JPH0486833A - Image forming device - Google Patents

Abstract

PURPOSE:To execute copying on both sides of a paper and to obtain an image which is not deviated between both sides of the paper even when both-side copying is performed to the original of an undefined size by exposing and scanning the original which is either side by taking one end as reference and continuously exposing and scanning the original which is the other side by taking the other end as reference. CONSTITUTION:When copying is performed on both sides of the paper P, in the case of the original 12 of the undefined size, an undefined both-side copying key 63 is inputted. Then, the scanning mechanism or the lighting circuit of an exposing and scanning means 21 is set at the exposure by taking a left end as reference in which an area A is exposed and scanned, and a paper supply means 51 erects a switching gate 56a so as to guide the paper P to an intermediate tray 56b. Furthermore, an aligning roller 55 is also allowed to cope with the exposure by taking the left end as reference. When the original 12 is placed in a state where an upper end 12a(reference end) abuts on a reference body 16a and a copying start key 3 is pushed, the paper P where the image is formed on its surface side is guided by the switching guide 56a and housed in the intermediate tray 56b after fixing, then an image forming device is stopped. Then, the device is switched to copying by taking a right end as reference according to the command of a controller 62. When the copying is performed in a state where the original 12 is inverted and the upper end 12a is allowed to abut on the reference body 16b, the copy P where the upper end 12a of the original 12 is aligned between the surface side and the back surface side of the paper is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to an image forming apparatus that forms images on both the front and back surfaces of an image carrier.

(Prior Art) Generally, image forming devices such as copying devices often form an image on only one side of an image carrier (hereinafter referred to as paper), but recently, a front-back reversing mechanism that can copy on both the front and back sides has been installed. Double-sided copying devices equipped with the following functions have become widespread.

This is equipped with a front-back reversing mechanism 101 as shown in FIG. 17, and supplies paper P from a paper supply means 102 to a transfer unit 104 of a photosensitive drum 103 with the front side of the paper P as a forming surface, and after copying, After passing through the reversing conveyance path 105, it is stored in the intermediate tray 106.

When copying the back side, the paper P is transported in a switchback manner, with the trailing edge of the paper P as the leading edge in the feeding direction, and is then reversed and fed again to the photosensitive drum 103, and copies are made to the back side of the paper P. It is supposed to be done.

When copying is to be performed on the front side of paper P, as shown in FIG.
4, the original 110 is reversed and the front and back sides are switched, and the upper and lower ends of the original 110 are also switched in accordance with the front and rear reversal of the paper P, and a copy is made on the back side of the paper P.

For normal copying, that is, when the original 110 is a standard paper size, check whether the top edges of the front and back copies are aligned and there is no problem with the original 110.
There is a problem in the case of an irregularly sized original that is not a standard size.

That is, as shown in FIG.
11a is brought into contact with the reference body 112 to copy it onto the front side of the paper P. Next, as shown in FIG. When copying onto the back side of the paper P, as shown in FIG. 21, due to the difference in length between the irregular size of the original 110 and the regular size of the paper P, a copy with the top edge shifted will be obtained.

Therefore, there are various inconveniences, such as the inability to cut the copies to an appropriate size and arrange them.

(Problems to be Solved by the Invention) As described above, the double-sided image forming apparatus, which reverses the paper along its conveyance path and forms images on both the front and back sides, is capable of forming images on both the front and back sides. There is an inconvenience that the copy is misaligned between the front and back sides.

The present invention has been made to eliminate the above-mentioned disadvantages.
Paper with an image formed on the front side can be conveyed in a swing-like manner, reversed, and copied to both the front and back sides of the paper, and even when double-sided copying is performed with irregular-sized originals, the image will not shift between the front and back sides. The purpose is to provide a forming device.

[Structure of the Invention (Means for Solving the Problems)] In order to achieve the above object, the image forming apparatus of the present invention is provided with an image forming apparatus that is placed with one end of a document table as a reference and forms images on the front and back sides of an image carrier. an exposure scanning means for exposing and scanning one document with reference to one end and scanning the exposure of the other document placed on the document table with reference to the other end; and an image forming means for forming an image of the document thereby. , the image carrier is supplied to the image forming means in response to the exposure scan based on one end, and after image formation, the image carrier is reversed by switchback-like conveyance and then supplied again in response to the exposure scan based on the other end. The invention is characterized by comprising means.

