Light source

Abstract

To provide a light source capable of using a common optical element to each LED, and having less fluctuation of a beam diameter or a beam position on an irradiation surface even in a case where positional deviation occurs due to disturbance or environmental change.SOLUTION: A light source device that emits light toward a predetermined irradiation surface comprises: a plurality of light sources with different center wavelengths; collimator lenses of the same shape that are respectively arranged in an optical path of each light source, and shape light from each light source into approximately parallel light; a synthesis optical element that synthesizes light emitted from each collimator lens; and a condenser lens that condenses light emitted from the synthesis optical element, where a minimum optical path length from each light source to the irradiation surface is 80% or more of a maximum optical path length, and light from each light source is condensed closer to the condenser lens than the irradiation surface, and is made incident on the irradiation surface at the approximately same ray angle.SELECTED DRAWING: Figure 2

Description

Technical Field

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[0001] The present invention relates to a light source device that emits light toward a predetermined irradiation surface, and more particularly to a light source device including a plurality of light sources having different center wavelengths respectively.

Background Art

[0002] Conventionally, a light source device including a plurality of light sources (for example, LEDs, lasers, etc.) having different center wavelengths respectively has been put into practical use. Such a light source device can emit light in various wavelength bands by adjusting the light intensity from each light source, and is used as a light source for a multispectral camera or an endoscope device. (For example, Patent Document 1).

[0003] The light source device described in Patent Document 1 has, as light sources, five LEDs of V [violet], B [blue], G [green], A [amber], and R [red], and a plurality of dichroic mirrors. Light from each light source is emitted through the dichroic mirror and is configured to be condensed on the incident end face of an optical fiber by a condenser lens. Then, the light incident on the incident end face of the optical fiber is guided by the optical fiber and emitted from the emission end face. By controlling the light emission of each light source, illumination light suitable for the observation modes of the endoscope (WLI observation mode (white illumination mode) or three types of special light observation modes (NBI observation mode, AFI observation mode, RBI observation mode)) is emitted respectively.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

[0006] Furthermore, if a configuration is adopted in which light from each LED is focused on the incident end face of the optical fiber by a single focusing lens, as in the configuration of Patent Document 1, then if the LEDs or optical elements (collimator lenses, focusing lenses, etc.) experience positional shifts due to disturbances or environmental changes, the focus position may change or the ray angle may change, causing problems such as fluctuations in the beam diameter and beam position of the light incident on the incident end face (i.e., the irradiation surface). Furthermore, in a light source device coupled to an optical fiber, as in the configuration of Patent Document 1, if such a problem occurs, the amount of light incident on the optical fiber decreases significantly, and as a result, the amount of light emitted from the optical fiber also decreases significantly (fluctuations).

[0007] This invention has been made in view of these circumstances, and its objective is to provide a light source device that allows the use of common (identical shaped) optical elements for each LED, and that exhibits minimal fluctuations in beam diameter and beam position on the irradiation surface even when positional displacement occurs in each LED or optical element (collimator lens, focusing lens, etc.) due to disturbances or environmental changes. [Means for solving the problem]

[0008] To achieve the above objective, the present invention provides a light source device that emits light toward a predetermined irradiation surface, comprising: a plurality of light sources, each with a different central wavelength; collimating lenses of the same shape, each placed in the optical path of each light source and shaping the light from each light source into substantially parallel light; a composite optical element that combines the light emitted from each collimating lens; and a focusing lens that focuses the light emitted from the composite optical element, wherein the minimum optical path length relative to the maximum optical path length from each light source to the irradiation surface is 80% or more, and the light from each light source is focused on the focusing lens side of the irradiation surface and incident on the irradiation surface at substantially the same ray angle.

[0009] With this configuration, the minimum optical path length from each light source to the illumination surface is 80% or more of the maximum optical path length (i.e., each optical path length is approximately equal), so a common (identical shaped) collimating lens can be used. Furthermore, because the defocused light is incident on the illumination surface, even if there is a misalignment in each LED or optical element (collimator lens, composite optical element, coupling lens), the sensitivity is low, and fluctuations in beam diameter and beam position on the illumination surface are suppressed.

[0010] Furthermore, it is desirable that the angle of the light rays incident on the illumination surface be 60° or less with respect to the optical axis of the focusing lens.

[0011] Furthermore, it is desirable that the multiple light sources consist of a first LED emitting light of a first wavelength, a second LED emitting light of a second wavelength longer than the first wavelength, a third LED emitting light of a third wavelength longer than the second wavelength, a fourth LED emitting light of a fourth wavelength longer than the third wavelength, and a fifth LED emitting light of a fifth wavelength longer than the fourth wavelength. In this case, it is also desirable that at least one of the chip sizes of the first, second, third, fourth, and fifth LEDs differs from the chip sizes of the others.

[0012] Furthermore, when the direction parallel to the optical axis of the focusing lens is defined as the first direction, and the direction perpendicular to the first direction is defined as the second direction, the third LED is positioned at a distance from the incident end face of the focusing lens such that the optical axis of the third LED substantially coincides with the optical axis of the focusing lens, the fifth LED is positioned at a distance from the third LED in the second direction such that the optical axis of the fifth LED substantially parallel to the optical axis of the third LED, and the fourth, second, and first LEDs are positioned at a distance from the fifth LED in the second direction such that their respective optical axes are perpendicular to the optical axes of the third and fifth LEDs, and are arranged sequentially along the first direction in a direction approaching the incident end face of the focusing lens. Furthermore, in this case, it is desirable that the composite optical element comprises: a first mirror positioned at the intersection of the optical axis of the third LED and the optical axis of the fourth LED, which transmits light of the third wavelength and reflects light of the fourth and fifth wavelengths toward the focusing lens; a second mirror positioned at the intersection of the optical axis of the third LED and the optical axis of the second LED, which transmits light of the third, fourth, and fifth wavelengths and reflects light of the second and first wavelengths toward the focusing lens; a third mirror positioned at the intersection of the optical axis of the fifth LED and the optical axis of the fourth LED, which transmits light of the fourth wavelength and reflects light of the fifth wavelength toward the first mirror; a fourth mirror positioned at the intersection of the optical axis of the fifth LED and the optical axis of the second LED, which transmits light of the second wavelength and reflects light of the first wavelength toward the second mirror; and a fifth mirror positioned at the intersection of the optical axis of the fifth LED and the optical axis of the first LED, which reflects light of the first wavelength toward the fourth mirror.

