WO2016072360A1 - Multi-wavelength light source and light source device - Google Patents

Abstract

The purpose of the preset invention is to achieve high arrival efficiency for excitation light traveling from a light-emitting element to a fluorescent body and high outcoupling efficiency for light emitted externally from the fluorescent body. A multi-wavelength light source comprises: an integrated light source wherein multiple element light sources each including a light-emitting element and a collimator element are integrated side by side; a dichroic reflective element wherein regions that selectively reflect the light with the same emission wavelength as the light-emitting element are selectively provided at the points where light beams emitted from the integrated light source impinge; a condensing element for condensing a light beam; and a fluorescent body for absorbing the light with the same emission wavelength as the light-emitting element as the excitation light and emitting fluorescent light in another wavelength bandwidth. The condensing element converts a diverging light beam mixed with the fluorescent light emitted from a condensing region on the surface of the fluorescent body and the residual excitation light reflected from the condensing region into a light beam that is propagated in the direction opposite the direction of a focused light beam to form a distant image. The converted light beam passes through the dichroic reflective element and is thereby output externally as a mixed output light beam.

Description

Multi-wavelength light source and light source device

The present invention relates to a multiwavelength light source using a light emitting element such as a semiconductor laser, such as a white light source usable in an optical apparatus such as a projector, and a light source device including the multiwavelength light source.

For example, high-intensity discharge lamps (HID lamps) such as xenon lamps and ultra-high pressure mercury lamps have been used in light source devices for image display such as DLP (TM) projectors and liquid crystal projectors, and photomask exposure apparatuses. It has been.
As an example, the principle of the projector will be described with reference to FIG. 11, which is a diagram for explaining one form of a part of a conventional light source device related to the light source device of the present invention (reference: Japanese Patent Application Laid-Open No. 2004-252112, etc.) ).

As described above, light from the light source (SjA) composed of a high-intensity discharge lamp or the like is obtained with the help of a light condensing means (not shown) composed of a concave reflecting mirror, a lens, or the like. FmA) is input to the incident end (PmiA) and output from the exit end (PmoA).
Here, as the light homogenizing means (FmA), for example, a light guide can be used, which is also called a name such as a rod integrator or a light tunnel, and is a light transmissive material such as glass or resin. In accordance with the same principle as that of an optical fiber, the light homogenizing means (FmiA) repeats total reflection on the side surface of the light homogenizing means (FmA). By propagating through FmA), even if the distribution of light input to the incident end (PmiA) is uneven, the illuminance on the exit end (PmoA) is sufficiently uniformed. Function.

As for the light guide just described, in addition to the above-described prisms made of a light-transmitting material such as glass and resin, a hollow square tube, the inner surface of which is a reflecting mirror, Similarly, there are some which perform the same function by propagating light while repeating reflection on the inner surface.

The illumination lens (Ej1A) is arranged so that a square image of the emission end (PmoA) is formed on the two-dimensional light amplitude modulation element (DmjA), and is output from the emission end (PmoA). The two-dimensional light amplitude modulation element (DmjA) is illuminated with light. However, in FIG. 11, a mirror (MjA) is disposed between the illumination lens (Ej1A) and the two-dimensional light amplitude modulation element (DmjA).
The two-dimensional light amplitude modulation element (DmjA) modulates the light so that it is directed to the direction of incidence on the projection lens (Ej2A) or not to the direction of incidence according to the video signal. The image is displayed on the screen (Tj).

The two-dimensional light amplitude modulation element as described above is sometimes called a light valve. In the case of the optical system shown in FIG. 11, the two-dimensional light amplitude modulation element (DmjA) is generally DMD (TM) (digital).・ Micromirror devices are often used.

In addition to the above-described light guide, there is a light uniforming means called a fly eye integrator. As an example of a projector using this light uniformizing means, a conventional light source related to the light source device of the present invention is used. The principle of the apparatus will be described with reference to FIG. 12, which is a diagram for explaining one form of a part of the apparatus (reference: JP-A-2001-142141, etc.).

Light from a light source (SjB) composed of a high-intensity discharge lamp or the like is converted into a substantially collimated light beam with the help of collimator means (not shown) composed of a concave reflecting mirror, lens, etc. It is input to the incident end (PmiB) of the eye integrator (FmB) and output from the exit end (PmoB). Here, the fly eye integrator (FmB) is composed of a combination of a front stage fly-eye lens (F1B) on the incident side, a rear stage fly-eye lens (F2B) on the exit side, and an illumination lens (Ej1B).
Both the front fly-eye lens (F1B) and the rear fly-eye lens (F2B) are formed by arranging a large number of rectangular lenses having the same focal length and the same shape in the vertical and horizontal directions.

Each lens of the front-stage fly-eye lens (F1B) and the corresponding lens of the rear-stage fly-eye lens (F2B) in the subsequent stage constitute an optical system called Koehler illumination. A large number of optical systems are arranged vertically and horizontally.
In general, the Kohler illumination optical system is composed of two lenses. When the front lens collects light and illuminates the target surface, the front lens does not form a light source image on the target surface, but the center of the rear lens. A light source image is formed on this surface, and the rear lens is arranged so as to form an image of the quadrangle of the outer shape of the front lens on the target surface (surface to be illuminated), thereby uniformly illuminating the target surface.
The function of the latter lens is to prevent the phenomenon that the illuminance around the square of the target surface falls depending on the size when the light source is not a perfect point light source but has a finite size if it is not Thus, the rear lens can make the illuminance uniform to the periphery of the square of the target surface without depending on the size of the light source.

Here, in the case of the optical system of FIG. 12, the fly-eye integrator (FmB) is basically input with a substantially parallel light beam, so the front fly-eye lens (F1B) and the rear fly-eye lens (F2B). ) Are arranged to be equal to their focal lengths, so that an image of the target surface of uniform illumination as the Kohler illumination optical system is generated at infinity. However, since the illumination lens (Ej1B) is disposed at the rear stage of the rear fly-eye lens (F2B), the target surface is drawn toward the focal plane of the illumination lens (Ej1B) from infinity.
Since many Koehler illumination optical systems arranged in the vertical and horizontal directions are parallel to the incident optical axis (ZiB) and the light fluxes are input substantially axially symmetrically with respect to the respective central axes, the output light flux is also substantially axially symmetric. Because of the nature of the lens, that is, the Fourier transform action of the lens, all rays incident on the lens surface at the same angle are refracted toward the same point on the focal plane regardless of the incident position on the lens surface. The output of the Koehler illumination optical system is imaged on the same target surface on the focal plane of the illumination lens (Ej1B).

As a result, all the illuminance distributions on the respective lens surfaces of the preceding fly-eye lens (F1B) are superposed, so that the illuminance distribution becomes more uniform than in the case of a single Koehler illumination optical system. A square image is formed on the incident optical axis (ZiB).
By disposing a two-dimensional light amplitude modulation element (DmjB) at the position of the composite square image, the two-dimensional light amplitude modulation element (DmjB) that is an object to be illuminated by light output from the emission end (PmoB). Is illuminated. However, for illumination, a polarizing beam splitter (MjB) is disposed between the illumination lens (Ej1B) and the two-dimensional light amplitude modulation element (DmjB), so that light is transmitted to the two-dimensional light amplitude modulation element ( DmjB) is reflected.
The two-dimensional light amplitude modulation element (DmjB) rotates the polarization direction of light by 90 degrees for each pixel according to the video signal, or modulates and reflects the light so that only the rotated light is reflected. Then, the light passes through the polarizing beam splitter (MjB) and is incident on the projection lens (Ej3B) to display an image on the screen (Tj).

In the case of the optical system shown in FIG. 12, generally, LCOS (TM) (silicon liquid crystal device) is often used as the two-dimensional light amplitude modulation element (DmjB).
In the case of such a liquid crystal device, since only the light component in the specified polarization direction can be effectively modulated, normally the component parallel to the specified polarization direction is transmitted as it is, but only the component perpendicular to the specified polarization direction is polarized. A polarization alignment function element (PcB) for rotating the direction by 90 degrees and, as a result, enabling effective use of all light, is inserted, for example, in the rear stage of the rear fly-eye lens (F2B).
For example, a field lens (Ej2B) is inserted immediately before the two-dimensional light amplitude modulation element (DmjB) so that substantially parallel light is incident thereon.

As for the two-dimensional optical amplitude modulation element, in addition to the reflective type as shown in FIG. 12, a transmission type liquid crystal device (LCD) is also used with an optical arrangement suitable for the same (reference: No. 10-133303).

By the way, in a normal projector, in order to display an image in color, for example, a dynamic color filter such as a color wheel is disposed after the light uniformizing means, and R, G, B (red, green, blue) The two-dimensional light amplitude modulation element is illuminated as a color sequential light beam, and color display is realized by time division, or a dichroic mirror or dichroic prism is arranged at the subsequent stage of the light uniformizing means, and R, G, B To illuminate a two-dimensional light amplitude modulation element provided independently for each color with light separated into the three primary colors and arrange a dichroic mirror or dichroic prism to perform color synthesis of modulated light beams of the three primary colors R, G, and B Although not shown in FIGS. 11 and 12, it is omitted in order to avoid complexity.

However, the high-intensity discharge lamp described above has drawbacks such as low conversion efficiency from input power to optical power, that is, a large heat loss or a short life.
In recent years, solid light sources such as LEDs and semiconductor lasers have attracted attention as alternative light sources that have overcome these drawbacks.
Among them, the LED has a smaller heat loss and a longer life than the discharge lamp, but the emitted light has no directivity like the discharge lamp, so the light source device and the exposure device described above. In applications where only light in a specific direction can be used, there is a problem that the light use efficiency is low.

On the other hand, semiconductor lasers, like LEDs, have low heat loss, long life, and high directivity, so that only light in a specific direction such as the above-described light source device and exposure device can be used. In use, there is an advantage that the utilization efficiency of light is high.
However, there is a problem when trying to realize each of the three primary colors R, G, and B with a semiconductor laser.
For example, what is currently readily available as a red semiconductor laser has a wavelength band of 635 to 640 nm and requires a large optical power due to low visibility, and for example, as a green semiconductor laser, What is available has a wavelength band of 522 to 526 nm, and from the viewpoint of image reproduction, there is a problem that it is too short from an ideal wavelength.

