JPS61266285A - Printer - Google Patents

Abstract

PURPOSE:To enable a printing operation to be restarted without causing missing or overlapping of printing pages through simply giving a printing-restarting command after removing a jammed paper, by providing a means for storing the contents of printing pages, a means for detecting a jam of a paper, and a controlling means. CONSTITUTION:The storage means for storing the contents of a plurality of printing pages, the jam-detecting means J1, J2, J3, a means for stopping a printing sequence according to an output from the jam-detecting means, a means for giving a printing-restarting command after the jam is cleared, and the controlling means 16 for printing the contents of pages stored in the storage means in response to the printing-restarting command, are provided. When a jam is detected by the jam-detecting means J1, J2, J3, the printing sequence is stopped. After a printing operation is restarted in response to the restarting command, the controlling means performs printing of the pages stored in the storage means, prior to printing of pages newly inputted. Accordingly, the contents of the page which is made invalid due to stoppage of the printing sequence during printing thereof can be printed without being misses.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a printer, and particularly to a printer that uses electrophotography.

(Prior Art) When an image forming apparatus using an electrophotographic method, such as a copying machine or a printer, is operated continuously, the image formation on one sheet of paper (copying or printing) is completed before the next sheet is printed. There are multiple sheets of paper in the device at the same time.
Processing sequences for multiple sheets of paper are being performed in parallel.

By the way, even if a paper jam occurs during such parallel processing, it is necessary to count the number of sheets that have been effectively copied or printed, regardless of the jam.

For copying machines that use electrophotography, a technique for counting the number of effective sheets is disclosed in Japanese Patent Application Laid-Open No. 57-664.
There is one disclosed in Publication No. 47. This conventional technology is
The desired number of copies can be accurately counted by counting the sheets that have been completely copied and are substantially ejected. This technique is effective when a plurality of copies of the same original are made in succession, such as in a copying machine.

However, printers that use electrophotography often print multiple pages with different content in succession, rather than making multiple copies of the same document as in a copying machine. Therefore, if a jam occurs during printing, after removing the jammed paper,
For continuous printing, it is necessary to accurately determine from which page printing is necessary.

(Problem to be Solved by the Invention) Conventionally, in such cases, the user confirms the printed page number, and then checks the electronic meter WtJ to which the printer is connected.
The data output device such as lt was operated again to resume printing from the required page onwards. Therefore, special operations such as checking the page to start reprinting and instructing the printer about the number of pages are required, making the operations at the time of starting reprinting cumbersome. Further, there is also the inconvenience that a data output device (such as an electronic T1W machine) that supplies print data to the printer must be operated again in some cases.

Therefore, the main object of the present invention is to provide a printer that is free from complicated operations when restarting printing after removing jammed paper.

(Means for Solving the Problems) The present invention includes a storage means for storing the contents of a plurality of printed pages, a jam detection means, a means for stopping a printing sequence based on the output of the jam detection means, and a means for stopping a printing sequence after clearing a jam. The printer includes means for giving a restart command, and control means for printing the contents of a page stored in a storage means in response to the restart command.

(Operation) In the case of continuous printing, before the printing sequence of the corresponding page is completed, the next paper is taken in and the printing sequence of the next page is started. Therefore, the printer executes a printing sequence for multiple pages one after the other. The contents of the page in the middle of the printing sequence are stored in the storage means.

For example, when printing processing for three pages is executed one after the other, the contents for the three pages are stored in the storage means page by page. When a jam is detected by the jam detection means, the printing sequence is stopped. At this point, the paper existing in the printer that is in the middle of a printing sequence cannot become a paper that has undergone effective printing processing even after the jam state is cleared. Therefore, after restarting the printing process in response to the restart command, the control means first prints the page stored in the storage means before printing a newly input page. As a result, the contents of pages that have become invalid due to the printing sequence being stopped midway are printed without being omitted.

(Effects of the Invention) According to the present invention, printing can be restarted without missing or duplicating printed pages by simply issuing a printing restart command after removing jammed paper. Therefore, even if printing stops in the middle of continuous printing, the user does not have to judge the number of invalid pages due to the printing stop or perform special operations on the printer or print data output device, making the printer easy to operate. can be provided.

The above objects, other objects, features and advantages of the present invention will become more apparent from the following detailed description of embodiments with reference to the drawings.

