JP3627347B2 - Thermal head pressing mechanism and printer using the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a thermal printer used in a POS system, a cash register, a copying machine, a facsimile, and the like, and more particularly to a pressing mechanism that supports a thermal head on a frame and presses it against a platen roller.
[0002]
[Prior art]
Conventionally, in this type of printer, a shaft is passed through the head support member, supported by the main body frame, an elastic member is disposed between the head pressing member and the head support member, and the thermal head is biased in the platen direction. Is generally known. When the thermal head is incorporated in the printer, it is necessary to dispose the head pressing member against the elastic force of the elastic member, and the assembling work is complicated and the productivity of the device is reduced.
[0003]
Therefore, as described in Japanese Patent Application Laid-Open No. 5-24308 and the like, a subassembly in which the head support member and the head pressing member (the support arm 19 and the pressing arm 21 in the publication) are connected is prepared in the previous stage of the assembly. Thereafter, a method of assembling the main body frame has been proposed.
[0004]
In particular, in the case of a line thermal printer having a long width direction, if the pressing force in the line direction is not uniform, the pressing force is insufficient at the end of the printing line, resulting in a problem that printing becomes thin. Thus, an automatic alignment mechanism for a thermal head has been proposed. For example, as described in Japanese Patent Application Laid-Open No. 6-336069, etc., the rotation support point of the head support member fixed to the thermal head is a long hole, and a plurality of springs are arranged on the back surface of the head support member. Even if the head support shaft and the platen roller are not exactly parallel due to variations in component accuracy, or even if the cylindricality of the platen roller is not exactly cylindrical, the thermal head moves following the platen roller, There is a mechanism in which a uniform pressing force acts in the line direction.
[0005]
In each of the two conventional examples described above, the thermal head is attached to the head support member, and the rotation fulcrum coincides with the shaft being passed.
[0006]
[Problems to be solved by the invention]
However, the conventional head pressing mechanism described above has the following problems. First, in the configuration described in Japanese Patent Laid-Open No. 5-24308, although it is certainly improved in terms of productivity, it is at the time of the main assembly, and in the sub-assembly before the main assembly, Similarly, it is necessary to assemble the thermal head against the elastic force of a spring or the like. Overall productivity gains are negligible. On the contrary, in addition to the support member and the pressing member, a member called a member (stopper arm 26 in the publication) that locks the pressing member is required, which increases the number of parts and increases the cost.
[0007]
Further, in the configuration described in Japanese Patent Laid-Open No. 6-336069, since the hole through which the shaft passes is a long hole, the pressing force of the head becomes uniform and the print quality becomes good. Must pass through the shaft. This structure is the same as that of JP-A-5-24308. That is, in a conventional technique, in a printer in which a thermal head is rotatably supported, a method of passing a shaft through a head support member is generally used. When replacing a thermal head, the head support member is largely rotated. The thermal head was removed or the shaft was pulled out to remove the thermal head together with the head support member. For this reason, the productivity of the printer is not only poor, but also the exchangeability at the time of head failure is poor, and the maintenance time is long. In addition, the configuration of the printer is complicated, which hinders cost reduction.
[0008]
Therefore, the present invention has been made in consideration of such conventional problems, and the object of the present invention is excellent productivity, easy exchangeability of the thermal head, and stable head pressing force. It is to provide a thermal printer with good print quality.
[0009]
Another object of the present invention is to provide a low-cost thermal printer by reducing the number of components and eliminating a fastening member such as a screw in the pressing mechanism portion of the thermal head. is there.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, the pressing mechanism of the thermal head of the present invention is:
(1) A thermal head including a heating element disposed on the side facing the platen roller, and rotating support shafts disposed on both side surfaces;
A frame having a support groove portion with which the rotary spindle of the thermal head engages;
A head pressing member comprising an elastic portion and biasing the thermal head to the platen roller;
Have
A position between the position of the rotary spindle of the thermal head and a position where the heating element is pressed by the platen roller is pressed by the elastic portion;
In the support groove portion of the frame, an opening is formed on a side opposite to a direction in which the head pressing member biases the thermal head.
[0011]
As a result, the thermal head can move to the opening side along with the platen roller even if the platen roller cylindricity is not accurate or the platen roller and head support shaft are not exactly parallel. A centering function is provided, and a uniform pressing force can be applied in the line direction. In addition, the pressing force surely acts on the platen roller side.