Therefore, the wavelength band that directly uses the emitted light of the semiconductor laser is only blue, and red and green are obtained by converting the wavelength of the emitted light of the blue semiconductor laser using a phosphor that can easily adjust the emission wavelength by adjusting the components. Technology has been developed to achieve this.
For example, in Japanese Patent Application Laid-Open No. 2011-165555, light from a solid-state light source such as a semiconductor laser emitting blue light is condensed as one excitation light at one point of a rotating disk, and the rotating disk has a blue complementary color. A technology relating to a white light source that sequentially generates yellow and blue luminous fluxes by providing a segment provided with a yellow phosphor layer emitting yellow fluorescence and a segment provided with a blue scattering reflection layer is described.
However, in this technology, a simple polarization dichroic mirror is used as an output light separation and extraction element for directing excitation light from a solid light source to a rotating disk and extracting light from the rotating disk as output light. Therefore, the ratio of the amount of light that returns to the solid light source out of the blue light coming out of the rotating disk is high, and there is a problem that the light use efficiency is not good.

Further, for example, in Japanese Patent Application Laid-Open No. 2012-108486, light from a solid light source such as a semiconductor laser emitting blue light is condensed as one excitation light onto one point of the rotating disk. Are provided with a segment provided with a yellow phosphor layer emitting yellow fluorescence, which is a complementary color of blue, and a segment provided with a blue specular reflection layer, whereby yellow and blue light fluxes are sequentially generated. By inserting a quarter-wave plate for the excitation light between the output light separation / extraction element using a simple polarization dichroic mirror and the rotation disk, the blue light emitted from the rotation disk A technique for reducing the ratio of the amount of light returning to the solid light source and improving the light use efficiency is described.
However, in the case of this technique, the blue light coming out of the rotating disk is generated by specular reflection rather than scattering reflection, so the coherency of the excitation light from the semiconductor laser is high, and thus speckle noise is high. There's a problem.

Further, for example, in Japanese Patent Application Laid-Open No. 2012-119121, a plurality of concave reflecting mirrors (spheroid ellipsoids) provided with excitation light from a plurality of solid light sources by a semiconductor laser emitting blue light corresponding to each of the solid light sources. ) Describes a technology relating to a white light source with high luminance that uses scattered excitation light and fluorescence by focusing light on one point of the phosphor or a plurality of adjacent points.
However, in the case of this technique, the number of concave reflecting mirrors equal to the number of solid light sources needs to be arranged three-dimensionally symmetrically, and each solid light source needs to be accurately arranged at a predetermined position relative to each concave reflecting mirror. Therefore, there is a problem that the structure becomes complicated.
Further, the problem of how to improve the utilization efficiency of light emitted from the phosphor is not yet solved.

Also, for example, in Japanese Patent Laid-Open No. 2013-156657, excitation light from a plurality of solid-state light sources such as a semiconductor laser emitting blue light is collected by a lens so as to pass through a small entrance opening provided in a mirror box. The phosphor provided on the exit side in the mirror box is caused to emit light, and at the exit of the mirror box, a dichroic filter that reflects excitation light and returns to the mirror box and transmits fluorescence is provided. A technique is described in which the use efficiency of excitation light and fluorescence is enhanced by reflecting the fluorescence toward the exit side.
However, in this technology, the excitation light and fluorescence that reach the dichroic filter become scattered light, and the direction distribution of the light is large, so that the wavelength selectivity of reflection / transmission of the dichroic filter becomes very poor and efficiency is lowered. If the size of the specular box is not sufficiently large compared to the size of the excitation light entrance opening, the effect of providing the specular box does not appear. Since the area of the exit becomes large and the point light source property is lowered, there is a problem that it is difficult to obtain high light utilization efficiency.

Further, for example, in Japanese Patent Application Laid-Open No. 2014-082144, excitation light from a plurality of solid light sources such as a semiconductor laser emitting blue light is combined with one light beam as a whole by a collimator lens provided corresponding to each of the solid light sources. And a technology related to a high-brightness white light source that uses fluorescence emitted from the phosphor, or scattered excitation light and fluorescence, by condensing on a small area of the phosphor with a common concave reflecting mirror. ing.
However, in the case of this technique, the problem of how to increase the utilization efficiency of light emitted from the phosphor is not yet solved.

JP 2011-165555 A JP 2012-108486 A JP 2012-119121 A JP 2013-156657 A Japanese Patent Application Laid-Open No. 2014-082144

A problem to be solved by the present invention is to provide a multi-wavelength light source and a light source device that achieve high arrival efficiency of excitation light from a light emitting element to a phosphor and high extraction efficiency of light emitted from the phosphor to the outside. It is to provide.

The multi-wavelength light source according to the first aspect of the present invention converts the light emitting element (Y1) and the radiated light (Fa1) emitted from the light emitting element (Y1) into a light beam (Fbl) that forms a distant image. An integrated light source (W) in which a plurality of element light sources (U1, U2,...) Are arranged side by side as a single element light source (U1).
Each of the luminous fluxes (P1, P2,...) Having spectral characteristics that selectively reflects light having a radiation wavelength of the light emitting elements (Y1, Y2,...) Is output from the integrated light source (W). A dichroic reflection element (M) selectively provided at a position where Fb1, Fb2,.
A condensing element (Ef) for condensing the luminous flux (Fcl, Fc2,...) Generated by reflecting the luminous flux (Fbl, Fb2,...) By the dichroic reflecting element (M);
When the focused light beam (Fd) generated by condensing the light beam (Fcl, Fc2,...) By the light collecting element (Ef) forms the light collection region (Aq), the light collection region (Aq). Is formed such that the position where the light is formed is on the surface thereof, and the phosphor (N) that absorbs the light having the emission wavelength of the light emitting element (Y1, Y2,... )When,
It has
A mixed divergent light beam (Fe) of fluorescence emitted from the light collection region (Aq) on the surface of the phosphor (N) and residual excitation light reflected from the light collection region (Aq) is generated. With
The mixed divergent light beam (Fe) is converted by the light collecting element (Ef) into a light beam (Ff) that propagates in the opposite direction to the focused light beam (Fd) to form a distant image.
The luminous flux (Ff) is transmitted through the dichroic reflection element (M), whereby a mixed output luminous flux (Fg) is output to the outside.

The multi-wavelength light source according to another aspect of the first aspect of the present invention is a light-emitting element (Y1) and a luminous flux (Fb1) that forms a distant image of radiated light (Fa1) emitted from the light-emitting element (Y1). And a collimator element (E1) for conversion into a single element light source (U1), and an integrated light source (W) in which a plurality of element light sources (U1, U2,...) Are arranged side by side,
The regions (P1, P2,...) Having spectral characteristics that selectively transmit light having the emission wavelength of the light emitting elements (Y1, Y2,...) Are transmitted through the respective luminous fluxes (W) output from the integrated light source (W). A dichroic reflection element (M) selectively provided at a position where Fb1, Fb2,.
A condensing element (Ef) for condensing the luminous flux (Fcl, Fc2,...) Generated by transmitting the luminous flux (Fbl, Fb2,...) Through the dichroic reflection element (M);
When the converged light beam (Fd) generated by condensing the light beams (Fc1, Fc2,...) By the light collecting element (Ef) forms the light collection region (Aq), the light collection region (Aq). Is formed such that the position where the light is formed is on the surface thereof, and the phosphor (N) which absorbs the light having the emission wavelength of the light emitting element (Yl, Y2,...) As excitation light and emits fluorescence in other wavelength bands. )When,
It has
A mixed divergent light beam (Fe) of fluorescence emitted from the light collection region (Aq) on the surface of the phosphor (N) and residual excitation light reflected from the light collection region (Aq) is generated. With
The mixed divergent light beam (Fe) is converted by the light collecting element (Ef) into a light beam (Ff) that propagates in the opposite direction to the focused light beam (Fd) to form a distant image.
The light flux (Ff) is reflected by the dichroic reflection element (M), so that a mixed output light flux (Fg) is output to the outside.

The multi-wavelength light source according to the second aspect of the present invention, when focusing on the principal rays (Lp1, Lp2,...) In the luminous flux (Fbl, Fb2,...), The fluorescence of the principal rays (Lp1, Lp2,...). The component regularly reflected on the surface of the body (N) is propagated by the condensing element (Ef) in the direction opposite to that at the time of condensing and reaches the dichroic reflecting element (M). The regions (P1, P2,...) Are not formed.

The multiwavelength light source according to a third aspect of the present invention is characterized in that the condensing region (Aq) is an exit pupil formed by the condensing element (Ef) and an optical system in front thereof. Is.

The multi-wavelength light source according to a fourth aspect of the present invention is characterized in that the phosphor (N) is a normal line while keeping the normal of the surface of the phosphor (N) in the light collection region (Aq) unchanged. It is possible to move in a vertical direction.

In the multiwavelength light source according to the fifth aspect of the present invention, the phosphor (N) is:
The content ratio of the phosphor that emits fluorescence that belongs to the green wavelength band and the phosphor that emits fluorescence that belongs to the red wavelength band,
Alternatively, the content ratio of the phosphor that emits fluorescence belonging to the green wavelength band, the phosphor that emits fluorescence belonging to the red wavelength band, and the reflector that reflects light in the blue wavelength band is,
The phosphors (N) are distributed monotonically depending on the positions on the surface.

In the multiwavelength light source according to the sixth aspect of the present invention, the light condensing element (Ef) is constituted by a lens, and the light from the phosphor (N) along the optical axis of the light condensing element (Ef). When viewed in the direction in which the fluorescence comes, the integrated light sources (Wi, Wj) are arranged on both the left side and the right side of the light collecting element (Ef), and the dichroic reflective element (M) is arranged between the left side and the right side. It consists of two parts,
A dichroic surface (Smi) of the left dichroic reflector (Mi) for a light beam (Fbil, Fbi2,...) From the left integrated light source (Wi) and a light beam (Fbj1) from the right integrated light source (Wj). , Fbj2,...) And the dichroic surface (Smj) of the right dichroic reflector (Mj) are arranged in a roof shape.

