JP2524261Y2 - Head gap adjustment mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a mechanism for adjusting a head gap between a print head and a platen in a serial printer, and particularly to a mechanism for adjusting a head gap by manual operation of a lever.

<Related Art> A serial printer that performs printing by moving a print head along a platen is provided with a mechanism that adjusts a gap between the print head and the platen, that is, a head gap according to the thickness of a print medium. The head gap adjusting mechanism includes a means for adjusting the gap and a means for detecting the adjusted gap. The gap detecting means transmits the adjusted gap to the control system, and adjusts printing energy and printing speed according to the thickness of the medium. As the gap adjusting means, there is a means for operating a lever, and as the gap detecting means, there is a means for detecting the movement of a lever (for example, Japanese Patent Laid-Open No. 61-237669).

FIG. 7 is a schematic perspective view of a conventional serial printer having such a head gap adjusting mechanism, and FIG. 8 is a schematic side view of the same.

As shown in the drawing, a print head 52 facing the platen 51 is mounted on a carriage 53, and the carriage 53 is slidably mounted on a carriage shaft 54 parallel to the rotation axis of the platen 51. The print head 52 is moved along the platen 51 by moving the carriage 53 by a drive mechanism (not shown), and printing is performed on the medium P via the ribbon 55.

Both ends of the carriage shaft 54 are loosely inserted into a horizontally long hole 57 that is formed facing the left and right side frames 56,
Moreover, the right and left springs 58 urge the platen 51 toward the platen 51. Eccentric cams 59 are fixed to both ends of the carriage shaft 54. Each eccentric cam 59 is pressed against a limiter 60 formed by cutting and raising the left and right side frames 56 by the tensile force of the spring 58. A substantially L-shaped adjustment lever 61 (hereinafter, simply referred to as a lever 61) is fixed to one end of the carriage shaft 54.
By operating the lever 61 to rotate the carriage shaft 54, the eccentric cam 59 causes the carriage shaft 54 to rotate.
Moves in the horizontal hole 57 and the print head 52
Approaches and separates from 51. As a result, the head gap g
Can be adjusted.

A projection 62 is formed on an upper portion of the lever 61 toward the side frame 56, and the projection 62 fits into one of a plurality of square holes 63 formed in the side frame 56. Thus, the head gap g can be selectively changed and held. Also, at the end of the lever 61 opposite to the protrusion 62,
A substantially horizontal tongue piece 61a is formed.

On the other hand, on the side frame 56 on the same side as the lever 61,
A gap sensor 62 using a micro switch or the like is fixed. At the upper end of the gap sensor 64, an action portion 64a that is pressed by the tongue piece 61a of the lever 61 protrudes. In the case of this conventional example, the gap sensor 64 is turned on when the lever 61 is moved to a position where the head gap g is maximized, as shown in the operation explanatory view of FIG. I have. That is, the gap sensor 64
Is turned on / off, it is detected that the head gap g is set to the maximum. An on / off signal from the gap sensor 64 is transmitted to a control system (not shown) via a connector 66 via a lead wire 65.

<Problem to be Solved by the Invention> However, in the head gap adjusting mechanism having the above configuration, in order to detect the movement of the lever 61, a gap sensor 64 using a microswitch, a photo interrupter, a Hall element, or the like is used.
It is necessary to provide
66 is required. That is, there are drawbacks that the number of parts is large, the cost is high, and the workability of assembly is poor.

<Means for Solving the Problems> The present invention has been devised to eliminate the above-mentioned disadvantages. The head gap adjusting mechanism according to the present invention moves a print head mounted on a carriage along a platen to perform printing. An adjustment lever for adjusting the head gap between the print head and the platen and means for detecting the movement of the adjustment lever to detect the head gap are provided on the carriage, and the print head is provided on the carriage. In a head gap detection mechanism having a substrate on which a control signal line for transmitting a control signal and a power supply line for supplying power to a print head are formed, a plurality of fixed electrical contacts are formed as a wiring layer on the substrate, and the carriage is The fixed electric contacts selectively contact with the plurality of fixed electric contacts as the adjust lever moves. A movable electric contact that conducts between the contacts is attached, and a power supply cable that integrates a wiring from the movable electric contact and a wiring to the control signal line and the power supply line is connected to the substrate. I have.

The power supply cable is a flexible printed circuit board, and the plurality of fixed electrical contacts are formed as a wiring layer on the flexible printed circuit board.

<Operation> In the above configuration, the fixed electric contact and the movable electric contact function as switches, and the head gap is detected based on the on / off of the adjustment lever by the movement.

<Example> Hereinafter, an example of the present invention is described based on a drawing.

FIG. 1 is a schematic side view of a serial printer having a head gap adjusting mechanism according to the present invention, and FIG. 2 is an exploded perspective view of a carriage with a part omitted.

As shown in the figure, a print head 2 facing a platen 1 is mounted on a carriage 3, and the carriage 3 is slidably mounted on a carriage shaft 4 parallel to the rotation axis of the platen 1. The carriage 3 is self-propelled and has a motor 5 mounted thereon. A pinion 6 is attached to a shaft extending downward from the motor 5, and the pinion 6 is engaged with a rack 7 fixed in parallel with the carriage shaft 4.

On the motor substrate 8 of the motor 5, a lower holder 9 and a cartridge receiving base 10 are mounted in a stacked state, and a ribbon cartridge 11 is mounted on the cartridge receiving base 10. A flexible power supply cable 12 for supplying power to the motor 5 and the print head 2 and transmitting control signals is connected to the motor board 8.

In the above configuration, by driving the motor 5, the carriage 3 moves by itself and the print head 2 moves along the platen 1 to perform printing.

Further, the carriage 3 is provided with the head gap adjusting mechanism of the present invention. The gap adjusting means in this mechanism is operated by lever operation, and an adjusting lever 13 (hereinafter simply referred to as a lever 13) for that is mounted between the lower holder 9 and the cartridge receiving table 10.

As shown in the exploded perspective views of the main parts in FIGS. 1, 2 and 3, the lever 13 has a plate-shaped rotating portion 13a having a tip protruding outside the lower holder 9 and the cartridge receiving base 10. A grip 13b vertically fixed to the tip of the rotating portion 13a. The base of the rotating portion 13a is rotatably attached to a support shaft 14 protruding from the lower holder 9. Have been. Rotating part 13a
A gear portion 13c is formed at the base of the.

On the other hand, an adjusting screw 15 is vertically screwed to an end of the motor substrate 8 opposite to the carriage shaft 4 with the substrate 8 penetrating therethrough. The lower end of the adjusting screw 15 is in contact with a support 16 fixed in parallel with the carriage shaft 4.
By rotating the carriage 15, the carriage 3 rotates around the carriage shaft 4, and the size of the head gap G changes. An adjusting gear 17 is fixed to an upper end of the adjusting screw 15.

The gear portion 13c of the lever 13 and the adjustment gear 1
7 is connected to the lower holder 9 via two idle gears 18 and 19 supported on the lower holder 9. Therefore, by rotating the lever 13, the adjusting screw 15 can be rotated to adjust the head gap G. In this embodiment, the head gap G is widened when the lever 13 is rotated counterclockwise.

The grip 13b of the lever 13 can be engaged with any one of the plurality of cutouts 20 formed on the side of the cartridge cradle 10, so that the head gap G can be selectively changed and held. .

The carriage 3 is provided with a contact 23, which is a movable electric contact, as means for detecting the rotation of the lever 13 and detecting the size of the gap G.

On the motor board 8, two conductive pads 21 and 22, which are fixed electric contacts, are adhered and connected to a control system (not shown) via a power supply cable 12. That is, the wiring connecting the gap detection means and the control system can be integrated with the power supply cable 12.

The contact 23 is formed by bending a single elastic wire into a hairpin shape and applying gold plating in order to enhance conductivity, and includes two substantially parallel linear portions 23a and 23.
Contact portions 23c and 23d are formed downward at each end of b, and the straight portion 23b on the side where one of the contact portions 23d is formed is bent substantially in a letter shape so as to project upward. Pressed portion 23e is formed. And this contact 23
As shown in a perspective view from below in FIG.
Are fastened to three fastening portions 9a, 9b, 9c formed on the back surface of the. In addition, the pressing portion 23e of the contact 23 protrudes above the lower holder 9 from a long hole 9d formed in the lower holder 9.

Pads 21 and 22 and contacts 23 mounted as described above
As shown in the operation explanatory view of FIG. 5, normally, one contact portion 23c of the contact 23 is in contact with the corresponding one pad 21, and the other contact portion 23d is normally in the corresponding other pad 21. In a state away from 22. That is, the two pads 21 and 22 are electrically disconnected.

When the lever 13 is fully rotated counterclockwise to maximize the head gap G, the rotating portion of the lever 13
13a presses down the pressing portion 23e of the contact 23, and the contact portion 23d of the contact 23 contacts the corresponding pad 22. As a result, the two pads 21 and 22 are electrically connected.

As described above, the pads 21 and 22 and the contact 23 function as a switch that is turned on when the head gap G is maximum, and the head gap G is detected based on the on / off state. This on / off signal is transmitted to the control system through the power supply cable 12.

The shape and the mounting method of the pads 21 and 22 with the contacts 23 are not limited to the present embodiment. For example, as shown in the exploded perspective view of FIG. You may comprise so that it may do. Thereby, the structure can be further simplified.

Further, if the number of pads and the number of contact portions and pressing portions of the contacts are increased, the rotation of the lever 13 can be detected stepwise, and the head gap G can be detected more finely.

The carriage having the head gap adjusting mechanism of the present invention may be of a type that is not self-propelled, that is, a type that does not have a driving mechanism.

<Effects of the Invention> As described above, according to the head gap detection mechanism of the present invention, a control signal line for transmitting a control signal to the print head provided on the carriage and a power supply line for supplying power to the print head are formed. A plurality of fixed electrical contacts are formed as a wiring layer on a substrate, and the carriage is provided with movable electrical contacts for selectively making contact with the plurality of fixed electrical contacts and moving between the fixed electrical contacts as the adjustment lever moves. Since the wiring from the movable electrical contact and the power supply cable integrating the control signal line and the wiring to the power supply line are connected to the substrate, a lead wire for a head gap detection mechanism and a dedicated connector are provided. And other parts are not required. In addition, the head gap detecting means is formed as a wiring layer on the substrate, and has a simple configuration of a plurality of fixed electrical contacts and movable electrical contacts passing between the fixed electrical contacts. Compared with the conventional head gap detecting mechanism used, the cost is reduced, the workability of assembly is improved, and the reliability as the head gap detecting mechanism is also improved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic side view of a serial printer provided with a head gap adjusting mechanism according to the present invention, FIG. 2 is an exploded perspective view partially omitted in the embodiment, FIG. FIG. 4 is an exploded perspective view of a main part of the embodiment, FIG. 4 is a perspective view of the embodiment viewed from below, FIG. 5 is an operation explanatory view of the embodiment, and FIG. 6 is an exploded perspective view of another embodiment. FIG. 7 is a schematic perspective view of a serial printer having a conventional head gap adjusting mechanism, FIG. 8 is a schematic side view of the same, and FIG. 9 is an operation explanatory view in a conventional example. 2… Print head, 3… Carriage, 13… Adjust lever,
21,22… Pad (fixed electrical contact), 23… Contact (movable electrical contact), G… Head gap.

Claims (2)

(57) [Scope of request for utility model registration] An adjusting lever for adjusting a head gap between the print head and the platen, and detecting movement of the adjust lever. The serial printer performs printing by moving a print head mounted on a carriage along a platen. A head gap detecting means for detecting a head gap by mounting a control signal line for transmitting a control signal to the print head and a power supply line for supplying power to the print head on the carriage. In the mechanism, a plurality of fixed electrical contacts are formed as a wiring layer on the substrate, and the carriage is selectively contacted with the plurality of fixed electrical contacts with movement of the adjustment lever to conduct between the fixed electrical contacts. A movable electrical contact is attached, and the wiring from the movable electrical contact and the control Route and head gap detection mechanism, characterized in that connecting the feeder cable integrating the wiring to the power supply line. 2. The head according to claim 1, wherein the power supply cable is formed of a flexible printed circuit board, and the plurality of fixed electrical contacts are formed as a wiring layer on the flexible printed circuit board. Gap detection mechanism.