JPS5815169Y2 - Printing machine detection plate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a small printer having a detection means for detecting a desired signal by contacting a contactor, and more particularly to a detection plate cooperating with a detection brush.

An object of the present invention is to provide a detector with a simple shape, low cost, and low power consumption by using a brush and a detection plate as a detection means.

Another purpose of the present invention is to provide a highly reliable printing machine by removing dust attached to the detection brush using a slit provided in the detection plate to obtain a stable pulse signal with less chattering. be.

Generally, a so-called mechanical contact type detection mechanism using a brush and a detection plate as a detection means is said to be inferior in reliability compared to non-contact detection such as optical detection or magnetic detection.

However, so-called non-contact detection mechanisms for optical detection and magnetic detection require a secondary circuit to amplify the signal from the sensor.

There is an advantage in cost and power consumption that the detection mechanism consumes a large amount of power to drive the secondary circuit.

The present invention has been developed in view of these points, and provides an extremely reliable mechanical contact type detection mechanism.

Hereinafter, embodiments will be shown while generally explaining the parts related to the printer of the present invention.

FIG. 1 is a schematic diagram showing a printing mechanism of a small printer according to the present invention, FIG. 2 is a schematic diagram showing a detection mechanism of a small printer according to the present invention, and FIG. 3 is a timing chart diagram according to the present invention. FIG. 4 is a diagram showing a detection plate of a conventional detection mechanism section, and FIG. 5 is a structural diagram of a detection plate according to an embodiment of the present invention.

This will be explained below along with the drawings. In FIG. 1, 26 is a type wheel shaft having sawtooth grooves 27 on its outer periphery, and supports a plurality of type wheels 29 having type characters 28 on their outer peripheries.

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 with and disengaging from the type ring spring 30 .

33 has a notch part 331 on a part of the circumference, and meshes with the drive gear 34 which has a tooth part and a circular diameter notch part 341 on a part of the circumference. This is a driven gear that rotates approximately twice.

35 is pivotally supported by a type wheel shaft 26, and has a character selection brush 36;
This is a detection plate having patterns 361, 371 and 381, respectively, in contact with the auxiliary brush 37 and the common brush 38.

The structure of the detection plate 35 of the present invention will be explained in detail with reference to FIG.

39 is a stop signal brush that generates a stop signal to control stopping of the motor.

A mask 40 is driven by a cam 41 coaxially engaged with the drive gear 34 and controls the common brush 38.

Reference numeral 42 indicates a weak spring of the mask 40, reference numeral 43 indicates a perpendicular shaft of the mask 40, and reference numeral 44 indicates a printing hammer that performs printing by interposing a printing paper 46 at a printing position 45 of the type 28.

47 is an electromagnetic coil that drives the iron core 48; 49 is an attraction disk that is inserted through the selection claw shaft 50 and rotates at the same time as 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 selection mechanism, 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.

A driven gear 33 and a detection plate 35 are engaged with the type wheel shaft 26 .

When the type wheel shaft 26 rotates in the same direction as the driven gear 33, the type ring spring 30 engages with the groove 27 of the type wheel shaft 26 by its own spring force, and also engages with the recess 31 on the side surface of the type wheel, so that the type wheel spring 30 rotates in the same direction as the driven gear 33. An attempt is made to rotate the wheel 29 in the same direction as the type wheel 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 is removed. The ring spring 30, the type wheel 29, and the type wheel shaft 26 idle.

On the other hand, patterns 361 corresponding to the respective character positions provided on the detection plate 35. The pattern 371 detects each character position and energizes the electromagnet 47 corresponding to the desired character position.
The process starts when the groove portion 27 corresponding to the type character 28 to be printed comes to a position facing the type ring spring 30.

When the electromagnet 47 starts to be energized, the iron core 48 attracts the attraction disk 4
9 and the yoke 51 constitute a magnetic circuit, and since the attraction disc 49 is rotating in the direction of the arrow j, the iron core 48 closes the magnetic circuit with the attraction disc 49, and the attraction disc 49 The selection claw 32 moves in the direction of arrow i by the rotational force in the direction of arrow j.
The type ring spring 30 is rotated in the direction of arrow f by moving the arm part 324 of the type ring spring 30 to rotate the selection claw 32 in the direction of the arrow f against the force of the spring part 322 and move it to the part where it does not come into contact with the head 301 of the type ring spring 30. In order to move in the direction of arrow a and engage with the groove 27 of the type wheel shaft 26, the type wheel shaft 26 and the type wheel 29 are rotated together, and the type 28 is rotated to the printing position 45.

The above is the selection process, and the same operation is performed for each digit, and when all the characters 28 to be printed are aligned in the printing position 45, the printing hammer 44 comes into contact with the characters 28, sandwiching the printing paper 46, and performs printing.

During printing, the type wheel shaft 26 completes approximately one rotation, and the driven gear 3
A notch 341 having a circular diameter of the drive gear 34 is engaged with the notch 331 of No. 3 and locked.

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 contact is released, the type wheel 29 stops, and the type wheel shaft 26 idles and rotates approximately.

This is the reset process and one printing cycle is completed.

Next, the operation of the detector section will be explained with reference to FIGS. 1, 2, and 3.

FIG. 1 shows the state at the start of the selection process, and as described above, when the type wheel shaft 26 rotates in the direction indicated by the arrow, the detection plate 35 also rotates in the direction indicated by 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 moved in the direction of the arrow g by the return spring 42. direction and is stopped at a perpendicular shaft 43.

In this state, the common brush 38 is in contact with the pattern 381, so when the detector 35 rotates approximately one rotation, it reaches T shown in FIG.

Auxiliary pulses R8-R12 are generated between the ~TT2O character selection pulse and each pulse To-T1□.

These T. The leading edge of each pulse of ~T1□ and the leading edge of each pulse of R8-R1□ result in a composite pulse Q in FIG.

-Q12 is obtained, and a signal that is not affected by chattering can be extracted.

This signal energizes the electromagnet 47 of each digit corresponding to the desired character position when selecting the above-mentioned type wheel.

When the detection plate 35 rotates once, the printing process begins and the drive gear 34 enters 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 pattern 361, and the auxiliary brush 37 is pattern 371.
However, if the above-mentioned energizing pulse to the electromagnet 43 is generated at the time of reset, a malfunction will occur as soon as the type wheel is selected.

A composite pulse Q consisting of a character selection pulse of -T12 and an auxiliary pulse of R6-R1□.

When -Q12 occurs, the cam 41 coaxially locked to the drive gear 34, which rotates once per printing cycle, drives the mask 40 in the section A shown in FIG.

At this time, the portion 412 of the cam 41 in FIG. 2 pushes up the common brush 38 to drive the mask 40 in the direction of arrow m and breaks contact with the pattern 381.

For this reason, the detection plate 35 is locked during printing, the reset process is started, and when it starts rotating again in the direction of the arrow, the character selection brush 36 contacts the pattern 361 and the auxiliary brush 37 contacts the pattern 371 one after another, but they are common. Since brush 38 is out of contact with pattern 381, no pulse is generated.

Therefore, T"o-'r"12 in FIG. R'o-
R'12. Rs is not actually generated.

Next, regarding the S pulse, if the paper is being fed during the reset process and the motor is stopped, the pulse can be set to be generated at the best position where paper feeding has already finished, as shown in Figure 3. A stop pulse was generated just before the end of paper feeding.

When this is driven by the opening shown in FIG. 3, a portion 413 of the cam 41 shown in FIG. 2 pushes the mask 40 further up in the direction of arrow m.

At this time, the stop brush 39 supported by the mask 40
When the common brush 38 comes into contact with the common brush 38, a stop pulse S is generated.
The motor stops and the printer goes into standby mode.

As mentioned above, since the synthetic leather pulse Q5 is formed at the leading edge of the stop pulse S, it is possible to immediately release the contact with the stop brush 39 when applying the common brush, but character selection is still not possible on the detection plate 35. Brush 36, auxiliary brush 37
The common brush 38 cannot immediately contact the pattern 381 because the respective patterns 361 and 371 are in contact with each other.

Therefore, T'l□ and R'l□ of each pattern 361, 371
Immediately after passing through the character selection brush and auxiliary brush, respectively, the third
At part C in the figure, a portion 413 of the cam 41 releases the push-up of the mask 40, and the return spring 42 returns the mask 40 to the perpendicular shaft 43 in the direction of arrow l.

At this time, the stop pulse S is cut off, but since the auxiliary pulse R is not generated, the composite pulse Q5 remains in a rising state.

The common brush 38 then starts contacting the pattern 381 again, and immediately the auxiliary brush 37 starts contacting the pattern 371 with Rs.
The auxiliary pulse R8' is generated by sensing the conduction with the stop pulse S, and can be used as the falling pulse of the composite pulse Q5 of the stop pulse S described above, and the selection starts again.

