JP6929058B2 - Light source device and image projection device - Google Patents

Description

The present invention relates to a light source device used in an image projection device (hereinafter referred to as a projector) or the like.

A laser diode (LD) is used as a light source, light from the LD is irradiated to an optical characteristic conversion element such as a phosphor, and light emitted from the conversion element is used as illumination light for a liquid crystal display element, a digital micromirror device, or the like. There is a projector that projects an image by guiding it to a modulation element. Patent Document 1 and Patent Document 2 disclose a projector that uses fluorescent light generated by exciting a phosphor with excitation light from LD as illumination light.

In such a projector, when the intensity of the excitation light incident on the phosphor increases or the temperature of the phosphor rises accordingly, the phenomenon of brightness saturation and temperature quenching of the phosphor, and further deterioration of the phosphor This reduces the wavelength conversion efficiency of the phosphor. As a result, the color of the illumination light changes. To solve this problem, Patent Document 1 includes a plurality of phosphors that emit fluorescent light in different color ranges, and switches the phosphor that irradiates excitation light among the plurality of phosphors in each color range to form a phosphor. A projector that suppresses a change in the tint of illumination light due to deterioration or the like is disclosed.

Further, Patent Document 2 discloses a projector that includes a plurality of phosphors that emit fluorescent light having different color gamuts and can change the irradiation timing of excitation light for each phosphor. In this projector, it is possible to change (adjust or adjust) the color of the illumination light while suppressing deterioration of the phosphor.

Japanese Unexamined Patent Publication No. 2012-178319 Japanese Unexamined Patent Publication No. 2013-1566639

Each of the projectors disclosed in Patent Documents 1 and 2 is provided with phosphors that emit fluorescence in different color gamuts as a plurality of phosphors. However, no phosphor that emits fluorescence of different wavelengths in the same color gamut is provided. Therefore, in these projectors, the tint of the illumination light cannot be adjusted or adjusted, and even if the adjustment is possible, the range is narrow.

The present invention provides a light source device capable of adjusting or adjusting the color of emitted light generated by using a phosphor in a wide range, and an image projection device using the same.

The light source device as one aspect of the present invention is provided for each region in which a plurality of light sources and wavelength-converted light having a wavelength different from that of the light incident from the light sources are generated and the light from the plurality of light sources is irradiated. It has a wavelength conversion unit including a plurality of wavelength conversion regions, and a light source having a color range different from that of the plurality of light sources. The plurality of wavelength conversion regions include two or more wavelength conversion regions that generate wavelength conversion light having wavelengths different from each other by a predetermined wavelength or more in the same color region, and the wavelength conversion unit receives light from light sources having different color regions. It is characterized by including a diffusing plate for diffusing.

Further, the light source device as another aspect of the present invention generates wavelength conversion light having a wavelength different from that of the light incident from the light sources with a plurality of light sources, and for each region where the light from the plurality of light sources is irradiated. It has a wavelength conversion unit including a plurality of wavelength conversion regions provided in the above. The plurality of light sources include two or more light sources that emit light having wavelengths different from each other in a predetermined wavelength or more in the same color gamut, and are characterized by including a light source having a color gamut different from that of the plurality of light sources.

An image projection device provided with the light source device also constitutes another aspect of the present invention.

According to the present invention, by having two or more wavelength conversion regions that generate wavelength conversion light having different wavelengths in the same color range or two or more light sources that emit light having different wavelengths in the same color range, the emitted light can be generated. It is possible to realize a light source device in which the color tone can be adjusted or adjusted in a wide range. Then, by using this light source device, it is possible to realize an image projection device capable of projecting images having good or various colors.

The figure which shows the structure of the light source apparatus which is Example 1 of this invention. The figure which shows the emission spectrum of the laser light source and the phosphor in Example 1. FIG. The figure which shows the sRGB chromaticity in Example 1. FIG. The figure which shows the composition of the fluorescent substance in Example 1, Comparative Example 1 and Comparative Example 2, the brightness of D65, and the coverage rate of sRGB. The figure which shows the structure of the projector which is Example 2 of this invention. The figure which shows the DCI chromaticity in Example 3 of this invention. The figure which shows the composition of the fluorescent substance in Example 3, Comparative Example 3 and Comparative Example 4, the brightness of white of DCI, and the coverage rate of DCI. The figure which shows the composition of the fluorescent substance in Example 4, Example 5-1 and Example 5-2 of this invention, the brightness of white of DCI, and the coverage rate of DCI. The figure which shows the emission spectrum of the laser light source in Example 5-1 and Example 5-2. The figure which shows the emission spectrum of the laser light source and the phosphor in Example 6 of this invention. The figure which shows the composition of the phosphor, the brightness of D65, and the coverage rate of sRGB in Example 6 and Comparative Examples 5-7. The figure which shows the structure of the light source apparatus which is Example 7 of this invention. The figure which shows the composition of the phosphor in Example 7, the white brightness of D65 and DCI, and the coverage rate of sRGB and DCI. The figure which shows the structure of the light source apparatus which is Example 8 of this invention. The figure which shows the composition of the phosphor of Example 8, the brightness of D65 and the coverage rate of sRGB. The figure which shows one frame period and a plurality of subframes in Example 2. FIG. The figure which shows the high-order bit and all gradation data in Example 2. The flowchart which shows the control in Example 7.

