JPH01280770A - Scan controller for scanning type copying machine - Google Patents

Abstract

PURPOSE:To eliminate the restriction caused by the device constitution by the arrangement of a paper sensor by delaying the starting time of scanning by means of a carriage by prescribed time and, at the same time, setting the scanning time in corresponding to the size of an original when the original has a special size. CONSTITUTION:When an original 2 has a regular size, a controller 17 calculates the scanning time corresponding to the size of the original 2 and moves the carriage in accordance with the calculated scanning time. After the carriage scans the original 2 for the prescribed time from a reference point C for exposure, the controller 17 returns the carriage 16 to its home position. When the original 2 has a special size, the controller 17 delays the scan starting time of the carriage 16 by the difference between the time t1 required for feeding paper 11 to a transferring position B from a paper sensor 13 and the time t2 required for moving the surface of a photosensitive body 9 to the transferring position B from an image forming position A and returns the carriage 16 to the home position after the carriage scans the original for the scanning time corresponding to the size of the original 2. Therefore, the arrangement of the paper sensor 13 does not restrict the device constitution and, in addition, scanning can be performed effectively irrespectively of the sizes of the original 2 and paper 11.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a scanning copying machine, and more particularly to a scanning time control device for the copying machine.

In a scanning copying machine, the document is of a specified size, for example B5.
, A4, B4, A3, etc., the carriage of the scanning optical system is moved from the exposure reference position of the platen at a predetermined speed for the time required to scan the document of the specified size. This is preferable because the necessary scanning area can be accurately scanned, but in the case of originals of a size other than the specified size, such as postcards, it takes a long time to scan and has the disadvantage that unnecessary parts are scanned.

In addition to the above device, a paper sensor is provided in the copy paper feeding path, as shown in Japanese Patent Laid-Open No. 57-38465. The sensor is arranged so that the time t required for the copy paper to be sent from the sensor to the transfer position is equal to the time t2 required for the photoreceptor surface to move from the imaging position to the transfer position.

There is also a device that finishes scanning when the trailing edge of the copy paper passes a sensor. This has the advantage that even if the original or paper size is not the specified size, unnecessary parts are not scanned. However, since the length from the image forming position of photoconductor 2 to the transfer position and the moving speed of the photoconductor are strictly determined by the image forming process, it is necessary to place the paper sensor at one point on the feeding path according to this. This poses problems, especially in small copying machines, such as limited space and short feeding paths.

Therefore, an object of the present invention is to provide a scanning control method that is not limited to the above-mentioned device configuration and that does not scan unnecessary portions even if the original or paper size is not a specified size.

In order to achieve such an object, according to the present invention, an optical system is moved relative to an original, and an optical image from the original is projected onto a moving photoreceptor to form a latent image on the surface of the photoreceptor. A scanning control device for a scanning copying machine that transfers a developed image obtained by developing a latent image to copy paper that has passed a paper sensor in a copy paper feeding path at a transfer position, the paper sensor The copy paper is arranged so that the time required for the copy paper to be fed to the transfer position is longer than the time required for the photoreceptor surface moving at a predetermined speed to move from the imaging position to the transfer position, and There is provided a scanning control device characterized in that the movement of the optical system is terminated when a predetermined time has elapsed after the trailing edge passes the copy paper sensor.

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, an original 2 is placed on a platen 1, and the placed original 2 is illuminated by a lamp 3.
A reflected light image from the photoreceptor 9 is projected via mirrors 4 to 7 (a lens may be provided if necessary) onto an imaging position iA of a photoreceptor 9 rotating in the direction of the arrow. A corona charger 8 is provided on the photoreceptor 9 upstream of the imaging position A, and uniformly charges the surface of the photoreceptor 9 to impart photosensitivity. Therefore, when an optical image is projected at the imaging position A, an electrostatic latent image is formed on the surface of the photoreceptor 9. This image is developed by the developing device 10, and the developed toner image is moved to the transfer position B.

Copy paper 11 is fed on feeding path 12 at a speed synchronized with the surface speed of photoreceptor 9. Note that a paper sensor 13 is provided in the feeding path 12 so that the paper is aligned with the toner image. Transfer corona discharger 14 at transfer position B
The toner image on the surface of the photoreceptor is transferred onto the paper 11 with the help of. After the transfer, the copy paper 11 passes through a fixing device (not shown), the toner image is fixed on the paper, and the copy is output as a copy. On the other hand, the photoreceptor 9 is provided with a cleaning device 15 downstream of the transfer position B, and the toner and latent image remaining on the surface of the photoreceptor are neutralized and cleaned in preparation for the next image formation. The above is a general description of a copying machine and should be sufficient for understanding the present invention.

There are two types of scanning copying machines: one in which an optical system such as a lamp, a mirror, or a lens is moved relative to a document on a fixed platen, and the other in which the optical system is fixed and the platen is moved. Although the present invention can be applied to any type of copying machine, for convenience of explanation, a scanning copying machine using a moving optical system will be described.

In the copying machine shown in FIG. 1, a lamp 3 and a mirror 4 are supported by a carriage 16, and the carriage moves in the direction of the arrow at a speed synchronized with the surface speed of the photoreceptor 9. This movement is controlled by the scanning time control device 17 according to the present invention, which controls the main control section 1 of the copying machine.
8 is connected. Further, a sensor 19 is provided on the lower surface of the platen 1 to define an exposure reference point C, and this position C is also a position where the edges of the original 2 are aligned. The output of the sensor 19 is input to the manufacturing device 17, and the lamp 3 starts emitting light, that is, scanning of the document for exposure is started. Furthermore, in the present invention, a signal indicating passage of the copying spindle 11 from the copy paper sensor 13 is sent to the main control unit 1 of the copying machine.
It is also input to the Mi+ control device 17 as well as to the B.

