JPS6134398B2 - - 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 wheel is mounted on a carriage and the carriage moves from the left side to the right side, the alphabet letters A, B, a, b, etc. are printed. Based on the key command, it is printed at any digit position as shown in the figure.

Also, when printing lowercase letters such as a and b, reduce the paper feed pitch to, for example, 3/4.
Print like the 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 central processing unit, PF is printing paper P
HD is the drive control unit for the type wheel KH, CA is the carriage that carries the type wheel KH and moves from side to side, and CD is the drive control unit for the carriage CA, which includes 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, and has a capacity of 300 characters for two lines, for example. Inside, for example, as shown in Figure 3, an address with three digits per character,
, and 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. When the alpha character A to be printed is entered from the keyboard KB, the address circuit
In response to an instruction from AD, code information representing character type A is stored at the address of the first character digit of row buffer LB. In addition, the address has the above-mentioned fixed printing pitch information 1.
PT, and code information NMP, which means simple printing, is stored in 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 address of the first character digit of the line buffer LB, and the well-known matching circuit outputs a match signal, and the character A reaches the printing position. 1 figure 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 address of the second character digit of LB is designated, and 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 printing digit 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 above, and as is well known, the printing of the character B is the first one. 1 figure 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 CA, for example "2", is memorized.

Similarly, when characters C and D are entered from the keyboard KB, the address circuit AD stores the code information of the characters C and D in each address of the 3rd and 4th character digits, and the same information 1PT and NMP as described above are stored in the address. As shown in the first row and column of FIG. 1, letters C and D are printed, and a 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 address of the 5th character digit of the row buffer LB, stores the code information RET indicating the return or retraction of the carriage CA, and also sets the moving distance "4" from the left end of the carriage CA to the carriage position. It is taken out from the counter CC and stored as 4ST at that address according to the instruction from the address circuit AD. Further, the 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 buffer that stores each printing state. 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 FIG. 1, since the next second line is to be printed as a blank character, press the space key K3 on the keyboard KB to move the carriage CA one character to the right. At this time, the address counter AD specifies the address of the 6th character digit of the row buffer and stores code information SPA indicating a blank feed. The printing pitch 1PT of the blank character digit is stored in the address, and the information NOP indicating no printing is stored in the address. In addition, the carriage position counter CC counts "2" as in the previous example, and then inputs the letters E and F to obtain code information representing E and F.
Print pitch and print type are line buffer LB 7 and 8
It is stored at each address of each character digit. As shown in Figure 1, letters E and F are printed,
Further, 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. When the back trace key K2, which is provided exclusively for correction and replenishment, is pressed once (step S1 in Figure 4), the CPU decrements the address circuit AD by one (step S2), and the 7th character column of the line buffer LB is The content is taken in and decoded (step S3).
As shown in FIG. 3, the contents are NMP, 1PT, so the CPU sends the carriage CA to the left by one print pitch (step S4). When the back trace key K2 is pressed once more (step S1), the address circuit AD changes from "7" to "6" (step S2), indicating the 6th character digit of the row buffer LB, and the CPU similarly Decipher (Step S)
3), it is further sent to the left by one print pitch and reaches the left end (step S4). Pressing the back trace key K2 one more time (step S1)
The fifth character digit of the row buffer LB is decoded by the CPU (steps S2 and S3). This time, feed the paper one pitch,
Carriage movement distance is 4 steps, and the CPU decodes the carriage return command, so the carriage CA moves to the right by 4 character digits from the left end and automatically stops at the printed character D in the first line of Figure 1. 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 S4).

