JPH0230572A - Serial recording device - Google Patents

Abstract

PURPOSE:To allow high-definition printing to be performed at high speed without being influenced by the speed variation of a carriage by driving the carriage with a supersonic waves motor and controlling the printing timing of a recording head from a signal for the detection of a position for and a movement speed of the carriage. CONSTITUTION:A control circuit 21 controls each heater 7b of a recording head 7 through a head drive circuit 26, and at the same time, controls the energization to piezoelectric elements 14A, 14B through a carriage drive circuit 24, then controls a sheet feed motor 23 through a circuit 22. In the meantime, the position and speed of a carriage 2 are detected by a photosensor 16 which cooperates with an encoder 11, and an output signal from the photosensor is shaped into a pulsed wave-type signal, then the shaped signal is transmitted to the head drive circuit 26. There, the scanning by the carriage 2 and the printing action by a recording head 7 are controlled to be synchronized. This piezoelectric element drive system constitutes a supersonic waves motor formed integrally with the carriage 2. In addition, if the drive step of the supersonic waves motor to the dot pitch of the recording head is made adjustable, the step amount of the supersonic waves motor may be adjusted.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is a serial recording method in which a dot image is formed on a sheet based on print data while scanning in the printing digit direction with a recording head mounted on a carriage. Regarding equipment.

[Conventional technology]

As a recording device such as a printer or facsimile, a recording head is mounted on a carriage that moves in the direction of the printing digits, and by driving the recording head based on print data while scanning with the recording head, dot images are created on the sheet. Serial recording devices are widely used.

FIGS. 12 to 15 are partial perspective views showing essential parts of various types of the carriage drive mechanism, respectively.

FIG. 12 shows a rack and pinion type carriage drive mechanism.

In FIG. 12, a carriage 62 carrying a recording head 61 is guided and supported so as to be movable along a guide shaft 63 and a guide rail 64. As shown in FIG.

The carriage 62 includes a carriage motor (not shown).
A pinion 65 rotated by the carriage motor is pivotally supported, and the pinion 65 meshes with a long rank 66 installed at the base of the recording device to control the rotation of the pinion 65 by the carriage motor. By doing so, the position and movement of the carriage 62 can be controlled. A rotary encoder 67 for detecting rotation of the pinion 65 is mounted on the carriage 62.

FIG. 13 shows a carriage drive mechanism of the Heald transmission type.

In FIG. 13, a carrier equipped with a recording head 71 is shown.
The seventh gear 72 is connected to a heald 75 stretched between a pair of pulleys 73 and 74. One pulley 73 is a driving pulley rotated by a carriage motor 76, and the other pulley 74 is a driven pulley.

Therefore, by controlling the rotation of the motor 76, the movement and position of the carriage 72 can be controlled.

FIG. 14 shows a wire rope transmission type carriage drive mechanism.

In FIG. 14, a carriage 82 carrying a recording head 81 is driven by a carriage motor 83 via a wire rope 84.

Both ends of the wire rope 184 are connected to the carriage 82, and the wire rope 84 is connected to four guide pulleys 85.
The movement and position of the drive pulley 86 is controlled by a drive pulley 86 which is stretched by A, 85B, 85C185D and rotated by a motor 83.

FIG. 15 shows a lead screw one-type carriage drive mechanism.

In FIG. 15, a carriage 92 carrying a recording head 91 is threadedly engaged with a threaded rod 93.
is rotationally driven by a carriage motor 94 via gears 95 and 96. The moving direction and running speed of the carriage 92 are controlled by the rotational direction and rotational speed of the threaded rod 93.

On the other hand, a speed control method for keeping the moving speed of the carriage constant, or an encoder 6 as shown in FIG.
A closed loop method is used in which the drive voltage of the DC motor or the oscillation frequency of the pulse motor is controlled according to the output of the motor.

Regarding the printing method in the recording head, the wire dot method, thermal transfer method, or piezo inkjet printing method is the mainstream, and each element of the recording head (
The response frequency of the dot forming element (dot forming element) is 1,000 to 3,000 Hz in the wire dot method, and 500 to 1,000 Hz in the thermal transfer method.
500Hz, 1000 to 300 for piezo jet method
Furthermore, the dot density in images output by these printing methods is in the range of 7 dots/double to 14 dots/1 m.

