JPH01175457A - Copying machine - Google Patents

Abstract

PURPOSE:To execute high speed continuous copying and copying of enlargement, reduction and movement with high accuracy by controlling a starting start position and a starting start timing of a sub-scanning unit by a position profile control. CONSTITUTION:When a copying operation is started, a sub-scanning unit 29 reads white reference data for shading correction at a point A, and thereafter, completes a movement to a point B by a speed profile control until a feed paper sensor 53 detects a print form. Said unit stops at the point B, and thereafter, starts to accelerate in accordance with a position profile control. The sub-scanning unit 29 executes a scan of a document 11 by the position profile control extending from a point C to a point D, and when it reaches the point D, it returns to the point A by the profile control. Therefore, an approach time and an approach distance of the sub-scanning unit can be known exactly, and even at the time of copying of enlargement, reduction, movement, etc., the portion accuracy of a copied image is high.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a copying machine, and more particularly to control of a sub-scanning unit.

2. Description of the Related Art In recent years, copying machines have been required to have higher copying speeds and to have various editing functions, so there has been a demand for higher accuracy in positioning images.

The driving sequence of the sub-scanning unit that mechanically scans the original in a conventional copying machine is that the sub-scanning unit accelerates from the standby position (Bahm position), reaches a constant speed, and continues sub-scanning until it reaches the position where it finishes reading the original. and return to Baume position. For example, even when pre-scanning the original to detect the position of the original or manually inputting the scanning area of the original, the sub-scanning unit starts accelerating from the Baum position, so the time spent sub-scanning outside the original scanning area is It will be wasted. For example, if an A4 document is placed on the document table,
If the sub-scanning unit is placed at a position far from the Baum position, or if a portion of an A3 original is to be trimmed and copied onto A4 paper, the copying machine may be unable to print continuously at a rate of 30 A4 sheets/minute, for example. The copy speed is 1-
This cannot be achieved even though the paper is A4.

Further, when copying by enlarging, reducing, moving, etc., it is necessary to know the acceleration time of the sub-scanning unit, so it is necessary to measure the acceleration time of the sub-scanning unit in advance. (For example, JP-A-5163876 and JP-A-61-45670).

Problems to be Solved by the Invention The problems of conventional copying machines as described above are due to the difficulty in accurately controlling the sub-scanning unit. In other words, the control of the conventional sub-scanning unit is based on the PLL system (i
This is done by oven loop control of l or stepping motor. With these control methods, it is difficult to precisely and flexibly control the sub-scanning unit.

SUMMARY OF THE INVENTION An object of the present invention is to provide a copying machine whose sub-scanning unit can be precisely controlled.

Another object of the present invention is to provide a copying machine that can perform continuous copying at high speed.

Still another object of the present invention is to provide a copying machine that can perform enlargement, reduction, movement copying, etc. with high precision.

Means for Solving the Problems A copying machine according to the present invention includes a document table on which a document is placed, and an image reading means for reading an image on the document on the document table, and a sub-scanning device that scans the document in a sub-scanning direction. unit, printing means for printing the image read by the image reading means on a print sheet, and control means for controlling the operation of the sub-scanning unit by selectively using position profile control and speed profile control.

As one preferable control example, the control means controls the starting position of the sub-scanning unit according to the reading starting position of the document using position profile control.

The copying machine further includes copying mode selection means for selecting a copying mode including at least one of enlarging, reducing, and moving the copied image, and in one preferred control example, the control means selects the reading start position of the document and the selected copying mode. The activation start position and activation start timing of the sub-scanning unit are controlled according to the mode.

The control means includes a drive means for driving the sub-scan unit, a state detection means for detecting the position and speed of the sub-scan unit, a storage means for storing position reference data and speed reference data, and the drive means. position control means forming a position servo loop together with the drive means and the state detection means, speed control means forming a speed servo loop together with the drive means and the state detection means, and a servo loop selection for selecting one of the position servo loop and the speed servo loop. and a central processing unit that selectively controls the position control means and the speed control means by selectively using the position reference data and the speed reference data, respectively.

The control means further includes a storage means for storing data that determines the start position and start timing of the sub-scanning unit, and reads the data from the storage means according to the document reading start position and the copy mode. Controls the start position and start timing of the scanning UNISO 1.

Operation The present invention can precisely and flexibly control the sub-scanning unit 71- with the above-described configuration.

Embodiment A copying machine according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic external view of a digital copying machine.

