JP6735243B2 - Light source device and projector using the same - Google Patents

Description

The present invention relates to a light source device for irradiating an image forming element with blue component light, red component light, and green component light in a time-divided manner to form a color image on a screen and a light source device using the same. Regarding the improvement of the projector.

2. Description of the Related Art Conventionally, there is known a projector that irradiates an image forming element with blue component light, red component light, and green component light in a temporally divided manner to form a color image on a screen by the image forming element ( For example, see Patent Document 1).

The projector disclosed in Patent Document 1 includes a blue laser diode as one light source unit, a phosphor, and a dichroic mirror. The phosphor is composed of a rotating disk. The phosphor includes a phosphor region that emits green component fluorescence by irradiation with blue component laser light as excitation light, and a phosphor region that generates red component fluorescence by excitation light irradiation, and blue laser light. And a transmissive region that transmits the light are formed at predetermined angles.

The optical paths of the blue component laser light, the green component fluorescence, and the red component fluorescence are combined by a dichroic mirror, and the image forming element is temporally divided and irradiated. As a result, a color image is formed on the screen.

However, in this conventional projector, it is necessary to form each fluorescent region and each transmissive region at a predetermined angle in the phosphor, which makes the manufacture of the phosphor complicated.
In addition, since the angular size of the fluorescent region and the transmissive region to be formed on the phosphor varies depending on the type of projector, it is necessary to manufacture a phosphor with a different angle of the fluorescent region for each type of projector. Has the inconvenience of being complicated.

The present invention can generate a color image without using a single light source unit and dividing the fluorescent region of the phosphor into a fluorescent region that emits green component fluorescence and a fluorescent region that emits red component fluorescence. By doing so, it is possible to simplify the production of the phosphor, and to provide a light source device and a projector using the same that can simplify the configuration of the optical system and improve the degree of freedom of layout. With the goal.

A projector according to the present invention includes a light source device that emits light of a plurality of colors and an image forming element that is sequentially irradiated with the light of the plurality of colors to form an image, and displays an image formed on the image forming element. In a projector that projects
The light source device,
A light source unit that emits excitation light of visible light,
A fluorescent part that emits fluorescence by the excitation light emitted from the light source part,
From the fluorescent light emitted from the fluorescent portion, the color light different from the fluorescent light is taken out, and the excitation light and the color light are provided with a color component switching portion that switches and emits the light.
Timing of emission of the fluorescence in the fluorescent unit, and the timing at which the color component switching unit switches the excitation light and the color light are synchronized,
The colored light extracted from the fluorescent light and having a color different from the fluorescent light is lower in illumination efficiency for the screen than the excitation light,
Of the timing when the color component switching unit switches between the excitation light and the color light, the brightness of the projected image is reduced by at least one of the light source unit and the image forming element during the period closer to the color light, and the excitation light period of deviation is characterized in that it does not reduce the brightness of the previous SL projected image.

According to the present invention, it is possible to generate a color image without using a single light source unit and dividing a fluorescent region of a phosphor into a fluorescent region that emits fluorescence of a green component and a fluorescent region that emits fluorescence of a red component. Since this is possible, the manufacture of the phosphor can be simplified, which in turn simplifies the configuration of the optical system and improves the degree of freedom in layout.

First Embodiment FIG. 1 is an optical diagram showing a main part configuration of an optical system according to a first embodiment of a projector of the present invention. FIG. 2 is a plan view of the optical path switching board shown in FIG. FIG. 3 is a side view of the optical path switching board shown in FIG. FIG. 4 is a plan view of the color component switching board shown in FIG. FIG. 5 is an explanatory diagram showing the relationship between the angle of the transmission area and the angle of the reflection area of the optical path switching board shown in FIG. FIG. 6 is an explanatory diagram showing the relationship between the angles of the blue component reflection area and the red component reflection area of the color component switching board. FIG. 7 shows the time distribution ratio of the blue component light, the green component light, and the red component light, which are applied to the image forming element by using the optical path switching board shown in FIG. 5 and the color component switching board shown in FIG. It is explanatory drawing which shows an example. FIG. 8 is an optical diagram showing a modified example of the optical system according to the first embodiment of the projector of the present invention. FIG. 9 is a plan view of the optical path switching board shown in FIG. FIG. 10 is a side view of the optical path switching board shown in FIG. FIG. 11 is a plan view of the color component switching board shown in FIG. FIG. 12 is an optical diagram showing a main configuration of an optical system according to a second embodiment of the projector of the present invention. FIG. 13 is a plan view of the optical path switching board shown in FIG. FIG. 14 is a side view of the optical path switching board shown in FIG. FIG. 15 is a plan view of the color component switching board shown in FIG. FIG. 16 is an optical diagram showing another example of the light source section for focusing the laser light emitted from the light source section shown in FIGS. 1, 8 and 12. FIG. 17 is an optical diagram showing a main configuration of an optical system according to Example 3 of the projector of the invention. FIG. 18 is an explanatory diagram schematically showing the relationship between the optical path switching board and the beam spot according to the third embodiment. FIG. 19 is an explanatory diagram schematically showing the relationship between the color component switching board and the beam spot according to the third embodiment. FIG. 20 is an explanatory diagram showing another example of the color component switching board. FIG. 21 is a timing chart schematically showing color mixing that occurs when the beam spot according to the third embodiment crosses the boundary between regions. FIG. 22 is a timing chart schematically showing an example of color mixing prevention that occurs when the beam spot according to the third embodiment crosses the boundary between regions. FIG. 23 is an explanatory diagram showing another example of the phosphor according to the third embodiment.

