JPH07228024A - Printer mechanism - Google Patents

Abstract

(57) [Summary] [Purpose] A printer mechanism that improves operability by making it easier to replace recording paper. A recording paper 1 is sandwiched between a thermal head 4 supported by a guide bar 18 slidably up and down and pressed downward by a coil spring 17, and a platen roller 3 which is rotated by a drive of a motor 5 for printing. Done. A lever 6 is attached to the shaft of the platen roller, and one end 6a of the lever 6 is engaged with the tip of a solenoid 7.
The cassette 2 containing the recording paper roll 1 is provided with a pinch roller 15 and an idle roller 16 at the recording paper feed-out portion, and the rotation of the motor is transmitted to the rollers to send out the recording paper. A limit switch 8 for detecting the remaining amount of recording paper is attached to the rear portion of the cassette 2, and a projector 20 and a light receiver 21 for detecting the presence or absence of recording paper are provided at the sending-out portion of the thermal head 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printer mechanism used for FAX or the like.

[0002]

2. Description of the Related Art As shown in FIG. 4, a printer mechanism used for a fax machine or the like has a belt 11 driven by a motor 5 stretched over a platen roller 3 and pressed by a pressure spring 17 by the platen roller 3. Printing is performed by pressing the recording paper 1 against the thermal head 4. The intermediate shafts 9 and 10 are driven via the belt 12 from the sliding shaft of the platen roller 3, and the recording paper is pinched and conveyed between the pinch roller 15 and the idle roller 16 connected to the belt 13 by the intermediate shaft. There is. The recording paper is rolled into a roll and stored in the printer mechanism. When replacing the recording paper, pull out the rolled paper, insert it between the idle roller and the pinch roller, and then operate the lever 22 manually to set the gap between the platen roller 3 and the thermal head 4. It was necessary to open it and insert a paper sheet to set it, which was troublesome in terms of operability.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and integrates a recording paper roll into a cassette to facilitate the exchange of recording paper and to detect the remaining amount of recording paper. Provides an automatic loading mechanism for the recording paper cassette that automatically opens between the platen roller and the thermal head and automatically closes between the platen roller and the thermal head when a new cassette is installed. It is a thing.

[0004]

In order to solve the above-mentioned problems, the present invention provides a thermal head which is slidably supported by a guide bar and is pressed downward by a spring.
A platen roller that is rotated by the driving force of a motor to sandwich recording paper between the thermal head, a lever that is attached to one side of the platen roller shaft and that moves the thermal head up and down, and drives the lever. A recording sheet cassette provided with a solenoid, a recording sheet roll, and a pinch roller and an idle roller that rotate when the drive of the motor is transmitted to the recording sheet delivery section is detected, and the remaining amount of recording sheet in the recording sheet cassette is detected. A detector that sends out the operation signal of the solenoid, and is located in the recording paper sending-out portion of the thermal head,
And a detector for detecting the presence or absence of recording paper.

[0005]

With the above-described structure, the printer mechanism according to the present invention detects when the remaining amount of the roll-shaped recording paper integrated in the cassette becomes a certain value or less by the limit switch and prints. When it stops, the space between the platen roller and the thermal head opens automatically. Further, when a new cassette is mounted, when the recording paper passes between the platen roller and the thermal head, the roller and the thermal head are automatically closed to provide a printable state, thereby providing a printer mechanism with improved operability. be able to.

[0006]

Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a sectional view showing a printer mechanism according to the present invention, and FIG. 2 is a view showing a state of the printer mechanism when a recording paper cassette is replaced. FIG. 3 is a perspective view showing a cassette in which a recording paper roll is incorporated and integrally replaced. The recording paper pulled out from the cassette is driven to be sandwiched by an idle roller and a pinch roller, and pressed against a thermal head by a platen roller for printing.

The rectangular thermal head 4 is vertically slidably supported by a guide bar 18 that hangs downward from the sheet metal unit housing 1, and is stretched between the housing 1 and the thermal head 4. It is constantly pressed downward by the coil spring 17. A cylindrical platen roller 3 made of a rubber material is rotatably supported on both sides of the sheet metal housing 1, and a lever 6 made of a thin sheet metal is rotatably supported on one side thereof. The short diameter portion 6b of the lever 6 is in contact with a metal fitting attached to one side of the thermal head 4. A long hole 6a is provided at the tip of the long diameter portion of the lever 6, and a pin 7b provided at the tip of the sliding shaft 7a of the solenoid 7 is engaged with the long hole 6a.

A small motor 5 is arranged below the platen roller 3, and a rubber belt 11 is stretched between a pulley 5a attached to the rotating shaft of the motor 5 and a pulley 3a attached to the shaft of the platen roller. It is installed so that the rotation of the motor can be transmitted. A pulley 3b is provided inside the pulley 3a, and the pulley 3b is coaxially connected to the pulley 3a. An intermediate shaft 9 and an intermediate shaft 10 are provided on the side of the motor 5 facing the solenoid 7.
Are arranged above and below the intermediate shaft 9 and the pulley 3b.
A rubber belt 12 is stretched between the intermediate shaft 9 and the intermediate shaft 9, and a rubber belt 13 is stretched between the intermediate shaft 9 and the intermediate shaft 10. The intermediate shaft 10 has a gear on the same axis and meshes with a small gear 14.

