JP6580511B2 - Lighting device - Google Patents

Description

  The present invention relates to an illumination device in which a plurality of light sources are arranged in a line.

  Conventionally, as an apparatus for illuminating a region having a predetermined shape, an illuminating apparatus in which a plurality of light sources are arranged according to the predetermined shape has been used. For example, in order to illuminate a long and narrow area, an illumination device in which a plurality of light sources are arranged in a line shape has been used. By illuminating a desired area, defects in the area can be inspected.

  In order to acquire information on the surface without omission, for example, to detect a defect formed on the surface such as a flaw without omission, it is necessary to illuminate the surface with light that is close to uniform. By arranging a large number of light sources side by side and superimposing light emitted from adjacent light sources, it is possible to illuminate light with reduced brightness unevenness and uniform brightness.

  Illuminance unevenness can be suppressed to some extent by arranging a large number of light sources side by side. However, the life of the light source may be shortened by heat generated from a plurality of light sources, and it may be difficult to illuminate light that is stably and uniformly approached over a long period of time.

  For this reason, a device has been proposed in which a heat radiating fin is provided in a housing that accommodates the light source, and heat generated from the light source is radiated through the heat radiating fin (see, for example, Patent Document 1).

  Furthermore, when only heat radiation by the heat radiation fins is insufficient, a device for supplying air to the heat radiation fins and forcibly cooling (forced air cooling) has been proposed (for example, see Patent Document 2).

JP 2010-203923 A JP 2014-179224 A

  The present invention has been made in view of the above-described points, and an object of the present invention is to provide an illuminating device that can stably illuminate a desired region with light whose brightness is close to a certain level.

In order to solve the above-described problem, the lighting device of the present invention includes:
A plurality of light sources arranged along a predetermined direction;
A first lens that collects light emitted from the light source;
A diffusing lens for diffusing light emitted from the first lens in the predetermined direction;
A second lens that condenses the light emitted from the diffusion lens,
In the direction from the plurality of light sources toward the second lens, the second lens is disposed at a position separated by a distance of at least twice the radius of curvature of the first lens with reference to the center of curvature of the first lens. It is characterized by being.

  Since the light emitted from the first lens is diffused in a predetermined direction by the diffusing lens, the brightness can be made close to constant.

  According to the present invention, it is possible to illuminate a region having a desired shape with light whose brightness is close to a certain level.

It is a perspective view which shows the external appearance of the illuminating device 100 by this Embodiment from the lower side. It is a perspective view which shows the external appearance of the illuminating device 100 by this Embodiment from an upper side. It is a side view which shows the state which removed the cover of the illuminating device 100 by this Embodiment. It is a perspective view which shows the optical system of the illuminating device 100 by this Embodiment. It is a perspective view which shows the optical system of the illuminating device 100 by this Embodiment. It is a perspective view which shows the thermal radiation system of the illuminating device 100 by this Embodiment. It is a perspective view which shows the outline of the optical path formed with the illuminating device 100 by this Embodiment. It is a side surface which shows the outline of the optical path formed with the illuminating device 100 by this Embodiment. It is a front 74 figure which shows the outline of the optical path formed with the illuminating device 100 by this Embodiment. A diagram (FIG. 10A) showing light traveling along the optical axis direction (Z), a graph (FIG. 10B) showing an intensity distribution at position D1 shown in FIG. 10A, and an intensity distribution at position D2 shown in FIG. 10A. It is a graph (FIG. 10C), a graph (FIG. 10D) showing the intensity distribution at the position D3 shown in FIG. 10A, and a graph (FIG. 10E) showing the intensity distribution at the position D4 shown in FIG. 10A. It is the schematic which shows the structure arrange | positioned by making the length among each of LED212, the rod lens 220, and the cylindrical lens 240 differ. 11A to 11C are graphs obtained by calculating illuminance at positions including the positions of D1, D2, D3, and D4 illustrated in FIG. 10A for each case.

  Embodiments will be described below with reference to the drawings.

<< First Embodiment >>
According to a first embodiment of the invention,
A plurality of light sources (for example, a plurality of LEDs 212 to be described later) arranged along a predetermined direction;
A first lens that collects light emitted from the light source (for example, a rod lens 220 described later);
A diffusion lens (for example, a diffusion lens 230 described later) that diffuses light emitted from the first lens in the predetermined direction;
A second lens (for example, a cylindrical lens 240 described later) that condenses the light emitted from the diffusion lens,
In the direction from the plurality of light sources to the second lens, the radius of curvature of the first lens (for example, the radius of curvature described later) with reference to the center of curvature of the first lens (for example, the center of curvature cc described later). a lighting device in which the second lens is disposed at a position separated by a distance of 2 times or more and 4 times or less of cr).

<Optical system>
The illumination device includes a plurality of light sources, a first lens, a diffusion lens, and a second lens. The optical system of the illumination device is configured by the plurality of light sources, the first lens, the diffusion lens, and the second lens. The optical system of the illumination device has a common optical axis (for example, an optical axis direction Z described later). The optical axis is a virtual light beam that is representative of the luminous flux.

<Direction of light>
In the present embodiment, three directions are defined as directions in which light travels.

<Optical axis direction (for example, Z direction described later)>
One of the three directions is the optical axis direction. As described above, the optical axis is a virtual light beam that is representative of light beams emitted from a plurality of light sources. The optical axis does not have to be a one-dimensional single line and may be a two-dimensional plane. In this embodiment, the optical axis direction is assumed to be virtual when the light intensity is the highest among the light beams emitted from a plurality of light sources and passes through the first lens, the diffusion lens, and the second lens, and passes through a central position. The direction of the light beam can be made. The optical axis direction is the overall traveling direction of light emitted from a plurality of light sources. In the present embodiment, when it is necessary to distinguish this optical axis from the optical axis of an optical element such as a light source, the optical axis of the optical system (for example, the optical axis T in FIGS. 7 to 9 described later). Etc.).

<Diameter direction>
In addition, light emitted from each of the plurality of light sources gradually spreads as it travels in the optical axis direction. This light spreads in a substantially conical shape around each of the plurality of light sources (see L1 in FIG. 7 described later). Two directions perpendicular to each other can be defined with respect to the direction in which the light spreads (hereinafter referred to as the diameter increasing direction).

<Arrangement direction of light sources (first diameter expansion direction (for example, X direction described later))>
The first diameter increasing direction is a direction along a direction in which a plurality of light sources are arranged, and this direction is referred to as a “light source arrangement direction”. The above-mentioned “predetermined direction” means the arrangement direction of the light sources. The arrangement direction of the light sources, which is the first diameter increasing direction, is a direction perpendicular to the optical axis direction. The length N of the illumination area of the illumination device (see FIG. 7 described later) can be defined by the “array direction of the light sources”.

<Width direction of light source (second diameter expansion direction (for example, Y direction described later))>
Furthermore, the second diameter expansion direction is a direction perpendicular to the first diameter expansion direction, and is a direction that defines the width of light emitted from each of the plurality of light sources. This direction is referred to as the “light source width direction”. The width direction of the light source, which is the second diameter expansion direction, is also a direction perpendicular to the optical axis direction. That is, the width direction of the light source is perpendicular to the two directions of the optical axis direction and the first diameter increasing direction. The width W of the illumination area of the illumination device (see FIG. 7 described later) can be defined by the “light source width direction”.

<Multiple light sources>
The plurality of light sources are arranged along a predetermined direction. As described above, “predetermined direction” means “light source arrangement direction”. The arrangement direction of the light sources may be determined according to the shape and size of an object to be illuminated (hereinafter referred to as an object to be illuminated), and may be a linear direction or a curved direction. Further, the plurality of light sources may be arranged in a plurality of rows as well as a case where they are arranged in a row.

  The plurality of light sources are arranged so that the optical axes of the plurality of light sources are in the same direction. Each optical axis of the plurality of light sources is a virtual light beam that is representative of the light flux emitted from each of the plurality of light sources. The direction of the optical axis of each of the plurality of light sources is the same as the optical axis of the optical system.

<First lens>
The first lens functions as a condensing lens that collects light emitted from the light source. Preferably, the first lens condenses light emitted from each of the plurality of light sources. The first lens is not necessarily a lens, and may be an optical element that can collect light emitted from a light source.

  In addition, the 1st lens should just condense at least one part of the light emitted from the several light source. The first lens collects the light emitted from the light source and emits the collected light.

  It is preferable that the first lens has a length equivalent to a length in which a plurality of light sources are arranged, and the longitudinal direction of the first lens is arranged along the arrangement direction of the light sources. By arrange | positioning the longitudinal direction of a 1st lens along the arrangement direction of a light source, a 1st lens can be arrange | positioned so that it may align with the arrangement | sequence of several light sources. For example, the first lens is preferably arranged in parallel with the arrangement of the plurality of light sources. Light emitted from a plurality of light sources can be incident on the first lens with less leakage.

<Diffusion lens>
The light emitted from the first lens is incident on the diffusion lens. The diffuser lens mainly diffuses light of the component in the arrangement direction of the light sources out of the light incident on the diffuser lens. By diffusing the light of the component in the light source arrangement direction, unevenness in the brightness of the light of the component in the light source arrangement direction can be suppressed, and the brightness can be made nearly uniform. As the parameter indicating the brightness of light, illuminance, luminance, luminous intensity, intensity, and the like can be used as appropriate. Regardless of which parameter is used, it is only necessary to illuminate the illuminated body with brightness that is close to uniform.

  The diffusion lens also preferably has a length in which a plurality of light sources are arranged and a length equivalent to the length of the first lens, and the longitudinal direction of the diffusion lens is preferably arranged along the arrangement direction of the light sources. By arranging the longitudinal direction of the diffusion lens along the arrangement direction of the light sources, the light emitted from the plurality of light sources can be incident on the diffusion lens with less leakage, and the light emitted from the plurality of light sources The brightness can be made closer to the light source in the arrangement direction. For example, the diffusing lens is preferably arranged in parallel with the arrangement of a plurality of light sources and the first lens. By arranging the diffusing lens along the arrangement direction of the light sources, the brightness of the light emitted from the plurality of light sources can be made uniform and the unevenness of the brightness can be reduced, and the light emitted from the plurality of light sources can be reduced to a single light. It can be handled in the same way as light emitted from a light source.

