JPH09178419A - Encoder pattern projector and position detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect the moving amount and position of a moving body without using a conventional encoder pattern. SOLUTION: An encoder pattern projector 2 to project light 8 changed in regularly streak brightness and darkness is formed with a light source 3, a filter 4 and a lens 5 and mounted on a moving body 1 so that light sensors 9 set up on a fixed material can be selected in sequence to receive the projected light 8 from the encoder pattern projector 2. The output change of the light sensors 9 is counted by a counter circuit 20 to detect the moving amount and position of the moving body 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for detecting a moving amount and a position of a moving object.

[0002]

2. Description of the Related Art A conventional technique will be described with reference to FIGS. 13 to 17 and FIGS.

As a technique for detecting the movement amount or position of a moving object such as an elevator (hereinafter, these may be referred to as movement amount etc.), a method of detecting the movement amount etc. by counting changes in light and dark such as black and white It has been known. For this method, it is necessary to prepare stripes with repeated light and dark such as black and white,
This stripe is called an encoder pattern. The encoder pattern 14 shown in FIG. 13 includes a bright portion 15 and a dark portion 16.

<First Conventional Example> The principle of a detection system using such an encoder pattern 14 will be described with reference to FIGS.
This will be described with reference to FIG.

As shown in FIG. 14, in order to detect the difference in brightness of the encoder pattern 14, the light source 3 is attached to the moving object 1.
And the optical sensor 9 is mounted, and the encoder pattern 14 is moved to another object (not shown) other than the moving object 1 in the moving direction 1.
2, the light 17 is emitted from the light source 3 toward the encoder pattern 14. When the irradiation light 17 hits the dark portion 16, there is no reflection, but when it hits the bright portion 15, there is reflected light 18, and the reflected light 18 enters the optical sensor 9 and is converted into an electric signal. The output voltage of the optical sensor 9 is high when there is reflected light and is low when there is no reflected light, as shown in FIG. Therefore, as the moving object 1 moves, the output voltage of the optical sensor 9 changes from the encoder pattern 14
The height changes according to the lightness and darkness (see FIG. 3B).

The output voltage of the optical sensor 9 is transmitted to the counter circuit 30 through the signal cable 11.

As shown in FIG. 5, the counter circuit 30 is composed of a waveform shaping circuit 22 and a counter 23. The waveform shaping circuit 22 determines whether the electric signal output from the optical sensor 9 is high or low, for example, "1" and "0" as shown in FIG.
Is converted into a binary digital signal of and is given to the counter 23. The counter 23 counts, for example, only "1" of digital signals and outputs the count value 24. Therefore, counter 2
The count value 24 of 3 corresponds to the number of changes in the brightness of the encoder pattern 14, and the amount of movement of the moving object 1 can be detected.

Now, the accuracy of the encoder pattern 14 will be described. As shown in FIG. 14, the stripe interval of the encoder pattern 14 is determined by the resolution of how much the change in brightness and darkness with respect to the movement amount of the moving object 1 is captured, and in order to maintain the accuracy of the resolution. The fringe spacing of the encoder pattern 14 requires high accuracy over the entire length. If the stripe spacing of the encoder pattern 14 is displaced, it is not possible to count the change in brightness and darkness corresponding to the amount of movement and the like, which causes an error in the measurement of the amount of movement and the like.

Therefore, conventionally, the encoder pattern 14 is manufactured by using a high-level printing technique or by cutting and adhering thin lines with time and effort. Also, when the encoder pattern 14 is attached, the encoder pattern 14 is carefully attached and adjusted so as not to cause a deviation (particularly, an inclination).

<Second Conventional Example> Further, it is necessary to know in which direction the moving object 1 has moved forward and backward (up, down, front and back, left and right, etc.), which is shown in FIGS. 15, 8 and 17.
This will be described with reference to FIG.

As shown in FIG. 15, the moving object 1 is equipped with two light sources 3A and 3B and two optical sensors 9A and 9B, and the object other than the moving object 1 (not shown) has two light sources. Encoder patterns 14A and 14B are provided.

However, two encoder patterns 14A,
14B are lined up in the moving direction 12 with a shift of 1/4 of the stripe interval (bright / dark pitch). Two optical sensors 9A, 9
B is at the same position in the moving direction 12.

The light 17 from the light source 3A illuminates the encoder pattern 14A, and the reflected light 18 is reflected by the optical sensor 9A.
A receives light, light 17 from the light source 3B illuminates the encoder pattern 14B, and the reflected light 18 is received by the optical sensor 9B.

