JP2017054751A - Lighting device and lens - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lighting device and a lens thereof which can emit light aligned in a line and having a directivity of narrow light distribution in a predetermined inclination direction without degrading a light utilization efficiency even when a light emitting element having a directivity of wide light distribution.SOLUTION: A lighting device includes: a plurality of light-emitting elements (21) having each optical axis direction to an X direction, the elements being aligned in a Y direction orthogonal to the X direction; and a plurality of lenses (31) aligned in the Y direction and provided in a direction of the optical axes of the plurality of light-emitting elements. On each of the plurality of lenses (31), a first convex-shaped incidence surface and a first convex-shaped emission surface are provided, and a first lens and a second lens are integrally provided. The first lens diverts the light emitted from the light-emitting element to inclined parallel light, and the second lens includes a second incidence surface and a second emission surface which are inclined so that a distance therebetween becomes wider as they go away from the first lens, and an end surface which totally reflects the light incident into the second incidence surface.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an illumination device that emits inclined light and a lens that generates inclined light.

2. Description of the Related Art An inspection apparatus that inspects a specimen for defects such as scratches by irradiating a plate-like or sheet-like specimen with linear and continuous light has been known (for example, patents). Reference 1).
Conventionally, in order to obtain such light, the following method has been adopted. For example, in the illumination device of Patent Document 1, a method of irradiating light using a plurality of optical fibers arranged at an inclination is employed. Moreover, in the illuminating device of patent document 2, the system which irradiates light through the prism sheet in which the some prism was formed is employ | adopted. In addition, a plurality of light-emitting diodes with a narrow directivity with a lens are mounted in a line and inclined, and a light is emitted from these, and a light-shielding mask is provided on a part of the light guide to irradiate from the light guide There is known a method for limiting the light to be inclined to light.

JP 2008-216148 A JP 2010-205560 A

However, in the method using a plurality of optical fibers, the mounting process of arranging the plurality of optical fibers is very complicated, and there is a problem that a lot of light loss occurs when light is incident on the optical fibers. It was.
Also, in the method using a prism sheet, light emitted from one light source reaches a plurality of prisms and is refracted. Therefore, components in various inclination directions are mixed in the light emitted to the outside, and a desired inclination direction is obtained. However, there was a problem that the directivity of light distribution could not be narrowed down. In particular, when a light-emitting diode having high brightness and wide directivity is combined with a prism sheet, the light emitted from the light-emitting diode reaches many adjacent prisms, and the directivity of the light emitted to the outside is set to a desired inclination. It was difficult to squeeze in the direction.

In addition, in the method of arranging a plurality of light emitting diodes at an inclination, the mounting process becomes very complicated, and furthermore, it becomes difficult to take measures against heat dissipation of the light emitting diodes, so that there is a problem that it is difficult to apply a super bright light emitting diode. there were. In addition, the method using a light shielding mask has a problem that light loss occurs due to light shielding, and there are problems that light in various tilt directions is mixed in light irradiated due to heat generation of the light shielding part and irregular reflection of the light shielding part.
In view of this, the present inventor has studied to efficiently generate light having a narrow directivity in a desired tilt direction using a lens. Specifically, a plurality of high-luminance type light-emitting diodes having a wide directivity are arranged in a row, one lens is associated with one light-emitting diode, and the plurality of lenses are respectively arranged on the optical axes of the plurality of light-emitting diodes. The light is arranged in the direction, and light having narrow directivity in a desired tilt direction is generated by each lens.

However, light is emitted radially from the light emitting diode. For this reason, if a simple lens is simply arranged, a large amount of light is mixed into an adjacent lens, so that it has a narrow directivity in a predetermined tilt direction without reducing the light use efficiency. Irradiating light was not easy.
Further, when the lens is molded from a resin, if there is a thick portion in the design shape of the lens, there is a problem that it becomes difficult to mold the lens into a desired shape due to distortion such as sink marks.
According to the present invention, even when a light emitting element having a wide light distribution directivity is used, light having a narrow directivity in a predetermined inclination direction can be irradiated without reducing light utilization efficiency. An object of the present invention is to provide a lighting device and a lens thereof.

