WO2015025593A1 - Proximity sensor - Google Patents

Proximity sensor Download PDF

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Publication number
WO2015025593A1
WO2015025593A1 PCT/JP2014/065632 JP2014065632W WO2015025593A1 WO 2015025593 A1 WO2015025593 A1 WO 2015025593A1 JP 2014065632 W JP2014065632 W JP 2014065632W WO 2015025593 A1 WO2015025593 A1 WO 2015025593A1
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WO
WIPO (PCT)
Prior art keywords
light
light receiving
lens
proximity sensor
crosstalk
Prior art date
Application number
PCT/JP2014/065632
Other languages
French (fr)
Japanese (ja)
Inventor
学道 重光
宏之 花戸
Original Assignee
シャープ株式会社
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Filing date
Publication date
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Publication of WO2015025593A1 publication Critical patent/WO2015025593A1/en

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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01V—GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS
    • G01V8/00—Prospecting or detecting by optical means
    • G01V8/10—Detecting, e.g. by using light barriers
    • G01V8/12—Detecting, e.g. by using light barriers using one transmitter and one receiver
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
    • G01S7/481—Constructional features, e.g. arrangements of optical elements
    • G01S7/4811—Constructional features, e.g. arrangements of optical elements common to transmitter and receiver
    • G01S7/4813—Housing arrangements
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
    • G01S7/481—Constructional features, e.g. arrangements of optical elements
    • G01S7/4816—Constructional features, e.g. arrangements of optical elements of receivers alone
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01V—GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS
    • G01V8/00—Prospecting or detecting by optical means
    • G01V8/10—Detecting, e.g. by using light barriers
    • G01V8/12—Detecting, e.g. by using light barriers using one transmitter and one receiver
    • G01V8/14—Detecting, e.g. by using light barriers using one transmitter and one receiver using reflectors
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/02—Details
    • H01L31/0232—Optical elements or arrangements associated with the device
    • H01L31/02325—Optical elements or arrangements associated with the device the optical elements not being integrated nor being directly associated with the device