The above-described copy paper sensor 13 is configured such that the surface of the photoreceptor moving at a predetermined speed reaches the image forming position A when the copy feeding time required for the copy paper to be sent from the sensor 13 to the transfer position iB is also
The time t2 required to move from to the transfer position B is 1. is set to be large.

To explain the operation of the carriage 16, the platen 1
When a document of a specified size, for example, a B5, A4, B4, or A3 size document is placed on the copying machine, the predetermined size is specified on the operation panel (not shown) of the copying machine. In response to this size specification, a size specification signal is sent from the copying machine control section 18 to the control device 17, and the scanning time T corresponding to the specified size is calculated by the device 17. By pressing the start switch (not shown) of the copying machine, the control device 17 moves the carriage 16 at a predetermined speed in the direction of the arrow, and when the exposure reference point C is reached, the device 17 receives a signal from the sensor 19 to move the carriage 16 to the lamp 3. lights up and scanning of the original begins. After scanning has been performed for the calculated time T, the carriage 16 quickly returns to its original or home position. In addition, in this scanning, it is possible to scan an extra time α, thereby completely covering the document surface.

Next, if an original of a special size other than the standard size, such as a postcard, is placed on platen 1, scanning the standard size will require extra scanning, image formation, transfer, cleaning, etc. Undesirable.

In response to this, the present invention employs a method different from the above-described scanning method when making copies from such special-sized originals. Simply put, the start of scanning the document and the scanning time are determined by the paper sensor 3 on the copy paper feed path 12.
determined by the signal from. An example of this will be explained below.

Assume that a postcard is placed as an original on the platen 1, the copy paper is a postcard, etc., and a special size copy is specified from the operation panel of the copying machine.

When the star 1~ switch is pressed, feeding of copy paper starts, but the carriage 16 does not move.

Next, when the copy paper reaches the paper sensor 3 and energizes the sensor, this is communicated not only to the copier main control section 18 but also to the scanning time control device 17.

In response to a signal from the control device 17, the time t1 required for the ruby paper to be sent from the sensor 3 to the transfer position WB at a predetermined speed, and the time t1 required for the ruby paper to be sent from the sensor 3 to the transfer position WB, and the moving photoreceptor surface to be transferred from the image forming position A to the transfer position at a predetermined speed. The time t2 required to move to position B is calculated, and the time 1. The difference time t3 is calculated by subtracting the time t2 from the time t2. The control device 17 controls the carriage 16 to detect the document (i.e., postcard) on the platen when a time t has elapsed after the copy paper reaches the sensor 13.
The carriage 16 is controlled to start scanning.

During the scanning period of the carriage 16, the copy paper is detected by the sensor 13.
is set approximately equal to the period during which it passes through.

Since the copy paper has a size corresponding to the original, the scanning time of the carriage 16 becomes appropriate, and unnecessary scanning is completely eliminated.

In the case of a special size original, the edge of the original may be aligned with the exposure reference point C, but it may also be placed on the opposite side of the platen 1 from the zero point.

In this case, the carriage 16 may be moved earlier than the scanning start time, or the home position of the carriage 16 may be shifted to the right in FIG. 1 by a predetermined distance. Further, although the scanning start delay time was calculated based on the time when the copy paper reaches the sensor 13, the scanning start time can also be determined based on the time when the copy paper finishes passing the sensor 13. In this case as well, it is necessary that the time L1 be equal to or longer than the time t2 plus the time t3 for the copy sheet to finish passing.

FIG. 2 is a flowchart of the scanning operation by the scanning time control device 17. As is clear from this figure, the control device 17
In the case of originals of specified sizes such as B5, A4, B4, A3, etc., the scanning time corresponding to each size was calculated, the carriage 16 was moved accordingly, and the original was scanned for a predetermined time from the exposure reference point C. After that, the carriage 16 is returned to the home position. Also, if the original is a special size,
delaying the start of scanning by the carriage 16 for a predetermined time;
Thereafter, it scans for a period corresponding to the document size, and returns to the Baume position after scanning.

Therefore, according to the present invention, the arrangement of the paper sensor on the feeding path is not restricted by the device configuration, and scanning can be performed without any wasted parts regardless of whether the document or paper is of a specified size or not.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a scanning copying machine to which the present invention is applied, and FIG. 2 is a flowchart of a scanning operation performed by the control device of the present invention. 1...Platen, 2...Document, 3...Lamp, 4
．． 5.6.7... Mirror, 9... Photoreceptor, 10...
・Developer, 11... Copy paper, 12... Feeding path,
13... Paper sensor, 15... Cleaner, 16...
Gear ridge, 17...Scanning time control device, 18...
Copying machine main control unit, A...imaging position, B...transfer position, C...exposure reference position.

Claims (2)

[Claims] (1) The optical system is moved relative to the original, an optical image from the original is projected onto a moving photoreceptor, a latent image is formed on the surface of the photoreceptor, and the latent image is developed. In a scanning control device for a scanning copying machine that transfers an image to copy paper that has passed a paper sensor in a copy paper feed path at a transfer position, the paper sensor is configured to transfer an image to a copy paper that has passed a paper sensor in a copy paper feed path to the transfer position. The photoreceptor surface, which moves at a predetermined speed, is arranged such that the time required is longer than the time required for the surface of the photoreceptor to move from the imaging position to the transfer position, and the trailing edge of the copy paper passes the copy paper sensor for a predetermined time. A scanning control device characterized in that the movement of the optical system is ended when a time elapses. (2) The scanning control device according to claim 1, wherein the movement of the optical system starts when the leading edge of the copy paper reaches the paper sensor.