JPH01218844A - Printing effective range setting apparatus of printer - Google Patents

Abstract

PURPOSE:To perform time control with high accuracy and to enhance printing quality, by controlling all of a synchronous signal and a range signal based on a hardware system. CONSTITUTION:A synchronous signal VCK is generated from a synchronous signal generator 1 and the flashing of a laser beam source is started and a counter 2 starts the counting of the synchronous signal VCK. When the count value of the counter 2 reaches a comparing value A, a comparator 5 detects said coincidence to supply a coincidence signal MATCH to a VCK/VSY generation control part 7 and the control part 7 reverses a control signal VSYON to a low level. A range signal generator 8 outputs a low level range signal VSY in synchronous relation to the synchronous signal VCK from the synchronous signal generator 1 to start printing using laser beam. Thereafter, the count value of the counter 2 reaches a set count value C and the counter 2 performs counting-up to supply a signal CNTUP to the control part 7 which in turn reverses the signal VSYON from a low level to a high level. By this method, the signal generator 8 reverses output to a high level in synchronous relation to the signal VCK to stop the generation of the signal VSY and stops the scanning of a printing image.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a device for setting an effective printing range in a printer such as a laser printer.

[Prior Art] For example, in a laser printer that sets the reference position for printing on paper at the center of the paper, a synchronization signal for blinking the laser light source and a range signal that determines the effective range of the laser blinking operation are generated and managed. .

This is to print in a well-balanced manner on the paper.
For example, as shown in Fig. 3, when the start signal 5TART becomes low level, a synchronization signal VCK for blinking the laser light source is generated, and after the synchronization signal VCK is generated a certain number of clocks, a range signal vSY indicating the range in which the print image can be scanned is generated.
is inverted from the low level to the low level. The period during which the range signal VSY is at a low level is the range in which the print image can be scanned within the enable range of vSY.

When the synchronizing signal VCK is generated a certain number of clocks in this enable range, the range signal vSY is again inverted to high level to change from the enabled state to the disabled state. Furthermore, when a synchronizing signal VCK having the same number of clocks as the first disabling range is generated thereafter, the generation of the synchronizing signal VCK is stopped and the blinking of the laser light source is stopped.

In this way, it is necessary to manage the first disabled period A, the enabled period B1, and the last disabled period A, respectively.

In conventional printers, the generation and termination of the synchronization signal VCK and the management of the range signal VSY were performed by software.

[Problem to be solved by the invention] However, in the case where signals are managed using software, if other work is interrupted by the microprocessor during management, a time lag occurs, and this Therefore, there was a problem that accurate management was not possible. On the other hand, if other interrupts are prohibited during management, a problem arises in that the microprocessor is unable to do any other work during that time.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a printing effective range setting device for a printer that allows highly accurate time management and improves print quality by managing synchronization signals and range signals entirely by hardware.

[Means for Solving the Problems] The present invention provides a synchronization signal generator that generates a synchronization signal for dot operation, and a synchronization signal generator that generates a synchronization signal for dot operation in a printer that performs a dot printing operation by sequentially scanning each scanning line. When the count value reaches the preset number of synchronization signals until the end of the print image scanning range, it counts up and outputs a count-up signal, and starts counting the synchronization signals again. The counter starts from , and in response to the start signal 1 generated at the start of line scanning, the synchronizing signal generator and counter are allowed to start operating, and in response to the end signal, the synchronizing signal generator and counter are prohibited from operating. a comparator that compares the count value of the counter with a preset comparison value smaller than the set number of synchronization signals and outputs a match signal when they match; and a comparator that outputs a match signal when they match, and a A range signal generator generates a range signal indicating the range in which the printed image can be scanned by scanning the range signal, and a match signal from the comparator causes the range signal generator to start generating the range signal, and a count-up signal from the counter causes the range signal generator to start generating the range signal. A management section is provided which stops the generation of the range signal from the signal generator and outputs an end signal to the permission section when a matching signal is input again from the comparator.

[Operation] In the present invention having such a configuration, the synchronization signal generator is operated by the start signal and generation of the synchronization signal is started, and the counter counts the synchronization signal. When the count value of the counter reaches the first set comparison value, a match signal is generated from the comparator, and the range signal generator is controlled by the management section to generate a range signal. This allows scanning of the printed image.

After that, when the count value of the counter reaches the number of synchronization signals until the end of the range in which the print image can be scanned, a count-up signal is generated from the counter, and the management section controls the range signal generator to stop generating the range signal. .

In this way, the range in which the print image can be scanned can be accurately set by a hardware process of counting synchronization signals by a counter.

When the counter counts up, the current of the synchronization signal is restarted from the beginning. When the count value of the counter reaches the comparison value and a match signal is generated again from the comparator, an end signal is generated from the management section, and the operation of the synchronizing signal generator and counter is prohibited by the permission section, completing one line scanning. do. Then, when starting the next line scan, a start signal is generated again.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings. In this embodiment, the present invention will be described as applied to a laser printer.

In FIG. 1, 1 is a synchronization signal generator that generates a synchronization signal VCK for blinking the laser light source on the laser scanning line, and 2 is an autoload counter that counts the synchronization signal VCK from this synchronization signal generator 1. VCK composed of
It is a counter.

3 is a start signal 5T generated at the start of each line scan
In response to the ART, the synchronization signal generator 1 and the counter 2
The VCK permission section supplies a low-active permission signal EN to the VCK to permit the start of its operation, and prohibits the operation of the synchronization signal generator 1 and counter 2 in response to an end signal END, which will be described later.

The counter 2 stores the count value C set in the memory 4.
is entered. When the count value of the synchronization signal reaches this count value C, the counter 2 counts up and outputs a count-up signal CNTUP, and also counts the synchronization signal VCK from the beginning again.

