JP2966872B2 - Color thermal printer - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color thermal printer for transferring ink of a transfer type recording medium to an image receiving body such as paper by a heated thermal recording head, and more particularly, to an image receiving body. And a color thermal printer which performs color transfer by repeatedly performing a moving operation within a predetermined range.

2. Description of the Related Art In a color thermal printer, a transfer type recording device in which ink is adhered to an image receiving body (hereinafter, referred to as a receiver) such as paper between a thermal recording head (hereinafter, referred to as a thermal print head) and a platen roller. A medium (hereinafter, referred to as an ink donor film) is inserted and moved, and is sequentially transferred to a receiver by a heated thermal print head.

FIG. 5 and FIG. 6 show examples of a transport mechanism of a receiver and a recording unit in a conventional color thermal printer, respectively.

FIG. 5 shows an example of a color thermal printer adopting a reciprocating movement method of a receiver. In the figure, a receiver 10, which is paper, is sandwiched between pinch rollers 12 and 14 each having two rollers. Pinch roller 12 and
It is reciprocated by the rotation of 14. The receiver 10 passes through a transfer portion between the pinch rollers 12 and 14, which is a gap between the platen roller 16 and the thermal print head 18.

In addition, an ink donor film 20 is also inserted into the transfer portion so as to overlap the receiver 10. The ink donor film 20 is moved by the film rollers 22 and 24 in accordance with the movement of the receiver 10.

The thermal print head 18 selectively transfers the ink of the ink donor film 20 to the receiver 10 sandwiched between the platen roller 16 by heat.

FIG. 6 shows a mechanism of a one-way rotation type color thermal printer for moving the receiver 10 in one direction. The platen roller is constituted as a platen drum 28 as shown in FIG. Gripper 30
The receiver 10 is fixed to the outer periphery of the platen drum 28 by the gripper 30. The film rollers 22 and 24 for moving the thermal print head 18 and the ink donor film 20 are described in the fifth embodiment.
This is the same as the conventional example shown in FIG.

Next, the printing operation of each printer shown in FIGS. 5 and 6 will be described.

First, in the apparatus shown in FIG. 5, the receiver 10 is sent out by the pinch roller 12, circumscribes the platen roller 16, passes through the transfer portion between the thermal print head 18, and the tip of the receiver Is transported until it is pinched. During this time, the thermal print head 18
Is separated from the platen roller 16, and the ink donor film 20 is wound up to a predetermined position.

Next, the thermal print head 18 is
At a predetermined pressure to start thermal transfer. During thermal transfer, the receiver 10 holds the pinch roller 14 and the platen roller while being held by the frictional force of the pinch roller 12.
Printing is performed while being conveyed and moved in the direction of arrow 100 by the rotation of 16. At this time, the pinch rollers 12, 14 and the platen roller 16 are rotating in synchronization so that the receiver 10 cannot be loosened. The ink donor film 20 is also wound around the film roller 22 in synchronization with the feed speed of the receiver 10. When the transfer of one color of the ink donor film 20 is completed, the rear end side of the receiver 10 is a pinch roller.
It must still be sandwiched between twelve. Next, an operation of returning the receiver 10 to a predetermined transfer start position is performed to transfer another color. First, the thermal print head 18 pressed by the platen roller 16 is separated from the platen roller 16, and the ink donor film 20 is wound up to a predetermined position (a position of a desired color ink).
Meanwhile, the pinch rollers 12 and 14 rotate in the reverse direction, and the receiver 10 is transported in the direction of arrow 200 and stopped at the transfer start position.
At the transfer start position, the state in which the distal end side of the receiver 10 is sandwiched by the pinch rollers 14 is maintained.

The thermal transfer of one color is completed by the above series of operations, and by repeating this operation the number of times corresponding to the number of colors, color thermal transfer is performed. For example, in the case of three colors (yellow, magenta, and cyan), the above operation is repeated three times to perform transfer.