Definitions

  • the present invention relates to a proximity sensor that detects the presence of an object based on reflected light from the object.
  • liquid crystal panels used in electronic devices such as mobile phones
  • display of the liquid crystal panel can be suppressed and functions of the touch panel can be suppressed when the user is not operating the electronic device.
  • In order to identify the situation where the user is not operating the electronic device there is a known method for detecting the proximity of the detection target such as the user's face to the liquid crystal panel by installing a proximity sensor in the electronic device. Yes.
  • a general proximity sensor has a structure in which a light emitting element such as an IR-LED and a light receiving element such as a photodiode are provided on a substrate. The light emitted from the light emitting element is reflected by the detection object and enters the light receiving element. When the light receiving element receives the reflected light from the detection object, the presence of the detection object can be detected in proximity.
  • a light emitting element such as an IR-LED and a light receiving element such as a photodiode are provided on a substrate.
  • the light emitted from the light emitting element is reflected by the detection object and enters the light receiving element.
  • the light receiving element receives the reflected light from the detection object, the presence of the detection object can be detected in proximity.
  • noise light that is incident on the light receiving element without being reflected by the object to be detected out of the light emitted from the light emitting element lowers the detection accuracy.
  • an opaque metal foil is embedded in a substrate on which a light emitting element and a light receiving element are mounted. Thereby, out of the emitted light of the light emitting element, it is possible to shield the noise light that propagates through the substrate and enters the light receiving element.
  • FIG. 16 is a schematic view showing an optical path of emitted light of a light emitting element in a conventional proximity sensor.
  • the proximity sensor when a proximity sensor is mounted on an electronic device, the proximity sensor is covered with a housing cover.
  • the housing cover also functions as a filter that shields light other than the light emitted from the light emitting element.
  • the light emitted from the light emitting element preferably passes through the housing cover and reaches the detection target, but part of the light is reflected on the surface of the housing cover and enters the light receiving element without reaching the detection target. .
  • the light reflected by the housing cover and incident on the light receiving element is called crosstalk light, and is received regardless of whether a detection target exists in the detection region. It is noise light that enters the element, and causes a decrease in detection accuracy. Further, by providing the housing cover, a part of the light emitted from the light emitting element does not reach the detection target, so that the light use efficiency is lowered.
  • the proximity sensor of Patent Document 1 has low detection accuracy because crosstalk light enters the light receiving element when a housing cover is provided.
  • the infrared proximity sensor of Patent Document 2 is disposed between a shield disposed above an infrared transmitter (light emitting element) and an infrared receiver (light receiving element), and between the infrared transmitter and the infrared receiver, and is a liquid crystal polymer.
  • Crosstalk light is attenuated or absorbed by a partitioning divider including
  • the proximity sensor of Patent Document 3 includes a pair of cylindrical light shielding bodies capable of blocking at least infrared rays on the front surface of the light emitting element and the light receiving element, thereby blocking the optical path of the crosstalk light, and SN The ratio is improved.
  • the light emitting element and the light receiving element are covered with a mold resin part having a lens-shaped convex part.
  • FIG. 17 is a cross-sectional view of the optical proximity sensor 300 of Patent Document 4.
  • the light reflected by the detection target 1 out of the light emitted from the light emitting element 320 is collected by the light receiving lens 333 and enters the light receiving element 330.
  • the light receiving efficiency of the light receiving element 330 can be increased and the amount of light incident on the light receiving element 330 can be increased, so that the detection sensitivity can be improved.
  • Increasing the light receiving surface of the light receiving element can increase the amount of light incident on the light receiving element, but also increases the amount of crosstalk light incident on the light receiving element. Moreover, the problem that a proximity sensor will enlarge will arise.
  • the crosstalk light is condensed on the light receiving surface of the light receiving element. At this time, an area where the amount of received crosstalk light is high appears on the light receiving surface at a position corresponding to the incident angle of the crosstalk light with respect to the axis of the lens.
  • the influence of the crosstalk light can be reduced relatively easily by providing a constant threshold for the light reception amount.
  • the optical proximity sensor 4 since a region having a high light reception amount appears at a position corresponding to the incident angle of the crosstalk light, it is not easy to reduce the influence of the crosstalk light.
  • the present invention has been made in view of the above problems, and an object of the present invention is to provide a proximity sensor capable of improving detection sensitivity and reducing the influence of crosstalk light.
  • a proximity sensor includes a light-emitting element and a light-receiving element that receives reflected light that is reflected by a detection target among light emitted from the light-emitting element.
  • the light emitting element and the light receiving element are arranged along a first direction, have a light incident surface, and receive light incident from the light incident surface.
  • a lens for condensing light on the light receiving element is provided, and the light incident surface includes a cylindrical outer portion that has a linear shape in a cross-sectional shape when the lens is cut along the first direction. It is characterized by being.
  • a proximity sensor that can improve the detection sensitivity and reduce the influence of crosstalk light without increasing the size.
  • the change in the distribution of the amount of received crosstalk light in the light receiving part of the conventional proximity sensor when the irradiation angle ⁇ i is changed by changing the distance g between the top of the light receiving lens and the housing cover is shown.
  • (A) shows the change in the distribution of the amount of received crosstalk light at the light receiving portion when the distance g is 2 mm, and (b) shows the reception of the crosstalk light at the light receiving portion when the distance g is 3 mm.
  • (C) shows the change in the distribution of the amount of crosstalk light received at the light receiving portion when the distance g is 4 mm, and (d) shows the cross at the light receiving portion when the distance g is 5 mm.
  • the change in the distribution of the received amount of talk light is shown.
  • FIG. 6A is a diagram showing changes, and FIG. 5A shows a change in the distribution of the amount of crosstalk light received at the light receiving portion when the distance g is 4 mm, and FIG. The change in the distribution of the amount of received light is shown.
  • 6 is a perspective view of a proximity sensor according to Embodiment 2.
  • FIG. FIG. 1 is a diagram showing changes, and FIG. 5A shows a change in the distribution of the amount of crosstalk light received at the light receiving portion when the distance g is 4 mm, and FIG. The change in the distribution of the amount of received light is shown.
  • 6 is a perspective view of a proximity sensor according to Embodiment 2.
  • FIG. 4 is a schematic diagram of a proximity sensor according to Embodiment 2, wherein (a) is a plan view, (b) is a cross-sectional view along AA ′ in (a), and (c) is a cross-sectional view along BB in (a).
  • 'Cross section It is a figure which shows distribution of the light quantity of the crosstalk light in the light-receiving part of the proximity sensor which concerns on Embodiment 2 when the distance g between the top part of a light-receiving lens and a housing
  • casing cover is 4 mm.
  • Embodiment 1 Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS.
  • FIG. 1 is a perspective view of the proximity sensor of the present embodiment.
  • 2A and 2B are schematic views of the proximity sensor of the present embodiment, in which FIG. 2A is a plan view, FIG. 2B is a cross-sectional view taken along the line AA ′ in FIG. 2A, and FIG. It is BB 'sectional drawing.
  • the proximity sensor 100 includes a substrate 10, and a light emitting element 20 and a light receiving element 30 disposed on the substrate 10.
  • the light emitting element 20 and the light receiving element 30 are arranged along the X direction (first direction) in FIG.
  • the light emitting element 20 for example, an LED chip that emits infrared light can be used.
  • the light receiving element 30 includes a light receiving unit 31 capable of detecting light on the upper surface thereof, and the light receiving unit 31 is configured by, for example, a photodiode.
  • the light emitting element 20 is covered with a light emitting lens 21.
  • the light emitting lens 21 is a convex lens formed so as to form a hemisphere on the light emitting side of the light emitting element 20.
  • the light emitting lens 21 is not an essential configuration, and the light emitting element 20 may not be covered with the light emitting lens 21.
  • the light receiving element 30 is covered with a sealing resin 32.
  • a light receiving lens 33 (lens) is provided above the sealing resin 32.
  • the light receiving lens 33 is a cylindrical lens linear in the direction in which the light emitting element 20 and the light receiving element 30 are arranged, and condenses light incident from the light incident surface (upper surface) on the light receiving unit 31 of the light receiving element 30.
  • a sealing resin 32 and a light-shielding resin 40 that covers the upper surface of the substrate 10 are provided on the substrate 10.
  • the light shielding resin 40 is provided so that the upper surface of the light emitting lens 21 and the upper surface of the light receiving lens 33 are exposed.
  • the light incident surface which is the upper surface of the light receiving lens 33, is composed of a cylindrical outer portion that is a cylindrical shape.
  • the cross sectional shape of the light receiving lens 33 is rectangular.
  • the light incident surface has a linear shape.
  • the cross-sectional shape of the light receiving lens 33 is a semicircle. Shape.
  • the light receiving lens 33 has a focal line parallel to the X direction.
  • the light emitting lens 21, the sealing resin 32, and the light receiving lens 33 are members that transmit at least light emitted from the light emitting element 20.
  • the sealing resin 32 and the light receiving lens 33 may be formed as an integral member.
  • the light blocking resin 40 is a member that blocks visible light and infrared light.
  • FIGS. 3A and 3B are diagrams for explaining the amount of light received by the light receiving element.
  • FIG. 3A is a schematic diagram for explaining the relationship between the size of the light receiving portion and the amount of light received by the light receiving element.
  • FIG. It is a partial enlarged view of a).
  • the distance between the light emitting element 20 and the detection target is the object distance d
  • the distance between the light emitting element 20 and the center of the light receiving unit 31 is the base line length k
  • X The width of the light receiving portion 31 in the direction is defined as a detection opening D.
  • the angle formed by the line connecting the light receiving element 30 and the detection target and the line connecting the center of the light receiving unit 31 and the detection target is ⁇ 1, and the line connecting the light receiving element 30 and the detection target.
  • a hemisphere having an arbitrary radius r with the position of the detection object as a midpoint is considered. Let the surface area of the hemisphere be s 0 .
  • a plane passing through the intersection of the minute and the hemisphere is defined as a plane P.
  • the surface area of the spherical crown when the hemisphere is cut along the plane P is s, and the height of the spherical crown is h.
  • the light receiving efficiency I is represented by the ratio of the hemispherical surface area s 0 and the spherical crown surface area s as shown in the following equation.
  • the light receiving efficiency I is expressed by the ratio between the height h of the sphere crown and the radius r of the sphere as in the following equation.
  • FIG. 4 is a graph showing the relationship between the light receiving efficiency and the object distance.
  • the horizontal axis of the graph is the object distance d, and the vertical axis is the light receiving efficiency I.
  • the graph shows the relationship between the light receiving efficiency I and the object distance d when the base line length k is 2.65 mm and the detection aperture D is 0.9 mm.
  • the light receiving efficiency I is small, and the ratio of the light receiving amount of the light receiving element to the total light amount of the reflected light of the detection target is very small.
  • the larger the detection aperture D the higher the light receiving efficiency I.
  • the light receiving element 30 itself must be enlarged, resulting in an increase in the size of the proximity sensor 100 as a device.
  • the reflected light of the detection target is condensed on the light receiving unit 31 using a lens. Is preferred.
  • the proximity sensor 100 of the present embodiment includes a light receiving lens 33 above the light receiving element 30, and the light incident on the light incident surface of the light receiving lens 33 is condensed on the light receiving unit 31.
  • the reflected light of the detection target can be efficiently incident on the light receiving unit 31, and the light receiving efficiency can be improved.
  • the proximity sensor 100 when a housing cover is provided between the proximity sensor 100 and the detection target, a part of the light emitted from the light emitting element 20 is reflected by the housing cover and received by the light receiving element 30.
  • the crosstalk light is incident on the light receiving portion 31.
  • the amount of crosstalk light is larger than the amount of reflected light of the detection target. In order to improve the detection accuracy of the proximity sensor 100, it is preferable to increase the amount of received reflected light of the detection target and decrease the amount of received crosstalk light.
  • the amount of crosstalk light received by the light receiving unit 31 when a housing cover is provided between the proximity sensor 100 and the detection target was simulated.
  • FIG. 5 is a perspective view of a conventional proximity sensor as a comparative example.
  • the proximity sensor shown in FIG. 5 has the same structure as the conventional proximity sensor described with reference to FIG.
  • the light receiving element 330 is covered with a sealing resin, and the light receiving lens 333 is placed on the top of the sealing resin, like the proximity sensor of the present embodiment. Is provided.
  • the light receiving lens 333 is a substantially hemispherical convex lens.
  • the shape of the cross section of the light receiving lens 333 is a semicircular shape, and the light incident surface has a curved shape. Yes. Also, when cut in the Y direction orthogonal to the X direction, the cross-sectional shape of the light receiving lens 333 is a semicircular shape, and the light incident surface has a curved shape.
  • the conventional proximity sensor 300 includes a substantially hemispherical convex lens above the light receiving element 330, light incident on the light incident surface of the light receiving lens 333 from all directions is incident on the light receiving unit 331 by the light receiving lens 333. Focused.
  • FIG. 6 is a perspective view showing the positional relationship among the proximity sensor, the housing cover, and the detection target used for the simulation of the amount of received crosstalk light.
  • the housing cover 2 was provided between the proximity sensor 300 and the detection target 1, and the distance g between the top of the light receiving lens 333 and the housing cover 2 was 4 mm.
  • the case cover 2 is a plate member having a size of 250 mm ⁇ 200 mm ⁇ 0.7 mm and a refractive index of 1.5.
  • a light receiving portion 331 having a width (detection opening D) of 0.4 mm was used as the light receiving element 330.
  • FIG. 7 is a diagram showing an optical path of crosstalk light. As shown in FIG. 7, the light emitted from the light emitting element 320 is collected by the light receiving lens 333, and a part of the light is reflected on the surface of the housing cover 2 to be crosstalk light and passes through the light receiving lens 333. Is incident on.
  • the light emitted from the light emitting element 320 includes light reflected on the lower surface of the housing cover 2 and light reflected on the upper surface of the housing cover 2. Both lights become crosstalk light.
  • an angle formed by the Z axis and the optical path of the crosstalk light in the XZ plane is referred to as an irradiation angle ⁇ i .
  • the irradiation angle ⁇ i is equal to the distance g between the top of the light receiving lens 333 and the housing cover 2 or the housing in the Z direction. It changes according to the angle of the body cover 2 surface.
  • FIG. 8A and 8B are diagrams showing the optical path of the crosstalk light when the irradiation angle ⁇ i is 0 °.
  • FIG. 8A shows the optical path of the crosstalk light incident on the hemispherical light receiving lens, and FIG. The distribution of the amount of crosstalk light in the section is shown.
  • the crosstalk light is uniformly incident on the light receiving unit arranged on the XY plane.
  • the distribution is uniform.
  • FIGS. 9A and 9B are diagrams showing the optical path of the crosstalk light when the irradiation angle ⁇ i is 18 °
  • FIG. 9A shows the optical path of the crosstalk light incident on the light receiving lens
  • FIG. 9B shows the cross path in the light receiving unit. The distribution of the amount of talk light is shown.
  • FIG. 9 shows the optical path of crosstalk light when the base line length k is 2.65 mm and the distance g between the top of the light receiving lens 333 and the housing cover 2 is 4 mm.
  • the light incident surface of the light receiving lens 333 of the conventional proximity sensor 300 has a spherical shape. Therefore, when the irradiation angle is not 0 °, the light receiving unit 331 disposed on the XY plane. Since the crosstalk light is incident unevenly, the distribution of the crosstalk light in the light receiving unit 331 is not uniform.
  • the amount of received crosstalk light is large, and in the region on the right side of the light receiving unit 331, the amount of received crosstalk light is small.
  • FIG. 10 is a diagram illustrating the distribution of the amount of crosstalk light in the light receiving unit of the proximity sensor of the comparative example when the irradiation angle ⁇ i is 18 °.
  • a region where the amount of received crosstalk light is large is indicated by a dark color
  • a region where the amount of received crosstalk light is small is indicated by a light color.
  • an arc-shaped region with a large amount of received crosstalk light is formed in the end region of the light receiving unit 331.
  • FIG. 11 shows the amount of crosstalk light received by the light receiving unit of the proximity sensor of the comparative example when the irradiation angle ⁇ i is changed by changing the distance g between the top of the light receiving lens and the housing cover. It is a figure which shows the change of distribution, (a) shows the change of distribution of the received amount of crosstalk light in a light-receiving part when the distance g is 2 mm, (b) in the light-receiving part when the distance g is 3 mm. The change in the distribution of the amount of received light of crosstalk light is shown. (C) shows the change in the distribution of the amount of received light of crosstalk light in the light receiving part when the distance g is 4 mm. 6 shows changes in the distribution of the amount of crosstalk light received by the light receiving section.
  • the position and shape of the region where the amount of crosstalk light received by the light receiving unit 331 is large changes according to the change in the irradiation angle ⁇ i .
  • the area for setting the threshold is widened, and the effective light receiving area for measuring the amount of received light is reduced.
  • the dynamic range of the detected light amount is increased, so that the detection accuracy is lowered.
  • FIG. 12 shows the amount of crosstalk light received by the light receiving unit of the proximity sensor according to the present embodiment when the irradiation angle ⁇ i is changed by changing the distance g between the top of the light receiving lens and the housing cover.
  • (A) shows the change in the distribution of the amount of received crosstalk light at the light receiving portion when the distance g is 4 mm
  • (b) shows the light receiving portion when the distance g is 2 mm. Shows the change in the distribution of the amount of received crosstalk light.
  • the light incident surface has a linear shape in a cross-sectional shape when the light receiving lens 33 is cut in the X direction. Therefore, as shown in FIG. 12, it is possible to suppress the occurrence of a region where the light reception amount of the crosstalk light is increased in the light receiving unit 31, and the crosstalk light in the light receiving unit 31 does not depend on the irradiation angle ⁇ i .
  • the amount of light is uniform.
  • the distribution of the amount of crosstalk light in the light receiving unit 31 is uniform regardless of the distance between the light receiving lens 33 and the housing cover 2. Therefore, regardless of the arrangement of the housing cover 2, the crosstalk light can be uniformly cut as background noise, and the influence of the crosstalk light can be reduced.
  • the proximity sensor 200 can widely correspond to the installation distance of the housing cover 2 when mounted on an electronic device.
  • FIG. 13 is a perspective view of the proximity sensor of the present embodiment.
  • 14A and 14B are schematic views of the proximity sensor of the present embodiment, in which FIG. 14A is a plan view, FIG. 14B is a cross-sectional view taken along line AA ′ in FIG. 14A, and FIG. It is BB 'sectional drawing.
  • the proximity sensor 200 includes a light receiving lens 233 instead of the light receiving lens 33 of the proximity sensor 100 of the first embodiment.
  • the light incident surface has a cylindrical outer portion 233a having a linear shape, and a spherical outer portion 233b having a curved shape. have.
  • the spherical outer portion 233b is disposed closer to the light emitting element 20 than the cylindrical outer portion 233a.
  • the light receiving lens 233 of the proximity sensor 200 of the present embodiment has a structure in which a cylindrical lens and a hemispherical convex lens are joined.
  • light having an optical path on the YZ plane in the drawing is condensed on the light receiving unit 31 by the light receiving lens 233.
  • light having an optical path on the XZ plane in the drawing and incident on the cylindrical outer portion 233 a is not collected by the light receiving lens 233.
  • light having an optical path on the XZ plane in the drawing and incident on the spherical outer portion 233b is collected by the light receiving lens 233.
  • the proximity sensor 200 of the present embodiment includes the spherical outer portion 233b in the light receiving lens 233, the light receiving efficiency is higher and the detection sensitivity is higher than the proximity sensor 100 of the first embodiment.
  • the amount of crosstalk light collected on the light receiving portion 31 is not uniform.
  • the spherical outer portion 233b is disposed closer to the light emitting element than the cylindrical outer portion 233a, the angle formed by the optical path of light incident on the spherical outer portion 233b and the contact surface at the incident position is a relatively large angle. It becomes. Therefore, even if the light incident on the spherical outer portion 233b is refracted by the lens, the amount of crosstalk light collected on the light receiving element is not excessively nonuniform.
  • FIG. 15 is a diagram showing the distribution of the amount of crosstalk light in the light receiving unit of the proximity sensor of the present embodiment when the distance g between the top of the light receiving lens and the housing cover is 4 mm.
  • the proximity sensor 200 has a uniform amount of crosstalk light in the light receiving unit 31 and a uniform distribution of the amount of crosstalk light in the light receiving unit 31 compared to the conventional proximity sensor. . Further, in the light receiving unit 31, a region where the amount of received crosstalk light is high does not appear.
  • a proximity sensor includes a light emitting element (20) and a light receiving element (30) that receives reflected light that is reflected by the detection object (1) among the light emitted from the light emitting element.
  • the light emitting element and the light receiving element are arranged along a first direction (X direction), have a light incident surface, and the light sensor and the light receiving element.
  • a lens for condensing light incident from the incident surface on the light receiving element is provided, and the light incident surface has a linear shape in a cross-sectional shape when the lens is cut along the first direction. It is characterized by including a cylindrical outer shape portion (233a).
  • the reflected light can be condensed on the light receiving element, the light receiving efficiency of the light receiving element can be increased, and the amount of incident light on the light receiving element can be increased. Thereby, detection sensitivity can be improved.
  • the cross-sectional shape when the lens is cut along the first direction is a semicircular shape. Therefore, in the cross section, the amount of crosstalk light collected on the light receiving element is non-uniform according to the incident angle of the lens to the light incident surface.
  • the incident angle of the crosstalk light to the lens varies depending on the distance between the lens and the housing cover, and thus is condensed on the light receiving element.
  • the distribution of the amount of crosstalk light varies depending on the position of the housing cover with respect to the lens. In this case, it is difficult to uniformly cut the crosstalk light as background noise by providing a certain threshold for the amount of received light.
  • the lens since the lens includes the cylindrical outer portion, the crosstalk that is condensed on the light receiving element in the cross section regardless of the incident angle on the light incident surface of the lens.
  • the amount of light is uniform. Furthermore, it is possible to make the distribution of the amount of crosstalk light incident on the cylindrical outer portion and condensed on the light receiving element uniform regardless of the distance between the lens and the housing cover.
  • the proximity sensor according to aspect 2 of the present invention is the proximity sensor according to aspect 1, wherein the light incident surface has a spherical outer shape portion (233b) having a curved shape in a cross-sectional shape when the lens is cut along the first direction.
  • the spherical outer portion is disposed closer to the light emitting element than the cylindrical outer portion, and the lens collects light incident on the spherical outer portion on the light receiving element. Also good.
  • the light receiving efficiency of the light receiving element can be further increased, and the amount of light incident on the light receiving element can be increased. Thereby, detection sensitivity can be further improved.
  • the light incident surface of the lens includes a spherical outer portion
  • the spherical outer portion is arranged closer to the light emitting element than the cylindrical outer portion, the angle formed by the optical path of light incident on the spherical outer portion and the contact surface at the incident position is a relatively large angle. Therefore, the light incident on the spherical outer portion is refracted by the lens, so that the amount of crosstalk light collected on the light receiving element is not excessively nonuniform.
  • the lens may be a cylindrical lens, and a direction in which a focal line of the cylindrical lens extends may be parallel to the first direction.
  • the present invention can be used in various electronic devices such as a light sensor such as an illuminance sensor, an RGB color sensor, and a proximity sensor, a smartphone equipped with a reflective light sensor, a digital camera, and a car navigation system.
  • a light sensor such as an illuminance sensor, an RGB color sensor, and a proximity sensor
  • a smartphone equipped with a reflective light sensor a digital camera, and a car navigation system.

