JP3085563B2 - Thermal printer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal printer for performing thermal transfer printing on ordinary recording paper or thermal printing on thermal recording paper using an ink ribbon.

[0002]

2. Description of the Related Art Conventionally, a thermal printer is, for example, shown in FIG.
As shown in FIG. 1, on a printer base (not shown), a thermal head 1 and a roller-shaped platen 2 which is moved toward and away from a heating element on a printing surface 1a of the thermal head 1 are provided.

[0005] The thermal head 1 is supported by a head support mechanism 3. The head support mechanism 3 has a support member 4 fixed to a printer base, and a mounting member 5 on which the thermal head 1 is mounted is rotatable about a support shaft 5 a. And a lock member 6 removably engaged with the pin 5b of the mounting member 5 is rotatably mounted on a support shaft 6a. Then, with the lock member 6 engaged with the pin 5b of the mounting member 5, the thermal head 1 is held at the printing position (position in the drawing), and by removing the lock member 6 from the pin 5b of the mounting member 5, The thermal head 1 rotates around the support shaft 5a to a ribbon mounting / dismounting position (a position above the drawing position).

The platen 2 is supported by a platen support mechanism 7. The platen support mechanism 7 has a lever 9 rotatably mounted on a support shaft 8 protruding from the printer base side. The platen 2 is rotatably mounted on the lever 9, and a spring 10 and a solenoid (not shown) are connected to the other end of the lever 9. When the solenoid is not operated, the lever 9 rotates clockwise in the figure by the bias of the spring 10, and the platen 2 presses against the thermal head 1, and when the solenoid is operated, the lever 9 is moved in the figure. Rotating in the counterclockwise direction, the platen 2 separates from the thermal head 1.

Further, a ribbon cassette is provided on the printer base.
11 is set, and the ribbon cassette 11 is detachable in a state where the thermal head 1 is rotated to the ribbon attaching / detaching position, that is, the mounting member 5 is pivoted clockwise in FIG. At the time of setting, the ink ribbon 11a is guided to the printing surface 1a side of the thermal head 1 at the printing position.

A paper feed path 12 for feeding recording paper is formed between the thermal head 1 and the platen 2 by guide plates 13 on both sides, and a pair of paper feed rollers 14 are provided upstream of the paper feed path 12. One of them is provided on the downstream side with the support shaft 8.
A pair of paper feed rollers 15 are disposed so as to be rotatably supported by a pair.

A belt 17 is stretched around the platen 2 and a roller 16 rotatably supported on the printer base side, and a belt 19 is stretched around the roller 16, the paper feed roller 14 and the rotation shaft of the motor 18. The motor 18 drives the platen 2 and the paper feed rollers 14 and 15 to rotate in the paper feed direction.

In the thermal printer constructed as described above, the recording paper is fed by the paper feed rollers 14 and 15 to the paper feed path 12.
Through the thermal head 1 and the platen 2. Immediately before the printing position of the recording paper reaches the printing position, the platen 2 is pressed against the printing surface 1a of the thermal head 1 via the recording paper and the ink ribbon 11a, and the recording paper and the ink ribbon 11a are integrally joined in a close contact state. Sent on the printing surface
By controlling the power supply to the heating element 1a, the ink on the ink ribbon 11a is transferred to the recording paper and printed. In addition, the platen 2 is separated from the thermal head 1 except for the printing portion of the recording paper, and only the recording paper is fed.

[0009]

In the thermal printer, the uppermost part of the outer periphery of the platen 2 is correctly aligned with the position of the heating element on the printing surface 1a of the thermal head 1 in the recording paper width direction orthogonal to the recording paper traveling direction. If you do not crimp
The ink ribbon 11a and the recording paper cannot be brought into close contact with the heating element on the printing surface 1a, resulting in poor thermal transfer of the ink of the ink ribbon 11a to the recording paper, resulting in uneven print density, such as a decrease in print density. Occurs.

Therefore, in the conventional thermal printer,
Thermal head 1 and platen 2 for printer base
At the time of assembling, fine adjustment of the thermal head 1 and the platen 2 must be performed while performing the printing operation so that the center position of the heating element on the printing surface 1a matches the center position of the platen 2. In addition, there is a problem that the adjustment work takes time. In particular, in the structure as shown in FIG. 7, since the platen 2 rotates with the support shaft 8 as a fulcrum, the platen 2 comes into contact with and separates from the thermal head 1, so that the position adjustment between the thermal head 1 and the platen 2 is difficult and requires much time and effort. .

