JPS6131290A - Thermal transfer color printer - Google Patents

Abstract

PURPOSE:To achieve registration without using registration patterns, by a method wherein a dot printed in the first color is detected, and feeding velocity of a recording paper is corrected on the basis of the time point of the detection. CONSTITUTION:Transition from a blank area into an image area is detected from a change in the quantity of reflective light by a sensor 20a for optical detection through an optical fiber glass 19, and a detection signal is amplified by an amplifier 20b to be a signal (a), which is outputted to a wave-shaping circuit 20c. By the circuit 20c, the signal (a) is wave-shaped to be a rectangular wave signal (b) having a steep leading edge characteristic, and the signal (b) is outputted to a leading edge detecting part 17a. Simultaneously with detecting the leading edge of the signal (b), the detecting part 17a starts a fixed-duration pulse generating part 17b, and starts a controlling circuit (not shown) to generate a gate signal (d) for starting a thermal head driver 12, whereby printing by a magenta recording signal is started.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a heat-sensitive transfer color print that enables registration of heat-sensitive transfer color prints without using a resist pattern using, for example, optical fiberglass optical detection means. The present invention relates to a color printing device.

[Prior art]

As a thermal transfer color printing device, for example, cyan (
C), magenta (M), and yellow (Y), in which color is obtained by subtractive color mixing of three colors. Coated ink donor film (ID
F>1, and an ink ribbon 2 around which the IDFI is wound;
The film base surface of the IDFI is provided between the take-up wheel 3 for winding the used DFl, the ink ribbon 2 and the take-up rule 3, and runs in contact with it, and is arranged at regular intervals in the width direction of the IDFI. Thermal head 4 equipped with a heating resistor in the head
There is a swing-type printer comprising a platen 6 which is disposed opposite to the thermal head 4 and between which the recording paper 5 is supplied with the recording paper 5 superimposed on the ink-applied surface of the IDPI. The length of the ink-applied surface of each color of IDF1 is equal to the length of the recording paper 5 in the conveyance direction, and is set to be the same length for each color.

In the above configuration, first, the recording paper 5 and the yellow IDFL are superimposed and their leading edges are made to coincide with each other, and the paper is conveyed between the thermal head 4 and the platen 6 at a predetermined speed.

At the same time as the leading edge of the yellow ink passes the position of the thermal head 4, the heating resistor of the thermal head 4 is driven by the recording signal of the original nozzle component, the ink is melted by the heat generated energy, and the melted ink is transferred to the recording paper 5. Make it adhere. After the transfer is completed, the IDF1 is sequentially wound onto the take-up reel 3, and the recording paper 5 is taken up by the IDF1.
It is transported separately from the DFI. When the yellow transfer is completed, the magenta transfer is performed, but for this purpose it is necessary to return the recording paper 5 to its initial state. Therefore, while stopping the conveyance of the IDFI, the rad 4 or the platen 6 is released by pulling away, and the recording paper 5 is conveyed in the direction B shown in the figure.
Align the leading edge of the recording paper 5 with the leading edge of the magenta ink. In this state, the recording paper 5 and the IDPI are conveyed in a superimposed state, and the thermal head 4 is driven by a recording signal of the green component of the original to transfer magenta. Furthermore, by carrying out cyan transfer in the same manner as the magenta transfer, a color print can be obtained by mixing three colors at a reduced rate.

By the way, since the C, M, and Y transfers are performed individually, if the subsequent transfers are not performed at the same position with respect to the first transfer image, image shift will occur, which will deteriorate the image quality of the recorded image. Become. In order to prevent this, various control means have been proposed in the past, one of which is to obtain registration using optical fiberglass. This is 1. A registration pattern is recorded at the beginning of the first color print, and this pattern is detected by optical fiberglass when printing the second and third colors to obtain registration. be.

[Problem that the invention seeks to solve]

However, according to conventional thermal transfer color printing equipment,
Since registration is performed by printing a registration pattern, not only is a configuration for applying the registration pattern required, but there is also the problem that the pattern remains on the recording paper.

[Means and effects for solving the problems] The present invention has the following features:
This was done in view of the above, and in order to be able to obtain registration without using a registration pattern, the first color print dots are detected,
The present invention provides a thermal transfer color printing device that corrects the conveyance speed of recording paper based on this detection time point.

[Example] Hereinafter, a thermal transfer color printing apparatus according to the present invention will be described in detail.

