JP2005141039A - Lighting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lighting device which can efficiently and uniformly irradiate a lighted area with light, even when the lighted area is elongated. <P>SOLUTION: The light emitted from a light source system is converted into the light expanding with respect to one direction as the light propagates, using a lens having the refractive power which directionally varies or a lens having the refractive power which varies along the direction. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an illumination device that efficiently and uniformly irradiates light on a long slit-shaped illumination area.

  In recent years, with the progress of image processing technology and photolithography technology, the demand for uniformly and efficiently irradiating a rectangular region has increased. For example, when an image is captured by a one-dimensional CCD camera, an area to be captured and captured as an image is a long and narrow rectangle. Therefore, it is desirable that the irradiation area for increasing the illuminance is also a long and narrow rectangular irradiation area. Also, when measuring height information using a light cutting method, a moire method, or the like, an extremely thin slit-shaped illumination is required to increase the illuminance and improve the measurement accuracy.

For such a purpose, a conventional illumination device that irradiates a rectangular irradiation region uses an optical element that transmits only a part of the light emitted from the light source unit, and emits light emitted from the optical element. The irradiation area was irradiated. As this optical element, elements such as a rectangular rod, a slit-like fiber, and a mechanical slit have been used. This conventional illuminating device irradiates the irradiation region by making the exit surface for emitting light from the optical element a shape corresponding to the shape of the irradiation region. For this reason, in the conventional illumination device, the shape of the exit surface of the optical element has to be similar to the shape of the irradiation region in advance (see, for example, Patent Document 1 or Patent Document 2).
JP-A-11-149058 Japanese Patent Laid-Open No. 08-211155

  As described above, since the conventional illumination device needs to make the shape of the exit surface of the optical element similar to the shape of the irradiation region in advance, if the shape of the irradiation region is a rectangle, for example, the aspect thereof The ratio could not be changed greatly.

  In addition, as described above, the conventional illumination device irradiates using only a part of the light emitted from the light source unit, and thus has to be low in efficiency.

  Furthermore, when the shape of the irradiation region is an extremely long rectangle, it is necessary to increase the size of the light emitting portion in advance. However, as described above, even if the size of the light emitting part is increased, only a part of the light emitted from the light emitting part is used, so the efficiency of irradiation has to be lower, When the size of the light emitting part is increased, it is difficult to make the brightness such as the illuminance of the light emitted from the light emitting part uniform.

  The present invention has been made in view of the above-described points, and an object of the present invention is to irradiate the illumination area efficiently and uniformly even when the illumination area has a long shape. It is in providing the illuminating device which can be performed.

  In order to achieve the above object, as the light travels, the light emitted from the light source system using a lens whose refractive power varies depending on the direction or a lens whose refractive power changes along one direction. It transforms into light that spreads in one direction.

More specifically, the present invention provides:
A light source system including a light source unit that emits light, and a lens system that irradiates a long slit-shaped irradiation region with light emitted from the light source system,
The lens system is an optical element having a predetermined refractive power in one direction and having a refractive power in a direction substantially orthogonal to the one direction different from the predetermined refractive power. Including at least one optical element positioned substantially orthogonal to the optical axis of the lens system, and
The lens system is provided at a position where an image of the light source system is formed on the irradiation region.

The present invention also provides:
A light source system including a light source unit that emits light, and a lens system that irradiates a long slit-shaped irradiation region with light emitted from the light source system,
The lens system is an optical element whose refractive power changes along one direction and whose refractive power in a direction substantially orthogonal to the one direction is substantially constant, and is substantially in the one direction and the one direction. An orthogonal direction includes at least one optical element positioned substantially orthogonal to the optical axis of the lens system, and
The lens system is provided at a position where an image of the light source system is formed on the irradiation region.

