JP2003127350A - Ink jet recording device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable both a high-speed control in a high-speed feeding and an accurate stop position control in a low-speed feeding, in a sheet feeding movement of an ink jet printing device. SOLUTION: The ink jet recording device comprises: a rotary encoder 17 provided with first and second slits 17a and 17b having different lengths in a radial direction and formed alternately at equal spaces; first light receiving and emitting parts 18a1 and 18b1 detecting the first and second slits 17a and 17b; second light receiving and emitting parts 18a2 and 18b2 detecting the second slits 17b; a detection sensor consisting of these light receiving and emitting parts, and detecting a rotation angle of the rotary encoder 17 from the number of movements of the slights 17a and 17b; an encoder selection part selecting the first light receiving and emitting parts 18a1 and 18b1 , or the second light receiving and emitting parts 18a2 and 18b2 from input information of the detection sensor; and an acceleration and deceleration control part selecting the acceleration and deceleration of the sheet feeding system from a result of calculation by the encoder selection part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording apparatus for recording by ejecting ink from nozzles and adhering the ink onto a recording medium.

[0002]

2. Description of the Related Art In recent years, ink jet recording apparatuses are required to print at higher speed and with higher quality. In order to realize this requirement, not only high-speed movement of the carriage reciprocating operation but also accurate speed control in printing during low-speed operation including during acceleration / deceleration are required. Further, in terms of paper transport operation, it is essential to achieve both higher speed transport and accurate stop position control.

Against this background, at present, control technologies for carriages and paper conveyance using optical encoders are
The motor output is controlled by calculating the moving speed and the current position of the driven object from the signal from the encoder sensor, for example, the time interval between rising edge pulses or the number of integrated pulses, and comparing and calculating it with the target value. .

For example, in order to improve the accuracy of the paper feed amount in the paper feed mechanism, it is necessary to minimize the moment of inertia of the drive system and shorten the time from the stop command to the actual physical stop of the drive unit as much as possible. Therefore, for that purpose, it is desirable to move the driving unit immediately before stopping at the lowest speed possible.

[0005]

However, as the speed decreases, the influence of load fluctuations due to frictional fluctuations of the drive system increases, or the speed decreases, so that the interval between encoder pulses becomes longer, and the control of the encoder pulse becomes longer. If the time interval becomes long, the load fluctuation cannot be dealt with, and a phenomenon such as stopping before the target stop position or overshooting occurs. And if it stops before the target stop position, it will start to overcome the static friction load from the stopped state,
Immediately, it becomes even more difficult to stop by sending a small amount of necessary corrections again, and time loss occurs.
The same is true if you go too far.

Therefore, it is important to control at a short time interval during low speed conveyance such as during acceleration of paper conveyance or during deceleration immediately before stop. For that purpose, the higher the encoder resolution, the better. .

However, when the encoder resolution becomes high, the number of encoder outputs per hour becomes enormous during high-speed conveyance of the paper, and the processing time from the encoder input to the calculation necessary for control to output an appropriate motor current may not be in time. Or, such a process takes too much time, which causes a problem in other processes in the entire system.

Further, since the moment of inertia becomes large during high-speed conveyance, it is difficult to instantaneously change the speed of the load even if control is performed at short time intervals, and the necessity of performing control for each encoder pulse is low.

On the other hand, there has been a technique for decimating signals from an encoder by software during high-speed operation. However, since a high-speed encoder signal is always received once and then soft-processed, the above-mentioned processing time is reduced. Increasing is inevitable.

Therefore, the present invention provides an ink jet recording apparatus capable of achieving both high-speed control during high-speed conveyance and accurate stop position control by speed control at short time intervals during low-speed conveyance in the paper conveyance operation. The purpose is to

[0011]

In order to solve this problem, an ink jet recording apparatus of the present invention is provided with a carriage provided so as to be capable of reciprocating in parallel with a first direction, and a plurality of nozzles mounted on the carriage. A recording head that ejects ink from the recording medium and a recording medium on which an image is formed by the ink ejected from the recording head adhering to the second direction orthogonal to the first direction.
In the direction of, the driving force transmitting means for transmitting the driving force of the driving means for operating the conveying means to the conveying means, and the coaxially with the rotary shaft of any rotating member constituting the driving force transmitting means. A rotary encoder that is attached and has a plurality of types of action parts with different action conditions alternately formed at equal intervals over the entire circumference, and is provided corresponding to the plurality of types of action parts, and all types of action parts are provided. A detection sensor for detecting the rotation angle of the rotary encoder from the number of movements of the action portion due to rotation of the rotary encoder, comprising a full action portion detection part for detecting and a partial action portion detection part for detecting a part of the action portion, Based on the input information from the detection sensor, the encoder selection unit that selects all action unit detection units or partial action unit detection units to be used, and based on the calculation results of the encoder selection unit, the paper transport system addition It is obtained by a structure having a deceleration control unit for controlling the speed.

