JPH01306249A - Printer - Google Patents

Abstract

PURPOSE:To output a print without data-receiving again an output image when a recording medium is clogged to become impossible to print by reading a stored image pattern when a transfer to an nonoperation due to a printing mistake state is detected, and reforming the image. CONSTITUTION:Whether a sheet fed by a sheet feed roller 209 into a printer arrives at a jam sensor 212 within a predetermined period of time or is completely discharged out of a discharge sheet stacker 217 through a jam sensor 216 is checked. If the sheet is stayed at any position, a printing mechanisms is immediately stopped, and it is transmitted to a CPU 101. On the other hand, sheets of 4 pages at the maximum can be stayed in a sheet conveying passage from the roller 209 to the stacker 217. If a jam occurs, information of corresponding page is always retained on a save memory 106, and after the jam is processed, it is reprinted for lost sheet without retransmitting data from a hot computer 102.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a printing device, and more particularly, to a printing device that receives page-by-page data and prints out the data.

[Prior Art] Normally, this type of printing device develops data input from a data source (host computer, etc.) in a bitmap memory in correspondence with a print image, converts it into an image signal, and sends it to the printing mechanism. It is printed by doing this.

Furthermore, due to the structure of recent printing devices, especially electrostatographic printing devices, the conveyance path for the recording medium (printing paper) has become long, and by the time the printed recording medium is ejected from the device, It took time.

Therefore, in order to increase printing speed, normally, instead of waiting for one recording medium to be ejected before moving on to the next printing process, when one recording medium is printed, the next recording is started immediately. In many cases, a method of recording on a medium is used.

In other words, a plurality of recording media exist within the conveyance path.

[Problems to be Solved by the Invention] By the way, in the above-described printing apparatus, if the recording medium becomes clogged in the conveyance path, it is necessary to retransmit the page data dating back to the number of times when the recording medium remaining in the conveyance path is closed. However, the operator has to perform operations related to print output again at the data source, which is a very troublesome task.

The present invention has been made in view of this problem, and when a printing becomes impossible due to a jam in a recording medium, it is possible to print out the output image that caused the printing impossible state without receiving the data again. The aim is to provide a printing device that makes it possible to do this.

[Means for Solving the Problem] In order to solve this problem, the printing apparatus of the present invention has the configuration shown below.

A printing device that prints an image on a recording medium based on page-by-page information inputted from the outside, comprising a developing means for developing an image pattern based on the inputted information, and forming an output image based on the developed image pattern. an image forming means for detecting the occurrence of a printing error and a storage means for storing a plurality of pages of image patterns on a recording medium on which an image has been formed by the image forming means; and a detecting means for detecting.

[Function] In the configuration of the present invention, when the detection means detects that the printing error occurrence state has been released, the image pattern stored in the storage means is read out, and an image is formed by the image forming means. It is something that can be repaired.

[Embodiments] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Explanation of the outline of the configuration (Fig. 1)> Fig. 1 shows the laser beam printer (Fig. 1) in this embodiment.
2 is a diagram showing the relationship between the configuration of the LBP (hereinafter simply referred to as LBP) and the host computer 102 that is a data generation source.

As shown in the figure, the LBP includes a printing mechanism section 112 and a control section 10 that controls data reception and data output to the printing mechanism section 112.
It consists of 0.

In the figure, 101 is a CPU that controls the entire LBP and analyzes input data, and 103 is a host computer 102.
This is an input interface circuit for inputting data from. 104 is a ROM that stores programs related to flowcharts shown in FIGS. 5 to 7, which will be described later, and font patterns corresponding to character codes. A RAM 105 is used as a work area for the CPU 1, and stores various counters and tables during processing. 106 is a storage memory (RAM) that stores various registration information (download fonts, overlay page information, etc.) input from the host computer 102, and stores compressed data after printing in page memory, which will be described later.
). l○7 is host computer 1
This is a page memory (consisting of RAM) that stores one page's worth of bitmap images based on the input data from 02. In addition, in order to simplify the explanation, the recording medium (printing paper) size handled by LBP in the example is as follows.
It is fixed to A4 size and this page memory 1
The capacity of 07 is hereinafter referred to as page memory size, 108
is a page storage amount selection switch that selects the upper limit of the capacity of compressed page data to be stored in the storage memory 1.6;
- Consists of a rotary switch with the above-mentioned page memory sizes xi, x2. x3. Four positions of x4 are set. Reference numeral 109 is a timer that outputs an interrupt pulse signal to the CPU 1 at predetermined intervals, and in the embodiment, this cycle is set to 100 m5. When CPUt receives this pulse signal manually, it executes an interrupt processing routine shown in FIG. 7, which will be described later.

