JP3306158B2 - Dot 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 dot printer such as a thermal dot printer, a wire dot printer, and an ink jet dot printer.

[0002]

2. Description of the Related Art Conventionally, in this type of dot printer, print data received from a personal computer or the like is developed into dots and printed dot data is output by a print head.

[0003] Such a dot printer has a problem in that, in a print head in which the print head performs one line, for example, one line print in one run, the temperature of the print head increases when the number of dots to be printed in one line print is large. is there.

Therefore, conventionally, the number of dots to be printed when printing is actually performed is counted, and after the printing of one line is completed, a pause is provided according to the counting result, and after the print head is cooled, the printing of the next line is performed. Had to start.

However, when counting is performed while actually performing printing as described above, there is a problem that when the number of dots to be printed is large, the temperature of the print head becomes considerably high at the end of printing one line. .

Therefore, as a further improvement,
Immediately before printing, the print dot data developed in the print buffer is read out by software and the number of dots to be printed is counted.
After that, there is known an apparatus that performs dot printing while controlling the operation of a print head according to the number of dots to be printed.

[0007]

However, the method of reading out the print dot data developed in the print buffer immediately before printing and counting the number of dots to be printed by software is only required for counting the number of dots to be printed. There was a problem that the start of printing was delayed.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a dot printer which counts the number of dots to be printed before printing and can start printing quickly.

[0009]

The invention corresponding to claim 1 is:
A dot printer that writes print dot data to the print buffer in a predetermined bit unit, and when writing for the print head in one run is completed in the print buffer, print dot data is read from the print buffer and dot output is performed by the print head. A write detecting means for detecting writing of print dot data in a predetermined bit unit to a print buffer and outputting a detection signal; and print dot data for writing to the print buffer in response to a detection signal from the write detection means. Print dot number counting means for calculating the total number of dots when the print head has completed writing for printing in one run in the print buffer. The printing operation of the print head is controlled based on the calculated total number of dots.

[0010]

[0011]

In the invention having such a configuration, every time the print dot data is written into the print buffer in a predetermined bit unit,
The number of dots to be printed out of the predetermined bits is added, and the printing operation of the print head is controlled based on the total number of dots when the writing of the print head in one run to the print buffer is completed.

[0012]

[0013]

An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a CPU (Central Processing Unit) constituting a control unit main body. The CPU 1 stores a ROM (Released) storing program data for controlling each unit.
Memory, a RAM (random access memory) 3, a printing controller 4, a communication controller 5, a mechanical controller 6, and a counter 7, which are electrically connected via a data bus 8 and an address bus 9. It is connected to the.

The print controller 4 drives the print head 10 under the control of the CPU 1. The communication controller 5 is controlled by the CPU 1 to control communication with a host computer 11 connected externally. The mechanical controller 6 is controlled by the CPU 1 to control the running of a carriage on which the print head 10 is mounted, the feed control of a print sheet wound around a platen, and the like.

As shown in FIG. 2, an address range is set in the RAM 3 and a work area 3a and a print buffer 3 are set.
Various memories such as b are formed. For example, the print buffer 3b is set in the range between address a and address b.

When the communication controller 5 receives the print data from the host computer 11, the CPU 1 temporarily stores the print data in a reception buffer formed in the RAM 3 and then develops the data into a dot pattern to form the print buffer 3.
b is a predetermined bit unit, for example, an 8-bit unit, ie, 8
They are stored in dot units.

If the print head 10 has been printed in the print buffer 3b for one run, for example, for one run and one line printing, the print dot data for one line is developed, and the print dot data is read out and printed. It is sent to the controller 4.

As shown in FIG. 3, the counter 7 comprises an address detecting section 12 as writing detecting means and a dot number adder 13 as printing dot number counting means. The address detection unit 12 is provided with the CPU 1
The dot number adder 13 is connected to the CPU via a data bus 8 and an address bus 9.
It is connected via a tabus 8.