Further , for example, Japanese Utility Model Laid-Open No. 1-62058
Or described in JP-A-3-92374.
The engagement groove of the engagement member protruding from the thermal head side
To the platen shaft and print the thermal head.
There is a configuration that aligns the surface with the platen
But either the thermal head or the platen has a fixed position.
When the thermal head is separated from the platen,
The movement is regulated by the engagement between the engagement member and the platen shaft.
In the engaging groove of the engaging member.
Inevitably, this requires the engagement groove of the engagement member and the platen
Smooth separation cannot be performed due to contact with the shaft
Problems.

Also, if the head is separated from the thermal head,
Or the platen moves from the predetermined printing position
If you move in the opposite direction,
If the paper or ink ribbon is in the opposite direction to the
Paper may be dragged upstream from the paper
Slack in the ink ribbon, for example,
The used part of the ribbon returns to the print position at the next printing.
It will be sent, leading to a decrease in print quality.

[0013] The present invention has been made in view of these points, the printed surface and the platen down Sa Maruheddo accurately aligned, moreover, the thermal head and the platen
Can achieve a smooth separation operation
At the upstream of the printing position, for example, recording paper or ink ribbon
Use of the ink ribbon once used to prevent slack
The used part is sent to the printing position again at the next printing.
And to provide a thermal printer that can prevent Uno.

[0014]

Means for Solving the Problems The present invention provides a thermal printer for printing on recording paper fed between the printing surface and the platen Sa Maruheddo, the thermal head is taken
A mounting member that is attached in a direction parallel to the printing surface of the thermal head and that can move in accordance with the feeding direction of the recording paper, and the printing surface of the thermal head is provided on the mounting member with respect to the platen. Head support hand having an engagement portion slidably engaged in a direction perpendicular to the head
And the platen corresponding to the recording paper feed direction.
Platen supporting means for movably supporting, and the thermal
The head and platen are relatively moved toward and away from each other.
Place both the thermal head and the platen at the time of separation.
Move the recording paper in the feed direction from the fixed printing position
A contact / separation operation means .

[0015]

According to the present invention, fitted with a thermal head attached
Record components in a direction parallel to the print surface of the thermal head
The position of the thermal head follows the position of the platen by allowing the movable portion to move in accordance with the paper feed direction, and by engaging the engaging portion of the mounting member with the platen. The positioning between the print surface of the head and the platen is maintained. In addition, the platen moves in the direction
It can be moved correspondingly, and the thermal head and the platen
At the time of separation, both the thermal head and the platen are
Moving in the recording paper feed direction from the print position
As a result, a smooth separation operation is realized, and for example,
Sag on the upstream side of printing position such as recording paper or ink ribbon
Used part of the ink ribbon that has been used once
Will not be sent to the print position the next time printing is performed.
Is stopped.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The construction of an embodiment of a thermal printer according to the present invention will be described below with reference to FIGS.

In FIG. 1, reference numeral 21 denotes a thermal head, which is formed to be horizontally long with a horizontal direction perpendicular to a recording paper conveyance direction, and a printing surface 22 formed on a lower surface.
, Heating elements (not shown) are juxtaposed along the left-right width direction. A paper guide 23 is attached to the rear of the printing surface 22 (right side in FIG. 1).

Reference numeral 31 denotes a head support mechanism as a thermal head support means . The head support mechanism 31 includes a support member 32.
, A mounting member 33, and lock members 34 and 35.

The support member 32 is fixed to a printer base (not shown) of the thermal printer, and has a vertical substrate portion.
Side plate portions 42 are bent forward from both left and right sides of 41, and a support shaft 43 for supporting the support member 32 and the lock member 34 and a support shaft 44 for supporting the lock member 35 are provided between the both side plate portions 42. It is attached (see the plan view of the head support mechanism 31 in FIG. 3).

