JP5962089B2 - Light irradiation device - Google Patents

Description

  The present invention relates to a light irradiation apparatus that reduces illuminance unevenness using a rod integrator lens.

Conventionally, it has been equipped with a lamp unit that combines a lamp such as a halogen lamp or a metal halide lamp and a reflecting mirror that reflects the light of the lamp, and the luminous flux from the reflecting mirror is condensed by a condenser lens and introduced into a rod integrator lens. There is known a light irradiation device that reduces irradiation unevenness on an irradiation surface by mixing light with a rod integrator lens to make it uniform and irradiating the irradiation surface (see, for example, Patent Document 1).
This type of light irradiation apparatus includes a light control plate having a variable area opening between the lamp unit and the incident end surface of the rod integrator lens, and transmits the light control plate by changing (squeezing) the aperture area. By adjusting the amount of light incident on the rod integrator lens by changing the amount of light, the intensity of light emitted from the light irradiation device is adjusted.

JP 2004-335199 A

By the way, in the light beam incident on the rod integrator lens, the angled light beam reflected around the opening end of the reflecting mirror is reflected many times on the side surface of the rod integrator lens, but near the center of the reflecting mirror. The reflected light beam substantially parallel to the optical axis is not reflected by the rod integrator lens or is reflected only a few times. In order to reduce illuminance unevenness, the length of the rod integrator lens is increased to increase the number of reflections of light flux from the surroundings, and the ratio of light flux with relatively few reflections is reduced to reduce the illumination surface with less illuminance unevenness. Have achieved. However, when the aperture of the light control plate is made smaller, the light beam reflected around the aperture end is shielded as the aperture becomes smaller, and substantially parallel to the optical axis reflected near the center of the reflector. Light flux is mainly incident on the rod integrator lens. Therefore, there is a problem that the smaller the aperture is, the more uneven the illuminance becomes and the illuminance becomes uneven on the irradiated surface.
An object of the present invention is to provide a light irradiation apparatus that solves the problems of the conventional techniques described above and can reduce unevenness in illuminance even at a small aperture.

In order to achieve the above object, the present invention provides a lamp unit including a light source, a reflecting mirror that is disposed at a focal point and reflects light emitted from the light source, and an optical path of the reflecting mirror. A first and second focal points arranged at equal focal lengths from the first principal point and the second principal point on the incident side and the emission side, respectively. A condensing lens for condensing the light beam reflected by the reflecting mirror at the second focal point, and an incident end surface disposed at the second focal point of the condensing lens, and the light beam incident from the incident end surface a columnar rod integrator lens emitted from the emitting end face and uniform, between the first focus and the incident surface of the condenser lens, or is disposed between the exit surface and the second focus, the rod integrator Light incident on the incident end face of the lens Bei example and a dimming plate adjusting, the dimming plate at the incident side of the converging lens, between the first principal point, one-half of the focal length of the condenser lens It is arranged with an interval that does not exceed, or has an interval that does not exceed one half of the focal length of the condenser lens between the exit surface and the exit surface on the exit side of the condenser lens. It is characterized by being arranged .

  According to the present invention, in the light irradiation apparatus, the light control plate has an opening through which a light beam is transmitted on an optical axis of the concave mirror, and the opening is continuously opened by moving the light control plate. It is characterized in that the area is variable.

  Further, the present invention is the light irradiation apparatus, further comprising a guide unit that guides the light control plate movably in a state of being separated from the condenser lens and the lens holder that holds the condenser lens by a predetermined distance or more. It is characterized by that.

  According to the present invention, in the light irradiation device, the light control plate is provided in the vicinity of a lens surface on the incident side of the condenser lens.

  Further, the present invention provides the light irradiating device, wherein the light control plate is disposed on the exit side of the condenser lens, and the distance from the lens surface on the exit side is ½ or less of the focal length of the condenser lens. It arrange | positions in the position which becomes.

  According to the present invention, in the light irradiation device, the light control plate is disposed in the vicinity of the lens surface on the exit side of the condenser lens.

