JP2732255B2 - Ink sheet cassette - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an ink sheet cassette capable of suppressing a change in tension applied to a sheet material.

<Prior Art> Conventionally, in an ink sheet cassette used in a thermal transfer recording apparatus or the like, when an ink sheet stored in the ink sheet cassette is moved from a supply core to a take-up core and pulled out to a recording unit, the ink sheet is removed. A mechanism for applying a constant tension is provided so that the sheet can be stably conveyed. As this mechanism, a certain tension is generally given by a frictional force generated between the ink sheets by pressing the ink sheet with a felt pad attached to a leaf spring. Also, a mechanism for applying tension to prevent the ink sheet from being loosened when the recording head that has been pressed down and pressed the ink sheet onto the recording sheet during recording and headed up with the end of the recording and retracted. Separately, it is provided between the leaf spring and the recording section.

<Problems to be solved by the invention> However, in the above-described conventional technology, the tension applied to the ink sheet is determined by the coefficient of friction between the felt pad and the ink sheet and the leaf spring to which the felt pad is attached. Determined by pressing force.

Therefore, the frictional force between the felt pad and the ink sheet may change due to a change in temperature, humidity, or the like, or the tension may change due to variations in manufacturing the ink sheet.

In this case, for example, when the humidity is low, the tension of the ink sheet becomes small, the running of the ink sheet becomes unstable, and the sheet bends. There are problems such as the possibility of occurrence.

Furthermore, when using several types of ink sheets,
There was a problem that the leaf spring had to be changed in accordance with the sheet and the cost was likely to increase.

An object of the present invention is to provide an ink sheet cassette that solves the above-mentioned conventional problems and that can suppress fluctuation in the tension applied to an ink sheet.

<Means for Solving the Problems> A representative configuration of the present invention that solves the problems includes a guide mechanism that changes the transport path of the ink sheet by a change in tension acting on the ink sheet, and presses the ink sheet. An elastic member, and an opposing member disposed opposite to the elastic member via the conveyance path to receive the ink sheet pressed by the elastic member. A tension applying mechanism for adjusting a holding pressure of the ink sheet, wherein the guide mechanism reduces a holding pressure of the ink sheet by the elastic member and the opposing member when a tension acting on the ink sheet increases. The elastic member is configured to move in a weakening direction.

<Operation> According to the above-described means, when the tension applied to the ink sheet changes, the frictional force between the ink sheet and the member with which the sheet comes into contact changes accordingly. Therefore, the tension applied to the ink sheet is kept substantially constant, and the ink sheet can be transported stably.

<Example> Next, an example of an ink sheet cassette according to the present invention will be described with reference to the drawings.

(First embodiment)

In FIG. 1, reference numeral 1 denotes a dry-type ink sheet cassette which is removably mounted on a recording apparatus (not shown), and has an ink in which an ink which is melted or reduced in viscosity by heat is applied on a base film. Sheet 2 is supply core 3a
The cassette 3 is guided so as to be exposed once from the core 3a in the concave portion 1a of the cassette 1 and wound around the winding core 3b.

The winding core 3b is configured to be rotatable by engaging with a rotating shaft connected to a friction clutch (not shown) and transmits a driving force for transporting the ink sheet 2.

Reference numerals 4a and 4b denote plate-shaped felt springs made of an elastic member such as phosphor bronze disposed to face each other with the ink sheet 2 interposed therebetween. As described later, the springs 4a and 4b are formed by protrusions 1a and 1b projecting into the cassette 1 so that the springs 4a and 4b do not return to a no-load state even when the tension of the ink sheet 2 changes and the pressing force fluctuates. One end of each of the holding members 1c, 1c provided in the cassette 1 is curved.
By d, the ink sheet 2 is held so as to slightly move and lock when the ink sheet 2 is conveyed.

