JPS58160180A - Printing apparatus - Google Patents

Abstract

PURPOSE:To obtain a printing apparatus enabling the erasure of an undesired character and the printing of a correct character without fail by a simple operation, by a constitution wherein a printing type is shifted vertically to the direction of the escapement of a carriage and operated in a plurality of times to erase the character. CONSTITUTION:A head carriage 1 is provided with a ribbon shifting mechanism 6, whereby a ribbon is lifted in the direction shown by an upward arrow. When the ribbon shifting mechanism 6 is driven, an erasing ribbon 5 is made effective, while a printing ribbon 4 is made effective in the ordinary state wherein the mechanism is not driven. A plurality of erasing operations are performed right on an undesired character already printed and vertically to the direction of the escapement of the head carriage.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a printing device used in the evening, evening, etc., and more particularly to a printing device having a mechanism for erasing characters once printed.

In recent years, many impact typewriters have been equipped with a so-called double-strike type print erasing mechanism, in which an erasing ribbon is placed on top of the printed literature and the same type is struck to erase the text. Now you can. For many typists, it's a great blessing to no longer have to make time-consuming and unpleasant corrections with an eraser, but overstrike erasing is a typeface with a coating of the same color as the type paper. It is possible to double strike the same type as the undesired characters through eraser tape coated with the material, or use adhesive tape (double strike and remove the ink from the undesired characters). Erasing can be done quickly and cleanly compared to traditional methods, and the erased areas are less noticeable.

Nevertheless, many high-end impact typewriters do not have an overlapping type erasing mechanism. This is because this desirable mechanism still has many drawbacks, as discussed below.

First, in typewriters that use flexible spokes made of plastic or other material around the outer periphery of a petal-shaped wheel and a carriage with type formed on the tip, the precision and operating accuracy of the carriage installation is very high once printing is completed. The problem is that it is not sufficient to engrave exactly the same type on a character, and if you try to improve the accuracy sufficiently, it will result in high costs.

In order to avoid this problem, a method has been proposed in which the conventional double-strike type erasing mechanism uses special type for erasing, which can cover the printing area of all the type within an operational error. However, this method has the disadvantage that it is necessary to add type that cannot be used for printing, and that the special type is used in a relatively large impact area, which can damage the type paper.

Furthermore, against this background, the following invention has been disclosed (Public Notice Sho 56-46992). That is, when erasing undesired characters by overstriking, one side of the type is moved in the direction of the escapement of the carriage. This is a method in which overlapping is performed twice, by shifting to the side and overlapping, then shifting to the other side and performing overlapping again.

According to this method (2), complete erasure can be performed even in the ordinary assembly accuracy and operation accuracy range (2).

However, when this method is applied to modern electronic typewriters, the following problems arise.

Many modern electronic typewriters allow you to type underlined characters with a single keystroke. FIG. 1(a) shows the result of printing continuous underlined characters "143ts" using such a typewriter. If you want to retype ``SAT'' with ``DAN'', use the above-mentioned overstrike method to erase the underlined type ``TO'' over ``±'' using the erasing ribbon little by little left and right in the escapement direction. Shift it and hit it twice. The result of this erasing is shown in Figure 1. Since the erasing is performed twice, an area wider than the print area in the left and right direction (2) is erased, so the underlined corrected character "2" is erased. ”, as shown in Figure 1 (c) (:
Underlines that should be continuous are cut off.

The present invention was made in view of the above-mentioned shortcomings of conventional electronic typewriters, and allows for reliable erasure of undesired characters and printing of corrected characters through simple operations, and correction of characters with a beautiful finish. It is an object of the present invention to provide a printing device suitable for use in electronic typewriters, etc., which can perform printing.

In order to achieve the above object, the present invention employs a mechanism in which, when erasing undesired characters, the characters are shifted in a direction perpendicular to the escapement direction of the carriage and are then stamped multiple times.

The present invention will be described in detail below based on the drawings.

