JPS5942983A - Apparatus for detecting abnormality of printing apparatus - Google Patents

Abstract

PURPOSE:To provide the titled apparatus capable of preventing error printing caused by address abnormality, by detecting whether the address of a printing data memory storing one line printing data is read out in predetermined order or not. CONSTITUTION:A printing control apparatus 20 generates three bits of flag data SSFLAG0-SSFLAG2 corresponding to the numbers of sub-scannings. In each sub-scanning, by monitoring whether flag bits PDMFLAG0-PDMFLAG2 of a printing data memory PDM19 storing one line printing data are respectively coincided with the flag data or not, the read-out address abnormality of PDM19 is detected. When one of non-coincidence gates 22-24 outputs one logical valve 1, a D-type flip 21 generates a signal ERROR of a logical value to the Q-side output terminal thereof in CHECKPULSE timing.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an abnormality detection device that can prevent erroneous printing in a printing device such as an impact rhino printer.

A printing device that uses a type carrier such as a type band that continuously runs across a printing position has a type code memory (a type code memory) that stores the code of the type on the type band 1, as shown in FIG.
The comparator 7 compares the character codes and print data in the print data memory (hereinafter referred to as PDM) 9 that stores the print data of one line (hereinafter referred to as COM) 6 and one line of print data, and if they match, the corresponding digit is printed via the hammer driver 10. The hammer 3 is driven to print. The address of the C0M6 is indicated by a sensor 2 that detects the type mark on the type band 1, a type position counter (hereinafter referred to as CPC) 4, and a code address counter (hereinafter referred to as OAO) 5,
The address of D M 9 is indicated by PDM counter 8 .

In such a printing device, if the output values of the C0M6 or PDM9 become abnormal, erroneous printing will occur.

For this reason, it is common practice to perform a harness check on these outputs to detect whether or not they are abnormal.

However, there is a drawback that a quality check error does not occur (if there is an abnormality in the !PC 4, OAC! 5, or PDM counter 8, etc.), and even erroneous printing cannot be detected.

An object of the present invention is to eliminate the above-mentioned drawbacks of the prior art, detect an abnormality in the PDM address caused by an error in the PDM counter that indicates the address of the PDM, and thereby prevent erroneous printing. It is to do so.

The present invention provides that the at1/s of the PDM read in each sub-scan of each print scan for printing by comparing the type code of the CCM and the print data of the PDM have a predetermined order (rule). The object of the present invention is to make it possible to detect whether addresses of PDM are read out in a predetermined order.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiment drawings.

First, a printing method of a printing device to which the present invention is applied will be briefly described.

FIG. 2 shows the facing relationship between the type characters on the type band 1 and the printing hammer. The printing type and the printing hammer 3 do not have a one-to-one correspondence, but approximately a five-to-six correspondence. For this reason,
A print scan consisting of five sub-scans is performed every time one print pitch moves, and during the sub-scan period, a comparison is made between every fourth print character code and every five digits of print data.

The digits and character positions to be compared in each sub-scanning are collectively shown. In addition, each line should be 1st and 6th digits, and type band 1.
The character types above are 64 character types, and the print positions are shown in parentheses. Also, all digits and character positions are read out in regular order according to the direction of the arrow.

As is clear from the above, the print data in each sub-scan is always read out in a predetermined order and is the same. Therefore,
By monitoring whether the print data is read out in the above order, it is possible to detect PDM errors caused by PDM counter errors.
address anomalies can be detected.

Figure 5 shows PDM19 applied to the present invention.
3 and a print data storage section that stores the print data of 8 pits.
flag bits PI) M FLAG OlPDM F
It is composed of a flag storage section that stores LAG 1 and PDM F'LAG 2 . In the flag storage section, the same data is written at the position read in each sub-scan. That is, sub-scanning 1, sub-scanning 2, sub-scanning ji, sub-scanning 1
The addresses of print data read in 1 scan 4 and sub scan 5 are (010, O) and (1
,0,0), (0,1,0), (1,1,0) and (0
, 0, 1) are written. Therefore, in the same -MIJ scan, flag bits of the same data are read out.