  According to the present invention, the dimming plate is spaced from the first focal point of the condensing lens by a half or more of the focal length on the optical axis between the first focal point and the second focal point of the condensing lens. Therefore, when the light control plate is a small stop, light rays emitted from the condenser lens through the focal point of the condenser lens in parallel are reduced, and angled rays from the reflector are incident on the rod integrator lens. It is possible to make the illuminance on the irradiated surface uniform and reduce illuminance unevenness.

It is a schematic diagram which shows schematic structure of the light irradiation apparatus which concerns on embodiment of this invention. It is a perspective view which shows the structure of a light irradiation apparatus. It is a front view which shows the structure of a light control board. It is a fragmentary sectional view which shows the installation state of a condensing lens and a light control plate at the time of putting a light control plate in front of a condensing lens. It is a schematic diagram which shows the state of a light ray. It is a fragmentary sectional view which shows the installation state of a condensing lens and a light control plate at the time of arrange | positioning a light control plate immediately after a condensing lens. It is a schematic diagram which shows the state of a light ray. It is a figure which shows the relationship between illumination intensity ratio and illumination intensity nonuniformity. It is a schematic diagram which shows the state of the light ray at the time of arrange | positioning a light control board to the 1st focus position of a condensing lens.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
<First Embodiment>
FIG. 1 is a schematic diagram showing a schematic configuration of a light irradiation apparatus 1 according to an embodiment to which the present invention is applied. The light irradiation device 1 can be used for, for example, a projection optical system, a fiber illumination light source device, a solar simulator, a liquid crystal substrate inspection device, various exposure devices, and the like. The light irradiation device 1 includes a lamp unit 10, a rod integrator lens 20 that outputs radiated light from the lamp unit 10 with a uniform light amount distribution in the cross section of the optical axis K, and a radiated light from the lamp unit 10. A condensing lens 50 that collects light on the incident end face 22, and a light control plate 30 that adjusts the amount of light emitted from the exit end face 23 of the rod integrator lens 20.

The lamp unit 10 is a condensing lamp unit including a lamp (light source) 11 and an elliptical reflecting mirror (reflecting mirror) 12 on which the lamp 11 is disposed at the focal point.
The lamp 11 is a light source that emits light including ultraviolet rays, and may be a short arc type discharge lamp such as a halogen lamp, a mercury lamp, and a metal halide lamp, or a light emitting diode such as an LED. The structure which is may be sufficient.
The ellipsoidal reflecting mirror 12 has an ellipsoidal reflecting surface, reflects light emitted from the lamp 11 arranged at one focal point, and condenses the light beam L at the other focal point on the optical axis K. For the reflecting mirror 12, a mirror film having an appropriate configuration is made on the inner surface according to the application. For example, a reflecting mirror dedicated to the ultraviolet region, a general metal mirror, or a dielectric multilayer film is deposited to make visible light. It is configured as a so-called cold mirror that reflects light and transmits infrared rays.

  The condensing lens 50 is a plano-convex lens, and includes a first focal point F1 and a second focal point F2 that are at the same focal length f from the first principal point H1 and the second principal point H2 on the incident side and the emission side, respectively. . In the present embodiment, the light flux L reflected by the elliptical reflecting mirror 12 enters the condenser lens 50 from the convex surface 51 that is the lens surface on the incident side, and exits from the flat surface 52 that is the lens surface on the output side. Thus, the condenser lens 50 is configured to condense at the second focal point F2. The condenser lens 50 is arranged closer to the elliptical reflecting mirror 12 than the other focal point of the elliptical reflecting mirror 12, and is elliptical to the second focal point F2 of the condenser lens 50 at a position closer to the lamp unit 10 than the other focal point. The light beam reflected by the reflecting mirror 12 can be condensed. Thus, since the light irradiation apparatus 1 can focus the light beam L on the second focal point F2 at a desired position by disposing the condenser lens 50 in the optical path of the lamp unit 10, the apparatus main body 5 is The light irradiation device 1 can be made compact by reducing the length.

  The rod integrator lens 20 is a columnar lens having a cross-sectional shape that matches the shape of irradiation light desired on the irradiation surface. One end side is an incident end surface (one end) 22, and the other end side is an emission end surface (other end) 23. ing. The rod integrator lens 20 is arranged such that the central axis is coaxial with the optical axis K of the lamp unit 10. The cross-sectional shape of the rod integrator lens 20 is formed in a rectangular shape having the same aspect ratio when the shape of irradiation light desired on the irradiation surface is, for example, a rectangular shape having a predetermined aspect ratio. It is formed in a polygon such as a regular hexagon.

