Light source device

Abstract

To achieve a light source device which includes a plurality of LED elements, and which can suppress deterioration in illuminance accompanying positional deviation.SOLUTION: A light source device includes: a plurality of LED elements; a first optical system for converting each light emitted from the plurality of LED elements into collimated light; and a second optical system for condensing the plurality of collimated lights emitted from the first optical system. The first optical system includes: a first collimating optical system arranged corresponding to each of the plurality of LED elements; and a second collimating optical system including optical components arranged corresponding to each of the plurality of LED elements at a subsequent stage of the first collimating optical system. The second collimating optical system can adjust a relative optical positional relation with respect to the plurality of LED elements and the first collimating optical system when viewed in the optical axis direction, under a state where the plurality of LED elements and the first collimating optical system are fixed.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a light source device, and more particularly to a light source device equipped with multiple LED elements. [Background technology]

[0002] Traditionally, light-based photoprocessing technologies have been used in a variety of fields. For example, exposure equipment is used for microfabrication using light. In recent years, exposure technology has been developed in various fields, and is used for the creation of relatively large patterns and three-dimensional microfabrication within the realm of microfabrication. More specifically, exposure technology is used in the fabrication of LED electrode patterns and in the manufacturing process of MEMS (Micro Electro Mechanical Systems), such as acceleration sensors.

[0003] In these photoprocessing technologies, high-brightness discharge lamps have long been used as light sources. However, with recent advances in solid-state light source technology, the use of a light source consisting of multiple LED elements is being considered. As an example of such technology, Patent Document 1 discloses an exposure apparatus in which a unit consisting of multiple LED elements is used as a light source, and a fly-eye lens is placed between this light source and a mask. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2004-335953 [Overview of the project] [Problems that the invention aims to solve]

[0005] Compared to light source devices composed of lamps, devices composed of LED elements produce less radiant light. Therefore, in order to construct a light source device that achieves high light output, it is necessary to collect the light emitted from multiple LED elements as much as possible. In this case, if there is a misalignment between the multiple LED elements and the subsequent optical system, it will not be possible to guide sufficient light to the optical system that is intended to utilize the light. Such misalignments occur to some degree, but are unavoidable.

[0006] In view of the above problems, the present invention aims to provide a light source device equipped with multiple LED elements that can suppress the decrease in illuminance due to positional misalignment. [Means for solving the problem]

[0007] The light source device according to the present invention is Multiple LED elements are dispersed and arranged in a plane direction perpendicular to the optical axis, A first optical system that converts the light emitted from each of the plurality of LED elements into collimated light, The system comprises a second optical system that collects a plurality of collimated lights emitted from the first optical system, The first optical system is, A first collimating optical system including optical components arranged in correspondence to each of the plurality of LED elements, The second collimating optical system, located downstream of the first collimating optical system, includes optical components arranged in correspondence with each of the plurality of LED elements. The second collimating optical system is characterized in that, with the plurality of LED elements and the first collimating optical system fixed, the relative optical positional relationship with respect to the plurality of LED elements and the first collimating optical system, as viewed in the direction of the optical axis, can be adjusted.

[0008] As mentioned earlier, the light emitted from a single LED element is less bright than that from a lamp. Therefore, when considering its use as a light source in applications requiring a large amount of light, such as exposure equipment, it is important to collect the light from many LED elements without reducing the brightness as much as possible.

[0009] According to the above configuration, the light emitted from multiple LED elements is collimated in the first optical system and then focused. This allows the light emitted from each LED element to be imaged at the focusing position. Furthermore, by adjusting the arrangement of the first optical system, which functions as a collimating optical system, the spacing between the light beams emitted from each LED element can be narrowed, resulting in a light source with a small non-emitting region. This enables the realization of a high-brightness light source device.

[0010] If misalignment occurs between multiple LED elements and the first optical system, it is expected that the amount of light guided to the subsequent stage of the second optical system will decrease. For example, if there is individual misalignment between each LED element and its corresponding collimating lens (first optical system), the focusing position of the second optical system will shift, making it difficult to efficiently guide light to the subsequent stage of the second optical system. As a result, the amount of light guided to the subsequent stage of the second optical system decreases, and if used as an exposure device, for example, the illuminance on the exposure surface will decrease.

[0011] In contrast, the light source device according to the present invention is configured to allow adjustment of the relative optical positional relationship between the multiple LED elements and the first optical system when viewed in the direction of the optical axis. Therefore, even if the light source device is installed with a misalignment between each LED element and the corresponding collimating lens (first optical system), the misalignment of the light-gathering position by the second optical system can be corrected by adjusting the relative optical positional relationship between the two, making it possible to efficiently guide light to the downstream stage of the second optical system.

