Light source device

Abstract

To provide a light source device capable of suppressing a lens from shifting in position when expanding and also suppressing the lens from interfering with fixation means when contracting.SOLUTION: A light source device 10 comprises a metallic substrate, a light source fixed to the substrate, and a resin-made lens 13 fixed to the substrate by the metallic fixation means 14. The lens 13 is provided with a long hole 33 into which the fixation means 14 is inserted. The long hole 33 extends radially from a predetermined positioning point C of the lens 13. The long hole 33 has a width-expansion part 33e where the long hole 33 increases in width away from the positioning point C.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a light source device.

Background Art

[0002] The light source unit described in Patent Document 1 includes a metal support member, a light source fixed to the metal support member, and a silicone lens fixed to the metal support member by a mounting screw. The silicone lens is provided with an elongated hole through which the mounting screw is inserted.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The lens expands or contracts due to various factors. The lens expands or contracts, for example, due to temperature changes. Specifically, when the light source unit is used in a high-temperature environment or the light source generates heat, the lens thermally expands. When the lens expands, the width of the elongated hole also increases. For this reason, the distance in the width direction of the elongated hole between the inner peripheral surface partitioning the elongated hole and the mounting screw increases, making it easier for the position of the lens in the width direction of the elongated hole to shift. On the other hand, when the light source unit is used in a low-temperature environment, the lens thermally contracts. When the lens contracts, the width of the elongated hole also decreases. For this reason, the contraction of the lens is hindered by the interference between the inner peripheral surface partitioning the elongated hole and the mounting screw in the width direction of the elongated hole, which may cause the lens to deform. When the position of the lens shifts or the lens deforms in this way, the position of the lens with respect to the light source shifts. In this case, since the lens cannot exhibit its original condensing effect, the light source unit may not be able to satisfy the desired illuminance or the desired illuminance range.

Means for Solving the Problems

[0005] The light source device for solving the above problems includes a metal fixing member, a light source fixed to the fixing member, and a resin lens fixed to the fixing member by a metal fixing means. The lens is provided with a long hole through which the fixing means is inserted. The long hole extends radially around a predetermined positioning point in the lens, and the long hole has a width-expanded portion where the width of the long hole increases as it moves away from the positioning point.

[0006] According to the above configuration, the long hole extends radially around the positioning point in the lens. Therefore, expansion and contraction of the lens in the extending direction of the long hole are allowed. Also, the long hole has a width-expanded portion where the width of the long hole increases as it moves away from the positioning point. Thus, even when the lens expands or contracts, the distance between the inner peripheral surface partitioning the long hole and the fixing means is less likely to vary. Therefore, it is possible to suppress displacement of the lens during expansion of the lens and to suppress interference between the lens and the fixing means during contraction of the lens.

[0007] In the above light source device, when the fixing means has an insertion portion located in the long hole and the direction along the perpendicular line extending from the center of the insertion portion toward the surface partitioning the width-expanded portion among the inner peripheral surfaces partitioning the long hole is defined as the perpendicular direction, at the location where the insertion portion is located in the long hole, the shortest distance between the inner peripheral surface partitioning the long hole in the perpendicular direction and the outer peripheral surface of the insertion portion may be equal to or greater than the minimum clearance obtained by subtracting the maximum allowable dimension from the center of the insertion portion to the outer peripheral surface of the insertion portion in the perpendicular direction from the minimum allowable dimension from the center of the insertion portion to the inner peripheral surface partitioning the long hole in the perpendicular direction.

[0008] According to the above configuration, considering the dimensional errors of the long hole and the insertion portion, a gap is provided between the inner peripheral surface partitioning the long hole and the outer peripheral surface of the insertion portion. Therefore, the movement of the insertion portion in the long hole accompanying expansion or contraction of the lens becomes smooth.

[0009] In the above-described light source device, a case for housing the fixing member, the light source, and the lens is further provided. The fixing means has an insertion portion located within the long hole. When the direction along the perpendicular line extending from the center of the insertion portion toward the surface that partitions the widened portion among the inner peripheral surfaces partitioning the long hole is defined as the perpendicular direction, taking the temperature inside the case when the light source device is used at normal temperature as the reference temperature, the temperature inside the case when the light source device is used at the highest temperature among the assumed use temperatures of the light source device as the first temperature, and the temperature inside the case when the light source device is used at the lowest temperature among the assumed use temperatures of the light source device as the second temperature, the shortest distance between the inner peripheral surface partitioning the long hole and the outer peripheral surface of the insertion portion in the perpendicular direction may be the same when the temperature inside the case is the reference temperature, the first temperature, and the second temperature.

[0010] According to the above configuration, regardless of the temperature inside the case, the shortest distance between the inner peripheral surface partitioning the long hole and the outer peripheral surface of the insertion portion in the perpendicular direction can be made constant. In the above-described light source device, the inner peripheral surface partitioning the long hole may include a first curved surface that forms a part of the outer peripheral surface of a first virtual cylinder, a second curved surface that forms a part of the outer peripheral surface of a second virtual cylinder having a diameter larger than that of the first virtual cylinder, and a pair of planes that form a pair of common circumferential lines of the first virtual cylinder and the second virtual cylinder.

[0011] According to the above configuration, the formation of the long hole is easy. In the above-described light source device, the lens is provided with a first long hole and a second long hole as the long holes. The first long hole and the second long hole are located on a first virtual straight line passing through the positioning point, and the positioning point may be located between the first long hole and the second long hole.

[0012] According to the above configuration, among the lenses, the portion located on the first long hole side of the positioning point and the portion located on the second long hole side of the positioning point in the direction in which the first virtual straight line extends can expand so as to move away from each other. Also, among the lenses, the portion located on the first long hole side of the positioning point and the portion located on the second long hole side of the positioning point in the direction in which the first virtual straight line extends can contract so as to approach each other. Therefore, displacement of the positioning point in the direction in which the first virtual straight line extends can be suppressed.

[0013] In the above light source device, the lens is further provided with a third long hole and a fourth long hole as the long holes. The third long hole and the fourth long hole are located on a second virtual straight line that passes through the positioning point and intersects the first virtual straight line, and the positioning point may be located between the third long hole and the fourth long hole.

