JP2023148533A - Light source - Google Patents

Abstract

[Problem] It is possible to use a common optical element for each LED, and even if each LED or optical element is misaligned due to disturbance or environmental changes, the beam diameter on the irradiation surface can be To provide a light source device with little variation in beam position.
[Solution] A light source device that emits light toward a predetermined irradiation surface is arranged with multiple light sources each having a different center wavelength and in the optical path of each light source, and shapes the light from each light source into approximately parallel light. It is equipped with a collimating lens of the same shape, a combining optical element that combines the light emitted from each collimating lens, and a condensing lens that collects the light emitted from the combining optical element. The minimum optical path length is 80% or more with respect to the maximum optical path length up to Ru.
[Selection diagram] Figure 2

Description

The present invention relates to a light source device that emits light toward a predetermined irradiation surface, and particularly to a light source device that includes a plurality of light sources each having a different center wavelength.

Conventionally, light source devices equipped with a plurality of light sources (for example, LEDs, lasers, etc.) each having a different center wavelength have been put into practical use.
Such light source devices can emit light in various wavelength bands by adjusting the light intensity from each light source, and are used as light sources for multispectral cameras and light sources for endoscope devices. ing. (For example, Patent Document 1).

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

International Publication 2020/084698

According to the configuration of Patent Document 1, light emitted from five LEDs is guided by an optical fiber and emitted. However, in the configuration of Patent Document 1, a V [violet] LED is arranged on the optical axis of the optical fiber, and four dichroic mirrors arranged between the V [violet] LED and the input end face of the optical fiber, Since the configuration is such that the light from the B [blue], G [green], A [amber], and R [red] LEDs and the light from the V [purple] LED are combined in order, the distance from each LED to the input end face of the optical fiber is The distances (that is, the optical path lengths) differ greatly from each other.
Therefore, in order to condense the light from each LED onto the input end face of an optical fiber using one condensing lens, it is necessary to use multiple optical elements (for example, collimator lenses, etc.) corresponding to each LED (according to each wavelength). ), which poses problems such as the cost of designing each optical element and the cost of the mold.

Furthermore, if a configuration is adopted in which the light from each LED is focused on the incident end face of the optical fiber by one condensing lens, as in the configuration of Patent Document 1, each LED and optical element (collimator lens, condensing lens, etc. If a position shift occurs due to disturbance or environmental changes in the optical lens (optical lens, etc.), the focus position or light beam angle may change, causing the beam diameter and beam position of the light that enters the incident end surface (i.e., the irradiation surface) to change. This causes problems such as fluctuations in the
In addition, when such a problem occurs in a light source device coupled to an optical fiber as in the configuration of Patent Document 1, the amount of light incident on the optical fiber decreases significantly, and as a result, the amount of light emitted from the optical fiber decreases. A problem also arises in that the amount of light emitted decreases significantly (varies).

The present invention was made in view of these circumstances, and its purpose is to enable the use of a common (same shape) optical element for each LED, and to make it possible to use a common (same shape) optical element for each LED. To provide a light source device with little variation in beam diameter or beam position on an irradiation surface even when positional deviation occurs in optical elements (collimator lens, condensing lens, etc.) due to disturbance or environmental change. .

In order to achieve the above object, the light source device of the present invention is a light source device that emits light toward a predetermined irradiation surface, and includes a plurality of light sources each having a different center wavelength and arranged in the optical path of each light source. , a collimating lens of the same shape that shapes the light from each light source into approximately parallel light, a combining optical element that combines the light emitted from each collimating lens, and a condenser that collects the light emitted from the combining optical element. a light lens, the minimum optical path length of 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 condensed on the condensing lens side rather than the irradiation surface, and approximately The rays are characterized by being incident on the irradiation surface at the same angle.

According to such a configuration, the minimum optical path length from each light source to the irradiation surface is 80% or more of the maximum optical path length (in other words, each optical path length is approximately equal), so a common (same-shaped) collimator lenses can be used. In addition, since the configuration is such that defocused light enters the irradiation surface, even if there is a positional shift in each LED or optical element (collimator lens, synthetic optical element, coupling lens), the sensitivity will be low, and the Fluctuations in beam diameter and beam position can be suppressed.

Further, it is desirable that the angle of the light beam incident on the irradiation surface is 60° or less with respect to the optical axis of the condenser lens.

Further, the plurality of light sources includes a first LED that emits light of a first wavelength, a second LED that emits light of a second wavelength longer than the first wavelength, and a second LED that emits light of a third wavelength longer than the second wavelength. Consisting of a third LED that emits light, a fourth LED that emits light of a fourth wavelength longer than the third wavelength, and a fifth LED that emits light of a fifth wavelength longer than the fourth wavelength. is desirable. Moreover, in this case, it is desirable that at least one of the chip sizes of the first LED, the second LED, the third LED, the fourth LED, and the fifth LED is different from the other chip sizes.

Further, when the first direction is a direction parallel to the optical axis of the condensing lens, and the second direction is a direction perpendicular to the first direction, the third LED is such that the optical axis of the third LED is the same as that of the condensing lens. The fifth LED is arranged at a position spaced apart from the incident end surface of the condenser lens so as to substantially coincide with the optical axis, and the fifth LED is arranged from the third LED so that the optical axis of the fifth LED is substantially parallel to the optical axis of the third LED. The fourth, second, and first LEDs are arranged at positions spaced apart from each other in the second direction, and the fourth, second, and first LEDs are spaced apart from the fifth LED in the second direction so that their respective optical axes are perpendicular to the optical axes of the third and fifth LEDs. , are preferably arranged in order in a direction approaching the incident end surface of the condenser lens along the first direction. Further, in this case, the combining optical element is arranged at the intersection of the optical axis of the third LED and the optical axis of the fourth LED, and transmits the light of the third wavelength, and also transmits the light of the fourth wavelength and the fifth wavelength. A first mirror that reflects light toward a condensing lens; and a first mirror that is arranged at the intersection of the optical axis of the third LED and the optical axis of the second LED, and that emits light of a third wavelength, a fourth wavelength, and a fifth wavelength; a second mirror that transmits the light of the second wavelength and reflects the light of the second wavelength and the first wavelength toward the condenser lens; , a third mirror that transmits light of a fourth wavelength and reflects light of a fifth wavelength toward the first mirror; a fourth mirror that transmits light of the second wavelength and reflects light of the first wavelength toward the second mirror; It is desirable to include a fifth mirror that reflects light of the same wavelength toward the fourth mirror.