[0013] Furthermore, when the direction parallel to the optical axis of the focusing lens is defined as the first direction, and the direction perpendicular to the first direction is defined as the second direction, the third LED is positioned at a distance from the incident end face of the focusing lens such that the optical axis of the third LED substantially coincides with the optical axis of the focusing lens, the fourth LED is positioned at a distance from the third LED in the second direction such that the optical axis of the fourth LED substantially parallel to the optical axis of the third LED, and the fifth, second, and first LEDs are positioned at a distance from the fourth LED in the second direction such that their respective optical axes are perpendicular to the optical axes of the third and fourth LEDs, and are arranged sequentially along the first direction in a direction approaching the incident end face of the focusing lens. Furthermore, in this case, it is desirable that the composite optical element comprises: a first mirror positioned at the intersection of the optical axis of the third LED and the optical axis of the fifth LED, which transmits light of the third wavelength and reflects light of the fifth wavelength and the fourth wavelength toward the focusing lens; a second mirror positioned at the intersection of the optical axis of the third LED and the optical axis of the second LED, which transmits light of the third wavelength, the fourth wavelength and the fifth wavelength, and reflects light of the second wavelength and the first wavelength toward the focusing lens; a third mirror positioned at the intersection of the optical axis of the fourth LED and the optical axis of the fifth LED, which transmits light of the fifth wavelength and reflects light of the fourth wavelength toward the first mirror; a fourth mirror positioned at the intersection of the optical axis of the fourth LED and the optical axis of the second LED, which transmits light of the second wavelength and reflects light of the first wavelength toward the second mirror; and a fifth mirror positioned at the intersection of the optical axis of the fifth LED and the optical axis of the first LED, which reflects light of the first wavelength toward the fourth mirror.

[0014] Furthermore, when the direction parallel to the optical axis of the focusing lens is defined as the first direction, and the direction perpendicular to the first direction is defined as the second direction, the third LED is positioned at a distance from the incident end face of the focusing lens such that the optical axis of the third LED substantially coincides with the optical axis of the focusing lens, the fifth LED is positioned at a distance from the third LED in the second direction such that the optical axis of the fifth LED substantially parallel to the optical axis of the third LED, and the fourth, first, and second LEDs are positioned at a distance from the fifth LED in the second direction such that their respective optical axes are perpendicular to the optical axes of the third and fifth LEDs, and are arranged sequentially along the first direction in a direction approaching the incident end face of the focusing lens. Furthermore, in this case, it is desirable that the composite optical element comprises: a first mirror positioned at the intersection of the optical axis of the third LED and the optical axis of the fourth LED, which transmits light of the third wavelength and reflects light of the fourth and fifth wavelengths toward the focusing lens; a second mirror positioned at the intersection of the optical axis of the third LED and the optical axis of the second LED, which transmits light of the third, fourth, and fifth wavelengths and reflects light of the second and first wavelengths toward the focusing lens; a third mirror positioned at the intersection of the optical axis of the fifth LED and the optical axis of the fourth LED, which transmits light of the fourth wavelength and reflects light of the fifth wavelength toward the first mirror; a fourth mirror positioned at the intersection of the optical axis of the fifth LED and the optical axis of the first LED, which transmits light of the first wavelength and reflects light of the second wavelength toward the second mirror; and a fifth mirror positioned at the intersection of the optical axis of the fifth LED and the optical axis of the second LED, which reflects light of the second wavelength toward the fourth mirror.

[0015] Furthermore, when the direction parallel to the optical axis of the focusing lens is defined as the first direction, and the direction perpendicular to the first direction is defined as the second direction, it is desirable that the first LED be positioned at a distance from the incident end face of the focusing lens such that the optical axis of the first LED substantially coincides with the optical axis of the focusing lens, the second LED be positioned at a distance from the first LED in the second direction such that the optical axis of the second LED is substantially parallel to the optical axis of the first LED, and the third, fourth, and fifth LEDs be positioned at a distance from the second LED in the second direction such that their respective optical axes are perpendicular to the optical axes of the first and second LEDs, and are arranged sequentially along the first direction in a direction approaching the incident end face of the focusing lens. Furthermore, in this case, it is desirable that the composite optical element comprises: a first mirror positioned at the intersection of the optical axis of the first LED and the optical axis of the third LED, which transmits light of a first wavelength and reflects light of a second and third wavelength toward a focusing lens; a second mirror positioned at the intersection of the optical axis of the first LED and the optical axis of the fourth LED, which transmits light of a first, second, and third wavelength and reflects light of a fourth and fifth wavelength toward a focusing lens; a third mirror positioned at the intersection of the optical axis of the second LED and the optical axis of the third LED, which transmits light of a third wavelength and reflects light of a second wavelength toward the first mirror; a fourth mirror positioned at the intersection of the optical axis of the second LED and the optical axis of the fourth LED, which transmits light of a fourth wavelength and reflects light of a fifth wavelength toward the second mirror; and a fifth mirror positioned at the intersection of the optical axis of the second LED and the optical axis of the fifth LED, which reflects light of a fifth wavelength toward the fourth mirror.

[0016] Furthermore, when the direction parallel to the optical axis of the focusing lens is defined as the first direction, and the direction perpendicular to the first direction is defined as the second direction, the fifth LED is positioned at a distance from the incident end face of the focusing lens such that the optical axis of the fifth LED substantially coincides with the optical axis of the focusing lens, the fourth LED is positioned at a distance from the fifth LED in the second direction such that the optical axis of the fourth LED substantially parallel to the optical axis of the fifth LED, and the third, second, and first LEDs are positioned at a distance from the fourth LED in the second direction such that their respective optical axes are perpendicular to the optical axes of the fifth and fourth LEDs, and are arranged sequentially along the first direction in a direction approaching the incident end face of the focusing lens. Furthermore, in this case, it is desirable that the composite optical element comprises: a first mirror positioned at the intersection of the optical axis of the fifth LED and the optical axis of the third LED, which transmits light of the fifth wavelength and reflects light of the fourth wavelength and the third wavelength toward the focusing lens; a second mirror positioned at the intersection of the optical axis of the fifth LED and the optical axis of the second LED, which transmits light of the fifth wavelength, the fourth wavelength and the third wavelength, and reflects light of the second wavelength and the first wavelength toward the focusing lens; a third mirror positioned at the intersection of the optical axis of the fourth LED and the optical axis of the third LED, which transmits light of the third wavelength and reflects light of the fourth wavelength toward the first mirror; a fourth mirror positioned at the intersection of the optical axis of the fourth LED and the optical axis of the second LED, which transmits light of the second wavelength and reflects light of the first wavelength toward the second mirror; and a fifth mirror positioned at the intersection of the optical axis of the fourth LED and the optical axis of the first LED, which reflects light of the first wavelength toward the fourth mirror. [Effects of the Invention]