110 is an image signal generator that converts the image data developed in the page memory 107 into an image signal;
An image signal is sent to the printing mechanism section 112 via an output interface circuit 111 in response to a synchronization signal (for example, a beam detect signal) from 2. Further, this output interface circuit 111 is connected to the CPUl0I and the image generator 11.
0 and the printing mechanism section 112, and controls the interface of various control signals and image signals.

On the other hand, the printing mechanism section 112 is composed of components that implement a series of LBP printing processes such as feeding paper, generating laser light, transferring an image to paper, and fixing. Additionally, if a “jam” occurs (paper stays) in the printing mechanism section 112,
When detected, a status signal to that effect is transmitted to the CPU 101 via the output interface 111.

FIG. 2 is a sectional view showing the internal structure of this printing mechanism section 112.

In the figure, 200 is the main body of the LBP, and 201 is a circuit board including the control section 100 described above.

The laser driver 202 is a circuit for driving and controlling the semiconductor laser 203, and controls on/off of the laser beam 204 emitted from the semiconductor laser 203 according to the input image signal.

This laser beam 204 is transmitted to a rotating polygon mirror (polygon mirror) 2.
At step 05, the light is swung left and right and irradiated onto the electrostatic drum 206, forming a latent image of a character pattern or image information on the electrostatic drum 206. This latent image is developed by a developing unit 207 around the electrostatic drum 206 and then transferred onto a sheet of paper.

A4 size cut sheet paper is used for the paper, and the cut sheet paper is stored in the paper cassette 20 attached to the LBP main body 200.
8, a paper feed roller 209 and a conveyance roller 210
and 211 into the device and the electrostatic drum 20
6. Reference numerals 212 and 216 are jam (paper jam) sensors that are based on general optical sensors. These sensors check whether the paper taken into the apparatus by the paper feed roller 209 reaches the jam sensor 212 within a certain period of time, and whether the paper is detected by the conveyance roller 211 and the developing unit 207.
The paper sent to the fixing roller 2 within a certain period of time
13, the paper passes through the jam sensor 216 by the paper ejection rollers 214 and the paper ejection belt 215, and it is checked whether the paper is completely ejected to the outer paper ejection stacker 217. If the paper becomes stuck somewhere, the printing mechanism is immediately stopped and the CPU 101 is notified.

Description of processing outline> In the LBP of the embodiment, a maximum of four pages of paper can be retained in the paper conveyance path from the paper feed roller 209 to the paper discharge stacker 217. When a jam occurs, the information of the corresponding page always remains in the storage memory 106, and after the jam countermeasure processing is performed,
This allows reprinting on damaged paper without retransmitting data from the host computer 102.

For this reason, in the embodiment, at least the data on the page memory 107 for which the printing process itself has been completed is compressed and temporarily stored in the storage memory 106.

FIG. 3 shows an example of a data compression format.

The compressed data 300 in this embodiment uses a so-called run-length method, in which the number of consecutive "0"s and the number of consecutive "1"s are alternately counted and stored in the bitmap image on the page memory 107. 301 out of 9 figures
Wl denoted by indicates “O”, that is, the number of white bits,
B+ of 302 indicates "1", that is, the number of black bits. Then, this pair of Wl and B+ is i=1.2...
This is what follows. In addition, W t and B t are each 1
It consists of bytes, and if there are more than 255 consecutive “0” or “1” bits, a dummy “l” or “
Insert O" bytes. For example, if 300 "0" bits continue, W + = 255, B + = O
, W+, + =45.

Next, the data structure of the work memory 105 and the relationship between the work memory 105 and the storage memory 106 are shown in FIG.
explain.

