JPH03166964A - Positioner for printing head of printer - Google Patents

Abstract

PURPOSE:To enable a printing head to be aligned accurately to a platen roller by preventing printing irregularity from occurring by a method wherein the printing head is free adjustably in position borne with a printing head stand, an engaging means is provided to the printing head side, and a positional adjusting guide which can be free engaged with an engaging means is provided to the platen roller side. CONSTITUTION:A printing head 48 is free movably in a vertical direction and free movably in front and in rear, and its longitudinal axial line is free inclinably supported with a printing head stand. When a cover 6 is made to descent centering a rotary axle 4, fitting accessed parts of positional adjusting guides 20, 22 are fitted to engaging means 54 on the printing head 48 side, and a position to a platen roller 16 of the printing head 48 is forcedly adjusted. This positional adjustment is performed by regulation force of the positional adjusting guides 20, 22 and further, the cover 6 is deterred at a specified descending position. At that time, all area of a printing part 48a of the printing head 48 is stuck fast parallel to a surface of the platen roller 16 by specified pressure with a inclination operation. Then, recording paper 26 is sent between the platen roller 16 and the printing head 48, and recording is performed with the printing head 48.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a print head positioning device in a printer. [Prior Art] This type of printer has a print head disposed on the substrate side of the main body, a platen roller on the swing force bar side, and the swing force bar swings in a direction to close the top of the print head. The platen roller is pressed against the print head, and the recording paper is fed between the print head and the platen roller, and the print head generates heat according to the recorded image to perform recording. [Problems to be Solved by the Invention] The print head and the platen roller are aligned with high precision during assembly. Therefore, high precision is required during assembly to position the print head and platen roller, making assembly work difficult. If the rocking force bar is rocked in the opening/closing direction for a long time, the positional relationship between the platen roller and the printing roller is shifted, resulting in an error, which causes uneven printing. The present invention aims to eliminate the above-mentioned defects.

[Means to solve problems]

In order to achieve the above object, the present invention includes a platen roller supported by a cover that can freely swing around a rotation axis, and which presses the platen roller against a print head disposed on a substrate of a main body by swinging the cover downward. In a printer that performs recording on the recording paper by pressing the conveyed recording paper and the ink ribbon between the print head and the platen roller that generate heat according to the recorded image, a print head stand is fixed to the substrate, A print head is supported on the print head stand so that its position can be freely adjusted, an engaging means is provided on the print head side, and a position adjustment guide that can be freely engaged with the engaging means is provided on the platen roller side.

[Effect]

When the cover is swung toward the print head and the platen roller approaches the print head, the position adjustment guide on the platen roller engages with the engagement means on the print head, and the position of the print head changes from the position adjustment guide. Adjusted by force. Further, when the cover swings toward the print head, the platen roller is pressed against the print head.

〔Example〕

The structure of the present invention will be explained in detail below with reference to embodiments shown in the accompanying drawings.

