JP2009218243A - Optical lens, and illuminator and photodetector using the optical lens - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical lens which is constituted compactly and optionally changes the size of an annular irradiation pattern or photodetection pattern, and to provide an illuminator and a photodetector using the optical lens. <P>SOLUTION: The optical lens 12 has a convex lens portion 12a as a body of rotation, which is made of a transparent material, disposed around a center axis O, formed in a cross section passing through the center axis and on an inclined axis A extending at a predetermined angle θ from a focus position F on one side of the center axis at a predetermined distance, and rotated around the center axis and defined. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an irradiation or light receiving optical lens used in a lighting fixture, a light receiving sensor, or the like, and an illumination device and a light receiving device using the optical lens.

  Conventionally, for example, a lighting fixture using an LED as a light source is configured as shown in Patent Document 1 or Patent Document 2, for example.

Patent Document 1 discloses an LED in which a plurality of LEDs are arranged in a ring shape, and diffused light from each LED is collected in a specific direction by a ring-shaped cylindrical lens unit arranged along the ring-shaped illumination unit. An illumination device is disclosed.
According to the LED illumination device having such a configuration, light emitted from each LED is collected by the cylindrical lens unit. Thereby, a ring-shaped irradiation pattern is irradiated.

Further, in Patent Document 2, parallel light from a light source is incident on one end face inclined at a predetermined angle of the optical fiber, and after so-called skew reflection is repeated in the optical fiber, a predetermined angle from the other end face of the optical fiber is obtained. A ring illumination device is disclosed in which light is emitted as annular light having a divergence angle and the annular light is reflected by a spheroid mirror. Thereby, the final irradiation angle is controlled to irradiate the ring beam.
JP 2006-210025 A Japanese Patent Laid-Open No. 11-052286

  By the way, in the LED lighting device according to Patent Document 1, in order to form a ring-shaped irradiation pattern, it is necessary to arrange a large number of LEDs in a ring shape. For this reason, the number of parts increases and the cost increases. Moreover, when it is desired to change the size (diameter) of the irradiation pattern, it is necessary to change the arrangement of the LEDs and also change the size of the cylindrical lens portion.

Moreover, in the ring illumination apparatus by patent document 2, the light source which radiate | emits parallel light is required, and the light source to be used will be restrict | limited.
On the other hand, when a light source that emits non-parallel light is used, an optical system that converts light from the light source into parallel light is separately required. Therefore, the number of parts increases and the cost increases. Furthermore, a space for arranging the optical system is required, and the depth of the entire apparatus becomes long.

Such a problem is the same not only when an LED is used as a light source but also when another light emitting element is used.
Also, not only lighting fixtures, but also displays and illuminations that emit light from the light-emitting unit to the outside via an optical lens, and irradiation by area sensors that collect light from the outside with an optical lens and detect it by a light-receiving sensor Alternatively, the light receiving optical lens has the same problem with respect to directivity.

  In view of the above, the present invention provides an optical lens that can be configured in a small size and can arbitrarily change the size of an annular irradiation pattern or light receiving pattern, and an illumination device using the optical lens, and An object of the present invention is to provide a light receiving device.

  According to the first configuration of the present invention, the above-mentioned object is made of a transparent material, arranged in a ring around the central axis, and in a cross section passing through the central axis, a focal position that is located away from one side of the central axis This is achieved by an optical lens characterized in that it has a convex lens portion as a rotating body that is formed on an inclined axis extending at a predetermined angle from and is rotated around the central axis.

  In the optical lens according to the present invention, preferably, the convex lens portion is disposed for each of tilt axes having a predetermined angle different from the focal position.

  In the optical lens according to the present invention, preferably, the convex lens portion is formed as an annular Fresnel lens.

  In the optical lens according to the present invention, preferably, the convex lens portion is surrounded by a light shielding member on one side.

Further, according to the second configuration of the present invention, the above object is achieved by an illuminating device including the above-described optical lens and a light source disposed at a focal position of the optical lens. The
The illumination device according to the present invention is preferably configured to include a light shielding member having an appropriate opening between the optical lens and the light source.

