JPS58145969A - Copying device - Google Patents

Abstract

PURPOSE:To make the beginning end of an original and the preceding end of a copy always coincident even if the setting of the original deviates, by detecting the position of the material to be copied placed on a platen and controlling a feed timing for a copying material. CONSTITUTION:It is possible to detect the extent of deviation of beginning end position of an original from a reference position Sy optically by making use of the change in the output of a sensor 21 according to the difference in the intensity, wavelength, etc. of the light radiated from a light source 5 and reflected from the rear surface of a platen cover 4 and an original 2. If the timing for feeding paper is deviated in accordance with the output of said sensor, the beginning end of the original and the preceding end of copying paper are made always coincident. Here, the count number corresponding to the extent of deviation is added to the count number for timing of the feeding, and the timing for the feeding is deviated in accordance with the extent of deviation, whereby the timing is adjusted to a correct timing. The beginning end of the original and the preceding end of the copy are thus made coincident at all times even if the setting of the original deviates.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a copying apparatus, and more particularly to an optical scanning type electrophotographic copying machine.

In this glazed copying machine that has been used in the past, when placing a document to be copied, for example, on a glass original platen, it is placed at a reference position in the optical scanning direction of the original platen. It is necessary to align the edge of the document with respect to the original. However, a mechanism that can automatically perform such alignment does not yet exist, and deviation from the reference position due to misalignment when the user places the original or slippage when using a feeder As a result, copies are usually made with the edges of the document misaligned. As a result, the quality of the obtained copy is insufficient, such as a portion where no image appears at the leading edge.

SUMMARY OF THE INVENTION Therefore, it is an object of the present invention to provide an apparatus that can always align the starting edge of an original with the leading edge of a copy even if the original is set misaligned, and can perform reliable and good copying.

In order to achieve this object, according to the present invention, a detection means (including a photoelectric conversion element) for detecting a deviation between a reference placement position in the optical scanning direction and a placement position of an object to be copied (for example, a document) is provided. The feeding timing of the copying material is controlled based on the output of this detection means.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments shown in the drawings. In this embodiment, for ease of understanding, a case will be described in which the present invention is applied to a copying apparatus that makes copies at the same size.

First, with reference to FIG. 1, the schematic structure of a general electrophotographic copying machine will be explained. At the top of the cabinet 1, a glass original picking table 3 on which the original 2 is placed and a platen cover 4 that covers the original 2 are arranged.

Below the document table 3, an optical scanning table consisting of a first mirror unit 7 equipped with a light source 5 and a first reflection mirror 6 is arranged so as to be movable in a straight line in the horizontal direction of the drawing. The second mirror unit 71 moves in accordance with the speed of the first mirror unit to make the optical path length constant, and the reflected light from the document table 3 is reflected by the lens table through the reflection mirror 8. The light is incident on a photosensitive drum 9 as an image carrier in a slit shape.
Around the drum 9, there is a corona charger 10. Developing device 11
, a transfer section 12 , a separation section 13 , and a cleaning section 14 are arranged, and a paper feed roller 16 .
Copy paper 18, which is fed with red color 17, is further fixed in a fixing section 19 after the toner image is transferred from drum 9, and is then discharged.

Here, in order for the toner image corresponding to the original on the photoreceptor drum 9 to be accurately transferred onto the copy paper 18, the two leading edges of the Jj7A original must match the reference line sy in the optical scanning direction for placing the original. When the optical center (scanning point) in the optical scanning table 7 reaches the reference line Sv, the light image irradiation point 9A on the photoreceptor drum 9 and the copy paper 18 are in contact with the photoreceptor drum 9. The rotation start timing of the paper feed roller 17 is set based on the distance between the five peripheral surfaces of the drive roller at the contact point 9B, the feeding distance between the paper feed roller 17 called a registration roller among the paper feed rollers and the contact point 9B, and the speed of each moving object. I was doing what I was supposed to do.

Although this configuration itself is similar to that of a conventional copying machine, the actual IMN has additional configurations worth noting as shown in FIGS. 2 and 3.

