JPH0225863A - Original reader - Google Patents

Abstract

PURPOSE:To automatically correct the inclination of an original due to the installing dislocation of the original and to execute the reading start of the original by detecting the inclination quantity and direction of the original to a scanning direction due to the dislocation at the time of placing the original to an original platen in the middle of prescanning before can original reading, and rotating an original suction rotating member according to the direction and angle of the inclination in real time. CONSTITUTION:The inclination quantity and inclination direction of an original 107 to the scanning direction due to the dislocation at the time of placing the original 107 on an original platen 108 are detected in the middle of the prescanning before the original 107 reading by detecting means 101 and 201 using photoelectric converting means. A member 103 to suction-rotate the original 107 according to the direction and angle theta of the inclination of the original 107 to be detected is rotated in real time in direction and angle positions to calibrate the inclination, and the inclination of the original 107 is automatically calibrated. Thus, an original reading miss and a copying miss due to the dislocation of the original are eliminated, and a load by human intervention can be eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a document reading device, and more particularly to a document reading device capable of automatically correcting misalignment of a document.

[Prior Art] Conventionally, a C(:D (charge-coupled device) line sensor is used to read a document image as parallel information, this read information is converted to digital serial information, and a latent image is transferred onto a photosensitive drum using a laser optical system. In a so-called digital copying machine that writes on the original, the inclination of the original with respect to the scanning direction is detected by the CCOCC line sensor, and the original image data is rotated and corrected by an image processing circuit.

[Problem to be solved by the invention] However, the original image is directly written as image information on the photosensitive drum only through an optical system such as an imaging lens and a mirror, without using an image reading sensor such as a CCD line sensor. In so-called analog copying machines,
Since it does not have an image expansion processing section like the above-mentioned digital copying machine, it is necessary for the user of the apparatus to manually reposition the original after the original copy image is reproduced in order to deal with the skew of the original.

On the other hand, the above-mentioned conventional digital copying machine has drawbacks such as an increase in the scale of image processing required to correct the skew of the original, resulting in complexity and slow processing speed.

Therefore, the purpose of the present invention is to eliminate the above-mentioned drawbacks,
It is an object of the present invention to provide a document reading device capable of automatically correcting the inclination of a document due to misplacement of the document and then starting reading the document.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides an optical scanning member that optically scans and reads an image of a document on a document table, and an optical scanning member disposed on the optical scanning member. a first document leading edge detection means for detecting the position of the leading edge of the document during pre-scanning before reading the document using a first detection element including a photoelectric conversion element;
The first detection element and the second detection element are arranged on the optical scanning member at a predetermined distance in a direction perpendicular to the scanning direction. a second document leading edge detection means for detecting the position of the leading edge; and a document rotation amount for detecting the amount of rotation of the document in the scanning direction based on the output of the first document leading edge detection means and the output of the second document leading edge detection means. a detection means; a document rotation direction detection means for detecting the rotation direction of the document relative to the scanning direction based on the output of the document rotation amount detection means and the output of the first or second document leading edge detection means; and the document rotation amount detection means. drive signal generation means for generating a drive signal for calibrating the inclination of the document according to the output and the output of the document rotation direction detection means; and a drive signal generating means for generating a rotation force according to the drive signal of the drive signal generation means for rotating the document. The present invention is characterized in that it includes a power source and a document suction rotating member disposed inside the document table cover on the document table and driven by the document rotation power source to suction and rotate the document.

[Function] With the above configuration, the present invention detects the amount and direction of inclination of the original with respect to the scanning direction due to the positional deviation when the original is placed on the original platen before reading the original by the detection means using the charge conversion means. The document is detected during pre-scanning, and the document suction/rotation member is rotated in real time to the direction and angle position to calibrate the tilt according to the direction and angle of the detected document's tilt to automatically calibrate the document's tilt. Therefore, mistakes in reading or copying the original due to misalignment of the original can be eliminated, and manual labor can be eliminated. Further, according to the present invention, since the rotation proofreading of the original document itself is performed, there is no complexity associated with data rotation by image processing, so that the present invention can be provided with a simple configuration and at a low cost.