In the figure, 400 is a page storage table which is a management table for saving data on the page memory 107 to the storage memory 106, and there are four tables according to the maximum number of jammed sheets depending on the paper conveyance path. Each unit has a time counter 401.
, data length 4o2, and page pointer 403. The time counter 401 indicates that when the image data in the page memory 107 is printed and its compressed data is saved in the page storage table, "From this point on, the paper is
The time required for the water to be completely discharged is set. This time counter 401 is controlled by the timer interrupt processing routine 700.
It is subtracted periodically and is used to know when to end saving the page. The data length 402 is an area that stores the data capacity when the image data on the page memory 107 is compressed. The page pointer 403 is an address pointer indicating the start address of the compressed data compressed in the format shown in FIG. 3 and stored on the storage memory 106. The storage memory 106 is divided into segments of predetermined units, and has a structure in which free segments can be used freely, and the compressed data in the page memory 107 is stored in the storage memory 106.
It is saved at an arbitrary location in the empty area above, and connected to the page save table 400 by a page pointer 403 of all outputs. In the illustrated case, the diagonally shaded portions 420, 421, 422 indicate compressed data stored in the page memory 107.

Further, 410 is a next page pointer indicating the unit of the page storage table to be set next. When printing of one page is completed, the image data on the page memory 107 is compressed and is indicated in the next page pointer 410. A value is set for each parameter of the unit to be displayed, and the next page pointer 410 advances to the next unit. 411 is a byte counter when the image data on the page memory 107 is compressed according to the compression format, and the final result is set in the data length 402 as the compressed data length. A page capacity counter 412 counts the total data length of a plurality of compressed data existing in the storage memory 106 at that time in bytes. 413 is a page storage amount selection switch 10
This is a page capacity setting area in which the upper limit of the storage amount of compressed data selected by 8 is stored, and the setting of the page storage amount selection switch 108 is converted into the number of bytes and stored.

Description of the processing procedure (FIGS. 5 to 7)> The LBP control processing procedure of this embodiment based on the above-described configuration and principle will be explained according to the flowcharts of FIGS. 5 to 7.

FIG. 5 is a flowchart showing the main routine processing of the CPU 101.

First, in step S501, the entire LBP is initialized,
The tables and counters on the work memory 105 are reset and the storage memory 106 is cleared. Next, the process proceeds to step 502, where the page storage capacity selection switch 108 is checked and the corresponding setting value is entered in the page capacity setting area 41.
Set to 3. Then, the CPU 101 performs step 50
3 or less performs normal printing processing.

In step 503, data from the host computer 102 is received via the input interface circuit 103, and in step 504, the received data is analyzed, a corresponding character dot pattern is taken out from the ROM 104, and the pattern is expanded into the page memory 107. Then, it is determined in step 5505 whether or not this process has been performed for one page of data, and steps 3503 to 505 are performed until one page of data is received or character dot pattern development processing is completed. Repeat the process. Now, when one page has been expanded onto the page memory 107, it is checked in step 5506 whether or not a jam has already occurred. If no jam occurs, step 50
Proceeding to step 7, the image data on the page memory 107 is sent to the image signal generator 110, which outputs it as an image signal to the printing mechanism section 112 to execute a printing operation. Furthermore, if a jam has occurred, it is necessary to go back and print the page, so the process of step 507 is skipped. In any case, in step 5508, the image in the page memory 107 is compressed and stored (details will be described later).

Then, in step 509, it is checked again whether or not a jam has occurred, and if no jam has occurred, the process returns to step 503 to continue processing the next page.

On the other hand, if a jam is detected in step 509, the processes from step 5510 onwards are executed to perform jam processing.

First, in step 510, each timer counter 401 of the page storage table 400 is checked, and the one with the lowest count value, that is, the oldest one of the plurality of sheets that has been damaged due to accumulation in the conveyance path, is checked. The unit in the page storage table 400 that is to be used is found. Starting from this unit, in steps 511 to 516,
The past page data remaining in the storage memory 106 is reprinted in the unit order of the page storage table 400.