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Abstract

Provided is a proximity sensor capable of improving detection sensitivity and reducing the impact of crosstalk light. The proximity sensor comprises a light-emitting element (20), a light-receiving element (30), and a light-receiving lens (33) for condensing light incident from a light incidence surface, on to the light-receiving element. The light-emitting element and the light-receiving element are arranged along a first direction. The light incidence surface includes a cylindrical external section forming a straight line in a cross-section formed by cutting the light-receiving lens along the first direction.

Description

近接センサProximity sensor
　本発明は、物体からの反射光に基づいて当該物体の存在を検知する近接センサに関する。 The present invention relates to a proximity sensor that detects the presence of an object based on reflected light from the object.
　携帯電話などの電子機器に利用される液晶パネルでは、低消費電力化やタッチパネルの誤動作防止のために、ユーザーが電子機器を操作していないときに、液晶パネルの表示を抑制したりタッチパネルの機能を無効化したりする制御が求められている。ユーザーが電子機器を操作していない状況を特定するために、電子機器に近接センサを搭載し、例えば、液晶パネルにユーザーの顔などの検知対象物が近づいたことを検知する方法が知られている。 In liquid crystal panels used in electronic devices such as mobile phones, to reduce power consumption and prevent malfunctions of the touch panel, display of the liquid crystal panel can be suppressed and functions of the touch panel can be suppressed when the user is not operating the electronic device. There is a need for control that disables. In order to identify the situation where the user is not operating the electronic device, there is a known method for detecting the proximity of the detection target such as the user's face to the liquid crystal panel by installing a proximity sensor in the electronic device. Yes.
　一般的な近接センサは、基板上に、ＩＲ－ＬＥＤなどの発光素子と、フォトダイオードなどの受光素子とが設けられた構造を有している。発光素子の出射光は、検知対象物によって反射され、受光素子に入射する。検知対象物からの反射光を受光素子が受光することによって、検知対象物の存在を近接検知することができる。 A general proximity sensor has a structure in which a light emitting element such as an IR-LED and a light receiving element such as a photodiode are provided on a substrate. The light emitted from the light emitting element is reflected by the detection object and enters the light receiving element. When the light receiving element receives the reflected light from the detection object, the presence of the detection object can be detected in proximity.
　このような近接センサにおいて、発光素子の出射光のうち、検知対象物に反射されることなく受光素子に入射するノイズ光は、検知精度を低下させてしまう。 In such a proximity sensor, noise light that is incident on the light receiving element without being reflected by the object to be detected out of the light emitted from the light emitting element lowers the detection accuracy.
　特許文献１の近接センサは、発光素子と受光素子とを搭載した基板に、不透明な金属箔が埋設されている。これにより、発光素子の出射光のうち、基板の内部を伝播して受光素子に入射しようとするノイズ光を遮蔽することができる。 In the proximity sensor of Patent Document 1, an opaque metal foil is embedded in a substrate on which a light emitting element and a light receiving element are mounted. Thereby, out of the emitted light of the light emitting element, it is possible to shield the noise light that propagates through the substrate and enters the light receiving element.
　図１６は、従来の近接センサにおける発光素子の出射光の光路を示す概略図である。 FIG. 16 is a schematic view showing an optical path of emitted light of a light emitting element in a conventional proximity sensor.
　図１６に示すように、近接センサを電子機器に搭載する場合、近接センサは筐体カバーによって覆われる。筐体カバーは、発光素子の出射光以外の光を遮蔽するフィルタとしても機能する。発光素子の出射光は、筐体カバーを透過して検知対象物に達することが好ましいが、一部の光は筐体カバーの表面において反射され、検知対象物に達することなく受光素子に入射する。 As shown in FIG. 16, when a proximity sensor is mounted on an electronic device, the proximity sensor is covered with a housing cover. The housing cover also functions as a filter that shields light other than the light emitted from the light emitting element. The light emitted from the light emitting element preferably passes through the housing cover and reaches the detection target, but part of the light is reflected on the surface of the housing cover and enters the light receiving element without reaching the detection target. .
　このように、発光素子の出射光のうち、筐体カバーによって反射されて受光素子に入射する光はクロストーク光と呼ばれ、検出領域内に検知対象物が存在するか否かにかかわらず受光素子に入射するノイズ光であり、検知精度を低下させる要因となる。また、筐体カバーを設けることによって、発光素子の出射光の一部は検知対象物に達しなくなるため、光利用効率が低下する。 As described above, of the light emitted from the light emitting element, the light reflected by the housing cover and incident on the light receiving element is called crosstalk light, and is received regardless of whether a detection target exists in the detection region. It is noise light that enters the element, and causes a decrease in detection accuracy. Further, by providing the housing cover, a part of the light emitted from the light emitting element does not reach the detection target, so that the light use efficiency is lowered.
　特許文献１の近接センサは、筐体カバーを設けた場合にクロストーク光が受光素子に入射するため、検知精度が低い。 The proximity sensor of Patent Document 1 has low detection accuracy because crosstalk light enters the light receiving element when a housing cover is provided.
　特許文献２の赤外線近接センサは、赤外線送信機（発光素子）と赤外線受信機（受光素子）との上方に配置されたシールドと、赤外線送信機と赤外線受信機との間に配置され、液晶ポリマを含むパーティショニング・デバイダとにより、クロストーク光を減衰又は吸収する。 The infrared proximity sensor of Patent Document 2 is disposed between a shield disposed above an infrared transmitter (light emitting element) and an infrared receiver (light receiving element), and between the infrared transmitter and the infrared receiver, and is a liquid crystal polymer. Crosstalk light is attenuated or absorbed by a partitioning divider including
　また、特許文献３の近接センサは、少なくとも赤外線を遮断することができる一対の筒状の遮光体を、発光素子と受光素子との前面に備えることによって、クロストーク光の光路を遮断し、ＳＮ比を向上させている。 In addition, the proximity sensor of Patent Document 3 includes a pair of cylindrical light shielding bodies capable of blocking at least infrared rays on the front surface of the light emitting element and the light receiving element, thereby blocking the optical path of the crosstalk light, and SN The ratio is improved.
　また、特許文献４の光学式近接センサは、発光素子および受光素子が、レンズ形状の凸部を有するモールド樹脂部で覆われている。 Further, in the optical proximity sensor of Patent Document 4, the light emitting element and the light receiving element are covered with a mold resin part having a lens-shaped convex part.
　図１７は、特許文献４の光学式近接センサ３００の断面図である。図１７に示すように、発光素子３２０の出射光のうち検知対象物１に反射された光は、受光レンズ３３３によって集光され、受光素子３３０に入射する。これにより、受光素子３３０の受光効率を上げ、受光素子３３０への入射光量を増加させることができるため、検知感度を向上させることができる。 FIG. 17 is a cross-sectional view of the optical proximity sensor 300 of Patent Document 4. As shown in FIG. 17, the light reflected by the detection target 1 out of the light emitted from the light emitting element 320 is collected by the light receiving lens 333 and enters the light receiving element 330. Thereby, the light receiving efficiency of the light receiving element 330 can be increased and the amount of light incident on the light receiving element 330 can be increased, so that the detection sensitivity can be improved.
日本国公開特許公報「特開平１１－３５４８３２号公報（１９９９年１２月２４日公開）」Japanese Patent Publication “Japanese Patent Laid-Open No. 11-354832 (published on Dec. 24, 1999)” 日本国公開特許公報「特開２０１１－１１３９７５号公報（２０１１年６月９日公開）」Japanese Patent Publication “Japanese Unexamined Patent Publication No. 2011-113975 (published on June 9, 2011)” 日本国公開特許公報「特開２００７－５２９２８号公報（２００７年３月１日公開）」Japanese Patent Publication “JP 2007-52928 A” (published March 1, 2007) 日本国公開特許公報「特開２０１０－３４１８９号公報（２０１０年２月１２日公開）」Japanese Patent Publication “Japanese Patent Laid-Open No. 2010-34189 (published on February 12, 2010)”
　しかしながら、特許文献２の赤外線近接センサおよび特許文献３の近接センサでは、受光素子へのクロストーク光の入射は抑制されるものの、十分な検知光量を得ることができないため、検知感度が低い。 However, in the infrared proximity sensor of Patent Document 2 and the proximity sensor of Patent Document 3, the incidence of crosstalk light to the light receiving element is suppressed, but a sufficient amount of detected light cannot be obtained, so the detection sensitivity is low.
　受光素子の受光面を大きくすることによって、受光素子への入射光量を増加させることができるが、受光素子に入射するクロストーク光の光量も増えてしまう。また、近接センサが大型化してしまうという問題を生じる。 Increasing the light receiving surface of the light receiving element can increase the amount of light incident on the light receiving element, but also increases the amount of crosstalk light incident on the light receiving element. Moreover, the problem that a proximity sensor will enlarge will arise.
　特許文献４の光学式近接センサのように、受光素子を半球形状のレンズで覆った場合、クロストーク光は受光素子の受光面上に集光される。このとき、受光面上の、レンズの軸に対するクロストーク光の入射角度に応じた位置に、クロストーク光の受光量が高い領域が表れる。 When the light receiving element is covered with a hemispherical lens as in the optical proximity sensor of Patent Document 4, the crosstalk light is condensed on the light receiving surface of the light receiving element. At this time, an area where the amount of received crosstalk light is high appears on the light receiving surface at a position corresponding to the incident angle of the crosstalk light with respect to the axis of the lens.
　受光面の所定の位置に、クロストーク光の受光量の高い領域が表れる場合、受光量に一定の閾値を設けることによって比較的容易にクロストーク光の影響を低減することができるが、特許文献４の光学式近接センサは、クロストーク光の入射角度に応じた位置に受光量が高い領域が表れるため、クロストーク光の影響を低減することは容易ではない。 When a region with a high crosstalk light reception amount appears at a predetermined position on the light receiving surface, the influence of the crosstalk light can be reduced relatively easily by providing a constant threshold for the light reception amount. In the optical proximity sensor 4, since a region having a high light reception amount appears at a position corresponding to the incident angle of the crosstalk light, it is not easy to reduce the influence of the crosstalk light.
　本発明は、上記の問題点に鑑みなされたものであって、その目的は、検知感度を向上させ、かつ、クロストーク光の影響を低減することができる近接センサを提供することにある。 The present invention has been made in view of the above problems, and an object of the present invention is to provide a proximity sensor capable of improving detection sensitivity and reducing the influence of crosstalk light.
　上記の課題を解決するために、本発明の一態様に係る近接センサは、発光素子と、上記発光素子の出射光のうち、検知対象物に反射された光である反射光を受光する受光素子と、を備えている近接センサであって、上記発光素子と上記受光素子とは、第１の方向に沿って配されており、光入射面を有し、上記光入射面から入射した光を上記受光素子上に集光するためのレンズを備えており、上記光入射面は、上記レンズを上記第１の方向に沿って切断したときの断面形状において、直線形状となる円柱外形部を含んでいることを特徴とする。 In order to solve the above-described problem, a proximity sensor according to one embodiment of the present invention includes a light-emitting element and a light-receiving element that receives reflected light that is reflected by a detection target among light emitted from the light-emitting element. The light emitting element and the light receiving element are arranged along a first direction, have a light incident surface, and receive light incident from the light incident surface. A lens for condensing light on the light receiving element is provided, and the light incident surface includes a cylindrical outer portion that has a linear shape in a cross-sectional shape when the lens is cut along the first direction. It is characterized by being.
　本発明の一態様によれば、大型化することなく検知感度を向上させ、かつ、クロストーク光の影響を低減することができる近接センサを提供することができる。 According to one embodiment of the present invention, it is possible to provide a proximity sensor that can improve the detection sensitivity and reduce the influence of crosstalk light without increasing the size.
本発明の実施形態１に係る近接センサの斜視図である。It is a perspective view of the proximity sensor which concerns on Embodiment 1 of this invention. 本発明の実施形態１に係る近接センサの概略図であり、（ａ）は平面図であり、（ｂ）は（ａ）のＡ－Ａ’断面図であり、（ｃ）は（ａ）のＢ－Ｂ’断面図である。BRIEF DESCRIPTION OF THE DRAWINGS It is the schematic of the proximity sensor which concerns on Embodiment 1 of this invention, (a) is a top view, (b) is AA 'sectional drawing of (a), (c) is (a). It is BB 'sectional drawing. 受光素子の受光量を説明するための図であり、（ａ）は受光部の大きさと受光素子の受光量との関係を説明するための模式図であり、（ｂ）は（ａ）の一部の拡大図である。It is a figure for demonstrating the light reception amount of a light receiving element, (a) is a schematic diagram for demonstrating the relationship between the magnitude | size of a light-receiving part and the light reception amount of a light receiving element, (b) is a figure of (a). It is an enlarged view of a part. 受光効率と物体距離との関係を示すグラフである。It is a graph which shows the relationship between light reception efficiency and an object distance. 従来の近接センサの斜視図である。It is a perspective view of the conventional proximity sensor. クロストーク光の受光量のシミュレーションに用いた近接センサと筐体カバーと検知対象物との位置関係を示す斜視図である。It is a perspective view which shows the positional relationship of the proximity sensor used for simulation of the light reception amount of crosstalk light, a housing | casing cover, and a detection target. クロストーク光の光路を示す図である。It is a figure which shows the optical path of crosstalk light. 照射角度θｉが０°のときのクロストーク光の光路を示す図であり、（ａ）は半球形状の受光レンズに入射したクロストーク光の光路を示し、（ｂ）は受光部におけるクロストーク光の光量の分布を示す。It is a figure which shows the optical path of the crosstalk light when irradiation angle (theta) i is 0 degree, (a) shows the optical path of the crosstalk light which injected into the hemispherical light reception lens, (b) is the crosstalk in a light-receiving part. The distribution of the amount of light is shown. 照射角度θｉが１８°のときのクロストーク光の光路を示す図であり、（ａ）は半球形状の受光レンズに入射したクロストーク光の光路を示し、（ｂ）は受光部におけるクロストーク光の光量の分布を示す。It is a figure which shows the optical path of the crosstalk light when irradiation angle (theta) i is 18 degrees, (a) shows the optical path of the crosstalk light which injected into the hemispherical light reception lens, (b) is the crosstalk in a light-receiving part. The distribution of the amount of light is shown. 照射角度θｉが１８°のときの、従来の近接センサの受光部におけるクロストーク光の光量の分布を示す図である。It is a figure which shows distribution of the light quantity of the crosstalk light in the light-receiving part of the conventional proximity sensor when irradiation angle (theta) i is 18 degrees. 