JPH0517045A - Electrophotographic apparatus - Google Patents

Abstract

PURPOSE:To provide an electrophotographic apparatus wherein a copy is made without troubling user's hands in detection of width and length of a paper sheet only by setting a paper sheet of giving size. CONSTITUTION:In a transfer paper sheet regulation member moving mechanism, a transfer paper sheet end detection means 69 which detects the end of a transfer paper sheet 56 set by an operator is disposed. On the basis of a signal thus given by the transfer paper sheet end detection means 69, a transfer paper sheet regulation member 58b is moved to a specific position corresponding to the size of a transfer paper sheet 56.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic apparatus for controlling paper feeding and image formation in a copying machine or the like.

[0002]

2. Description of the Related Art As a conventional electrophotographic apparatus, a copying machine will be described as an example with reference to FIGS. First, the overall configuration of the copying machine will be described with reference to FIG. This apparatus includes an automatic document feeding / conveying unit 1 provided at the upper part of the main body, an exposing unit 2 as an exposing unit provided at the uppermost part of the main body, and an image forming unit provided below the exposing unit 2. And an image forming section 3 as a transfer sheet, a sheet feeding section 5 provided below the image forming section 3 and on an outer side surface as a transfer sheet feeding unit for feeding the transfer sheet 4, and the image forming section 3 forms an image. It comprises a transfer paper transporting section 6 as a transfer paper transporting means for discharging the formed transfer paper 4 to the outside, and a sorter section 7.

The automatic document feeding / conveying unit 1 includes a document feeding unit 10 as a document feeding unit for feeding a document 8 onto a contact glass 9 as a document placing table, and the document feeding unit 1.
The tray 11a includes a document transport unit 11 as a document transport unit that is disposed near 0 and that moves the document 8 between a position where the contact glass 9 is covered and a position where the contact glass 9 is released.

The exposure unit 2 includes a lamp 12 and a reflecting mirror 1.
3, a first mirror 14, a second mirror 15, a lens 16, and a third mirror 17.

The image forming section 3 includes a charging charger 1
8, a developing device 19, a transfer charger 20, a separation charger 21, a conveyor belt 22, a fixing device 23, a photosensitive drum 24, and the like.

In such a structure, the original 8 placed on the contact glass 9 is illuminated and scanned by the lamp 12, whereby the photosensitive drum 24 in the image forming section 3 is scanned.
An electrostatic latent image corresponding to the original image is formed on top. This electrostatic latent image is copied as an image on one sheet of transfer paper 4 fed from any of the paper feed cassettes 5a to 5c in the paper feed section 5. The copied transfer paper 4 is sent from the image forming unit 3 to the sorter unit 7 via the transfer paper transport unit 6. After that, when sorting work is performed, it is distributed to each bin 25, and when sorting work is not performed, one bin 25 is appropriately used.
Discharged inside.

On the other hand, the original 8 placed on the contact glass 9 is again exposed after the image exposure processing by the exposure unit 2 is completed.
The document transport belt 2 in the document transport unit 11 that has started to rotate around
The sheet is discharged onto the tray 11 a by 6.

Further, in FIG. 12, the original feeding portion 11 is placed at a position to cover the contact glass 9, and the original feeding portion 11 is hinged to the main body side by a hinge joint portion, and the hinge joint portion is formed. The contact glass 9 can be placed in a position where the surface of the contact glass 9 is released by lifting and rotating around. As a result, when a thick original such as a book-like original is copied, the above-described automatic original feeding function cannot be used. Therefore, the original conveying unit 11 is temporarily lifted to the release position to contact the thick original with the contact glass 9
The original is placed at the upper predetermined exposure position, and the original conveying section 11 is closed again, and then the exposure processing is performed.

Next, consider the case of copying a large-sized document (A2 or the like). As shown in FIG. 12, in the state where the original conveying section 11 is lifted and the contact glass 9 is released, the original conveying unit 27 shown in FIG. 13 is attached to the contact glass 9 at a position adjacent to the original feeding section 10. In this case, the document transport unit 27 is
A document table 28 on which the document 8 is placed, a side fence 29 for positioning the document 8 in the width direction, a turn roller 30 that rotates counterclockwise to convey the document 8, and an arm 31.
The pressure roller 3 supported by the turn roller 30 and in contact with the turn roller 30.
2, a stopper 33 that is positionally displaceable between a position (solid line) overhanging the document 8 fed from the document table 28 in the transport path and a position (chain line) retracted from the transport path.
A white plate 34 arranged to face a predetermined exposure position P, and a pressing roller 35 which is arranged on both sides of the white plate 34 and rotates counterclockwise while adhering the original 8 to the contact glass 9. , And a discharge roller 36 that rotates counterclockwise. The turn roller 30 is driven by a motor 37, and the set sensor 3 is provided at the entrance of the original 8 by the turn roller 30.
8, a registration sensor 39 is provided at the exit of the original 8 by the turn roller 30, and an end detection sensor 40 is provided at a position before the discharge roller 36.

