JPS6134991B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a key-controlled printing device, and more particularly to a printing device in which corrections, supplements, etc. of printed characters can be performed extremely easily and accurately.

In printing devices installed in conventional office computers, calculators, etc., or in key-controlled printing devices such as electronic typewriters, correcting or replenishing printed characters can be done by visually moving the carriage and printing paper, or by moving the printing paper. This was one of the most troublesome tasks even for experienced operators, as they had to remove it from the printing section of the main body and place it on the desk to make special corrections and additions using tools.

The present invention solves the above-mentioned difficulties and will be explained below with reference to the drawings.

Figure 1 shows an example of printing on printing paper P. For example, when a printing head using a petal-type type wheel is mounted on a carriage and the carriage moves from the left side to the right side, the letters A, B, a, b, etc. are printed. is printed at any digit position as shown in the figure based on the key command.

Also, when printing lowercase letters a, b, etc., reduce the paper feed pitch to, for example, 3/4.
Print as shown in the 4th line.

FIG. 2 is a block diagram of one embodiment of the present invention. KB is a keyboard with regular alphanumeric character keys KA~KZ, numeric keys, and other various control keys K1~K5 that give movement commands to the carriage.
It is equipped with a shift key K6 for giving a lowercase letter instruction.

CPU is a central processing unit, PF is a feed control unit for printing paper P, HD is a drive control unit for type wheel KH,
CA is a carriage that carries type wheel KH and moves from side to side, and CD is the drive control section of carriage CA, which is equipped with a pulse motor for driving. CC is a carriage position counter for detecting the carriage position, which appropriately counts drive pulses from the drive pulse motor, etc., and stores the carriage movement distance.
LB is a storage device (hereinafter referred to as line buffer) provided for correcting and replenishing printed characters.
It has a capacity of 300 characters per line. Inside, for example, as shown in Figure 3, one character digit is an address of three.
The types of printed characters, such as A, B, a, b=, . . . $, etc., are coded and stored at each address. At each address, the amount of carriage movement, ie, the printing pitch, corresponding to the size of each character is coded and stored. Further, even if the printing pitches for each character are the same value, the same value is temporarily stored at each address. Information related to printing formats such as underlined printing, overlapping printing, etc. is stored in each address.

In addition, as a prerequisite, regardless of the size of the characters to be printed, the printing pitch is set to a constant 1 printing pitch for each character, and the printing format is also special specifications such as simple printing of characters with underlining, overprinting, etc. This instruction is not given, and the paper feed pitch of the printing paper P is also set to the normal 1 pitch 1PF. Set the carriage CA to the left end of the printing paper P using the carriage return command key K1. Further, the printing paper P is fed one line. Alpha character A to be printed
When you enter from the keyboard KB, the address circuit AD
According to the instruction, code information representing the character type A is stored in the first address of the first character column of the row buffer LB. In addition, the address has the above-mentioned fixed printing pitch information.
1PT, and code information NMP, which means simple printing, is stored at the address.

When the type wheel KH starts rotating and the type A arrives at the printing position, the CPU takes in the contents of the first address of the first character column of the line buffer LB, and the well-known matching circuit outputs a match signal, and the character A Figure 1 1
The characters are printed as shown in the row and column, and the carriage CA is sent one character digit to the right by the carriage drive control unit HD. Next, when character B is input from the keyboard KB, the address circuit AD advances by one, and the row buffer
The first address of the second character digit of LB is designated, and the code information representing the character B is stored, and the same information 1PT and NMP as for the previous character A are stored at the next address.

Also, since the address circuit AD specifies the 2nd character digit 1 address of the row buffer LB, the CPU takes it in and performs a comparison match output detection in the same way as in the case of the character A, and as is well known, the character B is printed. Figure 1 1
This is done as shown in the row and column.

Also, at this time, the carriage position counter CC is 1.
The distance from the left end of the carriage, for example "2", is stored.