Next, the operation of the conventional apparatus shown in FIG.
Is rotated to the transfer start position. During this time, the thermal print head 18 is kept away from the platen drum 28, and the ink donor film 20 is wound up to a predetermined position where transfer is to be started. Then, after the platen drum 28 reaches the transfer start position and is stopped, the thermal print head 18 abuts on the receiver 10 on the platen drum 28 with a predetermined pressing force to start the transfer. The transfer of one color is completed when the platen drum 28 makes one rotation in the direction of arrow 300, and the transfer of the next other color is performed by making the platen drum 28 make one full rotation in the 300 direction from the transfer start position. Will be Therefore, when the number of rotations corresponds to the number of colors for transfer, that is, in the case of three colors, the platen drum is set to
The rotation completes the color thermal transfer.

[Problems to be Solved by the Invention] However, the conventional color thermal printer has the following problems.

First, in the case of the reciprocating movement system shown in FIG.
Is held and transported by the frictional force of the pinch rollers 12 and 14, that is, sandwiched between two rollers. Therefore, in order to always hold and convey the receiver 10 in an extended state, it is necessary to keep the pressing force and the frictional force of the pinch rollers 12 and 14 constant, and an adjusting mechanism for that is required. In the transfer of the second and subsequent colors,
Accurate positioning of the receiver 10 is required to prevent color misregistration, but with this conventional color thermal printer, it has been difficult to detect and position the receiver 10.

Next, in the case of the one-way rotation type color thermal printer shown in FIG. 6, the one (one color) transfer step is completed by rotating the platen drum 28 once. The problem of difficulty in position adjustment as shown in the figure is solved. However, when a large receiver 10 is used, a platen drum 28 having a large diameter is used. However, the transport mechanism and holding means of the receiver 10 must be increased. As a result, there is a problem that the entire apparatus becomes large.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems, and an object of the present invention is to make it possible to easily and accurately adjust the position of a print area of a receiver and to simplify the mechanism. An object of the present invention is to provide a color thermal printer capable of achieving a reduction in size.

Means for Solving the Problems In order to achieve the above object, a color thermal printer according to the present invention is a hollow drum having an opening in a peripheral wall and capable of controlling normal rotation and reverse rotation. A drum having holding means for pulling out and stacking an image receiving body as an image receiving body at a position eccentric from the drum rotation axis in the vicinity of the unit, and a rotatably provided with the drum, the image receiving body being pulled out A gripper that can be switched to fix or release the fixing to the drum, and a thermal recording head that is disposed near the drum and that can press a predetermined portion of the image receiving body sent out onto the outer periphery of the drum onto the outer peripheral surface of the drum A transfer-type recording medium to which a plurality of colors of ink are attached and which is inserted between the thermal recording head and the image receiving body and moved in synchronization with the image receiving body during transfer, and While the drum is in the fixed operation state, the drum is rotated forward and backward to move the image receiving body between the transfer start position and the transfer end position, and the thermal recording head selectively uses the thermal recording head to print a plurality of color inks on the transfer type recording medium. The image is superimposed and transferred onto an image receiving body.

[Operation] According to the above configuration, the drum holds the receiver in the vicinity of the opening eccentric from the rotation axis of the drum so as to be able to be pulled out, and the pulled-out receiver is placed on the outer periphery from the opening. Will be sent out. The thermal print head can press a predetermined portion of the ink donor film on the outer peripheral surface of the drum in a state where the ink donor film is overlaid on the receiver. By rotating the drum in this state, the receiver can be moved relatively to the thermal print head, and during this movement, the ink of the ink donor film can be selectively transferred onto the receiver.

As described above, the drum according to the present invention can perform two functions, that is, a function as a receiver holding unit that holds the receiver near the opening and a function as a platen drum that is disposed to face the thermal print head.

Therefore, the movement of the receiver during transfer can be accurately controlled by controlling the rotation of the drum, and the transfer area can be set accurately. By configuring the holding means for the platen drum and the receiver as one drum as described above, the number of components can be reduced, thereby simplifying the structure and reducing the size of the entire apparatus.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic cross-sectional view illustrating a basic configuration in a case where a receiver as an image receiving body is housed in a drum in the present embodiment, and is the same as the configuration of the conventional apparatus shown in FIGS. 5 and 6. Are given the same reference numerals.

In the figure, a drum 32 has a hollow structure and an outer wall thereof.
Inside the receiver 32a, a receiver holding shaft 32b is formed coaxially with the drum 32, and the receiver 10 is laminated and wound on the receiver holding shaft 32b.