When mounting the document feeding unit 27 on the upper portion of the main body, a recess previously formed on the bottom of the casing of the document feeding unit 27 is fitted into a fixing pin 41 provided on the upper surface of the main body to feed the document feeding section. 10
The original feeding unit 27 is attracted and fixed by the magnet 42 (see FIG. 13) provided in advance. When the document transport unit 27 is attached at a predetermined position in this way,
A detection signal is output from the setup switch 43 arranged at a position facing the magnet 42.

FIG. 14 shows another example of the method of attaching the document feeding unit 27. In this case, the magnet holder 45 to which the magnet 44 is fixed is screwed and fixed to the base 46 of the original feeding unit 27, and the magnet holder 4 is inserted into a hole (not shown) formed in the cover 47 of the main body.
After fitting 5, the magnet 44 is attracted to the inner frame 48 of the cover 47.

FIG. 15 shows an example of a control circuit of the document transport unit 27. The operation control of the document transport unit 27 is performed by the ADF control unit 49 having a microcomputer built therein. The ADF controller 49 is connected to the main body controller 50 of the copying machine via a serial interface 51, and information is exchanged via the interface 51. The ADF control unit 49 uses the arm 3 of FIG.
1, an output port for controlling the solenoid 52 for moving the stopper 33, the motor 37, etc., and an input port for receiving information from the various sensors.

Hereinafter, the operation of the original feeding unit 27 will be described with reference to FIG.
It will be described based on the timing chart of No. 6. When the document transport unit 27 is set to a predetermined position, the setup switch 53 is turned on, and the ADF control section 49 and the copying machine main body control section 50 indicate that the sheet through mode is different from the normal document stop exposure type mode. 8 is a mode in which exposure is performed while moving the contact glass 9 on the contact glass 9. For example, when an A2 size document (a size that is longer in the document feeding direction than the A3 size) is copied onto the A3 size transfer paper 4. Is the mode. When this mode is set, first, on the copying machine side, the lamp 12 of the exposure unit 2 illuminates the original 8 on the exposure position P (see FIG. 13), and the reflected light at that time is guided to the photosensitive drum 24. Thus, each component of the exposure unit 2 is fixed. The optical scaling ratio at this time is equal to (10
0%).

When the document 8 is loaded from the document table 28 into the document transport unit 27 during the sheet through mode,
The set sensor 38 is turned on, whereby the motor 37 is turned on and the original 8 is fed by the turn roller 30 until it abuts on the stopper 33. By abutting the document 8 against the stopper 33, skewing of the document 8 can be corrected, and the accuracy of the start position of the document 8 can be reliably obtained. Then, the motor 37 is turned off after a predetermined time has elapsed since the set sensor 38 was turned on. At this time, the ADF control unit 49 to the copying machine main body control unit 5
A READY status signal is transmitted to 0, and the copying machine is ready for copying based on this.

Next, when the operator presses the print key (copy start instruction key) of the copying machine, the signal is transmitted to the ADF control section 49. ADF control unit 4 receiving this signal
9 starts the timer operation. Predetermined time (To)
After the lapse of time, a feed start signal for the transfer paper 4 is transmitted from the ADF control unit 49 to the copying machine main body control unit 50. Based on this signal, the copying machine main body control unit 50 causes the transfer paper 4 to be fed. With reference to this time point, the solenoid 52 is turned on after T2 and the pressure roller 32 is pressed against the turn roller 30, and at the same time, the stopper 33 is retracted from the document transport path.

Next, the motor 37 is turned on after a lapse of T3 after the feeding start signal is transmitted. This T3 time is
The feeding of the transfer paper 4 is started, and the leading end of the original is adjusted to a position where an image is formed on the leading end of the transfer paper. Motor 37
When is turned on, the original 8 is accurately conveyed at a speed equivalent to the transfer paper conveying speed on the copying machine side, and the image on the original is projected on the photosensitive drum 24 at the same size. The synchronization between the original 8 and the transfer paper 4 is determined by T3. When the document 8 is conveyed and the trailing edge of the document passes the set sensor 38, the solenoid 52 is turned off to prepare for the next document 8.

When the original 8 passes through the exposure position P, the image exposure operation is performed by the exposure unit 2 fixedly arranged at that position. After the exposure, the original 8 is again fed by the original feeding section 1.
It is sent out to 0. After the trailing edge of the original has passed the sheet ejection sensor 40, the motor 37 is turned off after a certain period of time has elapsed.

When the sheet through mode is not used,
When the document transport unit 27 is removed from the copying machine, the setup switch 43 is turned off and the sheet through mode is released. When the setup switch 43 is turned off, the copying machine main body control unit 50 enters the normal copy mode, and the exposure unit 2 returns to the normal standby position.

