JPH09127740A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten image forming time at an image forming device equipped with an automatic document feeding device. SOLUTION: The image forming device where many sheets of documents are copied using the automatic document feeding device possesses a switching means 100 such as a flapper or the like provided on the upstream side of a resist roller 103 at the inside of an image forming device main body, a stack tray 102 and a paper path 101 from a sheet loading means switched by the switching means 100 to the stack tray 102. Then, when a device main body receives a document end signal from the automatic document feeding device while supplying paper from the sheet loading means 108 whose paper path is long at a specified paper interval, recording paper remaining at the inside of the paper path is stacked at the stack tray 102 using a path switched by the switching means 100.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus capable of efficiently forming an image on a recording medium.

[0002]

2. Description of the Related Art Conventionally, in a high-speed image forming apparatus capable of feeding a plurality of types of paper, a plurality of types of recording paper are stored in the image forming apparatus so that an image is formed. It is equipped with paper feed cassettes having different paper transport distances to the photoconductor.

Further, a high-speed image forming apparatus having a plurality of paper feeding cassettes may be
An automatic document feeder may be added or standard equipment. When attempting to duplicate one copy of a plurality of originals using such an automatic document feeder, the recording paper feeding sequence is performed in the flow or sequence shown in the flowchart of FIG. First, when an original is conveyed onto the original platen glass by the automatic original feeding device, the sensor 41 arranged on the original stacking tray detects the presence or absence of the next original, as shown in FIG. At this time, if there is a next document, the automatic document feeder sends a signal indicating that there is paper to the image forming apparatus main body, and the next sheet feeding operation is started based on the signal. When all the originals have been fed and there is no next original, the sensor 41 rotates counterclockwise in FIG. 4 to detect the absence of the original, and accordingly, the automatic original feeding device communicates with the image forming apparatus to signal the absence of paper. Is sent and the next paper feeding operation is not performed.

[0004]

However, the above-mentioned conventional example has the following drawbacks. That is, as shown in FIG. 5, in the above-described sequence, in the high-speed image forming apparatus having the long paper conveyance path 51, the document 52 just before is fed to the platen glass 53 by the automatic document feeder 54 before the next document. The presence of the original document 57 is detected, and then the recording paper 55 is started to be fed, so that the distance between the recording papers 55 to 56 is widened, and as a result, a high cpm (the number of copies per minute) is satisfied. Becomes difficult. For example, for a process speed of 513 mm / sec, A at 85 cpm
When the paper interval detection signal is transmitted from the automatic document feeder to the main body of the image forming apparatus with the distance between four sheets being 150 mm, and when the distance between A and B in FIG.
Achieving a cpm becomes difficult. Therefore, for paper feed cassettes having a paper transport path of a certain distance or more, cpm which is one rank lower has been set so far.

Therefore, an object of the invention according to the present application is to solve the above problems and to maintain a high cpm from a sheet feeding cassette having any sheet conveying path.
It is an object of the present invention to reduce the operating time of the image forming apparatus and shorten the working time and waiting time of the user.

[0006]

To achieve the above object, the first invention of the present application is an image forming apparatus for copying a plurality of originals by using an automatic original feeding apparatus. It has a switching means such as a flapper provided upstream of the registration rollers in the main body, a stack tray, and a paper path from the sheet stacking means to the stack tray that is switched by the switching means. When the main body of the device receives an original end signal from the automatic document feeder while the paper is being fed between the specified sheets, the switching means switches the recording paper remaining in the paper path because the paper feeding operation has already been performed. It is characterized by having a function of stacking in a stack tray using a pass.