  The illumination device according to the present invention uses an optical element having a different refractive power in one direction and a refractive power in a direction substantially orthogonal to the one direction, or an optical element in which the refractive power changes along the one direction. As the light travels, the light can be irradiated onto the irradiation surface so that the light gradually spreads in only one direction and does not spread in a direction substantially perpendicular to the one direction. That is, the aspect ratio between the emission area emitted from the light source and the irradiation area where light is irradiated can be adjusted, and the shape of the irradiation area can be changed to a desired shape. In particular, it is advantageous when the shape of the irradiation region is a long shape.

  In this specification, the “optical axis” means (1) a line connecting the centers of curvature of the refractive or reflective curved surfaces constituting the optical system, and (2) a straight line connecting the centers of the light source, lens, etc. of the optical system. This is a virtual straight line that serves as a reference for an optical machine incorporating an optical system.

  “Parallel arrangement” means that two or more objects are arranged side by side, and this “arrangement” means that two or more objects are positioned in the same direction in the same direction.

  Furthermore, “brightness” is an amount indicating the level of light and dark, for example, an amount indicating illuminance or luminance.

  The light source system described above preferably has an exit surface that emits light emitted from the light source unit and can define the exit surface. Further, the shape of the exit surface is desirably a long shape, but need not be similar to the irradiation region.

  Furthermore, the light source used in the light source system may be composed of a plurality of light sources or a single light source. As the light source, a light source such as a light emitting diode, a laser diode, an ultra-high pressure mercury lamp, a xenon lamp, a metal halide lamp, or a halogen lamp can be used.

  The optical element described above may have any refractive power different depending on the direction, or may have any refractive power that changes along one direction, regardless of whether the refractive power is positive or negative. By using such an optical element, the aspect ratio of the irradiated light can be adjusted by appropriately selecting the ratio of the refractive power of the optical element according to the shape of the irradiated area. The desired shape can be a long shape. In particular, the optical element is preferably a cylindrical lens or a gradient index lens. It is sufficient that at least one optical element is included. A plurality of optical elements such as a cylindrical lens and a gradient index lens may be combined, and the shape of the region irradiated with light may be appropriately changed depending on the combination. it can.

  As described above, since this optical element has different refractive power depending on the direction, or the refractive power changes along one direction, the lens system has two conjugate positions and includes the optical element. In addition, there are two conjugate positions: a conjugate position in the longitudinal direction and a conjugate position in the short direction.

  Accordingly, it is preferable that the exit surface for emitting the light emitted from the light source unit and the irradiation region for irradiating the light are positioned at a conjugate position in the short direction of the lens system. By doing so, it is possible to irradiate the irradiation surface with light so that the brightness is uniform and the brightness is uniform, and various aberrations of the lens are corrected well.

  Furthermore, the light source system preferably includes a light source unit in which a plurality of light sources are arranged in parallel, and a uniform unit that uniformly emits light emitted from the plurality of light sources and emits the light from the emission surface. By using the uniform means, the brightness of the light applied to the irradiation surface can be made more uniform.

  Furthermore, the light source system is preferably a long light source having a long shape in which light is emitted. For example, the long light source is preferably a laser diode, a line light guide, or the like. By using a laser diode, a line-type light guide, or the like, the brightness of the light applied to the irradiation surface can be made stable and uniform.

  Even when the illumination area has a long shape, the illumination area can be irradiated with light efficiently and uniformly.

  Embodiments of the present invention will be described below with reference to the drawings.

<< First Embodiment >>
FIG. 1 is a perspective view showing an outline of a first embodiment of a lighting device according to the present invention. In FIG. 1, the right direction is the + X direction, the left direction is the -X direction, the front direction is the + Y direction, the depth direction is the -Y direction, the down direction is the + Z direction, and the up direction is the -Z direction. And These X, Y, and Z directions are determined for the sake of explanation, and the components of the optical system described below are not limited to these directions. The X, Y, and Z directions are used for convenience to show the relative positional relationship.

