JPS6242797B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a printing device suitable for being attached to a display section of a small desktop calculator, a measuring instrument, etc., and relates to a printing device of a matrix printing type that is capable of printing multiple symbols. .

Traditionally, desktop calculators and measuring machines have often displayed calculation results and measurement values digitally using liquid crystal display devices, etc., and recently, these calculation results and measurement values have been displayed using small serial-type matrix-printing devices. Many items can now be recorded on recording paper using a printing device. This type of printing device used in these devices is subject to considerable restrictions on the mounting parts, so it is desirable to make it as small as possible. The reality is that it cannot be easily miniaturized because it includes many complex mechanisms such as a mechanism for advancing the carriage, a hammer drive mechanism for printing, and a paper feed mechanism.

In addition, recent desktop calculators have various calculation functions, and the capabilities of these calculators range from 0 to 9.
In addition to numbers up to, alphabetical characters from A to Z and 10 to 20
There is a desire to be able to print symbols of the size of a type, but in order to freely print a large number of types, the type carrier that stores them has to be large, and the mechanism for selecting type has also become larger and more complex, which requires the entire printing device. This increases the size of the printer, making it unsuitable especially as a printing device mounted on a portable desktop calculator or the like.

In order to solve these problems, so-called dot type printers have been developed, and thermal type, discharge destruction type, wire dot type, inkjet type, etc. have been implemented, but all of them have lower printing quality than matrix printing. It has the disadvantage of being significantly inferior.

Therefore, the present invention provides a compact and lightweight printing device that enables printing of a large number of symbols using a matrix printing method, and eliminates the above-mentioned conventional drawbacks. This will be explained in detail.

FIG. 1 shows the configuration of the present invention, in which side frames 1a and 1b forming part of the frame of a printing device are arranged oppositely at an interval, and a light and small size (not shown) is provided between both side frames 1a and 1b. a drive shaft 2 driven by a single DC motor with low power consumption, a type selection shaft 3 that rotates to select type, and a shift rotating shaft 4;
is mounted on a shaft.

On the type selection shaft 3, a plurality of type carriers, such as a numeric type carrier 5, alphabetical type carriers 6 and 7, and a code type carrier 8, are connected in a so-called spline manner so as to be movable in the axial direction and rotate with the shaft.

The shift rotation shaft 4 is freely inserted into the carriages 9, 10, 11 and 12 holding the respective type carriers 5, 6, 7 and 8, and a cam 13 is connected to the shaft 4 by a spline. 1
4, 15, and 16 are respectively disposed, and a spring 17 that biases the plurality of carriages to move them to a printing start standby position on the shaft 4 hangs around a guide roller 18 provided on the printing device frame. It is stretched between the frame 1a and the carriage 9.

In addition, the side frames 1a, 1 are provided in parallel with the shift rotation shaft 4.
The cam 1 is mounted on the rotation guide shaft 19 mounted between b.
3, 14, 15, and 16 are spline-coupled, and the rack rod is biased by a spring 21 on the rotation guide shaft 19 in a direction opposite to the direction in which the carriage is biased. and
Further, a plurality of teeth 50 provided on the back surface of the rack rod 20 are engaged with a lock claw piece 22 that prevents the spring 21 from moving the rack rod (the tip of the claw piece 22 has teeth). The solenoid SL ₁ , which is energized by the carriage selection command signal, moves the rack rod 20 against the urging force of the spring 21 to move the type carrier to the printing start standby position. A driving claw piece 23 that moves in the direction can be engaged.

Each carriage is equipped with a roll (not shown) for applying ink to the type carrier.

Further, a hammer shaft 24 installed in parallel with the drive shaft 2 and installed between the side frames 1a and 1b is provided with at least a printing paper P.
A hammer member 25 having a paper width of is fixedly installed. Reference numeral 26 is a paper feed roller for the printing paper P fixed to the paper feed shaft 26a.

Therefore, when printing is performed, when the motor is energized and the drive shaft 2 is rotated, the gear 27 loosely fitted on the type selection shaft 3 meshing with the coaxial gear 51 rotates. On one side of the gear 27, a gear 29 is provided rotatably on the same shaft 3, which engages and disengages the gear 27 via a one-way rotating clutch 28 having a notch 28', and on the other side, a one-way rotating clutch 31 is provided. The ratchet 30 fixed to the shaft 3 and the gear 27 are engaged and disengaged through the mechanism.

