JP2014085432A - Laser beam emission device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laser beam emission device capable of improving the low in-plane uniformity of light intensity distribution.SOLUTION: The laser beam emission device includes a bundle fiber 5 formed by bundling a plurality of optical fibers 3 for propagating the light emitted by a plurality of laser beam sources 2, and a light emission section 7 formed at an emission end of the bundle fiber 5. The plurality of optical fibers 3 are aligned in the light emission section 7 so that the in-plane uniformity of the light intensity at the emission end surface of a rod is a previously determined reference value or higher.

Description

  The present invention relates to a laser beam emitting apparatus equipped with a plurality of laser light sources.

  Conventionally, a laser beam emitting device equipped with a plurality of laser light sources has been developed. Patent Document 1 discloses a technique (hereinafter also referred to as Related Art A) that uses a light beam emitted from the exit end of a bundle fiber as a light source in the laser light emitting apparatus. The bundle fiber is obtained by condensing laser light emitted from each laser light source onto an optical fiber and bundling each optical fiber.

  Patent Document 2 discloses an exposure apparatus characterized in that the etendue of the bundle fiber of the light source is smaller than the etendue of the digital micromirror device that illuminates. Hereinafter, the technique disclosed in Patent Document 2 is also referred to as related technique B.

  Specifically, in Related Art A, a plurality of laser light emission units are arranged side by side, and a fiber is connected to each laser light emission unit. By bundling these fibers to form a bundle portion, laser beams are emitted in parallel to obtain a high-power laser beam.

  In Related Technology B, the shape of the light emitting portion of the bundle fiber connected to the lamp light source is configured to be substantially similar to the contour shape of the exit surface of the optical integrator. The optical integrator illuminates the digital micromirror device. Thereby, it is comprised so that it can couple | bond with high illumination efficiency.

JP 2009-253074 A JP 2004-228343 A

  However, the related technologies A and B have the following problems. Specifically, according to Related Technology A, it is possible to increase the output of light by bundling optical fibers. Further, according to the related art B, it is possible to improve the illumination efficiency by making the shape of the light emitting portion substantially similar to the contour shape of the exit surface of the optical integrator.

  However, when the related technologies A and B are applied to the laser projector device, there is a problem that the in-plane uniformity of the light intensity distribution is not sufficient.

  The present invention has been made to solve such a problem, and an object of the present invention is to provide a laser beam emitting apparatus that improves the in-plane uniformity of the light intensity distribution.

  In order to achieve the above object, a laser beam emitting apparatus according to an aspect of the present invention emits a light beam for use in an optical device of a projector that projects an image to a rod. The laser light emitting device includes a plurality of laser light sources that emit light, a bundle fiber configured by bundling a plurality of optical fibers that propagate light emitted from the plurality of laser light sources, and an emission end of the bundle fiber. A plurality of optical fibers arranged in the light emitting section so that the in-plane uniformity of the light intensity at the emitting end face of the rod is equal to or greater than a predetermined reference value. The etendue of the light emitting part is smaller than the etendue of the optical device.

  According to the present invention, the plurality of optical fibers are arranged in the light emitting portion so that the in-plane uniformity of the light intensity at the emitting end face of the rod is equal to or greater than a predetermined reference value. That is, the plurality of optical fibers are arranged so that the in-plane uniformity of the light intensity at the exit end face of the rod is equal to or greater than a reference value. Thereby, the insufficiency of the in-plane uniformity of the light intensity distribution at the exit end face of the rod can be improved.

It is a figure which shows the structure of the projector using the laser beam emitting apparatus which concerns on Embodiment 1 of this invention. It is a figure which shows the structure of the laser beam emitting apparatus which concerns on Embodiment 1 of this invention. It is a figure which shows the structure of the end surface into which the light beam from the light emission part 7 injects among rods. As a comparative example, it is a figure which shows the state by which the some optical fiber was arranged in the light-projection end of a light-projection part. As a comparative example, it is a figure which shows the state by which the some optical fiber was arranged in the light-projection end of a light-projection part. It is a figure which shows an example of the arrangement | sequence of the optical fiber which concerns on Embodiment 1 of this invention. It is a figure which shows the other example of the arrangement | sequence of the optical fiber which concerns on Embodiment 1 of this invention. It is a figure which shows the structure of the light-projection part which concerns on Embodiment 2 of this invention. It is a figure which shows the other example of a structure of the light-projection part which concerns on Embodiment 2 of this invention. It is a figure which shows an example of a structure of a laser beam emitting apparatus. It is a figure which shows an example of a structure of the laser beam emitting apparatus which concerns on the modification of Embodiment 2 of this invention. It is a figure which shows the arrangement | sequence of the optical fiber in the optical fiber output end which concerns on Embodiment 3 of this invention. The structure using three types of optical fibers is shown in each exit end holding part shown in FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same components are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof may be omitted.

  It should be noted that the dimensions, materials, shapes, relative arrangements, and the like of the constituent elements exemplified in the embodiments are appropriately changed depending on the configuration of the apparatus to which the present invention is applied and various conditions. It is not limited to those examples. Moreover, the dimension of each component in each figure may differ from an actual dimension.