Further, when the first direction is a direction parallel to the optical axis of the condensing lens, and the second direction is a direction perpendicular to the first direction, the third LED is such that the optical axis of the third LED is the same as that of the condensing lens. The fourth LED is arranged at a position spaced apart from the incident end surface of the condenser lens so as to substantially coincide with the optical axis, and the fourth LED is arranged from the third LED so that the optical axis of the fourth LED is substantially parallel to the optical axis of the third LED. The fifth, second and first LEDs are arranged at positions spaced apart from the fourth LED in the second direction such that their respective optical axes are orthogonal to the optical axes of the third and fourth LEDs. , are preferably arranged in order in a direction approaching the incident end surface of the condenser lens along the first direction. Further, in this case, the combining optical element is arranged at the intersection of the optical axis of the third LED and the optical axis of the fifth LED, and transmits the light of the third wavelength, and also transmits the light of the fifth wavelength and the fourth wavelength. A first mirror that reflects light toward a condensing lens; and a first mirror that is arranged at the intersection of the optical axis of the third LED and the optical axis of the second LED, and that emits light of a third wavelength, a fourth wavelength, and a fifth wavelength; a second mirror that transmits the light of the second wavelength and reflects the light of the second wavelength and the light of the first wavelength toward the condenser lens; , a third mirror that transmits light of a fifth wavelength and reflects light of a fourth wavelength toward the first mirror, and a third mirror that is arranged at the intersection of the optical axis of the fourth LED and the optical axis of the second LED. a fourth mirror that transmits light of the second wavelength and reflects light of the first wavelength toward the second mirror; It is desirable to include a fifth mirror that reflects light of the same wavelength toward the fourth mirror.

Further, when the first direction is a direction parallel to the optical axis of the condensing lens, and the second direction is a direction perpendicular to the first direction, the third LED is such that the optical axis of the third LED is the same as that of the condensing lens. The fifth LED is arranged at a position spaced apart from the incident end surface of the condenser lens so as to substantially coincide with the optical axis, and the fifth LED is arranged from the third LED so that the optical axis of the fifth LED is substantially parallel to the optical axis of the third LED. The fourth, first and second LEDs are arranged at positions spaced apart in the second direction from the fifth LED such that their respective optical axes are perpendicular to the optical axes of the third and fifth LEDs. , are preferably arranged in order in a direction approaching the incident end surface of the condenser lens along the first direction. Further, in this case, the combining optical element is arranged at the intersection of the optical axis of the third LED and the optical axis of the fourth LED, and transmits the light of the third wavelength, and also transmits the light of the fourth wavelength and the fifth wavelength. A first mirror that reflects light toward a condensing lens; and a first mirror that is arranged at the intersection of the optical axis of the third LED and the optical axis of the second LED, and that emits light of a third wavelength, a fourth wavelength, and a fifth wavelength; a second mirror that transmits the light of the second wavelength and reflects the light of the second wavelength and the first wavelength toward the condenser lens; , a third mirror that transmits light of a fourth wavelength and reflects light of a fifth wavelength toward the first mirror, and a third mirror that is arranged at the intersection of the optical axis of the fifth LED and the optical axis of the first LED a fourth mirror that transmits light of one wavelength and reflects light of a second wavelength toward a second mirror; and a fourth mirror that transmits light of one wavelength and reflects light of a second wavelength toward a second mirror; It is desirable to include a fifth mirror that reflects light of the same wavelength toward the fourth mirror.

Further, when the first direction is a direction parallel to the optical axis of the condensing lens, and the second direction is a direction perpendicular to the first direction, the first LED is such that the optical axis of the first LED is the same as that of the condensing lens. The second LED is arranged at a position spaced apart from the incident end surface of the condensing lens so as to substantially coincide with the optical axis, and the second LED is arranged from the first LED so that the optical axis of the second LED is substantially parallel to the optical axis of the first LED. The third, fourth and fifth LEDs are arranged at positions spaced apart 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. , are preferably arranged in order in a direction approaching the incident end surface of the condenser lens along the first direction. Further, in this case, the combining optical element is arranged at the intersection of the optical axis of the first LED and the optical axis of the third LED, and transmits the light of the first wavelength, and also transmits the light of the second wavelength and the third wavelength. a first mirror that reflects the light toward the condensing lens; and a first mirror that is arranged at the intersection of the optical axis of the first LED and the optical axis of the fourth LED, and that reflects the light of the first wavelength, the light of the second wavelength, and the third wavelength. A second mirror that transmits the light of the wavelength and reflects the light of the fourth wavelength and the light of the fifth wavelength toward the condenser lens, and is arranged at the intersection of the optical axis of the second LED and the optical axis of the third LED. and a third mirror that transmits the light of the third wavelength and reflects the light of the second wavelength toward the first mirror, and is arranged at the intersection of the optical axis of the second LED and the optical axis of the fourth LED, a fourth mirror that transmits light of a fourth wavelength and reflects light of a fifth wavelength toward the second mirror; It is desirable to include a fifth mirror that reflects light with a wavelength of .