In order to achieve the above object, the illumination device according to the present invention has a plurality of light emitting elements arranged in the Y direction, each of which has an optical axis in the X direction and intersects the X direction,
A plurality of lenses provided corresponding to the plurality of light emitting elements, arranged in the Y direction, and arranged in the direction of the optical axis of the plurality of light emitting elements;
A lighting device comprising:
Each of the plurality of lenses is
A first lens portion and a second lens portion, which are disposed on one and the other along the Y direction with respect to the optical axis of the corresponding light emitting element, and are provided integrally with each other;
The first lens unit is
A first incident surface having a convex curve shape and a first emission surface having a convex curve shape on one side and the other side along the X direction,
The center of curvature of the first entrance surface is closer to the first exit surface than the center of the first lens portion;
The center of curvature of the first exit surface is closer to the first entrance surface than the center of the first lens portion;
The second lens unit is
A second entrance surface and a second exit surface that are wider from each other as the distance from the first lens portion increases, and an end surface far from the first lens portion,
The light incident on the second incident surface from the corresponding light emitting element is totally reflected by the end surface and is irradiated to the outside from the second emission surface.

According to this structure, first, each light emitting element is arrange | positioned so as to oppose the trough part between a 1st incident surface and a 2nd incident surface. Therefore, even if light having a wide directivity is irradiated from the light emitting element, most of the irradiated light can be taken into the first incident surface and the second incident surface. The light taken into the first incident surface can be refracted in a predetermined tilt direction by the first lens unit and irradiated to the outside. Here, the first lens portion only needs to exert a refracting action on the light in the half range, not the entire range of the light of the light emitting element spreading radially. Therefore, the incident light can be obtained without increasing the size of the first lens unit and the curvature of the first incident surface and the first exit surface as compared with the case where the refractive effect is exerted on the entire range of light. Can be refracted at a predetermined inclination angle and irradiated to the outside. Thereby, the center of curvature of the first entrance surface and the center of curvature of the first exit surface can be set as in this configuration, and the thickness of the first lens portion can be reduced. Therefore, even when the lens is formed by resin molding, the occurrence of sink marks and the like can be avoided, and an accurate lens shape can be molded. Further, the light taken into the second incident surface is totally reflected by the end surface of the second lens unit, and can be irradiated in the same inclination direction as the refraction direction of the first lens unit.
Therefore, by providing such a plurality of lenses and a plurality of light emitting elements side by side, irradiation with light that is continuous in a line and has a narrow directivity in a predetermined inclination direction without reducing light utilization efficiency. can do.

Preferably, in the first lens portion, the portion farther from the second lens portion and closer to the light emitting element along the X direction, the light is at least in the X direction and the Y direction. It is preferable that a diffusing portion for diffusing in the Z direction orthogonal to is provided.
According to this configuration, the light of the light emitting element that deviates from the second incident surface and enters the adjacent lens can be diffused in the Z direction by the diffusion portion of the first lens portion. Therefore, it can reduce that the light from which inclination directions differ greatly is mixed in the light which continues in a line form.

More preferably, each of the plurality of light emitting elements is
The optical axis overlaps a trough between the first incident surface and the second incident surface of the corresponding lens, and between the first emission surface and the second emission surface of the corresponding lens. It is good to arrange | position so that the said optical axis may be located near the said end surface from the trough part.
According to this configuration, the light use efficiency can be further improved. That is, the light incident on the valley between the first incident surface and the second incident surface is separated into light refracted on the first incident surface and light refracted on the second incident surface, and remains in the optical axis direction as it is. Little light travels. Therefore, even if there is the first emission surface around the optical axis, the light refracted by the first lens portion does not pass through this portion. Therefore, by setting the optical axis closer to the end surface than the trough between the first emission surface and the second emission surface, the second emission surface is expanded from the optical axis to the first lens side. It is possible to increase the amount of light that passes through the two lens portions and is irradiated to the outside. Therefore, the light use efficiency is further improved.

