JP5267039B2 - Active object detection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an active type object detecting device that easily, optically removes an unnecessary detection area and reduces unnecessary internal reflection in the device of detection wave from a detection area as much as possible. <P>SOLUTION: The unnecessary detection area can be easily, optically removed by a light shielding section 11 of one area removing member 10Aa of a pair of area removing members (light shielding levers) 10Aa and 10Ab, and the incidence to a light receiving element 8 by reflection of the detection wave from the detection area is blocked by an internal reflection blocking section 12 of the other area removing member 10Ab, so that the light shielding effect by the light shielding section 11 can be easily maintained. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention transmits detection waves for object detection toward a plurality of detection areas, and detects an object such as a human body when a light reception signal generated when receiving a detection wave reflected by the object exceeds a set level. The present invention relates to an active object detection device for detection.

  Conventionally, a detection wave for detecting an object that cannot be seen by the human eye, such as infrared rays or near infrared rays, is sent from a projector toward a plurality of detection areas. There is known an active object detection device that detects an object such as a human body when the received light signal exceeds a set level. The plurality of detection areas are formed by an optical body such as a lens for projecting a detection wave transmitted from the light projecting element.

  As an example of this active type object detection device, in order to set a plurality of rows of detection areas from a position close to the projector to a position far from the projector, the projector is provided with one projector element that projects light for each column of the detection area. In addition, a plurality of detection areas are formed by allocating one light receiving element that receives light for each column of detection areas to the light receiver (Patent Document 1). This active type object detection apparatus is used for an automatic door sensor for detecting an object of an automatic door, for example.

The active object detection apparatus detects an object using light rays that are invisible to the human eye, such as infrared rays, as described above, and a plurality of detection areas formed by the optical body are also human eyes. Therefore, it is difficult to specifically recognize in which area of the plurality of detection areas the object exists.
JP 2002-285755 A

  By the way, there are cases where erroneous detection of an object is likely to occur in an area where a person does not pass, such as a wall next to a door, or an area where a tree swaying in the wind or an object reflecting sunlight is present. In this case, it is necessary to exclude detection areas that are prone to erroneous detection. However, as described above, it is difficult to recognize in which detection area an object exists, and it is difficult to exclude this unnecessary detection area. It was.

  In addition, there is a tendency to increase the size of automatic doors, and accordingly, the height of installation of automatic door sensors is increased, and improvement in detection capability is required. In order to improve the detection capability, it is necessary to improve the S / N ratio. For example, in the case of an AIR (active infrared method) sensor, it is effective to increase light projection power (improvement of S) and reduce noise (reduction of N). It becomes a means. When the light projection power is increased, when the detection wave reflected by the object from the detection area is incident on the light receiving element, the power of the incident detection wave is increased. Therefore, it is necessary to reduce the unnecessary internal reflection in the apparatus as much as possible with respect to the detection wave from the detection area to cope with the increase in light projection power. Similarly, when the amplification by the amplifier is large for the light reception signal from the light receiver, the influence of internal reflection appears.

  The present invention solves the above-mentioned problems, easily eliminates unnecessary detection areas optically, and reduces unnecessary internal reflection of detection waves from the detection areas in the apparatus as much as possible. An object of the present invention is to provide an active object detection apparatus capable of

  In order to achieve the above object, an active object detection device according to the present invention includes a light projecting element that transmits detection waves for object detection toward a plurality of detection areas, and a plurality of light detection elements that form the plurality of detection areas. A light projector having a light projecting lens composed of a lens segment, a light receiving element that receives the detection wave reflected by an object, and a plurality of light incident on the light receiving element that receives the detection wave reflected by an object in the plurality of detection areas. A light receiving lens including a lens segment, and a light receiver that receives the detection wave incident on the light receiving element and generates a light receiving signal, and between the light projecting element in the light projector and the plurality of lens segments. , And at least one of the light receiving element in the light receiver and the plurality of lens segments, and passes through a predetermined lens segment that is a part of the optical path therebetween. And shielding the road, and a optically exclude optical area excluding means the detection area formed by the lens segments.

  According to this configuration, the optical area excluding means shields the optical path passing through the predetermined lens segment which is a part of the optical path between the light projecting element and / or the light receiving element and the plurality of lens segments, and the lens. Since the detection areas formed by the segments are optically excluded, unnecessary detection areas can be easily optically excluded.