According to a seventh aspect of the present invention, the left and right integrated light sources (Wi, Wj) are configured such that the element light sources (U1, U2,...) Are arranged in a grid pattern. The arrangement pattern of the regions (P1, P2,...) Projected on a plane perpendicular to the optical axis of the optical element (Ef) is based on an arrangement that is symmetric with respect to the optical axis of the condensing element (Ef). The period of the arrangement pattern of the regions (P1, P2,...) In a direction parallel or perpendicular to the direction of the ridgeline of the roof in the roof type arrangement of the dichroic surfaces (Smi, Smj) described above. The arrangement is shifted.

According to an eighth aspect of the present invention, there is provided a light source device comprising: the multi-wavelength light source according to the first aspect; and a fly eye integrator (FmB) to which a mixed output light beam (Fg) output from the multi-wavelength light source is input. A light source device comprising:
The direction of the arrangement pattern when the arrangement pattern of the regions (P1, P2,...) Provided in the dichroic reflection element (M) is projected onto the front fly-eye lens (F1B) of the fly-eye integrator (FmB); The multi-wavelength light source and the fly eye integrator (FmB) are arranged so that the directions of the fly eye lenses of the fly eye integrator (FmB) do not coincide with each other.

It is possible to provide a multi-wavelength light source and a light source device that achieve high arrival efficiency of excitation light from the light emitting element to the phosphor and high extraction efficiency of the light emitted from the phosphor to the outside.

The block diagram which simplifies and shows the multiwavelength light source of this invention is represented. The block diagram which simplifies and shows the multiwavelength light source of this invention is represented. The schematic diagram which simplifies and shows a part of multi-wavelength light source of this invention is represented. The schematic diagram which simplifies and shows the multiwavelength light source of this invention is represented. The schematic diagram which simplifies and shows a part of multi-wavelength light source of this invention is represented. The conceptual diagram which simplifies and shows one form of a part of light source device of this invention is represented. The figure which simplifies and shows one form of the one part of the Example of the multiwavelength light source of this invention is represented. The figure which simplifies and shows one form of the one part of the Example of the multiwavelength light source of this invention is represented. The figure which simplifies and shows one form of the Example of the multiwavelength light source of this invention is represented. The figure which simplifies and shows one form of the Example of the multiwavelength light source of this invention is represented. The figure explaining one form of one kind of conventional light source device concerning the light source device of this invention is represented. The figure explaining one form of one kind of conventional light source device concerning the light source device of this invention is represented.

In the description of the present invention, regarding the term conjugate, as a general term in the field of geometric optics, for example, when A and B are conjugate, it has an imaging function such as a lens based on at least paraxial theory. It means that A is imaged on B or B is imaged on A by the action of the optical element.
At this time, A and B are images, and it is a matter of course that isolated point images are included as targets, and a set of a plurality of point images and a spread image in which point images are continuously distributed are also targets. include.

Here, a point image or an image point (that is, an image) is a general term in the field of geometric optics, in which light is actually radiated from that point, the light converges toward that point, and the screen is A bright spot appears when placed, the light seems to converge toward that point (but the point is inside the optical system and the screen cannot be placed), the light is emitted from that point (However, the point is inside the optical system and the screen cannot be placed), and no distinction is made. At this time, blurring occurs due to aberrations or defocusing in imaging, Ignore the phenomenon of disappearing from an ideal point or diffraction limited image.

In the case where the light emitting element is a semiconductor laser, if there is one semiconductor laser, the input image of the optical system can be considered as just one point light source, and it is usually on the optical axis of the optical system. In addition, the central beam of the diverging direction distribution of diverging light from the semiconductor laser may be arranged in a direction that coincides with the optical axis.
However, in the case of a light source that has multiple semiconductor lasers or whose radiation points are continuously distributed within a finite area, a design that takes into account the entrance pupil, exit pupil, and chief ray of the optical system is required. Describes this situation.

Taking an ordinary camera lens as an example, an aperture stop is usually present inside the lens, but when the lens is viewed from the side where the light enters, the image of the aperture stop that can be seen through the lens is the entrance pupil, the side from which the light exits. A light beam (usually a meridian light beam) that is directed to the center of the exit pupil or entrance pupil or that emerges from the center of the exit pupil when the lens is viewed from the lens is called a principal ray. In a broad sense, rays other than the principal ray are called peripheral rays.
However, in an optical system that handles light having directivity such as a laser, there is often no aperture stop because it is not necessary to cut out the light beam by the aperture stop, and in that case, depending on the form of light in the optical system. They are defined.

Normally, the central ray of the direction distribution of light in the luminous flux from the radiation point is the principal ray, and there is an entrance pupil at the position where the principal ray incident on the optical system or its extension intersects the optical axis, and exits from the optical system. The exit pupil is considered to be at a position where the principal ray or its extension intersects the optical axis.
However, to be exact, there may be a case where the chief ray and the optical axis defined in this way do not intersect due to, for example, an adjustment error and are only in a twisted position.
However, since this phenomenon is irrelevant in nature and is barren to the discussion, in the following, it is assumed that such a phenomenon does not occur or the principal ray and the optical axis are closest to each other Let's consider it to be crossing in position.
Further, when focusing on two partial optical systems A and B adjacent to each other in the optical axis direction (light propagation direction) in the optical system, and B is immediately adjacent to A, The exit pupil of A becomes the entrance pupil of B (in the same way as the output image becomes the input image of B), and the entrance pupil / exit pupil of the partial optical system arbitrarily defined in the optical system is (aperture) If there is a stop, it is an image of it all, and even if it does not exist, it should be conjugate. Therefore, if there is no need for distinction, the entrance pupil and the exit pupil are simply called pupils.

In the description and drawings of the present invention, the optical axis of the optical system is referred to as the z-axis. However, if the optical axis is bent by the reflecting mirror, the direction in which the light beam along the original z-axis is reflected and travels is also determined. It is called the z axis and does not take a new coordinate axis. In the drawings such as FIG. 4, the x axis and the y axis are expressed as axes perpendicular to the z axis for convenience.

First, the form for implementing this invention is demonstrated using FIG. 1 which is a block diagram which simplifies and shows the multiwavelength light source of this invention.
The light emitting element (Yl) constituting the element light source (Ul) is driven by a driver circuit (not shown) configured based on a DC / DC converter, which is configured by a circuit of a system such as a subordinate chopper or a boost chopper, for example. And emits radiated light (Fa1).
For each of the light emitting elements (Yl), here, for example, a semiconductor laser or a light source that converts the wavelength of the emitted light of the semiconductor laser using a nonlinear optical phenomenon such as harmonic generation or optical parametric effect. Etc.

The emitted light (Fa1) is converted into a light beam (Fb1) that forms a distant image conjugate with the image of the light emitting area of the light emitting element (Y1) by a collimator element (E1) made of, for example, an aspheric lens. .
As an example of the form of the light beam (Fb1), for example, it can be configured to be a parallel light beam, or can be configured to be a divergent light beam or a converged light beam that is nearly parallel.
By integrating a plurality of element light sources (U1, U2,...) Similar to the element light source (Ul), an integrated light source (W) is formed, and light fluxes from each of the element light sources (U1, U2,...). (Fbl, Fb2,...) Is output.
As an example of the form of the light beams (Fb1, Fb2,...), The principal rays (Lpl, Lp2,...) Of the light beams (Fbl, Fb2,...) Can be configured to be parallel to each other, for example. Also, it can be configured to be divergent or convergent near parallel.

The light beams (Fb1, Fb2,...) Are made incident on the dichroic reflection element (M).
The dichroic reflective element (M) has a region (P1, P2,...) Having a spectral characteristic that selectively reflects light having the emission wavelength of the light emitting elements (Y1, Y2,...) With as high efficiency as possible. Are selectively provided at the locations where the light beams (Fbl, Fb2,...) Strike.
In the region (P1, P2,...), Light having a wavelength other than the emission wavelength of the light emitting elements (Yl, Y2,...) Is formed so as to be transmitted with as high efficiency as possible. The dichroic reflective element (M) is configured to transmit light of all related wavelength bands with as high efficiency as possible in the regions other than the regions (P1, P2,...).
Therefore, the light fluxes (Fbl, Fb2,...) Are reflected by the dichroic reflection element (M), and as the light fluxes (Fc1, Fc2,...), For example, a light collecting element (Ef) having a light collecting function such as a convex lens or a concave mirror. It is made to enter.
As a result, the luminous fluxes (Fc1, Fc2,...) Are collected by the condensing element (Ef) and are incident on the phosphor (N) as a focused luminous flux (Fd).

On the surface of the phosphor (N), a condensing region (Aq) irradiated with the focused light beam (Fd) is formed.
In the condensing region (Aq) of the phosphor (N), the light having the emission wavelength of the light emitting element (Yl, Y2,...) Of the focused light beam (Fd) is absorbed as excitation light, and the wavelength is different from that. Emits fluorescence in the band. Incidentally, the wavelength of the emitted fluorescence is usually longer than that of the excitation light, but fluorescence having a shorter wavelength than that of the excitation light may be emitted by multiphoton fluorescence.
From the condensing region (Aq) on the surface of the phosphor (N), in addition to the fluorescence emitted by wavelength conversion of the excitation light, residual excitation light reflected without wavelength conversion is emitted. As a mixed divergent light beam (Fe), it propagates in the opposite direction to the focused light beam (Fd) and enters the light collecting element (Ef).
The phosphor (N) can be mixed with a reflector for increasing the reflectance of the excitation light.

When the mixed divergent light beam (Fe) exits from the light condensing element (Ef) functioning as a collimator, it is converted into a light beam (Ff) that forms a distant image and is incident on the dichroic reflecting element (M). .
Then, the fluorescence whose excitation light has been wavelength-converted is transmitted through the entire dichroic reflection element (M), and the remaining excitation light that has not been wavelength-converted is the region (P1, P2, P2) of the dichroic reflection element (M). ...)) And is transmitted to the outside as a mixed output light beam (Fg) in the z-axis direction.
Thus, a multi-wavelength light source that outputs a light beam in which light of a plurality of wavelengths is mixed, that is, fluorescence in which excitation light is wavelength-converted by the phosphor (N) and residual excitation light that has not been wavelength-converted, is realized. .