[0012] Furthermore, the light source device according to the present invention includes a first collimating optical system disposed closer to the plurality of LED elements and a second collimating optical system disposed downstream of the first collimating optical system. And, with the plurality of LED elements and the first collimating optical system fixed, the relative positional relationship between the plurality of LED elements and the first collimating optical system and the second collimating optical system can be adjusted. By adopting such a configuration, during position adjustment, the LED elements and the first collimating optical system close to the LED elements do not move relative to each other, and the risk of damaging the light emitting surface or wiring of the LED elements during adjustment can be avoided.

[0013] Here, when adjusting the relative optical positional relationship between the first collimating optical system and the second collimating optical system disposed downstream of the first collimating optical system, finer adjustment is possible when the distance from the light source is greater in the direction of light propagation. In other words, when adjusting using the first collimating optical system disposed closer to the light source, just by slightly moving the first collimating optical system, the position of the image formed by the second collimating optical system will move significantly. Therefore, when attempting to adjust with the first collimating optical system, more delicate adjustment is required and the adjustment is difficult. Thus, in addition to the risk of damaging the light emitting surface or wiring of the LED elements described above, it is more preferable to fix the plurality of LED elements and the first collimating optical system to achieve more favorable adjustment.

[0014] More specifically, the light source device may include a substrate on which the plurality of LED elements are mounted, a first lens holder that houses the first collimating optical system and is fixedly connected to the substrate, and a second lens holder that houses the second collimating optical system and is capable of adjusting the relative position with respect to the first lens holder.

[0015] According to the above configuration, the substrate on which the LED element is mounted and the first lens holder are fixed. Therefore, when adjusting the arrangement position of each lens, the surface of the substrate on which the LED element is mounted can be used as a reference surface.

[0016] In addition, by arranging a lens holder (first lens holder) at a position spaced apart in the optical axis direction of the substrate on which the LED element is mounted, a protection function for the LED element is achieved. More specifically, in the case of a COB (Chip On Board) type in which the light emitting surface of the LED element is arranged in an exposed state, the LED element can be positioned within the space partitioned by the first lens holder, so that the light emitting surface and wiring of the LED element can be protected. Also, even when the light emitting surface of the LED element is covered with resin or the like, the LED element can be positioned within the space partitioned by the first lens holder, so that it is possible to prevent dust, dew condensation, etc. from adhering to the resin surface.

[0017] Thus, by adopting a configuration in which the first lens holder covers the substrate on which the LED element is mounted, effects such as protection of the LED element and suppression of a decrease in light emission intensity due to the adhesion of foreign matter can be expected. On the other hand, when such a configuration is adopted, if the relative position of the first lens holder with respect to the substrate is moved during optical position adjustment, there is a risk of damaging the light emitting surface and wiring of the LED element, and in some cases, leakage of electricity. However, according to the above configuration, optical position adjustment is performed in a state where the substrate on which a plurality of LED elements are mounted and the first collimating optical system are integrally fixed, and the relative positional relationship between the second collimating optical system arranged at a position spaced apart from the plurality of LED elements and the substrate and the first collimating optical system is adjusted. As a result, even when a configuration in which the first lens holder covers the substrate on which the LED element is mounted is adopted, the risk of damaging the light emitting surface and wiring of the LED element during position adjustment can be significantly reduced.

[0018] As an example, the light source device may be attached to the first lens holder and include an adjustment mechanism that moves the first lens holder and the substrate integrally in a plane direction perpendicular to the optical axis direction while the position of the second lens holder is fixed.

[0019] As another example, the light source device may be attached to the second lens holder and include an adjustment mechanism that moves the second lens holder in a plane direction perpendicular to the optical axis direction while the positions of the first lens holder and the substrate are fixed.

[0020] As a more specific example, the light source device is A through hole is provided at a predetermined location in the second lens holder, which penetrates the second lens holder in a direction parallel to the optical axis. A groove having an inner diameter shorter than the inner diameter of the through hole, carved out from the surface of the first lens holder on the second lens holder side for a predetermined length in a direction parallel to the optical axis, The fixing member includes a shaft portion having an outer diameter shorter than the inner diameter of the through hole and insertable into the groove, and a head portion having an outer diameter longer than the inner diameter of the through hole and connected to the shaft portion. The adjustment mechanism may also be configured such that, with the head of the fixing member not in contact with the surface of the second lens holder, the first lens holder and the substrate can be moved in a plane direction perpendicular to the optical axis direction by a distance within a margin defined by the difference between the inner diameter of the through hole and the outer diameter of the shaft portion of the fixing member.

[0021] Screws can be used as fastening members. In this case, the groove may be provided with threads. Clamping screws, cams, or pins can be used as adjustment mechanisms.

[0022] The through-hole may also be provided on the first lens holder side. In other words, the light source device is A through hole is provided at a predetermined location in the first lens holder, which penetrates the first lens holder in a direction parallel to the optical axis. A groove having an inner diameter shorter than the inner diameter of the through hole, carved out from the surface of the second lens holder on the first lens holder side for a predetermined length in a direction parallel to the optical axis, The fixing member may also include a shaft portion having an outer diameter shorter than the inner diameter of the through hole and insertable into the groove, and a head portion having an outer diameter longer than the inner diameter of the through hole and connected to the shaft portion.