[0014] According to the above configuration, among the lenses, the portion located on the third long hole side of the positioning point and the portion located on the fourth long hole side of the positioning point in the direction in which the second virtual straight line extends can expand so as to move away from each other. Also, among the lenses, the portion located on the third long hole side of the positioning point and the portion located on the fourth long hole side of the positioning point in the direction in which the second virtual straight line extends can contract so as to approach each other. Therefore, displacement of the positioning point in the direction in which the second virtual straight line extends can be suppressed.

[0015] Further, when the fixing means inserted into the first long hole or the second long hole attempts to move along the direction in which the first virtual straight line extends, the fixing means inserted into the third long hole or the fourth long hole contacts the inner peripheral surface that partitions the long hole. For this reason, displacement of the lens in the direction in which the first virtual straight line extends is restricted. When the fixing means inserted into the third long hole or the fourth long hole attempts to move along the direction in which the second virtual straight line extends, the fixing means inserted into the first long hole or the second long hole contacts the inner peripheral surface that partitions the long hole. For this reason, displacement of the lens in the direction in which the second virtual straight line extends is restricted. Therefore, displacement of the lens caused by the fixing means moving in the extending direction of the long hole within the long hole can be suppressed.

Advantages of the Invention

[0016] According to the present invention, it is possible to suppress the displacement of the lens during the expansion of the lens and to suppress the interference between the lens and the fixing means during the contraction of the lens.

Brief Description of the Drawings

[0017]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Embodiments for Carrying Out the Invention

[0018] Hereinafter, an embodiment in which the light source device is embodied will be described with reference to FIGS. 1 to 8. <Light Source Device> As shown in FIGS. 1 and 2, the light source device 10 includes a substrate 11 as a fixing member, a light source 12, a lens 13, fixing means 14, and a case 15. Although not shown, the light source device 10 includes a drive circuit for driving the light source 12. The substrate 11, the light source 12, the lens 13, the fixing means 14, and the drive circuit are housed in the case 15. The case 15 is provided with a window (not shown) for transmitting light to the outside of the case 15.

[0019] The substrate 11 is made of metal. The substrate 11 of the present embodiment is made of aluminum. The substrate 11 has a rectangular shape. The substrate 11 is provided with female screw holes 11a. The female screw holes 11a are arranged at the respective corner portions of the substrate 11.

[0020] The light source 12 of the present embodiment is an LED. The light source 12 is fixed to the substrate 11. In the present embodiment, the light sources 12 are arranged in 4 rows in the longitudinal direction of the substrate 11 and in 3 rows in the short transverse direction of the substrate 11. Therefore, the light source device 10 of the present embodiment includes 12 light sources 12.

[0021] The lens 13 is made of resin. The lens 13 of the present embodiment is made of silicone rubber. The lens 〈13〉 has a rectangular plate-shaped plate portion 30. The plate portion 30 has a first surface 30a and a second surface 30b. The first surface 30a and the second surface 30b are surfaces orthogonal to the plate thickness direction of the plate portion 30.

[0022] The lens 13 has a substantially hemispherical protrusion 31 protruding from the first surface 30a of the plate portion 30. The number of the protrusions 31 is the same as the number of the light sources 12. That is, the lens 13 of the present embodiment has 12 protrusions 31. The protrusions 31 are arranged in 4 rows in the longitudinal direction of the plate portion 30 and in 3 rows in the short transverse direction of the plate portion 30.

[0023] The lens 13 has a pedestal portion 32 protruding from the second surface 30b of the plate portion 30. The pedestal portions 32 are provided at the respective corner portions of the plate portion 30. As shown in FIG. 3, the lens 13 is provided with a long hole 33. The long hole 33 is a through hole that penetrates the lens 13 in the plate thickness direction of the plate portion 30. The long holes 33 are provided at each corner of the plate portion 30. Therefore, four long holes 33 are provided in the lens 13 of the present embodiment. When distinguishing the four long holes 33, they are referred to as the first long hole 33a, the second long hole 33b, the third long hole 33c, and the fourth long hole 33d. Details of the long hole 33 will be described later.

[0024] As shown in FIGS. 1 and 2, the lens 13 has a cylindrical bulging portion 34 that protrudes from the first surface 30a of the plate portion 30. The bulging portion 34 surrounds the long hole 33. The inside of the bulging portion 34 communicates with the long hole 33.

[0025] The fixing means 14 is made of metal. The fixing means 14 of the present embodiment is made of stainless steel. The fixing means 14 of the present embodiment includes a bolt 41, a cylindrical collar 42, and a washer 43. The bolt 41 has a cylindrical shaft portion 41a and a head portion 41b located at one end in the axial direction of the shaft portion 41a. A male thread is provided on the outer peripheral surface of the shaft portion 41a. After the shaft portion 41a is inserted through the washer 43, it is inserted through the collar 42. The washer 43 is located between the head portion 41b and the collar 42. The axial dimension of the collar 42 is substantially the same as the dimension from the tip surface 34a of the bulging portion 34 of the lens 13 to the tip surface 32a of the pedestal portion 32. The outer diameter of the washer 43 is larger than the outer diameter of the head portion 41b of the bolt 41.

[0026] As shown in FIG. 1, the lens 13 is disposed overlapping the substrate 11. The longitudinal direction and the lateral direction of the plate portion 30 coincide with the longitudinal direction and the lateral direction of the substrate 11, respectively. The second surface 30b of the plate portion 30 faces the substrate 11. Each protruding portion 31 overlaps with each light source 12 in the plate thickness direction of the substrate 11 and the plate portion 30. A gap is provided between the second surface 30b of the plate portion 30 and the light source 12 by the pedestal portion 32.

