JPS6129278B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electronic typewriter.

Conventional typewriters include manual typewriters in which all mechanical parts are mechanically connected and the manual pressing force of each key on the keyboard is directly connected to the type bar's stamping operation, and typewriters that have a drive motor. There are electric typewriters in which a type bar corresponding to a key is driven by a directly connected ratchet wheel, but both of these mechanical typewriters have an independent key lever, bell crank, It requires an extremely large number of parts overall, such as having type bar wire and type bar, and the structure is inevitably complex, requiring advanced manufacturing technology, and it is difficult to realize something that is lightweight and has many additional functions. On the other hand, all of these were factors that increased costs.

In contrast to such conventional mechanical typewriters, the present invention includes a single type wheel with a large number of printing elements arranged around the periphery, and electronically processes keyboard key operations to correspond to each key. By converting electrical signals into mechanical actions to perform various operations, the number of parts is greatly reduced, and the simple structure allows for extremely simple assembly work, as well as easy maintenance and inspection. The present invention relates to a new electronic typewriter that is lightweight, has improved all the drawbacks of conventional mechanical typewriters, and is superior in quality.

The character selection operation and subsequent printing operation of this electronic typewriter are omitted since they are detailed in Japanese Patent Application No. 53-25856, which was already filed by the same applicant as the present application. Devices related to the reciprocating operation of a carriage carrying a carriage, such as a carriage advancement device, a carriage return device, a high-speed carriage back device, and a margin device, will be described in detail. The details of the present invention will be explained below with reference to the drawings.

Reference numeral 1 designates a printing head, which includes a type wheel 3 having a large number of printing elements 2 arranged in a petal shape, and a pulse motor 5 directly connected to the type wheel 3 to drive the type wheel 3 to rotate in a plane parallel to the platen 4.
and a detection mechanism (not shown) for detecting the rotational position of the type wheel 3. The type wheel 3 is divided into 88 parts in the circumferential direction, and a type is formed at the tip of each printing element 2.

Reference numeral 6 denotes a carriage on which the printing head 1 is placed, and is slidably guided by guide rods 7 and 8 supported by the machine frame F (only one part is shown), and is slidably guided by the platen 4
It is supported so that it can reciprocate in parallel along the A printing hammer 9 is rotatably supported by the carriage 6 like the printing head, and is driven by a solenoid (not shown) activated based on a hammer trigger signal, and is driven by a solenoid (not shown) that activates the printing element selected at the time. 2 is struck onto the printing paper P via the ink ribbon R, and printing is performed on the printing paper P.

The keyboard 10 is composed of a group of alphanumeric keys and a group of function keys as shown in FIG. It is possible to input so-called uppercase letters and lowercase letters) or numbers and symbol information. Function keys include a shift key 12, a repeat key 13, a space key 14, a backspace key 15, a return key 16, a high speed back key 17, and a line feed key 18. Pressing of each key on the keyboard 10 is converted into an electrical signal, which partially operates a control circuit which will be described later.

Electronic character selection operation performed based on the operation of the character and number keys 11, and the associated ink ribbon R
The lifting and feeding operations, and the driving operation of the printing hammer 9 are described in the above-mentioned patent application filed in 1983.
Since it is detailed in No. 25856, it will be omitted here, and the explanation will be omitted here. device, carriage 6 based on operation of return key 16
A series of devices associated with the return operation of the carriage 6 and a high-speed back device for high-speed back movement of the carriage 6 based on the operation of the high-speed back key 17 will be described in detail below.

First, a stepping device for moving the carriage 6 step by step will be explained.

Reference numeral 20 is a spring drum fixed to the machine frame F, and is similar to that used in ordinary typewriters.
A support shaft 21, which is rotatably supported by the support shaft 21, passes through the support shaft 21. A spring 22 is housed in the spring drum 20, and its outer end is fixed to the spring drum 20 and its inner end is fixed to the support shaft 21.
A first gear 23 adjacent to the spring drum 20 and a take-up pulley 24, which is a stepping pulley, are fixed to the support shaft 21, and the biasing force of the spring 22 is applied to the first gear 23 through the support shaft 21. 1 gear 23 and stepping pulley 24 as a rotational force in the direction of arrow A.

