JP6940788B2 - Light source device and projector equipped with the light source device - Google Patents

Description

The present invention relates to a light source device and a projector provided with the light source device.

In recent years, a time-division type projector that extracts light having a plurality of wavelengths by time division and sequentially modulates the extracted light having a plurality of wavelengths to form and project an image has become widespread. As a light source device used for such a time-divided projector, for example, a light source that outputs white light and a rotating wheel to which a plurality of color filters are attached are provided, and white light emitted from the light source is emitted at a constant speed. It is known that light of a plurality of wavelengths (for example, blue, green, and red light) is extracted by incident on a rotating wheel that rotates with.

Further, by using a light source that outputs single-wavelength light such as a semiconductor laser, a rotating wheel having a phosphor layer is used instead of a color filter, and single-wavelength light emitted from a light source such as a semiconductor laser is used for this. A light source device that extracts light of a plurality of wavelengths in a time-divided manner by incident light has also been proposed. For example, the light emitted from a blue semiconductor laser can be wavelength-converted to green or red light by a phosphor. As shown in Patent Document 1, the laser light source is attached by rotating the angle of the laser light source in the optical axis direction to widen the substantially elliptical shape of the laser light source when it is focused on a phosphor, and when projected by a projector. A method for making the brightness uniform has been proposed.

Further, as shown in Patent Document 2, by shifting the arrangement interval of a plurality of laser light sources and the lens interval of the collimator lens installed on the emission surface side, the focusing point on the phosphor differs for each semiconductor laser. A method of exciting a phosphor by lowering the light density in this way has been proposed.

JP 2011-133782 Japanese Unexamined Patent Publication No. 2012-215633

When the semiconductor laser is rotated and arranged in the optical axis direction as in the light source device shown in Patent Document 1, it is necessary to adjust the rotation direction of each laser. Further, since the light collection point positions are the same, there is a problem that the light density at the center is high and the luminous efficiency of the phosphor is lowered. Further, in the case of the light source device shown in Patent Document 2, since the focusing point position is different for each laser light source, the focusing point position can be changed, but the parallel light emitted from the collimated lens has a small focusing diameter. There is a problem that the light density is high and the luminous efficiency of the phosphor is lowered.

Therefore, an object of the present invention is to solve the above-mentioned problems, and in a light source using a plurality of semiconductor lasers, a light source device that suppresses a decrease in luminous efficiency of a phosphor and can be easily assembled, and by extension, this light source device. The purpose is to provide a projector using the above.

In order to solve the above problems, in one embodiment of the light source device according to the present invention,
A plurality of housings in which a plurality of light sources having a semiconductor laser and a collimated lens in which the light emitted from the semiconductor laser is substantially parallel light are arranged so that the light emitted from each light source becomes substantially parallel light in the same direction. When,
A condenser lens that collects the light emitted from the plurality of housings toward the phosphor and
A phosphor wheel having the phosphor and transmitting light from the condenser lens,
With
By making the mounting angles of the plurality of housings with respect to the support members different, the incident angles of the light emitted from the housings with respect to the optical axis of the condensing lens are made different.

In one embodiment of the projector according to the present invention, based on the light source device of the above embodiment and image data, light emitted from the light source device in a plurality of wavelength bands is sequentially modulated to form an image. It includes a modulation means and a projection means for enlarging and projecting the image.

As described above, the present invention provides a light source device using a plurality of semiconductor lasers, which suppresses a decrease in luminous efficiency of a phosphor and can be easily assembled, and by extension, a projector using this light source device. Can be done.

It is (a) schematic diagram and (b) axis explanatory view which shows one Embodiment of the light source apparatus of this invention. It is a schematic diagram for demonstrating the 1st Embodiment of this invention which inclined the mounting surface of a housing. It is a figure which shows the shape of the condensing region and the light intensity distribution (cross-sectional light intensity) in 1st Embodiment. It is a schematic diagram for demonstrating the 2nd Embodiment of this invention which changed the position of a collimating lens, and is the figure which shows the shape of the condensing region, and the light intensity distribution (cross-sectional light intensity). It is a schematic diagram which shows one Embodiment of the fluorescent wheel of this invention. It is a graph which shows the fluorescent substance light intensity when the 1st embodiment and the 2nd embodiment of this invention are combined, and the fluorescent substance light intensity in other cases. It is a schematic diagram which shows the structure of the projector which provided the light source device of this invention.

In the first embodiment of the light source device according to the present invention,
A plurality of housings in which a plurality of light sources having a semiconductor laser and a collimated lens in which the light emitted from the semiconductor laser is substantially parallel light are arranged so that the light emitted from each light source becomes substantially parallel light in the same direction. When,
A condenser lens that collects the light emitted from the plurality of housings toward the phosphor and
A phosphor wheel having the phosphor and transmitting light from the condenser lens,
With
By making the mounting angles of the plurality of housings with respect to the support members different, the incident angles of the light emitted from the housings with respect to the optical axis of the condensing lens are made different.

According to this embodiment, the light emitted from the plurality of housings is focused by the condenser lens at different positions on the phosphor wheel (that is, on the phosphor). Therefore, since the light density in the condensing region on the phosphor can be suppressed, the light emitted from the phosphor can be efficiently used.
Further, since the above can be realized only by changing the mounting angle with respect to the support member of the housing, manufacturing becomes possible without sacrificing productivity.
Therefore, it is possible to provide a light source device that can be manufactured without sacrificing mass productivity by suppressing a decrease in luminous efficiency of the phosphor as much as possible and realizing simple assembly.

In the second embodiment of the light source device according to the present invention, in the first embodiment described above,
In the light source, the mounting position of the collimating lens with respect to the semiconductor laser is deviated from the lens mounting position for emitting parallel light from the collimated lens.

According to the present embodiment, by shifting the position of the collimating lens with respect to the semiconductor laser in each light source, the light emitted from the collimated lens is deviated from the parallel light, so that the focusing diameter in the focusing region on the phosphor is increased. Although it is large, the displacement of the focusing points of the plurality of semiconductor lasers can be reduced.
That is, the light of the semiconductor laser provided in the same housing is focused at substantially the same position, but the light density is lowered by increasing the focusing diameter. Therefore, since the light density in the condensing region can be suppressed, the light emitted from the phosphor can be efficiently used. However, since the position of each condensing point of each semiconductor laser in one housing changes only slightly, it is possible to appropriately suppress the expansion of the area of the condensing region as a whole.
Further, by combining the first and second embodiments of the light source device, the light emitted from the plurality of housings is collected at different positions on the phosphor, and the light from each housing is collected. Since the diameter is large, the light density can be sufficiently suppressed to be low, and the decrease in luminous efficiency of the phosphor can be sufficiently suppressed.

In the third embodiment of the light source device according to the present invention, in the above-described first or second embodiment,
In the housing, the light sources are aligned in the minor axis direction in the farfield pattern of the semiconductor laser.
The mounting angle of the housing is changed in the direction of rotation about the long axis of the farfield pattern.

According to this embodiment, in the housing, the light sources are aligned in the minor axis direction in the farfield pattern, and the mounting angle of the housing with respect to the support member is in the direction of rotation about the long axis of the farfield pattern. Since the angle can be changed, the light emitted from each light source does not interfere with each other, and the light density can be appropriately suppressed in the condensing region.

In the fourth embodiment of the light source device according to the present invention, in any one of the above embodiments 1 to 3.
The housing is fixed to the same support member, and the mounting surface of the housing with the support member is inclined.

According to this embodiment, the light density can be surely suppressed in the condensing region only by inclining the mounting surface of the housing with the support member, and the production can be performed without sacrificing productivity.

In embodiment 5 of the light source device according to the present invention, in embodiment 4 described above,
When the two adjacent housings are fixed to the support member, the two adjacent housings are relatively rotated 180 degrees and fixed with the direction of the optical axis of the light emitted from the housing as the center of rotation. Will be done.

According to this embodiment, using a housing having the same shape with an inclined mounting surface with the support member, the mounting angle is relatively rotated by 180 degrees (in other words, rotated by 180 degrees in a certain rotation direction). By fixing it, the angle of incidence of the light emitted from each housing with respect to the optical axis of the condensing lens can be made different. Therefore, the light density can be surely suppressed in the condensing region by using a very simple structure.

In embodiment 6 of the light source device according to the present invention, in embodiment 4 described above,
When the four adjacent housings are fixed to the support member, the two adjacent housings are relatively rotated and fixed by 90 degrees with the direction of the optical axis of the light emitted from the housing as the center of rotation. Will be done.

According to this embodiment, using a housing having the same shape with an inclined mounting surface to the support member, the mounting angle is relatively rotated by 90 degrees (in other words, a constant housing with respect to one housing). By fixing (rotated 90 degrees, 180 degrees, 270 degrees) in the rotation direction, the incident angle of the light emitted from each housing with respect to the optical axis of the condensing lens can be made different. Therefore, the light density can be surely suppressed in the condensing region by using a very simple structure.

In embodiment 7 of the light source device according to the present invention, in any of the above embodiments 1 to 3.
The housing is fixed to the same support member, and the mounting surface of the housing of the support member is inclined.

According to this embodiment, by forming the mounting surface of the housing of the support member to be inclined, the incident angle of the light emitted from each housing with respect to the optical axis of the condensing lens can be made different. Therefore, once the support member is formed in this way, the shape of the housing is simplified, so that even when the housing is replaced for maintenance or the like, it can be easily performed at low cost.

In embodiment 8 of the light source device according to the present invention, in any of the above embodiments 4 to 7.
The inclination angle of the mounting surface of the housing or the support member is 0.25 to 2 degrees.

According to this embodiment, since the inclination angle is 0.25 to 2 degrees, the light density can be suppressed without unnecessarily increasing the area of the condensing region.

In embodiment 9 of the light source device according to the present invention, in any of the above embodiments 1 to 8.
The support member is a heat dissipation member.

According to this embodiment, since the support member is a heat radiating member, the housing can be efficiently cooled, the number of parts can be suppressed, and the miniaturization of the light source device can be promoted.

In embodiment 10 of the light source device according to the present invention, in any of the above embodiments 1 to 9.
The wavelength band of the emitted light from the housing is 370 to 500 nm.

In embodiment 11 of the light source device according to the present invention, in any of the above embodiments 1 to 10.
One of the phosphors is a phosphor that emits light including red light.

In the first embodiment of the projector according to the present invention, the light source device according to any one of the above embodiments 1 to 11 is used.
An optical modulation means that sequentially modulates light in a plurality of wavelength bands emitted from the light source device to form an image based on image data, and
A projection means for enlarging and projecting the image, and
It has.

According to this embodiment, it is possible to provide a projector that can be manufactured without sacrificing mass productivity by suppressing a decrease in luminous efficiency of a phosphor as much as possible and realizing simple assembly.
Next, the light source device of the present invention and the projector provided with the light source device will be described in detail below with reference to the drawings.

(Explanation of outline of light source device)
First, an embodiment of the light source device according to the present invention will be described with reference to FIG. 1 (a) shows a schematic view of the light source device, and FIG. 1 (b) shows an explanatory view of an axis of the light source device (FIG. 1 (a)) showing one embodiment of the light source device of the present invention. It is a cross-sectional view taken from the arrow AA of. As shown in FIG. 1A, the light source device 1 of the present embodiment includes a housing 10 which is a light source unit, a condenser lens 20, a fluorescent plate wheel 30, a light receiving lens 40, a rotation drive unit 50, and a heat radiation plate 60. ..
In the present embodiment, blue light is emitted from the housing 10, the emitted blue light is incident on the condenser lens 20, is condensed by the condenser lens 20 (details will be described later), and is collected by the rotation drive unit 50. It is incident on the rotating fluorescent plate wheel 30. The fluorescent plate wheel 30 is made of a material that allows light to pass through, and has a dielectric film 31 formed concentrically on the surface on the incident side and a phosphor layer 32 formed concentrically on the surface on the exit side. More specifically, a green phosphor region, a red phosphor region, and a blue transmissive region are concentrically provided on the emission side surface. The green phosphor emits green light when blue light is incident, and the red phosphor emits red light when blue light is incident. Therefore, when blue light is incident on the fluorescent plate wheel 30 from the condenser lens 20, green light, red light, and blue light are emitted from the fluorescent plate wheel 30 in a time-divided manner and incident on the light receiving lens 40. Then, the light is collected by the light receiving lens 40 and emitted from the light source device 1.
The wavelength of the semiconductor laser 12 used in the present embodiment preferably emits light within 370 to 500 nm, and more preferably emits light within 420 to 500 nm.

A plurality of housings 10 are attached to the attachment surface of the heat sink 60, which is a support member. In FIG. 1, one housing 10 is shown by a solid line, and the other housing 10 is shown by a broken line. In each housing 10, a plurality of light sources having a semiconductor laser 12 that emits blue light and a collimated lens 13 that makes the light emitted from the semiconductor laser 12 substantially parallel light are provided in the main body 11 of the housing. In one housing 10, the light emitted from each light source is arranged so as to be substantially parallel light in the same direction. Each housing 10 is mounted at a different mounting angle with respect to the heat sink (support member) 60 for each housing (see the housing 10 shown by the solid line and the housing 10 shown by the broken line in FIG. 1). As a result, the optical axis 14 of the light emitted from each housing 10 is not parallel to the optical axis 21 of the condenser lens 20, but is incident on the condenser lens 20 at different angles of incidence depending on the housing 10. As a result, as shown by the solid line and the broken line in FIG. 1, the light is collected at the position of the fluorescent screen wheel 30 by the condenser lens 20, but is collected at a different position for each housing 10. In FIG. 1, the light is drawn so as to be focused at the surface position of the dielectric film 31 provided on the incident side surface of the fluorescent plate wheel 30, but the dielectric film 31 is very thin, and the fluorescent plate wheel 30 is used. Since the light is not focused or diffused, it can be said that the light is focused at different positions on the phosphor 32.
A detailed description of the embodiment relating to the housing will be described later.

As described above, in the phosphor wheel 30, the dielectric film 31 is formed concentrically on the surface on the incident side and the phosphor layer 32 is formed concentrically on the surface on the exit side. FIG. 5 shows a schematic view of the phosphor wheel. FIG. 5A shows the incident side of the phosphor wheel, and FIG. 5B shows the exit side of the phosphor. The phosphor wheel 30 is provided with a green phosphor region, a red phosphor region, and a blue transmission region. In the green phosphor region, a dielectric film 31G that transmits blue light and reflects green light is formed on the incident side, and a phosphor 32G having a green wavelength band is coated on the exit side of the substrate. .. Similarly, in the red phosphor region, a dielectric film 31R that transmits blue light and reflects red light is formed on the incident side, and a phosphor 32R having a red wavelength region is applied to the emitting side. ing. In the blue transmission region, a dielectric film 31B that transmits blue light is formed on the incident side, and a phosphor is not coated on the exit side, but a dielectric that transmits blue light as in the incident side. The film 32B may be formed. Further, in order to improve the uneven brightness and uneven chromaticity, it is desirable that particles such as _{a scatterer such as SiO 2} , TiO ₂ , and Ba ₂ So _{4 are coated.}

The dielectric films 31G and 31R formed in the green and red phosphor regions of the phosphor wheel 30 are formed to be films that transmit blue light and reflect wavelengths corresponding to the colors of the respective regions. The phosphor light emitted from the phosphors 32G and 32R to the semiconductor laser 12 side can be reflected on the light receiving lens 40 side, whereby the phosphor light can be used efficiently.

It is desirable that the phosphor 32G applied to the green phosphor region of the phosphor wheel 30 generate green fluorescence having a wavelength band of about 500 to 560 nm. As an example of a specific material, β-Si _6-Z Al _{ZO Z} N _8-Z : Eu, Lu ₃ Al ₅ O ₁₂ : Ce, Ca ₈ MgSi ₄ O ₁₆ C _l2 : Eu, Ba ₃ Si ₆ O ₁₂ N ₂ : Eu, (Sr, Ba, Ca) Si ₂ O ₂ N ₂ : Eu and the like can be mentioned.

It is desirable that the phosphor 32R applied to the red phosphor region of the phosphor wheel generate a red tendency having a wavelength band of 600 to 800 nm. An example of a specific _{material, (Sr, Ca) AlSiN 3} : Eu, CaAlSiN 3: Eu, SrAlSiN 3: Eu, K 2 SiF 6: Mn , and the like.

The ratio of the green / red phosphor region and the blue transmission region in the phosphor wheel 30 can be arbitrarily determined. For example, it can be calculated from the chromaticity of white required for a projector and the efficiency of each phosphor or the like. Here, the green and red phosphor regions green are set to 150 degrees, and the blue transmission region is set to 60 degrees, respectively.
Further, in the present embodiment, there are three regions of green, red, and blue, but four or more regions may be used. The white light region of blue and yellow and the green, red, and blue regions may be increased to two each.

