JP3273731B2 - Printer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printer.

[0002]

2. Description of the Related Art Conventionally, a ticket issuing apparatus has a printing unit for writing predetermined information on the surface of a ticket, that is, a printing medium, and a printer such as a thermal printer is provided in the printing unit. ing. For example, a thermal printer has a thermal head, and in the thermal head, printing is performed by selectively driving a heating element arranged in a line direction.

FIG. 2 is a block diagram showing a conventional driving circuit for a thermal head. In the figure, reference numeral 111 denotes a shift register, 112 denotes a latch, and 113 denotes NAND gates G1 to G1.
Driver consisting Gn, d ₁ to d _n is the n number of heating elements arranged in the main scanning direction of the thermal head in correspondence with the respective NAND gates G1~Gn driver 113. Also,
DATA is a data signal, CLK is a clock, PLS is a latch signal, and ENB is a head application signal.

When a control unit (not shown) transfers a data signal DATA composed of n bit data to the shift register 111 in synchronization with n clocks CLK, the shift register 111 transmits the data signal DAT.
A is converted to parallel data and output to the latch 112. The latch 112 latches the parallel data from the shift register 111 at the timing of the latch signal PLS, and
3 is output.

At this time, of the NAND gates G1 to Gn of the driver 113, the one for which the parallel data output from the latch 112 is "1" is the head application signal EN.
B is turned on during the period of "1", while the electric current I _O to a corresponding heating element d ₁ to d _n, to generate Joule heat. When printing is performed by the direct thermal printing method, a printing medium (not shown) is locally heated by a thermal head, and an image is formed by the heated portion of the printing medium being colored. When printing is performed by the transfer thermal printing method, an unillustrated thermal transfer ribbon is locally heated by a thermal head, and an image is formed by transferring a heated portion of the thermal transfer ribbon to a print medium.

FIG. 3 is a time chart showing the operation of a conventional printer. In the description, reference numerals in FIG. 2 are used. In the figure, TIMING is a timing signal generated by a control unit (not shown) in synchronization with the transport speed V of the print medium, and a pulse is formed at each predetermined timing in the timing signal TIMING. DATA is a data signal transferred from the control unit to the thermal head, and ENB is the heating element d _1.
To d _n (FIG. 2).

In this case, assuming that the distance between dots in the sub-scanning direction, that is, the distance between lines is L and the transport speed of the print medium is V, the timing signal TIMIN
Period T _s pulse is generated in the G is represented by the formula (1). T _s = L / V (1) By the way, the head application signal ENB is for generating energy Q required for printing.
Relationship between said energy Q and the applied time T _e of the head applied signal ENB is represented by the formula (2).

T _e = Q / P (2) where P is a fixed value unique to the thermal head. The print data transfer time T _v required to transfer the data signal DATA from the control unit to the thermal head is represented by M, where M is the number of dots in the line direction of the thermal head.
When the transfer timing frequency is F, it is expressed by the following equation (3).

T _v = M / F (3) When the control unit receives print data and a command of a certain line from a higher-level device, the control unit generates a data signal DATA based on the print data and the command, The data signal DATA is transferred to the thermal head. continue,
The timing signal TI is synchronized with the transport speed V of the printing medium.
MING is generated, to enable the state energy Q corresponding to the application time T _e only head applied signal ENB needed to perform the printing, to print on the line.

Furthermore, the control unit, while the printing is being carried out, and transfers the data signal DATA for the next line to the thermal head with the print data transfer time T _v. And the period T
_{When s} elapses, the control unit drives a line feed motor (not shown) to convey the print medium by one line, and again generates the timing signal TIMING. Subsequently, the control unit is to enable the state energy Q corresponding to the application time T _e only head applied signal ENB needed to perform the printing, to print the next line.

Hereinafter, printing is performed line by line in the same procedure.
Will be returned. By the way, the thermal head with the above configuration
And the heating element d₁~ D_nCurrent I _OSink and Jules
Generates heat, but prints at high speed
Each heating element d₁~ D_nBy the heat storage action in
Tail, blur, etc. will occur.

[0012] Therefore, the heating element d ₁ to d _n a have been printer to perform a history control by driving based on the respective history provided in the history control performs printing for one line for each heating element d ₁ of the application time T _e of the head applied signal ENB to d _n
It is changed to correspond to the history of. Next, the operation of the printer that performs the history control will be described.