受光レンズの頂部と筐体カバーとの間の距離ｇを変化させることによって照射角度θｉを変化させたときの、従来の近接センサの受光部におけるクロストーク光の受光量の分布の変化を示す図であり、（ａ）は距離ｇが２ｍｍのときの受光部におけるクロストーク光の受光量の分布の変化を示し、（ｂ）は距離ｇが３ｍｍのときの受光部におけるクロストーク光の受光量の分布の変化を示し、（ｃ）は距離ｇが４ｍｍのときの受光部におけるクロストーク光の受光量の分布の変化を示し、（ｄ）は距離ｇが５ｍｍのときの受光部におけるクロストーク光の受光量の分布の変化を示す。The change in the distribution of the amount of received crosstalk light in the light receiving part of the conventional proximity sensor when the irradiation angle θ i is changed by changing the distance g between the top of the light receiving lens and the housing cover is shown. (A) shows the change in the distribution of the amount of received crosstalk light at the light receiving portion when the distance g is 2 mm, and (b) shows the reception of the crosstalk light at the light receiving portion when the distance g is 3 mm. (C) shows the change in the distribution of the amount of crosstalk light received at the light receiving portion when the distance g is 4 mm, and (d) shows the cross at the light receiving portion when the distance g is 5 mm. The change in the distribution of the received amount of talk light is shown. 受光レンズの頂部と筐体カバーとの間の距離ｇを変化させることによって照射角度θｉを変化させたときの、実施形態１に係る近接センサの受光部におけるクロストーク光の受光量の分布の変化を示す図であり、（ａ）は距離ｇが４ｍｍのときの受光部におけるクロストーク光の受光量の分布の変化を示し、（ｂ）は距離ｇが２ｍｍのときの受光部におけるクロストーク光の受光量の分布の変化を示す。The distribution of the amount of received crosstalk light in the light receiving unit of the proximity sensor according to Embodiment 1 when the irradiation angle θ i is changed by changing the distance g between the top of the light receiving lens and the housing cover. FIG. 6A is a diagram showing changes, and FIG. 5A shows a change in the distribution of the amount of crosstalk light received at the light receiving portion when the distance g is 4 mm, and FIG. The change in the distribution of the amount of received light is shown. 実施形態２に係る近接センサの斜視図である。6 is a perspective view of a proximity sensor according to Embodiment 2. FIG. 実施形態２に係る近接センサの概略図であり、（ａ）は平面図であり、（ｂ）は（ａ）のＡ－Ａ’断面図であり、（ｃ）は（ａ）のＢ－Ｂ’断面図である。FIG. 4 is a schematic diagram of a proximity sensor according to Embodiment 2, wherein (a) is a plan view, (b) is a cross-sectional view along AA ′ in (a), and (c) is a cross-sectional view along BB in (a). 'Cross section. 受光レンズの頂部と筐体カバーとの間の距離ｇが４ｍｍのときの、実施形態２に係る近接センサの受光部におけるクロストーク光の光量の分布を示す図である。It is a figure which shows distribution of the light quantity of the crosstalk light in the light-receiving part of the proximity sensor which concerns on Embodiment 2 when the distance g between the top part of a light-receiving lens and a housing | casing cover is 4 mm. 従来の近接センサにおける発光素子の出射光の光路を示す概略図である。It is the schematic which shows the optical path of the emitted light of the light emitting element in the conventional proximity sensor. 従来技術としての特許文献４の光学式近接センサの断面図である。It is sectional drawing of the optical proximity sensor of patent document 4 as a prior art.
　〔実施形態１〕
　以下、本発明の実施の形態について、図１～図１２に基づいて詳細に説明する。 Embodiment 1
Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS.
　＜近接センサの構造＞
　図１は、本実施形態の近接センサの斜視図である。図２は、本実施形態の近接センサの概略図であり、（ａ）は平面図であり、（ｂ）は（ａ）のＡ－Ａ’断面図であり、（ｃ）は（ａ）のＢ－Ｂ’断面図である。 <Proximity sensor structure>
FIG. 1 is a perspective view of the proximity sensor of the present embodiment. 2A and 2B are schematic views of the proximity sensor of the present embodiment, in which FIG. 2A is a plan view, FIG. 2B is a cross-sectional view taken along the line AA ′ in FIG. 2A, and FIG. It is BB 'sectional drawing.
　図１および図２に示すように、近接センサ１００は、基板１０と、基板１０上に配置された発光素子２０および受光素子３０とを有している。発光素子２０と受光素子３０とは、図２中のＸ方向（第１の方向）に沿って並べられている。 As shown in FIGS. 1 and 2, the proximity sensor 100 includes a substrate 10, and a light emitting element 20 and a light receiving element 30 disposed on the substrate 10. The light emitting element 20 and the light receiving element 30 are arranged along the X direction (first direction) in FIG.
　発光素子２０として、例えば赤外光を出射するＬＥＤチップを用いることができる。また、受光素子３０は、その上面に、光を検知することができる受光部３１を備えており、受光部３１は例えばフォトダイオードによって構成されている。 As the light emitting element 20, for example, an LED chip that emits infrared light can be used. In addition, the light receiving element 30 includes a light receiving unit 31 capable of detecting light on the upper surface thereof, and the light receiving unit 31 is configured by, for example, a photodiode.
　発光素子２０は、発光レンズ２１によって覆われている。発光レンズ２１は、発光素子２０の光出射側に半球状をなすように形成された凸レンズである。なお、本実施形態の近接センサ１００において、発光レンズ２１は必須の構成ではなく、発光素子２０は発光レンズ２１によって覆われていなくてもよい。 The light emitting element 20 is covered with a light emitting lens 21. The light emitting lens 21 is a convex lens formed so as to form a hemisphere on the light emitting side of the light emitting element 20. In the proximity sensor 100 of the present embodiment, the light emitting lens 21 is not an essential configuration, and the light emitting element 20 may not be covered with the light emitting lens 21.
　図２の（ｂ）および（ｃ）に示すように、受光素子３０は、封止樹脂３２によって覆われている。封止樹脂３２の上部には、受光レンズ３３（レンズ）が設けられている。受光レンズ３３は、発光素子２０と受光素子３０とが並ぶ方向にリニアなシリンドリカルレンズであり、光入射面（上面）から入射する光を受光素子３０の受光部３１上に集光する。 2 (b) and 2 (c), the light receiving element 30 is covered with a sealing resin 32. A light receiving lens 33 (lens) is provided above the sealing resin 32. The light receiving lens 33 is a cylindrical lens linear in the direction in which the light emitting element 20 and the light receiving element 30 are arranged, and condenses light incident from the light incident surface (upper surface) on the light receiving unit 31 of the light receiving element 30.
　図１および図２に示すように、基板１０上には、封止樹脂３２および基板１０の上面を覆う遮光性樹脂４０が設けられている。遮光性樹脂４０は、発光レンズ２１の上面および受光レンズ３３の上面が露出するように設けられている。 As shown in FIGS. 1 and 2, a sealing resin 32 and a light-shielding resin 40 that covers the upper surface of the substrate 10 are provided on the substrate 10. The light shielding resin 40 is provided so that the upper surface of the light emitting lens 21 and the upper surface of the light receiving lens 33 are exposed.
　図１に示すように、受光レンズ３３の上面である光入射面は、円柱形状である円柱外形部からなる。 As shown in FIG. 1, the light incident surface, which is the upper surface of the light receiving lens 33, is composed of a cylindrical outer portion that is a cylindrical shape.
　そして、図２の（ｂ）に示すように、受光レンズ３３を発光素子２０と受光素子３０とが並ぶ方向（Ｘ方向）に沿って切断したとき、受光レンズ３３の断面形状は長方形状であり、光入射面は直線形状となる。 As shown in FIG. 2B, when the light receiving lens 33 is cut along the direction in which the light emitting element 20 and the light receiving element 30 are aligned (X direction), the cross sectional shape of the light receiving lens 33 is rectangular. The light incident surface has a linear shape.
　また、図２の（ｃ）に示すように、受光レンズ３３を発光素子２０と受光素子３０とが並ぶ方向に垂直な方向（Ｙ方向）に切断したとき、受光レンズ３３の断面形状は半円形状である。 2C, when the light receiving lens 33 is cut in a direction (Y direction) perpendicular to the direction in which the light emitting element 20 and the light receiving element 30 are aligned, the cross-sectional shape of the light receiving lens 33 is a semicircle. Shape.
　そのため、図中ＹＺ平面上に光路を有する光は、受光レンズ３３によって受光部３１上に集光される。一方で、図中ＸＺ平面上に光路を有する光は、受光レンズ３３によって集光されない。 Therefore, light having an optical path on the YZ plane in the figure is condensed on the light receiving unit 31 by the light receiving lens 33. On the other hand, light having an optical path on the XZ plane in the drawing is not collected by the light receiving lens 33.
　すなわち、受光レンズ３３は、Ｘ方向に平行な焦線を有している。 That is, the light receiving lens 33 has a focal line parallel to the X direction.
　発光レンズ２１と、封止樹脂３２と、受光レンズ３３とは、少なくとも、発光素子２０の出射光を透過させる部材である。封止樹脂３２と受光レンズ３３とは一体の部材として形成されていてもよい。また、遮光性樹脂４０は、可視光および赤外光を遮光する部材である。 The light emitting lens 21, the sealing resin 32, and the light receiving lens 33 are members that transmit at least light emitted from the light emitting element 20. The sealing resin 32 and the light receiving lens 33 may be formed as an integral member. The light blocking resin 40 is a member that blocks visible light and infrared light.
　＜受光部＞
　以下、受光素子３０の受光量について説明する。 <Light receiver>
Hereinafter, the amount of light received by the light receiving element 30 will be described.
　図３は、受光素子の受光量を説明するための図であり、（ａ）は受光部の大きさと受光素子の受光量との関係を説明するための模式図であり、（ｂ）は（ａ）の一部の拡大図である。 3A and 3B are diagrams for explaining the amount of light received by the light receiving element. FIG. 3A is a schematic diagram for explaining the relationship between the size of the light receiving portion and the amount of light received by the light receiving element. FIG. It is a partial enlarged view of a).
　図３の（ａ）に示すように、発光素子２０と検知対象物との間の距離を物体距離ｄとし、発光素子２０と受光部３１の中心との間の距離を基線長ｋとし、Ｘ方向における受光部３１の幅を検出開口Ｄとする。 As shown in FIG. 3A, the distance between the light emitting element 20 and the detection target is the object distance d, the distance between the light emitting element 20 and the center of the light receiving unit 31 is the base line length k, and X The width of the light receiving portion 31 in the direction is defined as a detection opening D.
　また、受光素子３０と検知対象物とを結ぶ線分と、受光部３１の中心と検知対象物とを結ぶ線分とがなす角をθ１とし、受光素子３０と検知対象物とを結ぶ線分と、受光部３１の発光素子２０側の端部と検知対象物とを結ぶ線分とがなす角をθ２とし、θ１とθ２との差をθとすると、θは以下の式で表される。 The angle formed by the line connecting the light receiving element 30 and the detection target and the line connecting the center of the light receiving unit 31 and the detection target is θ 1, and the line connecting the light receiving element 30 and the detection target. min, when a line segment connecting the ends of the light emitting element 20 side of the light receiving portion 31 and the detection subject the contact angle of theta 2, the difference between the theta 1 and theta 2 and theta, theta is the following formula It is represented by
　θ＝θ１－θ２＝ａｔａｎ（ｋ／ｄ）－ａｔａｎ（（ｋ－Ｄ／２）／ｄ）　　　式（１）
　次に、検知対象物の位置を中点とし、任意の半径ｒを有する半球を考える。半球の表面積をｓ０とする。 θ = θ 1 −θ 2 = atan (k / d) −atan ((k−D / 2) / d) Equation (1)
Next, a hemisphere having an arbitrary radius r with the position of the detection object as a midpoint is considered. Let the surface area of the hemisphere be s 0 .
　図３の（ｂ）に示すように、受光部３１の中心と検知対象物とを結ぶ線分に垂直であって、受光部３１の発光素子２０側の端部と検知対象物とを結ぶ線分と、半球との交点を通る平面を平面Ｐとする。半球を平面Ｐで切断したときの球冠の表面積をｓとし、球冠の高さをｈとする。 As shown in FIG. 3B, a line that is perpendicular to the line connecting the center of the light receiving unit 31 and the detection target and connects the end of the light receiving unit 31 on the light emitting element 20 side and the detection target. A plane passing through the intersection of the minute and the hemisphere is defined as a plane P. The surface area of the spherical crown when the hemisphere is cut along the plane P is s, and the height of the spherical crown is h.
　検知対象物に反射された光（以下、検知対象物の反射光）の総光量をＩ０とし、Ｉ０のうち、受光部３１に入射する光の光量をＩ１とすると、受光部３１の受光効率Ｉは以下の式のように、半球の表面積ｓ０と球冠の表面積ｓとの比で表される。 Assuming that the total amount of light reflected by the detection object (hereinafter, the reflected light of the detection object) is I 0, and the light amount incident on the light receiving unit 31 out of I 0 is I 1 , The light receiving efficiency I is represented by the ratio of the hemispherical surface area s 0 and the spherical crown surface area s as shown in the following equation.
　Ｉ＝Ｉ１／Ｉ０＝ｓ／ｓ０　　　　　　　式（２）
　また、
　ｓ＝２πｒｈ
　ｓ０＝２πｒ２
　であるから、式（２）より、受光効率Ｉは以下の式のように、球冠の高さｈと球の半径ｒとの比で表される。 I = I 1 / I 0 = s / s 0 Formula (2)
Also,
s = 2πrh
s 0 = 2πr 2
Therefore, from the equation (2), the light receiving efficiency I is expressed by the ratio between the height h of the sphere crown and the radius r of the sphere as in the following equation.
　Ｉ＝ｈ／ｒ　　　　　　　式（３）
　また、
　ｈ＝ｒ－ｒｃｏｓθ
　であるから、式（３）より、
　Ｉ＝１－ｃｏｓθ　　　　式（４）
　となり、式（１）と式（４）とから、受光部３１の受光効率Ｉは以下の式で表される。 I = h / r Formula (3)
Also,
h = r−r cos θ
Therefore, from equation (3),
I = 1−cos θ Formula (4)
From the formulas (1) and (4), the light receiving efficiency I of the light receiving unit 31 is expressed by the following formula.
　Ｉ＝１－ｃｏｓ｛ａｔａｎ（ｋ／ｄ）－ａｔａｎ（（ｋ－Ｄ／２）／ｄ）｝　　式（５）
　図４は、受光効率と物体距離との関係を示すグラフである。グラフの横軸は物体距離ｄであり、縦軸は受光効率Ｉである。また、グラフは、基線長ｋが２．６５ｍｍであり、検出開口Ｄが０．９ｍｍのときの、受光効率Ｉと物体距離ｄとの関係を示す。 I = 1−cos {atan (k / d) −atan ((kD / 2) / d)} Equation (5)
FIG. 4 is a graph showing the relationship between the light receiving efficiency and the object distance. The horizontal axis of the graph is the object distance d, and the vertical axis is the light receiving efficiency I. The graph shows the relationship between the light receiving efficiency I and the object distance d when the base line length k is 2.65 mm and the detection aperture D is 0.9 mm.
　グラフに示すように、受光効率Ｉは小さく、検知対象物の反射光の総光量に対する受光素子の受光量の割合はごくわずかである。 As shown in the graph, the light receiving efficiency I is small, and the ratio of the light receiving amount of the light receiving element to the total light amount of the reflected light of the detection target is very small.
　式（５）からわかるように、検出開口Ｄが大きいほど、受光効率Ｉは高くなる。発光素子２０の出射光量に対して受光素子３０に多くの光量を受光させ、検知感度を向上させるためには、検出開口Ｄを大きくし、受光部３１の面積を大きくすることが好ましい。 As can be seen from Equation (5), the larger the detection aperture D, the higher the light receiving efficiency I. In order to make the light receiving element 30 receive a larger amount of light with respect to the emitted light amount of the light emitting element 20 and improve the detection sensitivity, it is preferable to increase the detection aperture D and increase the area of the light receiving portion 31.
　しかしながら、検出開口Ｄを大きくするためには、受光素子３０自体を大きくしなければならず、結果的にデバイスとしての近接センサ１００の大きさが大きくなってしまう。 However, in order to enlarge the detection aperture D, the light receiving element 30 itself must be enlarged, resulting in an increase in the size of the proximity sensor 100 as a device.