First, in step 511, the compressed data 420 on the storage memory 106 indicated by the page pointer 403 is decompressed based on the data compression format, and the page memory 10
7. Then, in step 512, the operator waits to remove the accumulated paper, and in step 513, as in step 507, the image data on the page memory 107 is printed. If it is checked in step 514 that a jam has occurred again at this time, step 5 is performed.
It will return to 511. Also, this is the timing to move to step 5513, but normally in the case of a jam, the lid of the device is opened and the paper is taken out, so this step is executed after detecting that the lid changes from the open state to the closed state. However, it is not limited to this. For example, a new sensor may be provided and the time point may be set at a time when this sensor no longer detects a paper jam.

Next, in step 515, the time counter 4o1 of the unit of the current page storage table 400 is reset to the initial value, and in step 516, it is checked whether all the jammed pages have been printed. When all pages have been printed, the process returns to step 503 to continue processing a new page.

A detailed procedure example of step 8508 in the above-described process will be explained according to the flowchart of FIG. 6.

First, in step 601, the compression counter 411 is set to “
O”.Then, the following steps 602 to 6
07 is repeated for one page. First, in step 602, it is checked whether the page capacity counter 412 has reached the value of the page capacity setting area 413,
If it has, wait until the storage memory 602 becomes free. Note that during this time, a timer interrupt routine, which will be described later, is executed at predetermined intervals, thereby creating an empty area in the storage memory 106. If it is determined that the page capacity counter is less than the page capacity setting counter, then in the next step 603, it is checked whether the compression counter 411 has reached the constant page memory size. If the page memory size has not been reached, the compression process continues and the process advances to step 604. Then, in step 604, the "white" pixel ("0" bit) and the black" pixel ("
Wl according to the data compression format.

B+ is stored on the storage memory 106. Then, in step 605, in preparation for saving the next compressed data, the compression counter 411 is updated by 2 bytes, and in step 5606
The page capacity counter 412 is also updated by 2 bytes. In step 607, it is checked whether the compression process has been completed for all areas of the page memory 107. When the compression and storage processing is completed, the process advances to step 613, and the page storage table 40 indicated by the next page pointer is saved.
For unit 0, set the time until the compressed page is completely ejected in the time counter 401, and set the compressed data in the data length 402 and the compressed data in the page pointer 403 in the unit of interest. Set the starting address on the storage memory 106 where the data is stored.

Then, the next page pointer 410 is updated to point to the next unit, and the page storage table update process is completed.

On the other hand, if it is determined in step 5603 that the compression counter 411 has reached the constant page memory size, in other words, it is determined that the data developed in the page memory 107 is not compressed by this compression method, so step In the process after 5608, the compression process is stopped.

Specifically, in step 5608, the previous processing (steps 602 to 607)
Clear the compressed data created in 06. Then, the process proceeds to step 5609, where the page memory size (capacity of page memory 107 = size of expanded image) is stored in the compression counter 411, and the page memory size is added to the page capacity counter 412 in the next step 610. Then, in step 611, as in step 602, wait until the storage memory 106 becomes free, and in step 612, the contents of the page memory 107 are copied as is (uncompressed) to the empty area of the storage memory 106, and in step 613 described above, Proceed to , and finish page memory compression processing.

Note that a possible cause of the compression being unsuccessful is, for example, when the pixels developed in the page memory 107 are arranged in black, white, white, and so on.

At this time, in the compression format shown in Figure 3, each pixel (1 bit on the page memory) has 1 byte (8 times more).
This is because it will be assigned. Therefore, if it is determined in step 5603 that the compression was unsuccessful, another compression format may be used. For example, it is conceivable to take a run length in units of 2 bits or more. At this time, storage memory 1
It is sufficient to provide a table indicating in which compression format the compressed data stored in 06 is compressed.

Next, timer interrupt processing in the embodiment will be explained according to the flowchart in FIG. As explained above, this process is executed by CPUl0I every 100m5.

First, in step 701, it is determined whether a jam is currently occurring or if the main routine 500 is
16. Check whether jam processing is in progress. Then, if a jam is occurring or a jam is being processed, this interrupt processing is finished.

Further, if it is determined that a jam is occurring or that the jam is not being processed, the processes from step 702 onwards are performed on all units of the page storage table 400.