[0012]
(2) a thermal head including a heating element disposed on the side facing the platen roller, and rotating support shafts disposed on both side surfaces;
A frame having a support groove portion with which the rotary spindle of the thermal head engages;
A head pressing member comprising an elastic portion and biasing the thermal head to the platen roller;
Have
A position between the position of the rotary spindle of the thermal head and a position where the heating element is pressed by the platen roller is pressed by the elastic portion;
The head pressing member includes an upper locking portion that locks the frame at the upper and lower portions, and a lower locking portion,
The frame includes a groove-like engagement groove that engages with the lower locking portion, a substantially arc-shaped guide rail that engages with the upper locking portion and has the engagement groove as a center, and the upper locking portion PartFittingAnd a mounting groove to be joined.
[0013]
As a result, the head pressing member can move the upper locking portion along the guide rail without moving the engaged lower locking portion, so that the assemblability is greatly improved.
[0014]
(3) a thermal head including a heating element disposed on the side facing the platen roller, and rotating support shafts disposed on both side surfaces;
A frame having a support groove portion with which the rotary spindle of the thermal head engages;
A head pressing member comprising an elastic portion and biasing the thermal head to the platen roller;
Have
A position between the position of the rotary spindle of the thermal head and a position where the heating element is pressed by the platen roller is pressed by the elastic portion;
The rotating support shaft of the thermal head is a shaft member that is press-fitted into holes formed on both side portions of the thermal head and elastically varies in diameter.
[0015]
As a result, since it is not necessary to form the shaft portion only with the hole portion in the thermal head, the manufacturing cost of the thermal head can be reduced, and the total cost can be greatly reduced.
[0016]
(4) Since the shaft material of (3) is a wave spring pin having a wave portion bent inward, the unit price is low and contributes to cost reduction.
[0017]
(5) When the platen roller is not attached to the printer main body, the frame engages with the thermal head to regulate the rotation of the thermal head toward the platen roller, and the platen roller When the printer is mounted on a printer main body, the printer has an engaging portion that is separated from the thermal head.
[0018]
Thereby, even if the platen roller is not assembled, the thermal head can be assembled.
[0019]
Moreover, the printer of the present invention includes a thermal head pressing mechanism according to any one of the above (1) to (5);
A lid portion disposed on the frame that is openable and closable in preparation for rotation of the platen roller;
A storage section for storing and holding recording paper in the main body frame;
It has an upper part of the pressing mechanism of the thermal head and has a paper cutting part that can be attached to and detached from the main body frame.
[0020]
With this configuration, the paper cutter unit covers the head pressing mechanism and is not touched by the operator, so there is no deterioration or failure in print quality due to position fluctuations in the print unit, and its reliability is improved and the width of the main body frame is increased. The direction is regulated, the positional accuracy is improved, and the strength of the head pressing mechanism is increased.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a preferred embodiment of a printer according to the present invention will be described in detail with reference to FIGS.
[0023]
FIG. 3 is a perspective view showing an external configuration of the embodiment of the printer according to the present invention.
[0024]
The printer 1 according to the present embodiment is applied to a receipt printer used for a POS system or the like, for example.
[0025]
The printer 1 according to the present embodiment performs recording such as printing on a roll-shaped recording sheet S by a thermal recording head, and generally has a recording unit at the front, a paper cutting unit, and a recording paper at the rear. And a roll paper storage section for storing and holding S.
[0026]
The internal printer mechanism 8 is fixed to the lower case 4 made of resin, the side surface portion and the rear portion are covered with the upper case 3, and the front portion thereof is covered with the panel 2. In addition, a printing unit is disposed inside the panel 2, and a paper cutting unit is disposed on the top of the panel 2. The paper cut portion is covered with a cutter cover 6, which can be pulled out by sliding in the direction of arrow A.
[0027]
On one side of the upper case 3, an open button 7 is provided for driving the internal cover open lever 9 to rotate the internal cover frame 10 when taking out the recording paper S. Here, the cover frame 10 is coupled to the upper cover 5. When the open button 7 is pressed in the direction of arrow B, the cover open lever 9 is rotated in the clockwise direction to release the locking mechanism, and the upper cover 5 is opened in the direction of arrow C to expose the roll paper storage unit. Is done.
