JPH04223940A - Serial printer - Google Patents

Abstract

PURPOSE:To transmit and cut the driving force of a paper feeding motor to a picking roller selectively with the simple structure. CONSTITUTION:An arm 19 abuts on a moving gear 17 with the movement of a carrier 13 to the home position, and the moving gear 17 is engaged with both of a picking gear 16 and a gear 19, resisting the energizing force of a compression coil spring 18, and the rotating force of the gear 9 is thereby transmitted to the picking gear 16, and a picking roller 3 is rotated for drive by the driving force of a paper feeding motor 11. The moving gear 17 is removed from the picking gear 16 and the gear 9 by the energizing force of the compression coil spring 18 with the movement of the carrier 13 to the central part, and transmission of the rotating force form the gear 9 to the picking gear 16 is thereby cut off to cut of the transmission of the driving force to the picking roller 3.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a serial printer in which a carrier carrying a print head is reciprocated in a direction perpendicular to a paper feeding direction.

0002

2. Description of the Related Art Some serial printers have a picking roller that takes out the uppermost recording paper in a paper storage section and is rotationally driven by a paper feed motor.

[0003] In this type of serial printer, after the recording paper is taken out from the paper storage unit and handed over to the paper feed roller, the transmission of the driving force from the paper feed motor to the picking roller is cut off and the paper is fed redundantly. There is no such thing. Conventionally, the mechanism for this purpose is to use an electromagnetic clutch that can selectively transmit or cut off the driving force of the paper feed motor to the picking roller. The transmission of the driving force from the paper feed motor to the picking roller is cut off after it is taken over by the roller.

0004

[Problems to be Solved by the Invention] However, the electromagnetic clutch has a complicated structure, which not only increases cost but also hinders miniaturization of the entire printer.

SUMMARY OF THE INVENTION An object of the present invention is to provide a serial printer in which the driving force of a driving means for a paper feeding device such as a paper feeding motor can be selectively transmitted to and cut off from a picking roller with a simple structure.

[0006]

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a paper feeding device for transporting recording paper, a carrier that is reciprocated in a direction perpendicular to the transport direction of the recording paper, and
This serial printer is equipped with a print head that is mounted on the carrier and records characters, etc. on recording paper, and includes a paper storage section that stores the recording paper, and a picking roller that takes out the uppermost recording paper in the paper storage section. , a picking gear that transmits rotational force to the picking roller, a drive gear that is rotationally driven by the drive means of the paper feed device, and a movable gear that is freely displaceable so as to selectively transmit or cut off the rotational force of the drive gear to the picking gear. A moving gear is provided at a blocking position where the rotational force of the driving gear is not transmitted to the picking gear during printing operation, and a driving gear is provided to move the moving gear in conjunction with the displacement of the carrier when the carrier moves to the home position. and a displacement means for displacing the rotational force of the gear to a transmission position for transmitting the rotational force to the picking gear.

[0007]

[Operation] According to the present invention, when taking out recording paper from the paper storage section, by moving the carrier to the home position, the moving gear is moved to the transmission position where the rotational force of the drive gear is transmitted to the picking gear by the displacement means. The picking roller is rotated by the driving force of the driving means of the paper feeding device, and the uppermost recording paper in the paper storage unit can be taken out. ◆During the printing operation, the movable gear is located at the blocking position where the rotational force of the driving gear is not transmitted to the picking gear, and the transmission of the driving force to the picking roller is cut off, and the recording paper is stored by the picking roller. It cannot be taken out from within the department.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a serial printer to which the present invention is applied. ◆In this serial printer, a picking roller 3 is disposed facing above the paper storage section 2 that stores the recording paper 1, and the picking roller 3 takes out the uppermost recording paper 1 in the paper storage section 2, and then The recording paper 1 is fed between a print head 5 and a platen 6 by a paper feed roller 4 serving as a paper feed device, so that the print head 5 can record characters, etc. on the recording paper 1.