The mounting member 33 (see FIG. 5) includes a horizontal substrate portion 45 on which the thermal head 21 is mounted on the lower surface.
Arm portions 46 are formed to rise from both left and right sides of the substrate portion 45, and rising portions 47 are formed to rise from the front side of the substrate portion 45. Long slots 48 are formed at the rear ends of the left and right arms 46 in a direction parallel to the printing surface 22. Each of the slots 48 is fitted to the support shaft 43, so that both ends of the thermal head 21 It is supported so as to be movable in a direction parallel to 22 and in the recording paper feed direction. In order to guide an ink ribbon 82 described later, a guide roller 49 is rotatably mounted between the tips of the left and right arms 46, and a guide plate 50 having a substantially L-shaped cross section is provided on the front surface of the rising portion 47. Installed.

An engagement member 51 is attached to the left and right arms 46 of the attachment member 33.
A mounting portion 52 is formed on the outer surfaces of the left and right arm portions 46, and an engaging portion 53 is formed to protrude downward from the mounting portion 52. The engagement portion 53 has a pair of engagement pieces 54 projecting downward, and a support shaft 75 of a platen 71 is provided between the engagement pieces 54.
Are slidably engaged in a direction perpendicular to the printing surface 22.
Are formed. Each engaging member 51 is provided with an engaging groove 55
Are attached to the left and right arm portions 46 such that the center position of the print surface 22 coincides with the center position of the heating element.

The lock member 34 has a board 56 formed shorter than the distance between the left and right arms 46, and side plates 57 are bent from both left and right sides of the board 56. An end is rotatably attached to the support shaft 43, and a lock shaft 58 is fixed between the front ends of both side plate portions 57. This lock axis
The length of 58 is longer than the distance between both arms 46, and the lock shaft
58 can contact the upper edge of the arm 46 (see the plan view of the head support mechanism 31 in FIG. 3).

1 and 3, the lock member 35
Is formed with a board portion 59 longer than the distance between both side plate portions 57 of the lock member 34, and the side plate portions 60 are formed from both left and right sides of the board portion 59.
The rear ends of the left and right side plate portions 60 are rotatably attached to the support shaft 44, and a lock hole 61 through which a lock shaft 58 penetrates is formed at a position closer to the front of the left and right side plate portions 60. I have.
A guide hole 62 is formed in the lock hole 61 along the front-rear direction of the side plate portion 60, and a lock hole 63 is formed at the front end of the guide hole 62 so as to be bent upward. In addition, an opening 64 is formed at a position closer to the rear of one side plate portion 60. Further, a spring 65 is provided between the substrate portion 59 and the rising portion 47.
Is stretched.

An operation lever 66 is rotatably mounted on the support shaft 44, and a pin 67 is formed to project from a side surface of the operation lever 66 into an opening 64 of the side plate portion 60.

The head support mechanism 31 is provided with a lock shaft 58
The two lock members 34 and 35
Is held, the arm 46 of the mounting member 33 urged by the spring 65 contacts the lock shaft 58, and the mounting member 33 is
Are held movably in a direction parallel to the recording paper and in the recording paper feed direction, and the horizontal position of the thermal head 21 is held at the printing position. Further, by rotating the operation lever 66 upward, the lock member 35 is rotated upward through the engagement between the pin 67 and the edge of the opening 64, and the fitting of the lock shaft 58 is performed in the lock hole portion. Moving from 63 to the guide hole 62, the lock member 34 rotates upward, the mounting member 33 rotates upward via the spring 65, and the thermal head 21
And rotate to the ribbon attaching / detaching position (not shown).

The platen 71 is composed of a roller and a roller support shaft, is formed in a laterally long shape corresponding to the lateral width of the thermal head 21, and has a platen supporting mechanism as platen supporting means.
Supported by 72.

The platen support mechanism 72 has a pair of levers 74 rotatably mounted on a support shaft 73 projecting from the printer base. The platen 71 is rotatable by a support shaft 75 between the front ends of the levers 74. , And a spring 76 and a solenoid (not shown) are connected to the rear end of the lever 74. Both ends of the support shaft 75 project from the outer surface of the lever 74,
The engaging portion 53 of each engaging member 51 is adapted to engage.

