JPH11227290A - Thermal recording equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent irregularities in the transport speed of a recording medium from occurring and improve image quality by holding a platen roller pressed against a belt so that the platen roller may be rotated together from the beginning even when recording is not to be executed by separating the platen roller from thermal heads. SOLUTION: During recording with a copying machine, an urging member 46 is moved with a moving means, and an ink ribbon r is transported by pressing platen rollers 32 to 35 against thermal heads 25 to 28 through a belt 30. A recording medium is transported by transporting the belt 30 while rotating the platen rollers 32 to 35 together, and a color image is recorded on a recording medium by transferring color ink of the ink ribbon (r) onto the recording medium. During non-recording, the base end of the urging member 46 is moved by a moving means and the platen rollers 32 to 35 are separated from the thermal heads 25 to 28 while held in contact with the belt 30, the transport of the ink ribbon (r) is suspended, and the delivery of the belt 30 is stopped.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention can be applied to, for example, a copying machine, a printer, a facsimile, and a multifunction machine thereof. More particularly, the present invention relates to a thermal recording apparatus that records an image by interposing a recording medium such as paper or a card with an ink ribbon between a platen roller and a thermal head and thermally transferring ink of the ink ribbon to the recording medium with the thermal head.

[0002]

2. Description of the Related Art Conventionally, in a thermal type recording apparatus of this kind, as shown in FIG. 9, for example, a thermal head is provided on a transport path 2 for transporting a recording medium 1 in order from the front in the transport direction shown by an arrow in the figure. 3a to 3d are arranged at equal intervals, and the ink ribbon 4 is hung on the end having a heat generating portion, respectively, while the platen rollers 5a to 5d can be freely moved toward and away from the thermal heads 3a to 3d below the transport path 2. In some cases.

As shown in FIG. 10, for example, an ink ribbon 4 is a color ink ribbon formed by repeatedly forming many sets of ink surfaces a, b, c, and d of four different colors. As shown in FIG. And the recording medium 1 is conveyed at a constant slow speed lower than the conveying speed of the recording medium 1 in the direction indicated by the arrow in FIG.

During recording, the recording medium 1 is fed between the platen roller 5a and the thermal head 3a.
At a position corresponding to the ink surface a of the first color of the ink ribbon 4, the first platen 5a is pressed against the thermal head 3a with the recording medium 1 interposed therebetween, and the thermal head 3a
The color ink is thermally transferred onto the recording medium 1.

After that, while the platen rollers 5a to 5d rotate to convey the recording medium 1, the thermal head 3a
The recording of the first color is continued while the ink ribbon 4
At positions corresponding to the ink surfaces b to d of the second to fourth colors,
The platen rollers 5b to 5d are sequentially moved to the thermal head 3b.
To 3d, and the thermal heads 3b to 3d
The fourth to fourth color inks are thermally transferred onto the recording medium 1 respectively. Thus, a four-color composite color image was formed on the recording medium 1.

[0006]

However, in such a conventional thermal type recording apparatus, the platen rollers 5a to 5a are used.
When the recording medium 1 is conveyed while rotating 5d, a slight difference in the peripheral speed between the platen rollers causes an irregularity in the conveying speed of the recording medium 1, and an image shift occurs due to the irregularity in the conveying speed. There was a problem that the quality deteriorated.

Further, when the platen rollers 5a to 5d are pressed against the recording medium 1 by the urging members, unevenness occurs in the pressing force applied to the recording medium 1 due to the difference in the pressing force between the platen rollers. However, there is also a problem that skew easily occurs when the recording medium 1 is conveyed.

[0008]

SUMMARY OF THE INVENTION Therefore, the invention according to a first aspect of the present invention is directed to a thermal recording apparatus, for example, as shown in an embodiment described with reference to the following drawings.
, An endless belt 30 that conveys the recording medium through the conveyance path 18, and a plurality of platen rollers 32 provided inside the belt 30.
And a plurality of thermal heads 2 provided outside the belt 30 so as to face the platen rollers 32-35.
5 to 28 and ink ribbons r having ink surfaces Y, M, C, and B of different colors according to the number of the thermal heads 25 to 28, and an ink ribbon r conveyed between the thermal heads 25 to 28 and the belt 30. An urging member 46 provided corresponding to each of the platen rollers 32 to 35 to individually urge each of the platen rollers 32 to 35, and a base end of each corresponding urging member 46 is moved. And the platen rollers 32-35 via the belt 30 to the thermal heads 25-28.
And a moving means 40 for separating the platen rollers 32-35 from the thermal heads 25-28 while maintaining contact with the belt 30 during non-recording.

