JPS6044372A - Gradation-type printer - Google Patents

Abstract

PURPOSE:To enable to control recorded density in accordance with gradation characteristics, by a method wherein time data A for impressed pulses read from a one-line memory and time data B for impressed pulses fed from a counter are compared with each other, and passage of electric currents to heating element dots is stopped when A<=B. CONSTITUTION:An input signal (a) is converted into gradation data by an AD converter 1, and by the gradation data and heating element dot position data fed from a divide-by-1728 counter 11, predetermined impressing time data A are read from a ROM10 for controlling gradation, and are stored into the one-line memory 2. the data A are read from the memory 2 in accordance with outputs from divide-by-64 and divide-by-27 counters 3, 4 for counting clock pulses. Impressed pulse time data B are outputted from a timer counter 13, and are compared with the data A by one-dot amount at a time by a digital comparator 16. Only when A>B, a high-level signal is fed to a 64-bit shift register 14, and when all the data are supplied, they are latched by a 64-bit latch 15, and a recording action is performed one time. Accordingly, the recorded density can be finely controlled in accordance with resistance characteristics of the heating element dots and the gradation characteristics of a recording material.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a gradation type mono-multi printer, and more specifically, a mono-multi print head consisting of a plurality of heating element dots arranged in a line. (Relates to gradation type thermal printers such as facsimile machines 6 and thermal transfer printers that perform gradation recording.

(Prior art) Conventionally, a thermal head consisting of a plurality of photothermal dots arranged in a line has been used to add gradation to a recorded image using a two-way printer or a thermal transfer printer.
There is something that is done.

When recording such gradation, [Yo, "1 Pa is II O.
Amplitude modulation of the pixel signal of II with a gradation signal or [Ma1-]C
M modulated and serially transmitted to the recording side, where the voltage level or pulse width applied to the thermal head is changed according to the gradation signal, and the energy applied to the thermal head is changed. ). The applicant has already proposed this in Japanese Patent Application No. 57-126051.

FIG. 1 is an explanatory diagram showing the size and configuration of an example of a diode matrix type multi-head, which is for recording a Δ4 plate (216 mm) at a resolution of 8 dots/1llnl, and is capable of recording i-dots of heat generated by a 1728f prisoner. 1-E is arranged in a line. In Fig. 1, heating elements 1 to TE are divided into 27 blocks with 64 heating elements in 11L1 block.
One end of the heating elements 171 to 17F in the same arrangement order in each circuit is connected in parallel to the corresponding dots 1 to 64; -C are connected in parallel to block selection terminals 113 to 27B for each block via diodes D, respectively.

Figure 2 shows l'i! using a single head like this! i
FIG. 1 is an explanatory diagram showing an example of a conventional drive circuit for performing key recording;
An example of changing the voltage level is shown. If the gradation signal is an amplitude signal, the 1-line input signal is converted into a digital signal by the Δ10 converter 1 and stored in the 1-line memory 2. In addition, if the input signal is a digital signal, A,
/D converter 1 is not required.

After that, according to the outputs of the J counter 3 (64-decimal) and the 27-decimal counter 4, the digital gradation data of 64 dots 1-minute, which constitutes the first block from 1 line count 2, is extracted, and 3. Each of the 64 laps (5) held in its downward position was set accordingly.

and the digital floor held in each latch 5, j
l,! l data is set for each latch 5.
/ In addition to the A converter 6, it is converted to a predetermined voltage level.

At this time, the decoder 7 selects the first block driving transistor according to the output of the 27-decimal counter 4. 1 (! Turn on for a certain period of time.
The heating element drums 1 to 1 are driven at a voltage level according to the respective gradation signals 15; Advancing forward, the second block is drawn from 1 line to 2. After reading out the digital gradation data from 641 to At the same time, the output of the 27-decimal counter 4 is decoded into 7-1-7 (1 to 1 transistor for driving the second block).

Cover 2 with A for a certain period of time. As a result, gradation recording is performed on the 64 heating element tons 1-TE constituting the second block. Thereafter, in the same manner, the drive will be performed up to the 27th block, and the IIJi tone recording of one line will be completed, and processing will proceed to the next line.

However, with the circuit configuration shown in Fig. 2, in order to obtain 16 gradations, for example, it is necessary to install 64 systems of 4-bit latches 5 and D/Δ converters 6. The configuration becomes considerably large-scale, and a large number of units are required for individual adjustment of the D/Δ converter 6 and the like.

