JPS585790B2 - printer detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a detection device for a printer, and more particularly to a detection device that controls a printer by bringing a detection brush into contact with a detection plate.

A conventional small printer is shown in Figures 1 and 2.
This will be explained using the time chart shown in the figure.

Reference numeral 1 denotes a printer driving motor, and a series of printing operations is started when the motor starts to be energized.

2 is a motor gear, 3 is a reduction gear that rotates approximately once per printing cycle, 4, 5, 6, and 11 are transmission gears, and 7 is provided with a tooth portion and a notch portion of the diameter of the tooth bottom in a part of the circumference. 8 is an intermittent gear with a part of the gear cut out; 9 is a type wheel disposed on the intermittent gear 8 and having type letters on its circumference from which arbitrary characters can be selected by a type wheel selection mechanism; 10 1 is a coil spring having one end fixed to the intermittent gear 8 and the other end fixed to the frame, and 12 is a printing gear having the same rotation ratio as the intermittent drive gear 7.

13 is a crankshaft engaged with the printing gear; 14 is a printing roller that is engaged with the crankshaft 13 and prints while rolling on the type sheet of the type wheel 9; 15 is printing paper; 16 is a ribbon;
2 is a type wheel shaft that supports the type wheel 9; 23 is a type wheel shaft 22;
a detection plate having a plurality of grooves, 24 a light emitting element;
25 is a light receiving element.

The principle of this operation will be explained.

When the power is turned on as shown in Figure 2, Figure 1 shows the standby state, but before the power is turned on, we do not know in what state it is stopped, so at most one line or more is empty as shown in Figure 2. Rotation A1 is provided and stopped in a standby state.

The printer and drive motor 1 are activated by the print command shown in Figure 2.
is driven, and the intermittent drive gear 7 begins to rotate in the direction of arrow 17, and the teeth on the intermittent drive gear 7 and the teeth on the intermittent gear 8 begin to mesh, and the intermittent gear 8 rotates in the direction of the arrow 18 with the coil spring 10.
It rotates while winding up.

When the intermittent gear 8 rotates, the type wheel 9 also starts rotating, and the detection plate 23 shown in FIG.
12) also occurs and a character is selected by the type wheel selection mechanism.When the intermittent drive gear 7 continues to rotate and the character selection is completed, the intermittent drive gear 7 and the intermittent gear 8 are disengaged, and the intermittent gear 8 is Because of the uncut portion 19 of the intermittent drive gear 7, the coil spring 10 is locked in a wound state.

At this time, the printing roller 14 is rotating in synchronization with the intermittent drive gear 7, and when the selection of the type wheel 9 is completed and the intermittent gear 8 is locked, the printing roller 14 rolls over the selected type and the printing paper 15 The printing process involves printing on the

When the printing is completed, the locking of the intermittent gear 8 is completed due to the notch in the bottom diameter of the intermittent drive gear 7, and the coil spring 10 returns to the standby position.

At the same time, the type wheel 9 also returns to its standby position in a return process.

At this time, the timing signal is unrelated to the selection, and a return signal R whose synchronization is unstable is generated.

Paper feeding is performed by a paper feeding mechanism after printing is completed.

A magnet 2 is installed on the reduction gear 3 during paper feeding or before and after paper feeding, taking into account the printer's mechanical load and motor inertia.
0 and reed switch 2 installed on the printer frame, etc.
Configure the detector from 1, create the stop command shown in Figure 2,
In response to this stop command, the printer drive motor 1 is de-energized and electrically controlled to suddenly stop, and the intermittent drive gear 7 is stopped at a predetermined standby position.

When the printer drive motor 1 stops and paper feeding ends, and the intermittent gear 8 and type wheel 9 return to their standby positions, the printer waits for the next printing command.

This completes one printing cycle, and printing is performed by repeating this cycle.

In conventional small printers, as mentioned above, a stop signal for stopping the drive motor is obtained by the magnet 20 on the reduction gear 3 that rotates once per line of printing and the reed switch 21 installed on the frame of the printer, etc. Therefore, a detector must be provided separately from the timing detector, which increases the number of parts and the price.