[0023] The adjustment mechanism may also involve moving the second lens holder. In other words, the adjustment mechanism may be configured such that, with the head of the fixing member not in contact with the surface of the second lens holder, the second lens holder can be moved by a distance within a margin defined by the difference between the inner diameter of the through hole and the outer diameter of the shaft portion of the fixing member, in a plane direction perpendicular to the optical axis direction.

[0024] The aforementioned light source device is The inner diameter of the through hole is φ h The outer diameter of the shaft portion of the fixing member is φ p If D is the maximum diameter of the light-emitting surface of the LED element, θ1 is the maximum light-gathering angle of each optical component in the first collimating optical system, and θ2 is the maximum light-gathering angle of each optical component in the second collimating optical system, 0.1D·(θ2 / θ1) ≤ (φ h -φ p ) / 2 ≤ D·(θ2 / θ1) It is acceptable to assume that this is true.

[0025] With the fixing member positioned within the through-hole, the adjustable amount of the relative positional relationship between the second collimating optical system, the first collimating optical system, and the multiple LED elements (substrates) is the difference between the inner diameter of the through-hole and the outer diameter of the shaft portion of the fixing member (φ h -φ p) depends thereon. Also, assuming that the maximum light capture angle of the optical component (typically a lens) included in the first collimating optical system is θ1 and the maximum light capture angle of the optical component (typically a lens) included in the second collimating optical system is θ2, moving the second collimating lens by a distance d with respect to the light source is optically equivalent to moving the light source by d·(θ2 / θ1).

[0026] 0.1D·(θ2 / θ1) ≦ (φ h -φ p ) / 2 holds, by designing the inner diameter of the through hole and the outer diameter of the shaft portion, the optical position in the plane direction orthogonal to the optical axis between the LED element and the first optical system (collimating optical system) can be adjusted within a distance of 10% or less of the maximum diameter of the light emitting surface of the LED element, and a sufficient adjustment amount can be ensured even in view of actual operation.

[0027] Of course, by increasing the adjustable amount, the optical positional relationship between the LED element and the first optical system (collimating optical system) in the plane direction orthogonal to the optical axis can be adjusted significantly. However, realistically, it is not possible to assume optical position adjustment over a distance greater than the maximum diameter of the light emitting surface of the LED element. Conversely, increasing the adjustable amount too much leads to increasing the inner diameter of the through hole provided in the lens holder more than necessary. (φ h -φ p ) / 2 ≦ D·(θ2 / θ1) holds, by designing the inner diameter of the through hole and the outer diameter of the shaft portion, the maximum adjustment amount of the optical positional relationship between the LED element and the first optical system (collimating optical system) in the plane direction orthogonal to the optical axis can be limited to the maximum diameter of the light emitting surface of the LED element.

[0028] The light source device may be provided with an integrator optical system whose incident surface is arranged at the focal position of the second optical system.

[0029] The light emitted from an LED element has a lower luminous flux compared to that of a lamp. Therefore, to use it as a light source for, for example, exposure, it is necessary to collect the light emitted from multiple LED elements as much as possible. To achieve this, it is necessary to increase the number of LED elements that are arranged as a light source.

[0030] Incidentally, because LED elements require wiring patterns for power supply, it is not possible to arrange the LED elements themselves in perfect close proximity. In other words, when arranging multiple LED elements, a certain distance must be left between adjacent LED elements. The region forming this distance constitutes a non-light-emitting region. Therefore, even if multiple LED elements are arranged and the light emitted from each LED element is focused, a non-light-emitting region will inevitably occur. Consequently, simply focusing the light emitted from multiple LED elements may result in uneven illumination on the illuminated surface.

[0031] In contrast, with the above configuration, since the integrator optical system is positioned at the focal point of the second optical system, the occurrence of uneven illumination on the illuminated surface is suppressed. The integrator optical system may be composed of a light guide member such as a rod integrator that guides light incident from the incident surface to the exit surface while repeatedly reflecting it on its inner surface, or it may be composed of a fly-eye lens in which multiple lenses are arranged in a matrix. [Effects of the Invention]

[0032] According to the present invention, even if a misalignment occurs between the optical system and the LED elements in a light source device equipped with multiple LED elements, the decrease in brightness and illuminance due to the misalignment can be suppressed. [Brief explanation of the drawing]

