JP2738302B2 - Printing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing apparatus and, more particularly, to a method for correcting an error in a printing apparatus, even if the printing is erroneous, such as printing blur or misalignment.

[0002]

2. Description of the Related Art Conventionally, in this type of error correction system, a printing pattern is optically read after printing, a printing result is notified to a host device, and error correction such as retry is performed by the host device.

Further, Japanese Utility Model Laid-Open Publication No. 59-59341 discloses a dot printer provided with inspection means for comparing character data before printing with character data after printing to check whether correct printing has been performed. 63-
Japanese Patent Application Publication No. 134760 discloses an electronic device with a printer provided with a control circuit for detecting erroneous printing and performing control to perform reprinting.

[0004]

However, in the conventional error correction method, errors are corrected by a higher-level device, so that opportunities for data transfer between a printing device and a higher-level device are increased, and channel efficiency is reduced. In addition to the worsening, there is a disadvantage that error correction takes time.

Further, in a printer which compares character data before and after printing and reprints when correct printing is not performed, if correct printing is not performed even if reprinting is repeated many times, time is required. Wasted.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a printing apparatus capable of performing error correction processing only by a printing apparatus and reducing a waste of time due to repeated reprinting to a certain level or less.

[0007]

According to the present invention, there is provided a printing apparatus for receiving print information from a higher-level device and performing printing, comprising: a printing unit for printing the print information received from the higher-level device; Optical reading means for reading the printing information, and when the printing information before printing and the printing information read by the reading means do not match, a reprint instruction is issued to the printing means and reprinting is performed until a match is detected. A printing apparatus is provided, comprising: control means for performing control; and means for making an abnormality notification when the number of reprints performed by the control means reaches a predetermined value.

[0008]

The printing device, which has received the printing information from the host device, prints in the printing device and compares the character data before printing with the character data after printing. Repeat printing again up to the number of times. When the predetermined number of times has been reached, an abnormality notification is made to the host device.

[0009]

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

FIG. 1 is a configuration diagram of an embodiment of a printing apparatus according to the present invention. However, the host device in the figure is not included in the printing device.

The upper device is included in FIG. 1 for convenience of explanation. In this embodiment, a so-called page printer that prints one page of data will be described. However, the present invention is not limited to this. For example, a printer that prints data in units of one line or a plurality of pages may be used. The printing device includes a printing unit 1 that prints the character data of one page received from the host device 10, an optical character reading unit 2 that reads the printed character data, character data before printing and character data after printing. , A print error detecting section 3 for detecting a print error, and a print control section 4 for controlling the printing section 1 based on the detection result of the print error detecting section 3.

The error detecting unit 3 stores a print information buffer 3a for storing one page of print information input from the host device 10 via the print control unit 4, and stores character data read by the optical character reading unit 2. Reading result buffer 3b, and a comparing unit 3c for comparing character data stored in the printing information buffer 3a with the reading result buffer 3b
And The print information includes print position information and character data.

The print control unit 4 has an error determination unit 4a for determining whether or not the printing unit 1 should reprint based on the comparison result of the comparison unit 3c, and a print information buffer 3a for reprinting. It comprises a reprint unit 4b for reading stored character data and a counter 4c for counting the number of reprints.

Next, the operation of the printing apparatus will be described.
First, when a print command and one page of print information are input from the host device 10 to the print control unit 4, the print control unit 4 sends the one page of print information to the print information buffer 3 a in the error detection unit 3. Store. Then, the character data is read from the print information buffer 3a and printed by the printing unit 1.

Next, the printed character data is read by the optical character reading unit 2 and stored in the reading result buffer 3b. Then, the comparison unit 3c sets the print information buffer 3
The character data before printing stored in a is compared with the character data after printing stored in the reading result buffer 3b. If the two character data match, a position where no printing is performed is read from the print information buffer 3a, and it is confirmed that the character data at this position is not read by the reading result buffer 3b. And
After this confirmation is made, the comparing unit 3c sends the error judgment unit 4
The result of "match" is notified to "a". The error discriminating unit 4a, having received the result notification, notifies the host device 10 of a printing result indicating that printing is normal.

On the other hand, if the character data before printing stored in the print information buffer 3a does not match the character data after printing stored in the reading result buffer 3b, the comparing unit 3c sends the error data to the error discriminating unit 4a. The result of the "mismatch" is notified. The error discriminating unit 4a that has received the "mismatch" notification instructs the reprinting unit 4b to perform reprinting and sets the counter 4c to "1".

Then, the reprint unit 4b reads the character data at the same print position as that previously printed from the print information buffer 3a and sends the character data to the print unit 3 for printing.

After the printed character data is again read by the optical character reading unit 2, the comparison unit 3c compares it with the character data before printing. Then, when the result of the comparison indicates “match”, as described above, the print control unit 4 notifies the host device 10 of a print result indicating that the print is normal.

If the result of comparison by the comparing section 3c becomes "mismatch" again, the comparing section 3c sends the error discriminating section 4
"a" is notified of the result. This "mismatch"
Upon receiving the notification, the error discriminating unit 4a instructs the reprinting unit 4b to perform reprinting, and further increments the counter 4c by one to “2”. Then, the same reprinting as described above is performed. If the printing does not become normal even after the reprinting, the reprinting operation is further repeated.

Incidentally, a predetermined number, for example, "5" is set as an upper limit value in the counter. In this case, if reprinting is continued five times, even if the comparison result of the fifth reprinting is “mismatch”, the error determination unit 4a does not instruct the reprinting unit 4b to perform reprinting, and Apparatus 10
Is notified of a print result indicating that the printer is abnormal. After the notification, the error determination unit 4a sets the counter 4
c is reset to "0".

When printing of one page of character data stored in the print information buffer 3a is completed, the print controller 4 clears the print information buffer 3a and the read result buffer 3b, and prints the next page of print information. wait.

In this embodiment, the print information buffer 3a
Are shared as character data buffers for printing and reprinting, but may be provided separately.

[0023]

According to the present invention, since a printing device corrects a printing error, the burden of error processing on a host device can be reduced, and the efficiency of the channel can be increased to correct the error in a short time. It can be carried out.

Further, since a printed image after printing is read and an error check is performed, it is also effective for erroneous printing such as blurring or misalignment.

Further, since a counter for limiting the number of times of reprinting is provided, waste of time due to repetition of reprinting can be kept below a certain level.

Further, since the present invention can be applied to a printing apparatus for printing in page units, versatility can be improved.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an embodiment of a printing apparatus according to the present invention.

[Explanation of symbols]

 Reference Signs List 1 printing unit 2 optical character reading unit 3 printing error detecting unit 3a printing information buffer 3b reading result buffer 3c comparing unit 4 printing control unit 4a error discriminating unit 4b reprinting unit 4c counter 10 host device

Claims (3)

(57) [Claims] 1. A printing device that receives print information from a host device and performs printing, comprising: a printing unit that prints the print information received from the host device; an optical reading unit that reads the printed print information; Control means for instructing the printing means to reprint when the previous print information and the print information read by the reading means do not match, and performing reprint control until a match is detected; and A means for giving an abnormality notification when the number of reprints by the printer reaches a predetermined value. 2. The printing apparatus according to claim 1, wherein the print information is print information in page units. 3. The printing apparatus according to claim 2, wherein said control means has a comparing means for comparing the print information before printing and the print information after printing, and is configured to give a print instruction again based on a result of the comparison. The printing device according to claim 1.