JPH0562501B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a copying apparatus that scans an image of a document by moving a scanning means and copies the scanned image of the document onto a recording material.

[Prior art]

Conventionally, when it comes to copying machines, a document is irradiated with a light source such as a halogen lamp or a fluorescent lamp, and the reflected light is focused by a lens and irradiated onto a photosensitive drum inside the main body via a mirror or the like. As a result, a latent image is formed on the photosensitive drum. Next, by bringing a developer or the like close to the photosensitive drum, the developer adheres to the photosensitive drum in accordance with the latent image. This allows the latent image to be visualized. The original document can be copied by transferring the portion to which the developer has adhered onto plain paper.

In such a copying apparatus, reflected light from an original document must be guided onto a photoreceptor by an optical system such as a reflective mirror, a lens, or as a special example, an optical fiber scope.

Therefore, in such copying apparatuses, functions such as scaling operations such as enlarging and reducing the original document, and movement have been realized by mechanical devices.

For example, in a magnification change operation, the lens position is moved to change the focal length of the lens, and the scanning speed of the document or the moving speed of the photoreceptor is relatively changed to obtain the desired magnification.

Furthermore, when attempting to transfer a portion of the original to a desired position on copy paper, the image forming position on the transfer paper is fixed by mechanical factors, and the user cannot adjust the image forming position. Nakatsuta. Therefore, the user must decide on the part of the original that he or she wants to copy and place that part on the document table in a position corresponding to the desired transfer position on the copy paper, and therefore, the positioning is imprecise and uncertain. In some cases, it may be necessary to make unnecessary copies and confirm their positions in advance.

〔the purpose〕

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and provide a copying apparatus that can accurately move an original image to a desired position on a recording medium.

〔Example〕

Hereinafter, the present invention will be explained in detail with reference to the drawings.

FIG. 1 shows the configuration of an embodiment of the copying apparatus of the present invention. This copying device has an image reading section (reader section)
Although the image forming section A and the image forming section (printer section) B are constructed as one unit, each can be used as an independent unit. There is no mechanical connection between these two parts A and B, and they only need to be electrically connected.

In FIG. 1, starting from the reader section A, reference numeral 1 denotes a document table, and an original document GK is placed on this document table 1. Also, its placement reference is on the back left side when viewed from the front. 2 is the original manuscript
Document cover that presses GK flatly and uniformly, 3
is a light source, such as a fluorescent lamp, that illuminates the original document GK. This lamp 3 lights up at the start of scanning.

The light reflected from the original by illuminating the original GK with the light from the lamp 3 is guided by the reflecting mirror 4 and the mirror unit 5 to the lens system 6, and from this lens system 6 onto the light-receiving surface of the light-receiving element 7 such as a CCD line sensor. imaged. Here, the reflecting mirror 4 and the mirror unit 5 are arranged to move at a relative speed of 2:1.

The scanning unit consisting of the light source 3, reflection mirror 4 and mirror unit 5 described above is driven by a DC servo motor 52 which is controlled by a PLL (phased lock loop) and scans the first scanning unit at a constant speed.
Sub-scanning is performed by moving from left to right in the figure. The speed of this movement is, for example, 180 mm/sec, and in order to increase the copy speed, when moving back from right to left, the scanning unit is moved back at several times the speed of the forward movement. do. The resolution in the sub-scanning direction is, for example, 16 lines/mm, and sub-scanning is performed continuously. In this example, the sub-scanning width can be up to a maximum of A3 size (horizontal orientation). In this example, A4
Place it vertically or A3 horizontally. Therefore, the number of lines in the sub-scanning direction is 210× for A4 size.
16 = 3360 lines, 420 x 16 = for A3 size
It has a resolution of 6720 lines.

On the left side of the document table 1, there is a sensor that detects when the scanning units 3, 4, and 5 reach the leading edge of the document.
An OHP is provided, and further to the left of this sensor OHP is a sensor HP that detects the stop position (home position) of the scanning unit. Therefore, when the scanning units 3, 4, and 5 reach the leading edge of the image, they continuously scan the image from the document portion at the position of this sensor OHP for a time corresponding to the width of the document.
The reflected light from the original is sent to the CCD line sensor 7,
Photoelectric conversion is performed. Here, the main scanning direction is
This is a direction perpendicular to the sub-scanning direction (vertical direction of the document GK), and this device uses a CCD line sensor to electrically perform main scanning of the document. In the main scanning direction, it is possible to read up to A4 size documents in the vertical direction (longitudinal direction). If the resolution in the main scanning direction is 16 lines/mm, when A4 size is used,
It has a resolution of 297 x 16 = 4752 bits. In this example, in order to achieve this resolution, two CCD sensors are used, and a resolution of 2628 bits x 2 = 5256 bits can be obtained.