<Embodiment 1>
FIG. 1 is a diagram showing a configuration of a projector 1000 using the laser beam emitting apparatus 100 according to Embodiment 1 of the present invention. The projector 1000 is a projector that uses a laser light source. The projector 1000 is a front projection type projector, for example. The projector 1000 is not limited to a front projection type projector, and may be a rear projection type projector, for example.

  Referring to FIG. 1, projector 1000 includes a laser light emitting device 100, a rod 110, an optical device 120, and a lens 130.

  The laser light emitting apparatus 100 emits a light beam to be used in the optical device 120 of the projector 1000 to the rod 110, as will be described in detail later.

  The rod 110 has a cylindrical shape. The rod 110 allows the light beam emitted from the laser beam emitting device 100 to pass therethrough. Further, the rod 110 makes the light beam passing through the rod 110 uniform. The light beam that has passed through the rod 110 is irradiated onto the optical device 120.

  The optical device 120 modulates the intensity of the light beam applied to the optical device 120 and guides the modulated light beam to the lens 130. The modulated light beam is a light beam constituting an image. The optical device 120 is, for example, a DMD (Digital Micromirror Device).

  The lens 130 guides the light beam (image) incident on the projection lens 30 to the screen 200. As described above, the projector 1000 projects an image on the screen 200.

  When projector 1000 is a rear projection type projector, projector 1000 includes a screen 200.

  FIG. 2 is a diagram showing a configuration of the laser beam emitting apparatus 100 according to Embodiment 1 of the present invention. Referring to FIG. 2, a laser beam emitting apparatus 100 includes a housing 1, a plurality of laser light sources 2, a plurality of optical fibers 3, an optical fiber bundle unit 4, a bundle fiber 5, and a light emitting unit 7. Is provided.

  FIG. 2 shows a state in which the bundle fiber 5 is drawn from the inside of the housing 1 of the laser beam emitting apparatus 100 to the outside of the housing 1.

  Each laser light source 2 emits a laser beam (light beam). Hereinafter, the laser light (light beam) emitted from the laser light source 2 is also simply referred to as light. An optical fiber 3 is connected to each laser light source 2. That is, the light beam (light) emitted from the laser light source 2 is coupled to the optical fiber 3.

  The optical fiber 3 connected to each laser light source 2 propagates the light emitted from the laser light source 2 in the optical fiber 3. That is, the plurality of optical fibers 3 propagate light emitted from the plurality of laser light sources.

  The optical fiber 3 emits the propagated light. The plurality of optical fibers 3 are bundled by an optical fiber bundle portion 4. The bundle fiber 5 is configured by bundling a plurality of optical fibers 3 by the optical fiber bundle portion 4.

  A light emitting portion 7 is provided at the end of the bundle fiber 5. In the present embodiment, the light emitting portion 7 is configured by one emitting end holding portion 6 (bundle fiber 5). That is, the light emitting unit 7 is configured using the emitting end holding unit 6 (bundle fiber 5). The emission end holding portion 6 is a portion that holds an end portion (outgoing end) that emits a light beam in the bundle fiber 5. That is, the light emitting unit 7 is configured by the emitting end of the bundle fiber 5.

  The light emitting unit 7 (the emitting end holding unit 6) emits a light beam (laser light) composed of light propagating through each optical fiber 3. Hereinafter, the end of the light emitting unit 7 that emits the light beam is also referred to as a light emitting end or an emitting end. In the following, the end face of the light emitting portion 7 that emits a light beam is also referred to as a light emitting end face or an emitting end face.

  FIG. 3 is a diagram illustrating a configuration of an end surface of the rod 110 on which the light beam from the light emitting unit 7 is incident. As shown in FIG. 3, the rod 110 has an opening H1. The shape of the opening H1 is rectangular. Therefore, the shape of the end surface of the rod 110 is a rectangular shape. The light beam emitted from the laser beam emitting device 100 enters the opening H1 of the rod 110.

  Hereinafter, of the openings H1 at both ends of the cylindrical rod 110, the opening H1 into which the light beam (light) is incident is also referred to as an incident opening, a rod incident opening, or a rod incident surface. In the description below, of the openings H1 at both ends of the cylindrical rod 110, the opening H1 that emits a light beam (light) is also referred to as a rod exit opening, a rod exit end, or a rod exit end face.

  4 and 5 are views showing a state in which a plurality of optical fibers 3 are arranged at the light emitting end of the light emitting unit 7 (exit end holding unit 6) as a comparative example. In FIG. 4 or FIG. 5, a fiber group is formed by the plurality of optical fibers 3.

  In the following, an end face that emits a light beam in a fiber group composed of a plurality of optical fibers 3 is also referred to as an optical fiber exit end face. 4 or 5, a region R <b> 11 indicates a region of the outermost shape (outer edge) of the optical fiber emission end face. In the following description, an end that emits a light beam in the fiber group is also referred to as an optical fiber exit end.

  The external shape (end face shape) of the rod 110 shown in FIG. 3 and the external shape (light output end shape) of the light emitting portion 7 (exit end holding portion 6) shown in FIGS. 4 and 5 are similar. . Therefore, the light beam emitted from the light emitting portion 7 (the emission end holding portion 6) is efficiently coupled (incident) to the opening H1 of the rod 110.

