JPS58195836A - Controller for scanning of document - Google Patents

Abstract

PURPOSE:To control inversion adequately in a min. time and to move a scanning system and a photoreceptor relatively with ease and high accuracy, by determining the inversion position for scanning determined beforehand in accordance with the size of a cassette and a variable magnification. CONSTITUTION:A motor M2 is run forward with a DC amplifier 34 and transistors (TRs) 35-1, 35-2 by the H signal of the forward signal FAW from a microcomputer 30, whereby scanning is accomplished. In the stage of changing a magnification, a CV37 divides down the pulse train E1 from an encoder 36 according to the data m1 on the frequency dividing ratio from the microcomputer 30 and converts the same to a pulse train E2 of the same frequency as a clock frequency CLK. A PLL32 compares the E2 and the CLK, outputs a voltage and controls the speed of the motor M2 with a DC amplifier 34. A main motor M1 is controlled similarly. When the FAW goes to an L and a backward signal BAW to an H according to the size of the cassette and the m1, the TRs 35-1, 35-2 turn on and the motor M2 is run backward, whereby the scanning system and the photoreceptor are moved relatively with high accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION Conventionally, only 1-size copying was possible.Copying 4! In order to determine the scan length for scanning a document, a position detector for determining the reversal position according to the size of the transfer sheet is provided in the optical system device in which the 1-movement optical system scans.

For example, transfer paper size B5゜4. B4. A detector for the inverted position of the optical system is installed according to each size of M3. It is configured to reverse control the optical system when the measurement is made.In addition, in a copying machine capable of variable magnification copying, the variable magnification is reduced from M3 size to M34 size, M3-!#
-Items that can only be copied at a predetermined magnification ratio such that the size is reduced from an image to a four-biz size are common.
Therefore, the scan length of the optical system could be determined relatively easily. For example, the magnification ratio ranges from M3 size to JB.
In the case of size reduction, a detector for the reversal position of the M3 size (therefore configured to control the scan length of the optical system) is used.

Furthermore, in a copying machine capable of stepless variable magnification, the variable magnification ratio can be set freely, making it extremely difficult to determine the scan length of the optical system.

A simple control method is to perform maximum scanning regardless of the magnification ratio or transfer paper size, but it is not practical as the copying speed is a matter of chance.

In addition, in a copying machine capable of stepless magnification, the optical system,
Since the speed of the reciprocating means for the document ring is adjusted steplessly, it is difficult to synchronize the speed with the overall speed of the copying machine.

The present invention eliminates the above-mentioned drawbacks, and enables the reversal control of the reciprocating means for document scanning during stepless variable magnification to be performed appropriately and in the minimum time. This allows the relative movement of the system and photoreceptor to be performed with high precision using a simple method.

Figure 1 is a sectional view of a copying machine cabinet to which the present invention can be applied.
1 is a photosensitive drum, 2 is a primary band container, 3 is a #i developer, 4 is a
5 is a transfer charger, 5 is a cleaner, 6 is a paper feed roller, and 7 is a fixing roller, which performs a well-known electrophotographic process to form a transfer paper image on the transfer paper P. 8 #i Lamp for exposing original horizontal 9, 10 to 13 are mirrors, 14 is lens 1
0' to 11' are the mirror positions at the end of the maximum scan, 13
', 14' is the mirror lens position during zooming, Ml is the main motor that drives each roller 6.7 of the drum 11, a scanning motor that reciprocates 8.10.11 as the MtFi scanning thread, and 13 is the mirror 13. , are position motors that determine the position of the lens 14, and each motor consists of a D-ro servo. 8°10 and 1
1 moves forward in the direction of the arrow at a speed ratio of 1:0.5, exposes and scans the document, and forms an IK image on the drum.

15 is a microswitch that detects the size of the sheet cassette 16, and 17 is a microswitch that indicates the home position Wt<start position of scanning #J original system.

@Figure 2 is the operation unit, 2o is a numeric keypad that manually inputs the copy number and magnification as binary data, and 21 is a function key 122q that allows data on the numeric keypad 20 to be entered as the copy number and displayed on the display 23. a key to input the magnification and display it on the display 24;
25 is a key for manually issuing a cohesive start command. For example, if you turn on key -22 and input the numeric keypad 50, it means 50% reduction and O"50 is displayed on the display 24, and when you input 150, it means 150%, that is, 50% enlargement, and the display 2
Display 15'o on 4. In either case, the original is copied in both the vertical and horizontal directions, as well as its magnification.