The reason why the multi-wavelength light source of the present invention described above has high arrival efficiency of excitation light from the light emitting element to the phosphor and high extraction efficiency of the light emitted from the phosphor to the outside will be described below. .
The region (P1, P2,...) Of the dichroic reflecting element (M) is formed so as to reflect the excitation light having the emission wavelength of the light emitting elements (Y1, Y2,...) As efficiently as possible. Therefore, high arrival efficiency of excitation light from the light emitting element to the phosphor can be realized.
In addition, for the excitation light, the dichroic reflection element (M) is made to transmit as efficiently as possible in a region other than the region (P1, P2,...), And With respect to the fluorescence from the phosphor (N), both the region (P1, P2,...) And other regions are made to transmit with the highest possible efficiency. High extraction efficiency can be realized.

However, it is important to form the regions (P1, P2,...) As narrow as possible as long as the light beams (Fbl, Fb2,...) Do not protrude.
If the region (P1, P2,...) Is too narrow, the luminous flux (Fb1, Fb2,...) Protrudes and the component that does not reach the phosphor (N) increases. If the region (P1, P2,...) Is too wide, it is reflected in the direction of the integrated light source (W) among the residual excitation light reflected without wavelength conversion in the mixed divergent light beam (Fe). This is because the number of components increases, and in any case, the light utilization efficiency is lowered.

In order to further achieve high arrival efficiency of the excitation light from the light emitting element to the phosphor, for example, the luminous flux (Fbl, Fb2,...) Is S-polarized with respect to the dichroic reflecting element (M). After configuring the integrated light source (W), the region (P1, P2,...) Functions as a polarization beam splitter that reflects the luminous flux (Fb1, Fb2,...) As efficiently as possible. A dichroic reflective element (M) can be devised.
What happens is that when the luminous flux (Fbl, Fb2,...) Reaches the phosphor (N) and is reflected, rotation of the polarized light occurs, so that when the light beam returns to the dichroic reflecting element (M), it is polarized. This is because the ratio of components that can pass through the region (P1, P2,...) Increases.
If the degree of polarization of the excitation light returning to the dichroic reflection element (M) is not sufficiently lowered, excitation light is interposed between the dichroic reflection element (M) and the condensing element (Ef). By inserting a quarter-wave plate relating to the wavelength and forcibly rotating the polarization of the excitation light returning to the dichroic reflection element (M) by 90 degrees, the region (P1, P2,...) It is possible to increase the proportion of the component that can pass through.

In the multi-wavelength light source shown in FIG. 1, the light beam (Fbl, Fb2,...) Output from the integrated light source (W) is first reflected by the dichroic reflection element (M). did.
However, the multi-wavelength light source of the present invention can be configured such that the luminous flux (Fbl, Fb2,...) First passes through the dichroic reflective element (M). FIG. 2 is a simplified block diagram showing the multi-wavelength light source of the invention.
The function of the multi-wavelength light source in this figure is to read the description of reflection and transmission at the dichroic reflection element (M), in the description of FIG. It can be understood by changing.

Specifically, the dichroic reflective element (M) has a spectral characteristic (P1) that selectively transmits light having the emission wavelength of the light emitting elements (Yl, Y2,...) With as high efficiency as possible. , P2,... Are selectively provided at locations where the luminous fluxes (Fb1, Fb2,...) Strike.
In the region (P1, P2,...), Light having a wavelength other than the emission wavelength of the light emitting elements (Y1, Y2,...) Is formed to be reflected with as high efficiency as possible. The dichroic reflection element (M) is configured to reflect light of all related wavelength bands with as high efficiency as possible in the regions other than the regions (P1, P2,...).

The luminous fluxes (Fbl, Fb2,...) Are transmitted through the dichroic reflection element (M) and are incident on the light collecting elements (Ef) as luminous fluxes (Fcl, Fc2,...), And the phosphor (N). A condensing region (Aq) is formed on the surface.
The condensing element (Ef) functions as a collimator for the fluorescence emitted from the condensing region (Aq) and the residual excitation light that has not undergone wavelength conversion. A light beam (Ff) that forms a distant image conjugate with the light region (Aq) is emitted, and the light beam (Ff) is reflected by the dichroic reflection element (M) to produce a mixed output light beam (Fg) in the z-axis direction. ) Is output to the outside.
Thus, a multi-wavelength light source that outputs a light beam in which light of a plurality of wavelengths is mixed, that is, fluorescence in which excitation light is wavelength-converted by the phosphor (N) and residual excitation light that has not been wavelength-converted, is realized. .

In the description of the present invention, regarding the part using the notation of “transmission / reflection” and “reflection / transmission”, when reading the right side of the symbol “/”, read the right side in other places, and read the left side. It is written so that it can be understood correctly by reading the left side in other places.

With respect to the surface of the phosphor (N), if it is flat, unless it is specially treated, it is not a perfect diffuse reflection surface, and its reflection characteristic shows a strong peak in the regular reflection component.
As described above, in the multi-wavelength light source shown in FIGS. 1 and 2, the residual excitation light that has not been wavelength-converted passes through the region other than the region (P1, P2,...) In the dichroic reflective element (M). Since it is outputted to the outside by using it, the region (P1, P2,...) Does not exist at the position where the specular reflection component of the residual pumping light of the dichroic reflecting element (M) passes. This is advantageous for increasing the utilization efficiency.
That is, when the dichroic reflective element (M) pays attention to chief rays (Lp1, Lp2,...) In the luminous fluxes (Fbl, Fb2,...), The phosphor of the chief rays (Lp1, Lp2,...) The component regularly reflected on the surface of N) is propagated by the condensing element (Ef) in the direction opposite to that at the time of condensing and reaches the dichroic reflecting element (M). It can be seen that the region (P1, P2,...) May be configured not to be formed.

This will be specifically described with reference to FIGS. 1 and 2. For the sake of simplicity, the light collecting element (Ef) has an axisymmetric structure with respect to the z axis, and the phosphor (N). Of the integrated light source (W) and the luminous flux (Fb1, F2) output from the element light sources (U1, U2, U4, U5) of the integrated light source (W). When it is assumed that the principal rays (Lp1, Lp2, Lp4, Lp5) of Fb2, Fb4, Fb5) are rays existing on the paper surface of FIGS. 1 and 2, the principal rays (Lpl, Lp2, Lp4) When Lp5) is traced along its path, it reaches the light collection region (Aq) from the region (P1, P2, P4, P5) of the dichroic reflective element (M), and the phosphor (N) Is regularly reflected on the surface of the light collecting region ( When returning from q) to the dichroic reflective element (M), the principal rays (Lp1 ′, Lp2 ′, Lp4 ′, Lp5 ′) pass through the position deviated from the region (P5, P4, P2, P1). Therefore, a strong specular peak component around the principal ray (Lpl ′, Lp2 ′, Lp4 ′, Lp5 ′) is returned to the integrated light source (W) by the region (P5, P4, P2, P1). Without being output to the outside.

In the multi-wavelength light source shown in FIG. 1 or FIG. 2, the most simplified / idealized condition is output from each of the element light sources (U1, U2,...) Constituting the integrated light source (W). The light beams (Fbl, Fb2,...) Accurately form a parallel light beam (in other words, accurately form an output image point at infinity), and all of the light beams (Fb1, Fb2,...) Assume a condition in which the principal rays (Lpl, Lp2,...) Are exactly parallel to each other (in other words, the luminous fluxes (Fbl, Fb2,...) Form exactly the same infinite output image point). Then, in this case, the condensing region (Aq) formed on the surface of the phosphor (N) is the above-mentioned output image point at infinity formed by (the light beams (Fb1, Fb2,...)). It becomes one point-like region (conjugate).
In an actual light source, such simplified / idealized conditions are not strictly realized. For example, due to constraints such as assembly error of each element, aberration of the condensing element (Ef), diffraction limit, etc. The light condensing region (Aq) will be a collection of light condensing regions having a finite size separated into a plurality, but it must be a small region where the optical power is concentrated. There is a problem that the phosphor (N) is rapidly deteriorated at a location.

In order to avoid this problem, it is preferable that the condensing region (Aq) is configured to be an exit pupil formed by the condensing element (Ef) and an optical system in front thereof. .
The position and size of the pupil are basic parameters of the optical system, and the size of the condensing region (Aq) required from the viewpoint of deterioration of the phosphor (N) is designed accurately. This is because it is possible to achieve this, and if such a design is used, it is not necessary to add an extra optical element that leads to a decrease in light utilization efficiency.
This will be described with reference to FIG. 3, which is a schematic diagram showing a part of the multi-wavelength light source of the present invention in a simplified manner.
This figure shows how each of the light beams (Fc1, Fc2,...) Is converted into a focused light beam (Fd1, Fd2,...) By the condensing element (Ef).

The fact that the condensing region (Aq) becomes an exit pupil means that the principal rays (Lpl, Lp2,...) Of the luminous flux (Fbl, Fb2,...) Output from the integrated light source (W) as shown in FIG. )) Passes through the center of the light collection region (Aq), that is, the point (Q) that is the intersection of the phosphor (N) and the z-axis, and if the luminous flux (Fbl, If the divergence angles of Fb2,... Are all the same, for example, if the thicknesses of the light beams (Fbl, Fb2,...) Immediately after being output from the integrated light source (W) are all the same, for example. The luminous fluxes (Fbl, Fb2,...) Become focused luminous fluxes (Fd1, Fd2,...) After passing through the condensing element (Ef), and each centered on the common point (Q). A light irradiation region having approximately the same diameter is formed.
In this figure, the diameter of the light irradiation region is represented by the distance between the tips of the arrows (A1, A2), and eventually the size of the light collection region (Aq) is defined. become.