  The illumination device 100 shown in FIG. 1 includes a light source system 110 and a lens system 130. The illuminating device 100 irradiates the irradiation surface 150 with light emitted from the light source system 110 so that the irradiation region 152 on the irradiation surface 150 has an elongated rectangular shape.

<Light source system 110>
The light source system 110 includes a light source unit 112, a condensing unit 114, and a light uniformizing unit 116.

  The light source unit 112 includes a plurality of light sources 118, and is juxtaposed linearly on a support member (not shown). These light sources 118 are light sources that emit light having a desired wavelength, and are preferably small. Specifically, a light source such as a light emitting diode, a laser diode, an ultrahigh pressure mercury lamp, a xenon lamp, a metal halide lamp, or a halogen lamp can be used.

  The condensing means 114 is provided in the vicinity of each of the plurality of light sources 118 and condenses the light emitted from each of the plurality of light sources 118 and guides it in the + Z direction. The condensing means 114 may be an optical element such as a condenser lens, in addition to a mirror such as an elliptical mirror, a parabolic mirror, and a spherical mirror.

  The light uniformizing means 116 is positioned by a support member (not shown) in front of the traveling direction (+ Z direction) of the light guided by the light collecting means 114 described above. The light uniformizing means 116 has an incident surface 120 that is an upper surface and an output surface 122 that is a lower surface. The entrance surface 120 and the exit surface 122 are substantially parallel to each other and have a similar long rectangular shape, and are positioned so as to be substantially perpendicular to the optical axis L. The size and shape of the entrance surface 120 and the exit surface 122 are determined based on the overall size and arrangement of the plurality of light sources 118 arranged in a straight line. The light that is condensed by the condensing unit 114 and guided downward is incident on the incident surface 120. From the emission surface 122, light whose brightness is uniformed by the light uniformizing means 116 is emitted. The light homogenizer 116 may be an optical element that can reduce unevenness in illuminance, color, etc. by mixing the angle components of the luminous flux as the light incident on the incident surface 120 travels in the light uniformizer 116. . As the light uniformizing means 116, for example, a rectangular rod lens that is long along the light traveling direction, or an optical element that is formed in a square cylinder shape by two pairs of planar reflecting materials facing each other is used. be able to.

  The light emitted from the light homogenizer 116 by appropriately changing the size and arrangement of the plurality of light sources 118 in the light source unit 112 and the size and shape of the incident surface 120 and the exit surface 122 of the light homogenizer 116. The emission region can be formed in a desired shape. In particular, it is preferable that the shape of the emission surface 122 of the light uniformizing means 116 is a long rectangular shape.

<Lens system 130>
The lens system 130 is positioned in the traveling direction (+ Z direction) of light emitted from the light source system 110 described above. The lens system 130 includes a convex lens 132, a cylindrical lens 134, and a convex lens 136.

  The convex lens 132 changes the size of the emission area of the light emitted from the light uniformizing means 116 and emits it to the cylindrical lens 134.

  The cylindrical lens 134 has an incident surface 138 on which light emitted from the convex lens 132 is incident, and an emission surface 140 that emits incident light. The entrance surface 138 and the exit surface 140 are both formed so as to form a part of a cylindrical surface. The entrance surface 138 has a shape recessed downward (+ Z direction), and the exit surface 140 is upward. It has a shape recessed toward (−Z direction). For this reason, the cylindrical lens 134 has a shape in which the thickness of the position through which the optical axis L passes is the thinnest, and the thickness gradually increases as it advances along the + X direction or the −X direction.

  By adopting such a shape of the cylindrical lens 134, the negative refractive power in the ± X direction can be made larger than the refractive power in the ± Y direction, and the light that has entered the incident surface 138 travels in the + Z direction. Accordingly, the light can be emitted from the emission surface 140 so as to gradually expand in the + X direction and the −X direction. Further, the cylindrical lens 134 can emit the light incident on the incident surface 138 from the emitting surface 140 without refracting it in the ± Y directions. For this reason, the cylindrical lens 134 is incident on the incident surface 138 so that it gradually spreads only in the + X direction and the −X direction and does not spread in the ± Y direction as the light travels in the + Z direction. Can be emitted from the emission surface 140.