When the solenoid is not operated, the platen support mechanism 72 is actuated by the spring
Rotates clockwise in the figure, and the platen 71 presses against the thermal head 21. Further, when the solenoid is operated, the lever 74 rotates counterclockwise in the drawing against the spring 76, and the platen 71 separates from the thermal head 21. What
Contact, head support mechanism 31, platen support mechanism 72, spring
And the thermal head 21
Move the platen 71 relatively to and away from it,
Sometimes, both the thermal head 21 and the platen 71
Contact / separation operation that moves the recording paper in the feed direction rather than the printing position
Means are configured.

The printer base includes a ribbon cassette.
The ribbon cassette 81 is detachable with the thermal head 21 rotated to the ribbon attaching / detaching position, and at the time of setting, the ink ribbon 82 is guided to the printing surface 22 side of the thermal head 21 at the printing position. (See FIG. 6).

Further, between the thermal head 21 and the platen 71, a paper feed path 91 for feeding the recording paper is formed by guide plates 92 on both sides. A pair of paper feed rollers 93a and 93b is disposed upstream of the paper feed passage 91, and one paper feed roller 94a is rotatably supported by a support shaft 73 on the downstream side to form a pair of paper feed rollers. Rollers 94a and 94b are provided.

A pulley 95 attached to a support shaft 75 of a platen 71, a pulley 96 attached to a support shaft 73 of a paper feed roller 94a, and a pulley 97 rotatably supported on the printer base side are endless. Belt 98 is stretched. And,
Pulley 97 and pulley 99 attached to the shaft of paper feed roller 93a
And a pulley 101 attached to the rotating shaft of the motor 100,
A belt 102 is stretched. Then, the rotation of the motor 100 drives the platen 71 and the paper feed rollers 93a, 93a.
b, 94a and 94b are driven to rotate in the paper feed direction.

Next, the operation of this embodiment will be described.

With respect to the printer base, a head support mechanism
When incorporating the platen support mechanism
The head support mechanism 31 and the platen support mechanism 72 are combined by engaging the engagement portions 53 of the engagement members 51 on both sides with the support shafts 75 protruding from both ends of the 71.

At the time of paper feeding without printing, the solenoid is operated, and as shown in FIG. 2, the lever 74 is rotated counterclockwise in FIG. Get away from. At this time, since the support shaft 75 moves forward with the rotation of the lever 74, the mounting member 33 moves forward via the engaging member 51 that engages with the support shaft 75. Therefore, both the thermal head 21 and the platen 71 are moving forward at the predetermined printing position.

The recording paper fed into the paper feed passage 91 is sent between the thermal head 21 and the platen 71 by paper feed rollers 93a, 93b, 94a and 94b.

Immediately before the printing portion of the recording paper reaches the printing position, the solenoid is deactivated, and as shown in FIG.
The lever 74 is rotated clockwise in the figure by the bias of the spring 76, and the platen 71
It is pressed against the thermal head 21 via 82.

At this time, the pivot 75
The shaft 75 enters the engaging groove 55 of the engaging member 51 while moving backward, and the mounting member 33 moves rearward via the engaging member 51. During the rotation of the lever 74, the support shaft 75
At the point when the central part of has entered the engagement groove 55 of the engagement member 51,
The center position of the engagement groove 55, that is, the printing surface of the thermal head 21
The center position of 22 and the center position of the support shaft 75 of the platen 71 match. Thereafter, with the rotation of the lever 74, the support shaft 75 slides upward in the engagement groove 55 of the engagement member 51, and the center position of the heating element on the printing surface 22 and the center position of the support shaft 75 are shifted. The matching state is maintained continuously.

Therefore, when the platen 71 is pressed against the thermal head 21 via the recording paper and the ink ribbon 82, both the thermal head 21 and the platen 71 move to a predetermined printing position, and the heat generated on the printing surface 22 of the thermal head 21 is generated. The center position of the body coincides with the center position of the support shaft 75 of the platen 71.
Therefore, the outer peripheral portion of the platen 71 is accurately pressed against the center of the heating element on the printing surface 22 of the thermal head 21, and the ink ribbon 82 and the recording paper can be brought into close contact with the center of the heating element on the printing surface 22. In particular, since both members are positioned at both ends of the thermal head 21 and the platen 71, the center of the heating element on the printing surface 22 of the thermal head 21 which is long in the left-right direction can be accurately aligned with the position of the platen 71. .