(Example 1)
FIG. 1 is an optical diagram showing a main configuration of an optical system of a projector having a light source device according to a first embodiment of the invention. In FIG. 1, reference numeral 1 indicates a light source unit. The light source unit 1 is roughly configured by a laser diode (LD) 1a as a laser light source, a coupling lens 1b, and a condenser lens 1c.

A plurality of laser diodes 1a are provided on the drive circuit board 2, and a coupling lens 1b is provided for each laser diode 1a. The laser light from the laser diode 1a is condensed by the coupling lens 1b and guided to the condenser lens 1c as a parallel light flux.

The condenser lens 1c plays a role of condensing the laser light that is made into a parallel light flux by each coupling lens 1b. Here, the description will be made assuming that the laser diode 1a generates the blue (B) component laser light BP of the blue component light, the red (R) component light, and the green (G) component light. However, it is also possible to use a laser diode that generates a green component laser beam and a red component laser beam. A light emitting diode LED may be used instead of the laser diode (LD).

An optical path switching board 3 as an optical path switching unit is provided on the optical path along which the blue component laser light BP emitted from the light source unit 1 travels. A laser beam B is placed on the optical path switching board 3.
P is formed in a spot shape. The size of the spot of the laser light BP is set to an appropriate size to prevent color mixing.

This optical path switching disk 3 is composed of an optical path time division rotary disk having a reflection area 3a and a transmission area 3b divided in the rotation direction as shown in FIG. The optical path switching board 3 is arranged obliquely (45 degrees with respect to the optical axis here) with respect to the optical axis of the condenser lens 1c.

The optical path switching board 3 is rotationally driven by a stepping motor 4 as a drive source, for example, as shown in FIG. In FIG. 2, reference numeral 4a indicates a drive shaft.
In the reflection area 3a of the optical path switching board 3, as shown in FIG. 3, a reflection film 3d is provided on the side of the surface on which the blue component laser light BP strikes.

In the transmissive area 3b of the optical path switching board 3, an antireflection film 3e is formed on the side of the blue component laser beam BP, and a diffusion surface 3f is formed on the surface opposite to the antireflection film 3e. Has been done. The diffusion surface 3f is used to remove the speckles of the laser light BP.
Instead of providing the diffusing surface 3f on the optical path switching board 3, a rotary diffusing plate may be provided.

The optical path along which the blue component laser light BP reflected by the reflection area 3a travels is an optical path for irradiating the phosphor 5 with the blue component laser light BP emitted from the light source unit 1.
The phosphor 5 is composed of a rotating disk here, and in FIG. 1, reference numeral 6 indicates a stepping motor as a drive source thereof.

The phosphor 5 is irradiated with the blue component laser light BP emitted from the light source unit 1, and the fluorescence containing the green color component different from the blue component laser light and the red component fluorescence. The fluorescent film 5a that generates the light is applied.
The rotation of the phosphor 5 prevents the laser light from being focused on the same location for a long time, and prevents the phosphor film 5a from being deteriorated. The fluorescent material of the fluorescent film 5a is excited by irradiation of the laser beam BP of the blue component, for example, to generate a fluorescent material of a green component and a fluorescent material to generate a fluorescent component of a red component (yellow fluorescent light). A mixture with a fluorescent material which is generated) is used. However, it is not limited to this.
For example, it is possible to use a fluorescent material having a fluorescence distribution characteristic that extends from the wavelength range of the green component to the wavelength range of the red component.

A condenser lens 7, a dichroic mirror 8 and a condenser lens 9 are provided in the optical path where the blue component laser light BP is reflected and travels toward the phosphor 5. The condenser lens 7 has a role of condensing the laser light BP of the blue component reflected by the reflection area 3a and converting it into a parallel light flux BP″.

The dichroic mirror 8 has a function of transmitting the blue component laser light BP and guiding it to the phosphor 5, and a function of reflecting the fluorescence of the color component of the laser light other than the blue component and guiding it to the color component switching board 10 as a color component switching unit. Have and.
In the first embodiment, the color component switching board 10 plays a role of switching between the fluorescence GP of the green component and the fluorescence RP of the red component. The condenser lens 9 has a function of focusing the parallel light flux BP″ on the phosphor 5 in a spot shape and a function of condensing the fluorescence from the phosphor 5 and converting it into a parallel light flux LP′.
In the first embodiment, an optical path for causing the fluorescence YP excited by the light of the color component emitted from the light source unit 1 by the condenser lens 9, the dichroic mirror 8, and the condenser lens 11 to travel toward the color component switching board 10. Are formed.

A condenser lens 11 is provided between the dichroic mirror 8 and the color component switching board 10. The fluorescence reflected by the dichroic mirror 8 is condensed by the condenser lens 11 and is applied to the color component switching board 10. The color component switching board 10 includes a condenser lens 11
Is obliquely arranged with respect to the optical axis of.

As shown in FIG. 4, the color component switching board 10 reflects the green component fluorescence GP and the red component fluorescence RP in the rotation direction, and the reflection region 10a which absorbs or transmits the red component fluorescence RP and the red component fluorescence RP. The reflective region 10b that absorbs or transmits the green component fluorescence GP is composed of a color component time division rotary disc formed by being divided in the angular direction. The color component switching board 10 is also rotationally driven by, for example, a stepping motor 12 as a drive source. In this Example 1,
The color component switching board 10 has been described as a structure that reflects both the fluorescent GP and the RP.
The configuration is not limited to this, and one of the fluorescence GP and RP may be reflected and the other may be transmitted. In FIG. 4, reference numeral 12a indicates a drive shaft.