[0028]
1 and 2 are perspective views showing the printer mechanism 8 inside the printer 1 of the present embodiment. FIG. 1 is an external view of the printer mechanism 8 with the cover frame 10 opened. FIG. 2 and FIG. 2 are external views of the right side of the printer mechanism 8 with the cover frame 10 closed.
[0029]
The printer mechanism has a cover frame 10 that can be opened and closed on a body frame 13 made of metal or the like, and an auto cutter unit 11 that houses a movable blade 32 and its driving means. In this case, when printing, that is, when the recording paper S is not cut, the movable blade 32 is housed inside the auto cutter unit 11 and the blade portion of the movable blade 32 is not exposed. This state is said that the movable blade 32 is in the standby position.
[0030]
The fixed blade 33 that crosses the movable blade 32 in a scissor shape is disposed on the cover frame 10 so as to face the auto cutter unit 11. A blade shutter 34 is provided above the fixed blade 33. The blade shutter 34 is urged by a shutter spring 35 in a direction to cover the blade portion of the fixed blade 33. As shown in FIG. 2, when the cover frame 10 is closed, a part of the blade shutter 34 is part of the main body frame. 13, the blade shutter 34 is lifted in a slightly opening direction. Therefore, the blade portion of the fixed blade 33 is exposed, and the movable blade 32 is configured to be able to cross in a scissor shape when the movable blade 32 moves.
[0031]
A hole 37 for confirming the position of the movable blade 32 and a knob 36 for manually moving the movable blade 32 are provided on the upper surface of the auto cutter unit 11. The operator slides the cutter cover 6 described above. As a result, a part of the upper surface of the auto cutter unit 11 is exposed, and the hole 37 and the knob 36 can be seen. As described above, in the embodiment of the present application, the movable blade 32 is manually operated in consideration of a case where the movable blade 32 remains crossed with the fixed blade 33 in the event of some abnormality such as a power failure and cannot return to the standby position. Means for moving are provided.
[0032]
The cover frame 10 is attached so as to be swingable, that is, openable and closable about a support shaft 14 provided at the upper end on both sides of the main body frame 13. The cover frame 10 is provided with an arcuate lid portion 15 for avoiding contact with the recording paper S when the cover frame 10 is closed. When changing the installation angle of the printer, the lid portion 15 also functions as a holding member that receives the recording paper S.
[0033]
Further, a cover detector 44 for detecting a state in which the cover frame 10 is closed is provided on the right side surface of the main body frame 13. The cover detector 44 is a transmissive optical detector, and detects whether the cover frame 10 is properly closed depending on whether a part of the cover frame 10 blocks the optical axis of the detector.
[0034]
As a detector, a paper detector 30 and a near-end detector 24 described later are provided in addition to the cover detector 44. These various detectors, the auto cutter unit 11, and a lead wire group 12 of a paper feed motor 23 described later are connected to a relay substrate 16 fixed to the right side surface of the main body frame 13. The relay board 16 and a main circuit board (not shown) for controlling the printer are connected by FFC or the like.
[0035]
FIG. 1 is an external view of the left side surface of the printer mechanism 8, showing a state in which the cover frame 10 is opened. The blade shutter 34 covers the fixed blade 33. With the cover frame 10 opened, care is taken so that the operator does not get injured by touching the fixed blade. The movable blade 32 is housed in the auto cutter unit 11, and there is no problem in safety.
[0036]
A resin roll paper holder 17 is arranged inside the cover frame 10 when it is opened. The roll paper holder 17 is provided with a paper detector 30 that detects the presence or absence of paper immediately before the printing unit. The paper detector 30 is a reflection type optical detector, and a hole 31 is provided on the upstream side of the paper detector 30 for dropping foreign matter and paper dust attached to the recording paper S downward. This prevents the detector from malfunctioning. Further, the roll paper holder 17 is provided with slit grooves 27 that engage with the left and right side plates of the main body frame 13, and when the slit grooves 27 engage with the left and right side plates of the main body frame 13, the roll paper holder 17. Since the width direction of the recording paper is regulated, an appropriate width is maintained inside the recording paper storage unit with respect to the recording paper.