[0027] The fixing means 14 is inserted into the long hole 33 of the lens 13. Therefore, the fixing means 14 has an insertion portion 14a located within the long hole 33. In the present embodiment, the shaft portion 41a of the bolt 41 and the collar 42 are inserted into the long hole 33. Therefore, the insertion portion 14a of the present embodiment is constituted by the portion of the shaft portion 41a inserted into the long hole 33 and the collar 42. The first end face in the axial direction of the collar 42 is located on substantially the same plane as the tip end face 34a of the bulging portion 34. The second end face in the axial direction of the collar 42 is in contact with the substrate 11. The shaft portion 41a of the bolt 41 is screwed into the female screw hole 11a of the substrate 11. Thereby, the lens 13 is fixed to the substrate 11 by the fixing means 14. The washer 43 is sandwiched between the head portion 41b of the bolt 41 and the collar 42 and the bulging portion 34. The tip end face 34a of the bulging portion 34 is a contact surface that contacts the washer 43.

[0028] The light source device 10 is assumed to be used not only in a normal temperature environment but also in a high temperature environment and a low temperature environment. Further, the light source 12 generates heat. For this reason, the ambient temperature inside the case 15 and the temperatures of the members inside the case 15 including the substrate 11, the lens 13, and the fixing means 14 change. The ambient temperature inside the case 15, the temperature of the substrate 11, the temperature of the lens 13, and the temperature of the fixing means 14 become substantially the same. Hereinafter, the ambient temperature inside the case 15, the temperature of the substrate 11, the temperature of the lens 13, and the temperature of the fixing means 14 are collectively referred to as "the temperature inside the case 15". The temperature inside the case 15 when the light source device 10 is used at normal temperature is defined as the "reference temperature". Among the assumed use temperatures of the light source device 10, the temperature inside the case 15 when the light source device 10 is used at the highest temperature is defined as the "first temperature". Among the assumed use temperatures of the light source device 10, the temperature inside the case 15 when the light source device 10 is used at the lowest temperature is defined as the "second temperature". The first temperature is, for example, 80 degrees. The second temperature is, for example, 0 degrees.

[0029] As described above, the lens 13 is made of resin. Therefore, when the temperature inside the case 15 changes, the lens 13 thermally expands or contracts. When the temperature inside the case 15 rises, the lens 13 thermally expands. When the temperature inside the case 15 drops, the lens 13 thermally contracts.

[0030] Figure 3 shows the lens 13 when the temperature inside the case 15 is the reference temperature. Figure 4 shows the lens 13 when the temperature inside the case 15 is the first temperature. The lens 13 is slightly larger than the lens 13 when the temperature inside the case 15 is the reference temperature due to thermal expansion.

[0031] Figure 5 shows the lens 13 when the temperature inside the case 15 is the second temperature. The lens 13 is slightly smaller than the lens 13 when the temperature inside the case 15 is the reference temperature due to thermal contraction.

[0032] On the other hand, the substrate 11 and the fixing means 14 are made of metal. Therefore, even when the temperature inside the case 15 changes, the substrate 11 and the fixing means 14 are less likely to thermally expand or contract compared to the lens 13. Thus, when the temperature inside the case 15 changes from the reference temperature, the position of the lens 13 with respect to the substrate 11 shifts. When the position of the lens 13 with respect to the substrate 11 shifts, the position of the lens 13 with respect to the light source 12 fixed to the substrate 11 also shifts. In the present embodiment, the positions of the respective protruding portions 31 of the lens 13 with respect to the respective light sources 12 fixed to the substrate 11 shift.

[0033] As shown in Figure 3, a positioning point C is set on the lens 13. The positioning point C is preferably a point where the position of the lens 13 with respect to the substrate 11 does not change even if the lens 13 thermally expands or contracts. In the present embodiment, the positioning point C is set at the center of the plate portion 30. Note that the center of the plate portion 30 is the intersection of the diagonals of the plate portion 30.

[0034] <elongated hole> The elongated hole 33 will be described in detail. The first elongated hole 33a and the second elongated hole 33b are located on a first virtual straight line L1 passing through the positioning point C. The positioning point C is located between the first elongated hole 33a and the second elongated hole 33b. The third elongated hole 33c and the fourth elongated hole 33d are located on a second virtual straight line L2 passing through the positioning point C and intersecting the first virtual straight line L1. The positioning point C is located between the third elongated hole 33c and the fourth elongated hole 33d. In the present embodiment, the first virtual straight line L1 and the second virtual straight line L2 coincide with the diagonal lines of the plate portion 30.

[0035] Each elongated hole 33 extends radially about the positioning point C. Each elongated hole 33 has a width-expanded portion 33e where the width of the elongated hole 33 increases as it moves away from the positioning point C. Note that the width of the elongated hole 33 refers to the dimension of the elongated hole 33 in the width direction that is orthogonal to both the extending direction of the elongated hole 33 and the direction in which the elongated hole 33 penetrates the lens 13.

[0036] The first elongated hole 33a and the second elongated hole 33b are symmetric with respect to the first virtual straight line L1 in the width direction of the first elongated hole 33a and the second elongated hole 33b. The third elongated hole 33c and the fourth elongated hole 33d are symmetric with respect to the second virtual straight line L2 in the width direction of the third elongated hole 33c and the fourth elongated hole 33d.

[0037] As shown in FIG. 6, the inner peripheral surface 330 partitioning the elongated hole 33 of the present embodiment has a first curved surface 331, a second curved surface 332, and a pair of flat surfaces 333. When the elongated hole 33 is viewed from the plate thickness direction of the plate portion 30, the first curved surface 331 and the second curved surface 332 face each other in the extending direction of the elongated hole 33. The first curved surface 331 is located closer to the positioning point C than the second curved surface 332. The pair of flat surfaces 333 face each other in the width direction of the elongated hole 33.

[0038] The first curved surface 331 is a curved surface that is concave in a direction away from the second curved surface 332. The first curved surface 331 forms a part of the outer peripheral surface of the first virtual cylinder C1. The second curved surface 332 is a curved surface that is concave in a direction away from the first curved surface 331. The second curved surface 332 forms a part of the outer peripheral surface of the second virtual cylinder C2. The diameter of the second virtual cylinder C2 is larger than the diameter of the first virtual cylinder C1.

