JP2014160259A - Projector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a projector capable of realizing least color unevenness on a projection image caused by variation with time, etc. even when employing an illumination device including a plurality of light sources.SOLUTION: A projector 1 of the present invention comprises: a first light source 9 for emitting light including a first color light; a second light source 10 for emitting light including a second color light and a third color light; a color separation part 3 for separating the incident light emitted from each of the light sources into the first color light, the second color light and the third color light; liquid crystal light bulbs 4R, 4G, 4B (a first to third light modulation elements); and a relay optical system 5 (a light transmission part) including a plurality of optical elements provided between the color separation part and the first light modulation element.

Description

  The present invention relates to a projector.

  A color separation optical system that separates light from a light source into three color lights, a display optical system that includes three light modulation devices corresponding to each color light, and a color composition that combines light modulated by each light modulation device A projector including an optical system is disclosed in Patent Document 1 below. In this projector, the optical path length (distance from the light source to the light modulation device) of the three color lights in the color separation optical system is made equivalent to suppress a decrease in light amount and initial color unevenness. ing. That is, this projector makes the optical path length of each color light optically equivalent by interposing a light transmission optical system composed of a relay lens, a field lens, a mirror, etc. in the optical path of the color light with the longest optical path length. Yes. This makes it possible to reduce the size of the projector as compared to an optical system in which the optical path lengths of all color lights are physically equal.

US Pat. No. 4,943,154

  However, there has been a problem that the deviation of illumination due to a change with time such as movement of the light emitting point of the light source differs depending on the color. This is because the illumination shift caused by the movement of the light source is reversed on the screen depending on the presence or absence of the light transmission optical system.

  The present invention has been made to solve the above-described problem, and is generated by a change over time by adopting an illumination device including a plurality of light sources and optimally arranging optical paths of three color light beams. An object of the present invention is to provide a projector capable of reducing color unevenness on a projected image as much as possible.

  To achieve the above object, a first projector of the present invention emits a first light source that emits light including first color light, and a first light source that emits light including second color light and third color light. 2 light sources, light emitted from the first light source, and light emitted from the second light source are incident, and the incident light is converted into the first color light, the second color light, the first light A color separation unit that separates each of the three color lights, a first light modulation element that modulates the first color light, a second light modulation element that modulates the second color light, and the third color light. A light transmission unit including a plurality of optical elements provided between the color separation unit and the first light modulation element, the first light modulation element, A second light modulation element, a color synthesis unit that synthesizes each color light modulated by the third light modulation element, and the color combination The light combined by part characterized by comprising a projection section which projects onto the projection surface.

  In the projector, as described above, in order to optically equalize the optical path lengths of the differently colored light beams, the optical path of the colored light having the longest physical optical path length includes a plurality of optical elements such as a relay lens and a field lens. A light transmission part including an element may be interposed. Here, the present inventor has found that the problem that the color unevenness on the projection screen increases is caused by the following causes. For example, when three color lights of red light (R), green light (G), and blue light (B) are used, a plurality of optical elements are provided for an optical image of two color lights with equivalent physical optical path lengths. The optical image of one color light in which the included light transmission part is interposed in the optical path is inverted due to the difference in the number of imaging with the other optical image. Then, for example, when the position of the light emitting point of the light source is shifted due to a change over time, the direction in which the optical image is shifted between the one color light having the light transmission portion interposed in the optical path and the other two color lights is reversed. This causes a problem that the color unevenness in the projected image becomes large. That is, when the two colored lights obtained by separating the light emitted from one light source are distributed to an optical path where the light transmission unit is interposed and an optical path where the light transmission unit is not interposed, color unevenness in the projected image is generated. There was a growing problem.

  In contrast, in the first projector of the present invention, the light transmission unit including a plurality of optical elements is interposed on the optical path of the first color light emitted from the first light source, while the second light source The light transmission unit is not interposed on the optical paths of the second color light and the third color light generated by separating the emitted light. As a result, even if the position of the light emission point is shifted in the first light source or the second light source, it is sufficient to shift the optical image in one direction, and the superimposed optical images are shifted in opposite directions. The amount of deviation will not double. Thus, according to the projector of the present invention, even when the illumination system including the first light source and the second light source is employed, color unevenness on the projected image can be reduced as much as possible. Note that the above-described problem and the operation and effect of the present invention are difficult to explain by text alone, and will be described in detail in the section of [DETAILED DESCRIPTION] using the drawings.

