JPH02178063A - Color thermal transfer printing device - Google Patents

Abstract

PURPOSE:To obtain a color shift-free, high-quality color image with less ink sheet consumption and suited to high-speed printing by arranging all color thermal transfer devices around a single paper transport drum and performing thermal transfer printing of paper sequentially in different colors using all the color thermal transfer devices while the paper is wound around the peripheral surface of a drum and transported. CONSTITUTION:A paper transport drum 1 which transports thermal transfer print paper while it is wound around the peripheral surface is driven by rotation of a main motor 87 to feed the paper in a printing subscan direction with the number of stops which is at an integer multiple of printing time. Four thermal transfer units 3Y (yellow), 3M(magenta) and 3C(cyan) and 3B(black), which are color transfer devices, are, for instance, arranged at an interval of about 70 degrees. After this, when paper is transported to a desired printing position, voltage is selectively applied to the thermal element of a thermal head 30 and the width of pulses is controlled to transfer the ink of a thermal transfer ribbon 31 to the paper while the density is changed in compliance with applied energy and form an image. Thus data is printed in order of yellow, magenta, cyan and black to form a color image.

Description

[Detailed Description of the Invention] [Table of Contents] Overview Industrial Application Fields Prior Art Problems to be Solved by the Invention Means for Solving the Problems Action Examples Effects of the Invention [Summary] Thermal transfer with at least four different colors The present invention relates to a color thermal transfer printer device for printing, which consumes less ink sheets, enables high-speed printing, and is capable of obtaining high-quality color images without color shift.

At least four color thermal transfer means, each of which performs thermal transfer printing in a different color, are all arranged around one paper transport drum, and while the paper is being transported while being wrapped around the outer circumferential surface of the paper transport drum. , all of the color thermal transfer means are configured to sequentially perform thermal transfer printing on paper in different colors.

[Industrial Application Field] The present invention relates to a color thermal transfer printer device that performs thermal transfer printing in at least four different colors.

In the early days of color printing using thermal transfer, color ink ribbons could only express a single gradation, and so-called seven-color printing or color printing using area gradation was performed. However, since the development of color ink ribbons that can express multiple gradations, it has become possible to express subtle tones with just four color ink ribbons. The challenge is how to print high-quality color images quickly and thermally using color ink ribbons.

[Prior Art] A conventional color thermal transfer printer device prints four colors of yellow, cyan, magenta, and black on one ink ribbon.
The colors were arranged as one set, each having the same size as the paper, and one thermal head sequentially thermally transferred each color onto the paper.

[Problems to be Solved by the Invention] However, the above-mentioned conventional color thermal transfer printer device has the following problems:
Each time thermal transfer is performed on a sheet of paper, a new ink ribbon, which is a set of four colors, must be used, resulting in extremely high running costs for the ink ribbon. In addition, since four colors are thermally transferred sequentially using one thermal printer, the printing speed is extremely slow.

As a problem in terms of image quality, there is a problem in that the print of each color is misaligned by two degrees, that is, color misregistration occurs, making it impossible to obtain a high-quality color image.

In order to improve such drawbacks, attempts have been made to provide a plurality of thermal heads for each color and arrange them around a plurality of paper transport drums. However, in such cases, the printing paper travels along a transport route that has multiple paper transport drums, so the transport route is long and the printing speed cannot be increased, and the eccentricity and feed that occur between the multiple drums also occur. Due to the difference in the amount, color shift is unavoidable, so it is not possible to obtain a high quality color image.

The present invention eliminates such conventional drawbacks, and provides a color thermal transfer printer device that consumes less ink sheets, enables high-speed printing, and can obtain high-quality color images without color shift. The purpose is to

Means for Solving the RFF Problem] In order to achieve the above object, the color thermal transfer printer device of the present invention has a color thermal transfer printer having A paper transport drum 1 that wraps and transports paper within an area that does not make one full rotation; a paper supply means 2 that supplies paper to the paper transport drum l; and at least four paper transport drums that perform thermal transfer printing on the paper in different colors.
In the apparatus having three color thermal transfer means 3Y, 3M, 3C, 3B and a paper discharge means 4 for discharging the printed paper from the paper transport drum l, all of the above color thermal transfer means 3Y, 3M, 3C , 3B are arranged around one paper transport drum l, and while the paper is being transported while being wrapped around the outer peripheral surface of the paper transport drum l,
Features: At least four color thermal transfer means 3Y, 3M, 3C,
3B performs thermal transfer printing independently in each different color, so the color source used therein (such as an ink ribbon) is consumed separately for each color.