25 and 26 are two wires that operatively connect the take-up pulley 24 and the carriage 6; one end of one wire 25 is fixed to the machine frame F on the right in FIG. After the carriage pulley 27 rotatably supported on the lower surface of the first guide pulley 2 is wound half a turn around the lower groove 27a and the direction is reversed, the first guide pulley 2 is rotatably supported on the machine frame F.
At 8, the direction is changed and guided to the take-up pulley 24, where it is wound counterclockwise by an appropriate amount and fixed. One end of the other wire 26 is fixed to the left machine frame F in FIG.
After the other end is wound half a turn around the upper groove 27b of the carriage pulley 27 and the direction is reversed, the second and third guide pulleys 29 are rotatably supported by the machine frame F,
At 30, the respective directions are changed and guided to the take-up pulley 24, where they are wound clockwise by an appropriate amount and fixed. Therefore, the biasing force from the spring 22 always acts in the direction to wind up the wire 25 and in the direction to send out the wire 26, so the carriage 6 is biased in the character feeding direction (arrow B direction) via the carriage pulley 27. .

Reference numeral 31 denotes a support shaft rotatably supported on the machine frame, with a ratchet wheel 32 at one end and a second gear 33 meshing with the first gear 23 at the other end.
is fixed. Reference numeral 34 denotes a control mechanism for controlling the rotation of the support shaft 21 in the direction of arrow A by the spring 22, and a space ratchet 35 that can be engaged with the ratchet wheel 32.
It also includes a half ratchet 36 and a stepping solenoid 37. As shown in FIG. 1, the space ratchet 35 and the half ratchet 36 are configured to operate integrally by a spring 38 stretched between them and a protruding pin 39 fixed to the half ratchet 36. , the space latch 35 is normally engaged with the ratchet wheel 32 by the biasing spring 40 to prevent rotation of the ratchet wheel 32, and the half latch 3
6 is in a state where it does not engage with the ratchet wheel 32.

That is, the space latchet 35 engages with the latchet wheel 32 and prevents the rotation of the latchet wheel 32, thereby preventing the spring 22 from rotating the take-up pulley 24 in the direction of arrow A. When the stepping solenoid 37 is excited by a space signal generated in synchronization with the printing operation described above or a space signal generated by pressing the space key 14, the half latch 36 resists the biasing spring 40. 1, and the space ratchet 35 is also rotated in the direction of arrow C via the protruding pin 39. As a result, the engagement between the space ratchet 35 and the ratchet wheel 32 is released, the rotation of the ratchet wheel 32, that is, the rotation of the take-up pulley 24 in the direction of arrow A is allowed, and the ratchet wheel 32 is brought into engagement with the half ratchet 36. Rotate half a pitch in the direction of arrow D until they are aligned. When the stepping solenoid 37 is released from the energized state, the half ratchet 36 is rotated in the opposite direction of arrow C by the biasing force of the biasing spring 40, and is disengaged from the ratchet wheel 32. The space ratchet 35 is rotated in the opposite direction of arrow C, and becomes ready to engage with the ratchet hole 32, and the ratchet wheel 32 is further rotated by half a pitch in the direction of arrow D until it engages with the space ratchet 35.

In this way, the space latch 35 and the half latch 36 integrally reciprocate based on the operation of the stepping solenoid 37, and the ratchet wheel 30 is rotated by one pitch in the direction of the arrow D. As a result, the first and second The winding pulley 24 rotates in the direction of winding up the wire 25 and the direction of feeding out the wire 26 via the gears 23 and 33, and the carriage 6 is moved in the direction of arrow B by one character, that is, by one step l. .

The accuracy of the step amount of the carriage 6 based on the operation of the step solenoid 37 is determined by the ratchet wheel 3.
2. Both ratchets 35, 36 and the first and second
It depends on the manufacturing accuracy of the gears 23, 33 and their assembly accuracy, but both have simple shapes that make it easy to manufacture them, and their simple structure also makes it easy to assemble them. Therefore, the printing quality of the typewriter can be maintained at a high level.

Next, the left and right margin detection device will be explained.

45 is a margin rack, and 46 is a support plate fixed to the left and right ends of the margin rack 45 (only the left side is shown in FIG. 1), and is supported movably along the moving direction of the carriage 6 with respect to the machine frame F. ing. As shown in FIGS. 3 and 4, the support plate 46 shown on the left in FIG.
0 and a pin 51, the positioning plate 47 is supported so as to be movable by 1/2 of the advance pitch l of the carriage 6, and the positioning plate 47 is stretched between the positioning plate 47 and the right machine frame F. The relationship between the first spring 48 and the second spring 49, which is stretched between the positioning plate 47 and the first hanging portion 46a of the support plate 46 and has a smaller spring constant than the first spring 48. Therefore, the right end of the elongated hole 50 shown in FIG. 3 and the pin 51 are always held in an engaged state.