  Further, according to the third configuration of the present invention, the above object is achieved by a light receiving device including the above-described optical lens and a light receiving element disposed at a focal position of the optical lens. Is done.

  According to the above configuration, for example, when a light source is arranged at the focal position, an illumination device is configured, and light emitted from the focal position is inclined in a plane extending in the radial direction through the central axis. Proceeding along the axis, the light enters the convex lens unit, becomes parallel light based on the optical characteristics of the lens unit, and exits from the lens unit along the optical axis direction. Accordingly, an annular irradiation pattern is formed at the irradiation position arranged on the side opposite to the focal position from the central axis.

In this case, the light emitted from the convex lens portion is parallel light in a plane passing through the central axis, and an annular irradiation pattern is formed regardless of the distance to the irradiation position.
The light emitted from the convex lens part is emitted as substantially parallel light along an inclined axis inclined by a predetermined angle with respect to the central axis in a plane passing through the central axis. For this reason, the size (diameter) of the annular irradiation pattern changes in proportion to the distance to the irradiation position. Thereby, the irradiation pattern of a desired magnitude | size is obtained by selecting the distance to an irradiation position suitably.

  Further, a light source or a light receiving element can be arranged at the focal position of the optical lens to define an annular irradiation pattern or light receiving pattern. For this reason, it is not necessary to arrange | position a light source and a light receiving element cyclically | annularly corresponding to an irradiation pattern like before. Accordingly, the number of parts can be reduced, the assembly can be easily performed, and the part cost and the assembly cost can be reduced.

In this case, it is not necessary to form an annular irradiation pattern via the optical lens with the light source arranged at the focal position, and to arrange a large number of light sources in an annular shape. Therefore, the configuration is simplified and the cost can be reduced.
In addition, the irradiation angle of light from the light source is controlled by the condensing action of the lens unit, and an annular irradiation pattern is formed. Therefore, the light source may not be a conventional light source that emits parallel light, and any light source may be used.

  On the other hand, when the light receiving element is arranged at the focal position, a light receiving device is configured, and the position or direction corresponding to the annular irradiation pattern in the case where the illumination device is configured with the light source described above, that is, the light receiving. Parallel light incident on the convex lens portion from the pattern is collected based on the optical characteristics of the lens portion and travels toward the focal position. Thereby, the light receiving element disposed at the focal position can receive and detect the light from the light receiving pattern.

  In the case where the convex lens portions are arranged for each of tilt axes having different predetermined angles with respect to the focal position, the above-described irradiation pattern or light receiving pattern is defined in a plurality of concentric shapes. become.

  When the convex lens portion is formed as an annular Fresnel lens, the convex lens portion can be formed thin with respect to the direction of the tilt axis and the central axis. Therefore, the entire optical lens, the illumination device, and the light receiving device can be configured to be thin, or a lens portion having a larger diameter can be configured if they are the same size.

  When the convex lens portion is surrounded by a light-shielding member on one side, light incident on a portion of the lens portion that does not bear the lens function is reduced, so-called miscellaneous in a direction different from the lens optical system. Light can be reduced. Furthermore, when the slit is defined at a position close to the light source to limit the light source light incident on the optical lens 12 other than the convex lens 12a or the planar portion 12b of the convex lens, the above-described configuration is used. The edge of the irradiation pattern or light receiving pattern is sharply defined. Therefore, the illumination part and the non-illumination part in the illumination device are clearly separated, or the detection area and the non-detection area in the light receiving device can be reliably distinguished.

  Thus, according to the present invention, an optical lens that can be configured in a small size and can arbitrarily change the size of an annular irradiation pattern or light receiving pattern, and an illumination device using the optical lens And a light receiving device can be provided.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to FIGS.
The embodiments described below are preferable specific examples of the present invention, and thus various technically preferable limitations are given. However, the scope of the present invention is particularly limited in the following description. As long as there is no description of the effect, it is not restricted to these aspects.

[Example 1]
1 and 2 show a configuration of a first embodiment of a lighting device using an optical lens according to the present invention.
1 and 2, the lighting device 10 includes a light source 11, an optical lens 12, a mount 13, and an LED substrate 14.

