JPS59101376A - Thermal transfer type color printer - Google Patents

Abstract

PURPOSE:To enable an easy color-printing both on sheet-form printing paper and on roll-form paper, by providing a pair of pinch rollers so that they can be pressed against a platen roller. CONSTITUTION:The recording paper S is wound around a platen roller 2, and a pair of pinch rollers P1, P2 are pressed against it to maintain the paper S in close contact with the platen roller 2. Using the region of a color ink ribbon SI of an ink of a certain color (e.g., yellow), a one-page portion is recorded in yellow, and then the ink ribbon SI is moved to bring the region of the next color (e.g., magenta) into position, and the paper S is returned to the beginning of that page. Recording is similarly conducted for all desired colors (e.g., cyan, black) to perform color printing. Accordingly, even when it is necessary to feed the paper in the forward direction and the reverse direction, the paper can be prevented from slipping, by pressing the paper against the platen roller 2 by the pair of pinch rollers P1, P2.

Description

[Detailed description of the invention] (Technical field) The present invention relates to a thermal transfer color printer.

(Prior art) The above-mentioned O sheet is stacked on the front side of an ink sheet formed by providing an ink layer on a base, that is, on the ink layer, and these ink sheets and the recording sheet are run against a recording head. A thermal transfer recording process is known in which a recording signal is applied to the ink sheet, and the ink on the ink sheet is positionally selectively melted and transferred onto the recording sheet according to the recording signal, thereby obtaining a desired image on the recording sheet. It is being The method of thermally melting the ink uses a heat-generating recording head.
There are two methods: one in which the ink is directly heated and melted, and the other in which an electrical current is applied to the ink layer using a current-carrying recording head, and the ink is thermally melted by the generated sealing heat.

Recently, thermal transfer color printers that utilize such a thermal transfer recording process have been proposed.

The ink sheet used in this thermal transfer color printer has ink layers of different colors in different area regions, and is configured in one or more ink sheets.

When the ink sheet is composed of a single ink sheet, the ink sheet is in the form of a long strip and is divided into area areas of a predetermined size in the longitudinal direction, and the area-saving areas are ink sheets of different colors. It has layers.

For example, the color of the ink layer can be black, magenta, cyan,
If four colors of yellow are used, the first area divided in the longitudinal direction of the strip-shaped ink sheet will have a yellow ink layer, and the second area will have a magenta ink layer. , a cyan ink layer is provided in the third area, a black ink layer is provided in the fourth area, and the color arrangement of the ink layers after the fifth area is a repetition of the above arrangement. Become. The area saving area has the same size, and this size is the maximum size that can be thermally transferred using the ink sheet.

When a plurality of ink sheets are configured, each sheet of a certain size has an ink layer of a different color,
For example, one ink sheet unit is composed of four sheets having separate ink layers of black, magenta, cyan, and yellow.

The recording sheet is sequentially superimposed on ink layers of different colors, and thermal transfer of ink is performed each time the recording sheet is superimposed.

For example, by thermally transferring inks of four colors: black, magenta, cyan, and yellow, a color image can be obtained by combining images of these four colors.

By the way, in this type of color printer that has been proposed in the past, the method of sequentially overlapping the recording sheet with ink layers of different colors is to wrap the recording sheet around the circumferential surface of a platen roller and hold it fixedly. A method is used in which a platen roller is rotated in a fixed direction while an ink sheet is conveyed in a fixed direction, and the ink layer superimposed on the recording sheet is switched every time the platen roller rotates once.

However, with this method, only sheet pieces can be used as recording sheets. For example, color printing is performed while pulling out a rolled sheet, and after recording, this is cut into sheet pieces. It is not possible to eject the sheet out of the printer, and the size of the sheet piece is also limited by the size of the platen roller.

Therefore, in order to perform color printing on a recording sheet of a certain size, a platen roller of the size that can wrap and hold the sheet of that sheet size is required. Therefore, the printer device itself tends to become larger.

