JP2015060092A - Light source device and projector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid appearance of a periodic pattern superimposed on a transmitted beam of a two-dimensional lens array and a cross cylindrical lens array for speckle reduction.SOLUTION: A light source device comprises: a light radiation area formed by a coherent light source, light mixing means for mixing components of the angle and position of an incident beam from an incident end and emitting light from an emission end; and a light flux matching optical system for projecting a light flux emitted from the light radiation area onto the incident end. The light flux matching optical system includes a two-dimensional lens array functioning as light diffusion means. The two-dimensional lens array has an effective area which is composed of at least one sub area, and the arrangement of vertices of individual lenses composing the sub area is nonperiodic.

Description

  The present invention relates to a light source device using a coherent light source such as a semiconductor laser that can be used in an optical device such as a projector.

For example, high-intensity discharge lamps (HID lamps) such as xenon lamps and ultra-high pressure mercury lamps have been used in image display projectors such as DLP (TM) projectors and liquid crystal projectors, and photomask exposure apparatuses. I came.
As an example, the principle of the projector will be described with reference to FIG. 13, which is a diagram for explaining one form of a part of a conventional projector related to the projector 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. 13, a mirror (MjA) is disposed between the illumination lens (Ej1A) and the two-dimensional light amplitude modulation element (DmjA).
Then, the two-dimensional light amplitude modulation element (DmjA) modulates the light so as to be directed to the direction in which the light is incident on the projection lens (Ej2A) or not to be incident on each pixel according to the video signal. An 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. 13, 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 also a light uniformizing means called a fly eye integrator. As an example of a projector using this light uniformizing means, a conventional projector related to the projector of the present invention is used. The principle will be described with reference to FIG. 14, which is a diagram for explaining one form of one kind (reference: Japanese Patent Application Laid-Open No. 2001-142141, etc.).

The light from the light source (SjB) composed of a high-intensity discharge lamp or the like is made into a uniform light beam by a fly-eye integrator with the help of collimator means (not shown) composed of a concave reflecting mirror or lens. Is input to the incident end (PmiB) of the converting means (FmB) and output from the exit end (PmoB).
Here, the light uniformizing means (FmB) is configured by a combination of an incident-side front stage fly-eye lens (F1B), an exit-side rear stage fly-eye lens (F2B), 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 shown in FIG. 14, since the light uniformizing means (FmB) is basically inputted with a substantially parallel light beam, the front fly-eye lens (F1B) and the rear fly-eye lens ( The distance from F2B) is set to be equal to the focal length thereof, and thus 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 of FIG. 14, LCOS (TM) (silicon liquid crystal device) is generally used as the two-dimensional optical amplitude modulation element (DmjA).
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.

  Regarding the two-dimensional optical amplitude modulation element, in addition to the reflective type as shown in FIG. 14, a transmissive liquid crystal device (LCD) is also used with an optical arrangement suitable for the same (reference: 10-133303 etc.).

  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 and 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. 13 and 14, it is omitted in order to avoid complication.

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. However, 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, for semiconductor lasers, as in the case of LEDs, the heat loss is small, the lifetime is long, and the directivity is high, so that only light in a specific direction can be used, such as the projectors and exposure apparatuses described above. Also, there is an advantage that the light use efficiency is high.
In addition, the high directivity makes it possible to perform optical transmission with high efficiency, so it is possible to separate the installation location of the semiconductor laser from the location where the light is used, such as a projector. The degree of freedom can be increased.

However, there is a problem that speckle noise is generated in the semiconductor laser.
Here, the speckle is a coherent light generated by wavelength conversion of laser light from a semiconductor laser or other laser or laser light (using a nonlinear optical phenomenon such as harmonic generation or optical parametric effect). A granular and speckled pattern that inevitably appears when light is projected, and is used to generate images for viewing, such as the projector described above, and a photomask pattern on a coating made of a photosensitive material. Since the exposure is a very troublesome phenomenon that significantly deteriorates the image quality, many improvements have been proposed for a long time.

For example, using a diffuser plate, fly-eye integrator, rod integrator, lens array, beam splitter, multiple reflection element, etc., the luminous flux is divided and overlapped in a cross section perpendicular to the optical axis, or the optical axis of the luminous flux The phase, polarization state, delay, etc. depending on the position of the cross section perpendicular to the surface are given, and the division state and the given state are changed with time by rotating, vibrating, or swinging the optical element.
Among these devices, the most frequently used means is to use a diffusion plate. However, when this means is used alone, the speckle noise reduction ability increases as the degree of diffusion increases. Since there is a trade-off relationship in which the utilization efficiency is lowered, there are few that reduce speckle noise by relying on the function of the diffuser alone, and most of them use other means in combination as described above.

  For example, Japanese Patent Laid-Open No. 51-064325 describes a technique for rotating a ground glass disk as a diffusion plate in a character pattern generator using a laser in order to prevent a decrease in resolution due to speckle. There are a large number of publications that propose similar techniques.

In the first place, the reason why the speckle noise reduction capability of the diffuser is high is that, for example, in the case of splitting the light beam by the beam splitter, the light beam is only split into two by one pass of the beam splitter. Then, at each point in the cross section perpendicular to the optical axis of the light beam, the light beam is divided into an infinite number of partial light beams, and a deflection angle including a random element is given.
The divided partial light beams are immediately superimposed on the downstream side, and the speckles are subdivided, but the speckle noise is reduced by making the speckles fine enough to be subdivided sufficiently and difficult to see. .
As shown in FIG. 15a which is a schematic diagram for explaining the concept of the prior art according to the present invention, when an incident parallel light beam (Li) is incident perpendicularly to the diffuser plate (Ed), its transmission The angular distribution of light rays has a peak in the axial direction with the original incident parallel light beam (Li) direction, that is, the optical axis (z) as the center of symmetry, and the angle (ψ) formed with the axis increases. As the distribution ratio decreases, the distribution has a shape like a distribution (P (ψ)) shown in b of FIG. 15 such as a Gaussian distribution having a wide tail.

The essence of speckle is an interference fringe, and the interference fringe becomes finer as the angle of rays to be superimposed becomes larger. Therefore, in the speckle noise reduction action of the diffuser, the central optical axis (peak of the angular distribution of transmitted light) The component around z) is not useful, and is a light component (Ap) that is separated from the center and has a distribution ratio lower than the peak, in the range of a certain lower limit angle (ψ1) or more and an upper limit angle (ψ2) or less. ) Is responsible for speckle noise reduction.
Here, the upper limit angle (ψ2) is a specific upper limit value of an angle at which a light beam can propagate through the inside to the end and can be effectively output depending on the NA in an optical system. .
Therefore, in order to increase the speckle noise reduction capability, it is only necessary to reduce the component around the central axis and increase the proportion of the component above the lower limit angle (ψ1). Should be widened.
However, if so, the number of components belonging to the bottom of the distribution also increases, the number of components exceeding the upper limit angle (ψ2) increases, and this component cannot be used effectively. As the degree increases, the speckle noise reduction capability increases, but the problem of lowering the light utilization efficiency arises.
Not only that, it results in increased light that is stray and harmful to the system.

  In order to avoid this problem that the diffuser plate potentially has, the diffuser plate has a transmitted light angle distribution that does not include components around the central axis that do not play a role in reducing speckle noise or components that belong to the tail that cannot be effectively used. An optical element that can be used instead of the above is considered, and specifically, a two-dimensional lens array can be used for this purpose.

  For example, in Japanese Patent Laid-Open No. 55-088002, a speckle pattern recorded is used as a diffuser plate. As a means for generating speckles, instead of using a normal diffuser plate, a haenocular lens It is described that (a fly-eye lens, that is, a two-dimensional lens array) or a lens in which the generatrix directions of the cylindrical lenses of the lenticular sheet are orthogonal (that is, a crossed cylindrical lens array) can be suitably used.