Further, the lens according to the present invention is a lens that is assumed to make light incident from a light emitting element having an optical axis directed in the X direction,
A first lens portion and a second lens portion, which are arranged on one side and the other side along the Y direction intersecting the X direction with respect to the optical axis, and are provided integrally with each other;
The first lens unit is
A first incident surface having a convex curve shape and a first emission surface having a convex curve shape on one side and the other side along the X direction,
The center of curvature of the first entrance surface is closer to the first exit surface than the center of the first lens portion;
The center of curvature of the first exit surface is closer to the first entrance surface than the center of the first lens portion;
The second lens unit is
A second entrance surface and a second exit surface that are wider from each other as the distance from the first lens portion increases, and an end surface far from the first lens portion,
The light incident on the second incident surface from the light emitting element is configured to be totally reflected by the end surface and irradiated to the outside from the second emission surface.

  According to this configuration, by combining a plurality of lenses and a plurality of light emitting elements arranged in the Y direction, light that is connected in a line and has a narrow directivity in a predetermined tilt direction without reducing the light use efficiency. Can be irradiated.

  According to the illumination device and the lens of the present invention, even if a light emitting element having a wide light distribution directivity is used, a narrow directivity that is continuous in a line and faces a predetermined inclination direction without reducing the light use efficiency. Can be irradiated.

It is a perspective view which shows the illuminating device of embodiment of this invention. It is a side view which shows the board | substrate with which the some light emitting element was mounted, and a lens group. The lens is shown, (a) is a perspective view seen from diagonally below, (b) is a perspective view seen from diagonally upward. The lens is shown, (a) is a plan view, (b) is a side view, and (c) is a front view. It is a figure explaining the effect | action of a lens, (a) is explanatory drawing which shows the whole effect | action, (b) is explanatory drawing which shows the effect | action of a 2nd lens part, (c) is description explaining the effect | action of a 1st lens part. FIG. It is a figure explaining the effect | action of the spreading | diffusion part of a lens. It is a perspective view which shows the lens of a modification. It is a graph which shows intensity distribution of the irradiation light of a light emitting element, and intensity distribution of the light which passed the lens.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a perspective view showing an illumination apparatus according to an embodiment of the present invention. FIG. 2 is a side view showing a substrate on which a plurality of light emitting elements are mounted and a lens group. In FIG. 1, the substrate 20 and the lens group 30 are shown in a simplified manner.
The illuminating device 1 of embodiment of this invention is an apparatus which irradiates the light which continues in a line form at the Y direction, and has a narrow directivity in the predetermined inclination direction A1. The illumination device 1 is applied to, for example, an inspection device that irradiates an inspection object with light and inspects for defects such as scratches. If there is a defect such as a scratch on the object to be inspected, the defect is projected with sufficient contrast by the inclined light of the illumination device 1, and the presence or absence of the defect can be easily inspected. The inclination direction A1 is a direction inclined at a predetermined angle (for example, 30 °) from the X direction to the Y direction.
The illumination device 1 includes a housing 10, a substrate 20, a lens group 30, and a cylindrical lens 40 that collects light in the Z direction.

The housing 10 accommodates the substrate 20, the lens group 30, and the cylindrical lens 40. The housing | casing 10 has the opening part 10a in the upper part, and irradiates light outside from the opening part 10a.
The substrate 20 includes a plurality of light emitting elements 21 (see FIG. 2). The plurality of light emitting elements 21 are arranged in the Y direction and aligned on the straight line at regular intervals, and are mounted on the substrate 20. The optical axis (light distribution center) of each light emitting element 21 is directed in the X direction. Although not particularly limited, in this embodiment, the X direction, the Y direction, and the Z direction indicate triaxial directions orthogonal to each other.
Each light emitting element 21 is, for example, a high-brightness LED (light emitting diode), and a heat dissipating portion is provided at the lower part. The heat generated from the light emitting element 21 is efficiently radiated through the substrate 20 and the housing 10 from the heat dissipation portion. The light emitting element 21 is configured, for example, by covering the periphery of a plate-shaped LED chip with a hemispherical dome-shaped light guide d (see FIG. 5). The light guide d is a member for guiding the light irradiated radially from the LED chip to the outside with a small amount of reflection, and is different from a lens having a light collecting action. Therefore, the light emitting element 21 has a relatively wide light distribution directivity.