(Purpose) Therefore, the present invention has developed a new method that can be performed using a small-diameter platen roller and is flexible enough to perform thermal transfer recording while pulling out not only a sheet piece but also a rolled sheet. The aim is to provide thermal transfer color printers.

(composition) The present invention will be explained below.

The thermal transfer color printer according to the present invention includes a sheet conveying means, a recording head, a platen roller, a platen roller driving means, a pressure release means, and a pair of pinch rollers.

The sheet conveying means is means for conveying the ink sheet.

The ink sheet may be in the form of a long strip or one unit made up of multiple sheets, but no matter which type of ink sheet is used, the sheet conveyance means is capable of moving the ink sheet in a fixed direction. transport.

As the recording head, both heat-generating type and current-carrying type can be used. This recording head contacts the ink sheet from the back side, that is, from the base side, at the recording position.

At the recording fσ position, the platen roller comes into pressure contact with the recording head via the recording sheet and the ink sheet, and presses the recording sheet against the surface of the ink sheet.

The platen roller drive means rotates the platen roller in either forward or reverse directions.

The pressure contact force release means is a means for releasing the EJe force between the platen roller and the recording head and bringing them into pressure contact with each other.

The pair of pinch rollers are arranged in parallel with the platen roller, and are given the ability to press against the platen roller.

The recording sheet is held on the platen roller by a pair of pinch rollers. Then, while maintaining this holding state, the platen roller is rotated forward and backward to reciprocate to the recording position. By this reciprocating movement, the recording sheet is sequentially superimposed on ink layers of different colors on the ink sheet.

Hereinafter, description will be given based on specific examples.

In the embodiment shown in FIG. 1, reference numeral J is a recording head, 2 is a platen roller, 3 is an ink sheet supply roller, 4 is an ink sheet take-up roller, 6 is a sensor, and 7 is a separating claw. It shows. Also, symbols M], M2, and M3 are drive motors, and symbols gpx and p2 are 1.
Each pair of pinch rollers is shown.

The recording head 1 is of a heat-generating type, and is in the form of a thin plate whose longitudinal direction is perpendicular to the drawing, and a minute heat-generating element is provided on the surface facing the platen roller 2.
The above-mentioned longitudinal hair array is arranged.

The recording head 1 is supported by a support 11, and this support 1
1 is swingably held by a shaft 11A at one end thereof. A belt 14 is wound around the disk 13 rotatably held by the shaft 13A and the drive motor M2. A bar J2 is passed between the disk 13 and the support body 11A for connection. One end of the bar 12 is pivotally connected to the support 11 by a pin 12A, and the narrow end is pivotally connected to the disk 13 by a pin 12B.

Thus, the support 11, the bar 12, and the disk]3 constitute a crank mechanism, and therefore, by rotating the drive motor M2 in one direction and rotating the disk 13, the support 11. Therefore, the recording head 1 can be oscillated about the shaft 11A, and by this oscillation, the recording head can be brought into pressure contact with and separated from the platen roller whose rotating shaft position is fixed. can.

That is, in this embodiment, support body ]1, bar 12
, the disk 13, the belt 14, and the drive motor M2 constitute a pressure release mechanism between the platen roller and the recording head.

The ink sheet SI is wound around a supply roller 3 in the form of a roll, is pulled out from the supply roller 3, and is wound around a take-up roller 4 by energizing the pressure contact portion between the recording device 1 and the platen roller 2.

Winding is performed by rotating the drive motor M3 in a fixed direction.

The platen roller 2 has a fixed rotating shaft position as described above, and the gear 20 is fixed to the rotating shaft. A timing belt 21 is wound between this gear 20 and a gear 22 fixed to the drive shaft of the drive motor M1.

The drive motor M1 is a step motor capable of forward and reverse rotation, and is loaded by a given number of pulses. Thus, the gears 20, 22, the timing belt 2], and the drive motor M] constitute means for rotating the platen roller 2 in forward and reverse directions.