On the other hand, FIG. 3 shows an example of a conventional drive circuit shown in FIG. 1, in which the voltage level applied to the thermal head is constant and the pulse width varies. In the circuit configuration shown in FIG. 3, after storing one line worth of input signals in the one line memory 2, the first block [J Configure a Tsuk (34
The digital gradation data for the dots is read out, and each value is assigned to the 64 N-adic down counters 8 provided in order to correspond to each arrangement order.
After completing the Bricht on the N-ary down counter 8, one of the preset flip-flops (hereinafter abbreviated as "7'") 9 is inserted into each N-ary down counter 8. The other parts will return to the ``O°'' position and the others will be in the Z1~ state.After that, turn on the power to the first block 1 of the thermal head, and turn all the N
The forward down counter 8 starts to be driven at the same times as n and 'r. As a result, the heating element drum with a low gradation level (record! II general)! ~ T[corresponding to/this N-ary town counter 8 bs I and sequentially Bo 1'' - is 1) 4 ka and 3・I
Response Jru1:, -'F9 is reset, the heating element driver l-1-[E/\ is energized, and Sui i+,'J
N-ary town counter 8 to fii corresponding to the highest (highest recording density) heating element driver 1-1[-
B[1- is output to Ff, and the corresponding F/'9 is reset. Next, the 27-decimal counter 4 is advanced by one to record the gradation of the second block. Bu[
The gradation recording of one line is completed by one turn and one FII, and the process moves on to the next line.

However, in the circuit configuration of FIG. 3, for example, 16
In order to record 1q gradations, 64 systems of 1G town counters 8 and F/[9 must be arranged, which increases the circuit size.

In addition, according to the configurations in FIGS. 2 and 3, the gradation of the recording medium, such as the color development degree characteristics of the thermal recording paper and the transfer mark characteristics on the transfer paper side using heat sublimation dye Ji31, can be adjusted. In order to match the characteristics of 1!1, the circuit constants must be changed and adjusted in consideration of the gradation characteristics of the recording medium.
It is difficult to use Nogami's circuit for recording materials having different gradation characteristics. Furthermore, since it is extremely difficult in manufacturing to reduce the variation in the heating resistance value of the heating element dots [E] of such a line-shaped thermal head to zero, it is difficult to reduce the variation in the heating resistance value of the heating element dots [E] by a maximum of ±25% to the γF capacity range. It is shipped from the manufacturer as. Therefore, when using such a linear adhesive head, it is desirable to correct the variation in the heating resistance value of the heating elements 1-1-1-F, but in conventional devices, such heating element dots TE No craftsman has been trained to correct the variation in the photothermal resistance of the heating element dots TE, and the method is to select and use line-shaped glue lines 1~ with less variation in the photothermal resistance of the heating element dots TE. (7/), and it is difficult to record 1q of high-quality gradations.

(Objective of the Invention) The present invention has been made in view of these points, and its object is to: The width is determined by the photothermal resistance value of the heating element dot and the gradation level 1SJ of the recording medium.
Our goal is to provide a gradation-type thermal printer with a simple circuit configuration, allowing detailed control according to the characteristics of the printer.

(Structure of the Invention) The present defense for achieving this object consists of a plurality of heating element drums 1 arranged in a line. outputs applied pulse time data according to the heating resistance value of each heating element dot in the legal heads 1 to 1 and the gradation characteristics of the recording medium according to the digital Iif'i tone data of the input signal and the position data of the photothermal element dot. a read-only memory; and 1 for holding application pulse time data for one line of the thermal head read from the read-only memory.
a line memory, a counter that counts 81 clock pulses and outputs an applied pulse time signal, applied pulse 01 interval data A read from the 1 line memory, and an applied pulse intercostal gate outputted from the counter. 1-3, and in the range of A l knee B, the heating element dot is energized to avoid heat generation, and △"≦
The device is characterized in that when the temperature reaches B, the current supply to the heating element dots (ζ1) is stopped.

