JPH021024B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a small serial printer used in calculators and the like.

Various small-sized printers of this type have been proposed in the past, and a typical example will be explained using Japanese Patent Publication No. 55-9298.

First, the embodiment will be explained using FIG. 1 and FIG. A spline shaft (rotation shaft) with a hexagonal cross section that is rotatably held, and the rotation of the step motor 1 is caused by the engagement between the bevel gear 4 fixed to the shaft 3 and the bevel gear 3. It is designed to be transmitted. 5 and 6 are type wheels that rotate together with the spline shaft 3, and one type wheel 5 is formed with only function symbols (for example, operation symbols such as +, -, ×, etc.), and the other Type wheel 6 has symbols representing numerical values (numbers, decimal point, and negative sign)
only is formed. The type wheel 5 for the function symbol is fixed to the spline shaft 3, and the type wheel 5 prints on the paper at a predetermined position on the paper (in this embodiment, the rightmost end in the line direction, that is, the unmarked position). digits). On the other hand, the type wheel 6 for numerical values is slidably installed on the spline shaft 3, and when the type wheel 6 prints on the paper, the type wheel 6 is shifted along the row direction by the equivalent of one character. It is configured as a so-called serial printing mechanism.

Reference numeral 7 denotes a magnetic retainer to which the type wheel 6 for numerical values is attached, and the magnetic retainer 7 has both ends connected to winding drums 8 and 9, respectively.
The holding body 7
is configured to move in the row direction. Reference numeral 11 denotes a support rod that is inserted through the holder 7, and its both ends are connected to the frame 1.
It is fixed at 2. 13 and 14 are type wheels 5 and 6
One of the ink rollers 13 is supported by the frame 12, and the other ink roller 14 is supported by the holder 7.

A support shaft 17 inserted through the rotation frames 15 and 16 is fixed to a bearing at both ends, and both rotation frames 15 and 16 are independently rotatable about the support shaft. 15a and 16a are striking bodies formed as parts of the rotating frames 15 and 16, respectively. A recording paper 28 is located between the type wheels 5 and 6 and the striking bodies 15a and 16a. A position detection plate 29 is fixed on the spline shaft 3 and has a magnet 29a attached thereto.The position of the magnet 29a is detected by the detection means 30, and becomes the starting position of the type wheels 5 and 6.

Next, the operation will be explained. First, the step motor 1 rotates in response to a print command, the position detection plate 29 rotates, the detection means 30 detects a signal opposing the start position, and the start position detection signal causes the counter to rotate. (not shown) operates to start counting. Here, when selecting "8" for the type wheel 6, the counter counts the signal from the pulse generator (not shown) for 8 pulses and rotates the step motor 1 by that amount. The upper "8" comes into play with the hitting body 16a. This is the selection process. Thereupon, the striking body 16a is driven by a plunger (not shown) or the like, and the recording paper 2 is
8 is printed. This is the printing process. After printing, the winding drum 9 rotates by a certain angle to move the holder 7 by one digit, and as a result, the type ring 6 is moved up by one digit. This is the carry process. This completes the steps of selecting, printing, and carrying one digit. Next, when selecting "5" for the type wheel 6, if the step motor 1 rotates the type wheel once with 11 pulses, the signal from the pulse generator is counted for 3+5 pulses. By rotating the minute step motor 1, the "5" on the type wheel 6 comes to the opposite surface of the striking body 16a. Then, the number "5" is printed on the recording paper by the striking body 16a. After printing, the winding drum 9 rotates by a certain angle to advance the type ring 6 by one digit. The above timing chart is as shown in FIG. In this way, each process of selection - printing - carry is repeated for the necessary digits,
When one line of printing is completed, the holder 7 is returned to its original position by the winding drum 8.

In this way, if you use the conventional printing method, you must select -
Each step of printing and carrying is required, which causes a decrease in the printing speed of one line of this type of serial printer.

The present invention eliminates these drawbacks and aims to increase the speed of serial printers.

A further object of the present invention is to simplify the mechanism, improve durability, and reduce costs by making the printing cycle of each digit of the serial printer at the same interval so that it operates as a cycle machine. be.

An embodiment of the present invention is shown in FIGS. 3, 4, and 5.
This will be explained using FIGS. 6 and 7.

The same numbers as in FIG. 1 are omitted because they indicate the same things and the same operations.

Reference numeral 20 denotes a preliminary selection member, which is engaged with the type ring 6 by a spring member 21. One end 24 of the spring member 21 is engaged with the type wheel 6, and the other end 25 is engaged with the protrusion 23 of the preselection member 20. 22
is a stopper that engages with the protrusion 23 and holds the preliminary selection member 20 and the type wheel 6 in a constant phase.
Reference numeral 17 denotes an ink roller that supplies ink to the type on the type wheel 6. Reference numeral 33 denotes a ratchet pawl located on the side of the type wheel 6, which corresponds to the type characters on the type wheel 6. Numeral 32 is a locking member that engages with the ratchet pawl 33 to lock the type wheel 6, and is operated by the plunger 31. The actuation of the plunger 31 causes the locking member 32 to engage one of the ratchet pawls 33 to lock the selected type on the type wheel 6. 35 is a striking member;
The selected type is printed on printing paper 28. 36 connects either the type wheel 5 or the type wheel 6 to the recording paper 2.
It is a mask that blocks against 8, and in this implementation,
During the standby period, the type ring 6 is shut off, and after printing the function symbol on the type ring 5, the type ring 5 is closed to the spring member 3.
7 to block the type wheel 5 and raise the type wheel 6 by one digit using the carry cam 43.
The type wheel 6 is removed from the mask 36, and thereafter the type ring 6 is removed from the mask 36 up to the highest digit. 40 is a motor;
It is meshed with the printing cam 42 via the gear means 41,
The printing cam 42 is set so that it can operate once in one printing cycle. Further, the carry cam 43 has a gear ratio set so that it can rotate one step after printing by the striking member 35 in a one-digit printing cycle, and functions as a cycle machine by the motor 40.