The phosphor wheel 30 is made of a transparent disk-shaped member that transmits light, and its center is fixed to the drive shaft 50a of the drive body 50. Here, as the material of the phosphor wheel 30, glass, resin, sapphire or the like can be used as long as it is a material having high light transmittance. Further, the region indicated by "SP" in FIG. 5A indicates a region (condensing region) to which the incident light from the housing 10 condensed by the condenser lens 20 hits. Further, the region indicated by "FL" in FIG. 5B indicates a region (fluorescent region) in which the phosphor layer emits light due to the incident light from the housing 10.
An additional substrate may be added to the emission side of the phosphor wheel 30, and a bandpass filter may be provided there (not shown). This makes it possible to obtain a purer green or red color.

Returning to the description of FIG. 1, the rotation drive unit 50 is a brushless DC motor, and is arranged so that the drive shaft 50a and the optical axis 21a of the condenser lens 20 are parallel to each other. Further, the surface of the phosphor wheel 30 is fixed so as to be perpendicular to the drive shaft 50a. The rotation speed of the rotation drive unit 50 is a rotation speed based on the frame rate of the moving image to be reproduced (the number of frames per second. The unit is [fps]). For example, when a moving image of 60 [fps] can be reproduced, the rotation speed of the rotation drive unit 50 (that is, the phosphor wheel 30) may be set to an integral multiple of 60 rotations per second.

The light emitted from the phosphor wheel 30 is collected by the light receiving lens 40 and emitted from the light source device 1. When the light source device 1 is used as a light source of a projector, the light emitted from the light source device 1 is collected by the modulation means, and the image formed by the modulation means is enlarged by the projection means and projected onto the screen. At this time, the Etendue calculated from the relationship between the image size formed by the modulation means and the spread angle of the light projected by the projection means is the size of the NA of the light receiving lens 40 and the light emitting region of the phosphor. Affect.
in short,
(Image size formed by the modulation means) x (projection angle) = (fluorescence region FL) x (light receiving lens NA)
Will be. Therefore, since the emission of the phosphor is substantially Lambertian, it is desirable that the light receiving lens 40 has as high an NA as possible. Further, it is desirable that the fluorescence region FL is small. When the ethandue on the phosphor side is larger than the ethandue on the projection side, the difference becomes an efficiency decrease.

As described above, since the NA of the light receiving lens 40 is high, it is desirable that the fluorescence region FL be as small as possible. However, in that case, the light density from the housing 10 becomes high. In the present embodiment, the size of the fluorescence region FL is preferably about 2 mm, so that the light from the housing 10 is preferably the size of the condensing region SP of 2 mm or less. Note that this shape is not the size of the light-collecting area of each housing 10, but the size of the entire light-collecting area when a plurality of housings 10 are attached.

(Description of housing)
Next, the housing according to the embodiment of the present invention will be described with reference to FIGS. 1 to 3. In the description of this housing, the incident angle of the light emitted from the housing 10 with respect to the optical axis of the condensing lens 20 is different by changing the mounting angle of each housing with respect to the heat radiation plate (support member) 60. The description of the first embodiment and the description of the second embodiment in which the mounting position of the collimating lens 13 with respect to the semiconductor laser 12 is shifted from the lens mounting position (focus position) for emitting parallel light from the collimated lens 13 are included. ..

(Explanation of the first embodiment)
First, a first embodiment of the present invention relating to a housing will be described with reference to FIGS. 1 to 3. As shown in FIG. 1A, the semiconductor lasers 12 are aligned in the short axis (X-axis) direction in the farfield pattern of the diffused light emitted from the semiconductor laser 12, and the mounting angle of the housing 10 is determined. The angle is changed in the direction of rotation about the long axis (Y axis) of the farfield pattern. In FIG. 1A, the vertical direction is the Y-axis direction. Here, the short axis (X axis) and the long axis (Y) in the far field pattern are shown in the axis explanatory view (see FIG. 1 (b)) which is a cross-sectional arrow view taken from the arrow AA of FIG. 1 (a). Axis) is shown.
In FIG. 1A, four light sources (pairs of the semiconductor laser 12 and the collimating lens 13) are arranged in the short axis (X-axis) direction, but not only in the case of one row, but also as shown in FIG. In addition, there may be two rows of four light sources arranged in the short axis (X-axis) direction, or three or more rows.

As described above, the mounting angle of the housing 10 changes from the angle at which the emitted light is incident parallel to the optical axis 21 of the condenser lens 20 in the rotation direction centered on the long axis (Y axis). Has been done. Therefore, the light emitted from the housing 10 is incident on the condenser lens 20 at an incident angle corresponding to the mounting angle (tilt angle). That is, the light is incident on the condenser lens 20 at an angle with respect to the optical axis 21 by the mounting angle (tilt angle). The mounting angle (tilt angle), that is, the incident angle (angle of the condenser lens 20 with respect to the optical axis 21) is preferably 0.25 to 2 degrees in absolute value.
If the light emitted from the housing 10 is incident parallel to the optical axis 21 of the condenser lens 20, it is condensed to a point on the optical axis 21, but is collected at a predetermined incident angle. When incident on the optical lens 20, as shown in FIG. 1A, the light is focused on different positions. Therefore, if the mounting angles of the housings 10 are different, the light is collected at different positions. However, if the inclination angle is in the range of 0.25 to 2 degrees in absolute value, the area of the condensing region SP (see FIG. 5A) in the fluorescent wheel 30 (fluorescent material) does not become too large.

Next, an embodiment in which the housing 10 is tilted and attached to the heat radiating plate 60, which is a support member, will be described with reference to FIG. In FIG. 2A, two housings 10 having two rows in which four light sources are arranged in the short axis (X-axis) direction (vertical direction in the figure) are arranged adjacent to each other (see M and N). ), The two housings 10 indicated by M and N are not inclined with respect to the mounting surface of the heat sink 60. That is, the housing 10 has a rectangular side shape as shown by the side shape seen from the arrows BB in FIG. 2A, and the housing 10 is mounted on the mounting surface of the heat sink 60. The surface and the exit surface are arranged in parallel. Therefore, if the mounting surface of the heat radiating plate 60 is arranged perpendicular to the optical axis 21 of the condenser lens 20, light is emitted from the housing 10 in a direction parallel to the optical axis 21 of the condenser lens 20. Will be done. A graph showing the shape of the condensing point (see M'and N') and the light intensity distribution (cross-sectional light intensity) in the condensing region SP condensed by the condensing lens 20 in this case is shown in FIG. 3A. show. The light-collecting point shape M from the housing 10 indicated by M and the light-collecting point shape N'from the housing 10 represented by N overlap. As is clear from this graph, since the light emitted from the housing 10 is focused on one point, it shows high light peak intensity in both the short axis (X axis) direction and the long axis (Y axis) direction. It can be seen that the light density of the condensing region SP is high.