When the platen 71 is pressed against the thermal head 21 via the recording paper and the ink ribbon 82, the ink ribbon 82 and the recording paper are fed together in a tight contact state. By performing the power supply control, the ink on the ink ribbon 82 is transferred to the recording paper and printed.

In addition, as shown in FIG. 2, the platen 71 is separated from the thermal head 21 at portions other than the printing portion of the recording paper, and only the recording paper is supplied to the paper feed rollers 93a, 93b, 94a, 94b.
And a discharge roller (not shown) for discharging from the printing position.

In addition, the platen 71 also moves in the recording paper feed direction.
It can be moved correspondingly, and the thermal head 21 and platen 71
When the thermal head 21 and the platen 71
Is more forward than the specified printing position in the recording paper feed direction.
Because it moves, it can realize a smooth separation operation
To the printing position upstream of the recording paper and ink ribbon 82
Use of ink ribbon 82 once used to prevent slack
Is sent to the printing position again at the next printing
Can be prevented.

When the ribbon cassette 81 is attached or detached, the head support mechanism 31 is moved to the ribbon attaching / detaching position,
The engaging portion 53 of the 51 is disengaged from the support shaft 75.

Further, when the thermal head 21 is replaced due to its service life or failure, the head support mechanism 31 is detached from the printer base, and when the head support mechanism 31 is attached again, the engagement portion 53 of the engagement member 51 is also provided. By engaging with the support shaft 75 of the platen 71, the printing surface 22 of the thermal head 21 and the platen 71 can be accurately positioned.

In the above-described embodiment, the platen 71 is moved toward and away from the thermal head 21 during printing and non-printing. On the contrary, the thermal head 21 is moved toward and away from the platen 71. Even when the present invention is applied to the thermal printer, the same operation and effect as those of the above embodiment can be obtained.

[0045]

According to the present invention, the mounting member on which the thermal head is mounted can be moved in a direction parallel to the printing surface of the thermal head and in accordance with the recording paper feed direction. by but it is engaged with the platen, the position of the thermal head to the position of the platen to follow, because the positioning of the printing surface and the platen of the thermal head is maintained, and a printing surface of the support Maruheddo platen Positioning can be performed accurately, and the platen is also a recording paper
Can be moved according to the feed direction of
When separating from the platen, the thermal head and platen
Both move in the recording paper feed direction from the predetermined print position.
As a result, a smooth separation operation can be realized and
For example, when printing paper or ink ribbon, etc.
Spent ink ribbon used once to prevent slack
Will be sent to the print position again the next time printing is performed.
Can be prevented .

[Brief description of the drawings]

FIG. 1 is a side view at the time of printing showing an embodiment of a thermal printer according to the present invention.

FIG. 2 is a side view of the embodiment when the platen is separated.

FIG. 3 is a plan view of the head support mechanism of the embodiment.

FIG. 4 is a front view of the head support mechanism of the embodiment.

FIG. 5 is a perspective view of a part of the head support mechanism of the embodiment.

FIG. 6 is a side view of the embodiment.

FIG. 7 is a side view of a conventional thermal printer.

[Explanation of symbols]

21 Thermal head 22 Printing surface 31 Head support mechanism as thermal head support means 33 Mounting member 53 Engagement part 71 Platen 72 Platen support mechanism as platen support means

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. ⁷ , DB name) B41J 25/304 B41J 2/32 B41J 11/14

Claims (1)

(57) [Claims] 1. A feeding direction of the thermal printer for printing on a recording sheet, and the recording sheet in a direction parallel to the printing surface of the thermal head thermal head is attached to be sent between the printing surface and the platen Sa Maruheddo Corresponding to
With a mounting member that is movable
Having a engaging portion slidably engaged in the direction perpendicular to the printing surface of the thermal head against the platen provided on the member
Thermal head supporting means, and the platen can be moved in a direction corresponding to the recording paper feed direction.
Platen support means for supporting the thermal head and the platen relative to each other.
As well as the thermal head and platen
Both in the feeding direction of the recording paper than the predetermined printing position.
A thermal printer comprising: a contact / separation operation means for moving .