JP3357703B2 - sensor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sensor for confirming the presence or absence of a light-shielding material and a method of manufacturing a slit used in the sensor, and more particularly, to a non-contact type used in an X-ray diagnostic apparatus or a nuclear medicine diagnostic apparatus. The present invention relates to a sensor suitable for a sensor.

[0002]

2. Description of the Related Art Conventionally, a predetermined interval is provided on the same plane, N light-emitting sensors are arranged on one side, and light-receiving sensors are arranged at positions opposing each other, so that light from the light-emitting sensor side can be caught by the light-receiving sensor. In general, an industrial sensor is used in which it is determined that there is no light-shielding material between the two sensors when there is no light-shielding object. The outline is shown in FIG. FIG.
, Light emitting sensors (1, 2,... N) on the same plane
Are arranged, and a light receiving sensor (1, 2,... N) is installed at a predetermined distance from this. The light from the light emitting sensor 1 is received by the light receiving sensor 1, the light from the light emitting sensor M is received by the light receiving sensor M, and the light from the light emitting sensor N is received by the light receiving sensor N. Therefore, the optical axes are respectively parallel as shown by the broken lines. When the light shielding material 1 exists in the sensor, the light receiving sensor M corresponding to the portion does not receive the light of the light emitting sensor M, so that the presence or absence of the light shielding material 1 can be determined. The light-emitting sensor and the light-receiving sensor are operated by the controller 2, and the obtained signal indicating the presence or absence of a light blocking object is used in each field according to the application. The plane on which the light-emitting sensor and the light-receiving sensor are installed is either a vertical plane or a horizontal plane, depending on the field of use.

[0003]

However, in a conventional industrial sensor of this type, as shown in FIG. 12, when a light-reflecting plane and a light-reflecting sensor are located adjacent to each other, as shown in FIG. In some cases, a light-shielding object cannot be accurately detected due to reflected light or scattered light from a flat body.
In an environment adjacent to such a reflector, there is a problem that these sensors cannot be used for danger prediction or non-contact type sensors. FIG. 13 illustrates a case where a reflector such as a floor or a wall is present in a direction perpendicular to the installation direction of the light-emitting sensor and the light-receiving sensor. Abnormal. On the other hand, such as medical gamma cameras, which have a light-emitting sensor and a light-receiving sensor attached to both ends of the gamma camera to detect a patient (shade), the gamma camera is parallel to the sensor installation direction. Because of the presence of the (reflector), the influence of the reflected light or the scattered light affects all the sensors, and there is a problem in that the sensor hits the patient due to a malfunction or the device stops.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a sensor capable of detecting a light-shielding object without being affected by a reflector even if an adjacent reflector is present. It is in. Another object of the present invention is to provide a method for manufacturing a slit which can be used for this sensor and can easily and effectively remove the influence of reflected light and scattered light.

[0005]

In order to achieve the above object, according to a first aspect of the present invention, a plurality of light emitting elements and the same number of light receiving elements as the light emitting elements are opposed to each other at a predetermined interval on the same plane. in the sensor placed in, the two signals of the signal received by the adjacent receiving element in a position adjacent to the light receiving signal and the light receiving element in the opposing light receiving element in a position facing the first light emitting element of the light emitting element And a failure detecting means capable of separately detecting a failure of the light emitting element and a failure of the opposite light receiving element based on the failure.

Further, according to the present invention, the n light emitting elements (L1 to Ln) and the same number of light receiving elements (D1 to Dn) are provided.
Are disposed on the same plane at predetermined intervals, and are opposed to each other. When L1 emits light, D1, D
2, when L2 emits light, D1, D2, and D3 receive light. When Lm emits light, D (m-1), Dm, and D (m
+1), and when Ln emits light, D (n-1), D (n-1)
n, and the light emitting elements (L1 to Ln) emit light for one scan at a specific timing and light emission for one scan are combined in a state where no light-shielding object is present. In addition, a failure of each light emitting element can be detected separately.

