JP2017133984A - Luminaire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a luminaire capable of efficiently using, for illumination, light coming from a light source.SOLUTION: A luminaire 1A includes a ring-shaped light source 2 and a reflection member 4A having a reflection surface 43c. The reflection surface 43c is a concave surface formed in a space by rotating, by one revolution about a central axis C, a curve defining a part of an ellipse B having two focal points F and F'. The positional relationship between each LED 6 and the reflection surface 43c is determined so that the entire light in an effective light distribution angle including an optical axis P of each LED 6 in the ring-shaped light source 2 radiates the reflection surface 43c, and the light that has been emitted from each LED 6 in the ring-shaped light source 2 and has been reflected on the reflection surface 43c is radiated to an irradiation surface X.SELECTED DRAWING: Figure 7

Description

  The present invention relates to an illumination device used for illuminating an object to be inspected, for example, in an image processing inspection or the like.

  Conventionally, when inspecting the quality of industrial products such as liquid crystal panels and semiconductors, for example, defective soldering, adhesion of foreign substances, etc., or the date printed on the beverage can, etc. on the production line, An image processing inspection using imaging by a CCD camera or the like is performed. In this image processing inspection, an optimal illumination device is used depending on the type and size of the inspection object. For example, a dome-shaped illumination device as shown in Patent Document 1 is used.

  FIG. 9 shows an example of a general dome illumination device. The dome-shaped illuminating device 101 reflects light emitted from a plurality of LEDs 106 by a dome-shaped reflecting surface 143, and illuminates the inspection object Y placed on the irradiation surface X by the reflected light thus reflected. It is configured as follows.

  Patent Document 2 proposes an illumination device in which a reflecting surface is configured by a curved surface that forms a part of an ellipse. In this illuminating device, a plurality of LEDs are arranged side by side on the outer periphery of the cylinder, and light from each LED is reflected by the reflecting surface toward the irradiation surface.

JP-A-11-84258 Japanese Patent Laid-Open No. 2003-4641

  However, in the dome-shaped illuminating device 101 as shown in FIG. 9, a part of the effective light emitted from the LED 106 is repeatedly reflected and attenuated in the dome 104 that defines the dome-shaped reflecting surface 143. There has been a problem that the light emitted from the LED 106 cannot be efficiently used for illumination of the inspection object by repeating.

  Moreover, in the illuminating device disclosed by patent document 2, since a some LED was arrange | positioned on the outer periphery of a cylinder, a structure became complicated and there existed a problem that manufacturing cost became high.

  An object of this invention is to provide the illuminating device which can utilize the light from a light source for illumination efficiently.

  An illumination device according to the present invention includes a ring-shaped light source having a plurality of light sources arranged in an annular shape around a central axis, and a reflective member having a reflective surface for reflecting light emitted from the light sources. And the reflective surface has a first half-section divided by the central axis of the cross section including the central axis and one of the plurality of light emitting sources. A curve that forms a part of an ellipse having a focal point and a second focal point located on the opposite side of the first focal point with the central axis in between is rotated in the space by rotating the central axis about the central axis. A positional relationship between each light emitting source and the reflecting surface is determined so that all the light within an effective light distribution angle including the optical axis of each light emitting source of the ring light source hits the reflecting surface. Emitted from each light source of the ring light source and reflected by the reflecting surface Characterized in that so as to irradiate the irradiation surface.

  The irradiation surface may be located between the first focus and the second focus.

In addition, an illumination device according to the present invention includes a ring-shaped light source having a plurality of light emission sources arranged in an annular shape around a central axis, and a reflection surface for reflecting light emitted from the plurality of light emission sources. A reflective member,
The reflecting surface has a second focal point with the light emitting source as a first focal point in one half cross section divided by the central axis of the cross section including the central axis and one of the plurality of light emitting sources. A curved surface forming a part of an ellipse with a focal point positioned on the central axis is a concave curved surface formed in the space by rotating once around the central axis, and each light emission of the ring light source The positional relationship between each light emitting source and the reflecting surface is determined so that all the light within the effective light distribution angle including the optical axis of the source strikes the reflecting surface, and the reflecting surface is emitted from each light emitting source of the ring-shaped light source. The light reflected by is irradiated to the second focal point on the rotation axis or the vicinity thereof, and the central axis extends along the optical axis of each light emitting source.

