JPS6194769A - Printing speed controlling system for dot-type serial printer - Google Patents

Abstract

PURPOSE:To reduce memory capacity and prevent distortion of printed images from occurring, by a system wherein the presence or absence and the density of dots in a spacing direction are detected from a dot image pattern of printing information, and the detected results are memontarily stored to be used for switching a spacing speed. CONSTITUTION:A one-line amount of information is received, is developed into dot image patterns, and low dot density regions, high dot density regions and space regions are detected. When utilizing the detected information for switching the printing speed, only in the case where a space region RS is present between a low dot density region and a high dot density region and the space region is wider than a transient region Rx in which the spacing speed becomes unstable with the result of distortion of printed images, the speed is switched over in the space region.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a printing speed control system suitable for dot-type serial printers that changes printing speed depending on the dot density of printed characters, etc.

(Background of the Invention) In the conventional method, the speed limit signal for switching the space speed of the print head determines the received print information for each character code and determines whether it is a high-speed printing mode or a low-speed printing mode. Get it by detecting whether you are in printing mode or
Alternatively, a speed designation signal or a speed switching command signal provided for each character code from a host device may be used. Such conventional methods have the drawbacks of increasing the memory capacity of the register for storing speed specification information and increasing the number of information transfer types. 57=49574, there is a method that detects the boundary between density and density of dots in the space direction from the dot image pattern obtained from the received print information, and uses the detection signal to switch the printing speed. It is known.

FIG. 1 is a diagram for explaining a method of printing by increasing the printing speed depending on the density of dots, and the horizontal axis shows the printing area and the vertical axis shows the printing speed.

In Figure 1, the area Rm is the dot spacing in one line.
In the 4-region, region Rx indicates a region where the dot spacing is dense. A region Rx included in the region R represents a transition region from when the speed switching signal is received until the designated speed is reached. However, in such a printing method, due to the inertia of the print head, when moving from area R to area RjC, the running speed of the print head does not shift linearly from V to Vr-. It is difficult, but the phenomenon shown by the breakage in Figure 1 often occurs, and the characters printed in the transient region Rx are
If the distance between the dots in the space direction forming a printed character is not shortened or expanded, so-called printing distortion occurs, which means that a printed pattern of a desired shape cannot be obtained.

[Purpose of the invention]

The present invention has been made in view of these points, and it is an object of the present invention to provide a speed control method for a dot-type serial printer that reduces memory capacity, improves information transfer efficiency, and does not cause printing distortion. This is the purpose.

[Summary of the Invention] Therefore, the present invention is capable of determining the original dot area and space (
Detecting the boundary point of the empty dot area, the boundary point between the dense dot area and the space area, and the amount of the space area,
When this detection information is used to switch the printing speed, a system is adopted in which the speed is switched only when the space violet is larger than the redundant amount.

[Embodiments of the invention]

An embodiment of the printing speed control method according to the present invention will be described below. Figure 2 shows 1. FIG. 5 is a block diagram of a circuit for determining the spacing between dots and the space area, and is a time chart for explaining the operation of the circuit. (cl) in Figure 5
is a strobe signal, and while this signal is being generated, signals to each print wire of the print head are guaranteed, but
Information that arrives during a period in which this signal is not generated is not considered to be regular print information. This block diagram is shown in Figure 4.
Either two or more dots are printed consecutively at an interval of 1 dot pitch, as in the x area, or dots are printed at an interval of 2 dots, not consecutively, as in the R true area.
Or, it detects whether there are two or more consecutive spaces like in the R8 area, and if even one of 1 to 8 spaces is printed continuously at a 1-dot pitch as shown in Figure 4, the dots are Treated as a dense area, all 1 to 8 lines are 2
If more than one dot is not printed consecutively, it is treated as a space area. (S) The open signal STB is output from the continuous dot detection circuit B+-Bi and the continuous space dot detection circuit 81-8-.
The signal is then input to a continuous dot area detection circuit 3 and a space area detection circuit 4. Continuous dot detection port*BI~Bm,
Print information is input to the space dot succession detection circuits 81 to BS from data input lines DT1 to DT13. Data input! DT1 to DT9 store dot image data received from a host device, or dot image data obtained by passing character codes received from the device through a galactor generator built into the printer. It is connected to a dot image buffer (not shown) and corresponds to the print wires W+-W-. Each of the 8 data input lines connects to 8 consecutive dot detection circuits B1 to Bm and consecutive space dot detection circuits B+ to 8.
Connected to SS. The continuous dot detection circuit B+-B6 is
While the strobe signal STB is being input, print information is input from the data input lines DT1 to DT8, and at tail time, the circuit outputs the signals BDOTI to BDOT8. A continuous signal is generated as shown in FIG. 2, and during this time, the second dot printing information is inputted, thereby outputting pulse signals of υBDOT1 to 8. This output signal is input to the eight-person chaor circuit 1.

