JP2529941Y2 - Recording device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a recording apparatus including a recording head that presses a platen via a recording medium and a head pressing device that presses the recording head against the platen. Things.

[Conventional technology]

For example, a recording apparatus configured as a printer, a facsimile, or a copying machine having a recording head such as a thermal head or a stylus head has been conventionally known.

FIG. 3 shows a conventional example of a printer provided with such a recording head. Reference numeral 101 denotes a roller platen, 102 denotes a thermal head, 103 denotes a mounting bracket, 104 denotes a compression spring,
5 is an overhang plate fixed to the mounting bracket 103, 106 is a driven plate fixed to the overhang plate 105, 107 is an eccentric cam, 10
Reference numeral 8 denotes a motor, 109 denotes a timing belt, 110 denotes a leaf spring for attaching the head,
Is swingable about a pivot 113 of the mounting bracket 103. During recording, the eccentric cam 107 pushes the driven plate 106 to press the head 102 against the platen 101 via the ink sheet 27 and the recording paper 28. On the other hand, at the time of non-recording, the eccentric cam 107 rotates 180 ° by the drive of the motor 108, pushes up the overhang plate 105, and moves the head 102 to the platen 10
Move away from 1.

In such a conventional example, the thermal head 102 is pressed against the platen 101 by the extension elasticity of the compression spring 104. In this case, a spring 104 having a short free length and a relatively large spring force is used. In this case, the operability of the head 102 in the vertical direction is limited, and if the cylindricity of the platen 101 is poor, the pressing force tends to fluctuate.

Therefore, conventionally, in order to increase the uniformity of the pressing force, a spring having a long free length is used so that the spring force is hardly changed even when the amount of expansion and contraction is changed.

If such a spring is used, as shown in FIG. 3, the head pressurizing device becomes bulky in the direction A of the printing pressure, and the recording device inevitably becomes large.

In addition, as this kind of head related technology,
No. 34762, JP-A-60-99669, JP-A-60-214979, and JP-A-64-82972 have been proposed, but in any case, for the head pressure contact in the printing pressure direction. It is configured to have a spring.

[Problems to be solved by the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a recording apparatus in which a head pressing device is configured not to be bulky so as to be able to further reduce the thickness.

[Means for solving the problem]

According to the present invention, in order to achieve the above object, in a recording apparatus of the type described at the beginning, a head pressing device is disposed along the longitudinal direction of the recording head and is screwed to each other. A transmission member composed of first and second cylindrical bodies whose total length is adjusted by changing the length of the transmission member; a tension spring disposed inside the transmission member; and a transmission member disposed at each longitudinal end of the transmission member. A first and a second spring mounting member, each end of which is locked with the tension spring, and holds the tension spring with a predetermined tension;
Reciprocating the spring mounting member in the longitudinal direction of the transmission member,
The spring mounting member, the transmission member, and the second spring mounting member,
A drive means for operating in the longitudinal direction of the transmission member, pivotally supported by the apparatus main body, one end of which is pivotally attached to the second spring mounting member, and the other end of which is pivotally attached to the recording head, A link for converting the operation of the transmission member into a contact / separation operation of the recording head with respect to the platen, wherein when the recording head operates in the direction of approaching or separating from the platen by the operation of the driving means, A predetermined tension of the tension spring is set so that the second spring mounting member and the transmission member are integrally operated, and the recording head is operated in a direction approaching the platen so that the recording head is operated. After pressing the platen against the platen, the first spring mounting member separates from the transmission member, and the tension spring further extends.
A recording device is proposed in which an operation stroke when the driving means pulls the first spring mounting member is set.

〔Example〕

 Hereinafter, the present invention will be described based on an embodiment.

The printing apparatus shown in FIG. 1 includes a thermal head 2 which is an example of a printing head which is in pressure contact with a platen 1 via a printing medium, as will be described later,
And a head pressurizing device 5 for pressing against the head. Heating elements (not shown) are provided in an array in the axial direction of the platen 1 at a portion indicated by reference numeral 2a of the thermal head 2. Hereinafter, the portion indicated by reference numeral 2a will be referred to as a heating element portion. In the thermal head 2, a driver circuit for supplying electricity to the heating element is provided.

