JP2563635B2 - Printer - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a printing apparatus that prints while moving a carriage, feeds paper, and performs a line feed operation.

[Prior Art] Conventionally, the price of a printing apparatus such as an electronic typewriter has been reduced. For example, even for paper feed drive, an inexpensive stepping motor is not used, but an inexpensive DC servo motor is used. When controlling the position of the DC servo motor, it must be controlled in a closed loop, and the rotational position of the DC servo motor must be detected using some kind of sensor.

The conventional printing device will be described below. FIG. 4 is a perspective view of a main part of a conventional printing apparatus, in which 1 is a printing hammer,
Reference numeral 2 is a carriage on which the print hammer 1 is mounted, and the carriage 2 is provided with a paper guide 2a for guiding the paper. Reference numeral 3 denotes a frame that holds the carriage 2 movably left and right, and the carriage 2 is driven by a stepping motor (not shown in the figure). Four
Is a sensor that is held by the frame 3 and detects that the carriage 2 is located at the home position. The home position is provided outside the moving range of the carriage 2 at the time of printing, and when the printer is powered on and initialized, the carriage 2 is moved to the home position, and thereafter the carriage 2 is positioned with reference to that position. Control. Therefore, the carriage 2 is not located at the home position after the initialization.

FIG. 5 is a side view of a main part of a conventional printing apparatus. Reference numeral 5 is a cylindrical platen that supports a sheet from the back side, and a paper guide 2a has a shape along the platen 5 and urges the sheet to the platen 5. To do. 6 is a gear that rotates integrally with the platen 5, 7 is an intermediate gear that is rotatably supported by the frame 3, and the intermediate gear 7 is provided with a worm 7a, a gear 7b, and a cam 7c that engage with the gear 6. There is. The worm 7a has teeth only within a certain angle range, and does not engage with the gear 6 in other parts,
One rotation of the intermediate gear 7 causes the gear 6 to rotate by one tooth. 8 is engaged with the cam 7c as shown in FIG.
This is a sensor that detects the rotational position of the intermediate gear 7. The sensor 8 outputs when the worm 7a is engaged with the gear 6.
Reference numeral 9 is a drive gear that engages with the gear 7b, and 10 is a DC motor that rotates the drive gear 9.

The operation of the conventional printing apparatus configured as described above will be described below. When you power on the printer,
First, the carriage 2 moves in the direction indicated by the arrow A, and when the output from the sensor A is detected, it is considered that the carriage 2 is located at the home position, and the subsequent position control of the carriage 2 is performed.

When feeding the paper, when the DC motor 10 is rotated, the sensor 8 starts outputting when the worm 7a engages with the gear 6, and the DC starts when the worm 7a leaves the gear 6 and the sensor 8 stops outputting. Stop the rotation of the motor 10. As a result, the intermediate gear 7 rotates once, the gear 6 advances by one tooth, and the platen 5 rotates.

[Problems to be Solved by the Invention] However, in the above-described conventional configuration, one sensor for initializing the carriage and one sensor for feeding the paper are required, and it is necessary to use two expensive sensors. , Was a cause of raising the price of the entire printing apparatus.

[Means for Solving the Problems] The present invention provides a carriage that is provided with a print head, is movable in a predetermined direction, a conveying unit that conveys print paper in a direction orthogonal to the moving direction of the carriage, and a conveying unit. And a detection mechanism that has a movable detection target member and outputs a signal by detecting that the detection target member has moved by a predetermined amount, and performs a printing operation based on the signal. In the printing device, the detection target member of the detection mechanism is configured to rotate in response to the rotation of the motor within a predetermined rotation angle range and the movement of the carriage within a predetermined movement range.

[Operation] With the above configuration, when the carriage moves in a predetermined direction to reach a predetermined position, and when the motor for transporting the paper rotates by a predetermined rotation angle, the detected member is located. A signal is output from the detection mechanism while moving by a fixed amount.