One of the springs 4a and 4b is an elastic member that presses the ink sheet 2, and the other spring 4b is disposed to face the spring 4a via the ink sheet 2 conveyance path. It is an opposing member for receiving the ink sheet 2 pressed by 4a.

Reference numerals 5a and 5b denote felt pads which are adhered to the felt springs 4a and 4b so as to oppose each other and press the ink sheet 2. The felt pads 5a, 5b are constantly urged by the elastic force of the felt springs 4a, 4b and come into contact with the ink sheet 2 with substantially equal pressing forces from the base film side 2a and the ink layer side 2b of the ink sheet 2, respectively. The back tension is applied to the conveying direction of the ink sheet 2 (the direction of arrow A in the figure) by the frictional force of the contact surface.

Reference numerals 6a, 6b, 6c, 6d, and 6e denote guide members formed of columnar pins protruding into the cassette 1 for guiding the ink sheet 2.

The guide member 6c is located downstream of the nip portions 5a and 5b in the transport direction of the ink sheet 2, and serves as a guide mechanism that changes the transport path of the ink sheet 2 against the pressing force of the spring 4a. This member is fixed in the cassette 1 in this embodiment.

Reference numeral 7 denotes a spring for preventing the ink sheet 2 wound around the winding core 3b from being pulled back when the cassette 1 is removed from the recording apparatus. 2 is pressed against the peripheral wall of the cassette 1 to apply tension.

Next, the operation of the ink sheet 2 stored in the cassette 1 configured as described above will be described.

At the time of non-recording, the ink sheet 2 wound around the supply core 3a passes between the felt springs 4a, 4b via the guide members 6a, 6b, and the felt pad 5a adhered to the tip of the springs 4a, 4b. , 5b. A guide member 6c that is located downstream of the pressing portions 5a and 5b in the transport direction of the ink sheet 2 and changes the transport path of the ink sheet 2 against the pressing force of the spring 4a. After the recording head (not shown) provided in the cassette 1 is exposed to the outside via the guide member 6d for guiding the recess 1a, the recording head is pressed by the spring 7 and then wound via the guide member 6e. It is configured to be wound around the core 3b.

When recording is started, a recording head (not shown) disposed in the concave portion 1a of the cassette 1 heads down and presses the ink sheet 2 and the recording sheet (not shown). Withdrawn from 3a. At this time, the tension of the ink sheet 2 increases toward the downstream side in the transport direction. The ink sheet 2 is spring-loaded by the guide member 6c as described above.
Since the ink sheet 2 is guided against the pressing force of 4a, the ink sheet 2 is strongly pressed against the pad 5a, and the spring 4a is further bent and bent in the direction of arrow B in FIG. Is weakened but is pressed by the elastic force of the spring 4b to return in the direction of arrow B in the figure. Therefore, the ink sheet 2 has the spring 4
A pressure is applied between the pads 5a and 5b attached to the ink sheets 2a and 4b, respectively, and tension is applied to the ink sheet 2 by the frictional force between the pads 5a and 5b and the ink sheet 2 as a whole during non-recording.

At this time, if the frictional force between the pads 5a and 5b and the ink sheet 2 increases due to a change in ambient temperature, humidity, or the like, or a manufacturing variation of the ink sheet 2, and the tension of the ink sheet 2 increases, The spring 4a bends further in the direction of arrow B in the figure. As a result, the force with which the spring 4b presses the ink sheet 2 decreases, and the frictional force generated between the pad 5b adhered to the spring 4b and the ink layer side 2b of the ink sheet 2 decreases. The applied tension can be prevented from further increasing. At this time, the base film side 2a of the ink sheet 2 strongly contacts the pad 5a. However, since the friction coefficient of the base film side 2a of the ink sheet 2 is generally smaller than that of the ink layer side 2b, the tension is not significantly increased. It can be kept almost constant.