The thermal head 2 has an elongated rectangular parallelepiped shape, and its longitudinal direction is perpendicular to the printing pressure direction A. The thermal head 2 has a large area on both upper and lower surfaces, and the head pressing device 5 is provided along such a surface. Thus, the recording apparatus itself can be made thinner in the printing pressure direction A.

One end of the thermal head 2 is fixedly locked to the other end of the leaf spring 4 fixedly locked to the mounting bracket 3. When the mounting bracket 3 is pivotally attached to the side plate 7 of the apparatus main body by the pivot shaft 6, the thermal head 2 can swing freely around the pivot shaft 6.

A head pressurizing device 5 for pressing the thermal head 2 against the platen 1 is provided in a central region in the width direction of the thermal head 2, and includes a first cylindrical member 8 and a threaded portion attached to the first cylindrical member 8.
It has a transmission member consisting of a second tubular body 9 screwed at 10. The first and second cylindrical bodies 8 and 9 are disposed along the longitudinal direction of the recording head including the thermal head 2 and are screwed together at a screw portion 10. By changing the position, the overall length is adjusted. Also, the head pressing device 5
A tension spring 13 disposed inside a transmission member comprising first and second cylindrical bodies 8 and 9; and a first and second spring mounting member disposed at each longitudinal end of the transmission member. Member 12,1
Have one. Each end of the tension spring 13 is locked to the first and second spring mounting members 12 and 11, respectively, and these spring mounting members 12 and 11 are pulled by the tension springs 13 and the first and second cylinders. The pressing members 8 and 9 are pressed against the respective longitudinal ends of the transmission member. Thus, the first and second spring mounting members 12 and 11 hold the tension spring 13 with a predetermined tension. The head pressurizing device 5 also has an L-shaped connecting link 18 pivotally supported on a side plate 7 of the apparatus main body via a pivot shaft 17, and one end of the link 18 is connected to a second spring mounting member. The other end is pivotally attached to the member 11 via a pin 117, and the other end is pivotally attached to the recording head including the thermal head 2 via a pin 118. The head pressurizing device 5 further reciprocates the first spring mounting member 12 in the longitudinal direction of the transmission member, and connects the spring mounting member 12, the transmission member, and the second spring mounting member 11 to the longitudinal direction of the transmission member. In the present example, the driving means has a motor 16 and a disk 15.
That is, the first spring mounting member 12 is
The disk 15 is rotatably driven by a motor 16. The hatching of the second tubular body 9 shown in FIG. 1 is omitted for convenience.

At the time of non-printing, the thermal head 2 is held at a position shown in FIG. 1 in which the heating element portion 2a is separated from the platen 1. On the other hand, at the time of printing, the thermal head 2 rotates around the pivot 6, and the heating element 2a
However, it comes into pressure contact with a platen 1 via an ink sheet (not shown in FIG. 1) and a recording paper as an example of a recording medium. The recording head including the thermal head 2 is pressed against the platen 1 via the recording medium.

To explain the operation up to this pressure welding, first,
As the motor 16 rotates, the disk 15 rotates in the direction of the arrow, and at this time, the pin 14 carries the first spring mounting member 12 together with the first spring mounting member 12 from the two cylindrical bodies 8 and 9. The transmission member is driven to be displaced rightward in the figure. At this time, the second spring mounting member 11, which also moves integrally, connects the connecting link 18 to the pivot shaft.
Rotate clockwise in the figure around 17. Along with this, the thermal head 2 rotates, and the heating element portion 2a is pressed against the platen 1 via the ink sheet and the recording paper.

When the pin 14 comes to the E position, the thermal head 2
Is pressed. Here, the E position is a position on the near side where the pin 14 reaches the F position (180 ° rotation position).

The first spring mounting member 12 is separated from the tubular body 9 while the pin 14 is further pivotally changed from the position E toward the position F, and at the same time, the tension spring 13 which has been expanded until now is moved. ,
It further extends a predetermined amount. Then, when the pin 14 reaches the F position, the motor 16 is stopped, and the tension spring 13 is also in a state of being extended to the maximum. When the pin 14 reaches the position E, the heating element portion 2a comes into pressure contact with the platen 1, and the rightward movement of the transmission member composed of the cylindrical bodies 8, 9 is prevented. From this stage, the first spring mounting member 12
Is separated from the second cylindrical body 9, and the tension spring 13 is further extended by a predetermined amount.