Furthermore, in order to obtain the drive motor stop signal, the roller switch 21 must be moved and installed at the optimal position, otherwise printing errors may occur, so adjustments such as making sure that there are no variations in the motor stop position are extremely necessary. It was unfortunate.

In addition, when the power is turned on, it is not known in what state the printer itself is stopped, so it must always idle for more than one line at most to prevent erroneous printing, resulting in paper wastage and consumption. There was a waste of power, which also affected printing speed.

Furthermore, when the power is turned on, the motor always rotates idly and stops at the home position, and the motor is shut off and started in response to a motor stop command, resulting in high power consumption and battery drive problems.

An object of the present invention is to stop counting character position signals until a reset signal is generated, and to start counting character position signals only after the reset signal is generated.
The objective is to provide a printer that does not malfunction.

An embodiment of the present invention will be described below with reference to FIGS. 3 and 4.

A type 30 is attached to the side surface of the type wheel 29, has a spring force in the direction of arrow a to engage with the groove 27 of the type wheel shaft 26, and is slidably engaged with a recess 31 provided on the side surface of the type wheel. It is a ring spring.

Reference numeral 32 denotes a selection pawl, which controls engagement and disengagement between the type ring spring 30 and the groove portion 27 of the type wheel shaft 26 by engaging and disengaging with the type ring spring 30 .

33 is provided with a notch 331 on a part of the circumference, and meshes with the drive gear 34 which has a tooth part and a notch 341 with a circular diameter on a part of the circumference, and A driven gear 35, which rotates approximately two times, is locked to the type wheel shaft 26, and has conductive foils 351, 352, and 353 in contact with the reset signal detection brush 36, timing signal detection brush 37, and conduction brush 38, which are detection brushes, respectively. The detection plate 39 is a printing hammer that faces the printing position 40 of the bracket 28 with a printing paper 41 in between and performs printing.

42 is a control member that moves the reset signal detection brush 36 up and down to control signal generation and has a switching cam 421; 43 is an electromagnetic coil that drives the iron core 44; 45 is a selection claw shaft 46;
47 is a yoke that creates a magnetic circuit.

The operation of the type selection mechanism constructed as described above will now be described.

In the type wheel selection process, when the drive gear 34 receives rotation from the motor in the direction of arrow b, the driven gear 33 rotates in the direction C.

Since the driven gear 33 and the detection plate 35 are locked to the type wheel shaft 26, when the type wheel shaft 26 rotates in the same direction as the driven gear 33, the type wheel spring 30 moves into the groove 2 by its own spring force.
7 and also engages with the recess 31 on the side surface of the type wheel, thereby attempting to rotate the type wheel 29 in the same direction as the type wheel shaft 26.

However, the selection pawl 32 in the standby state is rotated in the direction of the arrow e by the spring force of the integrally provided spring portion 322 and remains stationary against the contact portion 291 of the type wheel 29, so that it rotates integrally with the type wheel shaft 26. Type ring spring 3
The head 301 of 0 is stopped by the slope of the head 321 of the selection claw 32, and the type ring spring 30 is lifted in the direction of arrow d, and the engagement between the type ring spring 30 and the groove 27 of the type wheel shaft 26 is disengaged, and the type ring is removed. The spring 30, the type wheel 29, and the type wheel shaft 26 rotate idly.

On the other hand, a conductive foil 351 provided on the detection plate 35 corresponding to each character position detects each character position and energizes the electromagnet 43 corresponding to the desired character position in the groove portion corresponding to the character 28 to be printed. 27 comes to a position facing the type ring spring 30, and when the electromagnet 43 starts to be energized, the iron core 44 forms a magnetic circuit with the attraction disk 45 and the yoke 47, and the attraction disk 45 Since the iron core 44 is rotating in the direction of arrow J, the magnetic circuit with the attraction disk 45 is closed, and the rotational force of the attraction disk 45 in the j direction acts in the direction of arrow 1 and also causes the arm portion 324 of the selection claw 32 to By moving the selection pawl 32, it is rotated in the direction of arrow f against the force of the spring portion 322 and moved to a portion where it does not come into contact with the head 301 of the type ring spring 30.