  Therefore, the cylindrical lens 134 can be changed to a longer emission area obtained by extending the emission area of the light emitted from the light uniformizing means 116 in the ± X direction. That is, it is possible to change the aspect ratio of the emission area of the light emitted from the light uniformizing unit 116 and emit the light from the emission surface 140.

  The convex lens 136 changes the size of the emission area of the light emitted from the emission surface 140 and emits the light toward the irradiation surface 150 described later.

  The aspect ratio of the irradiated light can be adjusted by appropriately changing the ratio of the refractive power in the ± X direction and the refractive power in the ± Y direction of the cylindrical lens 134 described above. The shape can be changed to a desired shape.

  Further, since the refractive power in the ± X direction of the cylindrical lens 134 is different from the refractive power in the ± Y direction, the lens system 130 has two types of conjugates, a conjugate position in the X direction and a conjugate position in the Y direction. Has a position. The conjugate position in the X direction is a conjugate position in the short direction, and the conjugate position in the Y direction is a conjugate position in the long direction.

  In the above-described example, the case where the lens group 130 includes the single convex lens 132 and the single convex lens 136 is shown. However, the convex lens 132 and the convex lens 136 include a lens group including a plurality of lenses. May be. As this lens group, a plurality of types of lenses such as a convex lens and a concave lens as well as an aspherical lens can be combined. As described above, when the lens group is replaced instead of the convex lens 132 or the convex lens 136, the light irradiated on the cylindrical lens 134 or the light irradiated on the irradiation surface 150 can be converted into a desired light flux.

  In the above-described example, as described above, the cylindrical lens 134 has the smallest thickness at the position through which the optical axis L passes, and the thickness gradually increases as it proceeds along the + X direction or the −X direction. Although the case where it has such a shape was shown, it is good also as a cylindrical lens in which the thickness of the position where the optical axis L passes becomes the thickest. Specifically, the incident surface 138 swells upward (−Z direction), the exit surface 140 swells downward (+ Z direction), and the optical axis L passes through. The shape is such that the thickness is the largest, and the thickness gradually decreases as it advances along the + Y direction or the −Y direction. When a cylindrical lens having such a shape is used, the light incident on the incident surface 138 gradually narrows in the + Y direction and the −Y direction as the light travels in the + Z direction due to the positive refractive power in the ± Y direction. As a result, the emission region of the light emitted from the emission surface 140 can have a long shape.

<Irradiated surface 150>
The irradiation surface 150 is positioned in the traveling direction of the light emitted from the lens system 130 described above. The position of the irradiation surface 150 is a position at which the image of the exit surface 122 of the light homogenizer 116 described above is formed on the irradiation surface 150. That is, the relative positions of the light source system 110, the lens system 130, and the irradiation surface 150 described above may be determined so that the image of the emission surface 122 of the light uniformizing unit 116 is formed on the irradiation surface 150. Specifically, the emission surface 122 and the irradiation surface 150 of the light uniformizing means 116 are positioned at a conjugate position in the short direction of the lens system 130. In this way, by setting the image of the exit surface 122 of the light uniformizing means 116 to the position where the image is formed on the irradiation surface 150, the brightest and uniform brightness is obtained, and various aberrations of the lens are improved. It can correct | amend and can irradiate the irradiation surface 150 with light. A region irradiated with light on the irradiation surface 150 is referred to as an irradiation region 152. Since the shape of the irradiation region 152 is substantially similar to the emission region of the light emitted from the emission surface 140, the shape of the irradiation region 152 is a long irradiation extended in the ± X direction in which the aspect ratio is changed. Can be an area.