[0037]
A platen 18 made of a cylindrical rubber roller is rotatably supported by the cover frame 10 via a platen bearing 20. A platen gear 19 is press-fitted into one of the platens 18. The main body frame 13 is provided with a groove portion 21, and when the cover frame 10 is closed, the platen bearing 20 comes into contact with the groove portion 21 and the platen 18 is positioned downward. When the cover frame 10 is closed, a downward force acts on the cover frame 10 by the pressure applied to the platen by the print head, and the position of the platen 18 is determined. When the cover frame 10 is closed, the platen gear 19 and the paper feed transmission gear 22 mesh with each other, and the power from the paper feed motor 23 is transmitted to the platen 18.
[0038]
Further, a near-end detector 24 for detecting that the remaining amount of the recording paper S has decreased is attached to the left side surface of the main body frame 13 so as to be rotatable about a support shaft 25. This is to bring the near-end detector 24 in the optimum position in accordance with the installation angle of the printer. For example, as shown in FIG. 1, when installing the main body frame 10 with the bottom surface 28 facing down, the actuator 26 of the near end detector 24 is fixed at a position where it enters a hole 32 a provided in the frame main body 10. On the other hand, when installing with the back surface 29 of the main body frame 10 facing down, the actuator 26 is fixed at a position where it enters the hole 32b.
[0039]
Support groove portions 50 that support a print head 39 and a head pressing plate 41 described later are provided on the left and right side surfaces of the main body frame 13.
[0040]
FIG. 4 is a side sectional view of the printer mechanism 8 and shows a state in which the recording paper S is held in the roll paper holder 17 and is fed. 4 shows a state in which the recording paper S has a large diameter, and the recording paper S falls into the groove portion 38 when the recording paper S is reduced in diameter when fed. Then, the near-end detector 24 described above detects that the recording paper S has a small diameter.
[0041]
The recording paper S is nipped by the platen 18 and the print head 39 and is fed by the frictional force when the platen 18 rotates. Head support shafts 40 are provided on both side surfaces of the print head 39, and the head support shafts 40 are supported by a part of support groove portions 50 provided in the main body frame 13. The back surface of the print head 39 is biased toward the platen 18 by a spring 42. The spring 42 is fixed to the head pressing plate 41, and the head pressing plate 42 is supported by a part of the support groove portion 50 provided in the main body frame 13.
[0042]
The heating element position 43 of the print head 39 is positioned so as to be a substantially contact point between the platen 18 and the print head 39. A guide slope 45 is provided on the downstream side of the heating element position 43 of the print head 39. On the other hand, the cover frame 10 is provided with an introduction portion 47 that guides the recording paper S to the cutter portion so as to face the guide slope portion 45 of the print head 39. The recording sheet S that has passed through the print head 39 passes between the movable blade 32 and the fixed blade 33 and is discharged in the direction of arrow D. The print head 39 is provided with a connector 46, which is connected to a main circuit board (not shown) for controlling the printer by FFC or the like.
[0043]
The outline of the basic configuration of the entire printer of this embodiment has been described above. Next, the pressing mechanism for the thermal head, which is a feature of the present application, will be described in more detail with reference to FIGS.
[0044]
FIG. 5 shows a cross section of the recording unit before the print head 39 and the head pressing plate 41 are assembled. The auto cutter unit 11 is removed from the main body frame 13 and the cover frame 10 is opened. The print head 39 engages with the support groove 50 provided in the main body frame 13 and is positioned, and the platen 18 (not shown) is also engaged with the groove 21 provided in the main body frame 13 and positioned. Therefore, since the print head 39 and the platen 18 are positioned on the same plane of the main body frame 13 which is the same component, the positional accuracy is good. The print head 39 and the head pressing plate 41 are assembled before the platen 18 is assembled to the recording unit. First, the print head 39 is inserted into the support groove 50 provided in the main body frame 13. As shown in the figure, the support groove 50 is open at the top, so that the print head 39 can be easily inserted from above. Then, the head support shaft 40 is approximately aligned with the head support portion 50a. Next, a head pressing plate 41, which is a pressing member that biases the print head 39 in the direction of the platen 18, is assembled to the support groove 50. This assembly method will be described with reference to FIG.