This allows the carriage CA to automatically reach the final character position one line before. After that, if you press the back trace key K2 once more (step S1), the carriage CA will be sent one print pitch to the left and reach the position of the printed character C in the first column, so (steps S2, S3, S4), you can make corrections. By pressing the command key K6, the printed character C can be erased using the correction ribbon, and then by inputting the character Y, the character Y can be printed on top of it.The content of LB changes from C to Y according to the movement of AD described above. will be changed to

In this way, the line buffer LB serves as a storage means for information regarding the movement of the carriage CA carrying the print head, and the CPU stores information in the storage means when it is necessary to correct printed characters on the previous line after a line feed. It can be seen that control is performed to retroactively decode the moving distance information of the carriage CA in the current position, and to position the carriage CA by tracing back to the previous line that has already been printed based on the decoding result.

After completing the correction by repeatedly operating the back trace key K2 and the modification command key K6, when the relocate key K5 is pressed, the CPU returns to the address "8" immediately before the back trace key K2 was pressed.
Read out and calculate the horizontal direction of LB indicated by the current address value and the original address "8",
Calculations are made in the paper feed direction and the process returns to the position on the paper immediately before K2 was pressed. From then on, as above, the letter G,
Input H and I, address circuit to row buffer LB
The values are sequentially stored by AD, and the carriage position counter CC also increments to "6". Letters G, H,
When I is finished printing, press the carriage return command key K.
Press 1 to return the carriage CA to the left end and feed the printing paper P one line. If you want to print lowercase alphanumeric characters on the third line, change the paper feed pitch from 1 to 3/3, for example, before pressing key K1.
If you give the instruction to change to 4 from the keyboard KB,
When key K1 is pressed, only 3/4 lines of printing paper P are fed. From then on, lowercase letters a, b, ..., etc. are printed in the same way as before, and when feeding to the next 4th line, feed only 3/4 line and print lowercase letters h, i, ..., etc. It will look like the figure. Also, row batshua LB is the third
As shown in the figure, information regarding printed characters, carriage return command, carriage movement distance,
The paper feed amount is memorized one after another. In this way, even if the paper feed amount changes, each paper feed amount is memorized, and similarly, even if the print pitch information changes for each character, the print pitch information for each character is stored in the fixed storage device in the CPU. Because there is, I have to go back every time
It is sufficient to store different printing information in LB. Also, when performing backtrace for correction, if you press the backtrace key K2 once and then continue to press the repeat key K4, the address circuit AD will repeat subtraction, so the contents of the row buffer LB will be read into the CPU one after another. Furthermore, since the carriage CA returns continuously, it can 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 K2.
By operating the repeat key K4, it is possible to return to the line where printing was completed earlier.

That is, for example, within 300 printed characters, 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 print 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 first column. . To do this, prepare a register to store the number 4, and when the carriage return command RET is detected midway, the carriage is still
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 the maximum number of characters, 150 characters, are all printed on the printing paper P as in the example shown 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.

Furthermore, 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 switch is turned off during work, making it easier to make previous corrections when resuming work. 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 becomes possible to control the positioning retroactively,
This provides excellent effects such as being able to very easily correct the printed characters of the previous line and improving the operability of the printing device.

[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 carriage equipped with a printing head capable of printing on printing paper and movable in the horizontal direction; a paper feeding means for moving the printing paper forward and backward in the vertical direction; and a plurality of lines on the printing paper. a storage means for storing text information necessary to print a text over the entire length; and an instruction means for directing the head on the carriage to face a predetermined position on the current line where the head on the carriage is located and on the previous line preceding the current line. and an instruction signal output means for outputting a signal instructing a line feed, and a carriage horizontal position necessary to move the carriage from the position of the head on the carriage of the current line to a predetermined position on the previous line immediately before the line feed to the previous line. carriage movement control means for controlling movement in the direction based on the text information stored in the storage means; and carriage movement control means for controlling the paper feed based on a line feed instruction signal output from the signal output means in response to an instruction from the instruction means. The means feeds the printing paper in a direction opposite to the normal line feed direction, the previous line of the printing paper faces the front of the head on the carriage, and the carriage is moved by the carriage movement control means to feed the previous line. A printing device having control means facing each other at a predetermined position. 2. The printing device according to claim 1, comprising means for correcting already printed characters on a line before the current line of the carriage.