When the recording is completed, the recording head (not shown), which has pressed the ink sheet 2 onto the recording sheet, heads up and retreats into the concave portion 1a of the cassette 1. At this time, the ink sheet 2 that has been drawn out of the cassette 1 by the pressing of the head is loosened, but the spring 4a largely bent in the direction of the arrow B returns to the non-recording position by elastic force. The tension is applied to the ink sheet 2 via the guide members 6c and 6d on the upstream side in the transport direction of the ink sheet 2, and the ink sheet 2 is pulled back into the cassette 1 to remove slack.
Therefore, there is no need to replace the spring depending on the ink sheet to be used, and the number of components is reduced as compared with the conventional case, so that the cost can be reduced.

Although each guide member of the ink sheet 2 in the above embodiment is constituted by a cylindrical pin fixed to the cassette, a rotatable roller may be used.

(Second embodiment)

Next, another embodiment of the tension applying mechanism for the ink sheet 2 in the first embodiment will be described with reference to FIG.

In FIG. 2, the ink sheet 2 wound around the supply core 3a is guided by a guide member 6f, then curved into the cassette 1 and one end is slightly moved by the holding member 1e when the ink sheet 2 is conveyed. It is pressed by the protruding tip 4c 'of the plate-like felt spring 4c held so as to be locked, and comes into contact with the felt pad 5c provided on the peripheral wall of the cassette 1 so as to face the tip 4c' of the spring 4c. . Accordingly, the back tension is applied to the ink sheet 2 mainly by the frictional force generated between the ink layer 2b of the ink sheet 2 and the felt pad 5c. Next, the ink sheet 2 is provided with a slack removing arm 9 rotatable about a fulcrum 8 projecting from the cassette 1.
And the tip 4c 'of the spring 4c and the pad 5c.
A guide member which is a columnar guide mechanism which is located downstream of the pressurizing portion of the ink sheet 2 in the conveying direction of the ink sheet 2 and changes the conveying path of the ink sheet 2 against the pressing force of the spring 4c.
6g, a guide member 6h protruding into the cassette 1 located downstream of the guide member 6g in the conveying direction of the ink sheet 2, and a guide member 6i for guiding the ink sheet 2 to the concave portion 1a of the cut 1. The recording head (not shown) is guided to a concave portion 1a of the cassette 1 in which the recording head is arranged.

Numeral 10 denotes a torsion spring, which is a projection 11 projecting from the fulcrum 8 to which the arm 9 is attached.
And a projection 12 provided in the cassette 1 to constantly urge the arm 9 counterclockwise.

When the recording is started, the recording head (not shown) arranged in the concave portion 1a of the cassette 1 heads down and presses the ink sheet 2 onto the recording sheet (not shown), and the ink sheet 2 is supplied. Pulled out from core 3a. At this time, the tension of the ink sheet 2 increases toward the downstream side in the transport direction. Here, since the ink sheet 2 is guided so as to be wound around the guide member 6g, the arm 9 provided with the guide member 6g is rotated clockwise (the direction of arrow C in the drawing). as a result,
The conveying path of the ink sheet 2 from the pressure portion between the distal end portion 4c 'of the spring 4c, which is an elastic member, and the pad 5c, which faces the guide member 6g, faces leftward against the pressing force of the spring 4c (the ink sheet 2c). Changes in the direction away from the pad 5c) and the spring
4c warps in the direction of arrow D in the figure, the pressure contact state between the ink layer side 2b of the ink sheet 2 and the pad 5c is weakened, and the frictional force generated therebetween is reduced.

Accordingly, since the back tension applied to the ink sheet 2 is reduced, it is possible to reduce the increase in the tension due to the head down of the recording head. Further, even if the frictional force between the pad 5c and the ink sheet 2 increases due to a change in ambient temperature, humidity, or the like, or a manufacturing variation of the ink sheet 2, the tension of the ink sheet 2 increases. As in the case of recording, the tension applied to the ink sheet 2 can be kept substantially constant. Note that the base film side 2a of the ink sheet 2 is the tip 4c 'of the spring 4c.
However, since the coefficient of friction is generally smaller on the base film side 2a of the ink sheet 2 than on the ink layer side 2b, the tension does not significantly increase.

