JP2000071542A - Recording apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a recording apparatus which can obtain high-quality print results by eliminating a velocity instability because of a load change of a carriage motor in a simple constitution. SOLUTION: A portable printer 1 feedback controls a CR motor 30 for driving a carriage 27 transferring printing heads 15, 16. A load applied to the motor increases because a feed tube 12 for feeding ink to the printing heads 15, 16 comes in touch with a main body frame 6 at a predetermined place. A PID constant of a PID control is changed beforehand in accordance with the load, so that a gain of a control signal output to a CR motor driver is changed. The motor can be converged to a constant velocity immediately even when a large load is generated. Accordingly, the printer is stable in velocity and can obtain high-quality print results.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a printing apparatus provided with a carriage speed control means, and more particularly to a printing apparatus which controls a gain in accordance with a position of a carriage.

[0002]

2. Description of the Related Art Conventionally, in a printing apparatus, since a change in the transport speed in the main scanning of the carriage gives a large result to a printing result, the transport speed of the carriage is detected and P
In some cases, feedback control by ID control is performed to keep the carriage conveyance speed constant. Further, in such control, when the target carriage conveyance speed changes greatly when the motor is accelerated or the like, the load on the carriage motor is detected in order to quickly respond to the change in speed, and the load is detected in accordance with the load. In some cases, control is performed based on a gain schedule that adjusts the output so as to increase the output gain with respect to the deviation.

[0003]

However, when the speed of these carriages is feedback-controlled, the running resistance of the carriage may change greatly. In the conventional feedback control, if only the control that is adapted to the case where the resistance is small and the load on the carriage motor is small is performed, the control when the load is large is not performed properly, causing a control delay. There is a problem that convergence to the target speed is slow. On the other hand, when the control is performed only when the load is large, when the load is small, the reaction becomes oscillatory and the convergence to the target speed is delayed, or the hunting occurs because the vibration does not converge. There was a problem. Further, in order to perform control according to the load, it is necessary to detect a change in the load. However, to detect such a load, a complicated mechanism is required. There was a problem of inviting high prices.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problem, and eliminates the instability of the carriage speed due to a change in the load on the carriage motor during carriage conveyance, while maintaining a stable carriage speed, with a simple configuration. An object of the present invention is to provide a recording device capable of obtaining a high-quality printing result.

[0005]

According to a first aspect of the present invention, there is provided a recording apparatus, comprising: a carriage for conveying a print head; a carriage motor for driving the carriage; Speed detection means for detecting the conveyance speed of the carriage, and an output of the carriage motor for matching the conveyance speed of the carriage to the target speed from a difference between a preset target speed and the speed detected by the speed detection means. A calculating means for calculating and sending a control signal with a predetermined gain; and a driving means for outputting a driving current to a carriage motor based on the control signal from the calculating means, wherein the calculating means is provided within a scanning range of the carriage. A gain that changes a gain of a control signal to be output to the driving means according to a pattern determined in advance according to a load caused by a change in the position of Characterized by comprising a changing means.

[0006] In the printing apparatus according to this configuration, since the calculating means has a pattern determined in advance according to the load due to a change in the position of the carriage within the scanning range, the driving means is promptly sent to the driving means based on this pattern. By changing the gain of the control signal to be output by the gain changing means, it is possible to perform optimal speed control for the position of the carriage, and to achieve stable carriage travel with a simple structure. Therefore, the quality of printing can be high.

According to a second aspect of the present invention, in addition to the configuration of the recording apparatus according to the first aspect, the arithmetic means generates a control signal based on PID control.

In the recording apparatus according to this configuration, proportional control,
The speed can be appropriately controlled based on the integral control and the differential control, and the print result can be of high quality.

According to a third aspect of the present invention, in addition to the configuration of the recording apparatus according to the first or second aspect, the recording apparatus further comprises an ink cartridge, and ink from the ink cartridge to the print head. And a supply tube for supplying, when recording on the recording medium, the ink cartridge is fixed, and the print head is supplied with ink from the supply tube and conveyed on the recording medium by the carriage. While printing, the load due to the change of the carriage position is:
The load is a load generated by frictional resistance caused by sliding of the supply tube with the housing of the recording apparatus, and the gain of the pattern is determined according to a change in the load.

[0010] In the recording apparatus according to this configuration, even if frictional resistance is generated by the supply tube, proper control can be performed, so that the weight of the head is small and there is no change in weight. The control can be made more appropriate.

According to a fourth aspect of the present invention, in addition to the configuration of the recording apparatus according to the first or second aspect, the recording apparatus further comprises: an ink cartridge; and ink from the ink cartridge to the print head. A supply tube for supplying the ink, the ink cartridge is fixed at the time of recording on the recording medium, and the print head is conveyed over the recording medium by the carriage while receiving the supply of ink from the supply tube. The load due to the change in the carriage position is a load caused by the elasticity of the supply tube or the cable for driving the head, and the pattern is such that the gain is determined according to the change in the load. It is characterized by having been done.

In the recording apparatus according to this configuration, even if resistance occurs due to the elasticity of the supply tube, appropriate control can be performed, so that the weight of the head is small and the weight does not change. The head speed control can be made more appropriate.

According to a fifth aspect of the present invention, in addition to the configuration of the recording apparatus according to any one of the first to fourth aspects, the printing head is an ink jet head.

In the recording apparatus according to this configuration, since the ink jet head is used as the print head, high-quality printing results can be obtained in combination with the appropriate control of the carriage speed.

According to a sixth aspect of the present invention, in addition to the configuration of the recording apparatus according to any one of the first to fifth aspects, the recording apparatus includes a main CPU for processing input print data. And a calculating means for controlling the carriage motor separately from the main CPU.

In the recording apparatus according to this configuration, the carriage speed is not controlled by the main CPU, which has a large processing load such as processing of print data, and the carriage speed is controlled by another arithmetic means. Not only can be controlled, but also the load on the main CPU can be reduced and the processing speed can be increased. Therefore, an improvement in throughput can be achieved for the entire recording apparatus.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described with reference to the accompanying drawings by using a portable printer 1 according to a preferred embodiment of the present invention. Here, FIG. 2 is a partially cutaway perspective view schematically showing the internal structure of the portable printer 1.

The portable printer 1 has a plurality of ink cartridges 8 arranged at predetermined positions as shown in FIG.
And a small ink cartridge 9 (hereinafter abbreviated as ink cartridges 8 and 9), and supply tubes from the ink cartridges 8 and 9 to a print head right 15 and a print head left 16 (hereinafter abbreviated as print heads 15 and 16). 1
2, the ink is supplied to the nozzles 15 and 16 on the print heads 15 and 16, respectively.
6a (hereinafter abbreviated as nozzles 15a, 16a), the carriage 27 carrying the print heads 15, 16 is reciprocated in the main scanning direction, which is a direction orthogonal to the sheet conveyance direction, and the sheet is conveyed, and ink is printed on the printing paper PP. For printing.

The portable printer 1 configured as described above
According to the above, the ink cartridges 8 and 9
Since there is no need to mount the image forming apparatus, the load applied to the CR motor 30 is small, and the load does not fluctuate due to the remaining amount of ink. On the other hand, in the portable printer 1 configured as described above, the supply tube 1
2 is an essential configuration, and it is necessary to control the carriage speed in consideration of this.

Hereinafter, the configuration of the portable printer 1 will be described first, and then the carriage control will be described in detail.

FIG. 1 is a front view showing the appearance of a portable printer 1 according to one embodiment of the present invention. As shown in FIG. 1, the portable printer 1 includes a printer main body 3 which is a case formed in a substantially rectangular box shape. A paper discharge port 4 which is a rectangular opening formed wide in the longitudinal direction (the left-right direction in FIG. 1) of the portable printer 1 is formed at a lower substantially central portion of the printer main body 3. The paper discharge port 4 is an opening for discharging the printed printing paper PP, and has a longitudinal width corresponding to the paper width of the printing paper PP. In the portable printer 1 according to the present embodiment, the width of the paper discharge port 4 in the longitudinal direction is formed to be larger than the A4 size paper width (about 210 mm). An opening / closing lid 7 for exchanging the ink cartridges 8 and 9 is provided at an upper portion of the printer main body 3.

The arrow X in FIG. 2 indicates the direction of conveyance of the printing paper PP, and the arrow Y in the figure indicates the direction of movement of the print heads 15 and 16 during main scanning.