  The lens group 30 includes a plurality of lenses 31 arranged so as to be arranged at regular intervals in the Y direction. The plurality of lenses 31 have the same shape and the same size. In FIG. 2, the fixing structure of the lens 31 is omitted. The plurality of lenses 31 are provided in one-to-one correspondence with the plurality of light emitting elements 21, and each lens 31 is disposed in the light irradiation direction of the corresponding light emitting element 21.

  3A and 3B show a lens, in which FIG. 3A is a perspective view seen from obliquely below, and FIG. 3B is a perspective view seen obliquely from above. 4A and 4B show a lens, in which FIG. 4A is a plan view, FIG. 4B is a side view, and FIG. 4C is a front view.

  The lens 31 includes a first lens portion 32, a second lens portion 33, and fixing overhang portions 34, 34, and is integrally formed by injection molding of a transparent resin. In FIG. 4B, except for the overhang portion 34, the portion to the right of the virtual boundary line L <b> 1 is the first lens portion 32, and the portion to the left of the boundary line is the second lens portion 33. The first lens unit 32 and the second lens unit 33 are respectively disposed on one side and the other side along the Y direction with the corresponding light emitting element 21 optical axis L0 (see FIG. 5A) interposed therebetween. .

The first lens unit 32 includes a first incident surface 32a, a first emission surface 32b, and a diffusion unit 32d.
The first incident surface 32a is a surface on the light emitting element 21 side in the X direction, and has a convex curved surface shape. The first incident surface 32a may be, for example, a cylindrical bent surface having a central axis in the Z direction, or may be a bent surface having a convex curvature also in the Z direction. The center of curvature Oa (see FIG. 4B) of the first incident surface 32a is set closer to the first exit surface 32b than the center O of the first lens portion 32. Note that the center of curvature Oa is not a single point, and the position of the center of curvature may be different for each part of the first incident surface 32a. Even in this case, each center of curvature is set so as to satisfy the above-described conditions.

The first emission surface 32b is a surface on the opposite side of the light emitting element 21 in the X direction, and has a convex curved surface shape. The first emission surface 32b may be, for example, a cylindrical bent surface having a central axis in the Z direction, or may be a bent surface having a convex curvature also in the Z direction. The center of curvature Ob (see FIG. 4B) of the first exit surface 32b is set closer to the first entrance surface 32a than the center O of the first lens portion 32. Note that the center of curvature Ob is not a single point, and the position of the center of curvature may be different for each part of the first emission surface 32b. Even in this case, each center of curvature is set so as to satisfy the above-described conditions.
The diffusion unit 32d is a part that diffuses light mixed from another light emitting element 21 adjacent to the corresponding light emitting element 21 in the Z direction. In the present embodiment, the diffusing unit 32d is configured by an inclined surface that reflects or refracts light in the Z direction. The diffusing unit 32d is provided in a portion of the first lens unit 32 that is far from the second lens unit 33 and that is close to the light emitting element 21 in the X direction.

The second lens unit 33 has a second incident surface 33a, a second emission surface 33b, and an end surface 33c.
The end surface 33c is provided so as to totally reflect the light of the light emitting element 21 incident from the second incident surface 33a toward the second emitting surface 33b. The end face 33 c is formed in a parabolic shape in which the central axis L <b> 3 (see FIG. 5B) intersects with the light emitting element 21. Here, the paraboloidal shape is a complete paraboloid, a curved surface having a parabolic parabola and no curvature in the Z direction, or a curved surface or plane approximated to the same extent to have a similar effect. Means a shape containing
The second entrance surface 33a and the second exit surface 33b are inclined such that the distance from the first lens portion 32 side to the end surface 33c side gradually increases. The second incident surface 33a has, for example, a cylindrical surface shape having a central axis in the Z direction, or a convex curved surface shape obtained by adding a curvature in the Z direction thereto. The second emission surface 33b has a planar shape, for example.

Here, an example of an ideal shape of the second lens unit 33 will be described.
As an ideal shape, as shown in FIG. 5B, the paraboloid of the end face 33c has its focal point P3 set at the light emission center of the light emitting element 21, and the inclination angle θ1 of its central axis L3 emits light. It is good to set so that it may become the same as inclination angle (theta) to irradiate.
In addition, the second incident surface 33a may be formed with a curved surface so that the light incident from the light emitting element 21 is light that travels radially around the focal point P3 before reaching the end surface 33c.
Further, as shown in FIG. 5B, the second emission surface 33b may have an inclination angle orthogonal to the light irradiation direction of the inclination angle θ.