Further, when the first direction is a direction parallel to the optical axis of the condensing lens, and the second direction is a direction perpendicular to the first direction, the fifth LED is such that the optical axis of the fifth LED is the same as the condensing lens. The fourth LED is arranged at a position spaced apart from the incident end surface of the condenser lens so as to substantially coincide with the optical axis, and the fourth LED is arranged from the fifth LED so that the optical axis of the fourth LED is substantially parallel to the optical axis of the fifth LED. The third, second and first LEDs are arranged at positions spaced apart from the fourth LED in the second direction such that their respective optical axes are orthogonal to the optical axes of the fifth and fourth LEDs. , are preferably arranged in order in a direction approaching the incident end surface of the condenser lens along the first direction. Further, in this case, the combining optical element is arranged at the intersection of the optical axis of the fifth LED and the optical axis of the third LED, and transmits the light of the fifth wavelength, and also transmits the light of the fourth wavelength and the third wavelength. A first mirror that reflects light toward a condensing lens, and a first mirror disposed at the intersection of the optical axis of the fifth LED and the optical axis of the second LED, and a first mirror that reflects light toward a condensing lens, and a first mirror that reflects light of a fifth wavelength, a fourth wavelength of light, and a third wavelength of light. a second mirror that transmits the light of the second wavelength and reflects the light of the second wavelength and the first wavelength toward the condenser lens; , a third mirror that transmits light of a third wavelength and reflects light of a fourth wavelength toward the first mirror; a fourth mirror that transmits light of the second wavelength and reflects light of the first wavelength toward the second mirror; It is desirable to include a fifth mirror that reflects light of the same wavelength toward the fourth mirror.

As described above, according to the present invention, it is possible to use a common (same shape) optical element for each LED, and for each LED and optical element (collimator lens, condensing lens, etc.), A light source device is realized in which the beam diameter and beam position on the irradiation surface are less likely to fluctuate even when positional deviation occurs due to disturbances or environmental changes.

FIG. 1 is a diagram showing the configuration of a light source device according to a first embodiment of the present invention. 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. 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. 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. 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. FIG. 6 is a ray diagram of violet light emitted from the LED of the light source device according to the first embodiment of the present invention. FIG. 7 is a diagram showing the configuration of a light source device according to a modification of the first embodiment of the present invention. FIG. 8 is a diagram showing the configuration of a light source device according to a modification of the first embodiment of the present invention. FIG. 9 is a diagram showing the configuration of a light source device according to the second embodiment of the present invention. FIG. 10 is a diagram showing the configuration of a light source device according to a third embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that the same or corresponding parts in the figures are denoted by the same reference numerals, and the description thereof will not be repeated.

(First embodiment)
FIG. 1 is a diagram showing the configuration of a light source device 100 according to a 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, and supplies illumination light to the optical fiber F in order to illuminate an object inside the subject. It is a device. In the following description, the optical axis direction of the optical fiber F is defined as the X-axis direction, and the direction perpendicular to the X-axis is defined as the Y-axis direction.

As shown in FIG. 1, the light source device 100 includes a plurality of (five) LEDs 111 (first LED), 112 (second LED), 113 (third LED), 114 (fourth LED), 115 (fifth LED), and a plurality of (5) collimating lenses 121, 122, 123, 124, 125, multiple (5) dichroic mirrors 131, 132, 133, 134, 135 (synthesizing optical element), coupling lens 141 (condensing lens ).

The LEDs 111, 112, 113, 114, and 115 are LED (Light Emitting Diode) elements having different center wavelengths, and each of the LEDs 111, 112, 113, 114, and 115 is mounted on a substrate (not shown) and positioned at a predetermined position. The drive current is supplied through the substrate. When a drive current is supplied to each LED 111, 112, 113, 114, 115, each LED 111, 112, 113, 114, 115 emits light in an amount corresponding to the drive current. In this embodiment, the LED 111 has a chip size of 2.5 mm x 2.5 mm and emits purple light V with a wavelength of 400 nm (hereinafter referred to as "V light"), and the LED 112 emits purple light V with a wavelength of 500 nm. The chip size for emitting blue light B (hereinafter referred to as "B light") is 2.8 mm x 1.7 mm, and the LED 113 emits green light G (hereinafter referred to as "G light") with a wavelength of 550 nm. ), and the LED 114 emits amber light A with a wavelength of 600 nm (hereinafter referred to as "light A"). Chip size: 2.8 mm x 1. The LED 115 has a chip size of 2.1 mm x 1.3 mm and emits red light R (hereinafter referred to as "R light") with a wavelength of 650 nm (Figures 2 to 5). . As described above, in this embodiment, the chip size of the LED 111, the chip size of the LED 115, and the chip size of the LEDs 112, 113, and 114 are different depending on the required light intensity, wavelength, specifications of each LED, etc. It has become.

Further, in this embodiment, the LED 113 is arranged so that the optical axis of the LED 113 substantially coincides with the optical axis of the optical fiber F and the coupling lens 141 (that is, on the extension line of the optical axis of the optical fiber F, and The LED 115 is spaced a predetermined distance from the LED 113 in the Y-axis direction so that the optical axis of the LED 115 is approximately parallel to the optical axis of the LED 113. It is arranged at the second position L2.
Furthermore, the LEDs 114, 112, and 111 are located at positions spaced apart from the LED 115 by a predetermined distance in the Y-axis direction between the coupling lens 141 and the LEDs 113 and 115, so that their respective optical axes are orthogonal to the optical axes of the LEDs 113 and 115. , are sequentially arranged at predetermined intervals along the X-axis direction. More specifically, in order from the LEDs 113 and 115 toward the coupling lens 141, the LED 114 is placed at the third position L3, the LED 112 is placed at the fourth position L4, and the LED 111 is placed at the fifth position L5. has been done.

The collimating lenses 121, 122, 123, 124, and 125 are arranged in the optical path of each LED 111, 112, 113, 114, and 115, respectively, and are used to collect V light, B light, and G light from each LED 111, 112, 113, 114, and 115. This is an optical element that shapes each of the light, A light, and R light into substantially parallel light. Each of the collimating lenses 121, 122, 123, 124, and 125 of this embodiment is a circular plano-convex lens having the same shape (that is, the same), and the V light, B light, G light, A light, and R light are The distance from each LED 111, 112, 113, 114, and 115 is set so that the light is focused on the coupling lens 141 side of the incident end surface (irradiation surface) of the fiber F and enters the optical fiber F at approximately the same ray angle. They are adjusted and placed in each optical path. In addition, in this embodiment, since the collimating lenses 121, 122, 123, 124, and 125 are the same lens, each collimating lens 121, 122, 123, 124, and 125 is used as a representative in this specification and the drawings. The collimating lens 120 may also be referred to as the "collimating lens 120."