[Problem that the invention seeks to solve]

However, in conventional serial recording devices, the rotational movement of the motor for driving the carriage is controlled via a rack and pinion, a pulley and belt, a wire rope, a lead screw, etc., as shown in FIGS. 12 to 15, respectively. However, in order to maintain dot position accuracy in the above-mentioned dot density region, the frequency of the pulse motor must be increased. The carriage drive mechanism has a complicated structure and is difficult to downsize.

In addition, the noise generated during the reciprocating movement of the carriage increases due to play between each element in the mechanism, play in the guide part for linear guidance, and backlash in the meshing parts of gears, etc. The problem was that it was difficult to convert.

Furthermore, due to the presence of backlash and backlash in the mechanism, it has been difficult to improve the dot position accuracy.

Conventional printing methods such as wire dot method, heat transfer force method,
In the piezo inkjet method, it is necessary to keep the print cycle (driving cycle of the recording head) constant due to restrictions due to the recording method, so the carriage running speed, which should be synchronized with the print cycle, is also kept constant. ing.

If the carriage drive motor is a pulse motor and open-loop control is performed, control for stabilizing the speed of the carriage is performed by using a motor with sufficient margin for output torque. A closed-loop method using a pulse motor and an encoder has also been used to control the speed.

Here, the relationship between printing operation and carriage running speed in various conventional printing methods will be explained.

FIG. 16 is a graph illustrating the timing of the printing operation using the wire dot method, in which (A) shows the repeated printing cycle of the print wire, and (B) shows the energization time to the magnet coil of each print wire of the wire dot head. (C) shows each flight cycle as the print wire starts moving, prints, and returns.

FIG. 17 is a schematic cross-sectional view of the wire dot head.

In the case of the wire dot method, when the head response frequency is 250011z, which is close to the maximum speed, Figs. 16 and 17
As shown in the figure, the repeated printing cycle of the same print wire 52 is 400 μs ((A) in FIG. 16), and the energization time to the magnet coil 51 is normally set to about 200 μs ((B) in FIG. 16). be done.

On the other hand, after the print wire 52 starts moving, the sheet (
(C
)) Therefore, under conditions close to the maximum speed mentioned above,
Print cycle variation is 10μs (400p8-390μs)
If it is not regulated to a certain degree, the stable operation of the printed wire 52 will be impaired.

Also, in the case of the piezo inkjet method, it is similar to the case of the wire dot method described above, and instead of the wire flight time, the carriage speed varies depending on the time for the return of the piezo diaphragm and the return of the meniscus at the orifice. will be restricted.

Furthermore, in the case of the thermal transfer method, the frequency is 2500 to begin with.
Although it is extremely difficult to achieve a printing cycle of Hz and it is difficult to compare on the same level, the current application time is longer than in the above two methods, so stability of the carriage speed of the - layer is required.

FIG. 18 illustrates a control system for a carriage drive system in a conventional serial recording apparatus.

In FIG. 18, the control circuit (MPtJ) 1 of the recording device
01 is equipped with a ROM 102 that stores control programs, etc., and a RAM 103 that includes a working area such as a buffer register that temporarily stores various data.
) is sent to the control circuit 101.

The control circuit 101 controls the recording F' 105 via the head drive circuit 104, and
controls the carriage motor 10B via the motor timing control circuit 106 and the motor drive circuit 107;
Furthermore, a sheet feed motor 110 is controlled via a sheet feed motor drive circuit 109.

On the other hand, an output signal of the encoder for detecting the position and speed of the carriage is generated by a photo sensor 111, shaped into a pulse wave by a waveform shaping circuit 112, and transmitted to the head drive circuit 104 and the motor timing control circuit 106. The scanning of the carriage and the printing operation of the head are synchronized and controlled.

As is clear from the above description, the control system for driving the carriage in the conventional serial recording apparatus has a complicated configuration.

FIG. 19 is a partial perspective view showing the carriage configuration of the wire dot recording apparatus.

In FIG. 19, a recording sheet 121 as a recording medium such as paper or a thin plastic plate is held in close contact with the surface of a platen 122 which also serves as a sheet feeding roller, and a guide shaft 123 and a guide rail 1 are installed in parallel in front of the platen 122.
24, a carriage 125 is movably guided and supported.