With such a shape, the light emitted from the light emission center of the light emitting element 21 spreads radially and travels straight to the end surface 33c, and is reflected by the end surface 33c at an inclination angle θ, thereby being converted into parallel light. Then, the light is irradiated to the outside from the second emission surface 33b.
The curved surface of the end surface 33c and the inclination angle of the second emission surface 33b may be changed from each other so as to satisfy the following condition. That is, the inclination angle θ1 of the central axis L3 of the end face 33c that is a paraboloid is changed to an angle (θ + Δθ) obtained by adding an arbitrary variation Δθ to the inclination angle θ that irradiates light, and the variation Δθ The inclination angle of the second exit surface 33b is changed so that the influence is canceled out by refraction at the second exit surface 33b. Even if these changes are made, light irradiated at the inclination angle θ can be obtained as in the case of the ideal shape described above.

Similarly, the curved surface of the second incident surface 33a and the curved surface of the end surface 33c may be changed to satisfy the following condition. That is, the curved surface of the second incident surface 33a is such that the center point of the light traveling from the second incident surface 33a to the end surface 33c is a point (P3 + Δv) displaced by an arbitrary variation Δv from the light emission center of the light emitting element 21. Is changed, the curved surface of the end face 33c is changed to a parabolic shape with the point (P3 + Δv) as a focal point. Even if it changes in this way, the parallel light irradiated to inclination-angle (theta) can be obtained similarly to the case of said ideal shape.
Actually, the light emitting portion of the light emitting element 21 has a planar spread, and light is refracted at the light guide d and the second incident surface 33a. For this reason, even if the second lens portion 33 has the ideal shape described above, the light distribution is deviated from the ideal, but even in this case, the light distribution approximate to the ideal can be obtained.

At the boundary between the first lens unit 32 and the second lens unit 33, a valley is formed by the intersection of two different curved surfaces. An incident-side trough 36 is formed at the boundary between the first incident surface 32a and the second incident surface 33a, and an exit-side trough 37 is formed at the boundary between the first exit surface 32b and the second exit surface 33b. Has been.
The light emitting element 21 is disposed so as to face the incident-side trough portion 36 with the light irradiation direction as the front surface. Specifically, the light axis L0 of the light emitting element 21 may be arranged so as to overlap with the incident side trough portion 36 (see FIG. 5A). On the other hand, the optical axis L0 of the light emitting element 21 is preferably arranged so as not to overlap the trough portion 37 on the emission side but to be displaced toward the second lens portion 33 and overlap the second emission surface 33b (FIG. 5 ( see a)). This effect will be described later.

The overhang portions 34 and 34 are portions for fixing the lens 31 to the housing 10 or the substrate 20. The overhang portions 34 and 34 are provided so as to overhang one side and the other along the Z direction with respect to the first lens portion 32 and the second lens portion 33. For example, the projecting portions 34 and 34 are provided with a fixing hole 34a, and a fixing pin (not shown) is inserted into the hole 34a, whereby the lens 31 is fixed.
The cylindrical lens 40 (see FIG. 1) collects light in the Z direction. The light that has passed through the lens group 30 leaves a component that spreads radially on the XZ plane, and passes through the cylindrical lens 40 to generate light that is nearly parallel on the XZ plane.

<Operation of lens group>
Next, the operation of the lens 31 will be described.
5A is an explanatory diagram showing the overall operation of the lens 31, FIG. 5B is an explanatory diagram showing the operation of the second lens unit, and FIG. 5C is an explanatory diagram showing the operation of the first lens unit. FIG. FIG. 6 is an explanatory diagram showing the action of the diffusion portion of the lens.
The light emitting element 21 emits light radially around the optical axis L0. The light-emitting element 21 is arranged so that the optical axis L0 overlaps the incident-side trough portion 36, and a half range of the radially spreading light is irradiated toward the first lens unit 32, and a half range is the second range. The light is irradiated toward the lens unit 33. Since the second incident surface 33 a has a narrow width, a part of the light irradiated toward the second lens portion 33 enters the adjacent lens 31.