Dichroic mirrors 131, 132, 133, 134, and 135 are rectangular thin plate-shaped optical elements for synthesizing V light, B light, G light, A light, and R light from each LED 111, 112, 113, 114, and 115. It is.
2 to 6 are ray diagrams of the light emitted from each of the LEDs 111, 112, 113, 114, and 115 of the light source device 100 of this embodiment, and FIG. 2(a) shows the G light emitted from the LED 113. FIG. 3(a) is a ray diagram of R light emitted from the LED 115, FIG. 4(a) is a ray diagram of A light emitted from the LED 114, and FIG. ) is a ray diagram of B light emitted from the LED 112, and FIG. 6(a) is a ray diagram of V light emitted from the LED 111. Further, FIG. 2(b) is an enlarged view of section AA in FIG. 2(a), FIG. 3(b) is an enlarged view of section BB in FIG. 3(a), and FIG. 4(b) is an enlarged view of section BB in FIG. , FIG. 5(b) is an enlarged view of the CC section in FIG. 4(a), FIG. 5(b) is an enlarged view of the DD section in FIG. 5(a), and FIG. 6(b) is an enlarged view of the EE section in FIG. FIG.

As shown in FIGS. 1 to 4, the dichroic mirror 131 is arranged at the intersection of the optical axis of the LED 113 and the optical axis of the LED 114 at an angle of 45 degrees, and transmits the G light from the LED 113 and the A light from the LED 114. It is configured to reflect the R light from the LED 115 toward the coupling lens 141 and the optical fiber F. That is, in the dichroic mirror 131 of this embodiment, the transmission band wavelength is set to 575 nm or less, so that the G light, A light, and R light are combined on the optical axis of the coupling lens 141 and the optical fiber F. It looks like this.

As shown in FIGS. 1 to 6, the dichroic mirror 132 is arranged at the intersection of the optical axis of the LED 113 and the optical axis of the LED 112 at an angle of 45 degrees, and the dichroic mirror 132 is arranged at an angle of 45 degrees at the intersection of the optical axis of the LED 113 and the optical axis of the LED 112. It is configured to transmit R light and reflect B light from LED 112 and V light from LED 111 toward coupling lens 141 and optical fiber F. In other words, the dichroic mirror 132 of this embodiment has a transmission band wavelength set to 525 nm or more, so that the G light, A light, R light, B light, and V light are transmitted through the coupling lens 141 and the optical fiber F. It is designed to be composited on the axis.

As shown in FIGS. 1, 3, and 4, the dichroic mirror 133 is arranged at the intersection of the optical axis of the LED 115 and the optical axis of the LED 114 at an angle of 45 degrees, and transmits the A light from the LED 114, and also transmits the A light from the LED 115. is configured to reflect the R light toward the dichroic mirror 131. That is, the dichroic mirror 133 of this embodiment has a transmission band wavelength set to 625 nm or less, so that the A light and the R light are combined on the optical axis of the LED 114.

As shown in FIG. 1, FIG. 5, and FIG. 6, the dichroic mirror 134 is arranged at the intersection of the optical axis of the LED 115 and the optical axis of the LED 112 at an angle of 45 degrees, and transmits the B light from the LED 112 and transmits the B light from the LED 111. is configured to reflect the V light toward the dichroic mirror 132. That is, the dichroic mirror 134 of this embodiment has a transmission band wavelength set to 450 nm or more, so that the B light and the V light are combined on the optical axis of the LED 112.

As shown in FIGS. 1, 5, and 6, the dichroic mirror 135 is arranged at the intersection of the optical axis of the LED 115 and the optical axis of the LED 111 at an angle of 45 degrees, and directs the V light from the LED 111 toward the dichroic mirror 134. Designed to be reflective. That is, the dichroic mirror 135 of this embodiment has a transmission band wavelength set to 350 nm or less. Note that the dichroic mirror 135 may be anything that can reflect V light, and may be replaced by a general reflecting mirror.

As described above, the V light, B light, G light, A light, and R light from each LED 111, 112, 113, 114, and 115 are transmitted through the coupling lens 141 and the dichroic mirrors 131, 132, 133, 134, and 135. They are combined on the optical axis of optical fiber F. Then, the V light, B light, G light, A light, and R light emitted from the dichroic mirror 132 respectively enter the coupling lens 141 disposed between the dichroic mirror 132 and the optical fiber F (FIG. ~Figure 6).

The coupling lens 141 collects the V light, B light, G light, A light, and R light emitted from the dichroic mirror 132, and connects the optical fiber F at a predetermined distance (work distance WD) from the coupling lens 141. This is an optical element that makes the light incident on (couples with) the incident end surface (that is, the irradiation surface) (FIG. 1). The coupling lens 141 of this embodiment is a circular convex-planar lens (that is, a condensing lens), and as shown in FIGS. 2(b) to 6(b), The A light and the R light are each condensed closer to the coupling lens 141 than the incident end face of the optical fiber F, and are made to enter the optical fiber F at substantially the same beam angle.

As shown in FIG. 2(b), the G light that has passed through the coupling lens 141 is focused at a focusing position P1 in front of the incident end surface of the optical fiber F, and is The light enters at an incident angle θ1 (θ1 is the maximum angle between the optical axis of the coupling lens 141 and the optical fiber F and the ray of the G light): 44°, and a beam diameter: about 4 mm. In this embodiment, the optical path length of the G light (that is, the optical path length from the LED 113 to the input end face of the optical fiber F) is set to 165 mm.

