Light source device

Abstract

Light source device comprising: several light sources (4a-d) placed in one direction, an array lens (6) with a plurality of lenses (6a-n) corresponding to each of the light sources (4a-d), wherein, for concentrating light emitted from each of the lenses (6a-n) to one position, in a first lens (6c) of the plurality of lenses (6a-n), an optical axis of a first light source (4c), which is the light source (4c) of the plurality of light sources (4a-d) corresponding to the first lens (6c), is shifted from an optical axis of the first lens (6c) in the one direction, and wherein the first lens (6c) is formed such that a length (L2) from the optical axis to one end of the first lens (6c) in one direction is longer than a length (L1) from the optical axis to another end of the first lens (6c) in a direction opposite to said one direction, wherein a third lens (6b) of the plurality of lenses (6a-n) is arranged relative to the first lens (6c) in a direction opposite to said one direction, wherein a third light source (4b) of the plurality of light sources (4a-d) corresponds to the third lens (6b), wherein an offset amount (Δ) between the optical axes of the first light source (4c) and the first lens (6c) and an offset amount (Δ) between the optical axes of the third light source (4b) and the third lens (6b) are equal in absolute value.

Description

Re-referral to related applications

[0001] Under 35 USC §119, this application claims priority to Japanese Patent Application No. 2014-261740, filed on December 25, 2014. The contents of that application are incorporated herein by reference in their entirety. Background of the inventionField of the invention

[0002] The disclosure relates to a light source device that can be used in various applications, e.g., a lighting system. Description of related technology

[0003] Recently, a light source device using a laser diode (LD) or a light-emitting diode (LED) has been proposed and put into practice as a lighting device, which can be applied to various applications, such as lighting devices, displays, projectors, and backlights, for the purposes of reducing power consumption, miniaturization, and design. In particular, the laser diode can easily concentrate light into a small area, and, for example, a light source device that can emit light beams of various wavelengths and high luminance can be realized by placing a phosphor at the light concentrating position.

[0004] In this case, it is preferable to concentrate multiple light beams emitted from multiple laser diodes into one position to increase luminance. Since the light emitted from the laser diode is thus diverging light, a configuration is adopted in which the diverging light emitted from each laser diode is converted into approximately parallel light by a lens corresponding to each laser diode, after which the plurality of approximately parallel light beams are condensed by a condenser lens.

[0005] Furthermore, according to JP 2013-73079 A, ​​in order to condense light without using a condenser lens, a method is also proposed in which a plurality of light beams emitted from a plurality of laser diodes are condensed to the same position by placing them such that an optical axis of the laser diode is shifted from an optical axis (center) of the corresponding lens in the direction so as to be perpendicular to the optical axis of the corresponding lens.

[0006] DE10 2011 107 893 A1 describes an optoelectronic module with an optic arranged on a carrier, wherein the optic is in particular a micro-optic system with a plurality of micro-optical elements.

[0007] WO 2010 / 150 167 A1 describes a focusing optics for a biosensor, wherein the focusing optics has at least two focusing lenses arranged next to one another.

[0008] US 7 819 550 B2 describes an array of LEDs provided with a lens arrangement.

[0009] DE 10 2012 010 096 A1 describes an LED luminaire with optical elements which preferably use aspherical single lenses or single lens(es) consisting of a biconic surface as optical elements.

[0010] To realize a light source device that simultaneously achieves high power and miniaturization, it is necessary to narrow the distance between laser diodes and the distance between lenses corresponding to the laser diodes, as well as to increase the number of laser diodes. In this case, in JP 2013-73079 A, ​​since the optical axis of the laser diode is shifted from the optical axis (center) of the corresponding lens, when the divergence angle of the light emitted from the laser diode becomes large, the light may enter a neighboring lens and be emitted in an unexpected direction. Furthermore, this may cause stray light. Summary of the invention

[0011] A purpose of aspects of the invention is to solve the above-mentioned problem and to provide a compact, high-performance light source device that can condense light beams emitted from two or more light sources without using a condenser lens, and in which, even when a distance between each of the light sources and a distance between each of the lenses corresponding to each of the light sources are narrowed, light emitted from the laser diode is not emitted in an unexpected direction.

[0012] The present invention is defined by independent claims 1 and 12; the dependent claims describe embodiments of the invention. Effect of the invention

[0013] According to the aspect of the invention, it is possible to provide a compact, high-performance light source device that can condense light beams emitted from two or more light sources without using a condenser lens, and in which, even when a distance between each of the light sources and a distance between each of the lenses corresponding to each of the light sources are narrowed, light emitted from the laser diode is not emitted in an unexpected direction. Short description of the drawings Fig. 1A is an explanatory diagram (corresponding to a sectional view and a side view) for describing the basic configuration of a light source device according to an embodiment of the invention. Fig. 1B is an explanatory diagram (corresponding to a sectional view and a side view) for describing the basic configuration of a light source device as a comparative example. Fig. 2 is an explanatory diagram (corresponding to a sectional view and a side view) for describing a single embodiment 1 for determining a length to extend a transmitting surface of the lens in an offset direction (a direction) of the light source. Fig. 3 is an explanatory diagram (corresponding to a sectional view and a side view) for describing a single embodiment 2 for determining a length to extend a transmitting surface of the lens in an offset direction (a direction) of the light source. Fig. 4 is an explanatory diagram (corresponding to a sectional view and a side view) for describing an array lens according to a single embodiment 1 of the invention. Fig. 5 is an explanatory diagram (corresponding to a sectional view and a side view) for describing an array lens according to a single embodiment 2 of the invention. Fig. 6 is an explanatory diagram (corresponding to a sectional view and a side view) for describing a placement of a light source and an array lens according to a single embodiment 1 of the invention. Fig. 7 is an explanatory diagram (corresponding to a sectional view and a side view) for describing a placement of a light source and an array lens according to a single embodiment 2 of the invention. Fig. 8A is an explanatory diagram (corresponding to a sectional view and a side view) for describing a placement of a light source and an array lens according to a single embodiment 3 of the invention. Fig. 8B is an explanatory diagram (corresponding to a plan view) for describing a placement of a light source and an array lens according to a single embodiment 3 of the invention. Fig. 9A is an explanatory diagram (corresponding to a sectional view and a side view) for describing a placement of a light source and an array lens according to a single embodiment 4 of the invention. Fig. 9B is an explanatory diagram (corresponding to a plan view) for describing a placement of a light source and an array lens according to a single embodiment 4 of the invention. Fig. 10A is a perspective view (without a cover) schematically illustrating a light source device according to a single embodiment 1 of the invention. Fig. 10B is a perspective view (enclosed in a cover) schematically illustrating a light source device according to a single embodiment 1 of the invention. Fig. 10C is a plan view (without a cover) schematically illustrating a light source device according to a single embodiment 1 of the invention. Fig. 10D is a side view (without a cover) schematically illustrating a light source device according to a single embodiment 1 of the invention. Fig. 11 A is a perspective view (without a cover) schematically illustrating a light source device according to a single embodiment 2 of the invention. Fig. 11B is a perspective view (enclosed in a cover) schematically illustrating a light source device according to a single embodiment 2 of the invention. Fig. 11C is a plan view (without a cover) schematically illustrating a light source device according to a single embodiment 2 of the invention. Fig. 11D is a side view (without a cover) schematically illustrating a light source device according to a single embodiment 2 of the invention. Fig. 12A is a perspective view (without a cover) schematically illustrating a light source device according to a single embodiment 3 of the invention. Fig. 12B is a perspective view (enclosed in a cover) schematically illustrating a light source device according to a single embodiment 3 of the invention. Fig. 12C is a plan view (without a cover) schematically illustrating a light source device according to a single embodiment 3 of the invention. Fig. 12D is a side view (without a cover) schematically illustrating a light source device according to a single embodiment 3 of the invention. Fig. 13A is an explanatory diagram (corresponding to a sectional view and a side view) for describing a placement of a light source and an array lens as a comparative example. Fig. 13B is an explanatory diagram (corresponding to a plan view) for describing a placement of a light source and an array lens as a comparative example. Description of the embodiments