The paper feed roller 4 is integrally attached to a roller shaft 4a, and is rotatably supported by the printer frame 7 via the roller shaft 4a. The paper feed roller 4 is rotatably driven by the driving force of a paper feed motor 11 as a drive means of a paper feed device via gears 8, 9, and 10. The gear 8 is integrally attached to the roller shaft 4a and is capable of transmitting rotational force to the paper feed roller 4. The gear 9 is rotatably supported by the printer frame 7 via a support shaft 9a, and is meshed with the gear 8. The gear 10 is integrally attached to the drive shaft 11a of the paper feed motor 11 and is meshed with the gear 9.

A driven roller (not shown) is in elastic contact with the paper feed roller 4, and the recording paper 1 can be conveyed while being held between the driven roller and the driven roller. A paper sensor 12 is provided between the paper feed roller 4 and the print head 5, so that the paper sensor 12 can detect when the recording paper 1 reaches this position. The paper sensor 12 is a so-called reflective sensor having a light emitting element and a light receiving element, and is attached to the printer frame 7.

[0011] The print head 5 is mounted on a carrier 13,
It is designed to be able to move together with the carrier 13. The carrier 13 is slidably fitted onto a pair of guide shafts 14 and supported by the printer frame 7 via the guide shafts 14 so as to be movable in a direction orthogonal to the paper feeding direction. This carrier 13 can be driven to travel along a guide shaft 14 by the driving force of a carrier motor 15 (shown in FIG. 2) via a driving force transmission means (not shown).

The platen 6 is fixed to the printer frame 7 so as to face the print head 5, and extends in a direction perpendicular to the paper feeding direction.

To explain the driving mechanism of the picking roller 3, the picking roller 3 is integrally attached to a roller shaft 3a, and rotatably supported by the printer frame 7 via the roller shaft 3a. The picking roller 3 can be rotated by the driving force of the paper feed motor 11 via a picking gear 16, a moving gear 17, and gears 9 and 10 as the carrier 13 moves.

The picking gear 16 is integrally attached to one end of the roller shaft 3a so that rotational force can be transmitted to the picking roller 3. The picking gear 16 has the same structure as the gear 9, is arranged coaxially with the gear 9, and is rotatable independently of the gear 9.

The moving gear 17 is rotatably and axially slidably attached to a support shaft 17a, and the picking gear 16 and the gear 9 are connected to the printer frame 7 via the support shaft 17a.
The picking roller 3 is slidably and rotatably supported parallel to the roller shaft 3a of the picking roller 3. The movable gear 17 can be displaced by a sliding motion to an engagement position where it meshes with both the picking gear 16 and the gear 9, and a disengagement position where it disengages from both the picking gear 16 and the gear 9. That is, the moving gear 17 transfers the rotational force of the gear 9 to the picking gear 16 by sliding motion.
can be selectively transmitted and blocked. A compression coil spring 18 is wound around the support shaft 17a of the movable gear 17, and the compression coil spring 18 biases the movable gear 17 in a direction away from both the picking gear 16 and the gear 9.

Therefore, the movable gear 17 can mesh with both the picking gear 16 and the gear 9 against the urging force of the compression coil spring 18.

The carrier 13 has an arm 19 projecting rearward.
is integrally attached as an example of a displacement means, and this arm 1
9, a moving gear 17 can be actuated. When the carrier 13 moves to the home position on one side, the arm 19 comes into contact with the moving gear 17 and moves the moving gear 17 against both the picking gear 16 and the gear 9 against the biasing force of the compression coil spring 18. It is designed to be able to move in the direction of engagement. When the carrier 13 reaches the home position, the moving gear 1 is moved by the arm 19.
7 is held in a position where it meshes with both the picking gear 16 and the gear 9 against the biasing force of the compression coil spring 18, that is, in a transmission position where the rotational force of the gear 9 is transmitted to the picking gear 16. (the state shown by the two-dot chain line in Figure 1). Further, the arm 19 is configured not to come into contact with the moving gear 17 within the movement range of the carrier 13 during the printing operation. Therefore, during the printing operation, the movable gear 17 is held in the detached position where it is separated from both the picking gear 16 and the gear 9 by the biasing force of the compression coil spring 18, that is, in the blocking position where the rotational force of the gear 9 is not transmitted to the picking gear 16. (The state shown by the solid line in FIG. 1). In addition, a notch 19a for relief is formed in the arm 19, and a support shaft 17a is attached to this notch 19a.
is inserted so that the movable gear 17 moves in a direction in which it meshes with both the picking gear 16 and the gear 9.

