JP3221122B2 - Digital image forming equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital image forming apparatus such as a digital copying machine or a laser printer having a plurality of paper feed trays, and more particularly to a digital image forming apparatus characterized by the arrangement of the paper feed trays. The present invention relates to a forming apparatus.

[0002]

2. Description of the Related Art As shown in FIG. 3, a conventional digital copying machine F inherits the technical flow from an analog copying machine. 1, an image reading processing unit F1, a xerographic apparatus (image recording apparatus) F2, and a plurality of paper feed trays T1 to T5 corresponding to the types of recording sheets are sequentially arranged. The image reading processing unit F1 includes an exposure optical system 0
1. An image processing unit 05 that converts image data converged on the imaging surface of the solid-state imaging device 04 through the exposure optical system 1 into a laser drive signal. The xerographic apparatus (image recording apparatus) F2 is a photosensitive drum (latent image carrier) on which an electrostatic latent image is written by a laser beam of an optical writing / scanning apparatus (that is, a latent image writing apparatus) 06.
07, a charging charger 08, a developing unit (namely, a developing device) 09, a transfer charger (transfer unit) 010, a cleaner unit 011 and the like arranged therearound. Further, the conventional digital copying machine F is provided with a sheet conveying device H for taking out a recording sheet from each of the paper feed trays T1 to T5 and conveying the recording sheet to the transfer point.

[0003]

In the prior art, the path length (length of the recording sheet transport path) from each of the paper feed trays T1 to T5 to the position (transfer point) of the transfer unit 010 is greatly different. (M01) to (M02). (M01) The time required for the recording sheet supplied from the paper feed tray to reach the transfer point was significantly different between the uppermost paper feed tray and the lowermost paper feed tray. For this reason, software for controlling the conveyance timing of the recording sheet from each paper feed tray has been complicated. (M02)
In a high-speed copying machine having a high copying speed, in order to maintain the copying speed at a high speed, it is necessary to take out a recording sheet from the lowermost sheet feeding tray in advance and convey it. For this reason, the control of the processing at the time of a jam (paper jam) is complicated.

In view of the above circumstances, the present invention provides the following (O01)
Is the subject of the description. (O01) To reduce the difference in the path length from each of the plurality of paper feed trays to the transfer point, and to make the longest path length among the path lengths from each paper feed tray to the transfer point shorter than before.

[0005]

Next, the present invention devised to solve the above-mentioned problems will be described. Elements of the present invention are used to facilitate correspondence with elements of the embodiments described later. , The reference numerals of the elements of the embodiment are enclosed in parentheses. The reason why the present invention is described in correspondence with the reference numerals of the embodiments described below is to facilitate understanding of the present invention, and not to limit the scope of the present invention to the embodiments.

In order to solve the above problems, a digital image forming apparatus according to the present invention comprises an image recording apparatus (F2) for recording an image on a recording sheet at an image recording position, and a plurality of paper feed trays (T1 to T5). And a sheet conveying device (H1, H2) for taking out a recording sheet from each of the paper feed trays (T1 to T5) and conveying the recording sheet to the image recording position, the following requirements (Y01): A digital image forming apparatus comprising: (Y01) a sheet conveying device that takes out recording sheets from the plurality of paper feeding trays and each paper feeding tray and conveys the recording sheet to the image recording position;
The image recording device is arranged separately above and below. Further, in the digital image forming apparatus of the present invention, the image recording device (F2) is a latent image carrier (7), and a latent image writing device (6) for writing a latent image on the latent image carrier (7). A developing device (9) for developing the latent image into a toner image, and a xerographic device (F2) having a transfer unit (10) for transferring the toner image to a recording sheet at a predetermined transfer point. The recording position is the transfer point.

[0007]