The clutches 28, 31 are then controlled to engage and disengage by a lever 32 driven by a solenoid _SL2 energized by the type selection command signal. That is, when the solenoid SL ₂ is in the de-energized state, the clutch 28 is moved so that the pawl 32a of the lever 32 is in the notch 2.
8', the rotation of the gear 27 is not transmitted to the gear 29 in the disengaged state.
The one-rotation cam 33 provided at 9 prevents the hammer member 25 from hitting the print via the lever 34 attached to the hammer shaft 24, while the clutch 31 is not engaged because the pawl 32b of the lever 32 is disengaged from the ratchet wheel 30. When the gear 27 is in the matching state, the rotation of the gear 27 is
tell. Further, when the solenoid SL ₂ is in an energized state, the clutch 28 transmits rotation to the gear 29 by the pawl 32a disengaging from the notch 28'.
By locking at 0, it becomes a non-engaged state and no rotation is transmitted to the type selection shaft.

Such control of the clutches 28, 31 allows the hammer member 25 to operate and print on the printing paper P only when the type carrier stops rotating, as will be described later.

The conductive pattern of the detection plate 35 fixed to the type selection shaft 3 includes sensors 5', 6' and 7' corresponding to the rotation reference position of the type carrier and the number of pairs of contacts for detecting the position of each type. 8' comes into sliding contact to detect the position of the type on the rotating type carrier.

Further, the gear 36 fixed to the shift rotating shaft 4 meshes with the gear 29, and the pulse transmitting plate 37 fixed to the coaxial 4 transmits the rotational speed of the coaxial 4 by the pulse detector 38 to detect the digit position of the type carrier. . That is,
The pulse detector 38 is activated every rotation of the shift rotation shaft 4.
outputs a corresponding detection signal, one rotation of the same axis causes one rotation of the cams 13, 14, 15, and 16, and when the cam meshing with the rack rod 20 rotates one rotation, the carriage with the cam rotates with the spring 17 attached. Since the type carrier moves one digit higher against the force, counting one pulse means that the type carrier has moved one digit higher. Therefore, by detecting the number of counted pulses, the digit position of the type carrier can be determined. You can know. and the cams 13, 14, 15 and 16
Both of these are composed of a continuous semi-circular cam part and a semi-circular cam part having an inclined surface corresponding to a one-digit displacement, so when the teeth of the lock rod are meshing with the semi-circular cam, Since the carriage cannot be moved in advance, printing can be performed by the hammer member 25 at this time. (Regarding this cam shape, the applicant of this application previously filed a patent application filed in 1982.
Please refer to No. 105673. ) When the motor is energized, the solenoid SL ₂ is in the de-energized state as shown in FIG. 1, so the clutch 28 is in the disengaged state, so the gear 29 does not rotate, and the clutch 31 is in the engaged state. Therefore, the type selection shaft 3 rotates.

In such a state, the type selection command signal sends a signal to solenoid SL ₂ just before the selected type on the type carrier comes to the printing position, actuating the lever 32 and switching the clutches 28 and 31. When the clutch 28 is engaged and the clutch 31 is disengaged, the type selection shaft 3 stops rotating, the gear 29 rotates, and the one-rotation cam 33 rotates the hammer member 25 via the lever 34. The printing paper P is pressed against the selected type at the printing position on the type carrier to print. Further, the rotation of the gear 36 meshed with the gear 29 is such that when the hammer member 25 is rotated and pressed, the semicircular cam portion of the cam on the shift rotation shaft 4 meshes with the teeth of the rack rod 20, and the hammer member 25 is rotated. The cam 13,
Since the phase difference between 14, 15 and 16 and the one-rotation cam 33 is set in advance, the carriage remains stationary during printing by striking the hammer member, and after the striking of the hammer member is completed, the carriage is moved one digit higher. . As shown in an enlarged view in FIG. 2, the clutches 28 and 31 are disengaged when one pawl 32a of the lever pawl 32 engages with the notch 28' of the clutch 28, and the clutch 31 is disengaged. When the other pawl 32b is engaged with the integrated ratchet wheel 30, the ratchet wheel 30 stops and the clutch 31 is disengaged. Therefore, when the solenoid SL ₂ is energized from the state shown, the pawl 32a is cut out. Since the clutches 28 and 31 are disengaged from the portion 28' and the pawl _32b engages with the ratchet wheel 30, the engagement and disengagement positions of the clutches 28 and 31 are reversed from those shown in the figure. Since it is demagnetized, the lever pawl 32 is returned to the state before excitation by a return spring (not shown), and the pawl 32a engages the clutch 28 in the notch 28'.
Since the gear 29 is locked every rotation, the gear 29 rotates intermittently every rotation.

