JP2019003762A - Luminaire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably illuminate a lighting device while reducing the size of the lighting device. A lighting device that irradiates light emitted from an irradiation unit via a collimating optical system, wherein the irradiation unit has a plurality of light emitting elements and an incident surface on the light emitting element side for each of the light emitting elements. A plurality of rod lenses arranged so that the emission surface is directed toward the collimating optical system side, a lens holding portion that holds the plurality of rod lenses in a state of being separated from each other, and the lens holding portion. It is equipped with a lens fixing part for fixing a plurality of rod lenses. [Selection diagram] Fig. 3

Description

  The present invention relates to an illumination device that illuminates an irradiation surface using a plurality of light emitting elements such as LEDs (light emitting diodes).

  An exposure apparatus is used to manufacture semiconductor elements, liquid crystal substrates, and the like. In this exposure apparatus, in order to uniformly illuminate a large exposure area, an illumination apparatus having a basic configuration of a mercury lamp, a condensing mirror, a fly-eye lens, and a concave mirror is widely used (see, for example, Patent Document 1). . In the apparatus described in Patent Document 1, exposure light emitted from a mercury lamp enters a fly-eye lens via a condenser mirror and a plane mirror. And the light which passed the said fly eye lens is irradiated to an exposure irradiation surface via a concave mirror. Thereby, the exposure irradiation surface is illuminated uniformly and stably.

JP 2014-13303 A

  However, a mercury lamp is used as the light source in the illumination device, and the enlargement of the illumination device is inevitable, and this has been one of the main factors for the enlargement of the exposure apparatus equipped with the illumination device. .

  This invention is made | formed in view of the said subject, and it aims at providing the technique which can be stably illuminated with the said illuminating device, aiming at size reduction of a illuminating device.

  One embodiment of the present invention is a lighting device that irradiates light emitted from an irradiation unit via a collimating optical system, and the irradiation unit includes a plurality of light-emitting elements and a light-emitting element-side incident surface. And a plurality of rod lenses arranged with the exit surface facing the collimating optical system side, a lens holding unit that holds the plurality of rod lenses in a state of being separated from each other, and a plurality of rod lenses with respect to the lens holding unit And a lens fixing portion for fixing the lens.

  In the invention configured as described above, a plurality of light emitting elements and a plurality of rod lenses are arranged in a one-to-one correspondence relationship. Here, focusing on one light emitting element, an optical element that emits emitted light emitted from the light emitting element toward a collimating optical system by the light emitting element and a rod lens corresponding to the light emitting element (hereinafter referred to as “unit irradiation”). Part)). Then, light is incident on the collimating optical system for each unit irradiation unit, and the number of lights corresponding to the number of unit irradiation units is collimated by the collimating optical system. In this way, it is possible to illuminate the irradiation surface over a wide range using a plurality of light emitting elements as light sources, and it is possible to reduce the size of the apparatus as compared with the conventional apparatus using a single light source (mercury lamp). it can. Further, the collimation half angle can be changed by the arrangement of the unit irradiation units, and it is possible to provide an illumination device that meets various needs.

  The plurality of rod lenses are held by the lens holding unit in a state of being separated from each other, and the plurality of rod lenses are fixed to the lens holding unit by the lens fixing unit. Therefore, the assembly accuracy of the rod lens can be improved. Further, the positional shift due to disturbance such as vibration and temperature change is prevented, and the occurrence of light loss is suppressed.

  As described above, according to the present invention, it is possible to stably illuminate the illumination device while reducing the size of the illumination device.

It is a figure which shows 1st Embodiment of the illuminating device concerning this invention. It is a figure which shows the structure of the irradiation unit used with the illuminating device of FIG. It is a figure which shows the structure of the irradiation unit of FIG. It is a figure which shows adjustment operation | movement of the collimation half angle in the illuminating device of FIG. It is a figure which shows 2nd Embodiment of the illuminating device concerning this invention. It is a figure which shows 3rd Embodiment of the illuminating device concerning this invention. It is a figure which shows 4th Embodiment of the illuminating device concerning this invention. It is a figure which shows 5th Embodiment of the illuminating device concerning this invention. It is a figure which shows 6th Embodiment of the illuminating device concerning this invention. It is a figure which shows 7th Embodiment of the illuminating device concerning this invention. It is a figure which shows 8th Embodiment of the illuminating device concerning this invention.