Hereinafter, examples of the present invention will be described with reference to the drawings.

FIG. 1 shows the configuration of the light source device 1 according to the first embodiment of the present invention. The light source device 1 is composed of a light source unit 301 and a phosphor unit 302 as a wavelength conversion unit. In the light source unit 301, a plurality of sets of laser diodes (LD) 303 (A to D) and collimating lenses 304 as light sources provided on a one-to-one basis are arranged in an array. In this embodiment, the LD 303s (A to D) emit blue laser light (hereinafter, simply referred to as blue light) 305.

The phosphor unit 302 is a set of a plurality of phosphors 306 (A to D) provided one-to-one with respect to the plurality of LD 303s (A to D) and one phosphor 306 (A to D). It is composed of a condenser lens 307 and a collimating lens 308 provided respectively. The plurality of condenser lenses 307 and the plurality of collimating lenses 308 are each formed in an array on an integral optical member.

The plurality of collimating lenses 308 may be configured as separate lenses one by one instead of in an array shape. Further, in this embodiment, it is described that the condenser lens 307 and the collimating lens 308 have substantially the same power (that is, the focal length), but this is not the case. Specifically, it is desirable that the collimating lens 308 has stronger power (shorter focal length) than the condenser lens 307.

The phosphors 306 (A to D) are arranged between the condenser lens 307 and the collimating lens 308.

The blue light 305 from the LD 303 (A to D) of the light source unit 301 is condensed by the condenser lens 307 and incident on the phosphors 306 (A to D). A part of the blue light 305 incident on the phosphor 306 (A to D) as the wavelength conversion region (or wavelength conversion element) is wavelength-converted to the yellow light 309 which is the fluorescent light as the wavelength conversion light, and the phosphor 306 Emit from. Further, of the blue light 305 incident on the phosphors 306 (A to D), the unconverted light 305a whose wavelength has not been converted is emitted from the phosphors 306 (A to D) as the blue light. The unconverted light 305a as blue light and the white light as combined light of yellow light 309 emitted from the phosphors 306 (A to D) are collimated by the collimating lens 308 and the phosphor unit 302 (that is, the light source device 1). Emit from. The white light emitted from the light source device 1 is incident on the illumination optical system of the projector described later and used as the illumination light.

The emission spectra of LD303A, 303B, 303C, and 303D in this example are shown in FIG. 2A. Each LD has an emission spectrum with a peak wavelength of 455 nm and a half width of ± 4 nm.

Further, the spectrum of the fluorescent light emitted by the phosphors 306A, 306B, 306C, 306D in response to the excitation light from the LD 303A, 303B, 303C, 303D is shown in FIG. 2 (b). The "phosphor 1" emits fluorescent light having a peak wavelength of 525 nm. The "phosphor 2" emits fluorescent light having a peak wavelength of 545 nm. The "phosphor 3" emits fluorescent light having a peak wavelength of 565 nm. The "phosphor 4" emits fluorescent light having a peak wavelength of 585 nm. Here, 500 nm to 590 nm is the wavelength range of the green region. That is, "fluorescent body 1" to "fluorescent body 4" are phosphors that emit fluorescent light having wavelengths different from each other by at least 5 nm (predetermined wavelength or more) in the green area which is the same color gamut, and are, for example, different types of phosphors. Is. The predetermined wavelength referred to here does not mean a mere individual difference of the phosphor, but means a wavelength intentionally different. Further, the predetermined wavelength may be 10 nm or more or 20 nm or more as in this embodiment.

A general projector has a plurality of selectable display modes as modes related to image display. For example, there is a presentation mode that maximizes brightness and an sRGB mode that reproduces the sRGB color gamut, which is an international standard. In the sRGB color gamut, the xy chromaticity when displaying a single color in each of the red (R) region, the green (G) region, and the blue (B) region and when displaying RGB in combination with white (W) is specified. Has been done. FIG. 3A shows the xy chromaticity (xy coordinates) specified in the sRGB color gamut.