The light source 11 is composed of, for example, an LED, and is mounted on an LED substrate 14 (described later) in the illustrated case.
Here, as the light source 11, it is desirable to use not only an LED but also a small light source such as HID (High Intensity Discharge), LD (Laser Diode). In the case where an LD is used as the light source 11, it is necessary to diffuse the emitted light using, for example, a diffusion filter.

As shown in FIG. 3, the optical lens 12 is made of a transparent material such as plastic, glass, or quartz.
That is, in FIG. 3, the optical lens 12 is annularly arranged around the central axis O, and one side (lower side) of the central axis O in a cross section passing through the central axis O shown in FIG. Is formed on a tilt axis A extending at a predetermined angle θ from a focal position F located at, and is formed as a convex lens portion 12a as a rotating body defined by rotating around the central axis O.
Therefore, the optical lens 12 is rotationally symmetric with respect to the central axis O, and has a shape shown in FIG.

In the illustrated case, the lens portion 12a is formed as a plano-convex lens when viewed from the focal position F side, and the plane 12b on the focal position F side is formed perpendicular to the tilt axis A. The convex lens surface 12c on the opposite side is formed as a spherical surface centered on a point on the tilt axis A.
At this time, the plane 12b is disposed on the tilt axis A at a predetermined distance d from the focal position F.
Further, the radius of curvature of the lens surface 12c is selected so as to have a focal point at the focal position F.
In addition, although the said lens part 12a is formed as a plano-convex lens, it is not restricted to this, You may form as convex lenses of arbitrary shapes, such as a biconvex lens and an aspherical condenser lens.

Further, as shown in FIGS. 3A, 3C, and 3D, the optical lens 12 includes a hollow cylindrical portion 12d that extends downward from the peripheral edge on the focal position F side.
A male screw portion 12e is formed on the outer peripheral surface of the hollow cylindrical portion 12d.

The mount 13 is made of an opaque material such as plastic or metal, and is formed in a hollow cylindrical shape having an open top as shown in FIG.
A female screw portion 13c is formed on the inner wall surface 13b of the hollow portion 13a of the mount 13, and 12e of the optical lens 12 described above can be screwed into the female screw portion 13c.

Further, the mount 13 is configured such that the LED substrate 14 is attached on the bottom surface 13e of the hollow portion 13a as shown by a chain line in FIGS. 4B and 4D.
Here, the bottom surface 13e of the hollow portion 13a is formed with a recessed portion 13f and a through hole 13g for allowing the connection terminal and the lead wire (not shown) of the LED substrate 14 to pass therethrough.
Moreover, four screw holes 13h for attaching the LED substrate 14 are provided on the bottom surface 13e of the hollow portion 13a.

  The mount 13 includes a plurality of fin-like heat sinks 13i extending downward from the lower surface thereof. Thereby, the heat generated in the LED substrate 14 is transmitted from the bottom surface 13e of the hollow portion 13a of the mount 13 to the heat sink 13i and can be radiated to the outside.

The LED board 14 is composed of a printed board, and is formed in a substantially square shape as shown in FIG.
The LED board 14 includes mounting holes 14a at the four corners. As a result, a fixing screw (not shown) inserted through the mounting hole 14a is screwed into a screw hole 13h provided in the bottom surface 13e of the hollow portion 13a of the mount 13, whereby the LED substrate 14 is The mount 13 is fixed and held in close contact with the bottom surface of the hollow portion 13a.

Further, the LED board 14 includes three sets of electronic component mounting lands 14b at the center of the surface thereof, and the light source 11, a limiting resistor, and the like are mounted between each set of electronic component mounting lands 14b. It has become.
In this embodiment, a light source LED is mounted on the electronic component mounting land in the center, and a chip resistor is mounted as a limiting resistor on the other electronic component mounting lands.
Here, the LED chip mounting land 14b is connected to the electrode portion 14c through a conductive pattern not shown in detail, and a drive voltage is applied from the corresponding electrode portion 14c, whereby each light source 11 Can be lit.
A lead wire (not shown) connected to the electrode portion 14c is drawn downward from the recessed portion 13f and the through hole 13g of the mount 13, drawn out from between the heat sink 13i, and supplied to an external power source. Connected.