Similarly, when the character CD is input from the card board KB, the address circuit AD stores the code information of the characters C and D in each 1st address of the 3rd and 4th character digits, the same information 1PT and NMP as described above are stored in the address, and the 1st The letters C and D are printed as shown in the row and column of the figure.
Further, the carriage position counter CC counts and stores "4" to memorize the distance traveled by the carriage from the left end. Here, press the carriage return command key K1 on the keyboard KB. As a result, the address circuit AD specifies the first address of the fifth character digit of the row buffer LB, stores code information RET indicating the return or retraction of the carriage CA, and also specifies the moving distance "4" from the left end of the carriage CA. position counter
It is taken out from CC and stored as 4ST at that address according to the instruction from address circuit AD. Information 1PF for normal paper feed of 1 pitch is also stored at the address specified by the address circuit AD from within the CPU.

FIG. 3 shows the contents of the row buffers in which each printing state is stored. The carriage CA returns to the left end, and the printing paper P is fed upward by one normal paper feed pitch by the forward rotation of the feeding rubber roller RO, as is well known. It also resets the carriage position counter CC in the carriage drive control section CD. As shown in Figure 1, the next second line is printed as a blank character, so
Press the space key K3 on the keyboard KB to move the carriage CA one character to the right. At this time, the address circuit AD is 1 of the 6th character digit of the row buffer.
Specify the address and code information SPA that means empty delivery
Store. The address is printed with blank character digits.
1PT, and information NOP indicating no printing is stored at the address. In addition, the carriage position counter CC counts "2" as in the previous example, and after that, the characters E and F are input, and the code information representing the characters E and F, the print pitch, and the print type are set to the 7th and 8th character digits of the line buffer LB. are stored at each address, , . 1st
As shown in the figure, letters E and F are printed, and the carriage position counter CC counts and stores "3". Suppose that it is discovered that the character C in the first row needs to be modified to, for example, the character Y.
If you press the backtrace key K2, which is provided exclusively for corrections and replenishment, once (see step 4 in Figure 4),
_S1 ) The CPU reduces the address circuit AD by one in step _S2 , and takes in and decodes the contents of the seventh character column of the row buffer LB in step _S3 . As shown in Figure 3, the contents are NMP, 1PT, so the OPU takes the step of moving the carriage CA to the left by one printing bit.
_S4 . When the back trace key K2 is pressed once more, step _S1 , the address circuit AD changes from "7" to "6", and step _S2 , the 6th character digit of the row buffer LB is specified, and the CPU similarly decodes it. Step S ₃ , and step S ₄ to reach the left end, which is further moved one print pitch to the left. If the back trace key K2 is pressed one more time, step S ₁ occurs, and the fifth character digit of the line buffer LB is decoded by the CPU in steps S ₂ and S ₃ . This time, the CPU sends the paper feed 1 pitch, the carriage movement distance 4 steps, and the carriage return command.
is decoded, so the carriage CA advances from the left end to the right by four character digits, and prints the printed character D in the first column in Figure 1.
It will automatically stop at . At this time, the printing paper P is reversely fed downward by one paper feed pitch by the reverse rotation of the paper feed rubber roller RO (step S _{4 )} .

This allows the carriage CA to automatically reach the final character position one line before. After that, if the back trace key K2 is pressed once more, the step S ₁ carriage CA is sent to the left by one print pitch and reaches the position of the printed character C in the first column, so steps S ₂ , S ₃ , S ₄ , correction commands are executed. By pressing the key K6, the printed character C can be erased using the correction ribbon, and by inputting the sinful character Y, the character Y can be printed over it, and the contents of the line buffer LB can be erased according to the movement of the address circuit AD described above. is changed from C to Y. After completing the correction by repeatedly operating the back trace key K2 and the correction command key K6,
When the relocate key K5 is pressed, the CPU reads out the address "8" immediately before the back trace key K2 was pressed and stores the row buffer indicated by the current address value and the original address "8".
Performs calculations in the horizontal direction of LB and in the paper feed direction, and returns to the position on the paper just before K2 was pressed.
In this way, the line buffer LB serves as a means of storing information regarding the movement of the carriage CA equipped with the print head, and the CPU also stores the information stored in the memory means when it is necessary to correct the previous printed character after a line break. The movement distance information of the CA is traced back and deciphered, and based on the decoding result, the carriage CA is positioned tracing back to the previous line that has already been printed. It is understandable that the condition has been restored. Thereafter, the letters G, H, and I are input in the same manner as described above, and are stored in order in the row buffer LB by the address circuit AD, and the carriage position counter CC also increments to "6". When printing of the characters G, H, and I is completed, the carriage return command key K1 is pressed to return the carriage CA to the left end and feed the printing paper P one line. here,
If you want to print lowercase alpha characters on the third line, if you give an instruction from the keyboard KB to change the paper feed pitch from 1 to, for example, 3/4 before pressing the key K1, the printing paper P will be 3 when you press the key K1. / Only 4 lines are sent. From now on, as before, lowercase letters a, b,
... etc. are printed, and when feeding to the next 4th line.
If you send only 3/4 and print lowercase letters h, i, ..., etc., the result will be as shown in Figure 1. Further, as shown in FIG. 3, the line buffer LB sequentially stores information regarding printed characters, a carriage return command, a carriage movement distance, and a paper feed amount in the same manner as described above. In this way, even if the paper feed amount changes, each paper feed amount is memorized,
Similarly, even if the print pitch information changes for each character,
Since the fixed storage device in the CPU is provided with print pitch information for each character, it is sufficient to store different print information in the line buffer LB each time.
Also, when performing a backtrace for correction, press the backtrace K2 once and then press the repeat key K4 to read the address circuit AD, so the contents of the row buffer LB can be read by the CPU.
are read one after another, and the carriage CA returns in a continuous manner, allowing it to reach the corrected position at high speed.
At this time, after specifying the number of lines to return using the numeric keys on the keyboard KB, press the back trace key K.
2 and repeat key K4, it is possible to return to the line where printing was completed earlier.