In the drive mechanism for the picking roller 3 constructed as described above, its operation is controlled by a control device 20 shown in FIG. Control device 2
A paper sensor 12, a paper feed motor 11, and a carrier motor 15 are connected to the motor 0.

The operation of the driving mechanism for the picking roller 3 will be explained below based on the flowchart shown in FIG. ◆When a picking command is received in step 21, the carrier motor 15 is driven in step 22 to move the carrier 13 to one home position.

[0020] During this movement, the carrier 13
The arm 19 contacts the moving gear 17, and the moving gear 17 moves in the direction of meshing with both the picking gear 16 and the gear 9 against the urging force of the compression coil spring 18, and the carrier 13 reaches the home position. Then, the moving gear 17 is meshed with both the picking gear 16 and the gear 9 (
(state shown by the two-dot chain line in Figure 1).

After the carrier 13 has been moved to the home position, the paper feed motor 11 is driven in step 23. As a result, the paper feed roller 4 is rotationally driven via the gears 8, 9, and 10, and at the same time, the picking roller 3 is rotationally driven via the gears 9, 10, the moving gear 17, and the picking gear 16. The uppermost recording paper 1 in the paper storage section 2 is taken out.

After taking out the recording paper 1 from the paper storage section 2, it is determined in step 24 whether or not the paper sensor 12 is on, and if the paper sensor 12 is off, the paper sensor 12 is turned on. Wait until. When the paper sensor 12 is on, the carrier motor 15 is driven in step 25 to move the carrier 13 from the home position to the center. During this movement, the movable gear 17 follows the arm 19 of the carrier 13 by the biasing force of the compression coil spring 18 and moves in a direction away from both the picking gear 16 and the gear 9, and when the carrier 13 reaches the center,
The arm 19 of the carrier 13 separates from the moving gear 17, and the moving gear 17 is separated from both the picking gear 16 and the gear 9 by the urging force of the compression coil spring 18, and the rotational force is no longer transmitted from the gear 9 to the picking roller 3. (state shown by the solid line in FIG. 1).

At this time, the paper feed roller 4 has gears 8, 9,
The recording paper 1 is continuously rotated by the driving force of the paper feed motor 11 via the paper feed roller 10 , and the recording paper 1 is fed between the print head 5 and the platen 6 by the paper feed roller 4 . Therefore, after the transmission of the rotational force from the gear 9 to the picking roller 3 is interrupted, the picking roller 3 is rotated by the frictional force with the recording paper 1.

After the carrier 13 moves to the center, it is determined in step 26 whether or not the recording paper 1 has been fed by a predetermined amount, and if the recording paper 1 has not been fed by a predetermined amount, the recording paper 1 is Wait until a fixed amount is fed. The predetermined amount here is the feed amount that allows the print head 5 to print on the recording paper 1, and the determination as to whether or not the recording paper 1 has been fed by the predetermined amount is made by the timer after the paper sensor 12 is turned on. Alternatively, a sensor may be provided downstream of the print head 5, and this sensor may detect the leading edge of the recording paper 1. This may be done by detecting the position.