After all, when the thermal head 2 is pressed against the platen 1, the first and second spring mounting members 12 and 11 and the cylindrical bodies 8 and 9
The transmission member is integrally rigid and is displaced to the right. The elasticity of the tension spring 13 is set so that the members 8 to 12 maintain a rigid structure until the thermal head 2 is pressed against the platen 1 in the attached state shown in the drawing.

When the pin 14 reaches the F position, the tension spring 13 is extended to the maximum extent, and printing is performed by the thermal head 2 in this state. At this time, the thermal head 2 can move up and down following the surface of the platen 1. That is, for example, even if the cylindricity of the platen 1 is poor, the tension spring
Under the action of the 13 elasticity of elasticity, the thermal head 2 can be pressed against the platen 1 with a uniform pressure. In addition,
A rotation angle detector (not shown) is provided in the vicinity of the disk 15 so that the rotation position of the disk 15 is detected, and on / off control of the motor 16 is performed.

When the printing operation is completed, the motor 16 re-rotates in the same direction as before or reverses, and the pin 14 returns from the F position to the position shown in the figure. During this time, the first spring mounting member 12 separated from the tubular body 9 contacts the tubular body 9, and thereafter, the two tubular bodies 8, 9 are moved in the leftward direction in the drawing by the rigid structure as described above. As a result, the operation arm 18 is rotated counterclockwise, and the thermal head 2 is separated from the platen 1.

As described above, the driving means having the motor 16 and the disk 15 causes the first spring mounting member 12 to reciprocate in the longitudinal direction of the transmission member composed of the cylindrical bodies 8 and 9, and the first spring mounting member The 12, the transmission member and the second spring mounting member 11 are operated in the longitudinal direction of the transmission member. At this time, the connecting link 18 converts the operation of the transmission member into a contact / separation operation of the recording head including the thermal head 2 with respect to the platen 1. When the recording head composed of the thermal head 2 is moved toward or away from the platen 1 by the operation of the driving means, the first and second spring mounting members 12, 11 and the transmission member are integrated. The above-mentioned predetermined tension of the tension spring 13 is set so as to operate. Further, after the recording head including the thermal head 2 is operated in a direction approaching the platen 1 and the recording head is pressed against the platen 1, the first spring mounting member 12 is separated from the transmission member, and the tension spring is moved.
An operating stroke when the driving means pulls the first spring mounting member 12 is set so that 13 further extends.

According to the head pressurizing device described above, even if a tension spring having a long natural length is used, this spring 13 is arranged along the longitudinal direction of the thermal head 2 in order to make the pressing force of the thermal head against the platen 1 uniform. Since it is arranged inside the transmission member composed of the first and second cylindrical bodies 8, 9 provided,
The spring 13 and therefore the entire head pressure device 5 are not bulky in the printing pressure direction of the thermal head, and can be made thinner.

In addition, until the thermal head 2 is pressed against the platen 1, no spring force acts upon driving the motor 16, so that the rotational load of the motor is not increased and a small output motor can be used. On the other hand, in the conventional example shown in FIG. 3, since the thermal head 102 is pressed against the platen 101 while the spring 104 is contracted, a force for contracting the spring must be added to the rotation of the motor. Ten
8 must be a large output.

In the conventional example, when the thermal head is pressed against the platen, the spring 104 is interposed, so that the pressing operation time is delayed. In contrast, in this example,
Since the spring does not substantially intervene, the thermal head 2 can be quickly pressed against the platen 1.

By the way, in the conventional example as shown in FIG. 3, the width of the thermal head 102 becomes longer as the recording paper size becomes larger. Therefore, two springs 104 are inserted in that direction to make the printing pressure uniform. . However, when a plurality of such springs are provided, if the free length of the springs varies, or if the end faces of the springs are inclined, the printing pressure becomes uneven in the width direction.
In such a state, the recording image density fluctuates, and the image quality deteriorates.

Therefore, conventionally, a special elasticity adjusting mechanism is added to each spring. However, in this case, a large space is required above the thermal head, and the device is easily enlarged.