[Example] Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows the basic configuration of an embodiment of the present invention. In this figure, A indicates a first photoelectric conversion element formed by a photoelectric conversion element disposed on an optical scanning member that optically scans and reads an image of a document on a document table.
A first document leading edge detection means detects the position of the leading edge of the document during pre-scanning before reading the document using the detection element. B uses a first detection element and a second detection element, which is a photoelectric conversion element arranged on the optical scanning member at a predetermined distance in the direction perpendicular to the scanning direction, to detect the original during prescanning. This is a second document leading edge detection means that detects the position of another leading edge.

Reference numeral C denotes a document rotation amount detecting means for detecting the amount of rotation of the document in the scanning direction based on the output of the first document leading edge detecting means A and the output of the second document leading edge detecting means B. Document rotation direction detection means D detects the rotation direction of the document relative to the scanning direction based on the output of the document rotation amount detection means C and the output of the first or second document leading edge detection means A or B. Reference numeral E denotes a drive signal generating means for generating a drive signal for correcting the inclination of the document according to the output of the document rotation amount detection means C and the output of the document rotation direction detection means. Reference numeral F denotes a power source for rotating the document which generates rotational force in accordance with drive No. 45 of the drive signal generating means E. Reference numeral G designates a document suction rotating member disposed within the document table cover on the document table and driven by the document rotation power source F to attract and rotate the document.

2(A), ([1) shows an example of the arrangement of the original and the vicinity of the original platen cover according to an embodiment of the present invention. A power transmission mechanism 103 transmits the rotation of the document rotation motor; reference numeral 103 is a document suction rotation member capable of sucking and rotating the document by the power transmission mechanism 102; and reference numeral 104 is an opening at the bottom of the document suction rotation member 103. A plurality of document suction holes 105 are connection ports communicating with the holes 104 and connected to a vacuum device (vacuum pump) not shown.

Reference numeral 106 designates a document table cover that accommodates the document suction rotation member 103, 107 a document, lO8 a document table glass on which the document 107 is placed, and 109 an optical scanner (optical scanning member) with a built-in lamp for illuminating the document. The scanner 109 moves in the direction of the arrow Y in this figure and scans the original 8% 107, and the reflected light (original image) passes through an imaging optical system (not shown).
The light is irradiated onto a photosensitive drum (not shown).

A first detection element 1 detects the leading edge of the original 107, and a second sensing element 1-2 similarly detects the leading edge of the original 107. These detection elements 1-1
．． 1-2 is an optical scanner 109
are installed at a fixed distance atw in a direction perpendicular to the moving direction Y of the .

In the above configuration, the original 107 is now installed (placed) at an angle of rotation θ with respect to the direction perpendicular to the scanner movement direction Y, and the original 107 is placed on the original table cover 10.
6 is closed and a copy start key (not shown) is pressed by the user of the apparatus, a pre-scan in which the optical scanner 109 moves in the direction of arrow Y is started prior to reading the document. First, the optical scanner 10
9 moves to point A shown in this figure, the first detection element 1
-1, the leading edge A of the original 107 is detected, and then when the optical scanner 109 moves to point B, the other leading edge B of the original 107 is detected. Further, it is clear from this figure that the document rotation correction in this example can be performed by rotating the document clockwise by θ.

Therefore, if the distance between ^-6 is i, then the rotation correction angle θ is expressed as. On the other hand, if the moving speed of the optical scanner 109 is V and the time required for the optical scanner 109 to reach the 4th point and the 8th point is t, then 5. Since e==vXt,
It follows from equation (1).

Next, the motor control circuit 101 according to the embodiment of the present invention that calculates the rotation correction angle θ of this original will be explained.

FIG. 3 shows an example of the circuit configuration of the motor control circuit 101 and the control circuit of the optical scanner 109 shown in FIG. Third
In the figure, 1 is a document edge detection circuit for detecting the leading edge of a document having the above-mentioned first detection element 1-1, and 2 is a document edge detection circuit for detecting the leading edge of the document having the above-mentioned second detection element 2-1. The rain detection circuit 1.2 has the same circuit configuration. , 3 is a rotation amount detection gate consisting of an exclusive OR circuit (EX-OR gate) that detects the rotation amount of the document using the output of the document edge detection circuit 1.2 as an input signal, and 4 is the output of the document edge detection circuit 1. This is a rotational direction detection latch circuit that detects the rotational direction of the document by using the output of the rotation amount detection gate 3 as a human power signal.