Next, the preliminary selection operation will be explained. First, the function symbol on the type wheel 5 is rotated and selected by the step motor 1 in response to a print command. Thereafter, the motor 40 rotates to operate the print cam 42 and carry cam 43 as a cycle machine, and the function symbol on the type wheel 5 is printed by the striking body 35 and, after printing, by the operation of the carry cam 43. The holder 7 is carried up by one digit. When this holder is moved up by one digit, the type wheel 5 is simultaneously moved up by one digit by the spring force of the spring member 37, and corresponds to the position of the mask 36, and from then on, the striking body 35 is moved up by one digit. Even if it operates, the characters on the type wheel 5 will not be printed. The step motor 1 rotates in synchronization with the rotation of the motor 40, rotates the preliminary selection member 20, and selects an arbitrary position (for example, the position corresponding to "8" on the type wheel 6). At this time, the type ring 6 does not rotate because the locking member 32 is engaged with the ratchet pawl 33 by the plunger 31. Preselection member 2 by step motor 1
After 0 is selected (this timing is when type wheel 6
(e.g. 11 pulse minutes),
By disengaging the ratchet pawl 33 of the type ring 6 from the locking member 32, the type ring 6 is moved from the spring member 2.
1 is rapidly rotated and moved to the same position as the preliminary selection member 20, and the stopper 22 and the protrusion 23 are moved to the same position as the preliminary selection member 20.
It stops at , and "8" on the type wheel 6 is selected. At the same time that "8" is selected, the plunger 31 again engages the locking member 32 with the ratchet pawl 33, and the type ring 6 is completely fixed in the selected position. This ends the selection of type wheels 6, but these selection periods end during the printing and carrying period of the type on the previous type wheel 5 (for example, the type wheel of a function symbol). It is set to do so. The operation of printing "8" on the next type wheel 6 will be explained. Since "8" of the type wheel 6 has already been selected in the previous printing one carry stroke, the rotation of the motor 40 causes the printing cam 42 and the carry cam 4 to operate as the above-mentioned cycle machine.
3 is driven, "8" is printed on the type wheel 6 by the striking body 35, and the holder 7 holding the type wheel 6 is carried up by one digit again by the carry cam 43. During this printing and carry operation, the next selection operation is performed simultaneously and in parallel. In this operation, as described above, the step motor 1 is first rotated in synchronization with the rotation of the motor 40, and the necessary type wheel "5" is rotated and selected. In this case, since the previous selection was "8", the total number of selection pulses for the printed character "5" is (11-8)+5=8 pulses. but,
There is another method for this selection pulse, for example, a method of resetting every selection and counting all from 0, and it is up to the designer to decide which method to use. In this embodiment, the preselection member 20 corresponding to the character "5" is selected by inputting eight pulses to the step motor 1. After that, after the printing of "8" on the type wheel 6 is completed, the engagement between the ratchet claw 33 of the type wheel 6 and the locking member 32 is released, and the type wheel 6 is disengaged from the locking member 32.
is rotated to the same position as the preliminary selection member 20 by the spring force of the spring member 21 in the same manner as described above, and the locking member 32 engages with the ratchet pawl again by the plunger 31, and the type ring 6 is completely brought to the selection position. Fixed. It is clear from the above description that this selection operation of the type wheel 6 takes place during the carry period after the previous printing. The timing chart of the invention described above is as shown in FIG.

As described above, according to the present invention, since the type wheel is selected in parallel with the printing one-carry process as a cycle machine, the selection process is more efficient than in the conventional serial printer of selection-print-carry. minute, or about 1/3 of an hour, making it possible to increase the speed.
Furthermore, since it suffices to use a mechanism that functions as a cycle machine that increases printing by one digit, the mechanism becomes simple, and quality can be improved and costs can be reduced.

[Brief explanation of drawings]

FIG. 1 is a plan view of a conventional serial printer, and FIG. 2 is a timing chart of the serial printer shown in FIG. FIG. 3 is a plan view of a serial printer which is an embodiment of the present invention, and FIG. 4 is a plan view of a type wheel 6 which is an embodiment of the present invention.
FIG. 5 is a diagram showing the relationship between the type wheel 6 and the spring member 21 according to an embodiment of the present invention, and FIG. FIG. 4 is a diagram showing the relationship among a motor 40, a gear 41, a printing cam 42, and a carry cam 43 in one embodiment. FIG. 7 is a timing chart of the present invention.

Claims (1)

[Scope of Claims] 1. A small serial printer in which a type ring having type on its surface is printed with a striking body selected by a selection means, and then the type ring is carried up, comprising: A preliminary selection member that selects the type to be printed in the next digit in advance between a printing process for printing the selected type on the type wheel and a carry process for carrying the type wheel after printing; a spring member that connects the type wheel and the preliminary selection member and applies a biasing force to the type wheel in the rotational direction of the preliminary selection member; and a locking means that locks the type wheel during an arbitrary period; A small serial printer, wherein the type wheel is rotated after printing to a position where the preliminary selection member is rotated first.