[0033] [Figure 1] This is a schematic diagram showing the configuration of one embodiment of a light source device. [Figure 2] This is a cross-sectional view showing an example of the arrangement of multiple LED elements, a first collimating optical system, and a second collimating optical system. [Figure 3] This is a partially enlarged view of Figure 2. [Figure 4] This is a schematic diagram showing the state as described in Figure 3 with the fixing members removed. [Figure 5] This is a schematic cross-sectional view showing the structure of the fixing member. [Figure 6] This is a schematic plan view of multiple LED elements and the first optical system, as seen in the opposite direction to the direction of light propagation. [Figure 7] This is a schematic representation of Figure 6. [Figure 8A] This diagram schematically shows the image of the rod integrator at the incident surface before position adjustment. [Figure 8B] This diagram schematically shows the image of the rod integrator at the incident plane after the first stage of adjustment. [Figure 8C] This diagram schematically shows the image of the rod integrator at the incident plane after the second stage of adjustment. [Figure 8D] This diagram schematically shows the image of the rod integrator at the incident plane after the third stage of adjustment. [Figure 9] This diagram schematically shows the state in which the shaft portion of the fixing member is positioned inside the through-hole. [Figure 10] Figure 9 is a schematic diagram illustrating the preferred design criteria for the margin area 88. [Figure 11A] This is a cross-sectional view showing another example of the arrangement of multiple LED elements, a first collimating optical system, and a second collimating optical system. [Figure 11B] This is a cross-sectional view showing another example of the arrangement of multiple LED elements, a first collimating optical system, and a second collimating optical system. [Figure 11C] This is a cross-sectional view showing another example of the arrangement of multiple LED elements, a first collimating optical system, and a second collimating optical system. [Figure 11D] This is a cross-sectional view showing another example of the arrangement of multiple LED elements, a first collimating optical system, and a second collimating optical system. [Figure 11E]This is a cross-sectional view showing another example of the arrangement of multiple LED elements, a first collimating optical system, and a second collimating optical system. [Figure 12] This is a schematic diagram showing the configuration of another embodiment of the light source device. [Modes for carrying out the invention]

[0034] Hereinafter, embodiments of the light source device according to the present invention will be described with reference to the drawings. Note that the dimensional ratios in each figure do not necessarily correspond to the actual dimensional ratios.

[0035] Figure 1 is a schematic diagram showing the configuration of one embodiment of a light source device. The light source device 1 shown in Figure 1 comprises a plurality of LED elements 3, 3, ..., a first optical system 8, a second optical system 40, and an integrator optical system 50.

[0036] Multiple LED elements 3,3,... are mounted on a substrate 5 and are distributed in a plane direction perpendicular to the optical axis 2.

[0037] The first optical system 8 is an optical system that collimates the light emitted from each of the multiple LED elements 3,3,... and comprises a plurality of optical components arranged in correspondence to each LED element 3,3,... In this embodiment, the first optical system 8 includes a first collimating optical system 11 arranged closer to the multiple LED elements 3,3,... and a second collimating optical system 21 arranged downstream of the first collimating optical system 11. The first collimating optical system 11 and the second collimating optical system 21 may each comprise a plurality of optical components arranged in correspondence to each LED element 3,3,... Typically, these optical components are lenses.

[0038] Light emitted from multiple LED elements 3,3,... passes through the first collimating optical system 11 and the second collimating optical system 21, and is then guided to the second optical system 40 as collimated light. The second optical system 40 is an optical system that focuses this collimated light at its focal point 40f.

[0039] In this embodiment, the integrator optical system 50 is positioned such that its incident surface is at the focal point 40f of the second optical system 40. Figure 1 shows an example in which the integrator optical system 50 is composed of a fly-eye lens 51. As a result, high-intensity light is focused onto the incident surface of the fly-eye lens 51, and high-intensity light is emitted from the fly-eye lens 51.

[0040] In this embodiment, the light source device 1 allows for adjustment of the relative position of the second collimating optical system 21 with respect to the multiple LED elements 3,3,... and the first collimating optical system 11, while maintaining the relative positions of the multiple LED elements 3,3,... and the first collimating optical system 11. This point will be explained with reference to the drawings 2 and subsequent figures.

[0041] Figure 2 is a cross-sectional view showing an example of the arrangement of multiple LED elements 3,3,..., a first collimating optical system 11, and a second collimating optical system 21. The light source device 1 includes a first lens holder 10 that houses the first collimating optical system 11 and a second lens holder 20 that houses the second collimating optical system 21. The first lens holder 10 is integrated with the substrate 5 on which the LED elements 3,3,... are mounted.

[0042] In the following explanation, as shown in Figure 2, an XYZ coordinate system is introduced in which the direction of the principal ray of light L3 emitted from the multiple LED elements 3,3,… is defined as the Z direction, and the plane perpendicular to this Z direction is defined as the XY plane. Referring to this coordinate system, the multiple LED elements 3,3,… mounted on the substrate 5 are distributed on the XY plane. Furthermore, the outer periphery of the multiple LED elements 3,3,… in the +Z direction and along the XY plane is covered by the first lens holder 10. More specifically, with respect to the +Z direction, the first collimating optical system 11 housed in the first lens holder 10 is positioned at a distance from the multiple LED elements 3,3,…. In addition, the second collimating optical system 21 is positioned further to the +Z side than the first collimating optical system 11.