[0017] As described above, according to the present invention, it is possible to use a common (same shape) optical element for each LED, and even if a positional shift occurs in each LED or optical element (collimator lens, focusing lens, etc.) due to disturbances or environmental changes, a light source device is realized in which the beam diameter and beam position on the irradiation surface fluctuate little. [Brief explanation of the drawing]

[0018] [Figure 1] Figure 1 shows the configuration of a light source device according to the first embodiment of the present invention. [Figure 2] FIG. 2 is a ray diagram of green light emitted from the LED of the light source device according to the first embodiment of the present invention. [Figure 3] FIG. 3 is a ray diagram of red light emitted from the LED of the light source device according to the first embodiment of the present invention. [Figure 4] FIG. 4 is a ray diagram of amber light emitted from the LED of the light source device according to the first embodiment of the present invention. [Figure 5] FIG. 5 is a ray diagram of blue light emitted from the LED of the light source device according to the first embodiment of the present invention. [Figure 6] FIG. 6 is a ray diagram of purple light emitted from the LED of the light source device according to the first embodiment of the present invention. [Figure 7] FIG. 7 is a diagram showing the configuration of the light source device according to a modified example of the first embodiment of the present invention. [Figure 8] FIG. 8 is a diagram showing the configuration of the light source device according to a modified example of the first embodiment of the present invention. [Figure 9] FIG. 9 is a diagram showing the configuration of the light source device according to the second embodiment of the present invention. [Figure 10] FIG. 10 is a diagram showing the configuration of the light source device according to the third embodiment of the present invention.

Embodiments for Carrying Out the Invention

[0019] [[ID=3३]] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and their description will not be repeated.

[0020] (First Embodiment) FIG. 1 is a diagram showing the configuration of a light source device 100 according to the first embodiment of the present invention. The light source device 100 of the present embodiment is, for example, a device incorporated in an endoscope device having an optical fiber F or the like, and is a device that supplies illumination light to the optical fiber F in order to irradiate a subject inside a subject. Hereinafter, in the present specification, the optical axis direction of the optical fiber F will be defined as the X-axis direction, and the direction orthogonal to the X-axis will be defined as the Y-axis direction for description.

[0021] As shown in Figure 1, the light source device 100 includes a plurality (five) of LEDs 111 (first LED), 112 (second LED), 113 (third LED), 114 (fourth LED), and 115 (fifth LED), a plurality (five) of collimating lenses 121, 122, 123, 124, and 125, a plurality (five) of dichroic mirrors 131, 132, 133, 134, and 135 (composite optical elements), and a coupling lens 141 (focusing lens).

[0022] LEDs 111, 112, 113, 114, and 115 are each LED (Light Emitting Diode) elements with different central wavelengths. Each LED is mounted on a substrate (not shown) and positioned in a predetermined location, and a drive current is supplied to it via the substrate. When a drive current is supplied to each LED, light is emitted from each LED in an amount corresponding to the drive current. In this embodiment, LED111 is a chip size of 2.5mm x 2.5mm that emits violet light V (hereinafter referred to as "V light") with a wavelength of 400nm, LED112 is a chip size of 2.8mm x 1.7mm that emits blue light B (hereinafter referred to as "B light") with a wavelength of 500nm, LED113 is a chip size of 2.8mm x 1.7mm that emits green light G (hereinafter referred to as "G light") with a wavelength of 550nm, LED114 is a chip size of 2.8mm x 1.7mm that emits amber light A (hereinafter referred to as "A light") with a wavelength of 600nm, and LED115 is a chip size of 2.1mm x 1.3mm that emits red light R (hereinafter referred to as "R light") with a wavelength of 650nm (Figures 2 to 5). Thus, in this embodiment, the chip sizes of LED 111, LED 115, and LEDs 112, 113, and 114 are all different due to the relationship between the required light intensity, wavelength, and the specifications of each LED.

[0023] Furthermore, in this embodiment, LED 113 is positioned such that its optical axis substantially coincides with the optical axis of the optical fiber F and the coupling lens 141 (i.e., at a first position L1 which is on the extension of the optical axis of the optical fiber F and is spaced a predetermined distance from the coupling lens 141), and LED 115 is positioned at a second position L2 which is spaced a predetermined distance from LED 113 in the Y-axis direction, such that its optical axis is substantially parallel to the optical axis of LED 113. Furthermore, LEDs 114, 112, and 111 are arranged sequentially at predetermined intervals along the X-axis, at a predetermined distance in the Y-axis direction from LED 115, between the coupling lens 141 and LEDs 113 and 115, such that their respective optical axes are perpendicular to the optical axes of LEDs 113 and 115. More specifically, moving from LEDs 113 and 115 towards the coupling lens 141, LED 114 is positioned at the third position L3, LED 112 at the fourth position L4, and LED 111 at the fifth position L5.

[0024] The collimating lenses 121, 122, 123, 124, and 125 are positioned in the optical paths of each LED 111, 112, 113, 114, and 115, respectively, and are optical elements that shape the V light, B light, G light, A light, and R light from each LED 111, 112, 113, 114, and 115 into substantially parallel light. In this embodiment, each collimating lens 121, 122, 123, 124, and 125 is a circular plano-convex lens of the same shape (i.e., identical), and is positioned in each optical path with its distance from each LED 111, 112, 113, 114, and 115 adjusted so that the V light, B light, G light, A light, and R light are focused on the coupling lens 141 side of the incident end face (irradiation surface) of the optical fiber F and incident on the optical fiber F at substantially the same ray angle. In this embodiment, since the collimating lenses 121, 122, 123, 124, and 125 are the same lens, in this specification and drawings, each of the collimating lenses 121, 122, 123, 124, and 125 may be referred to as "collimating lens 120" in representative terms.

