JP2014021223A - Video display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a video display device able to output high quality video light of high chromatic purity even in use of a fluorescent body.SOLUTION: A video display device in the disclosed invention has two optical modulation elements for modulating light according to a video signal, and comprises: a light source configured to output excitation light which is light of a first wavelength area; a fluorescent body configured to emit fluorescence by being excited by the excitation light; a color separation element configured to separate the fluorescence into light of a second wavelength area and light of a third wavelength area and guide them respectively to the two optical modulation elements; and a color combining element configured to combine the light of the second wavelength area, subjected to modulation, and the light of the third wavelength area, subjected to modulation.

Description

  The present disclosure relates to an image display device using a phosphor as a light source, and more particularly to a two-plate image display device.

  Conventionally, in this projector, a high-intensity high-pressure mercury lamp has been frequently used as a light source. The high-pressure mercury lamp has a problem that the life of the light source is short and the maintenance becomes complicated, and it has been proposed to use a solid-state light source such as a light emitting diode (LED) or a laser as the light source of the video display device instead of the high-pressure mercury lamp. .

  A laser light source has a longer life than a high-pressure mercury lamp and has high directivity, and therefore has high light utilization efficiency. Further, a wide color reproduction range can be realized by the monochromaticity. On the other hand, the laser beam has a problem that speckle noise is generated due to its high coherence and the image quality is deteriorated.

  Although the LED light source does not generate speckle noise, there is a problem that it is difficult to realize a high-luminance video display device because of the large light emission area of the light source and the low light emission efficiency of the green LED.

  In order to solve these problems, there has been proposed a light source device that uses an LED or laser as excitation light to emit a phosphor and is used in an image display device (for example, Patent Document 1).

JP 2011-013313 A

  However, when emitting red fluorescence by irradiating the phosphor with excitation light, the current red phosphor has low luminous efficiency, and in order to achieve a color balance with other colors, the apparatus may be enlarged. was there.

  On the other hand, the green phosphor that emits green light has high luminous efficiency, but also emits light in the wavelength region longer than yellow, and removes the light of the long wavelength component when trying to ensure the green color purity. There was a problem that had to be.

  The present disclosure has been proposed in view of the above circumstances, and an object thereof is to provide an image display device that can output high-quality image light with high color purity even when a phosphor is used.

  In order to solve the above problems, a video display device according to the present disclosure is a video display device including two light modulation elements that modulate light according to a video signal, and is an excitation that is light in a first wavelength range. A light source that outputs light; a phosphor that is excited by the excitation light to emit fluorescence; and the fluorescence is separated into light in a second wavelength region and light in a third wavelength region, and the two light modulation elements And a color synthesizing element that synthesizes the modulated light in the second wavelength band and the modulated light in the third wavelength band.

  The light in the first wavelength band, the light in the second wavelength band, and the light in the third wavelength band are temporally separated, and the light in the first wavelength band is the two lights. It may be modulated to any one of the modulation elements.

  In addition, the light source further includes an additional light source that outputs light in a wavelength-determining wavelength region among the light in the first wavelength region, the light in the second wavelength region, and the light in the third wavelength region, and the light from the additional light source Is preferably modulated to the other of the two light modulation elements when light in the first wavelength range is modulated.

  The light source further includes an additional light source that outputs light in a wavelength region different from any of the light in the first wavelength region, the light in the second wavelength region, and the light in the third wavelength region, and the light from the additional light source is When the light in the first wavelength band is modulated, it is preferable that the light is modulated by the other of the two light modulation elements.

  Furthermore, a first additional light source that outputs light in a wavelength-determining wavelength region among the light in the first wavelength region, the light in the second wavelength region, and the light in the third wavelength region, and the first wavelength region A second additional light source that outputs light, the light from the first additional light source and the light from the second additional light source, the light in the second wavelength range, and the light in the third wavelength range The color separation element separates the light from the first additional light source and the light from the second additional light source and guides the light to each of the two light modulation elements. The gist.

  The video display apparatus according to the present disclosure is effective for providing high-quality video light using a solid light source and a phosphor.

1 is a configuration diagram of a projector 100 according to a first embodiment of the present disclosure. It is a lineblock diagram of phosphor wheel 54 concerning a 1st embodiment of this indication. FIG. 6 is a configuration diagram of a projector 200 according to a second embodiment of the present disclosure. FIG. 6 is a configuration diagram of a projector 300 according to a third embodiment of the present disclosure. FIG. 6 is a configuration diagram of a projector 400 according to a fourth embodiment of the present disclosure. FIG. 10 is a configuration diagram of a projector 500 according to a fifth embodiment of the present disclosure.

