JPH04264464A - Copying controller - Google Patents

Abstract

PURPOSE:To provide a controller capable of judging the size of transfer paper to be fed in order to erase the outer side of the part of a photosensitive body corresponding to the size of the transfer paper to prevent toner from adhering to the dielectric film of a transfer drum in a copying machine provided with the transfer drum. CONSTITUTION:The width range of the transfer paper is detected by a multiple sensor obtained by arranging plural sensors Sa-Sf in a lateral direction with respect to a paper feeding path. In the case that plural sizes exist in the same width range, the length of the transfer paper is detected and the detected value is compared with the data of every size of the transfer paper which is stored in a RAM so as to judge, select and set the size of the transfer paper, then an eraser is controlled according to the size.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a copy control device for an electrophotographic copying machine having a transfer drum.

0002

2. Description of the Related Art In a color copying machine using an electrophotographic process, as shown in FIG. 1A, a filter group 2 consisting of blue, green, and red color separation filters and a yellow or ND filter is arranged on one photoreceptor drum 1. The color-separated images of the document 3 are exposed through the respective filters to form four types of latent images, and the latent images are applied to yellow, magenta, cyan, and black developers provided along the photoreceptor drum 1, respectively. The resulting four-color toner image is developed by developing units 4Y, 4M, 4C, and 4BK that are built in, and the resulting four-color toner image is transferred to the transfer drum 5, which rotates synchronously and at the same linear speed in contact with the photoreceptor drum 1. Transfer paper is fed to position A from 11 and transferred onto the rolled transfer paper by the action of transfer charger 7, and after four transfers are completed, B
A full-color copying machine using a so-called color separation image superimposition transfer system is well known, in which the transfer paper is separated from the transfer drum by a separation charger and a separation claw 8 at the position , and is fixed by a fixing device 9 to obtain a color copy.

As shown in FIG. 1B, the above-mentioned transfer drum is made of a metal such as aluminum and consists of annular parts 10a at both ends of the drum and a connecting part 10b connecting these parts and extending in the axial direction. The support frame 10 is made up of a support frame 10, and a dielectric elastic film 12 such as a polyethylene terephthalate (trade name: Mylar) film is wrapped around the outer peripheral surface of the support frame 10. A gripper 13 that can be opened and closed is provided on the outer peripheral surface of the connecting portion 10b of the support frame, and rotates by gripping the leading edge of the transfer paper 14 conveyed from the paper feed section 6, and the transfer paper 14 is attached to a dielectric film. 12 and rotates integrally with the transfer drum 5 a predetermined number of times, toner images formed on the photosensitive drum are superimposed and transferred.

In an electrophotographic copying machine having such a configuration, if toner adheres to the dielectric film of the transfer drum, problems such as back staining occur, so the four circumferences of the image forming area on the photoreceptor are erased by an eraser before development. This prevents the electric charge from being developed and a solid black toner image from being transferred to the dielectric film of the transfer drum. The eraser is designated by the reference numeral 15 in FIG. In the figure, the eraser 15 is provided between the exposure position and the first developing device 4BK, but it may be provided before the exposure position after charging. The eraser is formed by a light source that irradiates light only to the portion to be neutralized.

Now, in order to accurately eliminate electricity from the image forming area of the photoreceptor, that is, around the four circumferences of the portion corresponding to the size of the transfer paper, it becomes necessary to detect the size of the transfer paper. As a means for detecting the transfer paper size, separate paper feed cassettes are provided for each transfer paper size, and when the paper feed cassette is installed in the main body of the device, one of the switches provided for each transfer paper size is activated. A device that sends a transfer paper size signal is known, but it is not suitable for small, low-priced popular copying machines and CPs.
In a copying machine with a low M (number of copies per minute), the number of paper feed cassettes is two at most, so cassettes must be replaced frequently to accommodate various sizes, making operations complicated. For this reason, a typical black-and-white copying machine has a manual feed mode, and performs exposure scanning and erase control with the transfer paper size as the maximum size that the machine can handle.

Furthermore, as shown in FIG. 6, the side fence 1
6 and end fence 17 can be moved to arbitrary positions, and the fences are moved according to the required transfer paper size to place the transfer paper and automatically feed the paper. Also used is a paper feed cassette 18 called a paper feed cassette 18. In this case as well, since the size of the fed transfer paper is unknown, the exposure scan scans the entire area of the maximum size transfer paper, and the eraser control erases the area outside the maximum size. In such a case, if you close the original pressure plate and perform exposure, there is no problem because the white color on the back of the pressure plate will be exposed outside the area of the document, but if the original is a thick book, the pressure plate will be exposed to the contact glass around the document. Since the toner does not adhere closely to the dielectric film, it becomes a solid black toner, and in copying machines with a transfer drum, the solid black toner adheres to the dielectric film and causes back stains. Therefore, when feeding transfer paper using a multi-size paper feed cassette as well as manual paper feeding, it is necessary to accurately detect the size of the fed transfer paper and perform erase control.