First, the light irradiated to the 1st lens part 32 is demonstrated.
As shown in FIG. 5C, on the XY plane, the light incident on the first lens unit 32 is refracted by the first incident surface 32a and the first emission surface 32b, and most of the light is predetermined. The light is collimated at an inclination angle θ and irradiated outside. The parallel lights S1 to S3 are irradiated to the outside from the entire range from one end to the other end on the XY plane of the first emission surface 32b.
Of the light incident on the first lens part 32, the light S1 passing through the vicinity of the valley part 36 is refracted by the first incident surface 32a and travels along an optical path deviated from the optical axis L0. For this reason, the trough 37 on the exit surface side is provided so as to be shifted from the optical axis L0 and overlap the optical path of the light S1. Thereby, the area of the adjacent 2nd output surface 33b is increased, and the utilization efficiency of light improves.
Of the light incident on the first lens unit 32, light with low intensity separated from the optical axis L0 (see, for example, the light S4 in FIG. 5A) enters the diffusion unit 32d and is diffused. The diffusion action of the diffusion part 32d will be described later.

Next, the light irradiated to the 2nd lens part 33 is demonstrated.
As shown in FIGS. 5A and 5B, most of the light incident on the second lens unit 33 on the XY plane is refracted by the second incident surface 33a and a parabolic surface. As a result of total reflection at the end face 33c, the light is converted into parallel light at a predetermined inclination angle θ and irradiated from the second emission surface 33b to the outside. Among these, the high-intensity light S11 close to the optical axis L0 is refracted by the second incident surface 33a, proceeds to the upper end portion of the end surface 33c, is totally reflected by the end surface 33c, and is irradiated to the outside. The light S13 incident on one end portion of the second incident surface 33a far from the optical axis L0 is totally reflected at the lower end portion of the end surface 33c, but enters the first lens portion 32 off the second emission surface 33b and is diffused. The Thus, some of the light incident on the second incident surface 33a is diffused away from the second exit surface 33b, but the intensity of the diffused light is low. On the other hand, the high-intensity light close to the optical axis L0 does not come off the second emission surface 33b.
As shown in FIG. 5A, among the light traveling toward the second lens unit 33, the light S <b> 14 traveling far from the optical axis L <b> 0 and deviating from the second incident surface 33 a is diffused by the adjacent lens 31. It enters the portion 32d.

Next, light incident on the diffusing unit 32d will be described.
As shown in FIG. 6, the light incident on the diffusing unit 32d is dispersed in the Z direction by refraction by the inclined surface of the diffusing unit 32d. This dispersion is such that the dispersion is out of the cylindrical lens 40 or is not condensed by the cylindrical lens 40, so that the light incident on the diffuser 32 d is irradiated to the outside from the opening 10 a of the illumination device 1. It is not mixed in the light and is diffused in the housing 10.
FIG. 7 is a perspective view showing a lens of a modified example.
In addition, as shown in the lens 31z of the modification of FIG. 7, the diffusing portion 32d2 may be configured such that the surface of the corresponding range of the first lens portion 32 is a surface having fine unevenness as a whole, such as a ground glass shape. Even with such a configuration, it is possible to reduce the light incident on the diffusing unit 32d2 from being scattered and mixing light in different inclination directions into the light emitted from the illumination device 1.

FIG. 8 is a graph showing the intensity distribution of the light emitted from the light emitting element and the intensity distribution of the light passing through the lens. The horizontal axis of the graph in FIG. 8 indicates the inclination angle on the XY plane with the X direction being zero degrees. The vertical axis represents the ratio of light intensity when the maximum intensity is 100%.
According to the lens 31 of the present embodiment, as shown in the graph of FIG. 8, light having a narrow directivity inclined at a predetermined angle (for example, −30 °) from light having a wide directivity of the light emitting element 21. Can be generated.