FIG. 2 shows a plan view of the fIt document table 3, and each end of the document table 30 at the front left position in the drawing is set as the reference line Sz and sy on which the document is placed. The document 2 on the document table 3 (indicated by the two-dot chain line) is aligned with each of the reference lines 5 above.
tXSy, but as mentioned above, due to setting deviation, for example,
It is normal for the optical scanning table to be slightly shifted to the right (IIIC, that is, in the forward movement direction of the scanning direction 20 of the optical scanning table) from V. Therefore,
According to the present embodiment, a large number of sensors 2 are installed on the edge of the lower surface of the document table 3 along the reference line Sz in parallel to the scanning direction 20 of the optical system.
1 array 22 is fixed. This sensor array itself may be composed of known photoelectric conversion elements.

Due to the existence of this sensor array 22, while the light from the light source is sequentially irradiated along the reference line #Sz while the optical system is scanning, the deviation of the starting edge position of the document from the reference line Sv is caused by the optical The amount of deviation is accurately detected by the signals of each sensor 21 making up the sensor array 22. However, in this case, the original image in the sensor array 220 portion will not be captured, but the surrounding area will be white 111 and 11! There is no problem if the il image does not exist. Furthermore, when separating sheets of paper using the belt separation method, the sensor array can be placed at a position corresponding to the portion where no image is formed by the separation belt. Furthermore, in a method in which a preliminary scan is performed before charcoal f'r for image reading, and the deviation of the leading edge of the document from the reference line sy is detected at that time, the deviation of the leading edge of the document from the reference line sy is detected. , during the main scan, it may be adjusted to move out of the scanned image area.

Furthermore, as another sensor installation method, as shown in FIG. 4, the mirror 8 disposed in the optical path that transmits the image of the original 2 as reflected light onto the photoreceptor is a half mirror, and the image information (reflected light) is A part of the light is transmitted to the rear of the mirror 8 [7], and the remaining part is reflected toward the photoconductor side, so that the transmitted light can be made incident on the sensor 211 consisting of a photoelectric conversion element. In this case, since the optical path indicated by the broken line in FIG. 1 is slint-like and narrow like a point in the direction corresponding to the optical travel direction, it is sufficient to provide the sensor 211 on one side. That is, based on a pre-known scanning speed, the sensor 211 detects the starting edge of the document 2 after receiving a signal indicating that the image reading center (traversing point) has passed the WA draft table reference line during optical forward movement. The amount of misalignment of the document 2 can be detected based on the time.

When detecting the starting edge position of document 2, as described above,
Since the starting edge of the copy paper is made to coincide with the leading edge of the copy paper, at least the lower surface of the platen cover 4 (original 2
M: The area near the rack side Sv does not necessarily need to be white during copying, and can be distinguished by a sensor (general photoelectric conversion element) from the starting edge of the original (generally white). At least a portion of the cover 4 may be colored in a color having a lower reflectance than white. When a color sensor (for example, semiconductor color sensor PD-150, PD-151 manufactured by Sharp Corporation) is used as a sensor, the color of the bottom surface of the platen cover 4 is very different because the sensor output is obtained according to a specific wavelength. Can be done. For example, if the color is yellow, the color sensor will output a signal that can be determined as white, but the yellow part will not be sensitive to, for example, an S# photoreceptor, and therefore will not form an image and will not appear as a copied image. There are times when it is desirable to have at least a portion of the underside yellow.

As described above, the light from the light source 5 is reflected by the lower surface of the platen cover 4 and the document 2, and the sensor output changes depending on the strength and wavelength of this reflected light. The amount of deviation of the document starting edge position from the reference position Sv can be optically detected with high precision.

Next, by shifting the timing of paper feeding based on the sensor output of This situation can be prevented.

For this purpose, a method in which the timing of the copying process based on the sensor output is determined by counting pulse signals such as encoder pulses and timing pulses is suitable for carrying out the present invention. By adding a count corresponding to the amount of set deviation to the count number used to determine the timing, the paper feeding timing can be shifted in accordance with the amount of deviation, and the timing can always be adjusted to the correct timing. In this (L) paper feed timing signal output system used in general copying machines, after the start of the copying process, the optical bench and photosensitive drum are moved (rotated) at a constant speed, and then A reference signal for generating a paper feed timing signal is obtained by a detector (for example, a microswitcher) that detects the arrival of a scanning point at a specific position as the optical system (or a transfer document table) moves. Immediately after receiving this reference signal, or after counting a predetermined number of pulses, the drive timing of the paper feed roller 17 is determined to match the leading edge of the image.In this embodiment, the reference signal i11 is After that, the pulse count derived from the size of the slippery and copying line speed can be added to the paper feed timing count. That is,
When paper feeding is performed immediately after receiving the reference signal, paper feeding is not performed until a pulse count corresponding to the width of the deviation is counted. In addition, for paper feeding after receiving the reference signal and counting the pulses,
Only the pulse count corresponding to the deviation is added to the normal pulse count when the paper feed timing control according to the embodiment is not performed.