Next, the printer section B will be explained. In this example, printer section B is a laser beam printer using an electrostatic process. First, leader part A
The image signal processed in the bit serial format is input to the printer section B. Printer section B
is equipped with a scanning optical unit 11, which includes a laser driver, a semiconductor laser, a collimator lens, a rotating polygon mirror, an Fθ lens,
It consists of a tilt correction optical system, etc. This image signal is input to a laser driver within the scanning optical unit 11. This laser driver drives a semiconductor laser in accordance with an image signal, and generates light modulated in accordance with "0" and "1" of the image signal. Further, this modulated light is applied to a rotating polygon mirror in the scanning optical unit 11, and main scanning is performed by rotating this mirror. This scanning output light passes through the Fθ lens and the tilt correction optical system in the scanning optical unit 11, and is made incident on the reflecting mirror 12.
Main scanning is performed on the photosensitive surface of the photosensitive drum 13 by irradiating the light onto the indicated position above.

The photosensitive drum 13 forms an image in the sub-scanning direction on the photosensitive surface by rotating at a constant speed in the direction of the arrow shown in the figure.

This photoreceptor 13 includes, for example, a conductive layer - a photosensitive layer -
Consists of three insulating layers. Also arranged here are process components that allow image formation. 14 is a pre-static eliminator, 28 is a pre-exposure lamp, 1
5 is a primary charger, 16 is a secondary charger, 27 is a full exposure lamp, 17 is a developer, 18 is a paper feed cassette, 19 is a paper feed roller, 20 is a paper feed guide, 21
22 is a registration roller, 22 is a transfer charger, 23 is a separation roller, 24 is a conveyance guide, 25 is a fixing device,
26 is a tray.

The position where the beam is irradiated has pixel information corresponding to "black", and is converted into a latent image by high-voltage chargers 14, 15, 16, etc. arranged around the photosensitive drum 13, and the toner in the developing device 17 is turned into a latent image. It is attached and visualized.

When the copy paper P is inserted into the paper feed cassette 18, the copy paper P is conveyed by the paper feed register 19 to the front side of the photosensitive drum 13 via the paper feed guide plate 20, and is transported by the operation of the registration clutch (not shown). The registration rollers 21 are driven, and the copy paper P passes under the photosensitive drum 13 at a constant speed. As described above, the image visualized by the toner is transferred to the copy paper P by the transfer high pressure applied by the transfer charger 22, and the copy paper with the toner image transferred passes through the separation roller 23 to the conveyance section. 24. That is, the image signal from the original document GK is transferred to copy paper. In this state, the toner is only attached to the copy paper P, so the transferred copy paper P is further fed from the conveying section 24 to the fixing device 25.
Here, the image is fixed at high temperature and pressure to form an unaltered image, and the image is discharged onto the tray 26.

Next, FIG. 2 shows a detailed example of the electric circuit of the reader section A shown in FIG. 1.

In FIG. 2, the reflected light of the document imaged on the CCD line sensor 7 is converted into an image signal. A transfer clock signal _φ1 is applied as a basic clock to the CCD line sensor 7, and image transmission signals are serially extracted at a predetermined speed. Since the output signal from the CCD line sensor is at a low level, it is amplified by a video amplifier 41 and then guided to a binarization circuit 42. This binarization circuit 42 quantizes the analog video signal and converts it into a digital signal. Although not shown, it is also possible to apply dither processing to a photographic original to obtain a halftone representation. Digitized first video signal
Input VA to the first memory 43.

As mentioned above, two CCD sensors 7 are used in this example, and the optical system 6, video amplifier 41, and binarization circuit 42 for this purpose are duplicated, so although they are not shown, another system is provided. do.
This system of signals is used as the second video signal VB.
It is stored in the memory 44. These memories 43
and 44 can be configured with two systems, for example, a front memory and a back memory. Therefore, it consists of four blocks of memory in total.