As shown in FIG. 3(b), the R light that has passed through the coupling lens 141 is focused at a focusing position P2 in front of the incident end surface of the optical fiber F, and is The light enters at an incident angle θ2 (θ2 is the maximum angle between the optical axis of the coupling lens 141 and the optical fiber F and the R light beam): 45°, and a beam diameter: about 4 mm. In this embodiment, the optical path length of the R light (that is, the optical path length from the LED 115 to the input end face of the optical fiber F) is set to 198 mm.

As shown in FIG. 4(b), the light A that has passed through the coupling lens 141 is focused at a focusing position P3 in front of the incident end surface of the optical fiber F, and is The light enters at an incident angle θ3 (θ3 is the maximum angle between the optical axis of the coupling lens 141 and the optical fiber F and the ray of the A light): 45°, and a beam diameter: about 4 mm. In this embodiment, the optical path length of the A light (that is, the optical path length from the LED 114 to the input end face of the optical fiber F) is set to 198 mm.

As shown in FIG. 5(b), the B light that has passed through the coupling lens 141 is focused at a focusing position P4 in front of the incident end surface of the optical fiber F, and is The light enters at an incident angle θ4 (θ4 is the maximum angle between the optical axis of the coupling lens 141 and the optical fiber F and the B light beam): 44°, and a beam diameter: about 4 mm. In this embodiment, the optical path length of the B light (that is, the optical path length from the LED 112 to the input end face of the optical fiber F) is set to 165 mm.

As shown in FIG. 6(b), the V light that has passed through the coupling lens 141 is focused at a focusing position P5 in front of the incident end surface of the optical fiber F, and is The light enters at an incident angle θ5 (θ5 is the maximum angle between the optical axis of the coupling lens 141 and the optical fiber F and the ray of the V light): 45°, and a beam diameter: about 4 mm. In this embodiment, the optical path length of the V light (that is, the optical path length from the LED 111 to the input end face of the optical fiber F) is set to 198 mm.

In this way, the V light, B light, G light, A light, and R light that have passed through the coupling lens 141 are focused by the coupling lens 141 at positions P5, P4, P1, P3, and P2, respectively, and are approximately The beams are configured to be incident on the incident end face of the optical fiber F at the same maximum incident angles θ5, θ4, θ1, θ3, θ2 (that is, 45° or 44°) and beam diameter (approximately 4 mm). That is, in this embodiment, the defocused V light, B light, G light, A light, and R light are made to enter the incident end face of the optical fiber F so that the beam diameters are approximately equal. .
Therefore, according to the configuration of this embodiment, even if a positional shift 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 The beam diameters and beam positions of the V light, B light, G light, A light, and R light incident on the input end face of the optical fiber F do not change significantly, and the V light, B light, and G light due to positional deviation do not change significantly. Since the sensitivities of the light, A light, and R light are approximately equal, the amounts of the V light, B light, G light, A light, and R light incident on the input end face of the optical fiber F do not vary greatly.
The maximum incident angles θ1 to θ5 are appropriately set depending on the diameter of the optical fiber F, but are preferably 60° or less, more preferably 45° or less.

Furthermore, as described above, in this embodiment, the LED 113 having the third longest emission wavelength among the five emission wavelengths (400 nm, 500 nm, 550 nm, 600 nm, 650 nm) is arranged at the first position L1, and the LED 113 By arranging the LEDs 115 and 114, which have longer emission wavelengths than the LEDs 115 and 114, at the second position L2 and the third position L3, the optical path lengths of the V light, A light, and R light are set to 198 mm, and the emission wavelengths are longer than those of the LED 113. By arranging the short LEDs 112 and 111 at the fourth position L4 and the fifth position L5, each optical path length of B light and G light is set to 165 mm, and the minimum optical path length (165 mm) is set to 165 mm for the maximum optical path length (198 mm). ) is approximately 83% (that is, each optical path length is approximately equal).
Therefore, according to the configuration of this embodiment, since each optical path length is approximately equal, a common collimating lens 120 (of the same shape) is used for each of V light, B light, G light, A light, and R light. can be used.
Note that in order to use a common collimating lens 120 (having the same shape), it is preferable to arrange the layout so that the minimum optical path length is 80% or more with respect to the maximum optical path length.

Although the present embodiment has been described above, the present invention is not limited to the above configuration, and various modifications can be made within the scope of the technical idea of the present invention.

For example, although the present embodiment includes dichroic mirrors 131, 132, 133, 134, and 135, dichroic prisms may be used instead of the dichroic mirrors 131, 132, 133, 134, and 135.

Furthermore, in this embodiment, five LEDs 111, 112, 113, 114, and 115 with different center wavelengths are used, but the optical path length from each LED to the optical fiber F is approximately equal (i.e., The layout may be such that the minimum optical path length is 80% or more with respect to the maximum optical path length), and the number of LEDs is not limited to five (that is, it may be configured with six or more LEDs, (It may be configured with four or fewer LEDs).

Further, in this embodiment, the chip size of the LED 111, the chip size of the LED 115, and the chip size of the LEDs 112, 113, and 114 are different from each other, but the configuration is not necessarily limited to this. The chip size of each LED 111, 112, 113, 114, 115 may be the same.

Furthermore, although the light source device 100 of this embodiment is a device that is incorporated into an endoscope device or the like having an optical fiber F, the use is not necessarily limited to such a purpose, and the light source device 100 is a device that emits focused light onto an irradiation surface. It can also be applied to equipment that irradiates (for example, semiconductor exposure equipment, etc.).

(First modification)
FIG. 7 is a diagram showing the configuration of a light source device 100A according to a first modification of the present embodiment. The light source device 100A of this modification has the following points: the LED 114 is arranged at the second position L2, the LED 115 is arranged at the third position L3, and the transmission band wavelength of the dichroic mirror 133A is set to 625 nm or more. , is different from the light source device 100 of the first embodiment.
In this way, the arrangement of the LED 114 and the LED 115 may be interchanged.

(Second modification)
FIG. 8 is a diagram showing the configuration of a light source device 100B according to a second modified example of the present embodiment. The light source device 100B of this modification has the following points: the LED 111 is arranged at the fourth position L4, the LED 112 is arranged at the fifth position L5, and the transmission band wavelength of the dichroic mirror 134B is set to 450 nm or less. , is different from the light source device 100 of the first embodiment.
In this way, the arrangement of the LED 111 and the LED 112 may be interchanged.