[0014] A light source device of aspect 1 of the invention is a light source device as defined by claim 1, comprising: two or more light sources placed in one direction, an array lens with two or more lenses corresponding to each of the light sources, wherein, for concentrating light emitted from each of the lenses to a position in a first lens in each of the lenses, an optical axis of the light source corresponding to the first lens is shifted from an optical axis of the first lens in said one direction, and wherein the first lens is formed such that a length from the optical axis to one end of the first lens in one direction is longer than a length from the optical axis to another end of the first lens in a direction opposite to the one direction.

[0015] According to this aspect, since the optical axis of the light source is shifted from the optical axis of the lens, light beams emitted from two or more light sources can be condensed without using a condenser lens. Furthermore, in one direction in which the optical axis of the light source is shifted from the optical axis of the lens, the lens is configured such that the length from the optical axis to one end of the first lens is longer than the length from the optical axis to another end of the first lens in the opposite direction. Thus, the transmitting surface of the first lens is elongated in the offset direction (one direction) of the light source.Therefore, it is possible to provide a compact high-performance light source device in which, even if a distance between each of the light sources and a distance between each of the lenses corresponding to each of the light sources are narrowed, the light emitted from the laser diode does not enter the neighboring lens and is not emitted in an unexpected direction, thereby securely concentrating light emitted from the light source.

[0016] The light source device of aspect 2 of the invention is the light source device according to the above-mentioned aspect 1, wherein a surface forming a second lens adjacent to the first lens in said one direction is farther from the optical axis of the first lens than one end of the first lens in said one direction.

[0017] According to this aspect, light emitted from the light source corresponding to the first lens can be securely prevented from entering the neighboring lens, thereby securely concentrating light emitted from the light source to a concentrating position.

[0018] The light source device of aspect 3 of the invention is the light source device according to the above-mentioned aspect 2, wherein the first lens and the second lens are continuously formed with a smooth curved surface.

[0019] According to this aspect, since the first lens and the second lens are continuously formed with a smooth curved surface, the array lens can be easily formed by molding or the like, and the array lens can be provided with advantageous strength.

[0020] The light source device of aspect 4 of the invention is the light source device according to any one of the above-mentioned aspects 1 to 3, wherein the optical axis of each of the lenses of the array lens is placed at a fixed interval and the light source is placed such that the optical axis of the light source is shifted from the optical axis of the lens corresponding to the light source.

[0021] According to this aspect, since the optical axis of each of the lenses of the array lens is positioned at a fixed interval, an array lens with high precision can be easily formed at a low manufacturing cost. Consequently, a light source device that can reliably condense light emitted from the light source without using a condenser lens can be provided at a low manufacturing cost.

[0022] The light source device of aspect 5 of the invention is the light source device according to any one of the above-mentioned aspects 1 to 3, wherein the optical axis of each of the light sources is placed at a fixed interval, and each of the lenses of the array lens is formed such that the optical axis of the light source is shifted from the optical axis of the lens corresponding to each of the light sources.

[0023] According to this aspect, since the optical axis of the light source is positioned at a fixed interval, the light source device can be easily assembled. Consequently, a light source device that can reliably condense light emitted from the light source without using a condenser lens can be provided at a low manufacturing cost.

[0024] The light source device of aspect 6 of the invention is the light source device according to any one of the above-mentioned aspects 1 to 5, wherein each of the lenses of the array lens is formed based on a same function expressing a curved surface.

[0025] The curved surface of the lens can be either a spherical surface or an aspherical surface. The lens is designed based on the same function that expresses such a curved surface. "Based on the same function" means that, in the case of a spherical surface, for example, a curvature (or radius of curvature) is the same. In the case of an aspherical surface, when the aspherical surface is expressed by polynomial equations, including an equation of a two-dimensional rotation curve or a polynomial of at least three degrees (e.g., even or odd degrees), the curvature, conic constant, or aspheric coefficient is the same.

[0026] According to this aspect, since the lens is formed based on the same function as the curved surface, the array lens can be easily and reliably formed by having its transmitting surface have a desired curved shape that is smoothly elongated in the offset direction (one direction) of the light source. Consequently, a high-performance light source device can be provided that can reliably condense light emitted from the light source without using a condenser lens.

[0027] The light source device of aspect 7 of the invention is the light source device according to any one of the above-mentioned aspects 1 to 6, wherein as a position becomes farther away from a concentrated position of light emitted from each of the lenses of the array lens, an offset amount between the optical axes of the light source and the lens corresponding to each other becomes larger.

[0028] According to this aspect, since the offset amount between the optical axis of the light source and the optical axis of the lens corresponding to the light source becomes larger as the position becomes farther away from the light condensing position, it is possible to provide a light source device that can surely condense light emitted from the light source without using a condenser lens.

[0029] The light source device of aspect 8 of the invention is the light source device according to any one of the above-mentioned aspects 1 to 7, wherein a phosphor is placed at a concentrated position of light emitted by each of the lenses of the array.

[0030] According to this aspect, since the phosphor is placed at the light concentrating position of the light, light having a desired wavelength can be radiated by means of light emitted from the light source and light whose wavelength is converted by the phosphor.

[0031] The light source device of aspect 9 of the invention is the light source device according to the above-mentioned aspect 8, where a size of the phosphor is smaller than a size of the array lens.

[0032] According to this aspect, since the size of the phosphor is smaller than the size of the array lens, a compact, high-power light source device capable of radiating light having a desired wavelength can be provided.

[0033] The light source device of aspect 10 of the invention is the light source device according to the above-mentioned aspect 8 or 9, wherein the phosphor emits light having a wavelength of a complementary color to the light entering the phosphor.

[0034] According to this aspect, since the phosphor emits light having the wavelength of the complementary color to the light entering the phosphor, the light source device of this aspect can be provided as a white light source that can be used in various applications.

[0035] The light source device of aspect 11 of the invention is the light source device according to any one of the above-mentioned aspects 1 to 10, wherein a light path from the light source to a concentrated position of light emitted from the lens is sealed.

[0036] According to this aspect, since the light path from the light source to the light concentrating position of the radiated light is sealed, the light path is not affected by dirt, dust, etc., and it is possible to provide a light source device that can maintain high performance even when used for a long time.

[0037] The light source device of aspect 12 is a light source device as defined by claim 12, comprising: two or more light sources placed in one direction, an array lens with two or more lenses corresponding to each of the light sources, wherein, for concentrating light emitted from each of the lenses to a position in a first lens in each of the lenses, an optical axis of the light source corresponding to the first lens is shifted from an optical axis of the first lens in said one direction, and wherein the first lens is formed such that a length from the optical axis to one end of the first lens in one direction is longer than a length from the optical axis to another end of the first lens in a direction opposite to the one direction, and wherein the array lens has a second lens adjacent to the first lens in one direction, and the first lens and the second lens are continuous.