The address detecting section 12 constantly monitors the address bus 9 and, when the CPU 1 accesses a write to a predetermined address between two addresses a and b of the RAM 3 by the CPU 1, detects the access, and the address is detected as shown in FIG. The supplied detection signal is supplied to the dot number adder 13.

The dot number adder 13 comprises a dot number calculation section 14 and an adder 15 as shown in FIG. 4, so that a detection signal from the address detection section 12 is input to these. Has become. The dot number calculation unit 14 and the adder 15 are reset by a reset signal before one line of data is developed in the print buffer 3b.

The dot number calculation section 14 receives print dot data from the data bus 8 in units of 8 dots. Then, the dot number calculation section 14 calculates the number n of dots to be actually printed out of the eight dot numbers, and supplies the number n of dots to the adder 15.

The adder 15 adds the current print dot number n to the previous print dot number k, and sets the addition operation to 1
When the printing dot data for the line is completed, the addition result is output as the total number of dots.

The CPU 1 controls the print controller 4 and the mechanical controller 6 based on the total number of dots from the adder 15 so that the temperature rise of the print head 10 due to one-line printing is within an allowable temperature range. It is supposed to.

In this embodiment having such a configuration, when the communication controller 5 receives print data from the host computer 11, the CPU 1 transmits the print data to the RA.
After the image data is temporarily stored in the reception buffer in M3, the image data is developed into a dot pattern and stored as print dot data in the print buffer 3b in RAM3.

At this time, writing of data to the print buffer 3b is performed sequentially in units of 8 bits, that is, in units of 8 dots by designating addresses in the range of addresses a to b. The address designation in the range of the addresses a to b is detected by the address detection unit 12, and the address detection unit 12
Supplies the detection signal to the dot number calculation unit 14. In this way, the dot number calculation unit 14 calculates the dot number n to be actually printed out of the eight dot numbers, and
To supply. The adder 15 adds the current dot number n to the previous addition value k. That is, the adder 15 adds the dot number n from the dot number calculation unit 14 to the addition value k at the rise of the detection signal as shown in FIG.

In this way, every time the print dot data is stored in the print buffer 3b in units of 8 bits, that is, in units of 8 dots, the number n of dots to be printed is added by the adder 15, and the data for one line is stored in the print buffer 3b. When the print dot data is stored, the adder 15 outputs the total number of dots to be printed.

Thus, the CPU 1 controls the print controller 4 and the mechanical controller 6 based on the total number of dots for printing one line, and controls the temperature rise of the print head 10 to be within the allowable temperature range.

Since the number of dots to be printed is simultaneously counted when the print dot data developed into the dot pattern is stored in the print buffer 3b, one line of print dot data is stored in the print buffer 3b. Immediately after that, the print dot data is read out and output to the print controller 4, and the print controller 4
Can be driven to perform dot printing. Thus, printing can be started quickly.

In addition, since the printing can be controlled in consideration of the total number of dots printed in one line, the temperature rise of the print head 10 can be suppressed within the allowable temperature range.

Next, another embodiment of the present invention will be described with reference to the drawings. The same parts as those in the above embodiment are denoted by the same reference numerals, and detailed description will be omitted.

As shown in FIG. 6, a RAM controller 22 for controlling the RAM 3 is provided, and a counter 23 for performing a counting operation different from that of the counter 7 is provided instead of the counter 7. The RAM controller 22 is connected to the data bus 8 and the address bus 9.

As shown in FIG. 7, the RAM controller 22 includes an address detector 3 as a write detector.
1, a controller signal generating unit 32, a logical operation unit 33, and a latch 34.

The address detector 31 is connected to the CPU 1 via the address bus 9. The address detection unit 31 constantly monitors the address bus 9 and
When a write operation in a predetermined bit unit, for example, an 8-bit unit, that is, an 8-dot unit, for a predetermined address between the addresses a and b of the RAM 3 is accessed, this is detected, and the detection signal shown in FIG. The signal is supplied to the control signal generator 32.

The control signal generating section 32 responds to the detection signal from the address detecting section 31 as shown in FIG.
The RAM read signal shown in FIG.
3 and a counter 23, respectively, and FIG.
A RAM write signal shown in FIG. 2C is supplied to the RAM 3.