The illuminating device 10 according to the embodiment of the present invention is configured as described above. The illuminating device 10 is attached to a ceiling of a room or the like, for example, as shown in FIG. Can be used as ceiling light or pendant light.
Each light source 11 emits light when a driving voltage is applied to each light source 11 from the external power source via the electrode portion 14c of the LED substrate 14.

The light L emitted from each light source 11 enters the optical lens 12 from the inside of the hollow portion 13a of the mount 13, and the direction of the tilt axis A in a cross section passing through the central axis O based on the optical characteristics of the lens portion 12a. , That is, the light is condensed so as to spread outward by an angle θ toward the lower side with respect to the central axis O, becomes substantially parallel light, and is irradiated in the direction of the inclined axis A.
The irradiation light L reaches a floor surface or the like located at a predetermined distance D below the central axis O, and forms an annular irradiation pattern P.

  In this case, the light traveling along the direction of the tilt axis A is substantially parallel light. For this reason, by appropriately selecting the distance D to the irradiation position, an irradiation pattern P having a desired diameter r (= D × tan θ) can be formed, and an irradiation pattern P having an arbitrary size can be easily formed. It is possible to respond.

Next, the simulation results when θ = 39 degrees in the above-described illumination device 10 will be described.
FIG. 7 shows the irradiation intensity distribution with respect to the irradiation angle emitted from the illumination device 10.
In FIG. 7, it can be seen that the maximum irradiation intensity can be obtained in the direction of the angle θ (= 39 degrees) with respect to the central axis O with respect to two directions perpendicular to the central axis O and perpendicular to each other.

On the other hand, FIG. 8 shows the irradiation intensity distribution on the screen when the screen is arranged at a predetermined distance d (= 247 mm) below the illumination device 10.
In FIG. 8, similarly, the maximum irradiation intensity can be obtained at a position corresponding to the direction of the angle θ (= 39 degrees) with respect to the central axis O, that is, at a position r (= 247 mm × tan 39 degrees) from the central axis O. I understand. Thereby, the annular irradiation pattern P is formed at the position of the radius r.
A small peak of the irradiation intensity distribution also appears on the central axis O. This is due to the light that has passed through the center of the lens portion 12a of the optical lens 12.

In the above-described simulation, the case where the tilt angle θ is 39 degrees has been described. However, the present invention is not limited to this, and the solid angle with respect to the focal position F can be covered by the optical lens 12 as θ increases. For this reason, when the light source is arranged at the focal position F, for example, the light use efficiency from the light source can be increased.
For example, when θ = 39 degrees, the light utilization efficiency from the light source is 80%, and when θ = 45 degrees, the light utilization efficiency is 92%.

[Example 2]
FIG. 9 shows a configuration of an optical lens used in the second embodiment of the illumination device according to the present invention.
In FIG. 9, in the lighting device 20, the optical lens 21 has a plurality of (four in the illustrated example) concentrically arranged convex shapes as compared to the optical lens 12 in the lighting device 10 shown in FIG. 1. The lens portions 21a, 21b, 21c, and 21d are different in structure.

Here, the lens portions 21a, 21b, 21c, and 21d are arranged apart from each other by a predetermined angular interval θ ′ from the focal position F in a cross section passing through the central axis O, and are continuously formed in the radial direction. Yes.
That is, the lens portion 21a closest to the central axis O is formed on an inclined axis A1 that is inclined from the focal position F by the angle θ ′ / 2 with respect to the central axis O, and rotates around the central axis O to rotate the image. It is the convex-shaped lens part as a formed rotary body.
The lens portion 21b is formed on an inclination axis A2 that is adjacent to the outside of the lens portion 21a and is inclined from the focal position F by the angle θ ′ + (θ ′ / 2) with respect to the central axis O. It is a convex lens part as a rotating body defined by rotating around a central axis O.