FIG. 3 shows an example of a control circuit diagram, and 30 is a microcomputer, which has a ROM for storing a program as shown in FIG. 4 at 70-. 31 is a clock pulse generator indicated by CItP in the time chart of FIG.
2 is the well-known PLL process, 0.33 is the Lohas filter, 34
is a DO amplifier, 35 is a circuit that switches the rotational direction of motor M2, 36 is a well-known encoder that detects the speed of the motor, and 7 is an otosensor that senses the hole in the perforated disc rotating on the shaft of motor M. Consisting of 37 is Do motor 4
A divider for determining the speed of the encoder 36 divides the frequency of the output signal of the encoder 36 to 4 and inputs the result to the PLL. The PLL compares the phases of 4 and the clock OLP, and calculates the difference [according to #
Take the output V as shown in Figure 15. This allows the speed of M2 to be maintained constant. The division ratio II+1 of the frequency divider CV is determined by the code output of the microcomputer 30.

In addition, the V icon outputs the optical system scanning forward signal PAN and backward movement signal B to the WVrig1 switching circuit 35, and the DO mode 1Mt.
By switching between forward and reverse, you can switch between backward and forward motion. 38 is the lens position 1h motor, which drives the DO
It is controlled by the output PM from the computer. 39 is an encoder similar to 36 for determining the lens position. 31a*32a related to %M1 related to main motor
t33m, 34m, 36at3 legs are each running -? 3 related to the survey 1.32.33,34,36,3? The same clock pulse generator, PLI circuit, low pass filter, DC amplifier, encoder, and divider are used.

The speed of M is kept constant from that of K.

Further, the microcomputer outputs the frequency division rule code data and rotational drive signal MM. 40 to 42 fi buffer amplifiers, and 43 an inverter amplifier.

In this example, the basic pulse f0 of the scanning motor town and the basic pulse f'6 of the mage motor M are different in circumference U &. Good image quality at the same magnification can be maintained even if the scanning system 1 and the drum thread do not match exactly. If the basic pulses have the same frequency, the diameter of the pulley and the number of stages of the head.

Unless the rotational speed and torque of the rotor are made to match each other, a strictly correct 1-1 magnification image cannot be obtained, and matching K is extremely difficult in terms of design. That is, it has been found that it is advisable to design the pulse sources 31, 31& to have different frequencies so that the resulting velocity tubes match the results.

The operation keys in Figure 2 are based on the well-known 7-trix method on the microcomputer 3.
0, home switch 17, size switch 1
5 is also input.

First, with reference to Figure 5, the main motor, j! The maintenance control of the scanning motor speed will be explained using the scanning motor M as an example. Signal I
The high level of the signal W activates the DO amplifier 34, turning on the transistor 35-1 and turning on the transistor 35-2. 35-1. Current flows through the motor 35-2, causing the motor to rotate in the normal direction and scanning. The encoder 36 generates a pulse having the same frequency as the clock pulse OLK that drives the motor M during rotation of the motor M.

If the frequency division ratio 1111 is 1, then R is equal, E is compared with the phase of CLK, and the motor speed is indirectly determined. Since the phases of E and OL are equal, there is no change in the ten-man power of the worker corresponding to the clock OLK. Therefore, the supply current to the town is varied and the motor speed is also constant. Motor M.

When becomes slow, m becomes like the fifth factor (&). PLL
compares that - with OLE, and outputs the pulse of NOILEBE NK repeating vt''.Therefore, in the filter 33, the pulse advances slightly :f,'IjL.As a result, D
The input voltage of o amplifier 54 increases, thus increasing the current to motor M, so as to increase the speed of the motor. (Q
) When the output of the encoder 36 matches OLK, the output V of (a) is stopped as described above. On the other hand, when the speed slows down, the PLL outputs a low level output V as shown in FIG. 5 (0). Therefore, the charge after the low-pass filter edge is slightly discharged. So DC! The input terminal of the amplifier goes down, which causes the speed of motor M to go down.Motor M! The current to the current decreases. Encoder output is 01
The operation continues until the phase becomes equal to the phase of 1. In this way, when the motor MFt becomes different from the 0L1-speed, the speed is not restored and machine control is performed to maintain it.