　そこで、受光部３１の面積を大きくすることなく受光素子３０の受光量を増大させ、検知感度を向上させるために、レンズを用いて、検知対象物の反射光を受光部３１に集光することが好ましい。 Therefore, in order to increase the amount of light received by the light receiving element 30 without increasing the area of the light receiving unit 31 and improve the detection sensitivity, the reflected light of the detection target is condensed on the light receiving unit 31 using a lens. Is preferred.
　本実施形態の近接センサ１００は、受光素子３０の上方に受光レンズ３３を備えており、受光レンズ３３の光入射面に入射した光は、受光部３１に集光される。 The proximity sensor 100 of the present embodiment includes a light receiving lens 33 above the light receiving element 30, and the light incident on the light incident surface of the light receiving lens 33 is condensed on the light receiving unit 31.
　そのため、検知対象物の反射光を効率的に受光部３１に入射させることができ、受光効率を向上させることができる。その結果、近接センサ１００を小型化しつつ、受光部３１に入射する光量を増大させることができ、検知対象物の反射光が微弱であっても検知感度を向上させることができる。 Therefore, the reflected light of the detection target can be efficiently incident on the light receiving unit 31, and the light receiving efficiency can be improved. As a result, it is possible to increase the amount of light incident on the light receiving unit 31 while reducing the size of the proximity sensor 100, and it is possible to improve the detection sensitivity even if the reflected light of the detection target is weak.
　＜クロストーク光の受光量＞
　以下、本実施形態の近接センサの受光部におけるクロストーク光の受光量を、比較例の近接センサの受光部におけるクロストーク光の受光量と対比して説明する。 <Amount of crosstalk light received>
Hereinafter, the amount of crosstalk light received by the light receiving unit of the proximity sensor of the present embodiment will be described in comparison with the amount of crosstalk light received by the light receiving unit of the proximity sensor of the comparative example.
　図１６に基づいて説明したように、近接センサ１００と検知対象物との間に筐体カバーを設けた場合、発光素子２０の出射光の一部は、筐体カバーによって反射されて受光素子３０の受光部３１に入射するクロストーク光となる。クロストーク光の光量は、検知対象物の反射光の光量よりも大きい。近接センサ１００の検知精度を向上させるためには、検知対象物の反射光の受光量を多くし、クロストーク光の受光量を小さくすることが好ましい。 As described based on FIG. 16, when a housing cover is provided between the proximity sensor 100 and the detection target, a part of the light emitted from the light emitting element 20 is reflected by the housing cover and received by the light receiving element 30. The crosstalk light is incident on the light receiving portion 31. The amount of crosstalk light is larger than the amount of reflected light of the detection target. In order to improve the detection accuracy of the proximity sensor 100, it is preferable to increase the amount of received reflected light of the detection target and decrease the amount of received crosstalk light.
　ここで、近接センサ１００と検知対象物との間に筐体カバーを設けた場合の、受光部３１におけるクロストーク光の受光量をシミュレーションした。 Here, the amount of crosstalk light received by the light receiving unit 31 when a housing cover is provided between the proximity sensor 100 and the detection target was simulated.
　＜比較例の近接センサの場合＞
　図５は、比較例としての従来の近接センサの斜視図である。図５に示す近接センサは、図１７に基づいて説明した従来の近接センサと同様の構造を有している。 <In the case of the proximity sensor of the comparative example>
FIG. 5 is a perspective view of a conventional proximity sensor as a comparative example. The proximity sensor shown in FIG. 5 has the same structure as the conventional proximity sensor described with reference to FIG.
　図５に示すように、従来の近接センサ３００は、本実施形態の近接センサと同様に、受光素子３３０は、封止樹脂によって覆われており、封止樹脂の上部には、受光レンズ３３３が設けられている。しかしながら、本実施形態の近接センサとは異なり、受光レンズ３３３は略半球形状の凸レンズである。 As shown in FIG. 5, in the conventional proximity sensor 300, the light receiving element 330 is covered with a sealing resin, and the light receiving lens 333 is placed on the top of the sealing resin, like the proximity sensor of the present embodiment. Is provided. However, unlike the proximity sensor of the present embodiment, the light receiving lens 333 is a substantially hemispherical convex lens.
　すなわち、受光レンズ３３３を発光素子３２０と受光素子３３０とが並ぶ方向（Ｘ方向）に切断したとき、受光レンズ３３３の断面の形状は半円形状であり、光入射面は曲線形状を有している。また、Ｘ方向に直交するＹ方向に切断したときも、受光レンズ３３３の断面の形状は半円形状であり、光入射面は曲線形状を有している。 That is, when the light receiving lens 333 is cut in the direction in which the light emitting element 320 and the light receiving element 330 are aligned (X direction), the shape of the cross section of the light receiving lens 333 is a semicircular shape, and the light incident surface has a curved shape. Yes. Also, when cut in the Y direction orthogonal to the X direction, the cross-sectional shape of the light receiving lens 333 is a semicircular shape, and the light incident surface has a curved shape.
　従来の近接センサ３００は、受光素子３３０の上方に略半球形状の凸レンズを備えているため、全ての方向から受光レンズ３３３の光入射面に入射する光は、受光レンズ３３３によって受光部３３１上に集光される。 Since the conventional proximity sensor 300 includes a substantially hemispherical convex lens above the light receiving element 330, light incident on the light incident surface of the light receiving lens 333 from all directions is incident on the light receiving unit 331 by the light receiving lens 333. Focused.
　図６は、クロストーク光の受光量のシミュレーションに用いた近接センサと筐体カバーと検知対象物との位置関係を示す斜視図である。 FIG. 6 is a perspective view showing the positional relationship among the proximity sensor, the housing cover, and the detection target used for the simulation of the amount of received crosstalk light.
　図６に示すように、近接センサ３００と検知対象物１との間に筐体カバー２を設け、受光レンズ３３３の頂部と筐体カバー２との間の距離ｇを４ｍｍとした。 As shown in FIG. 6, the housing cover 2 was provided between the proximity sensor 300 and the detection target 1, and the distance g between the top of the light receiving lens 333 and the housing cover 2 was 4 mm.
　また、筐体カバー２は、大きさが２５０ｍｍ×２００ｍｍ×０．７ｍｍであり、屈折率が１．５の板状部材を用いた。発光素子３２０は、配向特性Ｒが、Ｒ＝０．４５ｍｍ、Ｉ（θ）＝Ｉ０×ｃｏｓθ２０であり、出力が０．０１２５９Ｗ（ＬＥＤ出力０．０２Ｗに相当）の光源を用いた。 The case cover 2 is a plate member having a size of 250 mm × 200 mm × 0.7 mm and a refractive index of 1.5. For the light-emitting element 320, a light source having an alignment characteristic R of R = 0.45 mm, I (θ) = I 0 × cos θ 20 , and an output of 0.01259 W (corresponding to an LED output of 0.02 W) was used.
　受光素子３３０は、受光部３３１の幅（検出開口Ｄ）が０．４ｍｍのものを用いた。 As the light receiving element 330, a light receiving portion 331 having a width (detection opening D) of 0.4 mm was used.
　図７は、クロストーク光の光路を示す図である。図７に示すように、発光素子３２０の出射光は、受光レンズ３３３によって集光され、その一部が筐体カバー２の表面で反射されてクロストーク光として受光レンズ３３３を介して受光素子３３０に入射する。 FIG. 7 is a diagram showing an optical path of crosstalk light. As shown in FIG. 7, the light emitted from the light emitting element 320 is collected by the light receiving lens 333, and a part of the light is reflected on the surface of the housing cover 2 to be crosstalk light and passes through the light receiving lens 333. Is incident on.
　なお、図７に示すように、発光素子３２０の出射光は、筐体カバー２の下面において反射されるものと、筐体カバー２の上面において反射される光とを含んでおり、これらの反射光はともにクロストーク光となる。 As shown in FIG. 7, the light emitted from the light emitting element 320 includes light reflected on the lower surface of the housing cover 2 and light reflected on the upper surface of the housing cover 2. Both lights become crosstalk light.
　以下の説明では、ＸＺ平面において、Ｚ軸とクロストーク光の光路とがなす角度を、照射角度θｉとする。発光素子３２０と受光部３３１との間の距離である基線長ｋを固定した場合、照射角度θｉは、受光レンズ３３３の頂部と筐体カバー２との間の距離ｇや、Ｚ方向に対する筐体カバー２表面の角度に応じて変化する。 In the following description, an angle formed by the Z axis and the optical path of the crosstalk light in the XZ plane is referred to as an irradiation angle θ i . When the base line length k, which is the distance between the light emitting element 320 and the light receiving unit 331, is fixed, the irradiation angle θ i is equal to the distance g between the top of the light receiving lens 333 and the housing cover 2 or the housing in the Z direction. It changes according to the angle of the body cover 2 surface.
　図８は、照射角度θｉが０°のときのクロストーク光の光路を示す図であり、（ａ）は半球形状の受光レンズに入射したクロストーク光の光路を示し、（ｂ）は受光部におけるクロストーク光の光量の分布を示す。 8A and 8B are diagrams showing the optical path of the crosstalk light when the irradiation angle θ i is 0 °. FIG. 8A shows the optical path of the crosstalk light incident on the hemispherical light receiving lens, and FIG. The distribution of the amount of crosstalk light in the section is shown.
　図８の（ｂ）に示すように、照射角度θｉが０°のとき、ＸＹ平面上に配された受光部には、クロストーク光が均一に入射するため、受光部におけるクロストーク光の分布は一様となる。 As shown in FIG. 8B, when the irradiation angle θ i is 0 °, the crosstalk light is uniformly incident on the light receiving unit arranged on the XY plane. The distribution is uniform.
　図９は、照射角度θｉが１８°のときのクロストーク光の光路を示す図であり、（ａ）は受光レンズに入射したクロストーク光の光路を示し、（ｂ）は受光部におけるクロストーク光の光量の分布を示す。なお、図９は、基線長ｋが２．６５ｍｍであり、受光レンズ３３３の頂部と筐体カバー２との間の距離ｇが４ｍｍの場合のクロストーク光の光路を示す。 9A and 9B are diagrams showing the optical path of the crosstalk light when the irradiation angle θ i is 18 °, FIG. 9A shows the optical path of the crosstalk light incident on the light receiving lens, and FIG. 9B shows the cross path in the light receiving unit. The distribution of the amount of talk light is shown. FIG. 9 shows the optical path of crosstalk light when the base line length k is 2.65 mm and the distance g between the top of the light receiving lens 333 and the housing cover 2 is 4 mm.
　図９の（ａ）に示すように、従来の近接センサ３００の受光レンズ３３３の光入射面は球形形状であるため、照射角度が０°ではない場合、ＸＹ平面上に配された受光部３３１には、クロストーク光が不均一に入射するため、受光部３３１におけるクロストーク光の分布は一様とならない。 As shown in FIG. 9A, the light incident surface of the light receiving lens 333 of the conventional proximity sensor 300 has a spherical shape. Therefore, when the irradiation angle is not 0 °, the light receiving unit 331 disposed on the XY plane. Since the crosstalk light is incident unevenly, the distribution of the crosstalk light in the light receiving unit 331 is not uniform.
　具体的には、図９の（ｂ）中の受光部３３１の左側の領域ではクロストーク光の受光量が多く、受光部３３１の右側の領域ではクロストーク光の受光量が少ない。 Specifically, in the region on the left side of the light receiving unit 331 in FIG. 9B, the amount of received crosstalk light is large, and in the region on the right side of the light receiving unit 331, the amount of received crosstalk light is small.
　図１０は、照射角度θｉが１８°のときの、比較例の近接センサの受光部におけるクロストーク光の光量の分布を示す図である。 FIG. 10 is a diagram illustrating the distribution of the amount of crosstalk light in the light receiving unit of the proximity sensor of the comparative example when the irradiation angle θ i is 18 °.
　図１０では、受光部３３１において、クロストーク光の受光量が多い領域を濃い色で示し、クロストーク光の受光量が少ない領域を薄い色で示している。 In FIG. 10, in the light receiving unit 331, a region where the amount of received crosstalk light is large is indicated by a dark color, and a region where the amount of received crosstalk light is small is indicated by a light color.
　図１０からわかるように、受光部３３１の端部の領域に、クロストーク光の受光量が多い円弧状の領域が形成される。 As can be seen from FIG. 10, an arc-shaped region with a large amount of received crosstalk light is formed in the end region of the light receiving unit 331.
　図１１は、受光レンズの頂部と筐体カバーとの間の距離ｇを変化させることによって照射角度θｉを変化させたときの、比較例の近接センサの受光部におけるクロストーク光の受光量の分布の変化を示す図であり、（ａ）は距離ｇが２ｍｍのときの受光部におけるクロストーク光の受光量の分布の変化を示し、（ｂ）は距離ｇが３ｍｍのときの受光部におけるクロストーク光の受光量の分布の変化を示し、（ｃ）は距離ｇが４ｍｍのときの受光部におけるクロストーク光の受光量の分布の変化を示し、（ｄ）は距離ｇが５ｍｍのときの受光部におけるクロストーク光の受光量の分布の変化を示す。 FIG. 11 shows the amount of crosstalk light received by the light receiving unit of the proximity sensor of the comparative example when the irradiation angle θ i is changed by changing the distance g between the top of the light receiving lens and the housing cover. It is a figure which shows the change of distribution, (a) shows the change of distribution of the received amount of crosstalk light in a light-receiving part when the distance g is 2 mm, (b) in the light-receiving part when the distance g is 3 mm. The change in the distribution of the amount of received light of crosstalk light is shown. (C) shows the change in the distribution of the amount of received light of crosstalk light in the light receiving part when the distance g is 4 mm. 6 shows changes in the distribution of the amount of crosstalk light received by the light receiving section.
　図１１に示すように、照射角度θｉの変化に応じて、受光部３３１におけるクロストーク光の受光量が多い領域の位置および形状は変化する。 As shown in FIG. 11, the position and shape of the region where the amount of crosstalk light received by the light receiving unit 331 is large changes according to the change in the irradiation angle θ i .
　そのため、クロストーク光をバックグラウンドノイズとしてカットするためには、予めクロストーク光の受光量が多い領域を広めに想定して閾値を設ける必要がある。 For this reason, in order to cut the crosstalk light as background noise, it is necessary to set a threshold value in advance, assuming a wide area where the amount of received crosstalk light is large.
　このとき、クロストーク光の影響をより確実に除外するために、閾値を設定する領域が広くなり、受光量を測定するための有効な受光領域が小さくなる。 At this time, in order to more surely exclude the influence of the crosstalk light, the area for setting the threshold is widened, and the effective light receiving area for measuring the amount of received light is reduced.
　また、クロストーク光の影響を除外しない場合、検知光量のダイナミックレンジが大きくなるため、検知精度が低下してしまう。 Further, if the influence of crosstalk light is not excluded, the dynamic range of the detected light amount is increased, so that the detection accuracy is lowered.
　＜実施形態１の近接センサの場合＞
　図１２は、受光レンズの頂部と筐体カバーとの間の距離ｇを変化させることによって照射角度θｉを変化させたときの、本実施形態の近接センサの受光部におけるクロストーク光の受光量の分布の変化を示す図であり、（ａ）は距離ｇが４ｍｍのときの受光部におけるクロストーク光の受光量の分布の変化を示し、（ｂ）は距離ｇが２ｍｍのときの受光部におけるクロストーク光の受光量の分布の変化を示す。 <In the case of the proximity sensor of Embodiment 1>
FIG. 12 shows the amount of crosstalk light received by the light receiving unit of the proximity sensor according to the present embodiment when the irradiation angle θ i is changed by changing the distance g between the top of the light receiving lens and the housing cover. (A) shows the change in the distribution of the amount of received crosstalk light at the light receiving portion when the distance g is 4 mm, and (b) shows the light receiving portion when the distance g is 2 mm. Shows the change in the distribution of the amount of received crosstalk light.