As described above, by providing the document feeding unit 27, in the normal mode (the document feeding unit 2
It is possible to copy an A2 size original 8 larger than the maximum original size A3 (in the copy mode in which 7 is not used) to the A3 size transfer paper 4 while feeding at a constant speed. Further, here, the case where the A8 size original 8 is copied to the A2 size at the same size is taken as an example, but if the conveyance speed of the original 8 is made variable, the other size originals 8 are copied regardless of the magnification. be able to.

In FIG. 13, it is desirable that the distance between the white plate 34 provided corresponding to the exposure position P and the contact glass 9 is about 0.5 mm. As a result, it is possible to prevent the original 8 from floating up together with the function of the pressing roller 35 and obtain a good image. Further, in FIG. 13, the stop claw 5 is provided on the right side of the contact glass 9.
3 is provided. Normally, the stop claw 53 projects about 1.5 mm from the surface of the contact glass 9 in the copy mode (when the document transport unit 27 is not used).
It works as a stopper for the original 8 when the original 8 is automatically fed. When the document conveying unit 27 is attached, it is pushed down by an appropriate pressing member, such as a pressing pin, which is provided in the unit in advance. Stop claw 5
After the evacuation of No. 3, the thin plate member 54 contacts the contact glass 9
The original 8 is scooped up from the surface of the contact glass 9 by the thin plate member 54.

[0021]

In the apparatus having the fixed type document table (contact glass 8) as described above, the exposure lamp 12 and the mirror 1 are used when performing the copying operation.
An original image is projected on the photoconductor by moving and scanning 4, 15, 17, the lens 16, and the like. However, in such a method, it is naturally impossible to copy a document having a size larger than the size of the document table. Therefore, in the case of a larger size (however, the maximum copy width is less than or equal to the depth length of the document table), a method is generally adopted in which the document is copied at a constant speed while the exposure system is stopped. There is.

However, in practice, there are long originals of various sizes other than the standard sizes such as B3 and A2, and the conventional treatment for such long originals is the control program for copying. Processing using a modified custom-made copier, or giving up such processing, its application range was limited.

[0023]

According to a first aspect of the present invention, there is provided an original document feeding means for feeding an original document onto the original document placing table, and the original document placing table provided in the vicinity of the original document feeding means. A document conveying unit for moving the document between a covering position and a releasing position, an exposing unit located below the document conveying unit for illuminating the surface of the document, and a transfer sheet feeding unit for feeding the transfer sheet. A transfer unit, an image forming unit that exposes the reflected light from the original obtained by the exposing unit onto the surface of the transfer sheet to form an image, and a transfer sheet on which an image is formed by the image forming unit. In an electrophotographic apparatus provided with a transfer paper transporting means for discharging to the outside, a transfer paper edge detecting means for detecting an edge of the transfer paper set by an operator is provided and detected by the transfer paper edge detecting means. Transfer paper regulation member based on the signal Provided transfer sheet regulating member moving mechanism that moves to a predetermined position commensurate with the size of the transfer sheet.

According to a second aspect of the present invention, in the first aspect of the present invention, the amount of movement of the transfer sheet regulating member is detected, and unnecessary charging is arranged in proximity to the photosensitive member according to the detected amount of movement. An unnecessary charge removing drive control means for controlling the drive of the removing means is provided.

According to the third aspect of the present invention, a document feeding means for feeding a document onto the document placing table, a position which is arranged close to the document feeding means and which covers the document placing table and a position where the document placing table is released. A document transporting means for moving the document between the document transporting means, an exposing means located below the document transporting means for illuminating the surface of the document, a transfer paper feeding means for feeding the transfer paper, and the exposure means. Image forming means for forming an image by exposing the surface of the transfer paper with the reflected light from the original obtained by the means,
In an electrophotographic apparatus provided with a transfer paper transporting means for discharging the transfer paper on which an image is formed by the image forming means, a transfer paper size detecting means for detecting the width and length of the transfer paper is provided. An electrophotographic apparatus, comprising: an image forming time control means for driving and controlling an unnecessary charge removing means at the time of image formation by the detected signal and changing a series of control times required for the image formation.

According to a fourth aspect of the invention, in the third aspect of the invention, the width of the transfer sheet is detected by detecting the position of a transfer sheet regulating member that regulates the feeding position of the transfer sheet. The length of the transfer paper is detected by detecting the position of the transfer paper conveyed on the conveying path.

[0027]

According to the first aspect of the invention, the transfer paper regulating member is moved to the predetermined size corresponding to the size of the transfer paper by using the transfer paper regulating member moving mechanism based on the signal detected by the transfer paper edge detecting means. By moving to a position, transfer paper of any size is set automatically, so it is not necessary for the operator to adjust it to the correct position one by one as in the past, thus preventing jam due to skew Is possible.

