JP2596587B2 - Image forming device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an image forming apparatus provided with an automatic document feeder of a type in which a document is loaded and unloaded by a document transport means which can be brought into close contact with a document placing plate. Related to the device.

<Related Art> In recent years, in an image forming apparatus such as a copying machine, an automatic document feeder (ADF) that automatically feeds a document onto a document placing plate.
The automatic document feeder is disclosed, for example, in Japanese Patent Application Laid-Open No. 60-118551.

The above-mentioned automatic document feeder is provided with a document holder rotatably provided between a closed position for covering the transparent document loading plate and an open position for exposing the document loading plate, and provided adjacent to the document holder. A document sending means for sending a document one by one sequentially is additionally provided. Further, in the original holding section, the original sent out by the original sending means is carried into a required position on the original placing plate, and after the scanning exposure for the original is completed, the original on the original placing plate is moved to the original. A document conveying means for carrying out the document on the upper surface of the presser is additionally provided.

<Problems to be Solved by the Invention> However, this document conveying means is constituted by an endless conveyance belt attached to substantially the entire lower portion of the document press, and a mechanism for driving the conveyance belt is complicated. Therefore, there is a problem that the manufacturing cost of the automatic document feeder is increased, and the size of the apparatus is large, so that the apparatus cannot be applied to a small-sized copying machine or the like.

Therefore, in order to solve these problems, as a document conveying means, a conveying roller which is rotatably mounted in a concave portion under the document press and which can be in close contact with the upper surface of the document placing plate when the document press is closed is used. Japanese Patent Laid-Open Publication No. Sho 63-61333 (Japanese Patent Laid-Open Publication No. 1-236126) proposes a system in which a document is loaded and unloaded in accordance with the forward and reverse rotation of the transport roller.

However, in the closed state of the original press, the concave portion and the transport roller are arranged above the original placing plate.
Therefore, when a document is manually placed, if the document size is small and the concave portions or the transport rollers protrude outside the document, the images of these concave portions and the transport rollers clearly appear on the copy paper. In addition, when the original is a thin original that transmits light rays at the time of exposure, the above-described concave portion and the shadow of the transport roller appear on the copy paper. Thus, a new problem that a good copied image cannot be obtained occurs.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and can reduce the size and cost of an automatic document feeder and obtain a good transfer image when a document is manually placed. It is an object of the present invention to provide an image forming apparatus capable of performing such operations.

<Means for Solving the Problems> As this image forming apparatus for achieving the above object, a document is sandwiched between the document placing plate and the document conveying means at one end of the document placing plate. An automatic document feeder that conveys the document to the first document placement position, and the manual document placement position is manually shifted to a second document placement position that is shifted from the first document placement position by a predetermined distance in the document scanning direction. A set image forming apparatus, wherein a discriminating means for discriminating whether or not a document is conveyed by the automatic document feeder; and a document is manually placed based on an output signal of the discriminating means. A transfer timing delay unit that delays the transfer timing of the transfer paper conveyed to the photoreceptor by the transfer paper conveyance unit by a predetermined time corresponding to the second document placement position. To be Things.

<Operation> According to the image forming apparatus of the present invention, the document is manually moved to the second document placement position, which is shifted by a predetermined distance in the document scanning direction from the first document placement position, that is, from below the document feeder. When the document is placed, the discriminating means discriminates that the document is to be placed manually. Based on an output signal of the discriminating means, the transport timing delay means causes the transfer paper transporting means to transfer the paper to the photosensitive member of the transfer paper. By delaying the transport timing of the document by a predetermined time, the image of the
Transfer on the transfer paper can be prevented.

When a mark indicating the second document placement position or a document stopper that regulates the document placement position is provided corresponding to the second document placement position, the document is manually moved. When the document is placed, the document can be easily placed at the second document placement position by the mark or the document stopper.

<Example> Hereinafter, an example will be described in detail with reference to the accompanying drawings.

