JPS59187364A - Jam detector of copying machine - Google Patents

Abstract

PURPOSE:To obtain a jam detector which is controlled easily by actuating a stay jam timer only when recording paper stays on a detector. CONSTITUTION:When fed recording paper jams on a stand-by switch 3, a scanning table carried on moving forth and turns on a forward movement safety switch 16 finally. If a jam occurs at a point T1 of time and the forward movement safety switch 16 is turned on (at time T2), driving for forward movement is cut off to stop the scanning table, and at the same time, the stay jam timer on the stand-by switch 3 turns on to start counting. When this state is held for a specific time, the stay jam timer on the stand-by switch 3 counts up (at time T3) and generates a jam signal to perform jam processing. The jam timer is operated only when the scanning table is at the forward movement safety switch 16, and the jam timer is reset when the forward movement safety switch 16 is turned off within the specific time.

Description

[Detailed description of the invention] [Technical field of invention] The present invention relates to a jam detection device for a copying machine.

[Prior art and problems]

In a copier capable of continuous copying, if recording paper accumulates and jams on the recording material detector during continuous copying, multiple recording papers will become jammed on the detector, resulting in damage to the detector. There is a problem in that the guide plate for conveying the recording paper is deformed. To prevent this, conventionally, when a detector detects recording paper, a predetermined timer is set each time according to the length of the recording paper, and the on-time of the detector is longer than the set timer. When the problem was long, I decided to judge it as a stuck jam. However, this method has the disadvantage that a plurality of timers corresponding to the length of the recording paper are required, making control complicated.

[Purpose of the invention]

The present invention was devised to solve these conventional drawbacks, and the present invention was made to solve these conventional drawbacks.

An object of the present invention is to provide an easy-to-control jam detection device configured such that a retention jam timer is activated only when recording paper is retained on a detector. .

[Key points of the invention]

a position detecting element of a moving member provided in an optical system or a document table moving path; a timer means that is set by a detection signal of the position detecting element and continues recurrent by connection of the detection signal; and the timer 1. A jam detection device for a copying machine, characterized in that the device includes means for generating a jam signal using a count amplifier.

[Embodiments of the invention]

An embodiment of the present invention will be described with reference to two drawings.

In FIG. 1, reference numeral 1 denotes a paper feed cassette which is detachably installed in a machine frame 19 and is capable of storing a large number of recording papers. Reference numeral 2 denotes a paper feed roller, which is configured to come into contact with the uppermost surface of the recording sheets stored in the paper feed cassette 1, and feeds the recording sheets one by one. Standby switch 3 is paper feed roller 2
It is operated by recording paper fed by. The recording paper now fed by the print signal reaches the stopped standby roll 4 after a predetermined time and stops.

When the standby switch 3 was turned on, the scanning table on which the exposure lamp 8 was placed, which had the fixed position switch 17 turned on, turned on the exposure lamp 8 and exposed the original while moving the arrow. Start moving forward in the direction. This scanning table turns on the timing switch 18 while moving forward.

When the timing switch 18 is turned on, the standby roll 4
is rotated, and the charging electrode 11 and the original are exposed.

In order to align the leading edge with the image visualized on the photoreceptor 10 by the developing device 12, the recording paper that has been stopped on the standby roll section is fed.

The recording paper receives the image transferred onto the photoreceptor 10 at the position of the transfer pole 5 and is separated from the photoreceptor 10 at the nine separation pole 6. The toner image transferred onto the recording paper is transported to be fixed by a fixing roll 7.

On the other hand, the photoreceptor 10 after passing through the first separation electrode 6 is processed by the removal electrode 13° cleaning device 14 and the optical charge removal device 15 in order to remove the residual charge and toner on the surface of the photoreceptor 10. pass through. Here, as long as the standby switch 3 remains ON, the scanning table on which the exposure lamp 8 is mounted continues to move forward, and the trailing edge of the recording paper passes through the standby switch 3, and the switch 3 is turned OFF.
Then, the exposure lamp 8 is turned off and the scanning table starts to move backward until the scanning start position switch 17 is turned on.

In addition, in the case of continuous copying, the standby switch 3 is turned OFF.
At the same time (when the trailing edge of the recording paper passes the standby switch 3), the timer again controls the recording paper in the paper feed cassette 1 to wait at the position of the standby roll 4 by the paper feed roller 2 after a predetermined time.

Now, if the fed recording paper jams on the standby switch 3, the recording paper cannot be conveyed toward the transfer pole 5 even if the scanning table passes the timing switch 18.

For this reason, the copying machine determines that there is a long recording paper, the scanning table continues to move forward, and finally turns on the forward safety switch 16 to prevent the scanning table from overrunning.
It will be necessary to do so. Note that the forward safety switch 16 is located at a position where it will not be turned on in normal conditions even if a long recording paper is used.

The above is shown in a timing chart of the standby switch 3 and forward safety switch 16 as shown in FIG.

That is, a jam occurred at time T1, and the forward safety switch 1G was turned ON at time T2.

When the forward safety switch 16 is turned on (time T 2 ), the forward drive is cut off and the scanning table stops, and at the same time the jam timer on the standby switch 3 is turned on.
It becomes N and starts counting.

When this state continues for a predetermined period of time, the accumulated jam timer on the standby switch 3 starts counting up (at time T3), a jam signal is generated, and the jam processing is executed. At this time,
The jam timer is activated only when the scanning table is on the forward safety switch 16, and if the forward safety switch 16 is turned off within a predetermined time, the jam timer is canceled.

The above operation will be explained using the flowchart of the jam detection process shown in FIG. 3. When a jam occurs and the scanning table moves forward abnormally, the forward safety switch 16 sets the ONL jam timer. Next, turn on the forward safety switch 16.
After this is confirmed, reconfirm the timer seven times and add 1 to the jam timer counter. If the forward safety switch 16 is turned FF before the timer counts up, the jam timer is reset, but if the timer counts up, the jam is cleared.

As another embodiment, the jam timer on the standby switch 3 may count down instead of counting the amps.

〔Effect of the invention〕

As described above, according to the jam detection device of the present invention, in order to detect a jam on a detector such as the standby switch 3, it is not necessary to set a timer and monitor the accumulated jam every time the detector is turned on. Since the timer is set only when the recording paper stays on the detector, the control is not complicated.

[Brief explanation of drawings]

FIG. 1 is a schematic side view of a copying machine showing the operating state of the jam detection device of the present invention, FIG. 2 is a timing chart of the standby switch 3 and forward safety switch 16, and FIG. 3 is a diagram of the jam detection process. Flowchart 1 - Diagram. 1...Paper feed cassette 2...Paper feed roller 3...
・Standby switch 4・ ・ ・Standby roll
5... Transfer pole 6... Separation pole 7... Fixing roll 8... Exposure lamp 9... Lens
10... Photoreceptor 11... Charging electrode 1
2...Developer 13...Removal electrode 14...
・Cleaning device 15... Optical static eliminator 16・
...Forward safety switch 17...Fixed position switch 18...Timing switch 19...
Machine frame T1...Time when jam occurs T2
...Forward safety switch 16 and retention jam timer are O
Time T3 when the jam timer reaches the count limit Agent Patent Attorney Yoshiyuki Osuga Figure 1 Figure 2 12 13

Claims (1)

[Claims] In a copying machine that moves an optical system or a document table to scan a document and copy a document, a position detection element of a moving member provided in an optical system or a document table moving path, and the position detection element A jam in a copying machine, comprising: a timer that is set by a detection signal and continues counting as the detection signal continues, and a means that generates a jam signal by a count amplifier of the timer. Detection device.