The rod integrator lens 20 is arranged so that the axial center of the incident end face 22 is aligned with the position of the second focal point F <b> 2 of the condenser lens 50. The light beam L reflected by the elliptical reflecting mirror 12 is condensed by the condensing lens 50 and enters the rod integrator lens 20 from the incident end face 22. The rod integrator lens 20 mixes the incident light from the incident end face 22 by reflecting the incident light on the side face 21 a plurality of times, and emits the emitted light having a uniform illuminance distribution from the exit end face 23. The rod integrator lens 20 can be formed from glass or plastic.
The outgoing light emitted from the outgoing end face 23 of the rod integrator lens 20 is irradiated onto an arbitrary irradiation surface (screen) SC via the projection lens 60, for example. In addition, although illustration is abbreviate | omitted, the structure with which the light irradiation apparatus 1 equips the apparatus main body 5 with the projection lens 60 may be sufficient.

  The light control plate 30 is an optical member that is formed of a metal plate or the like and is disposed in the optical path of the lamp unit 10 between the lamp unit 10 and the rod integrator lens 20 and adjusts the amount of light incident on the rod integrator lens 20. is there. The light control plate 30 is half the focal length f on the optical axis K between the first focus F1 of the condenser lens 50 and the second focus F2 and between the first focus of the condenser lens 50. One or more are arranged at intervals. In other words, the dimming plate 30 is closer to the condenser lens 50 than the 1 / 2f point on the incident side of the condenser lens 50 where the distance from the first principal point H1 is half or less of the focal length, or On the exit side of the condenser lens 50, the condenser lens 50 is disposed between the flat surface 52 that is the lens surface on the exit side of the condenser lens 50 and the second focal point F <b> 2.

As shown in FIG. 2, the light control plate 30 has a light control slit (opening) 32 with a variable area. The light control plate 30 is driven so that the light flux L passes through portions where the opening widths (aperture ratios) of the light control slits 32 are different, that is, by changing the opening area through which the light flux L is transmitted. The amount of light incident on the rod integrator lens 20 can be adjusted by changing the amount of light transmitted through the rod integrator lens 20. The light irradiation device 1 includes a motor 40 that is a driving unit for driving the light control plate 30. In this figure, the motor 40 is arranged in the shape of a drive shaft of the light control plate 30 for convenience, but the motor 40 can be arranged at an arbitrary position outside the optical path of the lamp unit 10.
When the light control plate 30 is disposed on the incident side of the condenser lens 50, the distance α between the light control plate 30 and the first principal point H <b> 1 of the light collection lens 50 is 2 minutes of the focal length f of the light collection lens 50. Is set to be 1 or less.

  As shown in FIG. 3, the light control plate 30 includes a light control slit (opening) 32 (which may be a hole) in which the opening width gradually increases in the plate-like member 31. The light control plate 30 may be, for example, a rotary optical member as shown in FIGS. 2 and 3A, or a straight-sliding type as shown in FIG. 3B. The optical member may be used.

  The rotary light control plate 30A shown in FIG. 3A is formed with light control slits 32A that gradually increase in opening width along a circumference 42 having a predetermined diameter. By arranging the optical axis K along the circumference 42 of the light control plate 30A and rotating the light control plate 30A about the center O of the circumference 42, the area of the aperture through which the light beam L passes is increased or decreased. Thus, the amount of light transmitted through the light control plate 30A is varied.

  3B is formed with a dimming slit 32B in which the opening width gradually increases along an axis 41 perpendicular to the optical axis K of the lamp unit 10. The dimming slit 32B shown in FIG. . By aligning the optical axis K with the axis 41 of the light control plate 30B and sliding the light control plate 30B along the axis 41, the area of the aperture through which the light beam L passes is increased or decreased. The amount of light that passes through the plate 30B is varied.