There are roughly two methods for realizing the optical system having the light collection region (Aq) as the exit pupil in this way, and the first is the output from the integrated light source (W). The light beam (Fb1, Fb2,...) Is configured as a telecentric optical system that forms an image point on the same plane that has an exit pupil at infinity and is far (positive or negative distance) but not infinity. It is.
The second is that the luminous fluxes (Fbl, Fb2,...) That are the output from the integrated light source (W) are parallel luminous fluxes, that is, an infinite image point is formed. Thus, the exit pupil is configured to come to a finite position.
Of course, there is an intermediate method between them, i.e., the exit pupil is at a finite position and it is configured to form an image point on the same plane that is not infinity, but the complexity of the design and assembly adjustment of the optical system Increase.

Of these, the first method described above is considered to be the easiest to assemble and adjust the optical system.
First, in order to form the image points on the same plane that are far but not infinite, the output of each of the element light sources (U1, U2,...) The element light sources (U1, U1,...) Such that the distance between the active region of the light emitting elements (Y1, Y2,...) And the collimator elements (E1, E2,...) Is a predetermined distance so that the image point can be a predetermined distance. Assemble each of U2, ...). However, for simplicity, the specifications of the light emitting elements (Y1, Y2,...) And the collimator elements (El, E2,...) Are all the same.
In order for the integrated light source (W) to be a telecentric optical system, the principal rays (Lp1, Lp2,...) Of all the luminous fluxes (Fbl, Fb2,...) Of the element light sources (U1, U2,...). The element light sources (U1, U2,...) May be assembled so that.

The diameter of the light condensing region (Aq) can be easily obtained by the basic paraxial optical calculation from the design guideline of the telecentric optical system described above, but an explanation that is intuitively easy to understand is given below. Keep it.
The position of the pupil, that is, the point (Q) is generated at the focal point of the condensing element (Ef).
Further, the distance (zqj) of the output image point (Jl, J2,...) Conjugate with the active region of the light emitting element (Yl, Y2,...) From the point (Q) is the above-described collimator element (El, Y1,. If the focal distance of E2,... Is determined, it can be adjusted by the distance between the active region of the light emitting elements (Y1, Y2,...) And the collimator elements (E1, E2,...).
Further, the divergence angle of the focused light beam (Fdl, Fd2,...) That forms the output image point (Jl, J2,...) Is the radiated light (Fa1, Fa2,...) From the light emitting elements (Yl, Y2,. )) And the focal length of the collimator elements (El, E2,...).
The diameter of the condensing region (Aq) is determined from the divergence angle of the focused light beam (Fd1, Fd2,...) And the distance (zqj), as is apparent from FIG.

Incidentally, when the output image point (J1, J2,...) Is formed behind the position of the pupil (that is, inside the phosphor (N)) as shown in FIG. (Y1, Y2,...) And the collimator elements (E1, E2,...) Are spaced apart from the collimator elements (E1, E2,...) When the output light beam from the collimator elements (E1, E2,. It will be adjusted shortly.
When such adjustment is performed, it cannot be said that the output light beam from the collimator elements (E1, E2,...) Is strictly collimated, and therefore the name collimator element may not be correct. However, it must be an element that converts light into a substantially collimated light beam, and parts that are commercially available as collimator elements for semiconductor laser radiation can also be used in this multi-wavelength light source. In this specification, it will be called a collimator element as it is.

Needless to say, the output image points (J1, J2,...) May be formed in front of the pupil position, contrary to this figure.
However, in this case, depending on the structure of the optical system, the output image point (Jl, J2,...) May be placed inside the optical system from the dichroic reflective element (M) to the condensing element (Ef). Although there is a possibility of being formed, if there is no adverse effect, the size of the region (P1, P2,...) Can be slightly reduced, and the light utilization efficiency can be improved accordingly. Benefits can be gained.

As the size of the condensing region (Aq) is set larger, the irradiation power density of the excitation light becomes lower, which is advantageous from the viewpoint of deterioration of the phosphor (N). Since the size of the light source of the fluorescence from which the excitation light is wavelength-converted and the residual excitation light that has not been wavelength-converted emitted from Aq) is increased, the condensing region (Aq) generated by the condensing element (Ef) ) And a distant image are large, and the mixed output light beam (Fg) output to the outside is disadvantageous because the directional purity of the collimated light beam, that is, the light quality is lowered.
Therefore, there is an upper limit for increasing the size of the light condensing region (Aq) depending on the use of the mixed output light beam (Fg). In some cases, there is a possibility that a sufficient life of the phosphor (N) cannot be secured. There is sex.

In order to solve this problem, the phosphor (N) is placed in a direction perpendicular to the normal while keeping the normal of the surface of the phosphor (N) in the light collection region (Aq) unchanged. It is preferable to be configured to be movable.
In addition, as a form of movement, for example, the phosphor (N) is formed in a disk shape, and its central axis is arranged parallel to the z-axis and rotated, for example, the phosphor (N) is arranged on the side surface of the cylinder. It may be formed and rotated with its central axis perpendicular to the z-axis, or, for example, the phosphor (N) may be formed in a flat plate shape and translated in a direction perpendicular to the z-axis. .
Further, the movement may be performed continuously or stepwise, or may be performed continuously, or intermittently when the deterioration of the phosphor (N) is recognized. It may be executed automatically.
Further, the movement mechanism may be provided with power such as a motor or a solenoid, or may be based manually.

As the light emitting element (Yl, Y2,...), A device whose emission wavelength band is blue is used, and as the phosphor (N), fluorescence belonging to the green wavelength band and fluorescence belonging to the red wavelength band are used. The multi-wavelength light source of the present invention is particularly suitable for applications in which a white light source is realized by using a material that emits R, G, and B3 primary colors.
The white light source referred to here is not limited to the color (chromaticity) of the light beam emitted from the light source that can be regarded as strictly white, or R, G, B3 in an apparatus using the light beam emitted therefrom. The primary color is taken out, and if the content ratio of R, G, B components deviates from the ideal white, it can be used as a white light source as a result by reducing the utilization efficiency of the extra components included Including things.

As the phosphor (N), one type of phosphor may emit fluorescence belonging to the green wavelength band and fluorescence belonging to the red wavelength band, or emit at least fluorescence belonging to the green wavelength band. A mixture of a phosphor and a phosphor that emits fluorescence belonging to the red wavelength band may be used.
The emission spectrum of the phosphor (N) when excited by the emission wavelength of the light emitting elements (Yl, Y2,...) Is composed of a large continuous spectrum including at least a green wavelength band and a red wavelength band. Alternatively, it may have at least a peak belonging to the green wavelength band and a peak belonging to the red wavelength band.

For example, when there is a white light source composed of a light emitting element that emits radiated light in each wavelength band of R, G, and B, by adjusting the balance of the currents flowing through the radiated light of each color, the total luminous flux output to the outside It is possible to adjust the content ratios of the respective colors, that is, the components of the R, G, and B colors.
However, the emission wavelength band of the light emitting element (Yl, Y2,...) Is blue, and the phosphor (N) is a mixture of a phosphor emitting green fluorescence and a phosphor emitting red fluorescence. If it is, adjusting the content ratio of the green component and the red component of the mixed output light beam (Fg) output to the outside or the content ratio of the components of R, G, B colors is the light emitting element. This cannot be realized by adjusting the current flowing through (Y1, Y2,...).

In the multi-wavelength light source of the present invention, for applications where it is necessary to adjust the content ratio of the green component and the red component of the output light, a phosphor that emits fluorescence belonging to the green wavelength band, and The content ratio with the phosphor that emits fluorescence belonging to the red wavelength band is distributed monotonously depending on the position on the surface of the phosphor (N), or the R, G, B colors of the output light For applications where the content ratio of the components needs to be adjusted, the phosphor (N) emits fluorescence belonging to the green wavelength band, and phosphor emits fluorescence belonging to the red wavelength band; The phosphor (N) is configured so that the content ratio with respect to the reflector that reflects light in the blue wavelength band is monotonously distributed at positions on the surface of the phosphor (N). Position when the phosphor (N) is installed in a multi-wavelength light source By adjusting, it is possible to adjust the content ratio of the color components of the output light.

For example, an example of the latter configuration relating to the phosphor (N) will be specifically described. As described above, the normal of the phosphor surface is taken on the z axis, and the x axis and the y axis are taken on the phosphor surface. The content of the reflector that reflects light in the blue wavelength band with respect to the phosphor content of the green phosphor and the red phosphor is monotonous only in the y coordinate without depending on the x coordinate. The content ratio of the green phosphor out of the total phosphor content of the green phosphor and the red phosphor is monotonous only in the x coordinate without depending on the y coordinate. The phosphor (N) may be configured to be distributed depending on.
Here, for example, “distributed monotonically depending on the x coordinate” means that the distribution amount increases or remains constant (or decreases or decreases) when the x coordinate increases when the distribution is viewed while changing the x coordinate. It means that it does not decrease after increase (increase after decrease). However, the microscopic distribution smaller than the diameter of the condensing region (Aq) may be careless, and an average value over a region that is at least as large as the diameter of the condensing region (Aq). As long as the distribution amount is monotonous.

Among the components of the multi-wavelength light source of the present invention, the elements that rise in temperature due to heat generation or upon receiving energy irradiation from other elements are the integrated light source and the phosphor, so the balance between these arrangements must be balanced. It is necessary to consider.
As shown in FIG. 4 (a), which is a schematic diagram showing the multi-wavelength light source of the present invention in a simplified manner, as it is possible to achieve both the arrangement balance of the temperature rising elements and the compactness as the light source. The condensing element (Ef) is constituted by a lens, and when viewed in the direction in which the fluorescence from the phosphor (N) comes along the optical axis of the condensing element (Ef), the integrated light source (Wi, Wj) ) Are arranged on both the left side and the right side of the condensing element (Ef) to constitute the multi-wavelength light source.

Further, in this case, as shown in FIG. 4B, which is a side view of FIG. 4A, the dichroic reflecting element (M) is composed of two parts, the left side and the right side. The left dichroic reflector (Mi) for reflecting the light beam (Fbil, Fbi2,...) From the integrated light source (Wi) and the light beam (Fbjl, Fbj2,...) From the right integrated light source (Wj) are reflected. For the right dichroic reflecting portion (Mj) for the purpose, it is preferable to arrange the dichroic surface (Smi, Smj) in a roof shape.
The dichroic reflecting element (M) of the figure is illustrated as being configured by a dichroic prism, but by doing so, the joint portion of the dichroic surface (Smi, Smj), that is, the ridge line portion of the roof type arrangement It is possible to reduce the loss of the luminous flux from the condensing element (Ef) in comparison with the case where it is constituted by a dichroic mirror.