  Preferably, the optical area excluding means is provided between the light receiving element in the light receiver and the plurality of lens segments, and is formed on the light shielding portion and the second surface respectively formed on the first surface. Comprising a pair of area exclusion members having an inner surface reflection prevention portion, and the light shielding portion of any one of the area exclusion members shields the optical path between the light receiving element and the predetermined lens segment with the first surface, The detection area formed by the lens segment is optically excluded, and the inner surface reflection preventing portion of the other area exclusion member detects a detection wave from the detection area excluded by the first surface of the one area exclusion member. Is prevented from being reflected by the second surface of the other area exclusion member and entering the light receiving element. Therefore, an unnecessary detection area can be easily optically excluded by the light-shielding portion of one area exclusion member of the pair of area exclusion members, and from the detection area by the inner surface reflection prevention portion of the other area exclusion member. Therefore, it is possible to easily maintain the light shielding effect by the light shielding portion, and in the apparatus by providing a pair of area exclusion members for the detection waves from the detection area. Unnecessary internal reflection can be reduced as much as possible.

  Preferably, the area excluding member has a support shaft that is rotatable around an axis, and a plate-like lever portion connected to the support shaft, and is formed on the first surface of the lever portion. The inner surface reflection preventing portion is formed on the second surface opposite to the light shielding portion. Therefore, unnecessary detection areas can be optically excluded more easily, and the light shielding effect can be maintained.

  Preferably, the inner-surface antireflection surface comprises a large number of irregularities. Therefore, the light shielding effect by the light shielding part can be maintained with a simpler structure.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. First, the detection area will be described prior to the description of the configuration of the active object detection device according to the first embodiment of the present invention. In the first embodiment, a case where the automatic opening / closing door opening / closing control apparatus is activated is illustrated as an example, and FIG. 1 (a) is an explanatory view of a detection area viewed from the sliding direction of the automatic opening / closing door 18. FIG. 2B is a plan view showing the detection area. The active object detection device 100 is attached to the side surface of the eyeless 50, and as shown in FIG. 5A, the detection areas A1 to A5 are 5 toward a position far from a position near the installed active object detection device 100. The detection areas A1 to A5 in each column are each composed of 12 areas as shown in FIG.

  FIG. 2A is a perspective view showing a state in which a cover and a window (not shown) inside the cover are removed from the device main body 29 of the active type object detection device 100, and FIG. FIG. As shown in FIG. 2B, the active object detection device 100 is, for example, an AIR (active infrared type) sensor, and is set in five rows from a position close to the projector 1 to a position far from the projector 1. A projector 1 for projecting near infrared light, which is a kind of detection wave for object detection, and a light receiver 2 for receiving a detection wave reflected by the object and generating a light reception signal are provided.

  The light projector 1 detects 12 near-infrared rays transmitted from each light-projecting element 3 and the first to fifth-row light-emitting elements 3 made of infrared light-emitting diodes that transmit near-infrared rays as detection waves. A light projecting optical system comprising a plurality of lens segments (4-1, 4-2, 4-3, 4-4) divided in the lateral direction X so as to project a plurality of, for example, four predetermined patterns so as to have an area (Projecting lens) 4. The light receiver 2 receives the different first to fifth light receiving elements 8 that receive light for each of the five detection areas, and the near infrared rays reflected from the detection areas of each of the light receiving elements 8. And a light receiving optical system (light receiving lens) 9 composed of lens segments (9-1, 9-2, 9-3, 9-4) divided into four in the horizontal direction X.

  In the active object detection device 100, the first and second light projecting lenses 4 </ b> A and 4 </ b> B constituting the light projecting optical system 4 are provided on the lower surface side (front side in the drawing) of the device main body 29. The first and second light receiving lenses 9A and 9B constituting the light receiving optical system 9 are disposed apart from each other in the horizontal direction X which is a horizontal direction parallel to the mounting surface 29a of 50 (FIG. 1A). Is arranged. The first light projecting lens 3A and the first light receiving lens 9A in FIG. 2B set the first to third detection areas A1 to A3 in FIG. 1, and the second light projecting lens 3B in FIG. 2B. The second light receiving lens 9B sets the fourth and fifth detection areas A4 and A5 in FIG.

  Corresponding to the first light projecting lens 4A in FIG. 2B, first to third row light projecting elements 3 in which three each are arranged in a line along the horizontal direction X are mounted, and the second light projecting lens 3 is mounted. A fourth and fifth-row light projecting elements 8 (three as shown in FIGS. 4 (a) and 4 (b)), each of which is arranged in a line along the lateral direction X in correspondence with the optical lens 4B, are shown in FIG. To a third row of light receiving elements 8), and three each of which are arranged in a line along the lateral direction X corresponding to the first light receiving lens 9A. Third and fourth light-receiving elements (not shown) each having a third light-receiving element 8 mounted thereon and three each arranged in a line along the horizontal direction X in correspondence with the second light-receiving lens 9B. It is installed. The first and second light projecting lenses (a plurality of lens segments) 4A and 4B, and the first and second light receiving lenses (a plurality of lens segments) 9A and 9B are all divided into four, and each has one light projecting element 3. Four detection areas are assigned to the light receiving element 8. Therefore, the light projecting elements 3 in the first to fifth columns and the light receiving elements 8 in the first to fifth columns arranged three by three for each column are obtained by the corresponding lenses 4A, 4B, 9A, 9B. Five rows of detection areas A1 to A5 including 12 (= 3 × 4) detection areas in each row are set.

  It is determined whether or not the received light signal individually input for each light receiving element 8 in each row exceeds the set level, and when it is determined that the set light level is exceeded, the opening / closing control device for the automatic door 18 is opened. An object detection signal is output. The automatic opening / closing door 18 is opened / closed based on the object detection signal.

  As shown in FIGS. 2A and 2B, the active object detection apparatus 100 includes, for example, a light receiving element 8 in the light receiver 2 and a plurality of lens segments (9-1, 9-2, 9-3). 9-4), and optically excludes a detection area formed by the lens segment by shielding a light path passing through a predetermined lens segment which is a part of the optical path therebetween. An area exclusion means 5 is provided. In this example, the optical area exclusion means 5 is provided only in the light receiver 2, but the light projecting element 3 in the light projector 1 and its plurality of lens segments (4-1, 4-2, 4-3, 4 -4), or may be provided in both the light receiver 2 and the projector 1.

  In this example, the optical area excluding means 5 includes two pairs of area excluding members 10A and 10B, and the pair of left and right first area excluding members (light shielding levers) 10A (10Aa and 10Ab) includes the light receiving element 8 and the first. Between the light receiving lens (a plurality of lens segments) 9A, a pair of left and right second area exclusion members (light shielding levers) 10B (10Ba, 10Bb) are provided between the light receiving element 8 and the second light receiving lens (a plurality of lens segments) 9B. ing. As shown in FIGS. 3A and 3B, the two pairs of area exclusion members (light shielding levers) 10A and 10B are each provided with an operation portion 14 having a cross groove for adjusting the rotation angle at the tip. The support shaft 6 is rotatable about an axis, and the plate-like lever portion 7 is integrally formed and connected to the support shaft 6. The light shielding portion 11 is provided on the first surface 21 of the lever portion 7. The inner surface reflection preventing portion 12 is formed on the second surface 22 (the surface opposite to the first surface 21).

  In this example, as shown in FIG. 2B, the pair of area exclusion members (light shielding levers) 10 </ b> A and 10 </ b> B has the support shaft 6 orthogonal to the lateral direction X in the vicinity of the outer sides of the left and right sides of each light receiving element 8. A lever portion 7 arranged upright in the direction and having substantially the same area as the lens segment rotates integrally with the support shaft 6 as the support shaft 6 rotates. The rotation angle of the lever unit 7 is adjusted to a predetermined angle by the rotation operation of the operation unit 14, and the light path between the light receiving element 8 and the predetermined lens segment is blocked by the light blocking unit 11. An inner surface reflection preventing portion 12 is provided on the back surface of the light shielding portion 11.

  The two pairs of area exclusion members (light shielding levers) 10A and 10B are configured such that the light shielding portion 11 of the lever portion 7 of one of the area exclusion members (for example, one 10Aa of the light shielding lever 10A) is the light receiving element 8 and a predetermined lens segment. The optical path between them is shielded by the first surface 21, and the detection area formed by the lens segment is optically excluded. At the same time, the provision of the pair of area exclusion members (light shielding levers) 10A and 10B causes the problem of internal reflection, as will be described later. Therefore, the other area exclusion member (for example, the light shielding lever 10A) The detection wave from the detection area excluded from the first surface 21 of the one area exclusion member 10Aa is detected by the inner surface reflection prevention portion 12 of the lever portion 7 of the other 10Ab). The light reflected from the surface 22 is prevented from entering the light receiving element 8.

  In this example, two pairs of area excluding members (light shielding levers) 10A and 10B are used for the optical area excluding means 5, but one or three depending on the number and number of rows of a plurality of detection areas. Two or more may be used.

  The operation of the active object detection device 100 having the above configuration will be described below. As shown in FIG. 2B, a pair of light shielding levers 10A (10Aa, 10Ab) provided between the light receiving element 8 and the light receiving lens 9A is for the first to third rows (A1 to A3) of the detection area. A pair of light shielding levers 10B (10Ba, 10Bb) provided between the light receiving element 8 and the light receiving lens 9B are for the fourth and fifth rows (A4, A5) of the detection area. As shown in FIG. 2A, by inserting a tip of a driver or the like into the operation unit 14 having a cross groove for adjusting the rotation angle of the light shielding levers 10Aa and 10Ab exposed from the apparatus main body 29 and turning it, By adjusting the rotation angle of the lever portion 7 of the light shielding levers 10Aa and 10Ab, a predetermined lens segment of the light receiving lens (a plurality of lens segments) 9A can be shielded by the light shielding portion 11 of the lever portion 7. In this case, the light shielding levers 10Aa and 10Ab can be adjusted to different rotation angles. The pair of light shielding levers 10Aa and 10Ab optically excludes an unnecessary detection area in which, for example, a tree swaying in the wind or an object reflecting sunlight is present among the plurality of detection areas.

  As shown in FIGS. 3A and 3B, the inner surface reflection preventing portions 12 of the second surfaces 22 of the two pairs of light shielding levers 10 </ b> A and 10 </ b> B are, for example, many in the direction along the axis of the support shaft 6. It has a large number of irregularities such as a shape in which grooves are formed, and has a structure in which light rays are irregularly reflected by the irregularities and are not reflected to the light receiving element 8. Instead of the uneven shape that does not reflect the light beam, a hole may be formed at a position where the light beam gathers to diffuse the light beam, or a structure that absorbs the light beam such as a sponge may be formed.

  Since the detection areas A1 to A3 in the first to third rows are close to the active object detection apparatus 100 and the detection areas A4 and A5 in the fourth and fifth rows are far from each other, the angles to the detection areas are different from each other. Accordingly, the light shielding levers 10A for the first to third rows in FIG. 3A have a rectangular outer shape when viewed from the side, and the light shielding levers 10B for the fourth and fifth rows in FIG. It has a substantially semicircular outer shape as viewed.

  4A and 4B show the open / closed state of a pair of light shielding levers 10Aa and 10Ab, for example. When the light shielding levers 10Aa and 10Ab are opened as shown in FIG. 4A, the above-described twelve detection areas are provided for each of the first to third rows. In the state where the light shielding lever 10Aa is closed and the lens segment 9-4 of the light receiving lens 9A is shielded by the light shielding portion 12 as shown in FIG. 4B, three unnecessary detection areas are excluded (erased) (α in the figure). In the state where the light shielding lever 10Ab is closed and the lens segment 9-1 of the light receiving lens 9A is shielded by the light shielding part 12, the three unnecessary detection areas are similarly excluded (erased) (α in the drawing). There are six detection areas for every third row. Only one of the light shielding levers 10Aa or 10Ab may be closed. In this case, only three unnecessary detection areas are excluded (erased), and nine for each of the first to third columns. Detection area. The pair of light shielding levers 10Ba and 10Bb perform substantially the same operation for the fourth and fifth rows (A4 and A5) of the detection area.

  As a result, the optical area excluding means 5 blocks the optical path passing through the predetermined lens segment that is a part of the optical path between the light receiving element 8 and the light receiving lens (a plurality of lens segments) 9A. Since the detection area formed by (1) is optically excluded, unnecessary detection areas can be easily optically excluded.

  FIGS. 5A and 5B show the reflection state of light rays (detection waves) from the detection area when the pair of light shielding levers 10Aa and 10Ab are closed. In the figure, α indicates a light beam that is excluded (erased) by the light shielding portion 11 of one light shielding lever 10Aa, and β illustrated in the figure indicates that a light beam incident from another lens of the first light receiving lens 9A is applied to the other light shielding lever 10Ab. Indicates the rays that arrive. When the rotation angle of the light shielding lever 10Ab is within a certain range due to the provision of the pair of light shielding levers 10Aa and 10Ab, the second surface 22 becomes a reflection surface and the light from the detection area is received. It can happen that it enters the element 8.

  As shown in FIG. 5 (a), the uneven inner surface reflection blocking portion 12 of the light shielding lever 10Ab does not reflect the light beam β in the figure and does not enter the light receiving element 8, so that the light shielding effect by the light shielding portion 11 of the light shielding lever 10Aa is obtained. It will not disappear. However, as shown in FIG. 5B, if the second surface 22 of the light shielding lever 10Ab is made in a reflective state without any processing, the light beam incident from another lens of the light receiving lens 9A is reflected by the light shielding lever. Since the detection wave is incident on the light receiving element 8 from the detection area that should be reflected by the second surface 22 of 10Ab and shielded by the light shielding portion 11 of the light shielding lever 10Aa, the light shielding effect disappears. Become.

  Thus, an unnecessary detection area can be easily excluded optically by the light shielding portion 11 of one area exclusion member 10Aa of the pair of area exclusion members (light shielding levers) 10Aa and 10Ab, and the other area exclusion member 10Ab Since the inner surface reflection prevention unit 12 prevents the detection wave from the unnecessary detection area from being incident on the light receiving element 8, the light shielding effect by the light shielding unit 11 can be easily maintained, and detection from the detection area can be performed. Unnecessary internal reflection in the apparatus due to the provision of the pair of area exclusion members 10Aa and 10Ab for the wave can be reduced as much as possible.

  FIG. 6 is a perspective view of the active object detection device 110 according to the second embodiment of the present invention as seen from below, with a cover (not shown) removed from the device main body 33. The object detection device 110 according to the second embodiment is a type that is attached downward on a ceiling or the like, and the upper surface of the device main body 33 in FIG. 6 is an attachment surface 33a. The apparatus main body 33 is provided with a single light projecting optical system (light projecting lens) 4 and a light receiving optical system (light receiving lens) 9 in a downward orientation, and a detection area is set at a position below the mounting position. The Both optical systems 4 and 9 are composed of four divided lenses (a plurality of lens segments), and three each are arranged in a line above the light projecting optical system 4 in the apparatus main body 33 (inside). The first to sixth row light projecting elements (not shown) are mounted in a six-row arrangement so as to be opposed to the light projecting optical system 4. First to sixth light-receiving elements (not shown) arranged in a row are mounted to face the light projecting optical system 4 in a six-row arrangement. Therefore, in this object detection apparatus 110, the detection areas in which twelve are arranged in a row are set in six rows.

  As shown in FIG. 7, as in the first embodiment, a pair of light shielding levers 10 are provided between the light receiving element 8 and the light receiving lens 9, and this object detection device 110 is also the first embodiment. Similar to the description, by adjusting the operation unit 14 for adjusting the rotation angle of the pair of light shielding levers 10, an unnecessary detection area is optically excluded by the light shielding unit 11 and unnecessary detection is performed by the inner surface reflection prevention unit 12. Incidence due to reflection of the detection wave from the area can be prevented.

  In each of the above embodiments, the optical area excluding means (light shielding lever) 5 is provided in the light receiver 2, but it may be provided in the light projector 1, and in this case, the first area excluding member (light shielding lever) is provided. The inner surface reflection preventing portion formed on the surface 2 shields light and blocks inner surface reflection. That is, when light is projected from the light projecting element, a predetermined detection area is optically excluded by blocking light by the inner surface reflection preventing portion of the second surface of one light shielding lever, but the inner surface reflection of the other light shielding lever. It is possible to prevent the light from being reflected on the second surface and projected onto the detection area by the blocking unit. At this time, in order to prevent the reflection of the inner surface into the apparatus by the first surface of the light shielding lever, the inner surface reflection blocking portion may be formed not only on the second surface but also on the first surface.

  In each of the embodiments described above, the optical area exclusion unit 5 rotates the light shielding lever to shield the light. However, the light may be shielded by, for example, a linear movement method, or instead of the light shielding lever. May be shielded by a movable light shielding wall.

  In each of the above embodiments, light is shielded for each lens segment that forms one area of the plurality of detection areas. However, light may be shielded for each part of one lens segment.

  In each of the above embodiments, each of the pair of area excluding members (light shielding levers) includes the light shielding portion 11 and the inner surface reflection preventing portion 12, but the inner surface reflection preventing portion 12 is omitted as necessary. Also good.

(A) is explanatory drawing of the detection area seen from the sliding direction side of the automatic opening / closing door using the active type object detection apparatus based on 1st Embodiment of this invention, (b) is a top view which shows a detection area. (A) The perspective view which shows the state which removed the cover and window of the active type | mold object detection apparatus which concerns on 1st Embodiment of this invention, (b) is a perspective view which shows the state which removed the upper case further. (A), (b) is a perspective view which shows the shape of a light-shielding lever. (A), (b) is a front view which shows the open / close state of a light-shielding lever. (A), (b) is a front view which shows the reflective state of the light ray when a light-shielding lever is closed. It is the perspective view seen from the lower part which shows the active type object detection apparatus concerning 2nd Embodiment of this invention. FIG. 7 is a front view showing a reflection state of light rays when the light shielding lever of the active object detection device of FIG. 6 is closed.

Explanation of symbols

1: Projector 2: Light receiver 3: Projector element 4: Projection optical system (projection lens)
4-1, 4-2, 4-3, 4-4: plural lens segments 5: optical area exclusion means 6: support shaft 7: lever portion 8: light receiving element 9: optical system for light reception (light receiving lens)
9-1, 9-2, 9-3, 9-4: a plurality of lens segments 10Aa, 10Ab: a pair of area exclusion members (light shielding levers)
11: Shading part 12: Internal reflection prevention part 18: Automatic opening / closing door (automatic door)
21: 1st surface 22: 2nd surface 100, 110: Active type object detection apparatus A1-A5: Detection area

Claims (3)

A projector having a light projecting element for sending detection waves for object detection toward a plurality of detection areas, a light projecting lens comprising a plurality of lens segments forming the plurality of detection areas, and the detection reflected by an object A light-receiving element that receives a wave; and a light-receiving lens that includes a plurality of lens segments that cause the detection wave reflected by an object in the plurality of detection areas to enter the light-receiving element, and the detection that is incident on the light-receiving element An active object detection device comprising a light receiver that receives a wave and generates a light reception signal,
It is provided between at least one of the light projecting element in the light projector and the plurality of lens segments, and between the light receiving element in the light receiver and the plurality of lens segments, and is a part of the optical path therebetween. and shielding the light path through the predetermined lens segments, e Bei optically exclude optical area excluding means a detection area formed in the lens segments,
The optical area excluding means is provided between the light receiving element in the light receiver and the plurality of lens segments, and the light shielding portion formed on the first surface and the inner surface formed on the second surface, respectively. The lens segment includes a pair of area exclusion members having reflection preventing portions, and the light shielding portion of any one of the area exclusion members shields the optical path between the light receiving element and the predetermined lens segment with the first surface, and the lens segment. And the inner surface reflection prevention portion of the other area excluding member detects the detection wave from the detection area excluded by the first surface of the one area excluding member. An active type object detection device that prevents the light from being reflected by the second surface of the area exclusion member and entering the light receiving element . In claim 1 ,
The area exclusion member has a support shaft that is rotatable about an axis, and a plate-like lever portion connected to the support shaft, and the light shielding portion formed on the first surface of the lever portion. An active type object detection apparatus, wherein the inner surface reflection preventing portion is formed on a second surface opposite to the first surface. In claim 1 or 2 ,
An active-type object detection device, wherein the inner-surface reflection prevention unit is composed of a large number of irregularities.

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