  Hereinafter, an embodiment according to the present disclosure will be described with reference to the drawings. However, more detailed description than necessary may be omitted. For example, detailed descriptions of already well-known matters and repeated descriptions for substantially the same configuration may be omitted. This is to avoid the following description from becoming unnecessarily redundant and to facilitate understanding by those skilled in the art. The applicant provides the accompanying drawings and the following description in order for those skilled in the art to fully understand the present disclosure, and is not intended to limit the subject matter described in the claims. Absent.

In the following embodiments, a projector will be described as an example of a video display device. However, the video display device may be a television or a mobile phone, for example.
1. First Embodiment (Outline of this Embodiment)
The present embodiment is an image display device (for example, projector 100) having two light modulation elements (for example, DMDs 28 and 30) that modulate light according to an image signal, and is light in the first wavelength range. A light source (for example, a semiconductor laser 12) that outputs excitation light, a phosphor that is excited by the excitation light and emits fluorescence (for example, a phosphor region 58), and the fluorescence is converted into light in the second wavelength region and third. A color separation element (for example, a color separation / combination prism 26) that is separated into light of a wavelength band and led to each of the two light modulation elements; and the modulated light of the second wavelength band A color synthesizing element (for example, a color separation / combination prism 26) that synthesizes light of three wavelengths.

  In particular, the light in the first wavelength band, the light in the second wavelength band, and the light in the third wavelength band are temporally separated, and the light in the first wavelength band is the two lights. Modulation is performed by either one of the modulation elements.

(Projector configuration)
FIG. 1 is a configuration diagram of the projector 100.

  In FIG. 1, a projector 100 includes a light source unit 10, a video generation unit 20, a light guide unit 40 that guides light from the light source unit 10 to the video generation unit 20, and video light generated by the video generation unit 20. A projection lens 90 for projecting onto a screen (not shown).

  The light source unit 10 includes a plurality of blue semiconductor lasers 12 and a lens 14 provided in each of the semiconductor lasers 12. In the present embodiment, the semiconductor laser 12 that outputs blue laser light having a wavelength of about 450 nm is used, and 25 semiconductor lasers 12 are arranged in a 5 × 5 matrix. The lens 14 has a function of condensing light emitted from the semiconductor laser 12 with a divergence angle into a parallel light beam.

  The light emitted from the light source unit 10 is superimposed while being collected by the lens 42. The light collected by the lens 42 passes through the diffusion plate 44 and the lens 46 before entering the dichroic mirror 48. The diffuser plate 44 has a function of reducing the coherence of light from the semiconductor laser 12, and the lens 46 has a function of returning the light collected by the lens 42 back to a parallel light beam.

  The dichroic mirror 48 is a color synthesizing element having a cutoff wavelength set to about 500 nm. Therefore, the light collimated by the lens 46 is reflected by the dichroic mirror 48 and is irradiated to the phosphor wheel 54.

  In order to reduce the area of the phosphor region 58 of the phosphor wheel 54 and to improve the light utilization efficiency by reducing the etendue, the light irradiated to the phosphor wheel 54 is collected by the lenses 50 and 52. The In this embodiment, the diameter of the light irradiated to the phosphor wheel 54 is about 1.5 mm.

  2 is a configuration diagram of the phosphor wheel 54, (A) is a view in the same direction as FIG. 1, and (B) is a side view from the right of (A).

  The phosphor wheel 54 has a notch region 56 that is notched and a phosphor region 58 that is coated with a phosphor that emits yellow light having a main wavelength of 570 nm by light having a wavelength of about 450 nm. The phosphor wheel 54 is configured so that one notch region 56 and one phosphor region 58 form one frame (for example, 1/60 second). That is, the light irradiated on the phosphor wheel 54 is temporally divided into a first segment irradiated on the notch region 56 and a second segment irradiated on the phosphor region 58 in one frame. The

  In the present embodiment, in consideration of the weight balance of the phosphor wheel 54, the phosphor wheel 54 is configured to have two frames per rotation, and the motor 60 is controlled by a control unit (not shown). In this embodiment, an aluminum substrate is used for the phosphor wheel 54, and a yellow phosphor is applied on the substrate.

