JPH0399871A - Electronic typewriter - Google Patents

Abstract

PURPOSE: To increase the speed in the retreat operation of a carrier and to reduce noise by providing a control means rotating a carrier motor reversely by a predetermined angle prior to printing or erasing operation when there is input at first from a character key or an erasing designating function key and rotating a carrier motor in a forward direction by a predetermined angle to remove the backlash in the forward direction of a speed reducing gear mechanism. CONSTITUTION: When there is the input from a keyboard 10, an MPU 60 investigates whether the input is character input or function input. In the case of the function input, it is investigated whether the designated function thereof is one for moving a carrier 16. In the case of the function moving the carrier 16, it is investigated whether the moving direction of the carrier is a forward direction. If the moving direction of the carrier 16 is the forward direction, a flag is turned OFF and a carrier motor 20 is rotated in the forward direction by one character to shift the carrier 16 in the forward direction. If the shift direction of the carrier 16 is reverse, the flag is turned ON and the carrier motor 20 is reversely rotated by one character to reversely shift the carrier 16.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to electronic typewriters.

(Prior Art) The carrier of an electronic typewriter is moved by a carrier motor. The carrier motor is connected to the carrier via a reduction gear mechanism, and when the carrier motor rotates in the forward direction, the carrier moves forward, and when the carrier motor rotates in the opposite direction, the carrier moves backward. However, since the reduction gear mechanism is a combination of gears, basso crashes naturally occur in the gears. In normal use, the carrier moves forward, so the carrier motor rotates in the forward direction. If this state continues, the gears of the reduction gear mechanism will be in a state where the teeth are in contact with each other in the forward direction, and no deviation of the printing position due to backlash will occur. but,
For example, when a printed character is erased by retracting the carrier, the gears have backlash when the carrier motor rotates in the opposite direction, causing the teeth to be spaced apart from each other in the opposite direction.

When the carrier motor is rotated in this state, the amount of retraction of the carrier slightly deviates from the amount of advancement due to the backlash. If you erase this discrepancy,
It may not be possible to completely erase it. Therefore, in order to eliminate this problem, in conventional electronic typewriters, every time an instruction for retracting the carrier is input from the keyboard, the carrier motor is moved backwards by l characters plus an amount slightly greater than the amount to eliminate the bank lash of the gears of the reduction gear mechanism. Then, the carrier motor is rotated in the forward direction by an amount slightly equal to the amount of the line than the amount to remove the bank lash to remove the forward backlash and print or erase in the next forward direction. We are taking steps to prepare for the By performing this operation, it becomes possible to solve problems such as, for example, not being able to completely erase characters.

(Problems to be Solved by the Invention) However, the above conventional backlash removal method has the following problems.

In the conventional method described above, a backlash removal operation is performed every time the carrier is moved back by one character. Therefore, if you move back several characters in a row, you will receive the same number of barakuras as the number of characters.

There is a problem that if the target position is far away, it takes time to perform the backward movement.

Further, there is a problem in that when the number of backlash operations is large, the number of times noise is generated increases.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an electronic typewriter that can speed up the retraction operation of the carrier and reduce the noise generated during the retraction operation.

(Means for Solving the Problems) In order to solve the above problems, the present invention includes the following configuration. That is, a keyboard including a space and having a character key for instructing the character to be printed, and a function key for instructing functions such as erasing the printed character and retracting the carrier, and connected to the carrier through a reduction gear mechanism. a carrier motor that advances the carrier when rotated in the forward direction and retreats the carrier when rotated in the reverse direction, and whether the carrier motor is rotating in the forward direction;
a motor rotation detecting means for detecting whether the carrier motor is rotating in the opposite direction; and after the motor rotation detecting means detects rotation of the carrier motor in the opposite direction by two characters or more, first instructing the character key or deletion. When there is an input from a function key, the carrier motor is rotated by a predetermined angle in the reverse direction prior to the printing or erasing operation, and then the carrier motor is rotated by the predetermined angle in the forward direction, and the reduction gear mechanism is rotated in the order of the reduction gear mechanism. The electronic typewriter is characterized by comprising a control means for eliminating backlash in the direction,
The predetermined angle is set to be slightly larger than an angle at which backlash of the reduction gear mechanism can be eliminated.

(effect) The effect will be explained.

After the backward instruction is input, the backlash removal operation is not performed unless an input specifying a character or an input specifying deletion is input from the keyboard.

Therefore, since the backlash removal operation is performed only once in - times of retraction (including continuous retraction), it is possible to speed up the retraction of the carrier, and it is also possible to suppress noise during the backlash removal operation.

(Embodiments) Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

First, the configuration will be explained with reference to FIG. 1 (a perspective view of an electronic typewriter according to an embodiment) and FIG. 2 (a block diagram thereof).

IO is a keyboard, which has character keys for specifying letters, numbers, and symbols (hereinafter referred to as characters) including spaces to be printed on the paper surface 14 of the paper 12, as well as for selecting uppercase and lowercase letters of the alphabet, and for erasing printed characters. It is composed of function keys for instructing functions such as instructions and instructions for reversing the carrier.