Therefore, the rotating type carrier held by the carriage in the printing position is activated by the type selection command signal when the selected type on the type carrier comes to a position opposite to the hammer member. Then, the selected characters are printed on the printing paper by the printing strike of the hammer member, and when printing is completed, the carriage is moved one digit higher by the cam.

In this way, characters selected arbitrarily from a large number of characters on the same type carrier can be printed on the printing paper while being shifted.

Next, the operation of moving the type carrier in the digit direction without printing will be explained.

Each type carrier 5, 6, 7, and 8 is provided with a blank space SP (spacing position) and CR (carriage return position) where no type is provided at two corresponding positions on its diameter. ,
On the other hand, when the blank portion SP is selected by the type selection command signal, the above-described operation causes the print sheet to be sent one digit higher, leaving a blank digit that is not printed on the printing paper.

Furthermore, if the blank area SP is selected as the printing position facing the hammer member and the solenoid SL ₂ is continuously energized, the digit feed rotary shaft 4 is continuously rotated while the clutch 28 is in the engaged state, so that the carriage is not continuously moved. For example, if you want to print only the 5th digit of one of the characters stored in the type carrier 5 and use the other digits as a margin, the blank area
Turn the SP toward the printing position, energize the solenoid SL ₂ , count the pulses 4 times with the pulse detector 38, and then demagnetize the solenoid SL _2. At this time, the type carrier 5 is at the 5th digit position, so at this position. When the desired type is selected and printed using the type selection command signal, the digits are advanced, the blank area SP is selected again, and solenoid SL ₂ is continuously excited, the type carrier 5 sequentially prints the digits without printing any type on the printing paper. raised to reach the non-print mooring position. At this time, solenoid SL ₂
When demagnetized, the desired character is printed on the printing paper in the fifth digit and the other digits are completely blank.

Next, the operation of selecting one of the type carriers 5, 6, 7 and 8 will be described with reference to FIGS. 3a, b and c.

In the waiting state for starting printing for one line, the type carriers 5, 6, 7, and 8 are in a state in which only the carriage cam 13 of the leading type carrier 5 is engaged with the end teeth of the rack rod 20, as shown in FIG. 3a. Only the type carrier 5 is in a printable position, and the other type carriers 6, 7, and 8 are in standby positions for printing. The type carriers 5, 6, 7, and 8 are arranged in such a way that the type carriers containing the frequently printed characters come first.

Therefore, for example, when the type carrier 6 is selected, the first type carrier 5 is shifted by the above-described operation and removed from the front teeth of the rack rod 20 as shown in FIG. 3b. The next position is moved to the non-printing mooring position, and the driving claw piece 23 resists the biasing force of the spring 21 by energizing the solenoid SL ₁ by the carriage selection command signal, and the end tooth of the rack rod 20 is moved to the printing start standby position. The selected type carrier 6 is moved backward to the chain line position where it engages with the carriage cam 14, and even after the solenoid SL ₁ is demagnetized, the lock claw piece 22 maintains the retreated position shown in FIG. 3c. Then, the type carrier 6 is carried forward while printing by the same operation as described above.

The operation for selecting the type carrier is the same for the other type carriers 7 and 8, so the description thereof will be omitted.

When the printing of one line is completed by the selective printing operation as described above, the carriages 9 and 1
0, 11 and 12 are placed in various positions. For example, carriages 5 and 6 are in the non-print mooring position, carriage 7 is in the print position, and carriage 8 is in the print start standby position.