Returning to the description of FIG. 2, in FIG. 2B, the housing 10 represented by P and Q has two rows in which four light sources are arranged in the short axis (X-axis) direction (vertical direction in the figure). Are two adjacent to each other. Each of the housings 10 indicated by P and Q has the same shape, and has a side shape in which the mounting surface to be attached to the heat sink 60 is inclined. Here, when the housing 10 shown by P is described as an example, the mounting surface of the housing 10 to the heat radiating plate 60 has a predetermined angle as shown by the side shape seen from the arrows CC in FIG. 2 (b). It has an inclined shape. The inclination angle is preferably 0.25 to 2 degrees as described above, but in FIG. 2, the inclination is emphasized more than that. As a result, when the mounting surface of the heat radiating plate 60 is arranged perpendicular to the optical axis 21 of the condenser lens 20, the light emitted from the housing 10 indicated by P is directed to the optical axis 21 of the condenser lens 20. On the other hand, the light is incident at an incident angle corresponding to a predetermined tilt angle. That is, the light is incident on the condenser lens 20 at an angle with respect to the optical axis 21 by a predetermined angle. Compared with the direction perpendicular to the drawing that coincides with the direction of the optical axis 21 of the condenser lens 20, the light is emitted at an angle downward.
On the other hand, the housing 10 having the same shape (the shape in which the mounting surface is inclined by a predetermined angle) and indicated by the adjacent Q has the rotation center in the substantially optical axis direction of the light emitted from the housing 10. It is fixed at a position rotated 180 degrees relative to the adjacent housing 10 indicated by P. As a result, the light is emitted at an upward angle as compared with the direction perpendicular to the drawing that coincides with the direction of the optical axis 21 of the condenser lens 20. It is incident on the optical axis 21 of the condenser lens 20 at an incident angle corresponding to a predetermined angle (that is, it is incident on the condenser lens 20 at an angle with respect to the optical axis 21 by a predetermined angle).

A graph showing the shape of the condensing point (see P'and Q') and the light intensity distribution (cross-sectional light intensity) in the condensing region SP condensed by the condensing lens 20 in this case is shown in FIG. 3 (b). show. The light from the housing 20 indicated by P is focused at the lower position in the drawing to form a focusing point shape P', and the light from the housing 20 indicated by Q is collected at the upper position in the drawing. It is illuminated to form a condensing point shape Q'. The light emitted from the housing 10 is not focused on one point, but is dispersed and focused on two places. Therefore, as is clear from the graph of FIG. 3 (b), the short axis (X-axis). The light intensity distribution has two peaks in the direction (), and the light peak intensity is lower than that in the case of FIG. 3 (a).
Assuming that the original light peak intensity when the focusing point positions shown in FIG. 3 (a) are one is Po, the peak intensity in the case of FIG. 3 (b) is
P = Po / (number of focusing point positions = 2)
Will be. That is, since the value is obtained by dividing the original light peak intensity Po by the number of focusing point positions, the light peak intensity is halved in this example.
Further, the light intensity distribution is almost uniform in the long axis (Y axis) direction. Therefore, the light density of the condensing region SP is lower than that of the housing 10 shown in FIG. 2A, which is not attached at an angle. However, in the long axis (Y axis) direction, a Gaussian distribution may occur depending on the distance between P and Q.

Returning to the description of FIG. 2, in FIG. 2 (c), there are two rows in which two light sources are arranged in the short axis (X-axis) direction (vertical direction in the figure), which are indicated by R, S, T and U. Four housings 10 are arranged adjacent to each other (see R, S, T and U). Each of the housings 10 represented by R, S, T and U has the same shape, and the mounting surface to be attached to the heat radiating plate 60 has a side shape inclined at a predetermined angle. Then, based on the housing 10 indicated by R, in the order of S, T, and U, the rotation center is approximately the optical axis direction of the light emitted from the housing 10, and the relative counterclockwise direction is 90 degrees. , 180 degrees, 270 degrees rotated and fixed. Therefore, when the mounting surface of the heat radiating plate 60 is arranged perpendicular to the optical axis 21 of the condenser lens 20, it coincides with the direction of the optical axis 21 of the condenser lens 20 from the housing 10 indicated by R. Compared to the vertical direction, the light is emitted tilted downward, and the housing 10 indicated by S is inclined to the right side compared to the vertical direction, and the light is emitted, which is indicated by T. Light is emitted from the housing 10 in an upward direction when compared with the direction perpendicular to the drawing, and light is inclined to the left side from the housing 10 indicated by U as compared with the direction perpendicular to the drawing. Will be emitted. In either case, the light emitted from each housing 10 is incident on the optical axis 21 of the condenser lens 20 at an incident angle corresponding to a predetermined angle (that is, only by a predetermined angle with respect to the optical axis 21). At an angle, it is incident on the condenser lens 20).

