JPH041705B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field of the Invention The present invention relates to a printing device in which a printing section is moved by motor drive.

(b) Prior Art and Problems In serial dot printers, pulse motors are widely used as space control means for moving the print head. With high-speed printers, space control is also fast, so starting the pulse motor,
During braking, it becomes necessary to control the phase excitation period and excitation current of the pulse motor at high speed. Conventionally, these controls were carried out by a microprocessor built into the printer, but at the timing of phase excitation switching, the microprocessor must perform multiple processes for controlling printing, data reception, etc. The printing speed was limited by the processing power of the processor, which had the disadvantage of preventing printers from increasing their speed.

(c) Object of the Invention The present invention has been made to solve the above-mentioned drawbacks, and its object is to provide a printing device equipped with high-speed space control means.

(d) Structure of the Invention The present invention provides a system in which a processing device, a memory, and a printing device controlled by the processor are connected by a bus, wherein the printing device directly accesses the memory and transfers print data to the printing device. a first control section that reads the information into the second control section; a second control section that controls the pulse motor that drives the print head; a timer that sends an output signal to the second control section when a set time is reached; and a table storing time data to be set in the timer, and further, the first control unit accesses the table according to instructions from the processor, sequentially reads out the time data, and sets the time data in the timer. The second control unit is a printing device characterized in that the second control unit is configured to output a control pulse for controlling the pulse motor using an output signal output every time the timer reaches a set time. As described above, the present invention provides phase control for generating a signal to drive a pulse motor in a printing device having a DMA control section (first control section), a phase control section (second control section), and a microprocessor. By providing the DMA control section with a control means for supplying time pulses to the DMA control section at every time set in the table, the processing load on the microprocessor is reduced.

(e) Examples of the invention The present invention will be explained below with reference to the drawings. The drawing is a block diagram illustrating an embodiment of the present invention.
In the drawing, a processing device 1, a main memory 2, and a printer 3 are connected by a bus B. The printer 3 is a dot printer, and has a built-in DMA control section 5 in addition to a microprocessor 4. this
The DMA control unit 5 has control means for directly accessing the main memory 2. For example, data D in the main memory 2 can be directly taken out to the print buffer 6. On the other hand, the table 7 stores time data T ₁ to _{T 0} , and the pulse motor M is a motor for transporting the print head H, and is driven by the pulse P from the phase control section 8 . In the drawing, when performing phase control, the DMA control unit 5 accesses the table 7, first extracts time data _T1 , and sets it in the timer counter 9. Timer counter 9 is driven by clock pulse CL,
When the set time (time t ₁ specified by time data T ₁ ) is reached, output signal A is sent to phase control section 8 . As a result, a pulse P is output from the phase control section 8, and this is supplied to the pulse motor M. At the same time, the output signal A is sent to the timer counter 9 (to reset it) and is also sent to the DMA control section 5. This results in
The DMA control section 5 accesses the table 7 again, takes out the time data _T2 , and sets it in the timer counter 9. Therefore, the timer counter 9
When the time _t2 set by the time data _T2 is reached, the output signal A is output, and at this point, the pulse P is output from the phase control section 8. In this way, the time data T ₁ -T _o in the table 7 are sequentially taken out and set in the timer counter 9, thereby controlling the phase of the pulse motor M. Conventionally, this phase control was executed by the microprocessor 4.

(f) Effects of the invention As described above, the present invention provides a microprocessor and
In a printing device having a DMA control section, the DMA control section shares phase control for the pulse motor, which has the advantage of reducing the load on the microprocessor and improving printing efficiency (increasing printing speed).

[Brief explanation of drawings]

The drawing is a block diagram illustrating an embodiment of the present invention, and the symbols used in the drawing are as follows. 1 is a processing unit, 2 is a main memory, 3 is a printer,
4 is a microprocessor, 5 is a DMA control unit, 6 is a print buffer, 7 is a table, 8 is a phase control unit,
9 is a timer counter, A is an output signal, B is a bus,
CL is a clock pulse, D is data, H is a print head, M is a pulse motor, and T ₁ , T ₂ , and T _o are time data.

Claims (1)

[Claims] 1. In a system in which a processing device, a memory, and a printing device controlled by the processor are connected by a bus, the printing device directly accesses the memory and stores print data in the printing device. a first control section for reading, a second control section for controlling a pulse motor that drives the print head, and a timer for sending an output signal to the second control section when a set time is reached;
and a table in which time data to be set in the timer is stored; further, the first control unit accesses the table according to instructions from the processor, sequentially reads out the time data, and stores the time data in the timer. , and the second control unit is configured to output a control pulse for controlling the pulse motor using an output signal output every time the timer reaches the set time.