JPS6319158Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to an electronic typewriter, and more particularly to type selection on a type wheel.

[Prior art and problems to be solved by the invention] Conventionally, in an electronic typewriter that rotates a type wheel in response to an input from a keyboard to perform a predetermined printing operation, it is difficult to select the type that corresponds to the input key. Closed-loop control is used to control the motor for driving the type wheel, which rotates the type wheel to the printing position, by controlling the drive of the motor while constantly feeding back the current rotational position of the type wheel. is very complex and expensive to manufacture.

Another method is to generate a predetermined amount of rotation by comparing code signals corresponding to successively operated keys on the keyboard, regardless of the current rotational position during rotation of the type wheel. An open-loop control is possible in which the number of pulses is sent to a pulse motor for driving the type wheel. This method has a simpler and cheaper control system than the above-mentioned method, but on the other hand, there is a possibility that accurate rotational drive of the type wheel cannot be obtained due to external factors.

[Purpose of the invention] The present invention has been made to solve the above-mentioned problems. By correcting the rotational position of the type wheel when the space key is pressed, printing errors can be prevented, and the control system can be improved. To provide an electronic typewriter that is simple and inexpensive.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention provides a pulse motor that moves printed characters selected by operating keys on a keyboard to a printing position, and a drive that drives the pulse motor. and an arithmetic control circuit comprising an open-loop control that compares input data successively sent from the keyboard and sends a drive signal to the drive circuit, the electronic typewriter having a type wheel. a notch formed in one part and arranged to match the printing position when the type wheel stops at a specific stop position; and a detection means for detecting that the type wheel is at the specific stop position; It is characterized by comprising a rotation control circuit that outputs a drive signal to the drive circuit until a specific position of the type wheel is detected by the detection means, regardless of the arithmetic control circuit, when the space key is operated. It is something to do.

[Function] In this way, normally the arithmetic control circuit compares the input data sent successively from the keyboard and sends a drive signal to the drive circuit to drive the pulse motor and rotate the type wheel. let me,
Printed characters corresponding to key inputs are placed at printing positions and predetermined printing operations are performed. When a space key is input from the keyboard, the rotation control circuit outputs a drive signal to the drive circuit until a specific stop position of the type wheel is detected by the detection means, regardless of the arithmetic control circuit. By rotating the type wheel and stopping it at a specific stop position, it is possible to make sure to correct the rotational position of the type wheel on a word-by-word basis and to check whether or not the characters are correctly printed on the printing paper.

[Embodiment] Hereinafter, an embodiment of the present invention will be described in detail with reference to FIGS. 1 to 3.

FIG. 1 shows a schematic configuration diagram of an electronic typewriter according to the present invention, in which a platen 1 is loaded with printing paper. The carriage 2 is moved in parallel along the longitudinal direction of the platen 1 by a drive motor 3. A large number of type characters 7 are arranged around the type wheel 4, and a cutout portion 4a without the type characters 7 is provided in a part of the wheel 4 so that characters etc. printed on the printing paper can be clearly seen. Further, the type wheel 4 is mounted on the carriage 2 so that the notch 4a coincides with the printing position on the printing paper when the type wheel 4 stops at a specific stop position which will be described later. Further, the carriage 2 is equipped with a driving pulse motor 5 for rotationally driving the type wheel 4, a printing hammer 6 for hitting the type 7 on the type wheel 4 that has reached the printing position toward the printing paper, and the like. There is.

FIG. 2 is a block diagram of an electronic typewriter having such a configuration, and the keyboard 11 has character/symbol keys, a space key, function keys, etc. The input control circuit 12 sends code signals corresponding to key signals from the keyboard 11 to a function processing circuit 17, an arithmetic processing circuit 13, and a rotation control circuit 15.
Output to. The arithmetic processing circuit 13 is connected to the keyboard 1
1 and input control circuit 12 are compared, and a predetermined number of pulses for a rotation amount is sent to the drive circuit 14 based on the comparison result. The drive circuit 14 drives the pulse motor 5 for rotationally driving the type wheel 4 based on input signals from the arithmetic control circuit 13 or the rotation control circuit 15. The detection device 16 outputs a detection signal to the rotation control circuit 15 when the type wheel 4 reaches a specific stop position.

Next, the character selection and printing operation of the character wheel 4 in the electronic typewriter configured as described above will be explained.

As a specific example, a printed example of the sentence ``This〓invention〓...'' (where 〓 indicates a space) as shown in Fig. 3 is used. First, when the character/symbol key "T" on the keyboard 11 is operated, the key signal is input to the input control circuit 12, and a code signal corresponding to the key signal is output to the arithmetic control circuit 13. Then, the arithmetic control circuit 13 compares the code signal based on the character/symbol key "T" with the code signal of the print character currently facing the print position in order to rotate the print character "T" to the print position. The required rotation amount of the type wheel 4 is calculated as a number of pulses and sent to the drive circuit 14.
The drive circuit 14 rotates the pulse motor 5 based on this number of pulses, and rotates the type character "T" on the type wheel 4.
is brought to the printing position, and the printing hammer 6 is driven to print the letter "T" on the printing paper via a printing ribbon (not shown). Thereafter, the carriage 2 is moved parallel to the platen 1 by one character to the right by the drive motor 3. Next, the keyboard 11
When the upper character/symbol key "h" is operated, the key signal is input to the input control circuit 12, and the corresponding code signal is output to the arithmetic control circuit 13. Therefore, the arithmetic control circuit 13 compares the code signal corresponding to the character/symbol key "h" with the code signal corresponding to the previously operated character/symbol key "T", and replaces the printed character "T" with the code signal corresponding to the character/symbol key "T" operated immediately before. Then, the number of pulses required to bring the printed character "h" to the printing position is calculated. Based on this, the drive circuit 14 rotationally drives the pulse motor 5 to print the character "h" on the character wheel 4, and the carriage 2 further moves to the right by one character. Hereinafter, when the character/symbol keys "i" and "s" are operated in the same manner as described above, the characters "i" and "s" are printed on the printing paper.