In the second aspect of the present invention, the eraser is controlled in accordance with the set transfer paper width by controlling the drive of the unnecessary charge removing means using the unnecessary charge removing drive control means. As a result, it becomes possible to prevent stains inside the machine due to unnecessary toner adhesion and the like.

According to the third aspect of the invention, the image forming time control means can copy not only the transfer paper of a fixed size but also any transfer paper (especially, a long size). It is possible to prevent a decrease in productivity due to the limitation.

According to the invention described in claim 4, since the operator does not need to input the width and length of the different size transfer paper by the operation unit, mis-copying can be prevented. .

[0031]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the invention described in claims 1 and 2 is shown in FIGS.
It will be described with reference to FIG. First, in an electrophotographic apparatus as shown in FIG. 11, a large paper feeding unit 5 (external paper feeding unit) is provided on the outer side surface on the left side of the main body of the copying machine. A large amount of transfer paper 4 is loaded on the cassette 5a. FIG. 1 is an enlarged view of the area of the paper feed section 5, in which the upper portion of the paper feed cassette 5a is
A manual feed table 55 is provided for feeding a paper 56 as a non-standard size transfer paper. This manual table 5
5 is movable up and down in the direction of arrow C, and in the closed state (the state where it is lifted up), the paper feed roller 57 is in contact with the uppermost surface of the transfer paper 4 loaded in the paper feed cassette 5a, On the contrary, in the open state (lowered state), the lower end of the manual feed table 55 enters the lower side of the paper feed roller 57, thereby feeding the paper 56 placed on the table surface.

FIG. 2 is a view as seen from the direction A in FIG. 1, and the manual feed table 55 is provided with paper regulating members 58a and 58b as transfer paper regulating members facing each other. The sheet regulating member 58a is fixed to one side, but the sheet regulating member 58b is movably attached to the timing belt 60 via a supporting member 59. Further, a shielding plate 61 and a reflection type photosensor 62 as a transfer paper edge detecting means are attached to the paper regulating member 58b. The reflective photo sensor 62 and the paper regulating member 58b are separated by a distance ds. The timing belt 60 is stretched between pulleys 63a and 63b, and a motor 64 is connected to one of the pulleys 63a. An encoder disk 65 is attached to the motor 64, and the rotation amount of the motor 64 can be detected by a signal generated from the photo interrupter 66. The relationship between the amount of movement of the paper regulating member 58b and the number of encoder pulses generated from the encoder disk 65 is determined by the pulley diameter, but here, the paper regulating member 58b.
When 1 moves by 1 mm, one encoder pulse is obtained. Further, a photo interrupter 67 as a transfer paper edge detecting unit is provided at a position where the paper regulating member 58b is separated from the paper regulating member 58a by a distance dm, that is, a position where the shielding plate 61 is detected when the paper regulating member 58a is opened to the maximum width. Has been done. In this case, the timing belt 60, the pulleys 63a and 63b, the motor 64, and the encoder disk 65 form a transfer paper regulating member moving mechanism 68.
FIG. 3 is a view seen from the B side in FIG. 1.

Further, in FIG. 1, a photo sensor 69 as a transfer paper edge detecting means for detecting the presence or absence of the paper 56 on the manual feed table 55 is provided at a position close to the paper feed roller 57, and the photo sensor 69 is provided. A pair of transport rollers 70 are arranged on the path in front of the paper rollers 57. This allows
The paper 56 inserted from the manual feed table 55 is the paper feed roller 5
It is sent from the conveyance roller 70 into the inside of the main body via 7.

In FIG. 11, an eraser 72 as unnecessary charge removing means is provided between the charger 18 and the cleaning device 71. Here, the amount of movement of the paper regulating member 58b is detected, An unnecessary charge removing drive control means (not shown) for controlling the drive of the eraser 72 according to the detected movement amount is provided.

In such a structure, A2 is used in the conventional example.
The mode in which the original is copied in the see-through mode on the A2 sheet (transfer sheet) at the same size has been described.
A method of copying the original document 8 of any other size other than this onto the paper 56 of the same size at the same size will be described. As a specific example, a control method in the case of setting a paper 56 (an irregular size) having a width of 300 mm and a length of 800 mm on the manual feed table 55 will be described.