As shown in FIG. 2, the printer main body 3 also serves as a substantially rectangular box-shaped main body frame 6, and a rectangular shelf-shaped cartridge frame 5 is provided in the upper space 1a of the main body frame 6. A partition plate 5a is provided on the entire rear side below the cartridge frame 5 to partition the upper space 1a and the lower space 1b, and the front side of the upper space 1a is open to the lower space 1b. Ink cartridge 8, 9
Are arranged horizontally with their upper ends aligned with the cartridge frame 5 above the partition plate 5a.

In the lower space 1b of the main body frame 6 of the portable printer 1, an arrow Y and an anti-arrow Y
The print heads 15 and 16 are mounted on a carriage 27 that can reciprocate in the direction along the main scanning direction. The print heads 15 and 16 perform printing by ejecting ink. A right nozzle 15a is disposed on the lower surface of the right print head 15, and a large number of nozzles constituted by piezo elements (piezoelectric elements) are provided. Two nozzle rows composed of mouths are formed along the paper transport direction X. One of these nozzle rows includes an ink package 8.
The magenta ink supplied from each of the ink packages a is filled with black ink in the other row. A similarly configured nozzle left 16a is also provided on the lower surface of the print head left 16, and is filled with yellow and cyan inks. Hereinafter, yellow, magenta, cyan, and black are abbreviated as Y, M, C, and K, respectively. Then, these nozzle rows discharge the respective inks of Y, M, C, and K, thereby enabling color printing.

According to the print heads 15, 16, when a voltage is applied to the plurality of nozzles 15a, 16a composed of piezo elements, a distortion proportional to the voltage value is generated in the nozzles 1a, 16a.
5a, 16a, the nozzles 15a, 16a contract. Due to this contraction, the ink filled in the cavities (ink chambers) in the nozzle openings of the nozzles 15a and 16a is discharged onto the printing paper PP and printing is performed.

The cartridge frame 5 in the upper space 1a of the portable printer 1 above the print heads 15, 16
, Two ink cartridges 8, 9 formed in a substantially rectangular box shape are detachably stored in a horizontal state. Below the ink cartridges 8, 9, the above-mentioned partition plate 5a is provided. Of the ink cartridges 8, 9, the large ink cartridge 8 disposed on the left side in FIG. 2 contains an ink package 8a filled with ink ejected from the right 15 of the print head. 8a is composed of two ink packages, each of which is filled with magenta and black inks one color at a time.

A lower portion of the large ink cartridge 8 is provided with a waste ink reservoir 8b which is a space for storing waste ink sucked by a purge operation for preventing clogging of the print heads 15 and 16, which will be described later.

On the other hand, a substantially rectangular box-shaped ink cartridge small 9 is disposed on the right side of the ink cartridge large 8 in FIG. I have. Like the large ink cartridge 8, the small ink cartridge 9 houses an ink package 9a composed of two ink packages filled with ink ejected from the print head left 16;
The two ink packages are filled with yellow and cyan inks, respectively. The small ink cartridge 9 and the ink package 9a are formed smaller than the large ink cartridge 8 and the ink package 8a and contain a small amount of ink. Specifically, 8 ml of each color ink is stored in the ink package 8a, and 5.5 ml of each color ink is stored in the ink package 9a. This is based on the assumption that the ink ejection amounts of the nozzles 15a and 16a of the print heads 15 and 16 are different.

The ink packages 8a and 9a housed in the ink cartridges 8 and 9 are formed in a substantially rectangular bag, and include a plurality of film sheets made of polyethylene resin or the like, for example, a plurality of film sheets. It is formed of a laminated structure film material in which about ten sheets are laminated. The laminated structure film material forming the ink packages 8a and 9a is:
By forming the rigidity to be large, shape resilience is imparted, and a change in shape of the ink packages 8a and 9a can be suppressed. Therefore, even if the ink is supplied from the ink packages 8a, 9a to the print heads 15, 16 and the ink in the ink packages 8a, 9a decreases, the ink packages 8a, 9a are not crushed to the atmospheric pressure or the like. The internal pressure can be maintained at an appropriate negative pressure.

The ink cartridges 8, 9 are disposed above the print heads 15, 16, so that the print heads 15,
Ink is supplied to the ink cartridge 16, but the large ink cartridge 8 and the small ink cartridge 9 are stored horizontally at the same level. Therefore, the four color ink packages stored in the ink package are arranged on the same horizontal plane. The nozzles 15a and 16a on the nozzle surfaces of the print heads 15 and 16 are also arranged on the same horizontal plane.
The height difference between the ink of each color stored in a and 9a and the nozzle corresponding to the ink of each color is configured to be the same. Therefore, the water pressure on the nozzles generated from the height difference can be kept constant, the internal pressures of the nozzles of the respective colors become uniform, and uniform ink can be supplied.

By maintaining the ink supply pressure of the ink supplied to the print heads 15 and 16 at a uniform negative pressure, the ink liquid surface at the nozzle openings of the nozzles 15a and 16a of the print heads 15 and 16 has a concave surface. Since a meniscus (curved surface) is formed and these internal pressures are kept uniform, the ejection properties of the ink ejected from the nozzles 15a and 16a of the print heads 15 and 16 are maintained uniformly, and the printing quality is improved. Can be maintained. For example, in the print heads 15 and 16 of the present embodiment, if the ink supply pressure is within a range (operating pressure range) of about 0 mmAq (water column) or more and about -300 mmAq (water column) or less with respect to the atmospheric pressure, Fifteen
A concave meniscus can be formed on the ink liquid surface in the nozzle openings a and 16a. It should be noted that the print head 15, the print head 15, when printing is performed by the portable printer 1 of the present embodiment.
The 16 optimal operating pressure ranges (optimal operating pressure ranges) are approximately -30 mmAq (water column) or less and approximately -100 with respect to the atmospheric pressure.
It is a pressure value of mmAq (water column) or more.

A control unit 3 is located on the left side of the ink cartridges 8 and 9 in the upper space 1a of the portable printer 1 in FIG.
4 are provided. As shown in FIG. 14, the control unit 34 processes the input print data and controls the respective controls, the LF motor driver 47 and the head drive circuit 4 which are controlled by the CPU 40 and generate respective drive signals.
8. ASIC 45 which is a gate array for determining, analyzing and controlling the carriage position by the encoder 49, ASIC 45
A CR motor driver 46 for driving the CR motor under the control of the printer is arranged to control the entire printer.

The head drive circuit 48 of the control unit 34 is connected to four FPCs (flexible printed cables) for applying a voltage to each head, and is connected to the control unit 34 in the upper space 1 a of the portable printer 1. Four head driving FPCs 35 are stacked at the rear edge portion (the back side in FIG. 2), and further, at the rear edge portion (the back side in FIG. 2) of the ink cartridge 8 in the upper space 1a of the portable printer 1. The ink supply tubes 12 are connected to the ink cartridges 8 and 9 described below, and are stacked on the front side in FIG. 2 and connected to the upper portions of the print heads 15 and 16. The FPC 35 for driving a head is a film-shaped one in which a wiring pattern to be a conductive layer is formed on a polyimide base material, and this is further covered with a protective film.

FIG. 6 is a diagram showing the portable printer 1 in FIG.
FIG. 4 is a partial cross-sectional view schematically showing the IV line viewed from the right. For convenience, the carriage motor (CR motor) 3
0 is omitted. In the upper part of FIG. 6, the ink packages 8a,
9a, the ink extraction needle 10 is stabbed for each color. Each of the ink extraction needles 10 is for extracting the ink filled in the ink packages 8a and 9a, and is formed of a metal material such as stainless steel having corrosion resistance, a ceramic material, or the like. The ink extraction needle 10 is formed in a hollow needle shape, and an extraction hole, which is an opening for extracting ink in the ink packages 8a and 9a, is provided at a tip portion (left side in FIG. 6) of the ink extraction needle 10. 10 a is provided, and the extraction hole 10 a is formed so as to communicate with the space inside the ink extraction needle 10. For this reason, the ink extraction needle 10 is connected to the ink packages 8a, 9a.
When the ink is inserted into the ink extraction needle 10, the ink in the ink packages 8 a and 9 a is removed by the extraction hole 10 a.
It can flow into the space inside 0.

As shown in FIG. 8, the ink is sucked by a purging operation described later, and the waste ink tube 66 (see FIG. 8).
The injection needle 70 for injecting the waste ink transported by the printer is inserted into the first waste liquid chamber 83 of the waste ink provided in the lower portion of the ink cartridge 8, and the waste ink is injected and stored.