FIG. 1 is a schematic diagram showing one embodiment of an image forming apparatus according to the present invention, and an automatic document feeder (4) disposed on the upper surface of a housing (10) of a copying machine (1) as an image forming apparatus. An optical unit (2) for scanning and exposing a document placed on a document placing plate (11), an image forming unit (3) for forming an image corresponding to the document on transfer paper (B), A control section (8) for controlling the operation of the automatic document feeder (4), the optical section (2), the image forming section (3), and the transfer sheet conveying means (9);
And as a main part.

The automatic document feeder (4) includes the housing (1)
The document holder (0) attached to the housing (10) is pivotably movable between a closed position for covering the transparent document plate (11) on the upper surface of (0) and an open position for exposing the document plate (11). 5)
The document holder (5) is provided on the document holder (5), and the document (A) is carried in to a required position on the document placing plate (11), and the document (A) is carried out from the document placing plate (11). A document conveying means (6) and a document sending means (7) provided adjacent to the document holding means (5) and sequentially sending the document (A) to the document conveying means (6) one by one. Be composed.

As shown in FIG. 3, the document sending means (7) comes into contact with an inclined document table (71) on which a sheet-shaped document (A) is placed, and contacts the upper surface of the document (A) when necessary. And a delivery roller (72) for sending the document (A) to the downstream side in the delivery direction along the document table (71), and the document (A) sent by the delivery roller (72) to the document transport means (6). When the original (A) is fed by the feed roller (73) and the feed roller (73), the feed roller (73) rotates in cooperation with the feed roller (73), and two or more originals (A) are rotated. It has a reversing roller (74) for preventing simultaneous feeding.

A document set detection unit, such as a micro switch, for detecting that a document has been set on the document table (71) is provided downstream of the document table (71) of the document sending means (7) in the transport direction. A vessel (75) is provided.
The original set detector (75) has a detection arm (76) exposed through an opening (78).
Falls over due to the weight of the document set on the document table (71), thereby detecting the setting of the document.
The output signal of the document set detector (75) is transmitted to a determination means (81) described later.

Further, a restraining member (79) is provided downstream of the document set detector (75) in the transport direction of the document table (71) so as to allow the document to pass only when necessary. The document (A) is further downstream in the transport direction than
For example, an outgoing document detector (77) including an on / off switch and the like, which is turned on when passing through, is provided.

The document holder (5) includes a frame (51) rotatable around a pivot axis (not shown) along a rear edge of the housing (10), and a document table (51) of the frame (51). A roller housing (52) integrally formed on the 71) side and housing the document conveying means (6). When the document holder (5) is in its closed position, the frame (51) is in a substantially horizontal state, and the gap between the lower surface of the frame (51) and the document placing plate (11) is about 1 mm. The attachment to the pivot axis and the like are adjusted so that a gap is generated.

The roller accommodating portion (52) is formed of a box having a plurality of notches (53) at predetermined positions on the lower surface, and is provided on the frame (51) side.
A discharge opening (54) for conveying the document (A) is provided on the upper surface of the frame (51). In addition, a plurality of guide ribs (55) hang down at an appropriate interval in the width direction in the upper part of the roller housing (52). Furthermore, the roller housing (52)
A guide means (56) made of a flexible synthetic resin piece such as a polyester film having a thickness of about 0.075 mm is provided at a portion adjacent to the lower end of the document table (71).

The guide means (56) has an upper end fixed to the inner wall of the roller accommodating portion (52) and a lower end bendable inside the roller accommodating portion (52). (11) While allowing the original (A) to enter above, the original (A) is prevented from moving from above the original placing plate (11) toward the original table (71) and is deflected upward. Things.

The document conveying means (6) includes a shaft (61) rotatably disposed between a front wall and a rear wall of the roller accommodating portion (52), and a plurality of documents at predetermined positions in the axial direction of the shaft (61). A plurality of transport rollers (62) fixed and protruding downward from the notch (53),
It is constituted by a driven roller (63) which comes into contact with the upper part of each transport roller (62) and rotates following the transport roller (62). The driven roller (63) is rotatably mounted on a pin (64) attached to the guide rib (55).

