JPS61127372A - Height regulating mechanism for printing head - Google Patents

Abstract

PURPOSE:To enhance the quality of printing by adjusting the heightwise position of a printing head by providing the first recessed coupler and the second projected coupler to be positioned on the rotary shaft side of bracket from the first coupler to the printing head. CONSTITUTION:When a regulating screw 111 is turned toward one-way direction, a lever 107 is moved toward one-way direction in a rocking manner. A stopper plate 109 supported on the lever 107 is moved in the heightwise direction of a printing head. The height of the head 31 whose first coupler 102 is connected with the plate 109 is adjusted with the movement of the plate 109. In this case, an elastic part 106 serving to push the head 31 downwards in the heightwise direction exactly positions the head 31 by preventing the occurrence of clearance in the couplement between the plate 109 and the coupler 102. Since the head 31 can be adjusted only by operating the screw 111, the operations can be made much easier.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a printing device having two or more print heads, and particularly to a method for eliminating irregularities in the arrangement of characters in the print height direction caused by each print head. This article relates to a print head height adjustment mechanism that can be used.

For example, in a serial thermal transfer printer, the print head is attached to a rotatable support member, and the rotation of the support member positions the print head in a printing position where it comes into pressure contact with a jig grating and a retracted position where it is retracted from the platen. It is now possible to do so. When performing color printing in multiple colors, multiple ribbon cassettes containing film ribbons of different colors are placed adjacent to each other along the platen, and multiple prints corresponding to the adjacent ribbon cassettes are printed. A configuration in which a head is provided is adopted.

In this case, it is necessary to take measures to eliminate irregularities in the arrangement of characters in the print height direction caused by adjacent print heads.

[Conventional technology]

The conventional method for adjusting the character arrangement for this purpose is shown in FIGS. 8 and 9.

In the case of FIG. 8, the support member 31 and print head 32 are
The height of the print head 32 can be adjusted by connecting a fixing screw with a spacer in between, selecting the spacer blades, and using one with a thickness that matches the misalignment of the letters. This eliminates misalignment.

The support member 31 rotates clockwise and counterclockwise in the figure with the support shaft A as a fulcrum, and positions the print head 32 at the illustrated printing position where it is pressed against the platen and at the retreat position where it is evacuated from the platen audience.

In the case of FIG. 9, the height of the print head is adjusted using the adjustment screw 37, and the print head is fixed to the support member 40 using the fixing screw 39. A spring 41 is inserted between the springs, and the threaded portion at the tip of the adjusting screw 37 is screwed into the support portion cutout. When adjusting the height of the print head, loosen the fixing screw 39 and make adjustments by rotating the adjusting screw 37 in the forward and reverse directions. In this case, the adjustment screw moves back and forth, and the print head, which is biased by the spring 41, follows this movement and moves up and down to perform adjustment. Fixing screw 39
Tighten after completing the adjustment.

[Problem that the invention seeks to solve]

However, such a conventional mechanism has the following drawbacks.

That is, in the case of FIG. 8, it is necessary to select the spacers to match the amount of deviation, and it is also necessary to attach and detach the fixing screws, which is a cumbersome operation. In addition, in the case of Fig. 9, it is necessary to operate both the adjustment screw and the fixing screw), which makes the work cumbersome.

[Means for solving problems]

An object of the present invention is to provide a print head height adjustment mechanism capable of solving the above-mentioned problems. In a printing device having two or more print heads positioned at a print position and a retracted position, the print head has a concave first engagement part, and the first engagement part is connected to a rotating shaft of the bracket. The second protruding part located on the side
an engaging portion is provided, and the supporting member is configured to swingably support a lever that rotatably supports a stopper plate that engages with the first engaging portion, and between the lever and the supporting member. is provided with a spring and an adjustment screw that compresses the spring to connect the lever and the support member in an adjustable manner; When the print head is attached to the support by engaging the first engaging parts with the support member, the print head is biased in one direction to press the first engaging part against the stopper plate. A structure including an elastic member is adopted.

[For production]

When the adjustment screw is rotated in one direction, the lever swings in one direction, and the stopper plate supported by the lever moves in one direction in the height direction of the print head. Therefore, the height of the print head in which the stopper plate is engaged with the first engaging portion is adjusted in accordance with the movement of the stopper plate. In this case, the elastic member that urges the print head downward in its height direction reliably positions the print head so that there is no play in the engagement between the stopper plate and the first engaging portion. play a role.