　本実施形態の近接センサ１００は、受光レンズ３３をＸ方向に切断したときの断面形状において、光入射面は直線形状である。そのため、図１２に示すように、受光部３１においてクロストーク光の受光量が高くなる領域の発生を抑制することができ、また、照射角度θｉに依らず、受光部３１におけるクロストーク光の光量は均一となる。 In the proximity sensor 100 of the present embodiment, the light incident surface has a linear shape in a cross-sectional shape when the light receiving lens 33 is cut in the X direction. Therefore, as shown in FIG. 12, it is possible to suppress the occurrence of a region where the light reception amount of the crosstalk light is increased in the light receiving unit 31, and the crosstalk light in the light receiving unit 31 does not depend on the irradiation angle θ i . The amount of light is uniform.
　すなわち、受光レンズ３３と筐体カバー２との間の距離に依らず、受光部３１におけるクロストーク光の光量の分布は一様となる。そのため、筐体カバー２の配置に依らず、クロストーク光をバックグラウンドノイズとして一律にカットし、クロストーク光の影響を低減することができる。 That is, the distribution of the amount of crosstalk light in the light receiving unit 31 is uniform regardless of the distance between the light receiving lens 33 and the housing cover 2. Therefore, regardless of the arrangement of the housing cover 2, the crosstalk light can be uniformly cut as background noise, and the influence of the crosstalk light can be reduced.
　また、近接センサ２００は、電子機器に搭載される場合に、筐体カバー２の設置距離に広く対応することができる。 Further, the proximity sensor 200 can widely correspond to the installation distance of the housing cover 2 when mounted on an electronic device.
　〔実施形態２〕
　本発明の他の実施形態について、図１３～図１５に基づいて説明すれば、以下のとおりである。なお、説明の便宜上、前記実施形態にて説明した部材と同じ機能を有する部材については、同じ符号を付記し、その説明を省略する。 [Embodiment 2]
The following will describe another embodiment of the present invention with reference to FIGS. For convenience of explanation, members having the same functions as those described in the embodiment are given the same reference numerals, and descriptions thereof are omitted.
　図１３は、本実施形態の近接センサの斜視図である。図１４は、本実施形態の近接センサの概略図であり、（ａ）は平面図であり、（ｂ）は（ａ）のＡ－Ａ’断面図であり、（ｃ）は（ａ）のＢ－Ｂ’断面図である。 FIG. 13 is a perspective view of the proximity sensor of the present embodiment. 14A and 14B are schematic views of the proximity sensor of the present embodiment, in which FIG. 14A is a plan view, FIG. 14B is a cross-sectional view taken along line AA ′ in FIG. 14A, and FIG. It is BB 'sectional drawing.
　図１３および図１４に示すように、近接センサ２００は、実施形態１の近接センサ１００の受光レンズ３３に代えて、受光レンズ２３３を備えている。 As shown in FIG. 13 and FIG. 14, the proximity sensor 200 includes a light receiving lens 233 instead of the light receiving lens 33 of the proximity sensor 100 of the first embodiment.
　図１４の（ｂ）に示すように、受光レンズ２３３をＸ方向に切断したときの断面形状において、光入射面は、直線形状となる円柱外形部２３３ａと、曲線形状となる球形外形部２３３ｂとを有している。球形外形部２３３ｂは、円柱外形部２３３ａよりも発光素子２０側に配されている。 As shown in FIG. 14 (b), in the cross-sectional shape when the light receiving lens 233 is cut in the X direction, the light incident surface has a cylindrical outer portion 233a having a linear shape, and a spherical outer portion 233b having a curved shape. have. The spherical outer portion 233b is disposed closer to the light emitting element 20 than the cylindrical outer portion 233a.
　このように、本実施形態の近接センサ２００の受光レンズ２３３は、シリンドリカルレンズと半球の凸レンズを接合させた構造を有している。 As described above, the light receiving lens 233 of the proximity sensor 200 of the present embodiment has a structure in which a cylindrical lens and a hemispherical convex lens are joined.
　そのため、図中ＹＺ平面上に光路を有する光は、受光レンズ２３３によって受光部３１上に集光される。また、図中ＸＺ平面上に光路を有する光であって、円柱外形部２３３ａに入射した光は、受光レンズ２３３によって集光されない。一方で、図中ＸＺ平面上に光路を有する光であって、球形外形部２３３ｂに入射した光は、受光レンズ２３３によって集光される。 Therefore, light having an optical path on the YZ plane in the drawing is condensed on the light receiving unit 31 by the light receiving lens 233. In addition, light having an optical path on the XZ plane in the drawing and incident on the cylindrical outer portion 233 a is not collected by the light receiving lens 233. On the other hand, light having an optical path on the XZ plane in the drawing and incident on the spherical outer portion 233b is collected by the light receiving lens 233.
　本実施形態の近接センサ２００は、受光レンズ２３３に球形外形部２３３ｂを備えているため、実施形態１の近接センサ１００に比べて受光効率が高く、検知感度が高い。 Since the proximity sensor 200 of the present embodiment includes the spherical outer portion 233b in the light receiving lens 233, the light receiving efficiency is higher and the detection sensitivity is higher than the proximity sensor 100 of the first embodiment.
　なお、受光レンズ２３３の光入射面が球形外形部２３３ｂを含んでいるため、受光部３１に集光されるクロストーク光の光量は不均一となる。しかしながら、球形外形部２３３ｂは円柱外形部２３３ａよりも発光素子側に配されているため、球形外形部２３３ｂに入射する光の光路と、入射位置における接面とがなす角度は、比較的大きな角度となる。そのため、球形外形部２３３ｂに入射する光がレンズによって屈折されても、受光素子上に集光されるクロストーク光の光量を過度に不均一にすることがない。 In addition, since the light incident surface of the light receiving lens 233 includes the spherical outer shape portion 233b, the amount of crosstalk light collected on the light receiving portion 31 is not uniform. However, since the spherical outer portion 233b is disposed closer to the light emitting element than the cylindrical outer portion 233a, the angle formed by the optical path of light incident on the spherical outer portion 233b and the contact surface at the incident position is a relatively large angle. It becomes. Therefore, even if the light incident on the spherical outer portion 233b is refracted by the lens, the amount of crosstalk light collected on the light receiving element is not excessively nonuniform.
　図１５は、受光レンズの頂部と筐体カバーとの間の距離ｇが４ｍｍのときの、本実施形態の近接センサの受光部におけるクロストーク光の光量の分布を示す図である。 FIG. 15 is a diagram showing the distribution of the amount of crosstalk light in the light receiving unit of the proximity sensor of the present embodiment when the distance g between the top of the light receiving lens and the housing cover is 4 mm.
　図１５に示すように、近接センサ２００は、従来の近接センサに比べて、受光部３１におけるクロストーク光の光量は均一であり、受光部３１におけるクロストーク光の光量の分布は一様となる。また、受光部３１において、クロストーク光の受光量が高い領域は表れない。 As shown in FIG. 15, the proximity sensor 200 has a uniform amount of crosstalk light in the light receiving unit 31 and a uniform distribution of the amount of crosstalk light in the light receiving unit 31 compared to the conventional proximity sensor. . Further, in the light receiving unit 31, a region where the amount of received crosstalk light is high does not appear.
　〔まとめ〕
　本発明の態様１に係る近接センサは、発光素子（２０）と、上記発光素子の出射光のうち、検知対象物（１）に反射された光である反射光を受光する受光素子（３０）と、を備えている近接センサ（１００）であって、上記発光素子と上記受光素子とは、第１の方向（Ｘ方向）に沿って配されており、光入射面を有し、上記光入射面から入射した光を上記受光素子上に集光するためのレンズを備えており、上記光入射面は、上記レンズを上記第１の方向に沿って切断したときの断面形状において、直線形状となる円柱外形部（２３３ａ）を含んでいることを特徴とする。 [Summary]
A proximity sensor according to aspect 1 of the present invention includes a light emitting element (20) and a light receiving element (30) that receives reflected light that is reflected by the detection object (1) among the light emitted from the light emitting element. The light emitting element and the light receiving element are arranged along a first direction (X direction), have a light incident surface, and the light sensor and the light receiving element. A lens for condensing light incident from the incident surface on the light receiving element is provided, and the light incident surface has a linear shape in a cross-sectional shape when the lens is cut along the first direction. It is characterized by including a cylindrical outer shape portion (233a).
　上記の構成によれば、反射光を受光素子上に集光させることができるため、受光素子の受光効率を上げ、受光素子への入射光量を増加させることができる。これにより、検知感度を向上させることができる。 According to the above configuration, since the reflected light can be condensed on the light receiving element, the light receiving efficiency of the light receiving element can be increased, and the amount of incident light on the light receiving element can be increased. Thereby, detection sensitivity can be improved.
　受光素子の上方に半球形状のレンズを設けた従来の近接センサでは、レンズを第１の方向に沿って切断したときの断面の形状が半円形状である。そのため、当該断面において、レンズの光入射面への入射角度に応じて、受光素子上に集光されるクロストーク光の光量は不均一となる。 In a conventional proximity sensor in which a hemispherical lens is provided above the light receiving element, the cross-sectional shape when the lens is cut along the first direction is a semicircular shape. Therefore, in the cross section, the amount of crosstalk light collected on the light receiving element is non-uniform according to the incident angle of the lens to the light incident surface.
　さらに、近接センサの上方に筐体カバーを設けた場合、クロストーク光のレンズへの入射角度は、レンズと筐体カバーとの間の距離に応じて異なるため、受光素子上に集光されるクロストーク光の光量の分布は、レンズに対する筐体カバーの位置に応じて異なる。この場合、受光量に一定の閾値を設けてクロストーク光をバックグラウンドノイズとして一律にカットすることが困難となる。 Further, when the housing cover is provided above the proximity sensor, the incident angle of the crosstalk light to the lens varies depending on the distance between the lens and the housing cover, and thus is condensed on the light receiving element. The distribution of the amount of crosstalk light varies depending on the position of the housing cover with respect to the lens. In this case, it is difficult to uniformly cut the crosstalk light as background noise by providing a certain threshold for the amount of received light.
　これに対して、上記の構成によれば、レンズは円柱外形部を備えているため、上記断面において、レンズの光入射面上の入射角度に依らず、受光素子上に集光されるクロストーク光の光量は均一となる。さらに、レンズと筐体カバーとの間の距離に依らず、円柱外形部に入射し、受光素子上に集光されるクロストーク光の光量の分布を一様にすることができる。 On the other hand, according to the above configuration, since the lens includes the cylindrical outer portion, the crosstalk that is condensed on the light receiving element in the cross section regardless of the incident angle on the light incident surface of the lens. The amount of light is uniform. Furthermore, it is possible to make the distribution of the amount of crosstalk light incident on the cylindrical outer portion and condensed on the light receiving element uniform regardless of the distance between the lens and the housing cover.
　これにより、クロストーク光をバックグラウンドノイズとして一律にカットし、クロストーク光の影響を低減することができる。 This makes it possible to cut the crosstalk light uniformly as background noise and reduce the influence of the crosstalk light.
　本発明の態様２に係る近接センサは、上記態様１において、上記光入射面は、上記レンズを上記第１の方向に沿って切断したときの断面形状において、曲線形状となる球形外形部（２３３ｂ）を含んでおり、上記球形外形部は、上記円柱外形部よりも上記発光素子側に配されており、上記レンズは、上記球形外形部に入射した光を上記受光素子上に集光してもよい。 The proximity sensor according to aspect 2 of the present invention is the proximity sensor according to aspect 1, wherein the light incident surface has a spherical outer shape portion (233b) having a curved shape in a cross-sectional shape when the lens is cut along the first direction. The spherical outer portion is disposed closer to the light emitting element than the cylindrical outer portion, and the lens collects light incident on the spherical outer portion on the light receiving element. Also good.
　上記の構成により、さらに受光素子の受光効率を上げ、受光素子への入射光量を増加させることができる。これにより、検知感度をさらに向上させることができる。 With the above configuration, the light receiving efficiency of the light receiving element can be further increased, and the amount of light incident on the light receiving element can be increased. Thereby, detection sensitivity can be further improved.
　レンズの光入射面が球形外形部を含んでいる場合、レンズを第１の方向に沿って切断したときの断面において、クロストーク光の球形外形部への入射方向と、レンズ軸とがなす角度は、レンズと筐体カバーとの間の距離に応じて異なるため、受光素子上に集光されるクロストーク光の光量は不均一となる。 When the light incident surface of the lens includes a spherical outer portion, an angle formed by the incident direction of the crosstalk light into the spherical outer portion and the lens axis in a cross section when the lens is cut along the first direction. Is different depending on the distance between the lens and the housing cover, the amount of crosstalk light collected on the light receiving element is non-uniform.
　しかしながら、球形外形部は円柱外形部よりも発光素子側に配されているため、球形外形部に入射する光の光路と、入射位置における接面とがなす角度は、比較的大きな角度となる。そのため、球形外形部に入射する光がレンズによって屈折されることによって、受光素子上に集光されるクロストーク光の光量を過度に不均一にすることがない。 However, since the spherical outer portion is arranged closer to the light emitting element than the cylindrical outer portion, the angle formed by the optical path of light incident on the spherical outer portion and the contact surface at the incident position is a relatively large angle. Therefore, the light incident on the spherical outer portion is refracted by the lens, so that the amount of crosstalk light collected on the light receiving element is not excessively nonuniform.
　本発明の態様３に係る近接センサは、上記態様１において、上記レンズはシリンドリカルレンズであり、上記シリンドリカルレンズの焦線が延びる方向は、上記第１の方向に平行であってもよい。 In the proximity sensor according to aspect 3 of the present invention, in the aspect 1, the lens may be a cylindrical lens, and a direction in which a focal line of the cylindrical lens extends may be parallel to the first direction.
　本発明は上述した各実施形態に限定されるものではなく、請求項に示した範囲で種々の変更が可能であり、異なる実施形態にそれぞれ開示された技術的手段を適宜組み合わせて得られる実施形態についても本発明の技術的範囲に含まれる。さらに、各実施形態にそれぞれ開示された技術的手段を組み合わせることにより、新しい技術的特徴を形成することができる。 The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention. Furthermore, a new technical feature can be formed by combining the technical means disclosed in each embodiment.
　本発明は、照度センサ、ＲＧＢカラーセンサ、近接センサなどの光センサや、反射型の光センサを搭載したスマートフォン、デジタルカメラ、カーナビゲーションシステムなどの様々な電子機器に利用することができる。 The present invention can be used in various electronic devices such as a light sensor such as an illuminance sensor, an RGB color sensor, and a proximity sensor, a smartphone equipped with a reflective light sensor, a digital camera, and a car navigation system.
　１　　　　　　　検知対象物
　２０　　　　　　発光素子
　３０　　　　　　受光素子
　３３、２３３　　受光レンズ（レンズ）
　１００、２００　近接センサ
　２３３ａ　　　　円柱外形部
　２３３ｂ　　　　球形外形部 DESCRIPTION OF SYMBOLS 1 Detection target 20 Light emitting element 30 Light receiving element 33,233 Light receiving lens (lens)
100, 200 Proximity sensor 233a Cylinder outer portion 233b Spherical outer portion