Next, the operation of the present invention having the above-mentioned features will be described. In the digital image forming apparatus according to the present invention having the above-described features, the recording sheet taken out from the predetermined paper feed tray (T1 to T5) among the plurality of paper feed trays (T1 to T5) is fed to the sheet transport device ( H1, H2), the image recording device (F
The sheet is conveyed to the image recording position where the image is recorded on the recording sheet by 2). In the present invention, the plurality of paper feed trays (T1 to
T5) is disposed above and below the image recording device (F2), so that the position of the paper feed trays (T1 to T5) furthest from the image recording device (F2) is The image recording device (F2) is compared with the paper tray (the conventional paper feeding tray collectively arranged below the image recording device (F2)).
Can be located close to That is, variations in the length of the path (conveyance path) from each of the plurality of paper feed trays (T1 to T5) to the image recording apparatus (F2) are reduced, and the longest path can be shorter than before. For this reason, the transport time of the recording sheet from the paper feed tray (T1 to T5) to the image recording position of the image recording device (F2) can be shortened as a whole. Further, in the digital image forming apparatus of the present invention, the latent image is written on the latent image carrier (7) by the latent image writing device (6). The latent image written on the latent image carrier (7) is developed into a toner image by the developing device (9). This toner image is conveyed to a predetermined transfer point.
A recording sheet taken out from a predetermined paper feed tray (T1 to T5) among a plurality of paper feed trays (T1 to T5) is subjected to a xerographic device (F2) by a sheet transport device (H1, H2).
To the transfer point. In the present invention, the plurality of paper feed trays (T1 to T5) are provided with a xerographic apparatus (F2).
Of the paper feed tray (T1), which is arranged farthest from the xerographic apparatus (F2).
The position T5) can be located closer to the xerographic apparatus (F2) than a conventional paper feed tray (a conventional paper feed tray collectively arranged below the xerographic apparatus (F2)). That is, a plurality of paper feed trays (T1 to
The variation in the length of the path (transport path) from T5) to the xerographic apparatus (F2) is reduced, and the longest path can be shorter than before. For this reason, the transport time of the recording sheet from the paper feed trays (T1 to T5) to the transfer point of the xerographic apparatus (F2) can be shortened as a whole. The transfer unit (10) of the xerographic apparatus (F2) transfers the toner image on the latent image carrier (7) to the recording sheet at the transfer point.

[0008]

Next, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to the following embodiments. FIG. 1 is an explanatory diagram of Embodiment 1 of a digital image forming apparatus F of the present invention. This digital image forming apparatus F
Is a digital copying machine, which is used in combination with the automatic document feeder B. As the automatic document feeder B, various known devices can be used.

Next, the digital copying machine (ie, digital image forming apparatus) F will be described with reference to FIG. The digital copying machine F includes an image reading processing unit F1 and first and second sheet feeding trays T1,
T2, a xerographic apparatus F2, and third to fifth paper feed trays T3 to T5. Image reading processing unit F1
Has a transparent platen glass F1a on its upper surface, and an exposure optical system 1 is disposed below it. The exposure optical system 1 has a movable illumination unit 2, and the illumination unit 2 is configured by integrating an original illumination lamp 2a and a first mirror 2b. Further, the exposure optical system 1 has a movable mirror unit 3 that moves at half the speed of the illumination unit 2. The movable mirror unit 3 is a second mirror 3
a and a third mirror 3b. The image reading processing unit F1 includes a solid-state imaging device (CCD) 4
have. Then, the lamp unit 2 moves in the left-right direction in FIG. 1 in parallel with a document (not shown) on the platen glass F1a, and the moving mirror unit 3 moves at half the moving speed of the lamp unit 2. At the speed of 1 /
The reflected light of the document G illuminated by the lamp 2 a is converged on the imaging surface of the solid-state imaging device 4 through the exposure optical system 1 while moving by the distance 2.

The image data obtained by the solid-state imaging device 4 of the image reading processing unit F1 is converted into a laser drive signal by the image processing unit 5, and the optical writing and scanning device (Raster Optical Scanner) of the xerographic device F2 is used. That is, it is input to the latent image writing device 6. The xerographic device F2 comprises the optical writing and scanning device (ie,
A photosensitive drum (latent image carrier) 7 on which an electrostatic latent image is written by a laser beam of a latent image writing device 6, a charging charger 8 disposed around the photosensitive drum 7, a developing unit (that is, a developing device) 9, and transfer. Charger (transfer device) 10, a cleaner unit 11, and the like.

In the digital copying machine F, a first tray T1 and a second tray T2 for storing copying paper (that is, a recording sheet or a transfer paper) are arranged above the xerographic apparatus F2, And the third tray T3,
A fourth tray T4 and a fifth tray T5 are arranged.
Each tray T1, above the xerographic apparatus F2,
An upper sheet conveying device H1 is provided between T2 and a position (that is, a transfer point) where the transfer charger 10 is arranged. This upper paper transport device H1
Has a paper transport roll, a sensor, and the like for taking out and transporting copy paper (recording sheet) from each of the trays T1, T2. Further, the xerographic apparatus F2
A lower sheet conveying device H2 is provided between the lower trays T2, T3, T4 and the position where the transfer charger 10 is arranged (ie, the transfer point). The lower paper transport device H2 has a paper transport roll, a sensor, and the like for taking out and transporting copy paper (that is, a recording sheet) from each of the trays T3, T4, T5.