  The reflection surface is a diffusion reflection surface that diffuses and reflects light from each light source.

  Furthermore, the illumination device according to the present invention further includes a base that supports the ring-shaped light source, the ring-shaped light source is fixed to one surface of the base, and a plurality of radiating fins project from the other surface of the base. It is characterized by.

  According to the illumination device of the present invention, since the light source is located at the first focal point of the ellipse that defines the reflection surface, the effective light from the light source is reflected by the reflection surface toward the second focal point of the ellipse. Therefore, the illuminance on the irradiated surface can be improved without being repeatedly reflected and attenuated in the reflecting member. In addition, by placing the second focal point of the ellipse on the opposite side across the central axis from the first focal point, the irradiation region on the irradiation surface located between the first focal point and the second focal point is widened. In addition, the illumination intensity in the irradiation area can be made uniform.

  In addition, since the reflecting surface of the reflecting member is composed of a curved surface forming a part of an ellipse, the vertical dimension (length dimension in the direction along the central axis) of the reflecting member can be reduced.

  Further, by making the reflection surface a diffuse reflection surface, it is possible to irradiate light on the inspection object from various directions, and it is possible to prevent unnecessary shadows from being generated on the inspection object.

  Furthermore, since a plurality of heat radiation fins project from the other surface of the base to which the ring-shaped light source is fixed on one side, heat from each light source is transmitted to the heat radiation fins via the base, and the heat radiation fins are used. Can be released into the atmosphere.

The perspective view which shows the illuminating device which concerns on 1st Embodiment of this invention. The disassembled perspective view of the illuminating device shown in FIG. FIG. 2 is an enlarged cross-sectional view taken along line II ′ of FIG. The top view explaining the irradiation range in the illuminating device shown in FIG. Schematic explaining the verification method of the illumination intensity using the illuminating device shown in FIG. The graph which shows the illumination intensity of the illuminating device shown in FIG. 1, and the dome-shaped illuminating device of FIG. Sectional drawing of the illuminating device which concerns on 2nd Embodiment of this invention. The graph which shows the illumination intensity distribution in an illumination range. Sectional drawing of the conventional dome shaped illuminating device.

[First Embodiment]
Hereinafter, an illumination device according to a first embodiment of the present invention will be described with reference to the accompanying drawings. With reference to FIGS. 1-3, the illuminating device 1 which concerns on this embodiment is the ring-shaped light source 2, the ring-shaped base 3 which supports the ring-shaped light source 2, and the reflection member 4 attached to the base 3. .

The ring-shaped light source 2 includes a ring-shaped substrate 5 and a plurality of LEDs (light emitting sources) 6 disposed on the substrate 5. The substrate 5 is made of a metal having high thermal conductivity such as aluminum, and an opening 51 serving as a peephole for photographing with the CCD camera Z is provided at the center.
Each LED 6 is composed of a power LED with a wide light distribution that emits light within a predetermined light distribution region. These LEDs 6 are annularly arranged and fixed on the upper surface of the substrate 5 so that the optical axis P (FIG. 3) thereof is parallel to the central axis C of the illumination device 1. Further, the LEDs 6 are electrically connected to each other via lead wires (not shown), and power is supplied to the LEDs 6 from an external power source (not shown).

  The ring-shaped base 3 made of a metal having high thermal conductivity such as aluminum is provided with an opening 31 having the same size as the opening 51 of the substrate 5 at the center, and the ring-shaped light source 2 is mounted on one side 32 of the base 3. It is fixed. An annular notch step 32 a is provided on the peripheral edge of the one surface 32 of the base 3. On the other surface 33 of the base 3, a plurality of annular radiating fins 34 are concentrically projected. With this configuration, the heat from each LED 6 is transmitted to the base 3 through the substrate 5 and is radiated from the radiation fins 34 to the atmosphere.

  The reflecting member 4 is configured in a substantially cap shape, and its open end side portion 41 is fixed in contact with the notch step portion 32 a of the base 3. Further, an opening 42 serving as a peephole is provided on the base end side opposite to the open end side of the reflecting member 4. The inner surface of the reflecting member 4 is a reflecting surface, and here, in particular, the reflecting member 43 is a diffuse reflecting surface 43 that has been subjected to a white coating surface treatment so that light is diffusely reflected.