Reference numeral 2 denotes a substrate of the main body of the thermal transfer printer, and a bracket is provided on both sides of one end of the substrate, and a shaft body 4 is attached to the bracket.
has been erected. 6 is a cover, the side frame 6a of this
, 6b are rotatably supported by the shaft 4. A paper peeling plate 8 is attached to the side frames 6a, 6b,
Paper feed rollers 10 and 1 are located on the paper peeling plate 8.
1 is linked to a drive device (Il8, not shown), and the side frame 6
It is rotatably supported by a and 6b. Said side frame 6a6
A support tube 12.14 is fixed to b, and the support tube 12.1
A platen roller rotation shaft 18 having a platen roller 16 fixedly attached to the platen roller 4 is rotatably supported in conjunction with a drive device. Attached to the support tube 12.14 is a printhead alignment guide 20.22 having a mating recess. Reference numeral 24 denotes a paper feed guide installed above the side frames 6a, 6b, and the recording paper 26 is moved between the side frames 6a, 6b by a feed reel roller 2 rotatably supported by a drive device.
8 and a presser roller 30 which is rotatably supported between the side frames 6a and 6b, and further guides the recording paper 26 below the platen roller 16. Note that the paper feed guide 24 and the peeling plate 8 are not shown in FIG. 1. The lower portions of the side frames 6a and 6b are
It engages with a coil spring 32 wound around both ends of the shaft 4, and is biased counterclockwise around the shaft 4 in FIG. 6 by the elasticity of the spring 32. A box-shaped print head stand 34 has one end fixed to an example of the substrate 2 via a stand 36, and is perpendicular to the bottom surface of the substrate 2.
A pair of front and rear walls 34a parallel to the platen roller 16
, 34b, and side walls 34c, 34d perpendicular to the front and rear walls 4a, 34b. Said side walls 34c, 34
d is provided with an elongated hole 38 extending horizontally to the bottom surface of the substrate 2, and a hole adjacent to the elongated hole 38 at a predetermined distance to the rear. Reference numeral 42 designates a print head holder that is substantially similar in shape to the print head stand 34 and is smaller than the head stand 34. The head holder 42 is loosely fitted into the head stand 34, and is provided on both side walls of the head holder 42. A print head rotating shaft 44 protruding forward is rotatably and slidably inserted into the elongated hole 38 . A spring 46 is disposed on the inner bottom surface of the print head stand 34, and the spring 46
is in elastic contact with the rear position of the bottom surface of the print head receiver 42, and due to the elasticity of this spring 46, the print head receiver 42 rotates around the print head rotation axis 44 as shown in FIG.
In the figure, it is tilted counterclockwise. An elongated thermal line print head 48 having a printing portion 48 a is loosely fitted into the print head receiver 42 , and a seesaw shaft 50 protruding from the center of the front and rear surfaces of the print head 48 is attached to the front and rear walls of the print head receiver 42 . The print head 48 is rotatably fitted into a hole 52 formed through the center, and the print head 48 is pivoted about the axis passing through the hole 52 at its center.
It is supported by 2. At the rear of both sides of the print head 48 are shaft-shaped engagement means 5 for positioning the print head.
4 and 54 protrude, and the engagement means 54 and 54 are loosely fitted into square notches formed on both side walls of the print head receiver 42, and are fitted into the holes 40 and 40. It is arranged with loose fit.

Regarding the above-described structure, the print head 48 is mounted on the print head stand 34 so that it can be raised and lowered freely by rotation of the print receiver 42 about the print head rotation shaft 44, and is mounted along the elongated hole 38 of the print head rotation shaft 44. Due to the movement, it can move freely back and forth.
Furthermore, the longitudinal axis is supported so as to be tiltable by swinging around the seesaw shaft 50. A pair of cassette mounting pins 56 and 58 are provided protruding from the side wall of the print head stand 34. Front and rear walls 34a of the print head stand 34
, 34b constitute an ink ribbon cassette insertion guide. Reference numeral 60 designates an ink ribbon cassette, in which an ink ribbon mounting shaft 62 is rotatably supported between the upper portions of one side of a pair of frame plates 60a and 60b. It is possible to install it. Ribbon guide rollers 66, 68, and 70 are rotatably suspended between the frame plates 60a and 60b, and a take-up roller 72 is located below the mounting shaft 62 and rotatably supported. There is. One end of the take-up roller 72 slightly protrudes from the frame plate 60b, and a gear (not shown) is fixed to this protruding portion. A guide frame 74 is fixed to the frame plate 60a of the cassette 60, and the guide frame 74 extends from the open end to the front and rear walls 34a of the print head stand 34.
, 34b. When the cassette 60 is inserted to the innermost position along the print head stand 34, the pins 56 and 58 fit into the positioning holes 76 and 78 formed in the frame plate 60a, and
A gear (not shown) connected to a rotation drive device (not shown) provided on the side is configured to mesh with a gear fixed to one end of the winding roller 72. Next, the operation of this embodiment will be explained.

