JPS58108180A - Retracting method of printing head - Google Patents

Abstract

PURPOSE:To obtain an inexpensive printer having a simplfied structure without the needs for specific retracting mechanism and its control circuit by utilizing the retracting mechanism of a home position each time line feed is performed. CONSTITUTION:By a counter 40, line feed signal (a) sent from a controller 30 is counted and when a set value is reached, a retraction start signal (e) is sent out to an initiative signal generator 50 and a logic circuit 70. When an initiative signal (f) is sent through OR circuit 60 from the initiative signal generator 50 to the mechanism 20, the printing head is restored to its home position and retracted from a paper by a cam mechanism. When the printing head reaches the home position, a signal (d) is sent to the logic circuit 70, the output of the logic circuit 70 is stopped, and the prohibition of printing is released. At the same time, the output stoppage of the logic circuit 70 is detected by a breaking detector 90, a reset signal (g) is sent out, and the counter 40 is reset. Again, line feeding and printing are continued and the foregoing retracting operation is repeated.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a print head retraction method, and more particularly to a print head retraction method in a serial printer. ,, ・Technical Background> In recent years, various serial printers have been used as output devices for electronic computers and word processors.In such printers, the position of the print medium is specified according to the ejection stroke amount of the print element. To do this, the printer is equipped with a mechanism that presses the print medium against the platen with a constant pressure.

FIG. 1111 is a schematic diagram showing a print head portion of a wire dot printer. In the figure, the IFi print head, 2
is the head carrier, 3 is the carrier frame, 4Fi screener 2), and slj guide stay.

6 is a rotating shaft, 7 is a spring, 8Fi cam p-ra, 9Fi mask, 10tl;t platen, 11Fi ink ribbon, 1
2 is a printing medium (paper). The print head 1 is supported by a head carrier 2 and the head carrier 2 is supported by a carrier frame 3, and is driven by a screener 4 and guided by a guide stay 5 to move in the row direction. The head carrier 2 is rotatable around the rotating shaft 6, and the mask 9 presses the print medium 12 against the platen 10 by the return force of the spring 7. > In such printers, there is a problem in that line feeds are continued by rotation of the platen while the mask is pressed against the print medium (this causes slack in the print medium, resulting in misalignment of the print position).

Therefore, conventional printers are provided with a special mechanism such as a motor or a plunger magnet, and its control means so that the mask is retracted from the print medium at each line feed. Therefore, there is a problem that the device becomes complicated and expensive. <Objective of the Invention> An object of the present invention is to provide a print head Q retraction method that does not make the device complicated and expensive. Configuration> The method of the present invention is provided with initialization means for counting the number of iris line feeds and generating an initialization signal when a predetermined number is reached,
A feature of the present invention is that the print head is returned to the home position controller every predetermined number of line feeds, thereby retracting the blank print head from the scissor print medium.That is, the present invention is based on the knowledge that sagging of the print medium is caused by the accumulation of line feeds. Based on this, the permissible number of line feeds is determined, and the evacuation mechanism of the home pager is used for each number of line feeds, thereby solving the problem. FIG. 3 is a diagram for explaining an example of a print head retraction mechanism in the printer.

A cam 13 is fixed to the home position controller, and when the print head shown in FIG. 1 returns to the home position, the cam 13 applies a downward force to the cam roller 8.

Therefore, the head carrier 2Fi rotates to the left about the rotating shaft 6, and the mask 11 fixed to the head carrier
is moved away from the print medium 12.

FIG. 3 is a block diagram for explaining one embodiment of the system of the present invention. In Figure 3, 2041 mechanism 1i1S
, 30tf control 0m, 40tly transmission, 6011 initialization signal generator, 60 OR circuit, 7 (1 logic circuit consisting of an inverter and an AND circuit at one input, 80F
iOR circuit, 9 (1 falling edge detector; printer mechanism 112G and control unit 30 are provided in the conventional printer; all others are provided in 4 for implementation of the method of the present invention;
Next, the operation of the apparatus shown in FIG. 3 will be explained. counter 4G11
The signal generator 50 counts the line feed signal a sent from the control unit 30 and when it reaches a set value, generates an evacuation start signal.
The set value of the ◯ counter to be sent to the initialization signal generator 50#i and the logic circuit 70 is sent to the initialization signal generator 50#i initialization signal ft-0R circuit 60 using a start signal kK that varies depending on the printer model. An initialization signal is also input from the control 1130 to the OR circuit, and either the f or b signal is sent to the mechanism section 20. When the initialization signal f is sent to the mechanism section 20, the print head is returned to the home position 71y, and the print head is returned to the second position.
At this time, when the paper is retracted from the paper by the cam mechanism shown in the figure, the slack of the paper is eliminated by the return force of the paper itself.

When the printhead reaches the home location, a switch (not shown) is actuated and a signal d is sent to logic circuit 70 from a signal generator (not shown).

The save start signal e has already been input to the logic circuit 70, and the signal C that inhibits the 80 characters of the 〇〇ROR circuit that continues to be output to the OR circuit 80 is inserted into the circuit that sends it from the mechanism section 20 to the control section 30. The output from the logic circuit 70 prohibits printing. When the signal d is sent to the logic circuit 70, the output of the logic circuit 70 is stopped and the prohibition of egg production is lifted.

At the same time, the fall detector 90 detects the stop of the output of the logic circuit 70.
is detected and sends a reset signal g to reset the counter 40. Then, printing and line feed continue again, and the above evacuation operation is repeated.

<Effects of the Invention> As is clear from the above embodiments, according to the method of the present invention, a special evacuation mechanism and its control circuit are not required, and only a simple control circuit is required, so that the structure is It can provide a simplified and inexpensive printer.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing a print head portion of a wire dot printer, and FIGS. 2 and 3 are diagrams for explaining an embodiment of the present invention. In the figure, 8#'i cam roller, 13tf cam, 20
3G is a mechanism section, 3G is a control section, 40F1 counter, 50 is an initialization signal generator, and 60 and 80 are OR circuits. 70 is a logic circuit and a 90Fi falling detector.

Claims (1)

[Claims] A printer that moves the print head onto the paper and prints information with part of it in contact with the paper, and a printer that eliminates contact between the tip of the print head and the print medium when the print head is transferred to the home position printer. When the number of line feeds is counted and a predetermined number of line feeds has been reached, an initialization manual is set that generates a signal to transfer the print head to the home position every predetermined number of line feeds. A method for retracting a print head, characterized in that the print head is retracted from a print medium while the print head is being returned to its original state.