According to the above-mentioned means, the document feeding operation is continued by increasing the sheet interval without increasing the sheet interval due to the communication time lag between the automatic document feeder and the image forming apparatus as in the past. When a signal indicating that there is no document is transmitted from the apparatus to the image forming apparatus, the recording paper remaining due to the paper feeding operation already carried in the paper carrying path is carried to the residual paper stack tray. As a result, it is possible to feed paper between predetermined papers in any paper conveyance path, and as a result, cpm can be satisfied in all paper feed cassettes and the purpose can be achieved.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) FIG. 1 is a view best showing the features of the present invention. In FIG. 1, 100 is a paper path switching flapper, 101 is a residual paper transport path, and 102 is a residual paper stack tray. When attempting to copy one copy of a plurality of originals by the automatic original feeding device 109, the originals are conveyed one by one onto the original glass 110 and the originals are scanned by the mirror table 111. An image is formed on the photosensitive drum 104 serving as an image carrier based on the image signal read at that time, and the image is transferred to the recording sheet by the transfer unit 113. Therefore, the recording sheet is transferred from the sheet feeding cassette 108 to the sheet feeding device 107. Be carried out by. The discharged recording paper is stored in the first paper transport path 106.
After the sheet is conveyed to the registration roller 103, the timing is matched with that of the mirror base 111, the sheet passes through the second sheet conveying path 105, and reaches the photosensitive drum 104. The series of operations described above are all performed in an overlapping manner, and when the first sheet reaches the sheet conveying path 105, usually about 1 to 2 sheets of paper are provided in the sheet conveying path 106 with a predetermined interval. Exists.

At this time, when all the documents in the automatic document feeder have been conveyed, the automatic document feeder 109 transmits a document end signal to the image forming apparatus main body. At that time, the paper feeding device 107 stops the paper feeding operation.

After that, the paper conveyance path switching flapper 100 arranged upstream of or immediately before the registration roller 103 is switched, and the flapper 100 causes the residual paper conveyance path 1 to move.
07 and the residual paper stack tray 102 are used as one conveyance path, and the recording paper remaining in the paper conveyance path 106 is conveyed and stored in the residual paper stack tray 102.

According to the above-described embodiment, the recording paper can be conveyed toward the second conveyance path at a predetermined timing after the detection of the original without being affected by the length of the paper conveyance path 106, and the image formation can be performed. The operating time can be shortened and the operator's working time can be shortened, and the shortening of the operating time reduces the fatigue of the device, resulting in the improvement of reliability and the improvement of durability.
It is possible to obtain effects such as improvement in cost performance.

The stack tray 102 is equipped with the sensor 200 shown in FIG. 2, and an instruction is issued from the operation unit panel at an appropriate timing such as when all the jobs, that is, the copying work are completed, and the operator removes the tray. The residual paper can be taken out by pulling out.

[0013]

As described above, according to the present invention,
The cpm can be made equal from the paper feeding cassette having the paper feeding path of any distance, whereby the operating time of the apparatus and the working time of the operator can be shortened.

Shortening the operating time reduces the fatigue of the device,
As a result, it is possible to obtain effects such as improved reliability, improved durability, and improved cost performance.

[Brief description of the drawings]

FIG. 1 is a diagram schematically showing an image forming apparatus that best represents the features of the present invention.

FIG. 2 is a diagram showing a main part of an image forming apparatus that best expresses the features of the present invention.

FIG. 3 is a sequence flowchart of a conventional DF and an image forming apparatus main body.

FIG. 4 is a diagram showing a document sensor unit of a conventional DF.

FIG. 5 is a diagram showing a paper feed mode 1 in a conventional image forming apparatus.

FIG. 6 is a diagram showing a sheet feeding mode 2 in a conventional image forming apparatus.

[Explanation of symbols]

100 ... Paper transport path switching flapper 101 ... Residual paper transport path 102 ... Residual paper stack tray 103 ... Registration roller 104 ... Drum 105 ... Paper transport path 106 ... Paper transport path 107 ... Paper feeding device 108 ... Paper feeding cassette 109 ... Automatic original Feeding device 110 ... Document table glass 111 ... Mirror table 200 ... Stack tray sensor 41 ... Document detection sensor

Claims (2)

[Claims] 1. An image forming apparatus configured to copy a plurality of originals by using an automatic document feeder, a switching means such as a flapper provided upstream of a registration roller in a main body of the image forming apparatus, and a stack tray. A sheet path from the sheet stacking means to the stack tray which is switched by the switching means, and the automatic document feeder finishes the original document while the sheet stacking means having a long paper path is feeding a predetermined sheet. An image forming apparatus having a function of receiving a signal from the apparatus main body and stacking the recording paper remaining in the paper path on a stack tray using the path switched by the switching unit. 2. The image forming apparatus according to claim 1, further comprising a function of detecting the presence of paper by a sensor provided in the stack tray and notifying the user.