Also, all color thermal transfer means 3Y, 3M.

3C and 3B are arranged around one paper transport drum 1, and color thermal transfer means 3Y and 3M, respectively.

3C and 3B sequentially perform thermal transfer printing on one sheet of paper. Therefore, while the paper is being transported around one paper transport drum 1.

Thermal transfer printing is done in all colors.

[Example] Examples will be described with reference to the drawings.

FIG. 1 shows the configuration of a color thermal transfer printer device according to an embodiment, and illustration of the casing is omitted in FIG.

In the figure, 1 is a thermal transfer printing paper (hereinafter simply "
This is a paper transport drum (hereinafter simply referred to as the "drum") that wraps and transports the paper (hereinafter referred to as "the drum"), and is rotationally driven by a main motor 87 (not shown in FIG. 1) to transport the paper in the printing sub-scanning direction. , an integer multiple of the print timing (
For example, the number of steps is 8 times larger.

Further, around the drum 1, a plurality of pinch rollers 10 and guide plates 11 are each provided to press the paper against the drum 1 so that the paper is conveyed while being wrapped around the drum 1.

2 is a paper supply means for supplying paper to the drum 1;
Two paper cutters) 20.21 each containing cut sheets of different sizes, a bicker mechanism 22.23 that feeds paper from each paper cutter) 20.21, and a bicker mechanism 22.
．． The gate mechanism 25 temporarily holds the paper sent from 23, corrects the skew of the paper, and controls the timing of feeding the paper. 22a, 23
a is a big motor, 22b and 23b are big rollers, 2
5a is a gate motor, 25b is a gate roller, and 25c is a gate sensor for detecting paper.

Reference numeral 4 denotes a paper discharging means for discharging paper from the drum 1, which includes a discharging roller 40 for discharging paper and the discharging roller 4.
0, a stacker 42 that stacks the ejected sheets, and the like. Then, the paper is conveyed from the paper supply means 2 to the paper ejection means 4 in close contact with the outer peripheral surface of the drum l within a range that does not go around the circumference.

Around the drum l, there are four thermal transfer units 3Y, 3M, 3C, and 3B, which are color thermal transfer means, for example, about 70 units.
In this embodiment, 3Y is yellow, 3M is magenta, 3C is cyan, and 3B is black, which are different colors, and are units that perform thermal transfer printing at density gradations according to input energy. Each thermal transfer unit has the same configuration except for the color of the thermal transfer ribbon 31, and each unit has a thermal head 30 in which heating elements are arranged in one line, and a thermal transfer ribbon 31 of each color, which can be attached and removed from the thermal transfer unit. The configured ribbon cassette 32, a ribbon feeding mechanism that winds up the ribbon 31 during printing and applies pack tension to ensure stable feeding, and drives the thermal head 3o forward and backward toward the drum surface. It is composed of a head approach/escape mechanism 34 and the like.

2a and 2b show an enlarged view of the head approach/escape mechanism 34. FIG. 34a is an approach motor, 34b is a reduction gear, and the reduction gear 34b
A cam 34c is attached to the final portion of the cam 34c. One end of a lever 34e that rotates around a rotation shaft 34d contacts a cam 34c, and the other end of the lever 34e is connected to a rod 34f. 34g is a return spring for returning the lever 34e, and 34h is a coil spring that is compressed when the thermal head 30 is pressed against the drum 1 and presses the thermal head 3o against the drum 1 with a constant pressure, as shown in FIG. 2a. It is. Further, first and second microswitches 34f and 34J for detecting the state of the head approach/scoop mechanism 34 are connected to the lever 34e and the cam 34.
0(7) operation.

Then, as shown in FIG. 2a, when the approach motor 34a rotates and the lever 34e is rotated counterclockwise by the cam 34c, the rod 34f is lowered and the thermal head 30 presses the thermal transfer ribbon against the drum l. do.

This is the approach position. The thermal transfer ribbon is fed only in this state.

Conversely, as shown in Figure 2b, the approach motor 3
When the lever 34e rotates clockwise via the cam 34c due to the rotation of the lever 4a, the return force of the return spring 34g causes
The rod 34f and the thermal head 30 move away from the drum 1. This is the escape position.