At the time of recording, the base of the urging member 46 is moved by the moving means 40, and the platen roller 32 is moved by the urging force.
To the thermal heads 25 to 28 via the belt 30.
, The ink ribbon r is transported little by little, and the recording medium is transported by feeding the belt 30 while rotating the platen rollers 32 to 35 so that each color of the ink surface Y, M, C, and B of the ink ribbon r is The ink is thermally transferred by the thermal heads 25 to 28 to record a color image on a recording medium. At the time of non-recording, the urging member 4 is
6 while maintaining the contact with the belt 30 and moving the platen rollers 32-35 through the thermal heads 25-28.
To stop the conveyance of the ink ribbon r and stop the feeding of the belt 30.

According to a second aspect of the present invention, in a thermal recording apparatus, as in an embodiment described with reference to the following drawings, for example, a transport path 18 for a recording medium such as a card P, and the transport path 18 Belt 30, which conveys a recording medium through the belt 30, a plurality of platen rollers 32 to 35 provided inside the belt 30, and the belt 30
, A plurality of thermal heads 25 to 28 provided opposite to the platen rollers 32 to 35, and ink surfaces Y and Y of different colors according to the number of the thermal heads 25 to 28.
M, C, and B, an ink ribbon r conveyed between the thermal heads 25 to 28 and the belt 30, and an elastic member provided corresponding to each of the platen rollers 32 to 35 to individually urge them. First urging member 50 having a high coefficient
A second urging member 51 having a low elastic coefficient, which is provided corresponding to each of the platen rollers 32 to 35 and urges each of them individually, and a corresponding pair of urging members 50.
51, the platen rollers 32 to 35 are pressed against the thermal heads 25 to 28 via the belt 30 by the urging force at the time of recording, and at the time of non-recording,
Moving means 40 for separating the platen rollers 32-35 from the thermal heads 25-28 while maintaining the contact with the belt 30 by the second biasing member 51.

At the time of recording, the moving means 40 moves the base ends of the urging members 50 and 51, and presses the platen rollers 32-35 against the thermal heads 25-28 via the belt 30 by the urging force. While transporting the ink ribbon r little by little, the belt 30 is transported while rotating the platen rollers 32 to 35 to transport the recording medium, and the respective color inks on the ink surfaces Y, M, C, and B of the ink ribbon r are respectively transferred. A color image is recorded on a recording medium by thermal transfer with the thermal heads 25 to 28. At the time of non-recording, the moving means 40 moves the base ends of the urging members 50 and 51, and the second urging member 5
At 1, the platen rollers 32-35 are separated from the thermal heads 25-28 while maintaining contact with the belt 30,
The transport of the ink ribbon r is stopped, and the feeding of the belt 30 is stopped.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a thermal color printer according to the present invention, and shows an overall schematic configuration of an internal mechanism thereof.

This thermal color printer is a thermal recording apparatus that uses a card as a recording medium and records a color image on the card to create a telephone card, a cash card, and the like.

Reference numeral 10 in the drawing indicates an outer case in the form of a horizontally long box of the printer shown. Inside the exterior case 10, opposed side plates are provided before and after in the depth direction, and many of the following components are supported between the opposed side plates.

First, a card mounting table 11 is provided between the opposing side plates at the right end in the figure, and a large number of cards (recording media) P are stacked on the card mounting table 11. The card mounting table 11 is supported by a pair of support arms 12 each having a tip attached to a support member 11a extending downward therefrom. The support arms 12 are provided in parallel with each other, rotatably support the respective support shafts 12a on the base end side as fulcrums, and support the card mounting table 11 so as to be able to move up and down by an arm drive motor (not shown). I do.

On the other hand, a position detecting sensor 13 for detecting that the uppermost card is at a predetermined paper feeding height position is provided above the card mounting table 11. Then, in response to the detection result of the position detection sensor 13, the support arm 12 is rotated to set the uppermost card to a predetermined paper feeding height position and to set the supply roller 1
Pressed against 5.