In the projector according to the aspect of the invention, it is preferable that the light distribution distribution of the light emitted from the first light source is narrower than the light distribution distribution of the light emitted from the second light source.
In general, an optical path in which a light transmission unit is inserted has a longer optical path length than other optical paths and a large number of optical parts (lenses) that pass therethrough. That part of the light is blocked), and the optical loss is larger than when the light transmission unit is not used. In that respect, in the above configuration, the light distribution distribution of the light emitted from the first light source is narrower than the light distribution distribution of the light emitted from the second light source, and the light distribution distribution from the first light source is narrow. The light is distributed to the optical path through which the light transmission unit is interposed. Therefore, the overall light loss is reduced, and the light use efficiency can be increased.

  The second projector of the present invention includes a first light source that emits light including first color light, a second light source that emits light including second color light and third color light, and the first light source. Light that is emitted from a light source and light emitted from the second light source are incident, and the incident light is separated into the first color light, the second color light, and the third color light, respectively. A separation unit; a first light modulation element that modulates the first color light; a second light modulation element that modulates the second color light; and a third light modulation element that modulates the third color light. A first light transmission unit including a plurality of optical elements provided between the color separation unit and the second light modulation element, and between the color separation unit and the third light modulation element. A second light transmission unit including a plurality of optical elements provided on the first light modulation element, the first light modulation element, the second light modulation element, and the A color synthesis unit for synthesizing the respective color lights modulated by the three light modulation element, characterized by comprising a projection section which projects the light synthesized by the color synthesizing unit on the projection surface.

  The second projector of the present invention is different from the first projector of the present invention in that the present invention is applied to a configuration in which a light transmission unit is interposed in two optical paths of three color light paths. Therefore, in the second projector of the present invention, the light of the second color light and the third color light generated by separating the light emitted from the second light source, contrary to the first projector of the present invention. While the light transmission part including a plurality of optical elements is interposed on the path, the light transmission part is not interposed on the optical path of the first color light emitted from the first light source. As a result, even if the position of the light emission point is shifted in the first light source or the second light source, it is sufficient to shift the optical image in one direction, and the superimposed optical images are shifted in opposite directions. The amount of deviation will not double. Thus, according to the projector of the present invention, even when the illumination system including the first light source and the second light source is employed, color unevenness on the projected image can be reduced as much as possible.

In the projector according to the aspect of the invention, it is preferable that the first light source is a laser light source, and the second light source is a phosphor that emits light using excitation light as light emitted from the laser light source.
According to this configuration, since the laser light source is used as the first light source, it is possible to realize a projector that has excellent responsiveness of the light source and can obtain a projected image with high color purity. Further, it is not necessary to prepare a separate light source for emitting the excitation light of the phosphor, and the configuration of the illumination system can be simplified.

In the projector according to the aspect of the invention, the light including the first color light emitted from the first light source is blue light, and the second color light and the third color light emitted from the second light source are used. It is desirable that the light to be included is yellow light, and the phosphor transmits a part of the blue light emitted from the first light source.
According to this configuration, white light can be obtained with high efficiency by using a blue laser light source, and an efficient projector can be realized.

In the projector according to the aspect of the invention, it is preferable that the phosphor includes a phosphor layer formed on one surface of a rotatable plate.
According to this configuration, since the phosphor layer is irradiated with laser light while rotating the plate having the phosphor layer formed on one surface, overheating of the phosphor layer is suppressed, so that the phosphor layer is deteriorated and light is emitted. A decrease in efficiency can be prevented. Therefore, a projector with excellent reliability can be realized.

1 is a schematic configuration diagram of a projector according to a first embodiment of the invention. It is a figure for demonstrating the effect | action of a relay optical system. It is a figure for demonstrating an effect | action of the optical system except a relay optical system. It is a figure for demonstrating the effect | action and effect of this projector. It is a schematic block diagram of the projector of 2nd Embodiment of this invention. It is a schematic block diagram of the projector of 3rd Embodiment of this invention. It is a schematic block diagram of the projector of 4th Embodiment of this invention.

[First Embodiment]
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.
The projector according to the present embodiment is a so-called three-plate type liquid crystal projector including a liquid crystal light valve that modulates three color lights of red (R) light, green (G) light, and blue (B) light. Moreover, in this embodiment, the structure which inserted the relay optical system in the optical path of red light among three color lights is illustrated.

FIG. 1 is a schematic configuration diagram of a projector according to the present embodiment. FIG. 2 is a diagram for explaining the operation of the relay optical system. FIG. 3 is a diagram for explaining the operation of the optical system excluding the relay optical system. FIG. 4 is a diagram for explaining the operation and effect of the projector.
In the following drawings, in order to make each component easy to see, the scale of the size may be varied depending on the component.