[0043] In this embodiment, the light source device 1 includes an adjustment mechanism 31 and a fixing member 35. The adjustment mechanism 31 is a member that adjusts the relative position of the first collimating optical system 11 and the second collimating optical system 21. In the example shown in Figure 2, when the adjustment mechanism 31 is operated, the first lens holder 10 moves in a predetermined direction on the XY plane with respect to the second lens holder 20. The fixing member 35 is a member that restricts the movement of the first lens holder 10 and the second lens holder 20 in the Z direction, and is also a member that fixes the two after their positional relationship on the XY plane has been adjusted.

[0044] Figure 3 is a partially enlarged view of Figure 2, showing the state in which the positions of the first lens holder 10 and the second lens holder 20 are fixed by the fixing member 35. The fixing member 35 is a member that includes a head 36 and a shaft portion 37 which has a shorter outer diameter than the head 36 and extends in a predetermined direction, and is typically a screw member. In the example shown in Figure 3, the head 36 of the fixing member 35 abuts against the surface 20a of the second lens holder 20 on the side away from the first lens holder 10. Also, the shaft portion 37 of the fixing member 35 penetrates the inside of the second lens holder 20 in the Z direction, and its tip reaches a part inside the first lens holder 10.

[0045] Figure 4 is a schematic diagram of Figure 3 with the fixing member 35 removed. In the example shown in Figure 4, the second lens holder 20 has a through hole 38 formed at a predetermined location so as to penetrate the second lens holder 20 in the Z direction. The first lens holder 10 also has a groove 39 carved out in the Z direction for a predetermined length from the surface 10a on the second lens holder 20 side. The inner diameter of the groove 39 is the inner diameter φ of the through hole 38. h Shorter. According to Figures 3 and 4, the groove 39 is the region into which the tip of the shaft portion 37 of the fixing member 35 is inserted, and the through hole 38 is the region into which the central portion of the shaft portion 37 of the fixing member 35 is inserted.

[0046] Figure 5 is a schematic cross-sectional view showing the structure of the fixing member 35. The outer diameter φ of the shaft portion 37. p This is approximately equal to the inner diameter of the groove 39, and the inner diameter of the through hole 38 shown in Figure 4 is φh It is shorter than that. Also, the outer diameter of the head 36 is φ a The inner diameter of the through hole 38 is φ h It is longer than [the other part]. With this configuration, when the fixing member 35 is inserted across the through hole 38 and the groove 39, as shown in Figure 3, the head 36 abuts against the surface 20a of the second lens holder 20, and the tip of the shaft 37 reaches near the bottom surface of the groove 39. By threading the inner wall of the groove 39 and the tip of the shaft 37, the fixing member 35 can be used to screw the first lens holder 10 and the second lens holder 20 together.

[0047] Next, the adjustment mechanism 31 will be described with reference to Figure 6. Figure 6 is a schematic plan view of the multiple LED elements 3, 3, ... and the first optical system 8 as seen from the +Z side, that is, in the opposite direction to the direction of light L3 propagation. Figure 6 shows an example in which the light source device 1 is provided with four fixing members 35 and five adjustment mechanisms 31. However, in Figure 6, for illustrative purposes only, only the head 36 of the fixing member 35 is shown. For the sake of explanation, the five adjustment mechanisms 31 will be referred to as adjustment mechanisms 31a, 31b, ..., 31e. Figure 7 is a more schematic diagram of Figure 6. Here, we will explain using the case where adjustment mechanisms 31a, 31b, and 31c are clamping screws and adjustment mechanisms 31d and 31e are ball plungers as an example. As the adjustment mechanism 31, known mechanisms such as clamping screws, ball plungers, pins, and cams can be used.

[0048] The adjustment mechanisms 31d and 31e, which are composed of ball plungers, have springs built into them. When the restriction on the movement of the shaft portion 37 of the fixing member 35 within the groove portion 39 is released, more specifically, when the screw fastening is loosened, pushing and pulling the adjustment mechanisms 31a, 31b, and 31c, which consist of clamping screws provided in three locations, causes the rigid balls at the tips of the adjustment mechanisms 31d and 31e to move. This movement allows adjustment of the relative positional relationship between the first lens holder 10 and the second lens holder 20 on the XY plane. Specifically, movement in the X direction, movement in the Y direction, and rotational movement in the θ direction are possible, as shown by the double arrows in Figure 7.

[0049] As described above, the substrate 5 on which multiple LED elements 3,3,... are mounted is fixed to the first lens holder 10. Therefore, adjusting the relative positional relationship between the first lens holder 10 and the second lens holder 20 on the XY plane means adjusting the relative positional relationship between the multiple LED elements 3,3,... and the second lens holder 20 on the XY plane. In other words, this means adjusting the optical positional relationship between the multiple LED elements 3,3,... and the first optical system 8 on the XY plane.

[0050] In practice, with multiple LED elements 3,3,... lit, the adjustment mechanism 31 was operated to adjust the relative positional relationship between the first lens holder 10 and the second lens holder 20, and the image was measured. In this verification, a rod integrator was used as the integrator optical system 50 (see Figure 12 described later), and the image at the incident plane of this rod integrator was measured. As a light source, 85 LED elements 3,3,... were arranged within an 80mm x 80mm area.