Mounted on the carriage 125 are a wire printing head 126 containing a plurality of (for example, 64) print wires and driving means thereof, and an ink ribbon cassette 127 for feeding an ink ribbon for transfer.

FIG. 20 is a partial perspective view showing the carriage configuration of the thermal transfer recording device.

In FIG. 20, in front of the platen 132 that backs up the recording sheet 131 is a guide shaft 13 parallel to the platen 132.
3.134 are installed and these guide shafts 133.13
4, a carriage 135 is movably guided and supported.

A thermal head 136 having a plurality of (for example, 641) heating elements is supported on the carriage 135 so as to be able to move up and down.
An ink ribbon cassette 137 for feeding an ink ribbon for transfer is installed between the recording sheet 131 and the recording sheet 131 .

As is clear from the configurations in Figures 19 and 20,
In the carriage configuration of a wire dot type or thermal transfer type recording device, the carriage 125.13
As the load fluctuation factors during the running of step 5, the load of winding the ribbon and the load of the recording head 126, 136 contacting the sheet 121, 131 and the ribbon are added, so the carriage drive motor and its drive circuit are large and complex. There was also the problem of becoming

As mentioned above, in conventional serial recording devices, even if various carriage drive methods and printing methods are successfully combined, the structure becomes complicated when attempting to perform high-definition printing at high speed. Due to the large size, the energy of the operating sound increases, and it has been extremely difficult or impossible to reduce the size, weight, and noise.

SUMMARY OF THE INVENTION An object of the present invention is to solve the problems of the prior art described above, and to provide a serial recording device that has a simple configuration and can perform high-definition printing at high speed without being affected by carriage speed fluctuations.

[Means for solving problems]

The present invention is a serial recording device in which a recording head is mounted on a carriage that moves in the printing digit direction, and a dot image is formed on a sheet by driving the recording head based on print data while scanning with the recording head. The carriage is driven by an ultrasonic motor arranged between the carriage and the fixed side of the recording device, and the position and moving speed of the carriage are detected by an encoder, and the recording head is controlled based on the detection signal of the encoder. The above object is achieved by configuring the printer to control the printing timing.

In the above configuration, further, the drive step of the ultrasonic motor is made variable with respect to the dot pitch of the recording head,
If adjustable, the step amount of the ultrasonic motor can be adjusted in accordance with the characteristics of the recording device, thereby making it possible to easily perform printing with extremely high definition.

〔Example〕

Hereinafter, the configuration of the present invention will be specifically explained with reference to FIGS. 1 to 11.

1 to 3 are diagrams that best represent the features of the present invention. FIG. 1 is a perspective view showing an embodiment of the recording apparatus according to the present invention, and FIG. The partially broken left side view and FIG. 3 are perspective views of the carriage shown in FIG. 1, which are turned upside down and viewed from the bottom.

In FIGS. 1 and 2, reference numeral 1 indicates a base serving as a reference for the structure of the recording apparatus, and reference numeral 2 indicates a slide along the base guided by guide portions 1a, 1b, and 1c formed on the base 1. 3 is a platen installed parallel to the moving direction of the carriage 2; 4 is a sheet (recording medium such as paper) 5 inserted through the opening 1d of the base 1;
The sheet feed rollers that convey the sheet through the front surface (printing section) of the platen 3 are shown.

An ink cartridge 6 constituting an ink tank is removably mounted on the carriage 2, and in the illustrated example, an ink cartridge 6 is installed at the front of the ink tank 6 at a predetermined distance (for example, 0.811) from the platen 3. A recording head (inkjet head) 7 is provided in which a plurality of facing ink ejection ports (orifices) 7a are formed. The inkjet head 7 can be formed integrally with the ink tank 6, or can be detachably attached to the ink tank 6 (eg, inserted).

A base portion of an arm 8 that swings around the pin portion 2a is pivotally attached to a pin portion 2a formed on the rear surface of the carriage 2, and a roller is attached to the pin portion 8a formed at the tip of the arm 8. 9 is rotatably supported. This roller 9 is guided along the guide portion 1b (downward surface).

