JPH0269778A - Copying device - Google Patents

Abstract

PURPOSE:To reduce the vibration of an optical system in a holding time which is set before the next scan is started after the scan is completed, to execute stable copying without generating tip blurring, etc., and to improve the reliability of the device by measuring a scanning time before copying is started, and executing a correction of a cycle time, based on the measured scanning time. CONSTITUTION:Before copying is started, the time required for a scan is measured by moving a scanning part and executing a blank scan, a scanning period obtained by adding a holding time to the measured scanning time and a cycle time are compared, and when the scanning period is longer, it is set as a new cycle time. Accordingly, the vibration of an optical system 3 can be reduced in the holding time which is set before the next scan is started after the scan is completed, and stable copying can be executed without generating tip blurring, etc. Also, in a high speed copying machine, an interval between forms can be set surely, and an accident such as rolling-in, etc., can be prevented. In such a way, by executing surely copying, the reliability of the copying device can be improved.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a copying apparatus such as an electrostatic transfer copying machine, and more particularly, to a method for correcting the cycle time for controlling the copying interval so as to enable accurate copying. The present invention relates to a copying machine that uses the following methods.

[Conventional technology]

Conventionally, the cycle time in copying devices using the optical system scanning method or the table movement method mainly controls the copying process such as the paper feeding interval, and the start of movement of the scanning unit by the optical system and document table, registration rollers, etc. The timing of the start of driving also changes depending on this cycle time. Such a cycle time is, for example, 60 cycles per minute.
A certain period of time is predetermined according to the specifications, such as a cycle time of 1 second when copying a sheet.

For example, in the case of an optical scanning type copying machine, the process from when the optical system actually starts moving until it completes is the 5th step.
As shown in Figure (a), the optical system moves in the feed direction, stops at a predetermined position, reversely moves in the return direction, stops at a predetermined position, and returns to the initial position, completing the movement. Normally, the scanning time t5 from when the optical system starts to when the movement is completed is shorter than the cycle time Tc, resulting in a waiting time L8 until the start of the next movement J. During this time, the optical system reduces vibration, and the drive system such as registration rollers prepares for the next sheet feeding.

[Problems to be Solved by the Invention] However, in the above-mentioned conventional copying apparatus, the problem as shown in FIG.
), the scanning time t5 may be longer than the cycle time Tc due to a defect in the stopping position of the optical system, elongation of the drive system wire, or the like. In such a case, since the optical system must start moving immediately after completing the movement, the vibrations do not subside, resulting in blurring of the leading edge of the copy. In addition, in high-speed copying machines, a delay in scanning time causes a shift in the timing of exposing the photoreceptor.
The stopping time of the paper in front of the registration rollers becomes long, and the next paper is still fed at the interval of the cycle time, so there is a risk that there will be no space between the papers and problems such as entrainment may occur.

[Means for Solving the Problems] In order to solve the above-mentioned problems, a copying apparatus according to the present invention uses an optical system scanning method in which the original is scanned by fixing the original and moving an optical system, or In a copying apparatus of a table movement type that scans an original by fixing the system and moving the original placing table, an empty scanning control means for causing a scanning section using the optical system or the original placing table to scan prior to copying; a scanning time measuring means for measuring the scanning time required for the scanning time; and a comparing means for comparing the scanning period obtained by adding the waiting time to the scanning time measured by the scanning time measuring means and a cycle time which is a preset copying interval; The present invention is characterized by comprising cycle time correction means that sets a new cycle time when the scanning time is determined to be longer than the cycle time by the comparison means.

[Function] With the above configuration, the scanning unit is moved before copying starts and the time required for scanning is measured, and the cycle time is compared with the scanning cycle obtained by adding the standby time to the measured scanning time. However, if the scanning period is longer, this is used as the new cycle time, so it is possible to reduce the vibration of the optical system within the set waiting time from the completion of scanning to the start of the next scanning. It is possible to perform stable copying without causing any problems. Furthermore, in high-speed copying machines, it is possible to reliably provide space between sheets, and accidents such as entrainment can be prevented. Therefore, by performing copying reliably in this manner, the reliability of the copying apparatus can be improved.