5 is a negative AND circuit (2) which outputs an optical scanner reversal signal using the output of the document edge detection circuit 1.2 as a human signal;
This is an optical scanner reversal signal generation gate consisting of a manual NAND gate. A clock pulse generation circuit 6 generates a clock pulse signal, and is composed of an oscillation circuit and a multistage frequency divider, and a high frequency clock signal (2) is generated from the stage before the multistage frequency divider. 7 is an optical scanner control circuit that drives and controls the rotation of the scanner motor 20 that moves the optical scanner 109; 8 is a one-shot circuit that inputs a prescan start signal of the optical scanner 109 from the optical scanner control circuit 7 and generates a reset pulse]- It consists of a pulse generation circuit or a set pulse generation circuit.

Reference numeral 9 denotes a motor drive fh signal generation circuit that generates a motor drive signal 19 using the outputs of the rotation amount detection gate 3, the optical speed control reverse signal generation gate 5, and the clock pulse generation circuit 6 as input signals; Individual 3-person power AND
It consists of a gate, two series inverters, and two parallel T-type FFs (flip-flop circuits). lO is the output of the rotational direction detection latch circuit 4 mentioned above, and the output of the rotor!
! ! ! This is a rotation direction switching circuit that performs rotation direction switching control using the output of the dynamic signal generation circuit 9 as an input signal, and includes, for example, one inverter gate, four parallel two-man AND gates, two parallel two-man OR It consists of a gate. , 11
is a motor drive circuit that drives the original rotation motor 30 using the output of the rotation direction switching circuit 1O as an input signal.

FIG. 4 is a timing chart of output signals showing the operation of the circuit configuration example of FIG. 3. In FIG. 4, a is the clock pulse output from the clock pulse generation circuit 6, b is the optical scanner start signal manually input from the optical scanner control circuit 7 to the reset pulse generation circuit 8, and C is the clock pulse output from the clock pulse generation circuit 6.
is the reset pulse f generated from the reset pulse generation circuit 8 in response to the input of the star signal of the optical scanner.
No. 8, and the reset pulse signal is manually input to the reset terminal of each latch circuit of this circuit.

d is the output signal of the first document edge detection circuit 1, and e is the output signal of the second document edge detection circuit 1.
This is the document edge detection output signal of the document edge detection circuit 2. The document edge detection circuit 1.2 is composed of a photodiode, an operational amplifier, a comparator, etc., as described later.
The difference in the amount of reflected light due to the presence or absence of a document due to scanning by the optical scanner 109 is detected as a difference in photocurrent of the photodiode, the photocurrent is converted into voltage by an operational amplifier, and the voltage conversion value is compared with a reference value Vref by a comparator. and the latch outputs d and e.

f is the output signal d of the document edge detection circuit 1.2.

This is an output signal of the rotation amount detection gate 3 that is at a high level during a period when a mismatch of e is detected by an exclusive OR operation and a mismatch occurs. g is an output signal of the optical scanner reversal signal generation gate 5 which manually performs a negative AND operation on the output of the document edge detection circuit 1.2. In h and i, the rotation direction switching circuit 1 receives the two outputs of the motor drive signal generation circuit 9 and the output of the rotation direction detection latch circuit 4 as input signals, respectively.
This is No. 8 with a score of 0.

Next, the document edge detection circuit 1 shown in FIG. 3 will be explained in more detail. In this figure, ii is a first detection element consisting of a photodiode for photoelectric conversion. In addition, l-2 is an operational amplifier that converts the output of the detection element 1-1 into a voltage and amplifies it to a predetermined level, and 1-3 is a gain determination device that determines the gain (amplification factor) of the operational amplifier 1-2. resistor,
1-4 is a comparator that uses ref as a reference voltage. 1-5 is a multiple sampling latch circuit, which is reset by the reset signal C of the reset pulse generation circuit 8 and uses the high-frequency clock No. 3 ■ generated from the front stage of the multi-stage frequency divider of the clock pulse generation circuit 6 as a sampling pulse. Sampling is performed multiple times using this high-frequency clock 4J■, and for all of the samplings, when the data input manually from the C comparator 1-4 is at the same level (1 or O), the data is latched output Q
shall be.