The count value of the counter 2 is compared with a comparison value A set in a memory 6 by a comparator 5, and when the count value matches the comparison value A, a match signal MATCH is output from the comparator 5. There is.

The count-up signal CNTUP from the counter 2 and the match signal MATCH from the comparator 5 are tLV.
It is input to the CK/VSY generation management section 7.

When the first match signal MATCH is input from the comparator 5, the management section 7 first sets the control signal VSYON to a low level and supplies it to the range signal generator 8, and then outputs the count up signal CNTUP from the counter 2. When inputted, the control signal VSYON is inverted to high level and supplied to the range signal generator 8, and further the counter 2 to 2
When the second match signal MATCH is input, the end signal E
ND is generated and supplied to the VCK permission section 3.

When the range signal generator 8 receives a low-level control signal VSYON from the management unit 7, it generates a low-active range signal VSY that sets a range in which the print image can be scanned.
is output in synchronization with the synchronization signal VCK from the synchronization signal generator 1, and then when a high level control signal VSYON is input from the management section 7, the output of the range signal vSY is stopped in synchronization with the synchronization signal VCK. I try to do that.

Next, the operation of this embodiment will be explained with reference to FIG. 2.

First, a comparison value A is set to the number A of synchronization signals from when the start signal 5TART is generated to the position at which scanning of the print image is desired to start. Further, the count value C is set to a value obtained by adding the number of synchronizing signals A to the number B of synchronizing signals in the range in which the print image is scanned.

When scanning a line in this state, a start signal 5TART is first generated in sequence N111 and input to the permission section 3. In this way, the permission signal EN is supplied from the permission section 3 to the synchronization signal generation circuit 1 and the counter 2, and each of them comes to operate.

Then, the synchronization signal generator 1 generates the synchronization signal VCK, the laser light source starts blinking, and the counter 2 starts counting the synchronization signal VCK.

Then, in sequence N112, when the count value of the counter 2 reaches the comparison value A, the comparator 5 detects the match and supplies the match signal MATCH to the VCK/vSY generation manager 7. As a result, the management section 7 inverts the control signal VSYON to low level. As a result, the range signal generator 8 outputs a low-level range signal VSY in synchronization with the synchronization signal VCK from the synchronization signal generator 1. This makes it possible to scan the line print image, and the laser Printing using the light beam begins.

Thereafter, when sequence number 3 is reached, the count value of the counter 2 reaches the set count value C, and the counter 2 counts up and supplies a count-up signal CNTUP to the management section 7.

The management unit 7 then inverts the control signal VSYON from low level to high level. This allows the range signal generator 8
Inverts the output to high level in synchronization with the synchronizing signal VCK and stops generating the range signal VSY.

In this way, scanning of the print image is stopped.

On the other hand, when the counter 2 counts up, it starts counting the synchronizing signal VCK again from the beginning.

When the sequence reaches 4, the count value of the counter 2 reaches the comparison value A, and the second match signal MAT is sent from the comparator 5.
CH is input to the management section 7. An end signal END is generated from the management section 7 and inputted to the permission section 3. In this way, the permission unit 3 stops generating the permission signal EN. The operation of the synchronizing signal generator 1 and the counting operation of the counter 2 are then stopped, and the scanning of one line is completed.

The range signal v generated from the range signal generator 8 in this way
Management of SY generation start and generation stop and synchronization signal generator 1
Since the stoppage of generation of the synchronization signal VCK from the synchronization signal VCK is processed by hardware by comparing the count value of counter 2 that counts the synchronization signal VCK with the set comparison value A and the set count value C, there is a possibility that a time difference will occur. This allows for highly accurate time management.

Therefore, the scanning start position of the print image for each line can be determined with high precision, so that printing accuracy on paper can be improved, and printing quality can be improved.

Although the above embodiment describes the application of the present invention to a laser printer, the present invention is not necessarily limited to this, but can also be applied to a type of printer that prints with a collection of dots, such as a dot printer using a dot head or an inkjet printer. If so, it is applicable.

[Effects of the Invention] As detailed above, according to the present invention, the synchronization signal and range signal are all managed by hardware, thereby enabling highly accurate time management and improving the printing quality of the printer. A setting device can be provided.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is an output waveform diagram of each part in the embodiment, and FIG. 3 is a waveform diagram showing the timing relationship among a start signal, a synchronization signal, and a range signal. 1... Synchronous signal generator, 2... VCK counter, 3
...VCK permission section, 5...Comparator, 7...VCK
/VSY generation management section, 8...range signal generator. Applicant's agent Patent attorney Takehiko Suzue

Claims (1)

[Claims] In a printer that prints dots by sequentially scanning each scanning line, there is a synchronization signal generator that generates synchronization signals for dot operations, and the synchronization signals from this synchronization signal generator are counted and the count value is calculated. A counter that counts up and outputs a count-up signal when it reaches the preset number of synchronization signals until the end of the range that can scan the print image, and then starts counting the synchronization signals again from the beginning, and a counter that occurs at the start of line scanning. an enabling unit that allows the synchronization signal generator and the counter to start operating in response to a start signal and prohibits the operation of the synchronization signal generator and the counter in response to an end signal; and the setting of the count value of the counter. a comparator that outputs a matching signal when the number of synchronization signals is smaller than the number of synchronization signals, and a range in which the print image can be scanned in synchronization with the synchronization signal from the synchronization signal generator. a range signal generator for generating a range signal; a match signal from the comparator initiates generation of the range signal from the range signal generator; and a count-up signal from the counter initiates generation of the range signal from the range signal generator; A printing effective range setting device for a printer, comprising: a management unit that stops generation of the signal and outputs an end signal to the permission unit when a matching signal is input again from the comparator.