In this way, the print head can be adjusted simply by operating the adjustment screw, making the work extremely easy.

〔Example〕

The present invention will now be described in detail with reference to FIGS. 1 to 7.

FIG. 1 is an exploded perspective view showing details of the print head height adjustment mechanism according to the present invention, and FIG. 2 is a side view showing the assembled state.
FIG. 3 is a plan view showing the main parts of a serial thermal transfer printer to which the present invention is applied, FIG. 4 is a side view of the same, FIG. 5 is a side view showing the 7-bon shift mechanism of this printer, and FIG. 6 is a plan view of the same. , FIG. 7 is an explanatory diagram of the action of the same leaf spring.

In Fig. 3.4, 1 is a carrier frame, 2 is a ribbon frame, 31.3 is a print head, and 4 is a JJ Bon cassette.

The carrier frame 1 has a guide portion 6.7 (see FIG. 4) guided by a guide shaft (not shown) along the platen 5, and is movable along the platen 5.

The ribbon frame 2 is supported by the carrier frame 1 so as to be able to move up and down. $8 allows it to be positioned at a predetermined position in the vertical direction. As shown in detail in FIGS. 5 and 6, the ribbon shift mechanism 8 includes a pair of link-like members 10 that are swingably supported on a carrier frame l as a fulcrum on a shaft 9t, and a link member 10 that is attached to the carrier frame 1. The shift motor 11
It consists of a shift cam that is driven via a drive system such as a gear wheel. The link-like member 10 is constructed by overlapping a first shift link 13 and a second shift link 14 which is longer than the shift link 13 with their bases aligned, and at the opposite positions of the shift links 13 and 14, respectively. In the formed hole 15, there is a hole 7, which is a cross-sectional view taken along arrows ■-■ in FIG.
As shown in Figure (a), both shift links 13 and 14
A U-shaped leaf spring 16 is attached to elastically lock the relative movement in the swinging direction. Shift link 13 includes a first pin 17 and shift link 14 includes a second pin 18. The pin 17 penetrates the shift link 14 (allowing relative movement in the swinging direction of both links 13 and 14, which will be described later), and inserts into the cam groove 121 of the shift cam n.
The pin 18 is engaged with a retaining groove 2a provided in the ribbon frame 2.

Now, when the shift motor 11 is rotated by a predetermined amount in a predetermined direction from the state shown in FIG. 4.5, the shift cam ν is rotated by a predetermined amount in the counterclockwise direction as shown in FIG.
The shift link L, which is engaged with L through the pin 17, swings a predetermined amount in the counterclockwise direction in FIG.

Accordingly, the shift link 14 that engages with the shift link 13 via the leaf spring 16 also swings in the same direction, and the ribbon frame 2 that engages with the shift link 14 via the pin 18 moves upward. Then, at the end of the rotation of the shift cam n, the projecting piece 2b of the ribbon frame 2 is positioned to be locked to the locking part 19a of the stopper 19 provided on the carrier frame 1, and mounted on the ribbon frame z in two stages facing each other. Each has a different color (Y, M.

The lower two ribbon cassettes 4 of the four ribbon cassettes containing ribbons C, BL) are positioned at the printing position. After that, the shift force unevenness rotates a little further and stops, but during this time, the shift IJ link 14 continues compressing the plate spring 16 until the shift link ratio stops until t, as shown in FIG. 7(b). oscillate. That is, the rotation of the shift cam minor during this period is absorbed by the relative movement of the two shift links 13 and 14, but this is due to the fact that the pin 17 has a larger diameter than the pin 17 through the pin 17 through hole of the shift link 14, as described above. This is possible because it has a space of 9.

When positioning the two upper ribbon cassettes 4 to the printing position, the shift cam L is rotated by the same amount in the opposite direction to that described above. In this case, at the end of the rotation of the shift cam base, the protrusion 2b is engaged with the engagement portion 19b of the stopper 19, and the upper ribbon cassette 4 is positioned at the printing position. After that, only the shift link 13 swings as the shift cam rotates. Figure 4.5 shows the state immediately before the completion of this operation.