  FIG. 1 is a diagram showing a first embodiment of a lighting device according to the present invention. FIG. 2 is a diagram showing a configuration of an irradiation unit used in the illumination device of FIG. Further, FIG. 3 is a perspective view showing a configuration of a light source unit and a taper rod lens unit employed in the irradiation unit of FIG. The illumination device 100 includes an LED irradiation unit 1 that irradiates a plurality of lights, a collimation mirror 2, and a controller 3 that controls LED lighting in the LED irradiation unit 1. (Exposure surface) It has a function of illuminating S uniformly.

  The LED irradiation unit 1 includes a light source unit 10 having a plurality (49 in the present embodiment) of ultraviolet LEDs 11 (hereinafter simply referred to as “LED11”) and a plurality (49 in the present embodiment) of taper rod lenses 121. The taper rod lens unit 12 held by the lens holding unit 123, the incident side fly-eye lens 13, and the emission side fly-eye lens 14 are provided. Although not shown, in the light source unit 10, the LEDs 11 are arranged in a 7 × 7 two-dimensional matrix on one main surface of the flat substrate 111 (in FIG. 2, one LED row ( Or LED row). Each LED 11 is electrically connected to the controller 3, and can be turned on and off independently according to a command from the LED lighting control unit 31 of the controller 3. As to which LED 11 is to be lit, information given from the illumination condition setting unit 32 of the controller 3 to the LED lighting control unit 31 according to the illumination conditions such as the collimation half angle and the illuminance on the irradiation surface S, as will be described later. Determined by.

  Further, in the taper rod lens unit 12, 49 taper rod lenses 121 are in a 7 × 7 two-dimensional matrix shape as in the LED 11, as shown in FIG. Are arranged. More specifically, each taper rod lens 121 has a tapered shape whose cross-sectional area increases from the incident surface 121a toward the exit surface 121b. As shown in FIG. 2, the taper rod lens 121 is arranged so that the incident surface 121 a of the taper rod lens 121 faces the light emitting surface 11 a of the LED 11 and is in contact with the light emitting surface of the LED 11 for each LED 11. Yes.

  Here, when the tapered rod lens 121 deviates from the design position, light loss occurs between the LED 11 and the incident surface 121a of the tapered rod lens 121 and between the emission surface 121b of the tapered rod lens 121 and the lens element 131. . Therefore, in this embodiment. For example, as shown in FIG. 3, seven taper rod lenses 121 are made into one rod lens group 122, and the taper rod lens 121 is integrally held by a lens holding portion 123 for each rod lens group 122.

  The lens holding part 123 is composed of a strip-shaped metal plate 123a as shown by a broken line area in FIG. A plurality (seven in this embodiment) of through holes 123b are provided in the metal plate 123a at the same pitch as the arrangement pitch of the taper rod lenses 121. Of the two main surfaces of the metal plate 123a, the opening of the through hole 123b in the incident side main surface 123c on the side facing the LED 11 (right hand side in the figure) is also on the side facing the collimation mirror 2 (left hand side in the figure). The opening of the through-hole 123b in the exit side main surface 123d also has the same shape and the same size as the exit surface 121b of the tapered rod lens 121. For this reason, when the end on the emission surface 121b side of the taper rod lens 121, that is, the anti-LED side end 121d is fitted into the through-hole 123b, the plurality of taper rod lenses 121 are in a state of being separated from each other and the taper rod lens 121. Is held by the lens holding portion 123 in a state where the emission surface 121b is flush with the emission-side main surface 123d of the metal plate 123a. On the other hand, the tapered rod lens 121 is loosely inserted on the incident-side main surface 123c of the metal plate 123a, and a gap region is formed. In the present embodiment, the gap region is filled with the adhesive 124, and the taper rod lens 121 is firmly fixed to the metal plate 123a. Thus, in the present embodiment, the adhesive 124 functions as the “lens fixing portion” of the present invention. In addition, in the broken-line area | region of FIG. 3, in order to show typically the adhesive agent 124 which entered the inside of a clearance gap area, the dot is attached | subjected.

