JPH0316768A - Drive motor of printer carrier - Google Patents

Abstract

PURPOSE:To ensure compactness and weight reduction by using a piezo motor(ultrasound motor) as a carrier drive motor of a printer. CONSTITUTION:A rail 2 is kept in contact with member 9 fixed to a carrier 3 and a member 10 fixed to a plunger for pressure contact 11, both having an appropriate coefficient of friction, under pressure. In addition, a surface wave excited by a horn 1 advances in 'C' direction as it moves in an elliptic motion as shown by D on the surface of the rail 2. In this case, the carrier 3 runs in 'B' direction, then connects a signal to a printer control section 27 from a carrier left end position detector 26A. Further, a signal is connected to a horn 1 and a horn 1A by a drive section 24. In addition, a drive signal is connected to the horn 1A aligned with an angular difference of 90 deg. from the horn 1. Subsequently, the carrier 3 runs in 'B'' direction. Thus the subject motor can be made compact in size by arranging the horns to the right and left in a space under a ribbon cassette.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a carrier drive motor used in a printer.

[Conventional technology]

Conventionally, printers use a rotary motor as the drive source for the carrier on which the print head is mounted. [Problems to be solved by the invention] The carrier drive motor in conventional printers is large, making it unsuitable for miniaturizing printers. [Means for Solving the Problems] In the present invention, a viezo motor (ultrasonic motor) is used as a carrier drive motor used in a printer, thereby achieving a reduction in size and weight. The Viezo motor has an output/weight ratio of 5 to 8 compared to conventional motors.
It is twice as large and the volume is also 1/5 to 1/8.

Moreover, conventional motors were cylindrical, which was an inconvenient shape for rectangular parallelepiped printers, but this Viezo motor has the advantage of being small and can use space that was not previously used, and can be made smaller accordingly. be.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings. Referring to FIG. 1, 4 is a print head. 5 is an ink ribbon. Reference numeral 6 is a tractor, 7 is a platen, and 8 is a printing paper. Characters are printed on the surface of the paper 8 on the platen 7 via an ink ribbon 5 by a print head 4 mounted on a carrier 3 that moves in the left and right direction. The fact that the paper 8 is fed by the tractor 6 is the same as in conventional printers and is well known, so the details will be omitted. The rails 2 and 2A are the rail 2 on which the Viezo surface wave runs, and the rail 2A that receives impact force during printing. The rail 2 has a member 9 fixed to the carrier 3 and a member 10 fixed to the plunger 11, which have an appropriate coefficient of friction.
are pressed together with appropriate force.

The plunger 11 applies appropriate pressure to the members 9, 10 and the rail 2 by the pressure adjustment screw 13 via the female threads of the pair of carriers 3 of the pair of springs 12, and by the locking nut l4 of the screw 13. It will prevent it from loosening. Referring to FIG. 4, the bolted Langevin type horn 1 and IA have a half wavelength (λ/2) of the wavelength λ determined by the cross-sectional shape R of the rail 2 at a driving frequency of 5, constants depending on the material of the rail 2, and the ultrasonic velocity C. They are located at an integral multiple of 10λ/4 and at a length g, and are fixed to the printer body via a horn support 22 with screws 23. Horn 1. The tip portion 24 of the IA is equipped with a rail 2 and brazing to ensure that the vibrations of the horn are transmitted. Viezo 2 from the drive circuit
When a voltage according to a predetermined driving frequency is excited in the horn 1. The tips 24 and 24A of the IA vibrate in the X direction, and a surface wave (elastic wave) Y is generated by bending vibration on the rail 2. Referring to FIG. 5, when the surface wave excited by the horn 1 travels in the direction of arrow C, The surface of the rail 2 moves in an ellipse with a horizontal amplitude W and a vertical amplitude U as shown in D, and the traveling direction of the surface wave is C.
Then, this elliptical motion is rotating counterclockwise. This surface wave has vertices A, A'... for each wavelength, and the apex velocity V (surface wave velocity) is v = 2πfu. . Members 9, 10, vertices A, A', . . . are pressed against this surface, and the carrier 3 is driven in the direction of the arrow by the frictional force with the rail 2.

Referring to FIG. 6, the rail 2 is endless, and its length is an integral multiple of the wavelength λ. Therefore, referring to FIG. 7, when only the horn 1 is excited, the surface wave becomes a standing wave and does not contribute to driving the carrier 3.

(Figure 7(a)) Surface waves must always travel like traveling waves (b). Therefore, horn 1A is horn 1
When excited with a phase shift of 90 degrees, a unidirectional traveling wave is generated.

Referring to FIG. 6, the carrier 3 travels in the direction B, and the carrier left end position detector (magnetic sensor) 26A sends a signal to the printer control section 27, and the drive section 24 sends a drive signal to the horn 1 and horn IA. When a drive signal with a phase shift of 90" from horn 1 is sent to IA, carrier 3
’ direction. In this diagram, only the left and right ends are detected, but it goes without saying that the position of the carrier can be detected by a linear position sensor, etc. (not shown), and when the carrier reaches a predetermined position, it can travel in the opposite direction. In this way, by applying the Viezo motor to a printer, conventionally a large motor for driving the carrier was placed in the center or on either the left or right side of the device, and energy was transmitted using wires or timing belts. Therefore, the device becomes larger (width). Depth, etc.> Also, the motor is made of iron and is heavy, but the horn is light and has the advantage of being lightweight. Furthermore, as shown in Figure 1, conventionally,
By placing the horns on the left and right under the ribbon cassette, which was mainly a space, there is an advantage of miniaturization. [Effects of the Invention] As explained above, the present invention has the effect of providing a small and lightweight printer by forming a rail pressure welding machine oval on the rail and carrier of a pair of vibrators.

[Brief explanation of the drawing]

Fig. 1 is a schematic explanatory diagram showing an embodiment of the present invention, Fig. 2 is a sectional view of the carrier, Fig. 3 is an explanatory diagram of the press-contact mechanism to the rail, Fig. 4 is an explanatory diagram of the vibrator, and Fig. 5 is a diagram explaining driving force generation by surface waves, and Figure 6 is a block diagram explaining carrier operation.
FIGS. 7(a) and 7(b) are explanatory diagrams of standing waves and traveling waves. 1, IA... vibrator (horn), 2... rail (endless), 3... carrier, 4... print head,
9.10...Rail pressure contact member, 11...Plunger for pressure contact guide 12...Spring, 13...Screw for pressure contact force adjustment.

Claims (1)

[Claims] A printer having a carrier on which a print head is mounted includes an elastic rail on which the carrier runs, and a pair of elastic rails connected at one end to the rail and arranged at predetermined positions relative to each other to generate surface waves due to flexural vibration on the surface. A vibrator and
A carrier drive motor for a printer, comprising a member that is in pressure contact with the rail and transmits frictional force caused by vibration of a mass point on the rail due to the surface waves to the carrier.