(Function) In the present invention, a document is copied with the top edge as a reference aligned with one end of the document table, an image is formed on the front side of the paper, and the top edge is aligned with the other end of the document table. The original is copied based on the other edge, and the image is formed on the back side of the paper, and the rear edge (feeding direction) of the back side of the paper is aligned with the other edge of the document platen, so by reversing, the front side of the paper is Even if the leading and trailing edges are swapped, the images on the front and back sides will not shift.

(Example) The details of the present invention will be explained below with reference to an example shown in FIGS. 1 to 16.

The image forming apparatus of this embodiment includes a main body 1 and a document placement means 1.
1, exposure scanning means 21, image forming means 31, paper ejection means 41, paper supply means 51, and control means 61.

The main body 1 houses the entire device, and has openings on the top and both sides. Further, an operation panel 2 is provided in front of the top surface.

As shown in Figures 2 and 3, these include a copy start key 3, a copy number setting key 4, a paper cassette selection key 5 from the right end.
, display section 6, image density setting section 7, variable magnification key
8, etc., followed by an irregular double-sided copy key 63, a regular double-sided copy key 64, etc. of a control means 61, which will be described later.

The document placement means 11 includes a document table 13 on which the document 12 is placed;
It has a document cover 14 attached to the main body 1 so as to be openable and closable, and by closing the document cover 14,
The original 12 is held suppressed.

Further, a scale-shaped reference body 16a is provided at one end 15a (hereinafter referred to as the left end) of the document table 13, and the other end 15a is provided with a scale-shaped reference body 16a.
A reference body 16b is provided at b (hereinafter referred to as the right end). In both of these, the upper end 12a of the original document 12, which serves as a reference for positioning the original document 12, is brought into contact with and positioned.

Note that although a document supply device 11a is provided adjacent to the document cover 14, it is not used in this embodiment, so its explanation will be omitted.

The exposure scanning means 21 includes a moving light source 22, moving reflecting mirrors 23a and 23b, an imaging lens 24, and a reflecting mirror 2.
There are many types such as 5a, 25b, 25c.

Then, by moving and scanning the original 12 without illuminating the light source 22, the reflected light from the original 12 is incident on the imaging lens 24 by the moving reflecting mirrors 23a and 23b, and the resulting convergent light is focused on the fixed pair of mirrors 23a and 23b. Reflection mirror 25a, 2
5b and the final reflecting mirror 25c to the photosensitive drum 3.
2 and form an image.

Further, the document table 13 is
Exposure scanning is performed using the left end reference or right end reference. When the left end reference is used, the exposure scan of area A is performed from the left end to the right end with reference to the reference body 16a, and when the right end reference is used, the exposure scan is performed using the reference body 16a as the reference.
Area B is exposed and scanned from the left end to the right end with reference to b. These exposure lengths l are set from the respective reference ends in accordance with the length of the paper P.

The image forming means 31 includes a rotating photosensitive drum 32, and the image of the original 12 formed thereon becomes a latent image.
b, and the visible image is transferred to the paper P by the transfer device 32c.The paper P is further conveyed by the conveyor 33, heated and fixed by the pair of fixing rollers 34, and sent to the paper discharge means 41.

The paper discharging unit 41 includes a pair of paper discharging rollers 42 and a paper discharging tray 43 , and the fixed paper P is sent out by the paper discharging rollers 42 and stored in the paper discharging tray 43 .

The paper supply means 51 supplies paper P as an image carrier, and includes a manual feed cassette 52, a cassette 53, a large cassette 54, and a front-back reversing mechanism 56.

The paper P taken out by each pickup roller 52a, 53a, 54a is transported by a pair of feed separation rollers 53b, 54b.
to the aligning roller pair 55, and the control means 61
and is sent to the photoreceptor drum 32 as appropriate in response to left end reference exposure, right end reference exposure, and heavy exposure.