  FIG. 4 shows a state in which the optical fibers 3 are arranged in a square array. FIG. 5 shows a state in which the optical fibers 3 are arranged in an equilateral triangle arrangement.

  At this time, it is a condition with no optical coupling loss that the etendue from the optical fiber exit end is equal to or less than the etendue of the rod incident aperture. Here, etendue is a characteristic of the optical system. Etendue is the product of the cross-sectional area of the light cone in a plane perpendicular to the light propagation direction and the solid angle defined by the light.

  Specifically, etendue E is expressed by the product of the cross-sectional area of the light beam and the radiation solid angle. The etendue E is expressed by the following equation 1 using the numerical aperture NA and the cross-sectional area A of the luminous flux. The cross-sectional area A of the light beam is the area of the outermost shape (outer edge) of the optical fiber exit end face.

E = π × A × NA ² (Formula 1)
4 and 5, the outermost shape of the optical fiber emitting end face is smaller than the outer shape of the emitting end of the light emitting portion 7 (the emitting end holding portion 6), and satisfies the etendue conditions. Yes.

  On the other hand, in the arrangement of equilateral triangles in FIG. 5, the luminous flux density per unit area is high, but the total luminous flux is smaller than that in the square arrangement in FIG. That is, FIG. 4 and FIG. 5 show that the optimal arrangement of the optical fibers differs depending on the outer shape.

  In order to obtain the desired desired brightness and white balance, the light output (light intensity) of each laser light source is defined. This determines the number of laser light sources of each color that are required. Next, the number of necessary optical fibers is determined by defining a laser beam superimposing method.

  On the other hand, when the number of optical fibers is determined, the optical fiber at the exit end as shown in FIG. 4 or 5 becomes the maximum etendue with respect to the opening H1 (rod incident opening) of the rod 110 in FIG. It is not always necessary to take the arrangement of

  That is, if the etendue E derived from the formula 1 from the area of the outermost (outer edge) of the optical fiber exit end face and the NA satisfies the etendue of the rod incident aperture or less, no optical coupling loss occurs. . In this case, flexibility can be given to the number of optical fibers and the arrangement of the optical fibers.

  Although the laser light source generates monochromatic laser light, the laser light of each color needs to be superimposed on the screen (screen 200) on which the laser light is projected. As the wavelength superimposing method of the laser light, there are the following methods.

  The wavelength superimposing method is, for example, a method of combining optical fibers of respective colors with a combiner. The wavelength superimposing method is a method of spatially superimposing with a dichroic mirror, for example. In addition, the wavelength superimposing method is, for example, a method in which light of each color is propagated to the drawing device and superimposed at the time of projection. Depending on each of the above methods, the wavelength configuration of the light propagating in the optical fiber is different and the configuration of FIG. 1 is also modified. In the present invention, any method may be used unless otherwise noted. .

  On the other hand, the in-plane uniformity of the light intensity at the rod exit end surface includes the light intensity distribution at the rod entrance surface (rod entrance aperture), the ratio between the size of the rod entrance aperture and the length of the rod, and the entrance aperture. It is known to be determined in relation to numbers. Here, the in-plane uniformity of light intensity is the uniformity of light intensity on the surface from which light is emitted. Hereinafter, the in-plane uniformity of light intensity is also simply referred to as in-plane uniformity.

  This is understood by the following facts. The fact is that when the light flux incident on the rod is repeatedly reflected on the side surface of the rod and transferred to the exit end face of the rod, the light intensity distribution on the exit end face of the rod is folded back according to the spread of the light flux. This means that the distribution is superposed.

  That is, in order to obtain a distribution with good in-plane uniformity, it is preferable to use a rod that is relatively thin with respect to the beam spread. In general, the sizes of the vertical and horizontal sides of the entrance opening of the rod are different in accordance with the shape of the projection device for projecting a horizontally long image.

  On the other hand, in a general optical fiber, the number of exit apertures is isotropic. Therefore, the number of incident apertures on the rod can be considered to be the same in the vertical direction and the horizontal direction. That is, the number of incident apertures on the rod is the same in the vertical and horizontal directions, but the size of the sides of the incident aperture differs in the vertical and horizontal directions. The in-plane uniformity of the light intensity differs between the vertical direction and the horizontal direction, and the uniformity in the long side direction of the incident aperture is relatively poor. In the design stage, the length of the rod is determined so that there is no practical problem even in the long side direction where the uniformity is deteriorated.

  Here, in order to solve the problem in the configuration of the projector, consider a case where light is incident on the incident surface of the rod with a non-uniform distribution. At this time, in order to maintain practical in-plane uniformity at the rod exit end, it is derived that it is necessary to define the array of exit end surfaces according to the following conditions.

  Here, if the incident distribution function in the x direction is Pi (x) and the transfer function to the rod exit end is T (f, x), the exit distribution function is T (Pi (x), x). Considering the integration of a finite number of optical fibers, the distribution function obtained at the exit end can be expressed by the following equation (2).

ΣT (Pi (x), x) (Expression 2)
Note that f in T (f, x) is a distribution function, and Σ in Equation 2 is the total sum of T (Pi (x), x) when i = 1 to n (natural number).