[0039] Of the pair of planes 333, one connects one end of the first curved surface 331 and one end of the second curved surface 332, and the other connects the other end of the first curved surface 331 and the other end of the second curved surface 332. The pair of planes 333 forms a pair of common circumscribed lines L of the first virtual cylinder C1 and the second virtual cylinder C2. The distance between the pair of planes 333 gradually increases as it moves away from the positioning point C in the extending direction of the long hole 33. The width expansion portion 33e is constituted by the space located between the pair of planes 333. That is, the plane 333 is the surface that partitions the width expansion portion 33e.

[0040] The width of the width expansion portion 33e is the smallest at the connection portion between the first curved surface 331 and the pair of planes 333. The width of the width expansion portion 33e is the largest at the connection portion between the second curved surface 332 and the pair of planes 333. The width of the width expansion portion 33e gradually increases from the connection portion between the first curved surface 331 and the pair of planes 333 toward the connection portion between the second curved surface 332 and the pair of planes 333.

[0041] FIG. 6 shows the long hole 33 when the temperature inside the case 15 is the reference temperature. At this time, the insertion portion 14a of the fixing means 14 is located at approximately the central portion in the extending direction of the long hole 33. FIG. 7 shows the long hole 33 when the temperature inside the case 15 is the first temperature. As described above, when the temperature inside the case 15 rises, the lens 13 thermally expands. At this time, as the entire lens 13 expands, the width of the long hole 33 also increases.

[0042] FIG. 8 shows the elongated hole 33 when the temperature inside the case 15 is the second temperature. As described above, when the temperature inside the case 15 decreases, the lens 13 thermally contracts. At this time, as the entire lens 13 thermally contracts, the width of the elongated hole 33 also becomes smaller.

[0043] As shown in FIGS. 3 to 5, the center O of the insertion portion 14a inserted into the first elongated hole 33a and the center O of the insertion portion 14a inserted into the second elongated hole 33b are each located on the first virtual straight line L1. The center O of the insertion portion 14a inserted into the third elongated hole 33c and the center O of the insertion portion 14a inserted into the fourth elongated hole 33d are each located on the second virtual straight line L2. In the present embodiment, the center O of the insertion portion 14a coincides with the axis of the shaft portion 41a.

[0044] As shown in FIGS. 6 to 8, the direction along the perpendicular line T extending from the center O of the insertion portion 14a of the fixing means 14 toward the plane 333 that defines the width expansion portion 33e is defined as the perpendicular direction. In the present embodiment, when the temperature inside the case 15 is the first temperature, the intersection point of the perpendicular line T and the plane 333 coincides with the connection portion between the first curved surface 331 and the plane 333. When the temperature inside the case 15 is the second temperature, the intersection point of the perpendicular line T and the plane 333 coincides with the connection portion between the second curved surface 332 and the plane 333.

[0045] The shortest distance D between the inner peripheral surface 330 that defines the elongated hole 33 and the outer peripheral surface 140 of the insertion portion 14a in the perpendicular direction is the shortest distance between the inner peripheral surface 330 that defines the elongated hole 33 and the outer peripheral surface 140 of the insertion portion 14a. The shortest distance D is obtained by subtracting the dimension from the center O of the insertion portion 14a in the perpendicular direction to the outer peripheral surface 140 of the insertion portion 14a from the dimension from the center O of the insertion portion 14a in the perpendicular direction to the inner peripheral surface 330 that defines the elongated hole 33. In other words, the dimension from the center O of the insertion portion 14a in the perpendicular direction to the inner peripheral surface 330 that defines the elongated hole 33 is the sum of the dimension from the center O of the insertion portion 14a in the perpendicular direction to the outer peripheral surface 140 of the insertion portion 14a and the shortest distance D. In the present embodiment, the dimension from the center O of the insertion portion 14a in the perpendicular direction to the outer peripheral surface 140 of the insertion portion 14a coincides with the radius of the insertion portion 14a.

[0046] In this embodiment, the long hole 33 is configured such that a gap is formed between the inner peripheral surface 330 defining the long hole 33 and the outer peripheral surface 140 of the insertion portion 14a at a position where the insertion portion 14a of the fixing means 14 is located within the long hole 33. Specifically, if the dimension from the center O of the insertion portion 14a in the perpendicular direction to the inner peripheral surface 330 defining the long hole 33 is larger than the dimension from the center O of the insertion portion 14a in the perpendicular direction to the outer peripheral surface 140 of the insertion portion 14a, a gap is formed between the inner peripheral surface 330 defining the long hole 33 and the outer peripheral surface 140 of the insertion portion 14a.

[0047] In practice, dimensional tolerances are set for the dimension from the center O of the insertion portion 14a in the perpendicular direction to the inner peripheral surface 330 defining the long hole 33 and the dimension from the center O of the insertion portion 14a in the perpendicular direction to the outer peripheral surface 140 of the insertion portion 14a, respectively. For this reason, the minimum allowable dimension from the center O of the insertion portion 14a in the perpendicular direction to the inner peripheral surface 330 defining the long hole 33 is set to be larger than the maximum allowable dimension from the center O of the insertion portion 14a in the perpendicular direction to the outer peripheral surface 140 of the insertion portion 14a. Therefore, the shortest distance D between the inner peripheral surface 330 defining the long hole 33 in the perpendicular direction and the outer peripheral surface 140 of the insertion portion 14a is not less than the minimum gap obtained by subtracting the maximum allowable dimension from the center O of the insertion portion 14a in the perpendicular direction to the outer peripheral surface 140 of the insertion portion 14a from the minimum allowable dimension from the center O of the insertion portion 14a in the perpendicular direction to the inner peripheral surface 330 defining the long hole 33.

[0048] In this embodiment, the long hole 33 is configured such that the shortest distance D between the inner peripheral surface 330 defining the long hole 33 in the perpendicular direction and the outer peripheral surface 140 of the insertion portion 14a remains constant regardless of the temperature inside the case 15.

[0049] Specifically, as shown in FIG. 6, when the temperature inside the case 15 is the reference temperature, the shortest distance D is set to a predetermined distance Da. Further, as shown in FIG. 7, when the temperature inside the case 15 is the first temperature, the shortest distance D is set to the predetermined distance Da. Furthermore, as shown in FIG. 8, when the temperature inside the case 15 is the second temperature, the shortest distance D is set to the predetermined distance Da. The shortest distance D between the inner peripheral surface 330 partitioning the long hole 33 in the vertical direction and the outer peripheral surface 140 of the insertion portion 14a is the same when the temperature inside the case 15 is the reference temperature, the first temperature, and the second temperature.