  As described above, in the rotary light control plate 30A shown in FIG. 3A and the linear slide type light control plate 30B shown in FIG. 3B, the opening width of the light control slit 32 is wide. Then, both the light beam L1 reflected around the opening end 12A of the elliptical reflecting mirror 12 and the light beam L2 reflected near the central portion 12B of the elliptical reflecting mirror 12 are transmitted through the dimming plate 30 and the rod integrator lens. 20 introduced. In the portion where the opening width of the light control slit 32 is narrow, the light beam L having a high ratio of the light beam L2 reflected near the center portion 12B of the elliptical reflecting mirror 12 passes through the light control plate 30 and enters the rod integrator lens 20. be introduced.

As shown in FIG. 4, the light irradiation device 1 suppresses the movement of the edge 38 of the light control plate 30 in the optical axis K direction and allows the light control plate 30 to move along the above-described movement axis. A guide portion (guide means) 35 for guiding is provided. The guide portion 35 includes a groove 36 into which the edge portion 38 of the light control plate 30 is loosely fitted. The light adjustment plate 30 moves in a state where the edge portion 38 is loosely fitted into the groove 36. The condenser lens 50 is held in a lens holder 55 that surrounds the outer periphery, and is disposed in the optical path of the lamp unit 10. The guide unit 35 is a dimming plate so that the dimming plate 30 can move without interfering with the condenser lens 50 and / or the lens holder 55 when the dimming plate 30 is moved to increase or decrease the diaphragm. 30 edges 38 are carried.
According to this configuration, even if the light control plate 30 is provided in the vicinity of the convex surface 51 that is the incident side lens surface of the condenser lens 50, the edge portion 38 of the light control plate 30 is supported by the guide portion 35, and the light control plate 30 can be guided to move without interfering with the condenser lens 50 and / or the lens holder 55.

  By the way, when the light control plate 30 is disposed in the vicinity of the first focal point F1 of the condenser lens 50, the opening width of the light control slit 32 of the light control plate 30 is narrowed, that is, the light control plate 30 is made a small stop. Then, as shown in FIG. 9, the light beam L <b> 3 that has passed through the first focal point F <b> 1 enters the condenser lens 50, and becomes close to parallel light that is substantially parallel to the optical axis K through the condenser lens 50. In addition, the light beam indicated by a broken line in FIG. 9 indicates the state of the light beam that passes through the light control plate 30 when the light control plate 30 is released. As a result, almost no light beam is reflected from the side surface 21 of the rod integrator lens 20, so that the balance of the superimposition of the light beams L on the emission end surface 23 of the rod integrator lens 20 is lost, and the illuminance is reduced as the light control plate 30 is made smaller. Unevenness was a cause.

  On the other hand, when the light control plate 30 of this embodiment is arrange | positioned at the entrance side of the condensing lens 50, as shown in FIG. 5, the 1st main point of the light control plate 30 and the condensing lens 50 is shown. It arrange | positions so that the space | interval with H1 may become 1/2 or less of the focal distance f of the condensing lens 50. FIG. When the light control plate 30 is disposed on the incident side of the condenser lens 50, it is particularly desirable to arrange the light control plate 30 in the vicinity of the convex surface 51 that is the lens surface on the incident side of the condenser lens 50. The distance between the plate 30 and the first principal point H1 of the condenser lens 50 can be set to about 2 mm, for example.

  In this way, the light control plate 30 is arranged close to the lens surface of the light collecting lens 50 at a distance of at least one half of the focal length f from the first focal point F1 of the light collecting lens 50. When the opening width of the dimming slit 32 of the plate 30 is narrow, that is, when the dimming plate 30 has a small aperture, the light beam L3 that has passed through the first focal point F1 of the condenser lens 50 is blocked by the blocking portion 34 of the dimming plate 30. Thus, it is possible to prevent the light passing through the condenser lens 50 from becoming close to parallel light. In addition, since the angle of the light beam that has passed through the condenser lens 50 can be secured to an angle that is stronger than approximately one half of the angle when the light beam has passed through the light control plate 30, the rod integrator lens 20. Can be reflected by the side surface 21 for mixing, and the light quantity distribution in the irradiation surface can be made uniform. 5 indicates the state of the light beam that is shielded by the light control plate 30 when the light control plate 30 is in a small aperture state and is transmitted through the light control plate 30 when the light control plate 30 is released.

