JP2006053430A - Projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a projector capable of preventing color unevenness in a projected image. <P>SOLUTION: A color separating optical apparatus 30 constituting the projector 1 is provided with a dichroic mirror 31 for separating a luminous flux emitted from a light source apparatus 10 into blue light and light in another color, and a dichroic mirror 32 for separating the light in another color into green light and red light. Regarding respective optical paths from the dichroic mirror 31 to respective liquid crystal panels 42B, 42G and 42R, the geometric optical path length of the 3rd optical path Rop to the liquid crystal panel 42R is set longer than that of the 1st optical path Bop to the liquid crystal panel 42B, and also, set longer than that of the 2nd optical path Gop to the liquid crystal panel 42G. The projector 1 is provided with an image forming optical apparatus 50 for separately forming an image in the arrangement positions of respective liquid crystal panels 42 without forming the image in a position other than the arrangement positions of respective liquid crystal panels 42 on respective optical paths Bop, Gop and Rop. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a projector.

Conventionally, a light source device, an integrator optical system that uniformly forms a light beam emitted from the light source device on an illuminated area, and a color that separates the light beam emitted from the integrator optical system into three color lights of red, green, and blue A separation optical device, three light modulation devices that respectively modulate three color lights according to image information, a color synthesis optical device that combines the respective color lights modulated by the three light modulation devices and emits an optical image, A projector including a projection optical device that magnifies and projects an emitted optical image is known (see, for example, Patent Document 1).
In the projector described in Patent Document 1, the geometrical optical path lengths of the red and green color lights are set to be the same, and the geometrical optical path of the blue light with respect to the geometrical optical path lengths of the red and green color lights. The length is set to be long. A light guide means is provided in the optical path of the blue light. Specifically, the light guide means includes an entrance side lens, a relay lens, and an exit side lens. The incident-side lens has a geometrical position approximately equal to the geometrical optical path length from the light source device to each of the red and green light modulators in the blue light path, that is, the position where the red and green light beams are imaged. A primary image that is disposed at a position corresponding to the optical path length and is formed by the integrator optical system is condensed on the relay lens. The relay lens re-images the light beam guided by the incident side lens to form a secondary image on the image forming region of the light modulator for blue light. The exit side lens converts the light flux from the relay lens into a light flux parallel to the central axis (principal ray).
By providing the light guiding means as described above, the geometrical optical path lengths of the three color lights of red, green, and blue are made substantially equal to prevent a decrease in the amount of light emitted from the light source device.

JP-A-8-234205 (FIG. 19)

  However, in the projector described in Patent Document 1, the light guide means is provided, so that the light image of the blue light on the screen is turned upside down. In a state where the light image of the blue light is inverted, if the light emitted from the light source has uneven in-plane intensity, the intensity distribution on the screen will be different for blue light and red and green light. There is a problem that uneven color tends to occur in the projected image.

  An object of the present invention is to provide a projector that can prevent the occurrence of uneven color in a projected image.

The projector according to the present invention is disposed on a central axis of a light source device and a light beam emitted from the light source device, and the light beam has an intermediate wavelength between a short wavelength side, a long wavelength side, the short wavelength side, and the long wavelength side. A projector comprising: a color separation optical device that separates three color lights having different wavelength regions; and three light modulation devices that are arranged on the central axis and modulate the three color lights according to image information. The color separation optical device separates the light beam emitted from the light source device into first color light having a wavelength region on the short wavelength side and color light having a wavelength region other than the wavelength region on the short wavelength side. Color light having a wavelength region other than the wavelength region on the short wavelength side separated by the first color separation unit, second color light having the wavelength region of the intermediate wavelength, and Long wavelength And a second color separation means for separating into a third color light having a wavelength region of the optical path, and each optical path from the first color separation means to each light modulation device is from the first color separation means to the The geometric optical path length of the first optical path leading to the first light modulation device corresponding to the first color light, and the second color light from the first color separation means through the second color separation means. Corresponds to the third color light from the first color separation means through the second color separation means with respect to the geometric optical path length of the second optical path leading to the second light modulation device corresponding to The geometrical optical path length of the third optical path leading to the third optical modulation device is set to be long, and the luminous flux emitted from the light source device is arranged at the position of the optical modulation device in the optical path. The image is formed at the position where each light modulation device is disposed without forming an image at any other position except for Characterized in that it includes an image optical system.
According to the present invention, since the projector includes the imaging optical device, the light beam emitted from the light source device is transmitted in each of the light modulation devices in the first optical path, the second optical path, and the third optical path. It is possible to form an image at the arrangement position of each light modulation device without forming an image at any position other than the arrangement position. For this reason, the intensity distribution on the screen of each color light can be set to be substantially the same without reversing the optical image at other positions in each optical path except for the positions where the respective light modulation devices are disposed. Therefore, it is possible to satisfactorily prevent the occurrence of color unevenness in the projected image on the screen.
In addition, the third optical path of the third color light having the wavelength region on the long wavelength side is set to have a geometric optical path length longer than the geometric optical path lengths of the first optical path and the second optical path. Therefore, for example, by forming an imaging optical device with a lens having a large chromatic dispersion compared to a lens that images light of each wavelength at the same position as used in a normal optical system, a light source It is possible to easily realize a configuration in which the light beam emitted from the apparatus is imaged at each position of the light modulation device without being imaged at any position other than the position at which the light modulation device is disposed in each light path. .