Next, when the space key is operated, the key signal is output to the input control circuit 12, and the input control circuit 12 sends a predetermined code signal to the function processing circuit 17,
It is output to the calculation control circuit 13 and the rotation control circuit 15. As a result, the function processing circuit 17 drives the drive motor 3 to move the carriage 2 one character to the right. Furthermore, the arithmetic processing circuit 13 does not perform arithmetic processing to calculate the required amount of rotation as described above, only stores a code signal corresponding to the space key, and does not output a drive signal to the drive circuit 14. On the other hand, the rotation control circuit 15 receives a code signal corresponding to the space key from the input control circuit 12.
outputs a drive signal to the drive circuit 14, and this drive signal is detected by the detection device 16 as a detection signal indicating that the type wheel 4 has reached a specific stop position, that is, the notch 4a shown in FIG. 1 has reached the printing position. Continuous output until input. As a result, the type wheel 4 is rotated and stopped at a specific stop position, and as a result, the rotational position of the type wheel 4 is corrected. Also, at this time, the notch 4a faces the printing position, so the operator can know whether the rotational position correction has been performed reliably, and can also check whether the printing on the printing paper is correct. can.

Then, when the character/symbol key "i" is operated, the arithmetic control circuit 13 outputs the code signal corresponding to the previous space key (specific stop position) and the character/symbol key "i".
A predetermined arithmetic operation is performed using the code signal corresponding to the symbol key "i", and a drive signal is sent to the drive circuit 14. The drive circuit 14 rotates the type wheel 4, and the printing hammer 6 is driven to print the letter "i".

As mentioned above, this electronic typewriter does not particularly feed back position signals during the printing operation, but rotates the type wheel 4 by comparing code signals corresponding to sequentially operated keys. This is based on open-loop control such that predetermined printing is performed. Therefore, in such a rotary drive, there is a possibility that the type wheel 4 may not reach a predetermined rotational position midway due to an unexpected accident caused by external factors, etc. is operated, the detection operation 16 detects that the type wheel 4 has actually reached a predetermined rotational position, the rotation control circuit 15 and the drive circuit 14 rotate the type wheel 4, and the specified rotational position is detected. The control system is designed to be stopped at a stop position (reference position), and the control system is simpler and cheaper than a closed-loop control system that constantly feeds back the current rotational position. By operating the space key in this manner, the rotational position of the type wheel can be reliably corrected by at least the number of words for one print line, and printing errors can be prevented. Even if a rotational positional shift occurs, only one word will be misprinted. In addition, since the notch 4a always faces the printing position when correcting the rotational position, it is possible to know whether or not the rotational position correction has been performed reliably, and also whether or not the previous printing was performed correctly. , corrective action can be taken immediately.

Note that the rotational position of the type wheel may also be corrected when a specific character/symbol key that is frequently operated is operated.

[Effects of the invention] As described in detail above, the present invention includes a pulse motor that moves printed characters selected by operating keys on a keyboard to a printing position, a drive circuit that drives the pulse motor, and an electronic typewriter comprising an arithmetic control circuit that performs open-loop control that compares and calculates input data sent to the drive circuit and sends a drive signal to the drive circuit;
A notch formed in a part of the type wheel and arranged to match the printing position when the type wheel stops at a specific stop position, and a detection device for detecting that the type wheel is at a specific stop position. and a rotation control circuit that outputs a drive signal to the drive circuit until a detection signal from the detection means is obtained when the space key is operated, thereby ensuring that the type wheel is stopped at a specified position at least every time a word is input. position and correct the rotational position of the type wheel, thereby preventing printing errors. Even if rotational position deviation occurs, only one word will be incorrectly printed. If a printing error occurs, since the notch faces the printing position, it can be detected quickly and corrective action can be taken immediately. Another object of the present invention is to provide an electronic typewriter having a simple and inexpensive type wheel rotation control system.

[Brief explanation of the drawing]

Figure 1 is a schematic configuration diagram of an electronic typewriter, Figure 2
The figure is a block diagram, and FIG. 3 is an example of printing on printing paper. In the figure, 4 is a type wheel, 4a is a notch, 5 is a pulse motor, 7 is a type, 11 is a keyboard, 1
3 is an arithmetic control circuit, 14 is a drive circuit, 15 is a rotation control circuit, and 16 is a detection device.

Claims (1)

[Claims for Utility Model Registration] A keyboard having multiple keys such as a character/symbol key, a space key, and a function key, a type wheel around which a large number of characters corresponding to the character/symbol keys are arranged, and the characters・A pulse motor that moves the type on the type wheel to the printing position by operating a symbol key, a drive circuit that drives the pulse motor, and input data sent in succession from the keyboard are compared and calculated. An electronic typewriter comprising an arithmetic control circuit that performs open-loop control that sends a drive signal to the drive circuit, and sequentially drives the type wheel to rotate to execute a predetermined printing operation, the typewriter being formed on a part of the type wheel. , a notch arranged to match the printing position when the type wheel stops at the specific stop position, a detection means for detecting that the type wheel is at the specific stop position, and the space key and a rotation control circuit which, when operated, outputs a drive signal to the drive circuit until a specific stop position of the type wheel is detected by the detection means, regardless of the arithmetic control circuit. typewriter.