  As shown in FIG. 1, the projector 1 according to the present embodiment includes an illumination unit 2, a color separation unit 3, liquid crystal light valves 4R, 4G, and 4B (light modulation elements), a relay optical system 5 (light transmission unit), and a cross dichroic. A prism 6 (color synthesis unit), a projection lens 7 (projection unit), and the like are roughly configured. In FIG. 1, the projection lens 7 is represented by only one lens in order to simplify the drawing, but actually, the projection lens 7 is composed of a plurality of lenses.

  The illumination unit 2 according to the present embodiment includes a first light source 9, a second light source 10, a dichroic mirror 11, a first lens array 12, a pair of lens arrays 14 including a second lens array 13, a polarization conversion element 15, and a superimposition. A lens 16 is provided. The first light source 9 is a red solid light source that emits red light. As the red solid light source, a red light emitting diode (hereinafter abbreviated as LED) may be used, or a red laser light source may be used. The second light source 10 is a white lamp 17 such as a high-pressure mercury lamp or a metal halide lamp that emits white (W) light. The white lamp 17 includes an arc tube 18 and a reflector 19 that reflects the light from the arc tube 18 and emits it forward. Therefore, white light including red light, green light, and blue light is emitted from the white lamp 17 that is the second light source 10. A general high-pressure mercury lamp tends to lack red light, but the color can be improved by supplementing with red light from a red solid light source.

  On the optical path of the red light emitted from the first light source 9 and the white light emitted from the second light source 10, a dichroic mirror 11 for synthesizing the red light and the white light is installed. The dichroic mirror 11 is obtained by, for example, laminating a dielectric multilayer film on the glass surface. As a result, the dichroic mirror 11 selectively reflects colored light in a predetermined wavelength band and selectively transmits colored light in other wavelength bands. Specifically, the dichroic mirror 11 according to the present embodiment has a characteristic of reflecting green light and blue light while reflecting red light.

  Therefore, the red light emitted from the first light source 9 is reflected by the dichroic mirror 11 to change its traveling direction, and travels to the color separation unit 3 at the next stage. Of the white light emitted from the second light source 10, green light and blue light are transmitted through the dichroic mirror 11 and travel toward the next color separation unit 3. In this way, the red light emitted from the first light source 9 and the green light and blue light emitted from the second light source 10 are combined by the dichroic mirror 11 to become white light. In this configuration, since the red light derived from the red solid light source is used for display instead of the red light component contained in the white light spectrum from the white lamp 17, the red solid light source is appropriately selected. Thus, for example, red with high color purity can be expressed.

  The pair of lens arrays 14 and the superimposing lens 16 make the intensity distribution of the light emitted from the light sources 9 and 10 uniform. The white light synthesized by the dichroic mirror 11 is divided into a plurality of light beams by the pair of lens arrays 14, and these light beams are superimposed on the liquid crystal light valves 4R, 4G, and 4B, which are illuminated areas, by the superimposing lens 16. Thereby, the illuminance distribution of the light on the liquid crystal light valves 4R, 4G, 4B is made uniform. The polarization conversion element 15 includes a polarization beam splitter array (PBS array) and a half-wave plate array, although the detailed structure thereof is not shown. Of the light incident on the PBS array from the pair of lens arrays 14, linearly polarized light in the first polarization direction passes through the polarization separation film (PBS film) in the PBS array, and linearly polarized light in the second polarization direction is PBS. Reflect on the PBS film in the array. The reflected polarized light is emitted with the polarization direction changed to the first polarization direction by the half-wave plate array. Thus, the polarization conversion element 15 has a function of aligning the polarization direction of the light source light in one direction without impairing the light amount of the light source light.

  The light transmitted through the superimposing lens 16 is reflected by the mirror 21 and then enters the color separation unit 3. The color separation unit 3 includes two dichroic mirrors 22 and 23. Similar to the dichroic mirror 11 of the illumination unit 2, these dichroic mirrors 22 and 23 are formed by, for example, laminating a dielectric multilayer film on the glass surface, and selectively reflect colored light in a predetermined wavelength band, and other wavelengths. The band of color light is selectively transmitted. Specifically, the dichroic mirror 22 transmits the blue light LB and reflects the red light LR and the green light LG. The dichroic mirror 23 transmits the red light LR among the red light LR and the green light LG reflected by the dichroic mirror 22 and reflects the green light LG.

  The blue light LB transmitted through the dichroic mirror 22 is reflected by the mirror 24 and then enters the liquid crystal light valve 4B for blue light through the field lens 25. The green light LG reflected by the dichroic mirror 23 passes through the field lens 25 and enters the liquid crystal light valve 4G for green light.