[0038] According to this aspect, similarly to the above-mentioned aspect 1, since the transmitting surface of the first lens is formed to be elongated in the offset direction (one direction) of the light source, a distance between each of the light sources and a distance between each of the lenses corresponding to each of the light sources are narrowed, the light emitted from the laser diode does not enter the neighboring lens and is not emitted in an unexpected direction, thereby securely concentrating light rays emitted from the light sources.

[0039] Furthermore, since the array lens includes the first lens and the second lens, and the first lens and the second lens adjacent to the first lens in one direction are continuous, a compact light source device can be realized. Consequently, a compact light source device with high performance can be provided.

[0040] The light source device of aspect 13 of the invention is the light source device according to the above-mentioned aspect 12, wherein the first lens further has a cut-off portion of the surface in the direction opposite to the one direction.

[0041] According to this aspect, since the first lens has the cut-off portion of the surface in the direction opposite to the one direction, light emitted from the light source corresponding to the second lens can be securely prevented from entering the first lens adjacent to the second lens despite the compact array lens.

[0042] The light source device of aspect 14 of the invention is the light source device according to the above-mentioned aspect 13, wherein the first lens and the second lens are continuously formed with a smooth curved surface.

[0043] According to this aspect, since the first lens and the second lens having the smooth curved surface are continuously formed, the array lens can be easily formed by molding or the like, and the array lens can be provided with advantageous strength.

[0044] While the above-mentioned effect of the invention or the description of each aspect mentions that "according to the aspect of the invention, it is possible to condense light beams emitted from two or more light sources without using a condenser lens," the invention also includes a light source device including a condenser lens. For example, another condenser lens may be placed shortly after the array lens in the light movement direction. The focal length can be shortened by placing the condenser lens. Furthermore, in this case, a smaller condenser lens may be used.

[0045] Hereinafter, a light source device according to embodiments of the invention will be described in more detail with reference to the accompanying drawings. General description of the light source device

[0046] First, outlines of a light source device according to the embodiment of the invention will be described, wherein the Fig. 1A shown light source device according to the embodiment of the invention and a in Fig. 1B shown light source device of the comparative example. Fig. 1A is an explanatory diagram (corresponding to a sectional view and a side view) for describing the basic configuration of the light source device according to the embodiment of the invention. Fig. 1B is an explanatory diagram (corresponding to a sectional view and a side view) for describing the basic configuration of the light source device as a comparative example. Fig. 1A and Fig. 1B schematically shows a direction of light emitted from the light source, and two lines indicate a contour of the light.

[0047] First, the part common to the light source device according to the embodiment of the invention and that of the comparative example will be described. In the following description, a reference numeral of the Fig. 1A shown light source device according to the embodiment of the invention, after which a reference number of the in Fig. 1B shown light source device of the comparative example is indicated in parentheses.

[0048] A light source device 2 (102) has a group of light sources 4 (104) formed by several (four both in Fig. 1A and 1B) light sources 4a to 4d (104a to 104d) are formed, which are placed in the direction perpendicular to its optical axis (see arrow C in Fig. 1A, arrow D in Fig. 1B), and an array lens 6 (106) into which lenses 6a to 6d (106a to 106d) corresponding to each of the light sources 4a to 4d (104a to 104d) are integrally molded. Optical axes of light sources 4a to 4d (104a to 104d) and optical axes of the corresponding lenses 6a to 6d (106a to 106d) are placed parallel to each other.

[0049] As described in more detail later, each of the light sources 4a to 4d (104a to 104d) is positioned so that its optical axis is offset from the optical axis of each of the corresponding lenses 6a to 6d (106a to 106d). Consequently, it is possible to concentrate light to a single position without using a condenser lens. A phosphor 8 (108) is placed at a concentrated position of light emitted from the light source.

[0050] According to this configuration, for example, if the group of light sources 4 (104) is formed by the light sources that emit blue light, and the phosphor 8 (108) emits yellow light, which is a complementary color to the blue color, when the blue light enters the phosphor 8 (108), the blue light and the yellow light are mixed, and therefore the light source device 2 (102) can emit white light. Consequently, the light source device 2 (102) can be used as a white light source.

[0051] In the light source device 2 (102) according to Fig. 1A, Fig. 1B, each of the optical axes of the light sources 4a to 4d (104a to 104d) is shifted from the optical axis (ie, a center) of each of the corresponding lenses 6a to 6d (106a to 106d) in the direction perpendicular to the optical axis of the lens to condense light without using a condenser lens.

[0052] For example, in the case of the light source 4c (104c) and the lens 6c (106c) corresponding to the light source 4c (104c), the optical axis of the light source 4c (104c) is shifted from the optical axis of the corresponding lens 6c (106c) by the offset amount Δ in the direction indicated by the arrow C (arrow D) which is perpendicular to the optical axis (this offset direction of the light source may be referred to as “one direction”).

[0053] Similarly, with respect to the others, the light sources 4a (104a), 4b (104b) and 4d (104d) are shifted by the corresponding lenses 6a (106a), 6b (106b) and 6d (106d) with predetermined offset amounts in the direction perpendicular to their optical axes.

[0054] In more detail, light is concentrated at the center of the four light sources 4a to 4d (104a to 104d) on the line, that is, at the position between the light sources 4b and 4c (104b and 104c). The light sources 4b, 4a (104b, 104a) and the light sources 4c, 4d (104c, 104d) are each positioned symmetrically about the center line CL, which passes through the light concentration position and is parallel to the optical axis. The optical axis of each of the light sources 4a to 4d (104a to 104d) is positioned at the farther (outer) position from the center line CL than the optical axis of each of the corresponding lenses 6a to 6d (106a to 106d).

[0055] Consequently, in the light source 4a, 4b (104a, 104b), the direction opposite to the direction indicated by arrow C (arrow D) is the offset direction of the light source, and in the light source 4d (104d), similarly to the light source 4c (104c), the direction indicated by arrow C (arrow D) is the offset direction of the light source.

[0056] Since in the embodiment according to Fig. 1A, Fig. 1B the light sources are placed symmetrically to the center line CL, for the light sources placed closer to the center line CL (i.e., inside), the distance Lb (Lb') between the optical axis of the light source 4b (104b) and the center line CL is the same as the distance Lc (Lc') between the optical axis of the light source 4c (104c) and the center line CL. Similarly, for the light sources placed farther from the center line CL (i.e., outside), the distance La (La') between the optical axis of the light source 4a (104a) and the center line CL is the same as the distance Ld (Ld') between the optical axis of the light source 4d (104d) and the center line CL.

[0057] In the embodiment according to Fig. 1A, Fig. 1B, the further the light source is placed from the center line, the larger its offset amount becomes. Thus, the offset amount of the light source 4a (104a) is larger than the offset amount of the light source 4b (104b), and the offset amount of the light source 4d (104d) is larger than the offset amount of the light source 4c (104c). The offset amounts of the light sources 4b and 4c (104b and 104c) are identical (= Δ), and the offset amounts of the light sources 4a and 4d (104a and 104d) are identical. While the offset amounts of the light sources 4a and 4d (104a and 104d) are larger than Δ in this embodiment, there is no limitation to this, and they may be the same as Δ. Description of the array lens of the light source device of the comparative example

[0058] In the aforementioned light source device 102, each of the lenses 106a to 106d of the array lens 106 corresponding to the light sources 104a to 104d has a shape in which a length from the optical axis to one end of the lens in the offset direction (a direction) of the light source, which is perpendicular to its optical axis, is the same as a length from the optical axis to another end of the lens in the opposite direction. For example, Fig. 1B is based on lens 106c, which corresponds to light source 104c, the length L102 from the optical axis to one end of the lens in the offset direction (one direction) is the same as the length L101 from the optical axis to another end of the lens in the opposite direction. Thus, the lens is symmetrical about its optical axis. For the other lenses 106a, 106b, and d, the lens is also symmetrical about its optical axis.