As a result, accurate control is performed at short time intervals by detecting all operating parts during low speed operation, and unit time is detected by detecting only some operating parts during high speed operation. Since the number of encoder signals per hit is reduced, accurate stop position control is achieved by high-speed control during high-speed conveyance and speed control at short time intervals during low-speed conveyance, without increasing the processing time during high-speed operation. It becomes possible to be compatible.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is a recording device which is mounted on the carriage and is capable of reciprocating in parallel with the first direction and which ejects ink from a plurality of nozzles. Driving force of a head, a conveying unit that conveys a recording medium on which an image is formed by the ink ejected from the recording head is formed, in a second direction orthogonal to the first direction, and a driving force of a driving unit that operates the conveying unit. Of the driving force transmitting means for transmitting the driving force transmitting means to the conveying means and the rotating shaft of one of the rotating members constituting the driving force transmitting means, and a plurality of types of operating portions having mutually different operating conditions are alternately arranged on the entire circumference. A plurality of rotary encoders that are formed at equal intervals over the entire length, and a portion that is provided corresponding to a plurality of types of action portions and that detects all types of action portions and a portion that detects some types of action portions Action part Detection part It is equipped with a detection sensor that detects the rotation angle of this rotary encoder from the number of movements of the operation part due to the rotation of the rotary encoder, and selects all action part detection parts or partial action part detection parts to be used based on the input information from the detection sensor. An inkjet recording device having an encoder selection unit for controlling and an acceleration / deceleration control unit for controlling acceleration / deceleration of a paper transport system based on a calculation result of the encoder selection unit, without causing an increase in processing time during high-speed operation, This has the effect of making it possible to achieve both high-speed control during high-speed conveyance and accurate stop position control by speed control at short time intervals during low-speed conveyance.

According to a second aspect of the present invention, in the invention according to the first aspect, the plurality of types of action portions are ink jet recording apparatuses having mutually different reflection wavelengths, and a processing time at a high speed operation is provided. It is possible to achieve both high-speed control at the time of high-speed conveyance and accurate stop position control by speed control at short time intervals at the time of low-speed conveyance, without increasing the number of times.

According to a third aspect of the present invention, in the invention according to the first aspect, the plurality of types of action portions are ink jet recording apparatuses having mutually different transmission wavelengths, and a processing time during high-speed operation. It is possible to achieve both high-speed control at the time of high-speed conveyance and accurate stop position control by speed control at short time intervals at the time of low-speed conveyance, without increasing the number of times.

According to a fourth aspect of the present invention, in the first aspect of the invention, the plurality of types of action portions are ink jet recording apparatuses having mutually different reflectances, and the processing time during high-speed operation is high. It is possible to achieve both high-speed control at the time of high-speed conveyance and accurate stop position control by speed control at short time intervals at the time of low-speed conveyance, without increasing the number of times.

According to a fifth aspect of the present invention, in the invention according to the first aspect, the plurality of types of action portions are ink jet recording apparatuses having mutually different transmissivities, and a processing time during high-speed operation. It is possible to achieve both high-speed control at the time of high-speed conveyance and accurate stop position control by speed control at short time intervals at the time of low-speed conveyance, without increasing the number of times.

According to a sixth aspect of the present invention, in the invention according to any one of the first to fifth aspects, a plurality of types of action parts are composed of a first action part and a second action part. Is
The full action portion detection unit is an ink jet recording apparatus that detects the first action portion and the second action portion, and the partial action portion detection unit is the ink jet recording apparatus that detects the first action portion or the second action portion, and at the time of high speed operation. It is possible to achieve both high-speed control at the time of high-speed conveyance and accurate stop position control by speed control at short time intervals at the time of low-speed conveyance without increasing the processing time.

FIG. 1 shows an embodiment of the present invention.
Starting with FIG. In addition, in these drawings, the same members are denoted by the same reference numerals, and duplicate description is omitted.