[Example] An example of the present invention will be described below based on FIGS. 1 to 4.

In this embodiment, an optical scanning type copying apparatus that scans a document by moving an optical system will be described.

As shown in FIG. 1, the copying apparatus 1 includes a transparent original table 2, and below the document table 2, an optical system 3 consisting of a light source, a mirror, a lens, etc. is arranged. An original (not shown) placed on the original placing table 2 is irradiated by a light source of an optical system 3, and the photoreceptor 4 is exposed to light reflected from the original through the optical system 3. The photoreceptor 4 is
Since it is charged to a predetermined potential by the charger 5 prior to exposure, an electrostatic latent image corresponding to the image of the original is formed on the photoreceptor 4 by exposure to light reflected from the original.

When the electrostatic latent image is formed on the photoreceptor 4, toner is supplied from the developing device 6 to the photoreceptor 4, and the electrostatic latent image is developed with this toner to form a toner image on the photoreceptor 4. Ru. Then, paper feed rollers 10 to 12, conveyance rollers 13 to
16 feeds copying paper to registration rollers 17, and further the above-mentioned paper is fed from registration rollers 17 to photoreceptor 4 at a predetermined timing.

The toner image formed on the photoreceptor 4 is transferred to a transfer charger 18.
is transferred to the above paper by Then peel off the paper.
It is peeled off from the photoreceptor 4 by the container 19 and transported to the land transportation heald 2.
0, the image is sent to the fixing unit 21 by 1. Note that the toner remaining on the photoreceptor 4 after the toner image is transferred is removed by the cleaning device 22. Further, the photoreceptor 4 is uniformly neutralized by a static eliminating means 23 such as a static eliminating lamp in preparation for the next copying.

After the toner image is fixed on the sheet sent to the fixing section 2I, the sheet is transferred to the switching gate 2 when performing single-sided copying.
4 and is discharged onto the discharge tray 25. On the other hand, when double-sided copying is performed, the above paper is guided by the switching gate 24 to the paper transport path 26, sent to the reversing mechanism 28 via the switching gate 27, and after being reversed here, It is discharged onto the intermediate tray 29. Further, when performing composite copying, the paper is directly discharged from the paper transport path 26 to the intermediate tray 29 via the switching gate 27.

In this intermediate tray 29, the sheets 30 are stored so that the image forming surface faces upward in the case of double-sided copying, and with the image forming surface facing downward in the case of composite copying. ing. These papers 30... are
The sheets are sequentially stacked from the intermediate tray 29 starting from the uppermost one by a feed roller 31 and a feed roller 32, which are one of the conveyance rollers, which are arranged to face the intermediate tray 29.
The paper is transported by a registration roller 33, which is one of the transport rollers.

Furthermore, the sheets of paper 30 are conveyed 11 times to registration rollers I7 via transport rollers 16 and 14, and double-sided copying or composite copying is performed.

In the control section shown in FIG.
4 is ROM (Read Only Memory)
Each part of the copying apparatus 1 is controlled according to a control program stored in advance in the copying machine 35, and the scanning section for the idle scanning means is also controlled. Further, the microcomputer 34 is equipped with a timer (not shown) serving as a scanning time measuring means, and is configured to count and amplify by interrupting at regular intervals. Comparison means compares the cycle time Tc stored in advance in the ROM 35 and the scanning period obtained by adding the same <the waiting time stored in advance in the ROM 35 to the scanning time js measured by the above-mentioned timer. It is equipped. However, the waiting time tw is the time until the vibration of the optical system subsides and stabilizes, and is usually 30m5.
~40m5. Further, if it is determined by this comparison means that 1゛o ≧ts+5, the cycle time Tc is left as is, while if TC<1s+1. When it is determined that , , as shown in FIG. 3, a correction means is provided for correcting the cycle time T to Tc', that is, the scanning period (ts +t,).

