JPS60189469A - Printing device - Google Patents

Abstract

PURPOSE:To make the printing of high speed, medium tone and further full color possible, by a method wherein picture elements are formed by simultaneously turning ON the adjacent L switch for a low potential and H switch for a high potential, further divided into 5 groups and each group forms picture elements. CONSTITUTION:A H switch 50 for a high potential on positive side and a L switch 51 for a low potential on negative side to a power source 8 are alternately used and connected to needle electrodes of H1-Hm and L1-Lm. A picture element is formed between adjacent L electrode and H electrode by simultaneously turning ON the adjacent L switch 51 and H switch 50. These picture elements are divided into 5 groups represented by 5J+1, 5J+2-5J+5 (where J=1, 2, 3...) and each group forms picture elements. Thus, the reproduction or high speed recording of color CRT picture is made possible and at the same time, the gradation recording with a couple of L electrode and H electrode cab be carried out.

Description

[Detailed description of the invention] 〔Technical field〕 The present invention relates to a recording method for a printing device.

[Prior art]

Currently, there is an electrically conductive thermal transfer recording method as a method that allows multilevel recording and color printing. This method will be explained using FIGS. 1 and 2. FIG. 1 shows several examples of structures of ink films for electrically conductive thermal transfer recording. 1
is a melting ink layer, which is a layer in which pigment or pigment and dye are dispersed in wax, and has the property of melting at about 60°C.

2 is a resin film or capacitor paper using PIDT or the like, and in the case of (a), this layer becomes the support layer of this film. 6 is a layer in which fine carbon powder is dispersed in resin, and is electrically conductive. (Hereinafter, 5 will be referred to as the resistance layer.) 4 is
Although it is a conductive layer like 6, in the case of (1)) and (0), this layer becomes the film support layer.

5 is a heat-resistant resin layer which is a color prevention layer. The ink layer is melted by the Joule heat generated by passing a current through the resistance layer of these films, and the ink layer is transferred to the paper to be transferred, thereby performing printing.

Although each film structure in FIG. 1 has its own characteristics, they will not be mentioned in this specification. Figure 2 shows the principle of multilevel recording. (a) shows a cross section. FIG. 2(a) shows an example of the ink film 19 having the structure shown in FIG. 1(a). 10 is a transfer paper. Using the recording needle 6 and the common electrode 7, wire the power supply 8 and the switch 9.
When closed, a current 11 flows through the resistance layer 5. (1) is a diagram showing (a) from above. The distribution of current 11 is shown. Since Joule heat is proportional to the square of the current density, the temperature distribution will be as shown in (1). Depending on the time the switch 9 is closed, a difference in temperature distribution occurs as shown in 12.13. 12 is an example in which the closed time is short and the amount of heat generated is small. Tm14 is the melting temperature of the ink, and in a temperature range higher than Tm, the ink melts and is transferred to the transfer paper 10. The area of the transferred ink changes as shown in 15.16 in response to the temperature distribution in 12.16. Multi-level recording is possible by changing the time the current is applied in this way.

Becomes Noh. The next important thing is high speed recording. To do this, it is essential to be able to record simultaneously with a large number of needles. FIG. 3 shows an example in which a plurality of recording needles are used.

19 is an ink film, and 7.degree. 6 is a common electrode and a recording needle as in FIG. 2(b). The simplified equal circuit of FIG. 6 is shown in FIG. 7.6 correspond to the common electrode and the recording needle, respectively. Each recording needle is connected to a power source 8 through a switch 9. 17, rl is the equivalent resistance between the recording needle and the common electrode, and r2 is the equivalent resistance between adjacent recording needles. As is clear from Fig. 4, except for the case where r+ << rg, the value and direction of the current flowing through each recording needle are as follows:
The current changes depending on the open/closed state of each switch, and it is impossible to control the current of each recording stylus simply by opening/closing the switch corresponding to each recording stylus. Furthermore, even if rl<<r2 is realized, it is very difficult to uniformly bring the common electrode and a large number of recording needles into electrical contact with the resistance layer as shown in FIG. To summarize the problems here, when putting into practical use a recording method using a large number of recording needles using the ink film with the above-mentioned resistive layer, the most important thing that must be solved is electrical contact. Can you do it more evenly without any mistakes? As shown in FIG. 2, recording is performed simultaneously using a plurality of recording needles.

〔the purpose〕

The present invention is intended to solve the above-mentioned problems, and its purpose is to provide a highly reliable and low-cost printing apparatus capable of high-speed halftone recording and full-color recording.