[0051] Figures 8A to 8D schematically illustrate photographs of the image at different points in time. In each figure, the reference region is indicated by reference numeral 61, the region appearing as an image is indicated by reference numeral 60, and the center of the image 60 is indicated by reference numeral 62.

[0052] For example, the adjustment mechanisms 31a, 31b, and 31c, which are composed of clamping screws, can move 0.4 mm in the forward / backward direction by rotating them one full turn, and 0.1 mm by rotating them a quarter turn. Furthermore, as shown in Figure 7, by changing the amount of movement of the two adjustment mechanisms 31a and 31b, which are located on the same side (in this case, the side along the Y direction), the first lens holder 10, to which multiple LED elements 3, 3, ... are fixed, can be rotated in the θ direction relative to the second lens holder 20.

[0053] For example, if the distance between the two adjustment mechanisms 31a and 31b is 60 mm, then rotating the LED elements 3, 3, ... arranged within an 80 mm x 80 mm area by 1° can be achieved by shifting the relative position of the two adjustment mechanisms 31a and 31b by approximately 1 mm (2.5 rotations). In this case, only one of the two adjustment mechanisms 31a and 31b may be moved forward or backward, or one may be moved forward and the other backward.

[0054] Figure 8A corresponds, for example, to the initial state (before adjustment by the adjustment mechanism). According to Figure 8A, it can be seen that the center 62 of the image is shifted from the center O (origin of the XY coordinate system) of the reference region 61 (the rectangular region enclosed by the dashed line). Furthermore, the image 60 is circular in shape and blurred, indicating that the light from each LED element 3,3,... is not focused to approximately the same point. This situation suggests that there is a positional misalignment between the LED elements 3,3,... and the first optical system 8.

[0055] Figure 8B shows the measurement results after the adjustment mechanism 31 is operated from the state shown in Figure 8A, causing the first lens holder 10, to which multiple LED elements 3,3,… are fixed, to be rotated by 1° relative to the second lens holder 20. The image 60 shown in Figure 8B shows a shape corresponding to the shape of the light source formed by the LED elements 3,3,…, and it can be seen that the image is more clearly displayed compared to the state shown in Figure 8A. This indicates that the center of the LED element 3 and the corresponding optical axis of the first optical system 8 are closer together than in the state shown in Figure 8A.

[0056] Figure 8C shows the measurement results after the adjustment mechanism 31 is operated further from the state shown in Figure 8B, moving the first lens holder 10 0.2 mm in the X direction relative to the second lens holder 20. Figure 8D also shows the measurement results after the adjustment mechanism 31 is operated further from the state shown in Figure 8C, moving the first lens holder 10 0.2 mm in the Y direction relative to the second lens holder 20. Compared to the state shown in Figure 8B, in the state shown in Figure 8C, the position of the center 62 of the image 60 is closer to the center O of the reference region 61, and in the state shown in Figure 8D, it can be confirmed that the center 62 of the image 60 is even closer to the center O of the reference region 61.

[0057] In this way, by operating the adjustment mechanism 31, the light emitted from multiple LED elements 3,3,... can be focused to almost a single point, and the focusing position can be adjusted. In particular, by moving the focusing position to the light incident surface of the integrator optical system 50, high-intensity light can be guided to the light output surface of the integrator optical system 50.

[0058] As described above, the substrate 5 on which multiple LED elements 3,3,… are mounted is fixed to the first lens holder 10 which houses the first collimating optical system 11. A second lens holder 20 which houses the second collimating optical system 21 is positioned on the +Z side of the first lens holder 10, that is, on the side further away from the multiple LED elements 3,3,…. When the adjustment mechanism 31 is operated, the relative optical positional relationship between the second lens holder 20 and the first lens holder 10 is adjusted. In other words, with the light source device 1 of this embodiment, the optical positional relationship between the multiple LED elements 3,3,… and the first optical system 8 can be adjusted while maintaining the relative positional relationship between the multiple LED elements 3,3,… and the first lens holder 10 which houses the first collimating optical system 11 positioned close to the multiple LED elements 3,3,…. This makes it possible to suppress damage to the light-emitting surfaces and wiring of the LED elements 3,3,… during position adjustment.

[0059] Figure 9 is a schematic diagram showing the state in which the shaft portion 37 of the fixing member 35 is located inside the through hole 38. As described above, the outer diameter of the shaft portion 37 is φ p The inner diameter of the through hole 38 is φ h It is shorter than [the specified length]. Therefore, even when the fixing member 35 is inserted into the through hole 38, there is a margin area 88 within the through hole 38 where the fixing member 35 is not located. In other words, on the XY plane, the fixing member 35 can move by a length corresponding to the width of the margin area 88. To put it another way, the width of this margin area 88 determines the maximum amount of adjustment possible for the relative position of the first lens holder 10 and the second lens holder 20 on the XY plane.