1 is paper feed power, 2 is document cover, and 3 is ghee.

The operation panel includes a display section, etc., and 4 is a paper discharge tray, which is similar to a copying machine on a boat. 5a.

Reference numeral 5b denotes a coordinate input tablet and pen used when performing editing operations such as trimming.

FIG. 2 is a block diagram showing the internal structure of the copying machine shown in FIG. 1 and the driving portion of the sub-scanning unit.

Place the original 11 on the transparent original table 14, and close the original cover 2.
The original 11 is pressed against the original platen 14 by pressing the original 11 onto the original table 14. A light source 15 illuminates the surface of the document, and a rod lens array 16 focuses the light reflected from the document onto a line image sensor 28 . The image sensor 2B outputs an electrical signal 30 according to the amount of light reflected from the original 11. The image signal processing unit 21 receives the output 30 of the image sensor 28 and performs A/D conversion.

The video data 31 is sent to the printer section 23 after signal processing such as shading correction, gamma correction, and pseudo halftone processing.
Output.

Light source 15. Rod lens array 16. Image sensor 2
8, the sub-scanning unit 29 includes a wire 38, a pulley 1
The speed of the motor 19, which is driven in the direction of the arrow S via the sub-scanning unit 29 to perform sub-scanning of the original, is obtained based on the output of the pulse encoder 20. The white reference plate 13 is
Sensitivity variations for each element of the image sensor 28 and light source 15
This is to perform shading correction to correct uneven illuminance.

The document position detection circuit 22 detects the position of the document on the document table from data 32 including density output from the image signal processing section 21. The position of the original is detected by pre-scanning the original.

The sub-scanning unit control unit 24 receives the output signal 36 of the pulse encoder 20 connected to the motor 19, copy mode selection data 34 from the copy mode selection key 27 on the operation panel 3, and coordinate instructions from the coordinate input table recorder 5a. Using the data 35 and document position data 33 from the document position detection circuit 22, I/O is applied to the motor driver 25.
The sub-scanning unit 29 is controlled by outputting a torque command 37. The copy mode selection data 34 includes the same size, enlargement, reduction,
Copy mode instruction data such as movement and continuous copying, enlargement ratio,
Contains instruction data such as reduction ratio.

When the power is turned on, the sub-scanning unit 29 is driven in the direction of the origin sensor 18. When the origin sensor 18 detects the sub-scanning unit 29, it outputs a detection signal 136, and a motor position counter (described later) included in the sub-scanning unit control unit 24 outputs a detection signal 136.
Reset.

FIG. 3 is a schematic diagram of the printer section 23. As shown in FIG.

The print I paper 51 stored in the paper feed cassette 1 is guided between a pair of guide plates 54 by a paper feed roller 52.
The photosensitive drum 68 is brought into contact with the pair of rollers 55 . On the other hand, the scanner motor 66 rotates the horigon mirror 65. The polygon mirror 65 reflects the laser beam from the semiconductor laser 67 and scans the photoreceptor drum 68.

The photosensitive drum 68 rotates in the direction of arrow R. Charger 57
charges the photosensitive drum 68. Laser drive circuit 64
modulates the output laser beam of the semiconductor laser 67 with the video data 31. The modulated laser beam forms a latent image on photoreceptor drum 68.

A developing device 56 develops the latent image on the photosensitive drum 68 with toner. The transfer charger 59 transfers the toner on the photosensitive drum 68 onto the print paper. The peeling charger 60 peels the print paper from the photosensitive drum 68. The transport heald 61 transports the print paper peeled from the photoreceptor drum 68 to the fixing device 62 . The fixing device 62 fixes the toner transferred onto the print paper onto the print paper. The print paper is discharged onto the paper discharge plate 4 by a pair of paper discharge rollers 63. Paper feed sensor 53 detects that print paper is fed, and outputs a paper feed detection signal 135. Such a printer unit is well known as a laser beam printer using an electrophotographic process.

FIG. 4 is a block diagram of the sub-scanning Uniso I control section 24 shown in FIG. Central processing unit (CPU)
sing unit) 101 is a data bus 102
via I10 boat 103, read only memory (ROM)
-1~R0M-5,118,119,120,121
, 122. CPU10I is ROM-1
~Using the table data stored in ROM-5,
The position where the sub-scanning unit 29 should exist (hereinafter referred to as position reference), the speed it should have (hereinafter referred to as speed reference), etc. are calculated. ROM-1-ROM
The table data stored in -5 will be described in detail later.