Further, since the light control plate 30 is arranged at a distance from the first focal point by a half or more of the focal length f of the condenser lens 50, as shown in FIG. It can also be arranged. Even when the light control plate 30 is disposed on the exit side of the condenser lens 50, the light irradiation device 1 is provided on the light control plate 30 in the same manner as when the light control plate 30 is disposed on the incident side of the condenser lens 50. A guide portion (guide means) 35 that suppresses the movement of the edge portion 38 in the direction of the optical axis K and guides the light control plate 30 to be movable along the above-described movement axis is provided.
According to this configuration, even if the light control plate 30 is provided in the vicinity of the flat surface 52 that is the exit side lens surface of the condenser lens 50, the edge portion 38 of the light control plate 30 is supported by the guide portion 35, and the light control plate 30 can be guided to move without interfering with the condenser lens 50 and / or the lens holder 55.

  When the light control plate 30 is disposed on the exit side of the condensing lens 50, as shown in FIG. 7, the condensing lens 50 gives an angle more than the light ray angle before entering the condensing lens 50. The light beam passes through the light control plate 30. Thereby, the incident angle of the light beam that passes through the light control plate 30 and enters the rod integrator lens 20 can be increased, and the number of reflections on the side surface 21 of the rod integrator lens 20 can be increased. The illuminance at is uniform, and illuminance unevenness can be reduced. 7 indicates the state of the light beam that is shielded by the light control plate 30 when the light control plate 30 is in a small aperture state and is transmitted through the light control plate 30 when the light control plate 30 is released.

  By the way, when the light control plate 30 is disposed on the exit side of the condensing lens 50, the light control plate 30 transmits light beams with a more angle to the rod as the closer to the incident end surface 22 of the rod integrator lens 20. It is possible to make the light incident on the integrator lens 20, which is suitable for reducing the illuminance unevenness. However, when the light control plate 30 is brought close to the second focal point F2 of the condenser lens 50, the light control plate 30 is likely to be affected by heat due to light collection. Therefore, the light control plate 30 is disposed at a position where the distance β from the plane 52 which is the lens surface on the exit side of the rod integrator lens 20 is less than or equal to one half of the focal length f of the condenser lens 50. Is preferred. According to this configuration, the light control plate 30 can transmit the light beam having a stronger angle by passing through the condenser lens 50 without being affected by the heat of the condenser lens 50. In addition, the light beam passing through the rod integrator lens 20 can be reflected and mixed by the side surface 21, and the light quantity distribution in the irradiation surface can be made uniform.

  FIG. 8 is a diagram showing the relationship between the illuminance ratio, that is, the emitted light amount of the light irradiation device 1 with respect to the radiant light amount of the lamp unit 10 and the illuminance unevenness on the irradiated surface. As shown in FIG. 8, when the light control plate 30 is disposed at the position of the first focal point F1 of the condenser lens 50, the illuminance ratio is lowered (light control) as indicated by the line R1 in FIG. As the amount of light transmitted through the plate 30 is reduced), the illuminance unevenness is significantly worsened. On the other hand, the distance α from the convex surface 51 which is the lens surface on the incident side of the condenser lens 50 on the light control plate 30 is at a position of 1 / 2f where the focal length f of the condenser lens 50 is ½. When arranged, as shown by the line R2 in FIG. 8, even if the illuminance ratio is lowered to 10%, the illuminance unevenness can be suppressed to 30% or less. Further, when the light control plate 30 is disposed in the vicinity of the convex surface 51 that is the lens surface on the incident side of the condenser lens 50, the illuminance ratio can be reduced to 10% as indicated by the line R3 in FIG. The illuminance unevenness can be suppressed to about 20%. Further, when the light control plate 30 is disposed in the vicinity of the plane 52 which is the lens surface on the exit side of the condenser lens 50, the illuminance ratio can be reduced to 10% as indicated by the line R4 in FIG. The illuminance unevenness can be suppressed to about 15%.

  Thus, in the light irradiation device 1 of the present embodiment, the dimming plate 30 is 1/2 or more apart from the first focal point F1 of the condenser lens 50 on the optical axis K by a half or more of the focal length f. By disposing between the point 2f and the second focal point F2 of the condenser lens 50, it is possible to suppress a large variation in illuminance unevenness that occurs when the light amount is greatly reduced by the light control plate 30. Thereby, even if the light quantity which permeate | transmits the light control board 30 is changed a lot, the light irradiation apparatus 1 with little fluctuation | variation of illumination intensity nonuniformity can be provided.