In this way, the cam stroke of the shift cam L is determined to be S+α with respect to the shift stroke S of the ribbon frame 2, and this α is released to the leaf spring 16, and the ribbon frame 2 is moved to the locking portion 19a of the stopper 19. , 19b
Since the ribbon cassette is positioned by being locked by the ribbon cassette, it is possible to secure the shift amount accurately and position the ribbon cassette at the printing position.

Two print heads 31,3. are rotatably supported by the carrier frame 1 via shafts 20 (the manner of support will be described in detail later). One print head 31 corresponds to the two upper and lower ribbon cassettes 4 on one side, and the other print head 31 corresponds to the other two upper and lower ribbon cassettes 4. The print head 31 prints when the carrier frame 1 moves in the direction of the arrow A in FIG. A ribbon of a certain color is passed through the printing paper (not shown) to the platen 5.
Printing is performed in this state. Although detailed illustrations are omitted, printing is performed by energizing a predetermined heating element at a predetermined time among a plurality of heating elements provided on the surface of the print head 31 facing the platen 5. The ribbon contained in the ribbon cassette 4 facing this printing position remains in contact with the printing paper when the carrier frame 1 moves in the direction of the arrow, so that there is no slippage between the ribbon and the printing paper. It has become. That is, during this movement of the carrier 1, the ribbon is paid out from the payout side reel of the ribbon cassette 4 at the same speed as the moving speed of the carrier frame 1, and is wound onto the take-up side reel without slack. Although detailed illustration is omitted, this ribbon feeding is performed in conjunction with the movement of the carrier frame in the direction indicated by the arrow. The ribbon is fed out in this way only in the ribbon cassette used for printing (the one facing the platen 5).
This is not done with other ribbon cassettes. Print head 3! When the carrier frame 1 moves in the direction of arrow A', printing is performed using a ribbon of a certain color contained in the ribbon cassette 4 positioned at the printing position of the two ribbon cassettes corresponding to the print head 32. conduct. The printing procedure in this case is the same as described above, the print head 31 is retracted from the platen 5, and the ribbon is not fed out from the ribbon cassette 4 corresponding to the print head 31. By performing printing during each reciprocating movement of the carrier frame 1, it is possible to improve the efficiency and speed of the printing operation.

During these printing processes, the shifting of the ribbon cassette (the operation of positioning the ribbon cassette containing ribbon of a desired color to the printing position by the ribbon shift mechanism 8) is performed as needed in the manner described above.

During this printing, it is necessary to detect the ribbon end of each ribbon cassette and replace the cassette. Therefore, each ribbon cassette 4 is provided with an opening 21 (see FIG. 4) for detecting the ribbon end. Pair of reflective sensors 22
1.22! is provided.

The sensors 221.22z are attached to the gear rear frame 1 via brackets.
faces the opening 21 of the ribbon cassette 4 which has been shifted to the printing position in the ribbon cassette 4 corresponding to the print head 31, and the sensor 22m has been shifted to the printing position in the ribbon cassette 4 corresponding to the print head 3z. It faces the opening 21 of the ribbon cassette 4. In this way, since the sensors 22x and 2h are facing the opening 21 of the ribbon cassette 4 that has been shifted to the printing position,
The end of the ribbon used at the i printing position (the silver tape attached to the end of the ribbon) can be detected.

In this case, the ribbon end of the ribbon cassette that is not used for printing is not detected (because it is not fed), but it will be detected when the ribbon cassette is used for printing.

As a means for solving the problem of character alignment in the print height direction caused by adjacent print heads of a printer having such a configuration 1 effect, the present invention employs a print head height adjustment mechanism shown in FIGS. 1 and 2. ing.

Next, the second structure and operation of this mechanism will be explained.

FIG. 1 is an exploded perspective view of the print head height adjustment mechanism;
As shown in FIG. 2, which is a side view showing the assembled state, the print head 31 is detachably attached to a support member 101 rotatably supported by the shaft 20 and its position in the height direction can be adjusted. It has become.

The print head 31 includes a concave first engaging portion 102, a protruding second engaging portion 103 (located below the engaging portion 102), and a square hole 104. .