[0025] The dichroic mirrors 131, 132, 133, 134, and 135 are rectangular, thin optical elements for combining V light, B light, G light, A light, and R light from each of the LEDs 111, 112, 113, 114, and 115. Figures 2 to 6 show the ray diagrams of the light emitted from each LED 111, 112, 113, 114, and 115 of the light source device 100 of this embodiment. Figure 2(a) is the ray diagram of the G light emitted from LED 113, Figure 3(a) is the ray diagram of the R light emitted from LED 115, Figure 4(a) is the ray diagram of the A light emitted from LED 114, Figure 5(a) is the ray diagram of the B light emitted from LED 112, and Figure 6(a) is the ray diagram of the V light emitted from LED 111. Furthermore, Figure 2(b) is an enlarged view of section AA in Figure 2(a), Figure 3(b) is an enlarged view of section BB in Figure 3(a), Figure 4(b) is an enlarged view of section CC in Figure 4(a), Figure 5(b) is an enlarged view of section DD in Figure 5(a), and Figure 6(b) is an enlarged view of section EE in Figure 6(a).

[0026] As shown in Figures 1 to 4, the dichroic mirror 131 is positioned at a 45° angle at the intersection of the optical axes of LED 113 and LED 114, and is configured to transmit G light from LED 113 while reflecting A light from LED 114 and R light from LED 115 toward the coupling lens 141 and optical fiber F. In other words, the dichroic mirror 131 in this embodiment has a transmission band wavelength set to 575 nm or less, so that G light, A light, and R light are combined on the optical axis of the coupling lens 141 and optical fiber F.

[0027] As shown in Figures 1 to 6, the dichroic mirror 132 is positioned at a 45° angle at the intersection of the optical axes of LED 113 and LED 112, and is configured to transmit G light from LED 113, A light from LED 114, and R light from LED 115, while reflecting B light from LED 112 and V light from LED 111 toward the coupling lens 141 and optical fiber F. In other words, the dichroic mirror 132 in this embodiment has a transmission band wavelength set to 525 nm or higher, so that G light, A light, R light, B light, and V light are combined on the optical axis of the coupling lens 141 and optical fiber F.

[0028] As shown in Figures 1, 3, and 4, the dichroic mirror 133 is positioned at a 45° angle at the intersection of the optical axes of LED 115 and LED 114, and is configured to transmit A light from LED 114 and reflect R light from LED 115 toward the dichroic mirror 131. In other words, the dichroic mirror 133 in this embodiment has a transmission band wavelength of 625 nm or less, so that A light and R light are combined on the optical axis of LED 114.

[0029] As shown in Figures 1, 5, and 6, the dichroic mirror 134 is positioned at a 45° angle at the intersection of the optical axes of LED 115 and LED 112, and is configured to transmit B light from LED 112 and reflect V light from LED 111 toward the dichroic mirror 134. In other words, the dichroic mirror 134 in this embodiment has a transmission band wavelength set to 450 nm or higher, so that B light and V light are combined on the optical axis of LED 112.

[0030] As shown in Figures 1, 5, and 6, the dichroic mirror 135 is positioned at a 45° angle at the intersection of the optical axes of LED 115 and LED 111, and is configured to reflect the V light from LED 111 toward the dichroic mirror 134. In other words, the transmission band wavelength of the dichroic mirror 135 in this embodiment is set to 350 nm or less. Note that the dichroic mirror 135 can be any mirror capable of reflecting V light, and a general-purpose reflective mirror can be used as a substitute.

[0031] As described above, the V, B, G, A, and R rays from each of the LEDs 111, 112, 113, 114, and 115 are combined on the optical axis of the coupling lens 141 and the optical fiber F by the dichroic mirrors 131, 132, 133, 134, and 135. The V, B, G, A, and R rays emitted from the dichroic mirror 132 are then incident on the coupling lens 141, which is positioned between the dichroic mirror 132 and the optical fiber F (Figures 1 to 6).

[0032] The coupling lens 141 is an optical element that focuses the V, B, G, A, and R light emitted from the dichroic mirror 132 and directs (couples) it onto the incident end face (i.e., the illumination surface) of the optical fiber F, which is located at a predetermined distance (work distance WD) from the coupling lens 141 (Figure 1). The coupling lens 141 in this embodiment is a circular convex-flat lens (i.e., a focusing lens), and as shown in Figures 2(b) to 6(b), it focuses the V, B, G, A, and R light on the coupling lens 141 side of the incident end face of the optical fiber F, causing them to incident onto the optical fiber F at approximately the same ray angle.

[0033] As shown in Figure 2(b), the G light passing through the coupling lens 141 is focused at a focusing position P1 prior to the incident end face of the optical fiber F, and incident on the incident end face of the optical fiber F at a maximum incident angle θ1 (θ1 is the maximum value of the angle between the optical axis of the coupling lens 141 and the optical fiber F and the G light ray): 44°, and a beam diameter of approximately 4 mm. In this embodiment, the optical path length of the G light (i.e., the optical path length from LED 113 to the incident end face of the optical fiber F) is set to 165 mm.

[0034] As shown in Figure 3(b), the R light passing through the coupling lens 141 is focused at a focusing position P2 prior to the incident end face of the optical fiber F, and incident on the incident end face of the optical fiber F at a maximum incident angle θ2 (θ2 is the maximum value of the angle between the optical axis of the coupling lens 141 and the optical fiber F and the R light ray): 45°, with a beam diameter of approximately 4 mm. In this embodiment, the optical path length of the R light (i.e., the optical path length from LED 115 to the incident end face of the optical fiber F) is set to 198 mm.

[0035] As shown in Figure 4(b), the A light passing through the coupling lens 141 is focused at a focusing position P3 prior to the incident end face of the optical fiber F, and incident on the incident end face of the optical fiber F at a maximum incident angle θ3 (θ3 is the maximum value of the angle between the optical axis of the coupling lens 141 and the optical fiber F and the A light ray): 45°, with a beam diameter of approximately 4 mm. In this embodiment, the optical path length of the A light (i.e., the optical path length from LED 114 to the incident end face of the optical fiber F) is set to 198 mm.

[0036] As shown in Figure 5(b), the B light passing through the coupling lens 141 is focused at a focusing position P4 prior to the incident end face of the optical fiber F, and incident on the incident end face of the optical fiber F at a maximum incident angle θ4 (θ4 is the maximum value of the angle between the optical axis of the coupling lens 141 and the optical fiber F and the B light ray): 44°, with a beam diameter of approximately 4 mm. In this embodiment, the optical path length of the B light (i.e., the optical path length from LED 112 to the incident end face of the optical fiber F) is set to 165 mm.