Similarly, the lens portion 21c is formed on an inclined axis A3 that is adjacent to the outside of the lens portion 21b and is inclined from the focal position F by an angle 2θ ′ + (θ ′ / 2) with respect to the central axis O. It is a convex lens section as a rotating body defined by rotating around the central axis O.
Finally, the lens portion 21d is formed on an inclined axis A4 that is adjacent to the outside of the lens portion 21c and is inclined from the focal position F by the angle 3θ ′ + (θ ′ / 2) with respect to the central axis O. It is a convex lens section as a rotating body defined by rotating around the central axis O.

  According to the illuminating device 20 configured as described above, when the light source 11 emits light as in the illuminating device 10 of FIG. 1, the light L from the light source enters the optical lens 21, and the individual lens portions of the optical lens 21. Based on the optical characteristics of 21a, 21b, 21c, and 21d, along the direction of the inclined axes A1, A2, A3, and A4, that is, downward with respect to the central axis O, in the cross section passing through the central axis O, respectively. The light is condensed so as to spread outward by an angle θ ′, and becomes substantially parallel light L1, L2, L3, L4, respectively, and is irradiated in the directions of the inclined axes A1, A2, A3, A4.

The irradiation lights L1, L2, L3, and L4 reach a floor surface or the like located at a predetermined distance below the central axis O to form annular irradiation patterns P1, P2, P3, and P4, respectively.
In this case, the radii of the irradiation patterns P1, P2, P3, and P4 are determined by the tangent of the inclination angle with respect to the predetermined distance. As a result, as shown in FIG. 10, a plurality of irradiation patterns P1, P2, P3, and P4 that are concentric with each other are formed.

[Example 3]
FIG. 11 shows a configuration of an embodiment of a light receiving device using the optical lens according to the present invention.
In FIG. 11, the light receiving device 30 has a different configuration only in that a light receiving element 31 is disposed instead of the light source 11 in the illumination device 10 illustrated in FIGS. 1 and 2.
Here, a photodiode, a phototransistor, a photo IC, a CMOS, a CCD, or the like is used as the light receiving element 31 so that light incident on the focal position F of the optical lens 12 can be detected.

According to the light receiving device 30 having such a configuration, the lens portion 12a of the optical lens 12 from the annular light receiving pattern (light receiving area) P on the floor surface or the like, as shown in FIG. On the other hand, the light L5 incident at an inclination angle θ with respect to the central axis O is condensed at the focal position F by the optical action of the lens portion 12a and enters the light receiving element 31.
Thereby, the light receiving element 31 can detect the light from the light receiving pattern P5. Therefore, monitoring using the light receiving pattern P5 as a detection area can be performed by a change in the amount of light detected from the light receiving pattern P5.

  In the embodiment of the light receiving device, the light source for the light incident on the light receiving element 31 is used as long as the light receiving pattern P5 can be illuminated with a necessary light amount. In addition, it may be a general light source or illumination device that performs illumination uniformly. Moreover, you may use sunlight etc. as a light source, without using an illuminating device.

  The light receiving device 30 described above is configured to include the light receiving element 31, but may include a light source at the position of the light receiving element 31. In this case, the detection of the light from the light receiving pattern P by the light receiving element 30 may be influenced by the direct light emitted from the light source, but it is configured to detect a change in the detection amount based on a difference from the normal state, Those skilled in the art will readily understand that the object can be achieved by providing a partition between the light receiving elements, or by combining these methods.

In the above-described embodiment, the lens portion 12a of the optical lens 12 and the lens portions 21a, 21b, 21c, and 21d of the optical lens 21 are formed as plano-convex lenses from the focal position F side. As long as it is a convex lens, it may be a biconvex lens, an aspherical condenser lens, or the like, or may be formed as a Fresnel lens.
In particular, when the lens portions 12a, 21a, 21b, 21c, and 21d are formed as Fresnel lenses, the optical lenses 12 and 21 are thinned in the direction of the central axis O. Therefore, for example, when a relatively large light source such as a halogen lamp is used as the light source, an increase in the size of the lighting device can be suppressed.