The outer wall 32a of the drum has a receiver passage slit 3
4 is formed, and the laminated and wound receiver 10 is sent out from the slit onto the outer peripheral surface of the drum 32. The feed of the receiver 10 is performed by a feed roller formed near the roller 36 and the receiver passage slit 34.
38 and a small roller 40 arranged opposite thereto. That is, the receiver 10 is inserted into the gap between the rollers 38 and 40, and is guided on the outer peripheral surface of the drum 32 through the receiver passage slit 34. In this embodiment, a gripper 42 is mounted in the drum 32. This gripper 42
Switching is performed such that the receiver 10 is fixed by being pressed against the inner wall surface of the drum outer wall 32a, or is released from the outer wall 32a by releasing the receiver 10 from the outer wall 32a.
When the gripper 42 is performing the fixing operation, the receiver
The drum 10 moves with the rotation of the drum 32. When the gripper 42 is in the releasing operation, the receiver passage slit 34 of the drum of the receiver 10 is used.
Pulling out and sending out from is possible.

Further, the cutter 44 is located further in the sending direction position of the receiver 10 than the receiver passing slit 34 of the drum outer wall 32a.
Are mounted so that they can rotate with the drum 32.
In FIG. 1, it is composed of two cutter pieces 44a and 44b. One cutter piece 44a is disposed in an opening 46 formed in the drum outer wall 32a, and the other cutter piece 44a is provided.
b is disposed at a position facing the cutter piece 44a, and the receiver 10 is cut by the contact operation of the two pieces.

The thermal print head 18 is installed in the vicinity of the drum 32, and is configured such that the transfer portion performs pressure contact and separation operations on the drum 32.

Further, the ink donor film 20 is inserted between the receiver 10 and the thermal print head 18 as in the above-described conventional example.

 Next, the basic operation of transfer will be described.

First, the receiver 10 is loaded on the receiver holding shaft in the drum 32 in a state of being stacked and wound. This loading action is performed by the drum 32
The receiver 10 is loaded from the open side with one of the bottom surfaces being openable. At this time, gripper 42
Is in an unlocked state, and is loaded so that the winding end end of the receiver 10 is inserted between the feed roller 38 and the small roller 40 through the space between the gripper 42 and the inner peripheral surface of the drum outer wall 32a. In this state, the thermal print head 18 is separated from the drum 32. Here, by the operation of the feed roller 38, the receiver 10 is sent out from the receiver passage slit 34, passes through the cutter 44, and is sent out onto the outer peripheral surface of the drum 32. This receiver 10 drum
The feeding of the 32 onto the outer peripheral surface is performed until the length reaches a predetermined length. During this time, the ink donor film 20 is wound up to a predetermined position (a predetermined color portion) by the film roller 22. Then, the gripper 42 performs a fixed operation and
10 is fixed to the drum 32.

 In this state, the transfer preparation operation is completed.

Next, in the transfer operation, the thermal print head 18 is pressed against the drum 32 with a predetermined pressure, the drum 32 is rotated clockwise, and the thermal print head 18 performs thermal transfer while moving the receiver 10 with the rotation. This drum 32
The rotation during the transfer is controlled by a drum rotation drive unit and a drum rotation angle detection unit (not shown).
By accurately controlling the rotation of the drum 32, the transfer position of the receiver 10 can be directly set with high accuracy. Further, the transfer area to the receiver 10 can be adjusted by the rotation angle of the drum 32, and can easily correspond to the size of the receiver 10.

Further, since the movement of the receiver 10 can be performed only by the rotation of the feed roller 38 and the drum 32, there is no need to provide a transport mechanism for transporting the receiver 10, and the configuration of the printer can be extremely simplified.

First, when the transfer of the first color is completed, the thermal print head 18 is returned to the separation position, and the ink donor film is transferred.
The film 20 is wound up to a predetermined color position by the film rollers 22 or 24, and the second color is prepared for printing. Here, the drum 32 rotates counterclockwise and is returned to the transfer start position again. Since the receiver 10 is fixed to the drum 32 by the gripper 42, the position of the transfer start position is accurately set by the operation of the drum 32 in the counterclockwise direction. Here, the same operation as the operation of the first color is performed, and the transfer of the second color is completed. This operation is repeated for the number of colors to be transferred. For example, in the case of three colors of yellow, magenta, and cyan, the above printing operation is repeated three times.