〔overview〕

The printing device of the present invention has a recording head composed of recording needles arranged in a row, and an L switch that opens and closes a low potential and an H switch that opens and closes a high potential are alternately connected to the recording needle. , and by simultaneously closing the adjacent L switch and H switch, the resistive layer is energized to generate heat, the melted ink layer is melted, and the melted ink layer is transferred to the transfer paper to form a pixel. In the device, the pixels are arranged in order from the end to 5J-1-1, 5J+2, 5J-1-3゜5J+
4 and 5, r-1-5 (, T is 1, 2.5...
), and pixels are formed for each group.

〔Example〕

Hereinafter, the present invention will be explained in detail based on Examples.

FIG. 5 shows a recording head 22 used in the present invention. The material of the electrode substrate 20 is preferably ceramic from the viewpoint of heat resistance, durability, and reliability, but inexpensive materials such as glass epoxy can be used depending on the purpose. 21
is a recording needle, and there are several of them. The number of recording needles varies depending on the signal to be recorded, but approximately 500 needles are required for recording television screens. FIG. 6 shows a method of contacting the recording head 22 and the ink film 19 according to the present invention.

The main roller 50 is made of an elastic material such as rubber, and the transfer paper 10 is wound around the main roller 50 and fixed with a fixing jig 52. The ink film 6-22 is stored in a roll 66, wound along the direction of the arrow, and wound onto the roll 54. .

35 and 56 are ink film transport rollers. The end portion 26 of the recording head 22 is pressed onto the main roller by a spring 57 with a fulcrum 68 as the fulcrum. By pressing the recording head having the structure shown in FIG. 5 against the ink film in the manner shown in FIG. 6, the recording needle and the resistive layer are completely electrically connected. No.! As is clear from FIG. i and FIG. 6, the only recording electrode was the recording needle, which made it possible to bring the recording needle into contact with the resistance layer in an ideal manner.

Furthermore, since the recording needle and the '1tJi substrate are integrated, problems such as damage to the recording needle do not occur, and reliability has been significantly improved. Next, a method for recording and a method for performing gradation recording using a recording head having such ideal contact properties will be described.

FIG. 7(a) shows how to flow current. 40 and 41 are the portions where the recording needle is in contact with the resistance layer, and 42 is the current.

The voltages were applied such that 40 was negative and 41 was positive. As in FIG. 2, by changing the energization time, the temperature distribution changes as shown in 45.44. 45
44 is a case where the interval between voices is short, and 44 is a long interval. The ink transferred by this K is also 45°4.
6, and area gradation can be added. 8th
The figure shows the method for recording between all adjacent needle electrodes. For the power supply 8, use the positive side switch 50 and the negative side switch 51 alternately as shown in the figure, and
F (connected to the needle electrodes of m and L1 to Lm. The number of needle electrodes is 2m (m is a positive integer), and the recording pixels are 2m.
It becomes m-1. Hereinafter, the negative side switch (low potential switch) will be referred to as the L switch, the positive side switch (high potential switch) as the H switch, the needle electrode connected to the negative terminal as the Lt pole, and the positive side as the Hl pole. If we focus on Hl, by passing a current between Hl and 1, Hl
A pixel is formed between and Ll, and a pixel is formed therebetween by R1 and R2. In this way, all L electrodes and H
Pixels can be formed between the electrodes.

FIG. 9 shows an equivalent circuit when focusing on the k-th L electrode. A resistor 52 is interposed between all the H electrodes and the Lk electrode, and the way the current flows changes depending on how the H switch is turned on. This is similar to the conventional example shown in FIG. 4 and cannot be used. As a way to solve this problem, a patent application filed in 1986-186
495 etc. has been applied for. The present invention further improves the above patent application.

This eliminates the above drawbacks. First, the above patent application will be described, and then the improvements of the present invention will be described.

The basic principle of patent application No. 58-186495 is shown in FIG. (a) shows how current flows in the resistance layer, and (b) shows its equivalent circuit. H electrode 41 and L
The potential of the electrode 40 is determined depending on whether the switch is open or closed as shown in Figure (9).
7, 'closed' is 58. In such an open/closed state, current flows like 54 and 55. At this time, 56
Currents such as and 57 cannot exist in principle.

Therefore, the equivalent resistance of this circuit is only 55 shown in Figure (b), and the current that flows is always determined only by the resistance between adjacent electrodes. The equivalent circuit of (b) is 54 and 55
This holds true only when the direction of the current (arrow) is opposite. To explain further, in order to realize the equivalent circuit of Fig. 9 ('b), the closed state time of the H switch and L switch is Must be the same.

For example, when the k-th H switch and L switch are closed, the -1-1st H switch is closed, and the lc+2nd switch is open, a current of 57 is generated, which does not hold true.