The arm 8 is biased by a coil spring 10 in a direction in which the roller 9 is pressed against the guide portion 1b. In this way, when the rollers 9 are pressed against the guide part 1b, the carriage 2 is pressed against the guide part 1a and the guide surface of the IC from above by the reaction force 2'j7, and the carriage 2 (specifically, the carriage 2 (including a part of the ultrasonic motor provided integrally with the base 1) are guided and supported so as to slide closely together without play along the base 1.

A strip-shaped encoder 11 having shading or slits (windows) at a predetermined pitch is installed on the base 1 . This encoder 11 is used to detect the position and traveling speed of the carriage 2, as will be described later.

2 and 3, a diaphragm 13 is attached to the lower surface of the carriage 2 via a holding plate 12, and two pairs of piezoelectric elements 14 are mounted at predetermined positions on the diaphragm 13.
A and 14B are attached.

As shown in FIG. 3, the holding member 12 and the diaphragm 13 are both formed of oval plates with a predetermined thickness, and are integrally attached to the lower surface of the carriage 2 in a stacked state. There is.

A portion of the base 1 of the diaphragm 13 that slides into pressure contact with the guide member IC is provided with comb teeth 15 that are uneven at a predetermined pitch in the carriage traveling direction. The two pairs of piezoelectric elements 14A and 14B are attached to a region of the diaphragm 13 on the opposite side to the comb teeth, and each pair of piezoelectric elements 14
A and 14B are arranged with a predetermined interval (for example, a distance of one quarter of the total length of each piezoelectric element).

2 and 3, a photosensor is provided on the lower surface of the carriage 2 at a position sandwiching the encoder 11 on the base 1 for photoelectrically converting changes in light intensity based on the shading pattern or window (slit) of the encoder. 16 is installed.

Further, a flexible printed board 17 for power supply and signal transmission is connected to each of the piezoelectric elements 14A, 14B and the photosensor 16.

In addition, number 18 in FIG. 2 indicates a pinch roller for pressing the sheet 5 against the sheet feeding roller 4 and giving accurate feeding to the sheet 5.

The ink ejection +1 (orifice) is provided on the front surface of the inkjet head 7 provided in the front part of the ink tank (ink cartridge) 6, that is, on the side facing the platen 3.
A plurality of 7a are arranged in the vertical direction.

The vertical adjacent pitch of this ink discharge lower a is approximately 0.
04mm~0. 14 mm, that is, about 23.6 dots/mm to 7.1 dots/1 m, and in the examples described below, a structure of 14.17 dots/tomb will be used unless otherwise specified.

FIG. 4 is a control system block diagram of the serial recording apparatus shown in FIGS. 1 and 2.

In FIG. 4, a control circuit (MPU) 21 of the recording device is equipped with a ROM 27 that stores control programs, etc., and a RAM 28 that includes a working area such as a buffer register that temporarily stores various data. Various data are sent to the control circuit 21 via the interface (1/F).

The control circuit 21 controls ON/OFF of each heater (printing element) 7b of the recording head 7 via a head drive circuit 26.
F, and also controls energization to the piezoelectric elements 14A and 14B via the carriage drive circuit 24.

Furthermore, the control circuit 21 controls a sheet feed motor 23 via a sheet feed motor drive circuit 22.

On the other hand, the position and speed of the carriage 2 are determined by the encoder 1.
The output signal is detected by a photosensor 16 (FIG. 2) cooperating with the head drive circuit 1, and its output signal is shaped into a pulse waveform by a waveform shaping circuit 25 and transmitted to the head drive circuit 26. In this way, the scanning of the carriage 2 and the printing operation of the head 7 are synchronized and controlled.

The operation of the serial recording apparatus according to the present invention described with reference to FIGS. 1 to 4 will be described below.

Recording sheet (recording medium such as paper or thin plastic plate)
5 through the opening 1d of the base 1, then insert the control unit (MP
When U) 21 receives a detection signal indicating that there is a sheet (sheet feeding), it drives the sheet feed motor 23 via the sheet feed motor drive circuit 22, thereby rotating the sheet feed roller 4. The sheet 5 pressed by the pinch roller 18 is fed forward of the ink discharge lower a.