As shown in this figure (b), the arrangement of the luminous fluxes (Fbi1, Fbi2,...) In the height direction (z direction) and the arrangement of the luminous fluxes (Fbj1, Fbj2,...) The integrated light source (Wi) and the integrated light source (Wj) are arranged so as to be shifted by one.
Therefore, the regions (P1, P2,...) On the dichroic surfaces (Smi, Smj) for selectively reflecting the light beams (Fbi1, Fbi2,...) And the light beams (Fbj1, Fbj2,. In the view as shown in FIG. 5A, the arrangement is not symmetrical but is shifted in the x direction by a quarter of the period of the arrangement pattern of the regions (P1, P2,...).
By doing in this way, after the principal ray (Lpil) of the light beam (Fbil) is reflected by the region (P1), it is reflected regularly from the phosphor (N) and returned to the principal ray ( Lpil ′) passes through the part where the regions (P1, P2,...) Are not formed as shown in FIG. 5A, and thus it is possible to increase the utilization efficiency of the residual excitation light as described above. Become.

In FIG. 4A, the region (P1, P2,...) Is shifted in the x direction, but it is also a schematic diagram showing a part of the multi-wavelength light source of the present invention in a simplified manner. As described in FIG. 5A, the use efficiency can be similarly increased by shifting in the y direction.
In the case of this figure, after the principal ray (Lpjl) of the light beam (Fbi1) from the integrated light source (Wi) is reflected by the region (P1), it is specularly reflected from the phosphor (N). Then, the chief ray (Lpj1 ′) when it is returned passes through a portion where the region (P1, P2,...) Is not formed as shown in FIG.
Although a side view corresponding to this drawing is omitted, the arrangement of the light beams (Fbil, Fbi2,...) From the integrated light source (Wi) in the height direction (z direction) and the integrated light source (Wj). It is not necessary to arrange the light beams (Fbj1, Fbj2,...) From a position that is shifted by a half of the arrangement period as described in FIG.

In the case of the configuration of FIG. 5A, when the interval between the regions (P1, P2,...) In the x direction is narrow, these are merged to obtain the region (Pa, Pb,...
Similarly, in the case of the configuration of FIG. 4A, when the interval between the regions (P1, P2,...) In the y direction is narrow, these are merged to obtain the region (c) of FIG. Pa, Pb,...

As described above, the method of shifting the arrangement pattern of the regions (P1, P2,...) Described in (a) of FIG. 4 and (a), (b), and (c) of FIG. 5 is summarized. To say it is as follows.
That is, each of the left and right integrated light sources (Wi, Wj) is configured by arranging the element light sources (U1, U2,...) In a lattice pattern, and is perpendicular to the optical axis of the light collecting element (Ef). The arrangement pattern of the regions (P1, P2,...) Projected onto the plane is based on an arrangement that is symmetric with respect to the optical axis of the light condensing element (Ef), and the arrangement pattern of the dichroic surfaces (Smi, Smj). What is necessary is just to make arrangement | positioning shifted only 1/4 of the period of the arrangement | sequence pattern of the said area | region (P1, P2, ...) in the direction parallel or perpendicular | vertical with respect to the direction of the ridgeline of a roof type arrangement | positioning.
And it becomes possible to raise the utilization efficiency of residual excitation light by setting it as such an arrangement | positioning.

The multi-wavelength light source of the present invention is formed into a light source device in combination with the above-described rod integrator or fly eye integrator, and can be suitably used, for example, to configure a projector, but particularly when combined with a fly eye integrator. There are things to note.
In the multi-wavelength light source of the present invention, the residual excitation light that has not been wavelength-converted by the phosphor (N) cannot be output via the region (P1, P2,...). A shadow corresponding to the arrangement pattern of the regions (P1, P2,...) Described in (a) of FIG. 4 and (a), (b), and (c) of FIG. become.
As described above, the function as the light uniformizing means of the fly eye integrator is expressed by superimposing the illuminance distribution on each lens surface of the front fly eye lens (F1B). When the mixed output light beam (Fg) is input to the fly eye integrator (FmB), the shadow is also superimposed.

However, if the shadow has periodicity, depending on the conditions, the fly eye integrator (FmB) may be superposed so as to strengthen the influence of the shadow.
Such inconvenient shadow superposition is performed by changing the arrangement pattern of the regions (P1, P2,...) Provided in two types of arrangement directions, that is, the dichroic reflection element (M), to the fly eye integrator (FmB). Occurs most significantly when the direction of the alignment pattern when projected onto the first fly-eye lens (F1B) matches the direction of alignment of the fly-eye lenses of the fly-eye integrator (FmB).
When the arrangement pattern of the regions (P1, P2,...) Just described is projected onto the front fly-eye lens (F1B), the mixed output light beam (Fg) output from the multi-wavelength light source. Is projected in the direction of the central axis (z).

Therefore, in order to avoid this problem, it is only necessary that the two types of arrangement directions do not coincide with each other, and a state of such a configuration is shown in a simplified form of a part of the light source device of the present invention. FIG. 6 is a conceptual diagram.
In this figure, with respect to a virtual plane (Po) perpendicular to the central axis (z) of the mixed output light beam (Fg) of the multi-wavelength light source shown in FIG. A projection of the dichroic reflection element (M) and the condensing element (Ef) is drawn as a symbol of the multi-wavelength light source of the present invention, and the preceding fly-eye lens (F1B) is symbolized as the fly-eye integrator (FmB). ) And the x-axis and the y-axis are arranged so as to have an inclination with respect to the x′-axis and the y′-axis, which are the directions of the fly-eye lenses of the fly-eye integrator (FmB). I understand that.
Needless to say, the angle of the inclination is not limited, and the fly eye integrator (FmB) needs to be set to an angle that can be overlapped so as to weaken the influence of the shadow. A reasonable value may be obtained experimentally.

Next, the form for implementing this invention is demonstrated using FIG. 7 which is a figure which simplifies and shows one form of the Example of the multi-wavelength light source of this invention.
(A) of this figure shows one structural example of the said element light source (U1), the assembly structure for mounting | wearing a light emitting element (Y1) with a collimator element (E1), (b) is a collimator. The lens holder (Hz1, Hz2,...) To which the elements (E1, E2,...) Are fixed are mounted on the light emitting elements (Y1, Y2,...), And the light emitting elements (Y1, Y2,. ) Represents a state of being mounted on the heat sink (Hs), and shows a part of the integrated light source (W) in which a plurality of the element light sources (U1, U2,...) Are integrated.

The light-emitting elements (Yl, Y2,...) In this figure are covered with an envelope composed of metal case parts (My1, My2,...) And a light transmission window part (not shown), and are also connected to energization terminals. (TyA, TyB) and a structure generally called a can type.
A distant image point is generated in a direction perpendicular to the structural reference planes (Pz1, Pz2,...) Of the metal case portions (Myl, My2,...) Of the light emitting elements (Yl, Y2,...). In order to install the collimator elements (El, E2,...) So that a light beam is emitted, the collimator elements are first applied to the lens mount (Hzl ′, Hz2 ′,. (El, E2,...) Are fixed, and then, for example, a means such as adhesion is used for the lens holder (Hz1, Hz2,...) Fixed to the light emitting element (Yl, Y2,...). By fixing the lens mounts (Hzl ′, Hz2 ′,...), The collimator elements (El, E2,...) Are fixed to the lens holders (Hz1, Hz2,...).
That is, when the collimator elements (El, E2,...) Are fixed to the lens holder (Hz1, Hz2,...), The lens mounts (Hzl ′, Hz2 ′,. It is something to intervene.

With this structure, if the collimator elements (El, E2,...) Are fixed to the lens mount (Hz1 ′, Hz2 ′,. The lens holders (Hz1, Hz2,...) Fixed to the elements (Yl, Y2,...) Are caused to emit light by passing current through the light emitting elements (Y1, Y2,...), And the collimator elements (El, Y1,. E2,...)) While performing optical observation so that the light beam that has passed through a predetermined collimated state (a state in which an image conjugate with the active region of the light emitting element is formed at a predetermined position) The lens mount (Hz1, Hz2,...) Can be fixed to the lens holder (Hz1, Hz2,...) By moving the lens mount (Hz1 ′, Hz2 ′,...) To a predetermined position.
In FIG. 7B, adhesive potting (HpA) for fixing the collimator elements (E1, E2,...) And lens mounts (Hz1 ′, Hz2 ′,...) Are fixed. Although adhesive potting (HpB) is described, it is not necessary to apply it to the entire periphery of the collimator element (El, E2,...) Or the lens mount (Hz1 ′, Hz2 ′,...). A few places are enough.

As described above, each of the element light sources (U1, U2,...) Is configured, and these are integrated and mounted on the common heat sink (Hs), whereby one of the integrated light sources (W). Can be configured.
When the heat sink (Hs) is made of a metal material such as aluminum, the lens holder (Hz1, Hz2,...) Interposed between the heat sink (Hs) and the metal case (Myl, My2,...) When it is necessary to be an insulating member, it is made of a material such as ceramic having good thermal conductivity.

In FIG. 7, the light emitting element (Yl) and the collimator element (El) are assembled to constitute the element light source (Ul) as an entity, and a plurality of them are integrated to form the integrated light source (W). An example of what is configured is shown.
However, in the multi-wavelength light source of the present invention, a light emitting element assembly composed of a plurality of light emitting elements (Y1, Y2,...) And a collimator element assembly composed of a plurality of collimator elements (E1, E2,...) Are combined. By constructing one integrated light source (W), as a result, the element light source (U1) composed of one light emitting element (Y1) and one collimator element (E1) The integrated light source (W) formed may be regarded as an integrated unit.
In this regard, a simple explanation will be given with reference to FIG. 8, which is a diagram showing a simplified form of a part of the embodiment of the multi-wavelength light source of the present invention.