  Further, for example, in Japanese Patent Laid-Open No. 59-226317, in order to realize incoherent illumination using laser light in a semiconductor exposure apparatus or the like, scanning with a rotating oscillating mirror and a fly-eye lens (that is, a two-dimensional lens) are disclosed. Array), and a technique of superimposing a secondary light source image generated by a lenticular lens using a rod integrator or the like.

  Furthermore, in Japanese Patent Laid-Open No. 08-233544, in a three-dimensional shape measuring apparatus using a confocal optical system using a laser light source, coherence is reduced in order to reduce noise due to interference fringes caused by high coherence of the light source. For the purpose of lowering, a technique for inserting a light diffusing means and vibrating or rotating it is described. As a light diffusing means, for example, a microlens array (in addition to a normal diffusing element, such as a ground glass, a surface having a scattering structure, a volume scattering material such as opal glass, a diffraction grating, and an optical fiber array with irregular end faces, etc. That is, a two-dimensional lens array) is used.

  Further, Japanese Patent Application Laid-Open No. 11-014551 discloses that a laser pattern is transmitted to a microarray lens or a fly-eye lens (that is, a two-dimensional lens array) in a mask pattern defect inspection apparatus using ultraviolet laser light. A technique for eliminating interference by passing a rotating phase plate is described.

  Further, JP-A-2008-309827 discloses a technique for reducing speckle noise by inserting a rotating microlens array (that is, a two-dimensional lens array) immediately before a rod integrator in a projection type image display apparatus such as a projector. Is described.

  Further, in Japanese Patent Application Laid-Open No. 2009-043722, in a projector, in order to reduce speckles of light such as a semiconductor laser, a light diffusion intensity distribution by a microlens array (that is, a two-dimensional lens array) is centered. A technique is described in which an intermediate image is formed at a position on a light diffusing member having at least one convex portion on both sides with respect to an axis and the transmitted light is projected.

What is called a microlens array, fly-eye lens, fly-eye lens, etc. in the literature is a series of a large number of spherical lenses arranged in a two-dimensional plane, and the arrangement is a model explaining the concept of the prior art related to the present invention. As shown in FIG. 16, which is a diagram, square lenses are arranged vertically and horizontally, or rectangular lenses are arranged vertically and horizontally like the front stage fly-eye lens (F1B) and the rear stage fly-eye lens (F2B). There are various methods such as arranging the lenses in a honeycomb shape, but in the present invention, these are all referred to as a two-dimensional lens array regardless of the arrangement method.
In addition, the lenticular lens has a large number of cylindrical lenses arranged. However, since the method of use here is irrelevant to the original lenticular technology (stereoscopic display and multiple image display), in the present invention, this will be hereinafter referred to as “lenticular lens”. Is referred to as a cylindrical lens array, and a plurality of cylindrical lens arrays (Lca1 ′, Lca2 ′) having different generatrix directions are overlapped as shown in FIG. 17 which is a schematic diagram for explaining the concept of the prior art according to the present invention. This is called a crossed cylindrical lens array.

Here, as the diffusing plate increases the degree of diffusion, the speckle noise reduction capability increases. On the other hand, the problem of reducing the light utilization efficiency is avoided when the two-dimensional lens array is used instead of the diffusing plate. The reason why this is possible will be described with reference to FIG. 1, which is a schematic diagram of a concept related to the technology of the light source device of the present invention.
FIG. 1A is an enlarged view of one unit square (S0) out of many unit squares included in the two-dimensional lens array (Lar ′) shown in FIG. Hs) is a view from the front, and the lower part is a side view.

Consider the case where the refracting surface (Hs) is a spherical surface and the refracting surface on the back side is a substrate surface (Hb), and is therefore a flat surface, and a parallel light beam is incident perpendicularly to this surface.
Although the angle of the ray passing through the vertex or center of the refractive surface (Hs) does not change, according to the teaching of the paraxial theory of geometric optics, the light incident on the position shifted by the deviation radius (r) from the vertex is , It is deflected by an angle proportional to the deviation radius (r).
Paying attention only to the absolute value of the deflection angle, the proportion of the distribution of light deflected by a certain angle ψ (ie, the number of rays) P is the circumference of the circle (C1) having the deviation radius (r) corresponding to that angle. Since P is proportional to the length, P is proportional to 2πr.
However, when the deviation radius (r) is larger than the radius (R) of the inscribed circle (C0) of the unit square (S0) (that is, half of the side length of the unit square (S0)), the divided circle (C2 1), when multiplied by the ratio of the effective existence range angle (θ) to the entire circumference, the distribution amount (P) as a function of the deviation radius (r) is eventually expressed as shown in FIG. It becomes like this.
The specific form of the function is as shown in the lower equation.
However, the proportionality factor 2π is reduced so that the peak is 1.

  As described above, since the radius r corresponds to the deflection angle ψ, the horizontal axis of the graph of FIG. 1B is seen as ψ, and compared with the graph of FIG. There is no useless component around the axis, and there is no component corresponding to the tail of the distribution that lowers the light utilization efficiency. By using a two-dimensional lens array instead of a diffuser, speckle noise It can be seen that there is a possibility of functioning as a speckle noise reduction element having a high reduction action and low loss.

However, when comparing FIG. 1 and FIG. 15, it should be noted that the horizontal scale is different and direct comparison is not possible.
In order to perform direct comparable scaling, geometrical paraxial theory is used by using specific values of the radius of curvature of the refractive surface (Hs) and the refractive index of the material of the two-dimensional lens array (Lar ′). Then, the power of the refracting surface (Hs) is obtained according to the teaching of the above, and the maximum value of the deflection angle (r) is multiplied by the maximum value √2 · R to calculate a specific maximum deflection angle, that is, the maximum deflection angle Ψ. be able to.
Alternatively, as described in a of FIG. 1, the angle (Φ) formed by the normal (n) of the refracting surface and the optical axis (z) at the position corresponding to the maximum value √2 · R of the deviation radius (r). ) And the maximum deflection angle Ψ may be calculated according to Snell's law.
As a result, the correspondence between the maximum value √2 · R of the deviation radius (r) and the maximum deflection angle Ψ is determined, and scaling is possible.

Although the two-dimensional lens array has been described above, the same discussion can be made in the case of the crossed cylindrical lens array as shown in FIG. 17. In particular, in the case of the crossed cylindrical lens array in which the generatrix directions are orthogonal, If the interval between the cylindrical lens arrays (Lca1 ′, Lca2 ′) is small, at least in the range of paraxial theory, the optical function is completely equivalent to the two-dimensional lens array (Lar ′) composed of spherical lenses.
In the figure, for convenience of drawing, both the upper and lower cylindrical lens arrays are drawn such that a cylindrical lens is formed on the upper surface of the substrate. However, the upper cylindrical lens array has a cylindrical lens structure. The degree of approximation to the two-dimensional lens array (Lar ′) composed of spherical lenses is improved by arranging the formed side face downward and the upper and lower cylindrical lenses facing each other.

JP-A-51-064325 JP-A-55-0800002 JP-A-59-226317 JP-A-08-233544 JP-A-11-014551 JP-A-2008-309827 JP-A-2009-042372

However, although the two-dimensional lens array and the crossed cylindrical lens array should exhibit excellent speckle noise reduction action on the above-mentioned theory, the above-described projector is configured using these transmitted lights, When the image is projected onto the screen, another problem arises that periodic patterns such as striped patterns and lattice patterns appear to be superimposed.
The problem to be solved by the present invention is to provide a light source device and a projector that avoid the appearance of a periodic pattern superimposed on the transmitted light of a two-dimensional lens array for speckle reduction or a crossed cylindrical lens array.

