JP2002254743A - Position encoder, position control device using it, image recording device and electronic equipment, and controlling method for them - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a position encoder capable of controlling a position with high resolution, and to provide a position control device, an image recording device and electronic equipment, each using the encoder. SOLUTION: A phase-B phase and B phase-*A phase signals are generated from two phase analog signals (A and B phases) outputted from a sensor and two phase-inverted signals (*A and *B phases). Next, A phase-B phase is binarized, taking A phase-B phase>0 as a threshold, and B phase-*A phase is binarized, taking B phase-*A phase>0 as a threshold. As a result, two digital signals are obtained. Rising and falling of the two digital signals are counted as an increment of a position, then a first rough positional information is obtained. By a second fine positional information obtained by using the analog signals of A and B phases, and of *A and *B phases divided at the rising and the falling positions, the position is identified with high resolution.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a position encoder,
In particular, the present invention relates to a position control device, an image recording device, an electronic component, a control method thereof, and a storage medium using the same, particularly, having an output waveform with a duty of 50%, outputting a plurality of phases, and accurately outputting a relative phase of each phase. The present invention relates to a position encoder that performs position control with high resolution by performing the position control.

[0002]

2. Description of the Related Art As an information output device in a word processor, a personal computer, a facsimile, etc., there is an image recording device for recording desired information such as characters and images on a sheet-like recording medium such as paper or film.

Various methods are known as a recording method for an image recording apparatus. The reasons are that non-contact recording is possible on a recording medium such as paper, colorization is easy, and quietness is high. In recent years, the ink-jet method has attracted particular attention.As a configuration, a recording head that ejects ink according to desired recording information is mounted and reciprocating scanning is performed in a direction perpendicular to a feeding direction of a recording medium such as paper. The serial recording method for performing recording while being inexpensive and easy to miniaturize is widely used in general.

In a conventional ink jet type image recording apparatus, a sheet medium (hereinafter, referred to as a sheet) as a recording medium is used.
Is fed into the image recording device by a feed mechanism that uses one or more feed rollers and guides the image recording device along a predetermined sheet path.

[0005] The roller is usually constructed so as to frictionally mesh with a sheet in the input tray, and when a continuous sheet is pulled out from the input tray, it is guided to an image forming area where an image is formed.

In order to accurately form an image on a sheet, it is necessary to dispose the sheet at an accurate position, and for this purpose, it is necessary to move the rollers with high precision. Therefore, the quality of the image depends on the accurate positioning of the roller position, and a position encoder or the like is usually used for the accurate positioning of the roller position.

[0007] The position encoder uses one or more sensors to identify slits, which are position markers formed along the tracks of adjacent code wheels (typically disks).

The code wheel is preferably mounted such that both the feed roller axis and the code wheel axis have the same central axis and rotate with the feed roller.

[0009] As the code wheel rotates, the sensor and its associated structure count the number of slits that are incremental markers passing through. Each slit indicates a predetermined angular movement of the code wheel, so that the relative movement of the code wheel and the rollers and the sheet conveyed thereby can be detected.

[0010]

However, in the conventional position encoder, in order to accurately position the wheel that rotates forward and backward, two phases (A
Phase, B phase), and the signal change at the rising and falling points of the signal is used to quadruple (quadruple the spatial frequency). Therefore, it has not been possible to perform position control at a position between signal changes such as rising and falling of the signal.

Further, in order to control the position of the position encoder with high resolution, the outer shape of the code wheel is increased, and the position encoder device incorporating the code wheel is enlarged or the interval between the slits is reduced. Or high resolution.

However, when the slit interval, which is an incremental marker, is narrowed, factors that make the signal unstable due to factors such as the electric circuit of the sensor, the sensor sensitivity, the mechanical factor of the code wheel, and the optical factor increase. It becomes difficult to control the position with high resolution using a stable signal.

SUMMARY OF THE INVENTION The present invention has been made to solve the problems of the prior art described above, and has as its object to provide a high resolution code wheel position without significantly increasing the complexity and manufacturing cost of the position encoder. An object of the present invention is to provide a position encoder capable of performing position control with high resolution, a position control device using the same, an image recording device, an electronic device, and a control method thereof.

[0014]

A position encoder according to an embodiment of the present invention for achieving the above object has the following arrangement. That is, having a scale provided with a plurality of markers at predetermined intervals, and a sensor for detecting the markers,
A position encoder that generates position information of a measurement target based on a plurality of analog signals output from the sensor, and generates a signal corresponding to the plurality of analog signals and an inverted signal by inverting each of the signals. Inverting signal generating means, digital signal generating means for generating a digital signal based on a difference between respective amplitudes of the signal corresponding to the analog signal or the inverted signal, and counting a change point at which the value of the digital signal changes First position information generating means for generating first information relating to the position, and dividing a predetermined period at intervals of the change points, and dividing a signal corresponding to the analog signal or a signal selected from the inverted signal into the divided signals. Signal allocating means for allocating to each of the selected periods, and a second position generating second information relating to the position based on the selected signal. And having an information generating means.

Further, for example, the plurality of analog signals are signals composed of an A phase and a B phase having different phases, and the digital signal generating means outputs the first signal when the amplitude of the A phase is equal to or more than the amplitude of the B phase. Generating a digital signal having a second value.

Further, for example, the plurality of inversion signals are A
* A phase and * B phase in which the phases of the phase and the B phase are inverted. The digital signal generation means further sets the first value when the amplitude of the B phase is equal to or greater than the amplitude of the * A phase, A digital signal having a second value is generated when the amplitude is smaller than the amplitude of the * A phase.

Further, for example, the signal allocating means divides the predetermined period into four using a time when the digital signal changes, and the A-phase and the B-phase are respectively divided into the four divided periods.
Phase, the * A phase or the * B phase analog signal is selected and assigned.

Further, for example, the first information is approximate position information of the object to be measured, the second information is fine position information relating to the object to be measured that cannot be detected by the first information, By using information and the second information, accurate position information of the measurement object can be obtained.

Further, for example, the predetermined period is one cycle of the analog signal.

Further, for example, the position encoder is a rotary encoder or a linear encoder.