  The diffusion lens diffuses light of the component in the arrangement direction of the light sources and emits the diffused light. Further, the diffusing lens may diffuse light of components in other directions different from the arrangement direction of the light sources and transmit the light. By doing so, even when the brightness of the component light in a direction different from the arrangement direction of the light sources is uneven, the unevenness can be suppressed and the brightness can be made uniform. The degree of diffusion in the arrangement direction of the light sources and the degree of diffusion in a direction different from the arrangement direction of the light sources may be appropriately determined according to the unevenness in brightness that occurs in each direction. For example, the degree of diffusion in the light source arrangement direction can be made larger than the degree of diffusion in a direction different from the light source arrangement direction.

  Note that if the unevenness of brightness is negligible for light components in a direction different from the light source array direction, only the light source array direction is diffused and not diffused in a direction different from the light source array direction. The light may be transmitted through.

  In this way, the light diffused by the diffusing lens is transmitted through the diffusing lens and emitted.

<Second lens>
The light emitted from the diffusion lens is incident on the second lens. The second lens has a function of collecting incident light. The second lens collects the light emitted from the diffusing lens and emits the collected light. The second lens is not necessarily a lens, and may be an optical element that can collect the light emitted from the diffusion lens.

  The second lens also has a length in which a plurality of light sources are arranged, a length equivalent to the length of the first lens, and the length of the diffusion lens, and the longitudinal direction of the second lens is arranged along the arrangement direction of the light sources. It is preferable. By arranging the longitudinal direction of the second lens along the arrangement direction of the light sources, the light emitted from the diffusion lens can be incident on the second lens with less leakage and condensed. For example, the second lens is preferably arranged in parallel with the arrangement of the plurality of light sources.

<Condensation process and formed optical path>
The light emitted from the plurality of light sources travels along the optical axis direction of the optical system as a whole. In the present embodiment, the optical axis direction is a direction substantially perpendicular to the arrangement direction of the light sources. The light emitted from the light source travels while gradually spreading around the optical axis of each light source. The light emitted from the plurality of light sources includes light of a component in a direction different from the component in the optical axis direction, but travels along the optical axis direction of the optical system as a whole.

  The light traveling in the optical axis direction reaches the outer peripheral surface of the first lens and enters the first lens. Light spreading around the optical axis can also enter the first lens.

  The light incident on the first lens is refracted according to the refractive index of the first lens. The refracted light travels along the optical axis direction of the optical system as a whole inside the first lens. The light traveling in the first lens also includes light having a component in a direction different from the component in the optical axis direction, but travels along the optical axis direction of the optical system as a whole. The light traveling inside the first lens reaches the outer peripheral surface of the first lens.

  The light that travels inside the first lens and reaches the outer peripheral surface is refracted according to the refractive index of the first lens and is emitted from the first lens. The condensing characteristic of the first lens is determined by the refraction at the time of incidence of the first lens and the refraction at the time of emission. As described above, the light emitted from the first lens is the light condensed according to the condensing characteristic of the first lens.

  The light emitted from the first lens again travels along the optical axis direction as a whole. The light emitted from the first lens also includes light having a component in a direction different from the component in the optical axis direction, but proceeds as a whole along the optical axis direction of the optical system.

  The light traveling in the direction of the optical axis enters the diffusion lens. The diffusion lens diffuses the light of the component in the arrangement direction of the light sources more than the light of the component in a direction different from the arrangement direction of the light sources. The diffusion lens emits diffused light.

  The light emitted from the diffusing lens again travels along the optical axis direction as a whole. The light emitted from the diffusing lens also includes light having a component in a direction different from the component in the optical axis direction, but travels along the optical axis direction of the optical system as a whole.

  The light traveling in the optical axis direction reaches the incident surface of the second lens and enters. The light incident on the second lens is refracted according to the refractive index of the second lens. The refracted light travels inside the second lens along the optical axis direction of the optical system as a whole. The light traveling inside the second lens also includes light having a component in a direction different from the component in the optical axis direction, but travels along the optical axis direction of the optical system as a whole. The light traveling inside the second lens reaches the outer peripheral surface of the second lens.

  The light that travels inside the second lens and reaches the outer peripheral surface is refracted according to the refractive index of the second lens and is emitted from the second lens. The condensing characteristic of the second lens is determined by the refraction at the time of incidence of the second lens and the refraction at the time of emission. As described above, the light emitted from the second lens is the light condensed according to the condensing characteristic of the second lens.

  The light emitted from the second lens again travels along the optical axis direction as a whole. The light emitted from the second lens also includes light having a component in a direction different from the component in the optical axis direction, but travels along the optical axis direction of the optical system as a whole.

  Light that is emitted from the second lens and travels along the optical axis direction is applied to the illuminated body to illuminate the illuminated body.

<Center of curvature and radius of curvature of first lens and second lens>
In the direction from the plurality of light sources to the second lens, the second lens is arranged at a position separated by a distance of at least twice the radius of curvature of the first lens with reference to the center of curvature of the first lens. That is, with respect to the relative positions of the first lens and the second lens, the first lens and the second lens are arranged apart from the curvature center of the first lens by more than twice the radius of curvature of the first lens. The arrangement condition that

  The center of curvature of the first lens is the center of an arc that forms the surface of the first lens. The radius of curvature of the first lens is the radius of an arc that forms the surface of the first lens. In addition, when the curve which comprises the surface of a 1st lens is not a circular arc, the surface of a 1st lens can be made into the curvature radius and curvature center which approximated with the circular arc primarily.

  For example, when the first lens is a rod lens, the radius of curvature of the first lens is the radius of the cylindrical side surface that constitutes the rod lens, and the center of curvature of the first lens is the side surface of the cylinder that constitutes the rod lens. It is the heart obtained from Here, the rod lens is a cylindrical lens, and is generally a lens whose cylindrical side surface is polished and finished with high accuracy and whose end surface is a cut surface.

  Further, the radius of curvature and the center of curvature of the first lens may be defined as follows. The center obtained from the shape of the entrance surface and the exit surface of the first lens is the center of curvature, and the radius obtained from the shape of the entrance surface of the first lens and the shape of the exit surface of the first lens is the curvature radius. Can do. Here, the incident surface of the first lens is a surface on which light emitted from a plurality of light sources is incident on the first lens. Further, the emission surface of the first lens is a surface from which light is emitted toward the diffusion lens. The center of curvature is preferably located on the optical axis of the optical system. Moreover, it is preferable that the curvature radius is a length along the optical axis.

  As described above, the first lens and the second lens are disposed at a distance of at least twice the radius of curvature of the first lens with respect to the center of curvature of the first lens. The following arrangement condition is satisfied. Here, the reference position of the second lens may be the entrance surface, the exit surface, or the center of curvature of the second lens. The entrance surface of the second lens is preferable.

  For example, the second lens can be a cylindrical lens or the like. The cylindrical lens has a flat surface having no lens action and a cylindrical surface having a lens action. When the second lens is a cylindrical lens, the incident surface of the second lens can be flat. By using the plane as the reference plane of the second lens, it is possible to easily adjust the optical path to satisfy the above-described arrangement condition.

  In addition, by making the second lens a cylindrical lens, the thickness of the second lens in the optical axis direction can be reduced, and by reducing the distance in the optical axis direction, the overall size and weight can be reduced.

  As described above, in the optical system of the present embodiment, the relative position of the first lens and the second lens is set to be at least twice the radius of curvature of the first lens with reference to the center of curvature of the first lens. The arrangement condition that the first lens and the second lens are arranged apart from each other (hereinafter referred to as the first arrangement condition) is satisfied.

  In addition to the first arrangement condition, the relative positions of the first lens and the second lens are close to four times or less the radius of curvature of the first lens with reference to the center of curvature of the first lens. It is preferable to satisfy the second arrangement condition that the first lens and the second lens are arranged.

  That is, from the first arrangement condition and the second arrangement condition, the relative position of the first lens and the second lens is at least twice the radius of curvature of the first lens with reference to the center of curvature of the first lens. In addition, it is preferable that the first lens and the second lens are arranged within a range of 4 times or less. By satisfying this condition, it is possible to illuminate the object to be illuminated by forming parallel rays as described later.

<Formation of parallel rays>
In some cases, the light collected and emitted by the first lens gradually spreads as it moves away from the first lens. By arranging the second lens so as to satisfy the first arrangement condition described above, the light can be condensed again by the second lens and can be converted into light that travels approximately parallel along the optical axis direction. That is, by arranging the first lens and the second lens so as to satisfy the first arrangement condition described above, the light can be converted into light that is difficult to spread along the optical axis direction.

  Further, as described above, the diffusion lens diffuses the light emitted from the first lens in a predetermined direction, that is, in the arrangement direction of the light sources. For this reason, the brightness of light can be made close to constant in the arrangement direction of the light sources by diffusion.

  In this way, it is possible to form an illumination area in which the brightness of the area defined by the light source arrangement direction and the light source width direction is made nearly constant. Furthermore, since the optical axis direction is converted into light that travels substantially parallel along the optical axis direction, the size of the illumination area can be made constant along the optical axis direction. That is, while satisfying the first arrangement condition for the first lens and the second lens, the light is diffused in the arrangement direction of the light sources by the diffusing lens, so that it approaches the constant brightness and is constant along the optical axis direction. An illumination area having a size can be formed.

  Further, the first arrangement condition is that the first lens and the second lens are arranged so that the lower limit of the distance between the first lens and the second lens is at least twice the radius of curvature of the first lens. It was a thing. However, if the distance between the first lens and the second lens is too long, the second lens may not be able to condense sufficiently, and parallel rays may not be formed. For this reason, it is preferable to arrange the first lens and the second lens so that the upper limit of the distance between the first lens and the second lens is not more than four times the radius of curvature of the first lens (the second lens). Placement conditions). By arranging the first lens and the second lens so as to be included between the upper limit and the lower limit, it is possible to always form parallel rays necessary for illumination of the illumination target.