The carrier 16 is adapted to be shifted in the left-right direction by a carrier motor 20 driven via a carrier driver circuit 18. For example, the carrier 16 rotates for one character (for example, one
/10 inch) is designed to shift left and right. When the carrier motor 20 rotates in one direction (forward direction), the carrier 16 shifts to the right (forward), and the carrier motor 2
When 0 rotates in the other direction (opposite direction), it shifts to the left (retreats). The carrier 16 is provided with a type wheel 22 commonly called a daisy wheel, and the type wheel 22 is attached to a wheel motor 26 that is driven via a wheel driver circuit 24.
Type is selected depending on the rotational position of the . The selected characters are struck onto the paper surface 14 by the type hammer 28 via the ink ribbon 27 and printed on the paper surface 14. That type of hammer 28 is actuated by a hammer solenoid 32 driven by a hammer driver circuit 30.

34 is an erasing tape. For example, when the character rAJ is mistakenly printed on the paper surface 14, the erasing key of the keyboard 10 is pressed and the erasing tape 34 and the character rAJ of the type wheel 22 are pressed so as to face the erroneous character rAJ on the paper surface 14. move the
Hit type rAJ with type hammer 28 (erasure hammering). Then, the ink is peeled off from the adhesive surface of the erasing tape 34 on the paper surface 14 side, and the characters on the paper surface 14 can be erased. At that time, the type wheel 22
Movement of the eraser tape 34 up between the type and the paper surface 14 is effected by actuation of a tape lift solenoid 38 driven by a tape lift driver circuit 36. Further, when erasing is completed -1, the erasing tape 34 is wound up by one character. The winding is done by the tape winding driver circuit 40.
This is performed by a tape winding mechanism 42 driven by.

The paper 12 is pressed against the outer peripheral surface of a platen 44 by a roller (not shown) or the like, and by rotating the platen 44, it is possible to change the printing line. The platen 44 rotates with the rotation of a platen motor 48 driven by a platen driver circuit 46, thereby enabling a changeover operation. For example, the platen motor 48
When the platen 44 rotates three times, the platen 44 rotates by one line.

The electronic typewriter according to the present invention is controlled by a microcomputer, and the system will be explained.

50 is a RAM, which includes a first memory 52.

The first memory 52 stores the characters input from the keyboard 10 and printed on the paper surface 14, and also stores the printing position of the printed characters on the paper surface 14. The printing position is constantly detected by a microprocessor (MPU) 60, which is a motor rotation detection means, a control means, and the like. The printing position in the left-right direction with respect to the paper surface 14 can be determined by the MPU 60 measuring the rotation direction and amount of rotation of the carrier motor 20, and can be determined by the distance from the home position, for example.

On the other hand, the printing position in the vertical direction with respect to the paper surface 14 can be determined by the MPU 60 measuring the rotation direction and amount of rotation of the platen motor 48, and can be determined, for example, by the distance from the printing start line.

The MPU 60, as a control means, controls the operation of the electronic typewriter according to the control program 82 loaded in the ROM 80, and please refer to FIGS. 3 and 4 for the backlash removal operation that is the most characteristic feature of the present invention. and explain.

FIG. 3 shows an output gear 54 attached to the output shaft of the carrier motor 20 and a reduction gear 56 constituting a reduction gear mechanism for reducing its rotational speed.

In normal operating conditions, the output gear 54 rotates in the forward direction of arrow A with respect to the carrier motor 20. At that time, output gear 5
4 and the reduction gear 56 are in contact at a point 58, and the back rough sea 1.62 is on the rear side of the rotation direction A of the output gear 54, so the positional deviation of the print due to the backlash 62 during printing etc. Does not occur. The problem is "conventional technology"
This is a case where the carrier 16 is retracted as described in the section. When there is an input from the keyboard IO (step 100 in the flowchart in FIG. 4), the MPU 60 checks whether the input is a character input or a function input (step 102).
. In the case of function input, the specified function is carrier 1.
6 movement (shift) (step 104).
). If the carrier 16 is moving, it is checked whether the direction is the forward direction (step 106). If the moving direction of the carrier 16 is the forward direction, the flag is turned OFF (step 10B), the carrier motor 20 is rotated by one character in the six arrow directions (forward direction), and the carrier 16 is shifted in the forward direction (step 110). Return to 100 and wait for the next input. If the carrier 16 is shifted in the opposite direction in step 106, the flag is turned on (step 1
22) The carrier motor 20 is rotated by one character in the direction of arrow B (reverse direction) to shift the carrier 16 in the opposite direction (step 124), and the process returns to step 100 to wait for the next input.

Note that in step 104, the function input is performed on the carrier 16.
If it is not a movement, the instructed function is performed (step 120), and the process returns to step 100 to wait for the next input.