[0021] To achieve the above object, a position control device according to an embodiment of the present invention has the following configuration. That is, based on the position encoder according to any one of claims 1 to 7, and the input target position information of the measurement target, the first target value to which the first information should reach and the first target value. Target position setting means for setting a second target value to which the second information should reach.

Further, for example, the apparatus further comprises control means for controlling the object to be measured to reach the first target value and the second target value.

An image recording apparatus according to an embodiment of the present invention for achieving the above object has the following configuration. That is, an image recording apparatus that performs recording by scanning a carriage on which a recording head is mounted on a recording medium based on information transmitted from an external device. A position encoder according to the present invention or the position control device according to the eighth or ninth aspect is provided.

Further, for example, the recording head is an ink jet recording head which performs recording by discharging ink.

Also, for example, the recording head is a recording head that discharges ink using thermal energy,
It is characterized by having a thermal energy converter for generating thermal energy given to the ink.

An electronic apparatus according to an embodiment of the present invention for achieving the above object has the following configuration. That is,
A position encoder according to any one of claims 1 to 7 or a position control device according to claims 8 or 9 is provided.

A control method of a position encoder according to an embodiment of the present invention for achieving the above object has the following configuration. That is, a position encoder having a scale provided with a plurality of markers at predetermined intervals and a sensor for detecting the markers, and generating position information of the measurement target based on a plurality of analog signals output from the sensors. A control method, comprising: a signal corresponding to the plurality of analog signals; an inverted signal generating step of inverting each of the signals to generate an inverted signal; and a signal corresponding to the analog signal or a respective amplitude in the inverted signal. A digital signal generating step of generating a digital signal based on a difference between the two, a first position information generating step of generating a first information regarding the position by counting a change point at which the value of the digital signal changes; A predetermined period is divided at intervals of, and a signal corresponding to the analog signal or a signal selected from the inverted signal is divided into each of the divided periods. And having a signal assignment step of assigning, and a second position information generating step of generating a second information relating to the position based on the selected signal, to the.

A control method of a position control device according to an embodiment of the present invention for achieving the above object has the following configuration. That is, any one of claims 14 to 20
A first target value to which the first information should reach and a second target to which the second information should reach, based on the control method of the position encoder described in the paragraph and the input target position information of the measurement object. And a target position setting step of setting a value.

An image recording apparatus control method according to an embodiment of the present invention for achieving the above object has the following configuration. That is, based on information transmitted from an external device, a control method of an image recording apparatus that performs recording by scanning a carriage equipped with a recording head on a recording medium,
A control method according to any one of claims 14 to 22 is provided.

An electronic apparatus control method according to an embodiment of the present invention for achieving the above object has the following configuration.
That is, a control method according to any one of claims 14 to 22 is provided.

A computer-readable storage medium according to an embodiment of the present invention for achieving the above object has the following configuration. That is, a control program of the control method according to any one of claims 14 to 22 is stored.

A computer-readable storage medium according to an embodiment of the present invention for achieving the above object has the following configuration. That is, a computer-readable storage medium which is executed by a computer device connectable to an image recording apparatus and stores a program for driving the image recording apparatus via a bidirectional interface, wherein the program is stored in a storage medium.
A control method according to any one of claims 4 to 22 is included. In order to achieve the above object, a computer-readable storage medium according to an embodiment of the present invention has the following configuration. That is, a control program for a method of controlling an electronic device according to claim 26 is stored.

[0033]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the present invention will be described below with reference to the drawings.

In this embodiment, a serial type ink jet recording apparatus will be described as an image recording apparatus, but the scope of the present invention is not limited to the described examples.

[Schematic Description of Apparatus Main Body] FIG. 9 is an external perspective view showing an outline of the configuration of an ink jet printer IJRA which is an ink jet recording apparatus according to a typical embodiment of the present invention.

In FIG. 9, the helical groove 5 of the rotating lead screw 5005 is rotated via the driving force transmission gears 5009 to 5011 in conjunction with the forward / reverse rotation of the drive motor 5013.
The carriage HC that engages with 004 has a pin (not shown), and reciprocates in the directions of arrows a and b while being supported by the guide rail 5003.

On the carriage HC, an integrated ink jet cartridge IJC having a recording head IJH and an ink tank IT is mounted.

Reference numeral 5002 denotes a paper holding plate, which applies a platen 500 to the recording paper P in the moving direction of the carriage HC.
Press against 0.

Reference numerals 5007 and 5008 denote photocouplers.
This is a home position detector for confirming the presence of the carriage lever 5006 in this region and switching the rotation direction of the motor 5013.

A member 5016 supports a cap member 5022 for capping the front surface of the recording head IJH.
A suction unit 015 sucks the inside of the cap, and recovers the suction of the recording head through the opening 5023 in the cap.

Reference numeral 5017 denotes a cleaning blade.
Reference numeral 019 denotes a member which enables the blade to move in the front-rear direction, and these members are supported by the main body support plate 5018. The blade is not limited to this embodiment,
It goes without saying that a well-known cleaning blade can also be applied to the present embodiment.

Reference numeral 5021 denotes a lever for starting suction for recovery from suction, and a cam 5020 which engages with the carriage.
The driving force from the driving motor is controlled by a known transmission mechanism such as clutch switching.

The capping, cleaning, and suction recovery are configured so that desired processing can be performed at the corresponding position by the action of the lead screw 5005 when the carriage comes to the area on the home position side. It is needless to say that the present example can be applied to any setting if the desired operation is set at the timing.

[Description of Control Structure] Next, a control structure for executing the printing control of the above-described ink jet printing apparatus will be described.

FIG. 10 shows an ink jet printer IJR.
3 is a block diagram illustrating a configuration of a control circuit of FIG. 10, reference numeral 1700 denotes an interface for inputting a recording signal, 1701 denotes an MPU, and 1702 denotes
R storing a control program executed by MPU 1701
Reference numeral 1703 denotes a DR for storing various data (such as the recording signal and recording data supplied to the head).
AM.

Reference numeral 1704 denotes a gate array (GA) for controlling supply of print data to the print head IJH, and includes an interface 1700, an MPU 1701, and an R
Data transfer control between the AMs 1703 is also performed.

Reference numeral 1710 denotes a carrier motor for transporting the recording head IJH, and reference numeral 1709 denotes a transport motor for transporting the recording paper. Reference numeral 1705 denotes a head driver for driving the recording head, and 1706 and 1707 denote motor drivers for driving the transport motor 1709 and the carrier motor 1710, respectively.