FIG. 1 is a perspective view schematically showing an ink jet recording apparatus according to an embodiment of the present invention, and FIG. 2 is a side view showing a main part of the ink jet recording apparatus according to an embodiment of the present invention. 3 is an explanatory view showing a rotary encoder and a detection sensor in the ink jet recording apparatus which is an embodiment of the present invention, FIG. 4 is an explanatory view showing a detection mechanism by the rotary encoder and the detection sensor of FIG. 3, and FIG. 1 is a block diagram showing a drive system control mechanism in an inkjet recording apparatus according to an embodiment;
FIG. 6 is a block diagram schematically showing the configuration of the control unit shown in FIG.
7 is a flowchart showing a control process in the inkjet recording apparatus according to the embodiment of the present invention, FIG. 8 is a flowchart showing an operation of the encoder selection unit in the inkjet recording apparatus according to the embodiment of the present invention, and FIG. FIG. 10 is an explanatory view showing an output signal from the detection sensor at the time of low speed and forward rotation of the rotary encoder in the inkjet recording apparatus according to the embodiment of the present invention. FIG. 10 is a rotary view of the inkjet recording apparatus according to the embodiment of the present invention. FIG. 11 is an explanatory diagram showing output signals from the detection sensor at the time of high speed and forward rotation of the encoder. FIG. 11 shows output signals from the detection sensor at low speed and reverse rotation of the rotary encoder in the ink jet recording apparatus according to the embodiment of the present invention. 12 is an explanatory diagram showing the ink jet printer according to the embodiment of the present invention. FIG. 13 is an explanatory view showing an output signal from the detection sensor at the time of high speed and reverse rotation of the rotary encoder in the printing apparatus, FIG. 13 is a block diagram showing a configuration of an acceleration / deceleration control unit in the ink jet printing apparatus which is an embodiment of the present invention, FIG. 14 is a flowchart showing a speed detecting process in the inkjet recording apparatus according to the embodiment of the invention, and FIG. 15 is a flowchart showing a position detecting process in the inkjet recording apparatus according to the embodiment of the invention.

As shown in FIGS. 1 and 2, the ink jet recording apparatus according to the present embodiment includes black, yellow,
The recording head 1 is provided with a plurality of nozzles (not shown) for ejecting magenta and cyan inks. A sub-tank 3 that stores black, yellow, magenta, and cyan inks and supplies these inks to the recording head 1 is arranged above the recording head 1. The recording head 1 and the sub tank 3 are provided on the carriage 2.

In this embodiment, the number of colors is 4 as described above.
The color is not limited to this, but may be 5 or 6 as long as it is 4 or more.

A pressure chamber filled with ink and a piezoelectric element are provided at positions corresponding to the nozzles of the recording head 1, and the volume of the pressure chamber is reduced by applying a voltage in pulses to the piezoelectric element. And an actuator that deforms to a position (both not shown) are provided. When the actuator is vibrated by a head drive signal generator (not shown) installed in the carriage 2, the ink in the pressure chamber is positioned below the nozzle. The recording sheet (recording medium) 5 is ejected. The recording paper 5 is conveyed in the first direction in FIG. Further, as the actuator, a conventionally known actuator such as a thermal type or an electrostatic type may be used.

The recording head 1 is fixed to a carriage 2 which is movable relative to the recording paper 5. The carriage 2 is orthogonal to the conveyance direction of the recording paper 5 (first direction in FIG. 1) and parallel to the recording surface of the recording paper 5 (see FIG. 1).
In the second direction) in which the carriage is driven by a carriage drive motor 6 and is rotated by a drive pulley, and a driven pulley provided on the opposite side of the drive pulley. It is fixed to the lower span of the endless carriage drive belt 7 that rotates around the
In the second direction and slidably penetrates the carriage shaft 4 attached to the apparatus main body.

A linear encoder 11 arranged in parallel with the carriage shaft 4 is arranged on the opposite side of the carriage shaft 4 across the carriage 2. When the carriage driving belt 7 is rotated by the rotation of the carriage driving motor 6, the carriage 2 fixed to the carriage driving belt 7 is held by the carriage shaft 4 and is scanned in the second direction in FIG. Move back and forth in the direction. At this time, the linear encoder 1
Based on the information of the encoder pulse from 1, the moving speed and position of the carriage 2 are detected and controlled.

The carriage drive motor 6 is provided with a rotation detection board 12, and the rotation detection board 12 and a detection sensor (not shown) allow the rotation amount of the carriage drive motor 6 (that is, the first rotation of the recording head 1). 2) is detected.