For example, if there is an input to instruct the carrier 16 to retreat five times in a row, steps 106 to 122.
The routine of passing through 124 and returning to step 100 is repeated five times. Then, if a character indicating printing is input from the keyboard 10 after that, the process goes from step 102 to step 112 (in step 112, the flag is set to 0).
Check N10FF. At this time, since the flag is in the ON state in step 122, the process goes to step 114 and a backlash removal operation is performed.

The backlash removal operation will be explained with reference to FIG.

When the carrier motor 20 is rotated in the forward direction (direction A) as shown in FIG. Gears 56 abut and rotate relative to each other at point 59.

At this time, the output gear 54 rotates by a predetermined amount since the carrier motor 20 rotates by a predetermined amount. However, since backlash 62 exists in the reduction gear 56, the amount of rotation decreases by the amount of backlash 62 from the originally set amount of rotation.

In this state, after a printing instruction is input again and printing is performed, when the carrier motor 20 rotates in the direction of arrow A, the forward shift amount of the carrier 16 decreases by the amount of backlash 63 on the front side in the direction of arrow A. I end up doing it.

Therefore, the inventor of the present invention took into consideration that backlash does not accumulate no matter how many characters the carrier 16 retreats, and when the flag is ON and a character key instructing printing or a function key instructing erasing is input. The backlash removal operation is now performed only when the In this operation, the carrier motor 20 is first rotated in the direction of arrow B by a predetermined amount slightly larger than the amount that can eliminate the backlash 62.

Then, at point 59, output gear 54 and reduction gear 56
Even if they are not in contact with each other, both gears 54 and 56 can be brought into contact at a point 59 (FIG. 3(b)).

Then, reversely, the carrier motor 2o is rotated in the direction of arrow A by the same amount as the predetermined amount, and the output gear 54 and the reduction gear 56 are rotated.
are brought into contact at point 58 (Fig. 3(C)).

Thereby, even if the carrier 16 is shifted in the forward direction after printing, it is possible to prevent the shift amount of the carrier 16 from decreasing due to backlash 63. Note that the predetermined amount by which the carrier motor 2o is rotated in this embodiment is
This is the amount that can shift the distance by 1/20 inch.

When the above backlash removal operation is completed, turn off the flag.
It is set to FF (step 116), a printing operation (including a forward shift after printing) is performed (step 118), and the process returns to step 100 to wait for the next input.

Note that the above operation example is the printing operation after the carrier 16 has retreated, but if it is checked in step 102 whether or not it is erased, and the erasing operation is performed in step 118, the printing operation after the carrier 16 is retreated. Backlash removal operation becomes possible during erase operation.

Furthermore, as an application example, the reduction gear mechanism and the carrier are connected by a timing belt 1, wire, etc.
Timing belts, wires, etc. tend to temporarily stretch when reversing the vehicle, and this stretch may cause positional displacement similar to bank crash. Therefore, the positional deviation caused by the elongation of the timing belt, wire, etc. may be removed by rotating the carrier motor by a predetermined amount in the backlash removal operation.

Although various preferred embodiments of the present invention have been described above, the present invention is not limited to the above-mentioned embodiments, and it goes without saying that many modifications can be made without departing from the spirit of the invention. .

(Effects of the Invention) When the electronic typewriter according to the present invention is used, the backlash removal operation only needs to be performed once regardless of how many characters the carrier is retreating, thereby increasing the carrier's retreat speed. be able to.

Further, since noise is generated only once during the backlash removal operation, there is an effect that quiet operation is possible.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing an embodiment of an electronic typewriter according to the present invention, Fig. 2 is a block diagram thereof, Fig. 3 is a partial view showing the relationship between an output gear and a reduction gear, and Fig. 4 is a back view. Flowchart showing lash removal operation. 10...keyboard, 16...carrier, 20
...Carrier motor, 54...Output gear,
56...Reduction gear, 60...MPUG2.63
...backlash. Figure Figure Figure Figure

Claims (1)

[Claims] 1. A keyboard including a space and having a character key for instructing a character to be printed, and a function key for instructing functions such as erasing a printed character and retracting a carrier; and a reduction gear mechanism. a carrier motor that is connected to the carrier via a carrier motor that advances the carrier when it rotates in the forward direction and retreats the carrier when it rotates in the reverse direction; motor rotation detection means for detecting whether the carrier motor is rotating in the opposite direction; and after the motor rotation detection means detects rotation of the carrier motor in the opposite direction by two or more characters;
When an input is first made from the character key or a function key instructing erasing, the carrier motor is rotated in the opposite direction by a predetermined angle prior to printing or erasing operation, and then the carrier motor is rotated in the forward direction by the predetermined angle. An electronic typewriter characterized by comprising: a control means for rotating the reduction gear mechanism by an angle to eliminate forward backlash of the reduction gear mechanism. 2. The electronic typewriter according to claim 1, wherein the predetermined angle is set to be slightly larger than an angle capable of eliminating backlash of the reduction gear mechanism.