The optical path of the blue component laser beam BP that has passed through the transmission region 3b is an image of the blue component laser beam BP emitted from the light source unit 1 as an image as a known image forming element (for example, a digital mirror microdevice DMD). The optical path for irradiating the forming panel 13, that is, the light source unit 1
It is an optical path for advancing the light of the color components emitted from the image forming element toward the image forming element.

A condensing lens 14 is provided in the optical path, and the condensing lens 14 converts the laser beam BP of the blue component transmitted through the optical path switching board 3 into a parallel light beam BP″ and dichroic mirror 15
Has the function of leading to.

A condenser lens 16 is provided in front of the traveling directions of the green component fluorescence GP and the red component fluorescence RP reflected by the color component switching board 10. The condenser lens 16 has a function of condensing the green component fluorescence GP and the red component fluorescence RP into a parallel light beam LP″ and guiding the parallel light flux LP″ to the dichroic mirror 15. Lens 14
, 16 are arranged obliquely with respect to the optical axis.

The dichroic mirror 15 is located in the optical path between the image forming panel 13 and the color component switching board 10, and serves as the optical path of the parallel light flux BP″ as the blue component light and the green component light (or the red component light). And the optical path of the parallel light beam LP″ are combined and guided to the image forming panel 13 as a mirror for combining the optical paths.

The parallel light beams BP″ and LP″ whose optical paths are combined by the dichroic mirror 15 are condensed by a condenser lens 17 and guided to a known light tunnel 18. The light tunnel 18
Plays a role as an optical member for preventing unevenness in light quantity that reduces unevenness in light quantity. A fly-eye lens may be used instead of the light tunnel 18.

The light passing through the light tunnel 18 is collimated by the condenser lens 19, reflected by the reflection mirror 20, and guided to the image forming panel 13. The image forming panel 13
Is controlled by, for example, a known image generation unit GE. The light of each color component is reflected by the image forming panel 13 and is applied to the screen S via the projection lens 21. As a result, a color image is enlarged and formed on the screen S.

Next, the details of the temporal correspondence relationship between the optical path switching board 3 and the color component switching board 10 will be described with reference to FIGS.
The optical path switching board 3 and the color component switching board 10 are rotated at the same rotation speed and synchronously. As shown in FIG. 5, the angle φB of the transmissive region 3b is set so that the time tB (see FIG. 7) corresponding to the transmissive region 3b that transmits the blue component laser beam BP is secured. The angle φGB of the reflection area 3a is the remaining angle (360−φB).

While the blue component laser light BP is passing through the transmission region 3b of the optical path switching board 3, the phosphor 5 is not irradiated with the laser light BP, and the phosphor 5 does not emit fluorescence.
While the blue component laser beam BP is being reflected by the reflection region 3a, the phosphor 5 is irradiated with the laser beam BP, and thus the phosphor 5 emits fluorescence.

The time tGB during which the phosphor 5 is irradiated with the laser light corresponds to the angle φGB of the reflection area 3a. Here, as shown in FIG. 6, one of the boundaries q1 and q2 between the reflection region 10a of the color component switching board 10 that reflects the green component fluorescence GP and the reflection region 10b that reflects the red component fluorescence RP is switched to the optical path. It is set so as to be located within the transparent region 3b of the board 3.

Next, the other of the boundaries q1 and q2 is set so as to have a ratio of the times tG and tR (see FIG. 7) required for irradiation of the fluorescence GP and the fluorescence RP. Thus, the boundaries q1 and q2
By setting, since it is possible to allow a design margin in the setting range of the boundary q1, even if the angles of the reflection areas 10a and 10b of the color division switching board 10 are not strictly set, the optical path switching board when assembling the projector is set. By adjusting the rotation timing with respect to No. 3, it is possible to obtain the time distribution required to generate the blue light B, the green light G, and the red light G, as shown in FIG. 7.

In the first embodiment, the optical path is regularly switched as a configuration for rotationally driving the optical path switching plate 3, and the color components are periodically switched as a configuration for rotationally driving the color component switching plate 10. However, the present invention is not limited to this, and the optical path switching board 3 and the color component switching board 10 may be periodically reciprocated.

FIG. 8 is an explanatory diagram showing a modified example of the optical system of the first embodiment, in which the phosphor 5 is provided in the transmission optical path in which the blue component laser light BP transmitted through the transmission region 3b of the optical path switching board 3 travels. There is. Further, a dichroic mirror 15 for optical path combination is provided on the reflected optical path along which the blue component laser light BP reflected by the reflection area 3a of the optical path switching board 3 travels. That is,
The condensing lens 14, the dichroic mirror 15, and the condensing lens 17 form an optical path for advancing the light emitted from the light source unit 1 toward the image forming element. An optical path is formed by the condensing lens 9, the dichroic mirror 8, and the condensing lens 11 to advance the fluorescence excited by the light of the color component emitted from the light source unit 1 toward the color component switching board 10. ..

In this modification, as shown in FIG. 9, the reflection area 3a has the same angle as the angle of the transmission area 3b shown in FIG. 2, and the transmission area 3b has the same angle as the angle of the reflection area 3a shown in FIG. Has been done. In the transmission area 3b, as shown in FIG. 10, antireflection films 3e are formed on both surfaces of the optical path switching board 3.

Further, in the reflection area 3a, as shown in FIG. 10, a diffusion surface 3f is formed on the surface on which the laser beam BP is applied, and a reflection film 3d is formed on the surface on the opposite side.
The color component switching board 10 has here a transmission region 10a′ that transmits the green component fluorescence GP and blocks the red component fluorescence RP, and a transmission region 10a′ that transmits the red component fluorescence RP and the green component fluorescence GP. A transmissive region 10b' that prevents transmission is formed.