(A) of this figure is the external appearance of the package (Py) containing the light emitting elements (Yl, Y2,...), (B) shows the internal structure of the package (Py), and (c) shows the package (Py). Py) is an integrated light source (W) configured by combining a collimator element array (Exy).
The heat sink (Hs) is made of a material having good thermal conductivity such as metal and forms the bottom surface of the package (Py). The heat sink (Hs) is a larger heat sink through the fixing hole (Ph). It may be fixed and integrated to function as a heat sink.
The cover (Pc) made of metal, ceramic, or the like is provided with a window (Pw) for taking out a light beam emitted from the light emitting elements (Y1, Y2,...) And joined to the heat sink (Hs). And a hermetic seal structure.

Inside the cover (Pc), by using means such as adhesion on one surface of the heat sink (Hs) which is the reference surface Pz on the structure of the package (Py), for example, heat conductivity such as aluminum nitride is good. An insulating substrate (Pih) is fixed, and the light emitting elements (Yl, Y2, Y2, Y2, Y2, Y2, Y2) are bonded on the insulating substrate (Pih) directly or via a structure by using means such as adhesion. ...) is fixed.
Note that a gas such as an inert gas is enclosed in the space inside the cover (Pc) in order to prevent deterioration of the light emitting elements (Y1, Y2,...).
Note that the multi-wavelength light source of the present invention may be composed of a plurality of packages (Py).

When viewed from the outside of the window (Pw) of the package (Py), the light emitting regions of the respective light emitting elements (Y1, Y2,...) Are regarded as point image sets arranged vertically and horizontally independently in the same plane. Can do.
Corresponding to each point image of this point image set, the collimator element array (Exy) is configured by arranging independent partial lenses (Eml, Em2,...) Corresponding to the collimator elements (E1, E2,...). Then, by arranging it outside the window (Pw), the light flux from each point image is input to the dichroic reflection element (M) of the multi-wavelength light source corresponding to the light flux (Fbil, Fbi2,...). It can be converted into a luminous flux suitable for what it does.
The collimator element array (Exy) in which the partial lenses (Em1, Em2,...) Are arranged in a two-dimensional array can be molded as a single unit by a technique similar to the fly eye lens manufacturing technique described above. Is preferred.
At this time, the package (Py) is configured so that the collimator element array (Exy) configured by arranging the partial lenses (Eml, Em2,...) In a two-dimensional array as an integral one also serves as the window (Pw). May be.

Next, FIG. 9 which is a diagram showing a simplified form of an embodiment of the multi-wavelength light source of the present invention will be described.
The multi-wavelength light source of this figure is drawn as a more practical one based on the multi-wavelength light source shown in FIG. 4, (a) is a front view, and (b) is a side view.
The integrated light sources (Wi1, Wi2, Wj1, Wj2) and the phosphor (N) maintain good thermal contact with the common heat sink (Bh), which also serves as the base of the multi-wavelength light source. It is fixed.
Further, the heat sink (Bh) is fixed to a cooling structure of an air cooling type, a water cooling type, or a Peltier element.
The dichroic reflecting element (M) in this figure is configured by combining dichroic reflecting portions (Mi, Mj) made of two thin flat plates.

The condensing element (Ef) includes a spherical or aspherical lens (Efl) for converting a parallel light beam into a focused light beam, and a two-stage for converting the focused light beam into a focused light beam having a larger divergence angle. The aplanatic lens (Ef2, Ef3) (so-called luboschets lens) is drawn.
Since the fluorescence whose excitation light has undergone wavelength conversion is diverged from the condensing region (Aq) without directivity, the condensing element (Ef) is capable of collimating divergent light with a solid angle as large as possible. The condensing element (Ef) described in this figure is a configuration suitable for satisfying this necessity.
In addition, in order to collimate the fluorescence in which the excitation light emitted from the light collection region (Aq) is wavelength-converted and the residual excitation light that has not been wavelength-converted with high quality, the light-collecting element ( Ef) is preferably corrected for chromatic aberration of two colors or three colors. In this way, it is divided into at least three lenses and is designed to correct aberrations using an appropriate glass material. It will be possible.

With respect to the arrangement of the light beams output from the integrated light sources (Wi1, Wi2, Wj1, Wj2), the arrangement pitch in the x direction is not small. The step-like mirrors (Mil, Mi2,..., Mj1, Mj2,...) In which the 45-degree mirrors are arranged with the arrangement interval in the x direction different from the arrangement interval in the z direction are provided.
In this way, the arrangement pitch in the z direction of the light beams incident on the dichroic reflection element (M) can be made sufficiently small, so the excitation light provided on the dichroic reflection element (M) is selected. The regions (Pa, Pb,...) For reflective reflection can be merged as described above.

In this figure, the arrangement intervals in the y direction of the light beams incident on the dichroic reflection element (M) are not uniform, and therefore the arrangement intervals in the y direction of the regions (Pa, Pb,...) Are not uniform. However, since the principal ray (Lpil) from the integrated light source (Wi) is reflected by the region (Pa), since the arrangement is shifted with respect to the arrangement symmetrical to the z axis, The principal ray (Lpil ′) when it is reflected back from the phosphor (N) passes through a portion where the region (Pa, Pb,...) Is not formed, and thus the remaining excitation light is used. Efficiency is improved.
The integrated light sources (Wi1, Wi2) are in contact with each other and the integrated light sources (Wj1, Wj2) are in contact with each other with respect to the integrated light sources (Wi1, Wi2) and the integrated light sources (Wj1, Wj2). If the arrangement interval in the y direction of the light beams incident on the dichroic reflection element (M) cannot be made uniform even if it is adjusted until contact is made, it is made of parallel flat glass as shown by a two-dot chain line in the figure. The beam shift element (Es) is arranged so that the surface thereof is parallel to the z-axis, and the angle is adjusted around the z-axis, whereby the light beam incident on the dichroic reflection element (M) in the y-direction. It is possible to make the arrangement interval uniform (however, the beam shift element (Es) is a beam from both the integrated light sources (Wi2, Wj2) or the integrated light sources (Wi1, Wi2,). j1, Wj2) is arranged on the light beam from all.).

When the integrated light source (Wil, Wi2, Wjl, Wj2) is realized by a commercial product, NUBM05 (product name “blue laser diode bank”) manufactured by Nichia Corporation can be used.
In the case of this commercially available integrated light source, the collimator lens for making each output beam become a light beam forming an infinite image point is assembled in each semiconductor laser as a standard. When the first method for realizing an optical system using the light collection region (Aq) as an exit pupil is performed, the output beam is converted into a light beam that forms an image point of a finite distance at a specified position. For this purpose, a conversion lens may be inserted.
In this case, it is preferable that the conversion lens is manufactured as a lens array in which the conversion lenses are arranged in a two-dimensional array and integrally molded, similar to the collimator element array (Exy).

By the way, in FIG. 9A, the left element light source set composed of the integrated light sources (Wi1, Wi2) and the right element light source set composed of the integrated light sources (Wj1, Wj2) are respectively represented by the x-axis and y-axis. In the axial direction, an element formed by a matrix of element light sources composed of four and four arrays is illustrated.
Here, in order to increase the number of elements in the x-axis direction in order to increase the output light quantity of the multi-wavelength light source, the stepped mirrors (Mil, Mi2,..., Mj1) are adjusted accordingly. , Mj2,...). In this case, if it is not desired to increase the size of the dichroic reflecting element (M) or the condensing element (Ef), (b) in FIG. ), The arrangement pitch of the stepped mirrors (Mil, Mi2,..., Mj1, Mj2,...) In the z-axis direction must be shortened.

At this time, if the pitch of the step-like mirrors (Mil, Mi2,..., Mj1, Mj2,...) In the z-axis direction is the thickness of the light flux of each element light source (in FIG. 1, the light flux (Fbl, If there is no allowance for the thickness (ie, diameter) of Fb2,...), It is necessary to reduce the luminous flux thickness of each element light source simultaneously with the reduction of the pitch in the z-axis direction of the stepped mirrors.
In order to reduce the beam thickness of each element light source, the focal length of the collimator elements (the collimator elements (El, E2,...) In FIG. 1) of each element light source may be shortened.

However, when using a commercially available integrated light source as described above, when reducing the thickness of a standard light beam, FIG. 10 is a diagram showing a simplified form of an embodiment of the multi-wavelength light source of the present invention. As described, beam compressor lenses (Gil, Gi2,..., Gj1, Gj2,...) For reducing the beam thickness may be inserted into the output beams of the integrated light sources (Wi1 ′, Wj1 ′). .
Here, each of the beam compressor lenses (Gil, Gi2,..., Gj1, Gj2,...) Has a convex spherical surface on the incident side of the beam and a concave spherical surface on the exit side. Although a case where the lens is constituted by one meniscus lens having an infinite distance) is illustrated, two lenses of a convex lens and a concave lens may be arranged confocally.
In the case where the first method for realizing the optical system having the light collection region (Aq) as the exit pupil described above is also performed, the beam compressor lenses (Gil, Gi2,..., Gj1, Gj2 ,... Also serves as a conversion lens for converting into a light beam that forms an image point of a finite distance at the specified position as described above, the beam compressor lenses (Gil, Gi2,..., Gj1, Gj2,...) It is preferable to provide a finite focal length of an appropriate value, positive or negative, not infinite.

In the configuration just described, the beam compressor lens (Gil, Gi2,..., Gj1, Gj2,...) Is described as being provided for each output beam of the integrated light source (Wi1 ′, Wj1 ′).
However, among the thicknesses of the output beams of the integrated light sources (Wi1 ′, Wj1 ′), there is a special need to reduce the thickness component in the direction perpendicular to the paper surface of FIG. Therefore, the beam compressor lens (Gil, Gi2,..., Gj1, Gj2,...) Can be replaced with a cylindrical lens having a generatrix in the y-axis direction.
9A, the step-like mirrors (Mil, Mi2,..., Mj1, Mj2,...) Extend in the y-axis direction, and a plurality of beams arranged in the y-axis direction are collectively displayed. As reflected, the cylindrical lens also has a structure in which the generatrix extends in the y-axis direction, whereby the thickness in the x-axis direction is collectively reduced with respect to a plurality of beams arranged in the y-axis direction. Can be.
Even if this state is illustrated, since the beam compressor lens (Gil, Gi2,..., Gj1, Gj2,...) In FIG. To do.