As shown in FIG. 6, at the rear edge portion (right side in FIG. 6) of the upper space 1a of the portable printer 1, each ink extracted from the ink packages 8a and 9a is inserted into four ink packages. One end of a joint member 11 bent in a substantially L-shape is joined to the base (the opposite end (the right side in FIG. 6)) of the needle 10. On the other hand, ink supply tubes 12 are connected to the other end sides of these joint members 11, respectively. Each of the joint members 11 is formed in a hollow tubular shape, and a communication hole (not shown) communicating with the extraction hole 10a of the ink extraction needle 10 is formed in the inside thereof. Each supply tube 1
Reference numeral 2 denotes a flexible, substantially hollow cylindrical circular tube made of synthetic resin such as polypropylene, polyethylene, polyurethane, polyvinyl chloride, etc., through which ink flows and prints ink to the print heads 15, 16. Supply.

In this embodiment, each supply tube 1
Numeral 2 is a TYGON (registered trademark) tube manufactured by NORTON, and has a tube thickness of about 0.5 mm or more and about 1.5 mm or less, and a tube inner diameter of about 0.5 mm or more and about 0.5 mm or more. It is made of 1.5 mm or less. For example, each supply tube 12 of the present embodiment has a tube wall thickness of approximately 0.8 mm and a tube inner diameter of approximately 0.8 mm, and has an outer diameter (length twice as large as the tube wall thickness and tube inner diameter). And a TYGON tube of about 2.4 mm.
The minimum value (minimum radius of curvature) of the radius of curvature R of the curved portion in a state where each supply tube 12 is bent is approximately 20 mm.
It is.

The four supply tubes 12 will be described in further detail with reference to FIGS. 2 to 6. The ink supply of each color is substantially at the center of the rear edge portion (the back side in FIG. 2) of the upper space 1a of the portable printer 1. Each of the supply tubes joined to the packages 8a and 9a is fitted with an elongated square-shaped binder, stacked vertically and bundled in a line,
That is, inside the curved supply tube 12, the four head driving FPCs connected to the control unit 34 and stacked are stacked.
A protection film 14 for protecting the supply tube 12 from interference with the main body frame 6 is further laminated on the back side, that is, outside the curved supply tube 12.

The protective film 14 is a protective member that is arranged to smoothly slide when the ink supply tube 12 comes into contact with the inner wall of the main body frame 6. A material formed of a material having low adhesiveness and low tackiness in a film shape is used. Protective film 14
The print head 1 needs to be self-supporting, and is integrated with the supply tube 12 and the head driving FPC 35.
It is necessary to bend so as to move with the movement of 5, 16 and its thickness is preferably about 25 μm or more and 300 μm or less.
In the present embodiment, it is formed of polyethylene terephthalate (PET) having a thickness of about 100 μm.

The rear edge portion of the upper space 1a (the back side in FIG. 2)
At the approximate center of the head drive FP from the near side.
C35, supply tube 12, and protective film 14 are laminated in this order. These members are a binder 1 having a sun shape having a wide portion and a narrow portion of the opening.
3 binds at predetermined intervals. The narrow portion of the binder 13 is tightly fixed to the supply tube 12 so that the four rows of the supply tube 12 do not collapse. The wide portion of the binder 13 has a width 4 to 5 times the width of the narrow portion, and the four head driving FPCs 35 are bundled so as not to be largely separated from the bundle of the four supply tubes stacked. Yes, the inside is free to slide. Therefore, even if these bundles may be curved,
Since a sufficient space for the head driving FPC 35 to escape to the inside is secured, the bending is not hindered, and the head can be easily bent. Binder 1
A protective film 14 is provided outside the supply tube 3 so as to cover the supply tube 12.

The four supply tubes 12 and the head driving FPC 35 bundled by the binder 13 at intervals of about 5 cm are maintained on the same plane on the partition plate 5a while the laminated state is maintained, as shown in FIG. From the right hand direction to the front direction, and further, at the front edge portion (the front side in FIG. 2) of the upper space 1a of the portable printer 1, the print head direction,
In FIG. 2, since the print heads 15 and 16 are located at the left initial positions, they are curved to the left and are joined to the joints above the print heads 15 and 16. The inks of the respective colors pass through the respective supply tubes 12 and are provided with predetermined print heads 15 of the respective colors.
16 is transferred.

Further, since the supply tubes 12 are bundled and arranged in a vertically stacked state by the above-described binder 13, the supply tubes 12 are placed in the direction of gravity (the lower side in FIG. 2).
It can be prevented from hanging and bending toward. In addition, since the above-mentioned partition plate 5a is disposed below the supply tube 12, the four supply tubes 12 are supported from below by the partition plate 5a, and each supply tube 12 hangs down in the direction of gravity and is bent. Can be prevented. In addition, the head drive FPC 35 having elasticity similar to the elastic protective film 14.
Since the four supply tubes 12 are sandwiched between them, a sharp angle bend can be prevented in a portion other than the above-mentioned curved portion, so that the supply tube 12 is bent or bent at a steep angle. Accordingly, there is no possibility that the inner cross-sectional area becomes small and energy loss of ink flowing in each supply tube 12 occurs. In addition, since the projection 84 (see FIG. 6) of the waste ink reservoir 8b of the large ink cartridge 8 is provided inside the curved supply tube 12, unintended bending at this portion can be prevented.

Here, the laminated bundle of the protective film 14, the supply tube 12, and the head driving FPC 35 is
For convenience, it is referred to as a harness 17. 3 to 5
A harness 17 is joined to an upper portion of the print heads 15 and 16 from a substantially central portion of a rear edge portion (the back side in FIG. 2) of the upper space 1a, and a state of the harness 17 when the print heads 15 and 16 move. FIGS. 3, 4 and 5 show a partially cutaway view from the line III-III in FIG. 3 to 5, the Y direction is the main scanning direction.

FIG. 3 shows a state in which the print heads 15 and 16 are at an initial position before printing. That is, the print head right 15 is at the left end of the platen 32 which is the print area 43. This state represents the state located on the leftmost side in the figure. In this state, the print head left 1
6 is above the flushing area left 42. In this case, the harness 17 is pulled since there is a distance from the fixing portion (binder) of the supply tube 12 to the print heads 15 and 16, and the protective film 14 is separated from the front wall (the lower side in FIG. 3) of the main body frame 6. It has become. Therefore, in this state, no sliding resistance is generated in the harness 17, and the load for moving the carriage is small. From this state, as shown in FIG.
The motor 30 is rotated by applying a voltage, and the carriage 27 is rotated.
Is moved to move the print heads 15 and 16 rightward in the figure, that is, in the print direction Y, the harness 17 joined to the print heads 15 and 16 moves accordingly. In this case, the harness 17 is connected to the front wall of the main body frame 6 (FIG. 3).
With the protective film 14 separated from the lower side), it moves inside the front wall.

FIG. 4 shows a state in which the carriage 27 has moved in the Y direction. In this state, the carriage 27 is close to the fixing portion of the harness 17, and the harness 17 that has been pulled has room, the length of the harness 17 in the curved portion becomes longer, and the entire harness is resilient by its own elastic force. The harness 17 is pressed against the rear wall side of the main body frame 6 while the harness 17 is separated from the front wall (the lower side in FIG. 4) of the main body frame 6. In this state, the harness 17 comes into contact with the front wall of the frame 6 and slides in contact with the front wall. Therefore, the carriage 27
In this movement, sliding resistance is generated, and the load on the CR motor 30 increases.

FIG. 5 shows a state in which the carriage 27 is further moved in the Y direction and is at the rightmost end. In this state, the harness 17 is pulled in the direction opposite to the state shown in FIG. 3, and as a result, the harness 17 is separated from the front wall (the lower side in FIG. 5) of the main body frame 6. Therefore,
The sliding resistance with the front wall of the main body frame 6 is eliminated, and the load of the movement of the carriage 27 is reduced.

In the present embodiment, as described above, 2
By providing a nozzle row of color in one print head,
Although the print head is made compact, it is of course possible to configure each nozzle row for discharging each ink with a separate print head. The choice depends on the balance between production costs and the need for compactness. Therefore, the number of heads is not limited to two, but may be several.

Next, the arrow X in the drawing of FIG.
Is shown in FIG. As shown in FIG. 6, an insertion port 22 for inserting unused printing paper PP is formed in the lower rear part of the printer body 3 (right side in FIG. 6). A transport driven by an LF motor (line feed motor) 31 composed of a pulse motor for transporting the print paper PP is provided on the downstream side in the transport direction (the direction of the arrow X) of the print paper PP inserted from the insertion opening 22. Roller 23,
A press roller 24 for pressing the printing paper PP is provided on the transport roller 23, and the two cooperate to press and convey the printing paper PP while cooperating.