The angle of the transmission area 10a' is the same as the angle of the reflection area 10a shown in FIG. 4, and the angle of the transmission area 10b' is the same as the angle of the reflection area 10b shown in FIG. The color component switching board 10 is arranged in a direction orthogonal to the optical axes of the condenser lenses 11 and 16, and a reflection mirror 22 for bending an optical path is provided between the condenser lens 16 and the dichroic mirror 15. A reflection mirror 23 for bending the optical path is provided between the condenser lens 19 and the reflection mirror 20.

Since the operation of the optical system of the projector shown in FIG. 8 is the same as the operation of the optical system of the projector shown in FIG. 1, the description of the operation will be omitted. As described above, according to the present invention, the phosphor 5 may be provided on the optical path switching board 3 in either the optical path of the transmission light path of the laser light BP or the optical path of the reflection light path thereof. The degree of freedom of layout can be improved.

FIG. 12 is an optical diagram showing an optical system of the projector according to the second embodiment of the invention. Here, the dichroic mirror 8 which transmits the laser beam BP of the blue component to guide it to the optical path switching board 3 and reflects the light of the color component other than the blue component to guide it to the color component switching board 10 is the optical path switching board 3.
And the condenser lens 1c.

Between the condenser lens 1c and the dichroic mirror 8, a concave lens 1c′ for converting the laser light BP into a parallel light flux is provided. As shown in FIGS. 13 and 14, the optical path switching board 3 includes a reflection region 3a coated with a fluorescent film 5a and a transmission region 3 not coated with the fluorescent film 5a.
b and.

In the transmissive region 3b, as in the first embodiment, the antireflection film 3e is formed on the surface on which the laser light BP is applied, and the diffusion surface 3f is formed on the surface on the other side. A condenser lens 9 is provided between the dichroic mirror 8 and the optical path switching board 3.

The condenser lens 9 has a function of focusing the parallel light flux as the laser light BP on the optical path switching board 3 in a spot shape, and condenses the fluorescence generated by the reflection area 3a of the optical path switching board 3 to convert it into a parallel light flux. Have a function.

The laser light BP transmitted through the transmission region 3b of the optical path switching board 3 is made into a parallel light flux by the condenser lens 9'and guided to the dichroic mirror 15 for optical path synthesis by the reflection mirrors 22', 22 for bending the optical paths. Has been done.

The fluorescence RP containing the green component fluorescence GP and the red component fluorescence generated by the reflection area 3 a of the optical path switching board 3 is guided to the color component switching board 10 by the dichroic mirror 8.
As shown in FIG. 15, the color component switching board 10 includes a transmissive region 10a′ that transmits the green component fluorescence GP and absorbs or reflects the red component fluorescence RP and the red component fluorescence RP in the rotational direction.
And a transmissive region 10b' that transmits the light and absorbs or reflects the green component fluorescence GP is formed by a color component time division rotary disc formed by being divided in the angular direction.

A condenser lens 11 is provided between the dichroic mirror 8 and the dichroic mirror 15.
, A condenser lens 16 is provided, and the color component switching board 10 is arranged between the condenser lenses 11 and 16 and rotated in a plane orthogonal to the optical axes of the condenser lenses 11 and 16. ..
In the second embodiment, the light of the color component emitted from the light source unit 1 is directed toward the image forming element by the condenser lens 9′, the reflection mirror 22′, the reflection mirror 22, the dichroic mirror 15, and the condenser lens 17′. A traveling optical path is formed.
Further, an optical path is formed for allowing the fluorescence excited by the light of the color component emitted from the light source unit 1 toward the color component switching board 10 by the light condensing element 9, the dichroic mirror 8, and the condensing lens 11.

According to the second embodiment, since the phosphor 5 and the optical path switching board 3 can be integrally configured, the number of drive sources as rotary drive elements is reduced as compared with the first embodiment and the modification of the first embodiment. You can
The optical elements of the optical system can be simplified accordingly.

In the first and second embodiments, the light source unit 1 is provided with the condenser lens 1c to focus the laser light BP on the optical path switching board 3. However, the present invention is not limited to this, and for example, even if the condenser lens 1c is not provided in the light source unit 1, as shown in FIG. 16(a), the incident position of the laser light BP incident on the coupling lens 1b is cupped. Alternatively, the ring lens 1b may be provided at a position decentered from the optical axis center to focus on the optical path switching plate 3.

Alternatively, as shown in FIG. 16B, the laser diode 1a and the coupling lens 1b may be concentrically arranged and focused on the optical path switching board 3. The laser diode 1a, the coupling lens 1b, Various configurations are conceivable for the optical system for focusing using the optical lens 1c.
In addition, the relationship between the transmission and reflection of the dichroic mirrors 8 and 15 can be freely set according to the configuration of the optical system without departing from the spirit of the present invention.

As described above with reference to the first and second embodiments, according to the first and second embodiments, the light source section 1 can be of one type, so that the cooling structure of the light source section 1 can be simplified. be able to.

Further, since there is only one type of phosphor 5, and it is not necessary to divide the fluorescent region of the phosphor 5 into two or more types, so that the phosphor 5 can be easily manufactured. As a result, the degree of freedom in the layout of the components of the optical system is increased, which can contribute to downsizing of the projector.

(Example 3)
FIG. 17 is an optical diagram showing a main configuration of an optical system of a projector having a light source device according to the third embodiment of the invention.
In FIG. 17, the same components as those of the first embodiment will be described with the same reference numerals.

The light source unit 1 includes a laser diode (LD) 1a, a coupling lens 1b, and a condenser lens 1
and c.
A plurality of laser diodes 1a are provided on the drive circuit board 2, and each laser diode 1a is provided.
A coupling lens 1b is provided for each of them.