[0060] Figure 10 is a schematic diagram illustrating the preferred design criteria for this margin region 88. In Figure 10, the maximum diameter at the light-emitting surface of the LED element 3 is denoted as D, the maximum light-gathering angle of each optical component in the first collimating optical system 11 is denoted as θ1, and the maximum light-gathering angle of each optical component in the second collimating optical system 21 is denoted as θ2.

[0061] In the optical system shown in Figure 10, the light emitted from the second collimating optical system 21 is equivalent to the light emitted from an optically virtual LED element 3a. Here, if Da is the maximum diameter of the light-emitting surface of the virtual LED element 3a, then from the geometric relationship, Da = D·(θ² / θ¹) This is derived.

[0062] Conversely, moving the second collimating optical system 21 by a certain distance d relative to the LED elements 3,3,... in the XY plane is optically equivalent to moving the LED elements 3,3,... by d·(θ2 / θ1).

[0063] 0.1D·(θ2 / θ1) ≤ (φ h -φ p The inner diameter of the through hole 38 is such that ) / 2 is satisfied. h and the outer diameter of the shaft portion 37 φ p By designing it this way, the maximum amount of adjustment possible for the positional relationship between the LED elements 3,3,... and the first optical system 8 in the direction of the XY plane can be set to 10% or more of the maximum diameter of the light-emitting surface of the LED elements 3,3,...

[0064] [Alternative Embodiment] The following describes another embodiment.

[0065] (1) The installation configuration of the adjustment mechanism 31 and fixing member 35 shown in Figure 2 is merely an example. Figures 11A to 11E are diagrams showing a different configuration of the light source device 1, following Figure 2.

[0066] The light source device 1 shown in Figures 11A and 11B differs from the light source device 1 shown in Figure 2 in the installation position of the adjustment mechanism 31. Under this structure, the adjustment mechanism 31 is operated to adjust the position of the second lens holder 20 in the direction of the XY plane with respect to the first lens holder 10. As shown in Figure 11B, the adjustment mechanism 31 may be fixed to a support 71 provided separately from the first lens holder 10. This support 71 is a base that supports the first lens holder 10 and the adjustment mechanism 31.

[0067] The light source device 1 shown in Figure 11C differs from the light source device 1 shown in Figure 2 in the insertion direction of the fixing member 35. As shown in Figure 11C, the fixing member 35 may be inserted from the first lens holder 10 towards the second lens holder 20. In this configuration, unlike in Figure 4, the through hole 38 is provided in the first lens holder 10, and the groove 39 is provided in the second lens holder 20 (see Figure 4 for the through hole 38 and groove 39).

[0068] The light source device 1 shown in Figures 11D and 11E differs from the light source device 1 shown in Figure 11C in the installation position of the adjustment mechanism 31. Under this structure, the adjustment mechanism 31 is operated to adjust the position of the second lens holder 20 in the XY plane relative to the first lens holder 10. As shown in Figure 11E, the adjustment mechanism 31 may also be fixed to a support 71 provided separately from the second lens holder 20. This support 71 is a base that supports the second lens holder 20.

[0069] (2) As shown in Figure 12, a rod integrator 52 may be used as the integrator optical system 50.

[0070] <3> The light focused by the second optical system 40 may be incident on optical systems other than the integrator optical system 50. In other words, the present invention also applies to light source devices 1 that do not have an integrator optical system 50.

[0071] <4> In the embodiments described above, the relative positional relationship between the first lens holder 10 and the second lens holder 20 was described as being adjustable in the X direction, Y direction, and rotational direction on the XY plane. However, it is also possible to configure it to be adjustable in at least one of these directions. Furthermore, in addition to the direction on the XY plane, it is also possible to adjust in a direction intersecting the XY plane (for example, the Z direction).

[0072] <5> In each of the embodiments described above, the light source device 1 may be equipped with additional optical systems such as reflective optical systems for the purpose of changing the optical path.

[0073] Furthermore, at least one of the first collimating optical system 11 and the second collimating optical system 21 may include a plurality of lenses arranged in the direction of the optical axis 2. [Explanation of symbols]

[0074] 1:Light source device 2: Optical axis 3: LED element 5: Circuit board 8:First optical system 10: First lens holder 11: First collimating optical system 20: Second lens holder 21: Second collimating optical system 31:Adjustment mechanism 35: Fixing member 36:Head 37: Shaft 38: Through hole 39: Groove 40:Second optical system 40f:Focus 50: Integrator Optical System 51: Fly-eye lens 52: Rod Integrator 71 :Support 88: Reserve area L3: Light

Claims

1. A plurality of LED elements arranged in a plane direction perpendicular to the optical axis, A first optical system that converts the light emitted from each of the plurality of LED elements into collimated light, The system comprises a second optical system that collects a plurality of collimated lights emitted from the first optical system, The first optical system is, A first collimating optical system including optical components arranged in correspondence to each of the plurality of LED elements, The second collimating optical system, located downstream of the first collimating optical system, includes optical components arranged in correspondence with each of the plurality of LED elements. The second collimating optical system is arranged so as to be able to adjust the relative optical positional relationship between the plurality of LED elements and the first collimating optical system when viewed in the direction of the optical axis, while the plurality of LED elements and the first collimating optical system are fixed in place. A substrate on which the aforementioned multiple LED elements are mounted, The first collimating optical system is housed in a first lens holder which is fixedly connected to the substrate, A light source device characterized by comprising a second lens holder that houses the second collimating optical system and whose relative position to the first lens holder can be adjusted.