Further, on the left side of the supply roller 15 in the drawing,
A separation roller 16 is provided, and a drive transmission belt 14 is stretched between pulleys coaxial with the rollers 15 and 16. A friction pad 17 is pressed against the outer periphery of the separation roller 16.

Reference numeral 18 in the figure denotes a transport path for transporting the card P from right to left in the figure through the space between the separation roller 16 and the friction pad 17. A transport guide plate 19, a registration roller pair 20, a recording unit R, a discharge guide plate 23, and a discharge roller pair 24 are sequentially provided along the transport path 18.

The recording section R is provided with thermal heads 25 to 28 of yellow, magenta, cyan, and black arranged at equal intervals in this order from the front in the conveying direction of the card P on the upper side of the conveying path 18. Each of the thermal heads 25 to 28 has an elongated plate shape in the depth direction, and is formed by hanging an ink ribbon r on a tip having a heat generating portion.

The ink ribbon r is, for example, a thermal sublimation type multi-ink ribbon. For example, a large number of yellow, magenta, cyan, and black ink surfaces Y, M, C, and B are sequentially repeated in the ribbon transport direction shown by an arrow in FIG. Formed.
In a ribbon cassette (not shown), as shown in FIG. 1, it is wrapped around the right and left delivery cores 31 and 32 so as to be conveyed from the delivery side in the direction indicated by the arrow in FIG. Ink surface Y is thermal head 2
This is the initial position located just before 5.

In the recording section R, a thermal head 25 is provided.
Below 28, an endless belt 30 for transporting the card P through the transport path 18 is provided. The belt 30 extends between the left and right driving rollers 60 and driven rollers 61, a tension roller 62 provided below the driving roller 60, and a small-diameter guide roller 63, and presses the rear conveyance roller 22 on the driving roller 60. The front conveyance roller 21 is pressed against the driven roller 61. Then, the discharge guide plate 23
The drive of a belt drive motor 37 provided below is transmitted to a drive roller 60 via a drive transmission member such as a transmission belt 38 so that the belt 30 can be rotated counterclockwise in FIG.

Further, in the recording section R, a plurality of platen rollers 32 to 35 are provided inside the belt 30 between the driving roller 60 and the driven roller 61. Platen roller 32-3
Numeral 5 is provided rotatably in opposition to each end of the thermal head 25 via the belt 30 and the ink ribbon r. Then, the platen rollers 32 to 35 are provided at the pressing position and the retreat position with respect to the thermal heads 25 to 28 by respective separate contacting / separating mechanisms A so as to be freely contactable / separable. The contact / separation mechanisms A have the same configuration, and
3 shows the contact / separation mechanism A for the platen roller 32.

The contact / separation mechanism A engages a bearing member 45 slidably up and down with a vertically long guide hole 48 provided on the opposite side plate, and the roller members at both ends of the platen roller 32 are rotatable by the bearing members 45. Attach and hold. Further, the holding member 44 is slidably engaged with the guide hole 48 below the bearing member 45, and the both ends of the operating shaft 43 are attached and held by the holding member 44. An urging member 46 made of a compression spring is provided between the upper and lower bearing members 45 and the holding member 44, and a moving means 40 for the urging member 46 is provided below the operating shaft 43.

The moving means 40 has a support shaft 38 provided in parallel with the operating shaft 43, and supports the support shaft 38 rotatably between the opposed side plates. Further, a disk-shaped cam 39a is fixedly provided on the support shaft 38, and the operating shaft 4 is mounted on the cam 39a.
Put 3 and support. The cam 39a is a step motor 41
Is transmitted to the support shaft 38 by the drive transmission belt 42 to rotate. The cam 39a is rotated by the step motor 41, and the urging member 46 is turned on in accordance with the rotation position of the cam 39a.
Can be moved to upper and lower positions.

In the recording section R, when recording is not performed, the platen rollers 32 to 35 are moved by the above-described contact / separation mechanism A.
At standby positions away from the thermal heads 25 to 28.

