JPH02303875A - Dot printer - Google Patents

Abstract

PURPOSE:To automatically detect the breakage of dot pin by mounting a means successively selecting the respective dot pins of a printing head and a means printing a test printing pattern on printing paper. CONSTITUTION:A printing control part 11 receives printing data from a test printing pattern memory 24 to continuously output the first pin by a width (n) mm and subsequently feeds printing paper 14 by one dot diameter on the basis of the signal from a paper feed control circuit to continuously output the same by the width (n) mm. In the same way, when output is performed in the order of a3-a5, a black test printing pattern (a) having a length (n) mm and a width 1mm is outputted and the second and third pins are continuously printed by the width (n) mm to output test printing patterns (b), (c) but, when the third pin 3 is broken, the test printing pattern (c) becomes low in density. The printing paper 14 is successively fed during a time when the dot pins of a printing head 1 are continuously struck until the last pin and the test printing patterns are successively read by a reflection sensor 12 and a detection circuit part 13 judges that the test printing patterns (a), (b) are normal and the test printing pattern (c) is abnormal. Therefore, the breakage of the dot pin can be detected automatically.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a dot printer equipped with a dot pin break detection aII.

(Prior Art) Conventionally, serial printers using a dot print head have advantages such as a high degree of freedom in printing media and the ability to use copy paper, etc., and have been in high demand. Further, the dot print head drives the wire by a permanent magnet or the magnetic attraction force of a magnet.

The above printers are classified into plunger type, spring charge type, and clapper type based on the type of dot print head.

Among these, the spring-charged type has an armature with a dot pin fixed thereon that is swingably supported by a bias leaf spring, and the armature is held in advance by a permanent magnet against the elastic force of the bias leaf spring. The magnet is attracted to the core, and when printing, a coil wound around the core is energized to generate magnetic flux in the opposite direction to the permanent magnet, thereby releasing the armature.

On the other hand, the clapper type has a structure in which, on the contrary, when printing, a coil is energized and energized, a temporary spring is attracted to the coil, and printing is performed by the attraction force generated at that time.

The diameter of the dot pins of the dot print head tends to become smaller and the driving speed increases as printing speed increases.

Therefore, the load applied to each dot pin becomes large,
Dot pins often break.

Therefore, conventional dot printers are equipped with a mechanism for detecting dot pin bending.

FIG. 4 shows a schematic diagram of the above-mentioned conventional dot printer.

Reference numeral 1 denotes a print head, which strikes a print medium through an ink ribbon while moving in the direction of the arrow along a platen 2 to print.

3□3g+ . . . 311 is a pressure sensor embedded in the surface of the platen 2, and is attached corresponding to the printing position of each of the n dot pins of the print head 1. A detection circuit section 4 is connected to the pressure sensors 3++ 3z+ . . . 31.

When checking for broken dot pins in the dot printer with the above configuration, first connect the print head 1 to the pressure sensor 3.
Move to the position and output the first pin. If the first pin is normal, the impact is transmitted to the pressure sensor 31, and the detection circuit section 4 determines that it is normal.

Next, the print head 1 is connected to another pressure sensor 3□1...
37 and output the second, third, and so on pins sequentially, and the impact force of each is measured.

If the dot pin is broken, either the impact is not transmitted to the pressure sensor corresponding to that bottle, or the specified impact force is not reached.

Therefore, the detection circuit section 4 can detect this impact force and determine whether or not the dot pin is broken.

(Problem B to be solved by the invention) However, in the dot printer with the above configuration,
The error range of the relative position between each pressure sensor 33, 3□1...33 and the dot pin of the print head 1 is narrow, and the position where the dot pin hits deviates from the pressure sensor 3I, 3□,...3h. Sometimes.

In addition, in a line printer in which multiple printing pads 1 are arranged side by side, pressure sensors 3. ．． 3. ,...3,,
The number of detection circuits increases, and a plurality of detection circuit units must be provided.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the conventional dot printer and to provide a dot printer that can detect dot pin breakage with a simple structure and circuit without providing a pressure sensor on the platen. do.

(Means for Solving the Problems) To achieve this, the dot printer of the present invention includes a print head, a print control unit that drives the print head based on print data, and a memory that stores print data of a test print pattern. The apparatus includes means for sequentially selecting each dot pin of the print head, and means for printing a test print pattern on the print paper for each selected dot pin.

(Function) As described above, the present invention includes a print head, a print control unit that drives the print head based on print data, and a memory that stores print data of a test print pattern. Each dot pin is selected sequentially and a test print pattern is printed on the printing paper for each dot pin, so that the optical sensor that reads the print results can automatically detect dot pin bending, and visually detect the dot pin breakage. You can also check for broken dot pins.

Further, there is no need to dispose the pressure sensor on the platen, and detection errors due to misalignment between the pressure sensor and the dot pins can be prevented.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a control block diagram of a dot printer showing an embodiment of the present invention, and FIG. 2 is a diagram showing a test print pattern for detecting dot pin breakage.

In the figure, a print head (■) is provided facing the platen 2 and is connected to the print control unit 11.