As a result, the outputs of the two photosensors 9A and 9B are mutually 9 as shown in FIGS. 8 (A) and 8 (B).
The signals are the A-phase and B-phase signals that are 0 ° out of phase. For convenience, the optical sensor 9A is referred to as an A-phase optical sensor, and the optical sensor 9B is referred to as a B-phase optical sensor.

These A-phase optical sensor 9A and B-phase optical sensor 9
The output voltage of B is transmitted to the counter circuit 60 through the signal cable 11.

As shown in FIG. 17, the counter circuit 60 is composed of a waveform shaping circuit 22, a direction determining circuit 25, and a counter 23. The waveform shaping circuit 22 changes the level of the electric signal output from each of the A-phase and B-phase optical sensors 9A and 9B into "1" and "0" as shown in FIGS.
To a direction determination circuit 25. The direction determination circuit 25 determines the direction based on which output of the A-phase photosensor 9A and the B-phase photosensor 9B comes first based on the preset definition of the direction determination, and gives the determination result to the counter 23. The counter 23, based on the direction determination result and the definition of the predetermined counting method, outputs a digital signal corresponding to the output of the A-phase photosensor and the B-phase photosensor 9B.
The digital signal corresponding to is counted.

An example of the definition of the direction determination and the definition of the counting method is shown below. For example, when the output of the A-phase photosensor 9A comes first as shown in FIG. 8A, it is determined to be the rightward movement 12R as shown in FIG. 15, and the B-phase photosensor as shown in FIG. 8B. When the output of 9B is output first, it is determined to be the leftward movement 12L in FIG. 15, and further rightward movement 12R.
In the case of, the digital signal corresponding to the output of the A-phase photosensor 9A is counted up (increased count) only in the digital signal corresponding to the output of the A-phase photosensor 9A. Is defined as a countdown (decrease count) only.

In this way, it is possible to grasp in which direction the moving object 1 has moved forward and backward, and the count value 24 of the counter 23 represents the location (net moving amount) of the moving object 1.

<Third Conventional Example> Next, referring to FIG.
Another detection system equivalent to FIG. 15 will be described. In FIG. 16, the moving object 1 has two light sources 3A and 3B, and
Optical sensors 9A and 9B of two phase B phases are mounted,
The A-phase optical sensor 9A and the B-phase optical sensor 9B are positioned with a shift of 1/4 of the light / dark pitch of the encoder pattern 14 in the moving direction 12. Only one encoder pattern 14 is provided on an object (not shown) that is not the moving object 1. In this case also, there is a 90 ° phase difference between the output of the A-phase photosensor 9A and the output of the B-phase photosensor 9B. Therefore, by providing both optical sensor outputs to the counter circuit 60 shown in FIG. 17, it is possible to detect the forward and reverse directions of the moving object 1 and the position where the moving object 1 has moved.

[0020]

However, the above-mentioned conventional techniques have the following problems (1) to (5).

(1) Conventional encoder patterns 14, 1
4A and 14B are very expensive because they are manufactured by using a high-level printing technique or by a work such as cutting and sticking a fine line which requires a lot of work. In addition, the encoder patterns 14, 14A, and 14B are attached to an object so as not to cause an inclination and are adjusted, which is very time-consuming. Therefore, the conventional encoder patterns 14, 14A,
There is a demand for a new encoder pattern forming technique that replaces 14B and a moving amount detecting technique using the same.

(2) Further, the conventional encoder pattern 1
4, 14A, 14B need to have a length corresponding to the distance that the moving object 1 moves to the maximum, and the longer the maximum moving distance is, the more expensive it is. Therefore,
There is a demand for a technique capable of detecting the amount of movement of the moving object 1 having a maximum movement distance longer than the conventional encoder patterns 14, 14A, 14B.

(3) Further, conventionally, the moving object 1 was always equipped with the light sources 3, 3A and 3B, the optical sensors 9, 9A and 9B, the signal cable 11, and the counter circuits 30 and 60. However, it is possible to reduce the weight and speed up the reaction speed of the moving object 1 if the moving object 1 does not have a position detecting component or wiring as much as possible. Therefore, there is a demand for a technique for detecting the amount of movement that can reduce the weight of the moving object 1.