Since there is an upper limit to the frequency of the transfer clock _φ1 of the CCD sensor, this device converts image signals using two systems of CCD sensors in order to obtain high-speed image signals, and stores a write address counter 45 in each table memory. and write at the same time. In parallel, the contents of the back memory previously stored in the memory are successively read out by the read address counter 46 to enable high-speed processing.

At this time, the count speed of write address counter 45 is determined by clock signal _φ2 . This clock signal φ ₂ is formed by dividing the original oscillation output from a crystal oscillator 47 by a binary rate multiplier (BRM) 48. BRM
As is well known, the reference numeral 48 provides an output obtained by dividing the input frequency by an arbitrary desired frequency division ratio set from the outside, and its setting section is connected to the bus 50 of the microcomputer (CPU) 49.

By changing the period of this clock signal _φ2 , it is possible to perform a magnification change operation in the main scanning direction. That is, for transfer clock _φ1 ,
By changing the clock φ ₂ to φ ₁ /2−φ ₁ −2φ ₁ , the magnification can be changed from reduction to equal magnification to enlargement. This is because the sampling period for writing each of the first and second video signals into the memories 43 and 44 changes, which allows scaling in the main scanning direction to be easily performed.

At this time, the cycle of the read clock signal _φ3 , which determines the read cycle of the read address counter 46 which reads from the memories 43 and 44, is always constant. This clock signal φ ₃ is obtained from an oscillator 47.

Regarding the scanning speed of sub-scanning, the sequence driver section 51 controls the sub-scanning DC motor 5.
By changing the rotational speed of the motor 52, the high-speed rotation of the motor 52 can be set to a reduction mode, and the low-speed rotation can be set to an enlargement mode. The rotation speed of the motor 52 is controlled by PLL, and the sequence driver section 5 is used to determine the set speed.
1 is connected to the bus 50 of the microcomputer 49.

In addition to this PLL motor control circuit, the sequence driver section 51 controls the drivers 55 of the fluorescent lamps 3-A and 3-B, which generate light that illuminates the document surface during the necessary period during scanning, and also controls the scanning unit. Detection outputs from a stop position sensor HP and an image leading edge detection sensor OHP for detecting the stop position are supplied.

A microcomputer (arithmetic processing unit) 49 performs arithmetic commands for image processing, sequence control, magnification ratio calculation, protocol processing with the printer, control of the bus 50, and the like.

56 is memory consisting of ROM and RAM,
The ROM section stores programs for sequentially operating each circuit. The RAM section is for temporarily storing data during calculations.

In FIG. 2, 60 is a start bit counter that counts the readout clock signal _φ3 , and when the count value reaches a value corresponding to the image writing start position in the main scanning direction, it supplies a set signal to the flip-flop 61. However, the flip-flop 61 supplies a main scanning direction write position designation signal HC to the AND gate 62. The AND gate 62 is also supplied with a video signal VS1 obtained by combining the video outputs read from the first and second memories 43 and 44 with an OR gate 63, and controls the timing of whether or not to take out the video signal VS1 as a video signal VS2. Determined by signal HC. The read clock signal φ ₃ is also supplied to the end bit counter 64, and when the count value reaches a value corresponding to the image writing end position, a reset signal is supplied to the flip-flop 61, and the writing start position designation signal HC is supplied. Terminate it. For these counters 60 and 64, the number of bits representing the start and end positions of writing in the main scanning direction can be set by the central processing unit 49 via the bus 50. In other words, the central processing unit 49 extracts only the video signal VS1 within the designated range in the main scanning direction as the video signal VS2, and transfers it to the printer section B.

Note that the counters 60 and 64 receive beam detection signals.
It is reset every time BDET (described later) is input.

In FIG. 2, 65 is a sequence control logic unit for synchronizing with the printer unit B controlled by the central processing unit 49;
The VEN counter, 67, is the _φX counter.

The VEN counter 66 is a counter for determining the effective image portion in the CCD image signal, and counts the number of clocks _φ4 corresponding to the transfer clock _φ1 to determine the effective portion in the serial image signal obtained from the CCD sensor 7. Know. VEN counter 6
The output VEN of 6 is input to the interrupt terminal of the central processing unit 49, and an interrupt is generated at the timing of the rise or fall of the output VEN.