■! ] Next, when a printing command is given to the control system shown in FIG. 4 from the outside via an I/F (interface), the piezoelectric elements 14A, 1
A desired high frequency current is sent to 4B.

FIG. 5 is a surface view of the piezoelectric element shown in FIG. 3, and FIG. 6 is a partial vertical sectional view showing the principle of generation of driving force by the piezoelectric element.

This piezoelectric element drive system constitutes a traveling wave type ultrasonic motor integrated with the carriage 2.

As shown in FIGS. 3, 5, and 6, this piezoelectric element drive system has a substantially oval shape attached to a substantially oval holding member 12, and the comb teeth 15 are formed in a part of the piezoelectric element drive system. the diaphragm 13 and the two pairs of piezoelectric elements 14 attached on the diaphragm 13 in opposite directions (opposite sides) to the comb teeth 15.
A, 14B, and a flexible printed board 17 for feeding power to the piezoelectric elements 14A, 14B.

As shown in FIGS. 5 and 6, the two pairs of piezoelectric elements 14A and 14B each have a length of one quarter (λ
/4).

Therefore, the operation of the piezoelectric element drive system (ultrasonic motor) will be explained below.

If the two pairs of piezoelectric elements 14A and 14B are referred to as A phase and B phase, then when an alternating voltage expressed by the following formula is applied to these A phase and B phase, EA=EOs inωL EB=EOs in (ωt+π /2) The vibration [1] of the generated standing wave is: A-phase standing wave: ZA=ZOs 1nKXs inωtB-phase standing wave: ZB=ZOs in (KX+π/2)X
sin(ωt±π/2), and the traveling wave generated by the combination of A phase and B phase is Traveling wave: Z=ZA+ZB=ZOcos (ωt〒KX
) Here, = 2π/λ (wave number), ω = 2πf (angular velocity).

Therefore, due to the traveling waves generated by the sound, the diaphragm 13
A thrust force in the opposite direction to the traveling wave acts on the contact surface between the comb teeth 15 and the guide surface 1c of the base 1.

The traveling speed ■ of the carriage 2 due to this thrust is V-4π
・π・f−Z−e/λ Here, Z=travelling wave amplitude, e−1/2 of the diaphragm thickness.

The values in this example are f-40KHz, Z=1
Since p and e = 1.5 mm and λ-10, the traveling speed of carriage 2 is V''' 236.6 mm/s # 240 mm/
It will be about s.

Here, the value of the driving frequency f of the ultrasonic motor is 40KH.
z is the drive frequency 2 of conventional motors such as step motors.
The frequency is much higher than ~4 KHz, and by using an ultrasonic motor, it is possible to control the movement of the carriage 2 with high precision.

FIG. 7 shows the output waveform generated by the control system of FIG. 4 based on the signal from the encoder 11 and the piezoelectric element 14 when the carriage 2 moves at a constant speed. It is a figure which shows the energization pulse to A and 14B.

(A) in FIG. 7 shows a light emitting section 16A and a light receiving section 1 sandwiching an encoder 11 in which openings (slits) are formed at a predetermined pitch.
6B is a schematic diagram showing the arrangement of a photosensor 16 consisting of a photo sensor 6B.

The piezoelectric elements 14A and 14B are energized to drive the carriage, and when the carriage 2 reaches a constant velocity region, the photosensors 16A and 1 [i B of FIG. 7A]
An analog output as shown in FIG. 7(B) is generated.

This analog output is the waveform shaping circuit 2 of the control system in Fig. 4.
5, the head drive pulse (dot pitch regulating pulse) is shaped into a pulse waveform as shown in FIG. 5(C), and then a head drive pulse (dot pitch regulation pulse) with a predetermined period (250 μs in the illustrated example) as shown in FIG. 5(D). is created.

Note that the horizontal axes in FIGS. 7A to 7E are common axes representing time or carriage position.

(E) in FIG. 7 shows the piezoelectric elements 14A, 1413, and
＼The waveform of the applied ultrasonic motor drive pulse with a energization period of 25 μs is shown.

FIG. 8 is a timing chart showing the driving state of the inkjet head 7. (A) in FIG. 8 shows the drive signal of the inkjet head 7, that is, during the energization pulse and the energization period, and (B) in FIG. 9 shows a heat current waveform flowing through the heater 7b of the thermal inkjet head 7, which will be described later, and (C) of FIG. 7c (including the formation process) shows changes in the amount of protrusion and the amount of retraction of 7c.