  In the present embodiment, in order to smoothly and evenly fill the adhesive 124 with respect to the gap region, the lens holding portion 123 has a region corresponding to the ridgeline 121c of the tapered rod lens 121 in the inner wall of the through hole 123b. Is provided with a groove 123e. As a result, the adhesive 124 injected from the outside spreads over the entire gap region through the groove 123e, so that a relatively large bonding area can be obtained and the fixing strength can be increased. The provision of the groove 123e is not an essential requirement for fixing with the adhesive 124. For example, as shown in FIG. 5 described later, the adhesive 124 is filled in the gap region without providing the groove 123e. It may be configured.

  As described above, in this embodiment, the anti-LED side end portion 121d (the left hand side end portion in FIG. 3) of the tapered rod lens 121 is held by the lens holding portion 123 and fixed by the adhesive 124. For this reason, the assembly accuracy of the taper rod lens unit 12 can be improved, and the displacement due to disturbance such as vibration and temperature change can be effectively prevented, and the occurrence of light loss can be effectively suppressed. That is, in each LED 11, the light emitted from the LED 11 is efficiently incident on the tapered rod lens 121 via the incident surface 121a. Further, the incident light travels to the exit surface 121b while being repeatedly reflected inside the tapered rod lens 121 a plurality of times. For this reason, light with less luminance unevenness is irradiated from the exit surface 121b toward the incident-side fly-eye lens 13.

  The incident side fly-eye lens 13 has 49 lens elements 131. These lens elements 131 are arranged in a 7 × 7 two-dimensional matrix like the LED 11 and the taper rod lens 121, and are arranged in one-to-one correspondence with the taper rod lens 121. More specifically, as shown in FIG. 2, the lens element 131 is disposed for each tapered rod lens 121 so as to be in contact with the emission surface 121 b of the tapered rod lens 121. Thus, by making the lens element 131 and the exit surface 121b of the tapered rod lens 121 contact, light can be efficiently incident on the lens element 131 from the tapered rod lens 121.

  In the present embodiment, the exit-side fly-eye lens 14 is disposed at a position away from the entrance-side fly-eye lens 13 configured as described above on the side opposite to the LED (the left-hand side in FIG. 2). The exit side fly-eye lens 14 also has 49 lens elements 141 like the entrance side fly-eye lens 13. As shown in FIG. 2, the lens element 141 is provided in one-to-one correspondence with the lens element 131.

  As described above, in this embodiment, the light emitted from one LED 11 is applied to the collimation mirror 2 via the tapered rod lens 121 and the lens elements 131 and 141 corresponding to the LED 11. The LED 11, the tapered rod lens 121, and the lens elements 131 and 141 constitute an optical element that irradiates the light emitted from the LED 11 toward the collimation mirror 2, that is, a unit irradiation unit 15 (see FIG. 2). That is, in the LED irradiation unit 1 of the present embodiment, 49 unit irradiation units 15 are provided in a 7 × 7 two-dimensional matrix. Then, when the LED 11 is turned on, light is irradiated from each unit irradiation unit 15 to the collimation mirror 2, collimated by the collimation mirror 2, and irradiated onto the irradiation surface S.

  Furthermore, in this embodiment, it is possible to change the number and arrangement of the unit irradiation units 15 that emit light toward the collimation mirror 2 by selecting the LED 11 to be lit by the controller 3 as described above. This makes it possible to change the collimation half-width. This point will be described in detail with reference to FIG.

  FIG. 4 is a diagram illustrating a collimation half-angle adjustment operation in the illumination device of FIG. The figure shown in the right column of the figure is a schematic view when the LED irradiation unit 1 is viewed from the collimation mirror 2 side. The hatched ones of the lens elements 141 turn off the LEDs 11 corresponding to the lens elements 141. In other cases, the corresponding LED 11 is turned on. That is, FIG. 4A shows a case where all the LEDs 11 are turned on, and FIG. 5B shows a case where the central 5 × 5 LEDs 11 are turned on.