Claims (3)

  1. 　発光素子と、
    　上記発光素子の出射光のうち、検知対象物に反射された光である反射光を受光する受光素子と、を備えている近接センサであって、
    　上記発光素子と上記受光素子とは、第１の方向に沿って配されており、
    　光入射面を有し、上記光入射面から入射した光を上記受光素子上に集光するためのレンズを備えており、
    　上記光入射面は、上記レンズを上記第１の方向に沿って切断したときの断面形状において、直線形状となる円柱外形部を含んでいることを特徴とする近接センサ。     A light emitting element;
    A proximity sensor comprising: a light receiving element that receives reflected light that is light reflected by an object to be detected out of the light emitted from the light emitting element;
    The light emitting element and the light receiving element are arranged along a first direction,
    A light incident surface, and a lens for condensing the light incident from the light incident surface on the light receiving element;
    The proximity sensor according to claim 1, wherein the light incident surface includes a cylindrical outer shape having a linear shape in a cross-sectional shape when the lens is cut along the first direction.
  2. 　上記光入射面は、上記レンズを上記第１の方向に沿って切断したときの断面形状において、曲線形状となる球形外形部を含んでおり、
    　上記球形外形部は、上記円柱外形部よりも上記発光素子側に配されており、
    　上記レンズは、上記球形外形部に入射した光を上記受光素子上に集光することを特徴とする請求項１に記載の近接センサ。     The light incident surface includes a spherical outer shape having a curved shape in a cross-sectional shape when the lens is cut along the first direction,
    The spherical outer shape portion is disposed closer to the light emitting element than the cylindrical outer shape portion,
    The proximity sensor according to claim 1, wherein the lens condenses the light incident on the spherical outer shape onto the light receiving element.
  3. 　上記レンズはシリンドリカルレンズであり、
    　上記シリンドリカルレンズの焦線が延びる方向は、上記第１の方向に平行であることを特徴とする請求項１に記載の近接センサ。     The lens is a cylindrical lens,
    2. The proximity sensor according to claim 1, wherein a direction in which a focal line of the cylindrical lens extends is parallel to the first direction.
PCT/JP2014/065632 2013-08-20 2014-06-12 Proximity sensor WO2015025593A1 (en)