FIG. 3 shows an enlarged view of the ribbon feeding mechanism, 33
33b is a reduction gear, and 33c is a final gear. 33d is a shaft on the winding side for winding the thermal transfer ribbon, and 33e is a shaft on the ribbon feeding side.
Both shafts 33d and 33e are connected to each final gear 33c via a friction clutch mechanism 33f. This friction clutch mechanism 33f uses compression coil springs 33g and 33h to move a friction plate 33i made of felt or the like to the final gear 3.
3c, and the coil spring 33g on the winding side is set to have a stronger spring pressure than the coil spring 33h on the sending side. Therefore, when the thermal transfer ribbon is wound up from the feeding side to the winding side, an appropriate amount of back tension is applied to the ribbon.

FIG. 4 shows the device casing 7 in an open state. As shown in FIG. 4, in the printer device of this embodiment, the top surface of the housing 7 can be rotated around the rear end and opened wide. 70 is a portion on the lid side, and a hook 72 on the portion on the lid 70 side is locked to a pin 71 provided on the main body side. Two thermal transfer units) 3C and 3B are attached to the inside of the portion on the lid 70 side.

Further, the drum l is locked to the housing 7 by a lock lever 73. Then, as shown in FIGS. 5a and 5b, by opening the M2O and removing the lock lever 73, the drum 1 can be removed from the apparatus. Therefore, cleaning of the thermal head section, removal of paper jams, etc. can be easily performed.

FIG. 9 is a circuit block diagram of the embodiment. In FIG.
It is composed of OM, etc., and operates by software stored in ROM. The main control unit 80 exchanges image data, control signals, etc. with the controller 100 via an interface (not shown), and controls the above-mentioned operations and other operations of the printer device.

81 is a cover open sensor that detects whether the M2O of the housing 7 is open; 82 is a reset switch that returns the operating printer device to its initial state; and 83 is a test pattern that prints a test pattern to check the printing status. A test program switch 84 is a ribbon replacement sensor that detects that the ribbon is being replaced, and 85 is a paper remaining amount sensor that detects the remaining amount of paper in the paper cassette 20.21.

86 is a main drive circuit connected to the main control unit 80; 87 is a main motor that rotationally drives the drum l; 22a, 23;
a, 25a, and 41 are the aforementioned big motor, gate motor, and discharge motor, respectively.

8g (Y, M, C, B) is the thermal head 3 of each color
25C is the aforementioned gate sensor; 90 is a jam sensor that detects when a paper jam occurs; 91 (Y.

M, C, B) are ribbon cassette sensors that detect whether ribbon cassettes of each color are attached.

Each color printing section is provided with a print control section 92 and a sub-drive circuit 93, which exchange data with the main control section 80. 30 is the aforementioned thermal head;
4a and 33a are the above-mentioned approach motor and ribbon feed motor, 94 is a heater, 341 and 34j are the above-mentioned 2
An approach/escape sensor 95 composed of two microswitches is a ribbon end sensor that detects the end of the thermal transfer ribbon.

96 is a power supply circuit that supplies 5V voltage to the controller 100, main control section 80, and print control section, 5V and 24V to the main drive circuit 86, and 5V and 1V to the sub drive circuit 93.
It supplies 2V and 24V (7) power. 97 is a power switch, and 98a and 98b are fans for cooling the power circuit 96.

Next, a series of operations of the above embodiment will be explained with reference to the time chart of FIG. 7 and the operation flow diagrams of FIGS. 8a to 8e.

S indicates a step.

When commanded to start printing, two paper cassettes 20.2
1, the desired side big motor 22a or 23a is rotated to rotate the big roller 22b.

23b is driven to feed out only one sheet of paper from the paper cassette (S1). When the leading edge of the fed out sheet passes through the gate sensor 25c (S2), the big motor is stopped after a certain period of time (S3). ), during that time, the leading edge of the paper hits the gate roller 25b, which has not rotated once, so the skew of the paper is corrected.Next, the leading edge of the paper hits the gate roller 25b sufficiently!
! From the hit state, the gate roller 25b is driven by the gate motor 25a (s4), and at the same time or after a certain period of time, the main motor 87 is driven to drive the drum 1 (s5), whereby the paper is wound around the drum 1. The desired print position is sent to. In addition, the gate motor 25a
will be stopped after a certain period of time. And S6Y to 36
In B, each thermal transfer unit 6Y, 6M, 6C, 6B
is on, and if it is on, sl
If it is not on, proceed to S7Y or s7B.

When the thermal transfer unit is on, the ribbon feed motor 33a and the approach motor 34a are driven a certain period of time before the paper reaches the desired printing position (sll, 512).
), and when it is detected that the thermal head 30 is in the approach position by the signal from the first microswitch 34i (S13), the approach motor 3
4a is stopped (S14). In this way, the thermal head 30 presses the thermal transfer ribbon 31 and the paper against the drum l.