  The light source device according to the first aspect of the present invention performs emission by mixing the light emission region (Gs) formed by the coherent light source (Sc) and the components of the angle and position of the incident light from the incident end (Pmi). A light source having a light mixing means (Fm) emitted from the end (Pmo) and a light beam matching optical system (Eu) for projecting a light beam emitted from the light emission region (Gs) onto the incident end (Pmi) The light beam matching optical system (Eu) includes a two-dimensional lens array (Lar) that functions as a light diffusing unit, and the two-dimensional lens array (Lar) has an effective area of at least It is composed of one sub-region (A1, A2,...), And the arrangement of the vertices (Lo1, Lo2,...) Of the individual lenses (L1, L2,...) Constituting the sub-region is aperiodic. Also characterized by It is.

  In the light source device according to the second aspect of the present invention, the arrangement of the vertices (Lo1, Lo2,...) Of the lenses (L1, L2,...) In the sub-region (A1, A2,...) Is based on a periodic arrangement. There are positive and negative positional shifts (δx, δy) in the vertical and horizontal directions with respect to the basic position (Oxy), and the amount of the positional shift (δx, δy) is the lens (L1, L2,...) It is characterized by being determined for each.

  In the light source device according to the third aspect of the present invention, the arrangement of the vertices (Lo1, Lo2,...) Of the individual lenses (L1, L2,...) Constituting the sub-region (A1, A2,...) Is random. It is characterized by being.

  In the light source device according to the fourth aspect of the present invention, the individual lenses (L1, L2,...) Constituting the sub-regions (A1, A2,...) Are formed of cylindrical lens arrays (Lca1, Lca2) having different arrangement directions. Each cylindrical lens (Lc1, Lc2,...), Which is formed by overlapping a plurality of lenses and constitutes the cylindrical lens array (Lca1, Lca2), has an inclination angle (θ1) of its generatrix (Lx1, Lx2,...). , Θ2,... Are determined for each cylindrical lens.

  In the light source device according to a fifth aspect of the present invention, the individual lenses (L1, L2,...) Constituting the sub-regions (A1, A2,...) Are formed of cylindrical lens arrays (Lca1, Lca2) having different arrangement directions. Each cylindrical lens (Lc1, Lc2, Lc3,...) Forming the cylindrical lens array (Lca1, Lca2) is formed by overlapping a plurality of lenses, and the busbars (Lx1, Lx2, Lx3,...) The bus interval (d1, d2,...) Between adjacent ones in the line is not uniform.

  The light source device according to a sixth aspect of the present invention is characterized in that the light mixing means (Fm) is a light guide that guides light while confining light in a predetermined space and performing multiple reflection of the light.

  The light source device according to a seventh aspect of the present invention is characterized in that the light mixing means (Fm) is a fly eye integrator.

  According to an eighth aspect of the present invention, there is provided a projector for projecting and displaying an image using the light source device according to any one of the first to seventh aspects, wherein the light uniformizing means also serves as the light mixing means (Fm). Is.

  It is possible to provide a light source device and a projector that can avoid the appearance of a periodic pattern superimposed on the transmitted light of a speckle reduction two-dimensional lens array or a crossed cylindrical lens array.

The schematic of the concept relevant to the technique of the light source device of this invention is represented. The block diagram which simplifies and shows the light source device of this invention is represented. The schematic diagram which simplifies and shows an example of a part of light source device of the present invention is shown. The schematic diagram which simplifies and shows an example of a part of light source device of the present invention is shown. The schematic diagram which simplifies and shows an example of a part of light source device of the present invention is shown. The schematic diagram which simplifies and shows an example of a part of light source device of the present invention is shown. The schematic diagram which simplifies and shows an example of a part of light source device of the present invention is shown. The schematic diagram which simplifies and shows an example of a part of light source device of the present invention is shown. The schematic diagram which simplifies and shows an example of a part of light source device of the present invention is shown. The figure which simplifies and shows one form of the Example of the light source device of this invention is represented. The figure which simplifies and shows one form of the Example of the projector of this invention is represented. The figure which simplifies and shows one form of the Example of the projector of this invention is represented. The figure explaining one form of one part of the kind of the conventional projector concerning the projector of this invention is represented. The figure explaining one form of one part of the kind of the conventional projector concerning the projector of this invention is represented. 1 represents a schematic diagram of concepts related to the prior art according to the present invention. The schematic diagram explaining the concept of the prior art concerning this invention is represented. The schematic diagram explaining the concept of the prior art concerning this invention is represented.

The first cause of the periodic pattern appearing in the transmitted light of the two-dimensional lens array or the crossed cylindrical lens array in the prior art is that the two-dimensional lens array or the crossed cylindrical lens array has a periodic structure. .
Since the light beam refracted, diffracted and scattered by the periodic structure undergoes periodic phase modulation, when superimposed on the downstream side of the optical system, a periodic pattern appears due to interference and is superimposed.
The second cause is that the boundary between the lens constituting the two-dimensional lens array and the adjacent lens, or the boundary between the cylindrical lens constituting the crossed cylindrical lens array and the adjacent cylindrical lens is originally sharp in a V shape. What must be incised is actually a microscopically dull U-shape, and a sheet-like light beam that is nearly transparent is mixed into the transmitted light.
It can be said that the second cause is a factor that exacerbates the essential problem caused by the first cause.

First, the form for implementing this invention is demonstrated using FIG. 2 which is a block diagram which simplifies and shows the light source device of this invention.
In this figure, for example, when the coherent light source (Sc) is a semiconductor laser, the divergent light emitting portion present on the surface of the semiconductor chip housed in the semiconductor laser package is substantially treated as a point light source. This can be the light emission region (Gs).

A light beam matching optical system (Eu) composed of a lens or the like receives a light beam (Bs) from the light radiation region (Gs) and receives a light mixing means (a rear stage) as a projection region for the light radiation region (Gs). A light beam (Bf) that forms a matching light radiation region (Gf) is output in the vicinity of the incident end (Pmi) of Fm).
However, the luminous flux matching optical system (Eu) is provided with a two-dimensional lens array (Lar), which will be described later, in the interior, upstream or downstream, and a cross section perpendicular to the optical axis of the luminous flux with respect to the incident luminous flux. At each of the points, the light beam is divided into an infinite number of partial light beams, which are converted into diffused light including a non-periodic element and having a deflection angle.

The light mixing means (Fm) receives the light beam (Bf) from the light beam matching optical system (Eu) from the incident end (Pmi), and enters the light beam inside the light mixing means (Fm). The angle and position components are mixed, and a light beam (Bmo) is output from the emission end (Pmo).
The output light beam (Bmo) is subject to multiple interference by mixing the angle and position components of the incident light beam. As a result, the speckled granular / spotted pattern on the illuminated surface is projected. The property of being fine and difficult to visually recognize is imparted.

However, as shown in FIG. 3, which is a schematic diagram illustrating a simplified example of a part of the light source device of the present invention, the two-dimensional lens array (Lar) has at least one effective region in which lenses are arranged. Are formed of four sub-regions (A1, A2,...), As an example.
In each of the sub-regions, the arrangement of the vertices (Lo1, Lo2,...) Of the individual lenses (L1, L2,...) Constituting the sub-regions is aperiodic.

Here, in the present invention, the vertexes (Lo1, Lo2,...) Are positions on the lenses (L1, L2,...) From which the light rays perpendicularly incident on the substrate surface are emitted without being deflected. Point to.
Therefore, when the lenses (L1, L2,...) Are ordinary spherical lenses, the vertices (Lo1, Lo2,...) Coincide with the geometrical vertices of the refractive surfaces of the respective lenses.
The substrate surface referred to here constitutes the two-dimensional lens array (Lar) or the cylindrical lens arrays (Lca1, Lca2) described later, like the substrate surface (Hb) shown in FIG. A surface defined by the substrate that is the overall foundation.