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2018147222A1 (en) * 2017-02-10 2018-08-16 ローム株式会社 Semiconductor device
WO2020204580A1 (en) * 2019-04-04 2020-10-08 Samsung Electronics Co., Ltd. Cross-talk prevention structure of electronic device for measuring distance to external object
KR20240018411A (en) 2021-06-09 2024-02-13 세키스이가가쿠 고교가부시키가이샤 Curable composition for inkjet and partition forming, light emitting device and method for producing light emitting device

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH02114414A (en) * 1988-10-24 1990-04-26 Yamatake Honeywell Co Ltd Lens unit for reflex type photoelectric switch
JPH03269389A (en) * 1990-03-20 1991-11-29 Mutoh Ind Ltd Reflection type sensor
JPH0660043U (en) * 1993-01-28 1994-08-19 横河電機株式会社 Reflective photoelectric switch

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH02114414A (en) * 1988-10-24 1990-04-26 Yamatake Honeywell Co Ltd Lens unit for reflex type photoelectric switch
JPH03269389A (en) * 1990-03-20 1991-11-29 Mutoh Ind Ltd Reflection type sensor
JPH0660043U (en) * 1993-01-28 1994-08-19 横河電機株式会社 Reflective photoelectric switch

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2018147222A1 (en) * 2017-02-10 2018-08-16 ローム株式会社 Semiconductor device
WO2020204580A1 (en) * 2019-04-04 2020-10-08 Samsung Electronics Co., Ltd. Cross-talk prevention structure of electronic device for measuring distance to external object
US11852752B2 (en) 2019-04-04 2023-12-26 Samsung Electronics Co., Ltd. Cross-talk prevention structure of electronic device for measuring distance to external object
KR20240018411A (en) 2021-06-09 2024-02-13 세키스이가가쿠 고교가부시키가이샤 Curable composition for inkjet and partition forming, light emitting device and method for producing light emitting device

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