122 act as crazy pulleys. Thus, the second carriage 102 moves at half speed of the first carriage 100, and in the same direction as this one. The directions of the first and second carriages 100 and 102 can be controlled by switching the direction of rotation of the motor.

scan 110.

  FIG. 1 represents a control circuit which enables

  to provide general control of the copy machine.

  A main processor 130, developed for example using a single-chip computer, is coupled to the operation panel 80, and an input device 132 having various switches and sensors, such as the switches 501 and 502 of cassette size detection detects the output signals of these switches and sensors. The main processor 130 is further coupled to a high voltage transformer 134 for energizing the respective charging devices, the discharge lamp 68 and the solenoid of the blade 660 of the cleaning unit 66.

  main processor 130 is further coupled to the heating element

  580 of the pair of fixing cylinders 58 via a heating element control unit 136, to the exposure lamp 22 via a lamp regulator 138, and, via an excitation device of FIG. engine, a developer engine 380, a toner engine 382, a fixing motor 582, and a fan motor 700. The developing motor 380 is a motor for driving the developing cylinder, for example in the middle 38, and the toner engine 382 serves to supply the toner to the developing means 38. The fixing motor 582 drives the paper transport means 56, the pair of fixing rolls 58 and the pair of output rolls 60 The fan motor 700 is a motor used to drive the

cooling fan 70.

  The main processor 130 is coupled to a first and a

  second sub-processor, 142 and 144, and it controls these sub-processor

  processors. The first subprocessor 142 is coupled to a scanning engine 110, a shutter motor 148, and an optical lens motor 300, which will be described hereinafter, via an excitation device 146. stepper motor, and is further coupled to a motor position sensor 150. These engines are

  controlled by the first subprocessor 142. The second sub-processor

  processor 144 is coupled to a drum motor 340, a feed motor 420 and a match motor 460, which will be

  described below, and he commands them.

  The scanning engine 110, as established above, is

  intended to move the first carriage 100 carrying the exposure lamp

  22 and the mirror 24 for scanning an original, and second carriage 102 carrying the mirrors 26 and 28. The shutter motor 148 is a motor for moving a shutter (not shown) to adjust the width of the camera. The area of the photoconductive drum 34 to be charged by the charging device 36 when the magnification of the reproduced image is varied. The optical lens motor 300 is a motor for moving a variable magnification optical lens 30 to vary the magnification. The drum motor 340 is a motor for driving the drum 34. The feed motor 420 is a motor for driving the picking cylinders 421 and 422.

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  Matching motor 460 is a motor used to drive

  the pair of matching cylinders 46.

  The main processor 130 delivers to the first and second subprocessors 142 and 144 instructions to

  to drive and stop the engines. These subprocessors

  state signals representing the state of motors, for example

  example the trained state and the stopped state. The first sub-

  processor 142 receives position data from the engine position sensor for detecting the initial positions of the scan motor 110, the shutter motor 148, and

of the optical lens motor 300.

  The sub-processors 142 and 144 are each constituted for example by a microcomputer and a measurement device.

  programmable time interval for controlling the

  the phase switching value of the stepping motor by counting a reference clock pulse according to a fixed value which is

provided by the microcomputer.

  Reference numeral 154 denotes a source of food

  electrical system to excite devices and components

  needed in the copy machine.

  With reference to FIGS. 6 to 9, the operation of the main processor 130 and the first carriage of the copy machine thus conceived at the moment of formation will be described.

of an image.

  After the power source 154 of the main body of the copy machine has been put into operation, the

  first carriage 100 returns to the initial position. More special-

  For example, the main processor 130 energizes the scanning engine 110 through the subprocessor 142 and then the stepper motor excitation device 146. When the motor is energized, the first carriage 100 moves along the guide rails 104 and 106 towards the exit side (to the left of the drawing of FIG. 6) of the main body 10, in order to switch the sensor 72 into service. position of the first carriage which is placed in the part located under the upper panel 12, closer to the output side than the fixed scale 16. The position of the first carriage

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  detected by the position sensor 72 is loaded into a data register of the first subprocessor 142, for the start operation position S0 which will be considered as the initial position of the first carriage 100. The starting position which is stored as the initial position of the first carriage 100 is a reference position for determining for example the starting position of the first carriage 100 to be moved by

  function of magnification of enlargement or reduction.