FIG. 1 shows an embodiment of the present invention, showing green (G) and red (green) video signals obtained by optically scanning a color original.
A GRB-CMY converter lO converts each color signal component of R), blue (B) into recording paper signals of cyan (C), magenta (M), and yellow (Y), and each color signal component output from the converter 10 A buffer unit configured to include a logical product of the recording color signal and the gate signal G, and a logical sum of the output signals of the gates 11a to 11C1; 11, and a thermal head driver 12 which selectively supplies each of the heat generating resistors with a drive voltage at a level capable of supplying the output signal of the buffer section 11 to the thermal head 13 upon application of a gate signal d serving as a starting command. , a large number of heating resistors are arranged at regular intervals in correspondence with the recording dots, and each thermal head 13 performs recording by receiving a driving voltage from a thermal head driver 12; A motor 14 that serves as a drive source for conveyance, a motor drive section 16 that receives a start command e and drives the motor 14 at a constant speed, and supplies a start command e to the motor drive section 16, as well as gate signals d and g. a control unit 17 that outputs a signal, a lamp 18 that illuminates the leading edge of the recording paper 15, and an optical fiber glass (OFG>19) that captures reflected light from a predetermined position of the recording paper 15 illuminated by the lamp 18. , a sensor 20a that converts the light output from the 0FG19 into an electrical signal, an amplifier 20b that amplifies the output of the sensor, and a shaping circuit 20c that shapes the waveform of the output signal a of the amplifier and generates an output signal S.
The sensor section 20 includes each of the above.

For example, a glass fiber cable having a diameter of several tens of microns to several hundred microns is used for the 0FG19, and the diameter is determined depending on the required print dot diameter. sensor 2
For 0a, a photoelectric conversion element such as a phototransistor is used.

The control unit 17 includes a shaping circuit 2. A rise detection section 17a that detects the rise of the output signal of the OC, a constant time pulse generation section 17b that generates a pulse signal of a constant time width in synchronization with the output signal of the detection section 17a, and the constant time pulse generation section. a motor drive pulse generating section 17C that outputs the signal C to the motor drive section 16 based on the signal C output from the motor drive section 17b and the normal motor drive signal Sd;
Furthermore, it is configured to include a control circuit (not shown) necessary for performing print processing.

The rising edge detection section 17a can use a differentiating circuit when configured without synchronization with the synchronizing signal, and when synchronized with the clock signal, can obtain a rising signal by ANDing with the clock signal. The fixed time pulse generator 17b is
In an asynchronous configuration, a monostable multi-by-break can be used, and in a synchronous configuration, a circuit is used that outputs an H level signal in synchronization with the generation of a clock signal, counts with a programmable counter, and changes to an L level when the count is up. be able to. In this case, the fixed time can be made to match, for example, the time for moving one line in the main scanning direction, or can be set to a nearby time value.

In the above configuration, the operation will be explained based on the time chart shown in FIG. The video signal is subjected to color signal conversion in a GRB-CMY conversion section 10 and then applied to a buffer section 11 . A gate signal G for performing the first cyan recording is applied from the control section 17 to the AND gate 11a, only the cyan recording signal is applied to the buffer lle, and the thermal head 13 is driven via the driver 12. The heating resistor of the thermal head 13 generates heat in response to the cyan recording signal, and a cyan print is made on the recording paper 15 line by line. The conveyance of the recording paper 15 at this time is controlled by the drive signal S.
(The motor 14 is driven in a stepwise manner by the activation command e for conveying one line width generated based on (1).

When printing of the first color cyan is completed, printing of the second color magenta is performed, but prior to this printing, the recording paper 15 is returned to its original position, or the paper wrapped around the cylinder is ? i Turn it around and return it to its original position. At this stage, gate signal G is applied to AND gate 11.
While driving the thermal head 13 with the magenta recording signal L (signal g in Fig. 3), the motor 14
to start printing in the second color. As shown in FIG. 3, assuming that the first three lines of the first color print are white and the fourth and subsequent lines are the image part, the gate signal g is applied to the buffer unit 11, and at the same time, time t1
The recording paper 15 is sequentially transported as a transport time corresponding to one step. 3xt, the sensor 20a detecting light entering the image area from the white background is detected from the change in the amount of reflected light via the optical fiberglass 19. This detection signal is
After being amplified by 0b, the signal a is sent to the shaping circuit 20.
Output to G. The shaping circuit 20C shapes the signal a into a rectangular wave signal having a steep rise characteristic, and outputs the signal as a signal to the rise detection section 17a. Rise detection section 17
In a, at the same time as the rising edge of the signal S is detected, the pulse generator 17b is activated for a certain period of time, and a control circuit (not shown) is activated to generate a gate signal d (“H” level signal) that activates the thermal head drive 12. (Note that when printing the first color, an "H" level signal is always output from the beginning). As a result, printing using the magenta recording signal is started.