[0007]

[0008]

[0009]

[0010]

[0011]

[0012]

[0013]

[0014]

Embodiments of the present invention will be described below with reference to the drawings. In each embodiment, the same members are denoted by the same reference numerals. FIG. 1 shows a first embodiment of the sensor of the present invention. In FIG. 1, reference numeral 3 denotes a light emitting element, and the light emitting element 3 is provided on a light emission control circuit board 4.
Reference numeral 5 denotes a light receiving element, which is provided on a light receiving control circuit board 6. The light-emitting element 3 and the light-receiving element 5 are arranged in pairs or in multiple pairs facing each other at a predetermined interval on the same plane, and detect the presence or absence of an object (light-shielding object) that intercepts the light existing between them. On the front surfaces of the light emitting element 3 and the light receiving element 5, a slit 7 is supported by a slit fixing member 8 for the purpose of removing disturbance light and reflected light and scattered light from a flat body (reflector) adjacent to the sensor. It is arranged. The slit 7 may be provided on at least one of the front surfaces of the light emitting element 3 and the light receiving element 5, but it is more effective to provide the slit 7 on both front faces. In addition, as the slit, a plate-shaped one having a large number of holes, a plurality of thin plates laminated via a spacer,
Any of them can be used, but as a result of various studies, it is optimal to use a honeycomb-shaped thin plate as shown in FIG. The honeycomb-shaped thin plate shown in FIG. 2 is made of aluminum foil, the thickness of which is 0.04 mm, the distance between opposing surfaces is about 5 mm, and the length in the slit width direction is 15 mm. The thickness of the foil and the distance between the surfaces can be determined as required, but the length in the slit width direction is preferably about 5 mm to 30 mm, and more preferably 10 mm to 20 mm. If the length in the slit width direction is too short, the above-mentioned object is not achieved, and if it is too long, the apparatus becomes large and unsuitable.

Here, a method for manufacturing a slit using a honeycomb-shaped thin plate will be described. FIG. 3 illustrates this, and first, a honeycomb-shaped aluminum foil shown in FIG. 2 is prepared. In this embodiment, as shown in FIG.
The length used is 700 mm, the length in the height (number of steps) is 100 mm, and the length in the width direction is 15 mm. Then, in order to suppress reflection and scattering of light inside, it is painted in matte dark black or the like. Next, as shown in FIG. 3B, the both ends of the honeycomb-shaped aluminum foil are pressed and compressed by a flat plate while pulling both ends. At this time, care must be taken because the internal honeycomb may not be evenly compressed unless both ends are compressed while being pulled. The result of compression is shown in FIG. At this time, as shown in FIG. 3D, the honeycomb-shaped aluminum foil is appropriately peeled off as necessary to make the length in the height (number of steps) direction of the slit an arbitrary number of steps. Further, this honeycomb-shaped aluminum foil is fitted between two slit fixing bars while pulling both ends. Then, when the tension is released, the honeycomb-shaped aluminum foil itself is pressed against and fixed to the fixing bar plate by the spring force of the aluminum foil itself. This state is shown in FIG. Finally, both ends are cut to obtain the required length to form a honeycomb-shaped slit. According to the method for manufacturing such a honeycomb-shaped slit, (X2 +
X3) and H1, and the slit diameter Y1 of the light emitting element and the slit diameter Y of the light receiving element from the lengths X1 and X4 in the slit width direction.
2, that is, the distance between the surfaces of the honeycomb is determined. The lengths X1 and X4 in the slit width direction and the slit diameters Y1 and Y2 can be arbitrarily designed. In addition, the matte coating can be easily performed, and the number of honeycomb-shaped slits can be arbitrarily determined.

FIG. 5 shows a second embodiment of the sensor according to the present invention. FIG. 5A is a schematic cross-sectional view thereof, and FIG.
Is a schematic perspective view thereof. In FIG. 5A, in this embodiment, 940 nm is used to reduce the influence of natural light.
Light emitting element 3 and light receiving element 5 for near infrared
It is linearly arranged at a distance of 10 mm apart from each other in a direction perpendicular to the paper surface with respect to n. The light emitting element 3 and the light receiving element 5 are provided on a light emitting control circuit board 4 and a light receiving control circuit board 6, respectively. By disposing a honeycomb-shaped slit 7 on the front surface of each element row, reflected light and scattered light from the reflector 10 existing in parallel with each element row are removed. In addition,
Reference numeral 9 denotes an optical axis. FIG. 5B is a perspective view of this.
It is like. In the XYZ coordinate system, X
On the −Y plane, n pairs of light emitting element rows 11 are provided in the X-axis direction, and light receiving element rows 12 are provided opposite to the light emitting element rows 11.
On each front surface, a slit portion 13 composed of a honeycomb-shaped slit 7 and a holding rod plate 8 is provided. Then, n optical axes 9 can be formed in the Y-axis direction on the XY plane. In this case, the reflector 10 exists on the XY plane in the -Z direction, and the light-emitting element 3 and the light-receiving element 5 are arranged on the XY plane or a light-shielding object entering the XY plane. Will be detected. In this embodiment, according to the above-mentioned honeycomb-shaped slit manufacturing method, there is an advantage that the slits of the respective light receiving and emitting elements can be integrally processed like the slit portion 13 in the drawing, and the manufacturing is easy.