The operation of the above control configuration will be described. When a recording signal is input to the interface 1700, the recording signal is converted between the gate array 1704 and the MPU 1701 into recording data for printing. Then, the motor drivers 1706 and 1707 are driven, and the recording head is driven according to the recording data sent to the head driver 1705 to perform recording.

Although the control program executed by the MPU 1701 is stored in the ROM 1702 here,
An erasable / writable storage medium such as an EEPROM may be further added so that the host computer connected to the inkjet printer IJRA can change the control program.

As described above, the ink tank IT and the recording head IJH may be integrally formed to constitute a replaceable ink cartridge IJC. However, the ink tank IT and the recording head IJH are separated. It may be configured so that only the ink tank IT can be replaced when the ink runs out.

FIG. 11 is an external perspective view showing the structure of an ink cartridge IJC in which the ink tank and the head can be separated.

In the ink cartridge IJC, as shown in FIG. 11, the ink tank IT and the recording head IJH can be separated at the position of the boundary line K (black). When the ink cartridge IJC is mounted on the carriage HC, the ink cartridge IJC is provided with an electrode (not shown) for receiving an electric signal supplied from the carriage HC, and the electric signal causes the recording head IJH to operate as described above. Is driven to eject ink.

In FIG. 11, reference numeral 500 denotes an ink ejection port array. The ink tank IT is provided with a fibrous or porous ink absorber for holding ink.

[Position Encoder] Next, the position encoder 1 mounted on the above-described ink jet recording apparatus will be described.

Hereinafter, the position encoder 1 will be specifically described with reference to the drawings.

FIG. 1 is a diagram schematically illustrating a position encoder 1 and is shown in FIG. 1 and shows a code wheel 2 (tracking) that can move together with an object to be tracked to define the position of the object. Medium).

Although the position encoder 1 shown in FIG. 1 can be used for various electronic components, in the present embodiment, a case where it is used for an ink jet recording apparatus will be described as an example.

In an ink jet recording apparatus, a feed
Incorrect determination of the roller position causes various problems such as a color band being attached to a recorded image, an improper spacing, and overlapping of character recording lines. Therefore, the position of the feed roller must be accurately determined using the position encoder 1.

In FIG. 1, a position encoder 1 is configured to be used for determining an angular position of a feed roller (not shown) of an ink jet recording apparatus, and the feed roller rotates around an axis A. It is configured to be.

In FIG. 1, a code wheel 2 (preferably a disk) is used as a tracking medium, and a code wheel 2 is used.
Wheel 2 rotates around axis A.

The code wheel 2 is connected to a feed roller (not shown), and the movement of the feed roller (not shown) is tracked by tracking the corresponding movement of the code wheel 2. The code wheel 2 defines a track 3 extending to the outer edge of the disk as a series of incremental markers, slits 4.

FIG. 2 is a partially enlarged view of the code wheel 2. This part includes the code wheel 2 and part of the track 3 described above. The track 3 is defined by a plurality of equally-spaced slits 4 and each slit 4
Has an almost transparent trapezoidal shape. Therefore, the sensor 5
Identifies the slit 4 by generating an output corresponding to the passage of light through the transparent slit 4.

The gaps between the slits 4 are narrow and uniform, and the gaps between the slits 4 indicate a predetermined increment of movement along the outer periphery of the code wheel. It can be a quantity increment indicator. Thus, by examining the number of slits passing through the sensor 5, incremental angular movement of the code wheel 2 can be identified.

Using this, code wheel 2 (its current position relative to the position in front of code wheel 2)
And the relative position of a feed roller (not shown) associated therewith.

The position encoder 1 also has a sensor 5 for detecting passage of the slit 4 when the code wheel 2 rotates.

As shown in FIG. 3, the sensor 5 (such as an optical sensor) has a pair of periodic outputs 6 and 7 whose phases are shifted by 90 °.
(A phase, B phase), each output having a frequency corresponding to the resolution of the slit along the track. The period of each of the periodic outputs 6, 7 is 1 / M, where M is the number of slits along the track.

The period of the periodic outputs 6, 7 (Phase A, B) is determined by the code from the initial position at which the sensor 5 identifies the initial sign to the position at which the sensor identifies the next sign next to the initial sign. This corresponds to a predetermined movement of the wheel 2.

The periodic outputs 6, 7 (A
Phase B) is an analog signal that is 90 degrees out of phase and is generally characterized by a sine wave.

As shown in FIG. 3, the periodic outputs 6, 7 (A
Phase, B phase) is 90 ° out of phase, so a₁,
a₅, B₂Points corresponding to the rising of the sine wave
And a₃, B ₄Points corresponding to the fall shown in
You. This distinction between rising and falling and communication with other phases
Utilizing the relationship between signal waveforms, all points within a given period can be identified.
Can be different. Therefore, the phase shown in FIG.
The amount of position movement is quantified by the sensor output
And the code wheel 2 continuously varies accordingly
You can check where you are.

Further, in FIG. 1, the respective sensor outputs 6 and 7 are sent to a microprocessor 9 via an A / D converter 8. The microprocessor 9 has an up / down counter 10 for quantifying the sensor outputs 6,7.

In a preferred embodiment, the up / down counter 10 converts the square wave signal (both signals) to increase the resolution of the position encoder 1 relative to the resolution of the incremental marker slit 4 along the track 3. Count both rising and falling. Therefore, the up / down counter 10 counts four times while each slit 4 passes.

That is, for example, when a pair of phase-shifted sine wave signals 6 and 7 shown in FIG. 3 are sent from the sensor 5 to the microprocessor 9 through the A / D converter 8, these signals are sent to the microprocessor 9. Are converted into the square wave signals 12 and 13 shown in FIG. 4, and the rising and falling of the square wave signals 12 and 13 (the rising and the a3 and B phases of the A phase A1 and the B phase b2 in FIG. And the position is managed by a position counter.

In order to identify the absolute position of the code wheel 2, the position encoder 1
Utilizes a reference position indicator that can be used to determine the movement of the object.

The expression of the digital voltage in the present invention is as follows. Even when the analog signal output from the sensor is converted into a digital signal by A / D conversion, if it is illustrated in the drawings (for example, FIGS. 4 to 6), , Expressed in an analog manner.