  In the left column of FIG. 4, a part of the light beam applied to the irradiation surface S is indicated by a two-dot chain line. As is clear from these, the LEDs 11 are all lit (7 × 7) to partially lit (5 By changing to x5), the collimation half angle is reduced from the collimation half angle (θa / 2) to the collimation half angle (θb / 2). Further, although illustration in FIG. 4 is omitted, the collimation half angle can be further reduced by lighting only the central 3 × 3 LED 11. The collimation half angle can be changed by the arrangement of the LEDs 11 (unit irradiation unit 15) that are lit in this way. 4 shows only the collimation half angle, the illuminance and illuminance distribution on the irradiation surface S can also be changed by the on / off control of the LED 11.

  As described above, in this embodiment, the plurality of unit irradiation units 15 are two-dimensionally arranged to illuminate the irradiation surface S. Therefore, the illumination device 100 can be reduced in size as compared with the conventional device using a single light source (mercury lamp). Further, the LED 11 can be turned on / off independently to change and control the collimation half angle, the illuminance, and the illuminance distribution, thereby enabling illumination according to various needs.

  Further, as described above, the lens holding portion 123 is provided with a rectangular through hole 123b, and the anti-LED side end portion 121d of the tapered rod lens 121 is fitted into each through hole 123b to be held by the lens holding portion 123 and by the adhesive 124. It is fixed. Therefore, the occurrence of the optical loss can be effectively suppressed by improving the assembly accuracy of the taper rod lens unit 12 and preventing the positional deviation due to disturbance such as vibration and temperature change. Moreover, in the said embodiment, since the entrance surface 121a and the output surface 121b of the taper rod lens 121 are made to contact with LED11 and the lens element 131, respectively, a contact surface may be damaged by the position shift by a disturbance. However, in this embodiment, it is possible to effectively prevent the contact surface from being damaged due to the positional shift prevention effect by the lens holding portion 123 as described above.

  Thus, in the said 1st Embodiment, LED11 is equivalent to an example of the "light emitting element" of this invention. The collimation mirror 2 corresponds to an example of the “collimating optical system” of the present invention. Further, the metal plate 123a corresponds to an example of the “flat plate member” of the present invention.

  The present invention is not limited to the above-described embodiment, and various modifications other than those described above can be made without departing from the spirit of the present invention. For example, in the first embodiment, the openings of the through holes 123b in the incident-side main surface 123c and the emission-side main surface 123d have the same shape and the same size, but they may be different from each other. For example, as shown in FIG. 5, the opening of the through hole 123b in the exit-side main surface 123d has the same shape and the same size as the exit surface 121b of the tapered rod lens 121, while the opening of the through-hole 123b in the entrance-side main surface 123c You may spread more than that (2nd Embodiment). In this case, the through-hole 123b has a reverse taper shape in which a cross-sectional area decreases from the incident surface 121a toward the output surface 121b, and the degree of loose insertion of the tapered rod lens 121 on the incident-side main surface 123c is large. Is spreading. Therefore, the adhesive 124 can be satisfactorily filled into the entire gap region without providing the groove 123e.

  In the first embodiment and the second embodiment, the adhesive 124 functions as the “lens fixing portion” of the present invention. However, other systems such as the mechanical lens shown in FIGS. 6 to 9 are used. The taper rod lens 121 may be fixed to the lens holding portion 123 by a fixing portion (third to sixth embodiments).

  As shown in FIG. 6, a taper rod lens fitted in the through hole 123b by providing a through hole 123f communicating with the through hole 123b in the metal plate 123a and attaching a ball plunger 125 to the through hole 123f. The anti-LED side end 121d of 121 may be pressed and fixed (third embodiment).

  Further, as shown in FIG. 7, the shape of the through hole 123b is changed from a rectangle to a circle, and after inserting the rod ring 126a into the through hole 123b, the through hole provided in the through hole 123f and the rod ring 126a By attaching the ball plunger 126b, the opposite LED side end 121d of the tapered rod lens 121 fitted in the rod ring 126a may be pressed and fixed (fourth embodiment). As described above, in the embodiment shown in FIG. 7, the lens fixing portion 126 is configured by the rod ring 126a and the ball plunger 126b.