The recording paper 5 is a conveying roller (conveying means) arranged below the recording paper 5 and extending in the second direction.
It is sandwiched between 13a and a pinch roller 13b that presses the recording sheet 5 against the conveying roller 13a on the upper side of the recording sheet 5. A conveyance motor (driving means) 15 composed of a DC motor (DC electric motor) is arranged behind the pinch roller 13b in the conveyance direction of the recording paper 5, and the conveyance motor 1
A transmission gear train (driving force transmission means) 16 for transmitting the driving force of the conveyance motor 15 to the conveyance roller 13a is provided between the conveyance roller 13a and the conveyance roller 13a. As a result, the transport roller 13a is driven by the transport motor 15 and transports the recording paper 5 in the first direction. At this time, the pinch roller 13b is rotated by the recording paper 5 being conveyed.

In the present embodiment, the driving force transmitting means comprises a transmission gear train 16 composed of a plurality of gears, and the driving force of the carry motor 15 is transmitted by such a transmission gear train 16. However, as the driving force transmission means, a pulley and a belt, or a gear and a shaft,
Further, it can be realized by various means capable of transmitting the driving force of the carry motor 15 to the carry roller 13a, such as a combination thereof, and is not limited to the present embodiment.

A final gear 16a constituting the transmission gear train 16 is mounted on one side of the transport roller 13a coaxially with the rotation shaft of the transport roller 13a. Further, a rotary encoder 17 is attached to the outside of the final gear 16a coaxially with the rotation shaft of the transport roller 13a.

A plurality of slits (acting portions) extending in the radial direction are formed on the outer peripheral portion of the rotary encoder 17 at equal intervals over the entire circumference. A detection sensor 18 that detects the position of the slit is installed at a predetermined position of the rotary encoder 17. The detection sensor 18 includes a light emitting unit that emits detection light toward the rotary encoder 17, and a light receiving unit that is arranged on the opposite side of the light emitting unit with the rotary encoder 17 interposed therebetween and that receives the detection light emitted from the light emitting unit. It consists of Then, the rotation angle of the rotary encoder 17 is detected by recognizing the number of times that the detection light is blocked and transmitted by the movement of the slit when the rotary encoder 17 is rotated by the final gear 16a through the transport roller 13a. Thus, the rotation amount of the carry motor 15, that is, the feed amount of the recording paper 5 is detected.

The detection sensor 18 is not a transmission type in which a light emitting portion and a light receiving portion are arranged with the rotary encoder 17 interposed therebetween to detect transmitted light, but the rotary encoder 17 is used.
Various other sensors such as a reflection type in which a light emitting portion and a light receiving portion are arranged on one side to detect reflected light, or a magnetic sensor for magnetically detecting instead of such an optical sensor can be used. .

As shown in the figure, between the pinch roller 13b and the conveyance motor 15, a main tank 20 storing the above-mentioned black, yellow, magenta and cyan inks is fixed to the main body of the apparatus to form a second tank. They are arranged side by side.

The main tank 20 and the sub tank 3 supply the ink in the main tank 2 to the sub tank 3 4
It is connected by a flexible supply tube 8 of a book.
These four supply tubes 8 extend in the first direction, then extend to the driven pulley side in the second direction, are further curved and extend to the drive pulley side in the second direction, and reach the carriage 2. .

Then, as the carriage 2 moves in the second direction, the position of the curved portion of each supply tube 8 changes,
This allows the carriage 2 to move smoothly.

Here, in the sub tank 3, for example, A
Inks equivalent to several sheets of recording paper 5 of 4 sizes are stored. The ink in the sub-tank 3 is ejected during printing, and the ink is continuously replenished from the main tank 20 to the sub-tank 3 every time the ink is ejected with a negative pressure.

As described above, by providing the sub-tank 3 on the carriage 2 to absorb the change in the ink pressure in the supply tube 8 due to the movement of the carriage 2, the small mass of the sub-tank 3 reduces the total mass of the carriage 2. Increasing the moving speed of the carriage 2 and the carriage 2
The device is downsized by narrowing the moving space.

Next, the rotary encoder 17 and the detection sensor 18 described above will be described in more detail with reference to FIGS. 3 and 4.

Here, FIG. 3 shows the rotary encoder and the detection sensor, and FIG. 4 shows the detection mechanism by the rotary encoder and the detection sensor. 4A is a radial cross-sectional view of the rotary encoder, and FIG. 4B is a circumferential cross-sectional view of the rotary encoder.

As shown in FIG. 3, the rotary encoder 1
The slit formed in 7 has a first slit (first acting portion) 17a having a predetermined width d and a length l, and twice the first slit 17a having the same width d as the first slit 17a. Second slit (second acting portion) 1 having a length of 2 l
7b are alternately formed over the entire circumference at equal intervals d. The second slit 17b may be longer than the first slit 17a, and as in the present embodiment,
The length may not be twice the length of the first slit 17a.