<Example) Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 4 is an explanatory diagram showing a drive circuit according to an embodiment of the present invention, and the same parts as in FIGS. 2 and 33 are marked with the same line. In this example, a 7.16 gradation image (
ρ; is recorded. In this figure 4, there is d3,
The input signal is converted into 4-bit digital gradation data by the 4-pin I/D converter 1, and added to the read-only memory (hereinafter referred to as ROM).
0 to the heating element drum 1 of the inlet head 1-[position γ
'-data and c'I 72 Add the output of the octal input counter 11. This ROtvl '10 contains the applied pulse time data of the product value and the gradation 'l' of the recording medium, 'j l!l of 1.tl. is each gradation f of each heating element door 1~lower
Digicle gradation data of the input signal stored in lJ and applied from the A, 'D converter 1 and the optical missing one dot TE applied from the counter 11 for 1723 (approach) J.
According to the position data of the predetermined applied pulse +v7 interval
1 line is read out and stored in 1 line mark 2. After that, ri1] Tsuku￥N II; ii:i
According to the output of the 11 counter 3 and the 27-decimal counter 4, the first block [1 pulse is output from the 1-line memory 2 (14 becomes (34 Dot 1-minute applied pulse time data 'L 1i)c ; lj output C etc. On the other hand, 64
;! -(Counter 3 no 2 1 tree 1a timer January) J
It is added to the counter 13 as 1-clock (), but its initial state is 0. Also, the output of the clock oscillator 12 (one clock pulse has 64 pips [・shift register 1
4 as a shift clock, and the main 1 free of the J counter 3 is added as a latch pulse of the 64-pitch 1-latch 15 (64 base). Here, if the frequency of the output tarokku pulse of the clock optical oscillator 12 is set to 8 Ml-1z, for example, the timer power [1 to 1 kt applied to the clock pulse 13 is 0.125 (μS)×64 (
Since digit)=8(, czS), it becomes 8 μs. That is, 6/
Minimum ++ for each heating element driver 1-T[to I dot 1,
li resolution, and 8 for each heating element dot rE.
This means that it can be set according to μs Jy.

In accordance with Figure 5, the table on the next page shows the maximum gradation QCj color density of thermal paper, 1i11, 2, evenly divided into 16 gradations, and the [iJ applied pulse width and medium It is made of processed flannel keys.

(Left space on this page) Applied energy E (mJ) I, E-(V2 /l x) [... can be determined by (1). Note that ■ is the applied voltage, Rx is the heating resistance value, and [ is the applied pulse width. Here, if the applied voltage V is constant, the heating resistance value RX will vary to each heating element dot TEfii (also, the applied energy E required for each gradation of each heating element dot - [E can be calculated from the above table. (can be attached to each heating element)
By substituting the heating resistance value R of -T E into the equation (1), it is possible to set the application pulse rate 5'n data t required for each gradation of each heating element dot -E. The heat generated for one line in this way is 1~T.
Application pulse time data necessary for each gradation (16 gradations from O to 15 in this embodiment) (1728 dots 1 to 1 in this embodiment) is stored. Incidentally, if the result of 1 calculation of these applied pulse time data is not divisible by 811s, it is sufficient to divide it by 5 people, for example.

FIG. 6 shows a specific example of a circuit for measuring the heating resistance values of the heating element drums 1 to TE of the single-head head shown in FIG. 1. In Figure 6, ? R source lightning voltage [(v)
, the measurement reference resistance is Rr<o), and the detection voltage is (!o(V
), the resistance value of the heating element drum 1 to TE to be measured is Rx
(Ω) What should I do? No. 1 1” photothermal dot T E +
resistance (1 (microphone when measuring +) -1-l
switch driver 5D11. When SDa'a is driven and the first block selection switch ( ) 1 is turned on, the first dot selection switch 81 is turned on. As a result, J4 for measurement! t
The current 1 (△) flowing into the 1L resistor is i = (E-e o )/Rf - (2).

Here, the saturation voltage of tie A −1” I)/j−k V
When D(V) is used, e O=Vo +Rx + i ・= (3).

Note that the variation in diode D is 1% or more, and is constant 1.
It can be considered as 1r1. Substituting equation (2) into equation (3) and substituting the current 1, RX = (e o −V
o) −Rf, / (l2 −(〉 0)...
(/4), and to the first photothermal body dot 1 r-E, no 1 person 1
i'L11 "i can be set. In addition, detection m JN
O, IJ△, J taken into μP through /D converter,
Automatic measurement can be performed by reading the sea urchin. When measuring the resistance value of No. 2 [1 Binetsu I 4-1-tsu h l-E 2], No. 1-. 7.Turn on the a selection switch b1 and simultaneously turn on the second selection switch a2.
, No. 6 'l? To measure the resistance (Ji) of the heating element dot E64 of the 1st block I, set the 1st block selection switch b to A, and set the 64th block selection switch 1 to selection switch a64 to Δon. .Hereinafter, similarly, block selection switches), ~1) 27 and dot selection switches 81 to a
6. Measure the resistance value of each heating element dot TE by sequentially and selectively turning on A.1. In this way, C is measured and I, 2′
8 resistance (fJ) Substitute RX into equation (1), adjust the IC applied pulse width according to each gradation, and calculate the value as p −r< o~1
()) rogran+n+able Read On
By writing to the P-ROM using a writer (Mcmory), the gradation characteristic ROM 10 shown in FIG. 4 becomes 1! I run.