In the printer section B, the starting point of main scanning when laser scanning is performed using a rotating polygon mirror is detected by a well-known beam detector (not shown), and the detection output is sent to the sequence control logic section 65 and the beam detection signal BDET. Supplied to each counter, and then on the leader section A side,
The start position of the main scan of the read image is made to match the main scan position of the printer section B side.
Therefore, each counter will be reset by the beam detection signal BDET.

Here, when _{the beam} detection signal BDET from the printer section B is not input, the _φ
This _φX counter 67 is not necessarily necessary when the beam detection signal BDET is obtained from printer section B,
When the beam detection signal BDET cannot be obtained from the printer section B, each of the counters 68, which divide the output of the VEN counter 66 and the oscillator 47 to obtain the transfer clock signal _φ1 , is reset with this synchronization signal _φX . This allows the reader section A to perform main scanning, for example, in a preliminary scan.

The sequence control logic section 65 includes
The above-mentioned output VEN of the _VEN counter 66, output _φ
Generates PRTST etc.

The video enable signal VSEN is a signal indicating an effective image section for one line in the serial image signal sent out from the reader section A.

The vertical synchronization signal VSYNC is a signal representing the leading edge in the sub-scanning direction, and is used to notify the printer section B of the leading edge of the image during reading so that the original image can be copied from the leading edge of the copy paper P. In this device, the VSYNC signal is a signal for driving a resist clutch (not shown).

The print start signal PRTST is used to start preparations for printer section B when making a copy operation, and commands drum rotation, drum potential stabilization, and copy paper feeding to print the image. This is to prepare for transcription.

The printer enable signal PRTEN notifies that the preparation of printer unit B side is completed.
is input from the printer section B to the sequence control logic section 65.

In FIG. 2, the keyboard operation section 70 is equipped with keys for a copy start key, setting the number of copies, setting variable magnification, trimming instructions, and paper size instructions, and operation input using these keys is carried out by the central processing unit 49. The data is stored in RAM in memory 56 via bus 50. This RAM
The contents are read out according to a command from the central processing unit 49 and transferred to the printer section B via the bus 50.

FIG. 3 is a detailed explanatory diagram of the sequence driver section 51. Latch ICL1 for output and input,
Each of L2 and L3 is connected to a bus line 50, and each latch is connected to a control line C.
1, C2, and C3 are connected. The output latch L1 is used to change the rotational speed of the sub-scanning DC motor 52. 51-1 is an oscillator for outputting a pulse signal of a reference frequency, and the output of this oscillator 51-1 is sent to a frequency divider 51-
2 is input. The frequency divider 51-2 determines its frequency division ratio according to the output value from the output latch L1,
Outputs a signal at a predetermined frequency. In the output latch L1, the latch timing of the signal input via the bus 50 is determined by the control line C1.
Selected by a latch signal from.

Further, 52-2 is an encoder for detecting the rotation speed of the motor 52, and its output is inputted to one input terminal of the phase comparator 51-3. A frequency divider 51- is connected to the other input terminal of the phase comparator 51-3.
Since the output of 2 is input, the phase comparator 51-3
compares the frequencies of the signals input to each input terminal, and outputs a pulse signal so that the difference between them is reduced.

This pulse signal is passed through the low pass filter 51-
After the signal is integrated at step 4 and converted to a DC level, it is input to the power amplification section of the motor 52 to rotate the motor 52.

Therefore, the rotation speed of the motor 52 can be changed by changing the frequency division ratio of the frequency divider 51-2. In this example, the oscillator 51-1, frequency divider 51-2, phase comparator 51-3, L.P.F.
51-4 and the like constitute a PLL control circuit.

Output latch L2 turns driver 55 ON/
OFF signal 52-3, motor 52 rotation/stop signal 52-1, motor 52 forward/reverse rotation signal 52-
The latch timing is selected by the latch signal from the control line C2.

The input latch L3 latches the outputs from the sensors OHP and HP, and like the other latches, the latch timing is selected by the latch signal from the control line C3.

An example of changing the image position according to the present invention will be explained using FIG. 4. In this apparatus, the image is moved by switching the scan timing of the reader section A with respect to the registration drive timing of the printer section B.