On the downstream side of the conveying roller 23 and the pressing roller 24, the printing paper PP discharged from the conveying roller 23
Paper discharge roller 25 driven by an LF motor 31 for discharging paper to the outside of the printer main body 3, and the paper discharge roller 25
And a pressing roller 26 for pressing the printing paper PP. The paper discharging roller 25 and the pressing roller 26 cooperate to discharge the printing paper PP from the paper discharging port 4.

The transport roller 23 and the discharge roller 25
The print heads 15 and 16 described above are disposed above the printing paper PP located between the printing heads. Print head 15, 1
6 can reciprocate along a guide bar 29 laid across the main body frame 6 of the printer main body 3 in a direction substantially perpendicular to the paper surface of FIG. 6, that is, in directions indicated by arrows Y and Y in FIG. It is detachably mounted on the carriage 27. The plurality of nozzles 15 for discharging ink onto the printing paper PP sandwiched by the transport rollers 23 and the like are provided on the side of the printing paper PP of the print heads 15 and 16.
a, 16a are formed.

Next, the carriage 27 on which the print heads 15 and 16 are mounted will be described with reference to FIGS. The carriage 27 provided in the main body lower space 1b is
The guide bar 29 extended in the main scanning direction is located on the rear side (FIG. 6).
(Right side of the drawing), and is provided movably in the main scanning direction while being guided by the guide bar. Then, a timing belt 36 is wound around a driving pulley 38 and a driven pulley 39 disposed at the left end of FIG. 2 while being supported by the rotation shaft of the CR motor 30 disposed at the right end of FIG. The carriage 27 is fixed at one position. The ASIC 45 of the control unit 34
A voltage is applied by the CR motor driver under the control of the above, the CR motor 30 rotates to rotate the drive pulley 38, the timing belt 36 to rotate, and the carriage 27
In the main scanning direction (FIG. 2Y)
Direction and the anti-Y direction).

In order to recognize the position of the carriage 27, a timing fence 33 is provided on the rear side (the right side in FIG. 6) of the carriage 27. Timing fence is 3
Reference numeral 3 denotes a linear encoder, which is made of a glass plate having fine slits and has two sets of LEDs slightly shifted in phase.
A photosensor composed of a combination of a light projector composed of a phototransistor and a photodetector composed of a phototransistor, and a pair of photosensors (not shown) for detecting the origin are provided on the opposite side of the timing fence 33 passing through the timing fence 33. Light from a light projector (not shown) is detected by a light receiver (not shown). Two sets of the photosensors are arranged so as to have a phase difference of 1/2 of the slit so that the traveling direction can be recognized. One set of photosensors is used for origin detection. A pulse is generated from the edge of the signal obtained from the photosensor, and the arithmetic operation of the incremental type is performed to control the position of the carriage 27. Based on the data, the ASIC 45 provided in the control unit 34 controls , Analyzes and controls the CR motor 30.

In addition to the above-mentioned transmission type timing fence 33, as the timing fence 33, a fine stripe pattern is printed or baked on a plate made of aluminum or the like, and the light is projected by a laser projector to the timing fence. A reflection-type timing fence 33 that detects the reflected light from the fence 33 with a light receiver and recognizes the position similarly may be used. Further, a timing fence having an absolute type scale may be used. The current position is recognized based on the position information from the timing fence 33, the speed and acceleration of the carriage 27 are obtained, and feedback control by PID control is performed from these data.

The CR motor 30 is a DC motor, and can control the speed by well-known PWM control or current value control (not shown).
Is performing PWM control. Specifically, a diode that performs only rectification is applied to the rectifier to convert the voltage into a constant DC voltage, and the DC voltage is controlled at the inverter at the same time as the output voltage. According to this PWM control, since the rectifier may be a diode, phase control is not required, the control circuit can be simplified, and since the DC voltage is constant, the input ratio of the inverter can be close to 1, There are advantages in that the current is close to a sine wave, and harmonic loss, noise, vibration and torque pulsation of the motor due to high frequency can be suppressed.

FIG. 7 is a cross-sectional view of the portable printer 1 taken along the line VV in FIG. 6, and the arrow Y in the drawing indicates the moving direction of the carriage 27. As shown in FIG. 5, a driving force for reciprocating the carriage 27 in the left-right direction (the direction of the arrow Y and the direction of the opposite arrow Y) of FIG. 5 is provided on the upper portion of the main body frame 6 provided on the right side of the printer main body 3. Supply C
An R motor 30 is provided, and below it, an LF motor 31 for rotating the transport roller 23 and the paper discharge roller 25 is provided.

Here, the flushing operation will be described. In the print heads 15 and 16 which are ink jet heads for discharging ink from the nozzle openings, a solvent having a drying property is used for the ink so that the ink is dried and fixed after being discharged onto the printing paper PP. When the printer 1 is not used, the nozzles 15a, 16a
Is covered with a first cap 62 and a second cap 63 (hereinafter abbreviated as caps 62 and 63), so that drying is prevented. In addition, the nozzle opening during the printing operation always ejects ink in the case of monochrome printing,
The ink stored in the nozzle openings is constantly replaced, and the viscosity of the ink does not increase due to drying.

However, in the case of color printing, there is ink of a color that will not be used for a long time, and the ink stored in the nozzle opening exposed to the outside air without discharging the ink will dry and increase its viscosity. Therefore, if the printing operation is continued for a long time, the nozzle opening of a specific color may be clogged. Therefore, when the printing operation has been performed for a certain period of time, a flushing area is provided in which there is no printing paper PP, that is, the printing heads 15 and 16 are retracted from the platen 32 corresponding to the printing area 43. Is discharged to an ink absorber prepared in advance to replace clogged ink staying in the nozzle orifice with new ink to prevent clogging. In the case of the portable printer 1 of the present embodiment, the flushing operation is performed at the beginning and end of the printing operation, and every 10 seconds during the printing operation.

Next, the purge operation and its mechanism will be described. The purging operation is mainly intended to prevent the nozzles 15a and 16a of the print heads 15 and 16 from being clogged as in the flushing described above. In the flushing operation described above, ink is periodically discharged to the flushing areas 41 and 42 in order to prevent the nozzles 15a and 16a from drying during printing. In contrast,
In the purging operation, when the printer is not used, the print heads 15 and 16 are covered with drying prevention caps 62 and 63 to prevent drying. However, the sealing degree of the caps 62 and 63 is not perfect and drying is gradually performed. If the ink is not used for a long time, the viscosity of the ink in the nozzles 15a and 16a increases due to drying, and the flushing operation may not be able to discharge the ink having the high viscosity. In such a case, the high-viscosity ink in the nozzles 15a and 16a is forcibly discharged by the suction pump.

Hereinafter, the purge mechanism of this embodiment will be described in detail with reference to FIGS. FIG. 7 is a partial cross-sectional view of the portable printer 1 of the present embodiment as viewed from the front along line VV in FIG. FIG. 8 is a partial cross-sectional view of the portable printer 1 of the present embodiment as viewed from above the line VI-VI in FIG. The section of the pump 65 is shown in cross section, and other parts are partially omitted. When a voltage is applied to the LF motor 31 used to transport the printing paper PP, the LF motor 31
Rotates, but when purging, the LF motor gear 3
7, the driving force is transmitted to the pump driving gear 61.
The driving force of the pump drive gear 61 is transmitted to the pump drive cam 64 by a bevel gear at the tip, and the pump drive cam 64 is rotated. The pump driving cam 64 is a cylindrical member having an internal cavity whose lower part is open, and a bevel gear that meshes with the bevel gear of the pump driving gear 61 is formed on the upper surface. On the upper surface, a groove (inner) 64a and a groove (outer) 64b, which are deformed annular guide grooves, are double-engraved, and a groove (horizontal) 64c is also engraved on the side surface. Further, a projection (not shown) corresponding to the photosensor 68 is provided on the open inner lower surface. The protrusion is detected by the photo sensor 68, and detects the initial position of the pump drive cam 64.

A pump 65 is disposed on the left side of the pump driving cam 64 in the drawing. The pump 65 has two pistons, a first piston 65d and a second piston 65d.
e, the first piston 65d has a cylindrical rod, and a distal end of the rod is provided with a follower outside 65b which is a driven portion guided by a groove (outside) 64b. Also,
The second piston 65e has a rod that penetrates through the inside of the cylindrical rod of the first piston 65d, and a follower 65a that is a driven portion guided by a groove (inside) 64a is disposed at the tip of the rod. Is established. The pump 65 is provided with a suction port 65c and a discharge port 65f located rightward in the figure. An internal hollow purge tube 67 is provided at the suction port 65c.
And the purge tube 67 is connected to the caps 62 and 63.
It is connected to and joined. Therefore, the purging operation is performed on the first cap 62 and the second cap 63 at the same time. Further, an internal hollow waste ink tube 66 is connected to the discharge port 65f, and is connected to and connected to the waste ink reservoir 8b of the large ink cartridge 8. Therefore, any color ink is used as waste ink in the ink cartridge size 8
Is stored in the waste ink reservoir 8b.

