JPS582603Y2 - Detection mechanism - Google Patents

Description

[Detailed description of the invention] The invention consists of a selection process for selecting a type ring having printed characters such as letters and symbols around it, a printing process for printing the selected type;
The present invention relates to a small printer that undergoes a return process in which the type wheels are aligned and returned to a standby position, and particularly relates to a detection means that performs detection by bringing a contact into contact with it.

An object of the present invention is to provide a simple-shaped, low-cost detector by using a brush as a detection means.

Another object of the present invention is to easily generate a motor stop signal by arranging motor brushes opposite a common brush.

Still another object of the present invention is to provide a detector whose detection signal can be easily controlled by providing a mask.

A conventional small printer is shown in Figures 1a and 2b, which are schematic structural diagrams, 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 a part of the circumference that has a notch that corresponds to the diameter of the gear and tooth bottom. 8 is an intermittent drive gear, 8 is an intermittent gear with a part of the gear cut out; 9 is a type wheel which is disposed on the intermittent gear 8 and has type letters on its circumference from which arbitrary characters can be selected by a type wheel selection mechanism; 10 is an intermittent gear; A coil spring has 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 over the type on 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 is a light emitting element;
25 is a light receiving element.

The principle of this operation will be explained.

The printer drive motor 1 is driven by the print command shown in FIG. The gear 8 rotates in the direction of an arrow 18 while winding up the coil spring 10.

When the intermittent gear 8 rotates, the type wheel 9 also starts rotating, and the detection plate 23 shown in FIG.
Tlz) is also generated, resulting in a selection process in which characters are selected by the type wheel selection mechanism.

When the intermittent drive gear 7 continues to rotate and character selection is completed, the intermittent drive gear 7 and the intermittent gear 8 are disengaged, and the intermittent drive gear 8 winds up the coil spring 10 due to the uncut portion 19 of the intermittent drive gear 7. locked in a locked 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 detection is unrelated to the selection and the zero paper feed, in which a return signal R with unstable synchronization is generated, is performed by the paper feed mechanism after printing is completed.

A magnet 20 is installed on the reduction gear 3 before and after paper feeding in consideration of the printer's mechanical load and motor inertia.
and a reed switch 21 installed on the printer frame, etc.
The detector is then activated to generate a stop command as shown in FIG. Stop 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.

As mentioned above, in conventional small printers, timing signals are generated using light emitting and light receiving elements, which requires precision such as optical axis alignment, and has problems such as high component costs.
Furthermore, a stop signal for stopping the drive motor must be obtained by the magnet 20 on the reduction gear 3, which rotates once per line of printing, and the reed switch 21 installed on the frame of the printer, so timing detection is required. Since a separate detector had to be installed, the number of parts and the price increased.

Furthermore, in order to obtain the drive motor stop signal, the reed switch 21 must be moved and placed in the optimal position, otherwise printing errors may occur, so adjustments must be made to ensure that there are no variations in the motor stop position. It was extremely difficult.

The present invention eliminates such drawbacks, and FIG. 3 is a perspective view showing a specific example of the present invention.
This shows the detection and printing mechanism.

In FIG. 3, 26 is a type wheel shaft having sawtooth grooves 27 on its outer periphery, and a type wheel 29 having type characters 28 on its outer periphery.
It has multiple bearings.

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 of 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, so that the drive gear 34 rotates one side. In contrast, a driven gear 35, which rotates approximately twice, is locked to the type wheel shaft 26, and a character selection brush 36. Auxiliary brush 37. Detection plates each having patterns 361, 371, 381 in contact with the common brush 38, 39 a stop brush controlling the start of the motor;
40 is a mask driven by a cam 41 coaxially locked with the drive gear 34 and controls the common brush; 42 is a mask 4;
0 is a return spring, 43 is a perpendicular axis of the mask 40, and 44 is a printing hammer that faces the printing position 45 of the type 28 with a printing paper 46 in between to perform printing.

47 is a cell electromagnetic coil that drives the iron core 4B, 49 is an attraction disk that rotates with the selection claw shaft 50, and 51 is a yoke that forms 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 driving gear 34 receives rotation from the motor in the direction of the arrow C, the driven gear 33 rotates in the direction of the arrow 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 the recess 31 on the side surface of the type wheel, the type wheel 29 attempts to rotate 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 idle. On the other hand, the patterns 371 and auxiliary patterns 361 provided on the detection plate 35 corresponding to the respective character positions detect the respective character positions and move the characters to the desired character positions. The corresponding electromagnet 47 is energized by the groove 2 corresponding to the type 28 to be printed.
7 comes to a position facing the type ring spring 30, and when the electromagnet 47 starts to be energized, the iron core 48 forms a magnetic circuit with the attraction disk 49 and the yoke 41, and the attraction disk 4
9 is rotating in the direction of the arrow j, the iron core 48 closes the magnetic circuit with the attraction disc 49, and moves in the direction of the arrow i by the rotational force of the attraction disc 49 in the j direction, and the arm portion of the selection claw 32 32
4, the selection pawl 32 is rotated in the direction of the arrow f while resisting the force of the spring portion 322. By moving the selection pawl 32 in the direction of the arrow f so as not to contact the head 301 of the type ring spring 30, the type ring spring 30 is rotated in the direction of the arrow a. In order to move in the direction and engage with the groove 2T of the type wheel shaft 26, the type wheel shaft 26 and the type wheel 2
9 are rotated together to rotate the type 28 at the printing position 45. This is the selection process, and the same operation is performed for each digit. When all the type 28 to be printed at the printing position 45 are aligned, the printing hammer 44 starts printing. It comes into contact with the type 28 with the paper 46 in between to print.

During printing, the type wheel shaft 26 has approximately completed its rotation, 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 the arrow, and the type ring spring 30 and the 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. When the alignment is removed, the type wheel 29 stops, and the type wheel shaft 26 idles and completes approximately one revolution.This is a reset process, and the printing cycle is completed.

Next, the operation of the detector section is shown in Figures 3, 4, and 5 a, b,
c. This will be explained with reference to FIG.

Figure 3 is a perspective view, Figure 4 is a side view of the detector, Figure 5a,
b and c are detailed diagrams of brush control, and FIG. 6 is a timing chart.

FIG. 4 shows the state at the start of the selection process, and as described above, when the type wheel shaft 26 rotates in the direction of the arrow, the detection plate 35 also rotates in the direction of the arrow because it is locked to the type wheel shaft 26.

Then, the character selection brush 36 contacts the pattern 361 and the auxiliary brush 37 contacts the pattern 371 one after another.

At this time, the cam 41 coaxially locked with the drive gear 34 rotates in the direction of the arrow g, but the mask 40 is rotated in the direction of the arrow 1 by the return spring 42 and stopped by the rotation shaft 43, The situation is as shown in Figure 5a.

In this state, the common brush 38 is in contact with the pattern 381, so when the detection plate 35 rotates approximately one rotation, Ro-R□ is shown in FIG. 2 auxiliary pulses are generated.

As a result, the leading edge of each pulse of 'To-Ti2 and Ro-R
□By the leading edge of each pulse in 2, the composite pulse Qo in Fig. 6 is obtained.
``Qx2'' is obtained, and the electromagnet 47 of each digit corresponding to the desired character position is energized when selecting the above-mentioned type wheel using a signal that is not affected by chattering.

When the detection plate 35 makes one revolution, it enters the printing process, and as described above, the drive gear 34 is inserted into the notch 331 of the driven gear 33 in FIG.
The notch 341 having a circular diameter of is engaged, and even if the drive gear 34 is rotating in the direction indicated by the arrow, the detection plate 35 that is locked to the driven gear 33 is also locked.

Next, when the reset process begins, the detection plate 35 starts rotating in the direction of the arrow again and the character selection brush 36 starts to rotate in the direction of the arrow.
is the force that causes the auxiliary brush 37 to contact the pattern 361 one after another.＼ If the aforementioned energizing pulse to the electromagnet 43 is generated at the time of reset, the type ring will be selected and a malfunction will occur. ”
'When a composite pulse Qo=Qtz consisting of the character selection pulse of T12 and the auxiliary pulse of RO-R1° is generated, 1
A cam 41 locked on the same axis of the drive gear 34, which rotates one print cycle, drives the mask 40 at the section A shown in FIG.

At this time, the state shown in FIG. 5 is reached.

This means that the 412 part of the cam 41 in FIG.
The first stage 401 of the mask 40 pushes up the common brush 38 to break contact with the pattern 381 in order to drive it in the direction of the arrow, so the detection plate 35 is locked during printing, and the reset process is started and rotated again in the direction of the arrow. When you start, the character selection brush 36 touches pattern 361 and the auxiliary brush 37 touches pattern 371 one after another, but the common brush 38 touches pattern 3.
Since contact with 81 is broken, no pulse is generated.

Next, regarding stopping the motor, if paper feeding is performed during the reset process and the motor is stopped, it is only necessary to set the pulse to be generated at the best position where paper feeding has already been completed. , a stop pulse was generated just before the end of paper feeding as shown in FIG.

This is because even if the detection plate 35 in FIGS. 3 and 4 rotates in the direction of the arrow in the reset process, no pulse is generated as described above.