FIG. 6 shows a third embodiment of the sensor according to the present invention. In this embodiment, in order to reduce the influence of natural light, the light emitting element 3 and the light receiving element 5 for 940 nm near-infrared light are arranged linearly in a direction parallel to the plane of n at 15 mm intervals at a distance of 800 mm. The light emitting element 3 and the light receiving element 5
Light emission control circuit board 4 and light reception control circuit board 6 respectively
It is installed in. A short cut of a honeycomb-shaped slit 7 is superimposed on the front surface of each element row so as to remove reflected light and scattered light from the reflector 10 existing in a direction parallel to the paper surface. Note that reference numeral 8 denotes a slit pressing bar plate, and reference numeral 9 denotes an optical axis. By combining the second and third embodiments, reflected light and scattered light from all directions can be removed.

FIG. 7 shows a fourth embodiment of the sensor according to the present invention. In this embodiment, even if the slit 7 is not necessarily provided on the front surface of each light emitting / receiving element, a light shielding object can be detected without being affected by the reflected light or the scattered light from the reflector 10. As in FIG. 5B showing the second embodiment, as shown in FIG. 7, the light emitting elements (L1, L2,... Ln) are arranged on the XY plane.
A row 11 is provided, and light receiving elements (D1, D
2,... Dn) column 12 is provided. A) When L1 emits light, D1 and D2 as shown by the broken line 14
To detect the presence or absence of a light blocking object. b) When L2 emits light, D1, D
2. Light is received by D3, and the presence or absence of a light-shielding object is detected. c) When Lm emits light, D (m-1), Dm, D (m +
The light is received in 1), and the presence or absence of a light blocking object is detected. d) When L (n-1) emits light, D (n-2) and D (n-
1) The light is received by Dn, and the presence or absence of a light shielding object is detected. e) When Ln emits light, it receives light at D (n-1) and Dn, and detects the presence or absence of a light blocking object. f) Return to a). By repeating the operations a) to f) at a high speed, it is possible to detect a light-shielding object in such a manner that the optical axes of the adjacent light emitting and receiving elements cross each other. In this case, it is possible to detect a light-shielding object having a distance equal to or less than the distance between the light-emitting elements. Further, as in the second embodiment, the honeycomb-shaped slit 7 may be used in combination to remove reflected light and scattered light.

In the fourth embodiment, the above operations a) to f) are repeated, the output of each light emitting / receiving element is stored, and the position of each light emitting element is compared with the actual position of the light emitting / receiving element. The location of the light-shielding object can be detected with high accuracy.

In the fourth embodiment, the above a)
To e), the case where the light-emitting elements (L1 to Ln) emit light for one scan at a specific timing and the case where no light is emitted for one scan in a state where no light-shielding object is present are combined. The failure of each light receiving element and each light emitting element can be detected separately. For example, the operations (a) to (e) are executed in a state where there is no light blocking member between the light receiving and emitting elements, and the outputs (Pon1 to Ponn) of the presence or absence of the light blocking member of each light receiving and emitting element are stored. Next, g) light is received by D1 and D2 without detecting light from L1, and the presence or absence of a light shielding object (Poff1) is detected. h) Without emitting light from L2, light is received at D1, D2, and D3 to detect the presence or absence of a light-shielding object (Poff2). i) D (m-1), Dm, D
At (m + 1), light is received and the presence or absence of a light-shielding object (Poffm) is detected. j) D (n-2), D (n-1)
(N-1), presence or absence of a light-shielding object received at Dn (Poffn-
1) is detected. k) While not emitting light from Ln, light is received at D (n-1) and Dn, and the presence or absence of a light shielding object (Poffn) is detected. Similarly, the operations of g) to k) described above are executed in the state where there is no light blocking element between the light receiving and emitting elements, and the outputs (Poff1 to Poffn) of the presence or absence of the light blocking element of each light receiving and emitting element are stored. Here, all of Pon1 to Ponn are outputs without shading,
If Poff1 to Poffn are outputs with a light-shielding material, all the elements can be determined to be normal. Pon1 to Ponn are all outputs without light blocking material, and Poffm-1 · Poffm
If only Poffm + 1 is an output without a light-shielding object, it can be determined that the output of the m-th light receiving element is defective. If only Ponm is a light-blocking output and Poff1 to Poffn is a light-blocking output, it can be determined that the m-th light emitting element is defective. If only Ponm−1, Ponm, and Ponm + 1 are outputs with a light-shielding material, and Poff1 to Poffn are outputs with a light-shielding material, it can be determined that the output of the m-th light receiving element is defective.