Here, it supplements regarding the 1st method of implement | achieving the optical system which mentioned the above-mentioned condensing area | region (Aq) as an exit pupil mentioned above.
In the case of the multi-wavelength light source shown in FIG. 9B or FIG. 10, since the stepped mirrors (Mil, Mi2,..., Mj1, Mj2,...) Are used, each element light source in the integrated light source is used. The distances to the condensing element (Ef) are not uniform (however, the distance referred to here is, for example, from the output-side main plane of the collimator element of each element light source to the input-side main plane of the condensing element (Ef)) And the distance between them.)
Therefore, if the focal length of the conversion lens that is inserted into the light beam from each element light source and converts to a light beam that forms an image point of a finite distance at the specified position is the same regardless of the element light source, The arrangement of the output image points (J1, J2,...) From the optical element (Ef) is perpendicular to the axis of the condensing element (Ef) as shown in FIG. There is a possibility of causing a phenomenon of falling off and tilting.

However, this inclination is usually small. Therefore, in the condensing area (Aq) portion, due to this inclination, the size of the condensing area for each of the focused light beams (Fd1, Fd2,...) Since the amount of deviation is small, this phenomenon can be ignored.
Incidentally, the reason why the inclination is small is that the condensing element (Ef) that forms the output image point (Jl, J2,...) Is a reduction optical system. This is because the depth in the z-axis direction of the arrangement of the output image points (JI, J2,...) Is further reduced because it is square.

If it is desired to eliminate this phenomenon if it is small, an image point of a finite distance at the specified position is formed according to the distance from each element light source in the integrated light source to the light collecting element (Ef). What is necessary is just to adjust the focal distance of the conversion lens for converting into the light beam which carries out.

Note that it is desired to avoid that the light condensing region (Aq) becomes a small region where the optical power is concentrated by a method other than realizing the optical system having the light condensing region (Aq) as the exit pupil described above. In this case, for example, it can be realized by inserting a diffusion plate (Bi, Bj) at the position shown in FIG.

The present invention can be used in industries that design and manufacture multi-wavelength light sources using light emitting elements such as semiconductor lasers, such as white light sources that can be used in optical devices such as projectors.

A1 arrow A2 arrow Aq Condensing region Bh Heat sink Bi Diffusion plate Bj Diffusion plate DmjA Two-dimensional light amplitude modulation element DmjB Two-dimensional light amplitude modulation element E1 Collimator element E2 Collimator element Ef Condensing element Ef1 Lens Ef2 Aplanatic lens Ef3 Tick lens Ej1A Illumination lens Ej1B Illumination lens Ej2A Projection lens Ej2B Field lens Ej3B Projection lens Em1 Partial lens Em2 Partial lens Es Beam collimator element Exy Collimator element array F1B Pre-stage fly-eye lens F2B Sub-stage fly-eye light Fa1 Luminous flux Fb4 luminous flux Fb5 luminous flux Fbi1 luminous flux Fbi2 luminous flux Fbj1 luminous flux Fbj2 luminous flux Fc1 luminous flux Fc2 luminous flux Fd focused luminous flux Fd1 focused luminous flux Fd2 focused luminous flux Fe mixed divergent luminous flux Ff luminous flux Fg mixed output luminous flux FmA light uniformizing means Fmb fly eye integrator Gi1 beam compressor lens Gi2 beam compressor lens Gj1 beam compressor lens HjA beam compressor lens Hp Agent potting HpB Adhesive potting Hs Heat sink Hz1 Lens holder Hz1 'Lens mount Hz2 Lens holder Hz2' Lens mount J1 Output image point J2 Output image point Lp1 Primary ray Lp1 'Main ray Lp2 Main ray Lp2' Main ray Lp4 Main ray Lp4 'Main ray Ray Lp5 chief ray Lp5 'chief ray Lpi1 chief ray Lpi1' chief ray Lpj1 chief ray L j1 'principal ray M dichroic reflection element Mi dichroic reflection part Mi1 step-like mirror Mi2 step-like mirror Mj dichroic reflection part Mj1 step-like mirror Mj2 step-like mirror MjA mirror MjB polarization beam splitter My1 metal case part My1 metal case part My1 N phosphor P1 region P2 region P4 region P5 region Pa region Pb region Pc cover PcB Polarization alignment functional element Ph fixing hole Pih insulating material substrate PmiA incident end PmiB incident end PmoA exit end PmoB exit end Po virtual plane Pw window Py package Pz Reference surface Pz1 Reference surface Pz2 Reference surface Q point SjA Light source SjB Light source Smi Dichroic surface Smj Dichroic surface Tj Screen T A energization terminal TyB energization terminal U1 element light source U2 element light source U4 element light source U5 element light source W integrated light source Wi integrated light source Wi1 integrated light source Wi1 ′ integrated light source Wi2 integrated light source Wj integrated light source Wj1 integrated light source Wj1 ′ integrated light source Yj2 integrated light source Yj2 Light-emitting element Y2 Light-emitting element z Central axis ZiB Incident optical axis zqj Distance

Claims (8)

1. One set of a light emitting element (Y1) and a collimator element (E1) for converting radiated light (Fa1) emitted from the light emitting element (Y1) into a light beam (Fb1) that forms a distant image As an element light source (U1), an integrated light source (W) in which a plurality of element light sources (U1, U2,.
   Each of the regions (P1, P2,...) Having spectral characteristics for selectively reflecting / transmitting light having the emission wavelength of the light emitting elements (Y1, Y2,...) Is output from the integrated light source (W). A dichroic reflection element (M) selectively provided at a position where the light beam (Fb1, Fb2,...) Is applied;
   A condensing element (Ef) for condensing the luminous fluxes (Fc1, Fc2,...) Generated by reflecting / transmitting the luminous fluxes (Fb1, Fb2,...) By the dichroic reflecting element (M);
   When the converged light beam (Fd) generated by condensing the light beams (Fc1, Fc2,...) By the light collecting element (Ef) forms the light collection region (Aq), the light collection region (Aq). Is formed such that the position where the light is formed is on the surface thereof, and the phosphor (N) that absorbs the light having the emission wavelength of the light emitting element (Y1, Y2,...) As the excitation light and emits the fluorescence in the other wavelength band. )When,
   It has
   A mixed divergent light beam (Fe) of fluorescence emitted from the light collection region (Aq) on the surface of the phosphor (N) and residual excitation light reflected from the light collection region (Aq) is generated. With
   The mixed divergent light beam (Fe) is converted by the light collecting element (Ef) into a light beam (Ff) that propagates in the opposite direction to the focused light beam (Fd) to form a distant image.
   The multi-wavelength light source characterized in that the luminous flux (Ff) is transmitted / reflected by the dichroic reflection element (M) and a mixed output luminous flux (Fg) is output to the outside.
2. When attention is paid to principal rays (Lp1, Lp2,...) In the luminous fluxes (Fb1, Fb2,...), The components of the principal rays (Lp1, Lp2,...) That are regularly reflected on the surface of the phosphor (N) are obtained. The region (P1, P2,...) Is formed at a position where the light condensing element (Ef) propagates in the opposite direction to the time of condensing and reaches the dichroic reflecting element (M). The multiwavelength light source according to claim 1, wherein the multiwavelength light source is not.
3. The multi-wavelength light source according to claim 1, wherein the condensing region (Aq) is an exit pupil formed by the condensing element (Ef) and an optical system in front of the condensing element (Ef).
4. The phosphor (N) is movable in a direction perpendicular to the normal while keeping the normal of the surface of the phosphor (N) in the light collection region (Aq) unchanged. The multi-wavelength light source according to claim 1.
5. The phosphor (N) is:
   The content ratio of the phosphor that emits fluorescence that belongs to the green wavelength band and the phosphor that emits fluorescence that belongs to the red wavelength band,
   Alternatively, the content ratio of the phosphor that emits fluorescence belonging to the green wavelength band, the phosphor that emits fluorescence belonging to the red wavelength band, and the reflector that reflects light in the blue wavelength band is,
   The multi-wavelength light source according to claim 4, wherein the multi-wavelength light source is monotonously distributed at positions on the surface of the phosphor (N).
6. The condensing element (Ef) is constituted by a lens,
   When viewed in the direction in which the fluorescence from the phosphor (N) comes along the optical axis of the light collecting element (Ef), the integrated light source (Wi, Wj) is on the left side of the light collecting element (Ef). The dichroic reflective element (M) is composed of two parts, a left side and a right side,
   A dichroic surface (Smi) of the left dichroic reflector (Mi) for a light beam (Fbi1, Fbi2,...) From the left integrated light source (Wi) and a light beam (Fbj1) from the right integrated light source (Wj). , Fbj2,..., And the dichroic surface (Smj) of the right dichroic reflector (Mj) for the multi-wavelength light source according to claim 1 or 2.
7. Each of the integrated light sources (Wi, Wj) on the left side and the right side is configured by arranging the element light sources (U1, U2,...) In a lattice pattern, and in a plane perpendicular to the optical axis of the light collecting element (Ef). The projected pattern of the regions (P1, P2,...) Is based on an arrangement that is symmetric with respect to the optical axis of the light collecting element (Ef), and the roof type of the dichroic surface (Smi, Smj). The arrangement is shifted by a quarter of the period of the arrangement pattern of the regions (P1, P2, ...) in a direction parallel or perpendicular to the direction of the ridgeline of the roof in the arrangement. 6. The multi-wavelength light source according to 6.
8. A light source device comprising the multi-wavelength light source according to claim 1 and a fly-eye integrator (FmB) to which a mixed output light beam (Fg) output from the multi-wavelength light source is input,
   The direction of the arrangement pattern when the arrangement pattern of the regions (P1, P2,...) Provided in the dichroic reflection element (M) is projected onto the front fly-eye lens (F1B) of the fly-eye integrator (FmB); The light source device is characterized in that the multi-wavelength light source and the fly eye integrator (FmB) are arranged so that the direction of arrangement of the fly eye lenses of the fly eye integrator (FmB) does not match.
   

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