[0059] In order to ensure high performance and compactness of a light source device in general, it is necessary to shorten a distance between light sources and a distance between lenses corresponding to the light sources, as well as to increase the number of light sources. Although in this case, in the light source device 102 of the comparative example according to Fig. 1B, the optical axis of the light source is shifted from the optical axis of the corresponding lens, the lens itself is formed symmetrically to its optical axis. Therefore, taking the light emitted by the light source 104c as an example, it is possible that the light emitted by the light source 104c enters the neighboring lens 106d instead of the corresponding lens 106c and is emitted in the outward direction (an unexpected direction) opposite to the direction of the light concentration position, which is indicated by arrow B in Fig. 1B is designated according to a divergence angle of the light emitted by the light source 104c. This may also cause scattered light. Description of the array lens of the light source device according to the embodiment of the invention

[0060] In the light source device 2 having the above-mentioned configuration, each of the lenses 6a to 6d of the array lens 6 corresponding to the light sources 4a to 4d is formed such that a length from the optical axis to one end of the lens in the offset direction of the light source, which is perpendicular to its optical axis, is longer than a length from the optical axis to another end of the lens in the opposite direction. Fig. 1A is based on lens 1c, which corresponds to light source 4c. The length L2 from the optical axis to one end of the lens in the offset direction (one direction) is longer than the length L1 from the optical axis to the other end of the lens in the opposite direction. Thus, the lens is designed asymmetrically to its optical axis so that the transmitting surface of the lens is elongated in the offset direction of the light source.

[0061] Taking light emitted by the light source 6c according to the shape of the lens 6c as an example, which is indicated by the arrow A of Fig. 1A, it can be ensured that the light enters the lens 6c without allowing the light to enter the neighboring lens 6d.

[0062] Similarly, in the lenses 6a, 6b and 6d, a length from the optical axis to one end of the lens in the offset direction of the light source, which is perpendicular to its optical axis, is longer than a length from the optical axis to another end of the lens in the opposite direction.

[0063] According to such a configuration, in the light source device 2 of the embodiment of the invention according to Fig. 1A, the transmitting surface of the lens is designed to be elongated in the offset direction (one direction) of the light source. Therefore, light emitted from the laser diode does not enter the adjacent lens and safely enters the corresponding lenses 6a to 6d.

[0064] As a result, the optical axis of the light source is shifted from the optical axis of the lens, and light beams emitted from two or more light sources can be concentrated without using a condenser lens. Furthermore, it is possible to provide a compact, high-performance light source device in which, even when a distance between each of the light sources and a distance between each of the lenses corresponding to each of the light sources are narrowed, the light emitted from the laser diode does not enter the adjacent lens and is not emitted in an unexpected direction, thereby securely concentrating the light emitted from the light source.

[0065] Although in Fig. 1A shows the embodiment of the array lens with the four light sources and the four corresponding lenses, it is not limited thereto, and Fig. 8 and Fig. 9, for example, illustrate embodiments with six light sources and six corresponding lenses. Fig. 13A, Fig. 13B show comparative examples of a lens array with six light sources and six corresponding lenses. Description of the light source used in the light source device according to the embodiment

[0066] While a laser diode (LD) is preferred as a light source for use in a light source device due to its compactness and high power, it is not limited to this, and a light-emitting diode (LED), for example, may also be used. Preferably, such a laser diode or light-emitting diode is a semiconductor chip.

[0067] Light in any wavelength range can be used as the wavelength of light emitted by a light source. It is also possible to use not only light in the visible light range, but also light in the ultraviolet light range to enhance color rendering properties. For example, when emitting blue light, it is assumed that light is emitted in a wavelength range of 370 to 500 nm. Furthermore, it is preferable to emit light in a wavelength range of 420 to 500 nm, and even more preferable to emit light in a wavelength range of 440 to 470 nm. Description of the array lens according to the embodiment

[0068] An array lens is a lens in which multiple lenses arranged in a line or matrix are molded into one piece. The array lens can be formed from any material as long as it has superior light transmittance. For example, a glass material can be used, and a resin material can also be used as long as its heat resistance allows it. In the manufacturing process, the array lens can be formed not only by molding but also by machining or similar processes. When the array lens is formed by molding, the array lens can be manufactured repeatedly using the same mold once the mold is made, thus providing the array lens with a low manufacturing cost. Description of the lens forming the lens array

[0069] The curved surface of the lens forming the array lens can be a spherical surface or an aspherical surface. The lens according to the embodiment is designed based on the same function expressed by such a curved surface. Thus, the transmitting surface of the lens is designed to be elongated in the offset direction (a direction) of the light source by using the same function expressed by such a curved surface.

[0070] Here, “based on the same function” means that in the case of the spherical surface, for example, a curvature (or a radius of curvature) is the same, and in the case of the aspherical surface, when expressing the aspherical surface by polynomial equations, including an equation of a two-dimensional rotation curve or a polynomial of at least third degree (for example, even or odd degrees), for example, a curvature, a conic constant or an aspherical coefficient is the same.

[0071] Below is an example of the equation of a two-dimensional rotation curve and a polynomial equation with even degrees. Z(s)=Cs21+1−(1+k)C2s2+A4s4+A6s6+A8s8+… Z(s): s: Deflection size (distance from the optical axis) C: Curvature k: conical constant An: aspherical coefficient in n degrees

[0072] “Based on the same function” means that the curvature C, the conic constant k and the aspheric coefficient An are identical.

[0073] As mentioned above, since the lens is designed based on the same function as the curved surface, it can easily and reliably form the lens array in which its transmitting surface has a desired curved shape that is smoothly elongated in the offset direction (one direction) of the light source. Consequently, it is possible to provide a high-performance light source device that can reliably condense light rays emitted from the light sources without using a condenser lens. Description of the phosphor component according to the embodiment

[0074] As the phosphor component according to the embodiment, any phosphor component including a phosphor that emits light in any wavelength range when light in any wavelength range enters can be used. For example, it is considered to use a phosphor component including a phosphor that emits green light when blue light enters, a phosphor that emits yellow light when blue light enters, or a phosphor that emits red light when blue light enters.

[0075] One phosphor that emits yellow light is an yttrium-aluminium-garnet compound, which has the chemical formula Y3Al3O 12 By combining a light source that emits blue light and this phosphor, which emits yellow light when blue light enters, a compact, high-performance light source device that emits white light can be realized.

[0076] Therefore, if the phosphor component 8 emits light having a wavelength of a complementary color to the light entering the phosphor component 8, it is possible to provide the light source device 2 according to the embodiment as a white light source that can be used in various applications.

[0077] As mentioned above, since the phosphor component 8 is placed at the light concentrating position of the light emitted from each of the lenses of the array lens, light having any desired wavelength can be emitted by using light from the light source and light having a wavelength converted by the phosphor component 8.