Note that the symbols a and b in FIG. 8(C)
--Go is (a) and (b) in Figure 9--・-・・・・-
The meniscus position corresponding to each state in (f) is shown.

FIG. 9 is a longitudinal sectional view showing the process of forming ink droplets in the vicinity of the ink ejection opening (orifice) 7a of the thermal ink head 7.

In FIG. 9, 7a indicates an ink discharge port, 7b a heater consisting of a heating element, 7C a meniscus of the ink near the ink discharge port, and 7d an ink droplet.

In FIG. 9, (a) shows the standby state, (b) shows the state where the heater 7b is energized and foaming has started in the ink, and (C
) shows the state immediately before the ink droplet 7d flies off after the power supply to the heater 7b is stopped and defoaming begins, and (d) shows the state just before the droplet 7d is separated and the liquid surface tip (meniscus) 7C has retreated significantly. , (e) shows a state in which the meniscus 7C is raised from the ink ejection orifice surface due to the reaction of the meniscus receding in (d).
(f) shows when the device returns to the same standby state as in (a).

As illustrated in FIGS. 8 and 9 above, the heater 7b
According to the thermal inkjet method, which drives each ink ejection port with the ink droplets, it is possible to achieve a very short current application time (10 μs) and excellent responsiveness (ink droplet ejection operation time 180 μs) compared to other recording methods. becomes possible.

Therefore, even if the traveling speed of the carriage 2 fluctuates by about ±10% and the energization cycle changes between 225 μ3 and 275 μs, the stability of ink ejection is maintained, so that the carriage motor drive circuit 24 and the head drive circuit 26
can operate in a completely separate system, making it possible to simplify the drive circuit.

According to the embodiment described above, the piezoelectric elements 14A, 14B
Since an ultrasonic motor using an ultrasonic motor is used as the drive source for the carriage 2, a mechanism for power transmission and conversion can be eliminated, and a carriage drive system that can be simplified in structure and downsized can be realized. .

Furthermore, since there is no mechanism for transmitting or converting power, the noise level during operation can be significantly reduced, making it possible to realize a quiet recording device.

At the same time, we were also able to improve (speed up) the responsiveness during operation.

Furthermore, by using the piezoelectric elements 14A and 14B drive system, a self-holding force acts when the carriage 2 is stopped, so there is no need for a special mechanism to hold the carriage 2, and there is no winding part. Since the level of magnetic noise caused by each current flowing from the device is extremely low, there is no need to take measures to prevent magnetic radiation noise (e.g., printed circuit board structure or magnetic shield exterior), and therefore,
A serial recording device with a simple structure and low cost can be obtained.

FIG. 10 is a perspective view of a carriage cartridge of a serial recording device according to another embodiment of the present invention, as seen from the bottom after being turned upside down, and FIG. 11 is an exploded perspective view of the carriage mounting parts in FIG. 1O. .

In FIG. 10, a retaining plate 3 is provided on the lower surface of the carriage 31.
A piezoelectric element 33 and a diaphragm 34 are fixed in a laminated state via 2.

Further, on the lower surface of the carriage 31, a photosensor 16 and a flexible printed circuit board 35 are provided as in the case of FIG.
is attached, and the flexible printed circuit board 35
Power is supplied to the piezoelectric element 33 and signals are taken out from the photosensor 16 through the piezoelectric element 33.

In FIG. 11, the flexible printed circuit board 35
is provided with an electrode portion 35a that is electrically connected to the piezoelectric element 33 and the photosensor 16, and a connector 35b that is connected to the control circuit 21 of the recording device or a circuit board taken out from the control circuit 21. It is being taken.

As shown in FIGS. 10 and 11, the holding plate 32, piezoelectric element 33, and diaphragm 34 all have a circular ring shape.
is formed.

A rotor (not shown) constituting the ultrasonic motor has a shaft (not shown) that is concentric with the diaphragm 34 and provided on the lower surface of the carriage 31.
(not shown), and when assembled, one surface of the rotor is in contact with the diaphragm 34, and the other surface is in contact with the guide surface 1c on the base 1 shown in FIG.