Now, using the printer shown in FIG.
When a color image is to be recorded, the card supply motor is driven, the supply roller 15 is rotated, and the separation roller 1 is rotated.
Rotate 6. Then, the card P is fed out from the top by the supply roller 15 and guided between the separation roller 16 and the friction pad 17. At this time, when a plurality of cards are fed out while being overlapped, the cards P are conveyed to the conveyance path 18 while passing through the separation roller 16 and the friction pad 17 while being separated one by one.

Then, the card P is guided by the transport guide plate 19 and abuts against the pair of registration rollers 20 to be stopped. Then, the card P is fed between the thermal head 25 and the platen roller 32 at a certain timing.

On the other hand, in accordance with the transfer timing of the card P, the unillustrated ribbon feeding motor and the ribbon take-up motor are driven, and the ink ribbon r at the initial position is set in a stretched state so that the ribbon P is kept at a constant speed from the card transfer speed. Transport at a slow speed.

Then, as shown in FIG. 4A, when the ink surface Y and the leading end of the card P enter between the thermal head 25 and the platen roller 32, the first cam 39a is rotated by a predetermined angle. The operation shaft 43 is raised via the holding member 44, and the bearing member 45 is pushed up via the urging member 46 to raise the platen roller 32.
Is pressed against the thermal head 25 via the belt 30, the card P, and the ink ribbon r, and the thermal head transfers the ink on the ink surface Y onto the card P to start yellow image recording.

When the ink surface M and the leading end of the card P enter the space between the next thermal head 26 and the platen roller 33 while the yellow image is continuously recorded by the thermal head 25, the second cam 39b is rotated. Similarly, FIG.
As shown in (b), the platen roller 33 is pushed up and pressed against the thermal head 26, and the ink on the ink surface M is thermally transferred onto the card P by the thermal head to start magenta image recording.

Thereafter, while the image recording of yellow and magenta is continued, the belt 30 is similarly rotated to rotate the card P.
4C, when the ink surface C and the leading end of the card P enter between the next thermal head 27 and the platen roller 34, as shown in FIG. 4C, the third cam 39c is rotated. The platen roller 34 is pressed against the thermal head 27 to start thermal transfer of the ink on the ink surface C onto the card P,
Further, as shown in FIG.
Of the thermal head 28 and the platen roller 35
In the middle, the fourth cam 39d is rotated, and the platen roller 35 is pressed against the thermal head 28 to start thermal transfer of the ink on the ink surface B onto the card P.

In this manner, the platen rollers 32 to 3
5, the respective inks of the ink surfaces Y, M, C and B are thermally transferred onto the card P by the thermal heads 25 to 28 at the positions corresponding to the ink surfaces Y, M, C, and B, respectively, and are synthesized. Record a color image.

When the recording of all the yellow images on the first card P is completed, the cam 39a is reversed immediately before the rear end of the card P passes between the thermal head 25 and the platen roller 32. Rotate. Then, the operating shaft 43 is lowered together with the holding member 44, and at the same time, the base end of the urging member 46 is lowered, and accordingly, the platen roller 32 is lowered together with the bearing member 45. Then, FIG.
As shown in FIG.
Release from 5 to release the pressing.

Similarly, after all the magenta, cyan and black image recordings have been completed for the first card P, as shown in FIGS. 5 (b), (c) and (d) in order. When the rear end of the card P passes, the platen rollers 33, 34, 35 are sequentially moved in the same manner as described above.
When 0, the pressing is released by separating from the thermal heads 26 to 28.

Finally, when the rear end of the card P passes between the thermal head 28 and the platen roller 35, the ink ribbon r continues to be fed, and is positioned at the initial position as shown in FIG. Prepare for recording of card P.

After the four-color recording, the card P is conveyed through the belt 30 and the post-conveyance roller 22, guided by the discharge guide plate 23, and discharged by the discharge roller pair 24 to a discharge section (not shown). And discharge.

The present invention can be applied not only to such four-color printing but also to two-color or three-color printing, and also to five-color printing or more. Can be applied.

Further, in the present invention, it is preferable that a timing belt is used as a belt for conveying the recording medium. In the case of the above-described embodiment, toothed timing rollers are used as the driving roller 60, the driven roller 61, and the tension roller 62 provided inside the belt 30, for example, and the belt 30 is interposed between the rollers.
So that it passes over. When the timing belt is used as described above, the platen rollers 32 to 35 are used.
The timing roller may be a toothed timing roller that meshes with the belt 30.