Before starting the description of a concrete example of the non-standard size paper 56, consider a case where a normal standard size (A4, A3, etc.) is copied. Inside the main body of the copying machine as shown in FIG. 11, there is provided an eraser 72 in which light emitting bodies such as LEDs are arranged in a line in order to remove unnecessary charges on the photosensitive drum 24. FIG. 5 shows a state of the eraser 72. The LEDs 74 are arranged at a pitch of about 3 mm.
About 0 LEDs are arranged, and each LED 74 can be turned on and off arbitrarily by a program.
When the LED 74 is ON, the charge on the photosensitive drum 24 facing the position is removed, and the toner does not adhere. Therefore, in the non-image area 75 other than the image area 73 on the photoconductor drum 24 (see FIG. 4), unnecessary charging is removed by such a method. As described above, in the case of copying in a normal fixed size, since the width and length of the image area 73 are known in advance, the LED at the location corresponding to this width is turned on and off. For example, in the case of A4 size, the width is 297 × the length is 210 (mm), so 2
97/3 = 99 LEDs are turned off from the end, and the other LEDs are turned on during the copying operation to remove unnecessary charges on the photosensitive drum 24.

However, when using the paper 56 having an arbitrary width as in the present embodiment, it is necessary to detect the paper width and control the LED 74 of the eraser 72 based on the data. Therefore, a control method when the irregular size paper 56 is set will be described below. now,
One side of the paper 56 is moved toward the front so as to come into contact with the paper regulating member 58a and set, and the print key (see FIG. 6) is pressed. As a result, the motor 64 starts to rotate in the direction of opening the paper regulating member 58b, and thereafter, at the time when the photo interrupter 67 detects the shield plate 61, that is, at the position Ph.
Stop at. Next, the motor 64 starts rotating in the opposite direction, and at some point, the reflective photosensor 62 detects the paper 56 and generates a signal. Now, assuming that ds = 5 mm, if the motor 64 is stopped when five encoder pulses are generated after this signal is generated, the paper regulating member 58b
Is in contact with the paper 56 on the table, and the position in this state is indicated by Ps.

Now, while the paper regulating member 58b is moving from the Ph position to the Ps position, the photo interrupter 66 is moved.
It is assumed that the number of encoder pulses generated from is 130 pulses. As shown in FIG. 4, when dm = 430 mm, the width W of the paper 56 is W = 430-130 = 300 m.
m is required. If it is determined that the width W is 300 mm, the number N of the LEDs 74 that should be turned off from the front end portion of the eraser 72 in the image area 73 can be obtained as follows.

[0039]

[Equation 1]

In this way, the paper 5 is placed on the manual feed table 55.
By setting 6 and pressing the print key, the paper regulating member 58b is automatically moved to the correct position, and the number of LEDs 74 of the eraser 72 to be turned off is calculated.

Next, the eraser 72 relating to the paper feeding direction.
The lighting timing of will be described. Photoconductor drum 24
The upper charged area should look like FIG. 4 when developed. In this case, the shaded area is the image area 73 that coincides with the paper 56 and should be charged, but the surrounding area is the non-image area 75 and should not be charged in order to prevent unnecessary adhesion of toner. However, since the main charger cannot selectively charge the photoconductor drum 24 as described above, the charge is removed by the eraser 72 after the entire surface is once uniformly charged. In addition, in FIG.
The point indicates the image front end, and the point b indicates the image rear end.

When the print key is pressed to start the copying operation, first, the paper regulating member 58b is automatically moved to detect the width of the paper 56 and the manual feed table 5
5 regulates the paper 56 on. Next, the main motor is rotated to drive and rotate the photosensitive drum 24, the paper feed / conveyance roller, and the like. At the same time, the main charger is turned on to uniformly charge the photosensitive drum 24. Also, LE of the eraser 72
All of D74 are also turned on to remove unnecessary charges on the photosensitive drum 24. Next, when the point a on the photoconductor drum 24, which coincides with the leading edge of the original and the leading edge of the sheet, comes directly below the eraser 72, N (100 in this case) LEDs of the LEDs 74 of the eraser 72 are turned off. Thereafter, the original image is sequentially projected onto the photosensitive drum 24 to form a latent image, and the latent image is developed, and then the toner image is transferred onto the paper 56.

The trailing edge of the image (point b) is controlled as described below. When the paper 56 is conveyed and its rear end reaches the photo sensor 69, the signal is sent to the CPU.
Is detected, and after a certain time, all LEDs 74 of the eraser 72 are turned on. The fixed time in this case means that the photoconductor drum 2 is moved after the rear end of the paper 56 reaches the photosensor 69.
It is the time until the point b on 4 comes directly under the eraser 72. Further, after a lapse of a certain time, each load such as the main motor is turned off and the copying operation is completed. Therefore, if the control is performed in this manner, the position of the leading edge of the sheet with respect to the image on the photoconductor 56 is fixed by the registration rollers regardless of the length of the sheet 56, and the trailing edge of the sheet 56 is fixed. Is controlled by the signal of the photo sensor 69, and thus copying is possible.