2. The light source device according to claim 1, characterized in that it is provided with an adjustment mechanism attached to the first lens holder, which moves the first lens holder and the substrate integrally in a planar direction perpendicular to the optical axis direction while the position of the second lens holder is fixed.

3. The light source device according to claim 1, characterized in that it is attached to the second lens holder and includes an adjustment mechanism that moves the second lens holder in a plane direction perpendicular to the optical axis direction while the positions of the first lens holder and the substrate are fixed.

4. A through hole is provided at a predetermined location in the second lens holder, which penetrates the second lens holder in a direction parallel to the optical axis. A groove having an inner diameter shorter than the inner diameter of the through hole, carved out from the surface of the first lens holder on the second lens holder side for a predetermined length in a direction parallel to the optical axis, The fixing member includes a shaft portion having an outer diameter shorter than the inner diameter of the through hole and insertable into the groove, and a head portion having an outer diameter longer than the inner diameter of the through hole and connected to the shaft portion. The light source device according to claim 2, characterized in that the adjustment mechanism is configured such that the head of the fixing member is not in contact with the surface of the second lens holder, and the first lens holder and the substrate are movable in a plane direction perpendicular to the optical axis direction by a distance within a margin defined by the difference between the inner diameter of the through hole and the outer diameter of the shaft portion of the fixing member.

5. A through hole is provided at a predetermined location in the first lens holder, which penetrates the first lens holder in a direction parallel to the optical axis. A groove having an inner diameter shorter than the inner diameter of the through hole, carved out from the surface of the second lens holder on the first lens holder side for a predetermined length in a direction parallel to the optical axis, The fixing member includes a shaft portion having an outer diameter shorter than the inner diameter of the through hole and insertable into the groove, and a head portion having an outer diameter longer than the inner diameter of the through hole and connected to the shaft portion. The light source device according to claim 2, characterized in that the adjustment mechanism is configured such that, with the head of the fixing member not in contact with the surface of the first lens holder, the first lens holder and the substrate can be moved by a distance within a margin defined by the difference between the inner diameter of the through hole and the outer diameter of the shaft portion of the fixing member in a plane direction perpendicular to the optical axis direction.

6. A through hole is provided at a predetermined location in the second lens holder, which penetrates the second lens holder in a direction parallel to the optical axis. A groove having an inner diameter shorter than the inner diameter of the through hole, carved out from the surface of the first lens holder on the second lens holder side for a predetermined length in a direction parallel to the optical axis, The fixing member includes a shaft portion having an outer diameter shorter than the inner diameter of the through hole and insertable into the groove, and a head portion having an outer diameter longer than the inner diameter of the through hole and connected to the shaft portion. The light source device according to claim 3, characterized in that the adjustment mechanism is configured to allow the second lens holder to move in a plane direction perpendicular to the optical axis direction by a distance within a margin defined by the difference between the inner diameter of the through hole and the outer diameter of the shaft portion of the fixing member, with the head of the fixing member not in contact with the surface of the second lens holder.

7. A through hole is provided at a predetermined location in the first lens holder, which penetrates the first lens holder in a direction parallel to the optical axis. A groove having an inner diameter shorter than the inner diameter of the through hole, carved out from the surface of the second lens holder on the first lens holder side for a predetermined length in a direction parallel to the optical axis, The fixing member includes a shaft portion having an outer diameter shorter than the inner diameter of the through hole and insertable into the groove, and a head portion having an outer diameter longer than the inner diameter of the through hole and connected to the shaft portion. The light source device according to claim 3, characterized in that the adjustment mechanism is configured such that the head of the fixing member is not in contact with the surface of the first lens holder, and the second lens holder is movable in a plane direction perpendicular to the optical axis direction by a distance within a margin defined by the difference between the inner diameter of the through hole and the outer diameter of the shaft portion of the fixing member.

8. The inner diameter of the through hole is φ h The outer diameter of the shaft portion of the fixing member is φ p D is the maximum diameter of the light-emitting surface of the LED element, and θ is the maximum light-gathering angle of each optical component in the first collimating optical system. 1 The maximum light intake angle of each optical component in the second collimating optical system is set to θ. 2 So, 0.1D・(θ 2 / i 1 ) ≦ (φ h -φ p ) / 2 ≦ D・(θ 2 / i 1 ) A light source device according to any one of claims 4 to 7, characterized in that the following is achieved.

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