JPS6125553B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a printer in which a carriage equipped with a print head is provided so as to be movable left and right with respect to a platen.

Conventionally, in this type of printer, a printer is known in which the position of the carriage is detected every time the carriage moves by one character, and it is checked whether the carriage position is correctly located at the character printing position.

However, such a device has the disadvantage that the character printing position and the carriage position must be compared every time the carriage moves by one character, making abnormality detection control complicated. In addition, the amount of carriage movement must be adjusted in advance across all printing positions so that the movement of the carriage by one character is the same as the movement of one character of the character printing position, which requires a troublesome adjustment operation. There was a drawback.

The present invention has been devised to eliminate these drawbacks, and aims to provide a printer that can simplify abnormality detection control, eliminate the need for troublesome adjustments, and improve reliability.

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a carriage with a printing head 2 attached to its tip. This carriage 1 is placed on two shafts 5 and 6 installed between left and right frames 3 and 4. It is provided so as to be movable left and right with respect to the book shafts 5 and 6. The horizontal movement of the carriage 1 is controlled by a motor 7. That is, pulleys 8 and 9 are provided on the outside of the left and right frames 3 and 4, respectively, and the rotation shaft of the pulley 8 is connected to the rotation shaft of the motor 7. A closed loop belt 10 is passed between both pulleys 8 and 9, and the carriage 1 is fixed at a predetermined position on the belt 10. In other words, when the motor 7 rotates, the pulley 8
rotates, thereby causing the belt 10 to rotate between both pulleys 8 and 9, allowing the carriage 1 to move left and right. A first switch 11 as a left end detector and a second switch 12 as a right end detector are attached to the rear end of the carriage 1. When the carriage 1 moves to the left end in the drawing, the first switch 11 comes into contact with a stopper 13 erected inside the left frame 3 and is biased, and the second switch 12 is activated when the carriage 1 moves to the left end in the figure. When it moves to the right end in the figure, it comes into contact with a stopper 14 erected inside the right frame 4 and is biased. Further, at the rear end of the carriage 1, an operating bar 15 made of a magnetic member is provided upright. A proximity switch 17 as a specific position detector is attached to a wall surface 16 facing the rear end of the carriage 1. The proximity switch 1
Reference numeral 7 indicates an actuation bar 15 of the carriage 1 when the print head 2 is set at a specific print character position.
attached to a particular position biased by the proximity of the The distal end of the carriage 1 is connected to a platen 18 rotatably installed between the left and right frames 3 and 4.
For example, an ink ribbon (not shown) and paper (not shown) are interposed between the platen 18 and the print head 2 mounted on the front end of the carriage 1.

FIG. 2 is a block diagram showing the main circuit configuration, and this circuit can be constructed using a well-known microcomputer.

In FIG. 2, numeral 21 is a central processing unit (hereinafter simply referred to as CPU), and this CPU 21 has built-in arithmetic circuits, instruction decoders, memory control circuits, and the like. 22 is read only
23 is a random access memory (hereinafter simply referred to as RAM); 23 is a random access memory (hereinafter simply referred to as RAM);
The ROM 22 allows the CPU 21 to access the RAM 2 based on key inputs from the key input unit 24 in the printer or input signals from the first and second switches 11, 12 and the proximity switch 13.
3, various processing programs for controlling the print control circuit 24, key input control circuit 25, and input port 26 are stored. The RAM 23 is provided with a memory M that specifically stores movement amount data. In addition, the CPU 21, ROM 22, and RAM 2
3, print control circuit 24, key input control circuit 25,
Data exchange with the input port 26 is performed through an address bus 27 and a data bus 28.

