JPS6223769A - Control system for daisy wheel type printer - Google Patents

Abstract

PURPOSE:To enhance the quality of printing without sacrificing the speed of printing by applying a drive signal to a hammer drive source a fixed time after the application of drive signal to a carriage drive source is stopped. CONSTITUTION:In a signal C to be applied to a hammer drive source 5, setting is always made to generated trigger pulse a fixed time after application of signal B to a carriage motor 7 is stopped. Printing can therefore be made by striking hammers 4 at the same position all the time for vibration even within the vibration range of the carriage 1. In the case(a) where the stoppage of applying signal B to the motor 7 is later than the stoppage of applying signal A to a daisy motor 3 for selection of types, the stoppage setting is not changed, and also in the case where time taken for the selection of types is longer, the setting is made in such a way that it is the same time as stoppage of applying signal A or later than the stoppage.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to improvements in printing devices such as printers and typewriters equipped with daisy wheels, and in particular to improvements in printing devices such as daisy wheels and their drive motors, hammers, cassette ribbons, etc. The present invention relates to a method of controlling a printing device using a stepping motor as a drive motor for a carriage on which a printing element is mounted.

<Prior Art> In general, a daisy-wheel printing device, in which a carriage carrying print elements such as a daisy-wheel, cassette ribbon, and hammer, is moved left and right along the axis of a platen to print, is not compatible with other devices, e.g. Compared to dot-type printing devices and thermal printing devices, the type formed on each spoke of the daisy wheel is struck directly onto the paper using a hammer, so even though the printing speed is slower than the above-mentioned printing devices, Demand has been increasing in recent years because high printing quality can be obtained.

The schematic structure of this type of daisy-wheel printing device is explained in the second section.
As shown in the figure.

The carriage 1 shown in the figure includes a daisy wheel 2, a daisy motor 3 that drives the daisy wheel 2, a hammer 4, and a hammer drive section 5 that drives the hammer 4.
It is equipped with a cassette ribbon 6, etc. This carriage 1 is moved along a main shaft 8 by a carriage motor 7.

The printing process of this daisy wheel type printing device includes a character selection step in which the daisy motor 3 rotates the daisy wheel 2 to select the printed characters formed on each spoke of the daisy wheel 2, and selects a desired character. , a carriage moving process in which the carriage motor 1 carrying printing elements such as the hammer 4 is moved to the next printing position by the carriage motor 7, and a hammer driving unit 5 driving the hammer 4 at the printing position to drive the type on the daisy wheel 2. It is generally composed of a hammer driving process for printing on paper 9. The character selection step and the carriage movement step are generally set so that the carriage movement step overlaps with the character selection step in order to improve printing speed.

The conventional relationship among the character selection process, carriage movement process, and hammer drive process is shown in FIG. 3 by the timing of signals applied to the daisy motor 3, carriage motor 7, and hammer drive section 5.

As shown in the figure, since the time required for the character selection process is not constant, the application time of the signal A applied to the daisy motor 3 is not constant. For example, when printing the same character as "EE" consecutively, there is no need to rotate the daisy wheel 2 to select the character when printing the second character "E". The time required for the selection process is zero, and if the next character is located on the daisy wheel 2 at a symmetrical position to the printing position, the daisy wheel 2 must be rotated 180 degrees, and the character selection process This takes the longest time compared to selecting other typefaces.

Therefore, the time required for this type selection process will vary within the time required for the daisy wheel 2 to rotate 180 degrees from zero.

On the other hand, in the carriage movement process, the carriage 1 only needs to print at a predetermined constant interval for each print, so the carriage motor 7 The application time of signal B was kept constant6. On the other hand, in the hammer driving process, actual printing cannot be performed unless the type selection process and carriage movement process are completed, so this type selection process It is started after both the carriage movement process and the carriage movement process are completed. That is, conventionally, as shown in FIG. 3(A), the time required for the character selection process was shorter than the time required for the carriage movement process, and the signal applied to the daisy motor 3 was applied earlier than the signal applied to the carriage motor 7. When the application is stopped, a trigger pulse is generated in the signal C and applied to the hammer drive unit 5 after a time t, l after the time when the application of the signal B is stopped, which is stopped later, and vice versa. ), the time required for the character selection process [51 is longer than the time required for the carriage movement process, and the signal A applied to the daisy motor 3 is stopped later than the signal B applied to the carriage motor 7. The trigger pulse was set to be generated in the signal C and applied to the hammer driving section 5 after a time Ll after the time when the application of the signal A stopped.

<Problems to be Solved by the Invention> In the above-mentioned carriage movement process, the carriage 1 is scheduled to stop even after the application of signal B is stopped, as shown in the carriage movement curve shown in Fig. 1, due to its inertia force. position(
It vibrates attenuated from the print position level E). For this reason, it is best to start the hammer driving process after the vibration of the carriage 7ji 1 has completely subsided, but this will drastically reduce the printing speed, so in reality, it is necessary to wait within the vibration range F. However, if the hammer is driven based on the stop of signal application during the character selection process or the carriage movement process, whichever ends later, as in the conventional example, the carriage 1 For example, in the case of FIGS. 3(a) and 3(b), the time t from the start of vibration to the striking of the hammer 4 changes in various ways. The time it takes for the unit 5 to be driven by the trigger pulse generated by the signal C is different from tl and tl, respectively.

Therefore, as shown in FIG. 4, when the hammer 4 is driven after a time tl after the application of the signal B is stopped and the carriage 1 comes to the printing position, even if it is possible to move the hammer 4 to the printing position, after a time t2. When the printing position is set, there is a problem that a printing deviation G occurs between the printing position and the normal printing position as shown in the figure, and the pitch of the printed characters is shifted.

<Means for Solving the Problems> The present invention provides a daisy-wheel type printing device in which a drive signal applied to a carriage drive source is applied to a daisy-wheel drive source at the same time as or delayed from the stop of application of a drive signal applied to the daisy-wheel drive source. The problems of the conventional method can be solved and the printing speed can be increased by setting the application to stop and applying a drive signal to the hammer drive source after a certain period of time after stopping the application of the drive signal to the carriage drive source. without damaging
The present invention provides a method for controlling a daisy-wheel printing device that achieves improved printing quality.

<Example> An embodiment of the present invention will be described below based on the drawings.

In the present invention, as shown in FIG. 1, a trigger pulse is generated in the signal C applied to the hammer drive unit 5 after a certain period of time from when the signal B, which is always applied to the carriage motor 7, stops being applied. It is set as follows. Therefore, as shown in FIG. 4, even if the carriage 1 is within the vibration range F, it is possible to always strike the hammer 4 at the same position against vibrations and print.

It is preferable to set the time from when printing of signal B stops to the application of signal C to the point where the vibration surface &LD of carriage 1 intersects the printing position level, for example, tl, but it is also preferable to set it to time t2. However, since the amount of deviation from the normal printing position level is constant, the upper printing pitch itself is constant at first glance.

On the other hand, if the stop of the signal B applied to the carriage motor 7 is later than the stop of the signal A applied to the daisy motor 3 for character selection (see FIG. 1 (a)), the state remains unchanged. , when the time required to select a printed character is long, it is set to be at the same time as when the application of the signal A is stopped or even later. For this reason, the hammer 4 always completes both the character selection process and the carriage movement process, and is further driven to print after a certain period of time from the completion of the carriage movement process.

As shown in FIG. 1, in this embodiment, the timing at which the application of the signal B starts is synchronized with the start of the application of the signal A. can also be set to be delayed in response to changes in the application time of signal A, and as a result, the timing of stopping the application of signal B can be set to be synchronized or delayed with the stoppage of application of signal A.6 <Effects of the Invention> The present invention According to this method, it is possible to obtain high print quality without occurrence of print pitch deviation.

Further, even if the carriage is moved at high speed, there is no variation in the printing pitch itself, so it is easy to increase the printing speed.

[Brief explanation of the drawing]

FIG. 1 is a timing chart of signals printed on each drive source in a control method according to an embodiment of the present invention, FIG. 2 is a diagram showing a schematic configuration of a daisy-wheel printing device, and FIG.
The figure is a timing chart of signals printed on each drive source in the conventional control method, and FIG. 4 is a diagram showing the moving state of the carriage shown in FIG. 2. 10.6 carriage, 211. Dizzy wheel, 31
1. Dizzy motor, 421. Hammer, 510. Hammer drive, 7.1. Carriage motor Figure 1 Figure 3

Claims (1)

[Claims] A daisy wheel drive source for rotating the daisy wheel for character selection, a hammer drive source for driving a hammer for hitting the daisy wheel at a printing position, and a carriage on which the daisy wheel and hammer are mounted. In a daisy wheel printing device, the drive signal applied to the carriage drive source is stopped at the same time as or delayed from the stop of application of the drive signal applied to the daisy wheel drive source. , and applying a drive signal to the hammer drive source after a certain period of time from the stop of application of the drive signal to the carriage drive source.