The right side in the figure is an enlarged view of a part of the sub-region of the two-dimensional lens array (Lar) drawn on the left side.
Polygonal regions surrounded by lens boundaries (Lb) represented by line segments represent individual lenses.
This figure is drawn on the assumption that the lenses (L1, L2,...) Are spherical lenses, but may be, for example, a hologram lens.
As described above, the arrangement of the lenses (L1, L2,...), In particular, the arrangement of the apexes (Lo1, Lo2,...) Is aperiodic, so that a two-dimensional lens array or a crossed cylindrical lens array in the prior art is used. It is possible to avoid the problem that the periodic patterns such as the stripe pattern and the lattice pattern appear to be superimposed due to the fact that has a periodic structure.

In addition, supplementing the sub-region, for example, when considering a region combining all of the sub-regions (A1, A2, A3, A4), the periodicity of the lenses may appear.
Specifically, for example, the sub area (A2, A3, A4) may be configured by copying the sub area (A1).
This is because, in such a configuration, although it has periodicity, the period is very large, so that the periodic pattern that appears due to interference becomes fine and becomes substantially invisible.

In that sense, increasing the size of the sub-region and configuring the entire effective region of the two-dimensional lens array (Lar) with one sub-region is ideal for making the periodic pattern that appears fine. It is.
However, in this case, it becomes difficult (high cost) to manufacture the two-dimensional lens array (Lar).
On the contrary, if the sub-region is made small, there is an advantage that the production of the two-dimensional lens array (Lar) is easy (low cost). On the other hand, if the sub-region is made too small, the appearing periodic pattern becomes rough and becomes visible. End up.
However, the appearance of the periodic pattern depends on the structure of the optical system.
For this reason, the size of the sub-region should be determined experimentally based on the specific structure of the light source device.
In FIG. 3, the sub-regions (A1, A2,...) Are illustrated as having a square shape. However, the sub-regions (A1, A2,...) May be of any shape as long as there is no significant gap between adjacent sub-regions. You can choose the shape.

As an example of the light emitting region (Gs), the emitting portion of the divergent light existing on the surface of the semiconductor chip has been described above. However, the semiconductor laser includes not only a single active region but also a plurality of emitting portions. A semiconductor laser array device in which active regions are arranged in a row and divergent light is emitted from each active region can also be used.
Alternatively, a plurality of single active region semiconductor lasers and semiconductor laser array devices are provided, and a plurality of divergent light beams from them are combined by a lens system, and the light emitting region (Gs) is formed as an aggregate of a plurality of point light sources. In the present specification, these are referred to as a semiconductor laser light source unit.

In addition to the light emitter itself as described above, for example, a core image of an emission end of an optical fiber into which light of a semiconductor laser or a semiconductor laser array device is input from an incident end is used as the light emission. It can also be a region (Gs).
Furthermore, an emission end of an optical fiber bundle in which a plurality of such optical fibers are bundled and a plurality of emission ends are densely arranged can be used as the light emission region (Gs).
As a matter of course, the present invention can be applied not only to a semiconductor laser but also to any device that uses the above-described coherent light emitter that can generate speckle as a light source.

Next, how to arrange the vertices (Lo1, Lo2,...) Of the lenses (L1, L2,...) In the sub-regions (A1, A2,.
In FIG. 3, there are positive and negative positional deviations (δx, δy) in the vertical and horizontal directions with respect to the basic position (Oxy) based on the periodic arrangement of vertices, as in the prior art. The case where the amount of the positional deviation (δx, δy) is configured to change depending on which lens belongs to which lens is depicted.
In the figure, the reference line when the vertices are arranged periodically is represented by a vertical and horizontal alternate long and short dash line, and each intersection is the basic position (Oxy), which is the position of the vertex of the lens.
On the other hand, the position of the vertex when the positional deviation (δx, δy) is given to the vertex of each lens is represented by a mark in which a cross is drawn in a circle. It turns out that it has shifted | deviated from the said basic position (Oxy) which is an intersection of a dashed-dotted line.

With respect to how to give the positional deviation (δx, δy), for example, the arrangement of the vertical and horizontal lenses in the two-dimensional lens array (Lar) is regarded as a matrix, and the positional deviation δx in the x direction of the lenses in a certain row is When viewed in order, a random number array is formed, and when a positional deviation δy in the y direction of lenses in the same row is viewed from the left, a random number array is formed, and the other rows are similarly viewed. When the positional deviation δx in the x direction is viewed from the top, a random number array is formed, and when the positional deviation δy in the y direction of the lens in the same column is viewed from the top, a random number array is formed. It can be random, i.e. random.
Alternatively, instead of the random number array, an aperiodic numerical sequence may be generated based on, for example, a mathematical deterministic algorithm.
Furthermore, when considering a vector (δx, δy) whose elements are the positional deviation δx in the x direction and the positional deviation δy in the y direction, the magnitude of this vector is the same for all lenses, and the direction depends on the lens. For example, it may be changed randomly.

Furthermore, as shown in FIG. 4 which is a schematic diagram illustrating a simplified example of a part of the light source device of the present invention, each of the lenses (L1, L2, L2) constituting the sub-region (A1, A2,...). ..)) May be configured so that the arrangement of the vertices (Lo1, Lo2,...) Is random.
Similarly, in this figure, the positions of the vertices are represented by marks drawn with a cross in a circle, and the polygonal region surrounded by the lens boundary (Lb) represented by a line segment represents each lens. Represent.
The arrangement of the vertices (Lo1, Lo2,...) May be random in a mathematically strict sense. However, in the present invention, the arrangement is not limited to this, and it may be a random appearance (pseudorandom). Often, the arrangement of this figure corresponds to the latter.

Next, an implementation method using the above-described crossed cylindrical lens array, that is, the individual lenses (L1, L2,...) Constituting the sub-regions (A1, A2,...) Are arranged in different cylindrical lens arrays (Lca1, Lca2). ) Will be described.
As shown in FIG. 5, which is a schematic diagram showing a simplified example of a part of the light source device of the present invention, there are two cylindrical lens arrays (Lca1, Lca2), each extending in the direction (that is, the long side). The case where there are two partial sub-regions (Ac11, Ac12) and partial sub-regions (Ac21, Ac22) orthogonal to each other is depicted.
In each partial sub-region, the direction of the generatrix of each of the cylindrical lenses (Lc1, Lc2,...) Is assumed to be parallel (or substantially parallel) to the short side of the partial sub-region, for example.
As shown by the arrows (t1, t2) in the figure, the cylindrical lens arrays (Lca1, Lca2) are stacked one above the other so that two partial subregions (Ac11, Ac12) and two partial subregions (Ac21, Ac22). ), A total of four sub-regions (A1, A2, A3, A4) having the shape shown on the left in FIG. 3 are formed.
Accordingly, in each of the sub-regions (A1, A2, A3, A4), the direction of the generatrix of the upper and lower cylindrical lens arrays is orthogonal (or substantially orthogonal), and therefore has an optical function equivalent to that of the two-dimensional lens array. It becomes.

Naturally, each of the cylindrical lens arrays (Lca1, Lca2) has four partial sub-regions, and when the cylindrical lens arrays (Lca1, Lca2) are overlapped, the partial sub-regions correspondingly overlap each other. You may comprise as follows.
When two cylindrical lens arrays are stacked, it is desirable that the upper and lower cylindrical lenses face each other as described above.
In addition, here, as an example, two cylindrical lens arrays are overlapped so that the directions of the generatrix are orthogonal (or substantially orthogonal), but three or more cylindrical lens arrays may be overlapped, and the direction of the generatrix May form an angle other than a right angle.
(In the above description, the reason why it is described as being substantially parallel or substantially orthogonal is that there is a configuration in which the directions of the generatrix of individual cylindrical lenses belonging to one partial sub-region described later are not parallel to each other. Because it does.)