The laser light from the laser diode 1a is condensed by the coupling lens 1b,
It is guided to the condenser lens 1c as a parallel light flux. The laser diode 1a generates a blue component laser beam BP.

The optical path along which the laser light BP of the blue component emitted from the light source unit 1 travels is excited by the light of the blue component emitted from the light source unit 1 in the optical path along which the light of the color component emitted from the light source unit 1 travels. An optical path switching board 3 is provided for periodically switching between an optical path for advancing the emitted fluorescence and an optical path for advancing the blue component light emitted from the light source unit 1 toward the image forming panel 13 as an image forming element. Has been.

As shown in FIG. 18, a beam spot BS is formed on the optical path switching board 3 by the laser light BP.
P is virtually formed. The optical path switching disk 3 is composed of an optical path time division rotary disk having a reflection area 3a and a transmission area 3b divided in the rotational direction.

The optical path switching board 3 is arranged obliquely with respect to the optical axis of the condenser lens 1c. The optical path switching board 3 is rotationally driven by a stepping motor 4.
The optical path of the blue component laser light BP reflected by the reflection area 3 a of the optical path switching board 3 is an optical path for advancing the blue component laser light BP emitted from the light source unit 1 toward the light tunnel 18. ing.

The optical path of the blue component laser light BP that has passed through the transmission region 3b of the optical path switching board 3 is an optical path for irradiating the phosphor 5 with the blue component laser light BP emitted from the light source unit 1.

A condenser lens 16 ′, a dichroic mirror 15 ′ for synthesizing optical paths, and a condenser lens 17 ′ are provided on the optical path that guides the blue component laser light BP emitted from the light source unit 1 to the light tunnel 18. ..

A color component switching board 10 is provided between the light tunnel 18 and the condenser lens 17'. The color component switching board 10 is equally divided into four segments here.

The dichroic mirror 15 ′ has a function of transmitting the laser beam BP of the blue component and reflecting the fluorescences RP and GP generated by the phosphor 5. The laser beam BP of the color component emitted from the light source unit 1 by the condenser lens 16′, the dichroic mirror 15′ and the condenser lens 17′.
An optical path for advancing the light beam toward the image forming element is formed.
A condenser lens 7', a dichroic mirror 8', and a condenser lens 9'are provided in the optical path along which the blue component laser beam BP transmitted through the transmission region 3b of the optical path switching board 3 travels.

The dichroic mirror 8′ has a characteristic of transmitting the blue component laser beam BP and reflecting the fluorescences RP and GP. The fluorescences RP and GP reflected by the dichroic mirror 8'are reflected by the reflection mirror 22' and guided to the dichroic mirror 15'.

In the third embodiment, the condenser lens 9', the dichroic mirror 8', the reflection mirror 22',
An optical path formed by the dichroic mirror 15 ′ and the condenser lens 17 ′ changes fluorescence RP and GP excited by the laser light BP of the color component emitted from the light source unit 1 to the color component switching board 1
It is an optical path that travels toward 0.

As shown in FIG. 19, the color component switching board 10 allows the laser light BP to pass therethrough and causes fluorescence G
A transmissive region 10c that blocks the transmission of both P and fluorescent RP, a transmissive region 10d that transmits the yellow component fluorescence YP (both fluorescent GP and fluorescent RP) and blocks the transmission of laser light BP, and fluorescent G
Transmission region 10e for transmitting P and blocking transmission of laser light BP and fluorescence RP, fluorescence RP
A transmissive region 10f is formed for transmitting the laser beam BP and blocking the laser beam BP and the fluorescent light GP.

The transmissive areas 10c to 10f are formed of arcuate areas. The angle formed by the arc with respect to the center O″ of the arc-shaped region 10c is, for example, 75 degrees.
0d to 10f are formed at equal angles, and the angle formed with respect to the center O″ is, for example, 95 degrees.

The laser light BP is reflected when the reflection area 3a of the optical path switching board 3 crosses the optical path of the laser light BP, and the color components are switched via the condenser lens 16′, the dichroic mirror 15′, and the condenser lens 17′. It is guided to the transparent region 10c of the board 10.

The laser light BP is transmitted when the transmission region 3b of the optical path switching board 3 crosses the optical path of the laser light BP, and passes through the condenser lens 7', the dichroic mirror 8', and the condenser lens 9'to the phosphor 5. Be guided.

The phosphor 5 is excited by the laser light BP to generate fluorescence RP and GP. Laser light B
The P, the fluorescent light RP, and the GP are guided to the dichroic mirror 8′, and the fluorescent light RP and GP are reflected by the dichroic mirror 8′. The reflected fluorescences RP and GP are further reflected by the reflection mirror 22' and guided to the dichroic mirror 15'.

The optical paths of the laser light BP, the fluorescent light RP, and the GP are combined by the dichroic mirror 15'. The fluorescences RP and GP are guided to the transmission regions 10d, 10e, 10f of the color component switching board 10 via the condenser lens 17'.

The light of each color component transmitted through each transmission region 10c to 10f of the color component switching board 10 is incident on the light tunnel 18.
The light amount distribution of the light of each color component is uniformized during the progress of the light tunnel 18. The light of each color component emitted from the light tunnel 18 is collimated by the condenser lens 19, reflected by the reflection mirror 22, and guided to the image forming panel 13.

The image forming panel 13 is controlled by the image generating unit GE, and the light of each color component is reflected by the image forming panel 13 and is applied to the screen S via the projection lens 21. As a result, as shown in FIG. 19, the lights of the B, R, G, and Y components of the respective colors are changed to the color component switching board 1.
The image is formed during one rotation of 0, and the color image is enlarged and formed on the screen S.

