JPS587384A - Scanning mechanism for printer - Google Patents

Abstract

PURPOSE:To bring a carriage into a steady travelling condition speedily and within a short distance of travelling, by a method wherein a tensioning mechanism for giving a tension to a wire for travelling a carriage is provided with a damping force with a predetermined timing at the rising-up time of the travelling. CONSTITUTION:A timing for driving a solenoid 10 is set by a generating circuit 13 for the timing, and at the rising-up time of the travelling of the carriage, the solenoid 10 is driven with a predetermined timing to exert a damping force on the carriage effectively. The dampling force is exerted at overshoot parts A1, A2, A3 of the wave form of vibration or it is gradually weakened. Accordingly, the carriage can be speedily brought into the steady travelling condition, and distortion in printing can be prevented from occurring due to vibrations.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in the scanning mechanism of a printer, and in particular, to effectively apply a braking force to the carriage when the carriage starts running, thereby stopping the carriage from moving for a short period of time.
It is designed to be able to maintain a steady running state within a short distance.

In printer scanning, when the carriage starts running,
It is preferable to keep the carriage in steady state for a short period of time and within a short distance, so that it is necessary to rapidly accelerate the carriage. If a sudden acceleration force such as force 5 is applied to the carriage, the carriage running system generates unnecessary vibrations, which adversely affects printing quality. Therefore, conventional methods have been to increase the start-up time and travel distance, to attach a dashpot to the movable part of the tension unit that applies tension to the running wire, or to constantly press a sliding member against the movable part to provide braking force. Alternatively, a sliding member holder is fixed to the carriage and the sliding member attached to the holder is pressed against a carriage traveling guide rail to apply a braking force to the carriage. However, the above-mentioned conventional techniques have drawbacks such as a reduction in printing half speed, an increase in the size of the printer, an increase in the size of the carriage drive upper, and an increase in the energy required to drive the carriage.

The present invention has been made in order to eliminate the drawbacks of the prior art as described above. In particular, when the carriage starts running,
The tension mechanism, which applies tension to the wire that makes the carriage run, applies braking force at a predetermined timing, thereby making it possible to quickly bring the carriage into a steady running state with a simple and inexpensive configuration. FIG. 1 is a schematic configuration diagram for explaining an example of a conventional printer scanning mechanism. In the figure, l is a carriage, 2 is a wire, 3 is a pulley, 4 is a carriage guide rail, 5Fi tension lever, 6Fi tension A spring, 7 is a lever fulcrum, and 8 is a motor (stepping motor) that drives the motor 8 to move the carriage 1 when printing starts. , it is necessary to give a large acceleration force to the carriage. However, the tension spring system vibrates due to the acceleration force at this time, resulting in vibrations as shown in FIG. This vibration is a natural vibration determined by the carriage 1, wire 2, -j-') 3, lever 5, tension spring 6, etc., and its vibration frequency f0 is (where M: carriage 1, wire 2, pulley 3 , total effective mass of lever 5, etc., K1: spring constant of tension spring 6).

Figure 3 is a schematic diagram showing the main parts of an example of a conventional braking device designed to eliminate the above-mentioned vibrations, as shown in the figure.
Although a braking member 9 is provided on the tension lever 7 of the printer mechanism shown in FIG. 1, this prior art also has the above-mentioned drawbacks.

FIG. 4 is a schematic diagram showing the main parts of an embodiment of the present invention. In the figure, 10 is a solenoid coil, 11 #i lunoid lever, 12 is a solenoid drive circuit, and 13 is a solenoid drive timing generation circuit (drive time (including a setting circuit), and other parts not shown are the same as in FIG. Accordingly, in the present invention, the solenoid drive timing generation circuit 13 generates an output signal.

When the carriage starts running, the solenoid coil 10 is driven at a predetermined timing to effectively apply braking force to the carriage. For example, as shown in FIG. As shown,
Overshoot A of the vibration waveform shown in Figure 2! Alternatively, as shown in Fig. 6, the braking force can be applied at multiple overpasses. -) Part A, A, ,A,
In this system, the braking force is gradually weakened as shown in FIG. Therefore, according to the present invention, the carriage 1 quickly enters a steady running state, and printing distortion phenomenon caused by vibration can be prevented. Note that the operating timing, operating time, solenoid drive voltage, etc. of the solenoid coil can be set arbitrarily, and the operating timing, operating time, etc. can be set using a program using a normal counter, monomulti, or microcomputer. However, the driving voltage can still be set using a voltage regulator or the like composed of ordinary transistors, variable resistors, etc.

FIG. 8 is a diagram showing an example of an electric circuit diagram for performing the braking shown in FIG. The timing pulses a and b are generated and the drive voltage applied to the solenoid coil 10 is set to R- as shown in FIG. 7(e).
It is made to gradually decrease by means of a C time constant circuit.

As is clear from the above description, according to the present invention, with a simple and inexpensive configuration, when the carriage starts running,
The carriage can be brought into a steady running state in a short time and over a short running distance.

[Brief explanation of the drawing]

Fig. 1 is a schematic configuration diagram for explaining an example of a conventional printer scanning mechanism, Fig. 2 is a drive characteristic diagram of the printer scanning mechanism shown in Fig. 1, and Fig. 3 is a conventional printer scanning mechanism. FIG. 4 is a schematic diagram of the main parts for explaining an example of a braking device, and FIGS. 5 to 7 are schematic diagrams of the main parts for explaining an embodiment of the printer scanning mechanism according to the present invention. are operational characteristic diagrams for explaining the present invention in detail, and FIG. 8 is a diagram showing an example of an electric circuit suitable for executing the operation shown in FIG. 7. --Wire, 3--Pulley, 4--Carriage guide rail, 5--Tension lever, 6--Tension shore spring, 7--Lever fulcrum, 8--Motor,
10...Solenoid coil, 11--Lunoid lever, 12...-Solenoid drive circuit, 13.14...
Solenoid drive timing pulse generation circuit. Figure 1 Figure 2 Figure 4

Claims (2)

[Claims] (1) In a printer running machine having a carriage, a wire for running the carriage, and a tension mechanism for applying tension to the wire,
A printer scanning mechanism 0 characterized in that a braking force is applied to the tension mechanism at a predetermined timing when the carriage starts running. (2) A scanning mechanism for a printer according to claim 3, characterized in that a braking force is applied to the tension mechanism multiple times at predetermined timing. A scanning mechanism for a printer according to claim 1 or 2, wherein a braking force is applied at a predetermined timing and the braking force is gradually weakened.