In the projector of the present invention, the geometric optical path length of the first optical path is r1, the geometric optical path length of the second optical path is r2, and the geometric optical path length of the third optical path is r3. In addition, r1 = r2 <r3 is set, and the imaging optical device is disposed on the front side of the optical path of the color separation optical device, and the first color light out of the light beams emitted from the light source device. Can be imaged in the vicinity of the arrangement position of the first light modulation device in a state dispersed in the central axis direction according to the wavelength region of the first color light, and the second color light and the third color light From the imaging distance of the first color light in the second optical path and the third optical path in a state of being dispersed in the central axis direction according to each wavelength region of the second color light and the third color light Can be imaged in the vicinity of each imaging position with a long imaging distance. And an optical element disposed in the second optical path, the imaging position of the second color light by the first optical element is changed, and the second color light is disposed in the second light modulation device. A second optical element capable of forming an image in the vicinity of the installation position, and only the first optical element or the first optical element on the rear side of the optical path of the second color separation means in the third optical path; The first optical element alone or the first optical element and the second optical element are disposed on the upstream side of the optical path from the imaging position of the third color light by both of the second optical elements. A third optical element that changes the imaging position of the third color light by both of them and enables the third color light to be imaged in the vicinity of the arrangement position of the third light modulation device; An optical path, a second stage side of the optical path of the second color separation means in the second optical path, and the third light In each of the second color separation means in the second stage of the optical path, respectively, and corrects the dispersion in the central axis direction according to each wavelength region of the three color lights by the first optical element, It is preferable to include a dispersion correction optical element that matches each imaging position of the color light with the position where the three light modulators are disposed.
Here, as the first optical element, a lens having a large chromatic dispersion can be employed as compared with a lens that forms an image of light of each wavelength at the same position as used in a normal optical system. As the second optical element, a lens having a positive refractive power can be adopted. The second optical element may be disposed in the second optical path, and may be disposed, for example, between the first color separation unit and the second color separation unit, or The second color separation means may be disposed on the downstream side of the optical path. As the third optical element, a lens having negative refractive power can be adopted. The dispersion correcting optical element can employ a so-called achromatic lens that corrects chromatic aberration.

In the present invention, the first optical element forms an image of the first color light in the vicinity of the position where the first light modulation device is provided, among the light beams emitted from the light source device. At this time, due to the chromatic dispersion of the first optical element, the imaging position of the first color light has a predetermined width corresponding to the wavelength region of the first color light. That is, the imaging position of the shortest wavelength and the imaging position of the longest wavelength of the first color light are different, and the imaging position can be widened by a difference between these imaging positions. In such a state, the size of the illumination area that illuminates the first light modulation device with the first color light has a predetermined width corresponding to the wavelength area of the first color light. That is, the size of the illumination region of the shortest wavelength and the size of the illumination region of the longest wavelength of the first color light are different, and the width of the illumination region can be increased by the difference between the sizes of these illumination regions. Therefore, in the entire illumination area of the first color light on the image forming area of the first light modulation device, the substantially central portion is a substantially uniform illuminance region, and the outer edge portion is a non-uniform illuminance region. Then, in order to make the optical image of the first color light formed by the first light modulation device clear, the size of the illumination region having substantially uniform illuminance is adjusted to the image formation region of the first light modulation device. In such a setting, the illumination area of the outer edge portion becomes a non-use area that is not used by the first light modulation device, and the light use efficiency of the first color light is reduced. Here, of the three dispersion correction optical elements, the dispersion correction optical element disposed in the first optical path is the width of the imaging position corresponding to the wavelength region of the first color light emitted from the first optical element. Is adjusted to be close to 0, and the imaging position of the first color light is made to coincide with the arrangement position of the first light modulator. For this reason, the entire illumination area of the first color light on the image forming area of the first light modulation device can be made to be a substantially uniform area of illuminance, and the illumination area of the first color light is the first light. It can be matched with the image forming area of the modulation device, and the light use efficiency of the first color light can be improved.
Accordingly, the first optical modulator and the dispersion correcting optical element allow the first light modulation device to form an image at a position other than the position where the first light modulation device is disposed in the first optical path. The first color light can be favorably imaged at the arrangement position.