<< Second Embodiment >>
FIG. 2 is a perspective view showing an outline of the second embodiment of the illumination device according to the present invention. In FIG. 2, the right direction is the + X direction, the left direction is the -X direction, the front direction is the + Y direction, the depth direction is the -Y direction, the down direction is the + Z direction, and the up direction is the -Z direction. And As in the first embodiment, these X, Y, and Z directions are determined for explanation, and the constituent elements of the optical system described below are limited to these directions. For convenience, the X, Y, and Z directions are used for convenience in order to indicate the relative positional relationship between the components of the optical system. The same elements as those shown in FIG. 1 are denoted by the same reference numerals.

  The lighting device 200 shown in FIG. 2 includes a light source system 210 and a lens system 230. The illumination device 200 irradiates the irradiation surface 150 with the light emitted from the light source system 210 so that the irradiation region 152 on the irradiation surface 150 has an elongated rectangular shape.

<Light source system 210>
The light source system 210 is composed of a laser diode, and the light emitter 212 has a long shape, and an emission surface is formed on the lower surface of the light emitter 212 so that light is emitted downward (+ Z direction). 214 is provided. Thus, since the shape of the emission surface 214 is a long shape, the shape of the emission region of the light emitted from the light source system 210 is a long shape.

<Lens system 230>
The lens system 230 is positioned in the traveling direction (+ Z direction) of the light emitted from the light source system 210 described above. The lens system 230 includes a convex lens 232 and a gradient index lens 234.

  The convex lens 232 changes the size of the emission region of the light emitted from the light source system 210 and emits it to the gradient index lens 234.

  The gradient index lens 234 has an incident surface 236 on which light emitted from the light source system 210 is incident, and an output surface 238 that emits incident light. The entrance surface 236 and the exit surface 238 are substantially parallel to each other and have the same long rectangular shape, and are positioned so as to be substantially perpendicular to the optical axis L.

  The gradient index lens 234 is formed using a medium with a non-uniform refractive index, and changes so that the negative refractive index gradually increases in the + X direction or the −X direction. Note that the refractive index in the + Y direction or the -Y direction is substantially constant. The gradient index lens 234 is provided so that the optical axis L is located at the position where the refractive index in the ± X direction is the smallest.

  By using the gradient index lens 234, the negative refracting power in the ± X direction can be made larger than the refracting power in the ± Y direction, and the light incident on the incident surface 236 is propagated in the + Z direction. The light can be emitted from the emission surface 238 so as to gradually expand in the + X direction and the −X direction. Further, the gradient index lens 234 can emit light incident on the incident surface 236 from the emission surface 238 without being refracted in the ± Y direction. Therefore, the gradient index lens 234 spreads only on the + X direction and the −X direction as the light travels in the + Z direction, and does not spread in the ± Y direction. Incident light can be emitted from the emission surface 238.

  Therefore, the gradient index lens 234 can change the emission region of the light emitted from the light source system 210 to a longer emission region that is extended in the ± X direction. That is, the aspect ratio of the emission area of the light emitted from the light source system 210 can be changed and emitted from the emission surface 238.

  The aspect ratio of the light to be irradiated can be adjusted by appropriately changing the ratio of the refractive power in the ± X direction and the refractive power in the ± Y direction of the gradient index lens 234 described above. Similarly to the embodiment mode, the irradiation region 152 can have a desired shape.

  Further, since the ± X direction of the gradient index lens 234 is different from the refractive power in the ± Y direction, the lens system 230 has two types of conjugate, a conjugate position in the X direction and a conjugate position in the Y direction. Has a position. The conjugate position in the X direction is a conjugate position in the short direction, and the conjugate position in the Y direction is a conjugate position in the long direction.

  Furthermore, although the case where the lens group 230 is configured by a single convex lens 232 has been described in the above-described example, the convex lens 232 may be configured by a lens group including a plurality of lenses. As this lens group, a plurality of types of lenses such as a convex lens and a concave lens as well as an aspherical lens can be combined. As described above, when the lens group is replaced instead of the convex lens 232, the light irradiating the gradient index lens 234 or the light irradiating the irradiation surface 150 can be converted into a desired light flux.

  Furthermore, in the above-described example, as described above, the gradient index lens 234 changes such that the negative refractive index gradually increases as it proceeds in the + X direction or the −X direction, and the + Y direction or −Y. Although the refractive index with respect to the direction is substantially constant, the positive refractive index gradually increases as it proceeds in the + Y direction or the −Y direction, and the refractive index in the + X direction or the −X direction. May be positioned on the gradient index lens 234 so that the optical axis L is located at the position where the refractive index in the ± Y direction is the smallest. When such a gradient index lens is used, the light incident on the incident surface 236 is gradually increased in the + Y direction and the −Y direction as the light travels in the + Z direction due to the positive refractive power in the ± Y direction. The light can be emitted from the emission surface 238 so as to be narrowed. As a result, the shape of the emission region of the light emitted from the emission surface 238 can be made long.

<Irradiated surface 150>
As in the first embodiment, the irradiation surface 150 is positioned in the traveling direction of the light emitted from the lens system 230 described above. The position of the irradiation surface 150 is a position where the image of the emission surface 214 of the light emitter 212 described above is formed on the irradiation surface 150. That is, the relative positions of the light source system 210, the lens system 230, and the irradiation surface 150 may be determined so that the image of the emission surface 214 of the light emitter 212 is formed on the irradiation surface 150. Specifically, the emission surface 214 of the light emitter 212 and the irradiation surface 150 are positioned at a conjugate position in the short direction of the lens system 230. In this way, by setting the image of the exit surface 214 of the light emitter 212 on the irradiation surface 150, the lens is brightest and uniform in brightness, and various aberrations of the lens are corrected well. Thus, the irradiation surface 150 can be irradiated with light. A region irradiated with light on the irradiation surface 150 is referred to as an irradiation region 152. Since the shape of the irradiation region 152 is substantially similar to the emission region of the light emitted from the emission surface 238 of the gradient index lens 234, the shape of the irradiation region 152 is changed in the ± X direction in which the aspect ratio is changed. It can be set as a long irradiation region extended in a straight line.

<< Third Embodiment >>
FIG. 3 is a perspective view showing an outline of the third embodiment of the illumination device according to the present invention. FIG. 3 shows only the light source system 310. In FIG. 3, the right direction is the + X direction, the left direction is the -X direction, the front direction is the + Y direction, the depth direction is the -Y direction, the down direction is the + Z direction, and the up direction is the -Z direction. And As in the first embodiment and the second embodiment, these X, Y, and Z directions are determined for the purpose of explanation, and the components of the optical system described below are the same. The X, Y, and Z directions are used for convenience in order to indicate the relative positional relationship of the components of the optical system, without being limited to these directions.

  The light source system 310 includes a light source unit 312 and light uniformizing means 314.

  The light source unit 312 includes a plurality of light sources 316 and is juxtaposed in two lines on a support member (not shown). These light sources 316 are light sources that emit light having a desired wavelength, and those that each emit light in a small and constant direction are preferable. Specifically, a light source such as a light emitting diode or a laser diode can be used. Since such a light source 316 itself emits light in a certain direction, it is possible to guide light in a desired direction without using a condensing means.

