JPH0586350B2 - - Google Patents

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention (first invention, second invention) provides a printing head that can be freely moved toward and away from a platen, and when feeding paper sheets, the printing head is moved. A part of the movable guide is placed in the middle of the print head to allow paper sheets to be fed between the platen and the print head, and after the paper has been fed, the movable guide is retracted out of the print head movement path to remove the print head from the print head. The present invention relates to a printing device that allows access to the platen.

[Conventional technology]

FIG. 6 shows an example of this type of printing device, in which a printing head 1 is provided so as to be movable toward and away from a platen 2 fixed at a fixed position. 3 in the diagram
is a movable guide, and when feeding paper sheets, this movable guide 3
A part of the paper sheet 4 is interposed in the movement path of the print head 1 to enable feeding of the paper sheet 4 between the platen 2 and the print head 1, and after feeding the paper sheet, the movable guide 3 is placed in the movement path of the print head 1. The print head 1 is retracted to the outside to allow the print head 1 to approach the platen 2 direction.

In addition, 5 in the figure is a fixed guide, and 6 is a paper sheet 4.
This is a belt-type conveyance mechanism for conveying. That is, a drive belt 8 is stretched between a pair of rollers 7a and 7b, and one of the rollers 7a is rotated by a motor (not shown) in the forward or reverse direction as appropriate.
Also, a pair of rollers 9a, 9 held in place
A rotary arm 10a, 10b is attached to each shaft of b, and the rotary end of each arm 10a, 10b supports movable rollers 11a, 11b, respectively. A driven belt 12 is wrapped around it. The driven belt 12 is normally pressed toward the drive belt 8 by springs 13a and 13b hooked to the rotating arms 10a and 10b, and when a sheet of paper 4 is inserted between both belts 8 and 12, both rotations occur. Arms 10a and 10b are springs 13
a and 13b, a gap is created between the drive belt 8 and the driven belt 12 by the thickness of the inserted paper sheet 4, and the paper sheet 4 is rotated by the rotating force of the roller 7a.
It is configured to send

In the figure, reference numeral 14 denotes a solenoid serving as a drive source for moving the movable guide 3 forward. This solenoid 1
The plunger 15 of No. 4 is connected to the movable guide 3 via transmission levers 16 and 17. Also,
The movable guide 3 is moved back out of the path of movement of the print head 1 by a return spring member 18. Note that 19 in the figure
is a guide roller that guides the movable guide 3.

[Problem that the invention seeks to solve]

In the conventional device described above, a solenoid is used as a drive source to move the movable guide 3 forward, so it is necessary to keep the solenoid energized while feeding paper sheets. However, there was a problem with high power consumption. Furthermore, in order to increase the amount of movement of the movable guide 3, a large solenoid 6 with a large stroke of the plunger 6a is required, resulting in the problem of increasing the size of the entire printing device.

The present invention has been made based on the above circumstances, and an object thereof is to provide a printing device that consumes less power in a drive source for driving a movable guide and that can be easily miniaturized.

[Means for solving problems]

Therefore, the printing device according to the first invention includes a platen fixed in a fixed position, a printing head that is movable toward and away from the platen, and a part of the printing head interposed in the movement path of the printing head to connect the platen and the printing head. A movable guide that allows paper sheets to be fed between the print head and the print head after the paper feed has been fed, and a movable guide that moves out of the print head movement path and allows the print head to approach the platen. A pulse motor that serves as a drive source for operation, a power transmission mechanism that transmits the power of this motor to the movable guide via a spring member and reciprocates the movable guide plate, and regulates the movement range of the movable guide. a stopper mechanism; a first sensor that detects when the movable guide reaches one end of its movement range; and a second sensor that detects when the movable guide reaches the other end of its movement range. and a control unit that detects with these first and second sensors that the movable guide has reached the end of its movement range, rotates the motor an extra predetermined number of pulses, and then stops the motor. configured.

