JPH0761633B2 - Cutter drive - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cutter driving device that drives a cutter for cutting roll paper or the like in a facsimile, a copying machine or the like.

2. Description of the Related Art Conventionally, a rotary cutter is often used to cut roll paper. The drive of this rotary cutter includes a method of rotating the cutter in one direction and a method of reciprocating the cutter within a predetermined angle range. In the method in which the cutter is rotated in one direction, it is necessary to stop the cutter at a certain angular position after cutting, and a mechanism therefor is required (for example, see Japanese Utility Model Laid-Open No. 60-45695). But,
In this method, there is a problem that the mechanism for stopping the cutter at a certain angular position becomes complicated.

As shown in FIG. 5, a conventional device of a type in which a cutter is reciprocally rotated within a predetermined angle includes a movable cutter 2 that cuts a recording sheet 1 in cooperation with a fixed blade (not shown), and a cutter 2. A fan gear 3 connected to the fan gear 3, a drive gear 4 meshing with the fan gear 3, a drive motor 5 for the fan gear 3, a position detection sensor 6 for the fan gear 3, and a signal from the position detection sensor 6 It has a control circuit (not shown) for controlling the forward rotation and the reverse rotation of the drive motor 5. Here, as the position detecting sensor 6, a photo interrupter composed of a light emitting element 6a and a light receiving element 6b is usually used as shown in FIGS. 6 (A) and 6 (B), and a side surface of the fan gear 3 is used. Is provided with a light shielding plate 7 at a position facing the photo interrupter. The light shield plate 7 does not shield the position detection sensor 6 when the sector gear 3 is at the steady position (standby position) and at the cutting operation end position, but shields the position detection sensor 6 at a position in the middle thereof. It is located in. Normally, the sector gear 3 is stopped at the steady position shown in FIG. 6 (A), and the light receiving element 6b receives the light from the light emitting element 6a. When the cutting command is applied to the motor 5, the motor rotates in the normal rotation direction, and the sector gear 3 rotates in the normal rotation direction indicated by the arrow A to perform the cutting operation. During this cutting operation, the light receiving element 6b is shielded by the light shielding plate 7 and does not receive light. When the sector gear 3 rotates by a predetermined stroke and the cutting operation is completed, the light shielding plate 7 passes between the light receiving element 6a and the light emitting element 6b and reaches the cutting end position shown in FIG. 6 (B). Light again passes through the light-receiving element 6a, which detects the end of the cutting operation, and the motor 5 reverses in response to the detection signal. Thus, the fan gear 3 is rotated in the direction of the arrow B to return to the original position, and the light receiving element 6a detects that the fan gear 3 has returned to the original steady position.
Stop and wait for the next disconnect.

However, according to such a conventional configuration, when the fan gear 3 is moved to the cutting operation end position and the power is cut off for some reason, a problem may occur. . That is, as shown in FIG. 6 (B), when the fan gear 3 is turned off at the cutting end position, the light receiving element 6a of the position detection sensor 6 receives light when the power is turned on next time. The circuit determines that the sector gear 3 is in the steady position. Therefore, when the cutting operation command is added, the motor 5
However, there is a problem that it rotates in the forward direction, which is the direction opposite to the arrow B, and places a burden on each place.

The present invention has been made in view of the above problems, and when the power is turned on, it is determined whether or not the fan gear for driving the cutter is in the steady position, and if it is not in the steady position, the fan gear is steady. An object of the present invention is to provide a drive device for a cutter that can be returned to the position.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention uses a stepping motor as a driving source of a sector gear connected to a cutter to be driven, and detects only a steady position of the sector gear. A sensor is provided, and further, control means is provided for positioning the fan gear at a steady position in accordance with a signal from the sensor and controlling the stepping motor so that the fan gear reciprocates a predetermined distance from the steady position. It has a configuration.