In the third embodiment, since the color component switching board 10 is provided between the light tunnel 18 and the condensing lens 17′, the condensing lens 17′ used in the color component switching board 10 (
(See FIGS. 1 and 8). That is, since the condenser lens 17 originally provided in the optical system shown in FIG. 1 and the optical system shown in FIG. 8 can be used also as the condenser lens 11, it is possible to simplify the optical system.

(Modification of the color component switching board 10)
In FIG. 19, the color component switching board 10 is composed of four segments of transparent areas 10c to 10f. However, the color component switching board 10 is originally provided in order to generate the fluorescence RP and the fluorescence GP from the fluorescence YP.

Since switching between the fluorescence YP and the laser light BP can be originally performed by the optical path switching board 3, it is not necessary to switch between the fluorescence YP and the laser light BP by the color component switching board 10.

By the way, when the fluorescence YP and the laser light BP are generated separately from each other, the color component switching board 10 causes the fluorescence RP and the fluorescence GP to exist between the fluorescence YP and the laser light GP. Therefore, the number of segments of the color component switching board 10 is four.

However, if the blue B generated by the laser light BP and the yellow Y generated by the fluorescence YP are generated adjacent to each other, the number of segments of the color component switching board 10 can be reduced from 4 segments to 3 segments. As a result, the number of manufacturing steps of the color component switching board 10 can be reduced, and the cost can be reduced.

FIG. 20 shows an example of the three-segment color component switching board 10. Here, as shown in FIG. 20, the color component switching board 10 transmits the arc-shaped region 10W formed by the notch or the transparent region and the fluorescence GP and blocks the transmission of the laser light BP and the fluorescence RP. The arc-shaped region 10e is composed of an arc-shaped region 10f that transmits the fluorescent light RP and blocks the transmission of the laser light BP and the fluorescent light GP.
If the color component switching board 10 shown in FIG. 20 is used, the switching between the laser light BP and the fluorescence YP can be performed only by the optical path switching board 3 as described above.

(Color mixture prevention control by the image forming unit GE)
Beam spots BSP and BSP′ are virtually formed on the optical path switching board 3 and the color component switching board 10, as shown in FIGS. The beam spots BSP and BSP' have a constant size.

As shown in FIG. 18, a boundary r1 between the reflection area 3a and the transmission area 3b of the optical path switching board 3,
In the region near r2, the beam spot BSP straddles the reflection region 3a and the transmission region 3b.

In addition, as shown in FIG. 19, in the region near the boundaries r3 to r6 of the transmissive regions 10c to 10f of the color component switching board 10, the beam spots BSP' straddle the transmissive regions adjacent to each other.

At the boundaries r1 to r6 straddling the beam spots BSP and BSP′, lights having different color components are simultaneously incident on the light tunnel 18, and color mixing occurs. Figure 2
1 is a timing chart schematically showing the relationship between the color mixture and the optical path switching board 3 and the color component switching board 10.

When the number of rotations of the optical path switching board 3 and the color component switching board 10 is the same, and the number of rotations per unit time is constant, the beam spots BSP and BSP′ have the same color mixing time.
Depends on the diameter of.

(Explanation of color mixing by the optical path switching board 3)
The angle formed by the two radial tangent lines r1′ and r1″ passing through the rotation center O of the optical path switching plate 3 and contacting the circle of the beam spot BSP is θs. Further, the boundary r1 is equal to the radial tangent line r1′. While doing so, the rotation angle θ of the optical path switching board 3 is set to 0 degree.

In this state, when the optical path switching board 3 rotates in the direction of the arrow Z1, mixing of the fluorescence YP and the laser light BP starts as shown in FIG. As the rotation angle θ of the optical path switching board 3 increases, the light amount of the fluorescent light YP decreases and the light amount of the laser light BP increases.

The optical path switching board 3 further rotates in the same direction, and the rotation angle θ of the optical path switching board 3 becomes the angle θs.
When the boundary r1 coincides with the radial tangent line r1″, the amount of fluorescence YP guided to the color component switching plate 10 becomes “0”, and the amount of laser light BP guided to the color component switching plate 10 becomes constant “1”. It becomes. Color mixing occurs while the boundary r1 crosses the beam spot BSP, and this is referred to as color mixing 1 for convenience.

Further, until the optical path switching plate 3 rotates and the boundary r2 coincides with the radial tangent line r1′, the beam spot BSP hits only the reflection region 3a of the optical path switching plate 3, so that the color component switching plate 10 is guided. The light amount of the laser light BP to be irradiated remains constant “1”.

Further, when the optical path switching board 3 rotates and the boundary r2 coincides with the radial tangent line r1′, a part of the beam spot BSP starts to hit the transmission area 3b of the optical path switching board 3.

Therefore, the light amount of the laser light BP guided to the color component switching plate 10 decreases, and the light amount of the fluorescence YP guided to the color component switching plate 10 increases. This boundary r2 is the beam spot BSP
Color mixture also occurs while crossing the. This is referred to as color mixture 2 for convenience.

When the boundary r2 of the optical path switching board 3 coincides with the radial tangent line r1″, the beam spot BSP does not hit the reflection area 3a of the optical path switching board 3. Therefore, the laser beam BP guided to the color component switching board 10 is The amount of light is “0”. On the other hand, the amount of light of the fluorescence YP guided to the color component switching board 10 is constant “1”. The above-mentioned color mixture 1 and color mixture 2 occur during one rotation of the optical path switching board 3.

(Explanation of color mixing by the color component switching board 10)
For the sake of convenience, the spot diameter of the beam spot BSP′ of the laser light BP which strikes the color component switching board 10 is Φ′=Φ. That is, the radial tangent line r3′ tangent to the beam spot BSP′
, R3″ is θs.