  The red light LR that has passed through the dichroic mirror 23 enters the liquid crystal light valve 4R for red light via the relay optical system 5. The relay optical system 5 includes a first relay lens 26, a mirror 27, a second relay lens 28, a mirror 29, and a third relay lens 30 arranged in this order from the dichroic mirror 23 side. The third relay lens 30 also functions as a field lens in front of the liquid crystal light valve 4R for red light. In the case of this embodiment, the optical path length of the red light LR is longer than the optical path lengths of the other color lights LG and LB, and in order to prevent light loss due to the long optical path, such a relay is placed on the optical path length of the red light LR. An optical system 5 is provided. The relay optical system 5 has an effect of making the illumination range near the first relay lens 26 and the illumination range near the third relay lens 30 substantially equal. Therefore, as compared with the case where the relay optical system 5 is not used, it is possible to reduce the loss due to the expansion of the illumination range and the non-uniformity (unevenness) of the illumination due to the imaging shift. Uneven illumination (unevenness) is undesirable because it causes initial color unevenness.

  Each of the liquid crystal light valves 4R, 4G, and 4B includes a transmissive liquid crystal cell and polarizing plates (both not shown) provided on the incident side and the emission side thereof. The transmissive liquid crystal cell is an active matrix liquid crystal cell, for example, and includes a liquid crystal layer sandwiched between a pair of electrodes. The liquid crystal light valves 4R, 4G, and 4B are electrically connected to an arbitrary signal source that supplies an image signal. When an image signal is supplied from the signal source, a voltage is applied between the electrodes of the transmissive liquid crystal cell, and the alignment direction of the liquid crystal molecules is controlled according to the applied voltage. Thereby, the incident light can be modulated. The red light LR, the green light LG, and the blue light LB modulated by the liquid crystal light valves 4R, 4G, and 4B are incident on the cross dichroic prism 6.

  The cross dichroic prism 6 has a structure in which a triangular prism is bonded, and a selective reflection surface (dichroic surface) that reflects the red light LR and transmits the green light LG and the blue light LB on the inner surface thereof, and the blue light LB. And a selective reflection surface (dichroic surface) through which the red light LR and the green light LG are transmitted are orthogonal to each other. The red light LR and the blue light LB are selectively reflected by these selective reflection surfaces, the green light LG is selectively transmitted through these selective reflection surfaces, and the three color lights are emitted on the same side. As a result, the three colored lights are superposed to become the combined light L. The combined light L emitted from the cross dichroic prism 6 is enlarged and projected onto the screen 31 (projected surface) by the projection lens 7 including a plurality of lens groups.

  In FIG. 2, the mirrors 27 and 29 are omitted from the components of the relay optical system 5, and only the first relay lens 26, the second relay lens 28, and the third relay lens 30 are taken out and developed linearly. It is drawing which shows a mode that L condenses. As shown in this figure, an optical image incident on the first relay lens 26 is formed as an intermediate image in the second relay lens 28, and this intermediate image is enlarged by the second relay lens 28 to be third relay lens 30. Is transmitted to. In this process, the optical image Y1 incident on the first relay lens 26 becomes an optical image Y2 that is inverted vertically and horizontally at the position of the third relay lens 30.

  FIG. 3 shows how the light LG is condensed by taking out optical elements other than the mirror and developing them linearly in the optical path of colored light (represented by the green light LG) not including the relay optical system 5. It is a drawing. Hereinafter, how the optical image is inverted in the optical path where the relay optical system 5 is not interposed will be described with reference to FIG. However, light is reflected by a mirror, a cross dichroic prism, or the like, and only the left / right inversion when the optical path is bent is not considered once, and the up / down / left / right inversion is considered.

  The light LG emitted from the first lens array 12 is combined as an inverted image on the surface of the liquid crystal light valve 4G via the second lens array 13, the polarization conversion element 15, the superimposing lens 16, and the field lens 25. Image. Further, the light LG is imaged again on the screen 31 through the dichroic prism 6 and the projection lens 7 as an inverted image. Therefore, the illumination image formed on the surface of the first lens array 12 is formed on the screen 31 as it is without being vertically and horizontally reversed.

  On the other hand, as described with reference to FIG. 2, in the optical path of the color light in which the relay optical system 5 is inserted between the second lens array 13 and the field lens 25, the relay optical system 5 reverses the image vertically and horizontally. Occurs once. Although the mirror and the cross dichroic prism cause left-right reversal, the number of reflections is an even number even if the number of times of light reflection (bending of the optical path) varies depending on the optical path regardless of the presence or absence of the relay optical system 5. Or whether it is an odd number of times coincides in all the optical paths. In the case of this embodiment, as shown in FIG. 1, the number of times each color light is reflected between the second lens array 13 and the field lens 25 is three times for blue light, three times for green light, and red light. 5 times, all odd numbers. That is, considering only the left-right reversal, the result of the left-right reversal of the optical image is the same between the optical path in which the relay optical system 5 is interposed and the optical path in which the relay optical system 5 is not interposed. Therefore, as a whole, in the optical path in which the relay optical system 5 is interposed, the up / down / left / right inversion of the optical image is increased once compared to the optical path in which the relay optical system 5 is not interposed.

  For example, consider a case where the position of the second light source 10 is displaced or the light emission point (arc) is moved due to a change with time. It is assumed that the first light source 9 is not displaced or the light emission point is not moved. In the case of the present embodiment, the red light LR is derived from the first light source 9 composed of a red solid light source, and the green light LG and the blue light LB are derived from the second light source 10 composed of a white lamp. The optical images of the green light LG and the blue light LB deviate from their original positions on the screen 31 due to changes over time.

  Here, unlike the configuration of the present embodiment, if the relay optical system 5 is inserted in either the optical path of green light or the optical path of blue light, as shown in FIG. The optical image YR (shown by a solid line) is in the original position on the screen 31, whereas the green light optical image YG (shown by a one-dot chain line) and the blue light optical image YB (shown by a one-dot chain line). Are reversed in the vertical and horizontal directions, the direction of displacement between the green light optical image YG and the blue light optical image YB is reversed, and the amount of displacement Z1 of the entire optical image is the original due to the positional deviation of the light source. It will be twice the amount of deviation. On the other hand, when the relay optical system 5 is inserted in the optical path of red light as in the configuration of the present embodiment, the optical image YG of green light and the optical image YB of blue light are not inverted. As shown in FIG. 4B, the deviation direction of the optical image YG of green light (indicated by a one-dot chain line) and the optical image YB of blue light (indicated by a one-dot chain line) coincide with each other. The amount Z2 is only the original amount of deviation caused by the positional deviation of the light source.

  As described above, according to the projector 1 of the present embodiment, even when the illumination unit 2 including the first light source 9 and the second light source 10 and the relay optical system 5 are employed, the light source due to changes over time. The color unevenness of the projected image due to the positional deviation of the light and the movement of the light emitting point (arc) can be reduced as much as possible. In the above description, it is assumed that the second light source 10 is misaligned, but if the first light source 9 emitting red light is misaligned or the light emission point is moved, the relay optical system 5 is used. No matter what optical path is inserted, the effect on color unevenness is not particularly changed. However, when comparing the first light source 9 using a solid light source and the second light source 10 using an ultra-high pressure mercury lamp or the like, the second light source 10 is more effective in positional deviation of the light source and movement of the light emitting point. From the viewpoint, the configuration of the present embodiment is very effective.

  In the case of a projector using a plurality of light sources, a configuration in which the plurality of light sources are arranged at positions separated from each other is conceivable. However, by arranging the plurality of light sources in one place as in the present embodiment. The light source cooling mechanism, the illumination integrating optical system including a pair of lens arrays, the polarization conversion optical system, and the like can be shared.

[Second Embodiment]
Hereinafter, a second embodiment of the present invention will be described with reference to FIG.
The basic configuration of the projector of the present embodiment is substantially the same as that of the first embodiment, but differs from the first embodiment in the configuration of the illumination unit and the point that a relay optical system is inserted in the optical path of blue light.
FIG. 5 is a schematic configuration diagram of the projector according to the present embodiment. In FIG. 5, the same reference numerals are given to the same components as those in FIG. 1 used in the first embodiment, and description thereof will be omitted.

  As shown in FIG. 5, the projector 41 according to the present embodiment includes an illumination unit 42, a color separation unit 43, liquid crystal light valves 4R, 4G, and 4B (light modulation elements), a relay optical system 5 (light transmission unit), and a cross dichroic. A prism 6 (color synthesis unit), a projection lens 7 (projection unit), and the like are roughly configured.

  The illumination unit 42 of this embodiment includes a first light source 44, a second light source 45, and a dichroic mirror 46. The first light source 44 is a blue laser light source that emits blue light. The second light source 45 includes an ultraviolet laser light source 47 that emits ultraviolet light, and a rotating fluorescent plate 49 on which a phosphor layer 48 is formed. The rotating fluorescent plate 49 includes a plate body 51 that can be rotated by a driving source 50 such as a motor, and a phosphor layer 48 formed on one surface of the plate body 51. The phosphor layer 48 emits yellow light using ultraviolet light as excitation light. Therefore, when the ultraviolet light emitted from the ultraviolet laser light source 47 is applied to the phosphor layer 48 of the rotating fluorescent plate 49, the ultraviolet light becomes excitation light, and yellow light (red light and green light is emitted from the phosphor layer 48). Containing light) is emitted.

  The blue light is reflected on the optical path of the blue light emitted from the first light source 44 and the yellow light emitted from the second light source 45, and the blue light and the yellow light are transmitted by transmitting the yellow light. A dichroic mirror 46 for synthesis is installed. Thereby, the blue light emitted from the first light source 44 and the yellow light emitted from the second light source 45 are combined by the dichroic mirror 46 to become white light. In the illuminating unit 42 of the present embodiment, since the first light source 44 and the second light source 45 are both laser light sources, the light source is excellent in responsiveness of the light source such as being capable of instantaneous lighting, and color light with high color purity is obtained. It is done. In addition, for green light and red light, a high-efficiency laser light source that matches the required wavelength has not been obtained. Therefore, by adopting the configuration of this embodiment, a part of the process of fluorescence emission is performed, but it is possible to obtain three color lights of blue light, green light, and red light using a laser light source.

  The configuration of the color separation unit 43 is the same as that of the first embodiment in that two dichroic mirrors 52 and 53 are used, but the spectral characteristics of the dichroic mirrors 52 and 53 are different from those of the first embodiment. . The dichroic mirror 52 transmits the red light LR and reflects the green light LG and the blue light LB. The dichroic mirror 53 transmits the blue light LB among the green light LG and the blue light LB reflected by the dichroic mirror 52, and reflects the green light LG. In the case of the present embodiment, the optical path length of the optical path of the red light LR and the optical path of the green light LG are equal, and the physical optical path length of the optical path of the blue light LB becomes longer. Therefore, the relay optical system 5 is inserted in the optical path of the blue light LB. Other configurations are the same as those of the first embodiment.

  In this embodiment, the blue light LB is derived from the first light source 44 composed of a blue laser light source, and the green light LG and the red light LR are derived from a second light source 45 composed of the ultraviolet laser light source 47 and the rotating fluorescent plate 49. doing. Since the relay optical system 5 is inserted in the optical path of the blue light LB, the optical image of the green light LG and the optical image of the red light LR are not reversed. For this reason, even if the positional deviation of the second light source 45 or the movement of the light emitting point occurs, the deviation directions of the green light image and the red light image coincide with each other, and the deviation amount of the entire optical image is the original amount. It does not expand beyond the amount of displacement. As described above, the projector 41 according to the present embodiment can achieve the same effect as that of the first embodiment in which unevenness in color of the projected image caused by the positional deviation of the light source due to the change with time can be reduced.

[Third Embodiment]
Hereinafter, a third embodiment of the present invention will be described with reference to FIG.
The basic configuration of the projector of this embodiment is substantially the same as that of the first embodiment, but the configuration of the illumination unit is different from that of the first embodiment. Moreover, the point which inserted the relay optical system in the optical path of blue light is the same as that of 2nd Embodiment.
FIG. 6 is a schematic configuration diagram of the projector according to the present embodiment. In FIG. 6, the same components as those in FIG. 1 used in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

  As shown in FIG. 6, the projector 61 of the present embodiment includes an illumination unit 62, a color separation unit 43, liquid crystal light valves 4R, 4G, and 4B (light modulation elements), a relay optical system 5 (light transmission unit), and a cross dichroic. A prism 6 (color synthesis unit), a projection lens 7 (projection unit), and the like are roughly configured.

  The illumination unit 62 according to the present embodiment includes a first light source 63 and a second light source 64. In this embodiment, the dichroic mirror 46 used in the second embodiment is unnecessary, and the configuration of the illumination unit 62 is further simplified. The first light source 63 is a blue laser light source that emits blue light. The second light source 64 is a rotating fluorescent plate 66 on which a phosphor layer 65 is formed. The rotating fluorescent plate 66 includes a plate body 51 that can be rotated by a driving source 50 such as a motor, and a phosphor layer 65 formed on one surface of the plate body 51. The schematic configuration of the rotating fluorescent plate 66 is the same as that of the second embodiment, but the characteristics of the phosphor layer 65 are different from those of the second embodiment.

  The phosphor layer 48 of the second embodiment emits yellow light using ultraviolet light as excitation light, whereas the phosphor layer 65 of this embodiment emits yellow light using blue light as excitation light. To do. Therefore, in the second embodiment, an ultraviolet laser light source 47 that emits ultraviolet light that functions only as excitation light is separately required, whereas in this embodiment, a laser light source that emits excitation light that does not contribute to display is used. It is unnecessary. That is, in this embodiment, a part of blue light emitted from the blue laser light source that is the first light source 63 is used as excitation light for the phosphor layer 65, and the rest is used for projection display. Therefore, the rotating fluorescent plate 66 has a function of transmitting blue light as a whole. Therefore, when the blue light emitted from the first light source 63 is applied to the phosphor layer 65 of the rotating phosphor plate 66, a part of the blue light becomes excitation light, and yellow light (red light and red light) is emitted from the phosphor layer 65. Light including green light) is emitted, and white light obtained by combining the remaining blue light and the emitted yellow light is emitted from the rotating fluorescent plate 66. For example, the ratio of blue light to yellow light can be adjusted by changing the thickness of the phosphor layer 65 or the concentration of the phosphor inside the phosphor layer 65. Other configurations are the same as those of the second embodiment.