Incidentally, the speed of the motor Mt may be set to 1/2°, etc. depending on the magnification. In that case, divide the frequency by 2 each,
l/2 (assuming the main motor is constant).

The motor can be rotated at the desired speed, and in that state, the above-mentioned return and 111 hold control is performed.In other words, the encoder is supplied with frequency division ratio data from the microcomputer according to the division ratio set by the microcomputer. The pulse train from 36 is frequency-divided and converted into a pulse train of the same frequency as the clock OLP. Therefore, the input voltage of the DO amplifier 34 is determined by the output of the P output so that the pulse train from the encoder 36 is maintained at a frequency that is 1/2 or twice the frequency of the clock 0iaP.

A similar control method is used for the main motor.

In any case, the output frequencies of the clock generators 31 and 31m can be changed depending on the frequency division ratio.

Next, the forward and reverse rotation of the motor will be explained. Advance signal PA
When W becomes low level, transistor 35-1゜35-
2 is off state MK 9, forward rotation stops. Reverse signal Bmu W
When becomes high level, transistor 35-3.35-4
is turned on9, and the motor reverses. From then on, the scanning optical system performs a backward movement process. During reverse rotation, the speed is the same as that during forward rotation (preferably, No. 2 V is applied to the motor circuit. Therefore, high-speed return for backward movement is possible independently of the speed detection circuit).

Next, scanning control during stepless magnification will be explained with reference to FIG. 4. When the device's power switch is turned on, the microcontroller executes a key entry routine. First, the variable key grave,
When the normal key N is turned on, the data is stored in the count area of the RAM as being for the number of copies, and the number is displayed on the display 23 (2). Subsequently, the division ratio data m1 is output as 1 (equal magnification) of 100≦ (3), and at the same time, 100 is displayed on the display 1!24. Next, the state of the cassette switch 15 is read and it is determined whether the cassette size is M4 or not.
M scanning timer area tIK! Store h4 (5)
. TA4 corresponds to the time it takes for the motor to scan 4 minutes of the document. When it's time 4 - when it's time 3! ,, is stored in the t-timer area t1 (6).

Next, the copy key input judgment (7) turns on the main motor M1 by turning on the cohi key, and the motor is set at a speed corresponding to the clock pulse that rotates the drum and other parts! rotates and scans. Then t corresponding to the scanning stroke.

Does it mean that it has passed or not? Cut the system W, output MAY, and switch from forward to reverse (1110
In the case of a variable magnification key, the data read from the numeric keypad is stored in the RAjl iC variable magnification 9A as magnification data MD. From this data MD, the frequency division ratio l111 is converted into 2 times when the input is 50% and outputted α4, and at the same time, the magnification is displayed on the display 24.

Next, the cassette size is determined as in step 4, σ9, and an appropriate scanning distance is calculated for that size sheet. That is, M4
Then, calculate the A4L by multiplying the A4 sheet length M41 by (1/wD) (Leo") 195053, the distance will be doubled.Then, the time required for this person to move 4L is calculated by multiplying the length of the A4 sheet by (1/wD). Calculate the speed from the timer and store it as -1 in the timer area 1.<aT.

It is stored in ILOM as a table memory in advance to be determined by the Maml Fi clock OLP and the frequency division rule.
Ru. In this example, since the speed of the main motor M is also changed in accordance with the magnification change, -9 is added between the magnification change data iiD and the frequency division rule. For example, step 14 so that M2 is the highest speed when the magnification is the same, and the speed is slow when changing the magnification.
You can also set the town.

If the t set is M3, the appropriate scanning length M3L is determined, and the required time is determined (18.19). Next, when the KN key is turned on and the numeric keypad is turned on, numerical data is stored in the count area of the RAM as the desired number of copies (20.degree. 21).

Thereafter, step 7 and subsequent steps are performed to perform variable magnification travel length control. By performing stepless magnification in this way, one cycle can be completed in the minimum necessary time. Therefore, the time required for continuous copying can be appropriately and minimized.