A pair of pinch rollers P] and P2 are arranged in parallel to the platen roller 2, and are given the ability to press against the platen roller 2 by a suppressing means (not shown).

The recording sheet S is held so as to be wrapped around the peripheral surface of the platen roller 2 facing the recording head 1 by a pinch roller circle P2.

Pinch rollers - PI, P2 to platen roller 2
Due to the contact force E, the recording sheet S is tightly held on the circumferential surface of the platen roller 2, and the pinch roller Pl
, P2 are driven by the platen roller 2, so by rotating the platen roller 2 forward and backward, the recording sheet S can be moved back and forth, and at this time, between the recording sheet S and the platen roller 2, No relative slippage occurs.

Such holding of the recording sheet S on the platen roller 2 is possible whether the recording sheet is a piece of sheet or a long string.

During recording, the platen roller 2 and recording head 1
The recording sheet S1 (ink sheet) comes into pressure contact with each other via SI, and the platen roller 2 rotates clockwise in the figure, and both sheets are conveyed by this rotation.

The take-up roller 4 is prevented from being subjected to a torque exceeding a certain level by a suitable sliding means. Therefore, during recording, the take-up roller 4 only receives the amount of transport carried by the platen roller 2. will be rolled up. In other words, both sheets S%SI are pressed between the platen roller and the recording head, and when the platen roller 2 is not driven, the take-up roller 4 does not wind up the ink sheet S■.

Thus, the take-up roller 4, belt 5, drive motor M
3, Ml, gear 20.22, timing belt 21
．． The platen roller 2 and the like constitute sheet conveying means for the ink sheet.

Now, as shown in Fig. 2, SI is divided into area areas of a constant size in the longitudinal direction, and each area area has one color ink layer, Y1, magenta, and yellow ink layer. The ink layer M, the cyan ink layer C1, and the black ink layer N are formed periodically in the order shown in the figure.

Marks Mr (N%■, MKC, MKY) for ink layer detection are formed on the side edges of the ink sheet S■ along the longitudinal direction.

The thermal transfer color printing process in this embodiment will be described below with reference to FIG.

First, the pressure of the recording head 1 is released. For this purpose, the drive motor M2 may be operated to rotate the recording head support 11 slightly counterclockwise around the shaft 11A.

In this state, when the drive motor M3 is driven, the Inksy) SI is wound around the take-up roller 4 and conveyed from the right to the left in FIG. At this time, the sensor 6 detects the mark, and when it detects the mark MKY, it issues a signal and stops the operation of the drive motor M3. At this time, the yellow ink layer is set at the recording position depending on the positional relationship between the sensor 6 and the mark MKY, and in this state, the discrimination parameter (2) in the sea fence control system is set to 1.

Next, the recording sheet S is held on the platen roller by a pair of pinch rollers PI and P2, as shown in the figure. At this time, one of the pinch rollers PI and P2 is rotated manually or automatically to cause the recording sheet S to be tightly wrapped around the platen roller 2.

In this state, the drive motor M2 is operated to bring the recording head 1 into pressure contact with the platen roller 2, and then the drive motor M3 is operated. As mentioned earlier, a certain amount of torque is not applied to the take-up roller 4, so
Regardless of the operation of drive motor M3, Inc.)S
I is not transported.

Next, a signal for a yellow image is applied to the recording head 1 for one line. In response to this signal, the heating element selectively generates heat, and yellow ink is transferred onto the recording sheet S. Subsequently, the platen roller 2 is rotated by a small angle by the drive motor M1, and a line feed is performed by one line. This transfer and line feed are repeated while the transfer for the yellow image is being performed.

Then, when the transfer for the yellow image is completed, further
The drive motor M1 is operated to convey both sheets S and SI, and the sheets are separated at the position of the separating claw 7, and in this state, the operation of the drive motor M1 is stopped.