In step 702, "1" is subtracted from the time counter 401 of the unit of interest, and in step 703, it is checked whether the time counter 401 has reached "O". When the time counter 401 becomes “O”, this indicates that the target page has been completely ejected from the LBP main body 200 (there is no longer a need to save it), so in step 704 it is stored in the storage memory 106. The memory area corresponding to the compressed data of the page of interest that was occupied is released, and in step 705, the number of bytes corresponding to the data length 402 is decremented from the page capacity counter 412. Furthermore, if it is determined that the timer counter 401 is greater than or equal to "0", the processing in steps 5704 and 5705 is skipped.

Thus, in step 5706, page save table 4
Steps 3702 to 52 described above are carried out until it is detected that the check for all units of 00 is completed.
Repeat the process of 05.

According to this embodiment as described above, at least the data related to the printed image in the conveyance path is stored in a compressed format, so that in the unlikely event that an unexpected situation such as a jam occurs, Also, it is possible to obtain a good output image without receiving print data again. In addition, the storage memory 106 in the embodiment can be used freely for not only compressed data if there is free space, so it can be used dynamically as a font cache for storing font download patterns from the host computer 102 or for pattern expansion of vector download fonts. become able to.

Note that although the embodiment has been described as an example of application to a laser beam printer, the present invention is not limited thereto. For example, L.E.
This is because it can be applied to various printing devices such as D printers and inkjet printers. Further, in this embodiment, the data compression method is based on the Lang Langes method, but the compression method is not limited to this, and various methods such as the MH method can be applied.

In addition, in this embodiment, page information is compressed and saved for reprinting when a jam occurs, but for example, even before printing bitmap information developed on page memory, bitmap information may be compressed and saved one after another. Then, the compressed data may be expanded and the image outputted in accordance with the paper feeding speed of the printing mechanism section. As a result, a large amount of page information can be prepared in advance in a relatively small amount of memory in an apparatus in which the control section has relatively high performance compared to the printing mechanism section, so that it is possible to improve the printing execution speed. In particular, when the image signal of the created page is processed by another unit such as an image generator as in this embodiment, a page memory for one more page is prepared as a buffer, and the image signal of the previous page is processed while printing. If you create them one after another and compress and save them, the overall printing efficiency will improve.

Furthermore, although this embodiment is an example of the present invention for single-sided printing, it goes without saying that the present invention can also be applied to a double-sided printing device.
It is necessary to store twice as many pages (front and back), so compressing data has a great effect on improving memory efficiency.

[Effects of the Invention] As explained above, according to the present invention, even if a recording medium becomes clogged in the conveyance path and a printing failure occurs, the printed image data is retained, so the printout can be performed again. It becomes possible to obtain an output image without receiving print information.

Furthermore, since the image data is held in a compressed format, memory efficiency can be improved.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing the configuration of the control system of the printing device in the embodiment, Fig. 2 is a sectional view showing the structure of the printing function section of the printing device in the embodiment, and Fig. 3 shows the compression format in the embodiment. Figure 4 is a conceptual diagram showing the state of data storage in the work memory and storage memory in the embodiment, Figure 5 is a flowchart of the main routine in the embodiment, and Figure 6 is the page memory compression in Figure 5. Flowchart showing the inside of the processing routine. FIG. 7 is a flowchart of the timer interrupt processing routine in the embodiment. In the figure, 100...control unit, 101...CP of the control unit
U, 102... host computer, 103... input interface circuit, 104... ROM, 105...
...Work memory, 106...Save memory, 107.
...Page memory, 108...Page storage amount selection switch, 109...Timer circuit, 110...Image signal generator, 111...Output interface circuit, 112
. . . Printing mechanism section, 400 . . . Page storage table. Patent applicant Canon Co., Ltd. Figure 3 Figure 4 Figure 7

Claims (2)

[Claims] (1) A printing device that prints an image on a recording medium based on page-by-page information inputted from the outside, comprising a developing means for developing an image pattern based on the inputted information, and an output based on the developed image pattern. an image forming means that forms an image; a storage means that resides at least in the apparatus main body and stores a plurality of pages of image patterns on a recording medium on which an image is formed by the image forming means; and a detection means for detecting cancellation, and when the detection means detects that the printing error occurrence state has shifted to cancellation, the image pattern stored in the storage means is read out, and the image forming means forms an image. A printing device characterized by being able to be rewritten. (2) The printing apparatus according to claim 1, wherein the storage means compresses and stores the image pattern expanded in the expansion means.