The support member 101 includes an engagement piece 105 for engaging the engagement portion 103.
and a cantilevered leaf spring (elastic member) 106 for pressing the attached print head 31 downward.

Further, the support member 101 rotatably supports a lever 107 via a pin 10g, and the lever 107 rotatably supports a stopper plate 109. A spring 110 is inserted between one end of the lever 107 and the support member 101, and an adjustment screw 111 is provided. The spring 110 urges one end of the harepah 107 and the support member 101 in a direction to separate them from each other, and the adjustment screw 11
The threaded part 112 (see Fig. 2) at the tip of the lever 107
It is screwed onto one end of the .

The print head 31 is attached to the support member 101 in the following steps. That is, when attaching the print head 31, the cantilevered leaf spring 106 is lifted up by the lower wall surface of the square hole 104 while the second engaging portion 103 is attached to the engaging piece 105.
This is done by engaging the first engaging portion 102 with the upper end of the stopper plate 109. In this state, one end of the lever 107 and the support member 101
The interval is maintained by the biasing force of the spring 110, and the leaf spring 106 biases the print head 31 downward, so that the print head 31 stops on the upper end surface of the stopper plate 109 and is reliably positioned.

When it is desired to move the print head 31 downward, the adjustment screw 111 is rotated in one direction by a predetermined amount. This),
One end of the lever 107 with which the threaded part is engaged is the spring 1.
The stopper grating 109 rises against the urging force of 10 and descends by a predetermined amount. Therefore, the print head 31, which is urged downward by the plate spring 10B, is moved by the stopper plate 109.
It also descends by a predetermined amount.

Print head 3! When moving the
11 may be rotated in the opposite direction to that described above. In this way, the position in the height direction in the printing direction can be adjusted by simply rotating the adjustment screw 111.

Note that when printing is performed using the print head 31 positioned in this manner, the print head 31 comes into pressure contact with the platen, so the engaging portion 103 comes into pressure contact with the engagement piece 105 to ensure positioning. Ru.

The print head 31 can be easily removed by disengaging each engaging portion from the other side while elastically deforming the plate spring 106 upward.

The print head height adjustment mechanism having the above configuration 1 effect may be provided not only for the print head 31 but also for the third print head.

〔Effect of the invention〕

As described above, according to the present invention, since the position of the print head in the height direction can be adjusted, it is possible to prevent irregularities in the arrangement of characters in the print height direction due to a plurality of adjacent print heads. It is possible to improve print quality by eliminating
Moreover, the adjustment work is easy.

[Brief explanation of drawings]

1 to 7 show embodiments of the present invention.
The figure is an exploded perspective view of the print head height adjustment mechanism, FIG. 2 is a side view showing the assembled state, FIG. 3 is a plan view showing the main parts of a serial thermal transfer printer to which the present invention is applied, and FIG. 5 is a side view showing the ribbon shift mechanism of this printer, FIG. 6 is a plan view thereof, and FIGS. 7(a) and 7(b) are illustrations of the action of the leaf spring. FIGS. 8 and 9 are explanatory diagrams of conventional character arrangement adjustment procedures. In the figure, 31.3g is the print head, 5 is the platen, 101
102 is a concave first engaging portion, 103 is a protruding second engaging portion, 105 is an engaging piece, and 106 is a leaf spring (
107 is a lever, 108 is a pin, 109 is a stopper gray), 110 is a spring, 111 is an adjustment screw, and 112 is a threaded portion.

Claims (1)

[Claims] In a printing device having two or more print heads that are attached to a support member and are positioned at a print position and a retracted position by rotation of the support member, the print head includes a concave first engagement portion and the first recessed engagement portion. a protruding second engaging part located closer to the rotating shaft of the bracket than the first engaging part, and a stopper plate that engages with the first engaging part is rotatably attached to the support member. A lever supported by the lever is swingably supported, and a spring and an adjustment screw are provided between the lever and the support member to compress the spring and connect the lever and the support member so that the distance between the lever and the support member can be adjusted; Furthermore, when the print head is attached to the support member by engaging the first engagement portion with the stopper plate and the second engagement portion with the support member, the print head 1. A height adjustment mechanism for a print head, comprising: an elastic member that presses the first engaging portion in one direction to press the first engaging portion against the stopper plate.