  Here, it is assumed that a function indicating the minimum value of the argument T is expressed as Min (T). A function indicating the maximum value of the argument T is represented as Max (T). In this case, when the following expression 3 is satisfied with respect to the determination reference value U (1 ≧ U ≧ 0) for the uniformity of the light intensity, only the light beam emitted from one optical fiber exit end is at the exit end. This indicates that the in-plane uniformity is insufficient. Here, the determination reference value U is a reference value for determining whether the in-plane uniformity of the light intensity on the surface from which light (light flux) is emitted is sufficient (excellent).

Min (T (Pi (x), x) / Max (T (Pi (x), x) <U) (Equation 3)
In Equation 3, Min (T (Pi (x), x) / Max (T (Pi (x), x)) is the in-plane uniformity of the light intensity (light intensity distribution) on the surface from which light (light flux) is emitted. It corresponds to (uniformity).

  When Expression 3 is satisfied, it is a condition when the light intensity distribution P (x) at the rod incident surface is steep or when sufficient repeated reflection cannot be obtained.

  In addition, in order to improve the uniformity of the intensity distribution at the emission end obtained by Expression 2 and satisfy the following Expression 4, T (f, x) does not depend on f and is uniform with respect to x. It is required to be.

Min (ΣT (Pi (x), x) / Max (ΣT (Pi (x), x) ≧ U) (Expression 4)
In Equation 4, Min (ΣT (Pi (x), x) / Max (ΣT (Pi (x), x)) is the in-plane uniformity of the light intensity on the light emitting surface (for example, the rod emitting end surface) ( When the in-plane uniformity of a certain light intensity is equal to or greater than the determination reference value U, the in-plane uniformity of the light intensity is sufficiently high (excellent).

  Therefore, in the present embodiment and the second embodiment to be described later, the light emitting section is such that the in-plane uniformity of the light intensity at the emitting end face of the rod 110 is equal to or greater than a predetermined reference value (determination reference value U). In FIG. 7, the plurality of optical fibers 3 are arranged. That is, the plurality of optical fibers 3 are arranged so that the uniformity of the light intensity at the exit end face of the rod 110 is equal to or greater than the determination reference value U. Further, in the present embodiment and the second embodiment described later, the plurality of optical fibers 3 are arranged so that the etendue of the light emitting unit 7 is smaller than the etendue of the optical device 120.

  Specifically, as shown in FIG. 6, the optical fibers 3 are arranged so that incident light is widely distributed in the incident surface of the rod 110 as shown in FIG.

  More specifically, as shown in FIG. 6, the emission end face of the light emission part 7 is composed of a plurality of optical fibers 3 and a plurality of fillers 3Z. The filling 3Z is an alternative to the optical fiber 3 for arranging the optical fibers 3 at intervals. That is, the filler 3Z is for holding each optical fiber 3 while keeping a space between the optical fibers 3. That is, the emission end holding unit 6 (light emission unit 7) holds the emission end of each optical fiber 3 and the filling 3Z that fills the gap between the emission ends in a plane.

  The shape of the filling 3Z is, for example, a cylindrical shape similar to the shape of the optical fiber 3. The filling 3Z is made of rubber, for example. The filler 3Z is not limited to rubber, and may be made of any material as long as it does not propagate light.

  As shown in FIG. 6, by arranging each optical fiber 3 and each filler 3 </ b> Z, the plurality of optical fibers 3 are arranged at intervals over the entire end face (outgoing end face) of the light emitting portion 7. In this case, the interval is s (natural number) times the diameter of the filling 3Z.

  According to the configuration of FIG. 6, the luminous flux is emitted with a uniform distribution while being scattered in the emission end face. In-plane uniformity is not sufficient with each light beam alone, but uniformity of light intensity is improved by spatially uniformly superimposing each light beam. As a result, the in-plane uniformity as the sum satisfies the desired determination reference value U. Further, according to the configuration of FIG. 6, the etendue of the light emitting unit 7 is smaller than the etendue of the optical device 120.

On the other hand, when the following expression 5 is satisfied, the minimum condition of in-plane uniformity at the rod exit end is satisfied. If Equation 4 is satisfied,
Min (T (Pi (x), x) / Max (T (Pi (x), x) ≧ U) (Expression 5)
When Expression 5 is satisfied, Expression 4 described above is also satisfied. In this case, the optical fibers 3 can be concentrated and arranged, and there is an advantage that the etendue can be kept small.

  However, in general, the sizes of the sides in the vertical and horizontal directions of the opening of the rod are different. Therefore, if the vertical direction and the horizontal direction are defined as the x direction and the y direction, respectively, the transfer functions T (f, x) and T (f, y) are different. That is, the uniformity of the transfer function in the long side direction of the rod is relatively poor. Therefore, when collecting the light flux in a part, it is derived that it is more effective to suppress the reduction in the size of the incident light in the long side direction of the rod than to maintain the shape similar to the shape of the rod incident surface.

  Therefore, the arrangement of the optical fibers 3 at the optical fiber output end in the present embodiment may be as shown in FIG. The arrangement shown in FIG. 7 is an arrangement in which the light flux is concentrated on a part of the rod incident surface to reduce the etendue.