As shown in FIGS. 3 and 4, this
Such as the slit 17a, 17b
The sensor 18 is the first slit of the rotary encoder 17.
The detection light is directed toward 17a and the second slit 17b.
The first light emitting portion 18a for irradiating ₁And a rotary encoder
First light emitting unit 18a with 17 in between₁Placed on the other side of
The first light emitting portion 18a₁Receives the detection light emitted from
The first light receiving portion 18b₁And the first light emitting portion 18a₁Of
Located on the side of the rotary encoder 17
The second light emitting unit 18 that irradiates the detection light toward the lens 17b.
a₂And the second light emission with the rotary encoder 17 in between.
Section 18a₂Is disposed on the opposite side of the second light emitting portion 18a.₂Or
The second light receiving portion 18b that receives the detection light emitted from the second light receiving portion 18b.₂When
Consists of. Then, the first light emitting unit 18a₁And the first received light
Section 18b₁And all slit detectors (all working part detectors)
Is the second light emitting portion 18a₂And the second light receiving portion 18b₂And part
Each of the minute slit detectors (partial action portion detectors)
Is made.

Further, the light emitting portions 18a ₁ and 18a ₂ and the light receiving portions 18b ₁ and 18b ₂ are mutually d / a in the rotational direction.
It is composed of an A phase and a B phase which are displaced by two. Then, due to this deviation, the rotary encoder 1
The rotation direction of 7 is determined.

That is, assuming that the rotary encoder 17 is rotating in the direction indicated by the arrow in FIG. 3, the output signal of the light received by the A phase of the first light receiving portion 18b ₁ is A1,
Let B1 be the output signal of the light received in the B phase,
The output signal of the light received by the A phase of the light receiving section 18b ₂ of
When the output signal of the light received in the 2nd and B phases is B2, the signals from the first light receiving portion 18b ₁ and the second light receiving portion 18b ₂ are as shown in FIG. Note that FIG. 9 will be described later.

In FIGS. 3 and 4, the light emitting section 18
Although a ₁ and 18a ₂ and the light receiving parts 18b ₁ and 18b ₂ are shown independently, they may be combined into one block or a plurality of blocks.

Next, the operation control of the ink jet recording apparatus of this embodiment will be described with reference to FIGS.

As shown in FIG. 5, the control mechanism of the drive system is
The light emitting units 18a ₁ and 18a ₂ to be used based on the input information from the detection sensor 18, the encoder selecting unit 30b to select the light receiving units 18b ₁ and 18b ₂ , and the encoder selecting unit 3
0b, the control unit 30 having an acceleration / deceleration control unit 30a for controlling the acceleration / deceleration of the sheet conveyance system, and the conveyance roller 13a and the rotary unit driven by the control output 33 of the acceleration / deceleration control unit 30a. A conveyance motor 15 that rotates the encoder 17, a detection sensor 18 that detects changes in transmitted light from slits arranged at equal intervals on the rotary encoder 17, and outputs the change to the encoder selection unit 30b.
The recording paper 5 includes a paper edge detection unit 31 that detects the edge of the recording paper 5 and a home detection unit 32 that detects the home position of the carriage 2.

Then, the conveyance roller 13a is rotated by the rotation of the conveyance motor 15 to convey the recording paper 5, and at the same time, the rotary encoder 17 is rotated, and the detection sensors 18 are slits arranged on the rotary encoder 17 at equal intervals. The change in the transmitted light from is detected and output to the encoder selection unit 30b.

As shown in FIG. 6, the control unit 30 has a CPU 42 that controls the entire operation, an IF 41 that receives print information transmitted from the PC 40, a memory 43 that stores predetermined data, and an input / output of new light. And the I / O 44 for performing.

The control processing by the control unit 30 will be described with reference to FIG.

The control unit 30 receives the print information sent from the PC 40 at the IF 41 (S1) and eliminates the extra information. Then, the print data analysis process for ink ejection is performed (S2), the drive system acceleration / deceleration control process is performed (S3), and the print process is executed.

Next, the operation of the encoder selection unit 30b provided in the control unit 30 will be described with reference to FIGS.

Here, FIG. 8 is a flow chart showing an outline of the operation of the encoder selecting section 30b. 9 shows the timing of the output signal from the detection sensor 18 when the rotary encoder 17 is rotating at low speed and forward rotation, and FIG. 10 is the detection sensor 1 when the rotary encoder 17 is rotating at high speed and forward rotation.
8 shows the timing of the output signal from the rotary encoder 17, FIG. 11 shows the timing of the output signal from the detection sensor 18 when the rotary encoder 17 rotates at low speed, and FIG. 12 shows the timing of the output signal from the detection sensor 18 when the rotary encoder 17 rotates at high speed. Signal timings are shown respectively.

[0052] In these figures, A1 is an encoder signal output from the light received by the first A-phase of the light receiving portion 18b _1, B1 is received in a first B-phase of the light receiving portion 18b ₁ The encoder signal, which is the output of the
B2 indicates an encoder signal which is an output of the light received by the A phase of the light receiving portion 18b ₂ and B2 indicates an encoder signal which is an output of the light received by the B phase of the second light receiving portion 18b ₂ . Further, the forward rotation means the rotation of the rotary encoder 17 in the direction of the arrow in FIG. 3, and the reverse rotation means the rotation in the opposite direction.

The encoder selection unit 30b is initially set to the low speed mode on the low speed side. Therefore, the encoder signal A1 and the encoder signal B1 from the _first light receiving unit 18b ₁ are input as encoder signals.

In FIGS. 8 and 9, if the encoder signal B1 (FIG. 9) is input at the start of the sheet conveying operation (S11), the period Tel from the A-phase rising to the B-phase rising is not less than the specified period T. If so, the current operation is determined to be the low speed mode (S12), and the input of subsequent encoder signals A1 and B1 is waited (S13).

Then, if the speed of the transport portion increases and Tel becomes smaller than T at some point (FIG. 10) (S1
4), it is determined whether or not the encoder signal B1 = the encoder signal B2 (S15), and if they are equal, the encoder selection unit 30b is switched to the high speed side (S16). If they are not equal, switching to the high-speed side makes the encoder count processing complicated because there is no previous encoder information in the counter processing in the next high-speed mode. Therefore, the encoder selector 30b is not switched. Wait for the next encoder input.

On the other hand, if the encoder selector 30b is on the high speed side and the encoder signal A2 is input, the high speed mode is determined in S12, and the input of the subsequent encoder signals B2 and A2 is waited (S17).

Then, if the speed of the transport unit decreases and Teh becomes larger than 8T at some point (S18), the encoder selecting unit 30b is switched to the low speed side (S19).

11 and 12 show changes in each output of the detection sensor 18 and the count value Cn when the rotary encoder 17 rotates in the reverse direction. FIGS. 9 and 10 show that the count direction is negative. Since the operation is basically the same as the normal rotation shown, the description is omitted.

The encoder information processed in this way is input to the acceleration / deceleration control section 30a as encoder information 33 in FIG.

FIG. 13 shows the configuration of the acceleration / deceleration control section 30 of the ink jet recording apparatus.

The encoder information 33 is the transport counter value Cn.
And the encoder cycle Te, and input mode information indicating whether the current encoder selector is high or low. Then, the acceleration / deceleration control unit 30 detects the transport speed of the recording paper from the encoder cycle Te of the encoder information 33, the next paper transport amount 36, the acceleration pattern from the acceleration table 42, and the constant value. Speed table 43
Based on the constant speed pattern from the deceleration table, the deceleration table from the deceleration table 44, and the stop pattern from the stop table 45, the positional information from the sheet edge is stored in the acceleration end position storage unit 38, the constant speed end position storage unit 39, and the deceleration start position storage unit 40. And the moving distance calculation unit 37 stored in the expected stop position storage unit 41 and position comparison between these position information and the current position information of the position detection unit 34 and output the selection information of the speed table to the selection unit 47. Position determining unit 46 and selecting unit 4
Using the selected speed table of No. 7 and the speed information 58 of the speed detection unit 35, a deviation amount, which is the difference between the estimated speed obtained from the speed table at the current position and the detected speed information 58, is calculated to obtain the speed deviation amount 57. From the control amount correction unit 50, a control amount correction unit 50 that outputs a corrected control amount by having a speed deviation amount calculation unit 48 that outputs, an addition unit 51 that adds the control amount, and a subtraction unit 52 that subtracts the control amount And a control output section 53 for correcting the control amount and outputting a control output 56 to the carry motor 15.

It should be noted that, in the speed detecting section 35, as shown in FIG.
As shown by, in the low speed mode, the speed V = 2d / T
It becomes el, and in the case of the high speed mode, the speed V = 4d / Te
h.

In the position detection process, as shown in FIG. 15, it is determined whether or not the mode is the low speed mode (S21). In the low speed mode, (Cn-1 + 1) is set as the count value Cn (S22), and the high speed mode is set. In this case, (Cn-1 + 9) is set as the count value Cn (S23).