Since the type ring spring 30 is not disengaged from the groove 27 of the type wheel shaft 26 by the selection pawl 32, the type ring shaft 26 and the type wheel 29 are rotated together to rotate the type 28 to the printing position 40.

Each digit performs the same operation, and when all the characters 28 to be printed are aligned at the printing position 40, the printing hammer 39 comes into contact with the characters 28 with the printing paper 41 in between to print.

During printing, the type wheel shaft 26 has completed almost one revolution, and the driven gear 33
A circular diameter notch 341 of the drive gear 34 is engaged and locked with the notch 331 of the drive gear 34 .

When printing is completed, the type wheel shaft 26 further rotates in the direction of arrow h, and the type ring spring 30 and type wheel 29 also rotate together.

When the head 301 of the type ring spring 30 comes into contact with the head 321 of the selection pawl 32 which is already stationary at the standby position, the type ring spring 30 is pushed up again in the direction of arrow d, and is no longer engaged with the groove 27 of the type ring shaft 26. The alignment is broken, the type wheel 29 stops, and the type wheel shaft 26 idles.

With this, one printing cycle is completed.

? The control member 42, the reset signal detection brush 36, the timing signal detection brush 37, the conduction brush 38, and the detection plate 3
The operation of No. 5 will be explained using the timing chart of FIG.

When the detection plate 35 rotates in the direction of arrow h, the conductive foils 351 at the character positions synchronized with the type 28 come into contact with the tips of the timing signal detection brush 37 one after another, electrical conduction with the conductive brush 38 occurs, and the type wheel shaft 26 If you go around once when selecting, T
o ” T I selection signal is generated and the selection process for type 28 is completed.

Thereafter, as described above, the type wheel shaft 26 is locked and the printing process is performed.

At this time, the detection plate 35 that is locked to the type wheel shaft 26 is also locked.

When the printing process is completed, the detection plate 35 starts to rotate in the h direction, the conductive foil 351 again contacts the tip of the timing signal detection brush 37 one after another, and the type wheel shaft 26 makes almost one full revolution when it returns to T13 as shown in FIG. A return signal of T21 is generated.

At this time, the type wheel 29 returns to the standby state as described above and the recovery process is performed.

Here, according to the present invention, the timing signals (return signals) T13 to T26 at the time of return have normal waveforms, so that they can be electrically counted.

Therefore, the timing signal (return signal) Tn at the optimal position with a small load is counted, and the timing signal (return signal) Tn
A motor stop signal is generated, the power to the motor is cut off, and electrical control is applied to stop the motor.

Further, after the completion of the return signal during the timing signal and before the generation of the selection signal, a reset signal R (Fig. 2) is generated by the conductive foil 352 on the detection plate 35 and the reset signal detection brush 36, and after this reset signal is detected. A circuit has been constructed which starts counting or selecting the timing signal mentioned above from To and counts Tn.

However, the reset signal generates two signals R and Rs because the type wheel set 26 rotates approximately twice in one printing cycle, but according to the present invention, the type wheel set 26 rotates from two intermittent rotations to one intermittent rotation (not shown). The structure is such that the reset signal Rs that is generated at the time of extraction and selection is not generated.

This is because when the detection plate 35 starts to return and starts to rotate in the direction of the arrow h, the control member 42 that takes out one intermittent rotation from the two intermittent rotations of the type wheel shaft 26 also starts to rotate in the direction of the arrow g, and the end of the control member 42 The provided switching cam 421 pushes up the tip 361 of the reset signal detection brush 36 that is in contact with the detection plate 35, releases the contact between the detection plate 35 and the reset signal detection brush 36, and the control member 42 stops rotating.

On the other hand, the detection plate 35 continues to rotate in the direction of the arrow h, and the conductive foil 352 appears under the reset signal detection brush 36 at the time of return, but cannot be detected because it is separated from contact by the switching cam 421.

When the return stroke is completed and the type wheel shaft 26 enters the selected state and begins to rotate in the direction of arrow h, the control member 42 again begins to rotate in the direction of arrow g, and the switching cam 421 that was pushing up the tip 361 of the reset detection brush 36 Reset detection brush 3
6, the detection plate 35 and the reset signal detection brush 36 are released from contact with each other and start contacting each other.