[0045]
FIG. 6 is a side view showing how the head pressing plate 41 is assembled to the support groove portion 50. The head pressing plate 41 is formed with a width slightly smaller than the inner dimension between the main body frames 13 except for the wide portion 41a. As shown in the figure, first, the spring 42 is applied to the spring receiving portion 48 on the back surface of the print head 39, and the lower end of the head pressing plate 41 is positioned in the lower groove 50 c of the supporting groove portion 50 so that the wide portion 41 a on the upper side of the head pressing plate 41. Is applied to the guide rail portion 50b. At this time, although there is no platen 18, the print head 39 abuts against a head engaging portion 49 provided on the main body frame 13 and the rotation of the print head 39 is restricted. Next, the head pressing plate 41 is pressed in the direction of arrow E from the back. Since the shape of the guide rail portion 50b is an arc shape with the lower groove 50c substantially at the center, the head pressing plate 41 is rotated about the position of the lower groove 50c, and the upper wide portion 41a is It moves along the guide rail portion 50b, moves downward at the opening, and stays in place. Thus, in the invention of this application, the assembly of the head pressing plate 41 is extremely easy by providing the guide rail portion 50b.
[0046]
FIG. 7 shows a perspective view of the state in which the head pressing plate 41 is assembled to the main body frame 13 as described above. A plurality of springs 42 are arranged on the head pressing plate 41 in the print line direction. This is for making the force uniform in the print line direction. The main body frame 13 is provided with a cutter receiving portion 53 for fixing the auto cutter unit 11. When the auto cutter unit 11 is not arranged, the head pressing mechanism is exposed. Therefore, the replacement of the print head 39 is facilitated, but on the other hand, the operator may touch it unnecessarily, which may cause a failure. That is, it is not preferable that the head pressing mechanism is exposed during normal use.
[0047]
Therefore, in normal use, this printer has a part of the bottom of the auto cutter unit 11 engaged with a part of the cutter receiver 53, and the auto cutter unit 11 is fixed to the cutter receiver 53 with screws or the like. . Thus, since the auto cutter unit 11 is arranged on the upper part of the head pressing mechanism, the head pressing mechanism is covered and is usually not touched by the operator, there is no safety problem, and the reliability is good. It becomes. Further, the auto cutter unit 11 is firmly fixed to the main body frame 13 with screws or the like, so that the width direction of the main body frame 13 is restricted, the position of the print head 39 is stabilized, and the print position accuracy is improved. In addition, the strength of the head pressing mechanism is increased. In the embodiment, an example in which the auto cutter unit 11 is fixed with a screw or the like has been described. However, the auto cutter unit 11 does not necessarily have to be fixed with a screw or the like, and the auto cutter unit 11 rotates on the main body frame 13 by a hinge portion. When the autocutter unit 11 is set at a proper position, it is possible to engage with a part of the main body frame 13 to increase the strength.
[0048]
FIG. 8 is a side view showing a state in which the platen 18 is attached to the head pressing mechanism shown in FIG. By mounting the platen 18, the print head 39 moves against the elastic force of the spring 42 and moves away from the head engaging portion 49. Therefore, the print head 39 is pressed against the platen 18 by the spring force of the spring 42. Thus, in this printer, since the platen 18 is separated from the head pressing portion when the head pressing plate 41 is assembled, the length for compressing the spring 42 against the elastic force of the spring 42 is a predetermined length. It is not necessary to shorten the length to the set length at which the pressing force can be obtained, and therefore the force required to assemble the head pressing plate 41 may be small. Also from this, the assembly of the head pressing plate 41 is facilitated.
[0049]
The point to be noted here is that the spring 42 urges the position between the contact position where the print head 39 contacts the platen 18 and the head support shaft 40 which becomes the rotation fulcrum of the print head 39. That is. As a result, even if the rear side of the head support portion 50a, that is, the back direction of the print head 39 is opened, the head support shaft 40 of the print head 39 is urged toward the platen 18 and the head support shaft 40 is released. No. Therefore, conventionally, the support hole of the head support shaft 40 is generally a long hole, and the shaft is passed through the long hole. However, by adopting a configuration like this printer, It becomes possible to do.