[0037] As shown in Figure 6(b), the V light passing through the coupling lens 141 is focused at a focusing position P5 before the incident end face of the optical fiber F, and incident on the incident end face of the optical fiber F at a maximum incident angle θ5 (θ5 is the maximum value of the angle between the optical axis of the coupling lens 141 and the optical fiber F and the V light ray): 45°, and a beam diameter of approximately 4 mm. In this embodiment, the optical path length of the V light (i.e., the optical path length from LED 111 to the incident end face of the optical fiber F) is set to 198 mm.

[0038] Thus, the V, B, G, A, and R light rays passing through the coupling lens 141 are focused by the coupling lens 141 at positions P5, P4, P1, P3, and P2, respectively, and are configured to be incident on the incident end face of the optical fiber F with approximately the same maximum incident angle θ5, θ4, θ1, θ3, θ2 (i.e., 45° or 44°) and beam diameter (approximately 4 mm). In other words, in this embodiment, the defocused V, B, G, A, and R light rays are incident on the incident end face of the optical fiber F so that they have approximately equal beam diameters. Therefore, according to the configuration of this embodiment, even if misalignment occurs in each LED 111, 112, 113, 114, 115, each collimating lens 120, and each dichroic mirror 131, 132, 133, 134, 135, the sensitivity is low, and the beam diameter and beam position of the V light, B light, G light, A light, and R light incident on the incident end face of the optical fiber F do not fluctuate significantly. Furthermore, the sensitivity of the V light, B light, G light, A light, and R light to misalignment is also approximately the same, so the amount of light in the V light, B light, G light, A light, and R light incident on the incident end face of the optical fiber F does not fluctuate significantly. The maximum incidence angles θ1 to θ5 are set appropriately according to the diameter of the optical fiber F, but are preferably 60° or less, and more preferably 45° or less.

[0039] Furthermore, as described above, in this embodiment, the LED 113, which has the third longest emission wavelength among the five emission wavelengths (400nm, 500nm, 550nm, 600nm, and 650nm), is placed at the first position L1, and the LEDs 115 and 114, which have longer emission wavelengths than LED 113, are placed at the second position L2 and the third position L3, thereby setting the optical path lengths of the V light, A light, and R light to 198mm. The LEDs 112 and 111, which have shorter emission wavelengths than LED 113, are placed at the fourth position L4 and the fifth position L5, thereby setting the optical path lengths of the B light and G light to 165mm. The layout is such that the minimum optical path length (165mm) is approximately 83% of the maximum optical path length (198mm) (i.e., the optical path lengths are approximately equal). Therefore, according to the configuration of this embodiment, since the lengths of each optical path are approximately equal, a common (same shape) collimating lens 120 can be used for each of the V, B, G, A, and R rays. Furthermore, in order to use a common (identical) collimating lens 120, it is preferable to lay out the lenses so that the minimum optical path length is 80% or more of the maximum optical path length.

[0040] The above describes this embodiment, but the present invention is not limited to the above configuration, and various modifications are possible within the scope of the technical idea of ​​the present invention.

[0041] For example, in this embodiment, dichroic mirrors 131, 132, 133, 134, and 135 are provided, but dichroic prisms can also be used instead of the dichroic mirrors 131, 132, 133, 134, and 135.

[0042] Furthermore, in this embodiment, five LEDs 111, 112, 113, 114, and 115, each with a different central wavelength, are used. However, the arrangement should be such that the optical path length from each LED to the optical fiber F is approximately equal (i.e., the minimum optical path length is 80% or more of the maximum optical path length), and the number of LEDs is not limited to five (i.e., it may be composed of six or more LEDs, or four or fewer LEDs).

[0043] Furthermore, in this embodiment, the chip sizes of LED111, LED115, and LED112, 113, and 114 are all different. However, the configuration is not necessarily limited to this, and the chip sizes of LED111, 112, 113, 114, and 115 may all be the same.

[0044] Furthermore, although the light source device 100 of this embodiment is incorporated into an endoscope device or the like having an optical fiber F, it is not necessarily limited to such applications and can also be applied to devices that irradiate a surface with focused light (for example, a semiconductor exposure apparatus).

[0045] (First variation) Figure 7 shows the configuration of a light source device 100A according to the first modified example of this embodiment. The light source device 100A of this modified example differs from the light source device 100 of the first embodiment in that LED 114 is located at the second position L2, LED 115 is located at the third position L3, and the transmission band wavelength of the dichroic mirror 133A is set to 625 nm or higher. As shown above, the positions of LED114 and LED115 can be swapped.

[0046] (Second variation) Figure 8 shows the configuration of a light source device 100B according to a second modification of this embodiment. This modified light source device 100B differs from the light source device 100 of the first embodiment in that LED 111 is located at a fourth position L4, LED 112 is located at a fifth position L5, and the transmission band wavelength of the dichroic mirror 134B is set to 450 nm or less. As shown above, the positions of LED111 and LED112 can be swapped.

[0047] (Second embodiment) Figure 9 shows the configuration of a light source device 200 according to a second embodiment of the present invention. The light source device 200 of this embodiment differs from the light source device 100 of the first embodiment in that LEDs 111, 112, 113, 114, and 115 are arranged at the first position L1, the second position L2, the third position L3, the fourth position L4, and the fifth position L5, respectively, and dichroic mirrors 231, 232, 233, 234, and 235 are used instead of dichroic mirrors 131, 132, 133, 134, and 135.

[0048] The dichroic mirror 231 is positioned at a 45° angle at the intersection of the optical axes of LED 111 and LED 113, and is configured to transmit V light from LED 111 while reflecting B light from LED 112 and G light from LED 113 toward the optical fiber F. In other words, the dichroic mirror 231 in this embodiment has a transmission band wavelength set to 450 nm or less, so that V light, B light, and G light are combined on the optical axis of the optical fiber F.

[0049] The dichroic mirror 232 is positioned at a 45° angle at the intersection of the optical axes of LED 111 and LED 114, and is configured to transmit V light from LED 111, B light from LED 112, and G light from LED 113, while reflecting A light from LED 114 and R light from LED 115 toward the optical fiber F. In other words, the dichroic mirror 132 in this embodiment has a transmission band wavelength set to 575 nm or less, so that V light, B light, G light, A light, and R light are combined on the optical axis of the optical fiber F.