In FIG. 4, the portion of interest PX of the document GK is moved to a desired position on the copy paper P. In addition, in this device, if the resist clutch is driven when the scanning unit comes to the position of the sensor OHP,
The leading edge of the read image and the leading edge of the transfer paper coincide, and a normal copying operation is performed. The original document GK is A4 or A3 size, and there is a portion of interest PX on the left side, the X direction of the document GK is the sub-scanning direction, and the Y direction is the main scanning direction. The reference point of the document GK is the left edge, which corresponds to the position of the image leading edge sensor OHP of the reader section A.

The target portion PX is moved to a desired position on the A3 size copy paper P, in this example, by 360 mm in the sub-scanning direction and copied. Now, assuming that the copying magnification is equal to the same magnification, and the sub-investigation speed is 180 mm/sec for both the reader and the printer, the time width tp corresponding to the image movement distance of 360 mm is 2 seconds. Therefore, if the scanning unit starts scanning from the position of the sensor OHP 2 seconds after driving the registration clutch, a copy sheet P as shown in FIG. 4 can be obtained. Also, let _t1 be the time it takes the scanning unit to move between the two sensors HP and OHP.

Here, both sensors HP in leader part A
Figure 5 shows the positional relationship of the OHP and OHP in an enlarged manner.
The scanning unit starts scanning from the position of the sensor HP, and reaches a predetermined speed by the time it reaches the position of the image leading edge sensor OHP (while moving by the run-up distance corresponding to the time width _t1 ). In this example 180
Since the document GK is sub-scanned at a sub-scanning speed of mm/sec, the above-mentioned predetermined speed is this value of 180
Equal to mm/sec. However, from the sensor HP to the sensor OHP, the speed changes continuously from a stopped state to a predetermined speed, so from the sensor HP to the sensor OHP
The time it takes to reach this point tends to be uncertain.

Furthermore, when performing continuous copying, the position at which the scanning unit stops relative to the sensor HP during backward scanning is difficult to become constant due to variations in the mass and sliding friction of the scanning unit. Also, when changing the magnification and moving the image as described above, the sub-scanning speed is changed according to the magnification.
The time from sensor HP to sensor OHP is different.

Therefore, in the present invention, in order to accurately measure the arrival time from sensor HP to sensor OHP, a preliminary scan of the original is performed at the same speed as the actual copying speed, and at that time the scanning unit Measure the time from HP to sensor OHP.

If you measure this time, you will know the scanning time _t1 , so after passing the sensor OHP, you can stop the scanning unit immediately and return it to the position of the sensor HP, or you can stop the scanning unit. Alternatively, the width of the document may be scanned instead of the width of the document.

As is clear from the above, in the example of FIG. 4, when moving the part of interest PX, the scanning start time of the scanning unit of the reader section A and the transfer paper of the printer section B are changed by the time t _p - t ₁ = t _X. By creating a difference between the registration drive time and the registration drive time, accurate document movement becomes possible.

This relationship will be explained in more detail using the timing chart shown in FIG.

First, the timing between the reader section A and the printer section B will be explained. The part to be read in the manuscript GK is the part of interest PX shown in Figure 4, so
This is the tip of the manuscript GK. Since the position of the original portion PX is moved and brought to the rear end of the copy paper P in the sub-scanning direction for copying, first a registration signal (VSYNC signal) is sent to the printer section B to start the transfer. do. At this time, leader section A
The side does not yet perform scanning for copying. In other words, no image signal is generated at this time;
It's a blank slate. When the sight drum 13 rotates and the copy paper P is further conveyed, a scanning control signal is output via the bus 50 on the reader section A side to start converting the original image into an electrical signal. Therefore, the video signal VS2 of the leading edge of the document is transferred to the printer section B, and a moving image of the portion of interest PX can be obtained. Incidentally, the scanning control signal is a signal for driving the scanning unit, and corresponds to the signal 52-1 etc. that is output after being latched for output in FIG. 3.

FIG. 6a shows the registration drive signal on the printer section B side, in this example, the VSYNC signal. When this signal rises and becomes an active signal, the registration clutch is driven and the transfer operation is started.
Note that at this preliminary stage, the photosensitive drum 13 is already rotating, the paper feeding operation has been completed, and it is ready to accept image signals, so that the transfer operation as described above can be immediately started.