The operating state of this document edge detection circuit 1 is shown in the table 7 in FIG.
It is indicated by Mingcha 1. In this figure, °[, j is the output (No. 8) of the above-mentioned comparator 1-4, and k is the sampling input signal of the multiple sampling latch circuit 1-5.

In this figure, if the data input j is all at the same level after three samplings, a latch output d is given.

In this way, since the manual data is determined by sampling multiple times in the UQ element circuit 1-5, it is possible to accurately detect the edge of the document, and even if dust or dirt adheres to the document table glass 108, There will be no false positives.

Note that the second document edge detection circuit 2 has the same configuration and function as the first document edge detection circuit 1, so a detailed explanation thereof will be omitted.

FIG. 6 shows another example of the circuit configuration of the motor control circuit 101 and the control circuit of the optical scanner 109 in FIG. 2.

Note that in this figure, parts with the same reference numerals as in FIG. 3 have the same configuration, so their explanation will be omitted.

In FIG. 6, 12 is a timer circuit that starts counting by manually inputting an optical scanner start signal generated from the optical scanner control circuit 7, and outputs an abort signal (count-up signal) n after a certain period of time; 13 is an optical An optical scanner start signal S of the scanner control circuit F, an abort signal N of the timer circuit 12, and a first optical scanner reversal signal G of the first optical scanner reversal signal generation gate 5.
This is a second optical scanner reversal signal generation gate which inputs a second optical scanner reversal signal 0 and outputs a second optical scanner reversal signal 0 to the optical scanner control circuit 7. 14 is the output f of the rotation amount detection gate 3
, a motor drive signal generation circuit which generates a motor drive signal for document rotation by manually inputting the output g of the optical scanner reversal signal generation gate 5, the output a of the clock pulse generation circuit 6, and the output n of the timer circuit 12. be.

Reference numerals 15 and 16 denote document edge detection circuits having the same circuit configuration, respectively. Second detection element 1-1.
It has 12. This document edge detection circuit 15.16
The difference from the original edge detection circuit 1.2 in FIG.
8, each with a reference voltage Vrefl.

with V r e f 2 and νrefl > Vref
2. What is going on? With this configuration, even if the reflectance of the original 107 is high or low compared to the reference reflector (white reference plate) not shown provided on the inner surface of the original force bar 1.06 in FIG. The leading edge of the document can be detected by detecting the difference in reflectance using two types of reference voltages Vrefl and Vref2, which also makes it possible to detect colored documents.

The operating state of circuit configuration example C in FIG. 6 is shown in the timing chart of FIG. 7. Note that the same reference numerals as in the timing chart of FIG. 4 are output signals having the same timing as in FIG. 4, so a description thereof will be omitted.

In FIG. 7, n is the output signal of the timer circuit 12 which starts counting in synchronization with the optical scanner start signal manually input from the optical scanner control circuit 7. j2 and m are output signals of the full drive signal generation circuit 14, respectively, and the full drive generation signal C is stopped according to the count-up time indicated by the output signal n of the timer circuit 12.

With this configuration, the inconvenience when the amount of inclination of the original 107 with respect to the reference direction is too large can be avoided, that is, the first original edge detection element 1 or the second original edge detection element 1-2 detects the leading edge of the original. After that, the second detection element 1-2 or the first detection element 1-3 detects the leading edge of the document. -1 or second detection element 1
It is possible to prevent the inconvenience that -2 reaches the image information area of the original and the signal is reversed. Further, since it is practically rare for the amount of document inclination to exceed a certain value, regulating the maximum value of the amount of document inclination does not cause any problem.

FIG. 8 shows an outline of the known ultrasonic motor 30 shown in FIG. 3 or FIG. 6 above. In this figure, an ultrasonic motor 30 according to the embodiment includes a stator made of a piezoelectric material and an elastic material, a rotor made of a metal ring and a plastic slider, and the like. 3m, :12 is the section 40 section B of the piezoelectric body constituting the stator, and between this section Δ31 and section B32 there is provided a region 33 that does not belong to either section. In addition, 34.35 are the piezoelectric material classifications ^31. A high frequency applied voltage φ is applied to the piezoelectric section 832 and has a temporal phase different by 90°. ,φ9
The sections 3311 and 32 are each subdivided as indicated by broken lines, and the subdivided regions are alternately polarized in the thickness direction.