In recording, for example, when the drive roller 60 is rotated by transmitting the drive of the belt drive motor 37 as described above, the rotation is transmitted to the belt 3 through the meshing of the teeth.
0 is reliably transmitted. Therefore, the belt 30 can rotate and carry the driven roller 61 and the tension roller 62 to carry the card P without slipping.

When the belt 30 is rotated in this manner, the teeth on the inner circumference of the belt 30 are
The meshing of the teeth on the outer periphery of the belt 5 and the meshing of the teeth with each other softens the impact and prevents the belt 30 from generating micro vibration.

In the illustrated printer described above, if the platen rollers 32 to 35 are at the retracted position during non-printing, and are away from the belt 30 as shown in FIG. Rotate the belt 30 to rotate the card P
When the sheet is conveyed, the platen rollers 32 to 35 are sequentially raised and pressed against the rotating belt 30 from below. Then, each time the pressing of the platen rollers causes a rotational load on the belt 30, the transport speed of the card P becomes uneven, and the speed unevenness may cause an image shift or the like, thereby deteriorating the image quality. .

Further, even when the belt 30 is a timing belt as described above, there is a possibility that the teeth on the outer periphery of the platen roller do not mesh with the teeth on the inner periphery of the rotating belt but abut on the rotating belt. As a result, it is conceivable that the transport speed of the card P becomes uneven and the image quality is similarly reduced.

Accordingly, the present invention is applicable to the case where the platen roller is separated from the thermal head and recording is not performed.
For example, as shown in a part of the contact / separation mechanism A for the platen roller 32, the platen roller 32 is
May be configured to be in contact with the belt 30 from the beginning.

For this reason, in this other example, when the platen roller 32 is placed via the bearing member 45 during non-recording, the urging member 46 has an elastic coefficient of contact with the belt 30 to such an extent that the platen roller 32 rotates together. Use a compression spring. In addition,
When the belt 30 is a timing belt as described above, the teeth on the inner periphery of the belt and the teeth on the outer periphery of the platen roller are engaged from the beginning.

Then, the platen roller 32
In order to rotate the platen roller 32 with the moving means 40 while recording, the platen roller 32 is pushed up by the moving means 40, and the platen roller 32 is rotated. While rotating the belt 30, the card P is transported.

When the pressing of the platen roller 32 is released after recording is completed, the urging member 46 is moved by the moving means 40 while the platen roller 32 is kept in contact with the belt 30 by the urging member 46. The platen roller 32 is separated from the thermal head 25 by lowering 46.

In the example shown in FIG. 7, the number of the urging members 46 for urging the platen rollers 32 to 35 is one, but as shown below, two such urging members are used.
It is also possible to provide one by one.

As shown in FIG. 8, for example, in the contact / separation mechanism A for the platen roller 32, two urging members 50 and 51 are provided between the upper and lower bearing members 45 and the holding member 44.
As described above, when an image is recorded on the card P by thermal transfer as described above, the platen roller 32 is attached to the thermal head 25 via the belt 30 with an elastic force necessary for the image recording. A compression spring having a high elastic coefficient to be pressed is used. Then, the first urging member 50 is
It is provided between the circular concave portions 45a and 44a provided to face the bearing member 45 and the holding member 44, respectively.

The second urging member 51 is provided between the circular recesses 45a and 44a, for example, by using an elongated compression spring having a low elastic coefficient and being inserted inside the first urging member 50. As shown in FIG. 8, when the platen roller 32 is separated from the thermal head 25 and recording is not performed, the circular recess 45a of the bearing member 45 is pressed by the tip of the second urging member 51, and the platen roller 32 is pressed. Is brought into contact with the belt 30 with such an elastic force that it can rotate.

However, in this other example, at the time of recording, the moving means 40 pushes up the base ends of the two urging members 50 and 51,
The platen rollers 32-35 are moved to the belt 3 by the urging force.
0, the ink ribbon r is transported little by little, and the belt 30 is transported while the platen rollers 32 to 35 are transported to transport the card P. 25-
At 28, a color image is recorded on the card P by thermal transfer.