[Embodiment] FIG. 1 is a perspective view of a main part of a printing apparatus according to an embodiment of the present invention. 1 is a printing hammer, 2 is a carriage, 2a is a paper guide, 3 is a frame, 7 is an intermediate gear, and 10 is DC
These are motors and have the same structure as the conventional example. 11 is a shaft attached to the frame 3, 12 is swingably held around the shaft 11 on the frame 3, is provided with an iron piece 12a, and is biased in the direction indicated by the arrow B.
Is a lever that swings when it is at the home position, and 13 is a magnetic sensor that detects that the lever 12 swings and the iron piece 12a approaches.

FIG. 2 is a cross-sectional view of the main part of the printing apparatus of this embodiment.
Is a platen, 6 is a gear, 9 is a drive gear, and 10 is a DC motor, and these have the same configurations as in the conventional example.

The operation of the printing apparatus of the present embodiment configured as described above will be described below with reference to FIG. Similarly to the conventional example, when the printing apparatus is powered on, the carriage 2 is first moved to the home position by a motor different from the DC motor 10, and when the home position is reached, the paper guide 2a moves the lever 12 to the arrow. Rotate as indicated by C, magnetic sensor
13 outputs.

When feeding the paper, when the DC motor 10 is rotated, when the worm 7a engages with the gear 6, the cam 7c rotates the lever in the direction indicated by the arrow C, the magnetic sensor 13 starts outputting, and the worm 7a Is separated from the gear 6 and the lever 12 is returned to stop the output of the magnetic sensor 13 to stop the rotation of the DC motor 10. As a result, the intermediate gear 7b rotates once, the gear 6 advances by one tooth, and the platen 5 rotates. Here, the detection mechanism is
Paper guide 2a, intermediate gear 7, cam 7c, shaft 11, lever (member to be detected) 12, iron piece 12a (member to be detected), magnetic sensor
13 and the mechanism.

Since the paper guide 2a is provided to bring the paper into close contact with the platen 5, the paper guide 2a usually has a width wider than the carriage 2 along the axial direction of the platen 5. Therefore, when the carriage 2 is located at the home position, the end portion of the paper guide 2a comes closest to the frame 3 or is located outside the frame 3. The paper guide 2a is close to the platen 5. Therefore, the lever 12 can be provided in the vicinity of the frame 3 and the length thereof can be set to be short, so that the intermediate gear 7 can follow the high speed rotation.

EFFECTS OF THE INVENTION The present invention includes a detection mechanism that outputs a signal by detecting that the detected member has moved by a predetermined amount, and the detected member of this detection mechanism is within a range of a predetermined rotation angle. Since it is configured to move in response to the rotation of the motor and the movement of the carriage within a predetermined movement range, a detection mechanism is provided when the motor rotates by a predetermined angle or when the carriage moves to a predetermined position. Since a signal is output from the device, a single detecting means (sensor) can be shared by an extremely simple configuration.

[Brief description of drawings]

FIG. 1 is a perspective view of an essential part of a printer according to an embodiment of the invention, FIG. 2 is a side view of the essential part, FIG. 3 is a top view of the essential part, and FIG. 4 is a perspective view of the essential part of a conventional printer. FIG. 5 and FIG. 5 are side views of the relevant part, and FIG. 6 is a top view of the relevant part. 1 ... Printing hammer, 2 ... Carriage, 2a ... Paper guide, 3 ... Frame, 5 ... Platen, 6 ... Gear, 7 ... Intermediate gear, 7a ... Worm, 7b ... Gear, 7c ... Cam, 9 ... Drive gear, 10 ... DC motor, 11 ... Shaft, 12 ... Lever, 12a ... Iron piece, 1
3 ... Magnetic sensor.

Claims (1)

(57) [Claims] 1. A carriage provided with a print head and movable in a predetermined direction, a conveying means for conveying a print sheet in a direction orthogonal to the moving direction of the carriage, and a motor for driving the conveying means. A printing apparatus having a movable detected member, comprising a detection mechanism that outputs a signal by detecting that the detected member has moved by a predetermined amount, and performing a printing operation based on the signal. The detection device of the detection mechanism moves in response to rotation of the motor within a predetermined rotation angle range and movement of the carriage within a predetermined movement range.