FIG. 6 shows the control timing as described above.
Shown in. When the paper 56 is set on the manual feed table 55 and the print key is pressed, the motor 64 once rotates in the opening direction, then detects the signal of the photo interrupter 67, and then rotates in the opposite direction. After detecting the signal of the photo interrupter 67, the encoder pulses generated from the photo interrupter 66 are counted. Reflective photo sensor 6
When 2 detects the edge of the paper 56, the motor 64 is stopped 5 pulses after that. After that, the loads such as the main motor and the main charger are turned on and the copying operation is started. The eraser 72 is initially fully lit to remove excess charges on the photoconductor drum 24 (C in FIG. 6). After that, when the point corresponding to the leading edge of the image on the photoconductor drum 24 comes directly below the eraser 72, the eraser 72 follows the number of pulses measured previously.
Part of the LED 74 is turned off (D portion in FIG. 6). Further, when the photo sensor 69 is turned off and the rear end of the paper 56 is detected, after a time Te, the eraser 72 is fully turned on again. Similarly, at time Tm, the eraser 725, the main motor, etc. are turned off, and the copying operation ends. In addition,
The time Te is the time after the trailing edge of the sheet passes the photo sensor 69, and the trailing edge of the image on the photosensitive drum 24 reaches directly below the eraser 72. The time Tm is the trailing edge of the sheet passes the photo sensor 69. It shows the time from when the paper 56 is completely discharged to the copying machine main body.

An embodiment of the invention described in claims 3 and 4 is shown in FIG.
~ It demonstrates based on FIG. It should be noted that the description of the same parts as those of the invention according to claims 1 and 2 (see FIG. 1) is omitted, and the same reference numerals are used for the same parts.

As shown in FIGS. 7 and 8, in the external sheet feeding unit of the electrophotographic apparatus, an elongated groove 76 is formed on the manual feed table 55, and along this groove 76, the sheet regulation is performed in the arrow direction. The member 58b is movably attached. A contact 77 is provided at the tip of the paper regulating member 58b, and a slide type resistor 78 (potentiometer) having one end grounded and a voltage of + 12V applied to the other end is provided at a position in contact with the contact 77. It is arranged. As a result, the contact 7 is placed on the slide type resistor 78.
As 7 moves, the voltage corresponding to the position is output to the terminal Vp. Manual table 55
A reflective photosensor 79 for detecting whether or not the sheet 56 (transfer sheet) is carried in is provided at a position close to the sheet feeding roller 57. In this case, the contactor 77, the slide resistor 78, and the reflective photosensor 79 are used as the transfer paper size detection means 8 for detecting the width and length of the paper 56.
Configures 0. However, the width of the paper 56 is detected by detecting the position of the contact 77 of the paper regulating member 58b that regulates the paper feed position of the paper 56, and the length of the paper 56 is conveyed on the conveyance path. The position of the sheet 56 is detected by the reflective photosensor 79.

In this embodiment, the detected signal is used to drive and control the eraser 72 (see FIG. 5) as an unnecessary charge removing means at the time of image formation, and a series of control time required for the image formation is set. Image forming time control means (not shown) for changing the image forming time is provided.

In such a structure, as a specific example,
A case will be described in which the paper 56 having a width of 300 mm and a length of 800 mm is set on the manual feed table 55. After setting the paper 56 in contact with the paper regulating member 58a,
The other sheet regulating member 58b is moved to contact the sheet 56. The maximum paper width that can be copied with this copier is shown in Fig. 9
As shown in (4), although it is 420 mm (length in the longitudinal direction of A3), if the paper regulating member 58a and the paper regulating member 58b are opened to the maximum of 420 mm, a voltage of 12 V is obtained for Vp. It is like this.

Therefore, assuming that the resistance value of the slide type resistor 78 is uniform, the sheet regulating members 58a, 58 will now be described.
If b is set to a width of 300 mm, Vp will be

[0050]

[Equation 2]

The voltage of will be obtained. Since the voltage of Vp is input to the control unit (CPU) of this copying machine, the paper width can be detected by the voltage.

If it is determined that the width is 300 mm, the LED 74 (see FIG. 5) which should be turned off from the front end portion of the eraser 72 in the image area 73 can be obtained in the same manner as the above-mentioned equation (1). . That is, the image area 7
In No. 3, it is necessary to turn off the 100 LEDs 74 from the near side (the side of the paper regulating member 58a) for a time period commensurate with the length of the image use area. In this way, the number of LEDs 74 of the eraser 72 that should be turned off is calculated only by setting the sheet regulating member 58b so as to match the sheet 56.

Next, the eraser 72 relating to the paper feeding direction.
The lighting timing of will be described. Photoconductor drum 24
The upper charging area is expanded as shown in FIG. Here, the shaded area should be charged in the image area 73 that coincides with the paper 56, but the surrounding area should not be charged in the non-image area 75 in order to prevent unnecessary toner adhesion. However, since the main charger cannot selectively charge the photosensitive drum 24 as described above,
Once the entire surface is uniformly charged, the eraser 72 removes the charge. In addition, in FIG. 9, point a indicates the leading edge of the image, and point b indicates the trailing edge of the image.