When setting the cassette 60 on the board 2, with the cover 6 raised, insert the guide frame 68 of the cassette 60 along the cassette insertion guide to a predetermined far end position, and then are fitted into the positioning holes 76 and 78. In this state, the ink ribbon 64 is located on the top surface of the thermal print head 48. When the cover 6 is lowered around the rotating shaft 4, the position adjustment guides 20, 2
The second fitting recess fits into the engagement means 54 on the print head 48 side, and by this fitting, the position of the print head 48 with respect to the platen roller 16 is forcibly adjusted. This position adjustment is performed by sliding the print head rotation shaft 44 along the elongated hole 38 by the regulating force of the position adjustment guide 20.22. The cover 6 is further lowered and locked at a predetermined lowered position.At this time, the platen roller 16 comes into pressure contact with the print head 48 from above the ink ribbon 64, and the print head 48 is moved by the spring 46 due to the pressure from the platen roller 16. The print portion 48a is lowered due to compressive deformation, and the entire area of the print portion 48a is brought into close contact with the surface of the platen roller 16 in parallel with the surface of the platen roller 16 under a predetermined pressure due to the tilting movement about the seesaw shaft 50.

Next, the recording paper 26 is fed onto the paper feed guide 24.

The recording paper 26 is fed between the platen roller 16 and the thermal print head 48 by the rotation of the feed roller 28, and recording is performed on the recording paper 26 by the print head 48. The recorded recording paper 26 is peeled off from the ink ribbon 64 by the tip of the peeling plate 8, and is sent on the peeling plate 8 in the paper ejection direction by paper feed rollers 11 and 10. The ink ribbon 64 pulled out from the roll section is attached to the print head 4
8, guide rollers 66, 68, and 70, and is wound up by a winding roller 72.

〔effect〕

As described above, in the present invention, the print head is forcibly aligned with the platen roller using the position adjustment guide on the platen roller side, and the print head is brought into close contact with the platen roller, so that uneven printing can be prevented. With,
Even if there is some error in the accuracy of the assembly position of the print head with respect to the platen roller, there are effects such as the ability to align the position of the print head with the platen roller with high precision.

[Brief explanation of the drawing]

1 is a schematic external view, FIG. 2 is an exploded perspective view, FIG. 3 is a front view, FIG. 4 is a side view, FIG. 5 is a perspective view, and FIG. 6 is a side view. 2... Board, 4... Shaft, 6... Cover. 6a,
6b...Side frame, 8...Paper peeling plate. 10.11...
・Paper feed roller. 12.14...Support pipe, 16...
・Platen roller, 18...rotation shaft. 20.22...
・Position adjustment guide, 24...Paper feed guide, 26・
... Recording paper, 28 ... Feed roller, 30 ... Press roller, 32 ... Coil spring, 34 ... Print head stand, 36 ... Stand, 34a ... Front wall, 3 4 b −・・
Rear wall, 34c, 34d-side wall, 38...long hole, 40.
... Hole, 42... Print head holder, 44... Rotating shaft, 46... Spring, 48a... Printing section, 48... Print head, 50... Seesaw shaft, 52... hole, 54
...Engagement means, 56, 58...pin. 60...Cassette, 60a, 60b-Frame plate, 62-...Mounting shaft, 6
4... Ink ribbon, 66, 68, 70... Guide roller, 72... Winding roller, 74... Guide frame, 76, 78... Positioning hole.

Claims (1)

[Claims] (1) A platen roller supported by a cover that can swing freely about the rotation axis is brought into pressure contact with the print head disposed on the substrate of the main body by swinging the cover downward, and the recording paper is In a printer that records on recording paper by pressing an ink ribbon between the print head that generates heat according to the recorded image and a platen roller, a print head stand is fixed to the substrate, and the position of the print head stand can be freely adjusted. A print head positioning device for a printer, characterized in that a print head is supported on the print head, an engaging means is provided on the print head side, and a position adjustment guide that can be freely engaged with the engaging means is provided on the platen roller side.