On the other hand, a cam 41 coaxially locked with the drive gear 34 is rotating in the direction of arrow g.

Then, 412 of the cam 41 was pushing up the mask 40 due to the weight of the baby, but when driven by the mouth part shown in FIG. 6, the cam 4 of FIG.
1 413 further pushes up the mask 40 in the direction of arrow m.

Then, as shown in FIG. 5, the mask 40 operates in the direction of arrow m, and the second stage 402 further pushes up the common brush 38.
The state shown in FIG. 5C is reached, and at this time, the stop brush 39 supported by the mask 40 and the common brush 37 come into contact, a stop pulse S is generated, the motor stops, and the printer enters a standby state and stops.

As described above, since the composite pulse Qs is formed at the leading edge of the stop pulse S, the common brush 3B can immediately break from contact with the stop brush 39, but the detection plate 3
On the top of 5, use the ordinary character selection brush 36. Since the patterns 361 and 371 of each of the auxiliary brushes 37 are in contact, the common brush 38 cannot immediately contact the pattern 381.

Therefore, 112 and R'1 of each pattern 361.371
Immediately after passing the character selection brush 2 and the auxiliary brush, the cam 41 413 releases the push-up of the mask 40 at the bottom of FIG. However, at this time, the stop pulse S is cut off, but since the auxiliary pulse R is not generated, the composite pulse Qs is in the state of rising fcll. Rs of pattern 371 of auxiliary brush 37 immediately after starting.
The auxiliary pulse Rs is generated by sensing the conduction with the stop pulse S, and can be used as the falling pulse of the composite pulse Qs of the stop pulse S, and the selection starts again.

As mentioned above, by using a brush to perform character selection signals, etc., which were conventionally performed by optical detection, parts costs are low, the shape can be simplified, and the auxiliary brush 37. By providing the auxiliary pattern 371, a highly reliable printer can be provided.

Furthermore, without providing a separate detector for motor stop, the motor stop pulse can be easily generated by simply arranging the stop brush 39 at a position opposite to the common brush 38 and placing it at the same location as the character selection brush, etc. By providing the mask 40, the number of parts is reduced, and by providing the mask 40, the pulse can be easily controlled.The position at which the motor stops after paper feeding is completed can be selected and set at the beginning, making it easier to adjust the motor stop position. We can provide printers you don't need.

As described above, according to the present invention, it is possible to provide a printer that is inexpensive, simple in shape, and does not require motor stop position adjustment, and has great effects.

[Brief explanation of drawings]

Figures 1a and 1b are schematic structural diagrams of a conventional small printer, in which 1 is a drive motor, 2 is a motor gear, 3 is a reduction gear,
4, 5, 6.11 are transmission gears 7 is an intermittent drive gear, 8 is an intermittent gear, 9 is a type wheel, 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, 20 is a magnet, 21 is a reed switch, 22 is a type wheel spindle, 23 is a detection plate, 24 is a light emitting element, 2
5 is a light receiving element. FIG. 2 is a time chart 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, 29 is a type wheel, 30 is a type wheel spring, 32 is a selection button, 33 is a driven gear, 34 is a drive gear, and 35 is a type wheel spring. Detection board, 36 character selection brush, 37 auxiliary brush, 38 common brush, 39 stop brush, 40 mask, 41
is a cam, 42 is a return spring, 43 is a perpendicular axis, 44 is a printing nozzle, 45 is a printing position, 46 is a printing paper, 47 is an electromagnetic coil, 48 is an iron core, 49 is a suction disk, 50 is a selection The claw shaft 51 is a yoke. FIG. 4 is a plan view of a detection section showing a specific example of the present invention. Figures 5a, b, and c are detailed views of a detection unit showing a specific example of the present invention, in which 35 is a detection plate, 38 is a common brush, 39 is a stop brush, and 40 is a mask. This is a time chart of the present invention.

Claims (1)

[Scope of utility model registration request] In a small printer of type wheel selection type in which the type wheel spindle starts in response to a print command, rotates twice in one print cycle, performs a series of printing operations, and stops at a predetermined standby position, and has a detection means that detects a desired signal by contacting it. , a detection plate that is synchronized with the type wheel axis and has a character selection pattern, an auxiliary pattern, and a common pattern; a character selection brush, an auxiliary brush, and a common brush that contact each pattern of the detection plate; and a position opposite to the common brush. It consists of a detection brush having a stop brush of a motor disposed on the detection brush, a mask for operating the common brush in the detection brush, and a mask cam for driving the mask, and the common brush is caused by the mask to be connected to the detection plate. The detection mechanism is characterized in that the detection mechanism generates a stop signal for the motor by releasing contact with the common pattern and making contact with the stop brush.