[Problems of Conventional Digital Signal Generation Method] A digital signal generation method using the above-described position encoder 1 will be described below. Prior to the description, first, a conventional digital signal generation method will be described with reference to FIG. A method for generating a digital signal will be described.

In the following description, a triangular wave will be used for the sake of simplicity of illustration. However, the waveform that can be used in the present embodiment is not limited to a triangular wave, and for example, a sine wave or another waveform can be used.

First, a conventional digitizing method will be described with reference to FIG.

In FIG. 5, the horizontal axis is position, and the vertical axis is
Output voltage of analog signal and digital signal.

The symbol AB represents the sensor 5 of the position encoder 1.
Are analog voltage signals having the same phase as that of the two-phase analog voltage signals 6 and 7 shifted by 90 °, and are hereinafter referred to as A phase and B phase, respectively. Symbol 31 is A phase,
This is the center voltage of the B phase.

Symbols A0 and B0 denote analog voltage signals shown in the A and B phases by thresholding the center voltage 31.
A-phase when the analog voltage signal shown in A-phase and B-phase is binarized with the voltage higher than the threshold (threshold) voltage as high level (HI) and the voltage lower than the threshold (threshold) voltage as low level (LO) , B-phase digital signals.

The symbol N0 is a point indicated by an arrow ("rise" from a low level to a high level or "high" to a low level) for the binary output signals A0 and B0 of the A and B phases, respectively. "Falling"), which is a multiple of four times the basic period. That is, if n is the number of basic periods, four position counts of 4n, 4n + 1, 4n + 2, and 4n + 3 are obtained in the basic period in the figure.

The increment (or decrement) of the position count
Indicates that the position has moved by a predetermined distance from the reference position in the positive direction (or the negative direction), and one increment of the position count indicates the minimum movement distance that can be measured by the position encoder.

That is, the conventional position encoder shown in FIG. 5 cannot measure a distance between position counts smaller than the position count.

Therefore, in order to control the position of the position encoder with high resolution, the outer shape of the code wheel is increased and the position encoder incorporating the code wheel is enlarged to increase the number of slits or to reduce the slit interval. There is a method of increasing the number of slits per unit length to increase the resolution, but there are problems with each method. Bulky. On the other hand, when the slit interval is reduced to increase the number of slits per unit length, factors that make the analog signal unstable, such as sensor electrical circuit factors, sensor sensitivity, code wheel mechanical factors, and optical factors increase. Therefore, it is difficult to control the position with high resolution using a stable signal.

[Method of Digitizing A and B Phases in the Present Embodiment] Next, a digitizing method that enables position control with high resolution using the position encoder 1 of the present embodiment that solves the above problem will be described. .

First, the outline of the digitizing method in the present embodiment will be described.

The position encoder of this embodiment generates a signal capable of identifying a position with high resolution by using an analog signal and a digital signal. That is, from the two-phase analog signals (A and B phases) output from the sensor 5 and the two signals (* A and * B phases) whose phases are inverted, the A-phase-B phase and the B-phase- * A
Combine the phase signals.

Next, the A-phase-B phase is binarized using the A-phase-B> 0 as a threshold, and the B-phase- * A-phase is binarized using the B-phase-A> 0 as a threshold, thereby obtaining two digital values. Get the signal.

The rising and falling edges of these two digital signals are counted as position increments to roughly calculate the first.
The position information is identified with high resolution by obtaining fine second position information using analog signals of A, B, * A, and * B phases divided at the rising and falling positions. it can.

Hereinafter, the contents described above with reference to FIG. 6 will be described in detail.

In FIG. 6, the horizontal axis is position, and the vertical axis is
Output of analog signal and digital signal.

First, two analog signals are synthesized based on the two-phase analog signals output from the sensor 5. That is, the symbol AB is a two-phase analog signal 6 whose phase output from the sensor 5 of the position encoder 1 is shifted by 90 °,
7, and are hereinafter referred to as A phase and B phase, respectively. Symbol 31 is the center voltage of the A phase and the B phase.

Based on the phases A and B, * A phase and *
Generates phase B. * A phase and * B phase are A phase and B
This is a signal obtained by inverting the phase.

Next, a method of generating digital signals A1 and B1 using the phases A, B and * A will be described. Symbol A1 generates an A-phase-B-phase signal using the A-phase and B-phase analog voltage signals, and A-phase-B ≧ 0 at position (x), that is, an A-phase signal at position (x) Is a high level (“1”) when the signal is greater than or equal to the B-phase signal. Is set to low level (“0”) (A phase−B
(A phase-B) when the analog voltage signal of (phase) is binarized.
(Phase).

For example, A1 is from position (x1) to position (x
In 3), it is at the high level (“1”), and the position (x3)
From position (x5) to the low level (“0”).

Similarly, the symbol B1 represents the B phase and * A
A phase B- * A phase signal is generated using the phase analog voltage signal, and at the position (x), the B phase- * A phase ≧ 0,
When the B-phase signal at the position (x) is greater than or equal to the * A-phase signal, the signal at the high level (“1”)
Phase- * A phase <0, that is, a signal when the B-phase signal at the position (x) is smaller than the * A-phase signal is set to the low level ("0"), and the (B-phase- * A phase) analog voltage signal Is a digital signal output corresponding to (B phase- * A phase) when is binarized.

For example, B1 is from position (x1) to position (x
2) From the position (x4) to the position (x5), it is at the low level (“0”), and from the position (x2) to the position (x4),
High level (“1”).

[Method of Detecting First Position Information] Next, a method of generating the counter value N1 will be described.

The symbol N1 represents the digital signals A1 and B1
Are the counter values obtained by counting the points indicated by the arrows in the figure ("rising" from low level to high level or "falling" from high level to low level), respectively, and are four times the basic period.

That is, the position of the digital signal A1 (x
1), a position (x3), a position (x5), and a position (x2) and a position (x4) at B1 are generated as a counter value N1 and counted by the position counter.

If n is the number of basic periods, the basic periods in the figure include 4n, 4n + 1, 4n + 2, and 4n + 3.
The position count value of the book is obtained.

