JPH02245366A - Shielding for printing head of printer - Google Patents

Abstract

PURPOSE:To protect the operator against any possible danger such as burns without touching a printing head directly by spacing the printing head to a specified position on a carriage shaft, then stopping the head and shielding the head from the operating side using a shielding cover provided at the specified position. CONSTITUTION:Printing form runs on the platen 11 of a printer, then is printed by driving of a printing head and is discharged onto a stocker 1b. A parking cover 2 is provided at a specified position on a carriage shaft 13 where the printing head 12 stops. The parking cover 2 is of an entirely air-permeable structure, e.g. such a structure as made of reticular or punching metal-like insulating material, positioned between the operating side 1a and the printing head 12 to shield the printing head 12 completely from the operating side 1a. Thus the operator is protected against his direct contact with the printing head when the printing form is set or an ink ribbon is replaced.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method for retracting and shielding a print head in, for example, a wire dot printer.

(Prior art and its problems) When using a printer, especially a wire dot printer,
The surface of the print head is heated by the increase in temperature of the coil built into the print head. Therefore, the entire outer surface of the print head is covered with a cover made of a heat insulating material such as rubber or plastic so that the operator will not suffer burns or the like even if the print head is heated to a high temperature and comes into direct contact with the print head. However, if the entire print head is covered with a cover made of the above-mentioned heat insulating material, the heat dissipation efficiency on the surface of the print head will be significantly reduced, and the thermal limit of the print head may be exceeded. If the thermal limit is exceeded, the coil inside the print head will burn out and printing will no longer be possible. Therefore, when the temperature of the print head rises to a predetermined temperature, it is necessary to stop the print drive and allow the surface of the print head to cool naturally.

The waiting time for naturally cooling the print head significantly lengthens the total print processing time, causing a deterioration of so-called throughput.

<Means for Solving the Problems> In view of the above-mentioned problems, the present invention provides space for the print head to be stopped at a predetermined position on the carriage shaft when the front cover is opened, and an evacuation cover provided at this predetermined position. The present invention provides a method for retracting and shielding a print head, which is characterized in that the print head is shielded from the operation surface side of the printer by using the above method.

<Function> When the front cover is opened, the print head is spaced to a predetermined position on the carriage, and at this predetermined position, the print head itself is shielded from the operation surface side of the printer by the evacuation cover.

This prevents the operator from directly touching the print head when setting print paper or replacing the ink ribbon.

(Example) Next, the print head evacuation and shielding method of the present invention will be described in detail based on the drawings.

FIG. 1 is a perspective view showing the configuration of a printer 1, and FIG. 2 is a partially omitted perspective view illustrating a retraction cover 2 provided in the printer 1. As shown in FIG.

The printer 1 arranges a print head 12 facing a platen 11, and slides the print head 12 onto a carriage shaft 13, so-called spacing, while printing on print paper (not shown) on the platen 11. Performs printing process. Also, between the operation surface side 1a and the print head 12,
A front cover 14 is provided, and this cover is normally closed to close the space between the operation surface side 18 and the carriage shaft 13, and is opened when printing paper is set or when the ink ribbon is replaced.

In the printer 1 having such a configuration, printing paper (not shown) runs on the platen 11, is printed on by driving the print head 12, and is then discharged onto the stocker lb. Carriage shaft 13 on which the print head 12 stops
A retraction cover 2 is provided at a predetermined position on the top (the left end when viewed from the operation surface side 1a). This evacuation cover 2 has a highly breathable structure as a whole, such as a heat insulating material in the form of a net or punched metal, and has an operation surface side 1a and a print head 1.
2, so that the print head 12 can be completely shielded from the operation surface side 1a.

On the other hand, in order to detect whether the front cover 14 is opened or closed, an opening/closing detection section S is provided at an appropriate location of the printer l. This opening/closing detection section S is constituted by, for example, a microswitch or an optical sensor.

FIG. 3 is a control circuit diagram of a printer according to the present invention. That is, in the opening/closing detection section S that detects whether the front cover 14 is open or closed, the common terminal C and the normally closed terminal NC are connected when the front cover 14 is closed.

This normally closed terminal NC is connected to a power supply E via an apple resistor R and is held at a High level.

Therefore, the gcPU connected to the common terminal C receives the old GH level signal. Further, the normally open terminal NO is grounded. On the other hand, in the control section of printer l,
ILcPU: 12 and program ROM 33. via pass line 31. and I10 boat 34 are connected. Drive information from the final CPU 32 is input to the spacing motor drive circuit 35 via the I10 boat 34, and the spacing motor drive circuit 35 rotates the spacing motor 36 in a predetermined direction to move the print head 12 onto the carriage shaft 13. Space to the specified position above and stop.

In the printer I described above, when the front cover 14 is opened by the operator, the opening/closing detection section S detects whether the front cover 14 is open or not. That is, the common terminal C and the normally open terminal No are connected.

Therefore, the input signal to the CPU 32 is converted to LOW level. , when the input signal of the JLCPU 32 goes to LOW level, it is sent to the program ROM 33 via the lotus line 31.
The ILcPU 32 moves the I10 boat 34 based on the information from
The spacing motor 36 is rotated by the spacing motor drive circuit 35 in order to space the pad 12 to a predetermined position for printing (for example, to perform a reverse operation).

When the front cover 14 is opened as described above, the print head 1
2 always moves to the predetermined position where the evacuation cover 2 is installed (
spacing) and the operation surface side 1a by the evacuation cover 2.
completely shielded from. Therefore, when the operator opens the front cover 14 to set printing paper or replace the ink ribbon, the presence of the evacuation cover 2 prevents contact with the printing pad 12.

In the above embodiment, the evacuation cover 2 is provided at the left end of the carriage shaft 13, but it may be provided at the center or right end if necessary. In this case, information for spacing and stopping the print head 12 at the center or right end is stored in the program ROM 33.

<Effects of the Invention> As described above, in the print head evacuation/shielding method of the present invention, when the operator opens the front cover, the print head is always shielded from the operation surface side of the printer by the evacuation cover. The operator never touches the print head directly. Therefore, risks such as burns are prevented. Furthermore, since the evacuation cover itself has a highly breathable structure, when the evacuation cover is evacuated from a predetermined position, heat will not be trapped within the evacuation cover, and rather the surface cooling of the print head can be promoted.

Therefore, the next printing process can be performed immediately after the operator completes the work, and it is possible to prevent a decrease in the overall throughput.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing the configuration of the printer, FIG. 2 is a partially omitted perspective view showing a retraction cover, and FIG. 3 is a control circuit diagram of the printer. l...Printer, 12...Print head. 13...Carriage shaft, 14...Front cover 18...Operation surface side, 2...Evacuation cover 3.
...Control circuit, S...Opening/closing detection section. Patent applicant Oki Electric Industry Co., Ltd. Agent Patent attorney Kuninori Funahashi Figure 2

Claims (1)

[Claims] When the front cover is opened, the print head is spaced to a predetermined position on the carriage shaft and stopped at that position, and the evacuation cover provided at the predetermined position prints from the operation surface side of the printer. A method for retracting and shielding a print head of a printer, the method comprising shielding the head.