When the printing of the first sheet is completed, the receiver 10 is cut into a predetermined length by the cutter 44.

Then, as a preparation for the transfer of the second sheet, a feed roller
38 sends the receiver 10 over the drum 32 by a predetermined length. In addition, sending out only a predetermined length of the receiver 10 is as follows.
The adjustment is performed by controlling the rotation of the feed roller 38 or by detecting the position of the distal end of the receiver 10 using a photo interrupter or the like.

FIG. 2 is a schematic cross-sectional view showing the entire configuration of a modification of FIG. 1, and the same elements as those in FIG. 1 are denoted by the same reference numerals and description thereof will be omitted.

The difference between FIG. 2 and FIG.
Instead of being provided at a predetermined distance from the drum 32.

In this example, after the printing of the first sheet is completed, the feed roller 38
, The receiver 10 is further fed out, the receiver feed length is detected by an edge sensor (not shown) for detecting the tip of the receiver 10, and the receiver 10 passing through the cutter 44 is cut off when the length reaches a predetermined length. Things.
Also, after the gripper 42 is released from the fixed state and the receiver 10 is fed out by the feed roller 38 for a predetermined length, the gripper 42 is fixed and the drum 32 is rotated counterclockwise by a predetermined angle to feed the receiver 10 to the cutting position. It is also possible to put out.

According to this example, it is not necessary to provide the cutter 44 on the drum 32, so that the configuration of the drum 32 is simplified.

FIG. 3 shows still another modification. FIG. 3 shows that the cutter 44 is provided at a predetermined distance from the drum 32 and the gripper 42 is provided outside the drum 32. With this configuration, the internal configuration of the drum 32 can be further simplified, and simplification of manufacturing is achieved.

FIG. 4 shows a schematic diagram of the characteristic features of the present invention incorporated in the basic structure shown in FIGS. That is, the winding center of the receiver 10 held in the drum 32 is set at a position shifted from the rotation axis of the drum 32. With this configuration, the distance from the wound receiver 10 to the receiver passage slit 34 can be reduced, and the receiver
10 settings are easy.

[Effects of the Invention] As described above, according to the color thermal printer of the present invention, the drum has a function of a platen roller, a function as a holding means of the receiver, and a function of moving the receiver. Simplification and a reduction in the number of parts can be achieved, and the size of the device can be reduced.

Further, by controlling the rotation of the drum, the transfer of the receiver and the setting of the transfer position can be accurately performed, and the printing performance of the color thermal printer can be further improved.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a basic structure for accommodating an image receiving body inside a drum in this embodiment, FIG. 2 is a schematic sectional view showing a modification of FIG. 1, FIG. FIG. 4 is a schematic cross-sectional view showing a further modified example of the drawing, FIG. 4 is a schematic cross-sectional view for explaining a storage position of an image receiving body which is a feature of this embodiment, and FIGS. FIG. 10 Receiver 18 Thermal print head 32 Drum 38 Feed roller 42 Gripper 44 Cutter

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) B41J 2/32-2/325 B41J 11/04 B41J 13/22 B41J 15/04

Claims (1)

(57) [Claims] 1. A hollow drum having an opening in a peripheral wall and capable of controlling normal rotation and reverse rotation, wherein an image receiving body which is an object to be transferred is positioned eccentrically from a drum rotation axis near the opening. A drum having holding means for holding and winding the stack so that it can be pulled out freely; a gripper rotatably provided with the drum and capable of switching the drawn-out image receiving member to be fixed or released from the drum; and A heat-sensitive recording head that is disposed at a nearby position and is capable of pressing a predetermined portion of the image receiving body sent out onto the drum outer circumference onto the drum outer circumferential surface; and a thermal receiving head that is inserted between the heat-sensitive recording head and the image receiving body during transfer. A transfer-type recording medium to which a plurality of colors of ink are attached, the recording medium being moved in synchronization with the drum. A plurality of inks of the transfer-type recording medium are selectively transferred onto the image receiving body by the thermal recording head while being moved to the end position.