  In addition, the arrangement shown in FIG. 7 does not have a similar shape of the outer shape of the rod incident surface, but relatively increases the aperture ratio of light in the long side direction, and increases the aperture ratio of light in the short side direction. This is a relatively small array. Hereinafter, the aperture ratio of light is also simply referred to as an aperture ratio.

  Specifically, the number of optical fibers 3 that fits in the outermost shape (outer edge) of the optical fiber exit end that satisfies the etendue is 13 × 7 = 91 in FIG. 4. That is, 91 optical fibers 3 are arranged in 7 rows and 13 columns.

  On the other hand, in FIG. 7, the number of optical fibers 3 is 21. Specifically, as shown in FIG. 7, the 21 optical fibers 3 are arranged in 3 rows and 7 columns. With this arrangement, in FIG. 7, the long side of the optical fiber exit end face is reduced by a ratio of 7/13 (0.54), and the short side of the optical fiber exit end face is a ratio of 3/7 (0.43). Is reduced. Thereby, the aperture ratio in the short side direction of the optical fiber emitting end face is relatively reduced.

  That is, in the configuration of FIG. 7, the plurality of optical fibers 3 are arranged so as to gather on a part of the end face (light emission end face) of the light emission portion 7.

  According to the configuration of FIG. 7, the etendue is reduced because the light flux is localized in the exit end face. Furthermore, by defining the outer shape of the opening so as not to reduce the in-plane uniformity of light, the in-plane uniformity satisfies the desired determination reference value U. That is, the in-plane uniformity (uniformity) of the light intensity at the rod exit end face is equal to or greater than the determination reference value U. Further, according to the configuration of FIG. 7, the etendue of the light emitting unit 7 is smaller than the etendue of the optical device 120.

  As described above, according to the present embodiment, the plurality of optical fibers 3 are arranged in the light emitting portion 7 so that the in-plane uniformity of the light intensity at the emission end face of the rod 110 is equal to or greater than a predetermined reference value. . That is, the plurality of optical fibers 3 are arranged so that the uniformity of the light intensity at the exit end face of the rod 110 is equal to or greater than the reference value (determination reference value U). Thereby, the insufficiency of the in-plane uniformity of the light intensity distribution at the exit end face of the rod 110 can be improved.

  In addition, according to the present embodiment, it is possible to provide a laser beam emitting apparatus including a light emitting unit having excellent in-plane uniformity of light intensity distribution. That is, according to the present embodiment, it is possible to provide a laser beam emitting apparatus with high in-plane uniformity of light intensity distribution.

<Embodiment 2>
Next, an example of the arrangement of the optical fibers 3 for adjusting the brightness of the projector 1000 within a range in which the incidence etendue to the rod 110 is allowed when the condition of FIG. 7 is satisfied will be described. In the present embodiment, the light emitting part 7 is constituted by a plurality of emitting end holding parts 6.

  Although details will be described later in the present embodiment, the arrangement of the bundle fibers 5 is changed according to the setting of the light output of each color of the laser light source. In addition, the light emission part 7 in this Embodiment is comprised so that the etendue of the said light emission part 7 may become smaller than the etendue of the optical device of a projector. The optical device is the rod 110, the optical device 120, or the like in the projector 1000 of FIG.

  FIG. 8 is a diagram showing a configuration of the light emitting unit 7 according to Embodiment 2 of the present invention. As shown in FIG. 8, the light emission part 7 is comprised by the three output end holding | maintenance parts 6 (bundle fiber 5). In FIG. 8, for example, the plurality of optical fibers 3 on the exit end face of the light exit section 7 are divided into three in the short side direction of the exit end face. Each of the three emission end holding parts 6 constituting the light emission part 7 is configured to be freely detached from the light emission part 7. That is, the light emitting unit 7 is configured so that the number of the emission end holding units 6 (bundle fibers 5) constituting the light emitting unit 7 can be changed.

  With such a configuration, the number of bundle fibers 5 constituting the light emitting unit 7 can be changed. Thereby, the brightness (intensity) of the light beam emitted from the light emitting unit 7 can be adjusted to 1 time, 2 times, and 3 times that of the configuration using one bundle fiber 5.

  In addition, the number of the output end holding parts 6 (bundle fibers 5) constituting the light emitting part 7 is not limited to 3, and may be 2 or 4 or more.

  FIG. 9 is a diagram illustrating another example of the configuration of the light emitting unit 7 according to Embodiment 2 of the present invention. As shown in FIG. 9, the light emission part 7 is comprised by the five output end holding | maintenance parts 6 (bundle fiber 5). In FIG. 9, the plurality of optical fibers 3 on the exit end face of the light exit portion 7 are divided into five on the exit end face. That is, in the light emitting unit 7, the optical fibers 3 are arranged in the vertical direction and the horizontal direction.

  Each of the five emission end holding parts 6 (bundle fiber 5) constituting the light emission part 7 is configured to be freely detached from the light emission part 7. That is, the light emitting unit 7 is configured so that the number of the emission end holding units 6 (bundle fibers 5) constituting the light emitting unit 7 can be changed. With the configuration of FIG. 9, the setting range of the brightness (intensity) of the light beam emitted from the light emitting unit 7 can be expanded to 1 to 5 times that of the configuration using one bundle fiber 5.

  According to the configuration of FIG. 9, the splitting direction of the optical fiber output end is not limited to one direction, and the output end holding portion 6 having a small output opening is combined. Thereby, the setting range of brightness can be expanded.