FIG. 2 shows an embodiment of an electronic typewriter using the printing device of the present invention, in which printing is performed on a platen 7 which is rotated by the drive of a platen motor 7', and one RAD is placed facing each other and moved in parallel from side to side. A rad carriage 1 is provided with a guide bar and a wheel 2 of an escapement mechanism, and a print head 3 with a type hammer 8 for its imprinting;
Print ribbon 4 pulled out from print ribbon cassette 4'
, below which an erasing ribbon 5 is arranged so as to pass in front of the type wheel 2. The head carriage 1 (= is further provided with a ribbon shift mechanism 6, which lifts the ribbon in the direction indicated by the upward arrow in FIG. 2. When the ribbon shift mechanism 6 is driven) The erasing ribbon 5 is effective (2); in the normal state where it is not driven, the printing ribbon 4 is effective.

FIG. 3 shows an embodiment of the key arrangement of the keyboard section of an electronic typewriter to which the printing device of the present invention is applied.

A display section 205, such as a liquid crystal display, is provided at the top of the keyboard, generally designated by the reference numeral 200, and a series of character keys 201 are arranged below the display section 205. On the right side thereof, an erase designation key 202 and a backspace key 203 are provided. A slide lever designated by the reference numeral 204 is used to specify underlined characters.

In use, the character string (sentence) input using a series of character keys 201 is displayed on the display section 205 and then printed or stored in memory. This can be specified using various function keys provided on the right, upper right, and left of column 201. Note that the keys at the upper left of the character key row are keys for specifying character pitch, line pitch, etc.

FIG. 4 is a block diagram of an electronic circuit used to control the printing apparatus of the present invention, in which a central control unit (CONT) is designated by reference numeral 10 and controls the printing mechanism in response to commands from a keyboard (KB) 9. 10 is the keyboard circuit 9
Based on orders from Ribbon Shifted Leiper (R
5D) 8',・□Type hammer driver (HMD) 8
′, type wheel control system (wsYS) 2′, ribbon shift mechanism (R5M) 6, type hammer (HM) 8, type wheel (WL) 2, respectively;
The operations of the head carriage 1 and platen (PLT) 7 are controlled through a head carriage control system (CSYS) 11 and a platen control system (PSYS) 7'', respectively.

FIG. 5 shows the electronic circuit described above in more detail, with emphasis on the central control unit 1o.

In FIG. 5, reference numbers in the 100s indicate each block of the central control unit collectively designated by the reference number 1o in FIG. show.

In the figure, character key 2 pressed on keyboard 200
The matrix for detecting the position of 01 is the key encoder (K
E) 1o1, the key encoder 101 controls the type wheel control system 2' by means of the data bus KDB and the strobe signal KST. B is connected to the input terminal A of the AND gate 108, which is connected to the signal KST, and the output of the AND gate 108 is also a set/reset type flip-flop (FF2).
It is connected to the set terminal S of 103. The output of flip-flop 103 controls ribbon shift driver 6'.

Further, the output terminal Q of the flip-flop 103 is connected to the input terminal ST of the timing sequencer 104.

The output signal 5EQI of the timing sequencer 104 is connected to the input terminal C of the down counter 105, and the signal 5EQ2 is connected to the input terminal C of the down counter 105.
The signal 5EQ3 is connected to the input terminal A of the R gate 11o, and the signal 5EQ3 is connected to the input terminal B of the kite game 109. In addition, an MΦ gate 108 is connected to the input terminal LD of the down counter 105.
is connected to the output terminal Q1. ROM 107 via Q2 (read only memory)
It is connected to the. RCM 107 is Datum x PD
The platen control system 7' is controlled by a data bus DB from B and other logic circuits (not shown).

Further, the output terminal 2 of the down counter 105 is connected to the input terminal A of the M gate 10B and the reset terminal R of the flip-flops 102 and 103 via the inverter 106, and the output terminal of the N0 gate 109 is connected to the OR gate 11.
1 controls a type hammer driver 8'.

Here, the head carriage control system 11 and OR gates 110 and 111 each receive signals SS3. Controlled by SSI and SS2.

The normal printing operation of the printing apparatus of the present invention having the above configuration will be described below (with reference to the timing chart of FIG. 6).

First, select the desired character key 201 (
In Fig. 5, rAJ is exemplified). This character key 201
The key matrix detects the position of key encoder 1.
01 is the type wheel 2 in the type wheel control system 2'.
Information such as the amount of rotation (selection of type) and printing pressure is sent to the type wheel control system 2' via the data bus KDB. When this information is confirmed, key encoder 1
o1 simultaneously sends a strobe signal KST to the type wheel control system 2' to drive the type wheel 2 and direct the desired type rAJ to the type paper on the platen 7.