Therefore, when printing information is continuously input to any one of the eight printing wires, the detection signal B is output from the OR circuit 1.
DOT is output. For example, if the printing information shown in Figure 3 (a) K is input to the first printing wire, then the first printing wire will have consecutive dots at the second and third strobe signals of 8TB. Therefore, at the timing of the third strobe signal STB, the continuous dot detection signal BDOT1 is output from the continuous dot detection circuit B+, passes through the OR circuit 1, and becomes the continuous dot signal BDOT.

This continuous dot signal is input to the continuous dot area detection circuit 5, and a continuous dot area signal BD as shown in Figure 3 is output. Output. While the continuous dot area signal BD is being generated, the print tilt is continuously input to at least one print wire at intervals of 1 dot pitch, so a deceleration command is sent to the space motor to speed up the space speed. is slow. If you do not want the printed information to be continuous and want to print with coarse dot spacing, the space speed must be high.
The BDF signal detected by the D falling edge detection circuit 6 is conveniently used. In the example shown in FIG. 3, since the dots on the first wire are no longer continuous from the sixth strobe signal, the BD fall 9 detection circuit 6 outputs the BDF signal at that timing. However, in this case, it is assumed that printing information is not continuously input to the second to eighth printing wires. The space dot continuous detection circuit S+-8m outputs the signals 5DOT1 to 8 at the same timing as the continuous dot detection circuits B1 to B1.
In this circuit, the first space dot signal generates a continuous signal as shown in Fig. 3 (CF), and during that time, the second space dot information is input, so that 5
Outputs pulse signals of DOT1 to DOT8. This output signal is input to the eight-person group circuit 2. Therefore, when the space dot information f information is continuously input to all eight printing wires, the AND circuit 2 outputs the space dot continuous detection signal 8DOT. For example, if the printing information shown in FIG. 3(a) is input to the first wire, space dots are consecutively displayed at the 5TBO locations of the 6th and 7th strobe signals on the first printing wire. Because
At the typing of the seventh strobe signal, a continuous space dot detection signal 5DoT1 is output from the continuous space dot detection circuit S1, and is passed through an AND circuit 2 to become a continuous space dot signal BDOT. However, in this case, it is assumed that the same printing information as the first wire is also input to the second to eighth printing wires. This space dot continuous signal 5DOT is input to the space area detection circuit 4, and a space reaching area signal EID as shown in FIG. This one
While No. g SD is occurring, the dots to be printed are in the blank area, the so-called space area. Therefore, the transient area that occurs when the print head's space speed is changed cannot be output as the space continuous area signal BD. If Vc6 is within the interval where Vc is 6, printing distortion due to space speed KO indeterminacy in the transient region will not occur.

FIG. 5 is a diagram showing the relationship between the boundary point between a region with a coarse or dense dot spacing and a space region and the space speed, where (a) is the dot density, (b) is the space speed of the print head, (c) is a mode register that stores the arrangement and amount of the coarse area, dense area, and space area of dots, and (c) is a speed change point register that stores the acceleration/deceleration start position of the space speed. In FIG. 5(A), the Rx area where the dot spacing is dense by one dot pitch is the high density area, the Rx area where the dot spacing is coarse or the low density area, and the R8 area where there are no printed dots is the space area. The RX region is a transition region from receiving a speed switching signal until reaching a specified speed. For example, if the transition region requires 16 dot pitches, then in the case of forward printing shown by arrow 41, printing is performed at a high space speed from the p' position, and at a low space speed from the p4 position. However, in reality, a transition region R1 is required, so in order to avoid printing distortion, it is necessary to set the transition region R1 at least before the p2 position.
Input the acceleration command from before the position where the transient region RX (16 dot pitches) is subtracted, and at least the transient region RX (16 dot pitches) before the p4 position.
The υ deceleration command must be input from the position where υ is subtracted, and the position at which the acceleration or deceleration command is input must be within the space area. For this purpose, speed change point register 7
is provided to store the position at which the speed switching command should be issued. At this time, as shown in FIG. 5(c), the mode register 7
Assuming that the starting and ending positions of the coarse dot area, dense dot area, and space area and the width (number of dots) of the area are stored in the speed change point register 80SCAD.
j contains the address of the p tube position, and 5CAD2 contains the address of p4.
An address obtained by subtracting the position from the transient region Rz (Is dot pitch) is stored. Here, after storage 1c6 in the speed change point register 8, the area R with coarse dot intervals is stored.
If there are no space regions Re wider than the transition region RX at both ends of the system, the space speed in the region R where the dot spacing is coarse is stored so as not to be high.

In the example of FIG. 5, the space region R8 between the pi position and the p4 position is narrower than the transient region RX (by 16 dot pitches), so the p1 position is stored in the speed change point register 8 as follows.
It is not stored as the acceleration start position.

During the printing operation, the current position counter is synchronized with the movement of the print head, and its value is compared with the value of the speed change point register 8, and the value of the current position counter is determined by the value of 8OADI of the speed change point register 8. (address of p+ position), an acceleration command is issued to the space motor using the BDIF signal output from the BD fall detection circuit 6. Also, the value of the current position counter is the speed change point register 8.
If it matches the value of 0SCAD2, issue a deceleration command to the space motor using the BDR signal 0. Conversely, when printing in the negative direction as shown by the arrow &2 direction, set the address of the p4 position in BCAD4 of the speed change point register 8, 8CAD3 has a transition region R1 (
When the value of the current position counter matches the value of 8CAD4, an acceleration command is issued to the space motor using the BDIF signal, and the value of the current position kakunta is EICAI). 3, a deceleration command is issued using the BDR signal.

Even if the detection operation using the circuit shown in FIG. 2 is performed during the printing operation due to the spacing of the print head, it will not be possible in time for the speed switching operation, so the dot image pattern for one line is read out once. The circuit shown in Figure 2 detects the dot density and space area.The detection information is written into the mode register 7, and based on the information in the mode register 7, the address for switching the space speed is written in the speed change point register 8. is stored, and the speed change point register 8 is read out during printing operation to switch the space speed of the print head.

〔Effect of the invention〕

As described above, in the present invention, when one line of print information is received from a host device, it is developed into a dot image pattern, and from this dot image pattern, areas with coarse dots, areas with dense dots, and space areas are detected. However, when this detection information is used for printing speed switching, there is a space area between the dot-based area and the dot-dense area.
In addition, if this space area is wider than the transient area where the space 4 degrees becomes unstable and print distortion occurs, we adopt a method in which the speed is changed within this space area, so the host device cannot change the printing speed. There is no need to manage signals, and there is no need to transfer the printing speed switching signal, so information transfer efficiency is improved, and printing distortion is reduced, resulting in high-quality printing.

[Brief explanation of the drawing]

Fig. 1 is a diagram for explaining the printing speed switching system, Fig. 2 is a block diagram of a circuit for determining dot density and space area, and Fig. 3 is a time chart for explaining the operation of the circuit. FIG. 4 is a diagram illustrating the phase difference in dot density, and FIG. 5 is a diagram showing the relationship between the boundary point between the dense dot area and the space area and the space velocity. Rm...Low density printing area RK...High density printing area

Claims (1)

[Claims] In dot-type serial printers in which the print head moves relative to the print medium and prints by changing the printing speed depending on the dot density, dots in the space direction are printed based on the dot image pattern obtained from the received print information. A printing speed control method for a dot type serial printer, characterized in that presence/absence and density are detected, the detected information is temporarily stored, and used for switching the space speed during printing operation.