For example, when the carriage 1 is located at the left end and the first switch 11 is energized by the stopper 13, the CPU 21 stops the rotation of the motor 7 to stop the carriage 1 at the left end, and then rotates the motor 7 in the reverse direction. The robot is waiting to move the carriage 1 to the right. Further, in the CPU 21, the carriage 1 is located at the right end, and the second switch 12 is located at the stopper 14.
When energized by , the rotating shaft of the motor 7 is stopped and the carriage 1 is stopped at the right end, and then the motor 7 is caused to move the reverse rotating carriage 1 to the left. When the CPU 21 moves the carriage 1 to the right, it drives the print head 2 to perform a printing operation. Also, the CPU2
1, when the printing operation of the movement amount data is performed in the key input section 24 before the printing operation is performed, the carriage 1 is moved from the left end side to the right and the first switch 11 is turned on as shown in a in FIG. When the active state is released, a timing signal is generated and counted as shown in FIG. 3B in accordance with each printed character position. Then, as shown in FIG. 3c, when the proximity switch 17 is energized by the operating bar 15 of the carriage 1 and a signal is output from the switch 17, the CPU 21 outputs the count data of the character position timing signal. is preset in the memory M of the RAM 23 as movement amount data. Also, the CPU2
1 stores data indicating non-output of a signal in place of the movement amount data when the carriage 1 moves from the left end to the right end but no signal is output from the proximity switch 17 during the presetting process of the movement amount data. I have it preset to M. If there is a key input from the key input section 24 after this preset operation is completed, the above-mentioned
The CPU 21 checks the data in the memory M, and if the memory M does not store data indicating non-output of the signal, it performs the printing operation based on the key input from the key input section 24 and also controls the generation of the character position timing signal. It is detected whether a signal is output from the proximity switch 17 in synchronization. When receiving a signal from the proximity switch 17, the movement amount data being counted at that time is compared with the preset movement amount data. Further, when data indicating non-output of the signal is stored in the memory M in the data check of the memory M, the printing operation is performed based on the key input from the key input section 24 regardless of the presence or absence of the signal from the proximity switch 17. That's what I do. Said
The CPU 21 compares the movement amount data when printing from the proximity switch 17 is detected through sampling with the preset movement amount data, and if a match is not detected between the two data, the movement operation of the carriage 1 is abnormal. If it is determined that there is an abnormality, the operator is notified of the occurrence of the abnormality using, for example, a display.

In this way, the carriage 1 is started to move from the left end in advance and the character position timing signal generated corresponding to each character position is counted, and the current count value is moved at the timing when the carriage 1 approaches the proximity switch 17. After that, when the printing operation is started, the proximity switch 17 is activated every time a character position timing signal is generated due to the movement of the carriage 1.
As a result, when the signal output from the proximity switch 17 is detected, the count data of the character position timing signal at that time is compared with the count data preset in the memory M. Since an abnormality in the movement of Carriage 1 is detected when the numbers do not match, it is necessary to compare the count data and preset data from time to time, compared to, for example, a method that compares count data and preset data every time Carriage 1 moves by one character. Since there is no need to carry out the comparison operation only when a signal is output from the proximity switch 17, abnormality in the moving operation of the carriage 1 can be detected by simple control. Further, since the adjustment only needs to be made for one proximity switch 17, it is extremely simple. Furthermore, if the proximity switch 17 is short-circuited, a signal is already output from the proximity switch 17 when the carriage 1 moves by one character, so that the abnormality can be immediately detected.

In addition, when presetting the movement amount data, if there is no signal output from the proximity switch 17 even after the carriage 1 is moved from the left end to the right end, data indicating the non-output of the signal is stored in the memory M instead of the movement amount data. is preset, and the printing operation is performed regardless of whether or not there is a signal output from the proximity switch 17 during the printing operation, so even if the proximity switch 17 has an open failure, the printing operation will be performed regardless of whether there is a signal output from the proximity switch 17. Printing will not become impossible. In this way, even if the proximity switch 17 has an open failure or a short circuit failure as described above, it can be coped with, thereby improving reliability. Further, since the adjustment can be simplified, malfunctions are reduced and the position of the carriage 1 at the time of presetting can be accurately matched with the position of character printing, so that abnormality detection can be performed with high precision.

In the above embodiment, a proximity switch is used as the specific position detector, but it is needless to say that the present invention is not limited to this.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; FIG. 1 is a schematic configuration diagram, FIG. 2 is a block diagram showing the main circuit configuration, and FIG. 3 is a timing chart showing the operation timing of each part. DESCRIPTION OF SYMBOLS 1... Carriage, 2... Print head, 7... Motor, 11... First switch, 15... Operating lever,
17...Proximity switch, 21...CPU (central processing unit).

Claims (1)

[Claims] 1 A carriage equipped with a printing head and movable left and right facing the platen, a motor that drives the carriage left and right, and a device that detects when the carriage reaches a specific position within its movable area. a specific position detector for outputting a signal; means for detecting the amount of movement of the carriage when it moves from one end position to the other end position within its movable region; is moved from one end position to the other end position, and when a detection signal is output from the specific position detector due to the movement, the movement amount data detected by the movement amount detection means is preset, and a memory in which data indicating non-output is preset when no detection signal is output from the specific position detector due to the movement, and when the movement amount data is preset in this memory, the means for detecting the presence or absence of a detection signal from the specific position detector every predetermined movement amount in response to movement of the carriage from one end position to the other end position; Compare the movement amount data preset in the memory at the time of detection with the movement amount data detected by the movement amount detection means to determine whether a detection signal is output due to movement of the carriage to a specific position. means for determining the movement amount data is provided in the memory, and when the determination means determines that the detection signal is output at a position other than the specific position of the carriage, an abnormality is detected; A printer characterized in that abnormality detection is prohibited when data indicating output is preset.