A graph showing the shape of the condensing point (see R', T', S'and U) and the light intensity distribution (cross-sectional light intensity) in the condensing region SP condensed by the condensing lens 20 in this case is shown in the figure. It is shown in 3 (c). The light from the housing 20 indicated by R is condensed to the lower position in the drawing to form a focusing point shape R', and the light from the housing 20 indicated by S is collected at the right position in the drawing. Light is emitted to form a condensing point shape S', and light from the housing 20 represented by T is condensed to an upper position in the drawing to form a condensing point shape T', and the housing represented by U is formed. The light from 20 is focused at the position on the left side in the drawing to form a focusing point shape U'. Therefore, the light emitted from the housing 10 is not focused on one point, but is dispersed and focused on four regions (R', T', S'and U'). As is clear from the graph of (c), the light intensity distribution has two peaks in each of the short axis (X axis) direction and the long axis (Y axis) direction. Assuming that the original light peak intensity when the focusing point positions shown in FIG. 3 (a) are one is Po, the peak intensity in the case of FIG. 2 (c) is
P = Po / (number of focusing point positions = 4)
Will be. That is, since the value is obtained by dividing the original light peak intensity Po by the number of focusing point positions, the light peak intensity is 1/4 in this example.
Therefore, the light peak intensity is much lower than that of FIG. 3 (a) corresponding to the embodiment shown in FIG. 2 (a), and compared with FIG. 3 (b) corresponding to the embodiment shown in FIG. 2 (b). Will have lower light intensity. Therefore, the light density of the condensing region SP is much lower than that of the housing 10 shown in FIG. 2A, which is not attached at an angle.
In the embodiment shown in FIG. 2 (c) (see the graph in FIG. 3 (c)), the light density is the lowest, but the embodiment shown in FIG. 2 (b) (graph in FIG. 3 (b)). Also in (see), the light density is sufficiently lower than in the case shown in FIG. 2 (a) (see the graph in FIG. 3 (a)), and the decrease in luminous efficiency of the phosphor can be sufficiently suppressed.

As described above, in the present embodiment, when a plurality of housings are fixed to the same heat sink (mounting member) 60, the mounting angles with respect to the heat sink (mounting member) 60 are different, so that the condenser lens The incident angles of the 20 with respect to the optical axis 21 are different from each other. Therefore, the light emitted from the plurality of housings 10 is focused on the phosphor wheel 30 by the condenser lens 20, but is focused on different positions on the phosphor. Therefore, since the light density in the condensing region SP can be suppressed, the light emitted from the phosphor can be efficiently used.
Further, since this can be realized only by changing the mounting angle of the housing 10 with respect to the heat radiating plate (mounting member) 60, manufacturing can be performed without sacrificing productivity.
Therefore, it is possible to provide a light source device 1 that can be manufactured without sacrificing mass productivity by suppressing a decrease in luminous efficiency of the phosphor as much as possible and realizing simple assembly.

Further, in the housing 10, each light source is aligned in the short axis (X-axis) direction of the farfield pattern, and the mounting angle of the housing 10 rotates around the long axis (Y-axis) of the farfield pattern. Since the angle is changed in the direction, the light emitted from each light source does not interfere with each other, and the light density can be appropriately suppressed in the condensing region SP.

Further, the light density in the condensing region SP can be surely suppressed only by inclining the mounting surface of the housing 10 with the heat sink (mounting member) 60, and the production can be performed without sacrificing productivity. It will be possible.

In particular, using a housing 10 having the same shape with an inclined mounting surface with the heat sink (mounting member) 60, the mounting angle is relatively rotated by 180 degrees (in other words, rotated by 180 degrees in a certain rotation direction). By fixing it, the angle of incidence of the light emitted from each housing with respect to the optical axis of the condensing lens can be made different. Therefore, the light density can be surely suppressed in the condensing region SP by using a very simple structure.

In particular, using a housing 10 having the same shape with an inclined mounting surface with the heat sink (mounting member) 60, the mounting angle is relatively rotated by 90 degrees (in other words, it is constant with reference to one housing). By fixing the light emitted from each housing by 90 degrees, 180 degrees, and 270 degrees in the rotation direction of the above, the incident angle of the light emitted from each housing with respect to the optical axis of the condensing lens can be made different. Therefore, the light density can be surely suppressed in the condensing region SP by using a very simple structure.

Further, if the inclination angle of the housing 10 with respect to the mounting surface with the heat sink (mounting member) 60 is 0.25 to 2 degrees, the light density is suppressed without unnecessarily increasing the area of the condensing region SP. be able to.

Further, since the heat radiating plate 60 is used as the support member, the housing 10 can be efficiently cooled, the number of parts can be suppressed, and the miniaturization of the light source device 1 can be promoted.

<Explanation of Modification Example in First Embodiment>
In the above-described embodiment, the mounting surface of the housing 10 to the heat sink 60 is inclined, but the present invention is not limited to this, and the mounting surface of the heat sink 60, which is a support member, is tilted. Therefore, the incident angle of the light emitted from each housing with respect to the optical axis of the condensing lens can be made different. In this case, the mounting surface side of the housing 10 is not inclined and can have a rectangular side surface shape.
Therefore, once the heat sink 60, which is a support member, is formed in this way, the shape of the housing 10 becomes simple, so that even when the housing 10 is replaced for maintenance or the like, it can be easily performed at low cost. Can be done.

In the above-described embodiment, the heat sink 60 is used as a support member to which the housing 10 is attached, but the present invention is not limited to this, and any other member may be used as the support member depending on the application.

(Explanation of the second embodiment)
Next, a second embodiment of the present invention relating to the housing will be described with reference to FIG. In the present embodiment, in the light source 1, the mounting position of the collimating lens 13 with respect to the semiconductor laser 12 is deviated from the lens mounting position for emitting parallel light from the collimated lens 13. FIG. 4A shows a case where the collimated lens 13 is arranged at a focal position for emitting parallel light. FIG. 4B shows a case where the collimating lens 13 is moved to the semiconductor laser 12 side by about 0.2 mm from the focal position and arranged. That is, the distance between the two is shorter by about 0.2 mm as compared with the case where the semiconductor laser 12 is arranged at the focal position of the collimating lens 13. In both cases of FIGS. 4A and 4B, the housing 10 described with reference to FIGS. 1 and 2 is attached to the heat sink (support member) 60 at an angle of a predetermined angle. It is shown by.
The amount of deviation of the collimating lens 13 from the focal position is preferably 0.1 to 0.5 mm. In FIG. 4B, the collimating lens 13 is displaced toward the semiconductor laser 13, but conversely, it is displaced toward the condenser lens 20. Is also possible.