Reference numeral 12 denotes a reflective sensor, which is composed of, for example, a light emitting diode and a phototransistor, and is connected to the detection circuit section 13, and is connected to the test print pattern a printed on the print paper 14.
, b, and c in order.

15 is a display section that displays the read test print patterns a and b.
, c are displayed. 16 is an ink ribbon disposed between the print head 1 and the platen 2.

A test print designation means 21 such as a key switch is connected to the print control section 1, and test printing is started by operating the test print designation means 21. Further, a paper feed control circuit 22 , a spacing control circuit 23 , and a test print pattern memory 24 are connected to the print control section 11 . The test print pattern memory 24 contains the test print pattern a.

b and c are stored as print data, and the print data is sent to the print control section 11 and printed on the print paper 14. At this time, paper feeding and spacing are performed by a paper feeding control circuit 22 and a spacing control circuit 23. The paper feed control circuit 22 changes the number of paper feed pulses and changes the paper feed pitch during test printing.

Next, the operation of the dot printer having the above configuration will be explained.

First, the print control section 11 receives print data from the test print pattern memory 24 and drives the print head 1.
As shown in FIG. 2, the first bin is concatenated by a width n■ and output (a,).

Next, the paper feed mechanism is activated by a signal from the paper feed control jB circuit 22, and the paper is fed by one dot diameter (for example, 0.2 mm), and the same first pin is continuously output with a width of nmmm (a).

Similarly, if a, ~a, are output in this order, a black test print pattern a with a length of n and a width of 1 mta (0.2 mm x 5) is output. This test print pattern a
does not necessarily need to be composed of a plurality of lines as described above, and various patterns can be adopted as long as the dot pin bending can be detected by the reflection sensor 12. Similarly, the second and third pins are set to a width n1.
Continuously print for 11 m and output test print patterns b and c.

Here, for example, if the third pin is broken and sufficient pressure is not applied to the ink ribbon 16, the test print pattern C will be thin compared to a and b.

While the dot pins of the RAD 1 are continuously being hit from the first bin to the final pin for printing, the printing paper 14 is fed in order and comes under the reflective sensor 12.

At this time, print position information regarding the paper position is transmitted from the print control section 11 to the detection circuit section 13, while the reflection sensor 12 sequentially reads test print patterns a, b, and c.

Then, the detection circuit section 13 detects the test print pattern a,
b is determined to be black (normal), and test print pattern C is determined to be white (
abnormal). That is, it can be seen that dot pin breakage has occurred on the third pin. Further, bottle breakage information is transmitted from the detection circuit section 13 to the display section 15, and the number of the dot pin where the bottle breakage has occurred is displayed on the display section 15.

Next, when a plurality of print heads 1 are lined up like a line printer, as shown in FIG.
．． , ig, ... 11, the reflective sensor 1 is installed.
By providing 21.12g...127, bottle breaks of all dot pins can be detected.

Note that the present invention is not limited to the above embodiments (
Various modifications are possible based on the spirit of the present invention, and these are not excluded from the scope of the present invention.

(Effects of the Invention) As described in detail above, according to the present invention, the present invention includes a print head, a print control unit that drives the print head based on print data, and a memory that stores print data of a test print pattern. The device has means for sequentially selecting each dot pin of the print head and means for printing a test print pattern on the print paper for each selected dot pin, so that the dots are automatically selected by an optical sensor that reads the print results. Not only can pin breaks be detected, but dot pin breaks can also be visually confirmed.

Further, there is no need to arrange the pressure sensor on the platen, and detection errors due to misalignment between the pressure sensor and the dot pins can be prevented, and alignment work becomes unnecessary.

Furthermore, the number of optical sensors that read the above-mentioned printing results need only be provided as many as the number of print heads, and the circuit can be simplified.

[Brief explanation of the drawing]

Fig. 1 is a control block diagram of a dot printer showing an embodiment of the present invention, Fig. 2 is a diagram showing a test printing pattern for detecting dot pin breakage, and Fig. 3 is an example of a line printer in which the dot pin breakage detection device is adopted. The figure shown in FIG. 4 is a schematic diagram of a conventional dot printer. ■... Print head, 2... Platen, 33.3t,
37... Pressure sensor, 4, 13... Detection circuit section, 11... Print control section, 12... Reflection sensor, 1
4...Print paper, 15...Display unit, 16...Ink ribbon, 21...Test print designating means, 22...Paper feed control circuit, 23...Spacing control circuit, 24
...Test print pattern memory. Patent Applicant: Oki Electric Industry Co., Ltd. Agent, Patent Attorney: Makoto Kawai (1 other person) Implementation of the present invention: 11 Shaku 1-dot printer shaving area 1+, 2, 2, 1, 1, 2, 1, 2, 1, 2, 1, 2, 1, 1 Tematata f mouth τrc nine show v
[2I Raisif 1 Nonta ni] 1 Master Otsu,
Figure 1 Figure 2 Figure 3 Deficiencies of conventional Φ dot printers 2 Figure 4

Claims (1)

[Claims] (a) a print head; (b) a print control unit that drives the print head based on print data; (c) a memory that stores print data of a test print pattern; (d) a print head. A dot printer comprising: means for sequentially selecting each dot pin; and (e) means for printing a test print pattern on printing paper for each selected dot pin.