FIG. 8 shows a fifth embodiment of the sensor according to the present invention. Also in this embodiment, even if the slit 7 is not necessarily provided on the front surface of each light receiving / emitting element, a light shielding object can be detected without being affected by the reflected light or scattered light from the reflector 10. As in FIG. 7, as shown in FIG. 8, an element row 16 is provided on the XY plane, and an element row 17 is provided opposite thereto. The light emitting elements L1 are provided at both ends of the element row 16.
And L2 are arranged, and light receiving elements D1 to Dm are arranged between them. Light emitting elements L3 and L4 are arranged at both ends of the opposing element row 17, and light receiving elements d1 to d
m is arranged. Each of these elements operates as follows. a) When L1 emits light, d1 to dm as shown by the broken line 18
At the same time to detect the presence or absence of a light blocking object. b) When L2 emits light, d1 to dm as shown by the broken line 19
At the same time to detect the presence or absence of a light blocking object. c) When L3 emits light, D1 to Dm as shown by the solid line 20
At the same time to detect the presence or absence of a light blocking object. d) When L4 emits light, as indicated by the solid line 21, D1 to Dm
At the same time to detect the presence or absence of a light blocking object. e) Return to a). By repeating the operations a) to e) at a high speed, it is possible to detect a light-shielding object. In this case, it is possible to detect a light-shielding object having a distance equal to or less than the distance between the elements. Further, as in the second embodiment, the honeycomb-shaped slit 7 may be used in combination to remove reflected light and scattered light. In this embodiment, the honeycomb-shaped slit 7 as in the second embodiment is advantageous because the directivity angle of light in the element row direction is widened. In this embodiment, the example in which the number of light emitting elements is four has been described, but the present invention is not limited to four and can be implemented.

FIG. 9 shows a sixth embodiment of the sensor of the present invention. Also in this embodiment, even if the slit 7 is not necessarily provided on the front surface of each light receiving / emitting element, a light shielding object can be detected without being affected by the reflected light or scattered light from the reflector 10. This embodiment is the reverse case of the fifth embodiment. FIG.
Similarly, as shown in FIG. 9, the element row 22 is placed on the XY plane.
Are provided, and an element row 23 is provided to face this. The light receiving elements D1 and D1 are provided at both ends of the element row 22.
2, light emitting elements L1 to Lm are arranged between them. Light receiving elements D3 and D4 are arranged at both ends of the opposing element row 23, and light emitting elements 11 to lm are arranged between them. Each of these elements operates as follows. a) L1 to Lm sequentially emit light, which are simultaneously received by D3 and D4 as indicated by the solid line 24, and the presence or absence of a light shielding object is detected. b) Il to lm sequentially emit light, and this is simultaneously received at D1 and D2 as indicated by the broken line 25 to detect the presence or absence of a light shielding object. c) Return to a). By repeating the operations a) to c) at a high speed, it is possible to detect a light-shielding object. In this case, it is possible to detect a light-shielding object having a distance equal to or less than the distance between the elements. Further, as in the second embodiment, the honeycomb-shaped slit 7 may be used in combination to remove reflected light and scattered light. Also in this embodiment, the honeycomb-shaped slit 7 as in the second embodiment is advantageous because the directivity angle of light in the element row direction is widened. In this embodiment, an example in which the number of light receiving elements is four has been described, but the present invention is not limited to four and can be implemented.

FIG. 10 is a diagram showing an application example of the sensor of the present invention. In this application example, an example in which the second embodiment shown in FIG. 5 is applied to a gamma camera used in a nuclear medicine diagnostic apparatus as shown in FIG. 10 will be described. In FIG. 10, a detector surface 27 of a gamma camera 26 which is a reflector 10 is shown.
Are mounted at both ends, and light receiving element rows 12 are mounted opposite to the light emitting element rows 11. Further, although not shown in FIG. 10, a honeycomb-shaped slit 7 and a slit portion 13 composed of a holding rod plate 8 are provided on each front face. The light receiving and emitting elements 3 and 5 are mounted so that the optical axis 9 is at a height of 20 mm from the detector surface 27.
Then, n optical axes 9 can be formed on the detector surface 27 in a direction parallel to this surface. Accordingly, an object (body surface of a patient) approaching within 20 mm from the detector surface 27 can be detected without being affected by reflected light or scattered light from the detector surface 27. With this application, SPECT (Single P
When collecting h0tonEmission CT), the gamma camera 26 can be obtained from the patient's body surface without storing the trajectory in advance.
Images can be collected while maintaining a constant distance. In addition, even when the whole body image (Whole Body) is acquired, the image acquisition can be performed while moving the gamma camera 26 along the patient's body surface without storing the trajectory in advance. As described above, when the sensor of the present invention is used as a non-contact type sensor, it is not necessary to memorize the trajectory in advance and the interruption of the image acquisition operation is reduced, so that the image acquisition time per patient is shortened, and the throughput speed is reduced. There is an advantage that the operation speed is reduced, the burden on the operator is reduced, and the reliability of the apparatus is improved. In addition, since the gamma camera 26 can approach and separate according to the patient's body surface and acquire images while maintaining a predetermined distance, there is an advantage that the resolution and resolution of images are improved. In addition, SPE
By installing two non-contact type sensors across the patient during CT acquisition, the patient's body axis can be extracted and a good tomographic image can be obtained. In this application example, an example of a gamma camera used in a nuclear medicine diagnostic apparatus has been described. However, the present invention is not limited to this, and may be used as a non-contact sensor of an X-ray diagnostic apparatus.

Although the embodiments and application examples of the present invention have been described above, the present invention is not limited to the above-described embodiments and application examples, and it can be appropriately modified and implemented within the scope of the present invention. Needless to say.

[0025]

As described above, according to the present invention, the failure of the light emitting element and the light receiving element is specified and detected, so that the failure can be dealt with smoothly.

[Brief description of the drawings]

FIG. 1 is a first embodiment of the sensor of the present invention.

FIG. 2 is a view showing an example of a honeycomb-shaped thin plate.

FIG. 3 is a diagram for explaining a method for manufacturing a slit using a honeycomb-shaped thin plate.

FIG. 4 is a diagram for explaining the effect of the method for manufacturing a honeycomb-shaped slit.

FIG. 5 is a second embodiment of the sensor of the present invention.

FIG. 6 is a third embodiment of the sensor of the present invention.

FIG. 7 is a fourth embodiment of the sensor of the present invention.

FIG. 8 is a fifth embodiment of the sensor of the present invention.

FIG. 9 is a sixth embodiment of the sensor of the present invention.

FIG. 10 is a diagram showing an application example of the sensor of the present invention.

FIG. 11 is a diagram for explaining a conventional technique.

FIG. 12 is a diagram for explaining a drawback of the related art.

FIG. 13 is a diagram for explaining a drawback of the related art.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 light shielding object 2 controller 3 light emitting element 4 light emitting control circuit board 5 light receiving element 6 light receiving control circuit board 7 slit 8 fixing member 9 optical axis 10 reflector 11 light emitting element row 11 12 light receiving element row 13 slit section 14, 15, 18 , 19, 20, 21, 24, 25 Optical axis 16, 17, 22, 23 Element array 26 Gamma camera 27 Detector surface of gamma camera

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-59-37446 (JP, A) JP-A-5-20555 (JP, A) JP-A-3-2591 (JP, A) JP-A 57-37 186186 (JP, A) JP-A-56-98667 (JP, A) JP-A-59-163587 (JP, A) JP-A-54-14079 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) G01J 1/00-1/60 G01V 9/04

Claims (2)

(57) [Claims] 1. A sensor in which a plurality of light emitting elements and the same number of light receiving elements as the light emitting elements are arranged facing each other at a predetermined interval on the same plane, wherein the light emitting element faces one of the light emitting elements. In position
Based on the two signals of the signal received by the adjacent receiving element in a position adjacent to the signal and the light receiving element which is received in the opposing light receiving element, detectable fault detection by the failure of the light emitting element and the facing light receiving elements individually distinguished A sensor comprising means. 2. A sensor in which n light-emitting elements (L1 to Ln) and the same number of light-receiving elements (D1 to Dn) are arranged facing each other at a predetermined interval on the same plane, wherein L1 emits light. Then, when light is received at D1, D2 and L2 emits light, light is received at D1, D2, D3, and when Lm emits light,
When light is received by D (m-1), Dm, and D (m + 1), and when Ln emits light, light is received by D (n-1) and Dn. ~ L
A sensor characterized in that a failure of each light-receiving element and each light-emitting element can be detected separately by combining a case where n) is caused to emit light for one scan and a case where light is not emitted for one scan at a specific timing.