h as a means of detecting the deviation of the IiA bucket from the base cicada.
It is also possible to use an analog signal output such as a general photosensor of iJ t'iLl. The sensor output changes depending on the ratio of the tail reflection area and the light absorption area in the area determined by the directivity of the sensor out of the range in which the light beam hits the irradiated object.
Utilizing this property, the sensor output changes in an analog manner depending on the ratio between the platen cover, which has a light-absorbing color, and the white part of the document, so this analog cover is A/D converted and transferred to the CPU as an integer data. (
(Central processing unit of the m child computer) and outputs the deviation amount of the S/C principle in comparison with the input level based on the table stored in advance in the j4Q l:1 section, Furthermore, processing can be performed to obtain a signal for adjusting paper feeding timing according to the output.

Note that +fIw4, which adjusts the axis assembly timing according to the misalignment of the original document set, may be switchable so as not to operate. For example, the detection means for detecting the starting position 11 of the original position +! From Jl to → movement Δ, change the entire lower surface of the platen cover to JJS1 white, and wait for fc to detect the starting edge position of the document. Make sure not to. In Fig. 5, a belt-like cover 23 that can be rotated manually or by a motor is incorporated in the blade/cutter itself, and a VJ is installed on one rotating shaft 24 (- or by rotating the drive motor). The colored portion 25 is rotated toward the upper side 77 so that only the white belt 23 comes into contact with the document 2. As a result, the belt 23 and the document 2 are of the same color.
The sensor output described above cannot be obtained. Of course, the sensors 4=h and the like may be stopped at the same time.

6th v! J and FIG. 7 show an embodiment that is a further improvement of the above-described example.

In this one group, so-called SDF (Single Do
Document feeder 3 called ``CumentFeeder''
0 is arranged, a manuscript is fed from the Hara Kusunoki kite board 31, the feed belt 32 starts rotating by f- (not shown), and the manuscript Pi46 is set on the manuscript b3 as shown in the figure.
Further, during copying, the receiver on the other side is discharged onto a tray 33.
The nine-scanning system consists of a first mirror unit 7 and a second mirror unit 71#, which are provided with a light source 5 and a mirror 6. A photoelectric conversion element 212 such as a color sensor is provided facing the original frame 3 .

When the unit moves forward, the sensor 21 is placed on the document table 3, z, Ht;
2 should always be positioned in front. That is, the lth
The mirror unit 7 is set at the position IK of the paper feed timing No. 14 of the nuclear paper (for example, as shown in the position in Fig. 7, the original 11.T'h
The optical center is shifted to the left by a distance l from the tip sy, at a position i
&), the sensor 212 is also placed directly below the start end of the scan on the document table 3.

In such a copying machine with a fixed document table, the relative image scanning unit including the light source does not appear within the surface of the document table in the idle link state, as in the case of a movable document table. It takes time 1 from when the copy start button is pressed until the entire document aligned with the reference line is scanned.
(1≧0) is required. Utilizing this principle, the optical system unit can be provided with a sensor 21 for detecting displacement.

The sensor 212 is used to detect that the original 2 is on the original platen 3 and that it is misaligned with the reference line. If the inner surface of the clay wall, the cover, or the lower surface of the belt 32 is painted with a color that absorbs infrared light (for example, black), the original YF on the document frame 3 can be
Only when the line point reaches the position where /42 exists, the sensor output is turned on, and the presence or absence of the document 2 can be detected. In this case, in order to turn on the sensor output for the document of each paper size, the sensor 212 is arranged so that it senses a portion of the document f1ii2 that is perpendicular to the scanning direction of the Sz base reference pressure 1r. Incidentally, the sensor 212 has a light beam incident thereon.
It is advisable to provide a separate light source (not shown) for complete sufficiency.

Next, the timing chart and process flow of the copy operation will be explained with reference to FIGS. 8 to 1O, but this may be similarly applied to the examples described in FIGS. 1 to 5.

FIG. 8A shows a timing chart of each signal output when the original is set at the reference position when the copy start button is pressed, and FIG. 8B shows a timing chart of each signal output when the original is not set at the reference position. In FIG. 8A, after pressing the copy start button, the photoreceptor and optical scanning system are driven,
Since the document is at the reference position when the optical center passes the position to the left of the reference line by #)l, the sensor output is OF.
Since the F signal is not output, the paper feed signal is output as is, and the copy paper waiting at the paper feed roller 17 is fed as the paper feed roller is driven. When the document is not set at the reference position as shown in FIG. Since the output of the sensor is off even in the case of 1), it is determined that the document has deviated from the reference position, and the document is not fed at the normal timing. When the sensor provided integrally with the optical system unit reaches the starting edge of the document together with the optical system unit, the sensor output is turned on, so that the presence of the document is detected from that point t6-. Paper feeding is performed from the timing when this is known.

That is, the paper feed is delayed by a time corresponding to the time axis corresponding to the deviation of the original from the time when the paper feed signal is issued when the original is placed in the normal position. However, this embodiment is for the case where a copy is made at the same size, and when the paper feeding and photoconductor speeds are different from the scanning speed of the optical scanning system, such as when copying with a reduction machine, the amount of document position deviation obtained from the sensor output is Since this is different from the paper feed timing delay amount, it is necessary to convert it, perform preliminary scanning, or use another sensor fixing method.

In this example, either the paper feed timing is determined based on the timing when the sensor output is turned on, or in any case, it is necessary to keep the paper feed unit in a standby state for a time equivalent to t8 hours or 11 hours thereof. However, in order to do this, the clutch of the paper feed roller must be connected directly by the ON signal of the sensor output, and the OFF time (ts) 1i of the sensor output must be detected in advance by preliminary scanning etc. It is conceivable to input the paper feed control by adding the number of pulses corresponding to the time t8 to the number of pulses corresponding to the output timing of the original paper feed signal, and perform drive control by the microconbeater. It should be noted that the sensor can be configured to be turned on at a position to the left of the reference line sy in the drawing, turned off only at the next mounting table 3, and then turned on again when a document is detected. Further, FIG. 9 is a schematic block diagram when a microconbeater is used.

When the microconbeater is not used, the rotation w6 Sakaki as shown in FIG. 10 may be used.

In the K rice paper copying machine, the paper feed timing roller 17 (first
For this purpose, the roller 17 is started to rotate when the optical center is located at the starting end of the m document table. However, depending on the model, the distance between the roller 17 and the transfer section 12 (see FIG. 1) may be relatively long, and when the copy paper starts to be fed from the roller 17, it is not always necessary to align the optical center with the original. It is necessary to start feeding the paper at the time when the former does not reach the latter position yet. In other words, if it is necessary to start feeding the paper at a position as shown in FIG. 7, it is necessary to check whether the starting edge of the document table 3 and the document 2 are aligned. This can be achieved by attaching the sensor 212 to the scanning table 34 at the position where the optical center is tilted to the right as described above, and when the scanning table 34 reaches the paper feeding start timing position, the sensor 212 is placed on the document table 3. Since the sensor 212 is located at 1k directly below the starting edge, it is possible to detect the misalignment of the original 2 and shift the paper feeding timing by the pulse count based on this sensor output.

In addition, in achieving the object of the present invention, the upper d self sensor 2
The position 12 does not necessarily have to be on the right side of the optical center, and can be selected from various positions.

Furthermore, if the sensor 21 is provided as shown in FIGS. 6 and 7, the sensor 22 will not interfere with the original image or the original table.

Although the present invention has been illustrated above, the above-mentioned example can be further modified based on the technical idea of the present invention.

For example, the position that serves as a reference for the deviation of the document position is not limited to the above-mentioned reference line sy, but can be arranged in various ways. Furthermore, various types of sensors can be used, including those that only receive light, and those that combine a light source and a light receiving element. In addition, position detection means other than the above-mentioned photoelectric sensor may be used as means for detecting the deviation. Note that the present invention is also applicable to a copying machine in which the document table moves.