Two caps, ie, a first cap 62 and a second cap 63 are arranged on the right side of the pump driving cam 64 in the drawing, and the caps 62 and 63 are formed by rotating the pump driving cam 64. Groove (horizontal)
The follower (not shown) is moved by 64c, and the caps 62 and 63 are moved up and down by the cap elevating unit 69.

Hereinafter, the purge operation will be described in detail with reference to FIG. When purging is required, a predetermined control means applies a voltage to the CR motor 30 (see FIG. 2), the carriage 27 moves, and the print heads 15, 16
When moved to the top of 2,63, the timing fence 3
3, the purge operation is started. First,
The rotation of the LF motor 31 is transmitted to the pump drive cam 64 by the LF motor gear 37, and the pump drive cam 64 at the initial position is rotated. Then, the groove (horizontal)
The follower 64c is moved to move the cap elevating unit 69, and the caps 62 and 63 are raised to move the print head 15,
A certain surface of the 16 nozzles 15a and 16a is hermetically covered.

In the initial position, the first piston 65d and the second piston 65e are substantially in contact with each other, the first piston 65d is in the initial position in a position to close the discharge port 65f, and the second piston 65e is in the initial position. In the position, the suction port 65c is in a position to close. Hereinafter the first piston 6
5d, second piston 65e and cap elevating unit 69
Performs the following operation under the guidance of the pump driving cam 64.

After the caps 62 and 63 are raised, the second piston 65e moves to the left, and the first piston 65d
The distance between the first piston 65d and the second piston 65e increases, the internal volume between the two pistons increases, a negative pressure is generated, and the suction port 65c closed by the first piston 65d is opened. Due to the negative pressure generated by the pump 65, the purge tube 6
Negative pressure is also generated in the caps 62 and 63 via the pressure switch 7. Therefore, the ink in the nozzle opening is sucked and the caps 62 and 6 are sucked.
3, and then flows into the pump 65 from the suction port 65c through the purge tube 67, and is stored in the space between the first piston 65d and the second piston 65e. When a predetermined amount of ink flows into the pump 65, the negative pressure disappears. The caps 62 and 63 are slightly moved down by the cap elevating unit 69 to be lowered below the surface of the platen 32 (see FIG. 6), and the print heads 15 and 16 are released thereafter.

Next, the first piston 65d and the second piston 65e move rightward at the same time while keeping the interval constant. Therefore, the internal pressure is kept constant, and it is unlikely that the ink is further sucked in from the suction port 65c, or that the ink is discharged and returned to the purge tube 67 to return the ink to the caps 62 and 63. Absent. The second piston 65e closes the suction port 65c, while the first piston 65d closes the discharge port 6c.
Open 5f. Here, the first piston 65d stops, and only the second piston 65e moves further rightward. Therefore, the first piston 65d and the second piston 6
The interval with 5e is reduced, and the internal volume between them is also reduced. Therefore, the waste ink stored in the pump 65 is pressurized and discharged from the discharge port 65f. The discharged waste ink passes through a waste ink tube 66 and is injected into a waste ink reservoir 8b provided in the large ink cartridge 8. Then, the first piston 65d and the second piston 65e are simultaneously moved leftward in a substantially contact state, and
5d closes the outlet 65f, and the second piston 65e stops at the position where it closes the inlet 65c.

Finally, a projection (not shown) projecting below the pump driving cam 64 is detected by the photo sensor 68, and the end of the purge operation is transmitted to the control unit 34, and
The transmission of the driving force from the F motor 31 to the pump driving gear 61 is released by the LF motor gear 37 and the pump driving cam 6
The rotation of No. 4 stops at the initial position, and the purge operation ends.

Next, a method of using the portable printer 1 and its operation will be described with reference to FIGS.
The cartridge member is mounted on the printer body 3, and the print heads 15, 1 mounted on the cartridge member are mounted.
6 is mounted on a carriage 27 mounted on the printer body 3. When the power is turned on after the ink cartridges 8 and 9 are installed, before printing starts, ink with dry nozzle openings, ink containing air bubbles, or ink with dust attached thereto is sucked and discharged, and good printing is performed. Is performed prior to printing. The initial position when the power is turned on is the print head 1
5, 16 nozzles 15a, 16a are caps 62, 63
7, the driving force is transmitted to the pump driving gear 61 by the LF motor 31 via the LF motor gear 37, and the purging operation is performed, as shown in FIG.

Thereafter, the operation of the carriage 27 is confirmed, and the carriage 27 is stopped at a predetermined home position. When the unused printing paper PP is inserted into the insertion slot 22 of the portable printer 1, the printing paper PP is moved to the LF motor 31.
Roller 23 and holding roller 24 rotated by
Is conveyed below the print heads 15 and 16.
When the transported printing paper PP passes below the printing heads 15 and 16 that are reciprocated in the main scanning direction (direction orthogonal to the paper transporting direction) in the directions of the arrow Y and the anti-arrow Y, Printing is performed using ink ejected from the 16 nozzles 15a and 16a.

The ink filled in the ink packages 8a and 9a of the ink cartridges 8 and 9 respectively passes through the extraction holes 10a of the ink extraction needles 10 inserted into the ink packages 8a and 9a respectively. , Through the communication ports (not shown) of the joint members 11, respectively, into the four supply tubes 12, and is supplied to the print heads 15, 16.
The ink is discharged from the nozzles 5a and 16a. The printed printing paper PP on which printing has been performed is discharged from the paper discharge port 4 by a discharge roller 25 and a pressing roller 26 rotated by the LF motor 31.

As described above, the print heads 15 and 16
It is mounted on a carriage 27 driven by a CR motor 30 and reciprocates in the lower space 1b of the portable printer 1 in the directions indicated by arrows Y and Y in FIG.
Printing is performed by discharging ink from the nozzles 15a and 16a. As described above, the print heads 15 and 16 are
7, the print heads 15, 16
The four supply tubes 12 connected to the upper part of the printer head reciprocate with the movement of the print heads 15 and 16. When the print heads 15 and 16 move to the right side portion (the right side in FIG. 2) of the lower space 1b of the portable printer 1, the supply tubes 12 are curved toward the print heads 15 and 16, and the curved portions (bends). The print heads 15, 16 are supported by a partition plate 5a in the upper space 1a of the portable printer 1 and disposed in the upper space 1a of the portable printer 1.
Curved towards the upper joint.

At the beginning and end of printing and during printing, the print head 1 is placed in the flushing area approximately every 10 seconds.
The flushing operation is performed with 5 and 16 saved. Then, after the printing is completed, the carriage 27 is
2 and 63, and the LF motor 31
The driving force is transmitted to the pump drive gear 61 via the motor gear 37, the purging operation is performed once, and the cap 6
2 and 63 stop at the raised position, and the nozzles 15a and 16
a is sealed by caps 62 and 63,
Drying of the nozzles 15a and 16a when not in use is prevented.

Next, FIG. 14 is a diagram showing a main configuration of a control system of the portable printer 1 according to the present embodiment. Hereinafter, the main configuration of the control system of the portable printer 1 will be described with reference to FIG.
This will be described with reference to FIG. The portable printer 1 includes a CPU 40 for performing various operations in the control unit 34 (see FIG. 2), and an interface (I / F) for receiving signals such as print data output from the host computer 41.
42, a ROM 43 in which various arithmetic programs and tables are stored, a RAM 44 for temporarily storing various types,
An ASIC (Applicator) configured as a gate array for counting and calculating pulse signals from the encoder 49
on-specific Integrated Circuit / specific application integrated circuit) 45 are connected to each other.

The ROM 43 stores a program for controlling the entire portable printer 1, a position of a first fixed point and a second fixed point required for PID control, a PID constant in that case, and the like.

The CPU 40 is connected to the host computer 4
1 stores the print data received via the interface 42 in a predetermined buffer area of the RAM 44, and various controls necessary for driving the LF motor 31 in accordance with a print control program stored in the ROM 43 in advance. A control operation for outputting a signal, a process for processing input image data, developing print data to be actually printed based on the image data, and driving the print heads 15 and 16 based on the data. Edit data to output signals. Also, in response to a control signal from the ASIC 45, a head drive signal is sent to the head drive circuit in synchronization with the movement of the CR motor 30,
The control signal is transmitted to the LF motor driver 47 in accordance with the movement of the LF motor driver 47 to rotate the LF motor 31, and the role of integrating the operations of the respective parts is also fulfilled.