When the recording is completed, the recording head (not shown), which has pressed the ink sheet 2 onto the recording sheet, heads up and retreats into the concave portion 1a of the cassette 1. At this time, the ink sheet 2 that has been drawn out of the cassette 1 by the pressing of the head is loosened, but the arm 9 rotates counterclockwise by the elastic force of the spring 10 to return to the non-recording position. Since the ink sheet 2 returns, tension is applied to the ink sheet 2 via the guide members 6g, 6h, and 6i on the upstream side in the winding direction of the ink sheet 2, and the ink sheet 2 is pulled back into the cassette 1 to remove slack.

(Third embodiment)

Next, FIG. 3A shows another embodiment in which the tension applying mechanism of the ink sheet 2 in the second embodiment is partially changed.
This will be described with reference to FIG.

In FIG. 3A, the ink sheet 2 wound around the supply core 3a is curved by a projection 1f projecting from the peripheral wall of the cassette 1, and one end of the ink sheet 2 is conveyed by a holding member 1g. At this time, the felt spring 4d, which is a plate-like elastic member held so as to be slightly moved and locked, is pressed by a felt pad 5d attached to the tip of the spring 4d and protrudes into the cassette 1. It is in contact with the columnar guide member 6j which is the provided opposing member so as to be wound therearound. Accordingly, the base film side 2a of the ink sheet 2 and the guide member
The back tension is applied to the ink sheet 2 by a friction force generated between the felt pad 6d and the ink layer side 2b of the ink sheet 2 and the felt pad 5d. Next, the ink sheet 2 is protruded from the tip of a slack removing arm 9 rotatable about a cylindrical guide member 61 protruding from the cassette 1 and is provided with a spring 4d.
Is located on the downstream side in the conveying direction of the ink sheet 2 from the pressing portion between the pad 5d adhered to the leading end of the sheet and the guide member 6j, and changes the conveying path of the ink sheet 2 against the pressing force of the spring 4d. It is guided to the recess 1a of the cassette 1 via a guide member 6k, which is a cylindrical guide mechanism to be made, the guide member 61, and a guide member 6i located above the guide member 6k.

A torsion spring 10 is provided between a projection 11 provided on the arm 9 and a projection 12 provided in the cassette 1 around a guide member 6l to which the arm 9 is attached. The arm 9 is always urged in a counterclockwise direction.

When the recording is started, the recording head (not shown) arranged in the concave portion 1a of the cassette 1 heads down and presses the ink sheet 2 onto the recording sheet (not shown), and the ink sheet 2 is supplied. Pulled out from core 3a. At this time, the tension on the ink sheet 2 is increased downstream in the winding direction.
Here, since the ink sheet 2 is guided so as to be wound around the guide member 6k, the arm 9 is rotated in the clockwise direction (direction of arrow C in the figure) about the guide member 61 as shown by the dotted line in the figure. The conveying path of the ink sheet 2 from the pressure portion between the guide member 6j and the pad 5d toward the guide member 6k is directed rightward against the pressing force of the spring 4d as shown by the dashed line in FIG. Direction away from 6j)
Changes to As a result, the spring 4d pressing the ink sheet 2 warps in the direction of arrow E in the figure, and the pressure contact state between the base film side 2a of the ink sheet 2 and the guide member 6j is weakened, so that the frictional force generated therebetween is reduced, The back tension applied to the ink sheet 2 at the pressure portion between the guide member 6j and the pad 5d decreases.

Therefore, it is possible to reduce the increase in the tension caused by the head down of the recording head. Further, at this time, the frictional force between the pad 5d and the ink layer side 2b of the ink sheet 2 increases due to a change in ambient temperature, humidity, or the like, or a manufacturing variation of the ink sheet 2, and the tension of the ink sheet 2 increases. However, since the frictional force between the guide member 6j and the base film side 2a of the ink sheet 2 is reduced, the tension applied to the ink sheet 2 as a whole can be kept substantially constant as in non-recording.