As described above, the present invention detects the position of the placed copy object and controls the feeding timing of the copy material based on the output of this detection means, so that the leading edge of the produced copy is Copying can be performed so as to always match the leading edge of the object to be copied. Therefore, it is possible to eliminate misalignment of the leading edge due to a user's setting error, and to always align the leading edge even when using an automatic document feeder or the like, thereby making it possible to reliably achieve good copying.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, in which FIG. 1 is a cross-sectional view schematically showing an electrophotographic copying machine, FIG. 2 is a planar view of a document table, and FIG. X-ray cross-sectional view, Figure 4 is a 1aT1 diagram of the main part of the optical system according to another example, Figure 5 is
The figure is a cross-sectional view of the main part of an example equipped with a cover color switching mechanism, Figure 6 is a cross-sectional view of the main part of yet another example, Figure 2 is an enlarged view of a part of Figure 6, and Figure 8 AXB 9 is a schematic block diagram when a microconbeater is used, and FIG. 10 is a schematic block diagram when a microconbeater is not used. In addition, in the symbols used in the drawings, 2...
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・・・・・・・・・・・・・・・・・・Manuscript 3・・・・
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・・・－・・・・・・・・・・・・・・・ Original ffl4 (mounting) stand 4・・・・・・・・・・・・・・・・・・・・・・
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・Flatenkahar 5・・・・・・・・・・・・・・・−
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・・Photosensitive drum 10・・・・・・・・・・・・・・・
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・・・・・・・・・Transfer part 16.17・・・・・・
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...Paper feed row 5-21, 211.212...
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・・・・・・－・・・Belt 30 for color switching
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...It is an optical scanning platform. Agent Patent Attorney Hiroshi Osaka 1st ID ;120 1 Patent Application No. 28576 2 Invention credit/FIJ device 3 Interaction with supplementary person case Patent Applicant (1, 11 Higashi 1; 26, Nishi-Shinjuku 1F, Shinjuku-ku, Tokyo)
Number 2 Mr. 6 (Toyama) (127) Konishiroku Photo Industry Co., Ltd. 4 Agent Address 21 Suzuki Hill, 3-9-17 Shibasaki-cho, Tachikawa-shi, Tokyo
1i! 6. Number of inventions increased by supplement + E 7 Target (1) of drawing 11-, "Can be detected." on the 15th line of the 14th member of the specification is changed to "Can be detected. # Theory, same as the example in No. 5111 , Pe1
Yuki), 11th purchase line 4-1 "This is...
・This applies to the case of the fourth embodiment. However, it can be applied to the II example (
In the example of No. gsi, *5 ail, the amount of deviation from the reference line of li@ is detected in a wII manner based on No. 1 of each 7th ray of Senna 7 Ray). (3), ``(■ point) also'' in the car line on page 1 I [
(Receive a ■ point) Correct it as KJ. −1 above

Claims (1)

[Claims] 1. A detection means is provided for detecting a deviation between the reference placement position in the optical scanning direction and the placement position of the object to be copied, and the feeding timing of the copy material is determined based on the output of the detection means. A copying apparatus characterized in that it is configured to control. 2. The apparatus according to claim 1, wherein the photoelectric conversion element as the detection means is fixed to the lower surface of the table for placing the object to be copied. 3. The photoelectric conversion element as the detection means is movably arranged in a position where it can receive a part of the reflected light guided from the object to the carrier, the first part of the pestle detection range. The device described in paragraph 1. 4. The device according to claim 1, wherein the photoelectric conversion element as the detection means is arranged on an optical scanning table. 5. Claim 1, wherein at least a portion of the lower surface of the cover material covering the object to be copied is subjected to a treatment that allows the photoelectric conversion element serving as the detection means to be distinguished from the object to be copied. - The device described in any one of paragraphs 4 to 4. 6. The device according to claim 5, wherein the photoelectric conversion element is a color sensor, and at least a portion of the lower surface of the cover material is colored yellow. 7. The device according to claim 5 or 6, wherein the color of the lower surface of the cover material is switchable. 8. When the optical center of the optical scanning table corresponds to the position where the copy material feeding timing signal is generated, the photoelectric conversion element is located directly below the scanning start end of the copying object mounting table; An apparatus according to any one of claims 2 to 7.