(4) Further, conventionally, the optical sensors 9, 9A, 9B of the moving object 1 must always have the encoder patterns 14, 14.
The movement amount and the like are detected on the premise that they are directed to A and 14B. However, when the moving object 1 has, for example, a cylindrical shape and moves in a tunnel or a pipe without being fixed in posture by rails or guides, the moving object 1 may rotate. In such a case, the optical sensors 9, 9
Since the directions of A and 9B are deviated, the change in brightness of the encoder patterns 14, 14A and 14B cannot be counted. Therefore, there is a demand for a technique capable of reliably detecting the movement amount and the like even when the moving object 1 moves while rotating.

(5) Furthermore, since the conventional detection system is an increment type, if the optical sensors 9, 9A, 9 are used.
The output signal of B is the encoder patterns 14, 14A, 14
When it is disturbed by external influences such as dust adhering to B, ambient light, etc., the change in brightness of the encoder patterns 14, 14A, 14B cannot be counted, or counting errors such as extra counting are accumulated, and the movement amount is increased. May cause measurement errors such as Therefore, there is a demand for a detection technique that prevents counting errors from accumulating even if the output signals of the optical sensors 9, 9A, and 9B are disturbed by these external influences.

[0026]

A first invention for solving the above-mentioned problems is an encoder pattern projector,
An optical system that includes a filter having bright and dark stripes, a light source that irradiates the filter with light, and an optical system that inputs the light that has passed through the filter, and converts the light from the light source into light with regular light and dark changes. It is configured to project from.

A second invention is a position detecting device, and the encoder pattern projector of the first invention, and an optical sensor for receiving light projected from the encoder pattern projector,
And a counter circuit that counts a change in the output of the optical sensor.

A third aspect of the invention embodies the second aspect of the invention, in which the encoder pattern projector is mounted on a moving object, and the optical sensor and counter circuit are installed on a part other than the moving object. Characterize.

A fourth aspect of the invention also embodies the second aspect of the invention, characterized in that the optical sensor is mounted on a moving object, and the encoder pattern projector is installed on a part other than the moving object.

A fifth aspect of the invention embodies the fourth aspect of the invention, characterized in that a plurality of the encoder pattern projectors are installed along the moving direction of the moving object.

A sixth aspect of the present invention is another position detecting device, which includes an encoder pattern provided on a moving object along the moving direction thereof, and a plurality of light beams provided along the moving direction of the moving object other than the moving object. It is characterized by comprising a sensor and a counter circuit which selects an optical sensor and counts an output change thereof.

A seventh aspect of the present invention is still another position detecting device, wherein an encoder pattern is provided on a moving object along the moving direction thereof, and a bright and dark stripe surrounds the moving object.
It is characterized in that it is provided with an optical sensor provided other than the moving object and a counter circuit for counting the output change of the optical sensor.

An eighth invention further embodies the third and seventh inventions, wherein a plurality of the optical sensors are installed along the moving direction of the moving object, and the counter circuit selects the optical sensor. It is characterized by having a circuit.

A ninth aspect of the invention further embodies the sixth and eighth aspects of the invention, wherein a moving object detecting sensor for detecting a moving object is installed on the optical sensor side, and the counter circuit detects the moving object. It is characterized by having a circuit for presetting the count value to the absolute position value based on the output of the sensor.

A tenth aspect of the invention further embodies the second to ninth aspects of the invention, wherein the optical sensor has a phase difference of 90 °.
Is a set of two optical sensors that output two signals of
The counter circuit has a circuit for determining a moving direction of a moving object from two output signals of the optical sensor.

<Operation> With the configuration described above, the encoder pattern projector of the first invention projects light with regular light and dark changes, so this projection light can be used in place of the conventional encoder pattern. Therefore, it is possible to eliminate the troublesome work of using a high-level printing technique for manufacturing the conventional encoder pattern and cutting and sticking a thin line. In addition, it is possible to greatly reduce the time and effort required for the adjustment for eliminating the inclination when attaching the conventional encoder pattern.

In each of the position detecting devices of the second to fifth inventions,
The light projected from the encoder pattern projector is received by the optical sensor, and the output change of the optical sensor is counted by the counter circuit.
This makes it possible to detect the amount of movement and the position of the moving object, as in the case of using the conventional encoder pattern.

In particular, when the optical sensor is mounted on a moving object, the optical sensor sequentially receives the projected light from a plurality of encoder pattern projectors as in the fifth invention, and the encoder pattern projector projects the moving object. When mounted on, select a plurality of optical sensors in sequence as in the eighth invention,
By counting the output change, the amount of movement and the position can be detected even if the maximum movement distance is longer than the range of the projected light.