[0007] Now, the size of paper that is generally commercially available as copy paper is JIS based on the ISO standard in Japan.
The standards are A3, B4, A4, B5, A5, B6, and A6, and some of them are used both vertically and horizontally. By installing transfer paper width range detection sensors arranged at appropriate intervals across the paper on one side of the paper passing standard, it is possible to specify the transfer paper size using the difference in paper width for each transfer paper size. be.

[0008] However, in Europe and America, the above ISO A column,
In addition to the size of paper in column B, various sizes are used. These are listed in Table 1.

[0009]

[Table 1]

[0010] As seen from Table 1, the dimensions of paper of sizes other than JIS standards are 81/2" (=216 mm) and 1
1” (=279.4mm).21
6mm is the width of A4 size 210mm, or 279.4m
m is approximate to the width of A3 size 297mm, and 10
” (=254mm) is almost the same as the width of B4 size 257mm.It is quite difficult to accurately identify this with a sensor due to the accuracy of the sensor installation position.
It is theoretically impossible for a width range detection means to distinguish between 1" width and 81/2" width.

[0011]

[Problems to be Solved by the Invention] The present invention is capable of accurately detecting the transfer paper size, which is strongly required for copying machines having a transfer drum, and based on this, erases areas other than those corresponding to the photoreceptor transfer paper. An object of the present invention is to provide a copying control device for a copying machine that is capable of performing erase control to perform erase control.

0012

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention provides a copying control device for a copying machine having a transfer drum having the above-mentioned configuration. a storage means for storing size information of the transfer paper fed from the paper feeding means; and a means for detecting size information of the transfer paper fed from the paper feeding means; It has a means for determining which paper size corresponds to the paper size and selecting and setting the transfer paper size. The transfer paper width range detection means is composed of a plurality of sensors arranged side by side in the horizontal direction, and the length detection means in the transport direction of the transfer paper, and the above-mentioned transfer paper size is determined by the transfer paper width range detection means. If there is only one transfer paper size stored in the storage means in the detected width range, it is determined based on the width range information, and if there are multiple sizes in the same width range, the transfer is performed based on the width range information and length information. The present invention is characterized in that the paper size is determined, and the charge removing means is controlled to remove the charge from a portion outside the portion on the photoreceptor corresponding to the transfer paper size selected and set as a result of the above judgment.

[0013]

[Operation] Since this copying control device is constructed as described above, the transfer paper width range in which the transfer paper fed from the paper feed section to the transfer drum is first detected by the transfer paper width range detection means. Ru. If there is only one transfer paper size stored in the storage means as a transfer paper size that exists in that width range, the fed transfer paper is determined to be that transfer paper size, and that size is selected and set. be done.

If there are a plurality of transfer paper sizes stored in the storage means in the width range detected by the transfer paper width detection means, the front edge and the rear edge of the transfer paper may be detected by the same sensor while the transfer paper is being conveyed. By comparing the length information of the transfer paper obtained from the time and conveyance speed during which the paper passes through the paper and the length information about the plurality of transfer paper sizes stored in the storage means, the fed transfer paper Since the size of is determined, that size is selected and set.

[0015] Then, control is performed so that the portion outside the portion on the photoreceptor corresponding to the selected transfer paper size is removed by the charge removal means.

As a result, toner does not adhere to the outer portion of the photoreceptor corresponding to the selected transfer paper size due to development, so that the toner image is not transferred to the transfer paper carried and conveyed on the transfer drum. At this time, toner does not adhere to the surface of the dielectric film surrounding the transfer paper of the transfer drum.

If the size information detected by the above-mentioned transfer paper size information detection means does not correspond to any of the transfer paper size information stored in the storage means, the stored transfer paper size within the width range is By setting the transfer paper size as the minimum transfer paper length and the minimum transfer paper width, and removing the charge from the photoreceptor, the fed transfer paper can be Even if the information detected by the size information detection means does not match any transfer paper size information stored in the storage means, it is possible to prevent toner from adhering to the dielectric film of the transfer drum. can.