[0050] [Operation of this Embodiment] The operation of this embodiment will be described. As shown in FIG. 7, when the temperature inside the case 15 rises, the lens 13 made of resin thermally expands. On the other hand, the substrate 11 and the fixing means 14 made of metal hardly thermally expand. In this embodiment, the lens 13 is provided with a long hole 33 extending radially around the positioning point C. Therefore, thermal expansion of the lens 13 in the extending direction of the long hole 33 is allowed. The lens 13 moves relative to the fixing means 14 such that the insertion portion 14a of the fixing means 14 approaches the first curved surface 331 within the long hole 33.

[0051] When the lens 13 thermally expands, the width of the long hole 33 also increases. The long hole 33 of this embodiment has a width enlarging portion 33e in which the width of the long hole 33 increases as it moves away from the positioning point C. For this reason, when the lens 13 thermally expands and the insertion portion 14a moves so as to approach the first curved surface 331 within the long hole 33, the insertion portion 14a moves to a portion of the long hole 33 where the width is small. Therefore, even when the lens 13 thermally expands, the distance between the inner peripheral surface 330 partitioning the long hole 33 and the insertion portion 14a of the fixing means 14 is unlikely to increase. As a result, displacement of the lens 13 in the width direction of the long hole 33 is suppressed.

[0052] As shown in FIG. 8, when the temperature inside the case 15 decreases, the lens 13 made of resin thermally contracts. On the other hand, the substrate 11 and the fixing means 14 made of metal hardly thermally expand. In the present embodiment, the lens 13 is provided with a long hole 33 extending radially around the positioning point C. Therefore, thermal contraction of the lens 13 in the extending direction of the long hole 33 is allowed. The lens 13 moves relative to the fixing means 14 such that the insertion portion 14a of the fixing means 14 approaches the second curved surface 332 within the long hole 33.

[0053] When the lens 13 thermally contracts, the width of the long hole 33 also becomes smaller. The long hole 33 of the present embodiment has a width expansion portion 33e in which the width of the long hole 33 increases as it moves away from the positioning point C. Therefore, when the lens 13 thermally contracts and the insertion portion 14a moves so as to approach the second curved surface 332 within the long hole 33, the insertion portion 14a moves to a portion of the long hole 33 where the width is large. Therefore, even when the lens 13 thermally contracts, the distance between the inner peripheral surface 330 partitioning the long hole 33 and the insertion portion 14a of the fixing means 14 is unlikely to become smaller. As a result, the inner peripheral surface 330 partitioning the long hole 33 and the outer peripheral surface 140 of the insertion portion 14a are less likely to interfere, so that deformation of the lens 13 due to the contraction of the lens 13 being hindered is suppressed.

[0054] In this way, displacement of the lens 13 and deformation of the lens 13 are suppressed, so that the position of the lens 13 with respect to the substrate 11 is less likely to shift. When the position of the lens 13 with respect to the substrate 11 is less likely to shift, the position of the lens 13 with respect to the light source 12 fixed to the substrate 11 is less likely to shift. Therefore, even if the lens 13 thermally expands or contracts, the light source device 10 is more likely to satisfy a desired illuminance and a desired illumination range.

[0055] [Effects of the Present Embodiment] The effects of the present embodiment will be described. (1) The light source device 10 includes a substrate 11 as a metal fixing member, a light source 12 fixed to the substrate 11, and a resin lens 13 fixed to the substrate 11 by a metal fixing means 14. The lens 13 is provided with a long hole 33 through which the fixing means 14 is inserted. The long hole 33 extends radially around a predetermined positioning point C on the lens 13. The long hole 33 has a width-expanded portion 33e where the width of the long hole 33 increases as it moves away from the positioning point C.

[0056] According to this configuration, the long hole 33 extends radially around the positioning point C. Therefore, thermal expansion and contraction of the lens 13 in the extending direction of the long hole 33 are allowed. Further, the long hole 33 has a width-expanded portion 33e where the width of the long hole 33 increases as it moves away from the positioning point C. Therefore, even when the lens 13 thermally expands or contracts, the distance between the inner peripheral surface 330 partitioning the long hole 33 and the fixing means 14 is less likely to vary. Thus, it is possible to suppress displacement of the lens 13 during thermal expansion of the lens 13 and to suppress interference between the lens 13 and the fixing means 14 during thermal contraction of the lens 13.

[0057] (2) At the location where the insertion portion 14a of the fixing means 14 is located within the long hole 33, the shortest distance D between the inner peripheral surface 330 partitioning the long hole 33 in the perpendicular direction and the outer peripheral surface 140 of the insertion portion 14a is not less than the minimum clearance obtained by subtracting the maximum allowable dimension from the center O of the insertion portion 14a to the outer peripheral surface 140 of the insertion portion 14a in the perpendicular direction from the minimum allowable dimension from the center O of the insertion portion 14a in the perpendicular direction to the inner peripheral surface 330 partitioning the long hole 33. According to this configuration, a gap is provided between the inner peripheral surface 330 partitioning the long hole 33 and the outer peripheral surface 140 of the insertion portion 14a, taking into account errors in the dimensions of the long hole 33 and the insertion portion 14a. Thus, the movement of the insertion portion 14a within the long hole 33 accompanying thermal expansion or contraction of the lens 13 becomes smooth.

[0058] (3) The shortest distance D between the inner peripheral surface 330 that partitions the long hole 33 in the perpendicular direction and the outer peripheral surface 140 of the insertion portion 14a is the same when the temperature inside the case 15 is the reference temperature, the first temperature, and the second temperature. According to this configuration, regardless of the temperature inside the case 15, the shortest distance D between the inner peripheral surface 330 that partitions the long hole 33 in the perpendicular direction and the outer peripheral surface 140 of the insertion portion 14a can be made constant.