The rotation of the control member 42 stops, but at this time, the eccentric portion 422 of the control member 42 is selected to prevent the head 301 of the type ring spring 30 from coming off from the head 321 of the selection claw 32 even if the selection claw 32 vibrates. It comes to a position facing the circular arc portion 323 of the claw 32.

On the other hand, the type wheel shaft 26 continues to rotate in the direction of the arrow h, and the reset signal conductive foil 352 comes into contact with the reset signal detection brush 36.

In this way, only the R signal of the reset signal is generated.

This reset signal does not count timing signals until the reset signal is input after a print command is input, regardless of the stop position of the printer, and once the reset signal is input, selection or counting starts from the next timing signal that appears, resulting in incorrect printing. does not occur at all.

In conventional small type printers that select type wheels, the motor must stop after the return signal ends, as described above, but according to the present invention described above, by providing a reset signal, the motor can stop at any point. This eliminates the restriction on the home position, provides more leeway in setting the motor power cutoff position, and provides a simple detection means for assembly and adjustment.

Furthermore, even when the power is turned on and off, the home position is arbitrary and there is no need for idle rotation, so selection can be made without cutting off the motor power.
1 process, and compared to the conventional method mentioned above, there is no wasted process and the printing speed is improved.Moreover, it is possible to reduce power consumption as it avoids shutting off and starting up the power, and it is easy to run on a battery. We can provide printers.

Further, by providing the timing signal and the reset signal on the same detection plate, the effect of reducing the number of parts is significant, and it is possible to provide a printer that is easy to assemble and adjust.

Further, according to the detector having a contactor according to an embodiment of the present invention, it is possible to reduce the cost of parts, the cost of assembly and adjustment, and the space required for mounting.

As detailed above, according to the present invention, the structure is simple, small,
A small, low-cost printer can be provided.

[Brief explanation of drawings]

Figure 1 shows an example of a conventional small printer, in which 1 is a printer drive motor, 2 is a motor gear, 3 is a reduction gear, and 4 is a motor for driving the printer.
, 5, 6.11 are transmission gears, 7, 8 are intermittent drive gears, 9
is a type ring, 10 is a coil spring, 12 is a printing gear, 13 is a crankshaft, 14 is a printing roller, 15 is a printing paper, 16 is a ribbon, 17 and 18 are rotation directions, 19 is a portion without teeth, 20 is a magnet, 21 is a reed switch, 22 is a type wheel spindle 23 is a detection plate, 24. 25 is a detector. FIG. 2 is a timing chart of an embodiment of a conventional small printer. FIG. 3 is a perspective view showing a specific example of the present invention, in which 26 is a type wheel shaft, 27 is a serrated groove, 28 is a type, 29 is a type ring, 30 is a type ring spring, 31 is a recess, and 32 is a select nails,
33 is a driven gear, 34 is a drive gear, 36 is a reset signal detection brush, 35 is a detection plate, 37 is a timing signal detection brush, 36 is a conduction brush, 39 is a printing hammer, 40 is a printing position, 41 is printing paper, 42 is a control member, 43 is an electromagnetic coil, 44 is an iron core, 45 is an attraction disk, 47 is a yoke,
46 is a selection claw shaft. FIG. 4 is a timing chart showing a specific example according to the present invention, where To''T21 is a timing generation signal and R is a reset signal.

Claims (1)

[Scope of Claims] 1. In a detection device for a small printer that is activated by a print command and selects, prints, and resets the type wheel by two rotations of the type wheel axis, the detection device corresponds to each type position provided on the type wheel. a character position detecting section, a reset detecting section that issues a reset signal instructing the start of counting of character position signals generated from the character position detecting section, and a continuity detecting section that connects the character position detecting section and the reset detecting section. a detection plate directly connected to the type wheel spindle; a character position detection brush, a reset detection brush, and a continuity brush corresponding to each of the character position detection section, the reset detection section, and the continuity detection section provided on the detection plate; a detection brush having: a detection brush that rotates the reset detection brush one rotation of the type wheel shaft so as to bring the reset detection brush into contact with the reset detection section before the character position extension brush contacts each of the character position detection sections; 1. A detection device for a printer, comprising: a control member that is controlled at intervals.