When a high frequency voltage of the natural frequency of the piezoelectric ceramic is applied to the above stator configured in this way, the stator causes bending vibration in the circumferential direction and generates a standing wave in the circumferential direction. Here, the phases of the positions of the section ^31 and the section B32 are shifted by 374 waves of the high frequency voltage (3/4λ), and the temporal phase of the section A31 and the section B32 is 90 degrees from the motor drive circuit 11.
゛Different high frequency voltage φ. When φ9o and φ9o are applied, both standing waves interfere and a composite traveling wave is generated. In addition, such ultrasonic motors are lightweight, thin, fast response,
Since it has advantages such as high controllability, it is suitable as the power sleeper for rotating the original of the present invention.

Note that the present invention can be applied not only to analog copying machines but also to devices that read original images using solid-state image sensors.
It can also be used in character recognition devices such as CR.

[Effects of the Invention] As explained above, according to the present invention, the amount and direction of inclination of the original with respect to the scanning direction due to positional deviation when the original is placed on the document table are detected by a detection means using a photoelectric conversion means. The document is detected during pre-scanning before reading the document, and the document suction rotating member is rotated in real time to the direction and angle position to calibrate the tilt according to the direction and angle of the detected document's tilt, thereby automatically correcting the tilt of the document. Since proofreading is performed, errors in reading or copying the original due to misalignment of the original can be eliminated, and the burden on manual labor can be eliminated. Further, according to the present invention, since the rotation proofreading is performed on the original document itself, there is no complexity associated with data rotation due to image processing, so that it can be provided easily with a simple configuration.

[Brief explanation of the drawing]

Figure 1 is a block diagram showing the basic configuration of an embodiment of the present invention, Figures 2 (^) and (B) are sectional views and plan views showing the arrangement of the embodiment of the invention, and Figure 3 is a FIG. 4 and FIG. 5 are timing charts showing the operating state of FIG. 3. FIG. 6 is a block diagram showing the circuit configuration of another embodiment of the present invention. , FIG. 7 is a timing chart showing the operating state of FIG. 6, and FIG. 8 is an explanatory diagram showing an outline of the ultrasonic motor shown in FIGS. 3 and 6. 101... Original rotation motor and control circuit, 102...
Power transmission mechanism, 103... Original suction rotation member, 106... Original platen cover 107... Original, 108... Original platen glass, 109... Optical scanning member, ii...th 1 detection element, 2-1... Second detection element, 1.15-... First document edge detection circuit, 2.16.
...Second document edge detection circuit, 3.. Rotation amount detection gate, 4.. Rotation direction detection latch circuit, 5.. Optical scanner reverse rotation signal generation gate, 9j4-.
・Motor drive signal generation circuit! 0... Rotation direction switching circuit, 11... Motor drive circuit, 30... Ultrasonic motor. P7t-t of Meiko example > Guo Qigi Oat Ming diagram of leather motor No. 8
figure

Claims (1)

[Claims] 1) Using an optical scanning member that optically scans and reads an image of a document on a document table, and a first detection element including a photoelectric conversion element disposed on the optical scanning member. a first document leading edge detection means for detecting the position of the leading edge of the document during pre-scanning before reading the document; a second document leading edge detection means for detecting the position of the other leading edge of the document during the prescanning using a second detection element formed of a photoelectric conversion element disposed on the optical scanning member; document rotation amount detection means for detecting the amount of rotation of the document relative to the scanning direction based on the output of the document leading edge detection means and the output of the second document leading edge detection means; Original rotation direction detection means for detecting the rotation direction of the original with respect to the scanning direction based on the output of the first or second document leading edge detection means; and the output of the original rotation amount detection means and the original rotation direction detection means. a drive signal generating means that generates a drive signal for calibrating the inclination of the document according to the output; a power source for rotating the document that generates a rotational force according to the drive signal of the drive signal generating means; A document reading device comprising: a document suction rotating member disposed within a document table cover on a document table and driven by the document rotation power source to suction and rotate the document.