When the paper reaches the printing position ψ, the thermal head 30
By selectively applying a voltage to the heat generating elements and controlling the energization time (pulse@), the ink on the thermal transfer ribbon 31 is transferred onto the paper while changing the density depending on the applied energy, thereby forming an image. Forming (S15) In this way, a color image is formed by printing yellow, magenta, cyan, and black in this order and overlapping one color.

Incidentally, FIG. 8b actually shows the thermal transfer unit 3 for each color.
Since Y, 3M, 3C, and 3B operate separately, there are four independent flows for each color, but they are simplified and shown as one flow.

When printing is performed, it is determined whether each thermal transfer unit is turned off in S7Y or s7B, and
If it is off, proceed to S31; if not, proceed to S2
Go to 1.

In each thermal transfer unit 3Y, 3M, 3C, 3B, when the unit is off, the head approach motor 34a is first reversed (S21), and the thermal head 3
When it is detected that 0 has returned to the escape position (S22
), then the approach motor 34a is stopped (S2
3) Stop the ribbon feed motor 33a. Mo and S
31. The flow shown in FIG. 8d is also simplified from four for each color to one.

In S31, the ejection motor 41 drives the ejection roller 40 to start ejecting the paper to the stacker 42 (s31), and when the ejection of the paper is completed (s32), the ejection motor 41 is stopped (s33). The main motor is stopped (s34).

However, until the ejection of the paper is completed, the process returns to S5 and performs the necessary printing on the remaining part of the paper, and when a new command to start printing is received, returns to SL to prepare for printing the next paper. (s35), and the operation of this final part is omitted from illustration in the time chart.

In addition, in the above normal operation, the thermal head 30
takes an approach state and an escape state, but in this embodiment, the ribbon end of the thermal transfer ribbon 31 is detected, and the signal causes the thermal head to retreat further from the drum 1 than in the normal escape state. ing. This position is controlled by the shape of the cam 34c. FIG. 6a shows the approach state, FIG. 6b shows the normal escape state, and FIG. 6C shows the large evacuation state.

In this way, the thermal head 30 is largely retracted from the drum 1, so that the ribbon cassette can be easily replaced.

[Effects of the Invention] According to the color thermal transfer printer device of the present invention, at least four color thermal transfer means independently perform thermal transfer with different colors, so that the color source (ink ribbon, etc.) for each color is used for each color. In addition, only the amount actually used is consumed, so running costs are low and economical.

Moreover, all the color thermal transfer means are arranged around one paper transport drum, and the thermal transfer of all colors is performed while the paper is transported around the drum, so the printing position of each color is shifted. Therefore, it is possible to obtain a high-quality printed image without so-called color shift. Furthermore, since the transport route is short, it has excellent effects such as high-speed printing.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of the embodiment, Figures 2a and 2b are partially enlarged views of the embodiment. FIG. 3 is a partially enlarged sectional view of the embodiment; FIG. 4 is an overall configuration diagram of the embodiment. Figures 5a and 5b are partial perspective views of the embodiment. Figures 6a to 6C are partial female claw diagrams 5 of the embodiment. FIG. 7 is a time chart diagram of the embodiment. FIGS. 8a to 8e are operational flowcharts of the embodiment. FIG. 9 is a circuit block diagram of the embodiment. 4...Paper ejection means. In the figure, l: paper transport drum; 2...Paper supply means. 3Y... Color thermal transfer means. 3M...color thermal transfer means, 3C...color thermal transfer means, 3B...color thermal transfer means, Enlarged view of outside of Kameto 2nd AV! J Real map of SP warrant Figure 2b Enlarged cross-sectional view of the name of Jitsuko 1 Figure 3 Figure 5a Touken Ben 1's Wakima Mizuguchi Figure 5b Figure 8e

Claims (1)

[Scope of Claims] A paper transport drum (1) that transports paper wrapped around its outer circumferential surface in a range that does not go all the way around the circumference, and a paper supply means (2) that supplies paper to the paper transport drum (1). and at least four color thermal transfer means (3Y, 3M, 3C, 3
B), and a paper ejecting means (4) for ejecting the printed paper from the paper transport drum (1), all of the above color thermal transfer means (3Y, 3M, 3C,
3B) are arranged around one paper transport drum (1), and while the paper is being transported by being wrapped around the outer peripheral surface of the paper transport drum (1), all the color thermal transfer means (3Y, 3
A color thermal transfer printer device, characterized in that thermal transfer printing is performed on the paper in sequentially different colors according to the printing methods (M, 3C, 3B).