Next, it is determined whether the acceleration end position is larger than the current position (S24). If the acceleration end position is larger, the proper speed is set as the acceleration table value (S25). Further, if the current position is larger in S24, it is determined whether or not the constant speed end position is larger than the current position (S26). If the constant speed end position is larger, the proper speed is kept constant. The speed table value is set (S27).

Further, if the current position is larger in S26, it is determined whether the deceleration start position is larger than the current position (S28), and the appropriate speed is set as the deceleration table value (S29).

According to the present ink jet recording apparatus,
When the operating speed of the
The first slit 17a and the second slit 1 that are cut
7b is the first light emitting portion 18a₁And the first light receiving portion 18b₁And with
By detecting, accurate control is performed in a short time interval.
Be done. When the operating speed of the device is high, the rotary
Only the second slit 17b provided in the encoder 17
The second light emitting portion 18a ₂And the second light receiving portion 18b₂Detected by
By doing so, high-speed control processing becomes possible.

As described above, accurate control is performed at short time intervals by detecting the first slit 17a and the second slit 17b during low speed operation, and the second slit 17a and second slit 17b are detected during high speed operation. Slit 1
Since the number of encoder signals per unit time is reduced by detecting only 7b, high-speed control during high-speed conveyance and short time intervals during low-speed conveyance can be achieved without increasing the processing time during high-speed operation. It is possible to achieve both accurate stop position control by speed control.

In the above-described embodiment, the example in which the slits of two kinds of lengths are alternately formed in the rotary encoder 17 is shown, but the slits of three or more kinds of lengths are alternately formed. Well, the more kinds of slit lengths there are, the finer the control can be performed, and the higher speed and higher image quality of the printing device can be achieved.

It is necessary to provide the light emitting portion and the light receiving portion of the detection sensor 18 in the same number as the types of the lengths of the slits. For example, when the slits of three types are formed, the light emitting portion and the light receiving portion are formed. You will need 3 of each, 1 of which
All slit detectors as a set detect slits of all three types of lengths, and the other two sets of partial slit detectors have slits of a certain length (one set has two types of slits, 1
The set detects one type of slit).

Further, for example, if the light from the _first light emitting portion 18a ₁ is accidentally incident on the second light receiving portion 18b ₂ as stray light, it becomes difficult to distinguish it from the light from the _second light emitting portion 18a ₂ . Since the detection sensor 18 may malfunction,
It is necessary to prevent light from the light emitting unit, which is not originally compatible, from entering the light receiving unit (or to prevent malfunction even if it enters). Therefore, the first light emitting unit 18a
₁ and the first light receiving portion 18b ₁ and the second light emitting portion 18a ₂
It is desirable that the pair of the second light receiving portion 18b ₂ and the second light receiving portion 18b ₂ are spaced apart from each other so as not to generate stray light. Further, a light shielding plate or the like may be inserted between the first light emitting portion 18a ₁ and the second light emitting portion 18a ₂ or between the first light receiving portion 18b ₁ and the second light receiving portion 18b _2. Good. Further, the first light emitting portion 18a ₁
And the second light emitting portion 18a ₂ may have different wavelengths, and the first light receiving portion 18b ₁ and the second light receiving portion 18b ₂ may have different wavelengths.

Here, in the present embodiment, an example in which the slits having different lengths are formed in the rotary encoder 17 has been shown, but the present invention is not limited to the slits, and the length thereof is limited. Not even a thing. That is, what is formed in the rotary encoder 17 may be something other than the slit as long as it is an operating portion having different operating conditions. Therefore, it suffices that the detection sensor 18 be able to detect such an action part, and the detection sensor 18 is not an optical sensor as in the present embodiment, but other sensors such as a magnetic sensor depending on the form of the action part. Various sensors can be used as appropriate.

In the case where the operating portion is optically detected, the operating portions having mutually different reflection wavelengths may be the operating portions having mutually different transmission wavelengths. The action parts may have different reflectances, or the action parts may have different transmittances.

[0073]

As described above, according to the present invention, accurate control is performed at short time intervals by detecting all slits during low speed operation, and some slits are detected during high speed operation. By detecting only the number of encoder signals per unit time, the speed of high-speed control during high-speed conveyance and the speed at short time intervals during low-speed conveyance can be reduced without increasing the processing time during high-speed operation. An effective effect that it is possible to achieve both accurate stop position control by control is obtained.

[Brief description of drawings]

FIG. 1 is a perspective view schematically showing an inkjet recording apparatus according to an embodiment of the present invention.

FIG. 2 is a side view showing a main part of an inkjet recording apparatus according to an embodiment of the present invention.

FIG. 3 is an explanatory diagram showing a rotary encoder and a detection sensor in the inkjet recording apparatus according to the embodiment of the present invention.