The increment (or decrement) of the position count
Is a sign indicating that the position has moved by a predetermined distance from the reference position in the positive direction (or the negative direction), so that the movement amount (first position information) can be detected from the count value counted by the position counter. .

However, the movement amount (first
The position information of the digital signal is not counted when the rising and falling edges of the digital signal are counted as position increments, and therefore, when further accuracy is required. That is, it is not possible to finely count between discrete digital count values.

[Second Method of Detecting Position Information] A method of measuring a position between discrete digital count values with high accuracy will now be described.

First, a method of generating S1 for selecting the A phase, * A phase, B phase, and * B phase will be described.

The symbol S1 is located at positions (x1 to x1) corresponding to four counts included in the basic cycle n from the counter value N1.
A), * A phase, B phase, which are analog signals in 5)
* B phase is selected.

That is, 4n-1, 4n, 4n + of N1
Using the position count value of 1, 4n + 2, 4n + 3, 4
The phase A is selected between n-1 and 4n (x1 to x2),
The phase B is selected between n and 4n + 1 (x2 to x3),
The * A phase is selected between n + 1 and 4n + 2 (x3 to x4), and the * B phase is selected between 4n + 2 and 4n + 3 (x4 to x5).

The A-phase, * A-phase, B-phase, and * B-phase analog signals selected in S1 among the analog signals of AB are represented by symbols C
Indicated by

A phase, * A phase, B phase selected in S1
The movement amount (second position information) between discrete digital count values can be measured with high accuracy using the analog signals of the phase and * B phase.

[High-precision position detection method] Next, the A-phase, * A-phase, B-phase, and * B-phase analog signals selected by the above-described counter values N1 and S1 shown in FIG. The detection of the position and the control of the position will be described with reference to FIGS.

When the information for moving to the predetermined position of the measurement object is input to the position encoder 1, the position encoder 1 calculates the amount of movement from the reference position, and calculates the target value of the counter value N1 and the digital value. A target value of S1, which is an analog value, is set.

That is, in FIG. 6C, the shaded area represented by the symbol 31 is the target value of the digital count value, and the symbol 32 is the target value of the analog value.

Therefore, the final destination of the movement is symbol 3
It becomes 3.

That is, in the case of the symbol 33 which is the final destination of the movement shown in FIG. 6C, the digital value N
By adding the movement amount (second position information) obtained from the analog value indicated by the A-phase symbol 32 selected in S1 to the movement amount (first position information) obtained from the counter value of 1, the position can be accurately determined. Can be detected.

Next, the voltages V (N) and * V (N) of the A-phase, * A-phase, B-phase and * B-phase analog signals will be described.

N represents N = (current location−target value). Symbol V (N) is analog output, A phase, * A
Phase, B-phase, and * B-phase cross point voltages are shown. The target value of the digital count value is N = 0 in the hatched portion.

For example, at the cross point between N = 0 and N = 1, the N = 0 side is the A-phase voltage and is represented by V (0), and the N = 1 side is the B-phase voltage and * V ( Represented by 1).

V at other positions indicated by symbol C
The same applies to (N) and * V (N).

At the target point N = 0, the voltage of the A phase is used. However, when the position of the encoder is shifted to N = 1, the voltage [V (0)-* V (0)] is set as an offset value. N =
1 is added to the B-phase signal which is a signal voltage. The added voltage is indicated by a symbol 35.

When the encoder moves in the opposite direction and the position of the encoder shifts to N = -1, the voltage [-V (0) + * V
(0)] as an offset value, and adds it to the B-phase signal which is the signal voltage of N = 1. The added voltage signal is represented by symbol 36.
Indicated by

[Method of Detecting Analog Output] Next, with respect to a method of obtaining an analog output with respect to the target position indicated by the symbol C in FIG. 6 described above, the operation of the position encoder 1 will be described using an example of a float chart shown in FIG. explain.

In step S1, a routine for generating a high-resolution analog output for a position near the target position counter is started.

In step S2, the difference between the current position and the target value is checked, and the value of the difference N between the current position and the target value is stored in the counter.
(N = current position−target value) is input.

In step S3, the counter is checked, and if the difference value N at the position is "0", the flow proceeds to step S4. If the difference value N at the position is not "0", the flow proceeds to step S6.

In step S4, the analog output Vab (m) of the A, B, * A, and * B phases is selected, and the output voltage V is output. That is, Vab (m) in step S4 is such that when the current position counter is represented by (4n + m), n is A
It is a value corresponding to each cycle of the phase and the B phase. The counter value is
Since the frequency is multiplied by 4, the analog signal in the basic period n is divided into four by each position.

Here, when m = 0, the A phase is selected, and m
When m = 1, the B phase is selected, when m = 2, the * A phase is selected, and when m = 3, the * B phase is selected. After outputting the selected analog voltage as the output voltage V, the process proceeds to step S5 to end a series of operations.

On the other hand, in step S6, the counter is checked, and if the difference value N at the position is equal to or smaller than "-1", the process proceeds to step S7.
When the difference value N of the position is equal to or greater than "-1", that is, when the difference value N is a positive integer, the process proceeds to step S12.

In step S7, the position difference value becomes "-
If the difference is equal to or less than 4 ", the process proceeds to step S8, where the difference value N =
After setting the limiter as -4, the process proceeds to step S9. Note that the limiter value can be an arbitrary value. In step S7, the position difference value is -1, -2,-
In the case of 3, the process proceeds to step S10.

Next, in step S9, the output voltage V at the limiter value (difference value N = -4) is calculated using the equation of step S9 in FIG. 7, and is output as the output voltage V. End the work.

On the other hand, in step S10, the position difference value N
Are "-1", "-2", and "-3", the respective analog outputs V are calculated using the equation of step S10 in FIG. 7, and the output voltage V is output. A series of operations are completed.

On the other hand, in step S12, when the difference value of the position is equal to or more than "4", the process proceeds to step S13, where the difference value is set to N = 4, and a limiter is provided.
Proceed to. Note that the limiter value can be an arbitrary value. In step S12, the position difference value is 1, 2, 3
In the case of, the process proceeds to step S15.

Next, in step S13, the output voltage V at the limiter value (difference value N = 4) is calculated by using the equation of step S14 in FIG. 7 and output as the output voltage V. Finish the work.