FIG. 4 shows an embodiment of the device of the present invention. 20
is the print control unit, and the 6-bit flag data ssπLAGO188FLAGI and 5SF corresponding to the sub-scanning number are
Generate T, AG2. That is, the flag data is
As shown in FIG. 5, (0, 0, 0), (1
,0,0), (0,1,0), (1,1,0) and (0
,0,1). Therefore, for each sub-scanning, the front PDM 19 (7) 7 lag pit PDM
FLAG Q~PDMFLAQ2 and flag data 5S
By monitoring whether each of FLAGo to 5SFLAG2 matches, the read PDMi9
address anomalies can be detected. The anti-coincidence gates 22 to 24 are provided for this purpose, and are connected to the PDM FLAGO, SS FLAGO, and PDM FL, respectively.
AGI and 5sFLAGI and PDM FLAG 2 and 5
SFLA()2 is used as input. That is, each of the anti-coincidence gates 22 to 24 generates an output of logic value 0 if the read address of the PDM 19 is normal, and at least one generates an output of logic value 1 if it is abnormal. The outputs of these anticoincidence gates 22 to 24 are applied via an OR gate 25 to a D input terminal of a D type flip (hereinafter referred to as y/F) 21. Therefore, if one of the anticoincidence gates 22-24 is producing an output of logic 1, the F/F 21 will receive the C! applied to its trigger input. HIUCK P
At the timing of ULSE, a signal ERROR with a logic value of 0 is generated at the Q side output terminal. The signal ERROR stops the printing operation, or by adding the signal to the input terminal of the comparator 70 shown in FIG. 1, it is possible to prevent erroneous printing due to an address error in the PDM 19. Gao, said CHECK PUL
Slii is generated every time each address of PDMi 9 is read.

As described above, according to the present invention, it becomes possible to quickly detect an abnormality in the address of the read PDM, and it is possible to prevent erroneous printing due to address abnormality.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing a schematic configuration of a printing device to which the present invention is applied, Fig. 2 is an explanatory diagram showing the opposing relationship between a printing hammer and type characters on a type band, and Fig. 6 shows the storage contents of PDM. FIG. 4 is a block diagram showing an embodiment of the apparatus of the present invention, and FIG. 5 is a time chart showing the relationship between each sub-scan and flag data. In the figure, 1 is the type band, 6 is the print hammer, and 4 is c.
:pc, 5 is CAC16 is OCM, 7 is comparator, 8 is P
DM counter, 9.19 is PDM. 20 is a print control unit, 21 is I'/1! ', 22-24
is an anti-match gate, and 25 is an or gate. Name of patent applicant Hitachi Koki Co., Ltd. Figure 2 3 Spear 30 Off-line diagram

Claims (1)

[Scope of Claims] Printing hammers are provided on a type conveyor that continuously travels across a printing position, facing the type conveyor and arranged in line along the printing position, and accessed by an address counter, Comparing the printed code storage means for storing the printed code corresponding to the above printed characters, the printed data storage means for storing the data to be printed, and the printed code and print data of the printed code storage means and the printed data storage means, and a comparison means for generating an output that drives the printing hammer of the corresponding digit when they match, and the printing scan is divided into a plurality of sub-scans in which comparison and printing are performed each time the printing type on the printing type conveyor moves. In the printing apparatus, the print data of a specific digit and the type code of a specific position are read out, compared, and printed in each sub-scanning. The flag storage section provided in the print data storage means and in which the same data is written in the digits read in each sub-scanning is compared with the sub-scanning number data and flag data of these print control section and flag storage section, and it is determined that they match. An abnormality detection device characterized by comprising: a detection means that generates an abnormality signal when the abnormality is not detected.