That is, for example, if the number of printed characters is 300 or less, it is possible to go back any number of lines and bring the carriage to the position of the last printed character.

In the case of the example in Figure 1, if the 5th line is the printing position, after inputting the numeric key 4, by operating the keys K2 and K4, the carriage CA can be moved back 4 lines to the position of the printed character D in the 1st column. . For this purpose, a register is prepared to store the value 4, and when the carriage return command RET is detected midway, the carriage is not yet returned.
Carriage CA is executed at RET when the number of RET detections matches the contents of the register without stopping CA.
It is only necessary to configure it so that it starts and stops.

Since it is rare that a maximum of about 150 characters, for example, are all printed on the printing paper P as in the example in FIG. 1, the method of managing line buffers as in this embodiment is useful.

Further, there is no need to store all of the carriage return command, travel distance, paper feed amount, etc. as shown in the 34 character digits and 35 character digits in Figure 3.

For example, paper feeding may be performed manually, and the CPU can decipher and determine the carriage return command even if it is included in the carriage movement distance information itself.

In addition, if the row buffer LB is equipped with a battery B as shown in Figure 2, the contents of the row buffer LB will not volatize even if the power is turned off during work, making it easier to make previous corrections when work is resumed. can.

As explained above, according to the present invention, information regarding the distance traveled by the carriage is stored, and when it is necessary to correct printed characters in the previous line, the information on the traveled distance is decoded to move the carriage to the previous line with great accuracy. Since it is possible to go back to the position and return the carriage to its original state before the start of correction, it is possible to very easily correct the printed characters of the previous line and to return the carriage to its original state. An excellent effect can be obtained in that the operability of the machine can be improved.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram showing an example of printing, Fig. 2 is a block diagram of an embodiment of the present invention, Fig. 3 is a table showing an example of storing a row buffer, and Fig. 4 is a diagram for correcting printing according to the present invention. FIG. 3 is a flowchart showing the flow of control. CA...carriage, LB...row buffer, CPU
...Central processing unit, KB...Keyboard.

Claims (1)

[Scope of Claims] 1. A printing head capable of printing on printing paper, a moving means for moving the printing head in the horizontal direction, a paper feeding means for moving the printing paper forward and backward in the vertical direction, and the printing paper. a storage means for storing text information over a plurality of lines in the storage means; a first instruction means for instructing the printing head to face a preceding line associated with the text information in the storage means; and instructions of the first instruction means. first control means for controlling the printhead along the row in which the printhead is located on the recording medium or in response to a preceding row; a second instruction means for instructing to move the print head from the print head position to a specific position in the last line; means for determining from the current print head position and a specific position of the last line; and based on the determination by the determining means, controlling forward feeding by the paper feeding means and horizontal movement of the print head to move the print head to the desired position. and second control means for causing the last line to correspond to a specific position of the last line. 2. The printing device according to claim 1, further comprising means for correcting already printed characters on a line before the current line of the carriage.