THERMAL TRANSFER RECORDING DEVICE

Abstract: In a thermal transfer recording device which performs thermal transfer recording by using an ink ribbon (7) which applies monochrome or polychrome transfer of ink to a base film and moves said ink ribbon (7) and paper (4) holding them between a thermal head (1) and a platen (2), a first control section outputs a signal for the control of the heat quantity of said thermal head based on input binary data, a second control section outputs a signal for the control of the heat quantity of said thermal head (1) based on input multi-value data, a setting unit outputs setting results based on the setting of the binary data print mode or the multi-value data print mode, and a selection unit selects the output signal of the first control section or the second control section based on the above mentioned setting results and supplies it to the above-mentioned thermal head (1).

Description: This invention relates to a heat transfer recording device which performs color and monochrome heat transfer recording, and more particularly to printing control based on binary and multi-valued data. Fig. 1 is a perspective view showing an outline of the structure of an example of the conventional heat transfer color recording device. It illustrates a device known as plane sequential swing type . In the figure, the recording head (thermal head) 1 has a plurality of heating resistors (printing elements) lined up in the main scanning direction. It performs transfer recording. Paper 4 moves from paper roll 3 in the direction indicated by arrow A (secondary scanning direction) pressed by pressure roll 8. Ink ribbon 7 moves from supply roll 5 to take-up roll 6 in conjunction with the movement of paper 4, between recording head 1 and platen 2. This recording head 1 performs transfer recording while being pressed against platen 2 by spring 14 fixed to a protrusion of bracket 12 which supports recording head 1, with support point 13, which is attached to bracket 12, as its rotational center. The width of ink ribbon 7 is almost the same as that of paper 4. It has tri-base-color (yellow, magenta, cyanogen) transfer printing inks applied in plane order to application areas 7b on base film 7a. Each application area 7b has a dimension L′ just a bit larger than dimension L of the transport direction of recording area 9 established beforehand on paper 4. In other words, as shown in Fig. 1, transfer inks are applied to ink ribbon 7 in order of color for rectangular application areas 7b on base film 7a. Marks 10a, 10b and 10c corresponding to the print beginning positions of respective colors of the transfer ink are printed beforehand along an edge of application areas 7b of ink ribbon 7. It is then possible for these marks to be detected by ribbon sensor 11. Head motor 15 rotates bracket 12 about support point 13 through cam 16 to move down so that recording head 1 is separated from platen 2 during recording (printing) standby and movement to set ink ribbon 7 at the print beginning position of each color. In a structure such as this the following operation is performed when it has been established beforehand to record (print) in the order yellow, magenta, cyanogen. First, when turning on power supply, after moving ink ribbon 7 until ribbon sensor 11 has detected mark 10a corresponding to the print beginning position of yellow and positioning it there, recording head 1 is pushed towards platen 2. By moving (transporting) paper 4 and ink ribbon 7 together in the secondary scanning direction yellow transfer is performed for recording area 9. Next. after paper 4 has been sent back, with recording head 1 separated from platen 2 by motor 15, to its original position, ink ribbon 7 is moved until sensor 11 detects magenta's mark 10b and as with yellow, magenta is transferred to recording area 9 to which yellow was transferred. Furthermore, paper 4 is backed as with yellow and magenta, and after mark 10c is detected cyanogen is transferred over recording area 9. In this way color recording is performed for a single frame (recording area 9). The ink ribbons 7 used for this kind of thermal transfer recording device are divided up into the following two types according to the composition of the ink applied. There is the fusion type ink ribbon which has wax as its main ingredient and is composed of pigments, additives, and softening agents, and the sublimation type ink ribbon which is composed of sublimating disperse dye, polyvinyl alcohol, synthetic resin, and a solution such as toluene, keton etc. Fig. 2 shows data concerning printing density of the ink transferred to paper 4 as measured with a Macbeth density meter, with respect to the energy applied to thermal head 1. When applied energy reaches a set value the printing density increases rapidly for the fusion type ink ribbon (shown with circles). If applied energy is increased beyond this it reaches a saturated state in which printing density does not increase. On the other hand printing density is almost proportional to applied energy for the sublimation type ink ribbon (shown with triangles). The main uses of fusion type ink ribbons are hard copies from CRT's for computer terminals performing image expression with binary data. On the other hand, sublimation ink ribbons are used mainly for full color hard copies from television used in broadcasting which perform image expression with multi-value data. Because of differences in print control methods, both are used with their own specialized recording devices. However, the thermal transfer recording device structure described above contains the problem described below. Because of the progress of CRT terminal devices, it is possible for the image to express binary and multi-value data. However, because of the differences in control method it is necessary to provide separate binary and multi-value hard copy devices to connect to them. SUMMARY OF THE INVENTION An object of this invention is to provide a single thermal transfer recording device which is able to print