Further, the printing device according to the second invention includes, in addition to the printing device according to the first invention, a spring member that returns the movable guide to a direction in which the movable guide is retracted out of the movement path of the printing head when the pulse motor is de-energized. It consists of

[Embodiments of the invention]

1 to 4 show an embodiment common to the first and second inventions, and FIGS. 1 and 2 show the structure of the print head 1 and the peripheral portions of the platen 2. FIG. 3, 4, and 5 in the figure are a movable guide, a paper sheet, and a fixed guide, respectively, similar to those in FIG. 6, and 6 in the figure is a belt-type conveyance mechanism.
This includes rollers 7a, 7b, 9a, 9b, 11a,
11b, belts 8, 12, rotating arms 10a, 10b
and springs 13a and 13b.
Further, reference numeral 19 in the figure is a guide roller that guides the movable guide 3.

In the figure, reference numeral 20 denotes a pulse motor serving as a drive source for reciprocating the movable guide 3, and a pulley 21 is directly connected to the rotating shaft of this motor 20.

On the other hand, 22 in the figure is a power transmission mechanism. This includes a transmission lever 23 whose rotation end is connected to the movable guide 3, a rotation lever 24 whose one end is rotatably mounted on the transmission lever 23, and the rotation lever 24 and the pulley 21. It is composed of two pulling wires 25a and 25b that connect the. In addition, 26a and 26b in the figure are each wire 25a and 25
This is the guide pulley that spans b.

The transmission lever 23 is rotatable about a shaft 27, and an engagement pin 29 provided on a portion of the movable guide is inserted into a long hole 28 provided at its rotation end.

Further, the rotary lever 24 is rotatable around a shaft 30 protruding from a part of the transmission lever 23,
As shown in FIG. 3, an engaging pin 31 provided at the rotating end is loosely inserted into a rectangular opening 32 provided in the movable guide. The amount of rotation of the rotation lever 24 relative to the transmission lever 23 is limited by the amount by which the engagement pin 31 can move within the opening 32.

As shown in FIG. 4a, one end of the one pulling wire 25a is fixed to a locking recess 33 provided in the pulley 21, and after being wound around the pulley 21, it is wound around the guide pulley 26a. , the other end is fixed to the engagement pin 31 to transmit rotation of the motor 20 in one direction to the rotation lever 24. Further, as shown in FIG. 4b, the other pulling wire 25b has one end fixed to the locking recess 33 of the pulley 21, and the one wire 25b is attached to the pulley 21.
After winding in the opposite direction to that of 5a, it is wound around the guide pulley 26b, and the other end is fixed to the engagement pin 31 to transmit the rotation of the motor 20 in the other direction to the rotation lever 24. It is. and both wires 25
Prepare wires a and 25b with the same length and specifications, and adjust the tension length of each wire as shown in Figure 4 a and 25b.
This is done by varying the amount of winding around the pulley 21, as shown in b. In other words, the pulley 21 when passing through one guide pulley 26a
If the distance from the pulley 21 to the engagement pin 31 is different from the distance from the pulley 21 to the engagement pin 31 when passing through the other guide pulley 26b, for example, when the traction wire 2 passes through one guide pulley 26a,
5a is wound 0.5 times around the pulley 21, and the pulling wire 25 passing through the other guide pulley 26b is wound 1.5 times.

Furthermore, two spring members, ie, tension springs 34a and 34b, are stretched between the engagement pin 31 of the rotary lever and the transmission lever 24 in a state in which the tension springs 34a and 34b are slightly biased. These springs 34a and 34b apply a tensile force to the rotating lever 24 from both sides, and maintain a balanced state in which the engaging pin 31 is positioned approximately at the center of the square opening 32 in its natural state. . Therefore, the rotational force of the motor 20 is transmitted to the movable guide 3 by the power transmission mechanism 22 via these tension springs 34a and 34b. Furthermore, if the engagement pin 31 is biased to either side as shown in FIG.
The transmission lever 23 receives rotational force from the stretched spring.