Encoder circuit 114 receives two signals from pulse encoder 20.
Direction discrimination is performed using the phase signal 36 as input, and forward and reverse rotation pulses 115 and 116 of the motor 19 are generated. The up/down counter 117 is a reversible counter that uses the forward and reverse pulses 115 and 116 output from the encoder circuit 114 as clock input. The up/down counter 117 is activated by the origin detection signal 136 from the origin sensor 18.
~ will be done. The CPU 10I reads the count output data of the up/down counter via the I10 port 103 and learns the current position of the sub-scanning unit 29. Furthermore, CP
Ul0I accesses copy mode selection data 34 from the copy mode selection key 27, coordinate instruction data 35 from the coordinate input tab 5a, and document position data 33 from the document position detection circuit 22 via the I10 baud i 103. can. A paper feed detection signal 135 from the paper feed sensor 53,
Input to CPUl0I as an interrupt signal.

CPUI O1, D/A converter 104. Leet/lag filter 105. Amplifier 106. Low pass filter 1
07. Motor driver 25. Motor 19. Pulse encoder 20. An encoder circuit 114 and an up/down counter 117 constitute a position servo loop that performs position control. CPU101, D/A converter 104. Amplifier 109°Low pass filter 110. Motor driver 25° motor 19. Pulse encoder 20. Encoder circuit 114. An up/down counter 117 constitutes a speed servo loop that performs speed control. Selector 108
selects either the position servo loop or the velocity servo loop.

The operation will be described when controlling the position of the sub-scanning unit 29. The D/A converter 104 inputs 8-bit data and outputs [■] when the data is "80° 11".The interrupt pulse generation circuit 112 generates a periodic interrupt pulse 134 and sends it to the CPUI O1.
01 writes data corresponding to the difference between the calculated position reference and the position data of the sub-scanning unit 29 to the D/A converter 104 via the I10 port 103 for each interrupt of the interrupt pulse 134, and processes the data corresponding to the data. The voltage is output to the D/A converter 104.

The lead/lag filter 105 is the D/A converter 104
Phase compensation is performed to stabilize the position servo loop for the output voltage. Amplifier 106 amplifies the output of lead/lag filter 105 and determines the feed hack gain of the position servo loop. Low-pass filter 107 removes high frequency components contained in the output of amplifier 1.06.

The selector 108 selects the low-pass filter 10 based on the position control/speed control switching signal 111 output from the CPUI O1.
7 and outputs the motor torque command 37 to the morph driver 25. Therefore, sub-scanning unit 2
9 is always controlled so that the position reference calculated by CPUI O1 and the position of sub-scanning unit 29 are equal.

Next, the operation when controlling the speed of the sub-scanning unit 29 will be described. CPU10,1 is D/A converter 10
4, data corresponding to the difference between the calculated speed reference and the speed of the sub-scanning unit 29 is written every time the interrupt pulse 134 occurs. The speed of the sub-scanning unit 29 is obtained by determining the distance that the sub-scanning unit 29 moves in a certain period of time. An amplifier 109 amplifies the output voltage of the D/A converter 104 and determines the foot hacking curve of the speed servo loop. Low-pass filter 110 is a noise filter. During speed control, the position control/speed control switching signal 111 controls the selector 108 to select the output 138 of the low-pass filter 110 and output the motor torque command 37.

Figure 5 shows one-domain/lag filter 10 using an operational amplifier.
5 is a circuit diagram. FIG. 6 is a Bode diagram of a beam-driving/lag filter, in which the phase of the position servo loop is compensated by advancing the phase at a frequency fn.

The document position detection circuit 22 will be explained using FIGS. 7 and 8. FIG. 7 is a block diagram of the original position detection circuit 22, and FIG. 8 is an operation timing chart 1- of the original position detection circuit 22. When detecting the document position, the color of the document side of the document table cover 2 is set to black. By pre-scanning the entire reading area once, both edges of the document in the main scanning direction are detected. The operation of the document position detection circuit 22 will be explained below. The density data 151 included in the data 32 from the image signal processing section 21 is 8-bit data, and is ``FF'H'' for black and 0''H for white.

The concentration data 151 is the clock 16 included in the data 32.
It is synchronized with 4. A slice level generation circuit 169 generates 8-bit data 152 (hereinafter referred to as slice level data) corresponding to an intermediate density between the background density of the original and the density on the original side of the original table. The slice level data may be output from the CPU.