[0078] As from Fig. 1A, a size of the phosphor component 8 is smaller than a size of the array lens 6, and it is possible to provide a compact, high-output light source device that can radiate light in a desired wavelength range.

[0079] The phosphor component can be in a fixed position, or it can be placed on the rotating plate connected by a motor (i.e. on a phosphor wheel). Description of the method for determining the length by which the transmitting surface of the lens is extended in the offset direction (one direction)

[0080] As mentioned above, in the embodiment of the invention, the optical axis of the light source is offset from the optical axis of the lens to condense light emitted from the light sources without using a condenser lens. Consequently, in each of the lenses, its transmitting surface is formed to be elongated in the offset direction (one direction) of the light source to ensure that the light emitted from the light source enters the lens corresponding to each of the light sources.

[0081] As the offset of the light source increases, it becomes possible to concentrate light within a short distance in the optical direction. However, as the offset of the light source increases, the transmitting surface of the lens must be extended further in the offset direction (one direction). Therefore, the dimension of the light source in the direction perpendicular to the optical axis becomes larger.

[0082] The degree of elongation of the transmitting surface of the lens in the offset direction of the light source is influenced not only by the offset amount of the light source, but also by the divergence angle of the light emitted by the light source and the distance between the light source and the lens. If the divergence angle is large, a length of the extension in the offset direction (one direction) must be extended. If the length between the light source and the lens is large, a length of the extension in the offset direction (one direction) must be extended. Therefore, it is necessary to determine the degree of elongation of the transmitting surface of the lens in the offset direction of the light source based on the offset amount, the divergence angle, and the distance between the light source and the lens, so that the light emitted by the light source can reliably enter the transmitting surface of the corresponding lens.Furthermore, it is preferable to minimize the length in the above-mentioned range, which contributes to the miniaturization of the light source device. Description of the individual embodiment 1 for determining the extension length of the transmitting surface of the lens.

[0083] Next, Fig. 2, in the array lens according to the embodiment of the invention, a single embodiment 1 for determining a length to extend a transmitting surface of each of the lenses in the offset direction (one direction) of the light source is described. Fig. 2 is an explanatory diagram (corresponding to a sectional view and a side view) for describing the individual embodiment 1 for determining the length to extend the transmitting surface of the lens in the offset direction (one direction) of the light source.

[0084] A lens 6e placed on a center side (i.e., a side of the light condensing position) of an array lens 6 and a lens 6f placed at the end of the array lens 6 are in Fig. 2. In the lens 6e, an optical axis of a light source (not shown, only light emitted from the light source is shown on a line) corresponding to the lens 6e is shifted from an optical axis of the lens 6e by an offset amount Δ1. In this case, when a distance from the optical axis to one end of the lens 6e in the direction opposite to the offset direction (one direction) is L3, a distance from the optical axis to the other end of the lens 6e in the offset direction (one direction) of the light source is extended beyond the length L3 by a length within the offset amount Δl.

[0085] In this case, it is possible to determine a most suitable extension length according to the offset amount Δ1, a divergence angle, and a distance between the light source and the lens. If the divergence angle of light emitted from the light source is relatively large or the distance between the light source and the lens is relatively long, it is preferable to extend the transmitting surface of the lens by a length almost equal to the offset amount Δ1. Nevertheless, the Fig. The embodiment shown in Figure 2 is only an example. According to the divergence angle of light emitted from the light source or the distance between the light source and the lens, there is no limitation to extending the length within the offset amount Δ1. The transmitting surface of the lens can be extended by any length, as long as the downsizing of the light source device is taken into consideration.

[0086] In the lens 6f placed at the end of the array lens 6, an optical axis of a light source corresponding to the lens 6f is shifted from an optical axis of the lens 6f by an offset amount Δ2. In this case, when a distance from the optical axis to one end of the lens 6f in the direction opposite to the offset direction (one direction) is L4, a distance from the optical axis to the other end of the lens 6f in the offset direction (one direction) of the light source is extended beyond the length L4 by a length within the offset amount Δ2.

[0087] Since the lens 6f is placed at the end of the array lens 6, the end of the lens 6f, i.e., the end of the array lens 6, is cut off at the position extended by the length within the offset amount Δ2. Alternatively, it is possible to extend the array lens 6 along the transmitting surface of the lens 6f without cutting off the lens 6f (array lens 6) at the position extended by the length within the offset amount Δ2. Description of the individual embodiment 2 for determining the extension length of the transmitting surface of the lens

[0088] Next, Fig. 3, in the array lens according to the embodiment of the invention, a single embodiment 2 for determining a length by which a transmitting surface of each of the lenses is to be extended in the offset direction (one direction) of the light source is described. Fig. 3 is an explanatory diagram (corresponding to a sectional view and a side view) for describing the individual embodiment 2 for determining the length to extend the transmitting surface of the lens in the offset direction (one direction) of the light source.

[0089] In this embodiment, based on a length between the optical axis and one end of the lens in the direction perpendicular to the offset direction (one direction) of the light source, which is the up and down direction in Fig. 3, determines the length by which the transmitting surface of the lens is to be extended in the offset direction (one direction) of the light source.

[0090] How Fig. 3 clearly shows, the light source (shown schematically) is shifted from the optical axis of the lens by the offset amount Δ. The lens according to Fig. 3 has a shape in which the transmitting surface of the lens is elongated in the offset direction (one direction) of the light source in the lens, which has a circular shape with a radius R in plan view. Thus, the lens is designed such that the length from the optical axis to the end of the lens in the offset direction (one direction) is longer than the length R from the optical axis to the end of the lens in the direction perpendicular to the offset direction (one direction).

[0091] In this embodiment, the lens has a shape configured to be extended by the offset amount Δ as the extension length beyond the length R from the optical axis to the end of the lens in the direction perpendicular to the offset direction (one direction). Thus, the length from the optical axis to the end of the lens in the offset direction (one direction) becomes R + Δ.

[0092] Thus, since the length from the optical axis to the end of the lens in the offset direction (one direction) is longer than the length R from the optical axis to the end of the lens in the direction perpendicular to the offset direction (one direction) by the length Δ corresponding to the offset amount from the optical axis of the lens, an array lens having an efficient lens shape can be formed, and light emitted from the light source can be made to surely enter the lens corresponding to the light source, which contributes to the downsizing of the light source device.

[0093] It is also possible to make the length from the optical position to the end of the lens in the direction opposite to the offset direction (one direction) shorter by the offset amount Δ than the length R from the optical axis to the end of the lens in the direction perpendicular to the offset direction. Thus, it is possible to make the length from the optical axis to the end of the lens in the direction opposite to the offset direction (one direction) R-Δ.

[0094] While in the above-mentioned embodiment, the length from the optical axis to the end of the lens is longer or shorter than the length R by the offset amount Δ, there is no limitation thereto, and it is also possible to make the length from the optical axis to the end of the lens longer or shorter than the length R by any length within the offset amount Δ. Furthermore, according to the divergence angle and the distance between the light source and the lens, it is also possible to make the length from the optical axis to the end of the lens longer or shorter than the length R by any length exceeding the offset amount Δ. Description of the array lens according to the individual embodiment 1]1

[0095] The following is based on Fig. 4 a lens array according to the single embodiment 1 of the invention is described. Fig. 4 is an explanatory diagram (corresponding to a sectional view and a side view) for describing an array lens according to a single embodiment 1 of the invention.