The movement range of the movable guide 3, that is, the rotation range of the transmission lever 23 is regulated by a pair of stopper members 35a and 35b constituting a stopper mechanism. Furthermore, the movable guide 3 is driven by a motor 20.
When the print head 1 is de-energized, the print head 1 is returned to the outside of the moving path by a return spring member, that is, a tension spring 36.

Furthermore, a light shielding piece 37 is attached to the movable guide 3, and by detecting the position of this light shielding piece 37 with first and second optical sensors 38a and 38b,
When the movable guide 3 reaches any terminal position, this is detected. The signals from each of the optical sensors 38a and 38b are input to the control section 39, and after receiving the signals, the control section 39 rotates the pulse motor 20 by one pulse or a plurality of pulses, and then stops the motor 20.

Next, the action will be explained.

When feeding a sheet of paper 4 between the platen 2 and the print head 1, the print head 1 is separated from the platen 2 as shown in FIG.
0 in the direction of the arrow in Figure 2. As a result, one of the pulling wires 25a is wound around the pulley 21, and the transmission lever 23 is rotated via the rotation lever 24, so that a part of the movable guide 3 is moved to the print head 1 as shown by the imaginary line in FIG. be located in the path of travel.
At this time, the transmission lever 23 comes into contact with the stopper member 35a and stops, and at the same time, the first optical sensor 38a detects the light shielding piece 37 and outputs it to the control section 39.
From that point on, the control unit 39 rotates the pulse motor 20 an additional predetermined number of pulses, and then stops the pulse motor 20. Therefore, one of the tension springs 34a applies a rotational force to the transmission lever 23 in the clockwise direction in the figure, thereby stably holding the movable guide 3.

Here, when the roller 7a of the belt type conveyance mechanism 6 is rotated and the paper sheet 4 is inserted between the belts 8 and 12, the paper sheet 4 is held between both the belts 8 and 12, and the fixed guide 5 and the movable guide 3 The paper is guided between the printing head 1 and the platen 2.

After the sheet 4 has been fed in this manner to such an extent that its end does not come off the belts 8, 12, the pulse motor 20 is rotated in the opposite direction. As a result, the other pulling wire 25b is wound around the pulley 21, and the transmission lever 23 is moved through the rotation lever 24.
is rotated to move the movable guide 3 out of the path of movement of the print head 1 and return it to the position shown in solid line in FIG. At this time, the transmission lever 23 comes into contact with the stopper member 35b and stops, and at the same time, the second optical sensor 38b detects the light shielding piece 37 and the control unit 39
However, the control section 39 rotates the pulse motor 20 for one additional pulse from that point, and then stops the pulse motor 20. Therefore, the other tension spring 34b applies a rotational force to the transmission lever 23 in the counterclockwise direction in the figure, thereby stably holding the movable guide 3.

The configuration of the above embodiment provides the following effects.

Since the drive source for driving the movable guide 3 is the pulse motor 20, the movable guide can be driven and held at a predetermined position with low power consumption.

Even if the moving amount of the movable guide 3 is the same, there is no need to make the motor 20 large, so the entire device can be downsized.

Also, after the movable guide 3 reaches the predetermined position,
By rotating the motor 20 by a predetermined amount of pulses and breaking the balance between the two tension springs 34a and 34b, the elasticity of the stretched spring is used to apply rotational force to the movable guide 3. The movable guide 3 can be held more stably.

Furthermore, by providing a tension spring 36 for biasing the movable guide 3 in the return direction, the movable guide 3 is partially interposed between the printing head 1 and the platen 2, so that it can be used even during a power outage. Even when the pulse motor 20 is de-energized, this spring 36
Since the movable guide 3 can be immediately returned to its original position, there is no possibility that the print head and the movable guide 3 will interfere with each other at the start of the next printing operation.

