JP3022075B2 - Printer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art FIG. 7 shows a conventional serial printer. In the printing process, print data is received by a printer control unit 100 from a host computer connected to the outside, print data is output from a central processing unit (CPU) 102 to a print head driver circuit 104, and a print head 200 is output by the drive output. Is performed. The print head 200 has a plurality of pins according to the number of print dots.

FIG. 8 shows the energization control of the print head, where A is a timing signal (T
Signal), B is the energizing time of pin a, which is one of the plurality of pins of the print head 200, and C is the energizing time of pin b, which is one of the plurality of pins of the print head 200. .
In this case, the drive relationship between the pin a and the pin b is such that the pin b is continuously energized after the pin a is energized.

In the printing process of such a serial printer, it may be necessary to perform another process such as a serial data reception interrupt during printing, for example, immediately before the completion of energization of the No. b pin.

FIGS. 9 to 11 show the interrupt processing. FIG. 9 shows a timing signal interruption process. In step S31, the print area is determined. If the print area is within the print area, the process proceeds to step S32 to start outputting the head data. In step S33, the timer B2
Is started, and the process returns in step S34. If it is determined in step S31 that the area is outside the print area, the process proceeds to step S35, and other processing is executed. FIG. 10 shows an interrupt process of the timer B1,
In step S41, the output of the head data is stopped.
It returns in step S42. FIG. 11 shows an interrupt process on the serial reception side, and is executed in step S5.
1 to enable the interruption of the timer B2, and store the received data in the reception buffer in step S52.
A return is made at 53.

If such interrupt processing is performed immediately before the energization of the No. b pin is completed, the energization time is slightly longer than the normal energization time t. In FIG. 8C, t + n represents an extended energization time, and n is the extension time. In other words, the energization time is affected by the execution of other processing, and becomes unstable. When continuous processing is performed, data is fetched at regular intervals, so the probability of such interrupt processing is high, and each time it affects the energizing time of a pin that is energized.

[0007] When the length of the power-on time varies, the impact force of the pins of the print head becomes uneven in accordance with the power-on time, and the print result becomes dark and light, that is, print unevenness occurs, and the print quality deteriorates. become.

[0008]

As means for avoiding the influence of the interruption process on the energizing time for each pin of the print head, a printer as shown in FIG. 12 has been proposed. This printer utilizes a timer function of the CPU 102 and has a latch circuit 106 provided between the CPU 102 and the print head driver circuit 104. That is, the output state of the timer output terminal 108 of the CPU 102 is added to the latch circuit 106, that is, the energizing time of the print head 200 is set only when the timer output terminal 108 is in the active state.

By doing so, the energizing time of the print head 200 is regulated by the timer of the CPU 102, so that it is possible to avoid instability of the energizing time by interrupt processing and obtain print quality without uneven printing. ,
Since the latch circuit 106 must be provided, there is a disadvantage that the configuration becomes complicated and the manufacturing cost increases.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a printer that does not require a latch circuit and prevents a decrease in print quality due to interrupt processing.

[0011]

As shown in FIGS. 1 to 6, a printer according to the present invention communicates with print data in accordance with print data.
First timer and printing mechanism (83) is energized to charging time, the print timing signal (T signal) slightly shorter than the energization time set in synchronization with the set (B1)
A second timer (B2) for setting the energization time to the printing mechanism; and an interrupt caused by the first timer.
Due to the second timer when performing processing
Control means for inhibiting interrupt processing other than interrupt processing (CP
U61). In addition, the present invention
As shown in FIGS.
Interrupt processing caused by the first timer (B1) is being executed.
Interrupt processing due to the second timer (B2)
The first timer when an interrupt process other than
Executed after completion of interrupt processing caused by
You.

As shown in FIGS. 1 to 6, the printer according to the present invention has an energizing time corresponding to print data.
Powered printing mechanism (83) and print timing signal
A time slightly shorter than the energization time set in synchronization
A first timer (B1) to be set;
A second timer (B2) in which the energization time is set;
When the first timer completes measuring the set time, the second timer
Interrupt processing other than the interrupt processing caused by the timer
Execute a first interrupt process, which is performed before the second timer.
Stops power supply to the printing mechanism when the set time has been counted.
Executing the second interrupt processing, and executing the second interrupt processing.
Control means for completing the first interrupt processing after completion
(CPU 61).

[0013]

[Action] until the energizing time of the print head is complete, place
Executes processing to prohibit interrupt processing other than fixed interrupt processing
The print head operates preferentially until the energization is completed.

The print timing signal is a signal generated by a printing process. The energization time is set according to the print timing signal. In the first timer, a time (to) slightly shorter than the energization time set by the print timing signal is set. The energizing time (t) is stored in the second timer.
Set. After the set time (to) of the first timer has arrived, a time (ts) until the energization time (t) set in the second timer is completed, a predetermined time other than the interrupt processing is set.
Disable interrupt processing . Such a time setting is to prohibit the power-on time from being extended by an interrupt that occurs immediately before the power-on time is completed. Since interrupt processing can be performed in a section that is not affected even during the power-on time, as a result, Thus, efficient processing is realized. Also,
After the completion of the interrupt processing caused by the second timer,
1 to complete interrupt processing caused by the timer
Power-on time is affected by setting
Interrupt processing immediately before the completion of energization.
Wear.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to embodiments shown in the drawings.