  Generally, in the conventional laser beam emitting device, the configuration of the light emitting unit cannot be changed. Therefore, there is a problem that the brightness cannot be adjusted by adding or reducing the light source device.

  Therefore, according to this embodiment as described above, not only the etendue is satisfied, but the brightness is adjusted by increasing or decreasing the number of bundle fibers 5 while maintaining the in-plane uniformity of the light intensity distribution. Is possible.

  Next, a configuration for realizing the configuration of the light emitting unit 7 according to the present embodiment will be described. The light emission part 7 which concerns on this Embodiment is comprised by the following laser beam emission apparatuses 300, for example.

  FIG. 10 is a diagram illustrating an example of the configuration of the laser beam emitting apparatus 300. As shown in FIG. 10, the laser light emitting device 300 includes, as an example, two laser light emitting devices 100 that share the light emitting unit 7. Note that the number of laser light emitting devices 100 included in the laser light emitting device 300 is not limited to two, and may be three or more. That is, the laser beam emitting device 300 includes a plurality of laser beam emitting devices 100 that share the light emitting unit 7. Further, the laser beam emitting apparatus 300 includes the light emitting unit 7 according to the present embodiment.

  The light emitting unit 7 according to the present embodiment is configured by two bundle fibers 5 (emission end holding units 6) provided in the two laser light emitting devices 100, respectively. That is, the light emitting unit 7 according to the present embodiment is configured by the bundle fiber 5 of the plurality of laser light emitting devices 100. In other words, the emission ends of the plurality of bundle fibers 5 are arranged in the light emission unit 7 shared by the laser light emission devices 100.

  Specifically, the light emitting unit 7 according to the present embodiment is configured by a bundle fiber 5 (emission end holding unit 6) drawn from the housing 1 of each laser light emitting device 100. That is, each bundle fiber 5 constituting the light emitting unit 7 according to the present embodiment is provided from a plurality of laser light emitting devices 100.

  The number of bundle fibers 5 constituting the light emitting unit 7 according to the present embodiment is not limited to 2, and may be 3 or more.

<Modification of Embodiment 2>
The light emission part 7 which concerns on the modification of this Embodiment is comprised by the following laser beam emission apparatuses 100A, for example.

  FIG. 11 is a diagram illustrating an example of a configuration of a laser light emitting apparatus 100A according to a modification of the second embodiment of the present invention. As shown in FIG. 11, the laser light emitting device 100A is provided with two optical fiber bundle portions 4 and two bundle fibers 5 as compared with the laser light emitting device 100 of FIG. The difference is that two exit end holding portions 6 are provided. Since the other configuration of laser beam emitting apparatus 100A is the same as that of laser beam emitting apparatus 100, detailed description will not be repeated.

  FIG. 11 shows a state in which two bundle fibers 5 (exit end holding portions 6) are drawn from the inside of the casing 1 of one laser light emitting apparatus 100A to the outside of the casing 1. In addition, the number of the optical fiber bundle part 4, the bundle fiber 5, and the output end holding | maintenance part 6 with which the laser beam emitting apparatus 100A is provided is not limited to 2, and may be 3 or more. That is, the laser beam emitting apparatus 100 </ b> A includes a plurality of bundle fibers 5.

  Hereinafter, in the projector 1000 of FIG. 1, a projector in which the laser light emitting device 100 is replaced with the laser light emitting device 100A is also referred to as a projector A. The laser beam emitting device 100A is used in a plurality of projectors A. In this case, the plurality of bundle fibers 5 are used by the plurality of projectors A, respectively. Note that the present invention is not limited to this, and the plurality of bundle fibers 5 may be used by one projector A. That is, the plurality of bundle fibers 5 are used in at least one of the plurality of projectors A.

  The light emission part 7 which concerns on the modification of this Embodiment is comprised by the some bundle fiber 5 (output end holding | maintenance part 6) with which 100 A of laser beam emission apparatuses are provided.

  Generally, in a conventional laser beam emitting device, in a projection system in which a laser light source having one or more bundle fibers and one or more projectors are combined, the flexibility of connection between the laser light source and the rod in the projector is ensured. Not. Thereby, there exists a subject that cost reduction is prevented.

  On the other hand, in the modification of the present embodiment, a plurality of bundle fibers 5 can be provided from one laser light emitting device 100A with the configuration of FIG. Specifically, a plurality of bundle fibers 5 can be pulled out from the casing 1 of one laser beam emitting device, and each can be connected to a plurality of different projectors.

  That is, with the configuration of FIG. 11, the bundle fiber can be changed to a desired configuration suitable for the projector. Thereby, the flexibility of the connection between 100 A of laser beam emitting apparatuses and the rod in each projector can be improved. As a result, it is possible to reduce the introduction cost and the operation cost.

  Furthermore, there is an effect of reducing the introduction cost and the running cost by centrally managing the laser beam emitting apparatus 100A.

  According to the second embodiment and the modification thereof, it is possible to configure the light emitting unit 7 having an emission pattern suitable for the incident optical system of the laser projector. As a result, it is possible to provide a light intensity distribution with high in-plane uniformity. That is, according to the present embodiment, it is possible to provide a laser beam emitting apparatus with high in-plane uniformity of light intensity distribution.