FIG. 4 is an explanatory view showing a detection mechanism by the rotary encoder and the detection sensor of FIG.

FIG. 5 is a block diagram showing a drive system control mechanism in an inkjet recording apparatus according to an embodiment of the present invention.

6 is a block diagram schematically showing a configuration of a control unit in FIG.

FIG. 7 is a flowchart showing a control process in the inkjet recording apparatus according to the embodiment of the present invention.

FIG. 8 is a flowchart showing the operation of the encoder selection unit in the inkjet recording apparatus according to the embodiment of the present invention.

FIG. 9 is an explanatory diagram showing an output signal from the detection sensor at the time of low speed and forward rotation of the rotary encoder in the inkjet recording apparatus according to the embodiment of the present invention.

FIG. 10 is an explanatory diagram showing an output signal from a detection sensor at high speed and forward rotation of the rotary encoder in the inkjet recording apparatus according to the embodiment of the present invention.

FIG. 11 is an explanatory diagram showing an output signal from the detection sensor at the time of low speed and reverse rotation of the rotary encoder in the inkjet recording apparatus according to the embodiment of the present invention.

FIG. 12 is an explanatory diagram showing an output signal from the detection sensor at the time of high speed and reverse rotation of the rotary encoder in the inkjet recording apparatus according to the embodiment of the present invention.

FIG. 13 is a block diagram showing the configuration of an acceleration / deceleration control unit in the inkjet recording apparatus according to the embodiment of the present invention.

FIG. 14 is a flowchart showing speed detection processing in the inkjet recording apparatus according to the embodiment of the present invention.

FIG. 15 is a flowchart showing a position detection process in the inkjet recording apparatus according to the embodiment of the present invention.

[Explanation of symbols]

1 Recording Head 2 Carriage 5 Recording Paper (Recording Medium) 13 Conveying Rollers (Conveying Means) 15 Conveying Motors (Drive Means) 16 Transmission Gear Trains (Driving Force Transmission Means) 17 Rotary Encoder 17a First Slits 17b Second Slits 18 Detection sensor 18a ₁ First light emitting part (all slit detecting part) 18a ₂ Second light emitting part (all slit detecting part) 18b ₁ First light receiving part (partial slit detecting part) 18b ₂ Second light receiving part (partial) Slit detector) 30a Acceleration / deceleration controller 30b Encoder selector

Continued front page    (72) Inventor Shichiro Michiteru             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. (72) Inventor Masashi Kawano             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. (72) Inventor Takami Koyama             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. F-term (reference) 2C056 EA01 EA04 EB12 EB36 EC12                       EC31 FA10                 2C058 AC07 AE02 AF14 GB07 GB19                       GE01

Claims (6)

[Claims] 1. A carriage provided so as to be capable of reciprocating in parallel with a first direction, a recording head mounted on the carriage for ejecting ink from a plurality of nozzles, and ink ejected from the recording head is attached. And a conveying means for conveying a recording medium on which an image is formed in a second direction orthogonal to the first direction, and a driving force transmission for transmitting the driving force of a driving means for operating the conveying means to the conveying means. And a plurality of types of action portions having different action conditions, which are attached coaxially with the rotation axis of any one of the rotating members constituting the drive force transmitting means, and are alternately formed at equal intervals over the entire circumference. A rotary encoder and an all-action-part detection section that is provided corresponding to a plurality of types of action sections and detects all types of action sections and a partial-action section detection section that detects some types of action sections A detection sensor for detecting the rotation angle of the rotary encoder from the number of movements of the operation unit due to the rotation of the rotary encoder; and the full-action-part detection unit or partial-action unit used based on input information from the detection sensor An inkjet recording apparatus comprising: an encoder selection unit that selects a detection unit; and an acceleration / deceleration control unit that controls acceleration / deceleration of a paper transport system based on a calculation result of the encoder selection unit. 2. The ink jet recording apparatus according to claim 1, wherein the plurality of types of action portions have mutually different reflection wavelengths. 3. The ink jet recording apparatus according to claim 1, wherein the plurality of types of action portions have mutually different transmission wavelengths. 4. The ink jet recording apparatus according to claim 1, wherein the plurality of types of action portions have mutually different reflectances. 5. The ink jet recording apparatus according to claim 1, wherein the plurality of types of action portions have mutually different transmittances. 6. A plurality of types of said action parts are composed of a first action part and a second action part, said all action part detection part detecting said first action part and second action part, The inkjet recording apparatus according to any one of claims 1 to 5, wherein the partial action portion detection unit detects the first action portion or the second action portion.