JPH06198970A - Printing controller - Google Patents

Abstract

PURPOSE:To prevent generation of a slippage from a specified printing location by a method wherein a printing command signal is generated a flight time period of a print head earlier than the estimated time at which the print head passes the specified printing location. CONSTITUTION:A control part A of a printing controller controls printing process in the following steps. (step 1): phase switching up to M (n-2) is carried out and a carriage is accelerated. (step 2): the phase of a phase switching signal M (n-1) is switched, (step 3): cycle tp (n-1) corresponding to the phase switching signal M (n-1) is read out from a ROM, (step 4): a delay time td (n-1)=tp (n-1)-tfly is calculated. (step 5); M (n-1) is switched in phase to confirm the fact that the delay time td (n-1) has elapsed. Then, after a printing command signal P(n) is generated, the actions described above are repeated every time of phase switching after M (n+1) on.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art In a printer that prints output from a computer or the like, a carriage equipped with a print head is being accelerated from a stopped state to a certain speed or decelerated from the certain speed to the stopped state in order to improve throughput. It is known that printing is performed even while the user is in the middle of work.

However, in a wire dot printer, for example, the distance that the carriage moves in the time from when a print command is given to when the tip of the wire reaches the print medium and forms dots (hereinafter referred to as flight time). Varies depending on the moving speed of the carriage. Therefore, if the printing operation is performed while the moving speed of the carriage is changing, the dot interval will not be constant. Therefore, for example, in Japanese Patent Laid-Open No. 55-85984, a delay time is set according to the moving speed of the carriage, and a dot command is corrected after the delay time has elapsed to make a fixed dot interval.

[0004]

However, the delay time Td corresponding to the carriage speed is calculated in advance for each speed and stored in the memory, and the value of the memory corresponding to the detected speed is referred to, or When the speed is detected, the delay time Td is set by performing the calculation according to the above-described calculation formula. Therefore, the former requires a large amount of memory capacity, and the latter has a problem that the processing throughput for calculation is long and thus the printing throughput is reduced.

Further, in the conventional correction method, since the print command signal is generated with a delay time after the phase switching timing of the step motor, the phase switching position is the original printing position, but the actual printing position is Is Smax
There is a problem that adjustment is necessary in the manufacturing process because the printing positions of the forward path and the backward path are displaced by 2Smax when the printing is performed back and forth.

[0006]

In order to solve such a problem, the printing control apparatus of the present invention moves a print head by a power source and receives a signal in synchronization with the motion of the power source to issue a print command. In a print control device that generates a signal and gives the print signal command to the print head, the print command signal is generated before a flight time of the print head from a scheduled time when the print head passes a predetermined print position. The print signal command is given to the print head.

[0007]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 5 shows a phase switching signal of the step motor when the carriage is moved from the left to the right in the figure while being accelerated by being driven by the step motor. Is getting shorter. Normally, a print command signal is generated in synchronization with this phase switching signal to perform printing.

In FIG. 5, when printing is performed by generating a print command signal at the same time as the phase switching signal while traveling in the direction of the arrow at the maximum speed Vmax, the print dot position D1 is displaced from the phase switching position by Smax.

On the other hand, when the carriage moving speed is V during acceleration, the print dot position D2 is generated at the same time as the phase switching signal, that is, when the print command signal is generated without correction. Is Sv from the phase switching position
It just shifts. The correction is performed by setting a delay time according to the speed so that the deviation Sv at the speed V becomes equal to the deviation Smax at the maximum speed Vmax, and giving a print command after the delay time has elapsed from the phase switching, The print dot position at the speed V is corrected to the position of D3 to make the print dot intervals constant.

The value of the delay time Td at this time can be obtained as follows. Maximum speed Vma in Fig. 5
When printing while running at x, the distance Smax until the dots are printed after the flight time Tfly has elapsed
Is represented by Smax = Vmax × Tfly. On the other hand, when printing is performed while traveling at the speed V, the print command signal is generated after the delay time Td elapses from the phase switching so as to match the position of Smax, so Td is Td = Tfly × (Vmax− It can be expressed as V) / V.

FIG. 1 shows the configuration of a serial dot printer to which the present invention is applied. By converting the rotary motion of the carriage drive motor 1 into a linear motion via the pulling member 2 such as a belt and the pulley 3, the carriage 5 having the print head 4 travels at a predetermined speed to print on the printing paper 6. .

In the present embodiment, the carriage drive motor 1 is a step motor, and causes the carriage to travel by rotational movement according to the cycle of the phase switching signal. Figure 2
(A) is a phase switching signal and shows a state in which the speed is changed from acceleration to constant speed. During acceleration, the phase switching cycle becomes shorter with the passage of time, and this series of values is stored in advance in the ROM 8 as a data table.

FIG. 3 is a control block diagram for controlling the carriage control device having such a configuration. In FIG. 3, reference numeral 7 is a CPU that controls the printer. Reference numeral 8 is a ROM in which the control program of this embodiment is written. Reference numeral 9 is a RAM for temporarily storing various data.

Print data from a host device 10 such as a computer is sent to the CPU 7 via an I / F unit (interface unit) 11. The print command signal is sent to the head drive unit 13 via the I / O unit 12, and in response to this, the head drive unit 13 drives the print head 4 to perform printing. The phase switching signal of the step motor 1 that drives the carriage 5 is sent to the step motor drive unit 14 via the I / O unit 12, and the step motor drive unit 14 causes the step motor 1 to operate.
To drive.

The control operation of the control unit A (broken line portion) will be described with reference to the flowchart of FIG. In FIG. 2, (a) is a phase switching signal of the step motor 1 and (b) is a print command signal. The phase switching position of M (n) is the start position of the printing area on the printing paper.

[Step 1] The carriage is accelerated by switching phases up to M (n-2) (not shown).

[Step 2] Phase switching of the phase switching signal M (n-1) is performed.

[Step 3] The period tp (n-1) corresponding to the phase switching signal M (n-1) is read from the ROM.

[Step 4] Delay time td (n-1), t
Find d (n-1) = tp (n-1) -tfly.

[Step 5] Phase switching of M (n-1) is performed and it is confirmed that the delay time td (n-1) has elapsed.

[Step 6] The print command signal P (n) is generated.

Printing is performed by repeating the above operation for each phase switching after M (n + 1).

As described above, there is no need to store the delay time in the ROM 8 or to perform complicated calculation as in the conventional case, and even during the acceleration and deceleration of the carriage only by performing the extremely simple calculation shown in step 4. It is possible to control printing.

Further, the timing of the phase switching signal of the step motor 1 in FIG. 2 also represents the scheduled time when the carriage 5 travels a distance of a unit step. According to the present embodiment, the print command signal is always generated before the flight time tfly for each phase switching timing (that is, the unit step movement scheduled time). Therefore, M (n) for the print command signal P (n) is generated. ), The print dots are formed, so
The dot interval can be made constant, and no shift occurs with respect to each phase switching position.

In the embodiment of the present invention, the print command signal is generated once for each phase switching for convenience, but the print command signal is generated by dividing or multiplying the phase switching signal. In that case, the output may be corrected.

[0027]

As described above, according to the present invention, the printing operation in which the dot interval is constant even when the carriage is being accelerated from the stopped state to the constant speed or being decelerated from the constant speed to the stopped state is performed. ROM for correction
Since the capacity is not burdened and the processing time is short, the throughput can be hardly affected. Further, since the deviation with respect to the predetermined printing position does not occur, there is no need for the conventional correction for the deviation amount at the time of reciprocal printing, and the manufacturing process can be simplified.

[Brief description of drawings]

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

FIG. 2 is a timing chart of an embodiment of the present invention.

FIG. 3 is a control block diagram showing an embodiment of the present invention.

FIG. 4 is a flowchart illustrating a control operation according to an embodiment of the present invention.

FIG. 5 is a diagram illustrating a conventional correction method.

[Explanation of symbols]

 1 Step Motor 2 Timing Belt 3 Pulley 4 Print Head 5 Carriage 6 Printing Paper 7 CPU 8 ROM 9 RAM 10 Host Device 11 I / F Unit 12 I / O Unit 13 Head Drive Unit 14 Step Motor Drive Unit

Claims (1)

[Claims] 1. A print control device for moving a print head by a power source, generating a print command signal in response to a signal synchronized with the motion of the power source, and giving the print command signal to the print head, A print control device, wherein the print command signal is generated before the scheduled time when the print head passes a predetermined print position by the flight time of the print head, and the print command signal is given to the print head.