The front/back reversing mechanism 56 includes a switching gate 56a provided on the discharge path of the pair of fixing rollers 34, an intermediate tray 56b, a reversing conveyance path 56c provided between these, and a plurality of feed Roller pair 56d..., pickup roller 56e, and separation feed roller pair 56
f, a conveyance path 56g, etc.

When copying only one side, the switching gate 56
is set horizontally as shown in Figure 1, and the paper P
is transported toward the paper discharge tray 43.

Further, according to a command from the control means 61, in the case of double-sided copying, the switching gate 56a is set diagonally upward as shown in FIG. As shown in Figure 5,
It passes through the reversing conveyance path 56c and is accommodated in the intermediate tray 56b as shown in FIG. When the set number of front side copies are completed, the switching gate 56a returns to the horizontal position, and when copying to the back side of the paper starts, the paper P is sequentially taken out by the pickup roller 56e, as shown in FIG. , the paper P is sent to the aligning roller 55 with the trailing edge in the feeding direction up to now as the leading edge in the feeding direction. Then, as shown in FIG. 7, when the paper is re-supplied and the image formation on the back side is completed, it passes through the horizontally set switching gate 56a and is stored in the discharge tray 43, as shown in FIG. .

The control means 6] is equipped with a control device 62 having a CPU, which controls the entire embodiment, and will mainly be described with respect to the portions related to double-sided copying of irregular-sized originals.

The control device 62 includes a copy start key 3, an irregular double-sided copy key 63, a regular double-sided copy key 64, and a number setting key 4.
, a discharge paper detector 57 provided in front of the switching gate 56a, an exposure motor driver 26 of the exposure scanning means 21, a lighting circuit 27 of the illumination body 22, a switching gate 56a of the paper supply means 51, an aligning roller 55, etc. are connected. has been done.

When copying both the front and back sides of paper P using irregular-sized original 12, first input the irregular-size double-sided copy key 63. Note that if this key 63 is not input, one-sided copying will be performed based on the left edge.

As a result, the scanning mechanism and lighting circuit of the exposure scanning means 21 are set to expose the area A with reference to the left end.

Further, in the paper feeding means 51, the switching gate 56a is set to stand up and guide the paper P to the intermediate tray 56b. Furthermore, the aligning roller 55 is also set corresponding to the exposure based on the left end side.

Now, as shown in FIG. 10, the original 12 has A on one side.
BC...... is written on the other side, and Irono... is written on the other side, and these are to be copied on one side and the other side of paper P, respectively. .

As shown in FIGS. 11 and 12, the original 12 is placed on the reference body 1.
When the upper edge 12a (reference edge) of the original 12 is placed on the sheet 6a, the number of sheets is set, and the copy start key 3 is pressed, copying starts.
The image forming apparatus is guided by the switching guide 56a and accommodated in the intermediate tray 56b with the front side up, and when the set number of copies has been completed, the image forming apparatus stops.

Accordingly, a command from the control device 62 switches to the right-end reference copy.

That is, the exposure scanning means 21 exposes and scans the area B,
The paper supply means 51 is supplied with paper P from the intermediate tray 56b with the back side as the image forming surface, and the paper P is supplied from the intermediate tray 56b to the switching gate 56.
a is set horizontally, and the aligning roller 55 is also set corresponding to the right-end reference copy.

Then, as shown in FIG. 13, when copying is performed by inverting the original 12 and bringing the upper edge 12a into contact with the reference body 16b, the rear edge of the back side of the paper P is aligned with the upper edge (reference edge) of the original 12. As a result, as shown in FIGS. 14 and 15, a copy P is obtained in which the top edge 12a of the original 12 matches the front and back sides of the paper, and the set number of sheets P of the double-sided copy is delivered to the output tray 43.
be accommodated in.

This completes the explanation of the configuration and operation of this embodiment.Next, the overall operation and operation will be explained with reference to the flowchart of FIG. 16.

An example of either an irregular double-sided copy or a regular double-sided copy will be explained.

First, it is determined whether the irregular-sized original 12 is to be double-sided copied onto standard-sized paper P (step P).