  In this way, since an illumination area having a certain size and a certain size can be formed along the optical axis direction, even when the distance from the illumination device to the object to be illuminated is different, An area of a certain size can be illuminated with a certain brightness. In other words, even when the distance from the lighting device to the object to be illuminated is changed according to the object to be illuminated and the usage conditions, it is possible to illuminate an area of a certain size with a certain brightness, and various illumination objects and usage conditions Can be provided.

  Light that is close to parallel light can be formed with a simple configuration with a small number of optical elements, and an illuminating device that can respond to various objects to be illuminated and use conditions can be provided.

<Second Embodiment>
According to a second embodiment of the present invention, in the first embodiment of the present invention,
The first optical path length (for example, the length of an optical path L11 described later) until the light emitted from the light source reaches the first lens is the same as the light emitted from the first lens to the second lens. This is shorter than the second optical path length (for example, the length of an optical path L31 and an optical path L41 described later).

  The first optical path length is the length of the optical path until the light emitted from the light source reaches the first lens. The second optical path length is the length of the optical path until the light emitted from the first lens reaches the second lens. The first lens and the second lens are arranged so that the first optical path length is shorter than the second optical path length.

  In the first embodiment of the present invention, the arrangement condition that the first lens and the second lens are arranged apart from the curvature radius of the first lens by more than twice the radius of curvature of the first lens with reference to the center of curvature of the first lens. Stipulate. Furthermore, in the second embodiment of the present invention, the optical path length condition is defined such that the first optical path length is shorter than the second optical path length.

  By making the first optical path length shorter than the second optical path length, the distance between the light source and the first lens can be shortened, and the light emitted from the light source can be efficiently incident on the first lens. Therefore, the light emitted from the light source can be used for illuminating the illuminated body without wasting it. In addition, since the distance between the light source and the first lens can be shortened, the lighting device can be reduced in size.

  Furthermore, since the second optical path length can be made longer than the first optical path length, the conditions for positioning the second lens can be relaxed, and the second lens can be arranged at an optimal position that is as close as possible to parallel light. .

<Third Embodiment>
According to a third embodiment of the present invention, in the first embodiment of the present invention,
A heat dissipating part (for example, a heat dissipating system 300 described later) having a plurality of heat dissipating fins (for example, a heat dissipating fin 350 described later) for dissipating heat generated by the light source;
A heat transfer unit connected to the heat dissipation unit for transferring heat generated by the light source to the heat dissipation unit, wherein the light source is provided so as to be capable of conducting heat (for example, a first transfer unit described later) A second transmission unit (for example, a second transmission unit 330 to be described later) that is connected to the first transmission unit so as to be capable of conducting heat and extends in a direction away from the light source. And a heat transfer part (for example, a heat dissipating frame 310 described later),
Each of the plurality of radiating fins is formed apart from each other,
Each of the plurality of radiating fins includes a fixed end (for example, a fixed end 352 described later) connected to the second transmission unit so as to be capable of conducting heat along the extending direction of the second transmission unit. And an open end (for example, an open end 354 described later) formed at a position away from the fixed end.

  The lighting device further includes a heat radiating unit and a heat transfer unit.

  The heat dissipating part has a plurality of heat dissipating fins. The heat generated by the light source is radiated by the radiation fins. Each of the plurality of radiating fins is formed apart from each other.

  The heat transfer unit is connected to the heat radiating unit and transfers heat generated by the light source to the heat radiating unit. The heat transfer unit includes a first transfer unit and a second transfer unit. It is preferable that the heat radiating section, the first transmission section, and the second transmission section are made of a metal, for example, a material having high thermal conductivity such as aluminum or copper.

  The first transmission unit is provided with a light source capable of conducting heat. The 2nd transmission part is connected with the 1st transmission part so that heat conduction is possible. The 2nd transmission part is formed so that it may extend in the direction away from a light source. For example, it is preferable that the second transmission unit is erected at a right angle with respect to the first transmission unit. The heat transmitted from the light source to the first transmission unit is transmitted to the second transmission unit. The second transmission unit is erected at a right angle to the first transmission unit, and can guide heat in a direction away from the light source. By comprising in this way, the heat emitted from the light source can be guided away from the light source positively.

  Furthermore, the fixed ends of each of the plurality of radiating fins are coupled so as to be able to conduct heat along the extending direction of the second transmission portion, and the heat transmitted to the second transmission portion is transmitted to each of the radiating fins. Is transmitted to the fixed end. The heat transmitted to the fixed end of the heat radiating fin is transmitted from the fixed end toward the open end, and in this process, it can come into contact with air to radiate heat.

  Thus, the heat generated in the light source is first transmitted from the first transmission unit to the second transmission unit, is transmitted to the radiation fin through the second transmission unit, and is transmitted from the radiation fin to the air, Heat can be transmitted away from the light source, making the light source less susceptible to heat. Rather than immediately transferring heat from the first transfer part to the heat radiating fins, by transferring heat to the second transfer part, the heat generated by the light source can be actively released to a position slightly away from the light source, The light source can be accurately protected from heat.

<Fourth embodiment>
A fourth embodiment of the present invention is the third embodiment of the present invention,
The heat transfer unit is connected to the first transfer unit so as to be capable of heat conduction, and is opposed to each other with a first opposing transfer unit (for example, a first opposing transfer unit 340R described later) and a second opposing unit. A transmission unit (for example, a second opposing transmission unit 340L described later);
A first clamping unit (for example, first clamping units 360RU and 360RB described later) and a second clamping unit that clamp the first lens at a certain position with respect to the light source and along the first lens. (For example, a second clamping unit 360LU and 360LB described later)
The first holding part is provided in the first opposing transmission part so as to be able to conduct heat, and the second clamping part is provided in the second opposing transmission part so as to be capable of conducting heat.

  The heat transfer unit includes a first counter transfer unit and a second counter transfer unit. The first counter transmission unit and the second counter transmission unit are arranged so as to be spaced apart from each other. The 1st opposing transmission part and the 2nd opposing transmission part are connected with the 1st transmission part so that heat conduction is possible. The heat transmitted to the first opposing transmission unit and the second opposing transmission unit can also be transmitted to the second transmission unit via the first transmission unit. It is preferable that the first opposing transmission part and the second opposing transmission part are also made of a metal having a high thermal conductivity such as aluminum or copper.

  The first lens is clamped along the first lens by the first clamping unit and the second clamping unit. That is, the first lens is entirely clamped by the first clamping unit and the second clamping unit. The first clamping unit and the second clamping unit clamp the first lens at a fixed position with respect to the light source. By holding the first lens by the first holding part and the second holding part, the distance between the light source and the first lens can be kept constant, and the optical system can be stably maintained. it can.

  The first clamping unit is provided in the first opposing transmission unit so as to be able to conduct heat. Similarly, the 2nd clamping part is provided in the 2nd opposing transmission part so that heat conduction is possible. It is preferable that the first sandwiching portion and the second sandwiching portion are also made of a metal having a high thermal conductivity such as aluminum or copper.

  The first lens may be affected by heat from the light source. When the first lens is affected by heat, the optical characteristics of the first lens may change due to deformation such as expansion or distortion. As described above, the first lens is entirely sandwiched between the first sandwiching portion and the second sandwiching portion, and the first sandwiching portion is provided in the first opposing transmission portion so as to be capable of conducting heat, The two clamping portions are provided in the second opposing transmission portion so as to be able to conduct heat. For this reason, the heat applied to the first lens can be transmitted to the first opposing transmission unit and the second opposing transmission unit via the first clamping unit and the second clamping unit.

  Since the first lens is entirely clamped by the first clamping unit and the second clamping unit, the first lens transmits heat to the first clamping unit and the second clamping unit everywhere. be able to. The heat of the entire first lens can be transferred to the first clamping unit and the second clamping unit.

  The heat transmitted to the first clamping unit and the second clamping unit is transmitted from the first transmission unit to the second transmission unit via the first opposing transmission unit and the second opposing transmission unit. As described above, the heat transmitted to the second transmission unit is transmitted to the heat radiation fin through the second transmission unit, and air is released from the heat radiation fin. Thus, even when heat is applied to the first lens from the light source, the optical characteristics such as the light condensing characteristic of the first lens can be maintained by radiating heat.

<Fifth Embodiment>
According to a fifth embodiment of the present invention, in the third embodiment of the present invention,
A control circuit unit (for example, a circuit system 400 described later) for controlling the light source is disposed with the heat radiating unit and the second transmission unit interposed therebetween.

  The control circuit unit and the heat radiating unit are arranged with the second transmission unit interposed therebetween. The control circuit unit is a circuit for controlling the light source. The control circuit unit also generates heat when energized. The characteristics of the control circuit section change due to heat, and the light source may not be driven sufficiently. The control circuit unit is provided directly on the second transmission unit, and heat generated from the control circuit unit is transmitted to the second transmission unit. In this way, heat generated in the control circuit unit can also be dissipated.

<Sixth Embodiment>
A sixth embodiment of the present invention is the third embodiment of the present invention,
Each of the plurality of radiating fins is provided to be inclined with respect to both the first transmission unit and the second transmission unit.

  Each of the plurality of radiating fins is provided to be inclined with respect to the first transmission unit and the second transmission unit.

  The open end of each of the plurality of heat dissipating fins can be positioned as far away from the light source as possible, and heat can be moved away from the light source as much as possible. In addition, by inclining each of the plurality of radiating fins, air convection can be generated between the adjacent radiating fins to increase the radiating efficiency.

<Seventh embodiment>
According to a seventh embodiment of the present invention, in the third embodiment of the present invention,
Each of the plurality of radiating fins gradually becomes thinner from the fixed end toward the open end.

  By making the space | interval of adjacent radiation fins gradually wide toward an open end, it becomes easy to move air from a fixed end toward an open end, and heat dissipation efficiency can be improved by convection of air. Moreover, weight reduction can be achieved by making it thin gradually.

<Eighth Embodiment>
An eighth embodiment of the present invention is the fourth embodiment of the present invention,
The second lens is provided on the first opposing transmission part and the second opposing transmission part by a heat insulating member.