Furthermore, if the copying control device stores a plurality of transfer paper sizes in the storage means within the width range detected by the width range detection means of the transfer paper fed from the paper feeding means, the user can It has means for selecting and setting the transfer paper size, and means for determining whether or not the transfer paper size desired by the user has been selected and set, and if the transfer paper size desired by the user has not been selected and set by the above means. By providing a means to warn when this is determined, a warning will be issued if the control device does not select or set the transfer size, or if the size of the set transfer paper does not match the size selected by the user, preventing the occurrence of copy mistakes. can do.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described below in detail with reference to the drawings.

FIG. 2 is a schematic block diagram of a copying control apparatus of the present invention applied to a copying machine having a transfer drum having the configuration described in FIGS. 1A and 1B.

The CPU 20 is connected to a ROM 21 and a RAM 22, and is also connected to an operating section 25 and an eraser device 26 via serial ports 23 and 24. Further, the CPU 20 is connected to the operation unit 25 via an I/O port, and the outputs of the sensors S1, S2, and S3 are connected to the I/O port.
It is coupled to be input to the CPU 20 via a port 28.

FIG. 3 is a diagram showing the main parts of the operation section 25, and the operation section includes a start key 30, like a normal copying machine.
It is equipped with a numeric keypad 31 and the like, and a display section 32 is provided with a user-desired transfer paper non-setting warning indicator light 33, which will be described later.

FIG. 4 is a diagram illustrating the arrangement of sensors S1, S2, and S3. As is well known, a pickup roller 36 is provided on the paper feed conveyance path 35 from the paper feed section 11 to the transfer drum 5.
, a double feed separation conveyance roller 37, a conveyance roller 38, and a registration roller 39 are provided, and the transfer paper stacked on the paper feed section 11 is picked up at a predetermined timing by pressing the start key 30 of the operation section 25. The sheets are fed out by the roller 36, separated from the double feed by the double feed separation conveyance roller 37, and conveyed one by one. After passing through the conveyance roller 38 and the registration roller 39, they reach point A of the transfer drum 5 at a predetermined timing, and are transferred to the clamper 13. , the tip is grasped.

The sensor S1 is a sensor for detecting the width range of the transfer paper, and is provided on the downstream side of the multifeed separation conveyance roller 37. The sensors S2 and S3 are provided at positions immediately in front of the conveyance roller 38 and the registration roller 39, respectively.

[0025] Here, it should be remembered that the sizes of transfer paper used in copying machines are A3, B4, and A4 as mentioned above.
Although there are many types of paper such as letter size, legal size, foolscap, etc., the vertical and horizontal dimensions of each are determined by standards, and paper of any other size can, in principle, be used as transfer paper. That is to say, there is nothing wrong with that.

[0026] Therefore, if data that can specify the size of transfer paper that can be used in the copying machine is stored in the RAM 22, the sensor S1 provided in the transfer paper conveyance path will receive information that can specify the size name of the transfer paper that is being conveyed. Detected and CPU20
The size of the transfer paper can be determined by comparing it with the data stored in the RAM 22 by the CPU 20, and the size can be selected and set. By storing the dimension data of each transfer paper size in the RAM, it becomes possible to erase the eraser 15 using the dimension data of the selected and set size.

For the above purpose, the sensor S1 is composed of six sensors Sa and Sb each comprising a light emitting element 41 and a light receiving element 42 in the transverse direction with respect to the conveying direction of the transfer paper, as shown in FIG.
, Sc, Sd, Se, and Sf are the paper passing standards (
This figure shows an example based on one side of the transfer paper) to 1
20mm, 140mm, 160mm, 190mm, 24
It is configured as 6 consecutive sensors provided at 0 mm and 270 mm positions.

As shown in FIG. 5, the transfer paper conveyance path passes through the center points of the six sensors Sa, Sb, Sc, Sd, Se, and Sf, and is formed by six straight lines extending in the conveyance direction, starting from the right. It is divided into seven bands of ~■. As is clear from Table 1, when the transfer paper is passed vertically with one side aligned with the reference line, the other side edges of A3, B4, A4, B5, A5, B6, and A6 are in the bands ■ and ■, respectively. , ■, ■, ■, ■, ■, and all sensors to the left of the passing band are turned on. Therefore, the size of the transfer paper used is A
If it is limited to seven types of vertical lines in rows and B rows, sensors Sa~
By inputting the Sf detection signal to the CPU 20 and comparing it with information stored in the RAM 21, it is possible to determine the size of the transfer paper being fed.

However, when A5, B5, and A4 are used horizontally, the width is the same as when A4, B4, and A3 are used vertically. In Figure 5, the vertical and horizontal directions are T and Y, respectively.
They are distinguished by the symbol. In addition, if letter size, legal size, etc. paper is used in addition to JIS A and B columns, as noted in the bands ■ to ■ in Figure 5,
Depending on the band, a plurality of sizes of transfer paper side edges may be arranged in one band. In particular, there are many types of sizes in the bands ■ and ■. Therefore, with only the above 6-sensor,
Transfer paper size cannot be determined.