  In a sub-region formed by superimposing the cylindrical lens arrays (Lca1, Lca2), the arrangement of the apexes of the lenses becomes aperiodic, and as a result, the cylindrical lens arrays (Lca1, Lca2) are superimposed However, the form of the cylindrical lens array (Lca1, Lca2) that makes it possible to function as one two-dimensional lens array (Lar) will be described below.

One form of the cylindrical lens array (Lca1, Lca2) is shown in FIG. 6, which is a schematic diagram showing a simplified example of a part of the light source device of the present invention.
In the cylindrical lens array (Lca1) in this figure, the buses (Lx1, Lx2,...) Of the individual cylindrical lenses (Lc1, Lc2,...) Constituting the cylindrical lens array (Lca1) are parallel or inclined with respect to the reference direction (y). The positive and negative tilt angles (θ1, θ2,...) Are given for each cylindrical lens.
With respect to how to give the tilt angles (θ1, θ2,...), For example, when the cylindrical lenses are viewed in order from the top, the respective tilt angles are enumerated to form a random number array, that is, random.
Alternatively, instead of the random number array, an aperiodic numerical sequence may be generated based on, for example, a mathematical deterministic algorithm.
In the figure, the generating line of the cylindrical lens is represented by a one-dot chain gland, and the lens boundary (Lcb) of adjacent cylindrical lenses is represented by a solid line.

The state of the sub-regions (A1, A2,...) Formed by superimposing the two cylindrical lens arrays (Lca1, Lca2) configured in this manner vertically as described above is the light source device of the present invention. FIG. 7, which is a schematic diagram illustrating a simplified example of a part of the above, is illustrated.
In the figure, the projections of the lens boundaries (Lcbx, Lcby) of the individual cylindrical lenses on the sub-region surface in the upper and lower cylindrical lens arrays are represented by solid lines, and the generatrix (Lx, Ly) of the individual cylindrical lenses are represented by solid lines. The projection onto the sub-region plane is represented by a one-dot chain line.
As apparent from the above-described method of constructing the upper and lower cylindrical lens arrays, the intersections (Lo) of the vertical and horizontal generatrixes are also aperiodically arranged.
In the two-dimensional lens array (Lar) described in FIG. 3, the quadrangular region surrounded by the solid line of the lens boundary and the intersection (Lo) of the generatrix are the lens (L1, L2,...) And the vertex ( Corresponds to Lo1, Lo2,.
Accordingly, in the crossed cylindrical lens array formed by superimposing the two cylindrical lens arrays (Lca1, Lca2) configured as described above vertically as described above, the arrangement of the vertices of the spherical lenses is aperiodic. It can be seen that an optical element equivalent to the two-dimensional lens array can be realized.
The reason why the intersection (Lo) of the bus line corresponds to the vertexes (Lo1, Lo2,...) Is, as described above, that the light beam perpendicularly incident on the substrate surface is emitted without being deflected. This is because the position in the lens is indicated.

FIG. 8 is a schematic view showing another example of the cylindrical lens array (Lca1, Lca2) in a simplified manner as an example of a part of the light source device of the present invention.
The cylindrical lens array (Lca1, Lca2) of this figure is adjacent to the adjacent ones in the arrangement of the respective busbars (Lx1, Lx2, Lx3,...) Of the individual cylindrical lenses (Lc1, Lc2, Lc3,...) Constituting the cylindrical lens array (Lca1, Lca2). The arrangement positions of the cylindrical lenses are determined so that the bus interval (d1, d2,...) Is not uniform.
With respect to how to determine the bus interval (d1, d2,...), For example, when the cylindrical lenses are viewed from the top in order, the respective bus interval is enumerated to form a random number array, that is, random.
Alternatively, instead of the random number array, an aperiodic numerical sequence may be generated based on, for example, a mathematical deterministic algorithm.
In the figure, the generating line of the cylindrical lens is represented by a one-dot chain gland, and the lens boundary (Lcb) of adjacent cylindrical lenses is represented by a solid line.

The state of the sub-regions (A1, A2,...) Formed by superimposing the two cylindrical lens arrays (Lca1, Lca2) configured in this manner vertically as described above is the light source device of the present invention. FIG. 9 is a schematic diagram showing a simplified example of a part of the above.
In the figure, the projections of the lens boundaries (Lcbx, Lcby) of the individual cylindrical lenses on the sub-region surface in the upper and lower cylindrical lens arrays are represented by solid lines, and the generatrix (Lx, Ly) of the individual cylindrical lenses are represented by solid lines. The projection onto the sub-region plane is represented by a one-dot chain line.
As apparent from the above-described method of constructing the upper and lower cylindrical lens arrays, the intersections (Lo) of the vertical and horizontal generatrixes are also aperiodically arranged.
In the two-dimensional lens array (Lar) described in FIG. 3, the quadrangular region surrounded by the solid line of the lens boundary and the intersection (Lo) of the generatrix are the lens (L1, L2,...) And the vertex ( Corresponds to Lo1, Lo2,.
Accordingly, in the crossed cylindrical lens array formed by superimposing the two cylindrical lens arrays (Lca1, Lca2) configured as described above vertically as described above, the arrangement of the vertices of the spherical lenses is aperiodic. It can be seen that an optical element equivalent to the two-dimensional lens array can be realized.

One of the advantages of constructing one two-dimensional lens array (Lar) with a crossed cylindrical lens array is that the maximum deflection angle of the upper and lower cylindrical lens arrays is different so that the direction distribution of diffused light is non-axial. It is easy to realize a diffusing plate that is symmetrical.
For example, it is possible to make a diffusing plate with the z axis as the optical axis and strong diffusion in the x axis direction and weak diffusion in the y axis direction.
Specifically, with respect to the individual cylindrical lenses of the cylindrical lens array whose diffusion is to be increased, the focal length is shortened, or if the focal length is the same, the bus interval is generally increased.
Of course, one of the upper and lower cylindrical lens arrays may be configured in the form of FIG. 6 and the other in the form of FIG.
Further, one or both of the upper and lower cylindrical lens arrays may be configured so as to have the characteristics of both the form of FIG. 6 and the form of FIG.

In the two-dimensional lens array (Lar) and the cylindrical lens array (Lca1, Lca2) described above, the intervals between adjacent vertices and buses are not uniform. The maximum inclination angle (Φ) of the normal line (n) for each cylindrical lens becomes uneven.
If there is a lens with this excessive angle, the deflection angle will be excessive and the efficiency will be lowered. Therefore, an upper limit value of the angle (Φ) is determined, and for lenses exceeding this angle, the apex and Without changing the position of the busbar, the radius of curvature can be corrected so that an excessively large angle does not appear.

  In FIGS. 3, 4, 6, and 8, the positions are naturally determined based on the vertexes of individual lenses and the positions of the generatrix of the two-dimensional lens array (Lar) and the cylindrical lens arrays (Lca1, Lca2). Although it is drawn so as to form a boundary line with an adjacent lens by the intersecting line of the refracting surfaces, the boundary line may be determined separately from the apex of each lens and the position of the generatrix.

By the way, as the light mixing means (Fm), it is possible to use various kinds of light mixing means (Fm) as long as the components of the angle and position of the incident light are mixed and emitted when light is incident thereon. is there.
As a particularly simple one, it is possible to use a light guide that guides light while confining light in a predetermined space and performing multiple reflection of light.

As described above with reference to FIG. 13, this is also called the name of a rod integrator, a light tunnel, or the like, and is constituted by a prism made of a light-transmitting material such as glass or resin, and the incident end (Pmi). In accordance with the same principle as that of an optical fiber, the light input to is propagated through the light mixing means (Fm) while repeating total reflection on the side surface of the light mixing means (Fm). The position components are mixed.
Further, as described above, the light guide described above is a hollow rectangular tube other than the above-described prisms made of a light-transmitting material such as glass or resin, and the inner surface thereof is a reflecting mirror. Similarly, it is possible to use a light that propagates light while repeating reflection on the inner surface and performs the same function.

  The reason why the components of the angle and position of the incident light are mixed by confining the light in the predetermined space and guiding the light while performing multiple reflection is that the total length of the light mixing means (Fm) is If the light propagates through repeated multiple reflections, if you look through the exit end (Pmo), you should see a very large number of wave sources according to the kaleidoscope principle, and therefore at the exit end (Pmo) Is equivalent to a state in which light from a large number of wave sources arrives and exits.

Further, as the light mixing means (Fm), a fly eye integrator similar to that described above with reference to FIG. 14 can be used.
The reason why the components of the incident light angle and position are mixed by using the fly-eye integrator is that, as described above, in the fly-eye integrator, the respective lenses arranged vertically and horizontally on the fly-eye lens on the incident side. Since all the square images of the outer shape are superimposed on one, a state like a kaleidoscope appears as in the case of the light guide described above, and light from a large number of wave sources appears on the illumination target. This is because they will arrive at the same time.

When a fly-eye integrator is used as the light mixing means (Fm), the matching light emission region (Gf) formed in the vicinity of the incident end (Pmi) is in the entire region of the incident end (Pmi). It is desirable to form as an illumination area extending over.
The reason is that if the matching light emission region (Gf) is incident only on a part of the fly-eye lens at the incident end (Pmi), the number of the quadrangular images of the lens outline to be superimposed is as follows. This is because the action of mixing the angle and position components of the incident light is weakened.

On the other hand, when a light guide is used as the light mixing means (Fm), light is incident in a form such as a point image that is concentrated at one place or a plurality of places on the incident end (Pmi). It does n’t matter.
The reason is that if the image divergence angle of the point image is appropriate, the light beam spreads while propagating through the light guide, and when it reaches the exit end (Pmo), the angle and position components of the incident light beam are mixed. This is because it is performed sufficiently.

As described above, in a projector that projects and displays an image using a certain light source such as a conventional high-intensity discharge lamp, a light uniformizing means such as a light guide or a fly eye integrator is an indispensable component. As described above, the light homogenizing means is used as the light mixing means (Fm) which is a constituent element of the present invention in order to make the granular / spotted pattern of speckles fine and difficult to see. Can also work.
Therefore, when realizing a projector that projects and displays an image using the light source device of the present invention as a light source, the cost can be reduced by configuring the light uniformizing means to also serve as the light mixing means (Fm). It becomes.

  As described above, in a conventional 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 and green) , Blue) is used to illuminate the two-dimensional light amplitude modulation element as a color sequential light beam and realize color display by time division, or arrange a dichroic mirror or dichroic prism at the subsequent stage of the light uniformizing means. Illuminates a two-dimensional light amplitude modulation element provided independently for each color with light separated into the three primary colors G and B, and arranges dichroic mirrors and dichroic prisms to synthesize the modulated light beams of the three primary colors R, G, and B An optical system for performing the above is configured.

  The projector of the present invention also requires a light source of a necessary type of hue. For example, a white light emission region (Gs) obtained by color-combining the three primary color coherent light sources of R, G, and B is used. As described above, after passing through the light beam matching optical system (Eu), white light is incident on the light mixing means (Fm) as the light uniformizing means, and the light mixing means (Fm) is the same as in the conventional projector. In a later stage, time division processing by a dynamic color filter, or color separation and color composition can be performed.

In the case of using the above-described optical fiber, an optical fiber bundle in which emission ends of a plurality of optical fibers into which light of different colors is incident is bundled at the incident end when the color-synthesized light emission region (Gs) is formed. By using it, the light emission region (Gs) can be composed of a plurality of color portions, or a single color light emission region (Gs) is formed for each color, and these are used as a dichroic mirror or the like. As a result, the light emission region (Gs) that has been color-combined can be formed by superimposing the light using the color synthesizing means and sending light to the light beam matching optical system (Eu).
When the color synthesizing unit side is viewed from the light beam matching optical system (Eu) side, one light emission region (Gs) having a plurality of colors can be seen. In the optical field, this state is pointed to color synthesis. It is considered that a light emission region (Gs) is formed.

  Alternatively, a monochromatic image is formed by illuminating the two-dimensional light amplitude modulation element through the formation of a light emission region (Gs) independently for each color, the light beam matching optical system (Eu), and the light mixing means (Fm) as the light uniformizing means. May be generated and color synthesized.

  Alternatively, for example, by driving a coherent light source in a time-sharing manner in the order of R, G, and B, a color-sequential light emission region (Gs) is formed, a light beam matching optical system (Eu), and light mixing as light uniformizing means. A color sequential color image may be generated by illuminating the two-dimensional light amplitude modulation element through the means (Fm).

Hereinafter, modes for carrying out the present invention will be described.
First, the light source device shown in FIG. 10, which is a diagram showing a simplified form of an embodiment of the light source device of the present invention, will be described.
In the semiconductor laser light source unit (Ls) that uses one or a plurality of semiconductor lasers as the coherent light source, a radiation portion of diverging light existing on the surface of the semiconductor chip is defined as a light emission region (Gs).
The light beam from the light emitting region (Gs) is fed to a light beam matching optical system (Eu) including a collimator lens (Es), a two-dimensional lens array (Lar) whose apex is aperiodic, and an imaging lens (Eu0). Incident.
The collimator lens (Es) converts the light emission region (Gs) into an image at infinity and illuminates the two-dimensional lens array. The illuminated area of the two-dimensional lens array is enlarged as an input image and the diffusion angle is reduced to form a matched light emission area (Gf).
By arranging the light mixing means (Fm) so that the incident end (Pmi) made of the light guide substantially coincides with the matching light emitting region (Gf), the periodic pattern described above is formed from the emission end (Pmo). A light beam (Bmo) with inconspicuous and reduced speckles can be taken out and used.

Next, the projector of the present invention using the light source device of the present invention as a mode for carrying out the present invention as a form for carrying out the present invention, using FIG. 11 which is a diagram showing a simplified form of an embodiment of the projector of the present invention. A more specific configuration of the optical fiber and after the exit end will be described.
This light source device corresponds to R, G, B3 primary colors, an optical fiber bundle composed of a plurality of optical fibers of each color, that is, an optical fiber bundle (Efr) for an R color light source, an optical fiber bundle (Efg) for a G color light source. ), Each of the optical fiber bundles (Efb) for the B color light source is configured by bundling with the incident ends of the respective optical fibers aligned.
By converting the images of the exit ends (Eor, Eog, Eob) of these three optical fiber bundles into infinite images using collimator lenses (EsR, EsG, EsB), respectively, an R color output light beam (Fr ), G color output light beam (Fg), and B color output light beam (Fb).

Each of these luminous fluxes is reflected by a mirror (Hur, Hug, Hub), respectively, and the vertex arrangement is aperiodic two-dimensional lens array (Larr) and G-color two-dimensional lens array (Larg), B It passes through the color two-dimensional lens array (Larb) and becomes diffused light, and the front fly-eye lens (F1r, F1g, F1b), the rear fly-eye lens (F2r, F2g, F2b), and the polarization alignment function element (Pcr, Pcg) , Pcb) and illumination lenses (Ejr, Ejg, Ejb), and is incident on light uniformizing means (Fmr, Fmg, Fmb) by the fly eye integrator.
That is, in the form of this figure, the matching light emission region (Gf) is formed on the exit side surface of the two-dimensional lens array, and the incident end of the light uniformizing means (Fmr, Fmg, Fmb) is used. The light uniformizing means (Fmr, Fmg, Fmb) is arranged so as to be close to the surface on the emission side of the two-dimensional lens array.