The logical operation unit 33 inputs the previous print dot data corresponding to a predetermined address read from the print buffer 3b of the RAM 3, that is, the RAM read data via the RAM bus 24 and the latch 34, and From the CPU 1 to the print buffer 3b of the RAM 3.
The print dot data to be written this time is input to a predetermined address.

The logical operation unit 33 performs a logical operation on the RAM read data (previous print dot data) and the print dot data to be written this time, and uses the operation result as RAM write data through the RAM bus 24 to the RAM 3. To be supplied.

The counter 23 receives the RAM read data. As shown in FIG. 8, the counter 23 includes an address detector 41 and a dot number subtractor 42.

The address detector 41 is connected to the CPU 1 via a data bus 8 and an address bus 9, and the dot number subtracter 42 is connected to the CPU 1 via the data bus 8.

The address detecting section 41 constantly monitors the address bus 9 and detects when the CPU 1 accesses writing of a predetermined address between the addresses a and b of the RAM 3 in units of 8 dots, and detects the access. Is supplied to the dot number subtractor 42.

[0041] The number of dots decrease adder 42, as shown in FIG. 9, Li Dodeta dot number calculation unit 43, La Itodeta dot number calculating section 44, and a reduced-adder 45 and a latch 46.

A detection signal from the address detection unit 41 is input to each of the dot number calculation units 43 and 44 and the subtraction adder 45. The dot number calculation units 43 and 44 and the decrement adder 45 are reset by a reset signal before the first data in one page is developed in the print buffer.

The read data dot number calculator 43
Is adapted to input RAM read data in units of 8 dots from the print buffer 3b of the RAM 3 via the data bus 8 and the latch 46.

The read data dot number calculator 43
Is the number of dots actually printed last time from the 8-dot RAM read data, that is, the number of dots m shown in FIG.
And supplies the dot number m to the subtractor 45.

The write data dot number calculator 44
The RAM write data in the unit of 8 dots, which is logically operated by the logical operation unit 33 of the RAM controller 22, is inputted from the data bus 8.

The dot number calculation section 44 calculates the R of 8 dots.
The number of dots to be actually printed this time, that is, the number of dots n shown in FIG. 10E is obtained from the AM write data, and the number of dots n is supplied to the subtractor 45.

The subtractor 45 stores the total number of dots k for the previous one row, and calculates the total number of dots k in units of 8 dots by the number of dots m and n obtained from RAM read data and RAM write data. , The total number of dots k corresponding to one line this time is obtained.
That is, the total number of dots k is changed from
The number m of dots included in the read data is subtracted, and RA
The print dot number n included in the M write data is added.

When the subtraction / addition operation is completed for one line of print dot data, the result of the subtraction / addition is output as the total number of dots (the number of print dots in one line this time) k.

The CPU 1 controls the print controller 4 and the mechanical controller 6 based on the total number k of dots from the subtractor 45 so that the temperature rise due to the one-line printing of the print head 10 is within an allowable range. Control.

In the present invention having such a configuration, when the communication controller 5 receives print data from the host computer 11, the CPU 1 stores the print data in the RAM 3.
After the image data is temporarily stored in the receiving buffer 3a, it is developed into a dot pattern, and one line is stored in the printing buffer 3b in the RAM 3, and then output to the printing controller 4 to drive the print head 10 to perform a printing operation.

In this operation, writing of dot data to the print buffer 3b is sequentially performed in units of 8 dots by designating a predetermined address among the addresses a and b.

When the address is specified, the RAM
The address is detected by the address detection unit 31 of the controller 22, and the control signal generation unit 3
2 is supplied with a detection signal, whereby a RAM read signal is supplied from the control signal generator 32 to the latch 34.

The latch 34 latches the previous print dot data stored at the address where the current 8 dot print dot data is written as RAM read data. Also, the print dot data of the eight dots this time is R
It is supplied to the logical operation unit 33 of the AM controller 22.