  The position data, which is the start position

  stored in the form S0 in the first sub-

  processor 142 serves to determine for example the start position S1 for the maximum reduction magnification, the start position

  S2 for 100% magnification and the exposure start position

  S3 of the front end of the original 0. The "exposure start position" (S 3) designates the position of the first carriage when the light emitted by the exposure lamp 22 is applied to the original 0 through the document table 14 and that the

  copy machine is ready for the show-scan operation.

  These starting positions, S1, S2 and S3, are determined by the number of pulses obtained from the device 146 for exciting the stepper motor. In response to the applied pulses, the scanning motor 110 is driven to displace the first carriage 100 by means of the timing belt 116.

  to the start positions S1, S2 and S3.

  Before the copy operation begins, while still in a waiting state, the first carriage 100 is placed

  in one position, called the rest position, which indicates a

  a copy range defined for example by the cooperation of a fixed scale 16 and the scale 108 of the first carriage 100 on the basis of the current copy magnification and the size of the original 0. For example, in FIG. 6 , SH is called the rest position, and

  the copy interval is between the beginning position of expo-

  sition S3 and the rest position SH.

  After the first carriage 100 has thus been initialized,

  if the play key 82 of the function panel is pressed

  80, the control device checks whether the magnification

  current is 100% at step ST1 (flowchart of FIG.

  7). If the magnification of reproduction is not the magnification

  100%, that is to say if it is a reduction of

  enlargement magnification, the device for

  command goes to step ST2. At this stage, the breeding operation

  This is done in a normal reduction or enlargement mode.

  For example, if the current magnification is

  For example, the first carriage 100 is moved from the rest position SH to the starting position.

  SO, and the subprocessor 142 counts the number of impulse

  The device 146 for excitation of the stepper motor is provided. Then, the carriage 100 is brought from the position SO to the

  start position S1 relating to the maximum reduction magnification

  maLe, which position is determined by the number of pulses. When a predetermined number of impulses has been

  counted, the carriage 100 is accelerated to a predetermined acceleration

  the starting position S1 has an exposure start position S3 by adjusting the rotation frequency of the step motor 110. When the speed at the first carriage 100 reaches the scanning speed (at the position of beginning of the S3 exposure of the anterior end of the original 0),

  the original O is exposed and worn with uniform speed, that is,

  to say constant. The above-indicated operation sequence is repeated a predetermined number of times, as set by the number keys 84 of the operation panel 80. Then, the first carriage 100 returns to the rest position SH and is

put in a state of waiting.

  In step ST1, when the controller decides that the 100% magnification has been fixed, the flow chart jumps to step ST3. In step ST3, the first carriage 100 moves from the

  rest position SH to the start position S2 for magnification

  100%, passing through the SO start operation position.

  This start position S2 is set as follows. The first carriage 100 is moved with an acceleration which

  is equal to the predetermined acceleration that is associated with the gross-

  maximum reduction. Thus, the acceleration of the first carriage 100 in the acceleration section from the start position to the exposure start position is the same for all magnifications. In this case, the scanning speed relative to the 100% magnification can be obtained at the position S3 of the beginning of exposure of the original 0. The distance between the

  start positions S1 and S2 is set at 3.93 mm, for example.

  When the first carriage 100 has been moved to the position

  start S2, a copy operation starts at ST4.

  This will be described in connection with FIG. 9, which represents

  The relationship between speed and time during a

  unique operation of the first carriage 100 in the case where the magnification

  100% was paid off. In Figure 9, the curve indicated by a solid line represents the variation of the

  speed of the first carriage of a copy machine according to the invention.

  tion, while the curve indicated by a dashed line represents the variation of the speed of the first trolley

  in a classic copy machine.

  The first carriage 100 is accelerated from the start position S2 relative to the magnification 100%, and its speed reaches the predetermined scanning speed at the position where the exposure position S3 of the leading end of the original 0 (duration T1 acceleration). From the exposure start position S3, it is moved at a constant speed so as to expose and scan the original 0 (scan time T2). The image is formed during the exposure and scanning operation of the original 0

as follows.

  The operator places the original 0 on the table

  document 14. Next, it fixes the desired number of

  using the numeric keys 84, for the reproduction magnification

  above, and press the key of reproduction

  82. When the play button is pressed, the exposure lamp

  22 illuminates the original 0, while the first and second carriages 100 and 102 move on the guide rails 104 and

  106, as indicated above. In this way, the exhibition operation

  sition and baLayage oF OrigAl 0 progresses. Reflected light

  the original 0 is sent via the variable magnification lens 30 and the mirror 32 to the photoconductive drum 34, which has been loaded by the main charging device 36, so that an image of the original 0 is formed on the drum 34. Next, the developing means 38 makes the formed image visible. The visible image is transferred onto the paper P by the transfer unit 48.

  The paper was transported to the transfer unit 48 from the upper paper feed cassette 401 or lower 402. The paper P carrying the transferred image is separated from the surface of the drum 34 and is brought to the printer. to the fixing rolls 58. The fixing rolls 58 fix on the paper the transferred image. Then the paper is unloaded on the

tray 62.

  Following exposure and scanning of the original 0, the first carriage 100 is decelerated (deceleration time T 3) temporarily stopped (switching time T4). This switching duration T4 is the time required to reverse the direction of rotation of the scanning motor 110 in order to return the carriage 100 to the start position S2. As the direction of rotation of the scanning engine has been reversed, the first carriage 100 is accelerated and moved

  in the opposite direction (acceleration time T5), and is brought back to

  S start-up referring to 100% magnification with a higher speed than the displacement during exposure and scanning (T6 return time, T7 deceleration time). Once brought back to the original position S2, the first carriage 100 is

  temporarily stopped there, waiting for the reproduc-

  not yet made, which may exist (switching

  T8). At step ST5, the controller checks whether the copy operation is complete or not. If this is not the case, and there are copies not yet made, the first carriage 100 moves again from the S2 position, and the above presented sequence of the copy operation is performed. , and is repeated until the copy operation is completed at

step ST5.

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  When all the remaining reproductions have been made, the carriage 100 moves to the rest position SH, and

  is placed in the waiting state (step ST6).

  In the present embodiment, as shown in FIG. 8, the duration during which the first carriage 100 is accelerated, i.e., the approach time, is shorter for

  100% magnification only for the maximum reduction magnification

  male. Thus, as shown in Fig. 9, the time taken for a run of the first carriage 100 is reduced compared with that of the conventional copy machine. This implies that we can reduce

  the time taken to perform a reproduction.

  In FIG. 9, the respective durations are as follows: Acceleration time T1 = 29.6 ms Scanning duration T2 = 1939.0 ms Deceleration time T3 = 29.6 ms Switching time T4 = 54.6 ms Duration acceleration T5 = 96.8 ms Return time T6 = 699 ms Deceleration time T7 = 96.8 ms Switching time T8 = 54, c ms Therefore, the time taken for a copy operation reaches 3000 ms. This time leads to a reproduction time of 20 sheets per minute in the A4 format for the repeated copy mode. In the 100% magnification reproduction operation having a fixed start position as in the copy machine

  conventional, if the first carriage 100 is accelerated from the position

  With the start ratio S1 associated with the maximum reduction magnification, the distance between the starting positions S1 and S2 is added to the forward and backward distances of the first carriage 100. If the scanning speed is 121 mm / s and the the return speed is 292.86 mm / s, the time taken by the first carriage 100 to move between the starting positions S1 and Si is: (3.93 / 121 + 3.93 / 292.86) x 10 = 45.9 ms

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  In this case, the de-translation distance of the first carriage 100 lasts 9 ms, so that the duration of a single copy operation is: 3000 + 45, 9 = 3045.9 ms This duration corresponds to a copy time 19.7 sheets per

  minute for A4 in the repeat copy mode.

  These figures indicate that, if the shifted start position is used, the copy speed of 0.3 sheets per minute can be improved. This means that the necessary copy time is greatly reduced when the number of copy sheets is large or when a large number of sheets are reproduced in a given lapse of time compared with the conventional copy machine.

  In the embodiment shown above, the posi-

  The first carriage 100 is shifted only for the copy operation corresponding to the 100% magnification. It is obvious that the idea of moving the start position of the first carriage 100 can be applied, correspondingly, to the copy operation associated with the magnification of magnification. In this case too, the copy time can be reduced. More specifically, the first carriage 100 is displaced with an acceleration equal to

  the predetermined acceleration of the maximum reduction magnification

  male. In this case, the start position S4 relative to the magnification

  maximum magnification (eg 154%) can be set based on the exposure start position S3 of the original 0

  (Figure 8). The copying operation relating to magnification to increase

  maximum attenuation is similar to that associated with magnification in

  maximum reduction, so that the description will not be given

tion.

  In the embodiment mentioned above, the posi-

  The first carriage 100 is set at the position (SH position of FIG. 6) indicating a copy interval which depends on the copy magnification that was set. Alternatively, it can be set to the start operation position (position S0 in the same figure) or to the start position relative to the maximum reduction magnification (S1 on the same figure).

same figure) for example.

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  While the invention has been described with the aid of an embodiment in which the invention is applied to a copy machine, it can be applied to a scanning device by

example.

  Referring now to Figure 10, which shows the

  structure of a scanning device incorporating the invention.

  As shown, a document table (glass plate trans-

  parent) 14 to carry an original O is attached to the upper part of an upper panel 12 placed on the main body 10 'of the scanning device. The table 14 is provided with a fixed scale 16 providing a reference when the original O is placed on the table 14. In addition, a lid, which can be opened and closed, is arranged in the vicinity of the table 14. place the original O on the table 14, it is exposed to light and is scanned while an optical system comprising an exoosition lamp 22 and mirrors 24, 26 and 28 makes a go-and-go movement -return along the lower surface of the table 14 in the directions of the arrow "a '". In this case, in order to maintain the optical path, the mirrors 26 and 28 move at a speed of the mirror 24. The light reflected by the original as a result of the illumination provided by the lamp 22 is reflected by the mirrors 24, 26 and 28, passes through an optical objective at variable magnification 30, is reflected again by a mirror 32, and is brought to a photoelectric converter 160. The photoelectric converter

  160 converts the reflected light into an electrical signal

  feeling an image of the original and provides the electrical signal to

  an output device (not shown).

  The basic structure of the scanning device is identical

  to that of the copy machine described in the first embodiment. The only difference between them is that in the first, the reflected light from the exposure lamp 22 is led to a photoconductive drum 34, whereas in the

  scanning device, it is driven to a photo converter

  electric. Therefore, the training mechanism of the

  The scanning system is the same as that of the optical system of the first embodiment. The mechanism shown in FIGS. 5 and 6 can conveniently provide the mechanism for driving

  of the leash device. Thus, no description will be given

  the drive mechanism of the scanning device.

Claims (18)

  An image forming apparatus comprising: means for optically scanning an original; means for setting one of a plurality of magnifications relative to the scanned image of the original;   means for forming an image on a medium of   image formation at image-based training magnification; and means for controlling said optical scanning means so that said optical scanning means is moved in a predetermined direction.   characterized by further comprising means (92,94) for initializing said optical scanning means (22,110,146) to an initial position; and characterized in that said control means (130, 142) controls the distance from which said optical scanning means (22, 110, 146) is moved from the initial position to a start position, for which said optical scanning means begins to operate, according to the image-forming magnification set by said magnification fixing means (92, 94), said optical scanning means being accelerated from the initial position to the starting position and reaching the starting position in the first position. accelerated state. An apparatus according to claim 1, characterized in that said control means (130, 142) controls the displacement of said optical scanning means (22, 110, 146) so that said optical scanning means is accelerated from the position   based on the smallest of the said different magnifications   image of said at least two magnifications, and moves at a constant speed   after passing the start position.   An apparatus according to claim 2, characterized in that said control means (130, 142) controls the distance from which said optical scanning means (22, 110, 146) is moved to the start position so that the start position is set to   The same position as any of the said different magnifications   image formation that has been fixed.   4. Apparatus according to claim 1, characterized in that said optical scanning means (22,110,146) is set by said control means (130,142) at an initial position which indicates a resting imaging interval. both on   The imaging magnification fixed by said fixing means   magnification (92, 94) and on the size of said image formation.   5. Apparatus according to claim 4, characterized in that said control means (13D, 142) controls the displacement of said optical bay means (22, 110, 146) so that said optical bay means is accelerated from the initial position. at the start position according to the smallest of at least two different image-forming magnifications and is de-leased to a   constant speed after passing the start position.   Apparatus according to claim 5, characterized in that said control means (130, 142) controls the distance from which said optical balancing means (22, 110, 146) is moved to the start position so that start position is set to   the same position as any of the different magnifications   image formation that has been fixed.   7. Apparatus according to claim 1, characterized in that said means. optical bay (22, 110, 146) is provided by said control means (130, 142) at an initial position which is moved away from the starting position in a direction opposite to the direction in   Which scan operation is performed.   Apparatus according to claim 7, characterized in that said means (130,142) controls the movement of said optical pickup means (22,110,146) such that said optical pickup means is acclimated from the initial position. at the start position according to the smallest of at least two different imaging magnifications and moves to a   constant speed after passing the start position.   9. Apparatus according to claim 8, characterized in that said control means (130, 142) controls the distance 26 2 6 1 2 6   said optical scanning means (22, 110, 146) is moved to the start position so that the start position is set to   The same position as that of the said different magnifications   image formation that has been fixed.   A scanning apparatus comprising: means for optically scanning an original; means for setting one of a plurality of magnifications relative to the scanned image of the original; means for photoelectrically converting the image into an electrical signal to that of the different magnifications resting on the image; and means for controlling said optical scanning means so that said optical scanning means moves in a predetermined direction; characterized by further comprising means (92,94) for initializing said optical scanning means (22,110,146) to an initial position; and characterized in that said control means (130, 142) controls the distance from which said optical scanning means (22, 110, 146) is to move from the initial position to a start position, for which said optical scanning means begins to operate, depending on the magnification of the lens attached by said magnification fixing means (92, 94), said optical scanning means (22, 110, 146) being accelerated from the initial position to the starting position and reaching the start position in the accelerated state.   An apparatus according to claim 10, characterized in that said control means (130, 142) controls the displacement of said optical scanning means (22, 110, 146) so that said optical scanning means is accelerated from the initial position according to the smaller of said different scanning magnifications, said different scanning magnifications   number of at least two, and moves at a constant speed.   aunt after passing the start position.   Apparatus according to claim 11, characterized in that said control means (130, 142) controls the distance from which said optical bay means (22, 110, 146) is moved to the start position so that the start position is fixed at the same position as that of the said magnifications   different scanning that was fixed.   Apparatus according to claim 10, characterized in that said optical pickup means (22,110,146) is set by said control means (130,142) to an initial position which indicates a scanning interval residing on the magnification. scanning circuit set by said magnification setting means (92, 94).   Apparatus according to claim 13, characterized in that said control means (130, 142) controls the displacement of said occluded scanning means (22, 110, 146) so that said optical scanning means is accelerated from the initial position. at the start position according to the smallest of at least two different scanning magnifications and moves at a speed   contante after passing the start position.   Apparatus according to claim 14, characterized in that said control means (130, 142) controls the distance from which said scanning means (22, 110, 146) is moved to the start position of: that the starting position is fixed at the same position as the cue is that of said magnifications of   different scanning which has been fixed.   Apparatus according to claim 10, characterized in that said optical scanning means (22, 110, 146) is placed by said control means (130, 142) at an initial position which is moved away from the start position in a meaning opposite to the meaning in   which the scanning operation is performed.   An apparatus according to claim 16, characterized in that said control means (130, 142) controls the movement of said optical scanning means (22, 110, 146) so that said optical scanning means is accelerated from the initial position at the start position according to the smaller of at least two different scanning magnifications and moves at a speed   constant after passing the start position. 2626 1 26   Apparatus according to claim 17, characterized in that said control means (130,142) controls the distance from which said optical bay means (22,110,146) is moved to the start position so that start position is fixed at the same position regardless of the one of the said magnifications of   different scan that was fixed.