Although the embodiment of the present invention has been described above, the present invention is not limited to this. For example, in the above embodiment, the plurality of light emitting elements 21 and the plurality of lenses 31 are provided so that the optical axis L0 faces in a direction perpendicular to the mounting surface of the substrate 20. However, the present invention is not limited to this embodiment. For example, each of the plurality of light emitting elements 21 is mounted with a predetermined angle α inclined with respect to the mounting surface of the substrate 20, Each of the lenses 31 may be fixed at a similar angle α. Even in this case, the arrangement relationship of the corresponding individual light emitting elements 21 and lenses 31 is the same as in the embodiment. With this configuration, the optical axes L0 of the plurality of light emitting elements 21 are inclined at an angle α with respect to the substrate 20, and the plurality of lenses 31 further inclines the light from the light emitting elements 21 at an angle θ to the outside. Irradiate. Therefore, the light irradiation direction can be inclined at an angle θ + α. In addition, white may be applied as the emission color of the light emitting element, or other than white, for example, blue, green, red, near ultraviolet light, or near infrared, in order to make the defect contrast of the inspection object more prominent. Light or the like can be applied.
In addition, the details shown in the embodiments can be changed as appropriate without departing from the spirit of the invention.
Furthermore, although the present invention has shown an example in which the illumination device is applied to an inspection apparatus that inspects a defect of an inspection object, the illumination device of the present invention can be applied to various applications such as illumination for lighting. Good.

DESCRIPTION OF SYMBOLS 1 Illuminating device 10 Case 20 Board | substrate 21 Light emitting element d Light guide 30 Lens group 31,31z Lens 32 1st lens part 32a 1st entrance surface 32b 1st exit surface 32d Diffusion part 33 2nd lens part 33a 2nd entrance surface 33b Second exit surface 33c End surface 34 Overhang portion 36, 37 Valley portion 40 Cylindrical lens Oa, Ob Center of curvature O Center of first lens portion

Claims (4)

A plurality of light emitting elements arranged in the Y direction, each of which has its optical axis in the X direction and intersecting the X direction;
A plurality of lenses provided corresponding to the plurality of light emitting elements, arranged in the Y direction, and arranged in the direction of the optical axis of the plurality of light emitting elements;
A lighting device comprising:
Each of the plurality of lenses is
A first lens portion and a second lens portion, which are disposed on one and the other along the Y direction with respect to the optical axis of the corresponding light emitting element, and are provided integrally with each other;
The first lens unit is
A first incident surface having a convex curve shape and a first emission surface having a convex curve shape on one side and the other side along the X direction,
The center of curvature of the first entrance surface is closer to the first exit surface than the center of the first lens portion;
The center of curvature of the first exit surface is closer to the first entrance surface than the center of the first lens portion;
The second lens unit is
A second entrance surface and a second exit surface that are wider from each other as the distance from the first lens portion increases, and an end surface far from the first lens portion,
The illumination device is configured such that light incident on the second incident surface from a corresponding light emitting element is totally reflected by the end surface and irradiated to the outside from the second emission surface.   Of the first lens portion, the light is at least orthogonal to the X direction and the Y direction at a portion far from the second lens portion and closer to the light emitting element along the X direction. The illuminating device according to claim 1, further comprising a diffusing portion that diffuses in the Z direction. Each of the plurality of light emitting elements is
The optical axis overlaps a trough between the first incident surface and the second incident surface of the corresponding lens, and between the first emission surface and the second emission surface of the corresponding lens. The lighting device according to claim 1, wherein the optical axis is disposed closer to the end surface than a trough portion of the lighting device. A lens that is assumed to receive light from a light emitting element having an optical axis directed in the X direction,
A first lens portion and a second lens portion, which are arranged on one side and the other side along the Y direction intersecting the X direction with respect to the optical axis, and are provided integrally with each other;
The first lens unit is
A first incident surface having a convex curve shape and a first emission surface having a convex curve shape on one side and the other side along the X direction,
The center of curvature of the first entrance surface is closer to the first exit surface than the center of the first lens portion;
The center of curvature of the first exit surface is closer to the first entrance surface than the center of the first lens portion;
The second lens unit is
A second entrance surface and a second exit surface that are wider from each other as the distance from the first lens portion increases, and an end surface far from the first lens portion,
A lens configured such that light incident on the second incident surface from the light emitting element is totally reflected by the end surface and irradiated to the outside from the second emission surface.

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