In other words, instead of single-opening switches 60 and 61 in FIG. 11(a), double-opening switches 62 are used, and the adjacent H and L switches are connected to the same signal as shown in FIG. 11(1)). It needs to be opened and closed. In FIG. 11(b), 65 is an open/close signal for the switches Ll and Hl, 64 is Hl and R2, and 65 is an open/close signal for the switches R2 and R2. 63°64.65 must have different closed signal sections.

When the recording method shown in FIG. 9 is used, one-sixth of all the pixels in one example can be formed at the same time. To form one row of pixels, 6
Record the times at different times. This is shown in Figure 1 10-12. By opening and closing each switch as shown in (a), (b), and (c), a current 70 sequentially flows through the equivalent resistance 55 between adjacent electrode needles, forming one column of all pixels. Next, we will discuss the drawbacks of this method. FIG. 16(a) shows a diagram in which only the closed switch of FIG. 12(a) is extracted. FIG. 13(a) shows an energized state in which all six pixels shown here are formed. Figure 15 (1)) is 5
The middle one is the case where no formation occurs. 20
The switch marked 0 is open. At this time, current flows through two circuits 201 and 202. 201 is 7
Slightly less than 0, 202 is 8-10% of 201
That's about it.

This crosstalk can be ignored for the most part when binary printing is performed, but when halftone printing is performed, it becomes a serious problem depending on the number of halftones. The smaller this crosstalk, the better. The present invention reduces this problem.

In the present invention, pixels are formed in one group for every five pixels in the above-mentioned patent application, whereas pixels are formed in one group for every five pixels, that is,
Starting from the end of the pixels, 5J+1.5J+2.5J+3.
5J+4 and 5.7-1-5 (, r is 0, 1, 2.5
. . . ), pixels are formed in each group, and this process is performed five times to reduce the above-mentioned drawbacks.

FIG. 14 shows the opening and closing of the switch of the present invention. This corresponds to FIG. 12(a).

Of these, the one with the closed switch drawn out is the 15th one.
It is figure (a). FIG. 15(b) shows the case where the middle switch is in the open state. The way the current flows in this group is
Although it is the same as the case of FIG. 15(b), the current 206 between adjacent electrode needles is almost the same as 70, and the crosstalk current 204 is about 2 to 4 times that of 205, which is halved. As a result, the number of gradations in halftone printing can be increased, and gradation reproducibility has been greatly improved.

Next, a specific example will be described.

[Example 1] The recording head shown in FIG. 16 was used. This shows the tip of the recording head. N1-C on ceramic substrate 101
! r102 and □u105 are deposited, an electrode is formed by photoetching, and N1-w- is selectively deposited on this electrode.
P electroless plating was applied. As shown in Fig. 14, the number of recording needles is 520 each for the L electrode and the H electrode (the first
In the arrangement shown in Figure 7, L1 to L520. H1~FI520)
The total number of recording needles is 640, and the number of pixels formed by these recording needles is 669. (P1 to P659 in Figure 17)
The pinch (P) 105 of the recording needle is 200 μm.

Using this recording head, a conveyance system for transfer paper and ink film was constructed as shown in FIG. The ink film is wound into a roll, and the ink is applied separately as shown in FIG. 111 is yellow, 112 is magenta, and 113 is cyan. 110 is a resistance layer.

FIG. 19 shows a block diagram of the circuit of the printing apparatus of the present invention. One column of image signals is input to 600, and the switch (3
01 or 602) and line memory A605.
Alternatively, it is stored in the line memory B604 at the address from the write address generator 505.

This image signal is sent to the read address generator 606-16.
- the reference signal 5 from the gradation reference signal generator 320 is read from the address of
21 and the result is stored in shift register 308.
and is transferred using the shift clock 405. Temporary memo by latch clock 406! J-509, and distributed by the distributor 610 to the H switch or the L switch according to the recording order selection signal 407. This output reliability has been described above, but will be explained in more detail below.

Each number is connected to a recording needle. Global signal flow No. 23
The figure shows the relationship between the image signal and the number of people.

:0:1jHx:Bufu layer two (7i8Mr:?1”.

It is reversed with a period of . The input image signal 400 is composed of a 640 pixel signal and is sent at a time of TW412. The input image signal 400 is stored in either the line memory A6 or the line memory B according to the address of the write address generator depending on the open/closed state of the switch 301 or 502. At this time, the output image signal 401 is read out from the external line memory according to the address of the read address generator. Signals on the data lines of line memories A and B are shown at 402 and 405. 4
00 to 405 are one of the parallel signals. Now, the '4F write address and read address will be explained.

Table 1 shows 640 addresses using a1 to a128 and b1 to b5. Table 2 is the write address order. The input image signals are signals connected in order from the end, and are stored in line memory A or line memory B in the order shown in Table 2. In other words, if you number the input image signal from 1 to 640, number 1 is address 0, number 2 is address 128, number 5 is address 2.
Numbers 56...639 are stored at address 511, and the last number 640 is stored at address 669. The read addresses are from al to a1 for each block b1 to b5.
Furthermore, in this embodiment, since the image signal is a 4-bit, 16-gradation signal, each block is read out 16 times.

The division into five blocks b1 to b5 as described above corresponds to the most important elements of the present invention on the circuit. When recording and forming pixels, 5. T+
1.5J+2...5J+5 (J is 0, 1.2
. . . 12B), the writing and reading addresses perform arrangement conversion of the image signals in order to record them in five groups represented by . . . 12B).

In this embodiment, the data is divided into five blocks based on the write address, but it is also possible to perform reading while dividing the data into blocks.

Table 1 Continued on next page Table 2 The read image signal 401 is sent to the digital comparator 50.
7 and is compared with a reference signal 321 from a gradation reference signal generator 320, and converted into a comparison binary signal 321 of 0/1 depending on the magnitude. Image-17- The signals are read out 16 times from a1 to a128 per block, but the reference signal is read out once from 0 to 15! Changes with f. The comparison circuit is operated 128×16 times. This time is the period of TRA 413 of the output image signal 401 in FIG. TRA is one-fifth of the line period TL. The compared binary signal 321 is sent to the shift register 308
sent to. FIG. 20 shows the circuit after the shift register. FIG. 20 shows a basic unit that operates five H switches and five L switches each, and in this embodiment, 64 of these basic blocks are connected in cascade or in parallel.

500 and 501 are D-type flip-flops with p, 5
00 is used for a shift register, and 501 is used for temporary storage. 5OK (shift clock) 405 and 1. respectively. The signal is read at the rising edge of OK (latch clock) 406.

BOKp, period of M small change in read address TRA
(128×16), and LCK is a clock with a period of TRA413. The above will be explained using FIG. 24. The reference signal 521 is a -18-ROKO to ROK604 bit signal.

ROKO is the least significant bit and ROK3 is the most significant bit. During the period of TRA, it changes from 0 to 15 at the cycle of TRa414 and returns 9 times. During the period of TRa, the image signal is
One block of al is output at a128t and compared. The period u T Ra of the latch clock LOK 406 is the period 405 of the shift clock 80, which coincides with the period at which the image signal is output.

Returning to the explanation of FIG. 20. The comparison binary signal 62'1 is 1
Input to the DA530 terminal of the stage and shift clock 5O
K405 shifts to the next stage after one application.

This signal is transferred to the 1-time storage flip-flop 501 in the subsequent stage by the latch clock LOK406,
It is retained for a period of 414 hours. Digital comparator 507
The image signal that has passed through has been subjected to pulse width conversion at this point. This signal is called a pulse width image signal 540. This signal selectively opens and closes the L switch 504 and the H switch 505i according to the recording order selection signal 407. 5
02 is an AND circuit, and 503 is an OR circuit. Here, the PD 551 and the ND 532 are connected between the front and rear stages. VH533 is a high potential voltage, and VL (d is a low potential voltage. Regarding the L switch and H switch, see Figures 21 and 22.
This will be explained using figures. The L switch and the ■ switch have the configuration shown in FIG. 21, and open and close the switch 522 according to the opening/closing control signal 510, and output the power line 5200 level to the output terminal 521. FIG. 22(a) shows an L switch. 506 is an NPN) run sister.

The low potential 511 is controlled by the opening/closing control signal 510, and the low potential is output to 512. FIG. 22(b) shows an H switch. 507fiPNP) Run sister, 508 is an inverting circuit. High potential 514 is output to 515.

FIG. 25 shows recording selection signals 407801-806.

801 lags behind signal 404 for switching between line memory A and line memory B by approximately TRA413. This means that there is a line memory Δ (8 is for the output image signal read from line memory B, the opening/closing side (goods) signal 510
This is because passing through causes a delay of TRA.

Each of the recording order selection signals 801 to so6 sequentially opens and closes the L switch and the H switch by a pulse width corresponding to the pulse width image signal 540 according to the write address order shown in the cloth 2.

A television screen was printed using the recording head, ink film transport system, and disturbance circuit described above.

After analog-to-digital conversion, the television image signal was once stored in a 6408480×3 color frame memory, and then inputted into the 300 in FIG.