When the print key is pressed to start the copying operation, the main motor is first rotated to drive the photosensitive drum 24, the paper feed roller 57, the transport roller 70 and the like.
At this time, all LEDs 74 of the eraser 72 are also turned on to remove unnecessary charges on the photosensitive drum 24. Next, when the point a, which coincides with the leading edge of the document and the leading edge of the sheet, comes directly under the eraser 72, 100 LEDs of the LEDs 74 of the eraser 72 are turned off from the front side (the sheet regulating member 58a side). afterwards,
The image of the original is sequentially projected onto the photosensitive drum 24 to form a latent image, and after development, the toner image is transferred onto the paper 56. The image edge (point b) is controlled as follows. When the paper 56 is conveyed and the trailing edge of the paper reaches the reflection type photo sensor 79, the signal is detected by the CPU,
After a certain time, all the LEDs 74 of the eraser 72 are turned on. Further, after a lapse of a certain time, each load such as the main motor is turned off, and the copying operation ends. In this case, for the latter fixed time, the rear end of the paper 56 is reflected by the photo sensor 79.
It suffices if the margin is added to the time from when the sheet passes through to the sorter section 7 on the right side of the copying machine main body. Regardless of the length of the paper 56, the position of the front end of the paper with respect to the image on the photosensitive drum 24 is fixed by being regulated by the registration roller, and the rear end of the paper 56 is a reflection type photosensor 79. Since it is controlled by a signal, copying can be performed.

Next, the control timing as described above will be described with reference to FIG. The load of the main motor etc. turns on at the same time as the print key turns on. At the same time,
The charging charger 18 is also turned on to charge the photosensitive drum 24. Then, the eraser 72 is also fully turned on to remove unnecessary charges (C portion in FIG. 10). Further, the LED 74 of the eraser 72 is turned off from the front side (the side of the sheet regulating member 58a) 100 at a position corresponding to the front end of the image (D portion in FIG. 10). After that, when the reflection type photo sensor 79 detects the trailing edge of the sheet and turns off, after a time Te from that point, all lights are turned on (C portion), and subsequently, after a time Tm, all other loads such as the main motor are also turned off. To end the copying operation.

[0056]

According to the first aspect of the present invention, the document feeding means for feeding the document onto the document placing table, the position arranged near the document feeding means and covering the document placing table, and the releasing position. A document transporting means for moving the document between a position where the document is moved, an exposing means located below the document transporting means for illuminating the surface of the document, and a transfer paper feeding means for feeding the transfer paper. Image forming means for forming an image by exposing the surface of the transfer paper with the reflected light from the original obtained by the exposing means;
In an electrophotographic apparatus provided with a transfer paper conveying means for discharging the transfer paper on which an image is formed by the image forming means, a transfer paper edge detecting means for detecting an edge of the transfer paper set by an operator. And a transfer paper regulating member moving mechanism for moving the transfer paper regulating member to a predetermined position corresponding to the size of the transfer paper on the basis of the signal detected by the transfer paper edge detecting means. The transfer paper regulating member is moved to a predetermined position corresponding to the size of the transfer paper by using the transfer paper regulating member moving mechanism based on the signal detected by the paper edge detecting means, whereby the transfer paper of any size is transferred. Since it is automatically set even when placed, it eliminates the need for the operator to align the correct position one by one as in the past, which prevents jamming due to skew. It is intended.

According to a second aspect of the present invention, in the first aspect of the present invention, the amount of movement of the transfer sheet regulating member is detected, and unnecessary charging is arranged in proximity to the photoconductor in accordance with the detected amount of movement. Since the unnecessary charge removing drive control means for controlling the drive of the removing means is provided, the eraser is controlled according to the set transfer paper width by controlling the drive of the unnecessary charge removing means using the unnecessary charge removing drive control means. As a result, it is possible to prevent the inside of the machine from being contaminated due to unnecessary toner adhesion and the like.

According to a third aspect of the present invention, a document feeding means for feeding a document onto the document placing table, a position which is arranged in the vicinity of the document feeding means and covers the document placing table, and a position where the document placing table is released. A document transporting means for moving the document between the document transporting means, an exposing means located below the document transporting means for illuminating the surface of the document, a transfer paper feeding means for feeding the transfer paper, and the exposure means. Image forming means for forming an image by exposing the light reflected from the original obtained by the means onto the surface of the transfer paper, and the transfer paper for discharging the transfer paper on which the image is formed by the image forming means to the outside. In an electrophotographic apparatus including a conveying unit, a transfer sheet size detecting unit for detecting the width and length of the transfer sheet is provided, and the unnecessary charge removing unit is driven and controlled at the time of image formation by the detected signal and the image thereof is provided. Series of controls required for formation Since the image forming time control means for changing the interval is provided, the image forming time control means allows not only the transfer paper of a fixed size but also any transfer paper (especially a long size) to be copied. It is possible to prevent a decrease in productivity due to the size limitation.