When the positioning plate 47 is positioned, the support plate 46
is always maintained in the state shown in FIGS. 3 and 4 in which the second hanging portion 46b is engaged with the bent portion 47a of the positioning plate 47 by the biasing force of the second spring 49.
Reference numeral 52 denotes a rubber stop member fixed to the left machine frame F, and is provided so as to be able to collide with the second hanging part 46b, so that the second hanging part 46b is in the state shown in FIG.
The gap between the rubber stop member 52 and the rubber stop member 52 corresponds to 1.5 times the advance pitch l of the carriage 6. Therefore, the margin rack 45 can always be moved 1.5l to the left and 1/2l to the right from the first position shown in FIG.
is supported.

Left and right margin stops 53 and 54 are selectively positioned relative to the margin rack 45, respectively, and are used to determine the printing width for the printing paper P. Reference numerals 55 and 56 denote first and second permanent magnets fixed near the right machine frame F of the margin rack 45, and are spaced a predetermined distance apart in the longitudinal direction of the margin rack 45 as shown in FIGS. 1 and 5. It is provided. 57 and 58 are first and second reed switches corresponding to the first and second permanent magnets 55 and 56, respectively. The first and second reed switches 57, 58 are connected to the margin rack 45 as shown in FIG.
When in the first position shown in FIGS. 4 and 5, it is in the closed state, and the margin rack 45 is moved 1/3 to the right.
When the reed switch 58 is moved by l, only the second reed switch 58 becomes open under the influence of the second permanent magnet 56, and the margin rack 45 is moved approximately 1/2l to the left from the first position in FIG. When the reed switch 5 is moved to the second position shown by the solid line, the first reed switch 5
7 is in the open state under the influence of the first permanent magnet 55, and the margin rack 45 is in the second position, further from the second position shown by the two-dot chain line in FIG.
1l Move leftward and stop member 52 and second hanging part 46
Only the first reed switch 57 is fixed to the machine frame F so as to maintain the open state as long as the first reed switch 57 is located between the first reed switch 57 and the engaged third position.

That is, the carriage stop 6a and the right margin stop 5, which are fixed to the carriage 6, are moved by the stepwise movement of the carriage 6 accompanying the above-described printing operation or by the stepwise movement based on the depression of the space key 14.
When the margin rack 45 is moved approximately 1/3 l to the right from the first position as shown in FIG.
The reed switch 58 is opened and a right margin operation signal is sent to notify that the right margin has been operated. With this right margin operation signal,
Subsequent letters, number key 11 and space key 1
All signals based on pressing 4 will be ignored. This allows the operator to know that the right margin has been activated. When the carriage 6 is then returned to the printing start direction by pressing the return key 16 or the like, the engagement between the right margin stop 54 and the carriage stop 6a is released, and the margin rack 45 returns to the first position. By returning, the typewriter becomes ready to print like a normal typewriter.

When the return key 16 is pressed down, the carriage 6 starts a return operation by a carriage return device to be described later, and as a result of the return operation, the carriage stop 6a of the carriage 6 engages with the left margin stop 53. margin rack 45
is moved to the left by 1/2l, as shown by the line in FIG.
The reed switch 57 is opened and a left margin operation signal is sent to notify that the left margin has been operated. This left margin operation signal acts as a return operation end signal, as will be described later, and the return operation of the carriage 6 is ended. When the return operation of the carriage 6 is completed, the carriage 6 is positioned at the printing start position as described later, thereby the margin rack 45 returns to the first position shown in FIG. 5, and the first reed switch 57 is closed. state.

Next, a return device for the carriage 6 and a series of operations related thereto will be explained.

60 is a drive shaft that constantly rotates in the direction of arrow E;
A third gear 61 is rotatably supported by the drive shaft 60 via a spring clutch 62 and meshes with the first gear 23 as shown in FIG. 6
3 is an operating lever for controlling a spring clutch 62;
4 is a coil spring that keeps the spring clutch 62 in a state where the operating lever 63 is not engaged, and 65 is a carriage return solenoid (referred to as CR solenoid).