(Embodiment) FIG. 2 is a schematic diagram showing an example of an electrophotographic printer to which the present invention can be applied. The printer 1 includes a photosensitive drum 3 built into a main body 2.

The photosensitive drum 3 is charged by a charger 4, and a latent image is formed by an exposure device 5. This latent image is then developed with toner in a developing device 6.

On the other hand, the paper on which predetermined data is printed is stored in the cassette 10.
The paper is sent out by the paper feed roller 11 from the paper feed roller 11 . Then, the toner image is transferred from the photosensitive drum 3 onto the paper by a transfer device 7, and the paper after the transfer is peeled off from the photosensitive drum 3 by a peeling device 8. After that, the fuser 13 is transferred by the conveyor belt 12.
sent to.

In the fixing device 13, the toner image on the paper is fixed to the paper by a heating/pressure roller 13', and the paper is discharged to a paper discharge tray 15 by a paper discharge roller 14. And photosensitive drum 3
The circular surface of is cleaned by a cleaner 9, and then static electricity is removed. The printer I is operated using the above series of operations as one cycle. Further, a path indicating the flow of paper is shown by a dotted line in FIG.

Jam sensors J1, J2.
J3 is provided. The jam sensor J1 detects a jam of paper fed from the paper feed roller 11. The jam sensor J2 detects a paper jam associated with the +U transport belt 12. Jam sensor J
3 detects a jam of paper discharged from the paper discharge roller 14. When a jam occurs, the print processing operation of the printer 1 is stopped, but the paper existing in the printer 1 at that time becomes invalid paper depending on the way the print is output. For example, immediately after a toner image has been transferred to paper, the transferred toner image is not fixed on the paper, and
Further, when the paper remains in the fixing device 13, the paper may be deteriorated due to heating or the like, and in either case, such paper becomes invalid as a print output.

The printer 1 further includes a control circuit 16. The control circuit 16 is connected to various parts within the printer 1 via connection lines (not shown) or the like. Further, the control circuit 16 is connected to an external print data output device such as a computer.

Referring to FIG. 3, this control circuit 16 includes a control section 17. The control unit 17 is composed of, for example, a CPU, and has a register N for the number of remaining print pages.

Contains a page buffer number register P and a parallel processing page number register C. Then, the operation according to the flowchart shown in FIG. 1, which will be described later, is executed. An operation key portion 18 including jam sensors Jl, J2, J3, and a print continuation key (not shown) is connected to the control unit 17 so as to provide various data necessary for executing the above control. There is. Further, an external print data output device (for example, an electronic computer, etc.) 20 is connected via the interface 9. Further, a print data buffer 21 for temporarily storing data provided from the print data output device 2o is connected to the control unit 17. A character font generator 22, a print data output section 23, and an exposure section 24 are sequentially connected to the print data buffer 21.

FIGS. 4A to 4C are timing charts for explaining printing timing. These figures 48 to 4
Diagram C shows print data input timing, exposure timing,
Jam sensor J1. The relationship between the output timings of J2 and J3 is shown.

FIG. 4A shows the case of printing one page. Referring to FIG. 4A, when print data for one page is input, exposure is started and a print processing sequence begins. and,
Each jam sensor J1. J2 and J3 derive a high level output for a predetermined time when the paper passes. The print processing sequence is completed when the timing of the jam sensor J3 in the paper discharge section falls. In FIG. 4A, the numerical value C shown below (C=0.C=1) indicates how many pages of the print processing sequence the printer is simultaneously performing.

Each jam sensor Jl, J2. The output pulse width and timing between pulses of J3 may deviate from the target pulse width and timing even during normal operation due to some dimensional error or paper feeding error of the paper, so a certain tolerance range is determined in advance. If a jam occurs, each jam sensor Jl, J2. The pulse width and timing of J3 will change significantly and will be out of this permissible range. Jam detection is performed by detecting that the pulse width or timing exceeds an allowable range.

Figure 4B is a timing diagram when printing 2 pages,
Figure 4C shows a typical example when printing 3 or more pages.
A timing diagram for four-page printing is shown. Fourth
As shown in Figure B, in 2-page printing, the maximum number of pages that can be processed simultaneously is 2 pages (C=2). In addition, when printing 3 or more pages, the maximum number of pages that can be processed simultaneously is 3 pages (C=
3).