Then, an R color image LCD (Dmr), a G color image LCD (Dmg), and a B color image, which are two-dimensional light amplitude modulation elements, are obtained by the respective light beams emitted from the light uniformizing means (Fmr, Fmg, Fmb). The LCD (Dmb) is illuminated, and the transmitted light beam is synthesized by the dichroic prism (Mj) into three colors to become a light beam (Fo) constituting a color image.
This light beam is projected onto the screen by a projection lens (not shown).

By the way, in the case of the light uniformizing means (Fmr, Fmg, Fmb) by the fly eye integrator in which the polarization alignment function elements (Pcr, Pcg, Pcb) as shown in the figure are present, the polarization alignment function elements (Pcr, The maximum angle of light rays that can pass through (Pcg, Pcb) is not an axis subject, and is, for example, large in a direction parallel to the paper surface and small in a direction perpendicular to the paper surface.
Therefore, the two-dimensional lens array for R color (Larr), the two-dimensional lens array for G color (Larg), and the two-dimensional lens array for B color (Larb) have a non-axial directional distribution of diffused light as described above. It is preferable that the light beam is diffused so as not to exceed the maximum angle of the light beam in each direction.
Note that speckle is conspicuous in R, G, and B colors due to human visibility, for example, it stands out in G color but not in B color.
Therefore, the diffusivities of the R color two-dimensional lens array (Larr), the G color two-dimensional lens array (Larg), and the B color two-dimensional lens array (Labb) are adjusted according to the conspicuousness of each color. Adjust separately.

Incidentally, the mirrors (Hur, Hug, Hub) efficiently reflect the R color output light beam (Fr), the G color output light beam (Fg), and the B color output light beam (Fb) incident thereon. Created as
However, there are not a few transmitted lights that are not reflected. Normally, these lights are discarded as stray light. However, in the present light source device shown in the figure, this light is used effectively to measure light beams (Fr ′, Fg ′, Fb ′). ).
The measurement luminous fluxes (Fr ′, Fg ′, Fb ′) are incident on the R color sensor (Ar), the G color sensor (Ag), and the B color sensor (Ab), respectively, and the amount of light is measured. Used for light quantity stabilization feedback.

  Next, referring to FIG. 12, which is a simplified diagram showing an embodiment of the projector according to the present invention, a specification using the two-dimensional lens array and the light deflecting means in combination as a form for carrying out the present invention. The configuration of the projector of the present invention using the light source device of the present invention as a white light source with enhanced light reduction will be described.

In the R, G, and B semiconductor laser light source units (LsR, LsG, and LsB), the diverging light emitting portions existing on the surface of the semiconductor chip are used as light emitting regions (GsR, GsG, and GsB), and these are collimator lenses (EsR , EsG, EsB), the light beam converted into an infinite image is color-combined using a mirror (HuR) and a dichroic mirror (HuG, HuB), and input to the imaging lens (Eu1). .
Conversely, when viewed from the imaging lens (Eu1) side, this arrangement is such that the light emission regions (GsR, GsG, GsB) of R, G, and B colors are macroscopically overlapped (microscopically). As a single image, it looks like a white light source as a whole.
The imaging lens (Eu1) forms a second light emission region (Gu) on the deflection mirror (Mdm) as a conjugate image with respect to the light emission region (GsR, GsG, GsB).

  In the case where the semiconductor laser light source unit (LsR, LsG, LsB) uses a plurality of semiconductor lasers as light sources, here, all chief rays from the light emitting region (Gs) are parallel to the optical axis. However, even if they are not parallel, an optical system having the same function can be realized by designing by controlling the position of the image plane and the pupil position on the optical axis.

The deflection mirror (Mdm) is, for example, circular and is attached to the rotation shaft of a mirror rotation motor (Mdd) and rotated. The normal vector of the reflection surface of the deflection mirror (Mdm) is It is attached so as to be inclined at a predetermined angle.
With this structure, the locus of the normal vector oscillates so as to draw a conical surface as the mirror rotation motor (Mdd) rotates, so that the deflection mirror (Mdm) rotates and oscillates. It becomes a mirror and functions as a light deflection means (Md).

The light beam (Bd) deflected by the light deflecting means (Md) is incident on the second optical system (Ef) including the lenses (Ef11, Ef12) and the final lens (Ef13), and the second optical system ( Ef) is a conjugate image with respect to the second light emitting region (Gu) on the deflecting mirror (Mdm) on the incident-side surface of the two-dimensional lens array (Lar) whose apex is aperiodic. A three-light emission region (Gf ′) is imaged.
And in the form of this figure, it is assumed that the matching light emission region (Gf) is formed on the exit side surface of the two-dimensional lens array (Lar), and the light mixing means (Fm) composed of the light guide described above. The light mixing means (Fm) is arranged so that the incident end (Pmi) is close to the exit side surface of the two-dimensional lens array (Lar).

By the way, the second light emission region (Gu) formed by the light beam (Bu) output from the optical system preceding the light deflection means (Md) is the deflection operation of the light deflection means (Md). Regardless of immobility.
Moreover, since the second light emitting region (Gu) is in the vicinity of the deflection point of the light deflecting means (Md), the light emitting region as the starting point of the light beam (Bd) deflected by the light deflecting means (Md). Is almost immobile.
And since the second light emitting region (Gu) and the third light emitting region (Gf ′) are conjugate, the third light emitting region (Gf ′) also remains almost stationary. Even if the deflection operation of the light deflecting means (Md) is performed, the state where the light beam (Bf) is incident on the incident end (Pmi) of the light mixing means (Fm) is always maintained.

It is preferable that the optical design is such that the principal rays are substantially parallel to each other after passing through the second optical system (Ef).
The reason is that, even in the light mixing means (Fm) comprising a light guide, there is a maximum angle of light rays that can propagate through the inside without any loss, so that the angle between principal rays and the two-dimensional lens array (Lar) It is necessary to keep the sum of the diffusion angle given by the deflection mirror and the deflection angle given by the deflection mirror (Mdm) within the maximum angle, but in order to maximize the speckle reduction effect, It is advantageous to reduce the angle formed by the principal rays that do not contribute to the reduction of light and to increase the diffusion angle provided by the two-dimensional lens array (Lar) or the deflection angle provided by the deflection mirror (Mdm). It is.

As described above, in the optical system in which the principal rays of the output light beams are substantially parallel to each other, the input-side focal point of the second optical system (Ef) and the entrance pupil of the second optical system (Ef) coincide with each other. Although it can be realized by designing, this can be understood more easily in accordance with this figure. Focusing on the final lens (Ef13), the focal point on the input side and the entrance pupil (Qf3) are changed. It is only necessary to match.
The entrance pupil (Qf3) is a conjugate image of the exit pupil (Qu) of the collimator lens (Es) based on the case where the deflection angle of the deflection mirror (Mdm) is zero. Considering the case where all the principal rays from the light emission region (Gs) are parallel to the optical axis, the exit pupil (Qu) coincides with the output side focal point of the collimator lens (Es).
With the configuration as described above, the light source device of this figure can maximize the maximum value of the deflection angle that can be given to the light deflection means (Md).

  The light deflection means (Md) continues the operation of continuously changing the direction in which the light beam (Bu) is deflected, thereby mixing the angle and position components of the incident light beam to the incident end (Pmi). Since the state changes continuously, the speckle always moves in the light beam (Bmo) emitted from the emission end (Pmo) of the light mixing means (Fm). When averaged within a suitable period, the speckled granular / spotted pattern becomes finer, and the speckles appear to disappear in synergy with the effect of being difficult to see.