- a3 m seconds to form a column pixel, that is, TL = a5 m seconds;
At a speed of TJtA=1°66ffi seconds, 480 rows of the entire screen were printed in 4 seconds for each of the three colors yellow, cyan, and agenta. The printed image U, almost the same image quality as the ORT screen was obtained. FIG. 27 shows a part of the printed image. arrow 60
0 is the center of the recording needle. Pixel 601 is formed between recording needles.

Furthermore, when printing, the ink film and the
- Since the transfer paper was continuously moved, pixel i was formed on the diagonal line indicated by 601. This resulted in an image without the scan lines seen on the ORT.

[Example 2] Printing was performed by changing the write address order in Example 1 above. Table 5 shows the write address order in this embodiment. The order of read address table 3 is the same as in the above embodiment. Corresponding to this, the recording order selection signal was changed. It is shown in FIG. As a result, the pixels are 5J+1.5J+3.5. T-1--22- 5.5J+2.5J+4 are formed in this order. When printing was performed in this recording order, similar to Example 1, almost the same image as on a CRT was formed. FIG. 28 shows a part of the printed image. Unlike FIG. 27 of Example 1, 2 of 603 and 604
Because the pixels were formed above the diagonal lines in the book, the resulting image resembled a regular halftone dot scale.

〔effect〕

As in the embodiments described above, the present invention makes it possible to copy a color ORT screen, and in addition to being capable of high-speed recording, it also has a simple recording head structure, gradation recording using a pair of L electrodes and H electrodes, and The present invention realizes a color image printing device at an extremely low cost due to the low recording energy and the low load on the power supply and drive circuit.

[Brief explanation of drawings]

FIGS. 1(a) to 1(c) are diagrams showing a method of performing area gradation recording using a conventional recording head used in the present invention. 3 and 4 are diagrams showing a conventional recording method and its equivalent circuit. FIGS. 5(a) to rc) are views showing the tip portion of the recording head used in the present invention. FIG. 6 is a diagram showing the configuration of a conveying system for the ink film and liquid transfer paper used in the present invention. FIGS. 7(a) to 7(c) are diagrams showing a method of performing area gradation recording using the recording head used in the present invention. FIG. 8 is a diagram showing the basic switch connections to each recording needle of the present invention. FIG. 9 is a diagram showing an equivalent resistance circuit between each recording stylus. FIGS. 10(a) and 10(b) are diagrams showing opening/closing and equivalent circuits of a conventional switch. FIGS. 11(a) and 11(b) are diagrams showing a method of controlling opening and closing of a switch. FIGS. 12(a) to 12(0) are diagrams showing the opening/closing order of conventional switches. FIG. 15('a)T(b) is a diagram showing the drawbacks in opening/closing the conventional switch. 14th South is a diagram showing the opening and closing of the basic switch of the present invention. FIGS. 15(a) and 15(b) are diagrams showing the crosstalk current of the present invention. FIGS. 16 and 17 are N showing the tip of the recording head used in the present invention. FIG. 18 shows the causes of the ink film used in the present invention. FIG. 19 is a block diagram of the circuit of the printing apparatus of the present invention. FIG. 20 is a diagram showing the basic expansion of H switch and L switch operations. FIG. 21 and FIGS. 22(a) and 22(b) are diagrams showing the configurations of the H switch and the L switch. FIGS. 25, 24, 25, and 26 are diagrams showing operating signals of the present invention. FIGS. 27 and 28 are diagrams illustrating a -25- arrangement of pixels formed according to the present invention. 3... Resistance layer 1... Melting ink layer 19... Ink film 22... Recording head 21... Recording needles 51 and 504... L switch 50 and 505... H switch and above Applicant stock Company Tanwa Seikosha Patent Attorney Agent Tsutomu Mogami-26= Figure 2 Figure 4 Figure 7 Figure 9 d 20 -No Figure 12 Figure 15

Claims (2)

[Claims] (1) An ink film consisting of at least a resistive layer and a melting ink layer is used, a recording head is composed of a plurality of recording needles arranged in a line, and a switch for opening and closing a low potential and an H switch for opening and closing a high potential are used. energizing the resistance layer by simultaneously closing adjacent L switches and H switches that are alternately connected to the recording needle;
In a printing device that generates heat to melt the melted ink layer and transfer it to transfer paper to form pixels, the pixels are sequentially printed from the end to 5.7+1,5J-1-2,5J-4.
-5, 5, r-1-4 and 5 J-1-5 (J is 0,1
, 2° 5, . . . ), and pixels are formed for each group. (2) The printing apparatus according to claim 1, wherein the area of the pixel is changed by changing the time during which the resistive layer is energized.