In addition, due to chromatic dispersion by the first optical element, the imaging distance of the second color light is longer than the imaging distance of the first color light. That is, since the geometric optical path length r1 of the first optical path and the geometric optical path length r2 of the second optical path are set to be the same, the second color light is transmitted by the first optical element by the second optical element. The image is formed on the downstream side of the optical path with respect to the position of the light modulator. Here, the second optical element is changed so that the imaging distance of the second color light by the first optical element is shortened, and the second color light is coupled in the vicinity of the position where the second light modulator is disposed. Let me image. At this time, due to the chromatic dispersion of the first optical element, the imaging position of the second color light has a predetermined width corresponding to the wavelength region of the second color light in the same manner as the first color light described above. . Here, of the three dispersion correction optical elements, the dispersion correction optical element disposed in the second optical path is similar to the dispersion correction optical element described above, and the second color light emitted from the first optical element. The imaging position width corresponding to the wavelength region is corrected so as to approach 0, and the imaging position of the second color light is matched with the arrangement position of the second light modulation device. For this reason, as with the first color light described above, the entire illumination area of the second color light on the image forming area of the second light modulation device can be made to be a substantially uniform area of illuminance, and the second The color light illumination area can be matched with the image forming area of the second light modulation device, and the light use efficiency of the second color light can be improved.
Therefore, the first optical element, the second optical element, and the dispersion correction optical element are used to form an image at a position other than the position where the second light modulation device is disposed in the second optical path. The second color light can be favorably imaged at the arrangement position of the second light modulation device.

Further, the third optical element is a first optical element alone or both of the first optical element and the second optical element on the downstream side of the second color separation means in the third optical path. 3 is disposed on the upstream side of the optical path with respect to the image forming position of the color light 3. Therefore, the third color light is changed so that the imaging distance of the third color light by only the first optical element or by both the first optical element and the second optical element is increased. An image can be formed in the vicinity of the arrangement position of the modulation device. At this time, due to the chromatic dispersion of the first optical element, the imaging position of the third color light has a predetermined width corresponding to the wavelength region of the third color light in the same manner as the first color light and the second color light described above. Will have. Here, of the three dispersion correction optical elements, the dispersion correction optical element disposed in the third optical path is similar to the dispersion correction optical element described above, and the third color light emitted from the first optical element. The imaging position width corresponding to the wavelength region is corrected so as to approach 0, and the imaging position of the third color light is matched with the arrangement position of the third light modulation device. For this reason, as in the first color light and the second color light described above, the entire illumination area of the third color light on the image forming area of the third light modulation device is made to be a substantially uniform area of illuminance. In addition, the illumination area of the third color light can be matched with the image forming area of the third light modulation device, and the light use efficiency of the third color light can be improved.
Accordingly, in the third optical path, the third light can be obtained by using only the first optical element or both the first optical element and the second optical element, the third optical element, and the dispersion correcting optical element. The third color light can be favorably imaged at the arrangement position of the third light modulation device without forming an image at other positions except the arrangement position of the modulation device.

  As described above, an imaging optical device including the first optical element, the second optical element, the third optical element, and the three dispersion correction optical elements is provided in place of the conventional relay optical system. By doing so, the light beam emitted from the light source device is imaged in the first optical path, the second optical path, and the third optical path at positions other than the arrangement positions of the respective light modulation devices. Each of the light modulators can be well imaged at the position where the light modulation device is provided, and when using a relay optical system, the light emitted from the light source does not cause uneven color due to in-plane intensity unevenness. A good projection image can be formed.

