JPH026150A - Impact type dot matrix printer - Google Patents

Abstract

PURPOSE:To detect the life of a printing head, and to determine the life of the printing head and the time of the exchange of the printing head by mounting a life detector counting the number of printing signals indicating the application of currents to a coil in an impact type dot matrix printer. CONSTITUTION:When a printing signal is output from a printing-signal output circuit 1 and input to a printing driver circuit 2, the printing driver circuit 2 applies voltage to a coil 3 corresponding to a printing wire to be operated, thus driving the printing wire, then conducting printing. A life detector 4 is connected in parallel with the printing driver circuit 2, and counts a printing signal corresponding to the printing wire to be operated. When the number of the transmission of the printing signal reaches the number set to the life detector 4, the life detector 4 detects the number of the transmission, and outputs a signal to a printing-head life control circuit 5. Driving pulses applied to a printing head are controlled in response to the output of the signal or printing is stopped and the life of the printing head is transmitted.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an impact dot matrix printer that prints by selectively impacting a recording medium with a print wire.

[Conventional technology]

This type of printing device excites a plurality of electromagnetic actuators provided in the print head in response to a print signal.
Printing is performed by moving the print wire and causing the tip of the print wire to collide with the paper.

[Problem to be solved by the invention]

The above-described conventional impact dot matrix printer has the disadvantage that even when the print head reaches the end of its lifespan due to abrasion of the tip of the print wire due to printing, it is difficult to know when to replace the print head. For this reason, printing defects (
It was only when the print head became unusable (faded print, missing dots) that it became clear that the print head was no longer usable. In other words, there was no way to check whether the print head had reached the end of its lifespan as stated in the manual. Furthermore, there is a possibility that the print head may continue to be used even though it has reached the end of its lifespan and must be replaced. Additionally, in this type of print head, the print wire tip is subjected to heavy use and wears out. Eliminating this wear is impossible due to the structure of this type of print head. Furthermore, as the tip of the print wire becomes worn, the printing pressure increases, and as the printing pressure increases, the wear of the print wire progresses at an even faster rate.

The main cause of print head life is wear at the print wire tip. The wear on the tip of the print wire varies depending on how frequently the print wire is used, and this difference leads to printing defects and shortens the life of the head. conventionally,
Attempts have been made to extend the life of the print head by using a high-cost material that is resistant to wear for the print head drive system (particularly the print wire).

[Means to solve the problem]

The impact type dot matrix printer of the present invention detects the lifespan of the print head by having a lifespan detection circuit that counts the number of print signals that instruct the application of current to the coil.

〔Example〕

Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing one embodiment of the present invention.

The print driver circuit 2 and the life detection circuit are connected in parallel to the print signal output circuit 1. Coil 3 is connected to print driver circuit 2. Although the number of coils 3 is equal to the number of printed wires to be driven, only one is shown in the figure and the others are omitted. The print head life control circuit 5 is connected to the life detection circuit 4.

In such a configuration, when a print signal is output from the print signal output circuit l and inputted to the print driver circuit 2, the print driver circuit 2 applies voltage to the coil 3 corresponding to the print wire to be operated. The print wire is driven and printing is performed. The life detection circuit 4 is connected in parallel with the print driver circuit 2, and counts print signals corresponding to the print wire to be operated. When the number of times the print signal is sent reaches the number set in the life detection circuit 4, the life detection circuit 4 detects this and outputs a signal to the print head life control circuit 5. In response, it controls the drive pulses applied to the print head or stops printing to signal the end of the print head's lifespan.

In this way, if the print head is capable of printing, optimal drive pulse control is performed to maintain the same printing pressure regardless of the number of printings. Therefore, the life of the print head can be extended, and a constant print quality can be maintained. Furthermore, this drive pulse control can also reduce the cost of components of the drive system of the print head, making it possible to manufacture the print head at low cost. Since the lifespan of the print head can be known, maintenance of the printer becomes easier.

〔Effect of the invention〕

As explained above, in the present invention, by counting the number of times a print signal is sent for each dot, it is possible to know the lifespan of the print head and the timing of replacement.

1... Print signal output circuit, 2... Print driver circuit, 3... Coil, 4...
Life detection circuit, 5...Print head life control circuit.

Claims (1)

[Claims] An impact type dot matrix printer equipped with a print head having a plurality of electromagnetic actuators constituted by a yoke, an armature, and a coil, including a life detection circuit that counts the number of print signals indicating the application of current to the coil. Impact type dot matrix printer with special features.