When the recording is completed, the recording head (not shown), which has pressed the ink sheet 2 onto the recording sheet, heads up and retreats into the concave portion 1a of the cassette 1. At this time, the ink sheet 2 pulled out of the cassette 1 by the pressing of the head is loosened, but the elastic force of the spring 10 causes the arm 9 to rotate counterclockwise to return to the non-recording position. The guide member 6
Tension is applied to the upstream side in the transport direction of the ink sheet 2 via k.6l and 6i, and the ink sheet 2 is pulled back into the cassette 1 to remove slack.

In the third embodiment, the frictional force between the base film side 2a of the ink sheet 2 and the guide member 6j is reduced so that the tension of the ink sheet 2 is kept constant. As shown in (b), a projection 4d 'made of a material (for example, metal) having a smaller coefficient of friction with the ink sheet 2 than the felt pad 5d is provided at the tip of the spring 4d so that the transport angle of the ink sheet 2 is rightward. When the projections change
It can also be configured to contact d '. In this case, the guide member 6j and the base film side of the ink sheet 2
In addition to 2a, the pad 5d and the ink layer side of the ink sheet 2
It is possible to keep the tension constant by reducing the frictional force generated between the wire 2b.

<Effect of the Invention> As described above, the present invention provides a tension applying mechanism for adjusting the holding pressure of the ink sheet by the elastic member and the opposing member, and changes the transport path of the ink sheet by a change in the tension applied to the ink sheet. When the tension acting on the ink sheet is increased by the guide mechanism, the elastic member is moved in a direction to decrease the holding pressure. Even when the frictional force between the ink sheet and the member that comes into contact with the ink sheet fluctuates due to variations or the like, the tension applied to the ink sheet can be kept constant, and the ink sheet can be stably conveyed.

Further, even when several types of ink sheets are used, common parts can be used, so that the cost can be reduced as compared with the related art.

[Brief description of the drawings]

FIG. 1 is an explanatory view when the present invention is applied to an ink sheet cassette, and FIGS. 2 and 3 (a) and 3 (b) are explanatory views of another example. 1 is a cassette, 1a is a recess, 2 is an ink sheet, 3a and 3b are cores, 4a, 4b, 4c, 4d, 7, and 10 are springs, 5a, 5b, 5c, and 5d are pads, 6a, 6b, 6c, and 6d. , 6e, 6f, 6g, 6h, 6i, 6j, 6k, 6l are guide members, 8 is a fulcrum, and 9 is an arm.

Claims (5)

(57) [Claims] A guide mechanism for changing a transport path of the ink sheet by a change in tension acting on the ink sheet; an elastic member for pressing the ink sheet; and an elastic member opposed to the elastic member via the transport path. An opposing member disposed to receive the ink sheet pressed by the elastic member; and a tension applying mechanism for adjusting a pressure for holding the ink sheet by the elastic member and the opposing member; A mechanism configured to move the elastic member in a direction to weaken a holding pressure of the ink sheet by the elastic member and the opposing member when a tension acting on the ink sheet increases. Ink sheet cassette. 2. The ink sheet cassette according to claim 1, wherein the direction in which the holding pressure of the ink sheet is reduced is a direction in which the frictional force between the opposed member and the ink sheet is reduced. 3. The ink sheet cassette according to claim 1, wherein the guide mechanism moves in contact with a base film surface of the ink sheet opposite to the ink surface. 4. The ink sheet cassette according to claim 1, wherein when the tension acting on the ink sheet changes, the elastic member is moved to change the holding pressure. 5. The ink sheet cassette according to claim 1, wherein when the tension acting on the ink sheet fluctuates, the nipping pressure is fluctuated by moving the guide mechanism and the elastic member.