Again, in FIG. 4, the applied pulse time data Δ for 1 g-in read from the 1-line screen 2 and the applied pulse intercostal data B output from the timer counter 13 are compared by the digital comparator 16 for each dot I-min. (The output of the digital comparator 16 becomes '1°' and is sent to the 64-bit shift register 14. Then, 64 bits are processed every 8 μs,
IQII for all 64 pips I~Shift 1~Register 14,
When the data of l111+ (“0'° does not record, “1” records 11) is complete, 64 pins 1-latch 15
, and one recording operation is performed. This sea urchin, 8
The applied pulse width data is updated 64 bits at a time with a time resolution of μS, and Δ≦B, so that the first point
Construct a block 6 4. If! The gradation recording by the photothermal drum 1- is completed. Hereinafter, the same (]i)
By driving up to the 27th block]], tone recording of one line is completed, and the process moves to step 311' for the next line. still,
In this embodiment, an example is shown in which one 1-line memory is used, but two 1-line memories are prepared, and the 1-line memory of =-jj executes the recording operation. High-speed processing can be achieved by overlaying the next data on the other line at the same time. In this case, the time to age one input signal is shorter than the recording intercostal space of one line, so that J5 <
Yoniriru.

Figure 7 shows another length hl of the present invention! ! 1114 is an explanatory diagram showing an example of a direct drive type thermal head used in the example, in which the 64-bit register 1 to register 14 and the 64-bit latch 15 shown in FIG. 4 are mounted on the thermal head side. Figure 7 shows J3 (X, 64 pits 1~
There are 27 series circuits consisting of a shift register 14 and a 64-bit latch 15.
The shift register 14 is DATA1~I) A T A
4 out of 4! Divided into IY (Xru.-yj,
64 pin] - Output terminal of latch 15
1 connected to the input terminal of −=y of N+), these j1 gates −1 − ΔN The direct 911 circuits of the system are divided into 7 groups of 1 each with 4 systems in accordance with the arrangement order. Furthermore, the final group consists of three strains.
The 21st
! The other input terminal of each AND gate △ND which bends over T is connected to the ST[1-B terminal 2;
1! The other input of each AND gate A N which yields to Ij is connected to the other input ☆v1: the child is connected to the child I]-b*i; the child is connected. By using such a single normal head, the number of photothermal drums 1-TE driven at one time increases, and the speed increases by 1111 times.

FIG. 8 is an explanatory diagram of a driving circuit 8 shown in FIG. 7 and shown in another embodiment of the present invention for driving a single head, and is shown in the same part as FIG. In FIG. 8, the data between applied pulse parts for 1 diin read out from the ROM 10 is 1/4 of 4.
The data is divided and stored in the line memory 17. When storing, the first 6/'If to 1-minute digital 1iiiI,
J! 1 data is stored in the first 1/4 line memory 17, and the next 611 bits of digital gradation data is stored in the second 1/4 line memory 17.
1/4 of the line 17 (stored in g+, and the same goes for the 3rd 1, -' /l line 17) → the 4th 1
74 line menu [S17 ta)-shi 1st line menu 17 ■->... and page turn; division. When all 811 input signals for one input signal have been stored in this way, the seventh
The one shown in the figure--Maru head 1, ru l! i! Perform i-key recording. The data A for the applied pulse 0h stored in the memory 17■ to ■ is read out at the same time and is 1/4'' each. digital comparator 1
At the same time, the applied pulse time data B of the timer counter 13 is added to the digital comparator 16.

Then, digital comparator 1 (from 3 A:=,
When it is B, “1” is output, and when △≦13, O” is output, and each of these outputs is converted into 64-bit data in Figure 7.
The signals are sequentially sent to the shift 1 register 14. In this way, all 64 bits 1' and shift register 1/'l are set to "'O".
, "1" data ("O" is not recorded, "1"
``' records) is wrapped in 34 bits 15, 256 dots 1-(64 dots l'
The data for X 4 ) is added to the fI column every moment.