The RAM 36 connected to the microcomputer 34 is
It is used as a flag necessary for buffer memory, copy control, etc., or as an area for calculation. Further, the signal input device 37 inputs to the microcomputer 34 a key inch activated by the operation of various keys provided on the copying device 1, a detection signal of the paper conveyance position, a detection signal of the rotational position of the photoreceptor 4, etc. It is a device for transferring the above-mentioned detection signals etc. to the microcomputer 34 via the interface circuit 38. On the other hand, the driver array 39 includes various display elements 41 for displaying copying magnification and other information based on signals supplied from the microcomputer 34 via an interface circuit 40, various loads 42 of the copying apparatus l, etc. Specifically, it drives and controls the drive of the first transport belt 20, the drive section of the reversing mechanism 28, and the like.

A control procedure for the copying apparatus 1 configured as described above will be explained below.

As shown in FIG. 4, first, in a standby state before the copy switch is turned on, the cycle time value stored in the ROM 35 is sent to the microcomputer 34 to initialize the cycle time (SL ). Next, ON/OFF of the copy switch is determined (S2)
When the copy switch is turned on, the timer in the microcomputer 34 is reset to 0, and at the same time as it starts counting up, the optical system starts moving (S3).
. Then, it is determined whether the optical system has completed its movement (
S4), if the optical system has completed its movement, the timer stops counting up (S5).

Here, the cycle time Tc is compared with the scanning period obtained by adding the waiting time t1 to the scanning time L5 measured by the timer (S6), Tc≧t, s+1. If it is determined that t
, +t.

If it is determined that this is the case, the cycle time Tc is correctly corrected to the scanning period (1s+1.) by the correction means (S8), and then the process moves to S7 to start copying.

Although this embodiment describes an optical scanning type copying apparatus, the cycle time can also be reduced for a table moving type copying apparatus by emptyly scanning the table in the same way as the optical scanning type optical system. Can be corrected.

[Effects of the Invention] As described above, the copying apparatus according to the present invention uses an optical system scanning method in which the original is fixed and the optical system is moved to scan the original, or the copying apparatus is fixed in the optical system and scans the original by moving the optical system. In a copying apparatus of a table moving type that scans an original by moving the table, there is provided an empty scanning control means for causing a scanning unit using the optical system or the original'R table to scan prior to copying, and measuring the scanning time required for the empty scanning. a scanning time measuring means for measuring the scanning time; a comparing means for comparing the scanning cycle obtained by adding the waiting time to the scanning time measured by the scanning time measuring means with a cycle time set in advance and serving as a copying interval; If it is determined that the cycle time is longer than the cycle time, the cycle time correction means sets the cycle time as a new cycle time.

As a result, the scanning time is measured before the start of copying, and the cycle time is corrected based on the measured scanning time, so that vibrations in the optical system can be avoided within the set waiting time from the completion of scanning to the start of the next scanning. This allows stable copying to be performed without leading edge wobbling or the like. In addition, in high-speed copying machines, it is possible to reliably provide space between sheets, thereby preventing accidents such as entrainment. Therefore, the reliability of the copying apparatus can be improved by reliably copying.

[Brief explanation of the drawing]

1 to 4 show an embodiment of the copying apparatus according to the present invention, in which FIG. 1 is an explanatory diagram showing the overall configuration, FIG. 2 is a block diagram showing the control section, and FIG. The figure is a graph showing temporal changes in the position of the optical system, and FIG. 4 is a flowchart showing the control procedure. FIG. 5 shows a conventional example, in which FIG. 5(a) is a graph showing temporal changes in the position of a normal optical system, and FIG.
b) is a graph showing temporal changes in the position of the optical system when the scanning time is longer than the cycle time. 3 is an optical system, and 34 is a microcomputer (empty scanning control means, scanning time measuring means, comparing means, cycle time correcting means).

Claims (1)

[Scope of Claims] 1. An optical system scanning method in which a document is scanned by fixing the document and moving an optical system, or a table in which the document is scanned by fixing the optical system and moving a document mounting table. In a mobile type copying apparatus, a blank scanning control means for causing the scanning unit using the optical system or the document table to scan prior to copying, a scanning time measuring means for measuring the scanning time required for the blank scanning, and a scanning time measuring means a comparison means for comparing a scan period obtained by adding a standby time to the scan time measured by the method and a cycle time which is a preset copying interval; and when the comparison means determines that the scan time is longer than the cycle time, A copying apparatus comprising cycle time correction means for setting a new cycle time.