The position detecting device of the sixth invention uses a conventional encoder pattern. In contrast to the conventional encoder pattern that is installed on a moving object, the encoder pattern is installed on a moving object. The optical sensors are sequentially selected and the output change is counted. As a result, the length of the encoder pattern can be shorter than the maximum moving distance, the manufacturing becomes relatively easy, and the labor for adjustment is reduced. Further, since a moving object does not need an optical sensor or a counter circuit, it contributes to weight reduction.

The position detecting apparatus of the seventh invention also provides a conventional encoder pattern on a moving object. However, since light and dark stripes make a round around the moving object, even if the moving object rotates and moves, The optical sensor can always receive the reflected light of the encoder pattern. Therefore, the movement amount and the position can be reliably detected. Also in this case, it is not necessary to mount the optical sensor or the counter circuit on the moving object, which contributes to the weight reduction. Further, as in the eighth invention, by sequentially selecting a plurality of optical sensors and counting the output change, it is possible to detect the movement amount and the position even when the maximum movement distance is longer than the encoder pattern. Therefore, the length of the encoder pattern can be shorter than the maximum movement distance, which facilitates the production and reduces the labor of adjustment for eliminating the tilt at the time of mounting.

The position detecting device of the ninth invention detects the presence of a moving object with a sensor in addition to receiving the projection light from the encoder pattern projector or the reflected light from the encoder pattern. Since the position of this sensor is known,
By presetting the count value to the absolute position based on the output of the same sensor, it is possible to eliminate the accumulation of count errors that has occurred in the conventional increment type detection system.

The position detecting apparatus according to the tenth aspect of the invention uses two signals with a phase difference of 90 ° from the optical sensor to move regardless of whether an encoder pattern projector is used or a conventional encoder pattern is provided on a moving object. By determining the direction, even if the moving object reciprocates, the true movement amount and position can be detected as in the conventional case.

[0043]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the embodiments shown in the drawings (FIGS. 1 to 13).

<First Embodiment> FIG. 1 shows a position detecting device according to a first embodiment of the present invention, which comprises an encoder pattern projector 2, a plurality of optical sensors 9 and a counter circuit 20. Has been done.

The encoder pattern projector 2 includes a light source 3 such as visible light and laser light, and a filter 4 in which bright and dark stripes are repeated.
The light source 3 irradiates the filter 4 with light, and the light emitted from the filter 4 is passed through the lens 5 to project light 8 with regular light and dark changes from the lens 5 to the outside. . That is, the light non-projection portion (dark portion) 6 and the light projection portion (bright portion) 7 are repeatedly generated in the projected light 8. The regularity of the light-dark change can be achieved by setting the light-dark stripe interval in the filter 4 and / or setting the characteristics of the lens 5.

In the present embodiment, such an encoder pattern projector 2 is mounted on the moving object 1 so that the projection light 8 repeats the light and dark changes along the moving direction 12. An optical sensor 9 that receives the projection light 8 from the encoder pattern projector 2 is installed in an object (hereinafter, referred to as a fixed object) 10 other than the moving object 1. Further, the output of the optical sensor 9 is connected to the counter circuit 20 by the signal cable 11.

However, since the projection light 8 reaches only a limited range, even if the moving object 1 moves a long distance, the projection light 8
A plurality of optical sensors 9 are installed along the moving direction 12 so that the light can be received without interruption.

By installing a plurality of optical sensors 9 in this way, as shown in FIG. 2, the counter circuit 20 includes an optical sensor selection circuit 21 in addition to the waveform shaping circuit 22 and the counter 23.

The output voltage of each optical sensor 9 changes in height depending on the presence or absence of incident light, as shown in FIGS. 3 (A) and 3 (B).

In the counter circuit 20, the optical sensor selection circuit 21 selects one optical sensor receiving the projection light 8 from the encoder pattern projector 2 among the electric signals obtained from the plurality of optical sensors 9. The signal from the optical sensor is given to the waveform shaping circuit 22.

The waveform shaping circuit 22 is the optical sensor selection circuit 21.
The change in high-low voltage of the output of the photosensor applied through is converted into a binary digital signal of "1" and "0" as shown in FIG. The counter 23 counts, for example, only "1" of digital signals and outputs the count value 24. Therefore, the count value 2 of the counter 23
4 corresponds to the number of changes in the brightness of the encoder pattern, and the amount of movement of the moving object 1 can be detected.