For example, as in Fig. 4, if the frequency of one pulse is changed to 8 M l-I Z and J', then VJ
i will be treated. These operations are carried out while the strobe terminal 1 of the differential valve 19, which decodes the output of the pressure counter 18, is on, that is, when the key pressure is output from the timer counter 13. During the time required for the maximum density of the thermal paper to reach its maximum density, the temperature is 11 times. When the carry from the timer counter 13 is added to the hexadecimal counter 18, it is incremented by 1, and when the upper j address of the 1/4 line memory 17 is specified, the strobe terminal 2 of the decoder 19 is turned on at JL, and the next 21] Recording of 6 dots and 1 minute will be performed.

According to the 14th generation, the number of recording gradations is determined according to the heating resistance value of the heating element driver 1- and the coloring of the thermal paper! ) according to 1
11 The width of the applied pulses (required duration) is the same, so by assigning these applied pulse widths to the ROM for each gradation of each dot and writing them as data -C1, you can accurately calculate the heating element of the thermal head. The heating resistance value characteristics of the drums 1 to 1 and the gradation characteristics of the thermal paper can be stored. Therefore, different photothermal resistances 1iri 4? When using a 4J-maru head with 4J-characteristics or thermal paper with different gradation characteristics, create a ROM according to the characteristics and achieve RO ~ 1 (
By changing the shape of J, it is possible to achieve more accurate gradation characteristics by changing and adjusting the circuit constants according to the gradation characteristics of conventional J and thermal paper. It is not necessary, and it is possible to use a common circuit for different thermal papers with different gradations.

In terms of production, there is no need to rework or readjust according to the gradation characteristics of the thermal paper, and the C effect is extremely good. Furthermore, the overall circuit structure can be simplified compared to the 1T''L model, and costs can be reduced.

Incidentally, in the above embodiment, an example of thermal paper has been described, but the same effect can be obtained even when thermal transfer paper is used. Also, I
By applying the present invention to a C-mounted single-head, high-speed gradation recording can be realized.

(Effects of the Invention) As explained below, according to the present invention, relatively fF
Il! li',': In the circuit configuration, the heating resistance value characteristics of the optical body dots 1 to 1 of the thermal head and l' of the recording medium)
li Kl! a Q': Record 11ia13 according to I nature
1' (applied pulse width of the thermal head) can be finely controlled. A gradation type thermal printer capable of recording i is realized, and is suitable for facsimile machines, thermal transfer type printers, etc.

[Brief explanation of drawings]

Figure 1 shows the diode:? L. Rix type 4 nonrut\
The structure shows an example of the program. ;2 Ming Figure, Figure 2 and Figure 33 (
The figures show examples of drive circuits for conventional neck braces.
FIG. 4 is an explanatory diagram showing a driving circuit according to an embodiment of the present invention, and FIG. 5 is an explanatory diagram showing the gradation characteristics of thermal paper.
An explanatory diagram showing llI, Figure 6 is an example diagram of a resistance measurement circuit for the heating element dot of the full head, and Figure 7 is a diagram showing the resistance measurement circuit of the heating element dot of the full head.
To 1 -t of live type thermal head! I'll show you iJ'
FIG. 8 is an explanatory diagram of a driving mechanism 8 according to another embodiment of the present invention for driving the thermal head shown in FIG. 7. 1...A/D converter 2...1 line marking 3.
...64-decimal count 4...27) How to do it 7.
... Decoder 10 ... ROM for gradation characteristics (readout Furukawa memory) 1
1...172 octal input counter 12...L1 clock oscillator 13...Timer counter 14...64 bit shift 1-register 15...64
Bit latch 16...Digital comparator 17...1/4 line count 18...Septinal counter 19...Decoder patent applicant Roku Konishi Photo Industry Co., Ltd.

Claims (1)

[Claims] A thermal head consisting of a plurality of heating element dots arranged in a line, a heating resistor of each heating element dot of the thermal head, and a recording medium according to the digital gradation data of the input signal and the position data of the heating element dots. 1iP of
a read-only memory for outputting data between applied pulse portions according to i-tone characteristics; and a 1-line memory having 1× applied pulse time data for one line of the normal head read from the read-only memory. , a counter that counts clock pulses and outputs an application pulse time signal, and an application pulse 1 that is read from the 1-line memory.
and a =1 comparator that compares the timer A with the applied pulse time data B output from the counter,
A gradation type thermal printer characterized in that in the range of Δ)B, the heating element dots are energized to generate heat, and when Δ≦B, the energization to the heating element dot 1- is stopped. .