As shown in FIG. 3, the cassette 2 for accommodating recording paper is integrally formed with a rectangular paper feeding portion 2b protruding from a cylindrical recording paper roll accommodating portion.
The recording paper 2a is sent out from the opening of. Same paper feeding unit 2
A notch is formed vertically near the tip of b, an idle roller 16 is supported on the upper part of the notch, and a pinch roller 15 is supported on the lower part of the notch. One end of the pinch roller 15 shaft is provided. The gear 23 is attached.

When the cassette 2 is set in the printer mechanism, the gear 23 meshes with the gear 14. A limit switch 8 is attached to the rear of the recording paper storage portion of the cassette 2, and a detection lever 8a of the limit switch is inserted from a shield-shaped notch provided in the cassette 2. Further, in front of the thermal head 4 and the platen roller 3, a light projector 20 and a light receiver 21 for detecting the presence or absence of recording paper are attached.

Next, the operation of the printer mechanism having the above configuration will be described. In the normal printing state, as shown in FIG. 1, the driving force of the motor 5 rotationally drives the platen roller via the belt 11, and the rotational force is transmitted by the belts 12 and 13, and the intermediate shaft 9 is rotated. And 10 are rotationally driven. The rotational force rotates the pinch roller 15 and the idle roller 16 attached to the cassette 2 via the gear 14. Same pinch roller 15
Then, the recording paper 2a sandwiched between the idle rollers 16 is sent out by this and the thermal head 4 prints. At this time, the solenoid 7 is in the OFF state.

The remaining amount of the recording paper roll 1 becomes small,
When it becomes a certain value or less, as shown in FIG. 2, the lever 8a contacting the recording paper of the limit switch 8 causes
When this is detected, printing is stopped at a break point through the control circuit, and the solenoid 7 is actuated to pull down the 6a portion of the lever 6. As a result, the lever portion 6b pushes up the thermal head 4 by the action of the lever.

When the cassette 2 with no remaining amount is taken out, a new cassette is mounted, and the printing start switch is turned on,
The motor 5 is actuated, whereby the recording paper is sent out from the cassette. The same recording paper is used for the projector 20 and the receiver 2.
When the sheet passes through 1, the presence / absence of the same recording paper is detected, and the solenoid 7 is activated by this signal to push up the lever 6, thereby lowering the thermal head 4 and starting printing.

[0014]

As described above, according to the printer mechanism of the present invention, when the remaining amount of the recording paper in the recording paper storage cassette becomes small, and when it becomes a certain value or less, the printing is automatically stopped and the printing is performed. The space between the thermal head as a unit and the platen roller is opened, and when a new recording paper cassette is attached, the space between the thermal heads is automatically closed to enable printing. As a result, the workability of exchanging the recording paper can be simplified and automated, and the operability of the device using the printer mechanism can be improved.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a printer mechanism according to the present invention.

FIG. 2 is a sectional view showing an embodiment of a printer mechanism according to the present invention.

FIG. 3 is a perspective view showing an embodiment of a recording paper cassette according to the present invention.

FIG. 4 is a cross-sectional view showing a conventional printer mechanism.

[Explanation of symbols]

 1 Sheet Metal Housing 2 Recording Paper Cassette 2a Recording Paper 3 Platen Roller 4 Thermal Head 5 Motor 5a Motor Pulley 6 Lever 7 Solenoid 8 Limit Switch 8a Detection Lever 9 Intermediate Shaft 10 Intermediate Shaft 11 Belt 12 Belt 13 Belt 14 Gear 15 Pinch Roller 16 Idle Roller 17 Coil spring 18 Guide bar 20 Emitter 21 Light receiver

Claims (3)

[Claims] 1. A thermal head which is slidably supported by a guide and is pressed downward by a spring; and a platen roller which rotates by a driving force of a motor and clamps a recording sheet between the thermal head and the thermal head. A lever for moving up and down the thermal head mounted on one side of the platen roller shaft, a solenoid for driving the lever, a pinch for accommodating a recording paper roll and transmitting the drive of the motor to a recording paper feed section, and rotating the pinch. A recording paper cassette provided with a roller and an idle roller, a detector that detects the remaining amount of recording paper in the recording paper cassette and sends out an operation signal of the solenoid, and is located in the recording paper sending-out portion of the thermal head,
A printer mechanism comprising a detector for detecting the presence or absence of recording paper. 2. The printer mechanism according to claim 1, wherein the detector for detecting the remaining amount of the recording paper in the recording paper cassette comprises a limit switch having a lever. 3. The printer mechanism according to claim 1, wherein the detector for detecting the remaining amount of the recording paper in the recording paper cassette comprises an optical sensor.