Therefore, in order to perform the printing operation for the next line again, it is necessary to return all the carriages to the standby state for starting printing for one line as shown in FIG.

This return movement is caused by the above-mentioned blank area provided on the type carrier.
This is done by selecting CR and rotating the rack rod 20 from the shift position to the non-shift position.

That is, when the blank portion CR on each type carrier is selected by the type selection command signal and positioned on the printing position line, the cam groove 40 of the cam plate 39 fixed on the type selection shaft 3 at this position is connected to the lever pawl. The lever pawl 41 is fixed in advance on the coaxial shaft 3 in a position opposite to the cam plate 3.
9 and the one-rotation cam 33, and the radius of the cam plate 39 is
The maximum cam radius of the one-rotation cam 33, which is made into a disc with the same diameter as the cam radius when the hammer member presses the printing paper against the type on the type carrier, and is in a stopped state, is the maximum cam radius of the lever. The notch 28' of the clutch 28 is located at a position opposite to the pawl 41.
Therefore, only when the cam groove 40 is stopped at a position facing the lever pawl 41, the lever pawl 41 falls into the cam groove 40 as the one-rotation cam 33 rotates, and one of the rotation cams 33 Each rotation, the lever pawl 41 rotates one reciprocating motion. "And this one reciprocating rotation causes the rotation guide shaft 19 to make one reciprocating rotation by a known transmission means, so that the teeth of the rack rod 20 are disengaged from the cam of the carriage, and all of the above-mentioned various positions are disengaged. The carriages are returned all at once to the position shown in FIG. do. Further, when the blank portion CR of the type carrier is at the printing position, no printing will occur on the printing paper even if the hammer member hits the printing.

One reciprocating rotation of the rotation guide shaft 19 is transmitted to the paper feed shaft 26a through a known transmission means such as a one-way rotation clutch, and the paper feed roller 26 is rotated to move the printing paper P by one line. It is something to send.

As described in detail above, the present invention selects a plurality of type carriers and moves them to the printing position, waits and moores the unselected type carriers that are not involved in printing at the non-printing position, and further moves the type carriers that are moored or in the printing position. can be returned to the printing start standby position all at once, making it possible to print many types of type clearly. Moreover, only a single DC motor is used as the drive source and two solenoids are provided for control. is sufficient, so the printing device as a whole does not become large, is lightweight, and consumes less power, so it can be used for desktop calculators,
It can also be installed in equipment such as measuring equipment that has severe limitations on the space in which it is installed, and has the excellent effect of being able to provide printed data using matrix type with better printing quality than the conventional dot method at a lower price. It has the following.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; FIG. 1 is a schematic perspective view of the main parts of the printing device, FIG. 2 is an enlarged perspective view of the clutch, and FIGS. . 2... Drive shaft, 3... Type selection axis, 4... Digit feed rotation axis, 5, 6, 7, 8... Type carrier, 9, 1
0, 11, 12...carriage, 13, 14, 1
5, 16... digit feed cam, 17, 21... spring,
20...Lack rod.

Claims (1)

[Claims] 1. A plurality of type carriers carrying a large number of type characters are spline-coupled onto a type selection shaft that rotates at an angle selected by a type selection command signal, and each type carrier is held and the type selection shaft is connected to the type selection shaft. A cam is rotatably attached to each of a plurality of carriages having biasing means for moving these type carriers to the print start waiting position above, and is aligned with the type selection shaft to move the carriage against the biasing force. It is spline-coupled to the provided shift rotation shaft, and one end is controlled to slide to a position where it meshes with the cam of the selected carriage in response to a carriage selection command signal, and the other end is controlled to slide to the non-print mooring position of the preceding carriage and is engaged with the cam of the carriage. A printing device equipped with a rack rod that can be rotated and controlled to move the carriage between a shift position and a non-shift position. 2. The printing device according to claim 1, wherein the type selection shaft and the shift rotation shaft are selectively rotated by a clutch which is switched by a single solenoid. 3. The printing device according to claim 1, wherein sliding control of the rack lever is performed by a single solenoid, and rotation control is performed by rotation of a cam plate on a type selection shaft.