  Returning to FIG. 1, during the first segment, the light applied to the phosphor wheel 54 passes through the phosphor wheel 54. In order to return the light transmitted through the phosphor wheel 54 to the dichroic mirror 48 again, mirrors 62, 64 and 66 are arranged in the optical path. In addition, since the light transmitted through the phosphor wheel 54 is collected by the lenses 50 and 52, the light is converted into parallel light by the lenses 68 and 70, and a lens 72 for relaying the extended optical path is disposed. .

  On the other hand, during the second segment, the light applied to the phosphor wheel 54 is converted into yellow light and reflected from the phosphor wheel 54. The yellow light is collimated by the lenses 50 and 52, returns to the dichroic mirror 48, and passes through the dichroic mirror 48.

  The light transmitted through the phosphor wheel 54, relayed through the optical path and returned to the dichroic mirror 48 is reflected by the dichroic mirror 48. In this way, the optical path of the light transmitted through the phosphor wheel 54 and the optical path of the reflected light are synthesized by the dichroic mirror 48.

  The light synthesized by the dichroic mirror 48 is collected by the lens 74 and enters the rod integrator 76. The light emitted from the rod integrator 76 is relayed to the lenses 78 and 80 and enters the image generation unit 20. As described above, the light guide unit 40 includes optical components such as various lenses and mirrors.

  The video generation unit 20 includes a lens 22, a total reflection prism 24, a color separation / synthesis prism 26, and two DMDs 28 and 30. The lens 22 has a function of focusing light on the exit surface of the rod integrator 76 on the two DMDs 28 and 30. The light incident on the total reflection prism 24 through the lens 22 is reflected by the surface 24 a and guided to the color separation / combination prism 26.

  The color separation / synthesis prism 26 is a color separation / synthesis element having a cutoff wavelength set to about 580 nm. Since the yellow light emitted from the phosphor is light having a main wavelength of 570 nm, it is separated into green light and red light by the color separation / synthesis prism 26. That is, the color separation / combination prism 26 reflects the blue light (B light) transmitted from the semiconductor laser 12 through the phosphor wheel 54, and also emits green light (G light) out of the light from the phosphor. Reflects and transmits red light (R light).

  The DMD 28 is guided with B light for the first segment and G light for the second segment. The R light is guided to the DMD 30 only in the second segment. The two DMDs 28 and 30 are controlled by a control unit (not shown) in accordance with the timing of each color light incident thereon and in accordance with the input video signal. The relationship between the two DMDs 28 and 30 and each segment is summarized in Table 1.

２枚のＤＭＤ２８、３０によって変調された光は、色分離合成プリズム２６において合成され、全反射プリズム２４に入射する。色分離合成プリズム２６側から入射した光は、面２４ａを透過して投写レンズ９０へ導かれる。投写レンズ９０は、時間的に、また、空間的に合成された映像光を図示しないスクリーンへ投写する。

The lights modulated by the two DMDs 28 and 30 are combined by the color separation / combination prism 26 and enter the total reflection prism 24. Light incident from the color separation / combination prism 26 side passes through the surface 24 a and is guided to the projection lens 90. The projection lens 90 projects the image light synthesized temporally and spatially onto a screen (not shown).

(Operational effect of this embodiment)
In the present embodiment, a phosphor that emits light with yellow having a high emission efficiency as a main wavelength is used, and a configuration in which yellow light is separated into green and red is adopted. Thereby, it becomes possible to generate red efficiently. In addition, since the red color is separated from the yellow color, the color purity of the green color can be ensured. Therefore, the video display apparatus according to the present embodiment can output high-quality video light with high color purity using a phosphor.

In the present embodiment, the light of each color is divided by temporal division and spatial division, and a configuration using a two-plate type light modulation element is adopted. As a result, the cost can be reduced as compared with the three-plate configuration, and the number of segments can be suppressed as compared with the one-plate configuration, so that the color braking can be suppressed.
2. Second Embodiment (Outline of this Embodiment)
The present embodiment is a video display device (for example, a projector 200) having two light modulation elements (for example, DMDs 28 and 30) that modulate light according to a video signal, and similarly to the first embodiment, The light in the first wavelength region, the light in the second wavelength region, and the light in the third wavelength region are temporally separated, and the light in the first wavelength region is the two light modulation elements. Is modulated into one of the two.

  Further, an additional light source (for example, a semiconductor laser 13) that outputs light in a wavelength-determining wavelength region out of the light in the first wavelength region, the light in the second wavelength region, and the light in the third wavelength region is further provided. The light from the additional light source is modulated to the other light modulation element of the two light modulation elements when at least the light in the first wavelength band is modulated.

(Projector configuration)
FIG. 3 is a configuration diagram of the projector 200.

  In FIG. 3, the projector 200 is similar to the projector 100 of the first embodiment. The light source unit 10, the video generation unit 20, the light guide unit 40 that guides light from the light source unit 10 to the video generation unit 20, and the video A projection lens 90 that projects the image light generated by the generation unit 20 onto a screen (not shown). In the present embodiment, the difference from the first embodiment will be mainly described.

  The light source unit 10 includes a plurality of blue semiconductor lasers 12, a lens 14 provided for each of the blue semiconductor lasers 12, a plurality of red semiconductor lasers 13, and a lens 15 provided for each of the red semiconductor lasers 13. . In this embodiment, as in the first embodiment, the semiconductor laser 12 that outputs blue laser light having a wavelength of about 450 nm is used, and the 25 semiconductor lasers 12 are arranged in a 5 × 5 matrix. Four semiconductor lasers 13 that output red laser light having a wavelength of about 640 nm were arranged in a 2 × 2 matrix. The lenses 14 and 15 have a function of condensing light emitted from the semiconductor lasers 12 and 13 with a spread angle into parallel light beams, respectively.

  The light emitted from the semiconductor laser 12 of the light source unit 10 is guided to the image generation unit 20 through the same optical path as that of the first embodiment. A difference from the first embodiment on the optical path is that a dichroic mirror 63 is used instead of the mirror 62.

  The dichroic mirror 63 is a color synthesizing element having a cutoff wavelength set to about 550 nm. Accordingly, as in the first embodiment, the blue light from the semiconductor laser 12 is reflected by the dichroic mirror 63, and the red light emitted from the semiconductor laser 13 passes through the dichroic mirror 63, and Synthesized.

  The semiconductor laser 13 is controlled to output during the first segment by a control unit (not shown). That is, the red light from the semiconductor laser 13 passes through the cutout region 56 of the phosphor wheel 54 and is guided to the video generation unit 20.

  The color separation / combination prism 26 of the video generation unit 20 is a color separation / combination element with a cutoff wavelength set to about 580 nm. Accordingly, the color separation / combination prism 26 reflects blue light (B light) from the semiconductor laser 12 and transmits red light (R light) from the semiconductor laser 13. Of the yellow light emitted from the phosphor, green light (G light) is reflected and the remaining red light (R ′ light) is transmitted.

  The DMD 28 is guided with B light for the first segment and G light for the second segment. The DMD 30 is guided with R light for the first segment and R ′ light for the second segment. The two DMDs 28 and 30 are controlled by a control unit (not shown) in accordance with the timing of each color light incident thereon and in accordance with the input video signal. Here, the DMD 30 generates red video light from the sum of the light amount of R light and the light amount of R ′ light and the total time (for example, 1/60 seconds) of the first segment and the second segment. The relationship between the two DMDs 28 and 30 and each segment is summarized in Table 2.

２枚のＤＭＤ２８、３０によって変調された光は、第１実施形態と同様に、投写レンズ９０へ導かれ、プロジェクタ２００は、映像光を図示しないスクリーンへ投写する。

The light modulated by the two DMDs 28 and 30 is guided to the projection lens 90 as in the first embodiment, and the projector 200 projects the image light onto a screen (not shown).

(Operational effect of this embodiment)
In the present embodiment, in addition to the configuration of the first embodiment, red laser light is added to red, which is most likely to have a shortage of light (the rate is limited) depending on the type of video in the configuration of the first embodiment. The configuration is adopted. Thereby, in addition to the effect of 1st Embodiment, it becomes possible to improve red purity and light quantity. Therefore, the video display device of this embodiment can output high-quality video light with higher color purity.
3. Third Embodiment (Overview of this embodiment)
The present embodiment is a video display device (for example, a projector 300) having two light modulation elements (for example, DMDs 28 and 30) that modulate light according to a video signal, and similarly to the first embodiment, The light in the first wavelength region, the light in the second wavelength region, and the light in the third wavelength region are temporally separated, and the light in the first wavelength region is the two light modulation elements. Is modulated into one of the two.

The light source further includes an additional light source (for example, LED 16) that outputs light in a wavelength region different from any of the light in the first wavelength region, the light in the second wavelength region, and the light in the third wavelength region. Is modulated by the other of the two light modulation elements when the light in the first wavelength band is modulated.
(Projector configuration)
FIG. 4 is a configuration diagram of the projector 300.

  In FIG. 4, a projector 300 includes a light source unit 10, a video generation unit 20, a light guide unit 40 that guides light from the light source unit 10 to the video generation unit 20, and a video, similar to the projector 100 of the first embodiment. A projection lens 90 that projects the image light generated by the generation unit 20 onto a screen (not shown). In the present embodiment, the difference from the first embodiment will be mainly described.

  The light source unit 10 includes a plurality of blue semiconductor lasers 12, a lens 14 provided in each of the blue semiconductor lasers 12, and an LED 16 that outputs infrared rays. In this embodiment, as in the first embodiment, the semiconductor laser 12 that outputs blue laser light having a wavelength of about 450 nm is used, and the 25 semiconductor lasers 12 are arranged in a 5 × 5 matrix. The LED 16 outputs infrared light having a dominant wavelength of about 940 nm.

  The light emitted from the semiconductor laser 12 of the light source unit 10 is guided to the image generation unit 20 through the same optical path as that of the first embodiment. On the optical path, the difference from the first embodiment is that, instead of the dichroic mirror 48, a dichroic mirror 49 with cutoff wavelengths set to about 500 nm and about 850 nm is used, and instead of the mirror 66, the cutoff wavelength is about 850 nm. The dichroic mirror 67 set in (1) is used.

  Infrared light emitted from the LED 16 is converted into parallel light by the lenses 82 and 84. The collimated light passes through the dichroic mirror 67 and is guided to the dichroic mirror 49.

  The dichroic mirror 49 is a color synthesizing element that reflects light in a wavelength range of about 500 nm or less and about 850 nm or more and transmits light in a wavelength range of about 500 to 850 nm. Therefore, as in the first embodiment, the blue light from the semiconductor laser 12 is reflected by the dichroic mirror 49, and the yellow light from the phosphor wheel 54 passes through the dichroic mirror 49. Infrared light emitted from the LED 16 reflects the dichroic mirror 49 and is combined with other color light.

  The color separation / combination prism 26 of the video generation unit 20 is a color separation / combination element with a cutoff wavelength set to about 580 nm. Accordingly, the color separation / combination prism 26 reflects blue light (B light) from the semiconductor laser 12 and transmits infrared light (IR light) from the LED 16. Of the yellow light emitted from the phosphor, green light (G light) is reflected and red light (R light) is transmitted.

  The DMD 28 is guided with B light for the first segment and G light for the second segment. The DMD 30 is guided with IR light when in the first segment and with R light when in the second segment. The two DMDs 28 and 30 are controlled by a control unit (not shown) in accordance with the timing of each color light incident thereon and in accordance with the input video signal. The DMD 30 is controlled in accordance with the timing at which IR light is incident and in accordance with a video signal for detecting a video state stored in advance in a storage unit (not shown). Similarly, the LED 16 is controlled to light up in accordance with the timing of the first segment. Table 3 summarizes the relationship between the two DMDs 28 and 30 and each segment.

２枚のＤＭＤ２８、３０によって変調された光は、第１実施形態と同様に、投写レンズ９０へ導かれ、プロジェクタ３００は、映像光を図示しないスクリーンへ投写する。

The light modulated by the two DMDs 28 and 30 is guided to the projection lens 90 as in the first embodiment, and the projector 300 projects the image light onto a screen (not shown).

(Operational effect of this embodiment)
In this embodiment, in addition to the configuration of the first embodiment, a configuration in which an LED that emits infrared light is added is adopted. Thereby, in addition to the effect of 1st Embodiment, the detection of the image | video state by an infrared camera, etc. are attained. Accordingly, it is possible to easily install a projector or add an interactive function, so that operability can be improved.
4). Fourth Embodiment (Outline of this Embodiment)
The present embodiment is a video display device (for example, a projector 400) having two light modulation elements (for example, DMDs 28 and 30) that modulate light according to a video signal, and similarly to the second embodiment, An additional light source (e.g., LED 17) that outputs light in a wavelength-determining wavelength region among the light in the first wavelength region, the light in the second wavelength region, and the light in the third wavelength region; Is modulated by the other light modulation element of the two light modulation elements when at least the light in the first wavelength band is modulated.

(Projector configuration)
FIG. 5 is a configuration diagram of the projector 400.

  In FIG. 5, similarly to the projector 300 of the third embodiment, a projector 400 includes a light source unit 10, a video generation unit 20, a light guide unit 40 that guides light from the light source unit 10 to the video generation unit 20, and a video. A projection lens 90 that projects the image light generated by the generation unit 20 onto a screen (not shown). In the present embodiment, the difference from the third embodiment will be mainly described.

  The light source unit 10 includes a plurality of blue semiconductor lasers 12, a lens 14 provided in each of the blue semiconductor lasers 12, and a red LED 17. In the present embodiment, the LED 17 outputs light having a dominant wavelength of about 630 nm.

  The light emitted from the semiconductor laser 12 of the light source unit 10 is guided to the video generation unit 20 through the same optical path as that of the third embodiment. A difference from the third embodiment on the optical path is that a dichroic mirror 49 ′ having cutoff wavelengths set to about 500 nm and about 610 nm is used instead of the dichroic mirror 49.

  The light emitted from the red LED 17 is converted into parallel light by the lenses 82 and 84. The collimated light passes through the dichroic mirror 67 and is guided to the dichroic mirror 49 '.

  The dichroic mirror 49 ′ is a color synthesizing element that reflects light having a wavelength range of approximately 500 nm or less and approximately 610 nm or more and transmits light having a wavelength range of approximately 500 to 610 nm. Accordingly, as in the third embodiment, the blue light from the semiconductor laser 12 is reflected by the dichroic mirror 49 ', and the yellow light from the phosphor wheel 54 is transmitted through the dichroic mirror 49'. The red light emitted from the LED 17 is reflected by the dichroic mirror 49 ′ and is combined with light of other colors.

  The color separation / combination prism 26 of the video generation unit 20 is a color separation / combination element with a cutoff wavelength set to about 580 nm. Therefore, the color separation / combination prism 26 reflects the blue light (B light) from the semiconductor laser 12 and transmits the red light (R light) from the LED 17. Similarly to the second embodiment, among the yellow light emitted from the phosphor, green light (G light) is reflected and the remaining red light (R ′ light) is transmitted.

  The DMD 28 is guided with B light for the first segment and G light for the second segment. The DMD 30 is guided with R light for the first segment and R + R ′ light for the second segment. The two DMDs 28 and 30 are controlled by a control unit (not shown) in accordance with the timing of each color light incident thereon and in accordance with the input video signal. Here, the DMD 30 generates red video light from the sum of the amount of R light for one frame and the amount of R ′ light for the second segment. Moreover, LED17 may control lighting time according to a video signal. Table 3 summarizes the relationship between the two DMDs 28 and 30 and each segment.

２枚のＤＭＤ２８、３０によって変調された光は、第１実施形態と同様に、投写レンズ９０へ導かれ、プロジェクタ３００は、映像光を図示しないスクリーンへ投写する。

The light modulated by the two DMDs 28 and 30 is guided to the projection lens 90 as in the first embodiment, and the projector 300 projects the image light onto a screen (not shown).

(Operational effect of this embodiment)
In the present embodiment, a configuration in which a red LED is added in addition to the configuration of the first embodiment is adopted. This makes it possible to improve the red purity and the amount of light. In particular, in the present embodiment, since the light from the red LED can be added regardless of the segment timing, it is possible to control the amount of red light adaptively.
5. Fifth Embodiment (Overview of this embodiment)
The present embodiment is a video display device (for example, a projector 500) having two light modulation elements (for example, DMDs 28 and 30) that modulate light according to a video signal, and includes light in a first wavelength range, A first additional light source (e.g., LED 17) that outputs light in a wavelength range that is rate limiting among light in two wavelength regions and light in a third wavelength region, and a second additional light source that outputs light in the first wavelength region. (E.g., LED 18), and the light from the first additional light source and the light from the second additional light source, the light in the second wavelength region, and the light in the third wavelength region are temporal The color separation element (for example, the color separation / combination prism 26) separates the light from the first additional light source and the light from the second additional light source, and separates the light from the two light modulation elements. Lead to each.

(Projector configuration)
FIG. 6 is a configuration diagram of the projector 500.

  In FIG. 6, similarly to the projector 100 of the first embodiment, a projector 500 includes a light source unit 10, a video generation unit 20, a light guide unit 40 that guides light from the light source unit 10 to the video generation unit 20, and a video. A projection lens 90 that projects the image light generated by the generation unit 20 onto a screen (not shown). In the present embodiment, the difference from the first embodiment will be mainly described.

  The light source unit 10 includes a plurality of blue semiconductor lasers 12, a lens 14 provided in each of the blue semiconductor lasers 12, a red LED 17, and a blue LED 18. In this embodiment, as in the first embodiment, the semiconductor laser 12 that outputs blue laser light having a wavelength of about 450 nm is used, and the 25 semiconductor lasers 12 are arranged in a 5 × 5 matrix. The LED 17 outputs red light having a dominant wavelength of about 630 nm, and the LED 18 outputs blue light having a dominant wavelength of about 460 nm.

  The light emitted from the semiconductor laser 12 of the light source unit 10 passes through the lens 42, the diffusion plate 44, and the lens 46, and enters the dichroic mirror 49 '. The dichroic mirror 49 'is a color synthesizing element having cutoff wavelengths set to about 500 nm and about 610 nm. Accordingly, the light that has been collimated by the lens 46 is reflected by the dichroic mirror 49 ′ and applied to the phosphor wheel 55.

  In order to reduce the area of the phosphor region of the phosphor wheel 55 and to improve the light utilization efficiency by reducing the etendue, the light irradiated to the phosphor wheel 55 is collected by the lenses 50 and 52. . In this embodiment, the diameter of the light irradiated to the phosphor wheel 55 is about 1.5 mm.

  Unlike the first embodiment, the phosphor region of the phosphor wheel 55 is formed over the circumference. Further, the rotation speed may be different from the time of one frame. Here, the matching with the length (time) of the segment is adjusted by controlling the lighting time of the semiconductor laser 12. Specifically, the semiconductor laser 12 is controlled to be lit at a second segment time to be described later by a control unit (not shown).

  The light applied to the phosphor wheel 55 is converted into yellow light and reflected from the phosphor wheel 55. The yellow light is collimated by the lenses 50 and 52, returns to the dichroic mirror 49 ', and passes through the dichroic mirror 49'.

  The light emitted from the red LED 17 is converted into parallel light by the lenses 82 and 84. The collimated light passes through the dichroic mirror 67 and is guided to the dichroic mirror 49 '. The light emitted from the blue LED 18 is converted into parallel light by the lenses 86 and 88. The collimated light is reflected by the dichroic mirror 67 and guided to the dichroic mirror 49 '.

  The red LED 17 and the blue LED 18 are controlled to be turned on by a control unit (not shown). Specifically, the LEDs 17 and 18 are controlled to be lit at least at the time of the first segment described later. Here, since red has a low luminous efficiency of the phosphor and may be insufficient, it may be lit for one frame.

  The dichroic mirror 49 ′ reflects light having a wavelength range of about 500 nm or less and about 610 nm or more and transmits light having a wavelength range of about 500 to 610 nm. Accordingly, the blue light from the semiconductor laser 12 is reflected by the dichroic mirror 49 'and guided to the phosphor wheel 55, and the yellow light from the phosphor wheel 55 passes through the dichroic mirror 49'. The red light and the blue light from the LEDs 17 and 18 are reflected by the dichroic mirror 49 ′ and are combined with the yellow light from the phosphor wheel 55.

  The light synthesized by the dichroic mirror 49 ′ is collected by the lens 74 and enters the rod integrator 76. The light emitted from the rod integrator 76 is relayed to the lenses 78 and 80 and enters the image generation unit 20. As described above, the light guide unit 40 includes optical components such as various lenses and mirrors.

  The color separation / combination prism 26 of the video generation unit 20 is a color separation / combination element with a cutoff wavelength set to about 580 nm. Therefore, the color separation / combination prism 26 reflects the blue light (B light) from the blue LED 18 and transmits the red light (R light) from the red LED 17. Of the yellow light emitted from the phosphor, green light (G light) is reflected and the remaining red light (R ′ light) is transmitted.

  The DMD 28 is guided with B light for the first segment and G light for the second segment. The DMD 30 is guided with R light for the first segment and R + R ′ light for the second segment. The two DMDs 28 and 30 are controlled by a control unit (not shown) in accordance with the timing of each color light incident thereon and in accordance with the input video signal. Here, the DMD 30 generates red video light from the sum of the amount of R light for one frame and the amount of R ′ light for the second segment. Table 5 summarizes the relationship between the two DMDs 28 and 30 and each segment.

２枚のＤＭＤ２８、３０によって変調された光は、第１実施形態と同様に、投写レンズ９０へ導かれ、プロジェクタ５００は、映像光を図示しないスクリーンへ投写する。

The light modulated by the two DMDs 28 and 30 is guided to the projection lens 90 as in the first embodiment, and the projector 500 projects the image light onto a screen (not shown).

(Operational effect of this embodiment)
In the present embodiment, a phosphor that emits light with yellow having a high emission efficiency as a main wavelength, separates yellow light into green and red, uses LEDs for blue, and red can also add light from the LEDs. Is adopted. As a result, it is possible to sufficiently ensure the purity and light amount of each color. Therefore, the video display device of this embodiment can output high-quality video light.

Further, similarly to the first embodiment, cost reduction and color braking can be suppressed.
6). Other Embodiments In the above embodiment, the phosphor wheel having the notched region is used. However, in consideration of the weight balance, transparent glass may be used for the notched region. In this case, a glass disk is used for the phosphor wheel, and a reflective film layer and a phosphor layer may be formed in the phosphor region. Further, an AR coating may be applied to the transmitting region.

  Although the description has been made using the semiconductor lasers arranged in a 5 × 5 matrix, the number and arrangement of the semiconductor lasers are not limited to this, and the light intensity of one semiconductor laser and the light source device are desired. What is necessary is just to set suitably according to an output. The wavelength of the laser light is not limited to 450 nm. For example, a violet semiconductor laser that outputs light of 405 nm, an ultraviolet semiconductor laser of 400 nm or less, and the like can be applied.

  In addition, a configuration has been described in which a phosphor is excited by blue laser light and light having a main wavelength of yellow is emitted, but cyan is used as a main wavelength by using the violet semiconductor laser or the ultraviolet semiconductor laser described above. Light can be emitted and separated into blue and green, and red can be configured using an LED or the like. In the case of this configuration, since there is a possibility that the green color is insufficient, a green LED can be further added in order to achieve color balance.

  As described above, the embodiments considered as the best mode by the applicant and other forms are provided by the accompanying drawings and the detailed description. These are provided to those skilled in the art to illustrate the claimed subject matter by reference to specific embodiments. Therefore, various modifications, replacements, additions, omissions, and the like can be made to the above-described embodiments within the scope of the claims or an equivalent scope thereof.

  The present disclosure can be applied to an image display device that emits red light by a phosphor. Specifically, the present disclosure can be applied to televisions, mobile phones, and the like in addition to projectors.

DESCRIPTION OF SYMBOLS 10 Light source part 12, 13 Semiconductor laser 14, 15 Lens 16, 17, 18 LED
20 Image generation unit 22 Lens 24 Total reflection prism 24a Surface 26 Color separation / combination prism 28, 30 DMD
40 Light guide 42, 46, 50, 52, 68, 70, 72, 74, 78, 80, 82, 84, 86, 88 Lens 44 Diffuser 48, 49, 49 'Dichroic mirror 54, 55 Phosphor wheel 56 Notch area 58 Phosphor area 60 Motor 62, 64, 66 Mirror 63, 67 Dichroic mirror 76 Rod integrator 90 Projection lens 100, 200, 300, 400, 500 Projector

Claims (5)

A video display device having two light modulation elements for modulating light according to a video signal,
A light source that outputs excitation light that is light in the first wavelength range;
A phosphor that is excited by the excitation light and emits fluorescence;
A color separation element that separates the fluorescence into light of a second wavelength range and light of a third wavelength range and guides the fluorescence to each of the two light modulation elements;
A color synthesizing element that synthesizes the modulated light in the second wavelength range and the modulated light in the third wavelength range;
A video display device comprising: The video display device according to claim 1,
The light of the first wavelength range, the light of the second wavelength range and the light of the third wavelength range are separated in time,
The image display apparatus according to claim 1, wherein the light in the first wavelength range is modulated to one of the two light modulation elements. The video display device according to claim 2,
An additional light source that outputs light in a rate-determining wavelength region among the light in the first wavelength region, the light in the second wavelength region, and the light in the third wavelength region;
The light from the additional light source is modulated by the other light modulation element of the two light modulation elements when at least light in the first wavelength band is modulated. The video display device according to claim 2,
An additional light source that outputs light in a wavelength range different from any of the light in the first wavelength range, the light in the second wavelength range, and the light in the third wavelength range;
The light from the additional light source is modulated by the other light modulation element of the two light modulation elements when the light in the first wavelength band is modulated. The video display device according to claim 1,
A first additional light source that outputs light in a rate-determined wavelength region among the light in the first wavelength region, the light in the second wavelength region, and the light in the third wavelength region; and the light in the first wavelength region A second additional light source for outputting,
The light from the first additional light source and the light from the second additional light source, and the light in the second wavelength region and the light in the third wavelength region are temporally separated,
The video display device, wherein the color separation element separates light from the first additional light source and light from the second additional light source and guides the light to each of the two light modulation elements.

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