[0096] In Fig. 4, a lens 6g placed on a center side (i.e., a light condensing position side) of an array lens 6 and a lens 6h placed at one end of the array lens 6 are shown. In the lens 6g, an optical axis of a light source (not shown, only light emitted from the light source is shown on a line) corresponding to the lens 6g is shifted from an optical axis of the lens 6g by an offset amount Δ. In this case, when a length from the optical axis to one end of the lens in the direction opposite to the offset direction (one direction) is L5, a transmitting surface of the lens 6g is elongated to be longer than the length L5 by a length within the offset amount Δ.

[0097] In this case, in the extended portion by the length within the offset amount Δ, a lens surface of the neighboring lens 6h is formed such that a certain portion thereof is cut off. Thus, a cut-off portion 16 is formed to prevent an adverse effect on the extended transmitting surface of the lens 6g. A virtual transmitting surface of the lens 6h assuming that the cut-off portion 16 is not formed is shown in Fig. 4 is shown with a dotted line. Consequently, it is possible to reliably prevent light emitted from the light source corresponding to the lens 6g from entering the adjacent lens 6h. The cut-off portion 16 is formed so that the portion into which light emitted from the light source corresponding to the lens 6h enters is not included.

[0098] In other words, the transmitting surface of the lens 6h (second lens) adjacent to the lens 6g (first lens) in the offset direction (one direction) is formed in the position farther from the optical axis 6g than the end of the lens 6g in the offset direction (one direction).

[0099] According to the above configuration, it is possible to securely prevent light emitted from the light source corresponding to the first lens from entering the adjacent second lens, thereby securely concentrating light emitted from the light source. Description of the array lens according to the individual embodiment 2

[0100] The following is based on Fig. 5 a lens array according to the single embodiment 2 of the invention is described. Fig. Fig. 5 is an explanatory diagram (corresponding to a sectional view and a side view) for describing an array lens according to a single embodiment 2 of the invention. In the single embodiment 2 according to Fig. 5, which corresponds to the embodiment according to Fig. 4, in a lens 6g' placed on a center side (i.e., a light condensing position side) of an array lens 6 and a lens 6h' placed at one end of the array lens 6, the lens surface of the lens 6h' adjacent to the lens 6g' is cut off in the portion where the lens 6g' is extended.

[0101] Here, in the single embodiment 2, the lens 6g' (first lens) and the lens 6h' (second lens) are continuously formed with a smooth curved surface (see the radius r). The smooth curved surface can be a spherical surface and any other curved surface that is an aspherical surface.

[0102] According to the above configuration, since the lens 6g' (first lens) and the lens 6h' (second lens) are continuously formed with a smooth curved surface, the array lens can be easily formed by molding or the like, and the array lens can be provided with advantageous strength. Description of the placement of the light source and array lens according to the individual embodiment 1

[0103] The following is based on Fig. 6 describes a placement of a light source and a lens array according to the single embodiment 1 of the invention. Fig. 6 is an explanatory diagram (corresponding to a sectional view and a side view) for describing a placement of a light source and an array lens according to a single embodiment 1 of the invention.

[0104] In the placement of the light source and the lens according to Single Embodiment 1, each of the lenses 6i, 6j, and 6k constituting an array lens 6 is placed at a fixed interval D, and each of the optical axes of the light sources 4i, 4j, and 4k corresponding to the lenses 6i, 6j, and 6k, respectively, is shifted from each of the optical axes of the lenses 6i, 6j, and 6k. Therefore, if the offset amount is identical in the same offset direction (one direction), the distance between each of the light sources becomes identical.

[0105] If the offset amount is different, the distance between each light source will be different. The same amount can be applied to each offset amount between the optical axis of the light source and the optical axis of the lens, or a different amount can be applied.

[0106] As mentioned above, since the optical axis of each of the lenses 6i to 6k of the array lens 6 is positioned at a fixed interval D, the array lens 6 can be easily formed with high precision and at a low manufacturing cost. Consequently, a light source device 2 that can reliably condense light emitted from the light source can be easily provided without using a condenser lens at a low manufacturing cost. Description of the placement of the light source and array lens according to the individual embodiment 2

[0107] The following is based on Fig. 7 describes a placement of a light source and a lens array according to the single embodiment 2 of the invention. Fig. 7 is an explanatory diagram (corresponding to a sectional view and a side view) for describing a placement of a light source and an array lens according to a single embodiment 2 of the invention.

[0108] When placing the light source and the lens according to the individual embodiment 2, according to Fig. 7, each of the optical axes of a plurality of light sources 41 to 4n is placed at a fixed interval d, and each of the optical axes of the light sources 41 to 4n is shifted from each of the optical axes of lenses 6l to 6n corresponding to the light sources 41 to 4n, respectively. Therefore, if the offset amount is identical in the same offset direction (one direction), a distance between each of the lenses becomes identical. Therefore, if the offset amount is different, a distance between each of the lenses becomes different. Regarding each offset amount between the optical axis of the light source and the optical axis of the lens, the same amount may be applied, or a different amount may be applied.

[0109] As mentioned above, since each of the optical axes of the light sources 4l to 4n is positioned at a fixed interval d, the light source device can be easily assembled. Consequently, a light source device 2 that can reliably condense light emitted from the light source can be easily provided without using a condenser lens at a low manufacturing cost.

[0110] While according to this embodiment, the distance between each of the optical axes of the lenses 6l to 6n constituting the array lens 6 is different, when the array lens is formed by molding, the array lens can be repeatedly manufactured using the same mold once the mold is prepared, thereby providing the array lens with a low manufacturing cost. Description of the placement of the light source and array lens according to the individual embodiment 3

[0111] The following is based on Fig. 8A, Fig. 8B describes a placement of a light source and a lens array according to the single embodiment 3 of the invention. Fig. 8A is an explanatory diagram (corresponding to a sectional view and a side view) for describing the placement of the light source and the array lens according to the single embodiment 3 of the invention. Fig. 8B is an explanatory diagram (corresponding to a plan view) for describing the placement of the light source and the array lens according to the single embodiment 3 of the invention.

[0112] Fig. 8A, Fig. 8B shows a group of light sources 4 formed by six of the light sources, and an array lens 6 formed by lenses corresponding to the light sources, respectively. In the placement of the group of light sources 4 and the array lens 6, optical axes of the light sources are shifted from optical axes of the lenses corresponding to the light sources by an offset amount S1, S2, or S3. Each of the lenses has a shape such that a transmitting surface thereof is elongated in the offset direction (a direction of the light source) by a length corresponding to the offset amount, respectively. In this embodiment, a distance between each of the light sources and a distance between each of the lenses are not constant, and they are each appropriately determined according to the offset amount.

[0113] Describing the placement of the array of light sources 4 and the array lens 6 in more detail, each of the light sources and each of the lenses is positioned symmetrically about the center line CL passing through the light concentration position. The light sources and lenses located closest to the center line CL are offset from each other by the offset amount S1. The light sources and lenses located second closest to the center line CL are offset from each other by the offset amount S2. The light sources and lenses located farthest from the center line CL are offset from each other by the offset amount S3. In this case, a relationship of S1 < S2 < S3 exists.

[0114] Thus, as each of the lenses of the array lens is positioned further away from the light condensing position (center line CL), the offset amount between the optical axis of the light source and the optical axis of the lens corresponding to the light source becomes larger.