  The first lens is provided in the first opposing transmission unit and the second opposing transmission unit by a first clamping unit and a second clamping unit capable of conducting heat. In other words, the first lens is disposed at a position close to the light source, and is configured to actively release heat. On the other hand, a 2nd lens is provided in a 1st opposing transmission part and a 2nd opposing transmission part by a heat insulation member. The second lens is arranged at a position far from the light source and is configured not to actively transmit heat.

  As described above, by selecting heat radiation or heat insulation according to the distance from the light source, it is possible to accurately cope with heat generated from the light source.

<<< Outline of Lighting Device 100 >>>
The illumination device 100 is a device for illuminating an object to be illuminated. For example, there is an article for inspecting the surface as an object to be illuminated. The illumination device 100 is used to illuminate the surface of an article and inspect the presence or absence of defects and the form of defects.

  As will be described later, a slit-shaped opening 110 (see FIG. 1) is formed in the lighting device 100, and the lighting device 100 emits elongated light or linear light from the opening 110 and is an object to be illuminated. It is a lighting device that illuminates the surface of an article, and is a so-called line-type lighting device.

  FIG. 1 is a perspective view of the lighting device 100 as viewed from below. FIG. 2 is a perspective view of the lighting device 100 as viewed from above. FIG. 3 is a side view of the lighting device 100 when the side cover is removed.

  The illumination device 100 mainly includes an optical system 200, a heat dissipation system 300, and a circuit system 400. The optical system 200 generates light for illuminating the object to be illuminated. The heat dissipation system 300 radiates heat generated from the optical system 200 and the circuit system 400. The circuit system 400 controls and drives the light source of the optical system 200 and the like.

  As shown in FIG. 1, the lighting device 100 has a long shape. The length of the lighting device 100 can be appropriately determined according to the length and size of the article that is the object to be illuminated. As shown in FIG. 1, the illumination device 100 has an opening 110 at the bottom. Light R generated by the optical system 200 is emitted from the opening 110. In the example shown in FIGS. 1 and 2, light R is emitted downward from the opening 110.

  As shown in FIGS. 1 to 3, the illumination device 100 is installed such that the opening 110 faces downward, and light R is emitted downward from the opening 110. Moreover, as shown in FIGS. 1-3, the illuminating device 100 is installed so that the radiation fin 350 may be located above the illuminating device 100. FIG. In other words, the illumination system 100 is installed so that the optical system 200 serving as a heat generation source is positioned on the lower side and the heat dissipation system 300 is positioned on the upper side, so that the opening 356 (FIG. 3) faces upward, and air convection is performed. Can actively dissipate heat.

<< Optical System 200 >>
The optical system 200 mainly includes a light source 210, a rod lens 220, a diffusion lens 230, and a cylindrical lens 240.

<Light source 210>
The light source 210 includes a plurality of LEDs 212. It is preferable to use so-called power LEDs as the plurality of LEDs 212. The power LED is an LED that is driven with a larger current than a general LED. By using the power LED, the luminance can be increased and the illuminance can be increased.

  In the present embodiment, the LED 212 is mounted on the light source mounting substrate 214. The light source mounting substrate 214 is a substrate for supplying a current for driving the LED 212. The light source mounting board 214 is a so-called aluminum board, and is a circuit board on which a printed wiring board is bonded to an aluminum base board with an insulating adhesive layer, and LEDs 212 are mounted on various electronic components.

  An aluminum base substrate (not shown) of the light source mounting substrate 214 has a flat shape, and the light source mounting substrate 214 also has a flat shape. The LED 212 is attached to a predetermined position of the light source mounting board 214 so as to emit light in a direction perpendicular to a plane including the light source mounting board 214.

  Further, a predetermined number, for example, 26 LEDs 212 are attached to one light source mounting substrate 214. In the light source mounting substrate 214, 26 LEDs 212 are attached in a straight line and in a line at equal intervals. As described above, the LEDs 212 are mounted so as to emit light in a direction perpendicular to the plane including the light source mounting substrate 214, and the light sources are mounted so that the optical axes of all 26 LEDs 212 are in the same direction. Attached to the substrate 214. The optical axis of the LED 212 is a virtual light beam that is representative of the luminous flux emitted from the light source.

  In this embodiment, 26 LEDs 212 are attached to the light source mounting substrate 214 in a straight line and in a line at equal intervals, but the arrangement of the plurality of LEDs 212 depends on the size of the article that is the object to be illuminated. It can be determined appropriately according to the shape. For example, they may be arranged along a predetermined curved line or arranged in a plurality of rows.

  As will be described later, in the present embodiment, six light source mounting substrates 214 are arranged in a straight line and in a line. Therefore, a total of 156 (= 6 × 26) LEDs 212 are arranged in a straight line and in a line. By arranging the LEDs 212 in a straight line and in a row, a plurality of LEDs 212 can be positioned along a rod lens 220 described later. Note that the number and arrangement of the light source mounting substrates 214 can be appropriately determined according to the size and shape of the article that is the object to be illuminated.

  The LEDs 212 are arranged up to a predetermined position at the end of the light source mounting substrate 214. When a plurality of light source mounting substrates 214 are arranged adjacent to each other, the LEDs 212 adjacent at the boundary of the adjacent light source mounting substrates 214 are also other Are arranged at the same interval as the adjacent LEDs 212. For this reason, when the plurality of light source mounting substrates 214 are arranged in a straight line and in a row adjacent to each other, all the LEDs 212 can be arranged in a straight line and in a line at equal intervals.

  By arranging all the LEDs 212 at equal intervals, the light emitted from all the LEDs 212 is overlapped with each other, and the brightness distribution is reduced while keeping the brightness distribution uniform, and the brightness of the light emitted from the plurality of LEDs 212 is made closer to uniform. be able to. In addition, what is necessary is just to determine the space | interval of adjacent LED212 according to brightness, such as required illumination intensity.

  The light spread (light distribution) of the plurality of LEDs 212 is preferably wide within a range where the light can enter a rod lens 220 described later. By spreading the light emitted from the LEDs 212, they can be easily overlapped with each other, and the brightness distribution can be reduced to make the brightness uniform.

<Rod lens 220>
The rod lens 220 is a cylindrical lens and has a cylindrical shape. The rod lens 220 has a long shape. The length of the rod lens 220 can be appropriately determined according to the size and shape of the article that is the object to be illuminated. The rod lens 220 is made of a synthetic resin such as acrylic. The rod lens 220 only needs to be formed of a material that has translucency and can collect light by refraction. In addition to synthetic resins such as acrylic, it may be formed of glass or the like.

  As described above, the plurality of LEDs 212 are linearly arranged in a line. The plurality of LEDs 212 are arranged along the longitudinal direction of the rod lens 220. Light emitted from the plurality of LEDs 212 is incident on the cylindrical side surface 222 of the rod lens 220. In particular, it is preferable that the light emitted from all of the plurality of LEDs 212 is incident on the cylindrical side surface 222 of the rod lens 220. The light emitted from the plurality of LEDs 212 can be used for illuminating the object to be illuminated without wasting it.

  Light emitted from the plurality of LEDs 212 is incident on the cylindrical side surface 222 of the rod lens 220. The light incident on the cylindrical side surface 222 is refracted by the cylindrical side surface 222 and enters the rod lens 220. The light that has entered the inside of the rod lens 220 reaches the cylindrical side surface 222 of the rod lens 220, is refracted by the cylindrical side surface 222, and is emitted from the rod lens 220. The rod lens 220 condenses the light emitted from the plurality of LEDs 212 by refraction upon incidence and refraction upon emission.

  The rod lens 220 collects the light emitted from the plurality of LEDs 212 and adjusts the traveling direction so as to be directed to the illuminated body.

<Diffusion lens 230>
The diffusion lens 230 has a thin plate shape. The diffusion lens 230 has a long shape. The length of the diffusing lens 230 can be appropriately determined according to the size and shape of the article that is the object to be illuminated. The diffusing lens 230 is made of a synthetic resin such as polycarbonate or acrylic.

  A minute and random lens array (not shown) is formed on the surface of the diffusion lens 230. The diffusion lens 230 diffracts and shapes the incident light by refracting the light at a desired diffusion angle (light distribution angle) by the diffusion function of the lens array. By diffusing light, unevenness in brightness can be reduced. Examples of diffusion modes include, for example, circular diffusion to a wide angle that diffuses in a wide range in all directions, circular diffusion to a narrow angle that diffuses in a narrow range in all directions, and diffusion in a certain direction with an aspect ratio. There is an elliptical diffuser that diffuses more strongly than other directions.

  In the present embodiment, the diffusing lens 230 is used for diffusing in the direction in which the plurality of LEDs 212 are arranged. The brightness distribution (unevenness) caused by the light emitted separately from each LED 212 when a plurality of LEDs 212 are arranged can be reduced by the diffusion lens 230 so that the brightness can be made uniform.

  The incident surface of the diffusing lens 230 is directed to the rod lens 220, and the exit surface of the diffusing lens 230 is directed to the cylindrical lens 240. The light emitted from the rod lens 220 enters the diffusion lens 230. The light that has entered the diffusing lens 230 is diffused by a minute lens array formed on the surface of the diffusing lens 230 so that the brightness is made uniform and is emitted from the exit surface of the diffusing lens 230.

  The diffusion mode of the diffusion lens 230 includes the brightness of the plurality of LEDs 212, the interval between the LEDs 212, the degree of condensing of the rod lens 220, the distance between the plurality of LEDs 212 and the rod lens 220, the rod lens 220 and the diffusion lens 230. It may be determined appropriately depending on the interval between and the like. By diffusing by the diffusing lens 230, the brightness can be made nearly uniform, and the light emitted from the plurality of LEDs 212 can be handled in the same manner as the light emitted from a single light source.

  In the present embodiment, the diffusing lens 230 only needs to sufficiently diffuse and transmit light in the direction in which the plurality of LEDs 212 are arranged, and may transmit the other direction as it is without being diffused. .