  The diffuse reflection surface 43 includes a first diffuse reflection surface 43a located on the proximal end side of the reflection member 4 and a second diffuse reflection configured in a cylindrical shape centered on the central axis C and located on the open end side. And a surface 43b. The first diffuse reflection surface 43a is a concave curved surface that constitutes a part of ellipses (secondary aspherical curves) A and A '. The ellipse A, A ′ has two focal points F, F ′, one focal point (first focal point) F is located on the LED 6, and the other focal point (second focal point) F ′ is the central axis C and the irradiation surface. Located at the intersection with X.

  That is, the long axis S that is a line connecting the two focal points F and F ′ of the ellipse A (or A ′) is inclined by the angle θ1 with respect to the central axis C, and the second focal point F ′ is fixed and the ellipse is fixed. A part of a curved surface formed by rotating A around the central axis C is a first diffuse reflection surface 43a in a three-dimensional space. Therefore, the major axis S of the ellipse A is inclined with respect to the optical axis P of each LED 6 by an angle θ1. In addition, even if these arrangement | positioning shifts a little, it does not interfere in practical use.

  Here, assuming that the half value of the effective emission angle centered on the optical axis P of the light emitted from each LED 6 is w, most of the light is emitted from the LED 6 within the effective emission angle range ± w centered on the optical axis P. Is done. The first diffuse reflection surface 43a is provided at a position that reliably covers the effective light emission angle range ± w emitted from each LED 6. That is, the first diffuse reflection surface 43a has the light L1 having the outermost angle separated from the optical axis P by the angle −w among the light within the effective emission angle range ± w emitted from the LED 6 (that is, the effective light), The other outermost angle light L2 that is separated from the optical axis P by the angle + w is determined so that it can be diffusely reflected by the first diffuse reflection surface 43a. In addition, although some light from LED6 is diffusely reflected by the 2nd diffuse reflection surface 43b, it does not contribute to illumination of a to-be-inspected object.

  With this arrangement, all the effective light (light within the effective emission angle range ± w) emitted from the LED 6 is diffusely reflected toward the focal point F ′ by the first diffuse reflection surface 43a. Further, since each LED 6 is disposed in the vicinity of the inner edge of the substrate 5, the diffuse reflected light (reflected light) diffusely reflected by the first diffuse reflection surface 43 a is not obstructed by the substrate 5 or the base 3. Irradiation is performed on the focal point F ′ of the irradiation surface X or its vicinity through the opening 51 of the substrate 5 and the opening 31 of the base 3. Therefore, the problem that the effective light within the effective emission angle range ± w radiated from the LED 6 is repeatedly reflected and attenuated by the reflection diffusion surface 43 does not occur, and the irradiation surface X is surely irradiated with the effective light from the LED 6. Can do.

  The ellipse A is determined as follows. That is, the size of the illuminating device 1 and the distance D from the illuminating surface X to the illuminating device 1 (work distance) based on the predetermined installation area of the illuminating device 1 (region between the CCD camera Z and the illuminating surface X). Based on the above, the positions of the focal points F and F ′ and the shape of the ellipse A are selected. For example, when the dimension (thickness) of the lighting device 1 in the vertical direction (the direction along the central axis C) is kept small, the inclination angle θ1 of the long axis S with respect to the central axis C is set large, and the horizontal direction (the central axis C) is set. It is assumed that the ellipse is relatively long in the direction perpendicular to. Conversely, in order to keep the lateral dimension of the lighting device 1 small, the inclination angle θ1 of the long axis S with respect to the central axis C is set to be small and an ellipse that is relatively long in the vertical direction.

  Next, operation | movement of the illuminating device 1 comprised in this way is demonstrated. When power is supplied to the ring-shaped light source 2, each LED 6 emits light. The LED 6 emits heat when the LED 6 emits light, but heat from each LED 6 is transmitted to the base 3 through the substrate 5 and radiated from the radiation fins 34 to the atmosphere.

  On the other hand, all of the effective light emitted from the LED 6 is diffusely reflected by the first diffuse reflection surface 43a and applied to the irradiation surface X. At this time, the irradiation range on the irradiation surface X by each LED 6 has a substantially elliptical shape centered on the focal point F ′ as indicated by D ′ in FIG. 4, but a plurality of LEDs 6 are arranged in a ring shape. Therefore, a plurality of such substantially elliptical illuminations overlap on the irradiation surface X, and as a result, a circular irradiation range as indicated by D in FIG. 4 is obtained.