The head drive circuit 48 prints the print head 1 based on print data based on image data from the CPU 40.
When 5, 16 come above a predetermined place of the printing paper PP,
A voltage is applied to a piezo element (not shown) provided in the print heads 15 and 16 to discharge ink to a predetermined position on the printing paper PP.

The LF motor driver 47 receives a small voltage control signal from the CPU 40, sends a predetermined number of pulse currents to the LF motor 31, and obtains a predetermined rotation speed. The LF motor 31 is formed of a stepping motor, and receives the predetermined number of pulse currents to rotate accurately. Therefore, the motor itself does not have a feedback mechanism.

By the driving force of the LF motor 31, the driving force is transmitted to the conveying roller 23 and the discharge roller 25 via the LF motor gear 37, and the printing paper PP is conveyed. The position of the transported printing paper PP is detected by a paper feeding sensor 51 and a paper discharging sensor 52 (not shown).
This signal is sent to the CPU 40 via the FPC. The state of the printing paper PP is fed back by this signal, and the LF motor 31 is controlled.

The switching mechanism 50 allows the LF motor 3
1 is transmitted to the pump drive gear 61 of the purge mechanism 60 (see FIGS. 7 and 8) to operate the purge mechanism 60. As described above, the purge mechanism 60 is operated by mechanically controlling the pump 65, the pistons 65a and 65b, the caps 62 and 63, and the like by the plurality of grooves provided in the pump drive cam 64, and performs a series of purge operations. The initial position is detected by the photo sensor 68 provided on the pump driving cam 64, and the signal is sent to the CPU 40 by the FPC.
Conveyed to. The signal from the photo sensor 68 controls the purge mechanism 60 to be set to the initial position so that the CPU 40 can always perform the purge operation.

Of the above control signals, the LF motor drive control signal for driving the LF motor 31 is input to the LF motor driver 47, and the LF motor drive signal (pulse signal) output from the LF motor driver 47 A voltage is applied to the LF motor 31 to drive the LF motor 31. The driving force of the LF motor 31 is reduced by the LF motor gear 37 by the switching mechanism 50 and transmitted to the transport roller 23 and the discharge roller 25, and the print paper PP is transported by the paper feed mechanism 20.

The ASIC 45 sends a drive control signal to the CR motor driver 46 under the control of the CPU 40. The CR motor driver 46 applies a PWM (Pulse Width Modulatio) to the CR motor 30 based on the drive control signal.
n) The drive signal is sent by the signal. The CR motor 30 that has received the PWM signal causes the carriage 27 to travel, and the position is detected by the timing fence 33, which is the encoder 49, and the light emitter and light receiver provided therein, and the position is fed back to the ASIC 45.

Here, FIG. 15 shows the ASIC shown in FIG.
It is a block diagram showing the structure of 45 in detail. The structure of the ASIC 45 will be further described with reference to this block diagram.

The ASIC 45 is provided with an edge detection circuit 451 for detecting edges (rising) of the encoder signals NEC1 and NEC2 generated from the encoder 49 and generating a reference pulse at the detection timing. Further, the edge detection circuit obtains the traveling direction of the carriage 27 from the phase difference between the two types of encoder signals, and outputs the direction as a direction flag signal using the direction as a flag.

Based on the direction flag signal and the reference pulse output from the edge detection circuit, a carriage position management section 452 for incrementing the pulse signal to obtain a position from the home position HP is provided. Position has been detected. The position of the carriage 27 determined here is fed back to the CPU 40.

The reference pulse generated by the edge detection circuit 451 is sent to the encoder period section 453, where the speed of the carriage 27 is calculated.

Further, the carriage 2 calculated here
7 and the PID constant stored in the ROM 43 are given by the CPU 40, and the PID control unit 454 performs PID control calculation for controlling the speed of the carriage 27 based on the input pulse signal. The PID constant input here is the same as the carriage position management unit 4.
According to 52, between the first fixed point and the second fixed point (see FIG. 9),
In other words, a different PID constant is provided between the case where the carriage 27 is present in the section and the case other than the carriage 27.

Based on the calculation result of the PID calculation unit 454, the PWM generation unit gives a predetermined duty ratio (the ratio of the ON time to the OFF time, which is the ratio of the ON time to a certain period). Is sent to the control signal generator 456.

The control signal generator 456 controls the LF motor 31 and the print heads 15, 1 under the control of the CPU 40.
A drive control signal is sent to the CR motor driver 46 while synchronizing with the movement of No. 6, and a drive signal is given to the CR motor 30 to drive the carriage 27 with a driving force to perform printing.

FIG. 16 is a flowchart showing an outline of control of the CR motor 30 of the portable printer 1 having the above-described configuration. Note that the description of the flushing operation is omitted for the sake of simplicity. Hereinafter, the control of the CR motor will be described with reference to this flowchart. When the power of the portable printer 1 is turned on (start), the print heads 15 and 16 are in a state in which the caps 62 and 63 are hermetically sealed to prevent drying of the ink. The aforementioned purge operation is performed by the motor 31 (see FIGS. 2, 7, and 8). When the old ink inside the nozzle openings of the print heads 15 and 16 is sucked by the purge operation, the caps 62 and 63 are lowered and the carriage 27 is released to be ready for running (step 1 (hereinafter, steps S and S)). Abbreviated))). When the carriage 27 can run, the carriage 27 is run by the CR motor 30 according to a test program stored in the ROM 43 in advance, and the result is sent as an encode signal from the encoder 49 provided in the timing fence 33 to the ASIC 45. The speed and the position are analyzed, and the CPU 40 checks whether there is any abnormality in the running result (S3). If there is any abnormality in the test drive, a warning lamp (not shown) is used to warn the user and inform the user of the abnormality. If there is no abnormality, the test drive is completed, and the carriage 27 is made to wait at the home position (HP) (S
5).

When the above preparatory operations (S1 to S3) are completed, image data or character data from the host computer 41 is transmitted to the CPU 40 via the interface 42.
And stored in the input buffer of the RAM 44 (S7). The read image data or character data is expanded into print data and print data by the CPU 40 as necessary, and stored in the output buffer of the RAM 44. On the basis of the developed print data, the printing paper PP
The nozzles 18 of the print heads 15 and 16 are located at the upper printing start positions.
Is read from the print data so that the print paper PP is moved, and the LF motor 31 is driven to drive the transport roller 2.
The paper is fed for this margin by 3 (S9).

Next, based on the print data stored in the output buffer of the RAM 44, the carriage 27 at the home position HP is moved to the print position and moved (S1).
1) Ink is ejected from the nozzle orifice at a predetermined position to start printing on the printing paper PP. Next, in this case, it is determined whether or not the carriage 27 is a section or a section each time the carriage 27 passes the first fixed point or the second fixed point (S13). If the section is or a section (S13: YES), The carriage speed is controlled by the first PID constant (S15),
If it is not the section or the section, that is, if it is the section (S13: NO), the carriage speed is controlled by the second PID constant (S17).

S13 to S17 will be described in more detail with reference to FIG.
When driven by 0, the timing fence 3
3 (see FIG. 2), the encoder 49 transmits the light passing through the slit to the encoder signals ENC1 and ENC by a light emitter and a light receiving unit (not shown) of the photo sensor provided so as to sandwich the photo sensor 3 (see FIG.
The signal is sent to the edge detection circuit 451 as C2, where the rising edge of the signal is converted to a pulse signal as an edge. Since the encoder signals ENC1 and ENC2 are detected with a phase difference of a half of the slit, whether the traveling direction of the carriage 27 is the Y direction or the opposite Y direction is determined based on the order of two consecutive signals. A flag for identifying the Y direction or the anti-Y direction is set. The home position HP of the carriage 27 is detected by a photo sensor for detecting the origin, not shown, and the information is also sent to the carriage position management unit 452 via the edge detection circuit 451. The carriage position management unit 452 sets the position detected by the photo sensor for origin detection to 0, counts and adds a pulse when moving in the Y direction, and subtracts and counts a pulse when moving in the opposite Y direction. Performs an incremental type operation. Then, the carriage position management unit 452 manages the position of the carriage 27 based on the coordinates in the Y direction determined by this calculation. The position management by the carriage position management unit 452 recognizes that the carriage 27 has passed a predetermined fixed point. In the carriage position management unit 452, the carriage 27 is moved to the first fixed point.
When passing through the second fixed point, information on the carriage position is transmitted to the CPU 40, and the CPU 40 issues a command to the PID calculation unit 454 of the ASIC 45 to change a predetermined PID constant.