In the projector according to the aspect of the invention, the second optical element is disposed on the downstream side of the second color separation unit in the second optical path, and the second optical element in the second optical path among the dispersion correction optical elements. It is preferable that the second color separation unit is configured integrally with a dispersion correction optical element disposed on the downstream side of the optical path.
According to the present invention, the second optical element and the dispersion correction optical element arranged in the second optical path are integrally configured as described above, so that the second optical element and the dispersion correction are provided in the projector. The member that supports the optical element can be shared, and the number of parts can be reduced. Therefore, it is possible to reduce the size and weight of the projector.

In the projector according to the aspect of the invention, the third optical element may be integrated with a dispersion correction optical element disposed on the downstream side of the second color separation unit in the third optical path of the dispersion correction optical element. It is preferable that it is comprised.
According to the present invention, the third optical element and the dispersion correction optical element arranged in the third optical path are integrally configured as described above, so that the third optical element and the dispersion correction are provided in the projector. The member that supports the optical element can be shared, and the number of parts can be reduced. Therefore, it is possible to reduce the size and weight of the projector.

In the projector of the present invention, the geometric optical path length of the first optical path is r1, the geometric optical path length of the second optical path is r2, and the geometric optical path length of the third optical path is r3. In addition, r1 = r2 <r3 is set, and the imaging optical device is disposed on the front side of the optical path of the color separation optical device, and the first color light out of the light beams emitted from the light source device. And a first optical element that forms an image of the second color light on the respective positions of the first light modulation device and the second light modulation device, and the second color in the third optical path. An imaging position of the third color light by the first optical element is disposed on the upstream side of the separation path of the third color light by the first optical element on the downstream side of the optical path. And the third color light is imaged at an arrangement position of the third light modulation device. Preferably comprises 3 of the optical element.
Here, as the first optical element, a lens with small chromatic dispersion that forms an image of light of each wavelength at the same position as used in a normal optical system can be employed. As the third optical element, it is possible to employ a lens having a small chromatic dispersion and a negative refractive power that forms an image of light of each wavelength at the same position as used in a normal optical system.
In the present invention, since the geometric optical path length r1 of the first optical path and the geometric optical path length r2 of the second optical path are set to be the same, a lens having small chromatic dispersion is adopted as the first optical element. As a result, the first color light and the second color light can be imaged at the respective arrangement positions of the first light modulation device and the second light modulation device.
The third optical element is disposed on the optical path downstream side of the second color separation means in the third optical path and on the optical path upstream side with respect to the imaging position of the third color light by the first optical element. . For this reason, it can change so that the imaging distance of the 3rd color light by a 1st optical element may become long, and can image 3rd color light on the arrangement | positioning position of a 3rd light modulation apparatus.
Therefore, in place of the conventional relay optical system, an imaging optical device composed of the first optical element and the third optical element is disposed, so that the light beam emitted from the light source device can be transmitted to the first optical path. In each of the second optical path and the third optical path, an image is formed well at each light modulation device arrangement position without being imaged at any position other than the light modulation device arrangement position. Can do.
In addition, since the imaging optical device can be composed of only the first optical element and the third optical element, the number of members that support the components of the imaging optical device in the projector is reduced, and the projector can be reduced in size and weight. It becomes feasible.

In the projector according to the aspect of the invention, the geometric optical path length of the first optical path is r1, the geometric optical path length of the second optical path is r2, and the geometric optical path length of the third optical path is r3. And the imaging optical device is disposed on the upstream side of the optical path of the color separation optical device, and the first color light out of the light beams emitted from the light source device is set to r1 <r2 <r3. Can be imaged in the vicinity of the arrangement position of the first light modulation device in a state dispersed in the central axis direction in accordance with the wavelength region of the first color light, and the second color light is converted into the second color light. The third color light can be imaged in the vicinity of the arrangement position of the second light modulation device in a state dispersed in the central axis direction according to the wavelength region of the third color light, It is possible to form an image near the arrangement position of the third light modulation device in a state dispersed in the central axis direction. The first optical element, the first optical path, the optical path rear side of the second color separation means in the second optical path, and the optical path rear side of the second color separation means in the third optical path. And each of the three optical components is corrected by correcting the dispersion in the central axis direction according to the wavelength regions of the three colored lights by the first optical element. It is preferable to include a dispersion correction optical element that matches each position of the apparatus.
Here, as the first optical element, a lens having a large chromatic dispersion can be employed as compared with a lens that forms an image of light of each wavelength at the same position as used in a normal optical system. As the dispersion correction optical element, a so-called achromatic lens that corrects chromatic aberration can be employed.

