JPH02198944A - Recording device - Google Patents

Abstract

PURPOSE:To improve the productivity in copying, etc. by reducing jam by suspending the drive of a feeding means when a detecting means detects a length over the length of a sheet and restarting a transport means in correspondence with the transport timing of a sheet in a resisting part. CONSTITUTION:A grip sensor 7 for confirming the passing of sheet is installed on the upstream side of a grip roller 5, and in case of the normal passing of the sheet, the state where a sheet does not exist temporarily is detected after detecting the passing of the preceding paper, and then the passing of the next paper is detected. When the succeeding paper is sent, together with the preceding paper, and the sheet interval becomes zero in the grip sensor 7 part, and the fact that the preceding paper is abnormally long is detected, it is judged that the succeeding paper is sent together with the preceding paper, and the drive of the grip roller 5 is suspended, and the entrainment of the succeeding paper is prevented. The grip roller 5 in stop starts revolution again in correspondence with the timing when the succeeding paper is transported by a resisting roller 6.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a recording apparatus such as a copying machine, a facsimile machine, a printer, etc., which records an image on a fed sheet.

Conventionally, recording devices such as Ryomai Tokeisho copiers are equipped with a feeding means for feeding sheets to the registration section and a means for detecting the feeding of the sheets. double shipping,
When being taken away, it detects that the seat is long and
Normally, this was treated as a paper jam. As a result, sheet processing is interrupted, resulting in a problem of reduced productivity in copying and the like.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems in the prior art and to provide a recording device with improved productivity by reducing jams.

In order to solve the above-mentioned problems, the present invention provides a recording device that records an image on a fed sheet, a registration section that conveys the sheet in accordance with the timing of image recording, and a registration section that conveys the sheet in accordance with the timing of image recording. a feeding means for feeding the sheet to the sheet, a detecting means for detecting the sheet fed by the feeding means, and a detecting means for detecting the sheet fed by the feeding means; The apparatus further comprises a control means for controlling the feeding means to stop the driving of the feeding means and to start driving the feeding means again in accordance with the transport timing of the registration section.

According to the present invention, when the detection means detects the sheet fed by the feeding means to the registration section, if the detection means detects a length equal to or greater than the length of the sheet, the driving of the feeding means is stopped. , the feeding means is controlled to be re-driven in accordance with the sheet conveyance timing in the registration section, so that the second sheet that is multi-fed next to the first sheet to be fed is Instead of being immediately fed to the registration section, the second sheet is fed to the registration section at the timing when the second sheet should be fed from the registration section.

1 is a sectional view showing a schematic structure of a paper feeding portion of a laser beam printer, which is an example to which the present invention is applied. For example, when using the upper paper feed tray L, the paper feed operation is as follows:
When the print is started, an overprint paper drive solenoid (not shown) is activated, the pick-up roller 2 and the feed roller 3 are rotated, and the sheet sent out from the pickup roller 2 is placed under the feed roller 3. The sheets are separated by a friction pad 4, and only the sheets are fed to a grip roller 5, which is an example of a feeding means. However, depending on the performance of the friction pad 4, one sheet may not always be separated and fed to the grip roller 5, and a second sheet may be fed along with it.

The sheet that has reached the grip roller 5 is thereby fed to the registration rollers 6, and is conveyed into the main body of the apparatus with timing determined by the registration rollers 6. Further, on the upstream side of the grip roller 5, a grip sensor 7, which is an example of a detection means for confirming the passage of a sheet, is provided.

FIG. 2 is a timing diagram showing the operations of rollers, sensors, etc., and FIGS. 3(a) to 3(d) are explanatory diagrams showing the sheet feeding state. The operation of this embodiment will be explained with reference to FIG. 2.

Each sensor and roller operates at the timing shown in FIG. 2 relative to the timing of the OPC belt.

When the sheet passes normally, the grip sensor 7 detects the passing of the front paper, temporarily detects the state of no sheet, and then detects the passing of the next paper as shown by the chain line (■) in the figure. Detect. After the front paper has passed, the feed roller 3 and pickup roller 2 are rotated by the top paper drive solenoid to feed the rear paper, and these rollers are stopped after the rear paper is detected by the grip sensor 7. The timing is right (■).

However, the timing at which the grip sensor 7 rotates the feed roller 3, etc. after detecting the passage of the paper in front of the paper is very close to each other, especially when the sheet is long (■
,■), The timing is such that the rear paper feed operation starts before the front paper passes through i1, and the gap between the front paper and the rear paper disappears, and the rear paper passes through the grip sensor 7 section following the front paper. There are cases. Furthermore, as described above, there are cases where the rear paper is fed along with the paper feeding operation of the front paper. Such a state is shown in FIG. 3(a). In the conventional apparatus, when the grip sensor 7 detects that the sheet interval is short and the paper in front is abnormally long, it is normally treated as a jam.

However, in this embodiment, in such a case, it is determined that the rear sheet has been carried away, and a grip solenoid (not shown) is activated to stop the drive of the grip roller 5 (■, Fig. 3 (rotation)). ), (C)), the rear paper is prevented from being drawn into the downstream side from the grip roller 5. At this time, the feed roller 3 and pickup roller 2 also stop.

During this time, the front paper is normally conveyed by the registration roller 6 and printed, but the rear paper is stopped, so there is a gap between the front paper and the rear paper as shown in FIG. 3(C). Seat spacing is created. The registration roller 6 is stopped after the front paper passes the registration sensor 8 (Fig. 1) section (■).
, is rotated at the timing (■) of conveying the next backward paper.

The grip roller 5, which has been stopped at - degree (■), is moved from the grip roller 5 to the registration roller 6 so that the sheet reaches the registration roller 6 part before the registration roller 6 is rotated (■). The grip roller 5 is rotated again in consideration of the conveyance time (■), that is, the grip roller 5 is rotated again corresponding to the timing when the rear paper is conveyed by the registration roller 6. Then, the sheet is fed to the registration roller 6 and is registered, and the timing when the image writing position (■) and the leading edge of the sheet match on the O20 (■
), the registration roller 6 is rotated (■), and an image is printed on the sheet. By driving the grip roller 5 at such timing, there was no shift interval in the grip sensor 7 section (■), but there is a sheet interval in the registration sensor 8 (■). , it is possible to print normally even when sheets are fed multiple times.

The drive control of the grip roller 5 and the like as described above is performed by a laser beam printer main body control device, which is an example of a control means.

Furthermore, although the case where the overprint paper tray 1 is used has been described above, the operation is similar when the underprint paper tray 9 is used. In this case, the seat has friction pad 4
The sheet is fed to the grip roller 5 by the feed roller 10 while double feeding is prevented by the sheet a. Then, the paper feed roller lO is driven by a solenoid (not shown) at the same timing as the drive timing of the feed roller 3 and the like in FIG. 2.

According to the present invention, when sheets are fed in duplicate, the driving of the feeding means is stopped once, and the driving is restarted in accordance with the timing of conveyance of the registration section, so that jams do not occur. Normal Sea I-processing is performed without any problems, reducing jams and improving processing efficiency.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a feeding device portion of a laser beam printer showing an embodiment of the present invention, FIG. 2 is a control timing diagram thereof, and FIG. 3 is an explanatory diagram showing a sheet feeding state. Fig. 3 5...Grip roller (feeding means) 6...Registration roller 7...-Grip sensor (detection means) (1 other person)

Claims (1)

[Claims] A recording device that records an image on a fed sheet, comprising: a registration section that conveys the sheet in accordance with the timing of image recording; a feeding means that feeds the sheet to the registration section; a detection means for detecting a sheet fed by the feeding means; and when the detection means detects a length equal to or greater than the length of the sheet being fed, the driving of the feeding means is stopped and the conveyance of the registration section is stopped. A recording apparatus comprising: a control means for controlling the feeding means to drive again in accordance with timing.