When the return key 16 is pressed down, a carriage return signal (referred to as CR signal) is sent and inputted to a control circuit shown in FIG. ) is output,
CR solenoid 65 is energized. The actuating lever 63 is thereby pivoted against the coil spring 64 to bring the spring clutch 62 into the engaged state. The CR solenoid drive signal is the return key 1 as described later.
Once the push-down operation of 6 is performed, the output continues until the return is completed even if the operation is canceled.

When the spring clutch 62 is in the engaged state, the third gear 61 is rotated in the direction of arrow E, and the first gear 23 meshing therewith is rotated in the opposite direction of arrow A. The rotation of the first gear 23 in the direction of arrow A is caused by the rotation of the spring drum 2 via the support shaft 21.
0 spring 22 is unwound, and the take-up pulley 24 is rotated in the opposite direction of arrow A to let out the wire 25 while winding up the wire 26. As a result, the carriage 6 starts moving in the opposite direction of arrow B toward the printing start position. On the other hand, the rotation of the first gear 23 in the direction opposite to the arrow A causes the support shaft 31 and the ratchet wheel 32 to rotate in the direction opposite to the arrow D via the second gear 33. The rotation of the support shaft 31 in the opposite direction of arrow D is caused by the support shaft 3
The space ratchet 35 is rotated against the spring 38 out of the rotation locus of the ratchet wheel 32 by operating the ratchet removal piece 66 provided at the ratchet wheel 32. Therefore, the ratchet wheel 3
2 can rotate without engaging the space ratchet 35. This ratchet removal piece 6
A detailed explanation of the function and structure of 6 is provided in the Utility Model Publication No. 39-1999, which was filed by the same applicant as the present application and has already been published.
Since it is the same as that disclosed in No. 22322, it will be omitted.

Now, as the return operation of the carriage 6 progresses, the carriage stop 6a and the left margin stop 53 engage, and the margin rack 45 is moved to the fifth position.
From the state shown in the figure, the state shown by the solid line in FIG.
When the reed switch 57 is moved from the position to the second position, the first reed switch 57 becomes open as described above.
A left margin operation signal (referred to as LHM signal) is sent. As will be described later, this LHM signal acts as a release signal for the return operation when it is sent out, stopping the sending of the CR solenoid drive signal that will be described later, and operates a timer circuit that will be described later. When the transmission of the CR solenoid drive signal is stopped, the spring clutch 62 becomes disengaged, and the rotational drive of the take-up pulley 24 in the opposite direction of arrow A is stopped.

In this embodiment, the margin rack 45 is provided so as to be movable further to the left in order to soften the impact force when the carriage stop 6a and the left margin stop 53 engage, so that the carriage 6 is Move further to the left. That is, as shown in FIG. 4, the margin rack 45 is at a third position (FIG. 7) where the second hanging portion 46b engages with the stop member 52 against the biasing force of the second spring 49. As mentioned above, this third position is a position moved 1.5l to the left from the first position, and the margin rack 45 can be moved to this position. Therefore, the margin rack 4 is based on the inertia of the carriage 6.
The leftward movement of 5 and the leftward movement of the carriage 6 are forced to stop.

When the leftward movement of the carriage 6 is stopped, the rotation of the take-up pulley 24 in the opposite direction of arrow A is stopped.
The take-up pulley 24 rotates in the direction of arrow A in accordance with the biasing force of the spring 22 and attempts to move the carriage 6 in the character feeding direction. Take-up pulley 24
Rotation in the direction of arrow A is performed by the ratchet wheel 3.
2 in the direction of arrow D, and remove the ratchet removal piece 6.
6 is released, and the space ratchet 35 and the ratchet wheel 32 are immediately engaged. The position where the space ratchet 35 and the ratchet wheel 32 are engaged is the position where the margin rack 45 shown in FIG. and third
It is a position that has been moved to a position intermediate between the position of
This corresponds to the position where the carriage 6 has moved 1l before the printing start position.

Therefore, as mentioned above, the first reed switch 5
7 remains open and continues to send out the LHM signal.