<Second Embodiment> FIG. 4 shows a position detecting device according to a second embodiment of the present invention. In this embodiment,
An optical sensor 9 is mounted on the moving object 1, and the encoder pattern projector 2 described above is installed on the fixed object 10. Also in this case, the range of the projection light 8 from the encoder pattern projector 2 is limited. Therefore, a plurality of encoder pattern projectors 2 are installed along the moving direction 12 so that the optical sensor 9 can receive the projection light 8 without interruption even when the moving object 1 moves a long distance. . Of course, the projected light 8 repeats bright and dark along the moving direction 12.

In the case of the present embodiment, since only one photosensor 9 is required, the counter circuit 30 is composed of the waveform shaping circuit 22 and the counter 23 as shown in FIG. That is, the waveform shaping circuit 22 converts the change in the output voltage of the optical sensor 9 applied through the signal cable 11 into a binary digital signal, and the counter circuit 23 counts only one of "1" and "0". Therefore, the count value 2
4 corresponds to the movement amount and the position.

<Third Embodiment> FIG. 6 shows a position detecting device according to a third embodiment of the present invention. In the present embodiment, in order to determine the moving direction, each of the plurality of optical sensors 9 in the first embodiment shown in FIG. 1 is composed of two A-phase optical sensors 9A and B-phase optical sensors 9B. It is what
By arranging the A-phase photosensor 9A and the B-phase photosensor 9B with a shift of 1/4 of the light-dark pitch of the projection light 8 with respect to the moving direction 12, as shown in FIGS. The phase difference is 90 ° with each other. If the shift amount is g, the light / dark pitch is P, and n is an integer, then g = (2n-1) P / 4.

The output voltages of the A-phase photosensor 9A and the B-phase photosensor 9B are supplied to the counter circuit 40 through the signal cable 11 for each set.

As shown in FIG. 7, the counter circuit 40 comprises an optical sensor selection circuit 21, a waveform shaping circuit 22, a direction determination circuit 25, and a counter 23.

The photosensor selection circuit 21 selects one set of photosensors receiving the projection light 8 from the electric signals obtained from the plural sets of photosensors 9, and the A-phase photosensor 9A thereof.
And the signal from the B-phase photosensor 9B are applied to the waveform shaping circuit 22.

The waveform shaping circuit 22 indicates the level of the electric signal output from the A-phase and B-phase photosensors 9A and 9B, for example, "1" and "0" as shown in FIGS. 8 (A) and 8 (B). To a direction determination circuit 25. The direction determination circuit 25 determines the direction based on which output of the A-phase photosensor 9A and the B-phase photosensor 9B comes first based on the preset definition of the direction determination, and gives the determination result to the counter 23. The counter 23 counts the digital signal corresponding to the output of the A-phase photosensor and the digital signal corresponding to the B-phase photosensor 9B based on the direction determination result and the definition of the predetermined counting method.

An example of the definition of the direction determination and the definition of the counting method is shown below. For example, when the output of the A-phase photosensor 9A comes first as shown in FIG. 8A, it is determined to be the rightward movement 12R as shown in FIG. 6, and as shown in FIG.
When the output of the phase light sensor 9B comes first, it is determined to be the leftward movement 12L in FIG. 6, and further, for example, the rightward movement 1L.
In the case of 2R, only the digital signal "1" corresponding to the output of the A-phase photosensor 9A is counted up (incremental counting).
However, in the case of the leftward movement 12L, it is defined that only "1" of the digital signal corresponding to the output of the A-phase photosensor 9A is counted down (decreased count).

In this way, it is possible to grasp in which direction the moving object 1 has moved, the counter value 24 of the counter 23 indicates the location (net moving amount) of the moving object 1.

<Fourth Embodiment> FIG. 9 shows a position detecting device according to a fourth embodiment of the present invention. In this embodiment, a moving object detection sensor 13 is added to the third embodiment shown in FIG. 6 in order to eliminate the accumulation of counting errors due to disturbances and the like. That is, the A-phase optical sensor 9A and the B-phase optical sensor 9B
A moving object detection sensor 13 is installed on the fixed object 10 between the paired optical sensors 9. Each moving object detection sensor 13 is an arbitrary sensor such as a proximity sensor or an optical sensor that can detect the moving object 1.
Is detected, the output voltage changes in height.

The output signals of the moving object detection sensors 13 and the output signals of the A-phase photosensor 9A and the B-phase photosensor 9B for each set are supplied to the counter circuit 50 through the signal cable 11.

The counter circuit 50, as shown in FIG.
In addition to the waveform shaping circuit 22, the direction determination circuit 25, the optical sensor selection circuit 21, and the counter circuit 23, a counter preset circuit 26 is provided.

The waveform shaping circuit 22 indicates the level of the electric signal output from each of the A-phase and B-phase photosensors 9A and 9B for each set of photosensors 9 as shown in FIGS. 8A and 8B, for example. Is converted into a binary digital signal of “1” and “0” and is given to the direction determination circuit 25. In addition, the moving object detection sensor 13
Output signal of "1" when the moving object 1 is detected,
If not, the waveform is shaped like "0" and given to the direction determination circuit 25.

The direction determination circuit 25 receives the signals of both the A and B phases of the photosensors 9 of each set given from the waveform shaping circuit 22 and the signals of the moving object detection sensors 13 from the photosensor selection circuit 2.
Give to 1. Further, based on the preset direction determination definition, the A-phase optical sensors 9A and B
The direction is judged depending on which output of the phase light sensor 9B comes out first, and the judgment result is given to the photosensor selection circuit 21. For example, as shown in FIG.
When the output of A comes out first, the rightward movement 12 shown in FIG.
It is determined to be R, and as shown in FIG.
In case that the output of is output first, the leftward movement 12L as shown in FIG.
Is determined.

The optical sensor selection circuit 21 is a waveform shaping circuit 22.
And one set of optical sensors receiving the projection light 8 is selected from the electric signals obtained from the plurality of sets of optical sensors 9 through the direction determination circuit 25, and the signals from the A phase optical sensor 9A and the B phase thereof are selected. A signal from the optical sensor 9B is given to the counter 23. Further, the optical sensor selection circuit 21 includes the waveform shaping circuit 2
Among the electric signals obtained from the plurality of moving object detection sensors 13 through the 2 and direction determination circuit 25, one moving object detection sensor detecting the moving object 1 is selected, and the signal is given to the counter preset circuit 26. Further, the optical sensor selection circuit 21 gives a signal of the determination result obtained from the direction determination circuit 25 to the counter 23.

When the counter preset circuit 26 receives a signal obtained from the moving object detection sensor 13 through the optical sensor selection circuit 25, the preset value is a value representing the absolute position of the corresponding moving object detection sensor based on the signal. Give to the counter 23.

The counter 23 basically outputs a digital signal corresponding to the output of the A-phase photosensor and / or a digital signal corresponding to the B-phase photosensor 9B based on the direction determination result and the definition of a predetermined counting method. Count. For example, in the case of the rightward movement 12R, only "1" of the digital signal corresponding to the output of the A-phase optical sensor 9A is counted up (increased count), and in the case of the leftward movement 12L, the A-phase optical sensor 9 is detected.
Only "1" of the digital signal corresponding to the output of A is counted down (decreasing count). Further, the counter 23 presets the preset value to the count value at the time when the preset value is given from the counter preset circuit 26,
Continue counting.

As a result, even if the output of the optical sensor 9 is disturbed due to some influence, for example, ambient light or dust adherence, resulting in insufficient counting or excessive counting, the absolute value of the count value is detected each time the moving object 1 is detected. Since the value of is preset, these counting errors do not accumulate. Further, it is possible to grasp in which direction the moving object 1 has moved. Therefore, the count value 24 of the counter 23 accurately represents the location (net movement amount) of the moving object 1.

<Fifth Embodiment> FIG. 11 shows a position detecting device according to a fifth embodiment of the present invention. In this embodiment,
In place of the encoder pattern projector 2 in the fourth embodiment shown in FIG. 9, the conventional encoder pattern 14 shown in FIG. 13 is attached to the moving object 1, and this point and a phase difference of 90 ° from each other. Light sources 3A, 3B for visible light, laser light, etc. for each of the two optical sensors 9A, 9B that output signals
Is the same as that of the fourth embodiment including the counter circuit 50 except that is mounted on the fixed object 1. The light source 3A is an optical sensor 9
The light source 3B corresponds to A, and the light source 3B corresponds to the optical sensor 9B.