Comparator 153 is fm degree data (DDATA) 1
51 and slice level data 152, and outputs a comparison signal (COMP). Inverter 162
inverts clock 164. D flip flop 15
4 connects the output COMP of the comparator 153 to the inverter 1
It latches with the output signal of 62 and outputs the signal LCOMP. Line enable signal (LEN
BL) 165 is a signal indicating the effective range of one line of DDATA 151.

Counter 161 clears LENBL 165, uses clock 164 as clock input, and uses DDATA151 as clock input.
Outputs the coordinates of the position in the main scanning direction. A line synchronization signal (LSYNC) 166 included in the data 32 is a main scanning trigger signal.

The inverter 155 is the output L of the D flip-flop 154.
Invert COMP. The D flip-flop 156 uses the output of the inverter 155 as a clock input, and the D input is the old G
With H level test, LSYNC: 166 is used as clear input. The latch 157 uses the output of the D flip-flop 156 as a launch clock, launches the output of the counter 161, and outputs data L1. The latch 158 uses the output LCOMP of the D flip-flop 154 as a launch clock, latches the output of the counter 161, and outputs data L2.

Inverter 163 inverts LENBL I65.

The latch 159 clocks the output of the inverter 163, latches the output L1 of the launch 157, and data L3.
Outputs 167. The latch 160 is the inverter 163
The output of latch 158 is set as clock power, and the output of latch 158 is I, 2.
and outputs data L4168. latch 15
9.160 output 167.168 is data 33 and I1
0 port 103 by CPUI O1.

Next, the meaning of each signal of the document position detection circuit 22 will be explained using FIG. The concentration signal DDATA 151 is synchronized with the clock 164. Line enable signal LEN
BL 165 is an active high signal indicating the valid range of DDAT8 151 and is synchronized with clock 164. When the signal LENBL 165 is non-aclined (LO level), the current state of DDATA 151 is FF'H. The output COMP of the comparator 153 is clocked 1
The signal latched with the inverted signal of 64 is LCOMP.

Signal LENBL 165 is active (IIIGII
Ll is the data obtained by latching the output C0UNT of the counter 161 at the first falling edge of LCOMP after reaching the level (Level). L3 167 is data obtained by launching data L1 at the falling edge of LENBL. Signal L
L2 is the data latched from COUNT at the 7th stage of COMP's rise. L4168 is data obtained by latching data L2 at the falling edge of LENBL. That is, after one line of scanning is completed, if there is no document within one scanned line, the data L2 and L3 are 0. If there is a document, the coordinates of the edge portion of the document in the main scanning direction are data L2 and L4.

CPUI, 01 is data L2. By reading the position data of L4 and the sub-scanning unit 29 at any time during bliscanning, the coordinates of the edge of the document can be known.

The CPU displays a warning when the original is placed diagonally on the operation panel 3, and detects incorrect detection of the main scanning direction coordinates of the original edge due to dirt on the original platen 14 and original platen cover 2.
It can be removed by the O1 program.

ROM-1118, ROM-2119, ROM in Figure 4
The contents of the data stored in -3120 will be explained using FIG.

ROM-1118 stores a data table of acceleration position profile data of the sub-scanning unit. Let P be the moving distance of the sub-scanning unit corresponding to one focus of the up-down counter 117.

When the interrupt frequency of the interrupt pulse 134 to CPUI 01 is f (llz), the nth acceleration position profile data A (n) is A(n)-1NT(!4-a(1/f-n) 21/P)
Find it with

Here, INT() is an integerization function, and a is acceleration.

FIG. 9 (al represents the data arrangement of the data table of ROM-1. 1111
a(al) shows a graph of data in the data table of ROM-1.

ROM-2119 stores the address of ROM-1 where position data corresponding to the position at which acceleration is to be ended is stored. When performing enlargement or reduction copying in the sub-scanning direction, the enlargement ratio m
[%] can be expressed as m=Vp/VsXIoo C%], where the speed Vs of the sub-scanning unit 29 and the blinking process speed Vp are taken as m=Vp/VsXIoo C%.

That is, the sub-scan unit 7) 29 has Vs=Vp/mxlo
After accelerating to a speed of o based on the acceleration position profile data of ROM-1, the controller shifts to constant speed position profile control. The address of ROM-1118 where acceleration position profile control is to be terminated is set according to the enlargement ratio in the sub-scanning direction.
Store it in OM-2119. Data Z in the data table of ROM-2 (m+ is Zhl=INT(2X V p/(a Hm) + 1
00).

If the magnification ratio actually used is in the range of 50% to 400%, Zfm+(50≦m≦400) is valid data. FIG. 9 (bl shows the data arrangement of the data table of ROM-2. Z (m) β is the lower hide of z (m+), and Z fml u is the upper byte.

The ROM-3120 stores the run-up distance from when the sub-scanning unit 29 accelerates from a stopped state until it reaches a constant speed as table data. As described above, since the document scanning speed of the sub-scanning unit 29 changes depending on the magnification mark in the sub-scanning direction, the scanning speed of the sub-scanning unit 29 changes depending on the enlargement rate in the sub-scanning direction.
The acceleration distance changes. The run-up distance is the sum of the acceleration distance for accelerating using the acceleration position profile data and the settling distance from the end of acceleration until settling to a constant speed.

Run-up distance table data D (m+ is obtained by D'(ml-A (!42hl) +m ·b).

Here m-b is the settling distance and b is a constant. 9th
Figure (C1 shows the arrangement of table data in ROM-3.

D (ml 1 is D (ml lower byte D (ml
u is the upper hide.

Before explaining the data contents of ROM-4121, a method of moving copying in the sub-scanning direction will be explained.

First, the operation sequence of the sub-scanning unit 29 when copying the original 11 shown in FIG. 12(a) at the same position as (bl) will be explained using FIG. 13 and FIG. Arrow S indicates the direction of sub-scanning.
FIG. 3 is a diagram showing the positional relationship between the sub-scanning unit 29 and the document 11.

The home position A is the position where the sub-scanning unit 29 is stopped when the copying machine is not performing a copying operation. The run-up start position point B of the sub-scanning unit is a position on the side of point A by a run-up distance X1 from the document reading start position C. Point D is the original reading end position.

FIG. 14 is an operation sequence diagram when copying without moving the original. When a copying operation is not being performed, the sub-scanning unit is stopped at Baum position A. When the copying operation is started, the CPU 101 outputs a print paper feeding command 170 (FIG. 2) to the printer section 23. On the other hand, after reading the white reference data for shading correction at point A, the sub-scanning unit 29 completes the movement to point B under speed profile control before the paper feed sensor 53 detects print paper. TOsec after the paper feed sensor 53 detects the print paper, the sub-scanning unit 29 must reach point C and output an image signal to the printer section 23. The time required for the sub-scanning unit 29 to accelerate is Tl5ec
If so, the sub-scanning unit 29 is connected to the paper feed sensor 53.
After detecting the print paper and stopping at point B for TOTlsec, acceleration is started according to the position profile control. The sub-scanning unit 29 scans the original 11 from point C to point D under position profile control, and when it reaches point D, returns to point A under speed profile control.

Next, the operation sequence of the sub-scanning unit 29 when copying is performed by moving the sub-scanning unit 29 as shown in Fig. 12 (C) will be explained using Fig. 15. The starting position is point E. Point E is a position on the side of point A by an approach distance of X2 of the sub-scanning unit from point F. In other words, by moving the document reading start position from point B to point E, it is possible to move the document reading start position from point B to point E. Performs movement copying in the opposite direction.

Next, the operation sequence of the sub-scanning unit 29 when performing moving copying as shown in FIG. 12 (al to fd+) will be explained with reference to FIG. , the time it takes for the sub-scanning unit 29 to reach point C is TO + T2. When copying by moving the document by a distance in the sub-scanning direction, move copying is performed by setting T, , = L/Vp. I do.

Here, the data contents of RCIM-4121 will be explained. Since the run-up time Tl changes depending on the magnification ratio in the sub-scanning direction, data representing Tf)-TI is stored in the ROM-4 in advance as table data for the magnification ratio. The data is (TO-TI) fc, and the number of interrupts to the CPU by the interrupt pulse 139 of frequency fc generated by the time measurement interrupt pulse generation circuit 113 is counted. If the magnification rate in the sub-scanning direction is m%, the table data W (ml) of the ROM-4121 is Wfml=INT ((
IAZ (ml ・1/f+m-b/V s ) fc)
It can be found by

However, Vs=Vp/mX, 100 The interrupt count value of frequency fc corresponding to T2 is T2・
Since it is determined by fc, depending on the moving distance of the moving copy,
CPUl0I can calculate the interrupt count value that determines the time during which the CPU is stopped at point B. Figure 10 (R in al, OM-4
Shows the arrangement of table data. W (min is W+ml
is the 7th high of w h+ 1-1W +ml u is the upper hide.