When expressing the chromaticity reproducibility of the sRGB color gamut, the expression "coverage rate" is used. As shown in FIG. 3B, the coverage ratio is the ratio of the area of the area that can be represented inside the triangle whose apex is the xy coordinate specified in the sRGB color gamut to the area of the triangle. For example, if all the inside of the triangle can be expressed, the coverage rate is 100%. Further, when a part of the inside of the triangle cannot be expressed and the ratio of the area of the unrepresentable region to the area of the triangle is α%, the coverage rate is (100-α)%.

Further, the tint of the white display when RGB is combined is generally set with the xy coordinate of D65 as a target. The xy coordinates of D65 are shown in the column W in FIG. 3A. When setting the sRGB color gamut, it is necessary to improve the performance of all three items of coverage, brightness, and D65 tint.

In Comparative Example 1 shown in FIG. 4, "fluorescent body 2" is used for all of the four phosphors 306A to 306D (referred to as phosphor A, phosphor B, phosphor C and phosphor D in the figure). Is using. In this case, the brightness for realizing the color of D65 is 3000 lm, and the coverage rate is 98%. As can be seen from FIG. 2 (b), the fluorescence emission spectrum of "phosphor body 2" has high brightness in the green region but low brightness in the red region. Therefore, in order to combine RGB and realize the white color of D65, it is necessary to reduce the brightness of the green and blue areas and adjust the color to match the low brightness of the red area. As a result, the brightness of the white display is reduced.

Further, in Comparative Example 2, "fluorescent body 4" is used for all of the four fluorescent materials 306A to 306D. In this case, the brightness for realizing the color of D65 is 3000 lm, and the coverage rate is 98%. As can be seen from FIG. 2B, the fluorescence emission spectrum of the "fluorescence body 4" has a higher brightness in the red region than that of the "fluorescence body 2". Therefore, when synthesizing RGB to realize the white color of D65, the amount of reducing the brightness of the green area and the blue area can be reduced as compared with the case of using the "fluorescent body 2", and the color can be reduced. The amount of decrease in brightness due to taste adjustment is reduced. However, since the brightness of the green area of the "fluorescent body 4" is lower than that of the "fluorescent body 2", the total white brightness of the D65 is the same as when the "fluorescent body 2" is used.

On the other hand, in this embodiment, "fluorescent body 2" is used for the phosphors 306A and 306B, and "fluorescent body 3" is used for the phosphors 306C and 306D. As a result, the white color of D65 is realized with a brightness of 4000 lm and a coverage rate of 98%. As described above, the fluorescence emission spectrum of "phosphor 2" has high brightness in the green region, but low brightness in the red region. On the other hand, in the fluorescence emission spectrum of "phosphor body 3", the brightness of the green region is slightly low, but the brightness of the red region is high. Therefore, by combining the "phosphor 2" and the "phosphor 3" having different luminous efficiencies in the green region and the red region, good color and brightness can be realized.

According to this embodiment, by having two or more phosphors that generate fluorescent light having different wavelengths in the same color gamut, the tint of the emitted light (illumination light) can be adjusted or adjusted in a wide range. ..

In the above embodiment, a case where two or more phosphors that emit fluorescent light having different wavelengths are provided in a wavelength range (same color gamut) of 500 nm or more and less than 590 nm, which is a green area, has been described. However, two or more phosphors that emit fluorescent light having different wavelengths than a predetermined wavelength in another wavelength range of the same color gamut may be provided. For example, the blue region is a wavelength range of 400 nm or more and less than 500 nm, the red region is a wavelength range of 590 nm or more and less than 700 nm, and the ultraviolet region is a wavelength range of 280 nm or more and less than 400 nm.

Further, in the above embodiment, a plurality of LDs having the same (that is, the same) peak wavelengths are used as the LD 303A to 303D, but the peak wavelengths of the LD 303A to 303D are different from each other by a predetermined wavelength or more in the same color gamut. May be good. The predetermined wavelength at this time is also preferably 5 nm or more. Thereby, the chromaticity of the illumination light from the light source device 1 can be adjusted. Further, the number of LDs used does not have to be four.

Further, in the above embodiment, the case where the phosphors 306A, 306B, 306C, and 306D are used as wavelength conversion elements arranged so as to separate from each other has been described. However, the phosphors 306A, 306B, 306C, and 306D may be arranged adjacent to each other, or may be further provided as wavelength conversion regions that emit fluorescent light having different wavelengths from each other in the integrated phosphor.

These things are the same in other examples described later.

FIG. 5 shows the configuration of a projector as an image projection device according to a second embodiment of the present invention. The projector of this embodiment uses the light source device 1 described in the first embodiment. The components common to those of the first embodiment are designated by the same reference numerals as those of the first embodiment.

The white light as the illumination light from the light source device 1 is incident on the illumination optical system. The illumination optical system includes a collimator lens 407, a fly-eye lens 408, 409, a polarization (PS) conversion element 410, a condenser lens 411, a mirror 412 and a lens 414. The white light emitted from the illumination optical system is incident on the color separation compositing optical system. The color separation and synthesis optical system includes a dichroic mirror 421, a polarization beam splitter 422, 423, a color selective wave plate 424, a phase plate 425, 426, 427, a reflective liquid crystal display element (light modulation element) 428, 429, 430 and a color. Includes a synthetic prism 431.

The white light from the light source device 1 is collimated by the collimator lens 407 and incident on the fly-eye lenses 408 and 409, where it is divided into a plurality of luminous fluxes and incident on the PS conversion element 410. The white light converted into linearly polarized light having a predetermined polarization direction in the PS conversion element 410 is reflected by the mirror 412 while being condensed by the condenser lens 411, and is guided to the dichroic mirror 421 through the lens 414.

The dichroic mirror 421 transmits light in the green region (hereinafter referred to as G light) and reflects light in the red region (hereinafter referred to as R light) and light in the blue region (hereinafter referred to as B light). The G light transmitted through the dichroic mirror 421 passes through the polarizing beam splitter 422 and the phase plate 427 and is incident on the reflective liquid crystal display element 430G for G light. On the other hand, of the R light and B light reflected by the dichroic mirror 421, the B light has its polarization direction rotated by 90 ° on the color-selective wavelength plate 424, and the R light has its polarization direction not rotated by a polarization beam splitter. It is incident on 423. The R light is transmitted through the polarizing beam splitter 423, and the B light is reflected by the polarizing beam splitter 423.

The B light reflected by the polarizing beam splitter 423 passes through the phase plate 425 and is incident on the reflective liquid crystal display element 428 for B light. Further, the R light transmitted through the polarizing beam splitter 423 passes through the phase plate 426 and is incident on the reflective liquid crystal display element 429 for R light.

The G light modulated and reflected by the reflective liquid crystal display element 430 passes through the phase plate 427, is reflected by the polarizing beam splitter 422, and is incident on the color synthesis prism 431. Further, the R light modulated and reflected by the reflective liquid crystal display element 429 passes through the phase plate 426, is reflected by the polarizing beam splitter 423, and is incident on the color synthesis prism 431. Further, the B light modulated and reflected by the reflective liquid crystal display element 428 passes through the phase plate 425, passes through the polarizing beam splitter 423, and is incident on the color synthesis prism 431. The R light, G light, and B light are combined by the color synthesis prism 431 and projected onto a projected surface such as a screen by a projection lens (not shown). As a result, a color image is displayed.

In the projector configured as described above, by using the light source device 1 described in the first embodiment, it is possible to project a bright and good color image.

The reflective liquid crystal display elements 428, 429, 430 are driven by a digital drive system. The digital drive method referred to here is to divide one frame into a plurality of subframes on the time axis, and on-voltage or off for each subframe for each subframe according to the display gradation (gradation data) of the pixel. This is a subframe drive system that applies voltage.

FIG. 16 shows each bit of a plurality of subframes divided within one frame period. The numbers 1, 2, 4, and 8 indicate the time weights of multiple subframes. Here, the time weight when expressing 96 gradations is shown. In the A period, the time weight of each bit is expressed in binary, and in the B period, the time weight of each bit is evenly distributed. Here, the bit in the A period is the lower bit, and the bit in the B period is the upper bit.

The gradation data of the lower bits is shown in FIG. 17 (a). The vertical axis is gradation and the horizontal axis is time. 16 gradations can be expressed by the lower bits. Further, all gradation data in which the upper bits are added to the lower bits are shown in FIG. 17 (b). In all gradation data, the lower bits are arranged at the center of time in one frame, and the upper bits are divided into two over the lower bits in time. Gradation 0 corresponds to black display, and the larger the gradation value, the brighter the display, and the higher the gradation value 96, the whiter the display.

The gradation in one frame is expressed by the fact that the illumination light is always incident in the one frame (that is, the LD 303A to 303D continue to emit light). If the illumination light becomes dark or does not enter in the middle of one frame, the gradation cannot be expressed by the ON time (white parts in FIGS. 17A and 17B) at that time in digital drive. As a result, it becomes impossible to express the gradation scale in one frame. Therefore, in the digital drive system, it is necessary that the LD 303A to 303D are always lit in one frame. That is, the LD 303A to 303D are driven by CW (continuous oscillation).

Even in the digital drive system, it is not necessary to drive the LD 303A to 303D in CW during the time when blanking is occurring.

Further, in the light source device 1, when emitting light from each LD, the light from the LD 303A is always incident on the phosphor 306A, and the light from the LD 303B is always incident on the phosphor 306B. Further, the light from the LD 303C is always incident on the phosphor 306C, and the light from the LD 303D is always incident on the phosphor 306D. In this way, by constantly injecting light into a fixed (fixed) phosphor from each LD (without switching the phosphor that injects light from the LD), the brightness changes within one frame of the digital drive system. It is possible to perform stable gradation expression.

Some projectors have a DCI mode that reproduces the DCI color gamut of the digital cinema standard as one of a plurality of display modes. In the DCI color gamut, the xy chromaticity when displaying a single color in each of the R, G, and B color gamuts and when displaying RGB by combining RGB is specified. FIG. 6A shows the xy chromaticity (xy coordinates) specified in the DCI color gamut. When expressing the chromaticity reproducibility of the DCI color gamut, the expression "coverage" is used as in the sRGB color gamut. As shown in FIG. 6B, this coverage ratio is the ratio of the area of the area that can be represented inside the triangle whose apex is the xy coordinate specified in the DCI color gamut to the area of the triangle. For example, if all the inside of the triangle can be expressed, the coverage rate is 100%. Further, when a part of the inside of the triangle cannot be expressed and the ratio of the area of the unrepresentable region to the area of the triangle is α%, the coverage rate is (100-α)%.

Further, the tint of the white display when RGB is combined is set with the xy coordinates shown in the W column of FIG. 6A as a target. When setting the DCI color gamut, it is necessary to improve the performance of all three items of coverage, brightness, and DCI white tint.

In Comparative Example 3 shown in FIG. 7, "fluorescent body 2" is used for any of the four phosphors 306A to 306D. In this case, the brightness for realizing the white tint of DCI is 2000 lm, and the coverage rate is 98%. As can be seen from FIG. 2 (b), the fluorescence emission spectrum of "phosphor body 2" has high brightness in the green region but low brightness in the red region. Therefore, in order to combine RGB and realize the white tint of DCI, it is necessary to reduce the brightness of the green and blue regions and adjust the tint according to the low brightness red region. As a result, the brightness of the white display is reduced.

Further, in Comparative Example 4, "fluorescent body 4" is used for all of the four phosphors 306A to 306D. In this case, the brightness for realizing the white tint of DCI is 2000 lm, and the coverage rate is 98%. As can be seen from FIG. 2B, the fluorescence emission spectrum of the "fluorescence body 4" has a higher brightness in the red region than that of the "fluorescence body 2". Therefore, when synthesizing RGB to realize the white color of DCI, the amount of reducing the brightness of the green area and the blue area can be reduced as compared with the case of using the "fluorescent body 2", and the color can be reduced. The amount of decrease in brightness due to taste adjustment is reduced. However, since the brightness of the green area of the "fluorescent body 4" is lower than that of the "fluorescent body 2", the total white brightness of the DCI is the same as when the "fluorescent body 2" is used.

On the other hand, in this embodiment, "fluorescent body 2" is used for the phosphors 306A and 306B, and "fluorescent body 4" is used for the phosphors 306C and 306D. As a result, the white color of DCI is realized with a brightness of 3000 lm and a coverage rate of 98%. As described above, the fluorescence emission spectrum of "phosphor 2" has high brightness in the green region, but low brightness in the red region. On the other hand, in the fluorescence emission spectrum of "phosphor body 4", the brightness of the green region is slightly low, but the brightness of the red region is high. Therefore, by combining the "phosphor 2" and the "phosphor 4" having different luminous efficiencies in the green region and the red region, good color and brightness can be realized.

FIG. 8 shows the wavelengths of the phosphors 306A to 306D and LD303A to 303D used in the light source device according to the fourth embodiment of the present invention. In this example as well, as in Example 3, "fluorescent body 2" is used for the fluorescent materials 306A and 306B, and "fluorescent material 4" is used for the fluorescent materials 306C and 306D. For LD303A to 303D, LDs having an emission spectrum having a peak wavelength of 455 nm and a half width of ± 4 nm are used. As a result, the white color of DCI is realized with a brightness of 3000 lm and a coverage rate of 98%.

Next, the light source device according to Example 5-1 and Example 5-2 of the present invention will be described. In this embodiment, at least one of LD303A to 303D uses an LD of a different type (that is, peak wavelength) from the others. FIG. 8 shows the peak wavelengths of the phosphors 306A to 306D and LD303A to 303D used in this example. In the figure, LD303A, 303B, 303C and 303D are shown as LDA, LDB, LDC and LDD, respectively.

In Example 5-1, “fluorescent body 2” is used for the fluorescent material 306A and the fluorescent material 306B, but a diffuser plate is used instead of the fluorescent material 306C and the fluorescent material 306D. Both LD303A and 303B are LDs having an emission spectrum having a peak wavelength of 455 nm and a half width of ± 4 nm. On the other hand, LD303C and LD303D have emission spectra having a peak wavelength of 640 nm and a half width of ± 4 nm, as shown in FIG.

In Example 4, as can be seen from FIG. 2B, the fluorescence emission spectrum of the phosphor 2 has high brightness in the green region but low brightness in the red region. Therefore, in order to combine RGB and realize the white tint of DCI, it is necessary to reduce the brightness of the green and blue regions and adjust the tint according to the low brightness red region. As a result, the brightness of the white display is reduced.

On the other hand, in Example 5-1, redness is added by using LDs that emit light having a wavelength of 640 nm in the red region having a longer wavelength than LD303A and LD303B as LD303C and LD303D. As a result, the brightness can be improved without reducing the brightness of the green area and the blue area. Further, the red region light from the LD303C and LD303D is diffused by a diffuser plate used in place of the LD303C and LD303D.

Further, in Example 5-2, "fluorescent body 2" is used for the fluorescent substance 306A and the fluorescent substance 306B, and "fluorescent body 4" is used as the fluorescent substance C. Further, a diffuser plate is used instead of the phosphor D. LD303A to LD303C have an emission spectrum having a peak wavelength of 455 nm and a half width of ± 4 nm. Further, as shown in FIG. 9, the LD303D has an emission spectrum having a peak wavelength of 640 nm and a half width of ± 4 nm.

Since the above-mentioned Example 5-1 uses two LDs in the red region, there is a tendency that the amount of light in the green region having high luminous efficiency tends to be small. Therefore, in this embodiment, by adding the LD303C that emits light in the blue region, it is possible to increase the light in the green region and further improve the brightness of the white of DCI. In this way, by using at least one of the LD 303A to 303D as an LD of a type different from the others, it is possible to improve the color and the brightness.

However, in the light source devices of Examples 5-1 and 5-2, the superiority or inferiority of brightness may differ depending on the characteristics of the optical system such as the illumination optical system, and therefore, which light source is used depending on the characteristics of the optical system. You may choose whether to use the device.

According to this embodiment, by having two or more light sources that emit light having different wavelengths in the same color gamut, the tint of the emitted light (illumination light) can be adjusted or adjusted in a wide range.

In the above embodiment, a case where two or more LDs that emit light having different wavelengths are provided in a wavelength range (same color gamut) of 400 nm or more and less than 500 nm, which is a blue region, has been described. However, two or more LDs that emit light having wavelengths different from each other by a predetermined wavelength or more in another wavelength range of the same color gamut may be provided. As described above, the green region is a wavelength range of 500 nm or more and less than 590 nm, the red region is a wavelength range of 590 nm or more and less than 700 nm, and the ultraviolet region is a wavelength range of 280 nm or more and less than 400 nm.

Next, the light source device according to the sixth embodiment of the present invention will be described. FIG. 10A shows the emission spectra of LDs having different emission wavelengths from each other. In general, when the emission wavelength of LD becomes longer, the peak intensity when the same current is passed becomes smaller. FIG. 10A shows the emission spectra of LDs having peak wavelengths of 445 nm, 455 nm, and 465 nm. For example, the ratio of the peak intensities when the same 3A current is passed is 0.92 for an LD with a peak wavelength of 455 nm and 0.84 for an LD with a peak wavelength of 465 nm, assuming that the LD has a peak wavelength of 445 nm and is 1. ..

Further, FIG. 10 (b) shows fluorescent light emitted from the three LDs shown in FIG. 10 (a) when they irradiate a fluorescent substance of the same type (here, “fluorescent body 2”) with light. The spectrum (fluorescence emission spectrum) of is shown. As described above, when the emission wavelength of the LD becomes longer, the peak intensity when the same current is passed becomes smaller, so that the emission intensity from the phosphor also becomes smaller as the emission wavelength of the LD becomes longer.

The sum of the emission spectra of LDs having different emission wavelengths and the fluorescence emission spectra of phosphors is the emission spectrum of the light source device. At this time, from FIGS. 10A and 10B, the shorter the emission wavelength of the LD, the shorter the peak intensity of the LD, so that the chromaticity (y) value is low and the emission intensity from the phosphor is strong. Bright. On the other hand, the longer the emission wavelength of the LD, the higher the peak intensity of the LD on the longer wavelength side, so that the y value is high and the emission intensity from the phosphor is weak and dark.

As in Comparative Example 5 shown in FIG. 11, when "phosphor 2" is used for all of the phosphors 306A to 306D and the emission wavelengths of the LD 303A to 303D are all 445 nm, the tint of D65 is obtained. The brightness to be realized is 3000 lm, and the coverage rate is 98%. At this time, since the emission wavelengths of the LD 303A to 303D are shorter than those of 465 nm and 455 nm, which will be described later, they are bright but have a low y value before the color adjustment to D65. Therefore, in order to realize the tint of D65 at the time of white display in which RGB is combined, it is necessary to reduce the brightness of the red region and the blue region to adjust the color, and as a result, the brightness of the white display is lowered. ..

Further, as in Comparative Example 6, at this time, the emission wavelengths of the LD 303A to 303D are all longer wavelengths than those of 445 nm and 455 nm. Therefore, it is dark and the y value is high before the color is adjusted to D65. Therefore, in order to realize the tint of D65 at the time of white display in which RGB is combined, it is necessary to further reduce the brightness of the green region and adjust the color, and as a result, the brightness of the white display is further lowered.

Further, as in Comparative Example 7, when "phosphor 2" is used for all of the phosphors 306A to 306D and the emission wavelengths of the LD 303A to 303D are all 455 nm, the tint of D65 is realized. The brightness for this is 3500 lm, and the coverage rate is 98%. At this time, the emission wavelengths of LD 303A to 303D are both intermediate wavelengths between 445 nm and 465 nm. Before the color adjustment to D65, the brightness is intermediate, and the y value is slightly high because the red region is insufficient in the fluorescence emission spectrum of the phosphor itself. Therefore, in order to realize the tint of D65 at the time of white display in which RGB is combined, it is necessary to further reduce the brightness of the green region and adjust the color, and as a result, the brightness of the white display is lowered.

On the other hand, in this embodiment, "phosphor 2" is used for all of the phosphors 306A to 306D, the emission wavelengths of LD303A and LD303B are set to 445 nm, and the emission wavelengths of LD303C and LD303D are set to 455 nm. In this case, the brightness for realizing the color of D65 is 4000 lm, and it is possible to realize a coverage rate of 98%.

At this time, since the LD having a short emission wavelength (445 nm) and an intermediate wavelength (455 nm) is used, it is bright before the color adjustment to D65 and the y value is slightly low. Therefore, in order to realize the tint of D65 at the time of white display in which RGB is combined, it is necessary to slightly reduce the brightness of the red region and the blue region to adjust the color. However, since the red region and the blue region have low relative luminous efficiency that contributes to brightness, it is possible to suppress a decrease in brightness for color adjustment. In this way, by combining a plurality of LDs having different emission wavelengths (peak wavelengths) from each other, good color and brightness can be realized.

Further, in this embodiment, the case where the phosphors 306A to 306D are all the same fluorescent material has been described, but as shown in FIG. 4, by using a plurality of types of fluorescent materials, the coverage rate remains constant. , It is possible to further improve the brightness.

FIG. 12 shows the configuration of the light source device 1A according to the seventh embodiment of the present invention. In this embodiment, the components common to those in the first embodiment are designated by the same reference numerals as those in the first embodiment. In the light emitter unit 302A, phosphors 306AA, 306AB, 306BA, 306BB, 306CA, 306CB, 306DA, 306DB are arranged between the plurality of condensing lenses 307 and the plurality of collimating lenses 308.

Further, in this embodiment, the switching mechanism (switching means) 500 for moving (sliding) the phosphor unit 302A with respect to the light source unit 301 in the direction orthogonal to the optical axis of each lens, and the operation of the switching mechanism 500 are operated. A control unit 600 for controlling is provided. A mode selection unit (selection means) 700 that allows the user to select (input) a display mode is connected to the control unit 600 so that wired or wireless (remote control) communication is possible.

The control unit 600 configured by a computer such as a CPU determines in step S601 shown in FIG. 18 whether the display mode selected by the user through the mode selection unit 700 is the sRGB mode or the DCI mode. If the sRGB mode is set, the process proceeds to step S602, and if the DCI mode is set, the process proceeds to step S603.

In step S602, the control unit 600 operates the switching mechanism 500 to slide the phosphor unit 302A to the sRGB position where the incident light 305 from the light source unit 301 is incident on the phosphors 306AA, 306BA, 306CA, 306DA. Further, in step S603, the control unit 600 operates the switching mechanism 500 to slide the phosphor unit 302A to the DCI position where the incident light 305 from the light source unit 301 is incident on the phosphors 306AB, 306BB, 306CB, 306DB. ..

FIG. 13 shows examples of phosphors 306AA, 306AB, 306BA, 306BB, 306CA, 306CB, 306DA, and 306DB. In the figure, the phosphors 306AA and 306AB are indicated by the phosphor A, and the phosphors 306BA and 306BB are indicated by the phosphor B. Further, the phosphors 306CA and 306CB are indicated by the phosphor C, and the phosphors 306DA and 306DB are indicated by the phosphor D.

In the sRGB mode, the "fluorescent body 2" is used for the phosphors 306AB and 306BB that incident the incident light 305 from the light source unit 301, and the "fluorescent body 4" is used for the phosphors 306CB and 306DB. At this time, the color of D65 can be realized with a brightness of 4000 lm and a coverage rate of 98%.

Further, in the DCI mode, the "fluorescent body 2" is used for the phosphors 306BA and 306BA that incident the incident light 305 from the light source unit 301, and the "fluorescent body 4" is used for the phosphors 306AC and 306AD. At this time, the tint of white W of DCI can be realized with a brightness of 3000 lm and a coverage rate of 98%.

By switching the phosphor that incident the incident light according to the display mode (color gamut mode) in this way, it is possible to realize a light source device that can obtain good color and brightness in a plurality of display modes.

FIG. 14 shows the configuration of the light source device 1B according to the eighth embodiment of the present invention. In this embodiment, the components common to those in the first embodiment are designated by the same reference numerals as those in the first embodiment. In the light emitter unit 302B, phosphors 306E and 306F are arranged between the plurality of condensing lenses 307 and the plurality of collimating lenses 308.

In Example 1, one LD and one phosphor were provided in a one-to-one relationship, but in this embodiment, one phosphor is provided for a plurality of (two in the figure) LD. ing. Specifically, the incident light 305 from the LD 303A and 303B is incident on the phosphor 306E via the two condenser lenses 307, and the combined light of the unconverted light (blue light) 305a and the fluorescent light 309 from the phosphor 306E. Emits through two collimating lenses 308. Similarly, the incident light 305 from the LD 303C and 303D is incident on the phosphor 306F via the two condenser lenses 307, and the combined light of the unconverted light (blue light) 305a and the fluorescent light 309 is 2 from the phosphor 306F. Emit through one collimating lens 308.

FIG. 15 shows the brightness and coverage of the phosphors E and F and D65 in the sRGB mode. "Fluorescent body 2" is used as the phosphor E, and "fluorescent body 3" is used as the phosphor F. In this embodiment, the optical action is the same as that in Example 1, and the tint of D65 can be realized with a brightness of 4000 lm and a coverage rate of 98%.

Each of the above-described examples is only a representative example, and various modifications and changes can be made to each of the examples in carrying out the present invention.

1 Light source device 303A to 303D Laser diode (light source)
306A-306D Fluorescent material

Claims (10)

With multiple light sources
A wavelength conversion unit that generates wavelength conversion light having a wavelength different from that of light incident from the light source, and includes a plurality of wavelength conversion regions provided for each region irradiated with light from the plurality of light sources.
It has a light source having a color gamut different from that of the plurality of light sources.
The plurality of wavelength conversion regions include two or more wavelength conversion regions that generate wavelength conversion light having wavelengths different from each other by a predetermined wavelength or more in the same color gamut.
The wavelength conversion unit is a light source device including a diffuser plate that diffuses light from light sources having different color gamuts. The light source device according to claim 1, wherein the two or more wavelength conversion regions are composed of wavelength conversion elements of different types. The light source device according to claim 1 or 2, wherein the wavelengths of the plurality of light sources are different from each other by a predetermined wavelength or more. With multiple light sources
Each has a wavelength conversion unit that generates wavelength conversion light having a wavelength different from that of the light incident from the light source and includes a plurality of wavelength conversion regions provided for each region irradiated with light from the plurality of light sources. ,
The plurality of light sources include two or more light sources that emit light having wavelengths different from each other by a predetermined wavelength or more in the same color gamut.
A light source device including a light source having a color gamut different from that of the plurality of light sources. The same color gamut is characterized in that the wavelength is any one of a range of 280 nm or more and less than 400 nm, a range of 400 nm or more and less than 500 nm, a range of 500 nm or more and less than 590 nm, and a range of 590 nm or more and less than 700 nm. The light source device according to any one of 4. The light source device according to any one of claims 1 to 5, wherein the predetermined wavelength is at least 5 nm. The light source device according to any one of claims 1 to 6, wherein in the plurality of wavelength conversion regions, the wavelength conversion region in which light is incident from each of the plurality of light sources is fixed. The claim is characterized in that the wavelength conversion unit is moved with respect to the plurality of light sources to switch the wavelength conversion region in which the light from the light source is incident among the two or more wavelength conversion regions. The light source device according to any one of 1 to 6. The light source device according to any one of claims 1 to 8.
Light modulation elements that modulate light and
An image projection device comprising an optical system that guides light from the light source device to the light modulation element and projects an image using the light from the light modulation element. A selection method that enables selection of one of multiple modes related to image display,
9. The ninth aspect of the present invention is characterized in that it includes a control means for switching a wavelength conversion region for incident light from the light source among the two or more wavelength conversion regions according to a mode selected from the plurality of modes. The image projection device described.

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