FIG. 1 shows an embodiment of the printer of the present invention. A host computer 4 is connected to the printer 2, and print data is given from the host computer 4. This printer also includes a word processor or the like in which the printer 2 and the host computer 4 are built in one housing.

The printer 2 includes a printer control unit 6 for performing print control in cooperation with the host computer 4, and a printer mechanism unit 8 as a mechanism controlled by the printer control unit 6.

A microcomputer is used for the printer control unit 6. Central processing unit (CPU) 61
Performs program control, calculations for the control, and the like according to a program. The CPU 61 includes first and second
And a third timer B1, B2, B3,
Each of the timers B1, B2, and B3 can be used as an independent timer according to various controls such as print control. The CPU 61 is linked with storage means, input / output means, display means, and the like in accordance with the control.

The storage means includes a main storage means for storing data necessary for the control operation executed by the CPU 61, a control program or various data in the course of calculation.
An OM 62 and a RAM 63 are provided. ROM62
Is a read-only memory having a control program, a table, and the like, and the RAM 63 is a random-access memory for storing data, print data, and the like in the course of calculation. Although not shown, a storage medium such as a flexible disk can be used as the storage means. In addition, a storage unit on the host computer 4 side can also be used as an auxiliary storage unit of the printer control unit 6.

As a data input means, an interface (I
/ F) 64, sensor receiver 65 and operation switch (S
W) 66 is installed, print data and the like are input from the host computer 4 to the I / F 64, and detection data from the printer mechanism 8 is added to the sensor receiver 65. Further, by operating the operation switch 66, the CP
The necessary data is input to U61.

A driver 68 is provided as data output means. The print data output from the CPU 61 is
It is applied to the printer mechanism 8 through the driver 68.
Further, an LED 69 is provided as a data output display means, and the LED 69 is turned on or off by a display output output from the CPU 61.

The printer mechanism 8 is provided with a carriage mechanism 81, a paper feed mechanism 82, and a printing mechanism 83, and a home position (H) of the carriage.
As sensor means for detecting P), an HP detector 84, a T signal generator 85 for generating a timing signal, and a paper detector 86 are provided. The carriage mechanism 81, the paper feed mechanism 82, and the printing mechanism 83 are supplied with electric power or drive output through the driver 68 of the printer control unit 6 in accordance with the printing process. A carriage mechanism 81 for transporting the print head; a paper feed mechanism 82 for feeding paper to be printed;
The printing mechanism 83 includes a print head and is a means for printing on paper.

Further, an HP detector 84, a T signal generator 85
The sensor output of the paper detector 86 is applied to the CPU 61 through the sensor receiver 65 of the printer control unit 6.
The HP detector 84 is a detecting means for detecting a home position serving as a starting point of printing, and the T signal generator 85 is a timing signal (T signal) generated when the carriage in the carriage mechanism 81 conveys the print head. ). The paper detector 86 detects the presence or absence of paper to be printed.

Next, FIG. 2 shows a specific embodiment of the print head transfer mechanism which is a part of the printer mechanism section 8. The print head 830 of the printing mechanism 83 is mounted on the carriage 810 of the carriage mechanism 81. The carriage 810 is slidably supported by a carriage stay 812 and supported by a drive shaft 814. The drive shaft 814 is a driving force converting unit that converts the rotational force into a linear driving force and acts on the print head 830 on the carriage stay 812. A carriage motor 818 is connected to the drive shaft 814 via a reduction gear mechanism 816. The rotation force generated by the carriage motor 818 rotates the drive shaft 814 through the reduction gear mechanism 816, and the rotation causes the print head 830 to move together with the carriage 810. The moving direction of the carriage 810 depends on the rotating direction of the carriage motor 818.

The carriage motor 818 is provided with a T signal generator 85 for converting the rotation into a timing signal. In this embodiment, the carriage motor 81
8, two pulse boards 852a and 852b having different slit intervals are attached to the rotation axis of each pulse board 85.
Timing detectors 854a and 854b that generate two types of T1 signals by transmitting and blocking light are installed in 2a and 852b. The timing signal used in this embodiment is obtained from a timing detector 854a.

Next, control processing of the printer will be described.

FIG. 3 shows the timing of control processing of the print head of the printer, where A is the T signal, B is the operation of the first timer B1, C is the operation of the second timer B2, and D is the print mechanism. Printhead energization time, E is LED69
Shows the operation of the third timer B3 for blinking.

When the printing operation starts, the T signal generator 85
When the T signal indicated by 3A is detected, the T signal is applied to the CPU 61 through the sensor receiver 65. CP
When the T signal is taken into U61, the process shifts to a T signal interruption process shown in FIG.