The data contents of Rot-5122 will be explained. R.O.
Data M-5 stores speed profile data used when moving the sub-scanning unit 29 from a certain position to a target position heated to a certain degree at high speed. That is, it is table data of a speed reference corresponding to the distance between the position of the sub-scanning unit 29 and the target position. At this time, the control method of the sub-scanning unit 29 is switched to speed control.

The speed ■ of the sub-scanning unit 29 is the distance D=j that the sub-scanning unit 29 moves in a time of ixl/f (i is an integer constant).
Obtained from XP (j is an integer). That is, V = (j X P ) / (i X 1 / f
) Speed reference table data V (n+ is determined by f.

Here, the value '80'H is the D/A converter 104104 (
Fi's OCV) offset data, a+ is acceleration. Figure 10 (bl shows the arrangement of the table data of ROM-5. Figure 11 (bl shows the graph of the table data of ROM-5).

Next, the driving sequence of the sub-scanning unit 29 when copying will be explained, focusing on the cOU 101 program flow. When the power is turned on, the CPU 101 writes "70'H" to the D/A converter 104. Since the D/A converter 104 outputs a negative voltage, the motor driver 25
The Herc command becomes negative, and the sub-scanning unit 29 moves in the direction of the origin sensor 18. When the origin sensor 18 detects the sub-scan unit 29, a counter 117 that counts the positions of the sub-scan units 1 to 29 is cleared. After clearing the counter 117, the selector 108 is switched to select the speed control loop. Letting dl be the difference between the Baume position and the position of the sub-scanning unit 1-29, it is obtained by retrieving data V(di) from ROM-5 as a speed reference. Calculate the difference between the speed reference and the speed of the sub-scan unit until it comes near the Baum position of the sub-scan unit.
/A converter 104. In such speed profile control, the sub-scanning unit moves at high speed when the target position and the sub-scanning unit are 29 distance apart, and decelerates as the target position approaches. When the sub-scanning unit moves sufficiently close to the home position, the selector 108 is switched to select the position control loop. Until a copy request is received from the operation panel, the position reference is used as the home position, and the difference between the position reference and the position of the sub-scanning unit is output to the D/A converter 104.

In the position control, the sub-scanning unit is controlled to stop at the position of the position reference.

When there is a copy request, a paper feeding command is output to the printer 23, switching to speed control, and speed profile control of the sub-scanning unit 29 is performed. The target position at this time is a position obtained by subtracting the run-up distance obtained from the table data of ROM-3 from the leading position of the original or the original reading start position input from the coordinate input tablet. This position is the standby position. Position control is performed at the standby position to stop the sub-scanning unit 71. TO using table data of ROM-4
-Tl is obtained, the paper feed sensor 53 detects the print paper, and after TO-Tl, the sub-scanning unit 29 starts accelerating. At this time, the position reference is obtained by applying Atn+ to the standby position using table data in ROM-1. n is incremented every time an interrupt of frequency f occurs.

Position control is performed so that the position of the sub-scanning unit 29 is equal to the position reference. Acceleration is terminated using table data in ROM-2, and constant speed position profile control is performed. The position reference at this time is performed by incrementing the position reference for each interrupt. By changing the 7 wave numbers for interruption, the speed at constant speed can be changed according to the magnification ratio. When the sub-scanning unit 29 reaches the document reading end position, it switches to speed control, sets the target position to the home position, performs speed profile control, and then performs position control at the Ho 1 position.

When copying multiple sheets continuously, set the target position to the standby position,
After performing speed profile control, position control is performed at the standby position. When performing a plurality of copies, the sub-scanning unit does not return to the home position each time, so the sequence operation time of the sub-scanning unit required for one sub-scanning is shortened, and the copying speed can be made faster than before.

In addition, since the position profile control of the sub-scanning unit is performed, the run-up time and run-up distance of the sub-scan unit can be accurately known, so the position accuracy of the copied image is high even when copying such as enlarging or reducing one movement. . Furthermore, when moving the sub-scan unit 1 to a target position that is a certain distance away from a certain position, speed profile control is performed, so the torque of the motor can be used to the maximum and it is possible to move at high speed.