Next, the pressure contact force against the recording head 1 is released, the ink sheet s is conveyed by the driving force of the drive motor M3, and when the sensor 6 detects the clean mark, the operation of the drive motor M3 is stopped. . In this state, the setting of the magenta ink layer that follows the yellow ink layer Y is completed. Therefore, the value of the discrimination parameter I is set to I+1.

Next, the drive motor M1 is reversed, the platen roller 2 is reversely rotated, and the image recording start point of the recording sheet S is set as follows.
After returning to the recording position again, the recording head J is pressed toward the platen roller 2 side, the 1 drive motor M3 is activated, and the next transfer, that is, the transfer of magenta ink is performed. This process is repeated, and when the cyan ink transfer and the black ink transfer are completed, the determination parameter is 4, so once this is determined, the recording sheet S is discharged. At this time, if necessary, the recording sheet S is cut.

FIG. 4 shows a system diagram in the embodiment shown in FIG.

A signal corresponding to a color image to be recorded, such as a video signal, is converted into magenta, yellow, cyan, and black color signals, which are subtractive color signals, by a color conversion circuit, and then converted into an A/D signal.
After being A/D converted by a conversion circuit, the signal is subjected to halftone reproduction conversion by a halftone reproduction conversion circuit, is stored in frame memory, and is then applied to the recording head 1 via a recording head driver.

The conveyance control of the ink sheet SI by the sensor 6, the forward/reverse rotation control of the drive motor M1, etc. are performed by a controller.

(Effects) As described above, according to the present invention, the recording sheet is held on the platen roller by a pair of pinch rollers, and in this state, the recording sheet is moved to the recording position by forward and reverse rotation of the platen roller. Since the length of the recording sheet is not limited by the diameter of the platen roller,
Not only recording sheets in the form of sheet strips, but also sheets wound into rolls can be used while being pulled out. or,
Since there is no direct relationship between the diameter of the platen roller and the length of the recording sheet, the diameter of the platen roller can be made smaller than that of conventional rollers.

For example, in the conventional system, a platen roller with a diameter of 95 mm must be used to hold an A4 size recording sheet, but in the case of the present invention, the diameter of the platen roller can be set to 20 to 30 mm.

Furthermore, in the conventional method, it is not possible to print on a recording sheet with a length longer than the circumference of the platen roller, but in the present invention, by increasing the size of the ink layer of the ink sheet, the length of the recording sheet can be increased. The size can be changed over a wide range.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 is a side view schematically showing only the essential parts of an embodiment of the present invention, FIG. 2 is a perspective view showing an ink sheet used in the above embodiment, and FIG. FIG. 3 is a flowchart showing the procedure of color printing according to the above embodiment, and FIG. 4 is a system diagram regarding the above embodiment. l... Recording head, 2... Platen roller, Ml
, M2, M3... Drive motor, 6... Sensor,
Pl, P2...1 pair of pinch rollers-6

Claims (1)

[Claims] The same recording sheet is sequentially superimposed on the ink layer of a different color of a single or plural ink sheet having an ink layer of a different color, and each time the overlapping is performed, the same recording sheet is applied to the recording head. A thermal transfer color printer which position-selectively heat-melts ink on an ink layer according to a recording signal and transfers it onto a recording sheet to obtain a desired color image,
A sheet conveying means that conveys the ink sheet in a fixed direction; A recording head that contacts the ink sheet from the back side at the recording position; A recording head that presses against the recording head via the ink sheet and the recording sheet at the recording position; , a platen roller brought into pressure contact with the ink layer on the surface of the ink sheet, means for rotating the platen roller in forward and reverse directions, means for releasing the pressing force between the platen roller and the recording head, and a means arranged in parallel with the platen roller. , a pair of pinch rollers that have a tendency to press against the platen roller, the recording sheet is held by the pair of pinch rollers and the platen roller, and in this state, the recording sheet is held by the platen roller. A thermal transfer color printer that is characterized by a recording sheet that moves back and forth to the recording position by rotating forward and backward.