On the other hand, at the time of non-recording, when the recording is completed and the pressing of the platen rollers 32 to 35 is released, the moving means 40 lowers the base ends of the two urging members 50 and 51, and
While maintaining the contact with the belt 30 by the urging member 51 of FIG.
Platen rollers 32-35 are connected to thermal heads 25-28.
And return to the retracted position.

[0052]

According to the first and second aspects of the present invention, during recording, the platen roller is pressed against the thermal head via a belt, and the belt is rotated to convey the recording medium. Therefore, unlike the related art, there is no possibility that the conveyance speed becomes uneven in the recording medium due to a slight difference in peripheral speed between the plurality of platen rollers. Therefore, it is possible to prevent the image quality of the recording medium from deteriorating due to the image deviation due to the uneven conveyance speed during recording. In addition, since the platen roller is not directly pressed against the recording medium, the pressing force applied to the recording medium during the pressing does not become uneven, thereby preventing a skew when the recording medium is conveyed. It can also be prevented.

Further, according to the first and second aspects of the present invention, even when the platen roller is separated from the thermal head and recording is not performed, the platen roller is pressed against the belt to the extent that the platen roller can be rotated together from the beginning. Therefore, at the time of recording, when the belt is driven and the recording medium is conveyed, by rotating while rotating the platen roller, it is possible to prevent the belt from causing speed fluctuation due to load fluctuation. As a result, it is possible to prevent unevenness in the conveyance speed of the recording medium sent by the belt and to further improve the image quality.

[Brief description of the drawings]

FIG. 1 is an overall schematic configuration diagram of an internal mechanism of a thermal color printer according to the present invention.

FIG. 2 is an enlarged configuration diagram of a portion where a plurality of thermal heads are covered with an ink ribbon in the printer.

FIG. 3 is an enlarged configuration diagram of a first contact / separation mechanism of the printer.

FIG. 4 is an explanatory diagram showing a recording order in the printer.

FIG. 5 is an explanatory diagram showing an order when the recording is completed.

FIG. 6 is a state explanatory diagram illustrating a case where the platen roller is away from the belt when the platen roller is at the retracted position in the printer.

FIG. 7 is a state explanatory view showing a state where the platen roller is pressed against the belt when the platen roller is at the retracted position in the first contact / separation mechanism of the printer.

FIG. 8 is a state explanatory view showing another example of the first contact / separation mechanism, showing a state where the platen roller is pressed against the belt by the second urging member when the platen roller is at the retracted position.

FIG. 9 is a schematic configuration diagram of a recording unit of a conventional thermal recording apparatus.

FIG. 10 is a schematic plan view showing an ink ribbon used for the recording apparatus.

[Explanation of symbols]

 Reference Signs List 18 conveyance path 25-28 thermal head 30 belt 32-35 platen roller 40 moving means 46 urging member 50 first urging member 51 second urging member P card (recording medium) Y, M, C, B ink Surface r ink ribbon

Claims (2)

[Claims] 1. A conveyance path for a recording medium, an endless belt for conveying the recording medium through the conveyance path, a plurality of platen rollers provided inside the belt, and a plurality of platen rollers outside the belt facing the platen rollers. A plurality of thermal heads to be provided, an ink ribbon having an ink surface of a different color according to the number of the thermal heads, an ink ribbon transported between the thermal heads and the belt, and a plurality of thermal heads provided corresponding to each of the platen rollers. Moving the base end of each corresponding urging member and pressing the platen roller against the thermal head via the belt with the urging force during recording, Moving means for separating the platen roller from the thermal head while maintaining contact with the belt during recording; Recording apparatus. 2. A conveying path for a recording medium, a belt for conveying the recording medium through the conveying path, a platen roller provided inside the belt, and a plurality of thermal elements provided outside the belt in opposition to the platen rollers. A head having an ink surface of a different color according to the number of thermal heads, and an ink ribbon transported between the thermal head and the belt; and an ink ribbon provided for each of the platen rollers and individually attached. A first urging member having a high elastic coefficient for urging; a second urging member having a low elastic coefficient provided for each of the platen rollers to individually urge each of the platen rollers; The base end of the urging member is moved, and at the time of recording, the urging force presses the platen roller against the thermal head via the belt with the urging force. And a moving means for separating the platen roller from the thermal head while maintaining the contact with the belt by the second biasing member, a thermal type recording apparatus.