Although the above embodiments have been described with respect to a digital copying machine using an image sensor, similar effects can be obtained with an analog copying machine.

Effects of the invention By controlling the start position and start timing of the sub-scanning unit using position profile control, high-speed continuous copying and high-precision enlargement and reduction are possible.

Mobile copying is possible.

[Brief explanation of the drawing]

FIG. 1 is an external view of a copying machine according to an embodiment of the present invention, FIG. 2 is a schematic block diagram showing the internal configuration of the copying machine of FIG. 1, and FIG.
The figure is a schematic configuration diagram showing the internal configuration of the printer section in Figure 2.
Fig. 4 is an internal block diagram of the sub-scanning UNISO 1 control section in Fig. 2, Fig. 5 is a circuit diagram showing an example of the glue/lag filter in Fig. 4, and Fig. 6 is a circuit diagram of the filter in Fig. 5. 7 is an internal block diagram of the document position detection circuit shown in FIG. 2, FIG. 8 is an operation timing chart of the circuit shown in FIG. 7, and FIG. ROM-], ROM-2 and ROM-3 in Figure 10 +a+, (b+ is a memory layout diagram showing the data tables of ROM-4 and ROM-5 in Figure 2, respectively, FIG. 11(a). (b+ is a graph showing the data of the data tables of ROM-1 and ROM-5, respectively; FIG. 12 is a relational diagram showing the positional relationship between the original document and the copied image to explain moving copying; Fig. 13 is a side view showing the positional relationship between the original and the sub-scanning unit 1-, Figs. 14 and 15. Fig. 16 is a sequence diagram showing the operation sequence of the sub-scanning unit 1-.29. ... Sub-scanning unit, 20 ... Encoder, 19 ... Motor, 105 ...
・Lead-lag filter, 108...Selector,
22... Original position detection circuit, 23...
Printer section.゛Name of agent Patent attorney Toshio Nakao Figure 9 (α) To goh-4 2 or misfortune 7 yen (b)
CC) P, OM -2g included-
3 Fig. 10 (C2・nF?, OI'Vl-ushiryoF response (b) ) < 0 questions - 5 Fig. 11 (a) (b) Fig. 12 (Cl3 f (bn (C) ( d]

Claims (7)

[Claims] (1) A document table on which the document is placed, a sub-scanning unit that includes an image reading means to read the image on the document and scans the document on the document table, and prints the image read by the image reading device on print paper. A copying machine comprising a printing means and a control means for controlling the operation of a sub-scanning unit by selectively using position profile control and speed profile control. (2) The control means controls the activation start position of the sub-scanning unit according to the document reading start position.
Copying machines listed in ). (3) It further includes copy mode selection means for selecting a copy mode including at least one of enlargement, reduction, and movement of the copy image, and the control means controls the sub-scanning unit according to the reading start position of the document and the selected copy mode. Claim No. 1 (1) for controlling the starting start position and starting timing of the
Copying machines listed in ). (4) The control means includes a storage means that stores data that determines the start position and start timing of the scanning unit, reads out the stored data in accordance with the start position of reading the document, and sets the start position and start timing of the sub-scanning unit. A copying machine according to claim (1), which controls timing. (5) A copy mode selection means is provided for selecting a copy mode including at least one of enlargement, reduction, and movement of the copy image, and the control means has a memory storing data that determines the start position and start timing of the sub-scanning unit. The copying apparatus according to claim 1, further comprising means for reading stored data according to a reading start position of a document and a selected copying mode to control a start start position and start timing of a sub-scanning unit. Machine. (6) The control means includes a drive means for driving the sub-scanning unit, a state detection means for detecting the position and speed of the sub-scanning unit, a storage means for storing position reference data and speed reference data, and a drive means. A position control means that forms a position servo loop together with the state detection means, a speed control means that forms a speed servo loop together with the drive means and the state detection means, and a servo loop selection means that selects either the position servo loop or the speed servo loop. Claim (1) comprises a central processing unit that selectively controls the position control means and the speed control means, respectively, by selectively using the position reference data and speed reference data stored in the storage means. Copying machine mentioned. (7) The control means includes a position control means for controlling the position profile of the sub-scanning unit, a speed control means for controlling the speed profile of the sub-scanning unit, and a position control means and a speed control means are selected according to the operating state of the sub-scanning unit. A copying machine according to claim (1), comprising control selection means for selectively switching.