  In addition, as shown in FIG. 8, a lens fixing portion 127 constituted by a rod hold plate 127a may be used (fifth embodiment). The rod hold plate 127 a is provided with a through hole 127 b that can be engaged with the ridgeline 121 c of the tapered rod lens 121. The taper rod lens 121 can be fixed by attaching the rod hold plate 127a from the incident surface 121a side of the taper rod lens 121 and attaching it to the lens holding part 123 with the cap screw 127c.

  Further, as shown in FIG. 9, a lens including a rod lens holder 128b having a through hole 128a into which the taper rod lens 121 can be freely inserted, two types of rod rings 128c and 128d, and a tin (Zn) plate 128e. The fixing unit 128 may be used (sixth embodiment). Here, the rod lens holder 128b is attached to the lens holding portion 123 with a cap screw 128f. Further, the taper rod lens 121 is inserted through the through hole 128a of the rod lens holder 128b, and the anti-LED side end 121d of the taper rod lens 121 is fitted into the through hole 123b. Further, rod rings 128c and 128d are fitted on the tapered rod lens 121, and a tin plate 128e is press-fitted between the tapered rod lens 121 and the rod rings 128c and 128d. Further, the rod rings 128c and 128d are fixed to the rod lens holder 128b with a set screw 128g. Thus, the taper rod lens 121 is not only fitted and held in the lens holding portion 123 but also fixed to the rod lens holder 128b by the lens fixing portion 128.

  Moreover, in the said embodiment, although the collimation mirror 2 is used as a collimating optical system, you may use the collimation lens 4 as shown, for example in FIG. 10 (7th Embodiment), and illumination using the said collimation lens 4 Also in the apparatus 200, the effect similar to the illuminating device 100 concerning 1st Embodiment thru | or 6th Embodiment is acquired.

  In the first embodiment, a fly-eye lens is used as the “lens array”. However, for example, a drum lens array may be used as the “lens array” as shown in FIG. 11 (eighth embodiment). That is, in the eighth embodiment, the LED irradiation unit 1 includes a total of 25 LEDs 11 of 5 × 5 and a taper rod lens unit 12 including a total of 25 taper lenses 121 of 5 × 5, and 5 And a drum lens array 16 composed of a total of 25 drum lenses 161 of x5. The LED 11, the taper rod lens 121, and the drum lens 161 are all arranged in a 5 × 5 two-dimensional matrix. Among these, the taper rod lens 121 is held by the lens holding portion 129 and fixed by an adhesive (not shown) as in the first and second embodiments. The emitted light from one LED 11 is applied to a collimating optical system such as the collimation mirror 2 and the collimation lens 4 via a tapered rod lens 121 and a drum lens 161 corresponding to the LED 11. Thus, in the eighth embodiment, 25 unit irradiation sections 15 (= LED 11 + taper rod lens 121 + drum lens 161) are provided in a 5 × 5 two-dimensional matrix. Then, when the LED 11 is turned on, light is irradiated from each unit irradiation unit 15 to the collimating optical system, collimated by the collimating optical system, and irradiated onto the irradiation surface S. In the eighth embodiment, the drum lens 161 corresponds to a “lens element”. Similarly to the first to seventh embodiments, the plurality of taper rod lenses 121 are divided into a plurality of rod lens groups 122, and the taper rod lenses 121 are integrated by the lens holding portion 123 for each rod lens group 122. May be retained.

  In the first to seventh embodiments, the rod lens group 122 is divided into a plurality of rod lens groups 122, and the taper rod lens 121 is integrally held by the lens holding portion 123 for each rod lens group 122. Similar to the eighth embodiment, the entire tapered rod lens 121 may be integrally held by one lens holding portion.