Therefore, it is possible to output a light beam (Bmo) in which the above-described periodic pattern is not conspicuous and speckle is reduced from the emission end (Pmo).
In the subsequent stage of the light mixing means (Fm), the light beam (Bmo) is subjected to R, G, B color separation, and the two-dimensional light amplitude is determined according to the video signal in the same manner as the conventional projector shown in FIG. A projector that generates a color image can be configured by combining an image for each of R, G, and B colors generated by performing two-dimensional spatial modulation by the modulation element (DmjA) using a dichroic prism or the like.

  In the description so far, the light emission region (Gs) and the light emission region (GsR, GsG, GsB) in the light source device shown in FIGS. 10 and 12 have been formed by the semiconductor laser light source unit. These can be replaced with the light emission region (Gs) formed by the exit end of the optical fiber or optical fiber bundle.

  The present invention can be used in an industry for designing and manufacturing a light source device using a coherent light source such as a semiconductor laser that can be used in an optical device such as a projector.

A1 sub-region A2 sub-region A3 sub-region A4 sub-region Ab B color sensor Ac11 partial sub-region Ac12 partial sub-region Ac21 partial sub-region Ac22 partial sub-region Ag G color sensor Ap component Ar R color sensor Bd luminous flux Bf luminous flux Bmo luminous flux Bs luminous flux Bu luminous flux C0 inscribed circle C1 circle C2 circle d1 bus interval d2 bus interval Dmb B color image LCD
LCD for Dmg G color image
DmjA Two-dimensional optical amplitude modulation element DmjB Two-dimensional optical amplitude modulation element Dmr LCD for R color image
Ed Diffuser Ef Second optical system Ef11 Lens Ef12 Lens Ef13 Lens Efb Optical fiber bundle Efg Optical fiber bundle Efr Optical fiber bundle Ej1A Illumination lens Ej1B Illumination lens Ej2A Projection lens Ej2B Field lens Ej3B Projection lens Ejb Illumination lens Ejg Illumination lens Ejr Illumination lens Eob exit end Eog exit end Eor exit end Es collimator lens EsB collimator lens EsG collimator lens EsR collimator lens Eu beam matching optical system Eu0 imaging lens Eu1 imaging lens F1b upstream fly-eye lens F1B upstream fly-eye lens F1g upstream fly-eye lens F1r Front stage fly-eye lens F2b Rear stage fly-eye lens F2B Rear stage fly-eye lens F2g Rear stage fly-eye lens F2r Stage fly-eye lens Fb B-color output beam Fb ′ Measurement beam Fg G-color output beam Fg ′ Measurement beam Fm Light mixing unit FmA Light homogenizing unit Fmb Light homogenizing unit FmB Light homogenizing unit Fmg Light homogenizing unit Fmr Light Uniform means Fo light beam Fr R color output light beam Fr ′ measurement light beam Gf matching light radiation region Gf ′ third light radiation region Gs light radiation region GsB light radiation region GsG light radiation region GsR light radiation region Gu second light radiation region Hb Substrate surface Hs Refractive surface Hub Mirror HuB Dichroic mirror HuG Dichroic mirror Hug Mirror HuR Mirror Hur Mirror L1 Lens L2 Lens La Two-dimensional lens array Lar Two-dimensional lens array Larb Two-dimensional lens array for B color Two-dimensional lens array for G color Larr R color 2D lens array Lb Lens boundary Lc Cylindrical lens Lc2 Cylindrical lens Lc3 Cylindrical lens Lca1 Cylindrical lens array Lca1 'Cylindrical lens array Lca2 Cylindrical lens array Lca2' Cylindrical lens array Lcb Lens boundary Lcbx Lens boundary Lcby Lens boundary LCD Liquid crystal device Li Incident parallel light beam Lo L Crossing L Laser light source unit LsB Semiconductor laser light source unit LsG Semiconductor laser light source unit LsR Semiconductor laser light source unit Lx Bus Lx1 Bus Lx2 Bus Lx3 Bus Ly Ly Bus Md Optical deflection means Mdd Mirror rotation motor Mdm Deflection mirror Mj Dichroic prism MjA Mirror MjB Polarization beam splitter n Normal Oxy Basic position P Distribution P (ψ) Distribution cb Polarization alignment functional element PcB Polarization alignment functional element Pcg Polarization alignment functional element Pcr Polarization alignment functional element Pmi Incident end PmiA Incident end PmiB Incident end Pmo Ejection end PmoA Ejection end PmoB Ejection end Qf3 Entrance pupil Qu Exit pupil R radius r Deviation radius S0 Unit Square Sc Coherent light source SjA Light source SjB Light source t1 Arrow t2 Arrow Tj Screen y Reference direction z Optical axis ZiB Incident optical axis δx Position shift δy Position shift θ Effective existence range angle θ1 Angle θ2 Angle Φ Angle ψ Angle ψ1 Lower limit angle ψ2 Upper limit angle

Claims (8)

  Light mixing means (Fm) for emitting light from the emission end (Pmo) by mixing the light emission region (Gs) formed by the coherent light source (Sc) and the components of the angle and position of the incident light from the incidence end (Pmi) ) And a light beam matching optical system (Eu) for projecting the light beam emitted from the light emission region (Gs) onto the incident end (Pmi), the light beam matching optical system (Eu) ) Includes a two-dimensional lens array (Lar) that functions as a light diffusing means, and the effective area of the two-dimensional lens array (Lar) is at least one sub-region (A1, A2,...). , And the arrangement of the vertices (Lo1, Lo2,...) Of the individual lenses (L1, L2,...) Constituting the sub-region is aperiodic.   The alignment of the vertices (Lo1, Lo2,...) Of the lenses (L1, L2,...) In the sub-region (A1, A2,...) Is vertical and horizontal with respect to the basic position (Oxy) based on the periodic alignment. There is a positive / negative positional deviation (δx, δy) in the direction, and the amount of the positional deviation (δx, δy) is determined for each lens (L1, L2,...). Item 2. The light source device according to Item 1.   The arrangement of the vertices (Lo1, Lo2, ...) of the individual lenses (L1, L2, ...) constituting the sub-region (A1, A2, ...) is random. Light source device.   The individual lenses (L1, L2,...) Constituting the sub-region (A1, A2,...) Are formed by overlapping a plurality of cylindrical lens arrays (Lca1, Lca2) having different arrangement directions, The individual cylindrical lenses (Lc1, Lc2,...) Constituting the cylindrical lens array (Lca1, Lca2) have inclination angles (θ1, θ2,...) Of the generatrix (Lx1, Lx2,...) Determined for each cylindrical lens. The light source device according to claim 1, wherein the light source device is a light source device.   The individual lenses (L1, L2,...) Constituting the sub-region (A1, A2,...) Are formed by overlapping a plurality of cylindrical lens arrays (Lca1, Lca2) having different arrangement directions, The individual cylindrical lenses (Lc1, Lc2, Lc3,...) Constituting the cylindrical lens array (Lca1, Lca2) are spaced from the adjacent ones in the row of the busbars (Lx1, Lx2, Lx3,...). 2. The light source device according to claim 1, wherein d2,.   6. The light source device according to claim 1, wherein the light mixing means (Fm) is a light guide that guides light while confining light in a predetermined space and performing multiple reflection of the light.   6. The light source device according to claim 1, wherein the light mixing means (Fm) is a fly eye integrator.   8. A projector for projecting and displaying an image using the light source device according to claim 1, wherein a light uniformizing means also serves as the light mixing means (Fm).

Images