〔Effect of the invention〕

As described in detail above, according to the printing device according to the first invention, since the drive source for driving the movable guide is a pulse motor, the power consumption for driving the movable guide can be reduced, and the movable guide Regardless of the amount of movement, there is no need to increase the size of the pulse motor that is the drive source, and the overall size can be reduced.

According to the second invention, in addition to the first invention,
By providing a spring member to bias the movable guide in the return direction, even if the motor is de-energized while a part of the movable guide is interposed between the print head and the platen, this The spring member allows the movable guide to be immediately returned to its original position, resulting in an excellent effect in that there is no possibility of interference between the print head and the movable guide at the start of the next printing operation.

[Brief explanation of the drawing]

Figures 1 to 4 show the present invention (first invention, second invention).
Fig. 1 is a perspective view showing a part of the printing device, Fig. 2 is a schematic side view showing a part of the printing device, and Fig. 3 shows a transmission lever and a rotation lever. 4a and 4b are side views showing the winding state of the traction wire around the pulley,
FIGS. 5a and 5b are explanatory views of the operation, and FIG. 6 is a partially schematic side view of a conventional printing device. 1... Print head, 2... Platen, 3... Movable guide, 4... Paper leaf, 20... Pulse motor,
21... Pulley, 22... Power transmission mechanism, 25
a, 25b... traction wire, 34a, 34b...
Tension spring (spring member), 35a, 35b...stopper member (stopper mechanism), 36...tension spring (returning spring member), 38a...first optical sensor, 38b...second optical sensor, 39 ...control section.

Claims (1)

[Scope of Claims] 1. A platen fixed at a fixed position, a print head that can be freely moved into and out of the platen, and a portion between the platen and the print head with a portion interposed in the movement path of the print head. A movable guide that enables the supply of paper sheets to the printing head and, after supplying the paper sheets, retreats out of the print head movement path and allows the print head to approach the platen direction, and a movable guide that moves the movable guide back and forth. a pulse motor serving as a drive source; a power transmission mechanism that transmits the power of the motor to the movable guide via a spring member and causes the movable guide to reciprocate;
a stopper mechanism for regulating the movement range of the movable guide; a first sensor for detecting when the movable guide has reached one end of the movement range; and a first sensor for detecting when the movable guide has reached the other end of the movement range. and a second sensor that detects this, and after the first and second sensors detect that the movable guide has reached the end of its movement range and rotate the motor an extra predetermined number of pulses. A printing device characterized by comprising a control section for stopping the printing device. 2. The printing device according to claim 1, wherein the power transmission mechanism is a wire type power transmission mechanism using a pulling wire. 3 The traction wire of the power transmission mechanism is a movable guide forward wire and backward wire of the same length,
3. The printing device according to claim 2, wherein the tension length of each wire is adjusted by adjusting the amount of winding around a pulley directly connected to the pulse motor. 4. A platen fixed in a fixed position, a print head that can move toward and away from the platen, and a part of the print head interposed in the movement path to supply paper sheets between the platen and the print head. A movable guide that moves out of the print head's movement path after paper sheets are fed and allows the print head to approach the platen, and a pulse that serves as the drive source for reciprocating the movable guide. a motor; a power transmission mechanism that transmits the power of the motor to the movable guide via a spring member and causes the movable guide to reciprocate;
a stopper mechanism for regulating the movement range of the movable guide; a first sensor for detecting when the movable guide has reached one end of the movement range; and a first sensor for detecting when the movable guide has reached the other end of the movement range. and a second sensor that detects this, and after the first and second sensors detect that the movable guide has reached the end of its movement range and rotate the motor an extra predetermined number of pulses. A printing device comprising: a control unit for stopping the pulse motor; and a spring member for returning the movable guide to a direction in which the movable guide is retracted out of the movement path of the print head when the pulse motor is de-energized.