Note that in order to configure an ultrasonic motor, the diaphragm 34 is connected to the guide surface IC of the base 1 without using the rotor.
It is also possible to make direct contact (pressure contact) with the material.

Other parts of the embodiment of FIGS. 10 and 11 are as follows.
This is substantially the same as the embodiment described in FIGS.

According to the embodiment explained above in FIGS. 10 and 11, the same effect as the embodiment explained in FIGS. The sonic morph (piezoelectric element drive system) and the carriage 31 can be manufactured easily, and furthermore, by interposing the rotor, the thrust force generated by the diaphragm 34 can be efficiently converted into linear force.

As explained above, according to the serial recording apparatus of the present invention, the piezoelectric elements 14A, 14'B, 33 are used to drive the carriage.
Since an ultrasonic motor consisting of a diaphragm and a diaphragm 13, 34 is used, the structure can be simplified, the size and weight can be reduced, the noise level during operation can be reduced to a large rIJ, and further, It is now possible to configure a serial recording device that has self-holding power when the carriage is stopped and has extremely low magnetic noise when driving the piezoelectric element, resulting in stable printing quality, high reliability, and cost reduction in the recording device. was able to achieve this.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, a recording head is mounted on a carriage that moves in the printing digit direction, and the recording head is driven based on print data while scanning with the recording head, thereby printing a sheet. In a serial recording device that forms a dot image on the recording device, the main carriage is driven by an ultrasonic motor configured between the carriage and the fixed side of the recording device, and the position and moving speed of the carriage are detected by an encoder. However, since the printing timing of the recording head is controlled based on the detection signal, even if the carriage speed changes, the position of the carriage and printing timing can be controlled with high precision, and dot misalignment can be prevented. A high-definition serial recording device that can ensure stable printing quality is obtained.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a main part of an embodiment of a serial recording device according to the present invention, FIG. 2 is a vertical cross-sectional view of a main part of FIG. 1, and FIG. Figure 4 is a block diagram of the control system of the recording device in Figure 1, Figure 5 is a plan view of the diaphragm and piezoelectric element in Figure 3, and Figure 6 is a schematic partial cross-sectional view of the main parts of Figure 5. , FIG. 7 is a graph showing the encoder of the recording device shown in FIG. 1, its output waveform, and ultrasonic motor driving pulse, FIG. 8 is a timing chart showing the driving state of the thermal inkjet head shown in FIG. 1, and FIG. 1 is a schematic vertical cross-sectional view showing the ink ejection process of the thermal inkjet head of FIG. 1, FIG. 10 is a bottom perspective view of the carriage of another embodiment of the serial recording apparatus according to the present invention, and FIG. 12 to 15 are perspective views showing various structural examples of conventional carriage drive mechanisms, FIG. 16 is a graph showing drive pulse waveforms of the wire dot head, and FIG. 17 is an exploded perspective view of an ultrasonic motor portion. 18 is a block diagram of the control system of a conventional serial recording device, FIG. 19 is a perspective view of the main parts of the wire dot type recording device, and FIG. 20 is the main part of the thermal transfer type recording device. FIG. la, lb, l c---11111---Guide part,
2---------- Carriage, 5------------
Sheet, 6--Inktan recording head (in encoder, 1 piezoelectric element, 11--carriage, diaphragm. Yasutake (cartridge), 7 Kujiesotohesodo), 11 3-diaphragm, 14A, 14B 16 - Photo sensor, 31

Claims (3)

[Claims] (1) In a serial recording device in which a recording head is mounted on a carriage that moves in the printing digit direction, and a dot image is formed on a sheet by driving the recording head based on print data while scanning with the recording head. , the carriage is driven by an ultrasonic motor configured between the carriage and the fixed side of the recording device, the position and moving speed of the carriage are detected by an encoder, and the printing timing of the recording head is determined based on the detection signal. A serial recording device configured to control. (2) The serial recording apparatus according to claim 1, wherein the drive step of the ultrasonic motor is made variable and adjustable with respect to the dot pitch of the recording head. (3) The serial recording apparatus according to claim 1 or 2, wherein the recording head is a thermal inkjet head.