Based on the timing diagrams in Figures 48 to 4C, when a jam occurs, which page to go back to and resume printing after removing the jammed paper is determined in parallel, including the page being exposed at that time. By resuming printing by going back to the previous page by the number of pages being processed (the number C), it is possible to continue printing pages without duplicating or missing pages. Furthermore, at this time, it can be seen that if at least the maximum number of print page buffers equal to or greater than C is provided, the printer alone can continue printing up to the required page.

FIG. 1 is a flow diagram for explaining one embodiment of the present invention. When the control operation of the printer 1 starts, the control unit 17 first sets the built-in remaining print page number register N and page buffer number register P in step 7 s1.
and the parallel processing page number register C, and waits for one page's worth of print data to be input in the next steps s2 and S3. If the print data for one page has been input, the remaining print page register N is set to 1 (step S4), and the printer is started (step S5).
).

When the start of exposure is detected in step S6, the page buffer number register P is shifted once, and the parallel processing page number register C is incremented by 1 in step S7. The page buffer number register P is shifted in the order of 0→1→2-0. Next, if the fall of the jam sensor J3 is detected in step s8, the remaining print page number register N and the parallel processing page number register C are each decreased by 1 (step S9), and it is determined whether the remaining print page number register N is 3 or not. Determine (step 51
0). In other words, in this embodiment, the maximum capacity that the print data buffer 21 can store is data for three pages, so in these steps, the data for three pages is stored in the print data buffer 21. It determines whether it is already stored or not.

If the print data for 3 pages has not yet been stored, wait for the input of the print data for 1 page in steps Sll, S12 and S13, add 1 to the remaining number of print pages N, and proceed to the next step. .

In step S14, it is determined whether any of the jam sensors J1 to J3 has detected a jam. If no jam has been detected, in step S15, the remaining print page number register N and the parallel processing page number register C are set. Determine whether it is zero or not.

That is, it is determined whether no print data has been input and whether all pages to be processed have been processed. and,
When all processing is completed, the printer is stopped (step 516) and the process returns to the beginning.

In step S14, if a jam is detected,
The printer is immediately stopped in step 317, and the printer waits for the jammed paper to be manually removed (step 818). When it is confirmed that the print continuation key has been pressed by the user (step 519), in the next step 320 and subsequent step S5, the page buffer number register P is set by the number of parallel processing pages stored at that time. Shift and start the printer. That is, when printing is restarted, first, the contents of the print data buffer 21 are sequentially read out from a predetermined buffer, and the contents are printed.

Therefore, after removing the jammed paper, the user only needs to operate the continuation print key to obtain normal print output of successive pages without missing or duplicating unfixed or deteriorated pages.

[Brief explanation of drawings]

FIG. 1 is a flow diagram for explaining the control operation of an embodiment of the present invention. FIG. 2 is a diagram showing the internal configuration of an electrophotographic printer to which the present invention is applied. FIG. 3 is a block diagram showing one embodiment of the present invention. FIGS. 4A to 4C are timing charts for explaining the print processing operation of this embodiment. In the figure, 1 is a printer, 16 is a control circuit, 17 is a control unit, 18 is a portion of operation keys including a print continuation key, 20 is a print data output device, and 21 is a print data buffer. Patent applicant Sanyo Electric Co., Ltd. agent Patent attorney Yama 1) Yoshito (and 1 other person)

Claims (1)

[Scope of Claims] 1. Storage means for storing the contents of a plurality of printed pages; Jam detection means for detecting a jam of printing paper; Means for stopping the printing sequence in response to the output of the jam detection means; After the jam is cleared. A printer comprising: a restart command means for commanding restart of a printing sequence; and a control means for printing the contents of a page stored in the storage means in response to a command from the restart command means. 2. Means for counting the number of pages to be invalidated for which a printing sequence has started but has not yet been completed, and the control means calculates the page content stored in the storage means based on the output of the counting means. The printer according to claim 1, wherein predetermined page contents are selected. 3. The second aspect of the present invention further comprises: exposing means, wherein the jam detecting means includes a discharged paper jam sensor, and the counting means performs the counting based on exposure start timing and an output of the discharged paper jam sensor. Printer mentioned in section. 4. The printer according to claim 1, wherein the restart command means includes a dedicated switch.