According to the present invention, with the above-described configuration, the sensor detects that the fan gear is not in the steady position, and the control means reversely and normally rotates the stepping motor until the sensor detects the steady position of the fan gear. The gear can be moved, which allows the sector gear to be positioned in a stationary position. Also, after the fan gear is positioned at the steady position,
The control means rotates the stepping motor forward by a predetermined number of steps, drives the fan gear and the cutter connected thereto to perform the cutting operation, and when the driving of the predetermined number of steps is completed, the control means reverses the stepping motor. , Drive the stepping motor by the same number of steps. As a result, the sector gear can reciprocate a predetermined distance from the steady position to perform the cutting operation and return to the original steady position.

Embodiment FIG. 1 is a schematic perspective view of a cutter driving device according to an embodiment of the present invention, in which the same parts as those of the conventional example shown in FIG. In FIG. 1, 1 is a recording paper to be cut, 2 is a movable cutter that cuts the recording paper 1 in cooperation with a fixed blade (not shown), 3 is a fan-shaped gear connected to the cutter 2, Reference numeral 4 is a drive gear that meshes with the sector gear 3. Reference numeral 10 is a stepping motor for driving the drive gear 3, and 11 is a fixed position sensor for detecting the steady position of the sector gear 3, which is arranged to face the side surface of the sector gear 3. As the fixed position sensor 11, as shown in FIG. 3 (A), a photo interrupter including a light emitting element 11a and a light receiving element 11b is used. The side surface of the sector gear 3 has a light emitting element 11a and a light receiving element 11b.
The light shielding plate 12 is attached at a position where the light shielding plate 12 can be traversed between and. The light shielding plate 12 is provided so as to block the light emitting element 11a from the light receiving element 11b only when the sector gear 3 is in the steady position. Therefore, the fixed position sensor 11 has the sector gear 3 in the steady position. It is possible to detect whether or not there is.

FIG. 2 is a block diagram showing a control system for the stepping motor 10. Reference numeral 14 is a motor drive circuit, and 15 is a control circuit composed of a microcomputer for controlling the stepping motor 10 via the motor drive circuit 14. The control circuit 15 inputs a signal from the fixed position detection sensor 11 and performs the following control operation.

The operation of the cutter driving device having the above configuration will be described below.

Usually, as shown in FIG. 3 (A), the sector gear 3 connected to the cutter 2 is stopped at a steady position. When the power is turned on in this state, the fixed position sensor 11 outputs an ON signal to detect that the sector gear 3 is in the steady position. During the cutting operation, after detecting that the sector gear 3 is in the steady position, the control circuit 15 causes the stepping motor 10 to rotate in the normal direction,
The sector gear 3 is driven in the direction of arrow A. At this time, the control circuit 15 counts the number of steps applied to the stepping motor 10. When the number of steps in which the fan gear 3 moves to the operation end position shown in FIG. The motor 10 is reversed and the same number of steps as in the normal rotation is applied to the stepping motor 10 to move the sector gear 3 in the direction of arrow B and return it to its original position. As a result, the sector gear 3 reciprocates a predetermined stroke required for cutting, and the cutter 3 performs the cutting operation.

Next, for some reason, the sector gear 3 may be stopped at a position other than the steady position. In that case, the control circuit 15
Drives the stepping motor 10 to position the sector gear 3 at a steady position. The operation will be described with reference to the operation flow chart of FIG. Now, it is assumed that the sector gear 3 is overrun at a stationary position and stopped (see FIG. 3 (C)). First, in step a, it is determined whether the signal from the fixed position sensor 11 is on. In the state of FIG. 3 (C), the signal of the fixed position sensor 11 is naturally off, so the process proceeds to step b, and the stepping motor 10 is rotated in the normal direction by a small fixed amount. As a result, the sector gear 3 moves a small amount in the direction of arrow A. Until the normal rotation amount of the stepping motor 10 exceeds the specified amount, the process returns to step a and the constant position sensor signal is determined. If this signal is still off, the stepping motor 10 is again rotated forward by a fixed amount and the constant position sensor signal is judged. While this operation is repeated, the fan gear 3 always reaches the steady position and the fixed position sensor signal is turned on. In that case, the process moves to step h and waits for the cutting operation.