By attaching the encoder pattern 14 to the moving object 1 in this manner, the optical sensor 9 (9A, 9A,
9B), the light sources 3A and 3B, and the counter circuit 50 are not present in the moving object 1, so that the weight of the moving object 1 is reduced and the reaction speed can be increased.
Further, the encoder pattern 14 needs to be shorter than the maximum moving distance, which facilitates manufacturing, mounting, and adjustment.

<Sixth Embodiment> FIG. 12 shows a position detecting device according to a sixth embodiment of the present invention. In this embodiment,
As a countermeasure against the case where the moving object 1 rotates or rotates during movement, the encoder pattern 14 in the fifth embodiment shown in FIG. 11 is configured so that each light and dark stripe makes one round in the rotating direction of the moving object 1. It was formed. Others (the light sources 3A and 3B, the optical sensors 9 (9A and 9B) and the counter circuit 50) are the same as those in the fifth embodiment.

Since each of the light and dark stripes goes around the moving object 1 in this way, the moving object 1 is, for example, a cylindrical shape, and the posture is not fixed by rails or guides, and the tunnel, pipe, etc. The optical sensor 9 (9A, 9B) can always receive the reflected light 18 from the encoder pattern 14 even when the optical sensor 9 (9A, 9B) moves while rotating in the moving space of the moving object 1. Therefore, the position and the moving amount of the moving object 1 are always detected. can do.

[0074]

As described above, the encoder pattern projector according to the first aspect of the invention projects light with a regular change in brightness and darkness, and this projection light substitutes for the conventional encoder pattern. Therefore, it is possible to eliminate the troublesome work of using a high-level printing technique for manufacturing the conventional encoder pattern and cutting and sticking a thin line. In addition, it is possible to greatly reduce the time and effort required for the adjustment for eliminating the inclination when attaching the conventional encoder pattern.

The position detecting device according to each of the second to fifth aspects of the invention is
The light projected from the encoder pattern projector is received by the optical sensor, and the output change of the optical sensor is counted by the counter circuit. Therefore, similar to the case where the conventional encoder pattern is used,
It is possible to detect the moving amount and the position of the moving object.

The position detecting device according to the invention of claim 6 uses the conventional encoder pattern. In contrast to the conventional encoder pattern, which is installed in a place other than the moving object,
On the other hand, since it is installed on a moving object and the output changes are counted by sequentially selecting multiple optical sensors, the length of the encoder pattern can be shorter than the maximum moving distance, making it relatively easy to manufacture and adjusting. It also reduces labor. Further, since a moving object does not need an optical sensor or a counter circuit, it contributes to weight reduction.

The position detecting apparatus according to the seventh aspect of the present invention also provides the conventional encoder pattern on the moving object. However, since the bright and dark stripes make a round around the moving object, even if the moving object moves while rotating, The optical sensor can always receive the reflected light of the encoder pattern. Therefore, the movement amount and the position can be reliably detected. Also in this case, it is not necessary to mount the optical sensor or the counter circuit on the moving object, which contributes to the weight reduction.

In particular, when the optical sensor is mounted on the moving object as in the fifth aspect of the invention, the optical sensor sequentially receives the respective projection lights from the plurality of encoder pattern projectors,
When the encoder pattern projector is mounted on a moving object as in the eighth aspect of the invention, a plurality of optical sensors are sequentially selected and output changes of the optical sensors are counted. Even if is long, it is possible to detect the amount of movement and the position. Further, even when the conventional encoder pattern is attached to a moving object, even if the maximum moving distance is longer than the encoder pattern by sequentially selecting a plurality of optical sensors and counting output changes as in the invention of claim 8, Since the movement amount and position can be detected, the length of the encoder pattern can be shorter than the maximum movement distance,
This makes it easier to manufacture, and also reduces the time and effort for adjustment to eliminate tilt when mounting.

In addition to receiving the projected light from the encoder pattern projector or receiving the reflected light from the encoder pattern, the position detecting device of the invention of claim 9 detects the presence of a moving object with a sensor, and outputs the same. Since the count value is preset to the absolute position based on the above, it is possible to eliminate the accumulation of count errors that has occurred in the conventional increment type detection system.

In the position detecting device of the tenth aspect of the present invention, two signals with a phase difference of 90 ° from the optical sensor are used regardless of whether the encoder pattern projector is used or the conventional encoder pattern is provided on the moving object. Since the moving direction is determined, even if the moving object reciprocates, the true moving amount and position can be detected as in the conventional case.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a position detection device according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a configuration of a counter circuit of the first embodiment.