On the other hand, a timer circuit T, which will be described later, starts operating from the time the LHM signal is sent, and detects the presence or absence of the LHM signal after a predetermined time (130 msec in the example).
When the LHM signal is present, the circuit is configured so that a 1-space signal is sent out as shown in the circuit of FIG. Therefore, in the above-mentioned state, that is, when the carriage 6 is at a position 1 l before the print start position and the margin rack 45 is at a position intermediate between the second position and the third position, the LHM signal continues to be output. The circuit shown in FIG. 8 outputs one space signal. When the space signal is output, the stepping solenoid 37 operates, the stepping device described above is activated, and the carriage 6 moves 1l to the right.
It is advanced by a minute. As a result, the carriage 6 is moved to a predetermined printing start position and stopped, the margin rack 45 is also returned to the first position shown in FIGS. 4 and 5, and the first reed switch 57 is also moved. Return to closed state. In this way, the return operation of the carriage 6 is completed, and the carriage 6 is accurately positioned at a predetermined printing start position.
As shown in Japanese Patent Application No. 53-25856, a return cam (not shown) rotates as the return key 16 is pressed, and with each rotation, the printing paper P
The printing line is advanced by one line.

Now, the high-speed backup device will be explained next.

The high-speed back device shares most of the same features as the previously described carriage return device, and therefore, a description of the mechanical structure will be omitted and only the operations that occur when the high-speed back key 17 is pressed will be described.

When the high-speed back key 17 is pressed, a high-speed back signal (referred to as an HSB signal) is sent out and input to a control circuit, which will be described later, from which the CR solenoid drive signal is output. Thereby said
The CR solenoid 65 is energized, the spring clutch 62 is engaged, and the carriage 6 begins to move in the opposite direction of arrow B as described above. This high-speed back movement is performed immediately when the high-speed back key 17 is released and the HSB signal is no longer output.
Since the output of the solenoid drive signal disappears and the spring clutch 62 becomes disengaged, the process immediately ends at that position. In other words, the carriage 6 is controlled by a control circuit, which will be described later, to perform high-speed backward movement only while the high-speed backward key 17 is pressed down.

When the carriage stopper 6a and the left margin stop 53 engage with each other by continuing to press the high-speed back key 17 to continue high-speed back movement of the carriage 6, the LHM is activated in the same way as in the return operation described above. The high-speed back movement is terminated at the signal. The subsequent operations of the carriage 6 and margin rack 45 are as explained in the return operation.

That is, this high-speed back movement effectively utilizes the carriage return device to perform high-speed back movement, and moreover, the high-speed back movement is performed only while the high-speed back key 17 is pressed down.

Next, the configuration and operation of the control circuit shown in FIG. 8 will be explained with reference to the signal waveform diagram in FIG. 9.

FIG. 8 shows the LHM signal sent from the keyboard 10 or the left and right margin detection device described above;
This is a control circuit that generates a CR solenoid drive signal or a space signal using the HSB signal and CR signal.The control circuit consists of two flip-flops (referred to as FF1 and FF2), a timer circuit T, and two OR gates (OR1 and OR2). ), one AND gate AND and two inverters (INV1,
INV2). That FF1
The D terminals of FF2 and FF2 are both grounded, and the clear terminals are both connected to the power supply voltage Vcc via a resistor.

In FIG. 8, the HSB signal is a signal that is continuously output while the high-speed back key 17 is pressed down, and is connected to the clock terminal of FF1 via INV1.
It is input to CK and also to OR1. When the HSB signal goes from high level to low level, as shown in the signal waveform in Figure 9a, FFF1 is triggered at the falling edge, and the output signal of FF1, whose signal waveform is shown in Figure 9c, changes from high level to low level. becomes low level. The HSB signal and the output signal of FF1 are input to OR1, and the output signal of OR1 changes from low level to high level as the signal waveform shown in FIG. 9d and is input to OR2. The OR
The CR solenoid drive signal, which is the output signal of No. 2, changes from low level to high level as the signal waveform is shown in FIG. 9, and drives the CR solenoid. When the HSB signal goes high, OR1 and the output signal go low, causing the CR solenoid drive signal to go low.

When the carriage 6 continues to move back at high speed and the operation of the left margin is detected, the LHM signal becomes low level as the signal waveform shown in FIG. Input to timer circuit T and AND.
As a result, the output signal of FF1 becomes high level.
The output signal of FF2 becomes low level, and as described above, the CR solenoid drive signal becomes low level. The operation of the timer circuit T will be explained in the following operation during carriage return.