binary and multi-value data. In order to solve the problem described above, this invention provides a thermal transfer recording device which uses an ink ribbon which applies monochrome or polychrome transfer ink to a base film, performs thermal transfer recording by holding and moving said ink ribbon and paper between a thermal head and platen, and is equipped with a first control section which outputs a signal for the control of the heat quantity of the above mentioned thermal head based on input binary data, a second control section which outputs a signal for the control of the heat quantity of the above mentioned thermal head based on input multi-value data, setting means which outputs setting results based on the setting of either the binary data print mode or the multi-value data print mode, and selection means which selects and supplies to the above mentioned thermal head the output signal of either the first control section or the second control section based upon the results of the above-mentioned setting. The thermal transfer recording device according to this invention operate as follows. The first control section works to output a signal to control the heat quantity of the thermal head based on input binary data and the second control section works to output a signal to control the heat quantity of the thermal head based on input multi-value data. Also, the setting means (for example, a switch) works to output the mode setting results and the selection means works to select the output signal of either the first control section or the second control section based on the setting results. For example, should the binary data print mode be set by the setting means, the thermal head would be controlled by the output signal of the first control section through the selection means and the printing of binary data would be performed. On the other hand, should the multi-value print mode be set by the setting means, the thermal head would be controlled by the output signal of the second control section through the selection means and the printing of multi-value data would be performed. It is therefore able to solve the problems described above. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective view of a conventional thermal transfer color recording device. Fig. 2 is a graph showing the transfer characteristics of ink ribbons. Fig. 3 is a block diagram showing a thermal transfer recording device of a first embodiment of this invention. Fig. 4 is a diagram showing an example of recording head. Fig. 5 is a block diagram showing an example of binary data control section. Fig. 6 is a block diagram showing an example of multi-value data control section. Fig. 7 and Fig. 8 are time chart showing operations of the recording head. Fig. 9 is a flow chart showing the operation of the device of the first embodiment. Figs. 10A, 10B and 10C are perspective views showing the mode setting system for a second embodiment of this invention. Figs. 11A and 11B are perspective views showing the mode setting system for a third embodiment of the invention. DETAILED DESCRIPTION OF THE EMBODIMENT Fig. 3 is a block diagram showing a control system of the thermal transfer color recording device of a first embodiment of this invention. In the figure reference symbols identical to those in Fig. 1 show structural elements of an identical nature. 20 is an interface for inputting the binary data or multi-value data which is to be printed. 21 is a control section composed of microprocessor, ROM, RAM, timer, I/O port, etc. The ROM contains program and parameter data. The RAM is used as a buffer memory to contain data received. 22 is a mode switch on the operation panel etc. It is used to change (set) between the binary printing mode and the multi-value printing mode. The change-over signal is output to signal line 21a through control section 21. 23 is a common bus. 24a to 24c are I/O ports. 25 is a multi-value data control section which outputs a signal for the control of the heat quantity of each print element (heating resistor) of recording head (line thermal head) 1 in response to multi-value data input from control section 21 through common bus 23 and I/O port 24a. 26 is a binary control section which outputs a signal for the control of the heat quantity of each print element of recording head 1 in response to binary data input from control section 21 through common bus 23 I/O port 24b. 27 is a multiplexer which supplies recording head 1 with the output signal of either multi-value control section 25 or binary control section 26 based on the change-over signal from signal line 21a. 28 is a motor driver. 29 is a paper feed motor to feed paper 4. 30 is a ribbon feed motor to feed ink ribbon 7. 31 is a paper sensor to detect the presence or absence of paper 4. Based on the data from interface line 20, whether mode switch 22 is on or off, and data obtained from paper sensor 31 and ribbon sensor 11 through I/O port 24c and common bus 23, control section 21 not only performs the control of recording head 1 through I/O port 24a and multi-value data control section 25 during the multi-value data print mode and the control of recording head 1 through I/O port 24b and binary data control section 26 during the binary print mode, it also controls head motor 15, paper feed motor 29, and ribbon feed motor 30 through I/O port 24c. Fig. 4 shows an example of recording head 1. As illustrated, it comprises a plurality of, e.g., n, heating resistors (print elements) H1 to Hn arranged in a line, AND gates A1 to An respectively associated with heating resistors H1 to Hn, a latch circuit 1a having n stages respectively associated with n heating resistors H1 to Hn, and a shift register 1b having n stages respectively associated with the n stages of latch circuit 1a and hence with heating resistors H1 to Hn. Print data from multi-value data control section 26 or binary data control section 25 are serially input into shift register 1b and shifted through it. When the n stages of shift register 1b are filled with print data for all the heating resistors H1 to Hn, a latch signal LS is supplied to latch circuit 1a, upon which the print data in shift register 1b are latched in latch circuit 1a. Then a timing signal TS is supplied to all the AND gates A1 to An to open them. Accordingly, heating resistors H1 to Hn are selectively energized depending on data of the corresponding stages of latch circuit 1a: they are energized when the data of the corresponding stage is "1". A example of binary data control section 25 is shown in Fig. 5. As illustrated, it comprises a shift register 26a. Binary data for one line of pixels are serially input into shift register 26a, shifted through it, and output from it, under control of various timing signals, not shown. Fig. 7 shows operation of printing in the binary mode. When binary printing data BPD for one line of pixels are produced from binary data control section 25, they are fed into shift register 1b in time with clock signals CLK. When data of n bits for all the n heating resistors H1 to Hn have been input, a latch signal LS is produced, upon which the contents of shift register 1b are latched into latch circuit 1a. When a timing signal TS is next produced, heating resistors H1 to Hn are selectively energized depending on the contents of the respective stages of latch circuit 1a. The feed motor 29 is then driven to feed the paper into the position for printing the next line. Print data for the next line may be supplied when the latch circuit has latched the data for the preceding line. An example of multi-value data control section 26 is shown in Fig. 6. As illustrated, it comprises a line buffer 25a having n stages, each stage storing multi-value data, e.g., 32-value data of 5 bits. The contents of line buffer 25a are circulated under control of timing signals not shown. The output of line buffer 25a is compared at a comparator 25b with an output of a counter 25c which is incremented by one each time the contents of line buffer 25a is circulated once. The output of comparator 25b is "1" when the output of line buffer 25a is greater than the output of counter 25c. Thus a serial data consisting of n bit are produced once for each level or tone of the 32-value print data and heating resistors H1 to Hn are selectively energized depending on whether the value of data for each pixel is greater than the current value of counter 25c. The circulation of data through line buffer 25a and accompanying operations including serial output of data of n bits and selective energization of heating resistors H1 to Hn are repeating 31 times (it is one less than 32 because level or tone "0" does not require energization of heating resistors H1 to Hn). These operations are illustrated in Fig. 8. Data (multi-value tone data) MTD from multi-value data control section 26 for each level or tone are serially input into shift register 1b, latched by latch circuit 1a and used for selective energization of heating resistors H1 to Hn. These operations are repeated 31 times before the feed motor 29 is driven and the contents of line buffer 25a are replaced by data for the next line of pixels, and counter 25c is reset to "O". In this way the total time of energization of each heating resistor during printing of a particular line of pixels is controlled to correspond to the desired printing density as represented by the multi-value print data. In the above example, all the AND gates are simultaneously enabled. Alternatively, it may be so arranged that heating resistors H1 to Hn and AND gates A1 to An are divided into several, e.g., four groups, and AND gates of respective groups are given timing signals (strobe signals) in sequence so that heating resistors H1 to Hn of respective groups are energized in sequence. Such an arrangement is advantageous in reducing the required capacity of the power supply and restraining temperature increases. The operation of the overall system is now described with reference to Fig. 9. First, printing start up is sent to control section 21 from an outside control device etc. through interface line 20 (Step 0), and control section 21 receives tri-base-color printing data from the outside control device etc. through the interface line and stores it in the buffer memory (RAM) (Step 2). Next, control section 21 controls ribbon feed motor 30, winding ink ribbon 7 up until yellow mark 10a is detected (Step 2). After the beginning of the yellow application area has been found in this way control section 21 controls head motor 15 pressing recording head 1 onto platen 2 with paper 4 and ink ribbon 7 between them (Step 3). Next, control section 21 discovers whether mode switch 22 is on or off and judges whether it is in the binary data print mode or the multi-value data print mode (Step 4). If mode switch 22 is on for the binary data printing mode, control section 21 not only transmits the yellow data (binary data) from the buffer memory to binary data control section 26 through I/O port 24b, it controls multiplexer 27 with a charge-over signal (signal line 21a) so that it chooses the output signal from binary data control section 26 and performs binary printing by control from binary control section 26 as follows (Step 5). In other words, signals to control the heat quantity of each print element (for example, data, clock signal, latch signal, strobe signal, as described above) are created in binary control section 26 to respond to binary data and supplied to recording head 1 through multiplexer 27. This results in each print element of recording head 1 being driven by a pulse of a specified pulse width corresponding to input data. If, on the order hand, it is judged in Step 4 that the mode switch is off and this is the multi-value data print mode, control section 21 not only transmits the yellow data (multi-value data) from the buffer memory to multi-value data control section 25 through I/O port 24a, it controls multiplexer 27 with a change-over signal (signal line 21a) so that it chooses the output signal from multi-value data