According to the present invention, when a lens having a large chromatic dispersion is employed as the first optical element, the imaging distance of each color light can be changed according to the wavelength region of each color light. That is, each imaging distance can be changed so as to increase in the order of the imaging distance of the first color light, the imaging distance of the second color light, and the imaging distance of the third color light. Further, the geometric optical path length r1 of the first optical path, the geometric optical path length r2 of the second optical path, and the geometric optical path length r3 of the third optical path are set to satisfy the relationship r1 <r2 <r3. Therefore, if the imaging distance of each color light by the first optical element is set in accordance with the geometric optical path length of each optical path, each color light is arranged by each first light element by the first optical element. Each can be imaged near the position. At this time, due to the chromatic dispersion of the first optical element, the image formation position of each color light has a predetermined width corresponding to the wavelength region of each color light, as described above. Here, similarly to the above, the three dispersion correction optical elements respectively correct the widths of the imaging positions corresponding to the wavelength regions of the respective color lights emitted from the first optical element so as to approach 0, and The image forming positions are matched with the arrangement positions of the respective light modulation devices. For this reason, as described above, the entire illumination area of each color light on the image forming area of each light modulation device can be set to a substantially uniform area of illuminance, and the illumination area of each color light can be set to each light modulation device. Therefore, it is possible to improve the light use efficiency of each color light.
As described above, by replacing the conventional relay optical system with the imaging optical device including the first optical element and the three dispersion correction optical elements, the light beam emitted from the light source device is In each of the first optical path, the second optical path, and the third optical path, each of the optical modulators is satisfactorily arranged without forming an image at any position other than the optical modulators. An image can be formed, and when a relay optical system is used, a good projection image can be formed without causing color unevenness caused by in-plane intensity unevenness in the light emitted from the light source.

In the projector according to the aspect of the invention, the imaging optical device is disposed in the second optical path, changes an imaging position of the second color light by the first optical element, and is combined with the first optical element. A second optical element capable of forming an image in the vicinity of an arrangement position of the second light modulation device in a state in which the second color light is dispersed in the central axis direction according to a wavelength region of the second color light; It is preferable to provide.
Here, as the second optical element, as long as the second color light can be imaged in the vicinity of the arrangement position of the second light modulation device together with the first optical element, a lens having a positive refractive power, or Any lens having a negative refractive power may be adopted. The second optical element may be disposed in the second optical path, and may be disposed, for example, between the first color separation unit and the second color separation unit, or The second color separation means may be disposed on the downstream side of the optical path.
According to the present invention, since the imaging optical device includes the second optical element, as compared with a configuration in which each color light is imaged in the vicinity of the arrangement position of each light modulation device using only the first optical element. For example, when the second optical element is disposed on the second stage of the second color separation means in the second optical path, the second color light is disposed in the vicinity of the position where the second light modulation device is disposed. It becomes the structure which makes it easy to image. In addition, for example, when the second optical element is disposed between the first color separation unit and the second color separation unit in the second optical path, the second color light and the third color light are used. Is easily imaged in the vicinity of the arrangement position of the second light modulation device and the third light modulation device. Therefore, the degree of freedom in designing the projector is improved, and the projector can be optimized according to the required performance.

In the projector according to the aspect of the invention, the imaging optical device may be disposed on the downstream side of the second color separation unit in the third optical path, and the third color light may be imaged by the first optical element. The position of the third light modulator is changed in a state where the third color light is dispersed in the central axis direction according to the wavelength region of the third color light together with the first optical element. It is preferable to include a third optical element capable of forming an image.
Here, as the third optical element, a lens having a positive refractive power, as long as the third color light can be imaged in the vicinity of the arrangement position of the third light modulation device together with the first optical element, or Any lens having negative refractive power may be used.
According to the present invention, since the imaging optical device includes the third optical element, compared with a configuration in which each color light is imaged in the vicinity of the arrangement position of each light modulation device using only the first optical element. Thus, the third color light is easily imaged in the vicinity of the position where the third light modulator is disposed. Therefore, the degree of freedom in designing the projector is improved, and the projector can be optimized according to the required performance.