  In addition, according to the second embodiment and the modification thereof, the light emitting unit can be configured by combining a plurality of bundle fibers 5. Therefore, the brightness of the projector can be adjusted by means of adding or reducing the number of laser light sources, and the operational flexibility is improved.

  Further, as described above, the configuration of the laser beam emitting apparatus used in the projector can be the configuration shown in FIG. 2, FIG. 10, or FIG. That is, the laser beam emitting apparatus having the configuration shown in FIGS. 6 to 9 and the projector can be connected using the bundle fiber 5 shown in FIG. 2, FIG. 10, or FIG.

<Embodiment 3>
When the related technologies A and B described above are applied to a laser projector device, there is a problem in that it is difficult for the color arrangement ratio of the light source corresponding to the light output of the laser light source to satisfy a predetermined reference value. In the present embodiment, the above problems are solved.

  In the present embodiment, when the light propagating through the optical fiber 3 is a single color and light of different colors is arranged on the same emission surface, in addition to the in-plane uniformity of the etendue and the light intensity distribution, The structure which ensures balance is shown. That is, in this embodiment, the optical fibers 3 are arranged so as to satisfy both the color arrangement ratio of the light source and the in-plane uniformity of the light intensity distribution.

  FIG. 12 is a diagram showing the arrangement of the optical fibers 3 at the optical fiber output end according to the third embodiment of the present invention. Specifically, FIG. 12 shows a configuration in which red, green, and blue laser beams are emitted from the light emitting unit 7 as light of three different colors in the configuration of FIG. In the arrangement of the optical fibers shown in FIG. 12, the laser beam emitting device 100 shown in FIG. 2 is used.

  Hereinafter, the optical fiber 3 that propagates red laser light (red light) and emits the red light is also referred to as an optical fiber 3R. In the following, the optical fiber 3 that propagates green laser light (green light) and emits the green light is also referred to as an optical fiber 3G. In the following, the optical fiber 3 that propagates blue laser light (blue light) and emits the blue light is also referred to as an optical fiber 3B.

  That is, each of the plurality of optical fibers 3 provided in the laser light emitting apparatus 100 according to Embodiment 3 propagates any one of a plurality of colors of light. Each of the plurality of laser light sources 2 included in the laser beam emitting apparatus 100 emits one of a plurality of colors of light for generating an image. Moreover, the light emission part 7 with which the laser beam emission apparatus 100 is provided is comprised by several optical fiber 3R, 3G, 3B.

  The required number of optical fibers 3 is derived from the light output (light intensity) of each color necessary for white balance and the light output (light intensity) obtained from the laser light source of each color. In the present embodiment, among the luminous flux emitted from the light emitting unit 7, the color arrangement ratio that is the ratio of each of the light of the plurality of colors propagated by the plurality of optical fibers 3R, 3G, 3B matches the reference color arrangement ratio. As described above, the optical fibers 3 are arranged. The reference color arrangement ratio is a predetermined color arrangement ratio for the projector 1000 to project a normal color image. Specifically, each optical fiber 3 (optical fibers 3R, 3G, 3B) is arranged as follows.

  In FIG. 12, as an example, a configuration using 21 optical fibers 3 including eight optical fibers 3R, nine optical fibers 3G, and four optical fibers 3B is shown. In this configuration, the same concept as the in-plane uniformity described with reference to FIGS. 6 and 7 applies to each color of light. Therefore, the arrangement (arrangement) of the optical fibers 3R, 3G, 3B is preferably the arrangement (arrangement) shown in FIG. 12, for example.

  Specifically, the 21 optical fibers are arranged in 3 rows and 7 columns so as to maintain in-plane uniformity. In FIG. 12, in addition to in-plane uniformity, in-plane uniformity is maintained for all three colors of light (red light, green light, and blue light). Specifically, as in FIG. 7, the distribution (arrangement) of the uniform optical fibers in the arrangement surface (optical fiber emission end face) while relatively reducing the aperture ratio in the short side direction of the optical fiber emission end face. Designed.

  In the following, the uppermost row in the 3 × 7 array is also referred to as the uppermost row or the uppermost column. In the following, the middle row of the 3 × 7 array is also referred to as a central row or a central column. In the following, the lowest row in the 3 × 7 array is also referred to as the bottom row or the bottom column.

  Specifically, as shown in FIG. 12, four optical fibers 3 </ b> B are arranged at intervals of one optical fiber 3 in the center row (center column). In the uppermost row and the lowermost row, the seven optical fibers 3R and the seven optical fibers 3G are arranged in a staggered manner. Further, in the center row (center column), one optical fiber 3R is disposed at the center of the three locations where the optical fibers 3B are not disposed. Further, in the center row (center column), two optical fibers 3G are arranged at two positions on the left and right of the three positions.

  With this configuration, among the light beams emitted from the light emitting unit 7, the color arrangement ratios of the light of the plurality of colors propagated by the plurality of optical fibers 3R, 3G, and 3B coincide with the reference color arrangement ratio described above.

  Note that the uniformly dispersed array is not limited to the array shown in FIG. 12, and may be another array.