In step 14, the position motor M3 is driven to determine the lens position for zooming, but this can be done by having the microcomputer oct the pulse from the encoder 39 and stopping the motor when the lens has moved a predetermined distance. .

Next, other examples of scanning control will be explained with reference to FIGS. 6 to 8.

Figure 6 shows the wI according to the size of the transfer paper in the optical system device (inside the ati6 of the mirror 10) where the moving optical system is scanned.
I! It is configured so that position detectors 18 to 21 of L are provided, for example, when the transfer paper size is B5゜4. B4. A3
By providing a detector for the mirror 10 for the optimal inversion position of the optical system when copying at 1:1 according to each size of the mirror 10, the system is configured so as not to slow down the copying speed of 1:1 copying, which is the most frequently used type. When changing magnification, the inversion position of the optical system is selected depending on the magnification ratio and transfer paper size. Table IK shows the distance from the original home position to the reversal position all.

Table 1 (Optical system scan length) B5 25 Wrap length 4 297m B4 364 Kakumu 3420 As an example, a case where the transfer paper size is set to B5 will be explained.

When the magnification ratio is LO (equal magnification) and 1! The reversal of the magnifying optical system is detected by the reversal position sensor 18 of B5, and the optical system is reversed. If the magnification ratio is smaller than 1 and larger than 0.86, then
The optical system is reversed by the reversal position sensor 19 of the camera 4.

Also, if the magnification is smaller than 0.86 and larger than 0.70, the optical system is reversed by the reversal position sensor 20 of B4, and if the magnification is smaller than 0.70 and larger than 0.61, then the magnification is smaller than 0.70.
The optical system is configured to be reversed by a reversal position sensor 21.

As mentioned above, by determining the predetermined reversal position according to the cassette size and magnification ratio, the scan length of the optical system can be adjusted without increasing the number of reversing sensors or slowing down the copying speed. It is something that can be controlled.

FIG. 7 shows the control example shown in FIG. 6 added to FIG. 3, in which each of the detection sensors (microswitches) described above is connected as an input to a human-powered boat.

Figure 8 is the control flow diagram, and the inversion step 1 in Figure 4
You can achieve this by changing 0 to KFI.

In the case of a B5 cassette, first it is determined whether the magnification data is 1 or not (81), and when the magnification is the same, the B5 sensor 18 is turned on and it is determined whether or not it is a friend (82). If it is on, proceed to step 11, turn off PAW, turn on BAY f, and switch to reverse. When the magnification X is 1) x) 0.86, for example 0.88, the system waits for the M4 sensor 19 to operate (83). 0.86
>X>0.70. For example, at 075, it waits for B4 senna 2o to operate (84). Similarly, in the case of 4 cassettes, select the one shown in the figure below according to the magnification. Although not shown, in the case of the first enlargement (L15>X>1), for 35 cassettes and 4 cassettes, 'B5
l-Select.

For the second expansion (L30 > x > 115), 3
For small cassettes of 4 or smaller, select B5 sen f, and in case of proverb 3 enlargement (L40>z>L30), select B5 senna for small cassettes of A3 or smaller.

is a control circuit diagram, Fig. f84 is a Thayert diagram of the control 70 in Fig. 3, Fig. 5 is an output waveform diagram, Fig. 6 is an explanatory diagram of the scanning section, Fig. 7
The figure is another control circuit diagram, and Figure J8 is another control 70-chart diagram.

1st ■Figure 6 /7　　　tgul! Existence Mil Immediate f

Claims (4)

[Claims] (1) means for scanning a document (reciprocating movement; 1) means for inputting and commanding the magnification of the reproduced image of the document; and deriving the reversal position of the reciprocating means by calculation of binary data from the input command means; and means for reversing the reciprocating means. (2) The document scanning control device according to item 1, further comprising means for detecting the position of the reciprocating means, and wherein the reversing means derives a distance from the position to the reversal and performs the reversal. (3) The document scanning control device according to item 1, wherein the reversing means derives the reversing position by also taking into account binary data of copying material or cassette size. (4) The document scanning control device according to item 1, further comprising means for detecting the speed of the drive source of the reciprocating means.