According to a fourth aspect of the invention, in the invention of the third aspect, the width of the transfer sheet is detected by detecting the position of a transfer sheet regulating member that regulates the sheet feeding position of the transfer sheet. Since the length of the transfer paper is detected by detecting the position of the transfer paper conveyed on the conveying path, the operator purposely inputs the width and length of the different size transfer paper by the operation unit or the like. Since it is not necessary to do so, it is possible to prevent miscopying.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the invention described in claims 1 and 2.

FIG. 2 is a configuration diagram of a manual feed table section viewed from a direction A of FIG. 1, that is, a sheet carry-in direction.

FIG. 3 is a configuration diagram of a manual labor table portion viewed in the direction B of FIG. 1, that is, a part of the table upper surface is cut away.

FIG. 4 is an explanatory view showing a charged area on a photosensitive drum in a developed manner.

FIG. 5 is a configuration diagram showing a state in which LEDs forming an eraser are arranged.

FIG. 6 is a timing chart showing a lighting timing of the eraser.

FIG. 7 is a configuration diagram showing an embodiment of the invention described in claims 3 and 4.

8 is a configuration diagram of a manual labor table portion viewed from the table upper surface side of FIG. 7. FIG.

FIG. 9 is an explanatory view showing a charged area on a photosensitive drum in a developed manner.

FIG. 10 is a timing chart showing a lighting timing of the eraser.

FIG. 11 is a side view showing the overall configuration of the copying apparatus.

FIG. 12 is a perspective view showing a state of a document conveyance unit provided on the upper part of the copying machine main body.

FIG. 13 is a side view of a document feeding unit.

FIG. 14 is a side view showing a state of an attachment portion of a document feeding unit to a copying machine main body.

FIG. 15 is a circuit diagram showing an example of a control circuit.

FIG. 16 is a timing chart illustrating the operation of the document transport unit.

[Explanation of symbols]

3 Image forming means 4 Transfer paper 5 Transfer paper feeding means 6 Transfer paper transport means 8 manuscript 9 Document holder 10 Document feeding means 11 Document transport means 62,67 Transfer paper edge detection means 68 Transfer paper regulating member moving means 69 Transfer paper edge detection means 72 Unnecessary electrostatic charge removing means 80 Transfer paper size detection means

Claims (4)

[Claims] 1. An original document feeding means for feeding an original document onto a document table, and the original document between a position which is arranged in the vicinity of the original document feeding means and which covers the original document table and a release position. A document transporting means for moving the sheet, an exposing means located below the document transporting means for illuminating the surface of the document, a transfer sheet feeding means for feeding a transfer sheet, and the exposure means obtained by the exposing means. An image forming means for exposing the surface of the transfer paper by reflected light from the original to form an image, and a transfer paper conveying means for discharging the transfer paper on which the image is formed by the image forming means to the outside are provided. The electrophotographic apparatus is provided with a transfer paper edge detecting means for detecting an edge of the transfer paper set by an operator, and the transfer paper regulating member is provided with the transfer paper regulating member based on a signal detected by the transfer paper edge detecting means. Predetermined position corresponding to the size of the transfer paper An electrophotographic apparatus provided with a transfer paper regulating member moving mechanism for moving the sheet to a sheet. 2. An unnecessary charge elimination drive control means for detecting an amount of movement of the transfer paper regulating member and controlling drive of the unnecessary charge elimination means arranged in proximity to the photoconductor according to the detected movement amount. The electrophotographic apparatus according to claim 1, wherein the electrophotographic apparatus is provided. 3. The original document feeding means for feeding the original document onto the original document placing table, and the original document between a position which is arranged in the vicinity of the original document feeding means and which covers the original document placing table and a releasing position. A document transporting means for moving the sheet, an exposing means located below the document transporting means for illuminating the surface of the document, a transfer sheet feeding means for feeding a transfer sheet, and the exposure means obtained by the exposing means. An image forming means for exposing the surface of the transfer paper by reflected light from the original to form an image, and a transfer paper conveying means for discharging the transfer paper on which the image is formed by the image forming means to the outside are provided. The electrophotographic apparatus is provided with a transfer paper size detecting means for detecting the width and length of the transfer paper, and the unnecessary charge removing means is driven and controlled at the time of image formation by the detected signal, and a series of series necessary for the image formation is provided. Image shape that changes control time An electrophotographic apparatus provided with a growth time control means. 4. The width of the transfer sheet is detected by detecting the position of a transfer sheet regulating member that regulates the sheet feeding position of the transfer sheet, and the length of the transfer sheet is detected on a conveying path. The electrophotographic apparatus according to claim 3, wherein the operation is performed by detecting the position of the transfer sheet.