From each of the trays T1 to T5, a sheet corresponding to the size detected by a size sensor of the automatic document feeder B described later or a sheet selected by a sheet selection button of the digital copier F at a predetermined timing. Taken out at
The sheet is conveyed between the photosensitive drum (latent image carrier) 7 and the transfer charger 10, that is, to a transfer point. The path length (transport distance) from the position of the transfer charger 10 (transfer point) to the first tray T1 and the path length to the fourth tray T4 are set to be equal. Further, the transfer charger 10
The path length (transport distance) from the position (transfer point) to the second tray T2 is set equal to the path length from the third tray T3.

In the digital copying machine F, a transfer mechanism that separates and transports the copy sheet (ie, the transfer end paper or the transfer end recording sheet) that has passed through the transfer point from the photosensitive drum 7 is transported by the transport mechanism. Fixing unit 18 for fixing the transferred image of the transferred transfer-completed paper, and a paper discharge tray 19 for discharging the fixed copy paper
Etc. are provided.

(Operation of First Embodiment) Next, the operation of the first embodiment of the digital image forming apparatus F having the above-described configuration will be described. In the first embodiment, the paper feed trays T1 to T5 are divided into upper groups T1 and T2 and lower groups T3 to T5, and the xerographic apparatus F2 is arranged in the middle. For this reason, the longest path length of the path lengths from the position of the transfer charger 10 (transfer point) to each of the trays T1 to T5 can be shortened as compared with the related art. The path length of the tray T1 and the path length of the tray T4 are set to be the same, and the path length of the tray T2 and the path length of the tray T3 are set to be the same. Since the timing control for taking out the copy sheet from the tray having the same path length can be made the same, the timing control pattern for taking out the copy sheet is reduced. For this reason, software development of the timing control of the copy sheet removal is facilitated.

Embodiment 2 Next, a digital image forming apparatus F according to Embodiment 2 of the present invention will be described with reference to FIG. In the description of the second embodiment, components corresponding to the components of the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.
The second embodiment differs from the first embodiment in that the sheet discharge tray 19 of the first embodiment is omitted and the fifth tray T5 of the first embodiment is used as a sheet discharge tray. The second embodiment is otherwise the same as the first embodiment. In the second embodiment, since the sheet discharge tray does not protrude from the digital copier F, the installation space can be reduced.

(Modifications) Although the embodiments of the present invention have been described in detail, the present invention is not limited to the above-described embodiments, but falls within the scope of the present invention described in the appended claims. Thus, various changes can be made. Modified embodiments of the present invention are described below in (H01)-
(H03).

(H01) In the first embodiment, the number of paper feed trays can be set to another number instead of the total of five paper feed trays. (H02) In the first embodiment, one of the sheet feeding trays can be used as a reversing tray for duplex copying. (H03) The present invention can be applied not only to a copying machine but also to a printer.

[0018]

The digital image forming apparatus of the present invention has the following effects (E01) to (E02). (E01) The difference in the path length from each of the plurality of paper feed trays to the image recording position (the position where the image is recorded on the recording sheet) can be reduced. When the image recording apparatus is a xerographic apparatus, the difference in the path length from each of the plurality of paper feed trays to the transfer point to the recording sheet can be reduced. (E02) The longest path length among the path lengths from each paper feed tray to the image recording apparatus (the position where an image is recorded on a recording sheet) can be made shorter than before. When the image recording apparatus is a xerographic apparatus, the longest path length among the path lengths from each paper feed tray to the transfer point can be made shorter than before.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of Embodiment 1 of a digital image forming apparatus F of the present invention.

FIG. 2 is an explanatory diagram of a digital image forming apparatus F according to a second embodiment of the present invention.

FIG. 3 is an explanatory diagram of a conventional digital image forming apparatus.

[Explanation of symbols]

F2: Xerography apparatus, H1, H2: Sheet transport apparatus, T1 to T5: Paper feed tray, F: Digital image forming apparatus (digital copying machine), 6: Latent image writing apparatus (optical writing scanning apparatus) , 7: latent image carrier, 9: developing device, 1
0: Transfer device,

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) H04N 1/00-1/00 108 B41J 13/00-13/32 B65H 1/00-3/68 G03G 15 / 00 510-534

Claims (2)

(57) [Claims] An image recording apparatus for recording an image on a recording sheet at an image recording position; a plurality of paper feed trays; a sheet conveying apparatus for taking out a recording sheet from each paper feed tray and conveying the recording sheet to the image recording position; A digital image forming apparatus having the following requirements (Y01): (Y01) a plurality of sheet trays and a recording sheet taken out from each sheet tray. The sheet conveying device that conveys the sheet to the image recording position is disposed above and below the image recording device. 2. An image recording apparatus comprising: a latent image carrier; a latent image writing device for writing a latent image on the latent image carrier; a developing device for developing the latent image into a toner image; A digital image forming apparatus comprising a xerography apparatus having a transfer device for transferring to a recording sheet at a transfer point, wherein the image recording position is the transfer point.