[0050] The dichroic mirror 233 is positioned at a 45° angle at the intersection of the optical axes of LED 112 and LED 113, and is configured to transmit G light from LED 113 and reflect B light from LED 112 toward the dichroic mirror 231. In other words, the dichroic mirror 233 in this embodiment has a transmission band wavelength set to 525 nm or higher, so that G light and B light are combined on the optical axis of LED 113.

[0051] The dichroic mirror 234 is positioned at a 45° angle at the intersection of the optical axes of LED 112 and LED 114, and is configured to transmit A light from LED 114 and reflect R light from LED 115 toward the dichroic mirror 232. In other words, the dichroic mirror 234 in this embodiment has a transmission band wavelength of 625 nm or less, so that A light and R light are combined on the optical axis of LED 114.

[0052] The dichroic mirror 235 is positioned at a 45° angle at the intersection of the optical axes of LED 112 and LED 115, and is configured to reflect the R light from LED 115 toward the dichroic mirror 234. In other words, the transmission band wavelength of the dichroic mirror 235 in this embodiment is set to 600 nm or less. Note that the dichroic mirror 235 can be any mirror capable of reflecting R light, and a general-purpose reflective mirror can be used as a substitute.

[0053] Thus, in this embodiment, the LEDs 111, 112, 113, 114, and 115 are arranged in order of increasing emission wavelength from shortest to longest at the first position L1, the second position L2, the third position L3, the fourth position L4, and the fifth position L5. This sets the optical path lengths of the V, B, and G lights to 198 mm, and the optical path lengths of the A and R lights to 165 mm. The layout is such that the minimum optical path length (165 mm) is approximately 83% of the maximum optical path length (198 mm) (i.e., the optical path lengths are approximately equal). Therefore, even with the configuration of this embodiment, since the lengths of each optical path are approximately equal, a common (same shape) collimating lens 120 can be used for each of the V, B, G, A, and R rays.

[0054] (Third embodiment) Figure 10 shows the configuration of a light source device 300 according to a third embodiment of the present invention. The light source device 300 of this embodiment differs from the light source device 100 of the first embodiment in that LEDs 111, 112, 113, 114, and 115 are arranged at the fifth position L5, the fourth position L4, the third position L3, the second position L2, and the first position L1, respectively, and dichroic mirrors 331, 332, 333, 334, and 335 are used instead of dichroic mirrors 131, 132, 133, 134, and 135.

[0055] The dichroic mirror 331 is positioned at a 45° angle at the intersection of the optical axes of LED 115 and LED 113, and is configured to transmit R light from LED 115 while reflecting A light from LED 114 and G light from LED 113 toward the optical fiber F. In other words, the dichroic mirror 331 in this embodiment has a transmission band wavelength set to 625 nm or higher, so that R light, A light, and G light are combined on the optical axis of the optical fiber F.

[0056] The dichroic mirror 332 is positioned at a 45° angle at the intersection of the optical axes of LED 115 and LED 112, and is configured to transmit R light from LED 115, A light from LED 114, and G light from LED 113, while reflecting B light from LED 112 and V light from LED 111 toward the optical fiber F. In other words, the dichroic mirror 332 in this embodiment has a transmission band wavelength set to 525 nm or higher, so that V light, B light, G light, A light, and R light are combined on the optical axis of the optical fiber F.

[0057] The dichroic mirror 333 is positioned at a 45° angle at the intersection of the optical axes of LED 114 and LED 113, and is configured to transmit G light from LED 113 and reflect A light from LED 114 toward the dichroic mirror 331. In other words, the dichroic mirror 333 in this embodiment has a transmission band wavelength set to 575 nm or less, so that G light and A light are combined on the optical axis of LED 113.

[0058] The dichroic mirror 334 is positioned at a 45° angle at the intersection of the optical axes of LED 114 and LED 112, and is configured to transmit B light from LED 112 and reflect V light from LED 111 towards the dichroic mirror 334. In other words, the dichroic mirror 334 in this embodiment has a transmission band wavelength of 450 nm or more, so that the B light and V light are combined on the optical axis of LED 112.

[0059] The dichroic mirror 335 is positioned at a 45° angle at the intersection of the optical axes of LED 114 and LED 111, and is configured to reflect the V light from LED 111 toward the dichroic mirror 335. In other words, the transmission band wavelength of the dichroic mirror 335 in this embodiment is set to 450 or higher. Note that the dichroic mirror 335 can be any mirror capable of reflecting V light, and a general-purpose reflective mirror can be used as a substitute.

[0060] Thus, in this embodiment, the LEDs 111, 112, 113, 114, and 115 are arranged in order of decreasing emission wavelength from the first position L1, the second position L2, the third position L3, the fourth position L4, and the fifth position L5, thereby setting the optical path lengths of the R light, A light, and G light to 198 mm, and the optical path lengths of the B light and V light to 165 mm, so that the minimum optical path length (165 mm) is approximately 83% of the maximum optical path length (198 mm) (i.e., the optical path lengths are approximately equal). Therefore, even with the configuration of this embodiment, since the lengths of each optical path are approximately equal, a common (same shape) collimating lens 120 can be used for each of the V, B, G, A, and R rays.

[0061] It should be noted that the embodiments disclosed herein are illustrative in all respects and not restrictive. The scope of the present invention is indicated by the claims rather than by the foregoing description, and all modifications within the meaning and scope equivalent to the claims are intended to be included. [Explanation of Symbols]

[0062] 100: Light source device 100A: Light source device 100B: Light source device 111: LED 112: LED 113: LED 114: LED 115: LED 120: Collimating lens 121: Collimating lens 122: Collimating lens 123: Collimating lens 124: Collimating lens 125: Collimating lens 131: Dichroic mirror 132: Dichroic mirror 133: Dichroic mirror 133A: Dichroic mirror 134: Dichroic mirror 134A: Dichroic mirror 135: Dichroic mirror 141: Coupling lens 200: Light source device 231: Dichroic mirror 232: Dichroic mirror 233: Dichroic mirror 234: Dichroic mirror 235: Dichroic mirror 300: Light source device 331: Dichroic mirror 332: Dichroic mirror 333: Dichroic mirror 334: Dichroic mirror 335: Dichroic mirror

Claims

1. A light source device that emits light incident on a predetermined irradiation surface, A plurality of light sources each having a different central wavelength; At least one combining optical element that combines light emitted from the plurality of light sources; Equipped with A minimum optical path length relative to a maximum optical path length from each of the light sources to the irradiation surface is 80% or more. A light source device characterized by:

2. A collimating lens disposed in the optical path of each of the light sources; a condenser lens that condenses the light emitted from the combining optical element; Further equipped with The light from each of the light sources is condensed on the condenser lens side of the irradiation surface and is incident on the irradiation surface at approximately the same light ray angle.