FIG. 4 is a time chart showing the operation when history control is performed in a conventional printer. In the description, reference numerals in FIG. 2 are used. A control unit (not shown) receives the print data and commands certain line from the host device, in synchronization with the conveying speed V of the print medium (not shown) by generating a timing signal TIMING at a period T _s, the head is applied only application time T _E The signal ENB is enabled, and printing is performed for the line.

The control unit forms three enable states in the head application signal ENB in order to perform printing on one line, and divides the data signal DATA into three times in accordance with each enable state to generate a thermal signal. Transfer to head. In this case, the energy Q required for printing is determined based on the history of each dot in the scanning direction, that is, whether a dot is formed on a previous line, whether a dot is formed on a previous line, and the like. Each data signal D obtained and transferred to the thermal head
The bit data of the ATA is changed in accordance with the energy Q.

In this case, the head application signal EN
Three enable states are formed in B, and times T _{e1 to} T _e3 of each enable state are set respectively. Therefore, the sum of the times T _{e1 to} T _e3 in each enabled state becomes the application time T _E. Thus, the three enabled head applied signal ENB is formed, while the printing is being performed, the control unit, the print data transfer time T _v a thermal head data signal DATA for the next line Transfer to

When the period T _s elapses, the control section drives the line feed motor to convey the print medium by one line, and again transmits the timing signal TIMIN.
G is generated. Subsequently, the control unit, the head applied signal ENB by application time T _E is in the enabled state, to print the next line. Hereinafter, printing is repeated line by line in the same procedure.

[0017]

However, in the conventional printer, when the history control is not performed, the application time T _e is set when the history control is performed.
Against _E, since they must be set a large margin enough to the period T _s of the timing signal TIMING,
The printing speed decreases accordingly.

If noise occurs in the timing signal TIMING, the timing state becomes unstable,
In addition to missing lines, printing may be forcibly stopped. Here, a case where the history control is not performed will be described. First, the print data transfer time T _v is very short, since it is T _e »T _v, it is not necessary to set a large margin sufficient to application time T _e with respect to the print data transfer time T _v.

However, the timing signal TIMIN
As described above, G is generated in synchronization with the transport speed V of the print medium. Therefore, when a DC motor is used as the line feed motor for transporting the print medium, uneven transport, variations in transport torque, aging, etc. Causes the speed of the DC motor to fluctuate. As a result, the timing signal T
Period T _s of IMING in proportion to variations in the speed of the DC motor varies, when the variation is A (%) (specific fixed value to the printer), as represented by the following equation (4).

[0020] T _s · A (%) ... (4) The fixed value P in the formula (2) for calculating the application time T _e is the head applied voltage is V _TH, the head resistance R Is expressed by the following equation (5) (actually, there is a detailed equation for each thermal head,
Omitted here).

P = (V _TH ) ² / R (5) The head applied voltage V _TH is expressed by the following equation (6) in consideration of the influence of the voltage fluctuation of the power supply of the printer. . V _TH ± B [%] (6) where B is a fixed value specific to the printer and is 5 to 10
[%].

The head resistance R has an error for each thermal head and is expressed by the following equation (7). R ± C [%] (7) where C is a fixed value unique to the thermal head,
It is about 20%.

Further, when the temperature of the thermal head fluctuates, the energy Q required for performing printing also fluctuates. In this case, depending on the thermal head and the printer, if the temperature of the thermal head fluctuates in the range of 0 to 40 ° C., the energy Q fluctuates in the range of about 50 to 150%. Thus, fluctuations in the speed of the DC motor,
Error of the head applied voltage V _TH, the error of the head resistance R, in consideration of the fluctuation of the energy Q, must be set large margin enough to the period T _s of the timing signal TIMING against application time T _e.

An object of the present invention is to solve the above-mentioned problems of the conventional printer and to provide a printer which does not need to set a large margin in a timing signal with respect to an application time.

[0025]

For this purpose, a printer according to the present invention comprises a plurality of elements arranged in a line direction, and a print head for selectively turning on and off the elements in accordance with a data signal. A control unit that sets a timing signal generated every time one line is printed as a start point, enables a head application signal for an application time set in advance by history control, and turns on the element.

The control unit includes enable state continuation means for continuously enabling the head application signal when the timing signal is generated while the head application signal is in the enable state. .

[0027]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a block diagram of a control circuit of the printer according to the first embodiment of the present invention. In the figure, 11 is an application counter, 12 is a JK-F / F, 13 is a signal latch, G1 to G3 are gates, TIMING is a timing signal, ABN is an abnormality notification signal sent to a control unit (not shown), and ENB is a print head. Are applied to the thermal head (not shown), and three enable states are formed in the head application signal ENB.

SG1 is the timing signal TIM.
SG2 is a signal generated when the timing at which ING is generated is abnormal, and SG2 is a timing signal TIMI.
If the timing at which NG is generated is normal,
A ripple carry-out signal for disabling the head application signal ENB (high level), SG3 is an OR signal formed by a logical sum of the signal SG1 and the ripple carry-out signal SG2, and SG4 is an inverted signal of the head application signal ENB. , DA1 is the time T of each enable state in the applied data generation means (not shown) of the control unit.
_e1 to correspond to through T _e3 allowed to occur, the applied data to be loaded into the application counter 11, PLS is caused to occur in the latch signal generating means (not shown) of the control unit,
This is a latch signal input to the application counter 11.

Next, the operation of the printer when the history control is performed and the timing when the timing signal TIMING is generated is normal will be described. FIG. 5 is a first time chart showing the operation of the printer according to the first embodiment of the present invention. A control unit (not shown) receives the print data and commands certain line from the host device, in synchronization with the conveying speed V of the print medium (not shown) by generating a timing signal TIMING at a period T _s, the head is applied only application time T _E The signal ENB is enabled, and printing is performed for the line.

The control unit forms three enable states in the head application signal ENB in order to perform printing for one line, and divides the data signal DATA into three times according to each enable state. Not transfer to thermal head. In the thermal head, the shift register 111 (see FIG. 2) is provided with the data signal DATA.
Is converted into parallel data, and latch 1
12 is output. The latch 112 operates at the timing of the latch signal PLS,
It latches the parallel data from 1 and outputs the parallel data to the driver 113.

At this time, among the NAND gates G1 to Gn of the driver 113, the one for which the parallel data output from the latch 112 is "1" is the head application signal EN.
B is turned on during the period of "1", while the electric current I _O to the heating element d ₁ to d _n as the corresponding elements, to generate Joule heat. Incidentally, the heating element d ₁ to d _n are arranged in the line direction of the thermal head.

When printing is performed by the direct thermal printing method, the print medium is locally heated by the thermal head, and the heated portion of the print medium is colored to form an image. When printing is performed by the transfer thermal printing method, an unillustrated thermal transfer ribbon is locally heated by a thermal head, and an image is formed by transferring a heated portion of the thermal transfer ribbon to a print medium.

In this case, it is necessary to perform printing based on the history of each dot in the scanning direction, that is, whether or not a dot has been formed in the previous line, and whether or not a dot has been formed in the previous line. The energy Q is determined, and the bit data of each data signal DATA transferred to the thermal head is changed in accordance with the energy Q.

In this case, the head application signal EN
Three enable states are formed in B, and times T _{e1 to} T _e3 of each enable state are set respectively. Therefore, the sum of the times T _{e1 to} T _e3 in each enabled state becomes the application time T _E. Thus, the three enabled head applied signal ENB is formed, while the printing is being performed, the control unit, the print data transfer time T _v a thermal head data signal DATA for the next line Transfer to

When the period T _s elapses, the control unit drives a line feed motor (not shown) to convey the print medium by one line, and again controls the timing signal TI.
Generate MING. Subsequently, the control unit sets the application time T
_The head application signal ENB is enabled only by _E , and printing is performed for the next line. By the way, the timing t
At 1, the JK-F / F 12 is disabled and the inverted signal SG4, which is the output of the JK-F / F 12, is at a low level. The terminal goes low, the pulse (low level) of the timing signal TIMING input to the inverting input terminal of the gate G1 becomes invalid, the signal SG1 remains low, and therefore, the signal SG1 and the ripple carry-out signal SG2
OR signal SG3 is also kept at the low level. on the other hand,
At the same timing t1, the JK-F / F12 which receives the latch signal PLS generated in synchronization with the pulse (low level) of the timing signal TIMING by the latch signal PLS generation circuit is enabled by the latch signal PLS. And the inverted signal SG4
Goes high, and the head application signal ENB is enabled. At the same time, the application data DA1 is taken into the application counter 11 at the timing of the latch signal PLS, and the application counter 11 starts counting. Further, at the same time, the transfer of the data signal DATA from the control unit to the thermal head is started.

Subsequently, at timing t2, when the application counter 11 finishes counting and the count value overflows, the ripple carry-out signal SG2 is output from the application counter 11, and the OR signal SG3 becomes high level. The F / F 12 is disabled. As a result, the inverted signal SG4 temporarily goes low, and the head application signal ENB is disabled.
Simultaneously, the latch signal PLS generated by the latch signal PLS generation circuit causes the applied data DA1 to be applied.
Is applied to the application counter 11, and the application counter 11 starts counting again, and at the same time, the JK-F / F to which the latch signal PLS is input by the latch signal PLS.
12 is enabled, the inverted signal SG4 goes high, and the head application signal ENB is enabled again.

By repeating such a state three times, 1
When printing for the line is completed, printing of the next line is started at timing t3. Next, the operation of the printer when the history control is performed and the timing of the timing signal TIMING is abnormal will be described. FIG. 6 is a second time chart showing the operation of the printer according to the first embodiment of the present invention.

In the figure, T _s is the timing signal TIM
ING cycle, T _v is print data transfer time, T _{e1 to} T _e3
Is the time of each enable state of the head application signal ENB, T
_E is the application time of the head application signal ENB. In this case, at timings t1 and t2, the control circuit of the printer (not shown) is operated in the same manner as when the timing at which the timing signal TIMING is generated is normal.

[0039] Then, at timing t4, a pulse is formed on the timing signal TIMING while the printing enabled state of three eyes being performed, the T _s <T _E. In this case, an enable state canceling means (not shown) is connected to the reset terminal RS of the JK-F / F12 (FIG. 1).
A pulse is input to T to forcibly disable the head application signal ENB. Then, the timing signal TI
At the same time that a pulse is formed on MING, a latch signal PLS is generated by latch signal generation means (not shown) as enable state continuation means.
Sent to 1. As a result, the application counter 11 captures the application data DA1 at the timing of the latch signal PLS,
The head application signal ENB is again enabled. At this time, the transfer of the data signal DATA from the control unit to the thermal head is started at the same time.

The time that elapses during this period is several [ns].
Therefore, in practice, the head application signal ENB can be continuously enabled. And at the same time,
The signal latch 13 generates the abnormality notification signal ABN, and notifies the control unit that the timing at which the timing signal TIMING is generated is abnormal.

As described above, in this embodiment, when the timing at which the timing signal TIMING is generated is abnormal, the head application signal ENB is continuously enabled, so that the application time T _E Therefore, it is not necessary to set a large margin for the timing signal TIMING. Therefore, the timing signal TIMIN
The period T _S of G can be shortened, and high-speed printing becomes possible.

Next, a second embodiment of the present invention will be described. FIG. 7 is a block diagram of a control circuit of the printer according to the second embodiment of the present invention. In the figure, 1
1 is an application counter, 12 is a JK-F / F for generating a head application signal ENB, 13 and 15 are signal latches,
G1 to G4 are gates, TIMING is a timing signal,
ABN is an abnormality notification signal sent to a control unit (not shown);
RG is a pseudo error notification signal sent to the control unit, ENB
Is a head application signal sent to a thermal head (not shown) as a print head, and SG1 is the timing signal TI.
SG2 is a signal generated when the timing of MING is abnormal, SG2 is a ripple carry-out signal that sets the head application signal ENB to a high level when the timing of generating the timing signal TIMING is normal, and SG3 is a signal SG1. SG4 is an inverted signal of the head application signal ENB, SG5 is a signal generated when the timing of the timing signal TIMING is considered to be abnormal, and DA1 is the control signal. The application data generated by the application data generation circuit (not shown) corresponding to each enable state time T _{e1 to} T _e3 and loaded into the application counter 11 and the PLS are control signal generation circuits (not shown) of the control unit. Generated in the application counter 1 Latch signal MOD input to MOD
E is in an enabled state while the data signal DATA (not shown) of each line is being transferred, and is disabled after the transfer of the data signal DATA is completed and before the transfer of the data signal DATA of the next line is started. Mode signal.

Next, the operation of the printer when the history control is performed and the timing at which the timing signal TIMING is generated is abnormal will be described. FIG. 8 is a time chart showing the operation of the printer according to the second embodiment of the present invention. In this case, the mode signal M
The ODE is enabled from the start to the end of the transfer of the data signal DATA for each line, and is disabled when the transfer of the data signal DATA is completed for the line at timing t6.

Then, at the time T _e3 during which printing is performed in the third enable state, and when the mode signal MODE is in the disable state, a pulse is formed in the timing signal TIMING at timing t 7. And T _s <T _E. In this case, an enable state canceling means (not shown) is connected to the reset terminal RS of the JK-F / F12 (FIG. 7).
A pulse is input to T to forcibly disable the head application signal ENB. Then, the timing signal TI
At the same time that a pulse is formed on MING, a latch signal PLS is generated by a latch signal generation means as an enable state continuation means and sent to the application counter 11. As a result, the application counter 11 outputs the latch signal PLS.
At this time, the application data DA1 is fetched and the head application signal ENB is enabled again. At this time,
At the same time, the transfer of the data signal DATA from the control unit to the thermal head is started.

The time that elapses during this period is several [ns].
Therefore, in practice, the head application signal ENB can be continuously enabled. And at the same time,
The signal latch 13 generates the abnormality notification signal ABN, and notifies the control unit that the timing at which the timing signal TIMING is generated is abnormal.

As described above, in this embodiment, when the timing at which the timing signal TIMING is generated is abnormal, the head application signal ENB is continuously enabled, so that the application time T _E Therefore, it is not necessary to set a large margin for the timing signal TIMING. Therefore, the timing signal TIMIN
The period T _S of G can be shortened, and high-speed printing becomes possible.

On the other hand, if a pulse is formed in the timing signal TIMING at the timing t5 while the mode signal MODE is in the enable state, the pulse is determined to be noise and is ignored. This is because no pulse is formed in the timing signal TIMING at the timing t5 even when all margins are considered.

When this state occurs,
The pseudo abnormality notification signal IRG is generated and sent to the control unit. As described above, in the present embodiment, when the timing at which the timing signal TIMING is generated is abnormal, depending on where the pulse is formed,
Since the signal SG1 and the signal SG5 are generated separately, it is possible to judge that the factor that makes the printer uncontrollable temporarily is caused by noise and ignore it.
Therefore, printing can be continued by that amount, and printing throughput can be improved.

In this case, when the pseudo abnormality notification signal IRG is repeatedly sent to the control unit, it can be handled in the same manner as the abnormality notification signal ABN by the judgment of the control unit. It should be noted that the present invention is not limited to the above-described embodiment, but can be variously modified based on the gist of the present invention, and these are not excluded from the scope of the present invention.

[0050]

As described in detail above, according to the present invention, a printer includes a plurality of elements arranged in a line direction, and selectively turns on / off the elements in accordance with a data signal. A print head to be controlled, a control unit that sets a timing signal generated for each printing of one line as a starting point, enables a head applied signal for an application time set in advance by history control, and turns on the element. Having.

The control unit includes enable state continuation means for continuously enabling the head application signal when the timing signal is generated while the head application signal is in the enable state. .

In this case, when a data signal is transferred from the control unit to the print head, the timing signal generated every time one line is printed is used as a starting point, and the head application is performed for an application time set in advance by history control. The signal is enabled, and the element is turned on in response to the data signal. When the timing signal is generated while the head application signal is in the enable state, the head application signal is continuously enabled. Therefore, it is not necessary to set a large margin for the timing signal with respect to the application time, so that the period of the timing signal can be shortened, and high-speed printing can be performed.

[Brief description of the drawings]

FIG. 1 is a block diagram of a control circuit of a printer according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a conventional thermal head drive circuit.

FIG. 3 is a time chart showing the operation of a conventional printer.

FIG. 4 is a time chart showing an operation when performing history control in a conventional printer.

FIG. 5 is a first time chart illustrating an operation of the printer according to the first embodiment of the present invention.

FIG. 6 is a second time chart illustrating the operation of the printer according to the first embodiment of the present invention.

FIG. 7 is a block diagram of a control circuit of a printer according to a second embodiment of the present invention.

FIG. 8 is a time chart illustrating an operation of the printer according to the second embodiment of the present invention.

[Explanation of symbols]

DATA data signal ENB head applied signal MODE mode signal T _e, T _E the application time TIMING timing signal V conveying speed d ₁ to d _n heating elements

──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Katsuo Mizuguchi 1-7-12 Toranomon, Minato-ku, Tokyo Oki Electric Industry Co., Ltd. (58) Field surveyed (Int. Cl. ⁷ , DB name) B41J 2 / 355

Claims (2)

(57) [Claims] [Claim 1 further comprising: (a) a plurality arranged in a line direction element, the printing head for selectively turning on and off the element in correspondence with the data signal, (b) generating for each printing of one line The timing signal is set as a starting point and set in advance by history control.
The During the application time, and <br/> head applied signal an enable state, and having a control unit for turning on the device, (c) said control unit, the head applied signal is in the enabled state when the timing signal is to generate
If a printer is characterized in that an enable state continuation means for <br/> a continuously enabled the head applied signal. (A) The control unit is configured to print one line .
Preparative to the to generate a mode signal to be enabled state from the start to the end of transfer of the data signal, (b) the control unit and the enable state continuation means,
Claim 1 Symbol placement printer ignoring the timing signal when said mode signal is in the enabled state.