On the other hand, in step S15, the position difference value N
Are "1", "2", and "3", the respective analog outputs V are calculated using the equation of step S15 in FIG. 7, and the output voltage V is output. Finish the work.

[Processing When Position Counter Changes] FIG. 8 illustrates processing when the position counter changes.

When the position counter changes, an interrupt is generated, and the analog output at the time when the position counter changes is stored.

Step S31 is a step of starting a data fetching routine.

In step S32, the A and B phase analog outputs Vab corresponding to the value of m (the same value as shown in FIG. 7) branch depending on the magnitude of the center voltage.

That is, if Vab is higher than the center voltage, the process proceeds to step S33, and if Vab is equal to or lower than the center voltage, the process proceeds to step S37.

In step S33, a remainder value obtained by dividing the counter value N by 4 is obtained, and the flow advances to step S34 to store Vab (m) corresponding to the difference value in the voltage V (N), and then to step S35. End a series of work.

In step S37, a remainder value obtained by dividing the counter value N by 4 is obtained, and the flow advances to step S38 to store Vab (m) corresponding to the difference value in the voltage V (N), and then to step S35. A series of operations are completed.

As has been clarified in the above description, the analog output increases in the positive direction when moving from the center in the positive direction with the target counter value as the center.
Analog output increases in the negative direction.

As described above, the position encoder of the present embodiment has two analog signals (A and B phases) output from the sensor and two signals (* A, *) with inverted phases.
Using the phase B), a digital signal is obtained by binarization using the method described above.

The rise and fall of the digital signal are counted as position increments to obtain rough first position information, and the A, B, * A and * B phases divided at the rise and fall positions By obtaining fine second position information using the analog signal of (1), the position can be identified with high resolution. Further, the position encoder according to the present embodiment can also control the measurement target at a position identified with high resolution.

Further, the position encoder of the present embodiment can be used by being mounted on a position control device, an image recording device, and an electronic device which need to identify a position with high resolution and control the position.

Therefore, by using the above-described position encoder, the position of the code wheel can be identified with high resolution without greatly increasing the complexity of the apparatus and the manufacturing cost, so that the position can be controlled with high resolution. A position encoder, an image recording device using the same, an electronic device, and a control method thereof can be provided.

In the above embodiments, the description has been made assuming that the droplets ejected from the recording head are ink, and that the liquid stored in the ink tank is ink. It is not limited. For example, an ink tank may contain a processing liquid discharged to a recording medium in order to improve the fixability and water resistance of the recorded image or to improve the image quality.

The above-described embodiment is particularly provided with a means (for example, an electrothermal converter or a laser beam) for generating thermal energy as energy used for performing ink ejection even in an ink jet recording system. By using a method in which a change in the state of the ink is caused by energy, it is possible to achieve higher density and higher definition of recording.

The typical configuration and principle are described in, for example, US Pat. Nos. 4,723,129 and 4,740.
It is preferable to use the basic principle disclosed in the specification of Japanese Patent No. 796. This method can be applied to both the so-called on-demand type and the continuous type. In particular, in the case of the on-demand type, liquid (ink)
By applying at least one drive signal corresponding to the recorded information and providing a rapid temperature rise exceeding the nucleate boiling to an electrothermal transducer arranged corresponding to the sheet or the liquid path holding the Since thermal energy is generated in the electrothermal transducer and film boiling occurs on the heat-acting surface of the recording head, bubbles in the liquid (ink) corresponding to this drive signal on a one-to-one basis can be formed. It is valid.

The liquid (ink) is ejected through the ejection opening by the growth and contraction of the bubble to form at least one droplet. When the drive signal is formed into a pulse shape, the growth and shrinkage of the bubble are performed immediately and appropriately, so that the ejection of liquid (ink) having particularly excellent responsiveness can be achieved, which is more preferable.

As the pulse-shaped drive signal, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable. Further, if the conditions described in US Pat. No. 4,313,124 relating to the temperature rise rate of the heat acting surface are adopted, more excellent recording can be performed.

As the configuration of the recording head, in addition to the combination of a discharge port, a liquid path, and an electrothermal converter (a linear liquid flow path or a right-angled liquid flow path) as disclosed in the above-mentioned respective specifications, The configurations described in U.S. Pat. No. 4,558,333 and U.S. Pat. No. 4,459,600, which disclose a configuration in which the heat acting surface is arranged in a bending region, are also included in the present invention. In addition, Japanese Unexamined Patent Application Publication No. 59-123670 discloses a configuration in which a common slot is used as a discharge section of an electrothermal transducer for a plurality of electrothermal transducers, and an opening for absorbing pressure waves of thermal energy is discharged. A configuration based on JP-A-59-138461, which discloses a configuration corresponding to each unit, may be adopted.

Further, as a full-line type recording head having a length corresponding to the width of the maximum recording medium that can be recorded by the recording apparatus, the length is determined by a combination of a plurality of recording heads as disclosed in the above specification. This may be either a configuration satisfying the above requirements or a configuration as a single recording head formed integrally.

In addition, not only the cartridge type recording head in which the ink tank is provided integrally with the recording head itself described in the above-described embodiment but also the apparatus main body can be electrically connected to the apparatus main body. A replaceable chip-type recording head, which enables a simple connection and supply of ink from the apparatus main body, may be used.

It is preferable to add recovery means for the printhead, preliminary auxiliary means, and the like to the configuration of the printing apparatus described above, since the printing operation can be further stabilized. Specific examples thereof include capping means for the recording head, cleaning means, pressurizing or suction means, preheating means using an electrothermal transducer or another heating element or a combination thereof. It is also effective to provide a preliminary ejection mode for performing ejection that is different from printing, in order to perform stable printing.

Further, the recording mode of the recording apparatus is not limited to the recording mode of only the mainstream color such as black, and the recording head may be integrally formed or a combination of a plurality of recording heads. Alternatively, the apparatus may be provided with at least one of full colors by color mixture.

In the embodiment described above, the description is made on the assumption that the ink is a liquid. However, even if the ink solidifies at room temperature or lower, it is possible to use an ink that softens or liquefies at room temperature. Or, in the ink jet method, generally, the temperature of the ink itself is controlled within a range of 30 ° C. or more and 70 ° C. or less to control the temperature so that the viscosity of the ink is in a stable ejection range.
It is sufficient that the ink is in a liquid state when the use recording signal is applied.