Therefore, in order to distinguish between different sizes within the same width range, the length of the transfer paper is detected and compared with the length data for each transfer paper size stored in the RAM. Determine the transfer paper size. The length of the fed transfer paper can be detected from the time difference between when the leading edge and the trailing edge of the transfer paper are detected by the sensor S1 and the conveyance speed of the transfer paper. The above transfer paper size can be detected when the leading edge of the fed transfer paper reaches the sensor S3 in front of the registration roller 36. The position of the sensor S3 is away from the sensor S1 by at least the transferable length of the maximum size, and the time it takes for the leading edge of the transfer paper whose leading edge is detected by the sensor S3 to reach the transfer position on the transfer drum 5 is longer than the length of the eraser 15. The time required for the point on the photoreceptor corresponding to 2 to reach the transfer portion is made sufficiently longer than the time required for the point on the photoreceptor to reach the transfer portion. Therefore, the transfer paper size determined as described above is selected and set by the CPU 20, and the eraser 15 can be controlled in accordance with the size in sufficient time. Note that when the paper passing reference for the transfer paper is the center reference, the interval between the six sensors may be half of the above value.

The flowchart of a series of main routines for copy sequence control including the transfer paper feeding mode from the multi-size paper cassette 18, transfer paper size detection, transfer paper size selection setting, and eraser control as described above is shown in FIG. 7.

FIG. 8 shows a flowchart of the subroutine "multiple paper feeding mode" shown in FIG. 7, and "transfer paper width detection".
The flowchart of "transfer paper size detection" is shown in FIG. 9, the flowchart of "transfer paper size detection" is shown from FIG. 10A to FIG. 10E, and the flowchart of "transfer paper selection control" is shown in FIG. 11. Flowcharts up to "control" are shown in FIGS. 12 to 18, respectively.

These flows are clear from the previous description and the flowcharts themselves, so they will not be described in detail. “db-width” in FIGS. 9 and 10A is a memory buffer (data bank) that stores the transfer paper width. As described above, as shown in FIG. 10A, the transfer paper size can be detected at the time when the sensor S3 is detected.

As mentioned above, since there are multiple transfer paper sizes for the same transfer paper width, in order to judge all the transfer paper sizes, as shown in FIGS. 11 to 18, the storage memory buffer db-1 ON is used. , db-2 ON, db-3
ON, db-1 OFF, db-3 OFF, db-
When the transfer paper length stored in 4 OFF and db-5 OFF and the transfer paper length detected by the sensor meet the same condition, the transfer paper size is determined to be the memorized size and is selected and set. As a result, as shown in FIG. 10, the size of the fed transfer paper can be determined, making it possible to perform erase control.

Furthermore, flags F-1ON, F-2ON, F-3O in the flowcharts from FIG. 10B to FIG. 10E
N, F-1 OFF, F-3 OFF, F-4 OFF,
F-5 OFF indicates each storage memory buffer db-1
ON, db-2 ON, db-3 ON, db-1 O
FF, db-3 OFF, db-4 OFF, db-5
This is to determine whether OFF is selecting a normal transfer paper, and if it is abnormal, the minimum transfer paper length among the stored transfer paper sizes within each transfer paper width range is set as the length. Set the transfer paper size with the minimum transfer paper width as the width. By doing so, toner is prevented from being transferred to the dielectric film of the transfer drum.

FIG. 19 is a flowchart for checking the completion of transfer paper selection, with flags F-1ON-POW, F-
2 ON-POW, F-3 ON-POW, F-1 O
FF-POW, F-3 OFF-POW, F-4OFF
-POW, F-5 OFF-POW is for determining whether the transfer paper desired by the user has been set. As shown in the figure, if the user determines that the desired size of transfer paper is not set, a non-setting warning light 33 is lit on the display section 32 of the operation section in FIG. Warn the user beforehand and prevent copy mistakes.

[0037]

As described above, according to the present invention as set forth in claim 1, it is possible to determine which size of transfer paper is being fed among various preset sizes of transfer paper used in the copying machine. Since the charge removal range of the eraser can be accurately determined and controlled based on pre-stored dimensions, toner will not adhere to areas outside the area where the transfer paper is placed on the dielectric film of the transfer drum, and the back side of the copy will not be smudged. can be prevented.

Further, according to the invention as claimed in claim 2, even if for some reason a paper of a size not previously stored in the storage means is used as a transfer paper and fed, the dielectric of the transfer drum This prevents toner from adhering to the film.