2. The light source device according to claim 1.

3. The distance between the collimating lens and each of the light sources is set so that the light from each of the light sources is focused on the focusing lens side of the irradiation surface and is incident on the irradiation surface at approximately the same light ray angle.

3. The light source device according to claim 2.

4. 4. The light source device according to claim 2, wherein an angle of the light beam incident on the irradiation surface is 60[deg.] or less with respect to an optical axis of the condenser lens.

5. 2. The light source device according to claim 1, wherein at least one of the chip sizes of the light emitting elements included in each of the light sources is different from the chip sizes of the other light emitting elements.

6. The plurality of light sources are composed of a first light-emitting element emitting light of a first wavelength, a second light-emitting element emitting light of a second wavelength longer than the first wavelength, a third light-emitting element emitting light of a third wavelength longer than the second wavelength, a fourth light-emitting element emitting light of a fourth wavelength longer than the third wavelength, and a fifth light-emitting element emitting light of a fifth wavelength longer than the fourth wavelength; When a direction parallel to the optical axis of the condenser lens is defined as a first direction and a direction perpendicular to the first direction is defined as a second direction, the third light-emitting element is disposed at a position spaced apart from the condensing lens such that an optical axis of the third light-emitting element substantially coincides with an optical axis of the condensing lens; the fifth light-emitting element is disposed at a position spaced apart from the third light-emitting element in the second direction such that an optical axis of the fifth light-emitting element is substantially parallel to an optical axis of the third light-emitting element; the fourth, second and first light-emitting elements are disposed in order along the first direction in a direction approaching the condenser lens at a position spaced apart from the fifth light-emitting element in the second direction such that the optical axes of the fourth, second and first light-emitting elements are perpendicular to the optical axes of the third and fifth light-emitting elements, The synthetic optical element is a first mirror that is disposed at an intersection of an optical axis of the third light-emitting element and an optical axis of the fourth light-emitting element, and transmits the light of the third wavelength and reflects the light of the fourth wavelength and the light of the fifth wavelength toward the condenser lens; a second mirror that is disposed at an intersection of an optical axis of the third light-emitting element and an optical axis of the second light-emitting element, and transmits the light of the third wavelength, the light of the fourth wavelength, and the light of the fifth wavelength, and reflects the light of the second wavelength and the light of the first wavelength toward the condenser lens; a third mirror that is disposed at an intersection of an optical axis of the fifth light-emitting element and an optical axis of the fourth light-emitting element, and transmits the light of the fourth wavelength and reflects the light of the fifth wavelength toward the first mirror; a fourth mirror that is disposed at an intersection of an optical axis of the fifth light-emitting element and an optical axis of the second light-emitting element, the fourth mirror transmitting the light of the second wavelength and reflecting the light of the first wavelength toward the second mirror; a fifth mirror that is disposed at an intersection of an optical axis of the fifth light-emitting element and an optical axis of the first light-emitting element and that reflects the light of the first wavelength toward the fourth mirror; The light source device according to claim 1 , further comprising:

7. The plurality of light sources are composed of a first light-emitting element emitting light of a first wavelength, a second light-emitting element emitting light of a second wavelength longer than the first wavelength, a third light-emitting element emitting light of a third wavelength longer than the second wavelength, a fourth light-emitting element emitting light of a fourth wavelength longer than the third wavelength, and a fifth light-emitting element emitting light of a fifth wavelength longer than the fourth wavelength; When a direction parallel to the optical axis of the condenser lens is defined as a first direction and a direction perpendicular to the first direction is defined as a second direction, the third light-emitting element is disposed at a position spaced apart from the condensing lens such that an optical axis of the third light-emitting element substantially coincides with an optical axis of the condensing lens; the fourth light emitting element is disposed at a position spaced apart from the third light emitting element in the second direction such that an optical axis of the fourth light emitting element is substantially parallel to an optical axis of the third light emitting element; the fifth, second and first light-emitting elements are disposed in order along the first direction in a direction approaching the condenser lens at a position spaced apart from the fourth light-emitting element in the second direction such that the optical axes of the fifth, second and first light-emitting elements are perpendicular to the optical axes of the third and fourth light-emitting elements, The synthetic optical element is a first mirror that is disposed at an intersection of an optical axis of the third light-emitting element and an optical axis of the fifth light-emitting element, and transmits the light of the third wavelength and reflects the light of the fifth wavelength and the light of the fourth wavelength toward the condenser lens; a second mirror that is disposed at an intersection of an optical axis of the third light-emitting element and an optical axis of the second light-emitting element, and transmits the light of the third wavelength, the light of the fourth wavelength, and the light of the fifth wavelength, and reflects the light of the second wavelength and the light of the first wavelength toward the condenser lens; a third mirror that is disposed at an intersection of an optical axis of the fourth light-emitting element and an optical axis of the fifth light-emitting element, and transmits the light of the fifth wavelength and reflects the light of the fourth wavelength toward the first mirror; a fourth mirror that is disposed at an intersection of an optical axis of the fourth light-emitting element and an optical axis of the second light-emitting element, and transmits the light of the second wavelength and reflects the light of the first wavelength toward the second mirror; a fifth mirror that is disposed at an intersection of an optical axis of the fifth light-emitting element and an optical axis of the first light-emitting element and that reflects the light of the first wavelength toward the fourth mirror; The light source device according to claim 1 , further comprising:

8. The plurality of light sources are composed of a first light-emitting element emitting light of a first wavelength, a second light-emitting element emitting light of a second wavelength longer than the first wavelength, a third light-emitting element emitting light of a third wavelength longer than the second wavelength, a fourth light-emitting element emitting light of a fourth wavelength longer than the third wavelength, and a fifth light-emitting element emitting light of a fifth wavelength longer than the fourth wavelength; When a direction parallel to the optical axis of the condenser lens is defined as a first direction and a direction perpendicular to the first direction is defined as a second direction, the third light-emitting element is disposed at a position spaced apart from the condensing lens such that an optical axis of the third light-emitting element substantially coincides with an optical axis of the condensing lens; the fifth light-emitting element is disposed at a position spaced apart from the third light-emitting element in the second direction such that an optical axis of the fifth light-emitting element is substantially parallel to an optical axis of the third light-emitting element; the fourth, first and second light-emitting elements are arranged in order along the first direction in a direction approaching the condenser lens at a position spaced apart from the fifth light-emitting element in the second direction such that the optical axes of the fourth, first and second light-emitting elements are perpendicular to the optical axes of the third and fifth light-emitting elements, The synthetic optical element is a first mirror that is disposed at an intersection of an optical axis of the third light-emitting element and an optical axis of the fourth light-emitting element, and transmits the light of the third wavelength and reflects the light of the fourth wavelength and the light of the fifth wavelength toward the condenser lens; a second mirror that is disposed at an intersection of an optical axis of the third light-emitting element and an optical axis of the second light-emitting element, and transmits the light of the third wavelength, the light of the fourth wavelength, and the light of the fifth wavelength, and reflects the light of the second wavelength and the light of the first wavelength toward the condenser lens; a third mirror that is disposed at an intersection of an optical axis of the fifth light-emitting element and an optical axis of the fourth light-emitting element, and transmits the light of the fourth wavelength and reflects the light of the fifth wavelength toward the first mirror; a fourth mirror that is disposed at an intersection of an optical axis of the fifth light-emitting element and an optical axis of the first light-emitting element, the fourth mirror transmitting the light of the first wavelength and reflecting the light of the second wavelength toward the second mirror; a fifth mirror that is disposed at an intersection of an optical axis of the fifth light-emitting element and an optical axis of the second light-emitting element and that reflects the light of the second wavelength toward the fourth mirror; The light source device according to claim 1 , further comprising:

9. The plurality of light sources are composed of a first light-emitting element emitting light of a first wavelength, a second light-emitting element emitting light of a second wavelength longer than the first wavelength, a third light-emitting element emitting light of a third wavelength longer than the second wavelength, a fourth light-emitting element emitting light of a fourth wavelength longer than the third wavelength, and a fifth light-emitting element emitting light of a fifth wavelength longer than the fourth wavelength; When a direction parallel to the optical axis of the condenser lens is defined as a first direction and a direction perpendicular to the first direction is defined as a second direction, the first light-emitting element is disposed at a position spaced apart from the condensing lens such that an optical axis of the first light-emitting element substantially coincides with an optical axis of the condensing lens; the second light emitting element is disposed at a position spaced apart from the first light emitting element in the second direction such that an optical axis of the second light emitting element is substantially parallel to an optical axis of the first light emitting element; the third, fourth, and fifth light-emitting elements are disposed in order along the first direction in a direction approaching the condenser lens at a position spaced apart from the second light-emitting element in the second direction such that the optical axes of the third, fourth, and fifth light-emitting elements are perpendicular to the optical axes of the first and second light-emitting elements, The synthetic optical element is a first mirror that is disposed at an intersection of an optical axis of the first light-emitting element and an optical axis of the third light-emitting element, and transmits the light of the first wavelength and reflects the light of the second wavelength and the light of the third wavelength toward the condenser lens; a second mirror that is disposed at an intersection of an optical axis of the first light-emitting element and an optical axis of the fourth light-emitting element, and transmits the light of the first wavelength, the light of the second wavelength, and the light of the third wavelength, and reflects the light of the fourth wavelength and the light of the fifth wavelength toward the condenser lens; a third mirror that is disposed at an intersection of an optical axis of the second light-emitting element and an optical axis of the third light-emitting element, and transmits the light of the third wavelength and reflects the light of the second wavelength toward the first mirror; a fourth mirror that is disposed at an intersection of an optical axis of the second light-emitting element and an optical axis of the fourth light-emitting element, the fourth mirror transmitting the light of the fourth wavelength and reflecting the light of the fifth wavelength toward the second mirror; a fifth mirror that is disposed at an intersection of an optical axis of the second light-emitting element and an optical axis of the fifth light-emitting element and that reflects the light of the fifth wavelength toward the fourth mirror; The light source device according to claim 1 , further comprising:

10. The plurality of light sources are composed of a first light-emitting element emitting light of a first wavelength, a second light-emitting element emitting light of a second wavelength longer than the first wavelength, a third light-emitting element emitting light of a third wavelength longer than the second wavelength, a fourth light-emitting element emitting light of a fourth wavelength longer than the third wavelength, and a fifth light-emitting element emitting light of a fifth wavelength longer than the fourth wavelength; When a direction parallel to the optical axis of the condenser lens is defined as a first direction and a direction perpendicular to the first direction is defined as a second direction, the fifth light-emitting element is disposed at a position spaced apart from the incident end surface of the condenser lens such that an optical axis of the fifth light-emitting element substantially coincides with an optical axis of the condenser lens; the fourth light emitting element is disposed at a position spaced apart from the fifth light emitting element in the second direction such that an optical axis of the fourth light emitting element is substantially parallel to an optical axis of the fifth light emitting element; the third, second and first light-emitting elements are disposed in order along the first direction in a direction approaching the condenser lens at a position spaced apart from the fourth light-emitting element in the second direction such that the optical axes of the third, second and first light-emitting elements are perpendicular to the optical axes of the fifth and fourth light-emitting elements, The synthetic optical element is a first mirror that is disposed at an intersection of an optical axis of the fifth light-emitting element and an optical axis of the third light-emitting element, and transmits the light of the fifth wavelength and reflects the light of the fourth wavelength and the light of the third wavelength toward the condenser lens; a second mirror that is disposed at an intersection of an optical axis of the fifth light-emitting element and an optical axis of the second light-emitting element, and transmits the fifth wavelength light, the fourth wavelength light, and the third wavelength light, and reflects the second wavelength light and the first wavelength light toward the condenser lens; a third mirror that is disposed at an intersection of an optical axis of the fourth light-emitting element and an optical axis of the third light-emitting element, the third mirror transmitting the light of the third wavelength and reflecting the light of the fourth wavelength toward the first mirror; a fourth mirror that is disposed at an intersection of an optical axis of the fourth light-emitting element and an optical axis of the second light-emitting element, and transmits the light of the second wavelength and reflects the light of the first wavelength toward the second mirror; a fifth mirror that is disposed at an intersection of an optical axis of the fourth light-emitting element and an optical axis of the first light-emitting element and that reflects the light of the first wavelength toward the fourth mirror; The light source device according to claim 1 , further comprising:

Images