The logical operation unit 33 performs a logical operation on the current print dot data and the previous print dot data latched by the latch 34, and the control signal generator 32 generates a RAM write signal based on the result. Print buffer 3 as RAM write data at timing
b is written to a predetermined address.

On the other hand, the latch 46 of the dot number subtractor 42
The previous print dot data, that is, the RAM read data is latched at the same timing as the latch 34 of the RAM controller 22 by the RAM read signal.

In this state, the address detector 4 of the counter 23
The detection signal is supplied to the dot number subtracting / adding unit 42 from 1 by the addressing detection. Is done.

As a result, the read data dot number calculation section 43 reads the 8-dot RA latched by the latch 46.
The number m of dots to be actually printed out of the M read data is obtained, and the number m of dots is supplied to the subtractor 45. Also,
The write data dot number calculation unit 44 is an 8-dot RAM.
Obtain the number n of dots to be actually printed out of the write data,
The dot number n is supplied to the subtractor 45.

The subtractor 45 subtracts the previous dot number m from the total dot number k and adds the current dot number n. That is, the subtractor 45 performs the operation of km + n, as shown in FIG.

In this way, every time the print dot data is written in the print buffer 3b in units of 8 dots, the previous dot number m of the corresponding address is subtracted and the current dot number n is added, and this is repeated. By doing
When one line of print dot data is written in the print buffer 3b, the decrementer 45 determines the total number k of dots to be actually printed in one line of print dot data to be printed this time. .

The CPU 1 reads out the print dot data written in the print buffer 3b and controls the print controller 4 and the mechanical controller 6 to perform a one-line printing operation. The print controller 4 and the mechanical controller 6 are
Is controlled so that the temperature rise of the device falls within the allowable temperature range.

When the print dot data developed into the dot pattern as described above is stored in the print buffer 3b, the number of dots to be printed is counted simultaneously. When the print dot data for one line is stored in the print buffer 3b, Part 1
Since the total number k of dots to be actually printed in a row is obtained and the printing control of the print head 10 is performed based on the total number k of dots, this embodiment also starts printing in the same manner as in the previous embodiment. Can be performed quickly, and the temperature rise of the print head 10 can be suppressed within the allowable temperature range.

[0062]

As described in detail above, according to the present invention, a dot printer which can start printing quickly in a device for counting the number of dots to be printed before printing can be provided.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention.

FIG. 2 is a diagram showing a main configuration of a RAM according to the embodiment.

FIG. 3 is a block diagram showing a configuration of a counter of the embodiment.

FIG. 4 is a block diagram showing a configuration of a dot number adder shown in FIG. 3;

FIG. 5 is a timing chart showing the addition operation timing of the dot number adder of the embodiment.

FIG. 6 is a block diagram showing the configuration of another embodiment of the present invention.

FIG. 7 is a diagram showing a configuration of a RAM controller according to the embodiment.

FIG. 8 is a block diagram showing a configuration of a counter of the embodiment.

FIG. 9 is a block diagram showing a configuration of a dot number subtraction adder shown in FIG. 8;

FIG. 10 is a timing chart showing the decrementing operation timing of the dot number decrementing and adding device of the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... CPU 2 ... ROM 3b ... Print buffer 7, 23 ... Counter 10 ... Print head 12 ... Address detector 13 ... Dot number adder 22 ... RAM controller

Claims (1)

(57) [Claims] The printing dot data is written in a printing buffer in a predetermined bit unit, and when writing for printing by a printing head in one run to the printing buffer is completed, the printing dot data is read out from the printing buffer and the printing is performed. In a dot printer that outputs dots by a head, a write detection unit that detects the writing of print dot data in a predetermined bit unit to the print buffer and outputs a detection signal, and in response to the detection signal from the write detection unit, A print dot count for adding the number of dots to be printed out of the print dot data to be written to the print buffer and calculating the total number of dots when the writing for printing by the print head in one run is completed in the print buffer. Means, and the printing based on the total number of dots calculated by the printing dot number counting means. The head of the printing operation, the print header
A dot printer characterized in that the temperature rise of the dot is controlled to be within an allowable temperature range .