In the T signal interruption process, it is determined in step S1 whether or not the area where the T signal is generated is a print area. If the area where the T signal is generated is within the print area, the process proceeds to step S2, where the output of head data is started, that is, print data prepared in advance is output to the print head of the print mechanism, and the process proceeds to step S3. I do. Step S3
Then, the count of the timer B2 in which the count value indicating the energization time t is set is started, and the process proceeds to step S4. In step S4, the timer B1 starts counting. A count value representing a set time to (<t) slightly shorter than the timer B2 is set in the timer B1. In step S5, the process returns to the original processing routine.

If it is determined in step S1 that the T signal generation area is outside the printing area, the flow shifts to step S6 to shift to other processing such as paper feed control processing.

Then, as shown in FIG.
When the set time to of 1 arrives, the CPU 61 shifts to an interrupt processing routine of the timer B1 shown in FIG. In this interrupt processing routine, in step S11, serial reception and interrupt processing of the timer B3 for blinking the LED 69 (E in FIG. 3), that is, interrupts other than the timer B2 are prohibited, and the process proceeds to step S12. In step S12, it is determined whether or not the interrupt processing of the timer B2 has been completed. If it has not been completed, the process returns to step S12, and the process returns to step S12 until the interrupt processing of the timer B2 is completed.
Wait at. This processing is performed by the time t between the set time to of the timer B1 and the set time t of the timer B2 shown in FIG.
s, and this time ts is a serial reception and timer B3 interrupt prohibition section. Then, when the interruption processing of the timer B2 is completed, step S13
To the original processing routine.

When the set time of the timer B2 has come, as shown in FIG. 3D, the energizing time t of the print head of the printing mechanism 83 is completed, and the CPU 61 executes the interrupt processing routine of the timer B2 shown in FIG. Move to Step S2
In step 1, the output of the print data to the print head is stopped, the process proceeds to step S22, and returns to step S12 in the original processing routine (FIG. 5). That is, the process waits until the interruption process of the timer B2 is completed.

The broken line E in FIG. 3 indicates an interrupt in the interrupt disabled section ts. As a result of the interrupt being prohibited by the above process, the process is delayed by the maximum time td until the time ts of the prohibited section ends. That is, the transition to the H section is performed after the time td
It is performed after a delay of only
69 will blink. In the conventional serial printer, this blinking operation causes an influence on the energizing time of the print head. However, the elimination of the interruption process in the prohibited section stabilizes the energizing time for the print head uniformly. Moreover, such interrupt prohibition processing during the energization time is executed by a program operation, and it is not necessary to increase hardware like a conventional latch circuit. Further, as in the embodiment, since the interruption is prohibited at the time ts immediately before the completion of the energization time t, the print quality can be improved without hindering the interruption processing and without reducing the processing efficiency. it can.

[0034]

As described above, according to the present invention,
It is possible to suppress the influence of the power supply time to the print head due to the interrupt processing, to obtain good and stable print quality without printing unevenness, and to reduce the manufacturing cost without complicating the configuration such as adding a latch circuit. Can also be reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an embodiment of a printer according to the present invention.

FIG. 2 is a perspective view showing a specific embodiment of a print head transfer mechanism of the printer of the present invention.

FIG. 3 is a timing chart showing an operation of the printer shown in FIG.

FIG. 4 is a flowchart showing a timing signal interruption process.

FIG. 5 is a flowchart showing a timer interrupt process.

FIG. 6 is a flowchart illustrating a timer interrupt process.

FIG. 7 is a block diagram showing a conventional serial printer.

8 is a timing chart showing the operation of the serial printer shown in FIG.

FIG. 9 is a flowchart showing a timing signal interruption process of the serial printer shown in FIG . 7 ;

FIG. 10 is a flowchart showing a timer interrupt process of the serial printer shown in FIG . 7 ;

FIG. 11 is a flowchart showing a timer interrupt process of the serial printer shown in FIG.

FIG. 12 is a block diagram showing another conventional serial printer.

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Claims (3)

(57) [Claims] 1. A printing mechanism that is energized for an energizing time according to print data, a first timer for setting a time slightly shorter than the energizing time set in synchronization with a print timing signal, and the printing A second timer for setting the energization time to a mechanism, and executing an interrupt process caused by the first timer
Control means for prohibiting interrupt processing other than interrupt processing caused by the second timer . 2. The printer according to claim 1, wherein an interrupt process caused by said first timer is executed.
When the interrupt other than the interrupt processing caused by the second timer
If the first timer has occurred,
A printer which is executed after completion of interrupt processing . 3. A power supply is performed during a power supply time according to print data.
Printing mechanism and the energizing time set in synchronization with the printing timing signal
A first timer for setting a slightly shorter time, and a second timer for setting the energization time to the printing mechanism.
Ma and the at time-out of the first of the set time of the timer the
Interrupt processing other than interrupt processing caused by timer 2 is prohibited
Execute a first interrupt process for stopping the second timer;
When the timing of the set time is completed, the power supply to the printing mechanism is stopped.
Executing a second interrupt processing to stop the second interrupt processing.
Control means for completing the first interrupt processing after completing the processing
And a printer comprising: