GB2150505A

GB2150505A - Printer

Info

Publication number: GB2150505A
Application number: GB08426233A
Authority: GB
Inventors: Takehisa Naito; Takashi Sawada; Masamitsu Nojima
Original assignee: Citizen Watch Co Ltd
Current assignee: Citizen Watch Co Ltd
Priority date: 1983-10-28
Filing date: 1984-10-17
Publication date: 1985-07-03
Also published as: GB8426233D0; DE3438490C2; GB2150505B; JPS6075063U; DE3438490A1

Abstract

A printer has a platen 15, a carriage 21 adjacent the platen, a print head 20 mounted on the carriage, and a ribbon cassette 23 provided in front of the platen 15 for feeding a ribbon to the print head 20. A paper feeding motor 30 and a carriage driving motor 31 are provided under the ribbon cassette 23, and capacitors 4,5 for the direct current supplies for the motors are disposed between the motors. <IMAGE>

Description

SPECIFICATION Printer The present invention relates to a printer such as a serial printer, and more particularly to an arrangement of parts eployed in the printer.

A printer, such as a serial printer, is provided with a servomotorfor reciprocating a carriage having a print head along a platen. Since the servomotor is provided in a portion adjacent to an axial end of the platen, the printer becomes large in size.

Further, as shown in Figure 1, in order to rectify an alternating current from a source 3 into direct currents, a pair of smoothing capacitors 4 and 5 are provided. The capacitor 4 applies a print head pin driving voltage 1 (for example 72 V) to a driving means for the print head and the capacitor 5 applies a carriage driving voltage 2 (for example 36 V) to the motor. In orderto apply such high voltage, capactors 4,5 have great capacities, for example 10,000 FF and 22,000 FF and hence large sizes, respectively. On the other hand, an electric circuit including the large capacitors 4 and 5 must be installed in a position behind the platen. Therefore, it is very difficult to mount the electric circuit.

The object of the present invention is to provide a printer which may improve a space efficiency in arrangement of parts.

According to the present invention, there is provided a printer having a pair of side frames, a platen rotatably mounted on the side frames, a carriage adjacent the platen, a print head mounted on the carriage, and a ribbon cassette provided in front of the platen for feeding a ribbon to the print head. A paper feeding motor and a carriage driving motor are provided underthe ribbon cassette, and capacitors for producing direct currents for the motors are disposed between the motors. The paper feeding motor and the carriage driving motor are disposed in both side portions of the printer.

These and other objects and features of the present invention will become more apparent from the following description with reference to the accompanying drawings.

In the drawings: Figure lisa block diagram showing a connection of capacitors with a source; Figure 2 is a schematic plan view showing a part of a printer according to the present invention; and Figure 3 is a side view of the printer.

Referring to Figures 2 and 3, a pair of side frames 10 has a pair of bars 11 laterally disposed at a front end portion and a rear end portion thereof. The bar 11 at the rear end portion is not illustrated in the drawings. Both ends of each bar 11 are supported on a pair of side frame supports 13 mounted on a base frame 12. A pair of platen supporting plates 14 are secured to side frames 10 for rotatably supporting a platen 15. A pair of pulleys 16, 17 are secured to shafts of the platen at both ends thereof. The pulley 17 on the right end of the platen 15 is engaged with a timing belt 18 which engaged with a pulley (not shown) of a paper feeding device.

A print head 20 is mounted on a cariage 21 and disposed in front of the platen 15. The carriage 21 is slidably engaged with a carriage guide bar 26 at a lower portion thereof, both ends of the guide bar being secured to side frames 10. A carriage roller 27 is rotatably mounted on a carriage roller shaft 28 secured to a lower portion of the carriage 21 opposite to the platen 15. The roller 27 is engaged with a guide rail 29b provided in an elongated slit 29a laterally formed in a carriage guide frame 29.

Thus, the carriage 21 is adapted to move in parallel to the axial direction of the platen 15.

A ribbon cassette 23 for storing an endless ribbon 22 is detachably mounted on cassette supports 24 secured to the side frames 10. Four ribbon guide rollers 25 are rotatably mounted on the carriage 21 to guide and feed the ribbon 22 in order, so that the ribbon 22 is positioned at a front end of the print head between the print head 20 and platen 15.

Under the ribbon cassette 23, a paper feed motor 30 and a carriage driving motor 31 are disposed on the frame 12 at a left end portion and a right end portion, respectively. Capacitors 4 and 5 each having a large size, are disposed between motors 30, 31 and connected to an electric circuit (not shown) disposed in a space behind the platen 15.

A pulley 32 which is engaged with an output shaft of the paper feed motor 30 is connected to the pulley 16 of the platen 15 through a timing belt 33 engaged therebetween. Accordingly, when the paper feed motor 30 is started, the platen 15 is rotated for rotating the pulley 17 engaged with the other end of the platen 15, and the paper feeding device is driven by the timing belt 18 for feeding a paper.

A drum 34 is engaged with an output shaft of the carriage driving motor 31. A pair of pulleys 36,37 for changing direction are rotatably supported on a shaft 39 which is vertically disposed to make the right angle with the axis of drum 34. The shaft 39 is secured to a pair of supports 40 mounted on one of side frames 10. A pulley 38 for changing direction is rotatably supported on a shaft 41 which is secured to a support 42 secured to the other side frame 10.

Those pulleys 34,36,37 and 38 are engaged with a carriage driving wire 35. The carriage driving wire 35 both ends of which are secured to both sides of the carriage 21 passes arround pulley 36, drum 34, pulleys 37 and 38. Thus, when the carriage driving motor 31 is rotated in the forward direction or reverse direction, the carriage 21 is reciprocated along the carriage guide bar 26 and guide rail 29b through the carriage driving wire 35.

In accordance with the present invention, a paper feed motor and a carriage driving motor are disposed in a space under a ribbon cassette. Further, capacitors are disposed between motors. Therefore, a printer can be compacted and an electric circuit can be easily mounted in the printer.

While the invention has been described in conjunction with preferred specific embodiments thereof, it will be understood that this description is intended to illustrate and not limit the scope of the invention, which is defined by the following claims.

Claims

1. A printer of the type having a pair of side frames, a platen rotatably mounted on the side frames, a carriage adjacent the platen, a print head mounted on the carriage, and a ribbon cassette provided in front of the platen for feeding a ribbon to the print head comprising: a paper feeding motor provided under the ribbon cassette; a carriage driving motor provided underthe ribbon cassette; and capacitors for producing direct currents for the motors, the capacitors being disposed between the motors.

2. A printer according to claim 1 wherein the paper feeding motor and the carriage driving motor are disposed in both side portions of the printer.

3. A printer according to claim 2 wherein output shafts of both motors are projected from the frames, and each output shaft has a rotation transmitting device.

4. A printer substantially as hereinbefore described with reference to, and as illustrated in, the accompanying drawings.