In the arrangement shown in FIGS. 4 (a) and 4 (b), the shape of the condensing point in the condensing region SP condensed by the condensing lens 20 and the light intensity distribution (cross-sectional light intensity) thereof are shown in FIGS. 4 (c) and 4 (c). Shown in (d).
FIG. 4C shows the shape of the condensing point and the light intensity distribution (cross-sectional light intensity) when the collimating lens 12 is arranged at the focal position, and FIG. 4D shows the collimating lens 12 from the focal position. The shape of the condensing point and the light intensity distribution (cross-sectional light intensity) when they are arranged out of alignment are shown.
A comparison between the case where the collimating lens 12 shown in FIG. 4 (c) is arranged at the focal position and the case where the collimating lens 12 shown in FIG. 4 (d) is arranged at a position shifted from the focal position is as shown in FIG. 4 (d). When the light is arranged so as to be offset from the focal position, the area of light in the condensing region SP is larger and the light peak intensity is lower than in the case of FIG. 4C.

Here, assuming that Po is the light peak intensity in the condensing region SP when the collimating lens 13 is arranged at the focal position, the light peak intensity P'in the condensing region SP when the collimating lens 13 is shifted from the focal position is
P '= Po / (πr2 / πr 0 2)
Will be. Where r is the radius of the focused diameter in the condensing region SP in the case where a collimator lens 13 to the focal position, r _o is the radius of the focused diameter in the condensing region SP in the case of staggered collimator lens Is.
Since the radius of the focusing diameter in FIG. 4C is about 0.1 mm and the radius of the focusing diameter in FIG. 4D is about 1 mm, the light peak intensity shifts the collimator lens 13 from the focal position. When the collimator lens 13 is arranged at the focal position, it is about 1/100 of the case where the collimator lens 13 is arranged at the focal position.

Even in the cases shown in FIGS. 4A and 4C, since the housing 10 is attached to the heat radiating plate (support member) 60 at an angle of a predetermined angle, the light is collected by the plurality of housings 10. The light density in the region SP can be suppressed, but in the cases shown in FIGS. 4 (b) and 4 (d), the light density can be further suppressed as shown below.
In each light source, when the position of the collimating lens 13 with respect to the semiconductor laser 12 is deviated from the focal position, the light from the collimating lens 12 deviates from the parallel light, so that the focusing diameter at the focusing point of the phosphor should be increased. The light source position deviation of the plurality of semiconductor lasers 12 can be reduced.
That is, the light of the semiconductor laser provided in the same housing 10 is focused at substantially the same position, but the light density can be reduced by increasing the focusing diameter. Therefore, the emitted light from the phosphor can be efficiently used. However, since the position of each condensing point of each semiconductor laser in one housing 10 changes only slightly, the expansion of the condensing region SP can be appropriately suppressed as a whole.

(Explanation of Combination of First and Second Embodiments)
Next, a phosphor when the first embodiment of the present invention in which the mounting angles of the housing 10 are different and the second embodiment of the present invention in which the collimating lens 13 is arranged so as to be displaced from the focal position are combined. The output of the above will be described with reference to the graph of FIG.
The graph of FIG. 6 shows the relationship between the light output of the phosphor and the excitation light output of the light source unit 10. The dotted line shown in (A) is a phosphor in a form in which the non-tilted form shown in FIG. 2 (a) and the form in which the collimating lens shown in FIG. 4 (b) is arranged deviated from the focal position are combined. The alternate long and short dash line showing the output and shown in (B) is a combination of the tilted and rotated form shown in FIG. 2 (b) and the form in which the collimated lens shown in FIG. 4 (b) is arranged deviated from the focal position. The solid line shown in FIG. 2C shows the output of the phosphor in the above-mentioned form, and the tilted and rotated forms shown in FIG. 2C and the collimated lens shown in FIG. 4B are arranged so as to be deviated from the focal position. The dotted line showing the phosphor output of the combined form and having a dense pitch shown in (D) is the non-tilted form shown in FIG. 2 (a) and the collimated lens shown in FIG. 4 (a) arranged at the focal position. The phosphor output of the form in combination with the form shown is shown.

In the form in which the collimating lens is arranged at the focal position and has no inclination as shown in FIG. 2 (a), which is indicated by the dense dotted line in (D), the phosphor output peaks as the excitation output is increased. On the contrary, it will decrease. The collimated lens shown by the dotted line in (A) is arranged so as to be deviated from the focal position, but in the form without the inclination shown in FIG. 2 (a), the effect as shown in FIG. 4 (b) is obtained. However, as the excitation output increases, the phosphor output also increases, but gradually saturates.
On the other hand, in the tilted and rotated form shown in FIG. 2B or FIG. In addition to the effects shown in 4 (b), the effects shown in FIGS. 3 (b) and 3 (c) suppress the saturation of the tilt and the rotating phosphor output, and the light output from the light source unit 10 is output. Even when it is high, the phosphor can be used effectively. This is because the light density in the condensing region SP can be suppressed to be low, so that the decrease in luminous efficiency of the phosphor is suppressed. Comparing the one-dot chain line graph of (B) and the solid line graph of (C), the form shown by the solid line of (C) corresponding to FIGS. 2 (c) and 3 (c) is more effective. A fluorescent substance can be used, but even in the form shown by the alternate long and short dash line (B) corresponding to FIGS. 2 (b) and 3 (b), the excellent performance regarding the fluorescent substance output can be obtained as compared with the conventional case. It is clear that it will work.