On the other hand, simultaneously with the gate signal d, the pulse generator 17
A pulse signal with a time width t1 is generated from b, and at the elapsed time of t1 when recording of image information for one line is completed, the motor 14 is activated again.
A signal e for activating is output to the motor drive unit 16, the recording paper 15 is conveyed to the next line, and the above-described operation is repeated thereafter.

Generally, in second and third color printing, if the registration of the leading edge bit of a page is correct, then there is often no problem with the true registration. Therefore, how to register the leading edge of the - page is an important issue. However, as in the present invention, the registration can be achieved by generating the signal C from the pulse generator 17b for a certain period of time and controlling the motor drive. You can get

(In addition, the print of the third color is the same as the print of the second color, only magenta changes to yellow.) Incidentally, if the first color and the second color are shifted, the print of the second color , a phenomenon occurs in which the leading edge of the first color is detected at the center of the paper feeding cycle of the motor 14, but if normal paper feeding is continued at this time, the registration of the two colors will not match. The colors overlap only half of one dot.

In this case, it is necessary to advance the paper feed for the latter half of one dot, but according to the present invention, this operation is automatically performed.

In addition, the dot diameter of the optical fiber glass 19 is
Thicknesses ranging from tens of microns to hundreds of microns are used, but 8
When trying to read fine dots such as books/fi to 16 books/cranes using 0FG19 as described above, the sensor 20a may not be exposed to a sufficient area of light, resulting in insufficient sensitivity and the first color print may not be detected. be. In particular, in the case of printers with a high density of printed dots, it is necessary to use fiberglass with a fine diameter in order to improve the detection accuracy of the first color print, but as the diameter becomes smaller, the light receiving area of the sensor becomes smaller and the detection ability decreases. descend.

This problem can be solved by disposing an optical lens 21 between the light output end of the 0FG 19 and the sensor 20a, as shown in FIG. By providing the lens 21 whose focal length and installation position are optimally selected, the light output from the 0FG 19 can be diffused, and the light-receiving area of the sensor 20a can be expanded, thereby increasing the detection ability.

〔Effect of the invention〕

As explained above, according to the thermal transfer color printing apparatus of the present invention, the print dots of the first color print are detected and the conveyance speed of the recording paper is corrected based on this detection point, so that the registration pattern Registration can be obtained without using .

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an embodiment of the present invention, Fig. 2 is a perspective view showing the basic structure of a thermal transfer color printer, Fig. 3 is a time chart of the embodiment of Fig. 1, and Fig. 4 is a 3 is a configuration diagram showing another example of the sensor section 20. FIG. Explanation of symbols 10...GRB-CMY conversion unit, 11...Buffer unit, 11a-llc...AND gate, lid...OR gate, lie...Buffer, 12...Thermal head driver, 13 ...Thermal head, 14...Motor, ]6...Motor drive section, 17...Control section, 17a...Rise detection section, 17b...Constant time pulse generation section, 17c... Motor drive pulse generator, 18...
Lamp, 19... Optical fiber glass (OFG),
20... Sensor part, 20a... Sensor, 20b... Amplifier, 20C... Shaping circuit, 21... Optical lens. Patent Applicant Fuji Xerox Co., Ltd. Agent Patent Attorney Shin Matsubara 2 Same Kiyoshi Muraki Same Same Tadao Hirata Same Same Jun Ueshima - Same Same Lead powder Hitoshi Go to Figure 2

Claims (2)

[Claims] (1) In a thermal transfer color printing device that drives a thermal head based on an image signal to thermally transfer color inks of different color ink donor films onto recording paper in a multiplex manner, the first color print on the recording paper is selectively transferred. an optical detection means that optically detects light reflected from the paper; a sensor section that converts the output light of the optical detection means into an optical-to-electrical converter; A pulse signal generating section that generates a pulse signal with a time width, and a recording paper conveyance control means that extends the driving time of a motor that conveys the recording paper by a certain time width pulse outputted from the pulse signal generating section. A thermal transfer color printing device characterized by: (2) In a thermal transfer color printing device that drives a thermal head based on an image signal to thermally transfer color inks of different color ink donor films onto recording paper in multiple ways, the first color print on the recording paper is selectively transferred. an optical detection means that optically detects light reflected from the paper; a sensor section that converts the output light of the optical detection means into an optical to electrical signal; and a sensor section that is provided between the optical detection means and the sensor section, and that detects the output of the paper. an optical lens means for controlling the luminous flux of light; a pulse signal generating section for generating a pulse signal of a constant time width in synchronization with a change point of the signal output from the sensor section; and a pulse signal generating section outputting from the pulse signal generating section. 1. A thermal transfer color printing device comprising a recording paper conveyance control means for extending the drive time of a motor for conveying recording paper by a fixed time width pulse.