(Second embodiment)
FIG. 9 is a diagram showing the configuration of a light source device 200 according to the second embodiment of the present invention. In the light source device 200 of this embodiment, the LEDs 111, 112, 113, 114, and 115 are located at the first position L1, the second position L2, the third position L3, the fourth position L4, and the fifth position, respectively. The light source device 100 of the first embodiment is different from the light source device 100 of the first embodiment in that dichroic mirrors 231, 232, 233, 234, and 235 are used in place of the dichroic mirrors 131, 132, 133, 134, and 135, which are arranged at L5.

The dichroic mirror 231 is arranged at the intersection of the optical axis of the LED 111 and the optical axis of the LED 113 at an angle of 45 degrees, and transmits the V light from the LED 111 and transmits the B light from the LED 112 and the G light from the LED 113 to the optical fiber F. It is configured to reflect towards. That is, in the dichroic mirror 231 of this embodiment, the transmission band wavelength is set to 450 nm or less, so that the V light, B light, and G light are combined on the optical axis of the optical fiber F. .

The dichroic mirror 232 is arranged at the intersection of the optical axis of the LED 111 and the optical axis of the LED 114 at an angle of 45 degrees, and transmits the V light from the LED 111, the B light from the LED 112, and the G light from the LED 113, and transmits the light from the LED 114. It is configured to reflect the A light and the R light from the LED 115 toward the optical fiber F. In other words, the dichroic mirror 132 of this embodiment has a transmission band wavelength set to 575 nm or less, so that the V light, B light, G light, A light, and R light are combined on the optical axis of the optical fiber F. It has become so.

The dichroic mirror 233 is arranged at an angle of 45 degrees at the intersection of the optical axis of the LED 112 and the optical axis of the LED 113, and is configured to transmit the G light from the LED 113 and reflect the B light from the LED 112 toward the dichroic mirror 231. It is composed of That is, the dichroic mirror 233 of this embodiment has a transmission band wavelength set to 525 nm or more, so that the G light and the B light are combined on the optical axis of the LED 113.

The dichroic mirror 234 is arranged at an angle of 45 degrees at the intersection of the optical axis of the LED 112 and the optical axis of the LED 114, and is configured to transmit the A light from the LED 114 and reflect the R light from the LED 115 toward the dichroic mirror 232. It is composed of That is, the dichroic mirror 234 of this embodiment has a transmission band wavelength set to 625 nm or less, so that the A light and the R light are combined on the optical axis of the LED 114.

The dichroic mirror 235 is arranged at the intersection of the optical axis of the LED 112 and the optical axis of the LED 115 at an angle of 45 degrees, and is configured to reflect the R light from the LED 115 toward the dichroic mirror 234. That is, the dichroic mirror 235 of this embodiment has a transmission band wavelength set to 600 nm or less. Note that the dichroic mirror 235 may be anything that can reflect R light, and may be replaced with a general reflecting mirror.

In this way, in this embodiment, each of the LEDs 111, 112, 113, 114, and 115 is placed in the first position L1, second position L2, third position L3, and fourth position in order of shortest emission wavelength. L4 and the fifth position L5, the optical path lengths of V, B, and G lights are set to 198 mm, and the optical path lengths of A and R lights are set to 165 mm, and the maximum optical path length ( The layout is such that the minimum optical path length (165 mm) is approximately 83% of the optical path length (198 mm) (that is, each optical path length is approximately equal).
Therefore, with the configuration of this embodiment, each optical path length is approximately equal, so a common collimating lens 120 (of the same shape) is used for each of the V light, B light, G light, A light, and R light. can be used.

(Third embodiment)
FIG. 10 is a diagram showing the configuration of a light source device 300 according to the third embodiment of the present invention. In the light source device 300 of this embodiment, the LEDs 111, 112, 113, 114, and 115 are located at the fifth position L5, the fourth position L4, the third position L3, the second position L2, and the first position, respectively. This embodiment differs from the light source device 100 of the first embodiment in that dichroic mirrors 331, 332, 333, 334, and 335 are used in place of dichroic mirrors 131, 132, 133, 134, and 135, which are arranged at L1.

The dichroic mirror 331 is arranged at the intersection of the optical axis of the LED 115 and the optical axis of the LED 113 at an angle of 45 degrees, and transmits the R light from the LED 115, and transmits the A light from the LED 114 and the G light from the LED 113 to the optical fiber F. It is configured to reflect towards. That is, in the dichroic mirror 331 of this embodiment, the transmission band wavelength is set to 625 nm or more, so that the R light, A light, and G light are combined on the optical axis of the optical fiber F. .

The dichroic mirror 332 is arranged at the intersection of the optical axis of the LED 115 and the optical axis of the LED 112 at an angle of 45 degrees, and transmits the R light from the LED 115, the A light from the LED 114, and the G light from the LED 113, and transmits the light from the LED 112. It is configured to reflect the B light and the V light from the LED 111 toward the optical fiber F. In other words, the dichroic mirror 332 of this embodiment has a transmission band wavelength set to 525 nm or more, so that the V light, B light, G light, A light, and R light are combined on the optical axis of the optical fiber F. It has become so.

The dichroic mirror 333 is arranged at an angle of 45 degrees at the intersection of the optical axis of the LED 114 and the optical axis of the LED 113, and is configured to transmit the G light from the LED 113 and reflect the A light from the LED 114 toward the dichroic mirror 331. It is composed of That is, in the dichroic mirror 333 of this embodiment, the transmission band wavelength is set to 575 nm or less, so that the G light and the A light are combined on the optical axis of the LED 113.