  In order to perform an image processing inspection using the illumination device 1, the inspection object Y (see FIG. 1) is placed in the irradiation range D on the irradiation surface X described above, and the inspection object Y is illuminated. . An image signal obtained by photographing an object to be inspected (irradiated object) Y from a viewing hole (that is, openings 42, 51, 31) of the illuminating apparatus 1 using a CCD camera Z installed above the illuminating apparatus 1. Based on the above, an image processing inspection is performed.

  Thus, in the illuminating device 1 according to the present embodiment, the effective light from each LED 6 is diffusely reflected by the diffuse reflection surface 43 (more specifically, the first diffuse reflection surface 43a), and then reliably the substrate. The irradiation surface X side can be irradiated through the five openings 51 and the opening 31 in the base 3. Further, by setting the irradiation surface X on the other focus F ′ (or in the vicinity of the focus F ′) of the ellipse A that defines the first diffuse reflection surface 43a, the effective light from each LED 6 is reliably used for illumination. Can be illuminated with higher illuminance.

  Furthermore, since the diffuse reflection surface 43 is used instead of the mirror surface, unnecessary shadows are less likely to occur when the object Y is illuminated, and image processing inspection can be performed more accurately.

[Example]
The difference in illuminance between the lighting device 1 according to the present embodiment and the conventional dome-shaped lighting device 1 ′ was compared. In this experiment, as shown in FIG. 5, an illuminance meter E is arranged facing each of the dome-shaped illumination device 1 ′ and the illumination device 1, and the illuminance by each of the illumination devices 1, 1 ′ using this illuminance meter E. Was measured. The conventional dome-shaped illumination device 1 ′ uses a dome illumination KDDD2-PK80W (manufactured by Kyoto Denki Co., Ltd.), and the illuminance meter E is a digital illuminance meter IM-5 (manufactured by Topcon Technohouse Co., Ltd.). Using. Work distance D (distance from illuminator 1, 1 'to illuminometer E) is 5 mm. That is, the position of the illuminance form E is the irradiation surface X on which the inspection object Y is placed. The applied current to the ring-shaped light source (2) was 1.1A.

The measurement results are shown in FIG. The horizontal axis in FIG. 6 indicates the distance in the left-right direction with respect to the central axis C, and the vertical axis indicates the ratio of brightness when the highest illuminance in the conventional dome-shaped illumination device 1 ′ is 100%. Yes. As can be seen from FIG. 6, the illuminating device 1 of the present embodiment was able to obtain an illuminance of about 117% compared to the conventional one.

[Second Embodiment]
Next, a lighting device according to a second embodiment of the present invention will be described. In addition, the same code | symbol is attached | subjected to the component substantially the same as the illuminating device 1 of 1st Embodiment mentioned above, and description is abbreviate | omitted.

  Referring to FIG. 7, an illuminating device 1A according to the present embodiment has substantially the same configuration as that of the illuminating device 1 described above, but includes a reflecting member 4A instead of the reflecting member 4, and a first of the reflecting member 4A. Is different in that a part of ellipses (secondary aspherical curves) B and B ′ are formed instead of the ellipse AA ′ of FIG.

  Each of the ellipses B and B ′ has two focal points F and F ′, and one focal point (first focal point) F is located on the LED 6. Each other focal point (second focal point) F ′ is located on the opposite side of the central axis C when viewed from the one focal point F. That is, the two focal points F and F ′ are located on the left and right sides of the central axis C.

  And, like the ellipse A (or A ′) described above, the long axis that is a line connecting the two focal points F and F ′ of the ellipse B (or B ′) is inclined by a predetermined angle with respect to the central axis C. A part of the curved surface formed by rotating the ellipse B around the central axis C is the first diffuse reflection surface 43c in the three-dimensional space. Further, the major axis of the ellipse B is inclined by the predetermined angle with respect to the optical axis (P) of each LED 6. The irradiation surface X is provided slightly above the focal point F ′ (close to the focal point F).

  Even in such a configuration, all of the effective light emitted from the LED 6 is diffusely reflected by the first diffuse reflection surface 43 c and irradiated onto the irradiation surface X through the opening 51 of the substrate 5 and the opening 31 of the base 3. Therefore, the problem that the effective light from the LED 6 is attenuated by being repeatedly reflected by the reflection diffusion surface 43A does not occur, and the irradiation surface X can be reliably irradiated with the effective light from the LED 6.

  Further, since the irradiation surface X is set between the two focal points F and F ′ of the ellipse B (or B ′), the irradiation range can be widened as compared with that in the first embodiment described above.

  That is, since the irradiation surface X is set closer to the focus F than the other focal point F ′, the irradiation surface X is irradiated as compared with the first embodiment in which the irradiation surface X is set to coincide with the position of the focal point F ′. Can widen the range. That is, in the irradiation apparatus 1 described above, when the irradiation surface is the irradiation surface X ′ (see FIG. 3) closer to the focus F ′ than the focal point F ′, the irradiation range is wider than when the irradiation surface is the irradiation surface X. However, as shown in FIG. 8A, there is a problem that the illuminance near the central axis C is lower than the illuminance around the center axis C. In this regard, in the illuminating device 1A according to the present embodiment, as shown in FIG. 8B, the illuminance in the vicinity of the central axis C and the illuminance in the surrounding area can be made substantially the same.

  In addition, as the position of the irradiation surface X, in the case where the two diffusely reflected lights (reflected lights) corresponding to the two outermost light beams L1 and L2 included in the effective light from the LED 6 are L1 ′ and L2 ′, It is preferable to set between one of the diffusely reflected light L1 ′, the center axis C and the intersection P1, and the other of the diffusely reflected light L2 ′ and the intersection P2 of the center axis C. By setting in this way, a wide irradiation range can be realized without lowering the illuminance at the center.

  As mentioned above, although the illuminating device which concerns on embodiment of this invention was demonstrated with reference to attached drawing, this invention is not limited to this embodiment, Various deformation | transformation and correction | amendment are possible without deviating from the scope of this invention. It is.

  For example, in the above embodiment, a plurality of ring-shaped radiating fins 34 are provided on the other surface 33 of the base 3. Instead of these ring-shaped radiating fins 34, flat plate-like or rod-like radiating and radiating fins are provided. May be provided.

1, 1 Illumination device 2 Ring-shaped light source 3 Base 4 Reflecting member 5 Substrate 6 LED
43 Reflective surface (diffuse reflective surface)
A, B Ellipse C Center axis F, F 'Focus

Claims (5)

A ring-shaped light source having a plurality of light-emitting sources arranged in a ring around the central axis;
A reflecting member having a reflecting surface for reflecting light emitted from the plurality of light emitting sources,
The reflecting surface has a second focal point with the light emitting source as a first focal point in one half cross section divided by the central axis of the cross section including the central axis and one of the plurality of light emitting sources. A concave curved surface formed in space by rotating a curve that forms a part of an ellipse with a focal point located on the opposite side of the first focal point across the central axis about the central axis. And
The positional relationship between each light emitting source and the reflecting surface is determined so that all the light within the effective light distribution angle including the optical axis of each light emitting source of the ring light source strikes the reflecting surface. An illumination device characterized in that light emitted from a light emitting source and reflected by the reflecting surface is irradiated onto the irradiation surface.   The illumination device according to claim 1, wherein the irradiation surface is located between the first focus and the second focus. A ring-shaped light source having a plurality of light-emitting sources arranged in a ring around the central axis;
A reflecting member having a reflecting surface for reflecting light emitted from the plurality of light emitting sources,
The reflecting surface has a second focal point with the light emitting source as a first focal point in one half cross section divided by the central axis of the cross section including the central axis and one of the plurality of light emitting sources. A curved surface forming a part of an ellipse with a focal point located on the central axis, and a concave curved surface formed in space by rotating the curved line around the central axis;
The positional relationship between each light emitting source and the reflecting surface is determined so that all the light within the effective light distribution angle including the optical axis of each light emitting source of the ring light source strikes the reflecting surface. Irradiating the light emitted from the light source and reflected by the reflecting surface to the second focal point on the rotation axis or the vicinity thereof;
The lighting device according to claim 1, wherein the central axis extends along the optical axis of each light emitting source.   The lighting device according to claim 1, wherein the reflection surface is a diffuse reflection surface that diffuses and reflects light from each light source.   2. The base according to claim 1, further comprising a base for supporting the ring-shaped light source, wherein the ring-shaped light source is fixed to one side of the base, and a plurality of radiating fins project from the other side of the base. The illuminating device in any one of -4.

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