Further, the optical path switching board 3 and the color component switching board 10 have a boundary r1 (boundary r2) and a boundary r.
It is assumed that they rotate synchronously in a state in which the rotation phase with 3 matches. That is, the boundary r3 of the area of the color component switching board 10 and the boundary r1 of the area of the optical path switching board are associated with each other one to one,
It is assumed that the phases are rotated in synchronization with each other.

Here, when the boundary r3 coincides with the radial tangent line r3′, the angle θ=0 degree, and when the color component switching board 10 rotates in the direction of the arrow Z2, the mixture of the fluorescence YP and the laser light BP is mixed. Matching begins, and the color component switching board 10 is between the angle θ=0 degree and the angle θs,
Mixed color 1 continues.

That is, in the latter half of the projection period of the fluorescence YP by the color component switching board 10, the color mixture 1a is generated by mixing the laser light BP with the fluorescence YP, and the fluorescence BP by the color component switching board 10 is generated.
In the first half of the projection period of, the color mixture 1b occurs due to the fluorescence YP being mixed with the laser light BP.

Further, the color component switching board 10 rotates in the direction of the arrow Z2, and the boundary r4 has a radial tangent line r3′.
Only the laser light BP is guided to the light tunnel 18 until it coincides with. During this period, only the laser light BP is guided to the light tunnel 18, so that color mixing by the color component switching board 10 does not occur.

Further, while the color component switching board 10 rotates, the color mixture 2 by the optical path switching board 3 continues until the boundary r4 coincides with the radial tangent line r3′ to the radial tangent line r3″.

That is, in the latter half of the projection period of the laser light BP by the color component switching board 10, the color mixture 1c is generated due to the fluorescence RP being mixed with the laser light BP, and in the first half of the projection period of the fluorescence RP by the color component switching board 10, the fluorescence RP is generated. A mixed color 1d is generated due to the laser light BP being mixed with.

The color component switching plate 3 is further rotated, and the laser beam BP is kept on the color component switching plate 10 from the time when the boundary r4 coincides with the radial tangent line r3″ to the time when the boundary r5 coincides with the radial tangent line r3′.
Since it hits only the transmissive region 10f of the above, only the fluorescent light RP is guided to the light tunnel 18 and no color mixing occurs.

Further, the color component switching board 10 rotates, and from the time when the boundary r5 coincides with the radial tangent line r3′ to the time when the boundary r5 coincides with the radial tangent line r3″, color mixing by fluorescence RP and fluorescence GP occurs. For convenience, this is color mixture 3.

That is, in the latter half of the projection period of the fluorescent RP by the color component switching board 10, a mixed color 1e occurs due to the mixing of the fluorescent GP with the fluorescence RP, and in the first half of the projection period of the fluorescent GP by the color component switching board 10, the fluorescence GP is changed. Color mixing 1f occurs due to the mixing of the fluorescent RP.

Further, during the period when the color component switching board 10 is rotated and the boundary r5 coincides with the radial tangent line r3″ until the boundary r6 contacts the radial tangent line r3′, only the fluorescence GP is transferred to the color component switching board 1.
Since it hits the transmission region 10e of 0, only the fluorescent GP is guided to the light tunnel 18 and no color mixing occurs.

Further, the color component switching board 10 rotates, and during the period from when the boundary r6 coincides with the radial tangent line r3′ to when the boundary r6 coincides with the radial tangent line r3″, a mixture of fluorescence GP and fluorescence YP occurs. For convenience of description, this is color mixing 4.

That is, in the latter half of the projection period of the fluorescent GP by the color component switching board 10, the fluorescent GP is
In the first half of the projection period of the fluorescence YP by the color component switching board 10, a color mixture 1g occurs due to the fluorescence YP being mixed with the fluorescence YP.

During the period when the color component switching board 10 is further rotated and the boundary r6 coincides with the radial tangent line r3″ and the boundary r3 coincides with the radial tangent line r3′, only the fluorescence YP is emitted.
Therefore, no color mixture occurs.
When such a color mixture 1 to color mixture 4 occurs, the color purity is lowered and the color reproduction range is narrowed.

Therefore, during the projection period in which the mixed colors 1 to 4 occur, the laser diode (LD)
It is possible to turn off 1a or the image forming panel 13.
However, the laser diode (LD) is used during the projection period in which the mixed colors 1 to 4 occur.
If 1a or the image forming panel 13 is turned off, the image becomes darker accordingly.

Therefore, in the third embodiment, in order to prevent the image from becoming dark as much as possible and to secure the color reproduction range, the following device is used.
From the viewpoint of the illumination efficiency with respect to the screen S, the laser light BP is emitted from the light source unit 1, so that the illumination efficiency is the highest.

The fluorescence YP is generated by irradiation with the laser light BP. The illumination efficiency of the fluorescent YP is determined by the excitation efficiency of the phosphor 5 with the laser light BP. In the phosphor 3, since the light amount conversion loss occurs, the illumination efficiency of the fluorescent light YP is smaller than the illumination efficiency of the laser light BP.

The laser light BP has a light amount loss or the like that occurs when passing through the dichroic mirror 15′, and the fluorescence YP, fluorescence RP, and fluorescence GP are reflected by the dichroic mirror 8′, the reflection mirror 22′, and the dichroic mirror 8′. There is a light amount loss, etc.

These light amount losses will be ignored here. Even if these light amount losses are ignored, there is a light amount loss that cannot be ignored in the fluorescent light RP and fluorescent light GP.
That is, essentially, the laser light BP and the fluorescent light YP can essentially pass through the color component switching board 10. On the other hand, the fluorescence RP and the fluorescence GP have a loss that occurs when they pass through the color component switching board 10. Therefore, the illumination efficiency of the fluorescent light RP and fluorescent light GP is smaller than that of the laser light YP.