[0059] (4) The inner peripheral surface 330 that partitions the long hole 33 has a first curved surface 331, a second curved surface 332, and a pair of flat surfaces 333. The first curved surface 331 forms a part of the outer peripheral surface of the first virtual cylinder C1. The second curved surface 332 forms a part of the outer peripheral surface of the second virtual cylinder C2 whose diameter is larger than that of the first virtual cylinder C1. The pair of flat surfaces 333 forms a pair of common circumscribed lines L of the first virtual cylinder C1 and the second virtual cylinder C2. According to this configuration, the long hole 33 can be easily formed.

[0060] (5) The lens 13 is provided with a first long hole 33a and a second long hole 33b as the long hole 33. The first long hole 33a and the second long hole 33b are located on a first virtual straight line L1 passing through the positioning point C. The positioning point C is located between the first long hole 33a and the second long hole 33b. [[ID=IO]]

[0061] According to this configuration, in the lens 13, the portions located on the first long hole 33a side of the positioning point C and the portions located on the second long hole 33b side of the positioning point C in the direction in which the first virtual straight line L1 extends can thermally expand so as to move away from each other. Also, in the lens 13, the portions located on the first long hole 33a side of the positioning point C and the portions located on the second long hole 33b side of the positioning point C in the direction in which the first virtual straight line L1 extends can thermally contract so as to approach each other. Therefore, the displacement of the positioning point C in the direction in which the first virtual straight line L1 extends can be suppressed.

[0062] (6) The lens 13 is further provided with a third long hole 33c and a fourth long hole 33d as long holes 33. The third long hole 33c and the fourth long hole 33d are located on a second virtual straight line L2 that passes through the positioning point C and intersects the first virtual straight line L1. The positioning point C is located between the third long hole 33c and the fourth long hole 33d.

[0063] According to this configuration, in the lens 13, the portion located on the third long hole 33c side of the positioning point C and the portion located on the fourth long hole 33d side of the positioning point C in the direction in which the second virtual straight line L2 extends can thermally expand so as to move away from each other. Also, in the lens 13, the portion located on the third long hole 33c side of the positioning point C and the portion located on the fourth long hole 33d side of the positioning point C in the direction in which the second virtual straight line L2 extends can thermally contract so as to approach each other. Therefore, displacement of the positioning point C in the direction in which the second virtual straight line L2 extends can be suppressed.

[0064] Further, when the fixing means 14 inserted into the first long hole 33a and the fixing means 14 inserted into the second long hole 33b attempt to move along the direction in which the first virtual straight line L1 extends, the fixing means 14 inserted into the third long hole 33c contacts the inner peripheral surface 330 partitioning the third long hole 33c, and the fixing means 14 inserted into the fourth long hole 33d contacts the inner peripheral surface 330 partitioning the fourth long hole 33d. For this reason, displacement of the lens 13 in the direction in which the first virtual straight line L1 extends is restricted.

[0065] When the fixing means 14 inserted into the third long hole 33c and the fixing means 14 inserted into the fourth long hole 33d attempt to move along the direction in which the second virtual straight line L2 extends, the fixing means 14 inserted into the first long hole 33a contacts the inner peripheral surface 330 partitioning the first long hole 33a, and the fixing means 14 inserted into the second long hole 33b contacts the inner peripheral surface 330 partitioning the second long hole 33b. For this reason, displacement of the lens 13 in the direction in which the second virtual straight line L2 extends is restricted.

[0066] Therefore, it is possible to suppress displacement of the lens 13 due to the fixing means 14 moving in the extending direction of the long hole 33 within the long hole 33. (7) The fixing means 14 has a collar 42. The first end face in the axial direction of the collar 42 is located substantially on the same plane as the tip end face 34a of the bulging portion 34 of the lens 13. Thereby, it is possible to suppress crushing of the lens 13 when the bolt 41 is tightened.

[0067] (8) The fixing means 14 has a washer 43. The outer diameter of the washer 43 is larger than the outer diameter of the head 41b of the bolt 41. The washer 43 is disposed between the head 41b of the bolt 41 and the first end face in the axial direction of the collar 42 and the tip end face 34a of the bulging portion 34. Thereby, it is possible to increase the pressing area of the bulging portion 34 by the fixing means 14.

[0068] [Modification Example] Note that the above-described embodiment can be modified as follows. The above-described embodiment and the following modification examples can be implemented in combination with each other within a technically non - conflicting range.

[0069] ○ The fixing member is not limited to the substrate 11. The fixing member may be a separate metal member from the substrate 11. As an example, the fixing member may be a heat sink. As another example, if the case 15 is made of metal, the fixing member may be the case 15. When the fixing member is a separate metal member from the substrate 11, the substrate 11 to which the light source 12 is fixed is fixed to the fixing member, whereby the light source 12 is fixed to the fixing member via the substrate 11. Note that the fixing means for fixing the substrate 11 to which the light source 12 is fixed to the fixing member and the fixing means 14 for fixing the lens 13 to the fixing member may be the same or different. However, it is assumed that the substrate 11 and the light source 12 are fixed so as not to be displaced with respect to the fixing member even when the temperature within the case 15 changes.

[0070] ○ Instead of the female screw hole 11a, a through hole may be provided in the substrate 11. In this case, the lens 13 and the substrate 11 may be clamped together by screwing a bolt 41 inserted through the long hole 33 of the lens 13 and the through hole of the substrate 11 into a nut.

[0071] ○ The light source 12 is not limited to an LED. The light source 12 may be another light source such as a halogen. ○ The number of the light sources 12 may be appropriately changed.

[0072] ○ The fixing means 14 may not have the collar 42. When the first end face in the axial direction of the collar 42 is not arranged on substantially the same plane as the tip end face 34a of the bulging portion 34, it is preferable that the washer 43 covers the entire tip end face 34a of the bulging portion 34 in the width direction of the long hole 33. In this case, when the bolt 41 is tightened, it is difficult for the washer 43 to sink into the bulging portion 34.

[0073] ○ The fixing means 14 may not have the washer 43. ○ Instead of the bolt 41, the fixing means 14 may have a pin that protrudes from a fixing member and has a male screw provided on its outer peripheral surface. After the pin is inserted through the long hole 33 of the lens 13, it is screwed into a nut.