Here, in FIG. 6 (2), the symbol WSYS is the output of the type wheel control system 2';
This is a control signal that controls the When the rotation of the type wheel 2 is completed, the OR gate 111 is activated in response to a signal SS2 from a block (not shown), and its output drives the type hammer 8 via the type hammer driver 8', and the type wheel 2 is activated. The type hammer 8 hits the type rAJ provided at the tip of the type spoke from the back side,
Characters are recorded on the type paper on the platen 7 via the printing ribbon 4 (see FIG. 2). Next, in response to a signal SS3 from a block (not shown), the head carriage control system 11 moves the head carriage 1 by one space via the escapement mechanism, holds it still, and waits for the next key input. .

Next, the operation of erasing already printed characters will be explained in detail with reference to the timing chart of FIG. 7.

First, pack space key 203 on keyboard 200
is pressed, and a signal SS3 from a block (not shown) causes the head carriage 1 to move to an undesired character (here, "A") via the head carriage control system.

) until the print head 3 is facing the print head 3, and then press the erase key 202. This sends a pulse to the set terminal S of flip-flop 102, whose output terminal Q is a logic 1.
1'' to the input terminal A of the N gate 108.

The timings of the input and output signals of this flip-flop are shown in FIG. 7 as FFl-5 and FFI-Q, respectively.

Next, key r for the same character as the undesired character already printed.
Press AJ. This causes the key encoder 101 to output the type wheel control system 2'l2 information and the strobe signal KST via the data bus KDB in the same way as in normal printing.
is sent out to select type. Strobe signal KS
T is simultaneously input to AND gate 108.

At this time, the flip-flop 102 controls the N■ gate 1.
Since the logic "1" is input to the other input terminal of 08, the MO gate 108 is opened by the length of the strobe signal KST, and a pulse is applied to the set terminal S of the flip-flop 103 and the input terminal LD of the down counter 105. Sent. This causes the flip-flop 103 to have a logic
1'' is sent to the input terminal ST of the timing sequencer 104, activated, and sent to the ribbon shift driver 6' to drive the ribbon shift mechanism 6 and move the erasing ribbon 5 in the direction indicated by the arrow in FIG. The flip-flop 103 is lifted up and inserted between the type and the type paper and is ready for use.The timing of the output signal of the flip-flop 103 is shown as FF2-Q in FIG.

At the same time, the output pulse of the gate 108 of 2M sets the flip-flop built in the down counter 105, and the voltage V+ that is about to be input to the input terminals A and H is sent from the output terminals Q1 and Q2 to the ROM 1071:, This is activated and O'' is sent to the platen control system 7' as the initial platen movement amount via the data bus PDB.

The timing sequencer 104 activated together with the ribbon shift driver 6' waits until the rotation of the type wheel 2 is completed and then outputs the first signal 5EQ2. As a result, when the OR gate 110 opens, the platen control system 7' drives the platen motor 7 according to the information already sent from the ROM 107 and attempts to rotate the platen 7, but the initial information is 0''. , that is, the amount of movement is 0
Therefore, the platen 7 does not actually move.

Continuing, the timing sequencer 104 outputs the signal 5E.
Q3 is sent to the input terminal B of the gate 109. The timing of the input terminal A of the NΦ gate 109 is shown as CNT-Z in FIG. Since the output signal of the output terminal 2 of the down counter 105, which is synchronized with the strobe signal KST via the MΦ gate 108, is input via the inverter 106, the M■ gate 109 and the OR gate 111 are opened, and the type hammer driver 8' The type hammer 8 is driven through the erasing tape 5 onto the undesired characters rAJ.
The same type is stamped through the .

Following this, in the pulse cycle < 5EQI → 5EQ2 → 5EQ3, the timing sequencer 104 first sends the signal 5EQI to the input terminal C of the down counter 105 to advance the count by one, and causes the RCM 107 to send out the next platen movement information. After that, the platen is moved and erased in the same way, but the platen movement amount information at this time is -1"
is fed, so the platen control system 1' drives the platen 7 to move the type paper slightly downward and
A printing operation is performed via the erasing tape 5.

In the next pulse cycle of 5EQI → 5EQ2 → 5EQ3, "+2" is sent to the platen control system as the platen movement amount information, so the platen 7 rotates upward by twice the amount of rotation in the previous cycle. Then, a printing operation is performed via the erasing tape 5.

In the next cycle, in response to signal 5EQI, down counter 105 outputs logic "1" from output terminal 2, resets flip-flops 102 and 103, releases ribbon shift mechanism 6, and enables printing ribbon 4. (see FIG. 2) and AND via the inverter 106.
The gate 109 is closed and the drive of the type hammer 8 by the timing sequence f-104 is stopped. After that, the platen 7 is rotated downward according to the platen movement amount information "-1" and returns to its original position. Finally, the timing sequencer 104 once again sends out the signal 5EQ3. Since the signal M1'09 is closed, the type hammer 8 is not driven.

As described above, first, the platen 7 is stamped once without rotating, then once while rotating downward, and then once while rotating upward, and then the marking is performed via the erasing tape 5. Since it returns to the original position, the erasing operation is performed three times, directly above the undesired character rAJ, in a direction perpendicular to the escapement direction of the head carriage 1, slightly above, slightly below, and by hand. become. During this series of operations, the erasing ribbon 5 continues to be shifted upward and held.

In the above embodiments, the erasing ribbon may of course be of the type that allows ink to be peeled off using an adhesive tape or the type that allows the covering material to be covered over the type.

By employing the configuration of the present invention as detailed above, the following effects can be expected.

First, the configuration is such that the erasing operation is performed multiple times, for example directly above the undesired characters that have already been printed, and also upwards and downwards in the escapement direction of the head carriage, so that the undesired characters can be reliably erased. At the same time, the drawback of the conventional multiple-strike type erasing mechanism, in which continuous underlined characters cannot be obtained when erasing consecutive underlined characters, is eliminated, and the problem that the head carriage or platen It is not necessary to maintain the operating accuracy of the escapement mechanism so high, so costs can be reduced, and the shift of the erasing ribbon continues to be shifted during a series of erasing operations.
There is less operational noise, etc.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram illustrating the drawbacks of the printing device of a conventional electronic typewriter, FIG. 2 is a perspective view showing the mechanical structure of the printing device of the present invention, and FIG. 3 is a diagram illustrating the printing device of the present invention. An explanatory diagram showing one embodiment of the keyboard section of an applied electronic typewriter, FIG. 4 is a block diagram showing an electronic circuit of the printing device of the invention, and FIG. 5 is an electronic circuit of the printing device of the invention. 6 and 7 are timing charts showing the signal timing of the electronic circuit of the printing device of the present invention. 1...Head carriage 2...Type wheel 2'
...Type wheel control system 3...Print head 4...Print ribbon 5...
・Erasing ribbon 6...Ribbon shift mechanism 6'・
... Ribbon shift driver 7 ... Platen 7' ... Platen control system 7 ... Platen motor 8 ... Type hammer 8
'...Type hammer dryer 9...Keyboard circuit 10...Central control unit 1
1... Head carriage control system 101... Key encoder 102.103... Flip-flop 104... Timing sequencer 105... Down counter 106... Inverter 107... ROM10
8.109...NO gate 110,111...O
R gate 200... Keyboard 201... Character key 202... Erase designation key 203... Pack space key Figure 1

Claims (3)

[Claims] (1) In a printing device equipped with a mechanism for overprinting and erasing low-print characters via an erasing ribbon, a platen moving device is provided to move the platen perpendicular to the printing direction, and the erasing operation 1. A printing device characterized in that said printing device is configured to move a printing platen a predetermined amount in said direction to erase low-print characters by overprinting a plurality of times. (2) The printing device according to claim 1, further comprising a specific person key for starting the erasing operation of the low-print characters. (3) A ribbon shift mechanism is provided that enables the erasing ribbon only during the erasing operation of the low-print characters and keeps the erasing ribbon positioned between the printed characters and the low-print characters throughout the erasing operation of the printed characters. A printing device according to claim 1 or 2, characterized in that: