JP6098742B2 - Light source device and projector using the same - Google Patents

Description

The present invention relates to a light source device that irradiates a blue component light, a red component light, and a green component light in a time-divided manner onto an image forming element, and forms a color image on a screen by the image forming element. Related to 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 time-divided manner and forms 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, a phosphor, and a dichroic mirror as one light source unit. The phosphor is composed of a rotating disk. The phosphor includes a phosphor region that generates green component fluorescence when irradiated with blue component laser light as excitation light, a phosphor region that generates red component fluorescence when irradiated with excitation light, and a blue laser beam. And a transmission region that transmits light is divided at predetermined angles.

The blue component laser light, the green component fluorescence, and the red component fluorescence are combined by a dichroic mirror so that the image forming element is divided in time 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 transmissive region for each predetermined angle on the phosphor, and the production of the phosphor is complicated.
In addition, since the angle size of the fluorescent region and the transmissive region to be formed on the phosphor differs depending on the type of projector, it is necessary to manufacture a phosphor having a different angle of the fluorescent region for each projector type, and manage the phosphor. There is also a disadvantage that it is complicated.

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 generates fluorescence of a yellow component and a fluorescent region that generates fluorescence of a red component. Accordingly, it is possible to provide a light source device that can simplify the production of the phosphor, and thus can simplify the configuration of the optical system and improve the flexibility of the layout, and a projector using the light source device. With the goal.

The projector according to the present invention includes a light source device, an image forming element, and a projection optical unit, and the image formed by sequentially irradiating the image forming element with each of a plurality of colors generated by the light source device. In the projector that projects with the projection optical unit,
The light source device
A light source that generates blue light;
A fluorescent part holder provided with a first fluorescent part that emits green fluorescent light or red first fluorescent light when irradiated with blue light generated by the light source part , and a second fluorescent part that generates yellow fluorescent light When,
Extracted from the blue fluorescence generated from the light source unit, the first fluorescence generated from the first fluorescence unit, and the green fluorescence extracted from the yellow fluorescence generated from the second fluorescence unit or from the yellow fluorescence a second fluorescent is a red fluorescence, and color component switching section for transmitting by switching a yellow fluorescence generated in the second fluorescent unit possess,
The timing of the emission of the first fluorescence or the emission of yellow fluorescence in the fluorescence unit holder and the timing of switching the light applied to the image forming element by the color component switching unit are synchronized,
At the timing, the brightness of the projected image is reduced by at least one of the light source unit and the image forming element .

According to the present invention, a single light source unit is used, and a color image is generated without dividing a fluorescent region of a phosphor into a fluorescent region that generates yellow component fluorescence and a fluorescent region that generates red component fluorescence. Since it is possible, it is possible to simplify the manufacturing of the phosphor, and thus it is possible to simplify the configuration of the optical system and improve the degree of freedom of layout.

FIG. 1 is an optical diagram showing a main configuration of an optical system according to Embodiment 1 of the 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 region and the angle of the reflection region of the optical path switching board shown in FIG. FIG. 6 is an explanatory diagram showing the angle relationship between 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 irradiated to the image forming element using the optical path switching plate shown in FIG. 5 and the color component switching plate shown in FIG. It is explanatory drawing which shows an example. FIG. 8 is an optical diagram showing a modification of the optical system according to Embodiment 1 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 Embodiment 2 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 unit that focuses the laser light emitted from the light source unit shown in FIGS. 1, 8, and 12. FIG. 17 is an optical diagram showing the main configuration of the optical system according to Embodiment 3 of the projector of the present 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 illustrating 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 straddles the boundary of the region. FIG. 22 is a timing chart schematically illustrating an example of color mixing prevention that occurs when the beam spot according to the third embodiment straddles the boundary of the region. FIG. 23 is an explanatory diagram illustrating 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 Embodiment 1 of the present invention. In FIG. 1, reference numeral 1 denotes a light source unit. The light source unit 1 is roughly composed of 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 condensing lens 1c as a parallel light beam.

The condensing lens 1c plays a role of condensing the laser light converted into a parallel light beam by each coupling lens 1b. Here, the laser diode 1a is described as generating the blue (B) component laser light BP among 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 green component laser light and red component laser light. Further, a light emitting diode LED can be used instead of the laser diode (LD).

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

As shown in FIG. 2, the optical path switching disk 3 is composed of an optical path time division rotating disk having a reflection area 3a and a transmission area 3b divided in the rotation direction. The optical path switching board 3 is disposed obliquely with respect to the optical axis of the condenser lens 1c (here, 45 degrees with respect to the optical axis).

For example, as shown in FIG. 1, the optical path switching board 3 is rotationally driven by a stepping motor 4 as a drive source. In FIG. 2, reference numeral 4a denotes a drive shaft.
In the reflection region 3a of the optical path switching board 3, as shown in FIG. 3, a reflection film 3d is provided on the side where the blue component laser beam BP strikes.

In the transmission region 3b of the optical path switching board 3, an antireflection film 3e is formed on the side of the surface on which the blue component laser beam BP strikes, and a diffusion surface 3f is formed on the surface opposite to the antireflection film 3e. Has been. The diffusion surface 3f is used for removing speckles of the laser beam BP.
Instead of providing the diffusing surface 3f on the optical path switching board 3, a rotating diffusing plate may be provided.

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

The phosphor 5 is irradiated with a blue component laser beam BP emitted from the light source unit 1, and a fluorescence including a green color component and a red component fluorescence different from the blue component laser beam. The fluorescent film 5a for generating the is applied.
The rotation of the phosphor 5 prevents the laser beam from being concentrated on the same place for a long time, and the deterioration of the phosphor film 5a is prevented. The fluorescent material of the fluorescent film 5a includes, for example, a fluorescent material that emits green component fluorescence and a fluorescent material that emits red component fluorescence (yellow Y fluorescence) when excited by irradiation with a blue component laser beam BP. A mixture with the generated fluorescent material) is used. However, the present invention is not limited to this.
For example, a fluorescent material having a fluorescence distribution characteristic extending from the wavelength range of the green component to the wavelength range of the red component can be used.

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

The dichroic mirror 8 transmits the blue component laser light BP and guides it to the phosphor 5 and reflects the fluorescence of the color component of the laser light other than the blue component and guides it to the color component switching board 10 as a color component switching unit. And have.
In the first embodiment, the color component switching board 10 plays a role of switching between the green component fluorescence GP and the red component fluorescence RP. The condenser lens 9 has a function of focusing the parallel light beam 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 beam LP ′.
In the first embodiment, the optical path for causing the fluorescent 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. Is formed.

A condensing 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 irradiated to the color component switching board 10. Note that the color component switching board 10 includes a condenser lens 11.
Are disposed obliquely with respect to the optical axis.

As shown in FIG. 4, the color component switching board 10 reflects a reflection region 10a that reflects the green component fluorescence GP and absorbs or transmits the red component fluorescence RP in the rotation direction, and reflects the red component fluorescence RP. The reflection region 10b that absorbs or transmits the green component fluorescence GP is formed of a color component time-division rotating disk formed by dividing the reflection region 10b 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 configuration that reflects both fluorescence GP and RP.
However, the present invention is not limited to this, and a configuration in which one of the fluorescent GPs and RP is reflected and the other is transmitted can also be employed. In FIG. 4, reference numeral 12a indicates a drive shaft.

The optical path through which the blue component laser light BP transmitted through the transmission region 3b travels is an image obtained by using the blue component laser light BP emitted from the light source unit 1 as a known image forming element (for example, a digital mirror micro device DMD). Optical path irradiating the forming panel 13, that is, the light source unit 1
The light path is a light path for causing the light of the color component emitted from the light to travel toward the image forming element.

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

A condensing lens 16 is provided in front of the green component fluorescence GP and the red component fluorescence RP reflected by the color component switching board 10 in the traveling direction. The condensing lens 16 has a function of condensing the green component fluorescence GP and the red component fluorescence RP, converting them into a parallel light beam LP ", and guiding them to the dichroic mirror 15. The dichroic mirror 15 is a condensing lens. 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 is used as the optical path of the parallel light beam BP "as the blue component light and the green component light (or red component light). The optical path of the parallel light beam LP "is combined to serve as a mirror for optical path synthesis that is guided to the image forming panel 13.

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

The light that has passed through the light tunnel 18 is converted into a parallel light flux by the condenser lens 19, reflected by the reflecting 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 applied to the screen S through the projection lens 21. As a result, a color image is enlarged and formed on the screen S.

Next, details of the temporal correspondence 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 rotational speed and in synchronization. As shown in FIG. 5, the angle φB of the transmission region 3b is set so that a time tB (see FIG. 7) corresponding to the transmission region 3b that transmits the blue component laser beam BP is secured. The angle φGB of the reflection region 3a is the remaining angle (360−φB).

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

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

Next, the other of the boundaries q1 and q2 is set so as to have a ratio of times tG and tR (see FIG. 7) necessary for irradiation with the fluorescence GP and the fluorescence RP. Thus, the boundaries q1 and q2
Since the design range can be given to the setting range of the boundary q1, the optical path switching board at the time of assembling the projector can be obtained without setting the angles of the reflection areas 10a and 10b of the color division switching board 10 strictly. By adjusting the rotation timing with respect to 3, as shown in FIG. 7, the time distribution necessary for generating the blue light B, the green light G, and the red light G can be obtained.

In the first embodiment, the optical path switching board 3 is rotationally driven and the optical path is periodically switched, and the color component switching board 10 is rotationally driven and the color components are periodically switched. However, the present invention is not limited to this. For example, the optical path switching board 3 and the color component switching board 10 may be reciprocated periodically.

FIG. 8 is an explanatory view showing a modification of the optical system of the first embodiment, in which a phosphor 5 is provided in a transmission optical path in which a blue component laser beam BP transmitted through the transmission region 3b of the optical path switching board 3 travels. Yes. Further, a dichroic mirror 15 for optical path synthesis is provided in the reflected optical path in which the blue component laser beam BP reflected by the reflection area 3a of the optical path switching board 3 travels. That is,
The condenser lens 14, the dichroic mirror 15, and the condenser lens 17 form an optical path for causing light emitted from the light source unit 1 to travel toward the image forming element. In addition, an optical path is formed by the condenser lens 9, the dichroic mirror 8, and the condenser lens 11 for causing the fluorescence excited by the light of the color component emitted from the light source unit 1 to travel 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 transmission area 3b shown in FIG. 2, and the transmission area 3b has the same angle as the reflection area 3a shown in FIG. Has been. As shown in FIG. 10, antireflection films 3e are formed on both surfaces of the optical path switching board 3 in the transmission region 3b.

Further, in the reflection region 3a, as shown in FIG. 10, a diffusion surface 3f is formed on the side where the laser beam BP strikes, and a reflection film 3d is formed on the opposite surface.
Here, the color component switching board 10 transmits the green component fluorescence GP and blocks the transmission of the red component fluorescence RP and the transmission region 10a ′ that transmits the red component fluorescence RP and the green component fluorescence GP. A transmission region 10b ′ for preventing transmission is formed.

The angle of the transmissive region 10a ′ is the same as the angle of the reflective region 10a shown in FIG. 4, and the angle of the transmissive region 10b ′ is the same as the angle of the reflective region 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 the 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 that of the optical system of the projector shown in FIG. 1, the description of the operation is omitted. As described above, according to the present invention, the phosphor 5 may be provided in any one of the transmission optical path and the reflection optical path of the laser beam BP with respect to the optical path switching board 3. The degree of freedom in layout can be improved.

FIG. 12 is an optical diagram showing an optical system of a projector according to Embodiment 2 of the present invention. Here, the dichroic mirror 8 that transmits the laser beam BP of the blue component and guides it to the optical path switching board 3 and reflects the light of the color component other than the blue component and guides 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 beam is provided. As shown in FIGS. 13 and 14, the optical path switching board 3 includes a reflective area 3a coated with the fluorescent film 5a and a transmissive area 3 coated with no fluorescent film 5a.
b.

In the transmissive region 3b, as in the first embodiment, an antireflection film 3e is formed on the side where the laser beam BP strikes, and a diffusion surface 3f is formed on the other side. A condensing lens 9 is provided between the dichroic mirror 8 and the optical path switching board 3.

The condensing lens 9 condenses the parallel light flux as the laser beam BP in a spot shape on the optical path switching board 3 and condenses the fluorescence generated by the reflection region 3a of the optical path switching board 3 to convert it into a parallel light flux. It has a function.

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

The fluorescence RP including the green component fluorescence GP and the red component fluorescence generated by the reflection region 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 transmission region 10a ′ that transmits the green component fluorescence GP in the rotation direction and absorbs or reflects the red component fluorescence RP, and the red component fluorescence RP.
And a transmission region 10b 'that absorbs or reflects green component fluorescence GP and is formed of a color component time-division rotating disk formed by dividing in the angular direction.

A condensing lens 11 is provided between the dichroic mirror 8 and the dichroic mirror 15.
The condensing lens 16 is provided, and the color component switching board 10 is disposed between the condensing lenses 11 and 16 and rotated in a plane orthogonal to the optical axis of the condensing lenses 11 and 16. .
In Example 2, the color component light emitted from the light source unit 1 by the condenser lens 9 ′, the reflective mirror 22 ′, the reflective mirror 22, the dichroic mirror 15, and the condenser lens 17 ′ is directed toward the image forming element. A traveling optical path is formed.
Further, an optical path is formed in which the fluorescence excited by the color component light emitted from the light source unit 1 by the condensing element 9, the dichroic mirror 8, and the condensing lens 11 travels toward the color component switching board 10.

According to the second embodiment, since the phosphor 5 and the optical path switching board 3 can be configured integrally, the number of drive sources as rotational drive elements is reduced as compared with the first embodiment and the modification of the first embodiment. Can
Accordingly, it is possible to simplify the optical elements of the optical system.

In the first and second embodiments, the light source unit 1 is provided with the condenser lens 1c, and the laser beam BP is focused on the optical path switching board 3. However, the present invention is not limited to this. For example, even if the condensing lens 1c is not provided in the light source unit 1, the incident position of the laser beam BP incident on the coupling lens 1b is determined as shown in FIG. It can also be configured to be provided at a position deviated from the center of the optical axis of the ring lens 1b and to be focused on the optical path switching board 3.

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

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

In addition, since there is only one kind of phosphor 5 and it is not necessary to divide the fluorescent region of the phosphor 5 into two or more kinds, the production of the phosphor 5 is facilitated. As a result, the degree of freedom of layout of the components of the optical system increases, which can contribute to the miniaturization of the projector.

(Example 3)
FIG. 17 is an optical diagram showing the main configuration of the optical system of the projector having the light source device according to Example 3 of the invention.
In FIG. 17, the same components as those in 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.
c.
A plurality of laser diodes 1a are provided on the drive circuit board 2, and each laser diode 1a is provided.
For each, a coupling lens 1b is provided.

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 beam. The laser diode 1a generates a blue component laser beam BP.

In the optical path in which the blue component laser light BP emitted from the light source unit 1 travels, the optical path in which the color component light emitted from the light source unit 1 travels is excited by the blue component light emitted from the light source unit 1. An optical path switching board 3 that periodically switches between the optical path for propagating the emitted fluorescence and the optical path for propagating the blue component light emitted from the light source unit 1 toward the image forming panel 13 as an image forming element is provided. It has been.

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

The optical path switching board 3 is disposed 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 in which the blue component laser light BP reflected by the reflection region 3 a of the optical path switching board 3 travels is an optical path for causing the blue component laser light BP emitted from the light source unit 1 to travel toward the light tunnel 18. ing.

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

A condensing lens 16 ′, a dichroic mirror 15 ′ for synthesizing the optical path, and a condensing lens 17 ′ are provided on the optical path for guiding 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 ′. Here, the color component switching board 10 is equally divided into four segments.

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

The dichroic mirror 8 ′ has a characteristic of transmitting the blue component laser light BP and reflecting the fluorescence RP and GP. The fluorescent RP and GP reflected by the dichroic mirror 8 ′ are reflected by the reflecting mirror 22 ′ and guided to the dichroic mirror 15 ′.

In Example 3, the condenser lens 9 ′, the dichroic mirror 8 ′, the reflection mirror 22 ′,
The optical path formed by the dichroic mirror 15 ′ and the condenser lens 17 ′ converts the fluorescence RP and GP excited by the laser beam BP of the color component emitted from the light source unit 1 into the color component switching board 1.
The light path travels toward zero.

As shown in FIG. 19, the color component switching board 10 transmits the laser beam BP and the fluorescence G
A transmission region 10c that blocks transmission of both P and fluorescence RP; a transmission region 10d that transmits yellow component fluorescence YP (both fluorescence GP and fluorescence RP) and blocks transmission of laser beam BP; and fluorescence G
A transmission region 10e that transmits P and blocks transmission of the laser beam BP and fluorescence RP, and fluorescence RP
And a transmission region 10f that transmits the laser beam BP and the fluorescence GP is formed.

The transmissive areas 10c to 10f are configured by 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. Further, the arc-shaped region 1
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 beam BP is reflected when the reflection region 3a of the optical path switching board 3 crosses the optical path of the laser beam BP, and the color component is switched via the condenser lens 16 ′, the dichroic mirror 15 ′, and the condenser lens 17 ′. Guided to the transmission region 10c of the board 10.

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

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

The optical paths of the laser beam BP, the fluorescence RP, and GP are synthesized by the dichroic mirror 15 ′. The fluorescence RP and GP are guided to the transmission regions 10d, 10e, and 10f of the color component switching board 10 via the condenser lens 17 ′.

The light of each color component that has passed through each transmission region 10 c to 10 f of the color component switching board 10 enters the light tunnel 18.
The light distribution of the light of each color component is made uniform while the light tunnel 18 is traveling. The light of each color component emitted from the light tunnel 18 is converted into a parallel light beam 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 irradiated onto the screen S via the projection lens 21. Thereby, as shown in FIG. 19, the light of each color B, R, G, Y component is changed to the color component switching board 1.
A color image is enlarged and formed on the screen S during one rotation of zero.

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

(Modification of color component switching board 10)
In FIG. 19, the color component switching board 10 is constituted by four segments of transparent regions 10c to 10f. However, the color component switching board 10 is originally provided for generating fluorescence RP and fluorescence GP from fluorescence YP.

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

By the way, if the fluorescence YP and the laser beam BP are generated separately from each other, the fluorescence RP and the fluorescence GP exist between the fluorescence YP and the laser beam GP by the color component switching board 10. For this reason, the number of segments of the color component switching board 10 is four.

However, if the blue B by the laser beam BP and the yellow Y 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, it is possible to reduce the number of manufacturing steps of the color component switching board 10 and, in turn, reduce the cost.

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 fluorescence GP and blocks the transmission of the laser beam BP and the fluorescence RP, and the arc-shaped region 10 </ b> W constituted by the notch or the transparent region. The arcuate region 10e is constituted by an arcuate region 10f that transmits the fluorescence RP and blocks the transmission of the laser beam BP and the fluorescence GP.
If the color component switching board 10 shown in FIG. 20 is used, the switching between the laser beam BP and the fluorescence YP can be performed only by the optical path switching board 3 as described above.

(Color mixing prevention control by image forming unit GE)
As shown in FIGS. 18 and 19, beam spots BSP and BSP ′ are virtually formed on the optical path switching board 3 and the color component switching board 10. The beam spots BSP and BSP ′ have a certain size.

As shown in FIG. 18, the 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.

Further, as shown in FIG. 19, in the vicinity of the boundaries r3 to r6 of the transmission areas 10c to 10f of the color component switching board 10, the beam spots BSP 'straddle the transmission areas adjacent to each other.

At the boundaries r1 to r6 over which the beam spots BSP and BSP ′ are straddled, lights having different color components enter the light tunnel 18 at the same time, resulting in color mixing. FIG.
1 is a timing chart schematically showing the relationship between the color mixture, the optical path switching board 3 and the color component switching board 10.

During the time when the color mixture occurs, if the rotation speeds of the optical path switching board 3 and the color component switching board 10 are the same, and the rotation speed per unit time is constant, the beam spots BSP, BSP ′.
It depends on the diameter.

(Description of color mixing by the optical path switching board 3)
An angle formed by two radial tangents r1 ′ and r1 ″ passing through the rotation center O of the optical path switching board 3 and in contact with the circle of the beam spot BSP is θs. The boundary r1 is equal to the radial tangent r1 ′. At the same time, 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 arrow Z1 direction, as shown in FIG. 21, mixing of the light of the fluorescence YP and the laser beam BP starts. As the rotation angle θ of the optical path switching board 3 increases, the amount of fluorescence YP decreases and the amount of 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 is an angle θs.
When the boundary r1 coincides with the radial tangent r1 ″, the light amount of the fluorescence YP guided to the color component switching board 10 becomes “0”, and the light quantity of the laser beam BP guided to the color component switching board 10 is constant “1”. " A color mixture occurs while the boundary r1 crosses the beam spot BSP, and this is referred to as color mixture 1 for convenience.

Furthermore, until the optical path switching board 3 rotates and the boundary r2 coincides with the radial tangent r1 ′, the beam spot BSP hits only the reflection area 3a of the optical path switching board 3, and therefore the light component is guided to the color component switching board 10. The quantity of the laser beam BP to be emitted remains constant “1”.

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

For this reason, the light quantity of the laser beam BP guided to the color component switching board 10 decreases, and the light quantity of the fluorescence YP guided to the color component switching board 10 increases. This boundary r2 is the beam spot BSP.
Color mixing also occurs while crossing. 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 r1 ″, the beam spot BSP does not hit the reflection area 3a of the optical path switching board 3. For this reason, the laser beam BP guided to the color component switching board 10 is lost. The amount of light is “0”. On the other hand, the light quantity of the fluorescent light YP guided to the color component switching board 10 is a constant “1”. During one rotation of the optical path switching board 3, the above-mentioned color mixture 1 and color mixture 2 occur.

(Description of color mixing by the color component switching board 10)
For convenience, the spot diameter of the beam spot BSP ′ of the laser beam BP impinging on the color component switching board 10 is Φ ′ = Φ. That is, the radial tangent r3 ′ that is in contact with 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.
Suppose that it rotates synchronously in a state where the rotational phase coincides with 3. 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 one-to-one,
A description will be given assuming that the phases are rotated in synchronization with each other.

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

That is, in the latter half of the projection period of the fluorescence YP by the color component switching board 10, a 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, the color mixture 1b is generated by mixing the laser beam BP with the fluorescence YP.

Further, the color component switching board 10 rotates in the arrow Z2 direction so that the boundary r4 is a radial tangent r3 ′.
Until the laser beam BP is matched, only the laser beam BP is guided to the light tunnel 18. During this period, since only the laser beam BP is guided to the light tunnel 18, no color mixing is caused by the color component switching board 10.

Further, the color mixing 2 by the optical path switching board 3 continues until the color component switching board 10 rotates and the boundary r4 coincides with the radial tangent r3 ′ until it coincides with the radial tangent r3 ″.

That is, in the latter half of the projection period of the laser beam BP by the color component switching board 10, a color mixture 1 c is generated by mixing the fluorescence RP with the laser beam BP, and in the first half of the projection period of the fluorescence RP by the color component switching board 10. 1d is generated by mixing the laser beam BP with the laser beam BP.

The color component switching board 3 further rotates so that the laser beam BP is emitted from the color component switching board 10 until the boundary r4 coincides with the radial tangent r3 ″ until the boundary r5 coincides with the radial tangent r3 ′.
Therefore, only the fluorescence RP is guided to the light tunnel 18 and no color mixing occurs.

Further, the color component switching board 10 rotates, and the color mixture due to the fluorescence RP and the fluorescence GP occurs until the boundary r5 coincides with the radial tangent r3 ′ until the boundary r5 coincides with the radial tangent r3 ″. This is referred to as color mixture 3 for convenience.

That is, in the second half of the projection period of the fluorescence RP by the color component switching board 10, a color mixture 1 e is generated by mixing the fluorescence GP with the fluorescence GP, and in the first half of the projection period of the fluorescence GP by the color component switching board 10, the fluorescence GP A color mixture 1f is generated by mixing the fluorescent RP.

Further, the color component switching board 10 rotates until the boundary r5 coincides with the radial tangent r3 ″ until the boundary r6 contacts the radial tangent r3 ′.
Since it hits the 0 transmission region 10e, 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 the color mixture between the fluorescent GP and the fluorescent YP occurs between the boundary r6 coincident with the radial tangent r3 ′ and the boundary r6 coincident with the radial tangent r3 ″. This is referred to as color mixture 4 for convenience.

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

When the color component switching board 10 further rotates and the boundary r6 coincides with the radial tangent r3 ″ until the boundary r3 coincides with the radial tangent r3 ′, only the fluorescent light YP is in the light tunnel 18.
Therefore, no color mixing occurs.
When such mixed colors 1 to 4 are generated, the color purity is lowered and the color reproduction range is narrowed.

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

Therefore, in the third embodiment, in order to secure the color reproduction range while preventing the image from becoming dark as much as possible, the following device is devised.
Considering from the viewpoint of the illumination efficiency for the screen S, the laser light BP is emitted from the light source unit 1 and therefore has the highest illumination efficiency.

The fluorescence YP is generated by irradiation with the laser beam BP. The illumination efficiency of the fluorescent YP is determined by the laser beam B
It depends on the excitation efficiency of the phosphor 5 by P. In the phosphor 3, since a light amount conversion loss occurs,
The illumination light rate of the fluorescent light YP is smaller than the illumination efficiency of the laser light BP.

The laser beam BP has a loss of light amount that occurs when it passes 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 loss of light amount that occurs at the time.

These light loss is ignored here. Even if these light quantity losses are ignored, there is a light quantity loss that cannot be ignored in the fluorescence RP and the fluorescence GP.
That is, the laser beam BP and the fluorescence YP can essentially pass through the color component switching board 10. On the other hand, the loss that occurs when passing through the color component switching board 10 occurs in the fluorescence RP and fluorescence GP. For this reason, the illumination efficiency of the fluorescence RP and fluorescence GP is smaller than the illumination efficiency of the laser beam YP.

Here, assuming that the light quantity of the fluorescence GP is larger than the light quantity of the fluorescence RP with respect to the ratio between the light quantity of the fluorescence GP and the light quantity of the fluorescence RP included in the fluorescence YP, the illumination light rate with respect to the screen S is the laser light BP> Fluorescence YP> fluorescence GP> fluorescence RP.

In this case, the light quantity of the fluorescent RP is smaller than the light quantities of the other laser beams BP, fluorescent YP, and fluorescent GP. Therefore, the influence of the decrease in color reproducibility caused by the color mixture in the fluorescent RP is the greatest.

Therefore, in the third embodiment, as indicated by a broken line in FIG. 22, at least one of the laser diode 1a and the digital mirror micro device DMD is turned off only during a period in which the mixed color 1d and the mixed color 1e occur. Accordingly, it is possible to provide a bright projector while preventing the color purity from being lowered and the color reproduction range from being narrowed as much as possible.

Here, the case where the illumination light rate of the fluorescence RP is the lowest has been described. However, when the illumination efficiency of the fluorescence GP is the lowest, the laser diode 1a and the digital mirror micro device DMD are used only during the period in which the mixed colors 1f and 1g occur. What is necessary is just to set it as the structure which turns off at least one.

That is, for the fluorescence or laser beam BP having the lowest illumination light rate, the laser diode 1a or the digital mirror micro device DMD may be turned off during a period in which color mixing occurs.

Further, the laser diode 1a or the digital mirror micro device DMD may be turned off even during a period in which color mixing occurs when different colors are projected.

In the third embodiment, the phase of the boundary r1 of the optical path switching board 3 and the color component switching board 10
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 so that 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 changed. In accordance with the timing of the larger diameter of either
At least one of the laser diode 1a and the digital mirror micro device DMD is turned off. Thereby, simplification of on-off control can be achieved.

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

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

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, there is no need to take out the green component fluorescence GP or the red component fluorescence RP from the phosphor film 5a by the color component switching board 10, and the illumination light rate of the green component fluorescence GP or the red component fluorescence RP can be improved. it can.

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

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

DESCRIPTION OF SYMBOLS 1 ... Light source part 3 ... Optical path switching board (optical path switching part)
5 ... phosphor 10 ... color component switching board (color component switching unit)
13. Image forming panel (image forming element)
S ... Screen

Japanese Patent No. 4711154

Claims (4)

A projector that includes a light source device, an image forming element, and a projection optical unit, and that projects an image formed by sequentially irradiating the image forming element with each of a plurality of colors generated by the light source device. In
The light source device
A light source that generates blue light;
A fluorescent part holder provided with a first fluorescent part that emits green fluorescent light or red first fluorescent light when irradiated with blue light generated by the light source part , and a second fluorescent part that generates yellow fluorescent light When,
Extracted from the blue fluorescence generated from the light source unit, the first fluorescence generated from the first fluorescence unit, and the green fluorescence extracted from the yellow fluorescence generated from the second fluorescence unit or from the yellow fluorescence a second fluorescent is a red fluorescence, and color component switching section for transmitting by switching a yellow fluorescence generated in the second fluorescent unit possess,
The timing of the emission of the first fluorescence or the emission of yellow fluorescence in the fluorescence unit holder and the timing of switching the light applied to the image forming element by the color component switching unit are synchronized,
A projector characterized in that, at the timing, the brightness of the projected image is reduced by at least one of the light source unit and the image forming element . A light source that generates blue light;
A fluorescent part holder provided with a first fluorescent part that emits green fluorescent light or red first fluorescent light when irradiated with blue light generated by the light source part , and a second fluorescent part that generates yellow fluorescent light When,
Extracted from the blue fluorescence generated from the light source unit, the first fluorescence generated from the first fluorescence unit, and the green fluorescence extracted from the yellow fluorescence generated from the second fluorescence unit or from the yellow fluorescence a second fluorescent is a red fluorescence, and color component switching section for transmitting by switching a yellow fluorescence generated in the second fluorescent unit possess,
The timing of the emission of the first fluorescence or the emission of yellow fluorescence in the fluorescent part holder and the timing at which the color component switching unit switches the light are synchronized,
A light source device that reduces the output of the light source unit at the timing .   The projector according to claim 1, wherein the fluorescent part holder is a rotating body that integrally rotates the first fluorescent part and the second fluorescent part.   The light source device according to claim 2, wherein the fluorescent part holding body is a rotating body that rotates the first fluorescent part and the second fluorescent part integrally.