JPS623239A - Image forming device - Google Patents

Abstract

PURPOSE:To take copies continuously at the same copying speed between a right and a left page by providing a means which detects the inversion position of an original scanning part, and moving it forward and backward in specific directions and controlling its position according to original size and a variable power rate. CONSTITUTION:A scanning mirror 14 is driven by an optical motor 11 to begin to scan as shown by an arrow 15 and when it passes by an image head sensor 17, a latent image is formed on a photosensitive drum. Then, pulses from a pulse encoder incorporated in the optical motor 11 begin to be counted and the scanning mirror 14 is scanned back after pulses are counted up. The image forming operation of the right page is started after the image formation of the left page is finished, and the scanning mirror 14 moves to the arrangement of an inversion sensor 21 which stops at a position determined by the original size ad variable power rate; when the mirror passes by the inversion sensor 21, pulses are counted and latent image formation is performed. When the mirror reaches the tail of the right page, the scanning mirror 14 is scanned back to the arrangement position of the inversion sensor 21.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image forming apparatus that continuously copies images of both pages of a document by reciprocating a document scanning section.

[Conventional technology]

Conventionally, this type of device scans both pages of a document placed side by side on the document table separately and copies both pages in succession, which is easy to do without complicated settings. It is structured so that it can be copied at any time. In this case, for example, if the document placement reference position of the document placement table is at the upper left, the scanning unit (not shown) scans the left page of the placed document 1 degree, then returns to the home position and moves to the right again. , ゛ type, which is configured to shift to ゛-page document scanning;
There is a type that has a reversal sensor for the right page and is configured to efficiently copy both pages.

[Problems to be solved by the invention].

However, in the former method, after scanning the left page, the system returns to the home position and then moves on to scanning the right page, resulting in problems such as extremely slow document scanning time and a significant reduction in copy efficiency. In addition, the latter uses a reversal sensor for the right page in each recording paper size, for example, in a device that takes up to A3 copies.
゛ is A4. There was a problem in that an independent sensor dedicated to B5 etc. was required, resulting in extremely high costs. Zara.

Regarding export models, due to differences in recording paper standards.
,'1'A further independent sensor is required.

This invention was made to solve the above problems, and it controls the position of a single reversing sensor according to the original size and magnification, and performs continuous copying where the copying speed of the left and right pages does not change. An object of the present invention is to provide an image forming apparatus that can be used as an image forming apparatus.

[Means for solving problems]

The image forming apparatus according to the present invention includes a reversal position detection means for detecting the reversal position of the document scanning section, a drive means for repeatedly moving the reversal position detection means in a predetermined direction, and a drive means that adjusts the document size and magnification. A drive control means is provided to control the position accordingly.

[Effect]

In this invention, the driving means for moving the reversal position detection means for detecting the reversal position of the document scanning section in a predetermined direction is
A drive control means performs positioning control according to the document size and magnification ratio.

〔Example〕

FIG. 1 is a control block diagram of an image forming apparatus showing an embodiment of the present invention. Reference numeral 1 denotes a CPU serving as a control means, which processes input/output data and controls each part. 1a is a drive control means, which is a document scanning section 2a provided in the image forming means 2;
The driving means 2b that drives the is controlled. Reference numeral 2c denotes a reversal position detection means for detecting the reversal position of the document scanning section 2a. 3 is an operation means for setting a copy mode. A paper feeding means 4 feeds recording paper to the image forming means 2. In addition,
'The paper feeding means 4 has a paper size detection means 4a.

Next, the scanning operation of the document scanning section 2a will be explained.
'ru.

First, when a copy mode 1, for example, continuous copying of both pages of an A3 size original and variable magnification, is set using the operating means 3, the drive control means 1a determines the reverse position of the original scanning section 2a, and sets the copy mode in the paper feeding means 4. After recognizing the recording paper size input from the paper size detection means 4a, a command to move the reversal position detection means 2c is sent to the drive means 2b.

In response to this, the drive means 2b moves the reversal position detection means 2c to a predetermined reversal position. “
FIG. 82 is a plan view of a document scanning section of an image forming apparatus showing an embodiment of the present invention. Reference numeral 11 denotes an optical system drive motor having a pulse encoder, which drives a wire 13 wound around a pulley 12. 14 is a scanning mirror, and wire 13
is driven to scan in the direction of arrow 15, and a photosensitive drum (not shown) is scanned with reflected light from an irradiation lamp (not shown). A home position sensor 16 detects a flag 14a placed at a predetermined location on the scanning mirror 14.

, 17 is an image tip sensor which, when the scanning mirror 14 passes, sends out a predetermined pulse signal to start forming a latent image on the photosensitive drum. 18 is a stepping motor, and pulley 1
The wire 20 wound through the wire 9 is driven to cause the reversal sensor 21 to reciprocate. A home sensor 22 detects the passage of the flag 23 and detects the home position of the reversal sensor 21.

Next, the operation will be explained.

For example, with an original with A3 size spread pages placed on the platen glass, set a copy of both pages at the same size from the operation panel, select A4 size recording paper, and press the copy key. Press .

First, the stepping motor 18 is driven to position the reversal sensor 21 at a distance corresponding to the lateral width of an A4 size sheet from the position where the image tip sensor 17 is placed. Then, by driving the optical motor 1], the scanning mirror 14 moves in the direction of the arrow 15.
When the image starts scanning in the direction and passes the image tip sensor 17, a latent image is formed on the photoreceptor drum and the image is transferred to the optical motor 11.

Pulse counting from an internally installed pulse encoder is started, and when the count is up, the scanning mirror 14 is scanned back. When the image formation on the left page is completed, the process moves on to the image formation operation on the right page, and the scanning mirror 14 is moved to the position of the reversing sensor 21'', which is stopped at a position determined based on the original size and magnification ratio. , after passing through this reversal sensor 21, pulse counting is performed in the same way as described above to form a latent image.
When the end of the right page is reached, the scanning mirror 4 is scanned back to the position where the reversal sensor 21 is placed.
If enlargement to A4 size is selected, B5
The size tree is determined to be an open document, that is, a B4 size document, and the stepping motor 18 is driven to move the reversal sensor 21 from the position of the image tip sensor 17 to a B5 size document.
Move it a distance equivalent to the short width of the size.

Furthermore, if, for example, B5 size recording paper is selected,
When reduction copying from A4 size to B5 size is selected, the document is determined to be an open A4 size book, that is, an A3 size document, and the stepping motor 18
is driven to move the reversal sensor 21 from the position of the image tip sensor 17 to a distance corresponding to the short width of an A4 size sheet.

Next, the scanback operation according to the present invention will be explained with reference to FIGS. 3 and 4.

FIG. 3 is a flowchart illustrating the left page scanback operation according to the present invention. In addition, (1) to (8
) indicates each step.

The optical motor] is driven forward, that is, the scanning mirror 14 is moved in the direction of the arrow 15 (1), and the flag 14a provided on the scanning mirror 14 waits for the image to pass through the optical sensor 17 (2). Then, start counting the pulse signals output from the pulse encoder (3), and judge whether the count determined by the document size, that is, the scanning mirror 14 has reached the reversal position (4). If NO, step (3) ) and YES
If so, move the optical motor 11 backward (5), wait for the scanning mirror 14 to return to the position of the home position sensor 16 (8), and when it returns to the position of the home position sensor 16, judge the end of copying (7). , if No, return to step (1); if YES, optical motor 1
1 and ends the control (8).

FIG. 4 is a flowchart illustrating the right page scan-back operation according to the present invention. In addition,(
11) to (22) indicate each step.