If YES, press the irregular double-sided copy key 63. (Step P+) With the front side of the irregularly shaped original 12 facing the original platen 13, the upper end 12a of the irregularly shaped original 12 is brought into contact with the reference body 16a at the left end for positioning. The number of copies is 1. (Step P2)
.

Press copy start key 3. Copying starts based on the left edge. (Step P3) The paper P copied on the front side is guided to the switching gate 56a, passes through the reversing conveyance path 56c, and is stored in the intermediate tray 56b (Step P4).

The irregular-sized original 12 is reversed along the scanning direction, and the original 12 is
with the back side facing the document table 13, and the upper end 12a facing the right end reference body 16.
- Position by contacting b. (Step P,).

Press copy start key 3 to copy based on the right edge (
Step P6).

The paper P copied on the back side is discharged as a double-sided copy with the leading edge of the irregular-sized original 2 matching the front and back sides, and is stored in the tray 43. (Step P)).

Also, step P. 2, the answer is No, and the double-sided copy key 64 is pressed (step P, 1).

The front side of the standard document 12 is directed toward the document table 13, and the upper end 12a is positioned by contacting the left end reference body 16a (step P).
12).

Press the copy start key 3 to copy to the left end reference (step P13).

The paper P copied on the front side is guided to the upright switching gate 56a and stored in the intermediate tray 56b (step P, 4).

Flip the standard original 12 along the scanning direction, and place the back side on the original platen 1.
3, the lower end 12b is brought into contact with the left end reference body 16a for positioning (step P15).

Press the copy start key 3 to copy based on the left edge (step P16).

The leading edge of the original 12 or the matching double-sided copy or paper output tray 43
(Step P17).

The overall work flow is as described above.

Note that in this embodiment, the case where the front and back sides of -sheets of originals are copied has been described, but separate originals may be used. Furthermore, it goes without saying that the number of copies may be more than one.

[Effects of the Invention] As described in detail above, the image forming apparatus of the present invention is capable of maintaining one end reference for the front side and the back side of the paper even if the front edge and the rear edge of the paper are switched by the front-back reversing mechanism. Since the images are formed separately for the copy and the other-edge reference copy, even for an irregularly shaped original, it is possible to obtain a sheet of paper with an image in which the top edge of the original is the same on both sides.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram of an image forming apparatus according to an embodiment of the present invention, FIG. 2 is a perspective view with the document cover removed, and FIG.
The figure is a plan view of the main part (operation panel), Figures 4 to 8 are overall configuration diagrams explaining the operation of the main part (front-back reversing mechanism), and Figure 9 is a block diagram of the main part (control means). figure,
FIG. 10 is an explanatory diagram of the relationship between an irregularly shaped original and paper, FIG. 11 is an external perspective view showing the document placed on one edge, and FIG. 12 is a plan view showing the document placed on one edge. Figure 13 is an external perspective view showing the document placed with the other end as the standard, Figure 14 is a plan view showing the original placed with the other end being the standard, and Figure 15 is a double-sided copy and the original. FIG. 16 is a flowchart explaining the same operation, FIGS. 17 to 21 are explanatory diagrams of a conventional image forming apparatus, FIG. 17 is an explanatory diagram of a front-back reversing mechanism, and FIG.
The figure is an external perspective view explaining the document placement state with one end as the reference, FIG. 19 is a plan view of the main part showing the positioning of one side of the original with the one end as the reference, and FIG. 20 is the other side of the original as the one end as the reference. Main part plan view showing positioning of the surface, 2nd
FIG. 1 is also an explanatory perspective view showing the relationship between a document and a copy.

Claims (1)

[Claims] One of the originals placed on one end of the original platen as a reference and images formed on the front and back sides of the image carrier is exposed and scanned using one end as a reference, and the other original placed on the other end of the original platen is scanned with the other end as a reference. an exposure scanning means that performs exposure scanning, an image forming means that forms an image of a document thereby, and an image bearing member that is conveyed to the image forming means in response to the reference exposure scanning, and is transported in a switchback manner after image formation. 1. An image forming apparatus comprising: an image bearing member supplying means for reversing the front and back sides and supplying the image carrier again in response to exposure scanning based on the other end.