control section 25 and performs multi-value printing by control from multi-value control section 25 as follows (Step 6). In other words, signals to control the heat quantity of each print element (for example, data, clock signal, latch signal, strobe signal, as described above) of recording head 1 are created in multi-value control section 25 to respond to multi-value data and supplied to recording head 1 through multiplexer 27. This results in each print element of recording head 1 being driven by a pulse of pulse width of a length corresponding to input data. When, in Step 5 or Step 6, the printing of one line is finished, paper feed motor 29 step feeds ribbon feed motor 30 and the next line is printed. By repeating this one frame (recording area 9) of yellow data is printed. When the printing of one frame of yellow data is finished, control section 21 controls head motor 15 separating recording head 1, which had been pressed toward platen 2, from platen 2 (Step 7). It also controls paper feed motor 29 rotating it in the opposite direction from the printing direction (direction A) and back feeding paper 4 to return it to the first yellow printing position. This ends the yellow printing operation (Step 8). Next the printing of magenta data is performed in the same way that the printing of yellow data was (Step 2-Step 7), using magenta data and the magenta application area of ink ribbon 7 (Step 9). When the magenta printing is finished, and paper 4 has been back fed as in Step 8 (Step 10), cyanogen data printing is performed in the same way the yellow data printing and magenta data printing were (Step 11). Once this has been completed paper 4 is fed and the printing operation (color recording) for one frame is finished. Figs. 10A to 10C are perspective views showing the mode setting system as it occurs in a second embodiment of this invention. In the first embodiment (Fig. 3) setting of the binary data printing mode or the multi-value data printing mode is performed using mode switch 21 which is found on the operation panel etc. In contrast to this, in the second embodiment, setting is made by detecting (identifying) the shape of ribbon reel on which the ink ribbon 7 which differs depending on the mode is wound on, as described below. In Figs. 10A, 10B and 10C, 50 is a ribbon reel upon which ink ribbon 7 is wound to make it into supply roll 5. 51 is a rod-shaped supporting body which supports ribbon reel 50 in such a way that it is possible for it to rotate in concave section 52a of ribbon holder 52. 53 detects the presence or absence of supporting body 52 and outputs a change-over signal to signal line 21a through control section 21 as did mode switch 22. Figs. 10B and 10C show that the length of supporting body 51 is different depending upon the type of ink ribbon 7 wound upon ribbon reel 50. When binary data printing is being performed a fusion type ink ribbon 7 is wound onto ribbon reel 50 which has a long supporting body 51a as shown in Fig. 10B and by setting it in ribbon holder 52 supporting body 51a pushes arm 53a of microswitch 53 down and microswitch 53 is turned on. When multi-value data printing is performed a sublimation type ink ribbon 7 is wound onto ribbon reel 50 which has a short supporting body 51b as shown in Fig. 10C and by setting it in ribbon holder 52 microswitch 53 stays off as supporting body 51b is short and does not touch arm 53a of microswitch 53. As described above, according to the on/off state of microswitch 31 the change-over between binary data printing and multi-value data printing can be performed using the form of ribbon reel 50 (or, supporting body 51). A string of printing operations is performed as in the first embodiment. The above effect can also be easily realized for cartridge type ink ribbons by modifying their cartridge form. Figs. 11A and 11B are perspective drawings showing the essential parts of the mode setting system for a third embodiment of this invention. They show an example of an ink ribbon to perform the change-over between binary data printing and multi-value data printing, detecting (identifying) the different types of ink ribbon 7 by the form of color marks on the ink ribbon 7. In Fig. 11A, 60a is a mark which shows the color yellow (Y) (comparable to 10a in Fig. 1) with a two line bar code. In Fig. 11B, 60b was made into the same type of mark to show the color yellow (Y), but with a 3 line bar code. Yellow is the very first step in printing. Thus, in the operation to search for the start of the yellow application area at the beginning of printing, control section 21 judges through a sensor whether binary data printing or multi-value data printing is to be performed by the number of lines in the yellow mark. A flag is then set for the judgement results in the working area of controls section 21's memory. After that, by referring to this flag it can change the printing mode and perform binary data printing and multi-value data printing with the same kind of control as in the first embodiment. Fusion type ribbons and sublimation type ribbon are used according to the difference in marks ink ribbon 7. The above has been a detailed description of a thermal transfer recording device to perform binary and multi-value printing for color recording. A similar description could be given for a device to perform monochrome thermal transfer recording using an ink ribbon which applies monochrome transfer ink. It is furthermore clear that the same effects could be obtained using heat sensitive paper. The explanation was made for color recording using the three colors: yellow, magenta and cyanogen. It is also clear that the same effects would be obtained from printing with 4 colors (with black having been added) or printing operations which use even greater numbers of colors. As explained in detail above, using this invention it is possible to choose and easily perform the printing of binary data and the printing of multi-value data with a single device. Furthermore it is possible to make the device less expensive.

Claims: A thermal transfer recording device which performs thermal transfer recording by using an ink ribbon (7) which applies monochrome or polychrome transfer of ink to a base film and moves said ink ribbon and paper (4), holding them between a thermal head (1) and a platen (2), comprising a first control section (26) which outputs a signal for the control of the heat quantity of the thermal head based on input binary data, a second control section (25) which outputs a signal for the control of the heat quantity of the thermal head based on input multi-value data, setting means (22) which outputs setting results based on the setting of the binary data print mode or the multi-value data print mode, and selection means (21) which selects the output signal of the first control section or the second control section based on the above mentioned setting results and supplies it to the above-mentioned thermal head. A thermal transfer recording device as set forth in claim 1 which uses ink ribbons (7) of different transfer characteristics to correspond to each of the abovementioned modes, wherein the setting means (22) outputs setting results through the identification of identification means (60a, 60b) constructed beforehand on the ink ribbon or on a material accessory to the ink ribbon in accordance with the abovementioned transfer characteristics. A thermal transfer recording device as set forth in claim 2, in which the identification means on the abovementioned ink ribbon comprises markings (60a, 60b). A thermal transfer recording device as set forth in claim 2, in which the identification means is on a material accessory to the ink ribbon (7) and comprises the shape of the reel (5) onto which the ink ribbon is wound or of the cartridge containing the ink ribbon. A method of thermal transfer recording using a thermal transfer recording device and a first type of ink ribbon (7) which applies monochrome transfer of ink to a base film (4) or a second type of ink ribbon (7) which applies polychrome transfer of ink to the base film (4) which thermal transfer recording device moves the ink ribbon and the paper, holding them between a thermal head (1) and a platen (2), the device comprising a first control section (26) which outputs a signal for the control of the heat quantity of the thermal head based on input binary data, a second section (25) which outputs a signal for the control of the heat quantity of the thermal head based on input multi-value data, setting means (22) which outputs setting results based on the setting of the binary data print mode or the multi-value data print mode, and selection means (21) which selects the output signal of the first control section or the second control section based on the above-mentioned setting results and supplies it to the above-mentioned thermal head, wherein the method comprises the steps of: providing identification means (60a, 60b) on the ink ribbon or on a material accessory to the ink ribbon, and identifying the ink ribbon in accordance with the above-mentioned transfer characteristics. A method as set forth in claim 5, in which the identification means (60a, 60b) comprise markings provided on the above-mentioned ink ribbon. A method as set forth in claim 5, in which the identification means is provided on a material accessory to the ink ribbon and comprises the shape of the reel onto which the ink ribbon is wound or of the cartridge containing the ink ribbon.

Inventors: KIKUCHI, HIROSHI C/O OKI ELECTRIC IND. CO.,LTD., OBARA, KAZUKI C/O OKI ELECTRIC INDUSTRY CO.,LTD., TANUMA, JIRO C/O OKI ELECTRIC INDUSTRY CO.,LTD., YOSHIDA, KAZUYOSHI C/O OKI ELECTRIC INDUSTRY CO.,
Applicants: OKI ELECTRIC INDUSTRY COMPANY, LIMITED
Application year: 1988
Main classification: B41J2
IPC codes: B41J2, B41J35, B41J17