Specifically, from Ps to the first fixed point, FIG.
Since the sliding resistance of the carriage 27 is a small section as shown in FIG. 1, the first ratio is set so that the output ratio to the deviation, that is, the PID control is performed with a small control gain.
The carriage speed is controlled by the above PID constant.

When the carriage 27 first passes through the first fixed point, as shown in FIG. 4, the harness 17 comes into contact with the main body frame 6 so as to enter a section where sliding resistance is generated. When the load increases as shown in FIG. 9 and the output of the CR motor 30 is the same as that for the deviation between the target speed and the speed measured by the encoder period measurement unit 453, the load is controlled to a constant target speed. It takes a lot of time, and as a result, the time required to converge to a constant speed is delayed (see FIG. 10). For this purpose, the carriage speed is controlled with the second PID constant so that the control gain is larger than that of the section, and the large deviation is controlled so as to converge to a constant speed in a short time.

Further, when the carriage moves from the section and passes through the second fixed point, the carriage enters a section as shown in FIG. Here, since the condition is the same as that of the section, PID using the PID constant used for PID control is used.
Since it is appropriate to perform control using the same first PID constant as the ID constant, the CPU 40 instructs the PID calculation unit 454 to change the PID constant.

In the present embodiment, the carriage is configured to perform printing not only in the Y direction of FIG. 2 but also in the opposite Y direction. If the beginning of the line is closer to the end of the line to be printed on the next line, the carriage travels
After the direction is reversed, the printing of the next line is performed in the Y direction from the position in the anti-Y direction from the beginning of the next line by the approaching section. In this case, the carriage 27 is positioned at Ps--the first fixed point--.
It moves in the order of the first fixed point --- the first fixed point. In other words, the first PID constant is used first, and the PID constant used for the control may be changed every time a certain fixed point is passed.

As described above, the carriage position management unit 45
2, every time the vehicle passes through the first fixed point or the second fixed point, information on the passage is sent to the CPU 40, and the CPU 40 sends an appropriate PID to the PID calculation unit 454 based on the information.
A constant is designated, and the PID calculation unit 454 controls the carriage speed based on the PID constant. In addition, PID
The actual setting of the constant varies greatly depending on the load of the device, the output of the motor, and the like, and needs to be set individually for each device, so that it is not specifically shown here.

As described above, the more appropriate PI
Printing is performed based on the D constant, and each time the printing passes the fixed point (S
21: YES), control is performed using an appropriate PID constant as described above (S13, S15, S17), the end of the line to be printed is reached (S19: YES), and if there is still a line to be printed (S23: YES). Then, the feed roller 23 is rotated by a predetermined amount by the LF motor 31 to feed a new line (S25). If the line feed is closer to the beginning of the line than the end of the line to be printed on the next line, the carriage travels in the opposite Y direction,
The printing of the next line is performed in the Y direction from a position shifted from the head of the next line by the approach section in the anti-Y direction. If the end of the line is closer to the beginning of the line to be printed in the next line, the carriage travels in the Y direction, and then prints the next line in the Y direction for the approaching section from the end of the next line. (S11).

As described above, the line feed is repeatedly printed, and if there is no next line to be printed, that is, if it is the last line (S23: NO), the carriage 27 is returned to the home position (S27), and the printing paper PP is printed. Is discharged by rotating the transport roller 23 and the discharge roller 25 by the LF motor 31 (S29), and if there is a next page to be printed (S3).
1: YES), repeat the procedure from S7 to S29 again, and when there are no more pages to be printed (S31: N)
O), the print heads 15 and 16 are cleaned by performing a purging operation, and the caps 62 and
63 is raised to seal and close the print heads 15 and 16 to prevent drying (S33).

The operation of the portable printer 1 according to the present embodiment having the above-described configuration will be described below.

Here, considering the case where the load of the control object becomes large due to disturbance, if this load has a large value with respect to the target value, and if the gain of the controller remains unchanged, the same output will be obtained for the same deviation. Even if is increased, it is difficult to increase the speed due to the large load, that is, the gain of the system becomes relatively small, and the response becomes slow. In this case, if the gain of the controller is increased in accordance with the gain of the system, it is possible to quickly respond to disturbance. However, if the gain of the controller is set too high, the response becomes oscillating at the original target value, causing hunting.

Here, for such a large disturbance, a method of gain scheduling control (adaptive gain control) for performing a multi-PID operation for changing the gain of the controller in accordance with a change in the measured value may be considered. . This method is a kind of adaptive control, in which a substantial gain of a controller can be made constant by changing a proportional band (proportional band) according to a measured value with respect to a large disturbance.
The disturbance can be appropriately converged using the D constant. However, it is difficult to detect the occurrence of the sliding resistance, which is the load of the actual carriage travel, with a simple configuration, and to detect such a change in the load complicates the apparatus.

On the other hand, the change in the traveling speed of the carriage can be easily detected. In this case, however, this is a post-reaction after the change in the measured value, and therefore the first-order lag process is inevitable. In the case where the occurrence of the sliding resistance, which is a disturbance, can be expected with considerably high accuracy as in the portable printer 1 of the embodiment, it is possible to respond to the disturbance more quickly by adjusting the gain of the controller in advance. In particular, with printers, slight fluctuations in speed appear immediately in the print results,
It is necessary to converge the speed disturbance due to disturbance as soon as possible.

Further, when a simple configuration is desired as in the present embodiment, control based on a complicated calculation process is performed.
It is highly desirable to achieve quick control adapted to the device with a simple configuration.

Therefore, in the present embodiment, FIGS.
The control unit 34 having the configuration shown in FIG. Hereinafter, the carriage speed control by the control unit 34 having this configuration will be described.

FIG. 9 shows the carriage 2 of the portable printer 1.
7 is a graph showing a load at the time of traveling. The vertical axis of the graph is
The running resistance of the carriage 27 during running, that is, the magnitude of the load on the CR motor 30 is shown. The higher the load, the higher the load. The left end of the horizontal axis of the graph indicates the position of the carriage 27 after the carriage 27 starts printing from the initial printing position shown in FIG. Is shown.
Further, in the section shown in FIG. 4, a sliding resistance (friction resistance) is generated in a section where the harness 17 contacts the main body frame at the position of the first fixed point and runs while sliding the harness 17, This is a section where the load on the CR motor 30 is large. Section is harness 1 as shown in FIG.
Reference numeral 7 denotes a position where the second fixed point is separated from the main body frame 6 again, the sliding resistance is eliminated, and the load on the CR motor 30 is reduced. As shown in this graph, when the harness 17 comes into contact with the main body frame 6, the CR motor 30
It can be seen that the load on is increased only for a certain section.

Next, FIG. 10 shows a change in speed in the case of the conventional PID control due to an increase in the load which is a disturbance as shown in FIG. In this case, the PID constant is determined so that the gain of the controller becomes a gain corresponding to the first section. As shown in FIG. 10, in the section, the carriage travels at a constant speed via an unillustrated approach section. However, when entering the section, the running resistance, which is a disturbance, suddenly increases, and the rotation of the CR motor 30 rotating at the same output becomes slow, and the running speed of the carriage 27 becomes slow. Here, the same speed cannot be obtained even with the same output due to the sliding resistance, and the same speed cannot be secured unless the output is further increased. That is, the ratio of the speed to the output has decreased. In other words, the process gain has decreased. Therefore, since the equivalent dead time and the equivalent time constant also change, the response becomes slow if the PID constant before the process gain decreases. Therefore, the speed V
Because of the dead time, after the speed drops to the speed 101 due to the increase in the load, the PID control starts to work, and the speed increases.
However, since the process gain has been substantially reduced, the time constant is no longer appropriate, the response is slow, and the time required to converge to the target speed is increased.

When the sliding resistance disappears after passing through the further section, the value returns to the same value as that of the section of the process gain. However, if the control cannot be performed so as to converge to the target speed in the section, further vibration occurs. It will continue.

On the other hand, FIG. 11 is a diagram showing the speed of the carriage when the PID constant is adapted to the section. In the case where the PID constant is adapted to the section of, overshoot occurs after entering the constant speed section from the approaching section, and the speed changes oscillatingly and it takes time to converge, or in some cases, the vibration converges. No hunting occurs and the vehicle does not converge to the target speed.