[0074] ○ Instead of the bolt 41, the fixing means 14 may have a rivet. ○ The positioning point C is not limited to the center of the plate portion 30. The positioning point C may be set at any position on the lens 13.

[0075] For example, when it is preferable that the position of the center of a specific one of the plurality of protruding portions 31 does not change with respect to the substrate 11, the positioning point C is set at the center of the protruding portion 31.

[0076] ○ The shape of the substrate 11 is not limited to a rectangle. The substrate 11 may be, for example, square or circular. ○ The shape of the plate portion 30 of the lens 13 is not limited to a rectangle. The plate portion 30 may be, for example, square or circular.

[0077] ○ The shape of the plate portion 30 may be different from the shape of the substrate 11. The size of the plate portion 30 may be different from the size of the substrate 11. ○ The number of the long holes 33 provided in the lens 13 is not limited to four. The number of the long holes 33 provided in the lens 13 may be appropriately changed.

[0078] ○ Either one of the first long hole 33a and the second long hole 33b may be a round hole. ○ Either one of the third long hole 33c and the fourth long hole 33d may be a round hole. ○ In the above embodiment, the long holes 33 are provided at the respective corner portions of the plate portion 30, but the arrangement of the long holes 33 is not limited thereto. For example, the first virtual straight line L1 may be a virtual straight line that passes through the positioning point C and extends along the longitudinal direction of the plate portion 30. The second virtual straight line L2 may be a virtual straight line that passes through the positioning point C and extends along the short-side direction of the plate portion 30.

[0079] ○ At the location where the insertion portion 14a is located within the long hole 33, the shortest distance D between the inner peripheral surface 330 that partitions the long hole 33 in the perpendicular direction and the outer peripheral surface 140 of the insertion portion 14a may be less than the minimum clearance obtained by subtracting the maximum allowable dimension from the center O of the insertion portion 14a in the perpendicular direction to the inner peripheral surface 330 that partitions the long hole 33. That is, the inner peripheral surface 330 that partitions the long hole 33 and the outer peripheral surface 140 of the insertion portion 14a may be in contact with each other.

[0080] ○ The shortest distance D between the inner peripheral surface 330 that partitions the long hole 33 in the perpendicular direction and the outer peripheral surface 140 of the insertion portion 14a may not be the same at the time when the temperature in the case 15 is the reference temperature, at the first temperature, and at the second temperature. That is, the distance between the inner peripheral surface 330 that partitions the long hole 33 and the outer peripheral surface 140 of the insertion portion 14a may not be constant regardless of the temperature of the lens 13.

[0081] ○ The inner peripheral surface 330 that defines the long hole 33 does not necessarily have to have the first curved surface 331, the second curved surface 332, and the pair of flat surfaces 333. If the long hole 33 has the width-expanded portion 33e, the shape of the long hole 33 may be appropriately changed. Also, the insertion portion 14a of the fixing means 14 does not have to be cylindrical. The shape of the insertion portion 14a may be changed according to the shape of the long hole 33. However, the long hole 33 and the insertion portion 14a are formed such that when the temperature inside the case 15 is the first temperature, the insertion portion 14a does not interfere with the first curved surface 331, and when the temperature inside the case 15 is the second temperature, the insertion portion 14a does not interfere with the second curved surface 332.

[0082] For example, as shown in FIG. 9, the long hole 33 may be trapezoidal, and the insertion portion 14a may have a quadrangular prism shape with a trapezoidal cross-sectional shape cut in a direction orthogonal to the plate thickness direction of the lens 13. In this case, the first curved surface 331 and the second curved surface 332 are flat surfaces. The outer peripheral surface 140 of the insertion portion 14a has a pair of opposing surfaces 140a that extend parallel to the pair of flat surfaces 333. According to this configuration, the area of the surface located at the position separated from the inner peripheral surface 330 that defines the long hole 33 by the shortest distance D in the perpendicular direction can be increased among the outer peripheral surfaces 140 of the insertion portion 14a.

[0083] For example, as shown in FIG. 10, the dimension in the extending direction of the long hole 33 may be longer than the dimension in the extending direction of the long hole 33 of the above-described embodiment shown by the broken line in FIG. 10. Specifically, when the pair of flat surfaces 333 are extended toward the positioning point C side, the first curved surface 331 may be located closer to the positioning point C side than the first curved surface 331 of the above-described embodiment. Also, when the pair of flat surfaces 333 are extended toward the edge side of the lens 13, the second curved surface 332 may be located closer to the edge side of the lens 13 than the second curved surface 332 of the above-described embodiment.

[0084] In this case, when the temperature inside the case 15 is the first temperature, the intersection point of the perpendicular line T and the plane 333 is deviated from the connection point between the first curved surface 331 and the plane 333. Also, when the temperature inside the case 15 is the second temperature, the intersection point of the perpendicular line T and the plane 333 is deviated from the connection point between the second curved surface 332 and the plane 333.

[0085] ○ In the above embodiment, the case where the lens 13 expands or contracts due to the temperature change inside the case 15 has been described. However, the lens 13 may expand or contract due to factors other than the temperature change.

[0086] For example, the lens 13 made of an organic resin material such as silicone rubber may swell due to contact with a solvent or the like. For example, the lens 13 may expand by absorbing moisture or water.

[0087] For example, when the light source device 10 is used for a long period of time, the lens 13 may contract when its hardness increases or its weight decreases due to aging deterioration. Even when the lens 13 expands or contracts due to factors other than the temperature change in this way, it is possible to cope with it. In this case, the long hole 33 is formed assuming the state of the lens 13 during expansion and contraction.

[0088] [Appendix] The technical idea grasped from the above embodiment and modification example is described below. [Appendix 1] A light source device comprising a metal fixing member, a light source fixed to the fixing member, and a resin lens fixed to the fixing member by a metal fixing means, wherein the lens is provided with a long hole through which the fixing means is inserted, the long hole extends radially around a predetermined positioning point in the lens, and the long hole has a width enlargement portion where the width of the long hole increases as it moves away from the positioning point.

[0089] [Appendix 2] The fixing means has an insertion portion located in the elongated hole. When the direction along the perpendicular line extending from the center of the insertion portion toward the surface defining the width-expanded portion among the inner peripheral surfaces defining the elongated hole is defined as the perpendicular direction, at the location where the insertion portion is located in the elongated hole, the shortest distance between the inner peripheral surface defining the elongated hole in the perpendicular direction and the outer peripheral surface of the insertion portion is not less than the minimum clearance obtained by subtracting the maximum allowable dimension from the center of the insertion portion to the outer peripheral surface of the insertion portion in the perpendicular direction from the minimum allowable dimension from the center of the insertion portion to the inner peripheral surface defining the elongated hole in the perpendicular direction. The light source device according to Supplementary Note 1.

[0090] <Supplementary Note 3> The light source device further includes a case that houses the fixing member, the light source, and the lens. The fixing means has an insertion portion located in the elongated hole. When the direction along the perpendicular line extending from the center of the insertion portion toward the surface defining the width-expanded portion among the inner peripheral surfaces defining the elongated hole is defined as the perpendicular direction, taking the temperature inside the case when the light source device is used at normal temperature as the reference temperature, the temperature inside the case when the light source device is used at the highest temperature among the assumed use temperatures of the light source device as the first temperature, and the temperature inside the case when the light source device is used at the lowest temperature among the assumed use temperatures of the light source device as the second temperature, the shortest distance between the inner peripheral surface defining the elongated hole in the perpendicular direction and the outer peripheral surface of the insertion portion is the same when the temperature inside the case is the reference temperature, the first temperature, and the second temperature. The light source device according to Supplementary Note 1 or Supplementary Note 2.

[0091] <Supplementary Note 4> The inner peripheral surface defining the elongated hole has a first curved surface that forms a part of the outer peripheral surface of a first virtual cylinder, a second curved surface that forms a part of the outer peripheral surface of a second virtual cylinder having a diameter larger than that of the first virtual cylinder, and a pair of planes that form a pair of common circumferential lines of the first virtual cylinder and the second virtual cylinder. The light source device according to any one of Supplementary Notes 1 to 3.

[0092] <Supplementary Note 5> The lens is provided with a first long hole and a second long hole as the long holes, and the first long hole and the second long hole are located on a first virtual straight line passing through the positioning point, and the positioning point is located between the first long hole and the second long hole. The light source device according to any one of Supplementary Notes 1 to 4.

[0093] <Supplementary Note 6> The lens is further provided with a third long hole and a fourth long hole as the long holes, and the third long hole and the fourth long hole are located on a second virtual straight line passing through the positioning point and intersecting the first virtual straight line, and the positioning point is located between the third long hole and the fourth long hole. The light source device according to Supplementary Note 5.

Explanation of Reference Numerals

[0094] 10… Light source device, 11… Substrate as a fixing member, 12… Light source, 13… Lens, 14… Fixing means, 14a… Insertion part, 15… Case, 33… Long hole, 33a… First long hole, 33b… Second long hole, 33c… Third long hole, 33d… Fourth long hole, 33e… Width expansion part, 140… Outer peripheral surface, 330… Inner peripheral surface, 331… First curved surface, 332… Second curved surface, 333… Plane, C… Positioning point, C1… First virtual cylinder, C2… Second virtual cylinder, D… Shortest distance, L… Common circumscribed line, L1… First virtual straight line, L2… Second virtual straight line, O… Center, T… Perpendicular line.

Claims

1. A light source device comprising a metal fixing member, a light source fixed to the fixing member, and a resin lens fixed to the fixing member by a metal fixing means, wherein the lens is provided with a long hole through which the fixing means is inserted, the long hole extends radially about a predetermined positioning point in the lens, and the long hole has a width-expanded portion where the width of the long hole increases as it moves away from the positioning point.

2. The fixing means has an insertion portion located within the long hole. When the direction along the perpendicular line extending from the center of the insertion portion toward the surface that demarcates the width-expanded portion among the inner peripheral surfaces demarcating the long hole is defined as the perpendicular direction, at the location where the insertion portion is located within the long hole, the shortest distance between the inner peripheral surface demarcating the long hole and the outer peripheral surface of the insertion portion in the perpendicular direction is not less than the minimum clearance obtained by subtracting the maximum allowable dimension from the center of the insertion portion to the outer peripheral surface of the insertion portion in the perpendicular direction from the minimum allowable dimension from the center of the insertion portion to the inner peripheral surface demarcating the long hole in the perpendicular direction. The light source device according to claim 1.

3. The light source device further includes a case for housing the fixing member, the light source, and the lens. The fixing means has an insertion portion located within the long hole. When the direction along the perpendicular line extending from the center of the insertion portion toward the surface that demarcates the width-expanded portion among the inner peripheral surfaces demarcating the long hole is defined as the perpendicular direction, taking the temperature inside the case when the light source device is used at normal temperature as the reference temperature, taking the temperature inside the case when the light source device is used at the highest temperature among the assumed operating temperatures of the light source device as the first temperature, taking the temperature inside the case when the light source device is used at the lowest temperature among the assumed operating temperatures of the light source device as the second temperature, the shortest distance between the inner peripheral surface demarcating the long hole and the outer peripheral surface of the insertion portion in the perpendicular direction is the same when the temperature inside the case is the reference temperature, the first temperature, and the second temperature. The light source device according to claim 1.

4. The inner peripheral surface demarcating the long hole includes a first curved surface that forms part of the outer peripheral surface of a first virtual cylinder, a second curved surface that forms part of the outer peripheral surface of a second virtual cylinder having a diameter larger than that of the first virtual cylinder, and a pair of planes that form a pair of common circumscribed lines of the first virtual cylinder and the second virtual cylinder. The light source device according to claim 1.

5. The lens is provided with a first long hole and a second long hole as the long holes, the first long hole and the second long hole are located on a first virtual straight line passing through the positioning point, the positioning point is located between the first long hole and the second long hole. The light source device according to claim 1.

6. The lens is further provided with a third long hole and a fourth long hole as the long holes, the third long hole and the fourth long hole are located on a second virtual straight line passing through the positioning point and intersecting with the first virtual straight line, the positioning point is located between the third long hole and the fourth long hole. The light source device according to claim 5.

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