Drive the optical motor 11 forward, that is, move the scanning mirror 14 in the direction of arrow 15 (11), wait for the flag 14a provided on the scanning mirror 14 to pass the reversal sensor 21 (12), and when it passes, the pulse encoder is activated. Start counting the pulse signals output from 13)
, it is determined whether or not the count number determined by the document size, that is, the scanning mirror 14 has reached the reversal position (14). If No, the process returns to step (13), and if YES, the optical motor 11 is moved backward (15). ), wait for the scanning mirror 14 to scan back to the placement position of the reversal sensor 2116), and wait for the end of the count-up of a dummy timer (not shown) after scanning back17).
, Once finished, judge whether the copying of the right page is finished 18).
If NO, the process returns to step (11); if YES, the optical motor 11 is moved backward (18), and the process waits for the scanning mirror 14 to return to the position of the home position sensor 16.
0), when it returns to the position of the home position sensor 16,
It is determined whether the copying is completed (21). If NO, the process returns to step (1) of the flowchart shown in FIG. 3; if YES, the optical motor 11 is stopped and the control is ended (22).

Note that in step (17), during pack scanning of the scanning mirror 14, even if the reversal sensor 21 is detected, the mirror does not immediately reverse, but rather overruns a little and then moves forward. This is the rise of the optical motor 11 during forward movement.
This is to earn money.

FIG. 5 is a cross-sectional view showing an embodiment of the image forming apparatus according to the present invention. Reference numeral 31 denotes an automatic document feeder, which automatically places both sides of a document on a document table 32. In FIG.

33 is an image forming section, and document scanning section 34. Developing section 35, transfer section 36. Cleaner section 37. It is composed of a photosensitive section 38, a fixing section 39, and the like. 4Q is a paper feeding section, and 41 is a duplex unit section, which inverts the recording paper on which the image has been fixed and feeds the recording paper to the image forming section 33 again. Reference numeral 42 denotes a paper discharge unit, which has a sorter mechanism for placing recording paper on pages.
It is configured to optionally also function as a stacker. Note that the document scanning section 34 has an image tip sensor 34a, a home position sensor 34b, and a reversal sensor 34c.

The image forming operation is based on a known electrophotographic method, so a description thereof will be omitted.

〔Effect of the invention〕

As described above, the present invention includes a reversal position detection means for detecting the reversal position of a document scanning section, a drive means for moving the reversal position detection means in a predetermined direction, and a drive means for moving the reversal position detection means in a predetermined direction. Since a drive control means is provided to control the position, it is possible to efficiently and cost-effectively perform continuous copying of left and right pages by simply controlling the position of a single reversal sensor, which serves as a reversal position detection means, according to the document size and magnification. It has excellent advantages that can be realized with

[Brief explanation of drawings]

FIG. 1 is a control block diagram of an image forming apparatus showing an embodiment of the present invention, FIG. 2 is a plan view of a document scanning section of the image forming apparatus showing an embodiment of the present invention, and FIG. FIG. 4 is a flowchart illustrating a page scanback operation; FIG. 5 is a flowchart illustrating a right page scanback operation according to the present invention; and FIG. 5 is a sectional view showing an embodiment of an image forming apparatus according to the present invention. In the figure, 1 is a CPU, 1a is a drive control means, 2 is an image forming means, 2a is a document scanning means, 2b is a driving means, 2c is a reversal position detection means, 3 is an operation means, 4 is a paper feeding means, 4a 11 is a paper size detection means, 11 is an optical motor, and 12 is a paper size detection means.
is a pulley, 13 is a wire, 14 is a scanning mirror, 14a
16 is a flag, 16 is a home position sensor, 17 is a tip sensor, 18 is a stepping motor, 21 is a reversal sensor, and 22 is a home sensor. 1st

Claims (1)

[Claims] In an image forming apparatus that continuously copies images of both pages of a document by reciprocating a document scanning section, there is provided a reversal position detection means for detecting a reversal position of the document scanning section, and a reversal position detection means for moving the reversal position detection means in a predetermined direction. What is claimed is: 1. An image forming apparatus comprising: a drive means for controlling the drive means; and a drive control means for controlling the position of the drive means according to a document size and a magnification ratio.