Furthermore, according to the invention as set forth in claim 3, the user can set the transfer paper of the desired size,
If transfer paper of a different size is set and fed, a warning will be given, thereby preventing the occurrence of copy errors.

[Brief explanation of the drawing]

FIG. 1A is a sectional view showing the overall general structure of a copying machine to which the present invention is applied.

FIG. 1B is a perspective view showing the structure of the transfer drum.

FIG. 2 is a schematic block diagram of a copy control device of the present invention.

FIG. 3 is a plan view showing a main part of an operation section of a copying machine equipped with a copying control device of the present invention.

FIG. 4 is a sectional view showing the arrangement of sensors used in the copy control device of the present invention.

FIG. 5 is an explanatory diagram showing the configuration of a multiple sensor for detecting a transfer paper width range of the present invention and various transfer paper sizes whose side edges fall within the width ranges divided by this sensor.

FIG. 6 is a perspective view showing the configuration of an example of a multi-size paper feed cassette.

FIG. 7 is a flowchart of the main routine of the control device of the present invention.

FIG. 8 is a flowchart of a paper feeding mode using the multi-size paper feeding cassette.

FIG. 9 is a flowchart of a transfer paper width detection subroutine.

FIG. 10A is a part of a flowchart of a transfer paper size detection subroutine.

FIG. 10B is another part of the above flowchart.

FIG. 10C is still another part of the above flowchart.

FIG. 10D is still another part of the above flowchart.

FIG. 10E is still another part of the above flowchart.

FIG. 11 is a flowchart of a transfer paper selection control subroutine.

FIG. 12 is a flowchart of a transfer paper 1 selection control subroutine.

FIG. 13 is a flowchart of a transfer paper 2 selection control subroutine.

FIG. 14 is a flowchart of a transfer paper 3 selection control subroutine.

FIG. 15 is a flowchart of a transfer paper 4 selection control subroutine.

FIG. 16 is a flowchart of a transfer paper 5 selection control subroutine.

FIG. 17 is a flowchart of a transfer paper 6 selection control subroutine.

FIG. 18 is a flowchart of a transfer paper 7 selection control subroutine.

FIG. 19 is a flowchart of checking the completion of transfer paper selection.

Claims (3)

[Claims] 1. A photoreceptor, a means for removing electric charge from areas on the photoreceptor where image formation is not necessary before development, and a main part of the outer peripheral surface of the photoreceptor made of a dielectric elastic film. a transfer drum that is in contact with the photoreceptor and rotates in synchronization with the photoreceptor; and a paper feeding means that feeds transfer paper of various sizes to the transfer drum, the paper being fed from the paper feeding section. The leading edge of the transfer paper is gripped by the gripping means of the transfer drum, electrostatically adsorbed onto the dielectric film, and rotated a predetermined number of times to superimpose the toner images of different colors sequentially formed on the photoreceptor. In a copying control device of a copying machine that performs transcription, a storage means for storing information on the size of various types of transfer paper that can be fed from the paper feeding means, a means for detecting size information of the transfer paper fed from the paper feeding means, and said detection. means for determining which of the transfer paper sizes stored in the storage means the fed transfer paper corresponds to, based on the information detected by the means, and selecting and setting the transfer paper size; The size information detection means of the fed transfer paper includes a transfer paper width range detection means consisting of a group of multiple sensors arranged in parallel in the paper feeding direction in the paper feeding direction, and a transfer paper width range detection means consisting of a plurality of sensors arranged in parallel in the paper feeding direction in the paper feeding path, and If there is only one transfer paper size stored in the storage means in the width range detected by the transfer paper width range detection means, the transfer paper size is determined based on the width range information. If there are multiple sizes in the same width range, the transfer paper size is determined based on the width range information and length information.
A copying control apparatus characterized in that the charge removal means controls the charge removal means to remove charge from a portion outside the portion on the photoreceptor corresponding to the transfer paper size selected and set by the above determination. 2. If the size information detected by the transfer paper size information detection means does not correspond to any of the transfer paper size information stored in the storage means, the stored transfer paper within the width range The transfer paper size is set as a size in which a minimum transfer paper length and a minimum transfer paper width are set as a transfer paper width, and charge removal from the photoreceptor is performed. Copy control unit. 3. If a plurality of transfer paper sizes are stored in the storage means within the width range detected by the width range detection means of the transfer paper fed from the paper feeding means, the user selects the transfer paper size. A means for determining whether or not the transfer paper size desired by the user has been selected and set, and when it is determined by the above means that the transfer paper size desired by the user has not been selected or set. 3. The copying control apparatus according to claim 1, further comprising means for issuing a warning.