When the recording paper 1 has been fed by a predetermined amount, the drive of the paper feed motor 11 is stopped in step 27. As a result, the rotation of the paper feed roller 4 is stopped, and the feeding of the recording paper 1 is stopped.
is provided for printing. During printing, the carrier motor 15 is driven to move the carrier 13 in a direction perpendicular to the paper feeding direction, but this movement is performed within a range where the arm 19 of the carrier 13 does not come into contact with the moving gear 17. Inside, the movable gear 17 is held in a blocking position where the rotational force of the gear 9 is not transmitted to the picking gear 16 by the biasing force of the compression coil spring 18, and the next recording paper 1 is stacked from the paper storage section 2 by the picking roller 3. It is never taken out. Note that the above operation is repeated when printing on the next recording paper 1.

As described above, in this embodiment, the driving force of the paper feed motor 11 is applied to the picking roller 3 by using a gear mechanism with a simple structure and the displacement of the carrier 13, without using a conventional electromagnetic clutch. Can be selectively transmitted and blocked.

In the above embodiment, the moving gear 17 is supported on the printer frame 7, but the moving gear 17 may be attached to the carrier 13 and moved together with the carrier 13.

Furthermore, in the above embodiment, the picking gear 1
6 is installed coaxially with gear 9, but picking gear 16
may be arranged side by side of the gear 9.

Furthermore, in the above embodiment, the movable gear 17 is separated from both the picking gear 16 and the gear 9 so that the rotational force of the gear 9 is not transmitted to the picking gear 16. For example, the moving gear 17 may be separated only from the gear 9 so that the rotational force of the gear 9 is not transmitted to the picking gear 16.

In the above embodiment, the movable gear 17 is provided so as to be slidable via the support shaft 17a, but the movable gear 17 is attached to a swingable lever so that when the carrier 13 moves to the home position, the movable gear 17 The movable gear 17 may be displaced to a position where it meshes with both the picking gear 16 and the gear 9 by swinging.

Furthermore, in the above embodiment, the driving of the paper feed motor 11 is temporarily stopped when the recording paper 1 is fed by a predetermined amount (FIG. 3, step 27). After feeding, the paper feed motor 11 is continuously controlled to enable line feed, and after printing of one sheet of recording paper is completed, the paper feed motor 1 is
1 may be stopped.

[0032]

As explained above, according to the serial printer according to the present invention, the driving force of the driving means of the paper feeding device is transferred to the picking roller using a gear mechanism with a simple structure and the displacement of the carrier or print head. Since the picking roller can be selectively transmitted and cut off, the driving mechanism of the picking roller is simplified, and it has the excellent effect of being able to be manufactured at low cost and downsized.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of main parts of a serial printer to which the present invention is applied.

FIG. 2 is a circuit block diagram of a driving mechanism for the picking roller in FIG. 1;

FIG. 3 is a flowchart showing the operation of the picking roller drive mechanism in FIG. 1;

[Explanation of symbols]

1 Recording paper 2 Paper storage section 3 Picking roller 4 Paper feed roller (paper feed device) 5
Print head 9 Gear (drive gear) 11 Paper feed motor (drive means) 13 Carrier 16 Picking gear 17 Moving gear 19 Arm (displacement means)

Claims (1)

[Claims] 1. A paper feeding device that conveys recording paper, a carrier that is reciprocated in a direction perpendicular to the conveyance direction of the recording paper, and a print head that is mounted on the carrier and records characters, etc. on the recording paper. A serial printer comprising: a paper storage section that stores recording paper; a picking roller that takes out the uppermost recording paper in the paper storage section; a picking gear that transmits rotational force to the picking roller; A drive gear is rotatably driven by the drive means of the feeding device, and is displaceably disposed so as to selectively transmit or cut off the rotational force of the drive gear to the picking gear, and the rotation of the drive gear is controlled during printing operation. A movable gear positioned at a cutoff position that does not transmit force to the picking gear, and a movable gear positioned at a blocking position that does not transmit force to the picking gear, and when the carrier moves to the home position, the movable gear is connected to the rotational force of the drive gear in conjunction with the displacement of the carrier. A serial printer comprising: displacement means for displacing the transmission to a transmission position to transmit the transmission to the picking gear.