The above is a series of operating principles of the small printer of the present invention. Conventionally, a detection plate as shown in FIG. 4 has been used as a detection plate.

In FIG. 4, a is a detection plate, and b is a side sectional view showing the state of contact between the detection plate and the brush.

Generally, this detection plate is a copper-clad paper phenol board or glass epoxy board, and a conductive pattern can be easily obtained by etching or the like.

Therefore, it is suitable for mass production and is inexpensive, but the brush 36
Brush 3 is constantly subjected to contact pressure due to friction.
There is a possibility that dust such as abrasion powder 102 may adhere to the bent portion 103 of No. 6.

Therefore, the bent portion 103 of the brush 36 is placed onto the pattern 361.
Even if they make contact, the contact resistance increases, resulting in a signal with a lot of chattering.

Of course, it goes without saying that a fairly severe design is required that takes into account not only wear-resistant detection plates, brush materials, and plating materials, but also environmental resistance, dust resistance, and brush contact pressure, but they are not readily available. It is very attractive to use a commercially available resin substrate, which is easy to process and inexpensive.

FIG. 5 shows the structure of a detection plate which is an embodiment of the present invention.
A slit is provided in a part of the detection plate, and a pattern is arranged around the slit.

To explain this in detail, as mentioned above, the detection plate 35 is
Although it rotates twice per printing cycle, when the contact pressure of the brush 36 is strong, the detection plate 35 rotates in the direction of the arrow, thereby generating frictional heat between the brush contact portion 103 and the contact portion of the detection plate.

For example, if the detection plate is made of resin, there is a good chance that it will become soft or carbonized, and there is a good possibility that it will generate dust.

Therefore, how to efficiently and reliably remove these dust particles is considered to be a key point in improving the reliability of the detector.

According to the embodiment of the present invention shown in FIG. 5, the bent portion 103 of the brush 36 falls into the slit 100 provided in the detection plate 35 as the detection plate 35 rotates in the direction of the arrow. By rotating in the direction, the bent portion 103 of the brush 36 comes into contact with the corner of the pattern 101.
Dust such as abrasion powder 102 adhering to the surface is self-cleaned.

Therefore, the bent portion 103 of the brush 36 is always kept free of dust, and a stable pulse signal with less chattering can be obtained.

Although one slit is provided as an embodiment of the present invention, the same effect can be obtained even if a plurality of slits are used, and the same effect can be expected even if the slit shape is a groove.

The pattern arranged around the slit has an effect of preventing wear on the corners of the slit, and when a resin substrate is used as the detection plate, the effect of wear resistance is extremely large.

According to the embodiment of the present invention, although it is a mechanical contact type, it is possible to provide an extremely reliable detector, and furthermore, it is possible to provide a detector that is simple in shape, low cost, low power consumption, etc., and is ideal for small plinks. became possible.

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

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the printing mechanism of the small printer of the present invention, in which 26 is a type wheel shaft, 29 is a type wheel, 3° is a type ring spring, 32 is a selection pawl, 33 is a driven gear, and 34 is a drive. Gear, 35 is a detection plate, 36 is a character selection brush, 37 is an auxiliary brush, 38 is a common brush, 39 is a stop brush, 4
0 is a mask, 41 is a cam, 42 is a return spring, 43 is a perpendicular shaft, 44 is a printing hammer, 45 is a printing position, 46 is printing paper, 47 is an electromagnetic coil, 48 is an iron core, 49 is a suction disk,
50 is a selection claw shaft, and 51 is a yoke. FIG. 2 is a plan view of the detection section of the present invention. FIG. 3 is a timing chart of the present invention. FIGS. 4a and 4b are diagrams showing a conventional detection plate and the state of contact between the brush and the detection plate. FIGS. 5a and 5l) are detailed views showing a detection plate according to a specific example of the present invention and the state of contact between the brush and the detection plate, where 35 is a detection plate and 100 is a slit provided in the detection plate.

Claims (3)

[Scope of utility model registration request] (1) In a small printer having a detection means for detecting a desired signal by bringing a contactor into contact, the detection means includes a detection plate provided with a conductive foil portion for detecting a print position signal corresponding to the print position. , a detection brush that comes into contact with the conductive foil portion of the detection plate, and the detection plate is provided with at least one slit for removing dust etc. adhering to the detection brush. detection board. (2) The detection plate for a printing press according to claim 1, characterized in that a conductive foil is disposed near the slit. (3) The detection plate for a printing press according to claim 1, wherein the conductive foil portion is embedded in the detection plate.