  In front of the traveling direction (+ Z direction) of the light emitted from the light source unit 312 described above, the light uniformizing means 314 similar to that of the first embodiment is positioned by a support member (not shown). The light uniformizing means 314 has an incident surface 318 that is an upper surface and an output surface 320 that is a lower surface. The entrance surface 318 and the exit surface 320 are substantially parallel to each other and have the same long rectangular shape, and are positioned so as to be substantially perpendicular to the optical axis L. The size and shape of the entrance surface 318 and the exit surface 320 are determined based on the overall size and arrangement of the plurality of light sources 316 arranged in a straight line. Light emitted from the light source unit 312 is incident on the incident surface 318. From the exit surface 320, light whose brightness is uniformed by the light uniformizing means 314 is emitted. The light uniformizing unit 314 may be any optical element that can reduce unevenness in illuminance and color by mixing the angle components of the light flux as the light incident on the incident surface 318 travels in the light uniformizing unit 314. . As the light uniformizing means 314, for example, a rectangular rod lens that is long along the light traveling direction or an optical element that is formed in a square cylinder shape by two pairs of planar reflecting materials facing each other is used. be able to.

  Light emitted from the light homogenizer 314 by appropriately changing the size and arrangement of the plurality of light sources 316 in the light source unit 312 and the size and shape of the entrance surface 318 and the exit surface 320 of the light homogenizer 314. The emission region can be formed in a desired shape. In particular, it is preferable that the shape of the exit surface 320 of the light uniformizing means 314 is a long rectangular shape.

  By replacing the light source system 310 shown in the third embodiment with the light source system 110 of the first embodiment or the light source system 210 of the second embodiment described above, an irradiation region having a long shape is obtained. Can emit light for irradiation. That is, the exit surface 320 and the irradiation surface of the light uniformizing means 314 described above are conjugate in the short direction of the lens system (the lens system 130 of the first embodiment or the lens system 230 of the second embodiment). Position to position. Thus, by setting the image of the emission surface 320 of the light uniformizing means 314 to the position where the image is formed on the irradiation surface 150, the brightest and uniform brightness is obtained, and various aberrations of the lens are improved. It can correct | amend and can irradiate the irradiation surface 150 with light.

<< Fourth Embodiment >>
FIG. 4 is a perspective view showing an outline of the fourth embodiment of the illumination device according to the present invention. FIG. 4 shows only the light source system 410. In FIG. 4, the right direction is the + X direction, the left direction is the -X direction, the front direction is the + Y direction, the depth direction is the -Y direction, the down direction is the + Z direction, and the up direction is the -Z direction. And As in the first to third embodiments, these X, Y, and Z directions are determined for explanation, and the components of the optical system described below are the same. The X, Y, and Z directions are used for convenience in order to indicate the relative positional relationship of the components of the optical system, without being limited to these directions.

  The light source system 410 shown in FIG. 4 includes a light source unit 412, a condensing unit 414, and a light uniformizing unit 416.

  The light source unit 412 is a single light source, and is a long light source having a linear shape like a fluorescent lamp. The light source unit 412 is a light source that emits light having a desired wavelength. As this long light source, a light source using a laser diode, a line type light guide or the like is preferable.

  The condensing means 414 is provided in the vicinity of the light source unit 412, condenses the light emitted from the light source unit 412, and guides it in the + Z direction. The condensing unit 414 has a long shape substantially parallel to the light source unit 412. The condensing means 414 has an incident surface 418 which is an upper plane, and an output surface 420 having a downwardly convex shape. By making the shape of the emission surface 420 convex downward, the light emitted from the light source unit 412 can be condensed and made incident on the incident surface 422 of the light uniformizing means 416 described later.

  In front of the traveling direction (+ Z direction) of the light emitted from the light source unit 412 described above, the light uniformizing means 416 similar to that of the first embodiment is positioned by a support member (not shown). The light uniformizing means 416 has an incident surface 422 that is an upper surface and an output surface 424 that is a lower surface. The entrance surface 422 and the exit surface 424 are substantially parallel to each other and have the same long rectangular shape, and are positioned so as to be substantially perpendicular to the optical axis L. The size and shape of the entrance surface 422 and the exit surface 424 are determined based on the size and shape of the light source unit 412 and the light collection degree of the light collecting means 414. Light emitted from the light source unit 412 is incident on the incident surface 422. From the emission surface 424, the light whose brightness is uniformed by the light uniformizing means 416 is emitted. The light uniformizing unit 416 may be an optical element that can reduce unevenness in illuminance and color by mixing the angle components of the light beam as the light incident on the incident surface 422 travels in the light uniformizing unit 416. . As the light uniformizing means 416, for example, a rectangular rod lens that is elongated along the light traveling direction, or an optical element that is formed in a square cylinder shape by two sets of planar reflecting materials facing each other is used. be able to.

  By appropriately changing the size and shape of the light source unit 412 and the size and shape of the entrance surface 422 and the exit surface 424 of the light homogenizer 416, an emission region of light emitted from the light homogenizer 416 is desired. The shape can be made. In particular, it is preferable that the shape of the emission surface 424 of the light uniformizing means 416 is a long rectangular shape.

  By replacing the light source system 410 shown in the fourth embodiment with the light source system 110 of the first embodiment or the light source system 210 of the second embodiment described above, an irradiation region having a long shape is obtained. Can emit light for irradiation. That is, the exit surface 424 and the irradiation surface of the light uniformizing means 416 described above are conjugated in the short direction of the lens system (the lens system 130 of the first embodiment or the lens system 230 of the second embodiment). Position to position. As described above, by setting the image of the exit surface 320 of the light uniformizing means 416 at the position where the image is formed on the irradiation surface 150, the brightest and uniform brightness is obtained, and various aberrations of the lens are improved. It can correct | amend and can irradiate the irradiation surface 150 with light.

It is a perspective view which shows the outline | summary of 1st Embodiment of the illuminating device concerning this invention. It is a perspective view which shows the outline | summary of 2nd Embodiment of the illuminating device concerning this invention. It is a perspective view which shows the outline | summary of 3rd Embodiment of the illuminating device concerning this invention. It is a perspective view which shows the outline | summary of 4th Embodiment of the illuminating device concerning this invention.

Explanation of symbols

100, 200 Illumination device 110, 210, 310, 410 Light source system 112, 212, 312, 412 Light source unit 116, 314, 416 Light uniformizing means (uniform means)
122, 214, 320, 424 Outgoing surface 130, 230 Lens system 134 Cylindrical lens (optical element)
152 Irradiation region 234 Gradient index lens (optical element)

Claims (5)

A light source system including a light source unit that emits light, and a lens system that irradiates a long slit-shaped irradiation region with light emitted from the light source system,
The lens system is an optical element having a predetermined refractive power in one direction and having a refractive power in a direction substantially orthogonal to the one direction different from the predetermined refractive power. Including at least one optical element positioned substantially orthogonal to the optical axis of the lens system, and
The illumination device according to claim 1, wherein the lens system is provided at a position where an image of the light source system is formed on the irradiation region. A light source system including a light source unit that emits light, and a lens system that irradiates a long slit-shaped irradiation region with light emitted from the light source system,
The lens system is an optical element whose refractive power changes along one direction and whose refractive power in a direction substantially orthogonal to the one direction is substantially constant, and is substantially in the one direction and the one direction. An orthogonal direction includes at least one optical element positioned substantially orthogonal to the optical axis of the lens system, and
The illumination device according to claim 1, wherein the lens system is provided at a position where an image of the light source system is formed on the irradiation region. The light source system has an emission surface that emits light emitted from the light source unit, and
The illumination device according to claim 1, wherein the emission surface and the irradiation region are positioned at a conjugate position in a short direction of the lens system.   The lighting device according to claim 3, wherein the light source system includes a light source unit in which a plurality of light sources are arranged side by side, and a uniform unit that uniformly emits light emitted from the plurality of light sources and emits the light from the emission surface.   The illuminating device according to claim 3, wherein the light source system includes a laser diode having a long shape in which light is emitted as the light source unit.

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