[0050]
As shown in FIG. 8, the spring 42 is a distance between the contact position between the platen 18 and the print head 39, which is the printing position, and the biasing position of the spring 42, and the distance between the head spindle 40 and the biasing position of the spring 42. If b is b, it is energized so that a <b. Thereby, for example, the cylindricity of the platen 18 is accurately set even though the line connecting the contact surface of the platen 18 and the print head 39 and the left and right head spindles 40 is set in parallel as in the present embodiment. If twisting occurs instead of being parallel due to variations in component accuracy such as when the cylinder is not cylindrical, one of the left or right of the contact surface of the platen 18 and the print head 39 or the left or right of the head support shaft 40 is Since the position of the spring 42 is a <b because of the floating, the force that urges the contact surface between the platen 18 and the print head 39 is strong, so that the print head 39 moves and the print position floats following the platen 18. Instead, one of the head support shafts 40 floats on the opening side of the head support portion 50a. Therefore, in this printer, since the rear side of the head support portion 50a is opened, the head is automatically aligned in the same manner as the head support portion of the conventional long hole, and the print side is reliably pressed. The print quality and reliability are improved without the occurrence of printing problems due to insufficient pressure or no contact, and without the problem of unclear printing.
[0051]
Further, as shown in FIG. 8, since the spring receiving portion 48 is provided on the back surface of the print head 39, the position of the spring 42 is correctly determined and the pressing force is stabilized. Therefore, the print quality is improved. Further, when the head pressing plate 41 is attached to and detached from the main body frame, there is an advantage that the spring 42 is difficult to come off. In the present embodiment, as a head pressing means, a method of providing a projection such as a burring on a head pressing plate 41 of a sheet metal and fitting a spring 42 of a compression coil spring is employed. However, the head pressing means is not limited to this method, and the spring and the head pressing plate can be made into one component by using a leaf spring material.
[0052]
As described above, the head pressing mechanism of the present invention facilitates the assembly work of the printer while maintaining the function of uniformly and stabilizing the head pressing force that greatly affects the print quality. Next, contents for reducing the cost of the print head used in the head pressing mechanism will be described below.
[0053]
FIG. 9 is a perspective view of the print head 39 of this printer, and the heat sink 51 is an aluminum drawing material. Reference numeral 52 denotes a head chip, which is attached to the heat radiating plate 51 with a double-sided adhesive tape. Since the width of the head chip 52 is shorter than the width of the heat radiating plate 51, a locking surface 51 b that is a part of the heat radiating plate 51 protrudes from the head chip 52 on the left and right sides of the head chip 52. When the print head 39 is mounted on the main body frame 13, the engaging surface 51 b and the head engaging portion 49 provided on the main body frame 13 are engaged. A guide slope 45 is formed in the print line direction above the head chip 52 of the heat sink 51. After the print head 39 is mounted on the main body frame 13, when the cover frame 10 is closed and the platen 18 is mounted on the recording unit, first, the guide slope 45 and the platen 18 come into contact with each other to attach the print head 39 to the head pressing plate 41. Therefore, the impact of the platen 18 hitting the head chip 52 is mitigated by the guide slope 45.
[0054]
The head support shaft 40 is a wave-shaped spring pin with a slit portion, and is press-fitted into holes provided in the left and right side portions of the heat radiating plate 51. The corrugated spring pin elastically changes its diameter in accordance with the hole of the heat sink 51 and does not deform the heat sink 51. If the heat radiating plate 51 is deformed, stress is applied to the head chip 52, resulting in disconnection of the internal wiring of the substrate and deterioration of the service life. However, this printer does not have such a problem and can ensure high reliability.
[0055]
Conventionally, the print head support shaft is provided with a head support member that is a separate part from the print head, and the shaft is passed there, the heat sink is manufactured by die casting, and the support shaft protrudes. was there. However, these methods have a large number of parts and increase costs. Therefore, as shown in the present embodiment, the number of parts can be reduced and the cost can be reduced by pressing the shaft material into the heat sink of the aluminum drawing material. Further, if the shaft of the spring pin is press-fitted, there is no need to increase the component accuracy of the shaft hole portion of the aluminum drawing material, which also reduces the cost.
[0056]
In addition, as for the spring pin used in this Embodiment, the wave part is bend | folded inside as shown in FIG. Accordingly, the slit portion does not protrude in the circumferential direction, and the head support portion 50a and the slit portion of the spring pin are not caught regardless of the position of the wave portion, and the print head 39 can be smoothly rotated. It becomes possible to move. Therefore, it is not necessary to manage the position of the slit portion when the spring pin is press-fitted, and assembly is easy.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an internal configuration of an embodiment of a printer according to the present invention, and shows a state in which a cover frame is opened.
