JPH0546913Y2 - - Google Patents

Description

[Detailed explanation of the idea] (Industrial application field) The present invention relates to print heads.

BACKGROUND OF THE INVENTION Conventionally, in order to prevent wear of the drive arm, printing element, core piece, etc., an oil-impregnated material is provided inside the print head to supply oil to the parts subject to wear.

(Problems to be Solved) According to the above-mentioned prior art, oil is not directly supplied to the portions where the drive arm and the core piece come into contact, making it impossible to effectively prevent wear of the portions. For this reason, there was a risk that the characteristics of the print head would deteriorate.

(Purpose of the invention) The purpose of the invention is to supply oil directly to the contact portion of the drive arm and the core piece to effectively prevent wear.

(Means for Solving the Problems) In order to achieve the above object, a printing head according to the present invention includes a driving arm for driving a printing element, a core piece facing the driving arm, and a core piece wound around the core piece. A drive coil for driving the drive arm, a spacer provided between the drive arm and the core piece, an oil-impregnated material provided inside the core piece, and a hole bored in the spacer. , and a slit extending from the end surface of the oil-impregnated material to the end surface of the core piece.

(Function) Oil is directly supplied from the oil-impregnated material to the contact portions of the drive arm, core piece, and slit due to capillary action in the slit portion.

(Embodiment) Hereinafter, an embodiment in which the present invention is applied to a spring charge type printing head will be described with reference to the drawings.

As shown in FIG. 1, a magnet 3 is provided on the front surface of the core piece 2 around which the drive coil 1 is wound, and a magnet plate 4 that forms a common magnetic path is provided on the front surface of the magnet 3. There is. A yoke plate 5 is provided on the front surface of the magnet plate 4, a leaf spring 6 is provided on the front surface of the yoke plate 5, and a drive arm 7 is fixed to the back surface of the leaf spring 6. A printing element 8 is fixed to the tip. A support plate 9 is provided on the front surface of the leaf spring 6, and a wire frame 10 is provided on the front surface of the support plate 9. The support plate 9 supports the outer end of the leaf spring 6 via the yoke plate 5, and the leaf spring 6 is swingable about the outer end.

A guide member 11 that guides the printing element 8 is provided at the tip of the wire frame 10.

An oil-impregnated material 12 such as felt is provided in the central concave portion of the core piece 2, and a thermistor frame 13 is provided on the back surface of the oil-impregnated material 12. A thermistor 14 for detecting the temperature of the drive coil 1 is held by the thermistor frame 13 .

Further, a yoke film 15 as an example of a spacer is provided between the iron core 2a of the core piece 2 and the drive arm 7, and its outer end is held between the magnet plate 4 and the yoke plate 5. There is. Yoke film 15 is provided to improve the magnetic performance of the print head.

Further, as shown in FIG. 2, a slit 15a is formed from a portion of the yoke film 15 facing the end surface of the oil-impregnated material 12 to a portion facing the end surface of the iron core 2a.

As shown in FIG. 1, a flexible cable 16 is provided on the back side of the core piece 2 for connecting the print head to a control circuit (not shown), and a flexible cable 16 is provided at the end of the drive coil 1 (not shown). ) and the lead wire 17 of the thermistor 14 are connected.

Next, the effect will be explained. As shown in the first figure, during non-printing, the drive arm 7 is attracted to the iron core 2a via the magnetic flux of the magnet 3 as shown in 7a in the figure, and the leaf spring 6 resists its own elastic force as shown in 6a in the figure. and the printing element 8 is also in the retracted position as shown at 8a in the figure.

Next, when printing, the drive coil 1 is energized,
The magnetic flux of the magnet 3 is canceled out, thereby releasing the magnetic attraction of the drive arm 7 to the iron core 2a. Then, the leaf spring 6 moves forward by its own elastic force as shown in 6b of the figure, and the printing element 8 moves forward as shown in 8b of the figure.
A dot is formed on a printing medium (not shown).

Oil is directly supplied from the oil-impregnated material 12 to the contact portions of the drive arm 7, the iron core 2a, and the yoke film 15 by capillary action caused by the slits 15a. Therefore, wear of the above-mentioned portions is effectively prevented, and deterioration of the print head characteristics can be prevented.

The thermistor 14 also detects the temperature of the drive coil 1 via the thermistor frame 13, and is useful for controlling the temperature of the print head.

Note that the printing method of the print head is not limited to this embodiment, and the present invention can also be applied to, for example, a clapper-type print head that does not use a permanent magnet. Further, the outer end of the yoke film 15 does not need to be held between the magnet plate 4 and the yoke plate 5, and the yoke film 15 may be installed within the print head by other methods.

Also, the oil impregnant 12 may be provided at other locations within the print head.

(Effects) According to the present invention, since oil is supplied using capillary phenomenon, the oil supply is stable over a long period of time, and wear of the parts in contact with the drive arm, core piece, and slit is reduced. This prevents deterioration of print head characteristics.

[Brief explanation of the drawing]

The drawings show an embodiment of the printing head according to the present invention, with FIG. 1 being a sectional view and FIG. 2 being a perspective view of the main parts. DESCRIPTION OF SYMBOLS 1... Drive coil, 2... Core piece, 7... Drive arm, 8... Printing element, 12... Oil-impregnated material, 15... Spacer (yoke film), 15
a...slit.

Claims (1)

[Claims for Utility Model Registration] A drive arm that drives a printing element; a core piece that faces the drive arm; a drive coil that is wound around the core piece and drives the drive arm; a spacer provided between the core piece; an oil-impregnated material provided inside the core piece; and a hole formed in the spacer that extends from the end face of the oil-impregnated material to the end face of the core piece. A printing head characterized by comprising a slit.