In addition, in order to positively prevent temperature rise due to thermal energy as energy for changing the state of the ink from the solid state to the liquid state, the temperature is positively prevented.
Alternatively, in order to prevent evaporation of the ink, ink that solidifies in a standing state and liquefies by heating may be used. In any case, the application of heat energy causes the ink to be liquefied by application of the heat energy according to the recording signal and the liquid ink to be ejected, or to start to solidify when reaching the recording medium. The present invention is also applicable to a case where an ink having a property of liquefying for the first time is used.

In such a case, ink is disclosed in JP-A-54-5
No. 6847 or Japanese Patent Application Laid-Open No. Sho 60-71260, in which the porous sheet is opposed to the electrothermal converter in a state of being held as a liquid or solid substance in the concave portions or through holes of the porous sheet. It may be. In the present invention, the most effective one for each of the above-mentioned inks is to execute the above-mentioned film boiling method.

In addition to the above, the recording apparatus according to the present invention may be provided not only as an image output terminal of an information processing apparatus such as a computer but also integrally or separately, a copying apparatus combined with a reader or the like, and a transmission / reception apparatus. It may take the form of a facsimile machine having functions.

As described above, the position encoder of the present embodiment uses the output corresponding to the position of the encoder together with the discrete digital counter value and the analog value that fills the gap between the discrete digital counter values. Positioning can be performed with high resolution.

Further, the position encoder of this embodiment can perform highly accurate and stable position control based on the positioning signal. Further, by mounting the position encoder, it is possible to provide a position control device, an image recording device, and an electronic device that can perform positioning and position control with high accuracy. Therefore, it is possible to generate a highly accurate position signal without significantly increasing the complexity and cost of the position encoder.

The position encoder includes an encoder that generates a signal corresponding to the position, a circuit that converts an optical signal of the encoder into an electric analog signal, a circuit that converts an analog signal into a digital signal, and a circuit that counts a digital signal. A target position setting circuit that sets a target value of the position counter and a target output value of an analog signal from an input moving position, a control circuit that holds a position encoder at the target position, and the like.

[0163]

[Other Embodiments] Even if the present invention is applied to a system including a plurality of devices (for example, a host computer, an interface device, a reader, a printer, etc.), an apparatus (for example, a copying machine) Machine, facsimile machine, etc.).

In the present invention, the analog output of the position encoder may be converted into digital multi-value data, and the digital multi-value may be applied in correspondence with the above-described analog value. In addition, the analog value of the position encoder and the multi-value data obtained by converting the analog value of the position encoder into multi-value data may be used in combination.

An object of the present invention is to supply a storage medium (or a recording medium) in which program codes of software for realizing the functions of the above-described embodiments are recorded to a system or an apparatus, and to provide a computer (a computer) of the system or the apparatus. Or a CPU or MPU) reads out and executes the program code stored in the storage medium,
It goes without saying that this is achieved. In this case, the program code itself read from the storage medium implements the functions of the above-described embodiment, and the storage medium storing the program code constitutes the present invention.
In addition, by executing the program code read by the computer, not only the functions of the above-described embodiments are realized, but also based on the instructions of the program code,
The operating system (OS) running on the computer performs part or all of the actual processing,
It goes without saying that a case where the function of the above-described embodiment is realized by the processing is also included.

Further, after the program code read from the storage medium is written in the memory provided in the function expansion card inserted into the computer or the function expansion unit connected to the computer, the program code is read based on the instruction of the program code. , The CPU provided in the function expansion card or the function expansion unit performs part or all of the actual processing,
It goes without saying that a case where the function of the above-described embodiment is realized by the processing is also included.

When the present invention is applied to the storage medium, the storage medium stores program codes corresponding to the above-described flowcharts (shown in FIGS. 7 and 8).

[0168]

As described above, according to the present invention, the position of the code wheel can be identified with high resolution and the position can be controlled with high resolution without greatly increasing the complexity and manufacturing cost of the position encoder. A position encoder, a position control device using the same, an image recording device, an electronic device, and a control method thereof can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory diagram of a position encoder according to an embodiment of the present invention.

FIG. 2 is a partially enlarged view of a code wheel.

FIG. 3 is a diagram illustrating an example of an analog waveform generated by a sensor.

FIG. 4 is a diagram illustrating an example of a digital waveform obtained from the analog waveform of FIG. 3;

FIG. 5 is a diagram illustrating a conventional method for generating a square wave signal and a position count signal from an analog signal.

FIG. 6 is a diagram illustrating a method for generating a square wave signal and a position count signal from an analog signal according to an embodiment of the present invention.

FIG. 7 is a flowchart illustrating a method of generating an analog output for movement of a position encoder from movement from a current position to a target position.

FIG. 8 is a flowchart illustrating a method of capturing and storing a voltage value at a change point of a position counter value in an interrupt routine.

FIG. 9 is an external perspective view illustrating an outline of a configuration of a recording apparatus.

FIG. 10 is an overall block diagram illustrating a configuration of a recording apparatus.

FIG. 11 is an external perspective view illustrating an outline of a configuration of an ink cartridge.

[Explanation of symbols]

 Reference Signs List 1 position encoder 2 code wheel 3 track 4 slit 5 sensor 6 sine wave output signal (A phase) 7 sine wave output signal (B phase) 8 analog-digital converter (A / D) 9 microprocessor (μP) 12 output Signal pulse (A phase) 13 Output signal pulse (B phase)

Continuation of the front page F term (reference) 2C056 EA04 EB12 EB36 EC12 EC34 FA03 FA10 KD06 2C480 CA01 CA36 CB34 CB35 2F077 AA25 CC02 NN02 NN05 NN23 PP19 QQ05 TT44 TT47 5H303 AA22 AA28 BB01 BB06 BB01 BB06 BB01 DD01 LL09

Claims (29)