In this example, by changing the screwing positions of the first and second cylindrical bodies 8 and 9 in the threaded portion 10, the total length of both cylindrical bodies can be adjusted and the elasticity of the tension spring 13 can be adjusted. Therefore, the large elasticity adjusting mechanism as described above is not required, and the size of the apparatus can be further reduced. In the case where two head pressing devices 5 shown in FIG. 1 are provided in the axial direction of the platen 1, the elasticity of each spring 13 can be changed by changing the screwing position for each head pressing device. it can.

In addition, since the entire length can be adjusted by changing the screw positions of the first and second cylindrical bodies 8 and 9, the spring force can be set to a desired size, and such a configuration uses a plurality of head pressing devices. The present invention can be advantageously applied not only to the case but also to a recording apparatus using only one of them.

Although the thermal head 2 of the type shown in FIG. 1 is called a flat type thermal head, the head pressing device 5 'can also be used in the case of using an end face type thermal head 2' as shown in FIG. By thus arranging the thermal head 2 'in the direction parallel to the printing pressure direction A along the longitudinal direction of the thermal head 2', it is possible to obtain a thin recording device in a direction perpendicular to the printing pressure direction.

In the above embodiment, a recording apparatus of a type that performs thermal transfer recording on recording paper using an ink sheet is applied.
In addition, the present invention is applicable to a recording apparatus using only thermal paper as a recording medium, and is also applicable to a recording apparatus using a recording head such as a stylus head in addition to a thermal head.

[Effect of the invention]

According to the present invention, even if a tension spring having a long natural length is used as the tension spring of the head pressurizing device, the first and second cylindrical bodies on which the tension spring is arranged are arranged along the longitudinal direction of the recording head. Therefore, the thickness of the head pressing device can be reduced, and the size of the entire recording device can be reduced.

Until the recording head comes into pressure contact with the platen, no spring force acts on the driving means, so that the load on the driving means can be reduced and a driving means with a small output can be used. Moreover, when the recording head is pressed against the platen, the recording head can be quickly pressed against the platen.

Further, the spring force of the tension spring, that is, the predetermined tension can be adjusted only by changing the screwing positions of the first and second cylindrical bodies constituting the transmission member. It is not necessary to use a large elasticity adjusting mechanism, and the recording apparatus can be further reduced in size.

[Brief description of the drawings]

FIG. 1 is a partial sectional view showing a recording apparatus according to one embodiment of the present invention, FIG. 2 is an explanatory view of another embodiment, and FIG. 3 is an explanatory view of a conventional example. DESCRIPTION OF SYMBOLS 1 ... Platen, 5,5 '... Head pressurizing device 8 ... 1st cylindrical body, 9 ... 2nd cylindrical body 11 ... 2nd spring mounting member, 12 ... 1st Spring mounting member 13 …… Tension spring, 18 …… Connection link

Claims (1)

(57) [Scope of request for utility model registration] 1. A recording apparatus comprising: a recording head that presses a platen via a recording medium; and a head pressing device that presses the recording head against the platen, wherein the head pressing device is disposed in a longitudinal direction of the recording head. And a transmission member composed of first and second cylindrical bodies whose lengths are adjusted by changing their screwing positions while being screwed with each other, and disposed inside the transmission member. Tension springs, and first and second springs respectively disposed at longitudinal ends of the transmission member, each end of the tension spring being locked, and holding the tension spring with a predetermined tension. An attachment member, and a driving unit that reciprocates the first spring attachment member in the longitudinal direction of the transmission member, and operates the spring attachment member, the transmission member, and the second spring attachment member in the longitudinal direction of the transmission member. Equipment book And the other end is pivotally attached to the second spring mounting member, and the other end is pivotally attached to the recording head. When the recording head operates in a direction approaching or moving away from the platen by the operation of the driving means, the first link is provided.
A predetermined tension of the tension spring is set so that the second spring mounting member and the transmission member operate integrally, and the recording head operates in a direction approaching the platen to perform the recording. The operating stroke when the driving means pulls the first spring mounting member is set so that the first spring mounting member is separated from the transmission member after the head is pressed against the platen, and the tension spring is further extended. A recording device, characterized in that: