JP2020068341A - Light receiving and emitting sensor and sensor device using the same - Google Patents

Abstract

To provide a light receiving and emitting sensor that can detect distance information and angle information, and a sensor device using the same.SOLUTION: A light receiving and emitting sensor 1 according to the present invention comprises: a substrate 2; a light emitting element 3 that is arranged on a top face of the substrate 2 to irradiate an object with light; a light receiving element 4 that is arranged on the top face of the substrate 2 separate from the light emitting element 3 and receives reflected light reflected on the object; and a lens member 5 that is arranged above the substrate 2 and passes the light from the light emitting element 3 toward the object and passes the reflected light reflected on the object toward the light receiving element 4. The light receiving element 4 has a central part light receiving area 41, and annular peripheral part light receiving areas 42 surrounding the central part light receiving area 41 and being divided into plurality at some points. A light receiving and emitting sensor and a sensor device that can detect distance information and angle information on an object can be achieved.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a light emitting / receiving sensor including a light receiving element and a light emitting element arranged on the upper surface of one substrate and suitable for detecting distance information and angle information of an object, and a sensor device using the same.

  Conventionally, light is emitted from a light emitting element to an object (object to be detected) which is an object to be detected, and reflected light from the object is received by a light receiving element to detect distance information of the object, and Various light emitting and receiving sensors for detecting angle information of an object and various sensor devices using the same have been proposed.

This sensor device is used in a wide variety of fields, and is used in various applications such as photo interrupters, photo couplers, remote control units, IrDA (Infrared Data Association) communication devices, optical fiber communication devices, and document size sensors. Has been.

  As a tilt angle detecting device for detecting angle information of this sensor device, for example, Japanese Utility Model Laid-Open No. 4-131712 discloses a light emitting element and a light receiving element, and the light emitting element projects light onto a detected object. A tilt angle detection sensor that detects the tilt angle of a detected object from the position where the reflected light from the detected object enters the light receiving element, where the photocurrent obtained from both ends of the light receiving element is proportional to the light incident position. A semiconductor position detecting element configured to do so is disclosed (see Patent Document 1). Further, Japanese Patent Laid-Open No. 10-82626 includes a light emitting element and a light receiving element having a plurality of light receiving areas and non-light receiving areas on a light receiving surface, and the light from the light emitting element is reflected by an object to be detected and is received. In an optical coupling device that outputs a signal according to the inclination of an object to be detected from each light receiving area when incident on an element, an optical coupling device for tilt detection, in which a light emitting element is mounted in a non-light receiving area of a light receiving surface of the light receiving element Is disclosed (see Patent Document 2).

Japanese Utility Model Publication No. 4-131712 JP 10-82626 A

  However, in the tilt angle detection sensor and the tilt detection optical coupling device, the detection of the distance information of the object is not considered, and it is necessary to use another sensor together in order to detect the distance information. It was

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a light emitting and receiving sensor capable of detecting both distance information and angle information of an object and a sensor device using the same. .

The light emitting and receiving sensor according to the present invention includes a substrate, a light emitting element for irradiating an object with light, which is disposed on an upper surface of the substrate, and an upper surface of the substrate, which is disposed apart from the light emitting element. A light receiving element for receiving the reflected light reflected by the object, and a light receiving element arranged above the substrate for passing the light from the light emitting element toward the object and receiving the reflected light reflected by the object. The light receiving element has a central light receiving region and a peripheral light receiving region that is divided into a plurality of portions and surrounds the central light receiving region. ing.

  A sensor device according to the present invention is a sensor device using the light emitting and receiving sensor of the present invention described above, irradiating the light passing through the lens member from the light emitting element to the object and reflecting the light on the object. The reflected light that has passed through the lens member is received by the light receiving element, and the output current output from the central light receiving region and the annular peripheral light receiving region according to the reflected light causes the distance of the object At least one of the information and the angle information is detected.

  According to the light emitting / receiving sensor of the present invention, the light receiving element, which is arranged on the upper surface of the substrate away from the light emitting element and receives the reflected light reflected by the object, has the central light receiving area and the central light receiving area. Surrounding, since it has an annular peripheral light receiving region divided into a plurality in the middle, when the distribution of the reflected light received by the light receiving element changes depending on the distance to the object and the angle of the object, Since the change can be detected by the distribution of the reflected light received by the central light receiving area and the annular peripheral light receiving area divided into a plurality, the distance information and the angle information can be detected. Moreover, since the light emitting element and the light receiving element are integrally arranged on the upper surface of the substrate, it is advantageous for downsizing.

  According to the sensor device of the present invention, since the light emitting and receiving sensor is provided, it is possible to excellently detect the distance information and the angle information of the object.

It is a figure which shows an example of embodiment of the light emitting / receiving sensor which concerns on this invention, (a) is a top view, (b) is sectional drawing. It is a figure explaining the mode of detection in an example of an embodiment of a light emitting and receiving sensor concerning the present invention, (a) is a sectional view showing an example of a mode of detection of distance information, and (b) by a light sensing element. It is a graph which shows the example of a change of output current. It is a figure explaining the mode of detection in an example of an embodiment of a light emitting and receiving sensor concerning the present invention, (a) is a sectional view showing an example of the mode of detection of angle information, and (b) is with a light sensing element. It is a graph which shows the example of a change of an output current, and (c) is a top view which shows the example of a mode of light reception in a light receiving element. (A) is a sectional view showing an example of the configuration of a light emitting element, and (b) is a sectional view showing an example of the configuration of a light receiving element.

  Hereinafter, an example of an embodiment of a light emitting / receiving sensor according to the present invention and a sensor device using the same will be described with reference to the drawings. It should be noted that the following examples exemplify the embodiments of the present invention, and the present invention is not limited to these embodiments. Various modifications can be made without departing from the scope of the present invention.

  1A and 1B are views showing an example of an embodiment of a light emitting and receiving sensor 1 according to the present invention, FIG. 1A is a top view, and FIG. 1B is a sectional view. In the light emitting and receiving sensor 1, if the object to be measured is a flat surface and the surface is a relatively smooth surface, the distance information (information about the distance to the object) and the angle information (the information about the distance to the object) are obtained. It functions as a sensor that detects information regarding the angle of the reflection surface of the object.

The light emitting / receiving sensor 1 includes a substrate 2, a light emitting element 3 arranged on the upper surface of the substrate 2 for irradiating the object with light, and an object arranged on the upper surface of the substrate 2 apart from the light emitting element 3. And a light receiving element 4 for receiving the reflected light reflected by. Further, a lens member 5 disposed above the substrate 2 is provided to pass the light from the light emitting element 2 toward the object and pass the reflected light reflected by the object toward the light receiving element 4. The light receiving element 4 has a central light receiving region 41 and an annular peripheral light receiving region 42 surrounding the central light receiving region 41 and divided into a plurality of parts in the middle. The peripheral light receiving area 42 of this example is composed of four peripheral light receiving areas 421, 422, 423, 424 which are equally divided into four in the circumferential direction.

  In this example, the lens member 5 includes a lens member 51 on the light emitting element 3 side and a lens member 52 on the light receiving element 4 side. The lens member 51 directs the light from the light emitting element 3 toward an object. The lens member 52 has a function of focusing in a beam shape, and has a function of focusing the reflected light from the object toward the light receiving element 4. The lens member 5 does not need to be composed of two members in this way, and one lens member 5 may have both the light emitting element 3 side function and the light receiving element 4 side function. The lens member 5 may be a spherical lens or an aspherical lens, and depending on the specifications of the object and the light receiving element 4, the light passing therethrough may be passed at equal magnification or may be enlarged or reduced. You may let it pass. The lens member 5 has various sizes and shapes depending on the size and distance of the object and the situation of reflected light entering the light receiving element 4, as well as the passing wavelength range, the focal length, and the depth of focus. Those having such characteristics may be appropriately selected and used.

  The lens member 5 is held at a predetermined relative position with respect to the substrate 2, the light emitting element 3 and the light receiving element 4 by an appropriate structure (not shown). In addition, this holding structure is a structure that covers the entire substrate 2 in order to block stray light from the outside and improve detection accuracy, and is a material having a light-shielding property except for the opening corresponding to the lens member 5. Is preferably formed.

  In FIG. 1, 6 is a light emitting side electrode for supplying electric power for causing the light emitting element 3 to emit light, and 7 is a light receiving side electrode for taking out an output current from the light receiving element 4. A plurality of light-receiving side electrodes 7 of this example are arranged corresponding to the central light-receiving region 41 and the peripheral light-receiving region 42 (421, 422, 423, 424) of the light-receiving element 4.

The light emitting element 3 is, for example, a light emitting diode (LED) or a semiconductor laser (laser diode: LD) arranged on the upper surface of the substrate 2. On the other hand, the light receiving element 4
Is, for example, a photo diode (PD) disposed on the upper surface of the substrate 2 as well.
Is.

  The light emitting element 3 is formed integrally with the substrate 2, for example, as having a plurality of semiconductor layers 3a to 3f stacked on the upper surface of the substrate 2, as shown in the sectional view of FIG. On the other hand, the light-receiving element 4 is formed on the upper surface of the substrate 2 made of a semiconductor material of one conductivity type (n-type or p-type), for example, as shown in the sectional view of FIG. It is integrally formed with the substrate 2 so as to include the opposite conductivity type semiconductor region 4a containing conductivity type impurities. That is, the light emitting element 3 and the light receiving element 4 are formed on the same substrate 2 and are integrally formed. Since the light emitting and receiving sensor 1 of the present example is integrally formed, the light emitting element 3 and the light receiving element 4 can be arranged in a desired positional relationship with high positional accuracy, so that accurate position adjustment is possible. Therefore, the distance information and the angle information can be accurately measured, and high sensing performance is provided.

  In the example shown in FIG. 4, a semiconductor material of one conductivity type is used as the substrate 2, the light emitting element 3 has a plurality of semiconductor layers laminated on the upper surface thereof, and the light receiving element 4 is provided on the upper surface of the substrate 2 of the opposite conductivity type. It is assumed to have an opposite conductivity type semiconductor region 4a doped with impurities. Each of the light receiving elements 4 (41, 42 (421 to 424)) includes a reverse conductivity type semiconductor region 4a formed in a part continuing from the upper surface of the substrate 2 and a region of one conductivity type of the substrate 2 adjacent thereto. A photodiode is formed by forming a junction. With this structure, the light emitting element 3 and the light receiving element 4 can be integrally formed on the substrate 2.

  It is sufficient that the light emitting element 3 and the light receiving element 4 are integrally formed on the substrate 2 and are arranged on the upper surface. Therefore, all the constituent elements may be arranged on the upper surface of the substrate 2, and the constituent elements may be arranged. A part or all of the above may be formed inside the substrate 2. In the latter case, at least the light emitting surface of the light emitting element 3 and the light receiving surface of the light receiving element 4 are exposed on the upper surface of the substrate 2.

The substrate 2 is made of one conductivity type semiconductor material. There is no limitation on the impurity concentration of one conductivity type. In this example, a silicon (Si) substrate containing phosphorus (P) as an impurity of one conductivity type at a concentration of, for example, 1 × 10 ¹⁷ to 2 × 10 ¹⁷ atoms / cm ³ is used. As the n-type impurity, besides P, for example, nitrogen (N), arsenic (As), antimony (Sb), bismuth (Bi), or the like may be used, and the doping concentration is 1 × 10 ¹⁶ to 1 × 10 ^20. It is set to atoms / cm ³ . Further, the substrate 2 has a crystal structure on the upper surface of which a semiconductor layer forming the light emitting element 3 is grown.

  In this example, the light emitting element 3 is arranged on the first end side of the upper surface of the rectangular substrate 2. Further, the light receiving element 4 is arranged on the second end side of the same substrate 2 apart from the light emitting element 3. The light emitting element 3 functions as a light source of the light with which the object is irradiated. The light emitted from the light emitting element 3 passes through the lens member 5 (51) and enters the object, and the reflected light reflected by the object passes through the lens member 5 (52) and enters the light receiving element 4. To do. The light receiving element 4 functions as a light detection unit that detects the incidence of reflected light. The light emitting surface of the light emitting element 3 and the light receiving surface of the light receiving element 4 are parallel to the upper surface of the substrate 2.

  The shape of the substrate 2 is an elongated rectangular shape in this example, but the shape is not limited to this, and various shapes can be adopted. For example, it may be an elongated trapezoidal shape in which the width on the light receiving element 4 side is wide, and in that case, the area of the light receiving element 4 (the area of the central light receiving region 41 and the peripheral light receiving region 42) can be made large. It is possible to improve the sensitivity and accuracy of detection.

  The light emitted by the light emitting element 3 is incident on the object as a beam of light that is narrowed to a predetermined size. The shape and beam diameter of the beam-like light are suitably adjusted by the lens member 5 (51). Then, the reflected light reflected on the surface of the object is incident on the light receiving element 4 and received as beam-shaped light or light having a deformed shape in a state where it is adjusted appropriately by the lens member 5 (52). At this time, since the light receiving element 4 has the central light receiving region 41 and the peripheral light receiving regions 42 (421 to 424) divided into a plurality of regions, the distribution of the output current received and output by these regions. Based on the above, the distance information and the angle information of the object can be detected.

  As shown in FIG. 4A, the light emitting element 3 is formed by stacking a plurality of semiconductor layers 3a to 3f on the upper surface of a substrate 2 made of an n-type semiconductor material.

  First, on the upper surface of the n-type substrate 2, a difference in lattice constant between the substrate 2 made of an n-type semiconductor material and a semiconductor layer (n-type contact layer 3b in this example) laminated on the upper surface of the substrate 2 is provided. A buffer layer 3a for buffering is formed. The buffer layer 3a relaxes a difference in lattice constant between the substrate 2 and the semiconductor layer formed on the upper surface of the substrate 2, thereby causing a lattice strain or the like generated between the substrate 2 and the semiconductor layer forming the light emitting element 3. It has the function of reducing the number of lattice defects. As a result, lattice defects or crystal defects in the entire semiconductor layer forming the light emitting element 3 formed on the upper surface of the substrate 2 are reduced.

  The buffer layer 3a in this example is made of gallium arsenide (GaAs) containing no impurities and has a thickness of about 2 to 3 μm. The buffer layer 3a can be omitted if the difference in lattice constant between the substrate 2 and the semiconductor layer forming the light emitting element 3 stacked on the upper surface of the n-type substrate 2 is not large.

An n-type contact layer 3b is formed on the upper surface of the buffer layer 3a. The n-type contact layer 3b is formed by doping GaAs with n-type impurities such as Si or selenium (Se) and has a doping concentration of about 1 × 10 ¹⁶ to 1 × 10 ²⁰ atoms / cm ³ and a thickness thereof. Is about 0.8 to 1 μm.

In this example, Si is doped as an n-type impurity at a doping concentration of 1 × 10 ¹⁸ to 2 × 10 ¹⁸ atoms / cm ³ . A part of the upper surface of the n-type contact layer 3b is exposed, and this exposed part is connected to the light emitting side electrode 6 through the light emitting element side first electrode 3g. In this example, although not shown, the light emitting side electrode 6 and the external power source are connected by wire bonding with a gold (Au) wire. For wire bonding, a wire such as an aluminum (Al) wire or a copper (Cu) wire may be selected instead of the Au wire.

  Further, in this example, the light emitting side electrode 6 and the external power source are connected by wire bonding, but instead of wire bonding, electric wiring may be joined to the light emitting side electrode 6 by soldering or the like. A gold stud bump may be formed on the upper surface of 6 and an electric wiring may be joined to the gold stud bump by soldering or the like.

  The n-type contact layer 3b has a function of lowering the contact resistance with the light emitting element side first electrode 3g connected to the n-type contact layer 3b.

The light emitting element side first electrode 3g and the light emitting side electrode 6 are made of, for example, a gold (Au) antimony (Sb) alloy, a gold (Au) germanium (Ge) alloy or a Ni-based alloy, and have a thickness of 0.5 to 5 μm. Formed in degrees. At the same time, the light emitting element side first electrode 3g and the light emitting side electrode 6 are arranged on the insulating layer 8 formed so as to cover the upper surface of the substrate 2 and the upper surface of the n-type contact layer 3b. And the semiconductor layers other than the n-type contact layer 3b are electrically insulated.

The insulating layer 8 is formed of, for example, an inorganic insulating film such as silicon nitride (SiN _x ) or silicon oxide (SiO ₂ ), or an organic insulating film such as polyimide, and has a thickness of 0.1 to 1
It is about μm.

An n-type clad layer 3c is formed on the upper surface of the n-type contact layer 3b and has a function of confining holes in the active layer 3d. The n-type cladding layer 3c is formed by doping aluminum gallium arsenide (AlGaAs) with n-type impurities such as Si or Se, and has a doping concentration of about 1 × 10 ¹⁶ to 1 × 10 ²⁰ atoms / cm ^3. The thickness is about 0.2 to 0.5 μm. In this example, Si is doped as an n-type impurity at a doping concentration of 1 × 10 ^{17 to} 5 × 10 ¹⁷ atoms / cm ³ .

  An active layer 3d is formed on the upper surface of the n-type clad layer 3c, and carriers such as electrons and holes are concentrated, and the carriers recombine to function as a light emitting layer that emits light. The active layer 3d is AlGaAs containing no impurities and has a thickness of about 0.1 to 0.5 μm. Although the active layer 3d in this example is a layer containing no impurities, it may be a p-type active layer containing p-type impurities or an n-type active layer containing n-type impurities. It suffices that the band gap is smaller than the band gaps of the n-type cladding layer 3c and the p-type cladding layer 3e.

A p-type clad layer 3e is formed on the upper surface of the active layer 3d and has a function of confining electrons in the active layer 3d. The p-type cladding layer 3e is formed by doping AlGaAs with p-type impurities such as zinc (Zn), magnesium (Mg), or carbon (C), and has a doping concentration of 1 × 10 ¹⁶ to 1 × 10 ²⁰ atoms / cm 3. The thickness is about ³ and the thickness is about 0.2 to 0.5 μm. In this example, Mg is doped as a p-type impurity at a doping concentration of 1 × 10 ^{19 to} 5 × 10 ²⁰ atoms / cm ³ .

A p-type contact layer 3f is formed on the upper surface of the p-type cladding layer 3e. The p-type contact layer 3f is formed by doping AlGaAs with p-type impurities such as Zn, Mg or C, and has a doping concentration of about 1 × 10 ¹⁶ to 1 × 10 ²⁰ atoms / cm ³ and a thickness thereof. Is about 0.2 to 0.5 μm.

  The p-type contact layer 3f is connected to another light emitting side electrode 6 via the light emitting element side second electrode 3h. Similarly, the light emitting side electrode 6 is also electrically connected to an external power source by wire bonding. The variations of the connection method and the joining form are as described above. The p-type contact layer 3f has a function of lowering the contact resistance with the light emitting element side second electrode 3h connected to the p-type contact layer 3f.

  A cap layer (not shown) having a function of preventing oxidation of the p-type contact layer 3f may be formed on the upper surface of the p-type contact layer 3f. The cap layer may be formed of, for example, GaAs containing no impurities and have a thickness of about 0.01 to 0.03 μm.

  The light emitting element side second electrode 3h and the light emitting side electrode 6 are, for example, AuNi, AuCr, AuTi or AlCr alloy in which Au or Al is combined with nickel (Ni), chromium (Cr) or titanium (Ti) which is an adhesion layer. Etc., and its thickness is about 0.5 to 5 μm. Since it is arranged on the insulating layer 8 formed so as to cover the upper surface of the substrate 2 and the upper surface of the p-type contact layer 3f, it is electrically connected to the semiconductor layers other than the substrate 2 and the p-type contact layer 3f. Insulated.

  In the light emitting element 3 configured in this manner, when a bias is applied between the light emitting side electrode 6 and the light emitting side electrode 6, the active layer 3d emits light and functions as a light source.

  The light receiving element 4 in the light emitting and receiving sensor 1 according to the present invention is provided with a central light receiving area 41 located in the central portion of the light receiving element 4 and a radial gap surrounding the central light receiving area 41. , And an annular peripheral light-receiving region 42 divided into a plurality in the middle of the circumferential direction.

  The central light receiving region 41 has a circular shape in this example, but other various shapes such as an elliptical shape, a quadrangular shape, a triangular shape, and a hexagonal shape can be adopted depending on the application. The size of the central light receiving region 41 is set to a size (diameter, size or area) smaller than the size (beam diameter or area) of the beam-like reflected light that enters the object from the light emitting element 3 and is reflected. , Is appropriately set according to the specifications. Since the size of the central light receiving region 41 is smaller than the size of the beam-like reflected light, the reflected light serving as a reference for detection can be positioned in the central light receiving region 41, and the distance information and the angle information It becomes possible to obtain the reference output current from the central light receiving region 41.

The peripheral light receiving region 42 is annularly arranged so as to surround the central light receiving region 41, and is divided into a plurality of regions in the circumferential direction. In this example, the annular peripheral light receiving region 42 (421 to 424) divided into four is arranged for the circular central light receiving region 41, but the shape is made to correspond to the shape of the central light receiving region 41. For example, the shape may be an elliptical ring, a square ring, a triangular ring, a hexagonal ring, or the like. Further, with respect to the polygonal central light-receiving region 41, the inner peripheral side may be a polygonal shape along the outer shape of the central light-receiving region 41, and the outer peripheral side may be a circular shape. The size of the peripheral light receiving region 42 is set such that the size of the entire arranged light receiving region is larger than the size of the beam-like reflected light (beam diameter or area) (total diameter or size). Is set appropriately. The number of divisions of the peripheral light-receiving region 42 may be appropriately set in accordance with the specifications of the distance information and the angle information of the object to be detected, and also in consideration of the space limitation for arranging the peripheral light-receiving region 42. . Normally, it is sufficient to divide into three to eight, and basically it may be divided into equal intervals (equal divisions), but those having different sizes and sizes may be arranged according to specifications and purposes. . Also, the arrangement of the divided peripheral light receiving regions 42 may be set appropriately according to the specifications and purposes.

  The distance between the central light receiving region 41 and the peripheral light receiving region 42 is not particularly limited or limited in the detection of reflected light. Therefore, the output current from each region is passed to the light receiving side electrode 7 through each region. It may be set in consideration of securing a space for arranging the wiring for sending.

  The light-receiving side electrode 7 connected to each of the central light-receiving region 41 and the peripheral light-receiving region 42 (421 to 424) in order to extract the output current does not hinder the light-receiving element 4 from receiving light. Then, it is arranged outside the light receiving element 4. There is no particular limitation on how to arrange these light-receiving side electrodes 7, and they may be appropriately set according to the specifications of the light emitting and receiving sensor 1.

  When such a light receiving element 4 is arranged close to the light emitting element 3, it tends to be difficult to accurately detect that the reflected light from the target object changes according to the distance or the angle of the target object. In addition, since a part of the light emitted from the light emitting element 3 tends to directly enter the light receiving element 4, the light emitting element 3 is disposed apart from the light emitting element 3 with a predetermined distance. The setting is appropriately set according to the distance to the object or the size of the light emitting and receiving sensor 1.

As shown in FIG. 4B, the light receiving element 4 is provided with an opposite conductivity type semiconductor region 4a (hereinafter, also referred to as p type semiconductor region 4a) on the upper surface of the substrate 2 made of an n type semiconductor material. A pn junction is formed by the region and the n-type substrate 2. The p-type semiconductor region 4a is formed by diffusing p-type impurities into the n-type substrate 2 at a high concentration. Examples of the p-type impurities include Zn, Mg, C, B, In, and Se, and the doping concentration is 1 × 10 ¹⁶ to 1 × 10 ²⁰ atoms / cm ³ . In this example, the thickness of the p-type semiconductor region 4a is 0.5 to 3 μm.
B is diffused as a p-type impurity so as to be about m.

  The p-type semiconductor region 4a is electrically connected to the light-receiving side electrode 7 via the light-receiving element side electrode 4b. The light-receiving element side electrode 4b and the light-receiving side electrode 7 are arranged on the upper surface of the n substrate 2 with the insulating layer 8 interposed therebetween, and thus are electrically insulated from the substrate 2. The light-receiving element side electrode 4b and the light-receiving side electrode 7 are formed of, for example, AuSb alloy, AuGe alloy, or Ni-based alloy, and have a thickness of about 0.5 to 5 μm.

  When light is incident on the p-type semiconductor region 4a in the light-receiving element 4 configured in this manner, a photocurrent is generated by the photovoltaic effect, and this photocurrent is extracted as an output current via the light-receiving side electrode 7. Functions as a photodetector.

  Next, how the light emitting and receiving sensor 1 of this example functions as a sensor for detecting distance information and angle information of an object will be described. FIG. 2 is a diagram for explaining a detection state in the light emitting and receiving sensor 1 of the present example, and FIG. 2A is a sectional view similar to FIG. 1B showing an example of a state of detecting distance information. Yes, FIG. 2B is a graph showing an example of changes in the output current due to the light receiving element.

In FIG. 2A, the broken line described above is an imaginary line indicating the position of the object, B is the position that serves as the reference of the distance, N is the position when the distance is short, and F is the case where the distance is long. Shows the position of. In addition, the alternate long and short dash line is an imaginary line that indicates the approximate direction of light travel, and the light passing from the light emitting element 3 through the lens member 51 shows the entire state of the light radiated to the object, and the lens member 52 is The passing light shows the state of the central portion of the light incident on the light receiving element 4 according to the distance of the object.

  In the three graphs in FIG. 2B, from the top, when the object is [F] (distance is long), when the object is [B] (distance is the reference), the object is [N] ( In the case where the distance is close), the left bar indicates the output current from the central light receiving region 41, and the central bar indicates two regions 423, 424 located on the side closer to the light emitting element 3 in the peripheral light receiving region 42. Relative to the output current from the two regions 421 and 422 of the peripheral light receiving region 42, which are located on the side farther from the light emitting element 3, by the right side bar. It is shown in.

  First, when the target object is at the position B, the light emitted from the light emitting element 3 to the target object through the lens member 51 is reflected by the target object at the position B whose distance is the reference, and the reflected light is the lens member. The light is mainly incident on the central light receiving region 41 of the light receiving element 4 through 52, and some of the light is also incident on the peripheral light receiving regions 423, 424 and 421, 422 around it. As a result, as shown in [B] of FIG. 4B, the output current from the central light receiving region 41 becomes large, and the output currents from the peripheral light receiving regions 423, 424 and 421, 422 are all. It will be small.

  Next, when the target object is at the position F, the light emitted from the light emitting element 3 to the target object through the lens member 51 is reflected by the target object at the position F whose distance is far, and the reflected light is the lens member 52. The light is incident on the light-receiving element 4 from the central light-receiving area 41 to the peripheral light-receiving areas 421 and 422. Further, the light hardly enters the peripheral light receiving regions 423 and 424 on the side close to the light emitting element 3. As a result, as shown in [F] of FIG. 4B, the output current from the central light receiving region 41 is smaller than that in the case of [B], and the output currents from the peripheral light receiving regions 421 and 422 are small. Is larger than in the case of [B], and the output currents from the peripheral light receiving regions 423 and 424 are almost eliminated.

  Next, when the target object is at the position N, the light emitted from the light emitting element 3 to the target object through the lens member 51 is reflected by the target object at the position N at a short distance, and the reflected light is the lens member 52. The light is incident on the portion of the light receiving element 4 which is shifted from the central light receiving region 41 toward the peripheral light receiving regions 423 and 424. Further, the light hardly enters the peripheral light receiving regions 421 and 422 on the side far from the light emitting element 3. As a result, as shown in [N] of FIG. 4B, the output current from the central light receiving region 41 is smaller than that in the case of [B], and the output currents from the peripheral light receiving regions 423 and 424. Is larger than in the case of [B], and the output currents from the peripheral light receiving regions 421 and 422 are almost eliminated.

  As described above, according to the light emitting and receiving sensor 1 of the present invention, the output from the central light receiving area 41 and the peripheral light receiving area 42 (421, 422, 423, 424) of the light receiving element 4 according to the distance of the object. Since the current changes, the change can be processed by, for example, an arithmetic processing unit or the like, and the ratio of the output current can be calculated to obtain the distance to the object, and the distance information can be detected.

  Next, FIG. 3 is a diagram for explaining a state of detection in the light emitting and receiving sensor 1 of this example, and FIG. 3A shows an example of a state of detection of angle information, similar to FIG. 2A. FIG. 3B is a cross-sectional view, FIG. 3B is a graph showing an example of changes in output current by the light receiving element, and FIG. 3C is a top view showing an example of how light is received by the light receiving element.

  In FIG. 3A, the broken line described above is an imaginary line indicating the position and inclination of the object, and B ′ is inclined to the right at the position B that is the reference of the distance shown in FIG. 2A. It shows the case. Further, the alternate long and short dash line is an imaginary line that indicates the approximate direction of light travel, and the light passing from the light emitting element 3 through the lens member 51 shows the state of the central portion of the light irradiated to the object, and the lens member 52. The light passing through shows the state of the central portion of the light incident on the light receiving element 4 according to the angle of the object.

  In the graph of FIG. 3B, the magnitude of the signal intensity S of the output current is relatively set in the same manner as in FIG. 2B when the object is [B ′] (distance is inclined with reference). It is shown.

  The top view of FIG. 3C shows a portion around the light receiving element 4 in the top view of FIG. The circles and ellipses of alternate long and short dash lines show the approximate shape of the beam-like reflected light that has entered the light-receiving element 4, where B is the object at the position of B and is not tilted, and B ′ is the object. Shows the position and shape of the reflected light when is tilted at position B.

  The shape of the dashed-dotted circle of B in FIG. 3C corresponds to the reflected light in the case of B shown in FIGS. 2A and 2B. On the other hand, when the object is tilted as shown in FIG. 3A, the position of the reflected light is the light emission in this case, as in the ellipse of the dashed line B ′ in FIG. 3C. Since the shape shifts to the element 3 side and the shape becomes distorted in accordance with the inclination of the object, the distribution of the output current from each region of the light receiving element 4 in accordance with the change in the position and shape is shown in FIG. The distribution shown in [B] of FIG. 3B changes to the distribution shown in [B ′] of FIG. The angle information can be detected from the inclination of the object based on the change in the distribution.

  In order to detect the angle information with high accuracy, the shape of the reflected light from the object becomes circular when the object is not tilted, and the shape of the reflected light is not biased according to the tilt of the object. In order to deform, it is preferable to use an aspherical lens for the lens member 5 (51, 52), which is designed so that the transmitted light has a symmetrical shape.

  As described above, according to the light emitting / receiving sensor 1 of the present invention, the central light receiving region 41 and the peripheral light receiving region 42 (421, 422, 423, 424), the output current changes, so that the change in the output current is processed by, for example, an arithmetic processing unit, and the ratio of the output current is calculated to obtain the inclination of the object, and the angle information can be detected. it can.

  Regarding the angle, in addition to the angle of inclination in the left-right direction shown in FIG. 3A, the angle of inclination in the front-rear direction about the direction connecting the light emitting element 3 and the light receiving element 4 is also detected. Is possible.

The distance information and the angle information of the object obtained by the light emitting and receiving sensor 1 of the present example may vary depending on the distance and angle to the object and their changes, and the specifications of the light emitting and receiving sensor 1, but for example, as the distance information. When the distance from the lens member 5 is designed to be about 5 to 6 mm as a reference, the distance reference is 5 mm, the angle of the irradiation beam with respect to the object is 5 °, and the beam diameter is 0.5 mm (5x lens). ), It is possible to detect a change within a range of about ± 2 mm in distance and about ± 2 ° in angle.

  Then, the sensor device using the light emitting and receiving sensor 1 according to the present invention irradiates the object with the light that has passed through the lens member 5 (51) from the light emitting element 3 and is reflected by this object to reflect the lens member 5 (52). ). The reflected light that has passed through the light receiving element 4 is received by the light receiving element 4, and the output current output from the central light receiving region 41 and the annular peripheral light receiving region 42 (421 to 424) according to the reflected light causes At least one of the information and the angle information is detected. With such a sensor device according to the present invention, it is possible to favorably detect the distance information and the angle information of the target object as described above.

  Note that such a sensor device includes a processing unit such as an arithmetic processing unit for obtaining distance information and angle information based on the output current, a control unit for controlling the light emitting element 3, and the like. Various publicly known ones may be adopted.

1 light emitting / receiving sensor 2 substrate 3 light emitting element 4 light receiving element
41 Center light receiving area
42,421,422,423,424 Peripheral light receiving area 5,51,52 Lens member

Claims (4)

Board,
A light emitting element arranged on the upper surface of the substrate for irradiating an object with light;
A light-receiving element that is disposed apart from the light-emitting element on the upper surface of the substrate, and receives the reflected light reflected by the object,
A lens member disposed above the substrate, which allows light from the light emitting element to pass toward the object and which allows reflected light reflected by the object to pass toward the light receiving element,
The light receiving and emitting sensor, wherein the light receiving element has a central light receiving region and an annular peripheral light receiving region that surrounds the central light receiving region and is divided into a plurality of parts in the middle.   The light emitting and receiving sensor according to claim 1, wherein the central light receiving region is circular, and the peripheral light receiving region is an annular ring that is concentric with the central light receiving region.   2. The substrate according to claim 1, wherein the substrate is made of one conductivity type semiconductor, and the central light receiving region and the peripheral light receiving region of the light receiving element have another conductivity type semiconductor formed on the substrate. The light emitting and receiving sensor described. A sensor device using the light emitting and receiving sensor according to claim 1,
The light passing through the lens member from the light emitting element is irradiated to the target object, the reflected light reflected by the target object and passing through the lens member is received by the light receiving element, and the light is reflected according to the reflected light. A sensor device for detecting at least one of distance information and angle information of the object by an output current output from a central light receiving area and an annular light receiving area.

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