Next, control of the carriage speed by the configuration of the embodiment according to the present invention will be described. FIG.
FIG. 7 is a diagram illustrating a change in a gain of a controller according to the present embodiment. As shown in FIG. 12, the section from the fixed point 1 to the fixed point 2 is a PID constant that increases the gain of the controller so as to correspond to the substantial process gain. With the PID control having such a configuration, an appropriate carriage speed can be obtained. FIG.
Shows the carriage speed controlled when the gain of the controller is changed in the section of FIG. As shown in FIG. 13, in the section, the constant speed is already controlled by the PID constant adapted to the section. Here, the load increases due to the contact of the harness 17 in the section of
Since the constant has been changed so as to increase the gain of the controller, it quickly responds to a change in speed and converges to a constant speed in a short time. Further, the load suddenly decreases when entering the section, but as in the section, the PID is set so that the control gain corresponds to the process gain with a small load.
Since the constant has been changed, the convergence is appropriately performed at a constant speed without causing hunting.

A portable printer 1 according to an embodiment of the present invention.
It is possible to provide a recording apparatus which has a simple configuration, eliminates instability of the carriage speed due to a change in the load of the carriage motor during carriage conveyance, maintains a stable carriage speed, and obtains high-quality printing results. It has the effect of being able to.

Although the present invention has been described based on one embodiment, the present invention is not limited to the above-described embodiment, and various modifications and changes can be made without departing from the spirit of the present invention. Can be easily inferred.

[0112]

As apparent from the above description, according to the recording apparatus of the first aspect of the present invention, the output of the carriage motor is calculated and the control means for transmitting the control signal with a predetermined gain is used. A calculating means for changing a gain of a control signal to be output to the driving means based on a predetermined pattern in accordance with a load caused by a change in position within the scanning range; Since a predetermined pattern is provided according to the load due to a change in the position within the scanning range, the gain of the control signal output to the driving means is promptly changed based on this pattern by the gain changing means. There is an effect that the optimum speed control can be performed for the position, and an effect that a stable carriage traveling can be achieved with a simple structure. That. Therefore, there is an effect that the quality of printing can be high.

According to the recording apparatus of the second aspect of the invention, in addition to the effect of the recording apparatus of the first aspect, the arithmetic means generates a control signal based on PID control. Therefore, in combination with the above-described control method, there is an effect that the speed can be appropriately controlled based on the proportional control, the integral control, and the differential control. Therefore, there is an effect that the quality of printing can be high.

According to the recording apparatus of the third aspect,
In addition to the effects of the recording device according to claim 1 or 2,
An ink cartridge and a supply tube are provided, and when printing on a recording medium, the print head receives ink from the supply tube and prints while being transported on the recording medium by the carriage while the ink cartridge is fixed. When the load caused by the change in the carriage position is a load caused by frictional resistance caused by the supply tube sliding with the recording apparatus housing, the load is controlled by a pattern in which the gain is determined according to the change in the load. Therefore, even if frictional resistance occurs due to the supply tube, there is an effect that appropriate control can be performed. Therefore, there is an effect that the head control of the recording apparatus having the feature that the weight of the head is small and there is no change in weight can be made more appropriate.

According to the recording apparatus of the fourth aspect,
In addition to the effects of the recording device according to claim 1 or 2,
An ink cartridge and a supply tube are provided, and when printing on a recording medium, the print head receives ink from the supply tube and prints while being transported on the recording medium by the carriage while the ink cartridge is fixed. When the load due to the change in the carriage position is a load caused by the elasticity of the supply tube or the cable for driving the head, the gain is determined from the pattern load determined according to the change in the load. Therefore, even if resistance occurs due to the elasticity of the supply tube, there is an effect that appropriate control can be performed. Therefore, there is an effect that the head control of the recording apparatus having the feature that the weight of the head is small and there is no change in weight can be made more appropriate.

According to the recording apparatus of the invention according to claim 5,
In addition to the effect of the recording apparatus according to any one of claims 1 to 4, the print head is an ink jet head, so that the carriage speed is appropriately controlled. This has the effect that a high quality printing result can be obtained.

According to the recording apparatus of the invention according to claim 6,
In addition to the effects of the printing apparatus according to any one of claims 1 to 5, the printing apparatus includes a main CPU that processes input print data, and controls the carriage motor separately from the main CPU. The operation speed of the carriage is not controlled by the main CPU, which has a large processing load such as processing of print data, and the carriage speed is controlled by another operation means. Not only can control the carriage speed, but also the main CPU
And the processing speed can be increased. Therefore, there is an effect that the throughput can be improved as a whole of the recording apparatus.

[Brief description of the drawings]

FIG. 1 is a front view showing the appearance of a portable printer 1 according to one embodiment of the present invention.

FIG. 2 is a partially cutaway perspective view schematically showing the internal structure of the portable printer 1. FIG.

FIG. 3 is a top view of the state of the harness 17 when the carriage 27 moves to the home position, with a part thereof omitted from the line III-III in FIG.

FIG. 4 is a view of the state of the harness 17 when the carriage 27 has moved to the vicinity of the center, viewed from above, with a part omitted from the line III-III in FIG. 1;

5 is a top view of the state of the harness 17 when the carriage 27 has moved to the vicinity of the end in the Y direction, with a part thereof omitted from the line III-III in FIG.

FIG. 6 is a partial cross-sectional view schematically showing the portable printer 1 as viewed from the right direction along the line IV-IV in FIG.

7 is a partial cross-sectional view of the portable printer 1 as viewed from the front along line VV in FIG.

8 is a partial cross-sectional view of the portable printer 1 as viewed from above the line VI-VI in FIG.

FIG. 9 is a graph showing a load when the carriage 27 of the portable printer 1 travels.

FIG. 10 is a diagram showing a change in speed in the case of the conventional PID control due to an increase in a load as a disturbance as shown in FIG.

FIG. 11 is a diagram showing a carriage speed when a PID constant is adapted to a section of FIG.

FIG. 12 is a diagram showing a change in the gain of the controller of the portable printer 1.

FIG. 13 shows a carriage speed controlled when the controller gain is changed in the section of FIG.

FIG. 14 is a block diagram illustrating a main configuration of a control system of the portable printer 1.

FIG. 15 is a block diagram illustrating a detailed configuration of an ASIC 45 of the portable printer 1.

FIG. 16 is a flowchart showing an outline of control of the CR motor 30 of the portable printer 1.

[Explanation of symbols]

 1 Portable Printer 27 Carriage 30 Carriage Motor (CR Motor) 33 Timing Fence (Speed Detector) 34 Controller 40 CPU 45 ASIC (Gate Array) 46 CR Motor Driver (Driver) 49 Encoder (Speed Detector) 451 Edge Detection Circuit (speed detection unit) 452 Carriage position management unit 453 Encoder cycle measurement unit (speed detection unit) 454 PID measurement unit (calculation unit) 455 PWM generation unit 456 control signal generation unit

Claims (6)

[Claims] A carriage for driving a print head; a carriage motor for driving the carriage; speed detecting means for detecting a conveying speed of the carriage; a target speed set in advance and detected by the speed detecting means. Calculating means for calculating an output of the carriage motor for causing the carriage conveyance speed to coincide with the target speed from the speed difference and transmitting a control signal with a predetermined gain; based on a control signal from the calculation means; A driving means for outputting a driving current to a carriage motor, wherein the calculating means has a gain of a control signal output to the driving means in a pattern determined in advance according to a load caused by a change in position of the carriage within a scanning range. And a gain changing means for changing the gain. 2. The recording apparatus according to claim 1, wherein the calculation unit generates a control signal based on PID control. 3. The recording apparatus includes: an ink cartridge; and a supply tube for supplying ink from the ink cartridge to the print head. When recording on a recording medium, the ink cartridge is fixed and the printing is performed. The head is configured to print while receiving the supply of ink from the supply tube while being conveyed on the recording medium by the carriage. 3. The recording apparatus according to claim 1, wherein the load is a load generated by frictional resistance due to sliding, and the gain is determined in the pattern according to a change in the load. 4. 4. The recording apparatus includes an ink cartridge and a supply tube for supplying ink from the ink cartridge to the print head. When recording on a recording medium, the ink cartridge is fixed and the printing is performed. The head is configured to receive the supply of ink from the supply tube and print while being conveyed on the recording medium by the carriage, and the load due to the change in the carriage position is caused by the supply tube or the cable for driving the head. 3. The recording apparatus according to claim 1, wherein the load is a load caused by elasticity, and the gain is determined in the pattern according to a change in the load. 4. 5. The recording apparatus according to claim 1, wherein the print head is an ink jet head. 6. The printing apparatus according to claim 1, further comprising a main CPU for processing the input print data, and further comprising an arithmetic unit for controlling a carriage motor separately from the main CPU. The recording device according to claim 5.