Next, it is assumed that the sector gear 3 is stopped between the steady position and the operation end position, as shown in FIG. 3 (D). Also in this case, the steps a, b, and c are repeated, and the sector gear 3 moves in the arrow A direction. However, in this case, the fan gear 3 does not reach the steady position due to the movement in the arrow A direction. Therefore, the normal rotation amount of the stepping motor exceeds the predetermined regulation amount. In addition,
The prescribed amount in step c is small enough to return the overrunning fan gear 3 to the steady position as shown in FIG. 3C, and the fan gear 3 greatly exceeds the operation end position. It prevents them from moving. If it is determined in step c that the specified amount has been exceeded,
Moving to step d, the stepping motor 10 is reversely rotated by a certain amount. As a result, the sector gear 3 moves a small amount in the direction of arrow B. Then, in step e, the fixed position sensor signal is determined. Until the amount of reverse rotation of the stepping motor 10 exceeds the specified amount, the process returns to steps d and e to determine the fixed position sensor signal. If this signal is still off, the stepping motor 10 is again reversed a certain amount and the constant position sensor signal is determined. While this operation is repeated, the fan gear 3 always reaches the steady position and the fixed position sensor signal is turned on. In that case, the process moves to step h and waits for the cutting operation. Here, the specified amount in step f is set so that the fan gear 3 can return to the steady position regardless of the position of the stop. If the fixed position sensor signal does not turn on and the prescribed amount is exceeded in step f, there is some abnormality, so the process moves to step g and an alarm signal is output.

EFFECTS OF THE INVENTION As is apparent from the above description, the present invention uses a stepping motor as a drive source of a sector gear connected to a cutter, and a sensor that detects only a steady position of the sector gear, and from this sensor. When the fan gear is not in the steady position, the control means for controlling the stepping motor is provided so that the fan gear is positioned at the steady position in accordance with the signal of and the fan gear reciprocates a predetermined distance from the steady position. The sensor detects this, and the control means rotates the stepping motor in the reverse and forward directions to move the fan gear until the sensor detects the steady position of the fan gear, thereby reliably positioning the fan gear at the steady position. In addition, after the sector gear is positioned at the steady position, the control means causes the stepping motor to move to a predetermined number of steps. By rotating the fan gear and the cutter connected to the fan gear reciprocally by the stroke required for cutting, the cutting operation can be performed. Therefore, unlike the conventional case, it is possible to avoid the inconvenience of mistakenly determining that the fan-shaped gear stopped at the operation end position is stopped at the steady position, immediately moving to the cutting operation and burdening each place, always,
It has an effect that a reliable cutting operation can be performed.

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing a cutter driving device according to an embodiment of the present invention, FIG. 2 is a block diagram showing its control system, and FIGS. 3 (A), (B), (C) and (D). Is a schematic side view showing various positions of the sector gear with respect to the fixed position sensor in the above embodiment, FIG. 4 is an operation flow chart for positioning the sector gear in a steady position in the above embodiment, and FIG.
FIG. 6 is a schematic perspective view showing a conventional cutter driving device, and FIGS. 6 (A) and 6 (B) are schematic side views showing the positional relationship of a sector gear with respect to a position detection sensor in the conventional device. 1 ... Recording paper, 2 ... Cutter, 3 ... Fan gear, 4 ...
… Drive gear, 10 …… Stepping motor, 11 …… Position sensor, 11a …… Light emitting element, 11b …… Light receiving element, 12 …… Light shielding plate.

Claims (1)

[Claims] 1. A fan gear connected to a cutter to be driven, a drive gear that meshes with the fan gear, a stepping motor that drives the drive gear, a sensor that detects a steady position of the fan gear, and the sensor. And a control means for controlling the stepping motor so that the sector gear is positioned at a steady position and reciprocates a predetermined distance from the steady position in response to a signal from the cutter drive device.