As described above, according to the embodiment to which the present invention is applied, the lamp unit including the lamp 11 and the elliptical reflecting mirror 12 that reflects the light emitted from the lamp 11 with the lamp 11 disposed at the focal point. 10 and a condensing light that is disposed in the optical path of the elliptical reflecting mirror 12, has a first focal point F1 and a second focal point F2, and condenses the light beam L reflected by the elliptical reflecting mirror 12 to the second focal point F2. An entrance end face 22 is disposed at the second focal point F2 of the lens 50 and the condenser lens 50, and a columnar rod integrator lens 20 that makes the light beam L incident from the entrance end face 22 uniform and exits from the exit end face 23, and the condenser. Between the first focal point F1 and the second focal point F2 of the lens 50, the distance from the first focal point F1 is arranged at a position that is at least half the focal length f of the condenser lens 50. Incident end A dimming plate 30 adjusts the amount of light incident on 22, with a.
Thereby, at the time of the small aperture of the light control plate 30, the light beam L3 that has passed through the first focus F1 of the condenser lens 50 can be shielded by the light control plate 30, and the light beam L3 that has passed through the first focus F1 can be blocked. Since it is possible to prevent light rays that have passed through and become parallel light from entering the rod integrator lens 20, it is possible to suppress the uneven distribution of the light amount and the deterioration of illuminance unevenness within the irradiation surface. Further, even when the light control plate 30 has a small aperture, a light beam having an angle reflected by a wider portion of the elliptical reflecting mirror 12 can be incident on the rod integrator lens 20, and the light beam can be incident on the rod integrator lens 20. Since the light can be reflected and mixed a plurality of times by the side surface 21, the light quantity distribution in the irradiation surface can be made uniform.

  Further, according to the embodiment to which the present invention is applied, the light control plate 30 has the light control slit 32 through which the light beam L is transmitted on the optical axis K of the elliptical reflecting mirror 12. Since the opening area is continuously variable by moving the plate 30, the light irradiation device 1 can continuously adjust the amount of light emitted, and regardless of the amount of emitted light, Unevenness in illuminance can be reduced by making the light amount distribution in the irradiation surface uniform. Thereby, it is possible to reduce the illuminance unevenness greatly fluctuating depending on the area of the dimming slit 32, and to irradiate the irradiation surface with any amount of irradiation light having no illuminance unevenness on the irradiation surface.

  In addition, according to the embodiment to which the present invention is applied, the light guide plate 30 is guided so as to be movable in a state of being separated from the condenser lens 50 and the lens holder 55 holding the condenser lens 50 by a predetermined distance or more. Since the unit 35 is provided, the light control plate 30 can be moved without interfering with the condenser lens 50 or the lens holder 55 when the light control plate 30 is moved to increase or decrease the aperture of the light control plate 30. The edge 38 of the light control plate 30 is carried. According to this configuration, even if the light control plate 30 is provided in the vicinity of one of the lens surfaces 51 and 52 of the condenser lens 50, the edge portion 38 of the light control plate 30 is supported by the guide portion 35, and light control is performed. The plate 30 can be guided so as to move without interfering with the condenser lens 50 and the lens holder 55.

  Further, according to the embodiment to which the present invention is applied, since the light control plate 30 is provided in the vicinity of the lens surface 51 on the incident side of the condenser lens 50, the elliptical reflecting mirror can be used even when the light control plate 30 has a small aperture. Since an angled light beam can be made incident on the rod integrator lens 20 from a wider portion of 12 and the light beam can be reflected and mixed by the side surface 21 of the rod integrator lens 20 a plurality of times. The light quantity distribution can be made uniform.

  Further, according to the embodiment to which the present invention is applied, the distance between the light control plate 30 on the exit side of the condenser lens 50 and the lens surface 52 on the exit side is two minutes of the focal length f of the condenser lens 50. Therefore, it is possible to transmit the light beam having a stronger angle by passing through the condenser lens 50, and to reflect the light beam passing through the rod integrator lens 20 by the side surface 21 for mixing. It is possible to make the light amount distribution in the irradiation surface uniform. Further, by arranging the light control plate 30 at a distance from the second focus F2 of the condenser lens 50 to some extent, the light control plate 30 is prevented from being affected by heat due to the light collection by the light collection lens 50. can do.