The CR signal whose signal waveform is shown in FIG. 9e is input to the clock terminal CK of FF2. When the return key 16 is now pressed and the CR signal goes high, the output signal of the FF2 goes high, causing the CR solenoid drive signal to go high. This state is maintained even if the CR signal changes to low level. Then, when the left margin operation is detected as in the case of high-speed back movement described above, the LHM signal becomes low level and the output signal of FF2 is made low level, thereby causing the CR
The solenoid drive signal becomes low level. The timer circuit T is triggered by the falling edge of the LHM signal and starts its timer operation, and its output signal remains at a low level for a predetermined time t (130 msec in the example), as the signal waveform is shown in Fig. 9h. It is held and input to AND via INV2. After time t, the output signal becomes high level, and at that time
If the LHM signal is at a low level, the output signal of the AND whose signal waveform is shown in FIG. 9j is at a high level, and the above-mentioned space signal is output.

In this way, the control circuit shown in Figure 8 is as described above.
It performs predetermined control in response to the LHM signal, HSB signal, and CR signal.

As described in detail above, in the present invention, the return mechanism for returning the carriage to the printing start position includes a drive shaft connected to a motor, a winding drum connected to the drive shaft via a clutch, and a winding drum connected to the drive shaft through a clutch. A connecting member with one end fixed to the drum and the other end fixed to the carriage, a solenoid that connects the clutch, and when the return key is operated, the solenoid maintains the operating state until the carriage return operation is completed. and a first control means for maintaining the engaged state of the clutch, and a first control means for operating a solenoid to engage the clutch and start a high-speed backspace operation of the carriage when the high-speed back key is operated, and for operating the high-speed back key. and a second control means that operates the solenoid to hold the clutch in the engaged state only while the clutch is in the engaged state, so that operating the high speed back key allows the carriage to back up at a higher speed than when operating the back space key. The printing head can be quickly moved to the desired printing position. Furthermore, since the carriage return device is used to enable high-speed backspace movement of the carriage, the configuration is simple and can be consolidated compactly, resulting in extremely large effects.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of the main parts showing an embodiment of the electronic typewriter according to the present application, Fig. 2 is a plan view of the keyboard, Fig. 3 is a plan view of the main parts showing the supporting state of the margin rack, and Fig. 4 is a front view of Fig. 3, Fig. 5 is a plan view showing the relative positions of the permanent magnet fixed to the margin rack and the reed switch fixed to the machine frame, and Figs. 6 and 7 are the operation of Fig. 5. Explanatory diagram, Figure 8 is the control circuit, Figure 9 is the waveform diagram of each signal, Figure 1
Figure 0 is a sectional view showing the area around the take-up pulley. In the figure, 1 is the print head, 4 is the platen, 6 is the carriage, 6a is the carriage stop, 10 is the keyboard, 15 is the backspace key, 16 is the return key, 17 is the high speed back key, 20 is the spring drum, and 24 is the winder. take-up pulleys, 25, 26 are wires, 28 are carriage pulleys, 28, 29,
30 is a guide pulley, 45 is a margin rack, 53
is a left margin stop, 54 is a right margin stop, 55, 56 are permanent magnets, 57, 58 are reed switches, 62 is a spring clutch, 65 is a carriage return solenoid, P is printing paper, F is a machine frame, l is a stepping pitch, and T is a timer circuit.

Claims (1)

[Scope of Claims] 1. A platen on which printing paper is placed; a carriage on which a printing head is placed and reciprocated along the longitudinal direction of the platen; and a carriage that returns the carriage and feeds the printing paper. a keyboard portion provided with a return key to backspace the carriage, a backspace key to backspace the carriage, and a high-speed backkey to backspace the carriage at high speed; when the return key is operated, printing of the carriage starts; In an electronic typewriter, the return mechanism includes a motor, a drive shaft connected to the motor, and a winding drum connected to the drive shaft via a clutch. a connecting member having one end fixed to the winding drum and the other end fixed to the carriage; a solenoid that brings the clutch into a connected state so that the drive shaft and the winding drum can rotate together; and the return key. a first control means for maintaining the operating state of the solenoid to maintain the engaged state of the clutch until the return movement of the carriage is completed when the high-speed back key is operated; a second control means for operating the solenoid to engage the clutch and initiate a high speed backspace operation of the carriage, and for operating the solenoid to maintain the clutch in the engaged state only while the high speed back key is operated; An electronic typewriter characterized by consisting of and.