The dichroic mirror 334 is arranged at an angle of 45 degrees at the intersection of the optical axis of the LED 114 and the optical axis of the LED 112, and is configured to transmit the B light from the LED 112 and reflect the V light from the LED 111 toward the dichroic mirror 332. It is composed of That is, the dichroic mirror 334 of this embodiment has a transmission band wavelength set to 450 nm or more, so that the B light and the V light are combined on the optical axis of the LED 112.

The dichroic mirror 335 is arranged at the intersection of the optical axis of the LED 114 and the optical axis of the LED 111 at an angle of 45 degrees, and is configured to reflect the V light from the LED 111 toward the dichroic mirror 334. That is, the dichroic mirror 335 of this embodiment has a transmission band wavelength set to 450 or more. Note that the dichroic mirror 335 may be anything that can reflect V light, and may be replaced with a general reflecting mirror.

In this way, in this embodiment, each of the LEDs 111, 112, 113, 114, and 115 is placed in the first position L1, the second position L2, the third position L3, and the fourth position in order of the longest emission wavelength. L4 and the fifth position L5, the optical path lengths of R, A, and G lights are set to 198 mm, and the optical path lengths of B and V lights are set to 165 mm, and the maximum optical path length ( The layout is such that the minimum optical path length (165 mm) is approximately 83% of the optical path length (198 mm) (that is, each optical path length is approximately equal).
Therefore, with the configuration of this embodiment, each optical path length is approximately equal, so a common collimating lens 120 (of the same shape) is used for each of the V light, B light, G light, A light, and R light. can be used.

It should be noted that the embodiments disclosed herein are illustrative in all respects and should not be considered restrictive. The scope of the present invention is indicated by the claims rather than the above description, and it is intended that all changes within the meaning and range equivalent to the claims are included.

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 (14)