  Further, according to the embodiment to which the present invention is applied, since the light control plate 30 is disposed in the vicinity of the lens surface 52 on the exit side of the condenser lens 50, the light beam having a stronger angle by passing through the condenser lens 50. Can be transmitted, the light beam passing through the rod integrator lens 20 can be reflected by the side surface 21 and mixed, and the light amount distribution in the irradiation surface can be made uniform.

As mentioned above, although this invention was demonstrated based on embodiment, this invention is not limited to this. In the present embodiment, the optical axis K is configured as a straight line. However, the present invention is not limited to this. For example, a mirror that changes the entire direction of the light beam L between the elliptical reflecting mirror 12 and the rod integrator lens 20 is used. The structure which provides an optical member may be sufficient.
In the present embodiment, the light control plate 30 is composed of a single plate. However, the present invention is not limited to this, and any light control plate that can mechanically change the opening area continuously can be used. For example, it may be a dimming plate composed of two plates and moving both plates, or a configuration using an iris diaphragm composed of a large number of plates.
In the present embodiment, the lamp unit 10 is a condensing lamp unit including the elliptical reflecting mirror 12. However, the present invention is not limited thereto, and the lamp unit 10 emits light from the lamp 11 disposed at the focal point. A configuration in which a parabolic mirror that reflects and forms a light beam L parallel to the optical axis K may be provided as a reflecting mirror.

DESCRIPTION OF SYMBOLS 1,100 Light irradiation apparatus F1 1st focus F2 2nd focus 10 Lamp unit 11 Lamp (light source)
12 Elliptical reflector (reflector)
20 Rod Integrator Lens 21 Side 22 Entrance End Face 23 Exit End Face 30, 30A, 30B Light Control Plate 32, 32A, 32B Light Control Slit (Opening)
35 Guide part (guide means)
50 Condenser lens 51 Convex surface (incident side lens surface)
52 plane (exit-side lens surface)
55 Lens holder K Optical axis L Luminous flux f Focal length

Claims (6)

A lamp unit comprising a light source, and a reflector that reflects the light emitted from the light source when the light source is disposed at a focal point;
A planoconvex lens that is disposed in the optical path of the reflecting mirror and has a convex entrance surface and a flat exit surface, and is located at the same focal length from the first principal point and the second principal point on the entrance side and the exit side, respectively. A condensing lens having a first focal point and a second focal point, and condensing the light beam reflected by the reflecting mirror on the second focal point;
A columnar rod integrator lens in which an incident end face is disposed at the second focal point of the condenser lens, and a light beam incident from the incident end face is made uniform and emitted from the exit end face;
A light control plate that is disposed between the first focal point of the condenser lens and the incident surface or between the emission surface and the second focal point and adjusts the amount of light incident on the incident end surface of the rod integrator lens; , Bei to give a,
The dimming plate is disposed on the incident side of the condenser lens with an interval not exceeding one half of the focal length of the condenser lens between the first principal point and the first principal point; Alternatively, the light irradiation is characterized in that it is disposed on the light exit side of the condenser lens and between the light exit surface and an interval not exceeding one half of the focal length of the condenser lens. apparatus.   The light control plate has an opening through which light flux is transmitted on the optical axis of the concave mirror, and the opening is provided so that the opening area can be continuously changed by moving the light control plate. The light irradiation apparatus according to claim 1, wherein   3. A guide unit that guides the light control plate so as to be movable at a predetermined distance or more from the condenser lens and a lens holder that holds the condenser lens. The light irradiation apparatus as described in.   The light irradiation apparatus according to claim 1, wherein the light control plate is provided in the vicinity of a lens surface on an incident side of the condenser lens.   The light control plate is disposed at a position where an interval between the light converging lens and a lens surface on the light exiting side is equal to or less than a half of a focal length of the light collecting lens. Item 4. The light irradiation device according to any one of Items 1 to 3.   The light irradiation apparatus according to claim 5, wherein the light control plate is disposed in the vicinity of a lens surface on an emission side of the condenser lens.

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