In the automatic document feeder (4), first, a document (A) on a document table (71) is
The sheet is fed out to a position where the leading end thereof comes into contact with the close contact portion between the transport roller (62) and the document placing plate (11) (see FIGS. 3 and 4). 5, the document (A) is carried into the first document placing position (P1) on the document placing plate (11) (see FIGS. 5 and 6), Further, after the scanning exposure for the original (A) is completed, the transport roller (62) is rotated in the reverse direction (clockwise in FIG. 7), so that the original (A) on the original placing plate (11) is removed. It is retracted along the guide means (56) and the guide rib (55), and is carried out from the discharge opening (54) onto the upper surface of the frame (51) of the document holder (5) (see FIG. 7). ).

The first document placement position (P1) is set so that the document (A) is loaded and unloaded by forward and reverse rotation of the transport roller (62). It is set at a position where it can be clamped between the transport roller (62) and the document placing plate (11).

Further, the transport roller (62) is connected to the output original detector (7
7) is turned off (the end of the passage of the original (A)), and then the forward rotation is continued for a predetermined time so that the original (A) can be accurately moved to the first original placing position (P1). Bring in.

Further, the copying machine (1) manually operates the original (A)
The second document placement position (P2) is set as the document placement position when the document is placed, and a mark (12) indicating this position is placed on the document placement plate (11) or the housing ( Ten)
(See FIG. 2). The second document placement position (P2) is set such that the end of the document placed at the second document placement position (P2) is displaced from below the document conveying means (6). It is set at a position shifted by a predetermined distance in the original scanning direction from the original placing position (P1). in this way,
When the document (A) is manually placed, the control unit (8) extends the scanning stroke of the optical unit (2) in accordance with the second document placement position (P2). The scanning stroke may be always extended regardless of whether the original is placed by the automatic document feeder (4) or manually.

The image forming section (3) forms an electrostatic latent image corresponding to a document on a photoreceptor drum (31) as a photoreceptor, and forms a toner image by adsorbing toner by a developing device (32). Then, the toner image is transferred onto the transfer paper (B) conveyed from the transfer paper conveyance means (9) to the photosensitive drum (31). The transfer paper transport means (9) includes a paper feed roller (91) for feeding transfer paper (B) from a paper feed cassette (not shown), and a transfer paper fed by the paper feed roller (91). (B) to a photoconductor drum (31).

The control unit (8) includes a microcomputer or the like,
The operation of the optical section (2) and the image forming section (3) is controlled, and when a document is placed by the automatic document feeder (4), the operation is linked with the operation of the automatic document feeder (4). Then, the optical unit (2) and the image forming unit (3) are operated.

The control section (8) determines whether or not the original (A) is conveyed by the automatic original feeder (4) based on the detection signal of the original set detector (75). ) And the output signal of the determination means (81),
When a document is manually placed, the drive start timing of the registration roller (92) is delayed by a predetermined time in accordance with the second document placement position (P2).
A transport timing delay means (82) for delaying the transport timing of the transfer paper (B) to the photosensitive drum (31) by a predetermined time is provided.

According to the configuration of this embodiment, the automatic document feeder (4)
However, since the document (A) is sandwiched between the document placing plate (11) and the document transporting means (6) at one end on the document placing plate (11) and transported, the transport mechanism is simplified, The size and price of the automatic document feeder (4) can be reduced.

Further, the original (A) is manually moved to a second original placing position (P2) shifted from the first original placing position (P1) below the original conveying means (6) by a predetermined distance in the original scanning direction. When the document is placed, the discriminating means (81) determines that the document is placed manually, and based on the output signal of the discriminating means (81), the transport timing delay means (82) By delaying the transfer timing of the transfer paper (B) to the photosensitive drum (31) by (92) by a predetermined time, the image of the document transfer means (6) or the like formed on the photosensitive drum (31) is formed. Can be prevented from being transferred onto the transfer paper (B). Therefore, when a document is manually placed, a good transfer image can be obtained.