FIG. 2 is a perspective view showing an internal configuration of the embodiment, showing a state in which a cover frame is closed.
FIG. 3 is a perspective view showing an external configuration of the embodiment.
FIG. 4 is a side sectional view showing the internal configuration of the same embodiment.
FIG. 5 is a partial cross-sectional view illustrating assembly of the recording unit according to the embodiment, showing a state before assembly.
FIG. 6 is a partial cross-sectional view illustrating the assembly of the recording unit according to the embodiment, showing a state after the assembly.
FIG. 7 is a partial perspective view illustrating a recording unit according to the embodiment.
FIG. 8 is a cross-sectional side view of the main part showing the recording unit of the embodiment.
FIG. 9 is a perspective view illustrating an appearance of the print head according to the embodiment.
FIG. 10 is a cross-sectional view of a spring pin used in the print head according to the embodiment.
[Explanation of symbols]
1 Printer
5 Top cover
8 Printer mechanism
9 Cover open lever
10 Cover frame
11 Auto cutter unit
13 Body frame
16 Relay board
17 Roll paper holder
18 Platen
20 Platen bearing
21 Groove
23 Paper feed motor
39 Print head
40 head spindle
41 Head pressing plate
42 Spring
43 Heating element position
45 Guide slope
48 Spring receiving part
49 Head engaging part
50 Support groove
50a Head support
50b Guide rail
50c Lower groove
51 Heat sink
53 Cutter receiving part

Claims (6)

A thermal head including a heating element disposed on the side facing the platen roller, and rotating support shafts disposed on both side surfaces;
A frame having a support groove portion with which the rotary spindle of the thermal head engages;
A head pressing member comprising an elastic portion and biasing the thermal head to the platen roller;
Have
A position between the position of the rotary spindle of the thermal head and a position where the heating element is pressed by the platen roller is pressed by the elastic portion;
A thermal head pressing mechanism, wherein an opening is formed in the support groove portion of the frame on a side opposite to a direction in which the head pressing member biases the thermal head. A thermal head including a heating element disposed on the side facing the platen roller, and rotating support shafts disposed on both side surfaces;
A frame having a support groove portion with which the rotary spindle of the thermal head engages;
A head pressing member comprising an elastic portion and biasing the thermal head to the platen roller;
Have
A position between the position of the rotary spindle of the thermal head and a position where the heating element is pressed by the platen roller is pressed by the elastic portion;
The head pressing member includes an upper locking portion that locks the frame at the upper and lower portions, and a lower locking portion,
The frame includes a groove-like engagement groove that engages with the lower locking portion, a substantially arc-shaped guide rail that engages with the upper locking portion and has the engagement groove as a center, and the upper locking portion And a mounting groove in which the portion is fitted. A thermal head including a heating element disposed on the side facing the platen roller, and rotating support shafts disposed on both side surfaces;
A frame having a support groove portion with which the rotary spindle of the thermal head engages;
A head pressing member comprising an elastic portion and biasing the thermal head to the platen roller;
Have
A position between the position of the rotary spindle of the thermal head and a position where the heating element is pressed by the platen roller is pressed by the elastic portion;
The thermal head pressing mechanism, wherein the rotary support shaft of the thermal head is a shaft member that is press-fitted into holes formed in both side portions of the thermal head and elastically varies in diameter. 4. The thermal head pressing mechanism according to claim 3, wherein the shaft member is a wave spring pin having a wave portion bent inward. When the platen roller is not attached to the printer main body, the frame engages with the thermal head to regulate the rotation of the thermal head toward the platen roller, and the platen roller is attached to the printer main body. The thermal head pressing mechanism according to claim 1, further comprising an engaging portion that is separated from the thermal head when the thermal head is mounted. The pressing mechanism of the thermal head according to any one of claims 1 to 5,
A lid portion disposed on the frame that is openable and closable in preparation for rotation of the platen roller;
A storage section for storing and holding recording paper in the main body frame;
A paper cut portion that is an upper part of the pressing mechanism of the thermal head and is detachable from the main body frame;
A printer comprising:

Images