  In the present embodiment, the diffusing lens 230 is provided in close contact with the incident surface 242 of the cylindrical lens 240. The light emitted from the diffusing lens 230 immediately enters the incident surface 242 of the cylindrical lens 240. Note that the diffusing lens 230 may be arranged separately from the cylindrical lens 240. Another optical element, for example, a lens, a prism, a mirror, or the like can be arranged between the diffusing lens 230 and the cylindrical lens 240 to adjust the optical path.

<Cylindrical lens 240>
The cylindrical lens 240 has a thin plate shape as a whole. The cylindrical lens 240 has a long shape. The length of the cylindrical lens 240 can be appropriately determined according to the size and shape of the article that is the object to be illuminated. The cylindrical lens 240 is formed of a synthetic resin such as polycarbonate or acrylic. Moreover, you may form with glass etc.

  The cylindrical lens 240 has a surface 242 that is formed flat and does not have a lens action, and a surface 244 that has a shape obtained by cutting a part of a side surface of a cylinder and has a lens action. In this embodiment mode, the surface 242 that does not have a lens action is the entrance surface 242, and the surface 244 that has a lens action is the exit surface 244.

  The light emitted from the diffusing lens 230 is incident on the incident surface 242 having no lens action, and travels inside the cylindrical lens 240. The light traveling inside the cylindrical lens 240 reaches the exit surface 244 having a lens action. The light that reaches the emission surface 244 is refracted by the emission surface 244. The cylindrical lens 240 functions to collect the light emitted from the diffusion lens 230 by the refraction at the emission surface 244.

  In the present embodiment, the cylindrical lens 240 condenses the light emitted from the diffusing lens 230 to convert it into light close to parallel light, and directs the light close to parallel light toward the illuminated object. Exit.

  In this way, the lighting device 100 brings the light emitted from the plurality of LEDs 212 closer to the brightness uniformly by the diffusion lens 230, and the light that is brought closer to the brightness closer to the parallel light by the cylindrical lens 240. Produces light that is nearly uniform and close to parallel light. Light that is nearly uniform in brightness and close to parallel light is emitted from the opening 110 of the illumination device 100 to illuminate the object to be illuminated.

  As described above, the optical system 200 according to the present embodiment has been illustrated as having the light source 210, the rod lens 220, the diffusing lens 230, and the cylindrical lens 240, but other optical elements such as a lens, You may have a prism, a mirror, etc. By providing these optical elements, the optical path can be further adjusted.

<< Optical axis direction (Z direction), light source arrangement direction (X direction), light source width direction (Y direction) >>
<Optical axis direction (Z direction)>
The optical axis is a virtual light beam that is representative of the light flux emitted from the plurality of LEDs 212. For example, in the present embodiment, the optical axis direction is the light beam having the highest light intensity among the light beams emitted from the plurality of LEDs 212 and passing through the rod lens 220, the diffusion lens 230, and the cylindrical lens 240. The direction of the light beam that can be imagined when passing through can be set. The optical axis direction is the overall traveling direction of the light emitted from the plurality of LEDs 212. In the present embodiment, the optical axis direction is the Z direction.

<Expansion direction (X direction and Y direction)>
Moreover, the light emitted from each of the plurality of LEDs 212 gradually spreads along the optical axis direction according to the light distribution characteristics. This light spreads in a substantially conical shape centering on the optical axis direction of each of the plurality of LEDs 212 (see L1 in FIG. 7 and L11 and L12 in FIG. 8). Two directions perpendicular to each other can be defined with respect to the diameter expansion direction in which the light spreads.

<Light source arrangement direction (X direction)>
As shown in FIG. 9, the first diameter expansion direction is a direction in which the plurality of LEDs 212 are arranged, and is an orientation along the plurality of LEDs 212, and this direction is referred to as a “light source arrangement direction”. In the present embodiment, 26 LEDs 212 are attached to the light source mounting board 214 in a straight line and in a line, and six light source mounting boards 214 are arranged in a straight line and in a line. A total of 156 (= 6 × 26) LEDs 212 are arranged in a straight line and in a line. The direction in which the 156 LEDs 212 are arranged in a straight line and in a line is the “light source arrangement direction”. The arrangement direction of the light sources (X direction) is a direction perpendicular to the optical axis direction (Z direction).

<Width direction of light source (Y direction)>
The second diameter expansion direction is a direction perpendicular to the first diameter expansion direction, and is a direction that defines the width of light emitted from each of the plurality of LEDs 212. This direction is referred to as the “light source width direction”. The width direction (Y direction) of the light source, which is the second diameter expansion direction, is also a direction perpendicular to the optical axis direction (Z direction). The width of the illumination area of the illumination device can be defined by the “light source width direction”.

<< Heat dissipation system 300 >>
The heat dissipation system 300 includes a heat dissipation frame 310. The heat dissipating frame 310 has a long shape, and the length in the longitudinal direction is slightly longer than that of the light source 210, the rod lens 220, the diffusion lens 230, and the cylindrical lens 240. The heat dissipating frame 310 is made of a member having high thermal conductivity, for example, a metal such as aluminum. As will be described later, the heat dissipating frame 310 may have a function of holding various components, and may be made of a material that can hold various components in a fixed position and can transmit heat generated from the various components. .

  Various components such as the optical system 200 and the circuit system 400 are attached to the heat dissipation frame 310. Heat generated from various components such as the optical system 200 and the circuit system 400 is transmitted to the heat radiating fins 350 through the heat radiating frame 310.

  The heat dissipation frame 310 also functions as a main part of the housing of the lighting device 100. Various components such as the optical system 200 and the circuit system 400 are attached to and held on the heat dissipation frame 310.

  The heat dissipating frame 310 mainly includes a first transmission unit 320, a second transmission unit 330, a first counter transmission unit 340R, and a second counter transmission unit 340L, and is integrally formed.

<First transmission unit 320>
The first transmission unit 320 has a long plate shape. The first transmission unit 320 is a frame that is positioned substantially at the center of the heat dissipation frame 310 and extends in the horizontal direction.

  The first transmission part 320 includes a thin plate part 322a formed with a small thickness and a thick plate part 322b formed thicker than the thin plate part 322a. In the thick plate portion 322b, two cylindrical through holes 324 are formed along the longitudinal direction of the first transmission portion 320. The heat radiating frame 310 can be cooled via the first transmission part 320 by allowing a refrigerant such as gas or liquid to flow through the two through holes 324 as necessary.

  The lower surface 326 of the first transmission unit 320 is formed flat. A plurality of light source mounting boards 214 are attached to the lower surface 326 of the first transmission unit 320 along the longitudinal direction by locking members 216 such as screws and bolts. As described above, the light source mounting substrate 214 has an aluminum substrate (not shown). The light source mounting substrate 214 is attached to the first transmission unit 320 with the aluminum substrate being in close contact with the lower surface 326 of the first transmission unit 320.

  The heat generated from the plurality of LEDs 212 is transmitted from the aluminum substrate of the light source mounting substrate 214 to the heat dissipation frame 310 via the lower surface 326 of the first transmission unit 320. As will be described later, the heat transferred to the heat radiating frame 310 is transferred to the heat radiating fins 350 and radiated. By providing the LED 212 as a heat source on the lower surface 326 of the first transmission unit 320, heat generated from the LED 212 can be easily transmitted in the direction opposite to the optical system 200 (upward side), and the optical system 200 is affected by heat. Can be difficult to give.

  By attaching the light source mounting substrate 214 so that the aluminum substrate of the light source mounting substrate 214 is in close contact with the lower surface 326 of the first transmission unit 320, the plurality of LEDs 212 has the first transmission unit 320 sandwiching the light source mounting substrate 214. Is located on the other side of By doing in this way, several LED212 can be arrange | positioned so that light may be emitted toward the downward direction (toward the rod lens 220).

  The plurality of light source mounting substrates 214 are arranged in close contact with each other on the lower surface 326 of the first transmission unit 320 and arranged horizontally. By arranging a plurality of light source mounting boards 214 in close contact with each other, all of the LEDs 212 attached to the light source mounting board 214 can be arranged linearly and in a line at equal intervals.

<Second transmission unit 330>
The second transmission unit 330 is erected and connected to a substantially central portion of the upper surface of the first transmission unit 320. The second transmission unit 330 has a long plate shape. The second transmission unit 330 is a frame that stands vertically with respect to the first transmission unit 320 and extends in the vertical direction. An upper region of the lighting device 100 can be defined by the second transmission unit 330.

  The second transmission unit 330 has a first surface 332 and a second surface 334 that are formed in parallel to face each other. The first surface 332 and the second surface 334 extend along the vertical direction.

  The first surface 332 and the upper surface of the first transmission unit 320 are substantially perpendicular to each other, and a plurality of radiating fins 350 are provided in a region between the first surface 332 and the upper surface of the first transmission unit 320. It is formed. The radiating fin 350 has a fixed end 352 and an open end 354. The fixed end 352 is connected to the first surface 332. The radiating fin 350 protrudes from the first surface 332 at an angle different from the right angle with respect to the first surface 332. The open end 354 is positioned so as to be separated from both the first surface 332 and the upper surface of the first transmission unit 320. The heat radiating fin 350 extends obliquely upward from the fixed end 352.

  The heat radiating fin 350 has a substantially rectangular parallelepiped shape with a thin plate shape and a long shape. It is formed along the longitudinal direction of the heat dissipating frame 310. The heat radiation fin 350 is formed so that the fixed end 352 is thick and gradually becomes thinner toward the open end 354.

  There is air for exchanging heat between adjacent radiating fins 350. An opening 356 is formed between the open ends 354 of the adjacent radiating fins 350. The air heated by the heat radiation from the heat radiation fins 350 flows upward along the heat radiation fins 350 and flows out from the opening 356. Along with the outflow from the open port 356, new air flows between the radiating fins 350 from the vicinity of the fixed end 352, thereby generating convection.

  The heat radiating fins 350 extend obliquely upward, and can easily flow the air warmed by heat radiation toward the opening 356, thereby improving the heat radiation efficiency.