Here, regarding the ratio of the light amount of the fluorescent GP and the light amount of the fluorescent RP contained in the fluorescent YP, assuming that the light amount of the fluorescent GP is larger than the light amount of the fluorescent RP, the illumination efficiency with respect to the screen S is laser light BP>fluorescent. YP>fluorescence GP>fluorescence RP.

In this case, since the amount of light of the fluorescent light RP is smaller than the amount of light of the other laser light BP, the fluorescent light YP, and the fluorescent light GP, the influence of the deterioration of the color reproducibility due to the color mixture of the fluorescent light RP is the largest.

Therefore, in the third embodiment, as shown by the broken line in FIG. 22, at least one of the laser diode 1a and the digital mirror microdevice DMD is turned off only during the period when the mixed colors 1d and 1e occur. As a result, it is possible to provide a bright projector while preventing color purity from decreasing and narrowing the color reproduction range as much as possible.

Here, the case where the illumination efficiency of the fluorescence RP is the lowest has been described, but when the illumination efficiency of the fluorescence GP is the lowest, at least the laser diode 1a and the digital mirror microdevice DMD are provided only during the period in which the mixed colors 1f and 1g occur. It may be configured so that one of them is turned off.

That is, for the fluorescent light or the laser light BP having the lowest illumination efficiency , the laser diode 1a or the digital mirror microdevice DMD may be turned off during a period in which color mixing occurs.

Further, the laser diode 1a or the digital mirror microdevice DMD can be turned off even during a period in which color mixture occurs when projecting different colors.

In the third embodiment, the phase of the boundary r1 of the optical path switching board 3 and the color component switching board 10 are used.
The phase is rotated in synchronization with the phase of the boundary r3.
As a result, the number of times color mixing occurs can be reduced.
Further, the diameter Φ of the beam spot BSP and the diameter Φ′ of the beam spot BSP′ are made different, and the diameter Φ of the beam spot BSP of the optical path switching board 3 and the diameter Φ of the beam spot BSP′ of the color component switching board 10 are set. According to the timing of the larger one of the two
At least one of the laser diode 1a and the digital mirror microdevice DMD is turned off. This can simplify the on/off control.

(Example 4)
In the fourth embodiment, the fluorescence G containing a green color component different from the blue component laser light BP.
In the above description, the phosphor 5 is provided with the phosphor film 5a that generates the yellow fluorescence YP containing P and the red component fluorescence RP.

However, as shown in FIG. 23, fluorescence G of the green component is excited by the laser beam BP.
Alternatively, the phosphor 5 may be provided with a fluorescent film 5 a ′ that generates P or a fluorescent film 5 a ″ that is excited by the laser light BP to generate fluorescence RP of a red component.

With such a configuration, the period during which the green component fluorescence GP is projected or the red component fluorescence RP
The fluorescent films 5a′ and 5a″ can be used during the period of projecting.

Therefore, it is not necessary to take out the green component fluorescence GP or the red component fluorescence RP from the fluorescent film 5a by the color component switching board 10, and the illumination efficiency of the green component fluorescence GP or the red component fluorescence RP can be improved. ..

In this case, the color component switching board 10 may be configured to cut off light of a specific wavelength.
For example, in the case of using the fluorescent film 5a′ that generates the fluorescent GP of the green component, the chromaticity of the fluorescent GP can be adjusted by cutting the fluorescent light of a specific wavelength in the spectrum of the fluorescent GP.

Specifically, the green purity can be increased by cutting off the light in the long wavelength region of the fluorescent GP.

1... Light source section 3... Optical path switching board (optical path switching section)
5... Phosphor 10... Color component switching board (color component switching unit)
13... Image forming panel (image forming element)
S... screen

Patent No. 4711154

Claims (2)

In a projector that includes a light source device that emits light of a plurality of colors and an image forming element that is sequentially irradiated with the light of the plurality of colors to form an image, and that projects an image formed on the image forming element.
The light source device,
A light source unit that emits excitation light of visible light,
A fluorescent part that emits fluorescence by the excitation light emitted from the light source part,
From the fluorescent light emitted from the fluorescent portion, the color light different from the fluorescent light is taken out, and the excitation light and the color light are provided with a color component switching portion that switches and emits the light.
Timing of emission of the fluorescence in the fluorescent unit, and the timing at which the color component switching unit switches the excitation light and the color light are synchronized,
The colored light extracted from the fluorescent light and having a color different from the fluorescent light is lower in illumination efficiency for the screen than the excitation light,
Of the timing when the color component switching unit switches between the excitation light and the color light, the brightness of the projected image is reduced by at least one of the light source unit and the image forming element during the period closer to the color light, and the excitation light projector, characterized in that the duration of the deviation does not reduce the brightness of the previous SL projected image. A light source unit that emits excitation light of visible light,
A fluorescent part that emits fluorescence by the excitation light emitted from the light source part,
From the fluorescent light emitted from the fluorescent portion, the color light different from the fluorescent light is taken out, and the excitation light and the color light are provided with a color component switching portion that switches and emits the light.
Timing of emission of the fluorescence in the fluorescent unit, and the timing at which the color component switching unit switches the excitation light and the color light are synchronized,
Wherein the color light of different colors from that of the fluorescent taken from fluorescence than said excitation light, lighting efficiency is low,
Of the timing at which the color component switching section switches between the color light and the excitation light, the color period of light toward reduces the output of the light source unit, the period of the excitation light toward the reduction of the output of the light source unit light source device according to claim was a Ikoto.