  According to the configuration of FIG. 12, while maintaining the white balance, a small etendue is maintained by collecting a plurality of optical fibers 3 at a part of the optical fiber exit end so that the outgoing light flux of each color is distributed widely. Arrange. Thereby, a laser beam emitting apparatus with high in-plane uniformity of the light intensity distribution for each color light can be provided.

  The arrangement of the optical fibers 3R, 3G, 3B according to the present embodiment may be applied to the configuration of FIG. 8 or FIG.

  FIG. 13 shows, as an example, a configuration in which optical fibers 3R, 3G, and 3B are used for the respective emission end holding portions 6 (bundle fibers 5) shown in FIG. Specifically, FIG. 13 is a diagram illustrating a state in which the optical fibers 3R, 3G, and 3B are arranged in each of the emission end holding portions 6 (bundle fibers 5) illustrated in FIG.

  In FIG. 13, as an example, an arrangement configuration using five optical fibers 3R, six optical fibers 3G, and three optical fibers 3B is shown. Similarly to FIG. 12, from the viewpoint of in-plane uniformity, for example, the arrangement (arrangement) of optical fibers shown in FIG. 13 is preferable.

  In the arrangement of the optical fibers shown in FIG. 13, the laser light emitting device 300 in FIG. 10 or the laser light emitting device 100A in FIG. 11 is used. With this configuration, among the light beams emitted from the light emitting unit 7, the color arrangement ratios of the light of the plurality of colors propagated by the plurality of optical fibers 3R, 3G, 3B coincide with the reference color arrangement ratio.

  According to the configuration of FIG. 13, a laser beam emitting device that can combine the emission end holding unit 6 (bundle fiber 5) while maintaining white balance and has high in-plane uniformity of small etendue and light intensity distribution. Can be provided.

  As mentioned above, according to this Embodiment, the ratio of the number of the optical fibers 3 of each color can be changed. That is, the number of laser light sources is increased or decreased according to the light intensity ratio of the laser light sources. Thereby, it is possible to appropriately set the color arrangement ratio of the projector. This has the effect of providing an efficient and inexpensive laser light emitting device that does not incorporate an excessive laser light source.

  In addition, according to the present embodiment, it is possible to provide a laser beam emitting apparatus including a light emitting unit that is excellent in coloration ratio and in-plane uniformity of light intensity distribution.

  In a conventional laser light emitting device that combines laser light sources that emit monochromatic light of different wavelengths, the number of optical fibers corresponding to light of each color is different. For this reason, it has been difficult to keep the color ratio and the in-plane uniformity of the light intensity distribution of the screen constant.

  Therefore, in each of the above-described embodiments, a fiber array design that improves the in-plane uniformity of the light intensity distribution within the allowable range of the etendue of the projector is performed. Thereby, it is possible to provide a screen having excellent in-plane uniformity of the color arrangement ratio and the light intensity distribution.

  In addition, within the scope of the present invention, the present invention can be freely combined with each embodiment and modifications of the embodiment, or can be appropriately modified and omitted with each embodiment and modification of the embodiment. It is possible.

  The laser beam emitting apparatus according to the present invention can be used for a laser projector apparatus that requires in-plane uniformity of the light intensity distribution. Furthermore, the present invention can be utilized for a laser projector apparatus that requires flexibility in brightness and operability.

  2 Laser light source, 3, 3B, 3G, 3R optical fiber, 4 optical fiber bundle section, 5 bundle fiber, 6 exit end holding section, 7 light exit section, 100, 100A, 300 laser light exit apparatus, 110 rod, 120 optics Device, 130 lenses, 200 screens, 1000 projectors.

Claims (7)

A laser beam emitting device that emits a light beam to a rod for use in an optical device of a projector that projects an image,
A plurality of laser light sources emitting light;
A bundle fiber configured by bundling a plurality of optical fibers for propagating light emitted from the plurality of laser light sources;
A light emitting portion constituted by an emission end of the bundle fiber,
The plurality of optical fibers are arranged in the light emitting portion so that the in-plane uniformity of the light intensity at the emitting end face of the rod is equal to or greater than a predetermined reference value,
Etendue of the light emitting unit is smaller than etendue of the optical device. The laser light emitting device according to claim 1, wherein the plurality of optical fibers are arranged at intervals over the entire end face of the light emitting unit. The laser light emitting device according to claim 1, wherein the plurality of optical fibers are arranged so as to gather on a part of an end face of the light emitting unit. A plurality of the laser beam emitting devices according to claim 3, wherein the light emitting unit is shared,
The laser beam emitting device according to claim 3, wherein the emission ends of the plurality of bundle fibers are arranged in the shared light emitting unit. 2. Each of the plurality of laser light sources emits one of a plurality of colors of light for generating an image, and each of the plurality of optical fibers propagates one of the plurality of colors of light. The laser beam emitting device according to any one of? 6. A color arrangement ratio, which is a ratio of each of the plurality of colors of light propagated by the plurality of optical fibers out of the luminous flux, coincides with a predetermined color arrangement ratio for the projector to project an image. The laser beam emitting device described in 1. The laser beam emitting device is used in a plurality of the projectors,
A plurality of the bundle fibers are provided,
The laser beam emitting device according to claim 1, wherein the plurality of bundle fibers are used in the plurality of projectors.

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