FIG. 3 is a diagram showing an output characteristic example of an optical sensor.

FIG. 4 is a diagram showing a configuration of a position detection device according to a second embodiment of the present invention.

FIG. 5 is a diagram showing a configuration of a counter circuit according to a second embodiment.

FIG. 6 is a diagram showing a configuration of a position detection device according to a third embodiment of the present invention.

FIG. 7 is a diagram showing a configuration of a counter circuit according to a third embodiment.

FIG. 8 is a diagram showing an example of output characteristics of two photosensors in one set.

FIG. 9 is a diagram showing the configuration of a position detection device according to a fourth embodiment of the present invention.

FIG. 10 is a diagram showing a configuration of a counter circuit according to fourth to sixth embodiments.

FIG. 11 is a diagram showing a configuration of a position detection device according to a fifth embodiment of the present invention.

FIG. 12 is a diagram showing a configuration of a position detection device according to a sixth embodiment of the present invention.

FIG. 13 is a diagram showing an encoder pattern.

FIG. 14 is a diagram showing a first conventional example of a position detection device.

FIG. 15 is a diagram showing a second conventional example of the position detection device.

FIG. 16 is a diagram showing a third conventional example of the position detection device.

FIG. 17 is a diagram showing a configuration of counter circuits of second to third conventional examples.

[Explanation of symbols]

 1 Moving Object 2 Encoder Pattern Projector 3, 3A, 3B Light Source 4 Filter 5 Lens 6 Optical Non-Projecting Section 7 Optical Projecting Section 8 Projected Light 9, 9A, 9B Optical Sensor 10 Fixed Object 11 Signal Cable 12 Moving Direction 12R Right Direction 12L Leftward direction 13 Moving object detection sensor 14, 14A, 14B Encoder pattern 15 Bright part 16 Dark part 17 Irradiated light 18 Reflected light 20, 30, 40, 50, 60 Counter circuit 21 Optical sensor selection circuit 22 Waveform shaping circuit 23 Counter 24 Count value 25 direction determination circuit 26 counter preset circuit

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuhiro Kamihiro 1-1-1, Wadasaki-cho, Hyogo-ku, Kobe-shi, Hyogo Prefecture Mitsubishi Heavy Industries, Ltd. Kobe Shipyard (72) Inventor Mana Kinugasa Akasaka, Minato-ku, Tokyo No. 9-13 Power Reactor / Nuclear Fuel Development Corp.

Claims (10)

[Claims] 1. A light source comprising: a filter having light and dark stripes; a light source for irradiating the filter with light; and an optical system for injecting the light passing through the filter. An encoder pattern projector configured to project from the optical system instead of. 2. The encoder pattern projector according to claim 1, an optical sensor for receiving light projected from the encoder pattern projector, and a counter circuit for counting a change in output of the optical sensor. A position detecting device characterized by. 3. The encoder pattern projector is mounted on a moving object, and the optical sensor and counter circuit are installed on a part other than the moving object.
3. The position detecting device according to claim 1. 4. The position detecting device according to claim 2, wherein the optical sensor is mounted on a moving object, and the encoder pattern projector is installed on a part other than the moving object. 5. The position detecting device according to claim 4, wherein a plurality of the encoder pattern projectors are installed along a moving direction of a moving object. 6. An encoder pattern provided on a moving object along the moving direction thereof, a plurality of optical sensors provided along the moving direction of the moving object other than the moving object, and an output change by selecting the optical sensor. And a counter circuit that counts the position. 7. An encoder pattern provided on a moving object along the moving direction thereof, in which bright and dark stripes surround the moving object, an optical sensor provided on a part other than the moving object, and an output change of the optical sensor. A position detecting device comprising a counter circuit for counting. 8. The position according to claim 3, wherein a plurality of the optical sensors are installed along the moving direction of the moving object, and the counter circuit has a circuit for selecting the optical sensor. Detection device. 9. A moving object detection sensor for detecting a moving object is installed on the optical sensor side, and the counter circuit has a circuit for presetting a count value to an absolute position value based on the output of the moving object detection sensor. The position detecting device according to claim 6, wherein 10. The optical sensor is a set of two optical sensors that output two signals with a phase difference of 90 °, and the counter circuit determines the moving direction of a moving object from the two output signals of the optical sensor. The position detecting device according to any one of claims 2 to 9, further comprising: