JP2005043705A - Projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a projector capable of enhancing color purity without complicating an optical system. <P>SOLUTION: The projector is equipped with a light source to emit light beams of wavelengths in all the region of a visible light beam, a lamp reflector to reflect the light beam generated by the light source, and the optical system to form an optical image by color-separating the light beam from the light source to three colors by a color separation element and then spatially modulating the color-separated light beam by an optical modulation element, and to enlarge and project the optical image to a screen with a projection lens. The color purity is enhanced by using the lamp reflector to remove an unnecessary light beam which deteriorates the color purity by transmitting the light beam in the specified partial band or a plurality of bands of the visible light beam radiated from the light source. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a projector that projects an image formed by modulating a light beam from a light source that emits light in a wavelength band of the entire visible light beam by an optical modulation element.

  A projector as shown in FIG. 3 is an example of a projector that spatially modulates illumination light with an optical modulation element based on a video signal, forms an optical image for projection, and projects the optical image on a screen by a projection lens. is there.

  The projector shown in FIG. 3 is one of the projectors manufactured by the present applicant, and includes a light source unit including a light source 1 and a lamp reflector 102 that reflects and collects light rays from the light source 1, a rod integrator 3, and a relay lens 4. , A reflecting mirror 5 and a reflecting prism 6 for deflecting an optical path, a filter 111 for removing unnecessary band rays, a color prism 7 which is a color separation element for dividing visible rays into three colors, and optical images by spatially modulating incident light. And an optical system having a projection lens 9 for projecting an optical image formed by the optical modulation element 8 onto the screen 10.

  According to this configuration, the visible light emitted from the light source 1 is reflected / condensed by the lamp reflector 102 and enters the rod integrator 3, and then sequentially, the relay lens 4, the reflection mirror 5, the filter 111, the reflection prism 6, and the color. It reaches the screen 10 via the prism 7, the optical modulation element 8, and the projection lens 9.

  As described above, in the projector that forms a projection optical image by spatially modulating light beams having a wavelength in the entire visible light range emitted from the light source 1 by the optical modulation element 8, the color of the image projected on the screen. Is a color formed by dividing the visible light from the light source 1 into a specific color within the optical system, for example, red, green, and blue light, removing unnecessary light, and then recombining them. is there.

  In order to divide visible light into specific colors, a color prism 7 with a dichroic coating is used. Specifically, the visible light is divided by the color prism 7 into red light, green light, and blue light which are the three primary colors of light. However, this only divides the light rays in the entire visible light range into three wavelength ranges, and the color purity is not good. In particular, green light contains a yellow wavelength, and the color purity is greatly inferior to other colors. For this reason, the image quality of the projected image is inferior.

  In order to increase the color purity of the projected image, it is necessary to increase the color purity of the color-separated light beam. For this reason, it is necessary to remove unnecessary band rays. For this purpose, in the projector shown in FIG. 3, specifically, a filter 111 that reflects and removes unnecessary band rays is disposed between the reflecting mirror 5 and the reflecting prism 6 in the optical system.

  In the configuration shown in FIG. 3 in which the filter 111 is provided in the optical system and the visible light in the unnecessary band is reflected / removed by the filter 111, the light reflected as the visible light in the unnecessary band by the filter 111 constitutes the optical system. Re-irradiating the optical component (for example, a lens, a reflection mirror, etc.) or the light source 1 causes an optical defect such as stray light. When the reflected light in the unnecessary band is locally irradiated in the optical system, the temperature of the optical system is locally increased, and the optical axis is shifted. When reflected light in the unnecessary band becomes reflected light to the light source 1, optical components between the lamp reflector 2 and the filter 111 and the light source 1 are deteriorated. Further, the provision of the filter 111 complicates the structure of the optical system and increases the cost, which is not economical.

  In addition, since the light source 1 has a different light spectrum depending on the type of the light source 1, it is necessary to change the unnecessary band and the reflection efficiency according to the desired color purity or the spectrum of the light source 1 used, and the filter 111 needs to be replaced. However, this replacement operation cannot be performed together with the light source change.

  The present invention eliminates the optical axis misalignment and deterioration due to the installation of the unnecessary band visible light removal filter as described above, and simplifies the structure of the optical system by reducing the number of components, downsizing and performance. The purpose is to provide a projector that is easy to replace the light source by improving the reliability and improving the color purity and image quality, being able to produce at low cost, and eliminating the need to align the light source and the lamp reflector at the light source replacement festival. It is said.

  In order to achieve the above object, the present invention provides a light source unit having a light source that emits light having a wavelength in the entire visible light range, a lamp reflector that reflects the light generated by the light source, and the light from the light source unit as a color separation element. An optical system that spatially modulates the color-separated light beam with an optical modulation element to form an optical image, and projects the optical image on a screen by a projection lens. Improve color purity by using a lamp reflector that selectively transmits visible light in a specific band or bands of visible light, that is, visible light in a wavelength band that degrades color purity. Color purity is improved by adopting a configuration in which only visible light obtained by removing unnecessary visible light with a lamp reflector is applied to the optical system. Here, visible light in an unnecessary band which is not desirable for improving color purity is, for example, a yellow light component, cyan which is an intermediate color component when separated into three primary color lights of red light, blue light and green light. It is a light component.

  Further, according to the present invention, in the above configuration, the lamp reflector is configured to be detachable from the light source, or the light source and the lamp reflector are integrated.

  When the lamp reflector is detachably provided to the light source, the lamp reflector can be changed according to the spectrum for each light source used. For this reason, by exchanging the lamp reflector, the wavelength band of the light beam to be removed as an unnecessary band can be freely adjusted, and there is an advantage that a desired color purity and color tone can be obtained.

  When the light source and the lamp reflector are integrated, it is not necessary to align the light source and the lamp reflector during the light source replacement, and the light source replacement is facilitated.

  Another configuration of the present invention is a method in which visible light in a wavelength band unnecessary for improving color purity is deteriorated and transmitted through a reflecting member provided in an optical system, for example, a reflecting mirror, instead of a lamp reflector. It is configured to remove from the formed light, or to remove visible light in a wavelength band unnecessary for improving the color purity by both the lamp reflector and the reflecting member in the optical system.

  In the present invention, micromirrors are arranged in a matrix in an optical modulation element used in an optical system for image formation, the inclination of each micromirror is controlled, and the reflection direction is controlled to modulate incident light. An optical modulation element, a reflective liquid crystal display element, a transmissive liquid crystal display element, or the like can be used.

  The present invention does not provide a filter for removing visible light in an unnecessary wavelength band that is not desirable for improving color purity in an optical system, and selectively allows visible light in an unnecessary wavelength band at a portion of a lamp reflector. Since the optical system is irradiated only with light that has been transmitted and removed to remove unnecessary visible light, the color purity of the light separated into three colors is high, and a high-quality image can be obtained. Further, since an unnecessary wavelength band elimination filter is not provided, the number of parts is reduced, the structure of the optical system is simple and small, and it can be produced at low cost. Further, there is a problem when the filter is provided, that is, stray light, local temperature rise, optical axis misalignment caused by re-irradiation of the light reflected by the filter to the optical components and the light source 1 constituting the optical system. As a result, the deterioration of the optical components is suppressed, and the reliability of the projector is improved.

  In the present invention, since the lamp reflector is detachable from the light source, the lamp reflector can be changed according to the spectrum for each light source used. As a result, by exchanging the lamp reflector, the wavelength band of the light beam to be removed as an unnecessary band can be freely adjusted, and the desired color purity and color tone can be easily obtained.

  In addition, the integration of the light source and the lamp reflector eliminates the need to align the light source and the lamp reflector during the light source replacement, making it easier to replace the light source.

  Furthermore, by adjusting the reflectance of the lamp reflector for each wavelength band, the light intensity in each wavelength band can be set to a desired light intensity, so that a desired color tone can be obtained.

  The projector according to the present invention does not include a filter for removing visible light in an unnecessary band that is not desirable for improving color purity in the optical system, and transmits visible light in an unnecessary band at a lamp reflector portion or in an optical path. It is configured to irradiate the color prism, which is a color separation element, with only the light that has been removed from the unnecessary visible rays by selectively transmitting and removing the reflection mirror that deflects the color purity of the image projected on the screen. It is an improvement. When removing visible light in a wavelength band that degrades color purity with a lamp reflector, adjusting the reflectance of the lamp reflector for each wavelength band allows the light intensity in each wavelength band to be the desired light intensity, A desired color tone can be obtained.

  Hereinafter, the projector of the present invention will be described in detail based on examples.

  Next, embodiments of the present invention will be described in detail with reference to the drawings.

  The configuration of this embodiment is shown in FIG. The projector according to this embodiment includes a light source unit and an optical system. The light source unit includes a light source 1 and a lamp reflector 2 that reflects and collects light rays from the light source 1. The optical system is arranged such that the incident end face comes to the condensing position of the lamp reflector 2, a rod integrator 3 that creates a plurality of light source images on the exit end face, a relay lens 4 that guides light to the optical modulation element 8, A reflection mirror 5 and a reflection prism 6 that turn back the optical path of the light source, a color separation element that includes a color prism 7 that separates incident light into three colors, and a light beam color-separated by the color prism 7 to spatially modulate the optical image. An optical modulation element 8 to be formed and a projection lens 9 for projecting an optical image formed by the optical modulation element 8 onto a screen 10 are provided.

  In this embodiment, a xenon lamp is used as the light source 1. In place of the xenon lamp, other types of light sources such as a high-intensity white light source such as a metal halide lamp, a high-pressure mercury lamp, and a halogen lamp can be used.

  The spectrum of the light source 1 varies depending on the gas component used in the light source 1. The visible light of a specific partial band or a plurality of bands of the spectrum is selectively transmitted by the lamp reflector 2 and incident by the rod integrator 3, thereby red light and green light separated by the color prism 7. The color purity of blue light is increased. Therefore, the lamp reflector 2 has a specific partial band of visible light or a plurality of visible light generated from the light source 1 for the purpose of improving the color purity of red light, green light, and blue light separated by the color prism 7. In order to selectively transmit visible light in the band and reflect visible light in the remaining band, that is, transmit visible light in an unnecessary band that degrades color purity, and visible light in a band necessary for improving color purity. The reflective surface is coated so as to reflect the light. In the present embodiment using a xenon lamp as the light source 1, in order to increase the color purity of green light, a light beam near 600 nm, which is a yellow light component, is transmitted through the lamp reflector 2 and visible light in other bands is reflected. The coating is applied to. At this time, it is more preferable that the reflectance of the lamp reflector 2 is adjusted for each wavelength band, and the light intensity in each wavelength band is coated so as to be a desired light intensity so as to obtain a desired color tone. The light beam reflected by the lamp reflector 2 is condensed on the rod integrator 3.

  The coating was composed of a multilayer film in which high refractive index layers and low refractive index layers were alternately laminated. For example, SiO 2 and Al 2 O 3 are used for the low refractive index layer, and TiO 2 and Ta 2 O 3 are used for the high refractive index layer.

  The lamp reflector of this embodiment is composed of a spheroid mirror, and is arranged such that the light emitting point of the light source 1 is located at one focal point and the end face of the rod integrator 3 is located at the other focal point. .

  Since the projector has a different spectrum when the desired color purity or gas of the light source 1 is different, it is necessary to change the band of the light beam transmitted through the lamp reflector 2 according to the color purity or the spectrum of the light source 1. For this reason, in this embodiment, the lamp reflector 2 is configured to be detachable and replaceable with respect to the light source 1.

  The positional relationship between the light source 1 and the lamp reflector 2 needs to be precisely aligned. For this reason, since it is easier to replace the light source when the light source 1 and the lamp reflector 2 are integrated, the light source 1 and the lamp reflector 2 may be integrated.

  The relay lens 4 is not a special configuration, and a commonly used one is used and is arranged so as to efficiently collect the light emitted from the rod integrator 3 on the optical modulation element 8.

  The reflection mirror 5 is arranged with a predetermined angle with respect to the optical axis so as to reflect the light beam that has passed through the relay lens 4 and to return the light path so that the light beam enters perpendicularly to the reflection prism. A prism may be used instead of the reflecting mirror.

  The reflecting prism 6 is configured by combining two wedge-shaped prisms, and reflects incident light on the joint surface of the prism and guides it to the optical modulation element 8 at a predetermined angle. The two wedge-shaped prisms are joined with a minute air gap so that total reflection of light occurs at the joint surface.

  The color prism 7 is configured by combining three wedge-shaped prisms. Each joint surface is coated to transmit and reflect a predetermined color. In the color prism 7, the incident light beam is separated into three color light beams of red, green, and blue. Here, the incoming light beam is only separated into three colors. Filtering such as removing unnecessary band light is not performed.

  In this embodiment, the optical modulation element 8 is a so-called DMD (digital micromirror) in which micromirrors are arranged in a matrix, the inclination of each micromirror is controlled, and the reflection direction is controlled to form an image. A device (registered trademark of Texas Instruments) was used. Instead of the DMD, a display element such as a liquid crystal light valve may be used as the optical modulation element 8.

  Next, the operation of this embodiment will be described.

  The light beam emitted from the light source 1 is reflected by the lamp reflector 2. The lamp reflector 2 is a spheroid mirror, and the reflected light beam is condensed toward the rod integrator 3. At this time, visible light in a wavelength band that deteriorates color purity, that is, visible light in a wavelength band that is not necessary for improving color purity, passes through the lamp reflector 2 and does not reach the rod integrator 3. Only visible light in the necessary wavelength band is reflected and reaches the rod integrator 3. The visible light in the unnecessary wavelength band is removed, and the light incident on the rod integrator 3 is internally reflected a plurality of times to form a plurality of light source images, and the light is distributed with a uniform light intensity distribution. It is emitted from. The light beam that has exited the rod integrator 3 is collected by the relay lens 4, reflected by the reflecting mirror 5, the optical path is turned back, and then enters the reflecting prism 6 perpendicularly. The light beam that has entered the reflecting prism 6 is totally reflected and deflected, enters the color prism 7, and is separated into light beams of three colors of red, green, and blue. The light beam that has passed through the color prism 7 irradiates the optical modulation element 8. The optical modulation element 8 reflects only light necessary for a predetermined image in the optical axis direction. The light beam reflected by the optical modulation element 8 passes through the color prism 7 again. At this time, the light beams separated into the three colors are combined to form a predetermined image and pass through the reflection prism 6 described above. Thereafter, the light beam is magnified and projected by the projection lens 9 to form an image on the screen 10.

  In this way, in this embodiment, a filter for removing visible light in an unnecessary band is not provided, and the visible light in an unnecessary band is removed at the lamp reflector 2 to remove unnecessary visible light. Only the optical system is irradiated. For this reason, the purity of the light separated into three colors of red light, green light, and blue light is high, a high-quality image is obtained, the number of parts is reduced, and the structure of the optical system is simplified. Further, there is a problem with the arrangement of the filter, that is, stray light, local temperature rise, optical axis misalignment caused by re-irradiation of the light reflected by the filter to the optical components and the light source 1 constituting the optical system. Deterioration of optical components is suppressed.

  In the present embodiment, the lamp reflector 2 is a spheroid mirror, but other shape concave mirrors such as a parabolic mirror and a spherical mirror may be used. For example, when a parabolic mirror is used, the reflected light beam from the lamp reflector 2 becomes a parallel light beam. Therefore, a condensing lens is provided between the light source 1 and the rod integrator 3 to collect the reflected light beam on the rod integrator 3. What is necessary is just to comprise so. As described above, when a lamp reflector having a shape other than the spheroid mirror is used, the optical system may be appropriately changed to a desired configuration in accordance with the lamp reflector.

  A projector according to this embodiment is shown in FIG. As can be seen from FIG. 2, this projector differs from the first embodiment in the light source portion, and the other optical system has the same configuration as the projector of the first embodiment. That is, the light source portion of this embodiment has a configuration in which a lamp house 21 in which the light source 1 and the lamp reflector 2 are integrated is arranged as shown in FIG. Since the operation of this embodiment is the same as that of the first embodiment, the description thereof is omitted.

  According to this configuration, if the light source 1 and the lamp reflector 2 are aligned in advance, and the light source 1 and the lamp reflector 2 are integrated into the lamp house 21, the lamp house can be replaced when the light source is replaced. When replacing the light source, it is not necessary to precisely align the optical axes of the light source 1 and the lamp reflector 2, and the operability when replacing the light source is superior to that of the first embodiment.

  The projector of the present embodiment is a projector having a configuration in which visible light in a band that adversely affects color purity improvement is transmitted and removed by the reflection mirror 5. This projector has substantially the same configuration as the projector of the first embodiment, and differs from the first embodiment in that the lamp reflector is the same as that of the conventional example, that is, the light in the entire wavelength band of visible light. The point is that a reflecting lamp reflector is used, and the point that the light in the visible light band unnecessary for improving the color purity is transmitted and removed by the reflecting mirror 5. For this reason, in this embodiment, instead of the reflection mirror 5 used in the first embodiment, visible light in a wavelength band that adversely affects the color purity improvement of visible light is transmitted, and visible light in a necessary wavelength band is transmitted. A reflection mirror having a reflection surface coated with a multilayer film is used so as to reflect only the light. Since the other configuration is the same as that of the first embodiment, description thereof is omitted.

  The operation of this embodiment is different from that of the first embodiment in that visible light in a wavelength band unnecessary for improving color purity is transmitted through the reflection mirror and removed. Others are the same as those in the first embodiment, and the description is omitted.

  In the present embodiment, the light source 1 and the lamp reflector are detachably provided (same configuration as in the first embodiment). However, as in the second embodiment, the light source unit includes the light source 1 and the lamp reflector in the lamp house. It is good also as a structure accommodated in 21 and integrated. Moreover, a configuration in which unnecessary band visible light is removed by both the lamp reflector and the reflection mirror may be adopted. In this case, there is an advantage that the band to be removed can be set finely.

  In any of the above embodiments, a reflective optical modulation element is used. However, a transmissive optical modulation element, for example, a transmissive liquid crystal display element may be used. In this case, it is necessary to provide a color combining optical element (for example, a cross prism or a dichroic mirror) between the projection lens and the optical modulation element.

  When a transmission type optical modulation element is used, the reflection mirror 5 and the reflection prism 6 that turn back the optical path are removed, and the relay lens 4, the color prism 7, the transmission type optical modulation element, the color synthesis optical element, and the projection lens 9 are arranged on a straight line. With this configuration, the optical system is simplified, and the configuration is preferable for downsizing.

  The optical system is not limited to the above embodiment. The optical system may have any configuration as long as the visible light is color-separated into three colors and then modulated by an optical modulation element to form an optical image and the optical image is projected onto a screen. For example, an optical system such as a configuration in which either one of the reflection mirror 5 or the reflection prism 6 in FIGS. 1 and 2 is removed, a configuration in which both the reflection mirror 5 and the reflection prism 6 are excluded, or the rod integrator 3 is replaced. Further, an optical system or the like having a configuration in which a fly-eye lens, a collimator lens, or the like is used to make the light intensity distribution of the light beam uniform may be used. Furthermore, for example, as shown in FIGS. 4 and 5, an optical system using a dichroic mirror as a color separation element and a color synthesis prism constituted by a cross prism as a color synthesis optical element may be used.

  Hereinafter, an example of a projector using an optical system different from the above-described embodiment will be described.

  FIG. 4 shows an example of a projector that uses a dichroic mirror as a color separation element and uses reflective liquid crystal display elements 8R, 8G, and 8B as optical modulation elements.

  The projector shown in FIG. 4 includes a reflective liquid crystal display element 8R for red light, a reflective liquid crystal display element 8G for green light, a reflective liquid crystal display element 8B for blue light, a white light source such as a metal halide lamp, and a collimator lens 43. , Dichroic mirrors 7RG and 7G, polarization beam splitters 46R, 46G, 46B, color synthesis prism 47, relay lens 4, reflection mirror 5, and projection lens 8.

  White light L emitted from the light source is reflected by the lamp reflector 2 and enters the collimator lens 43. At this time, visible light in a wavelength band that degrades the color purity passes through the lamp reflector 2 without being reflected, and is removed from the light incident on the collimator lens 43. The light rays incident on the collimator lens 43 are converted into parallel rays by the collimator lens 43, and then the red light ray R and the green light ray G are selectively reflected by the dichroic mirror 7RG, and the blue light ray B is selectively transmitted. The light beam RG reflected by the dichroic mirror 7RG enters the dichroic mirror 7G, where the green light beam G is selectively reflected and the red light beam R is selectively transmitted. The red light ray R transmitted through the dichroic mirror 7G is incident on the reflective liquid crystal display element 8R via the polarization beam splitter 46R. In the reflective liquid crystal display element 8R, the liquid crystal portion corresponding to each pixel is driven according to the red image signal, and modulates the incident red light beam R. The modulated red light beam R is reflected and enters the color synthesis prism 47 again through the polarization beam splitter 46R.

  The green light G reflected by the dichroic mirror 7G enters the reflective liquid crystal display element 8G via the polarization beam splitter 46G. In the reflective liquid crystal display element 8G, the liquid crystal portion corresponding to each pixel is driven according to the green image signal, and modulates the incident green light G. The modulated green light G is reflected and again enters the color combining prism 47 via the polarization beam splitter 46G.

  The blue light beam B transmitted through the dichroic mirror 7RG is incident on the reflective liquid crystal display element 8B through the relay lens 4, the reflective mirror 5, and the polarization beam splitter 46B. The relay lens 4 is provided in order to prevent light loss particularly for the blue light beam B having a long optical path, but may be omitted. Further, a relay lens may be provided in the optical path of the red light R and the green light G.

  In the reflective liquid crystal display element 8B, the liquid crystal portion corresponding to each pixel is driven according to the blue image signal, and modulates the incident blue light beam B. The modulated blue light beam B is reflected and enters the color combining prism 47 again through the polarization beam splitter 46B.

  The light rays R, G, and B of each color incident on the color combining prism 47 are selectively reflected by the dichroic mirror surface 47B, the blue light ray B is selectively reflected by the dichroic mirror surface 47R, and the green light ray G is reflected. Are transmitted without being reflected by any of the dichroic mirror surfaces 47B and 47R. The synthesized light beam is emitted from the color synthesis prism 47 and projected onto the screen 10 by the projection lens 9.

  FIG. 5 shows an example of a projector using a dichroic mirror as a color separation element and transmissive liquid crystal display elements 8r, 8g, and 8b as optical modulation elements.

  The projector shown in FIG. 5 includes a transmissive liquid crystal display element 8r for red light, a transmissive liquid crystal display element 8g for green light, a transmissive liquid crystal display element 8b for blue light, a white light source such as a metal halide lamp, and a collimator lens 43. The dichroic mirrors 7R and 7G, the color synthesis prism 47, the relay lens 4, the reflection mirror 5, and the projection lens 9 are provided.

  White light L emitted from the light source is reflected by the lamp reflector 2 and enters the collimator lens 43. At this time, visible light in a wavelength band that degrades the color purity is transmitted without being reflected, and is removed from the light incident on the collimator lens 43. The light beam incident on the collimator lens 43 is converted into a parallel light beam by the collimator lens 43, and then the red light beam R is selectively reflected by the dichroic mirror 7R, and the green light beam G and the blue light beam B are selectively transmitted. The red light ray R reflected by the dichroic mirror 7R is reflected by the reflection mirror 5 and enters the transmissive liquid crystal display element 8r. In the transmissive liquid crystal display element 8r, the liquid crystal portion corresponding to each pixel is driven according to the red image signal, and modulates the incident red light R. The modulated red light R passes through the transmissive liquid crystal display element 8 r and enters the color combining prism 47.

  The green light G and the blue light B transmitted through the dichroic mirror 7R enter the dichroic mirror 7G, the green light G is selectively reflected, and the blue light B is transmitted. The green light G reflected by the dichroic mirror 7G enters the transmissive liquid crystal display element 8g. In the transmissive liquid crystal display element 8g, the liquid crystal portion corresponding to each pixel is driven according to the green image signal, and modulates the incident green light G. The modulated green light G passes through the transmissive liquid crystal display element 8 g and enters the color synthesis prism 47.

  The blue light beam B transmitted through the dichroic mirror 7G is incident on the transmissive liquid crystal display element 8b through the reflection mirror 5, the relay lens 4, and the reflection mirror 5. The relay lens 4 is provided in order to prevent light loss particularly for the blue light beam B having a long optical path, but may be omitted. Further, a relay lens may be provided in the optical path of the red light R and the green light G.

  In the transmissive liquid crystal display element 8b, the liquid crystal portion corresponding to each pixel is driven according to the blue image signal, and modulates the incident blue light beam B. The modulated blue light B passes through the transmissive liquid crystal display element 8 r and enters the color synthesis prism 47.

  The light rays R, G, and B of each color incident on the color synthesis prism 47 are synthesized in the same manner as the projector shown in FIG. 4, emitted from the color synthesis prism 47, and projected onto the screen 10 by the projection lens 9.

  As described above, the present invention is an optical system having a configuration in which visible light is color-separated into three colors, then modulated with an optical modulation element to form an optical image, and the optical image is projected onto a screen. Any configuration of the optical system may be used.

  In any of the above embodiments, visible light in an unnecessary wavelength band is transmitted and removed without being reflected by the lamp reflector or reflecting mirror, but may be removed by being absorbed by the lamp reflector or reflecting mirror. However, if it is configured to be absorbed and removed, the temperature of the lamp reflector and the reflecting mirror rises, which is not a preferable configuration. A configuration in which light is transmitted and removed as in the embodiment is preferable.

  The present invention does not provide a filter for removing visible light in an unnecessary wavelength band that is not desirable for improving color purity in an optical system, and selectively allows visible light in an unnecessary wavelength band at a portion of a lamp reflector. Since the optical system is irradiated only with light that has been transmitted and removed to remove unnecessary visible light, the problem of providing a filter is suppressed, and the reliability of the projector is improved and the three colors are separated. The light has a high color purity and is useful for improving color reproducibility and images. Furthermore, it is useful for simplification, miniaturization and reduction of manufacturing cost of the projector due to a decrease in the number of parts.

It is a figure for demonstrating typically the structure of the projector which concerns on a 1st Example. It is a figure which illustrates typically the structure of the projector which concerns on the 2nd Example with which the light source and the lamp reflector were united. It is a figure which shows the structure of the conventional projector. It is a schematic diagram showing an example of a projector having an optical system using a dichroic mirror as a color separation element and a reflective liquid crystal display element as an optical modulation element. It is a schematic diagram showing an example of a projector having an optical system using a dichroic mirror as a color separation element and a transmissive liquid crystal display element as an optical modulation element.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light source 2 Lamp reflector 3 Rod integrator 4 Relay lens 5 Reflection mirror 6 Reflection prism 7 Color prism 7RG Dichroic mirror (for blue transmission)
7R Dichroic mirror (for red reflection)
7G dichroic mirror (for green reflection)
8 Optical modulation element 8r Transmission type liquid crystal display element (for red)
8g Transmission type liquid crystal display element (for green)
8b Transmission type liquid crystal display element (for blue)
8R reflective liquid crystal display element (for red)
8G reflective liquid crystal display (for green)
8B reflective liquid crystal display element (for blue)
9 Projection lens 10 Screen 102 Lamp reflector 111 Filter 21 Lamp house 43 Collimator lens 46R Polarization beam splitter 46G Polarization beam splitter 46B Polarization beam splitter 47 Color synthesis prism 47R Dichroic mirror surface 47B Dichroic mirror surface

Claims (7)

A light source that has a light source that emits light having a wavelength in the entire visible light range and a lamp reflector that reflects the light generated by the light source, and after color-separating the light from the light source into three colors using a color separation element, In the projector having an optical system that spatially modulates the color-separated light beam by an optical modulation element to form an optical image and enlarges and projects the optical image on a screen by a projection lens, the lamp reflector includes a visible light beam Among them, a projector that selectively transmits visible light in a specific wavelength band that degrades color purity and reflects visible light in other wavelength bands. A light source that has a light source that emits light having a wavelength in the entire visible light range, a lamp reflector that reflects the light generated by the light source, and a light separating unit that reflects the light from the light source by a reflecting member and deflects the optical path; An optical system that separates the three color beams into light beams, spatially modulates the color-separated light beams with an optical modulation element, forms an optical image, and magnifies and projects the optical image on a screen by a projection lens. In the projector having the above, the reflecting member may be configured to selectively transmit visible light in a specific wavelength band that degrades color purity out of visible light and remove it from visible light incident on the color separation element. Projector. A light source that has a light source that emits light having a wavelength in the entire visible light range, a lamp reflector that reflects the light generated by the light source, and a light separating unit that reflects the light from the light source by a reflecting member and deflects the optical path; An optical system that separates the three color beams into light beams, spatially modulates the color-separated light beams with an optical modulation element, forms an optical image, and magnifies and projects the optical image on a screen by a projection lens. In the projector having the above, the lamp reflector and the reflecting member are configured to selectively transmit visible light in a specific wavelength band that degrades color purity from visible light and remove it from the visible light incident on the color separation element. A projector characterized by that. 4. The projector according to claim 1, wherein the lamp reflector is detachably attached to the light source. 4. The projector according to claim 1, wherein the light source and the lamp reflector are integrated. 6. The projector according to claim 1, wherein visible light in a specific wavelength band that deteriorates color purity is a yellow light component. The optical modulation element is an optical modulation element in which minute mirrors are arranged in a matrix, the inclination of each minute mirror is controlled, and the reflection direction is controlled to modulate incident light. 6. The projector according to any one of 6.

Images