  The fixed end 352 of the heat radiating fin 350 may be formed not only on the first surface 332 of the second transmission unit 330 but also on the upper surface of the first transmission unit 320. The radiating fins 350 formed on the upper surface of the first transmission part 320 are also formed so as to protrude from the upper surface of the first transmission part 320 in an obliquely upward direction.

  By forming the heat radiation fins 350 on the upper surface of the first transmission part 320, the number of heat radiation fins 350 can be increased, and the heat radiation efficiency can be further increased.

  On the surface of the heat radiating fin 350, along the longitudinal direction, long protrusions (ridges) and long grooves are alternately formed in parallel with each other. By forming the long protrusions and the long grooves, the surface area of the radiating fin 350 can be increased, and by increasing the area in contact with the air, the heat dissipation efficiency can be further increased.

  A drive circuit 410 that is the circuit system 400 is attached to the second surface 334 of the second transmission unit 330 via a spacer. The drive circuit 410 is driven by being connected with a commercial power source or the like. The drive circuit 410 is a circuit that mainly supplies a power supply current, a control signal, and the like to the light source mounting substrate 214. The drive circuit 410 generates a constant current for driving the LED 212 and supplies it to the light source mounting substrate 214.

  As described above, it is preferable to use a power LED as a light source, and the power LED is driven by a large current. For this reason, the power consumption of the drive circuit 410 is large and the amount of heat generated is also large. By attaching the drive circuit 410 to the second transmission unit 330, heat generated from the drive circuit 410 can be easily transmitted to the second transmission unit 330, and the drive circuit 410 can be stably operated by cooling. .

  In the above-described example, the case where the plurality of heat radiating fins 350 extend obliquely upward is shown, but they may extend in the horizontal direction or in the vertical direction. Depending on the amount of heat generated from the LED 212 and the size and shape of the first transmission unit 320, the second transmission unit 330, the first counter transmission unit 340R, and the second counter transmission unit 340L, You only have to determine the direction.

<First opposing transmission unit 340R and second opposing transmission unit 340L>
The first transmission unit 320 is provided with a first counter transmission unit 340R and a second counter transmission unit 340L. As shown in FIG. 3, the first transmission unit 320 has a first end 329R and a second end 329L in the horizontal direction. In FIG. 3, the first end 329R is the right end, and the second end 329L is the left end.

  The first opposing transmission unit 340R is a frame that is connected to the first end 329R of the lower surface 326 of the first transmission unit 320 and extends in the vertical direction. The second opposing transmission unit 340L is a frame that is connected to the second end 329L of the lower surface 326 of the first transmission unit 320 and extends in the vertical direction. The lower region of the lighting device 100 can be defined by the first opposing transmission unit 340R and the second opposing transmission unit 340L.

  The rod lens 220 is disposed between the first opposing transmission unit 340R and the second opposing transmission unit 340L. The rod lens 220 is clamped by the first clamping units 360RU and 360RB and the second clamping units 360LU and 360LB, and is attached to the first opposing transmission unit 340R and the second opposing transmission unit 340L.

  The first clamping unit 360RU clamps the rod lens 220 from the upper right side, the first clamping unit 360RB clamps the rod lens 220 from the lower right side, and the second clamping unit 360LU is the rod lens from the upper left side. 220, and the second clamping unit 360LB clamps the rod lens 220 from the lower left side.

  The first clamping parts 360RU and 360RB and the second clamping parts 360LU and 360LB are formed of a metal such as aluminum. The first clamping parts 360RU and 360RB and the second clamping parts 360LU and 360LB have a long shape and have approximately the same length as the length of the rod lens 220 in the longitudinal direction. The first clamping parts 360RU and 360RB and the second clamping parts 360LU and 360LB press the rod lens 220 over the entire length of the rod lens 220.

  The first sandwiching portions 360RU and 360RB and the second sandwiching portions 360LU and 360LB all have the same structure, and include a fixed piece 362, a protruding piece 364, and a pressing piece 366. The fixed piece 362 and the protruding piece 364 are connected by the first bent side 368a. The protruding piece 364 and the pressing piece 366 are connected by a second bent side 368b. The fixed piece 362, the protruding piece 364, and the pressing piece 366 have a long shape and are disposed along the longitudinal direction of the rod lens 220. The first bent side 368 a and the second bent side 368 b also have a long shape and are arranged along the longitudinal direction of the rod lens 220.

  The fixed piece 362 is a portion fixed to the first opposing transmission unit 340R and the second opposing transmission unit 340L. The fixing pieces 362 of the first clamping portions 360RU and 360RB are fixed to the first opposing transmission portion 340R by a locking member 216 such as a bolt or a screw. The fixing pieces 362 of the second clamping portions 360LU and 360LB are fixed to the second opposing transmission portion 340L by a locking member 216 such as a bolt or a screw. By fixing the fixing piece 362 to the first opposing transmission part 340R and the second opposing transmission part 340L, the first clamping parts 360RU and 360RB and the entire second clamping parts 360LU and 360LB are fixed. Can do.

  The protruding piece 364 is formed to protrude from the fixed piece 362 through the first bent side 368a. The first bent side 368a is bent and can be elastically deformed around the first bent side 368a. The protruding piece 364 is bent at an angle of about 90 degrees with respect to the fixed piece 362. By fixing the fixing piece 362 to the first opposing transmission part 340R and the second opposing transmission part 340L, the protruding piece 364 can be elastically deformed from the first opposing transmission part 340R and the second opposing transmission part 340L. Protruding.

  The pressing piece 366 is formed to bend and protrude from the protruding piece 364 via the second bent side 368b. The second bent side 368b is formed by being bent, and can be elastically deformed around the second bent side 368b. The pressing piece 366 protrudes from the protruding piece 364 so as to be elastically deformable. The pressing piece 366 is bent at a predetermined obtuse angle with respect to the protruding piece 364. The angle formed by the pressing piece 366 and the protruding piece 364 is appropriately determined depending on the position at which the first holding portions 360RU and 360RB and the second holding portions 360LU and 360LB are fixed, the diameter of the rod lens 220, and the like. That's fine.

  The pressing piece 366 presses the rod lens 220 so as to contact the outer periphery of the rod lens 220 at the contact point P. The first clamping parts 360RU and 360RB and the pressing pieces 366 of the second clamping parts 360LU and 360LB come into contact with the outer periphery of the rod lens 220 at the contact point P, and the rod lens 220 is clamped. The contact point P exists along the longitudinal direction of the rod lens 220, and the pressing piece 366 presses over the longitudinal direction of the rod lens 220.

  The first bent side 368a and the second bent side 368b can be elastically deformed, and the rod lens 220 is appropriately pressed by the urging force generated by the elastic deformation, and is held in a fixed position by sandwiching the rod lens 220. can do. Since the rod lens 220 is pressed by the urging force generated by the elastic deformation, the rod lens 220 can be held without being damaged.

  The rod lens 220 is disposed in the vicinity of the plurality of LEDs 212 so that light emitted from the plurality of LEDs 212 enters without leakage. For this reason, the heat generated from the plurality of LEDs 212 may be transmitted to the rod lens 220. When the temperature of the rod lens 220 rises, the optical characteristics of the rod lens 220 may change, and it is necessary to release heat transmitted to the rod lens 220.

  The first clamping parts 360RU and 360RB and the second clamping parts 360LU and 360LB are made of metal such as aluminum. The heat transmitted to the rod lens 220 is transmitted to the first opposing transmission part 340R via the first clamping parts 360RU and 360RB, and the second opposing transmission part via the second clamping parts 360LU and 360LB. 340L. The heat transmitted to the first opposing transmission unit 340R and the second opposing transmission unit 340L is transmitted to the radiation fins 350 via the radiation frame 310 and can be radiated.

  Further, the pressing pieces 366 of the first sandwiching portions 360RU and 360RB and the second sandwiching portions 360LU and 360LB are in contact with each other along the longitudinal direction of the rod lens 220. For this reason, heat can be transmitted to the first opposing transmission part 340R and the second opposing transmission part 340L from any part in the longitudinal direction of the rod lens 220, and the entire rod lens 220 can be dissipated. The overall optical characteristics of the rod lens 220 can be maintained by the overall heat dissipation.

  The first sandwiching portions 360RU and 360RB and the second sandwiching portions 360LU and 360LB need only be made of not only aluminum but also elastically deformable and high thermal conductivity.

<Stepped portion 380 and tapered portion 382>
A stepped portion 380 is formed outside the first opposing transmission portion 340R and the second opposing transmission portion 340L. A cover (not shown) of the housing is locked to the step portion 380. By forming the stepped portion 380, the cover of the housing can be attached to the first opposing transmission portion 340R and the second opposing transmission portion 340L at a fixed position, and various optical elements constituting the optical system 200 can be attached. It can be protected accurately. Further, when the cover of the housing is attached, the outer surface can be flattened, and the positioning of the lighting device 100 can be facilitated and the handling can be simplified.

  Further, a tapered portion 382 is formed outside the first opposing transmission portion 340R and the second opposing transmission portion 340L. By forming the tapered portion 382 in accordance with the formation of the stepped portion 380, the thickness of the first opposing transmission portion 340R and the second opposing transmission portion 340L is maintained, and the first opposing transmission portion 340R and the second opposing transmission are maintained. The strength of the portion 340L can be ensured. Moreover, heat capacity can be adjusted and the heat dissipation state can be stabilized by maintaining the thickness.

<Groove part 384>
A groove portion 384 is formed on the upper side of the second end portion 329 </ b> L of the first transmission portion 320. The groove portion 384 is formed over the entire length of the first transmission portion 320, and a cover sheet metal (not shown) can be stably locked and attached to the groove portion 384.

<Groove part 386R and groove part 386L>
A groove portion 386R is formed at the first end portion 329R of the first transmission portion 320, and a groove portion 386L is formed at the second end portion 329L of the first transmission portion 320. Both the groove portion 386R and the groove portion 386L are formed over the entire length of the first transmission portion 320. A slide nut for attaching the lighting device 100 is inserted into the groove 386R and the groove 386L. The lighting device 100 can be supported by the slide nut at a plurality of locations of the groove portion 386R and the groove portion 386L, and the lighting device 100 can be held at a certain position. By holding the lighting device 100 at a certain position, it is difficult to be affected by external vibrations and the like, and the light R emitted from the opening 110 can be stably illuminated on the object to be illuminated.

<Holding of cylindrical lens 240>
Two holding members 370 are attached to the distal ends of the first opposing transmission portion 340R and the second opposing transmission portion 340L. The two holding members 370 hold the cylindrical lens 240 in the first opposing transmission unit 340R and the second opposing transmission unit 340L.

  The two holding members 370 are made of a heat-insulating resin. The cylindrical lens 240 is attached to the first opposing transmission part 340R and the second opposing transmission part 340L by a resinous holding member 370.

  The first counter transmission unit 340 </ b> R and the second counter transmission unit 340 </ b> L may increase in temperature due to heat generated from the plurality of LEDs 212 or heat transmitted through the rod lens 220. As described above, the cylindrical lens 240 is formed of a synthetic resin such as polycarbonate or acrylic. In addition, a diffusion lens 230 is provided in close contact with the cylindrical lens 240. The diffusing lens 230 is made of a synthetic resin such as polycarbonate or acrylic.

  For this reason, when heat is transmitted from the first opposing transmission unit 340R and the second opposing transmission unit 340L to the diffusing lens 230 or the cylindrical lens 240, the diffusing lens 230 or the cylindrical lens 240 is damaged by the heat, or the optical characteristics. May change.

  By configuring the two holding members 370 with a heat-insulating resin, heat is not easily transmitted to the diffusion lens 230 and the cylindrical lens 240 due to the heat-insulating characteristics of the resin, and the diffusion lens 230 and the cylindrical lens 240 are damaged or have optical characteristics. Can be prevented from changing.

  As described above, the rod lens 220 is sandwiched between the first sandwiching portions 360RU and 360RB and the second sandwiching portions 360LU and 360LB, and is attached to the first opposing transmission portion 340R and the second opposing transmission portion 340L. . The first sandwiching portions 360RU and 360RB and the second sandwiching portions 360LU and 360LB are formed of a metal such as aluminum having high thermal conductivity. The heat transferred from the LED 212 to the rod lens 220 is transferred to the first opposing transmission part 340R and the second opposing transmission part 340L via the first clamping parts 360RU and 360RB and the second clamping parts 360LU and 360LB. Can communicate and dissipate heat.

  As described above, not only the configuration in which the heat transmitted to the rod lens 220 is dissipated, but the rod lens 220 may be supported by a heat insulating member in the same manner as the cylindrical lens 240. Whether the support part for the rod lens 220 is configured to radiate heat or to be insulated depends on the heat generated from the LED 212, the distance between the LED 212 and the rod lens 220, etc. You can decide based on it.

<< Circuit System 400 >>
The circuit system 400 includes a drive circuit 410. The drive circuit 410 is a circuit that mainly supplies a power supply current, a control signal, and the like to the light source mounting substrate 214. The drive circuit 410 generates a constant current for driving the LED 212 and supplies it to the light source mounting substrate 214. The drive circuit 410 is driven by being connected with a commercial power source or the like. The drive circuit 410 generates a large current for supplying the LED 212 or generates various drive currents. For this reason, the power consumption of the drive circuit 410 is large and the amount of heat generated is also large. It is necessary to appropriately dissipate heat generated from the drive circuit 410.

  A LAN connector (not shown) that can connect a LAN cable is also provided. A control device is connected via a LAN cable, and the control device can perform detailed control such as dimming, turning on and off the LED 212.

  Furthermore, a BNC connector (not shown) to which a BNC cable can be connected is also provided. By inputting a pulse signal via the BNC connector, high-speed blinking control can be performed according to the frequency of the pulse signal.

<<< Optical Path in Optical System 200 >>>
As described above, the optical system 200 mainly includes the light source 210, the rod lens 220, the diffusion lens 230, and the cylindrical lens 240. Below, the optical path produced | generated by these optical elements is demonstrated.

<<< Formation of optical path >>>
As shown in FIGS. 7 to 9, the light L <b> 1 emitted from the plurality of LEDs 212 travels along the optical axis direction (Z direction) of the optical system as a whole. The light L1 emitted from the light source travels while gradually spreading around the optical axis T of the optical system according to the light distribution characteristics. The light L1 emitted from the plurality of LEDs 212 includes light (L12) having a component in a direction different from the component (L11) in the optical axis direction, but proceeds along the optical axis direction of the optical system as a whole. .

  The light L <b> 11 (see FIGS. 8 and 9) traveling in the optical axis direction reaches the cylindrical side surface 222 of the rod lens 220 and enters the rod lens 220. Light L <b> 12 (see FIGS. 8 and 9) that spreads about the optical axis T can also enter the rod lens 220.

  Of the light L 1 incident on the rod lens 220, the light incident obliquely on the cylindrical side surface 222 of the rod lens 220 is refracted according to the refractive index of the rod lens 220. The light L2 incident on the rod lens 220 travels inside the rod lens 220 along the optical axis direction (Z direction) of the optical system as a whole. The light L2 traveling inside the rod lens 220 includes light (L22) having a component different from the component in the optical axis direction in addition to the light component (L21) in the optical axis direction. The process proceeds along the optical axis of the optical system. The light L 2 that has traveled through the rod lens 220 reaches the cylindrical side surface 222 of the rod lens 220.

  The light that travels inside the rod lens 220 and reaches the cylindrical side surface 222 is refracted according to the refractive index of the rod lens 220. The refracted light is emitted from the rod lens 220. The condensing characteristic of the rod lens 220 is determined by the refraction at the time of incidence of the rod lens 220 and the refraction at the time of emission. As described above, the light L3 emitted from the rod lens 220 is light that is condensed according to the light condensing characteristic of the rod lens 220.

  The light L3 emitted from the rod lens 220 again travels along the optical axis direction as a whole. The light L3 emitted from the rod lens 220 also includes light (L32) having a component in a direction different from the component (L31) in the optical axis direction, but travels along the optical axis direction of the optical system as a whole.

  The light L3 emitted from the rod lens 220 enters the diffusion lens 230. As described above, a minute lens array is formed on the surface of the diffusion lens 230. The light L4 incident on the diffusion lens 230 is diffused by the lens array. The diffusion lens 230 diffuses and emits the light component (L43) in the arrangement direction (X direction) of the light sources (FIG. 9). Further, light of other components (L41, L42, etc.) different from the components in the arrangement direction of the light source is emitted without being diffused or weakly diffused (FIG. 8).

  As described above, in the present embodiment, the diffusing lens 230 is provided in close contact with the incident surface 242 of the cylindrical lens 240. The light emitted from the diffusing lens 230 immediately enters the incident surface 242 of the cylindrical lens 240. The light L5 incident on the cylindrical lens 240 is refracted according to the refractive index of the cylindrical lens 240. The refracted light L5 travels inside the cylindrical lens 240 as a whole along the optical axis direction of the optical system. The light traveling inside the cylindrical lens 240 also includes light (L52) having a component in a direction different from the component (L51) in the optical axis direction, but as a whole, in the optical axis direction (Z direction) of the optical system. Proceed along. The light traveling inside the cylindrical lens 240 reaches the emission surface 244 of the cylindrical lens 240.

  The light L5 that has traveled through the cylindrical lens 240 and reached the exit surface 244 is refracted according to the refractive index of the cylindrical lens 240. The refracted light exits from the exit surface 244 of the cylindrical lens 240. The condensing characteristic of the cylindrical lens 240 is determined by the refraction at the time of incidence of the cylindrical lens 240 and the refraction at the time of emission. As described above, the light R emitted from the cylindrical lens 240 is condensed light according to the condensing characteristic of the cylindrical lens 240.

  The light R emitted from the cylindrical lens 240 travels along the optical axis direction (Z direction) as a whole. The light R emitted from the cylindrical lens 240 is applied to the illuminated body to illuminate the illuminated body (see FIGS. 1 and 2).

<Arrangement condition of rod lens 220 and cylindrical lens 240 (first arrangement condition)>
In a direction (for example, the optical axis direction Z) from the plurality of LEDs 212 to the cylindrical lens 240, the distance from the center of curvature cc of the rod lens 220 is a distance that is at least twice the curvature radius cr of the rod lens 220. A cylindrical lens 240 is disposed. That is, with respect to the relative positions of the rod lens 220 and the cylindrical lens 240, the rod lens 220 and the cylindrical lens 240 are separated from the curvature radius cr of the rod lens 220 by at least twice with respect to the center of curvature cc of the rod lens 220. Satisfies the first arrangement condition that is arranged.

  The center of curvature cc of the rod lens 220 is the center of the cylindrical side surface constituting the side surface of the rod lens 220. The curvature radius cr of the rod lens 220 is a radius of a cylindrical side surface constituting the side surface of the rod lens 220.

  Further, the reference position of the cylindrical lens 240 may be the incident surface 242, the exit surface 244, or the center of curvature cc of the cylindrical lens 240. The incident surface 242 of the cylindrical lens 240 is preferable.

  As described above, the rod lens 220 and the cylindrical lens 240 are separated by at least twice the curvature radius cr of the rod lens 220 with respect to the center of curvature cc of the rod lens 220, and the rod lens 220 and the cylindrical lens 240 are disposed. The first arrangement condition is satisfied. Specifically, in the example shown in FIG. 8, the first arrangement condition is that the distance between the rod lens 220 and the cylindrical lens 240 (the radius of curvature cr + the length of the optical path L31 + the length of the optical path L41) is In other words, the rod lens 220 and the cylindrical lens 240 are arranged so as to be at least twice the radius of curvature cr of the rod lens 220.

<Formation of parallel rays>
The light collected and emitted by the rod lens 220 may gradually spread and travel away from the rod lens 220. By arranging the cylindrical lens 240 so as to satisfy the first arrangement condition described above, the light is condensed again by the cylindrical lens 240 and converted into light that travels approximately parallel along the optical axis direction (Z direction). it can. In other words, in the optical axis direction, the first arrangement condition is that the cylindrical lens 240 is arranged at a position separated by a distance equal to or more than twice the curvature radius cr of the rod lens 220 with reference to the center of curvature cc of the rod lens 220. By satisfying the above, it is possible to form light that hardly spreads along the optical axis direction (Z direction), that is, light close to parallel light.

  Furthermore, as described above, the diffusion lens diffuses the light emitted from the rod lens 220 in a predetermined direction, that is, in the light source arrangement direction (X direction). For this reason, the brightness of light can be made close to constant in the arrangement direction (X direction) of the light sources by diffusion.

  By doing in this way, the illumination area (A1, A2, A3 in FIG. 7) in which the brightness of the area defined by the arrangement direction (X direction) of the light sources and the width direction (Y direction) of the light sources is made nearly constant. Can be formed. Further, since the optical axis direction (Z direction) is converted into light that travels substantially parallel along the optical axis direction, the size of the illumination area (A1, A2, A3 in FIG. 7) is changed to the optical axis direction (Z Direction). That is, the rod lens 220 and the cylindrical lens 240 satisfy the first arrangement condition, and the light is diffused in the arrangement direction of the light sources by the diffusion lens, so that the brightness becomes constant along the optical axis direction (Z direction). Illumination areas (A1, A2, A3 in FIG. 7) that are close and have a certain size can be formed.

  In the first arrangement condition described above, the lower limit of the distance between the rod lens 220 and the cylindrical lens 240 is such that the distance between the rod lens 220 and the cylindrical lens 240 is at least twice the radius of curvature cr of the rod lens 220. The rod lens 220 and the cylindrical lens 240 are arranged so that However, if the distance between the rod lens 220 and the cylindrical lens 240 is too long, the cylindrical lens 240 may not be able to collect light sufficiently, and parallel rays may not be formed. Therefore, it is preferable to dispose the rod lens 220 and the cylindrical lens 240 so that the upper limit of the distance between the rod lens 220 and the cylindrical lens 240 is not more than four times the radius of curvature of the rod lens 220 (second). Placement conditions). By disposing the rod lens 220 and the cylindrical lens 240 so as to be included between the upper limit and the lower limit, it is possible to always form parallel rays necessary for illumination of the illumination target.

  As described above, the rod lens 220 and the cylindrical lens 240 have a relative position within a range in which the radius of curvature of the rod lens 220 is 2 times or more and 4 times or less with reference to the center of curvature of the rod lens 220. 220 and the cylindrical lens 240 are preferably disposed.

  In this way, illumination areas (A1, A2, and A3 in FIG. 7) that are close to a certain brightness and have a certain size can be formed along the optical axis direction (Z direction). Even when the distances to the body (D1, D2, D3 in FIG. 7) are different, it is possible to illuminate a region of a certain size with a certain brightness. That is, even when the distance (D1, D2, D3 in FIG. 7) from the illuminating device to the object to be illuminated is changed according to the object to be illuminated and the use conditions, an area of a certain size is illuminated with a certain brightness. It is possible to provide an illuminating device that can cope with various objects to be illuminated and use conditions.

  In this manner, light that is close to parallel light can be formed with a simple configuration with a small number of optical elements, and an illuminating device that can respond to various objects to be illuminated and use conditions can be provided.

  FIG. 10 is a diagram illustrating an optical path when the above-described arrangement condition is satisfied and intensity distributions at four locations D1, D2, D3, and D4 along the optical axis direction.

  As shown in FIG. 10A, there is also light that spreads along the optical axis direction (Z), but most of the light travels in the optical axis direction without spreading. FIG. 10B is a graph showing the intensity distribution at the position D1 shown in FIG. 10A. FIG. 10C is a graph showing the intensity distribution at the position D2 shown in FIG. 10A. FIG. 10D is a graph showing the intensity distribution at the position D3 shown in FIG. 10A. FIG. 10E is a graph showing the intensity distribution at position D4 shown in FIG. 10A.

  As shown in FIGS. 10B to 10E, the intensity in the range of −10 to +10 in the Y direction is greater than I1 at distances D1 to D4, and the brightness for illuminating the non-illuminating body can be ensured.

<< Illuminance Characteristics According to Distance from Cylindrical Lens 240 to Object to be Illuminated >>
<Arrangement configuration>
FIG. 11 is a diagram illustrating a configuration in which the lengths among the LED 212, the rod lens 220, and the cylindrical lens 240 are arranged different from each other. For the sake of simplicity, the diffusing lens 230 is omitted in FIG.

  11, the length from the LED 212 to the cylindrical side surface 222 of the rod lens 220 is L11, and the length from the cylindrical side surface 222 of the rod lens 220 to the incident surface 242 of the cylindrical lens 240 is L31 + L41 (FIG. 11). 8). The radius of curvature of the rod lens 220 is cr, and the center of curvature of the rod lens 220 is cc.

  11A satisfies the relationship of L11 <L31 + L41, and the length from the center of curvature cc of the rod lens 220 to the incident surface 242 of the cylindrical lens 240 (= curvature radius cr + L31 + L41) is twice the radius of curvature cr of the rod lens 220. It is a figure which shows the case where it becomes the above length.

  FIG. 11B satisfies the relationship of L11 <L31 + L41, and the length from the center of curvature cc of the rod lens 220 to the incident surface 242 of the cylindrical lens 240 (= curvature radius cr + L31 + L41) is less than twice the radius of curvature cr of the rod lens 220. It is a figure which shows the case where it becomes the length of.

  FIG. 11C is a diagram illustrating a case where the relationship of L11 = L31 + L41 is satisfied.

  FIG. 12 is a graph obtained by calculating the illuminance at the positions including the positions of D1, D2, D3, and D4 shown in FIG. 10A in each case of FIGS. 11A to 11C. The vertical axis represents illuminance, and the horizontal axis represents the distance from the exit surface 244 of the cylindrical lens 240 to the irradiated object.

  The straight line (a) in FIG. 12 shows the variation in illuminance in the case of FIG. 11A. The straight line (b) in FIG. 12 shows the variation in illuminance in the case of FIG. 11B. The straight line (c) in FIG. 12 shows the variation in illuminance in the case of FIG. 11C.

  As shown in FIG. 12, in any case, the illuminance at the position D1 is the highest, and the illuminance gradually decreases as the distance from the positions D2, D3, and D4 and the cylindrical lens 240 increases.

  Here, assuming that the variation rate of illuminance is (1-D4 / D1 × 100), the variation rate of illuminance in the case of FIG. 11A is about 40% from the slope of the straight line (a), and the variation of illuminance in the case of FIG. The rate is about 47% from the slope of the straight line (b), and the variation rate of illuminance in the case of FIG. 11C is about 66% from the slope of the straight line (c). In this way, the variation in illuminance is the smallest in the case of FIG. 11A.

  In addition, it is considered that by increasing the light emitting area of the LED 212, the illuminance can be further increased while suppressing fluctuations in illuminance. For reference, the light emitting area of the LED 212 is increased by about 1.5 times with the same arrangement in FIG. This case is shown as a straight line (a1) in FIG.

  When the straight line (a) is compared with the straight line (a1), the illuminance of the straight line (a) is higher than that of the straight line (a1) at the position D1. Moreover, it is a straight line (a) that the fluctuation | variation of illumination intensity is small between distance D1-distance D4. As described above, even if the light emission area of the LED 212 is increased, the fluctuation of the illuminance cannot be suppressed and the illuminance cannot be increased as compared with the case where the LED 212 light emission area is small. The variation rate of illuminance on the straight line (a1) was about 46%.

  In this way, by using the arrangement of FIG. 11A, fluctuations in illuminance can be reduced. In other words, it is possible to illuminate the object to be illuminated while bringing the brightness of the light emitted from the cylindrical lens 240 close to uniform while making the brightness of the light close to uniform. For example, it is possible to illuminate a certain area with constant brightness even when the position of the illuminated object varies due to vibration or the like.

DESCRIPTION OF SYMBOLS 100 Illuminating device 200 Optical system 300 Heat radiation system 400 Circuit system

Claims (7)

A plurality of light sources arranged along a predetermined direction;
A first lens that collects light emitted from the light source;
A diffusing lens for diffusing light emitted from the first lens in the predetermined direction;
A second lens that condenses the light emitted from the diffusion lens,
In the direction from the plurality of light sources toward the second lens, the first lens is located at a position separated by a distance that is not less than 2 times and not more than 4 times the radius of curvature of the first lens with reference to the center of curvature of the first lens. An illumination device in which two lenses are arranged.   The first optical path length until the light emitted from the light source reaches the first lens is shorter than the second optical path length until the light emitted from the first lens reaches the second lens. Item 2. The lighting device according to Item 1. A heat dissipating part having a plurality of heat dissipating fins for dissipating heat generated by the light source;
A heat transfer unit coupled to the heat dissipating unit for transmitting heat generated by the light source to the heat dissipating unit, wherein the light source is provided so as to be able to conduct heat; and the first transfer unit. A heat transfer portion having a second transfer portion that is connected to the portion so as to conduct heat and extends in a direction away from the light source,
Each of the plurality of radiating fins is formed at a position apart from the fixed end, and a fixed end connected to the second transmission portion so as to be able to conduct heat along the extending direction of the second transmission portion. The lighting device according to claim 1, further comprising an open end. The heat transfer part is connected to the first transfer part so as to be capable of heat conduction, and has a first opposite transfer part and a second opposite transfer part that face each other at a distance from each other,
A first clamping part and a second clamping part for clamping the first lens at a fixed position with respect to the light source and along the first lens;
The said 1st clamping part is provided in the said 1st opposing transmission part so that heat conduction is possible, and the said 2nd clamping part is provided in the said 2nd opposing transmission part so that heat conduction is possible. Lighting device.   The lighting apparatus according to claim 3, wherein a control circuit unit for controlling the light source is disposed with the heat dissipation unit and the second transmission unit interposed therebetween.   The lighting device according to claim 3, wherein each of the plurality of radiating fins is provided to be inclined with respect to both the first transmission unit and the second transmission unit. The lighting device according to claim 3, wherein each of the plurality of radiating fins gradually becomes thinner from the fixed end toward the open end.