Therefore, by combining the above-mentioned first embodiment and the second embodiment, the light emitted from the plurality of housings 10 is collected at different positions on the phosphor, and each housing is used. Since the light condensing diameter from No. 10 is large, the light density can be sufficiently suppressed, and the decrease in luminous efficiency of the phosphor can be sufficiently suppressed.

As described above, in the light source device 1 according to the embodiment of the present invention, by arranging the mounting surface of the light source unit 10 by inclining and rotating it, the positions of the focusing points of the plurality of light source units 10 are shifted and fluorescence is applied. It is possible to reduce the light density in the light collecting area of the body. Further, by shifting the position of the collimating lens 13, the shape of the phosphor in the condensing region SP can be increased without sacrificing etendue, and the light density can be reduced. As a result, it is possible to suppress a decrease in the light conversion efficiency of the phosphor and use the phosphor efficiently. Further, it is possible to change the arrangement of the housings 10 having the same shape and incorporate them, and the mass productivity is not sacrificed.

The number of housings 10 is not limited to the above-described embodiment, and any number may be used as long as it is at least two or more, and the number of semiconductor lasers 12 in the housing 10 is also at least two. Any number may be used as long as it is the above. Further, in the above-described embodiment, the number of collimating lenses 13 is one for each semiconductor laser 12, but a lens array may be used, for example.

(Explanation of the Projector of the Present Invention)
Next, a case where the light source device 1 shown in the above-described embodiment is used as a light source device in a so-called one-chip type DLP projector will be described with reference to FIG. 7. Note that FIG. 7 is a schematic view for showing the configuration of the projector 100 provided with the light source device 1 shown in the above embodiment, and is a schematic plan view of the light source device 1 and the projector 100 as viewed from above. be. In the two housings 10 of the light source device 1 shown in FIG. 7, a housing 10 tilted upward and a housing 10 tilted downward are arranged adjacent to each other. As a result, the angles of incidence of the light emitted from the two housings 10 with respect to the optical axis of the condensing lens 20 are different. The number of housings 10 is not limited to two, and as described above, any number of housings 10 can be provided.
In FIG. 7, the light emitted from the light source device 1 is reflected by the DMD (Digital Micromirror Device) element 110, which is an optical spatial modulator, is collected by the projection lens 120, which is a projection means, and is projected onto the screen SC. NS. The DMD element is a matrix of fine mirrors corresponding to each pixel of the image projected on the screen, and the light emitted to the screen by changing the angle of each mirror is turned on / off in microsecond units. Can be turned off.
In addition, by changing the gradation of the light incident on the projection lens according to the ratio of the time when each mirror is on and the time when it is off, it is possible to display the gradation based on the image data of the projected image. Become.

In the present embodiment, the DMD element is used as the light modulation means, but the present invention is not limited to this, and any other light modulation element can be used depending on the application. Further, the light source device 1 according to the present invention and the projector using the light source device 1 are not limited to the above-described embodiments, and various other embodiments are included in the present invention.

Although the embodiments of the present invention have been described, the disclosed contents may be changed in the details of the configuration, and changes in the combination and order of the elements in the embodiments deviate from the claimed scope and ideas of the present invention. It can be realized without.

1 Light source device 10 Housing 11 Housing body 12 Semiconductor laser 13 Collimating lens 14 Semiconductor laser optical axis 20 Condensing lens 21 Condensing lens optical axis 30 Phosphorus wheel 31 Dielectric film 32 Phosphorant 40 Light receiving lens 50 Rotation Drive body 50a Rotating shaft 60 Heat dissipation plate (support member)
100 Projector 110 DMD element 120 Projection lens SC screen SP Condensing area FL Fluorescent light emitting area

Claims (8)

A plurality of housings in which a plurality of light sources having a semiconductor laser and a collimated lens in which the light emitted from the semiconductor laser is substantially parallel light are arranged so that the light emitted from each light source becomes substantially parallel light in the same direction. When,
A condenser lens that collects the light emitted from the plurality of housings toward the phosphor and
A phosphor wheel having the phosphor and transmitting light from the condenser lens,
Equipped with a,
As varying the incident angle with respect to the optical axis of the condenser lens of the light emitted from the front Kikatami body, wherein the housing is mounted on the same support member,
When the plurality of housings are fixed to the support member, the mounting surface of the semiconductor laser has substantially the same shape that is inclined with respect to the mounting surface of the support member .
When the two adjacent housings are fixed to the support member, the two adjacent housings are relatively rotated 180 degrees and fixed with the direction of the optical axis of the light emitted from the housing as the center of rotation. A light source device characterized by being The light source device according to claim 1, wherein in the light source, the mounting position of the collimating lens with respect to the semiconductor laser is deviated from the lens mounting position for emitting parallel light from the collimated lens. In the housing, the light sources are aligned in the minor axis direction in the farfield pattern of the semiconductor laser.
The light source device according to claim 1 or 2, wherein the mounting angle of the housing is changed in a direction of rotation about a long axis of the farfield pattern. Any one of claims 1 to 3 , wherein the inclination angle of the mounting surface of the semiconductor laser with respect to the mounting surface of the support member when fixed to the support member is 0.25 to 2 degrees. The light source device according to the section. Light source device according to any one of 4 claims 1, wherein the support member is a heat radiating member. The light source device according to any one of claims 1 to 5 , wherein the wavelength band of the light emitted from the housing is 370 to 500 nm. Wherein one of the phosphor, the light source device according to any one of claims 1 to 6, characterized in that a phosphor emitting a light containing red light. The light source device according to any one of claims 1 to 7.
An optical modulation means that sequentially modulates light in a plurality of wavelength bands emitted from the light source device to form an image based on image data, and
A projection means for enlarging and projecting the image, and
A projector characterized by being equipped with.

Images