  Moreover, in the said embodiment, although the collimation half-angle can be changed by controlling each LED11 independently by the controller 3, it is not an essential requirement of this invention to control several LED11 independently. Is an optional requirement. For example, when the specifications (including the collimation half-width) of the lighting devices 100 and 200 are determined in advance, the number and arrangement of the unit irradiation units 15 may be set according to the collimation half-width. It is possible to provide a lighting device that meets the needs of

  Moreover, in the said embodiment, although ultraviolet LED11 is used as a light emitting element, the kind of light emitting element is not limited to this, For example, you may use LED other than an ultraviolet ray as a light emitting element.

  In the above-described embodiment, the quadrangular frustum-shaped tapered rod lens 121 is used as the “rod lens” of the present invention. A rod lens having a shape may be used. Moreover, although the entrance surface 121a and the exit surface 121b of the taper rod lens 121 are in contact with the LED 11 and the lens element 131, respectively, the contact is not essential and is optional. That is, a gap may be provided between the incident surface 121a of the tapered rod lens 121 and the LED 11 and / or between the emission surface 121b of the tapered rod lens 121 and the lens element 131 to prevent damage. However, in order to suppress the light loss, it is desirable to reduce the size of the gap as much as possible, and the tapered rod lens 121 is connected to the LED 11 using the lens holding portion 123 as in the fourth and fifth embodiments. It is preferable that the lens element 131 is precisely positioned.

  Moreover, in the said embodiment, although light emitting elements, such as LED11, are arrange | positioned in the two-dimensional matrix form, the arrangement pattern of a light emitting element is not limited to this, It is arbitrary.

  Furthermore, the application target of the illumination apparatus according to the present invention is not limited to the exposure apparatus, and includes an illumination apparatus for optical inspection.

  The present invention can be applied to all lighting devices that illuminate an irradiation surface using a plurality of light emitting elements.

DESCRIPTION OF SYMBOLS 1 ... LED irradiation unit 2 ... Collimation mirror (collimating optical system)
4 ... Collimation lens (collimating optical system)
11 ... LED (light emitting element)
DESCRIPTION OF SYMBOLS 12 ... Tapered rod lens unit 121 ... Tapered rod lens 121a ... Incidence surface 121b (tapered rod lens) Output surface 123b (tapered rod lens) 123, 129 ... Lens holding part 124 ... Adhesive (lens fixing part)
125 ... Ball plunger (lens fixing part)
126, 127, 128 ... Lens fixing portion

Claims (6)

An illumination device for irradiating light emitted from an irradiation unit via a collimating optical system,
The irradiation unit is
A plurality of light emitting elements;
For each of the light emitting elements, a plurality of rod lenses arranged with the incident surface facing the light emitting element and the exit surface facing the collimating optical system side;
A lens holding unit for holding the plurality of rod lenses in a state of being separated from each other;
An illumination device comprising: a lens fixing unit that fixes the plurality of rod lenses to the lens holding unit. The lighting device according to claim 1,
The rod lens has a tapered shape in which a cross-sectional area increases from the incident surface toward the emission surface,
An illuminating device in which an end portion on the emission surface side of the side surface of the rod lens is supported by being engaged with the lens holding portion and fixed to the lens holding portion by the lens fixing portion. The lighting device according to claim 2,
The lens holding portion can be fitted with a flat plate member having an incident-side main surface facing the light-emitting element and an emission-side main surface facing the collimating optical system, and an end on the emission surface side for each rod lens. A plurality of through holes provided,
The shape and size of the opening of the through hole in the exit side main surface are the same as the shape and size of the exit surface of the rod lens, respectively, and the exit surface of the rod lens and the exit side main surface are made to coincide with each other. Holding device. The lighting device according to claim 3,
The opening of the through hole in the incident side main surface is capable of loose insertion of the rod lens,
The illuminating device, wherein the lens fixing portion is an adhesive filled between the through hole and a side surface of the rod lens. The lighting device according to claim 4,
The rod lens has a polygonal frustum shape,
In the lens holding portion, a groove portion is provided in a region corresponding to a ridge line of the rod lens in the inner wall of the through hole. The lighting device according to claim 4,
The rod lens has a tapered shape in which a cross-sectional area increases from the incident surface toward the emission surface,
In the lens holding part, the inner wall of the through hole has an inversely tapered shape in which a cross-sectional area is reduced from the incident surface toward the emission surface.

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