[Claims] 1. A scale provided with a plurality of markers at predetermined intervals, and a sensor for detecting the markers, wherein position information of a measurement target is generated based on a plurality of analog signals output from the sensors. A position encoder, comprising: a signal corresponding to the plurality of analog signals; an inverted signal generating unit configured to invert the signal to generate an inverted signal; and a signal corresponding to the analog signal or a respective amplitude in the inverted signal. Digital signal generation means for generating a digital signal based on the difference between: a first position information generation means for counting change points at which the value of the digital signal changes to generate first information relating to the position; A predetermined period is divided at intervals of, and a signal corresponding to the analog signal or a signal selected from the inverted signal is divided into each of the divided periods. A position encoder comprising: a signal allocating unit to be applied; and a second position information generating unit that generates second information regarding the position based on the selected signal. 2. The method according to claim 1, wherein the plurality of analog signals have different phases.
A digital signal having a first value when the amplitude of the A phase is equal to or greater than the amplitude of the B phase, and a digital signal having a second value otherwise. The position encoder according to claim 1, wherein the position encoder is generated. 3. The plurality of inversion signals are * A phase and * B phase in which the phases of the A phase and B phase are inverted.
The position encoder according to claim 2, wherein a digital signal having a first value is generated when the amplitude of the phase is equal to or larger than the amplitude of the phase, and a digital signal having a second value is generated when the amplitude of the B phase is smaller than the amplitude of the * A phase. 4. The signal allocating means divides the predetermined period into four using a time when the digital signal changes, and
In each of the divided periods, the A phase, the B phase, and the * A
4. The position encoder according to claim 3, wherein an analog signal of any one of a phase and the * B phase is selected and assigned. 5. 5. The method according to claim 1, wherein the first information is approximate position information of the measurement object, the second information is minute position information relating to the measurement object that cannot be detected by the first information, and the first information is 5. The position encoder according to claim 1, wherein accurate position information of the measurement target is obtained by using and the second information. 6. 6. The position encoder according to claim 1, wherein the predetermined period is one cycle of the analog signal. 7. The position encoder according to claim 1, wherein the position encoder is a rotary encoder or a linear encoder. 8. A position encoder according to claim 1, further comprising: an input unit for inputting target position information of the object to be measured.
A position control device, comprising: target position setting means for setting a first target value to be reached by the first information and a second target value to be reached by the second information. 9. The position control device according to claim 8, further comprising control means for controlling the measurement target to reach the first target value and the second target value. 10. An image recording apparatus for performing recording by scanning a carriage equipped with a recording head on a recording medium based on information transmitted from an external device. An image recording device comprising the position encoder according to claim 1 or the position control device according to claim 8. 11. The image recording apparatus according to claim 10, wherein said recording head is an ink jet recording head which performs recording by discharging ink. 12. The recording head according to claim 1, wherein the recording head ejects ink by using thermal energy, and includes a thermal energy converter for generating thermal energy to be applied to the ink. Item 11. The image recording device according to Item 10. 13. An electronic device comprising the position encoder according to claim 1 or the position control device according to claim 8 or 9. 14. A scale provided with a plurality of markers at predetermined intervals, and a sensor for detecting the markers, and generates position information of a measuring object based on a plurality of analog signals output from the sensors. A method for controlling a position encoder, comprising: a signal corresponding to the plurality of analog signals; an inverted signal generating step of inverting the signals to generate an inverted signal; and a signal corresponding to the analog signal or the inverted signal. A digital signal generating step of generating a digital signal based on a difference between the respective amplitudes; a first position information generating step of counting change points at which the value of the digital signal changes to generate first information regarding the position; A predetermined period is divided at intervals of the transition points, and a signal corresponding to the analog signal or a signal selected from the inverted signal is divided into the divided periods. A method for controlling a position encoder, comprising: a signal allocating step to allocate to each of them; and a second position information generating step of generating second information relating to the position based on the selected signal. 15. The digital signal generating step according to claim 15, wherein the plurality of analog signals are signals comprising A-phase and B-phase having different phases. 15. The method according to claim 14, wherein a digital signal having the second value is generated at other times. 16. The method according to claim 16, wherein the plurality of inverted signals are the A-phase
* A phase and * B phase whose phases are inverted. In the digital signal generation step, the amplitude of the B phase is further * A
16. The position encoder according to claim 15, wherein a digital signal having a first value is generated when the amplitude of the phase is equal to or greater than the amplitude of the phase, and a digital signal having a second value is generated when the amplitude of the B phase is smaller than the amplitude of the * A phase. Control method. 17. The signal allocating step divides the predetermined period into four using a time when the digital signal changes, and performs the A-phase, the B-phase, and the * in each of the four divided periods.
17. The method according to claim 16, wherein an analog signal of either the A phase or the * B phase is selected and assigned. 18. The method according to claim 18, wherein the first information is approximate position information of the measurement object, the second information is minute position information relating to the measurement object that cannot be detected by the first information, 18. The position encoder control method according to claim 14, wherein accurate position information of the measurement target is obtained by using the second information and the second information. 19. The method according to claim 19, wherein the predetermined period is one of the analog signals.
19. A cycle according to claim 14, wherein:
The control method of the position encoder according to any one of the above. 20. The position encoder control method according to claim 14, wherein the position encoder is a rotary encoder or a linear encoder. 21. Any one of claims 14 to 20
Based on the control method of the position encoder according to the section, based on the input target position information of the measurement target,
A target position setting step of setting a first target value to be reached by the first information and a second target value to be reached by the second information. 22. The control method of a position control device according to claim 21, further comprising a control step of controlling the measurement target to reach the first target value and the second target value. . 23. A method of controlling an image recording apparatus for performing recording by scanning a carriage equipped with a recording head on a recording medium based on information transmitted from an external device. A control method for an image recording apparatus, comprising the control method according to any one of the above. 24. The method according to claim 23, wherein the recording head is an ink jet recording head that performs recording by discharging ink. 25. A recording head for ejecting ink by utilizing thermal energy, wherein the recording head includes a thermal energy converter for generating thermal energy to be applied to the ink. Item 24. The method for controlling an image recording device according to item 23. 26. One of claims 14 to 22.
A control method for an electronic device, comprising: the control method according to any one of the first to third aspects. 27. Any one of claims 14 to 22
A computer-readable storage medium storing a control program of the control method described in the section. 28. A computer-readable storage medium that is executed by a computer device connectable to an image recording apparatus and stores a program for driving the image recording apparatus via a bidirectional interface, wherein the program is a computer-readable storage medium. A computer readable storage medium comprising the control method according to claim 22. 29. A computer-readable storage medium storing a control program for the method for controlling an electronic device according to claim 26.