Further, since the mark (12) indicating the second document placement position (P2) is provided in correspondence with the second document placement position (P2), the document (A) is placed manually. At this time, the document (A) can be easily placed at the second document placement position (P2) by the mark (12).

Note that the transport timing delay means (82) is provided with a registration roller (9) from the paper feed roller (91) of the transfer paper (B).
The transfer timing of the transfer paper (B) to the photosensitive drum (31) may be delayed by delaying the timing of feeding the transfer paper (B). In this case, the timing for driving the registration roller (92) for transporting the transfer paper (B) to the photosensitive drum (31) is kept constant irrespective of whether the original is manually placed.

A plurality of transport rollers (62) of the document transport means (6)
Instead of a part of them, a small-sized conveyance belt having a size similar to that of the conveyance roller (62) can be used.

In addition, the image forming apparatus of the present invention is not limited to the above embodiment. For example, the mode in which the determination means (81) uses the automatic document feeder (4) and the mode in which the document is placed manually can be used. Signal from the open / close switch provided on the document holder (5), and the signal of the document (A) when the document (A) is manually placed. Place the second position
Various design changes can be made within a range that does not change the gist of the present invention, for example, by providing a document stopper that regulates the document mounting position (P2) so as to be detachable.

<Effects of the Invention> As described above, according to the image forming apparatus of the present invention, the document is conveyed by sandwiching the document between the document mounting plate and the document conveying means at one end of the document mounting plate. In spite of the fact that the transport mechanism is simplified and the size of the automatic document feeder can be reduced and the price can be reduced, when a document is manually placed on the second document placing position, the transfer timing The transfer timing of the transfer paper to the photoreceptor by the transfer unit can be delayed by a predetermined time, and the image of the document transfer unit or the like can be prevented from being transferred onto the transfer paper, and a good transfer image can be obtained. It has the unique effect of being able to.

When a mark indicating the second document placement position or a document stopper that regulates the document placement position is provided corresponding to the second document placement position, the document is manually moved. When the document is placed on the document, the mark or the document stopper has a unique effect that the document can be easily placed at the second document placing position.

[Brief description of the drawings]

FIG. 1 is a schematic structural view of an embodiment of the image forming apparatus of the present invention, FIG. 2 is a plan view of a document placing plate, and FIGS. FIG. (4) Automatic document feeder, (6) Document transfer means, (9) Transfer paper transfer means, (11) Document placement plate, (12) Mark, (31) .. Photoreceptor drum as a photoreceptor, (81)... Discriminating means, (82)... Transport timing delay means, (A)... Original, (B).
(P1): First document placing position, (P2): Second document placing position

Claims (2)

(57) [Claims] An automatic document feeder for sandwiching an original at one end of the original placing plate between the original placing plate and the original transporting means and transporting the original to a first original placing position;
An image forming apparatus in which a manual document placing position is set to a second document placing position which is displaced from the first document placing position by a predetermined distance in the document scanning direction; Determining means for determining whether or not the document is conveyed; and, when the document is manually placed based on the output signal of the determining means, the transfer paper is set in correspondence with the second document placing position. An image forming apparatus comprising: a transport timing delay unit that delays the transport timing of the transfer paper transported to the photoconductor by the transport unit by a predetermined time. 2. An automatic document feeder for holding a document at one end of the document placing plate between the document placing plate and the document transporting means and transporting the document to a first document placing position.
An image forming apparatus in which a manual document placing position is set to a second document placing position which is displaced from the first document placing position by a predetermined distance in the document scanning direction; Determining means for determining whether or not the document is conveyed; and, when the document is manually placed based on the output signal of the determining means, the transfer paper is set in correspondence with the second document placing position. A transport timing delay unit for delaying the transport timing of the transfer paper transported to the photoconductor by the transport unit by a predetermined time; and displaying the second document placement position in correspondence with the second document placement position. Mark,
Alternatively, there is provided an image forming apparatus including a document stopper for restricting a document placement position.