A light source device that emits light toward a predetermined irradiation surface,
Multiple light sources with different center wavelengths,
collimating lenses each having the same shape and arranged in the optical path of each of the light sources and shaping the light from each of the light sources into substantially parallel light;
a combining optical element that combines the light emitted from each of the collimating lenses;
a condensing lens that condenses the light emitted from the synthetic optical element;
Equipped with
The minimum optical path length from each of the light sources to the irradiation surface is 80% or more,
A light source device characterized in that the light from each of the light sources is condensed closer to the condenser lens than the irradiation surface and is incident on the irradiation surface at substantially the same ray angle. The light source device according to claim 1, wherein the angle of the light beam incident on the irradiation surface is 60 degrees or less with respect to the optical axis of the condenser lens. The plurality of light sources include a first LED that emits light with a first wavelength, a second LED that emits light with a second wavelength longer than the first wavelength, and a third LED that emits light with a second wavelength longer than the second wavelength. a third LED that emits light, a fourth LED that emits light of a fourth wavelength longer than the third wavelength, and a fifth LED that emits light of a fifth wavelength longer than the fourth wavelength. The light source device according to claim 1 or 2, characterized in that: The light source device according to claim 3, wherein at least one of the chip sizes of the first LED, the second LED, the third LED, the fourth LED, and the fifth LED is different from the other chip sizes. When a direction parallel to the optical axis of the condensing lens is defined as a first direction, and a direction orthogonal to the first direction is defined as a second direction,
The third LED is arranged at a position spaced apart from the condenser lens such that the optical axis of the third LED substantially coincides with the optical axis of the condenser lens,
The fifth LED is arranged at a position spaced apart from the third LED in the second direction so that the optical axis of the fifth LED is substantially parallel to the optical axis of the third LED,
The fourth, second, and first LEDs are arranged along the first direction at positions spaced apart from the fifth LED in the second direction so that their respective optical axes are perpendicular to the optical axes of the third and fifth LEDs. 5. The light source device according to claim 3, wherein the light source device is arranged in order in a direction approaching the condenser lens. The synthetic optical element is
The LED is disposed at the intersection of the optical axis of the third LED and the optical axis of the fourth LED, transmits the light of the third wavelength, and condenses the light of the fourth wavelength and the fifth wavelength. a first mirror that reflects toward the lens;
The second LED is disposed at the intersection of the optical axis of the third LED and the optical axis of the second LED, and transmits the third wavelength light, the fourth wavelength light, and the fifth wavelength light. a second mirror that reflects the light with a wavelength of and the light with the first wavelength toward the condenser lens;
A third LED disposed at the intersection of the optical axis of the fifth LED and the optical axis of the fourth LED, transmitting the light of the fourth wavelength and reflecting the light of the fifth wavelength toward the first mirror. mirror and
A fourth mirror disposed at the intersection of the optical axis of the fifth LED and the optical axis of the second LED, transmitting the light of the second wavelength and reflecting the light of the first wavelength toward the second mirror. mirror and
a fifth mirror that is disposed at the intersection of the optical axis of the fifth LED and the optical axis of the first LED and reflects the light of the first wavelength toward the fourth mirror;
The light source device according to claim 5, comprising: When a direction parallel to the optical axis of the condensing lens is defined as a first direction, and a direction orthogonal to the first direction is defined as a second direction,
The third LED is arranged at a position spaced apart from the condenser lens such that the optical axis of the third LED substantially coincides with the optical axis of the condenser lens,
The fourth LED is arranged at a position spaced apart from the third LED in the second direction so that the optical axis of the fourth LED is substantially parallel to the optical axis of the third LED,
The fifth, second, and first LEDs are arranged along the first direction at positions spaced apart from the fourth LED in the second direction so that their respective optical axes are perpendicular to the optical axes of the third and fourth LEDs. 5. The light source device according to claim 3, wherein the light source device is arranged in order in a direction approaching the condenser lens. The synthetic optical element is
The LED is disposed at the intersection of the optical axis of the third LED and the optical axis of the fifth LED, transmits the light of the third wavelength, and condenses the light of the fifth wavelength and the fourth wavelength. a first mirror that reflects toward the lens;
The second LED is disposed at the intersection of the optical axis of the third LED and the optical axis of the second LED, and transmits the third wavelength light, the fourth wavelength light, and the fifth wavelength light. a second mirror that reflects the light with a wavelength of and the light with the first wavelength toward the condenser lens;
A third LED disposed at the intersection of the optical axis of the fourth LED and the optical axis of the fifth LED, transmitting the light of the fifth wavelength and reflecting the light of the fourth wavelength toward the first mirror. mirror and
A fourth LED disposed at the intersection of the optical axis of the fourth LED and the optical axis of the second LED, transmitting the light of the second wavelength and reflecting the light of the first wavelength toward the second mirror. mirror and
a fifth mirror that is disposed at the intersection of the optical axis of the fifth LED and the optical axis of the first LED and reflects the light of the first wavelength toward the fourth mirror;
The light source device according to claim 7, comprising: When a direction parallel to the optical axis of the condensing lens is defined as a first direction, and a direction orthogonal to the first direction is defined as a second direction,
The third LED is arranged at a position spaced apart from the condenser lens such that the optical axis of the third LED substantially coincides with the optical axis of the condenser lens,
The fifth LED is arranged at a position spaced apart from the third LED in the second direction so that the optical axis of the fifth LED is substantially parallel to the optical axis of the third LED,
The fourth, first, and second LEDs are arranged along the first direction at positions spaced apart from the fifth LED in the second direction so that their respective optical axes are perpendicular to the optical axes of the third and fifth LEDs. 5. The light source device according to claim 3, wherein the light source device is arranged in order in a direction approaching the condenser lens. The synthetic optical element is
The LED is disposed at the intersection of the optical axis of the third LED and the optical axis of the fourth LED, transmits the light of the third wavelength, and condenses the light of the fourth wavelength and the fifth wavelength. a first mirror that reflects toward the lens;
The second LED is disposed at the intersection of the optical axis of the third LED and the optical axis of the second LED, and transmits the third wavelength light, the fourth wavelength light, and the fifth wavelength light. a second mirror that reflects the light with a wavelength of and the light with the first wavelength toward the condenser lens;
A third LED disposed at the intersection of the optical axis of the fifth LED and the optical axis of the fourth LED, transmitting the light of the fourth wavelength and reflecting the light of the fifth wavelength toward the first mirror. mirror and
a fourth LED disposed at the intersection of the optical axis of the fifth LED and the optical axis of the first LED, transmitting the light of the first wavelength and reflecting the light of the second wavelength toward the second mirror; mirror and
a fifth mirror that is disposed at the intersection of the optical axis of the fifth LED and the optical axis of the second LED and reflects the light of the second wavelength toward the fourth mirror;
The light source device according to claim 9, comprising: When a direction parallel to the optical axis of the condensing lens is defined as a first direction, and a direction orthogonal to the first direction is defined as a second direction,
The first LED is arranged at a position spaced apart from the condenser lens such that the optical axis of the first LED substantially coincides with the optical axis of the condenser lens,
The second LED is arranged at a position spaced apart from the first LED in the second direction so that the optical axis of the second LED is substantially parallel to the optical axis of the first LED,
The third, fourth, and fifth LEDs are arranged along the first direction at positions spaced apart 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. 5. The light source device according to claim 3, wherein the light source device is arranged in order in a direction approaching the condenser lens. The synthetic optical element is
The LED is disposed at the intersection of the optical axis of the first LED and the optical axis of the third LED, and transmits the light of the first wavelength, and condenses the light of the second wavelength and the third wavelength. a first mirror that reflects toward the lens;
The fourth LED is disposed at the intersection of the optical axis of the first LED and the optical axis of the fourth LED, and transmits the first wavelength light, the second wavelength light, and the third wavelength light. a second mirror that reflects the light with a wavelength of and the light with the fifth wavelength toward the condenser lens;
A third LED disposed at the intersection of the optical axis of the second LED and the optical axis of the third LED, transmitting the light of the third wavelength and reflecting the light of the second wavelength toward the first mirror. mirror and
A fourth LED disposed at the intersection of the optical axis of the second LED and the optical axis of the fourth LED, transmitting the light of the fourth wavelength and reflecting the light of the fifth wavelength toward the second mirror. mirror and
a fifth mirror that is disposed at the intersection of the optical axis of the second LED and the optical axis of the fifth LED and reflects the light of the fifth wavelength toward the fourth mirror;
The light source device according to claim 11, comprising: When a direction parallel to the optical axis of the condensing lens is defined as a first direction, and a direction orthogonal to the first direction is defined as a second direction,
The fifth LED is arranged at a position spaced apart from the incident end surface of the condenser lens such that the optical axis of the fifth LED substantially coincides with the optical axis of the condenser lens,
The fourth LED is arranged at a position spaced apart from the fifth LED in the second direction so that the optical axis of the fourth LED is substantially parallel to the optical axis of the fifth LED,
The third, second, and first LEDs are arranged along the first direction at positions spaced apart 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. 5. The light source device according to claim 3, wherein the light source device is arranged in order in a direction approaching the condenser lens. The synthetic optical element is
It is arranged at the intersection of the optical axis of the fifth LED and the optical axis of the third LED, transmits the light of the fifth wavelength, and focuses the light of the fourth wavelength and the third wavelength. a first mirror that reflects toward the lens;
The second LED is disposed at the intersection of the optical axis of the fifth LED and the optical axis of the second LED, transmits the fifth wavelength light, the fourth wavelength light, and the third wavelength light, and transmits the fifth wavelength light, the fourth wavelength light, and the third wavelength light. a second mirror that reflects the light with a wavelength of and the light with the first wavelength toward the condenser lens;
A third LED disposed at the intersection of the optical axis of the fourth LED and the optical axis of the third LED, transmitting the light of the third wavelength and reflecting the light of the fourth wavelength toward the first mirror. mirror and
A fourth LED disposed at the intersection of the optical axis of the fourth LED and the optical axis of the second LED, transmitting the light of the second wavelength and reflecting the light of the first wavelength toward the second mirror. mirror and
a fifth mirror that is disposed at the intersection of the optical axis of the fourth LED and the optical axis of the first LED and reflects the light of the first wavelength toward the fourth mirror;
14. The light source device according to claim 13, comprising:

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