[0115] As mentioned above, since the offset between the optical axis of the light source and the optical axis of the lens corresponding to the light source becomes larger with the distance from the light condensing position, it is possible to provide a light source device that can reliably condense light emitted from the light source without using a condenser lens. Description of the placement of the light source and array lens according to each Embodiment 4

[0116] Next, Fig. 9A, Fig. 9B describes a placement of a light source and a lens array according to the single embodiment 4 of the invention. Fig. 9A is the explanatory diagram (corresponding to a sectional view and a side view) for describing the placement of the light source and the array lens according to the single embodiment 4 of the invention. Fig. 9B is an explanatory diagram (corresponding to a plan view) for describing the placement of the light source and the array lens according to the single embodiment 4 of the invention.

[0117] Fig. 9A, Fig. 9B shows a group of light sources 4 formed by six of the light sources, and an array lens 6 formed by lenses corresponding to the light sources, respectively. In the placement of the group of light sources 4 and the array lens 6, each of the optical axes of the plurality of light sources is placed at a fixed interval and shifted from an optical axis of the lens corresponding to the light source by an offset amount S4, S5, or S6. Each of the lenses has a shape such that a transmitting surface thereof is elongated in the offset direction (a direction of the light source) by a length corresponding to the offset amount, respectively. In this embodiment, since the optical axis of the light source is placed at the fixed interval, the light source device can be easily assembled.Consequently, a light source device that can surely condense light emitted from the light source without using a condenser lens can be provided at a low manufacturing cost.

[0118] Describing the placement of the group of light sources 4 and the array lens 6 in more detail, similar to the embodiment according to Fig. 8A, Fig. 8B, each of the light sources and each of the lenses is positioned symmetrically about the center line CL passing through the light concentration position. The light sources and lenses located at the position closest to the center line CL are offset from each other by the offset amount S4. The light sources and lenses located at the second closest position to the center line CL are offset from each other by the offset amount S5. The light sources and lenses located at the position farthest from the center line CL are offset from each other by the offset amount S6. In this case, a relationship of S4 < S5 < S6 exists.

[0119] Thus, as each of the lenses of the array lens is positioned further away from the light condensing position (center line CL), the offset amount between the optical axis of the light source and the optical axis of the lens corresponding to the light source becomes larger.

[0120] As mentioned above, since the offset amount between the optical axis of the light source and the optical axis of the lens corresponding to the light source becomes larger as the position becomes farther away from the light condensing position, it is possible to provide a light source device that can surely condense light emitted from the light source without using a condenser lens.

[0121] In Fig. 13A, Fig. 13B illustrates a placement of a light source and an array lens as a comparative example corresponding to the case according to Fig. 9A, Fig. 9B. Similar to the case of Fig. 9A, Fig. 9B, as each lens of the array lens is positioned farther from the light condensing position (center line CL), the offset between the optical axis of the light source and the optical axis of the lens corresponding to the light source becomes larger. However, since each lens is formed symmetrically to its optical axis, light emitted from the light source may enter the adjacent lens instead of the corresponding lens and be emitted in an unexpected direction different from the light condensing direction. This may also cause stray light.

[0122] In the following, a light source device having the light source and the array lens according to the embodiments of the invention will be described with reference to Fig. 10A-10D to Fig. 12A-12D. Description of the light source device according to the individual embodiment 1

[0123] First, based on Fig. 10A to 10D, a light source device according to a single embodiment 1 of the invention is described. Fig. 10A is a perspective view (without a cover) schematically illustrating the light source device according to the single embodiment 1 of the invention. Fig. 10B is a perspective view (enclosed in a cover) schematically illustrating the light source device according to the single embodiment 1 of the invention. Fig. 10C is a plan view (without a cover) schematically illustrating the light source device according to the single embodiment 1 of the invention. Fig. 10D is a side view (without a cover) schematically illustrating the light source device according to the single embodiment 1 of the invention.

[0124] As in Fig. 10A, in the light source device 2 according to the embodiment, a group of light sources 4 formed by six of the light sources placed horizontally on a line, an array lens 6 formed by lenses each corresponding to the light sources and placed horizontally on a line, and a phosphor component 8 located at a light concentrating position onto which light emitted from the array lens 6 is concentrated are mounted on a substrate 10. In this embodiment, as shown by the arrow in the side view of Fig. 10D Light from the group of light sources 4 is emitted in a horizontal direction (right-left direction), and the light is concentrated by each lens of the array lens 6 and then enters the phosphor component 8. Mixed light of light having the wavelength of the light emitted from the group of light sources 4 and the wavelength converted by the phosphor component 8 is emitted in the horizontal direction (right-left direction). Consequently, it is possible to provide a compact, high-output light source device 2. Description of the light source device according to the individual embodiment 2

[0125] Next, Fig. 11A to 11D, a light source device according to a single embodiment 2 of the invention is described. Fig. 11 A is a perspective view (without a cover) schematically illustrating the light source device according to the single embodiment 2 of the invention. Fig. 11B is a perspective view (enclosed in a cover) schematically illustrating the light source device according to the single embodiment 2 of the invention. Fig. 11C is a plan view (without a cover) schematically illustrating the light source device according to the single embodiment 2 of the invention. Fig. 11D is a side view (without a cover) schematically illustrating the light source device according to the single embodiment 2 of the invention.

[0126] As in Fig. As shown in Fig. 11A, in the light source device 2 according to the embodiment, a group of light sources 4 constituted by six of the light sources placed horizontally in a line, an array lens 6 constituted by lenses each corresponding to the light sources and placed horizontally in a line, a prism 14 that reflects light emitted from the array lens 6, and a phosphor component 8 located above the prism 14 and further located at a light concentrating position to which light emitted from the array lens 6 is concentrated are mounted on a substrate 10. The phosphor component 8 is placed just above the prism 14 by a support component (not shown).

[0127] A point different from the above-mentioned light source device according to the single embodiment 1 is that a moving direction of the light horizontally irradiated from the light source is changed by 90 degrees by the prism 14 and then irradiated in an upward direction.

[0128] Thus, according to the arrow in the side view of Fig. 11D Light from the group of light sources 4 is radiated in one horizontal direction (right-left direction), and the light is concentrated by each lens of the array lens 6. After that, the direction of travel of the light is changed by 90 degrees by the prism 14, and the light radiated upward enters the phosphor component 8. Mixed light of light having the wavelength of the light radiated from the group of light sources 4 and the wavelength converted by the phosphor component 8 is radiated vertically upward. Consequently, it is possible to provide a light source device 2 with a small thickness, thus achieving efficient placement. Description of the light source device according to the individual embodiment 3

[0129] Next, Fig. 12A to 12D, a light source device according to a single embodiment 3 of the invention is described. Fig. 12A is a perspective view (without a cover) schematically illustrating the light source device according to the single embodiment 3 of the invention. Fig. 12B is a perspective view (enclosed in a cover) schematically illustrating the light source device according to the single embodiment 3 of the invention. Fig. 12C is a plan view (without a cover) schematically illustrating the light source device according to the single embodiment 3 of the invention. Fig. 12D is a side view (without a cover) schematically illustrating the light source device according to the single embodiment 3 of the invention.

[0130] How Fig. 12A, in the light source device 2 according to the embodiment, similarly to the light source device according to the single embodiment 2 of the invention, a moving direction of the light radiated from the light source in the horizontal direction is changed by 90 degrees by the prism 14, after which the light is radiated in the upward direction. A point different from the Fig. 11A to 11D is that there are two pairs of light sources 4 and an array lens 6 configured by a group of light sources 4 formed by six of the light sources and an array lens 6 formed by lenses corresponding to the light sources, respectively, and therefore light rays can enter the prism 14 from both sides in a horizontal direction.

[0131] More detailed information is provided in accordance with Fig. 12D two pairs of the group of light sources 4 and the array lens 6 are placed symmetrically to the center of the prism 14. As the arrow in the side view of Fig. As shown in Fig. 12D, light is radiated in one horizontal direction (right-left direction) from the group of light sources 4 located on the right side, and the light is condensed by each of the lenses of the array lens 6. After that, the moving direction of the light is changed by 90 degrees by the prism 14, and the light radiated upward enters the phosphor component 8. Mixed light of light having the wavelength of the light radiated from the group of light sources 4 and light having the wavelength converted by the phosphor component 8 is radiated vertically upward.

[0132] Similarly, light is emitted in a horizontal direction (left-right direction) from the group of light sources 4 located on the left side, and the light is concentrated by each lens of the array lens 6. After that, the direction of travel of the light is changed by 90 degrees by the prism 14, and the light emitted in the upward direction enters the phosphor component 8. Mixed light consisting of light having the wavelength of the light emitted from the group of light sources 4 and light having the wavelength converted by the phosphor component 8 is emitted vertically in the upward direction. Consequently, both light beams emitted from the group of light sources 4 and the array lenses 6 located on the right and left sides are combined and then emitted. Therefore, it is possible to provide a light source device with efficient placement and high performance compared to its size.

[0133] While the direction of movement is changed using the prism 14, there is no limitation, and any other optical component that can change the direction of movement of light, such as a mirror, is applicable. Furthermore, the angle of change of the direction of movement of light is not limited to 90 degrees, and it can be changed to any other angle according to its application or placement.

[0134] As mentioned before, the light source device is used under the condition that it is covered by a cover 12 in each embodiment according to Fig. 10A-10D to Fig.12A-12D. Thus, since the light path from the light source to the light condensing position of the radiated light is sealed, the light path is protected from dirt, dust, etc., and it is possible to provide a light source device that can maintain high performance even when used for a long time.

[0135] While the description of the above-mentioned embodiments states that "it is possible to condense light beams emitted from two or more light sources without using a condenser lens," a light source device with a condenser lens is also part of the invention. For example, another condenser lens can be placed shortly after the array lens in the direction of light movement. The focal length can be shortened by placing the condenser lens. Furthermore, in this case, a smaller condenser lens can be used. Description of reference numbers 2 light source device 4 group of light sources 4a to 4d light source 6 array lens 6a to 6j lens 8 phosphor component 10 carriers 12 Cover 14 Prism 16 cut-off section 102 Light source device 104 Group of light sources 104a to 104d light source 106 array lens 106a to 106d lens 108 phosphor component

Claims

[1] Light source device comprising: several light sources (4a-d) placed in one direction, an array lens (6) with a plurality of lenses (6a-n) corresponding to each of the light sources (4a-d), wherein, for concentrating light emitted from each of the lenses (6a-n) to one position, in a first lens (6c) of the plurality of lenses (6a-n), an optical axis of a first light source (4c), which is the light source (4c) of the plurality of light sources (4a-d) corresponding to the first lens (6c), is shifted from an optical axis of the first lens (6c) in the one direction, and wherein the first lens (6c) is formed such that a length (L2) from the optical axis to one end of the first lens (6c) in one direction is longer than a length (L1) from the optical axis to another end of the first lens (6c) in a direction opposite to said one direction, wherein a third lens (6b) of the plurality of lenses (6a-n) is arranged relative to the first lens (6c) in a direction opposite to said one direction, wherein a third light source (4b) of the plurality of light sources (4a-d) corresponds to the third lens (6b), wherein an offset amount (Δ) between the optical axes of the first light source (4c) and the first lens (6c) and an offset amount (Δ) between the optical axes of the third light source (4b) and the third lens (6b) are equal in absolute value. [2] A light source device according to claim 1, wherein a surface forming a second lens (6d) adjacent to the first lens (6c) in said one direction is farther from the optical axis of the first lens than the one end of the first lens in said one direction. [3] The light source device according to claim 2, wherein the first lens and the second lens are continuously formed with a smooth curved surface. [4] A light source device according to any one of claims 1 to 3, wherein the optical axis of each of the lenses (6a-n) of the array lens (6) is placed at a fixed interval, and the light source (4a-d) is placed such that the optical axis of the light source (4a-d) is shifted from the optical axis of the lens corresponding to each of the light sources (4a-d). [5] A light source device according to any one of claims 1 to 3, wherein the optical axis of each of the light sources (4a-d) is placed at a fixed interval, and each of the lenses (6a-n) of the array lens (6) is formed such that the optical axis of the light source (4a-d) is shifted from the optical axis of the lens corresponding to each of the light sources (4a-d). [6] A light source device according to any one of claims 1 to 5, wherein each of the lenses (6a-n) of the array lens (6) is formed on the basis of a same function expressing a curved surface. [7] A light source device according to any one of claims 1 to 6, wherein as a position is further away from a concentrated position of light radiated from each of the lenses (6a-n) of the array lens (6), an offset amount between the optical axes of the light source (4a-d) and the lens (6a-n) corresponding to each other becomes larger. [8] A light source device according to any one of claims 1 to 7, wherein a phosphor (8) is placed at a concentrated position of light emitted from each of the lenses (6a-n) of the array. [9] The light source device according to claim 8, wherein a size of the phosphor (8) is smaller than a size of the array lens (6). [10] A light source device according to claim 8 or 9, wherein the phosphor emits light having a wavelength of a complementary color to the light entering the phosphor (8). [11] A light source device according to any one of claims 1 to 10, wherein a light path from the light source (4a-d) to a concentrated position of light emitted from the lens (6a-n) is sealed. [12] Light source device comprising: several light sources (4a-d) placed in one direction, an array lens (6) with a plurality of lenses (6a-n) corresponding to each of the light sources (4a-d), wherein, in order to concentrate light emitted from each of the lenses (6a-n) to one position, in a first lens (6c) of the plurality of lenses (6a-n), an optical axis of a first light source (4c), which is the light source (4c) of the plurality of light sources (4a-d) corresponding to the first lens (6c), is shifted from an optical axis of the first lens (6c) in the one direction, wherein the first lens (6c) is formed such that a length (L2) from the optical axis to one end of the first lens (6c) in one direction is longer than a length (L1) from the optical axis to another end of the first lens (6c) in a direction opposite to the one direction, and wherein the array lens (6) has a second lens (6d) adjacent to the first lens (6c) in one direction and the first lens (6c) and the second lens (6d) are continuously formed, wherein a second light source (4d) of the plurality of light sources (4a-d) corresponds to the second lens (6d), wherein an offset amount (Δ) between the optical axes of the second light source (4d) and the second lens (6d) is greater than an offset amount (Δ) between the optical axes of the first light source (4c) and the first lens (6c). [13] The light source device according to claim 12, wherein the first lens (6c) further has a cut-off portion of the surface in the direction opposite to the one direction. [14] A light source device according to claim 13, wherein the first lens (6c) and the second lens (6d) are continuously formed with a smooth curved surface.

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