  Also in the projector 61 of the present embodiment, the same effects as those of the first and second embodiments can be obtained, such that the color unevenness of the projected image due to the positional deviation of the light source due to a change with time can be reduced.

  In both the second and third embodiments, rotating fluorescent plates 49 and 66 are used as the second light sources 45 and 64. Therefore, it is conceivable that the rotation axis of the rotating fluorescent plates 49 and 66 is inclined with respect to the optical axis or the rotation is shaken due to a change with time. Here, since the rotating fluorescent plates 49 and 66 are flat plates, even when the rotating fluorescent plates 49 and 66 are inclined, the angle of the blue light emitted from the first light sources 44 and 63 that are laser light sources is the rotating fluorescent plates 49 and 66. Saved before and after. On the other hand, the yellow light emitted from the second light sources 45 and 64 has a Lambertian luminance distribution from the surface of the rotary fluorescent plates 49 and 66 because the phosphor inside the rotary fluorescent plates 49 and 66 is the light emitting point. And emits light. Therefore, when the rotating fluorescent plates 49 and 66 are inclined, the angle of the yellow light emitted from the second light sources 45 and 64 is also inclined, and the incident position on the subsequent element is shifted. Therefore, even if the rotation fluorescent plates 49 and 66 as described above are tilted or shaken, the light emitted from the first light sources 44 and 63 causes only a slight translation of the optical axis. The light emitted from the second light sources 45 and 64 affects the subsequent optical system as a large positional deviation of the light emitting point. From this viewpoint, the configuration of the present embodiment is very effective.

  In general, the optical path in which the relay optical system is inserted has a longer optical path length than the other optical paths, and the number of transmitting lenses is large. Optical loss increases. Since it is necessary to secure the amount of swallowing of the lens in order to suppress the vignetting of light, it is desirable to allocate light having a narrow light distribution to the optical path in which the relay optical system is inserted. Here, the laser light source has high directivity and a sharp luminance distribution, whereas the lamp such as a high-pressure mercury lamp and the phosphor have almost no directivity and a wide luminance distribution. . In the configurations of the first to third embodiments, the light from the first light sources 9, 44, and 63, which are laser light sources, is allotted to the optical path in which the relay optical system 5 is inserted. Therefore, the overall light loss is reduced, and the light use efficiency can be increased.

[Fourth Embodiment]
Hereinafter, a fourth embodiment of the present invention will be described with reference to FIG.
The basic configuration of the projector of this embodiment is substantially the same as that of the first embodiment, but differs from the first to third embodiments in that a relay optical system is inserted into two optical paths among the optical paths of three colored lights. .
FIG. 7 is a schematic configuration diagram of the projector according to the present embodiment. In FIG. 7, the same components as those in FIG. 1 used in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

  As shown in FIG. 7, the projector 71 according to the present embodiment includes a lighting unit 62, a color separation unit including a cross dichroic mirror 72, liquid crystal light valves 4R, 4G, and 4B (light modulation elements), and a relay optical system 5 (light transmission). Part), a cross dichroic prism 73 (color composition part), a projection lens 7 (projection part), and the like. The illumination unit 62 includes a first light source 63 composed of a blue laser light source and a second light source 64 composed of a rotating fluorescent plate 66, and the configuration thereof is the same as that of the third embodiment.

  In the case of this embodiment, the color separation unit is configured by a cross dichroic mirror 72 composed of two dichroic mirrors 74 and 75. The dichroic mirror 74 has characteristics of transmitting the blue light LB and reflecting the green light LG and the red light LR. The dichroic mirror 75 has characteristics of transmitting the blue light LB, reflecting the green light LG, and transmitting the red light LR. According to the cross dichroic mirror 72 in which these dichroic mirrors 74 and 75 are combined, it is possible to realize a configuration that transmits the blue light LB and reflects the green light LG and the red light LR in opposite directions. Thereby, the physical optical path lengths of the green light LG and the red light LR become longer than the physical optical path length of the blue light LB. For this reason, the relay optical system 5 is inserted into the optical path of the green light LG and the optical path of the red light LR, respectively. The configuration of the contents of the relay optical system 5 is the same as in the first to third embodiments.

  The cross dichroic prism 73 (color combining unit) is formed so that two dichroic surfaces are orthogonal to each other. The spectral characteristics of these dichroic surfaces are the same as that of the two dichroic mirrors 74 and 75 of the cross dichroic mirror 72. The same as the spectral characteristics.

  In the projector 71 of this embodiment, contrary to the projector 61 of the third embodiment, relay optics are provided on the optical paths of the green light LG and the red light LR generated by separating the light emitted from the second light source 64. While the system 5 is inserted, the relay optical system 5 is not inserted on the optical path of the blue light LB emitted from the first light source 63. Therefore, the optical image of the green light LG generated from the second light source 64 and the optical image of the red light LR are not in a reversal relationship. As a result, even if the position of the light emitting point is shifted in the second light source 64, the optical image of the green light LG and the red light LR can be shifted in one direction, and the superimposed optical images are opposite to each other. The amount of displacement does not double by shifting in the direction. As described above, also in the projector 71 of the present embodiment, it is possible to reduce the color unevenness of the projected image that accompanies changes with time and the like as much as possible.

The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, in the first embodiment, red light is derived from a first light source composed of a red solid light source, and green light and blue light are derived from a second light source composed of a white lamp. It was described as if the total amount was from either one of the light sources. However, for example, most of the red light is emitted from the first light source while a small amount of red light is included in the light emitted from the second light source, and most of the green light and blue light are included in the second light source. A small amount of green light and blue light may be included in the light emitted from the first light source while being emitted from the light source. In this case, although there is a possibility that the color unevenness slightly increases as compared with the case where the total amount of each color light is derived from one of the light sources, the effect can be sufficiently obtained as compared with the case where the present invention is not applied. . Further, the specific configuration, arrangement, shape, number, and the like of each optical element of the projector can be appropriately changed without being limited to the above embodiment. The combination of the color light emitted from the light source can be changed as appropriate.

  DESCRIPTION OF SYMBOLS 1,41,61,71 ... Projector, 3,43 ... Color separation part, 4R, 4G, 4B ... Liquid crystal light valve (1st-3rd light modulation element), 5 ... Relay optical system (light transmission part), 6, 73 ... cross dichroic prism (color synthesis unit), 7 ... projection lens (projection unit), 9, 44, 63 ... first light source, 10, 45, 64 ... second light source, 48, 65 ... phosphor Layers 49, 66... Rotating fluorescent plate, 72... Cross dichroic mirror (color separation unit).

Claims (6)

A first light source that emits light including first color light;
A second light source that emits light including second color light and third color light;
The light emitted from the first light source and the light emitted from the second light source are incident, and the incident light is converted into each of the first color light, the second color light, and the third color light. A color separation unit to be separated into,
A first light modulation element for modulating the first color light;
A second light modulation element for modulating the second color light;
A third light modulation element for modulating the third color light;
A light transmission part including a plurality of optical elements provided between the color separation part and the first light modulation element;
A color synthesizing unit that synthesizes each color light modulated by the first light modulation element, the second light modulation element, and the third light modulation element;
A projection unit that projects the light synthesized by the color synthesis unit onto a projection surface;
A projector characterized by comprising:   The projector according to claim 1, wherein a light distribution distribution of light emitted from the first light source is narrower than a light distribution distribution of light emitted from the second light source. A first light source that emits light including first color light;
A second light source that emits light including second color light and third color light;
The light emitted from the first light source and the light emitted from the second light source are incident, and the incident light is converted into each of the first color light, the second color light, and the third color light. A color separation unit to be separated into,
A first light modulation element for modulating the first color light;
A second light modulation element for modulating the second color light;
A third light modulation element for modulating the third color light;
A first light transmission unit including a plurality of optical elements provided between the color separation unit and the second light modulation element;
A second light transmission unit including a plurality of optical elements provided between the color separation unit and the third light modulation element;
A color synthesizing unit that synthesizes each color light modulated by the first light modulation element, the second light modulation element, and the third light modulation element;
A projection unit that projects the light synthesized by the color synthesis unit onto a projection surface;
A projector characterized by comprising:   The first light source is a laser light source, and the second light source is a phosphor that emits light using light emitted from the laser light source as excitation light. The projector according to item. The light including the first color light emitted from the first light source is blue light, and the light including the second color light and the third color light emitted from the second light source is yellow light. Yes,
The projector according to claim 4, wherein the phosphor transmits a part of the blue light emitted from the first light source.   The projector according to claim 4, wherein the phosphor includes a phosphor layer formed on one surface of a rotatable plate.

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