  In the above-described embodiment, one LED is used as the light source 11. However, the present invention is not limited to this, and a plurality of LEDs may be used. However, considering the optical system, the light source is mounted in a narrower range. It is preferred that By adopting the above configuration, it is not necessary to arrange a large number of light sources in a ring shape corresponding to the irradiation pattern as in the prior art, and a small number of light sources can be used. For this reason, the number of parts can be reduced, and the part cost and assembly cost can be reduced.

The optical lens according to the present invention can constitute the above-described illumination device by disposing a light source at the focal position, and further illumination such as production illumination of automobiles and accent illumination of showcases for shops, or for example, hotels, department stores Used for indicator lighting for visual guidance, eye-catching, danger area display including guidance display in tenant buildings, etc., prohibition area display indicating danger zones such as construction sites, priority seat position display in railway vehicles, etc. It is possible.
Further, by arranging a light receiving element at the focal position of the optical lens according to the present invention, a device for detecting the passage and movement of an object in a conical detection area between the optical lens and the annular light receiving pattern, for example, at home It can be used as a monitoring device for preventing escape of infants and dementia patients and preventing entry into dangerous heating appliances and kitchens.

  Thus, according to the present invention, an extremely excellent optical lens that can be configured in a small size and can arbitrarily change the size of the annular irradiation pattern or the light receiving pattern, and the optical lens are provided. The used illumination device and light receiving device can be provided.

It is a schematic sectional drawing which shows the structure of 1st embodiment of the illuminating device provided with the optical lens by this invention. It is a schematic plan view which shows the illuminating device of FIG. It is (A) sectional drawing, (B) top view, (C) side view, and (D) perspective view which show the optical lens in the illuminating device of FIG. It is (A) sectional drawing, (B) top view, (C) sectional drawing of a different direction, and (D) perspective view which show the mount in the illuminating device of FIG. It is an enlarged plan view of the LED board in the illuminating device of FIG. It is a schematic perspective view which shows the use condition of the illuminating device of FIG. It is a graph which shows irradiation intensity distribution with respect to the irradiation angle by simulation by the illuminating device of FIG. It is a graph which shows the irradiation intensity distribution on the screen by the simulation by the illuminating device of FIG. It is sectional drawing which shows the structure of the principal part of 2nd embodiment of the illuminating device provided with the optical lens by this invention. It is a schematic perspective view which shows the irradiation pattern by the illuminating device of FIG. It is a schematic sectional drawing which shows the structure of one Embodiment of the light-receiving device provided with the optical lens by this invention. It is a schematic perspective view which shows the use condition of the light-receiving device of FIG.

Explanation of symbols

10 Illumination device 11 Light source (LED)
DESCRIPTION OF SYMBOLS 12 Optical lens 12a Convex lens 12b Plane 12c Lens surface 12d Hollow cylindrical part 12e Male thread part 13 Mount 13a Hollow part 13b Inner wall surface 13c Female thread part 13d Step 13e Bottom surface 13f Recessed part 13g Through hole 13h Screw hole 13i Sheet sink 14 LED board 14a Mounting hole 14b LED chip mounting land 14c Electrode part 20 Illumination device 21 Optical lens 21a, 21b, 21c, 21d Lens part A, A1, A2, A3, A4 Inclined axis L, L1, L2, L3, L4 L5 Light P, P1, P2, P3, P4 Irradiation pattern P5 Light reception pattern

Claims (6)

  The central axis is made of a transparent material, is annularly arranged around the central axis, and is formed on an inclined axis extending at a predetermined angle from a focal position located away from one side of the central axis in a cross section passing through the central axis. An optical lens having a convex lens portion as a rotating body defined by rotating around the lens.   2. The optical lens according to claim 1, wherein the convex lens portion is arranged for each of tilt axes having a predetermined angle different from each other with respect to the focal position.   The optical lens according to claim 1, wherein the convex lens portion is formed as an annular Fresnel lens.   The optical lens according to claim 1, wherein the convex lens portion is surrounded by a light shielding member on one side.   An illumination device comprising: the optical lens according to claim 1; and a light source disposed at a focal position of the optical lens.   A light receiving device comprising: the optical lens according to claim 1; and a light receiving element disposed at a focal position of the optical lens.

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