FIG. 6b shows the scanning control signal on the reader section A side. Here, the movement status of the scanning unit is detected.
Shown with HP and OHP locations.

The time required to move the document portion PX from its original position to a position 360 mm away in the sub-scanning direction on the copy paper _P is the exact time tX.
In determining this time _tX , _tp can be uniquely determined based on the relationship between the scanning speed and the moving position, and is 2 seconds in this example. The accurate time _t1 can be obtained by measuring the travel time of the scanning unit from the sensor HP to the sensor OHP prior to reading the document.

Therefore, in this apparatus, before starting the actual document reading scan, the scanning unit is moved at least from the sensor HP to the sensor OHP at the same speed as the actual reading scan, and time _t1 is measured. Then, a VSYNC signal is sent to the printer section B side to start the transfer operation, and the conveyance of the copy paper P is started. Then, after _t Let it start. Thereby, the portion of interest PX can be accurately moved to a desired position on the copy paper P.

FIG. 7 is a flowchart for moving the image position as described above, and this flowchart is programmed and stored in the ROM in the memory 56. The flowchart in FIG. 7 will be explained using FIGS. 2 and 3. The CPU 49 reads the magnification and image movement distance in the sub-scanning direction specified on the keyboard operation section 70 (steps 1 and 2), and calculates the time t _p corresponding to the image movement distance (step 3). In the example above, the magnification
1.0, and the moving distance is 360 mm, so t _p = 2 sec is obtained.
In step 4, it is determined whether the copy start key has been pressed. If the copy start key is pressed here, the process moves to step 5, where the output value of the output latch L1 is determined and the motor speed is determined. In the above example, the magnification is 1.0, so the motor speed is set so that the speed of the scanning unit is 180 mm/sec. Then, in step 6, the output latch L2 sets the rotational direction of the motor to normal rotation and starts rotation of the motor.

In steps 7 and 8, an internal timer counts the time _t1 until the scanning unit reaches the sensor OHP. After the scanning unit reaches the sensor OHP, the motor is reversed by the output latch L2 in step 9.

If it is determined in step 10 that the scanning unit has reached the position of the sensor HP, the motor is stopped by the output latch L2 in step 11, and the preliminary scan is completed. In step 12, t _X =t _p -t ₁ is calculated to determine the scanning start timing of the scanning unit. In step 13, a command is issued to the sequence control logic section to output the VSYNC signal, and in steps 14 and 15, the scanning start time _tX is counted by an internal timer. When the count of time _t
2, the rotation direction of the motor is set to normal rotation, and the motor is rotated to start reading and scanning the original. If it is determined in step 17 that scanning of the document has been completed, the motor is reversed in step 18 to return the scanning unit to the position of the sensor HP.
When the scanning unit reaches the position of the sensor HP (step 19), the motor is stopped in step 20, and reading and scanning of the document is completed.

In the embodiments of the present invention described above, a case has been described in which a device converts an original image into a digital signal before copying, but even in a conventional analog processing copying device, the registration timing is The present invention can be similarly applied to any device that is configured to freely change the start timing of document scanning. Similar effects can be obtained when doing this.

In the example of document position movement described above, when moving the target part PX of the document to the trailing edge of the copy paper P and copying it, in order to increase the accuracy of determining the movement position, before reading the document image, The arrival time _t1 from the sensor HP of the scanning unit to the sensor OHP is measured, but this means that the target part of the document is located further back than the normal copying position in the sub-scanning direction (in the X direction as shown in Figure 4). ), and in the case of moving the document in the opposite manner, the distance to be moved can be determined based on the time since the scanning unit passes the sensor OHP. There is no need to measure time _t1 .

In this embodiment, a preliminary scan is performed before scanning the original to obtain the time _t1 , but if the start-up characteristics of the motor and the mechanical accuracy of the scanning unit are excellent, it is not necessary to perform a preliminary scan for each reading scan. There is no need to perform a preliminary scan. For example, if a preliminary scan is performed for all copy modes (for example, all copy modes with different magnifications) during factory assembly, and the time t ₁ for each mode is stored in a memory such as RAM, copy efficiency can be increased. can.

Further, movement of the image in the main scanning direction can be easily performed by changing the readout timing from the memories 43 and 44.

Further, in this embodiment, the scanning start timing of the scanning unit is changed in accordance with the measurement time _t1 , but it is also possible to change the output timing of the VSYNC signal.

In other words, even if a reference time is set, the time from this reference time until the scanning unit starts scanning is fixed, and the time from this reference time to the generation of the VSYNC signal is controlled according to the above measurement time _t1 . It's good.

〔effect〕

As described above, according to the present invention, when performing image movement to move the position of an image of a document to be copied onto a recording material, the scanning means is moved at a predetermined speed in the first direction.
The scanning means is moved from the position to at least the second position and the counter is made to count, the scanning means is moved to the first position, the conveying means is started conveying the recording material, and then the recording material is started conveying the recording material according to the count value of the counter. After a period of time, the scanning means is controlled to move from the first position at a predetermined speed, and if the image is not moved, the scanning means is started to move from the first position at a predetermined speed and moved to the second position. When the installed sensor detects the scanning means, the conveying means is controlled to start conveying the recording material, so there is no possibility of variations in the start-up characteristics of the drive motor in the copying device or the mechanical rotating parts and sliding parts of the scanning means. Errors due to friction conditions of the moving parts can be reduced, and the original image can be accurately copied to a desired position on the recording medium regardless of whether the image is moved or not.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the overall configuration of a copying apparatus to which the present invention can be applied, FIG. 2 is a diagram showing the electric circuit of the reader section, FIG. 3 is a detailed circuit diagram of the sequence driver section 51, and FIG. 4 5 is a detailed view of the scanning portion of the reader section, FIGS. 6 a and b are time charts for explaining the operations of the reader section and the printer section, and FIG. 7 is a diagram for explaining document movement according to the present invention. The figure is a control flowchart for document movement. Here, A is an image reading unit (reader unit), 1 is a document table, 2 is a document cover, 3 is a light source for illuminating the document, and 4
is a reflecting mirror, 5 is a mirror unit, 6 is a lens system, 7 is a CCD line sensor, HP is a sensor for detecting the stop position (home position), OHP is a sensor for detecting the leading edge of the image, B is an image forming section (printer section) , 11 is a scanning optical unit, 12 is a reflecting mirror, 13 is a photosensitive drum, 14, 15, and 16 are high-voltage chargers, 17 is a developing device, 18 is a paper feed cassette,
19 is a paper feed register, P is a copy paper, 20 is a paper feed guide plate, 21 is a registration clutch, 41 is a video amplifier, 42 is a binarization circuit, 43 and 44 are memories, 45 is a write address counter, 46
is a read address counter, 47 is an oscillator, 48
is a binary rate multiplier (BRM),
49 is the central processing unit (CPU), 50 is the bus, 51
52 is the sequence driver section, and 52 is the sub-scanning DC.
55 is a fluorescent lamp driver, 60 is a start bit counter, 61 is a flip-flop,
62 is an AND gate, 63 is an OR gate, 64 is an end bit counter, 65 is a sequence control logic section, 66 is a VEN counter, 67
is the _φX counter, 68 is the dividing counter for _φ1 , and 70
is the keyboard operation section.

Claims (1)

[Scope of Claims] 1. A scanning device that starts moving from a first position and scans a document, a conveyance device that conveys a recording material, and an image of the document scanned by the scanning device that is transferred to the document by the conveyance device. a copying means for copying onto a conveyed recording material; a sensor provided at a second position different from the first position on the movement path of the scanning means and detecting the presence or absence of the scanning means; and the scanning means. a counter that counts from the time when the sensor starts moving from the first position until the time when the sensor detects the scanning means; and an image movement that moves the position of the image of the original to be copied onto the recording material. In this case, the scanning means is moved to the first position by moving the scanning means from the first position to at least the second position at a predetermined speed, causing the counter to count, and moving the scanning means to the first position; After a time period corresponding to the count value of the counter after starting conveyance of the recording material, the scanning means is rotated at the predetermined speed.
If the first control is performed to move the image from the first position and the image is not moved, the scanning means is started to move from the first position at a predetermined speed, and when the sensor detects the scanning means, the scanning means is moved from the first position. A copying apparatus comprising: a control unit that performs second control for causing the conveying unit to start conveying the recording material.