In the projector of the present invention, the geometric optical path length of the first optical path is r1, the geometric optical path length of the second optical path is r2, and the geometric optical path length of the third optical path is r3. And the imaging optical device is disposed on the upstream side of the optical path of the color separation optical device, and the first color light out of the light beams emitted from the light source device is set to r1 <r2 <r3. A first optical element that forms an image at a position where the first light modulation device is disposed, and an optical path upstream side of the second color light by the first optical element in the second optical path. Among the color lights having the wavelength region on the short wavelength side that are emitted from the first optical element and pass through the first color separation means, the second color light is converted into the wavelength of the second color light. Disposition position of the second light modulation device in a state dispersed in the central axis direction according to a region An image can be formed in the vicinity, and the third color light can be imaged in the vicinity of the arrangement position of the third light modulation device in a state where the third color light is dispersed in the central axis direction according to the wavelength region of the third color light. A second optical element that is disposed on the second optical path downstream side of the second color separation means in the second optical path, and the second optical path downstream side of the second color separation means in the third optical path, The dispersion in the central axis direction according to each wavelength region of the second color light and the third color light by the second optical element is respectively corrected, and each combination of the second color light and the third color light is corrected. It is preferable to include a dispersion correction optical element that matches an image position to each arrangement position of the second light modulation device and the third light modulation device.
Here, as the first optical element, a lens with small chromatic dispersion that forms an image of light of each wavelength at the same position as used in a normal optical system can be employed. As the second optical element, a lens having a large chromatic dispersion and a negative refracting power can be employed as compared with a lens that forms an image of light of each wavelength at the same position as used in a normal optical system. The dispersion correcting optical element can employ a so-called achromatic lens that corrects chromatic aberration.

In the present invention, the arrangement position of the first light modulation device is formed by the first optical element in the first optical path without forming an image at any position other than the arrangement position of the first light modulation device. Thus, the first color light can be imaged.
In addition, since the geometric optical path length r1 of the first optical path and the geometric optical path length r2 of the second optical path are set to have a relationship of r1 <r2, the first optical element emits the first color light. When the image is formed at the position where the first light modulator is disposed, the second color light is imaged on the upstream side of the light path of the position where the second light modulator is disposed. Here, since the second optical element is disposed on the optical path preceding stage from the imaging position of the second color light by the first optical element in the second optical path, the second optical element by the first optical element The second color light can be imaged in the vicinity of the arrangement position of the second light modulator by changing the color light imaging distance to be longer. At this time, due to the chromatic dispersion of the second optical element, the imaging position of the second color light has a predetermined width corresponding to the wavelength region of the second color light, as described above. Here, of the two dispersion correction optical elements, the dispersion correction optical element disposed in the second optical path is connected in accordance with the wavelength region of the second color light emitted from the second optical element, as described above. The width of the image position is corrected so as to approach 0, and the image forming position of the second color light is matched with the arrangement position of the second light modulation device. For this reason, in the same manner as described above, the entire illumination area of the second color light on the image forming area of the second light modulation device can be made to be a substantially uniform area of illuminance, and the illumination area of the second color light can be changed. It can be matched with the image forming area of the second light modulation device, and the light use efficiency of the second color light can be improved.
Therefore, the first optical element, the second optical element, and the dispersion correction optical element are used to form an image at a position other than the position where the second light modulation device is disposed in the second optical path. The second color light can be favorably imaged at the arrangement position of the second light modulation device.

Further, due to the chromatic dispersion of the second optical element, the image formation distances of the second color light and the third color light are increased in the order of the image formation distance of the second color light and the image formation distance of the third color light. Can be changed. In addition, since the geometric optical path length r2 of the second optical path and the geometric optical path length r3 of the third optical path are set in a relationship of r2 <r3, the first optical element and the second optical element If the image forming distances of the second color light and the third color light by and the geometric optical path lengths of the second light path and the third light path are set to be substantially the same, the first optical element and With the second optical element, the second color light and the third color light can be imaged in the vicinity of the arrangement positions of the second light modulation device and the third light modulation device, respectively. At this time, due to the chromatic dispersion of the second optical element, the imaging position of the third color light has a predetermined width corresponding to the wavelength region of the third color light in the same manner as described above. Here, of the two dispersion correction optical elements, the dispersion correction optical element disposed in the third optical path is connected according to the wavelength region of the third color light emitted from the second optical element, as described above. The width of the image position is corrected so as to approach 0, and the image forming position of the third color light is matched with the arrangement position of the third light modulation device. For this reason, in the same manner as described above, the entire illumination area of the third color light on the image forming area of the third light modulation device can be made to be a substantially uniform area of illuminance, and the illumination area of the third color light can be changed. It can be matched with the image forming area of the third light modulation device, and the light use efficiency of the third color light can be improved.
Therefore, the first optical element, the second optical element, and the dispersion correction optical element are used to form an image at a position other than the position where the third light modulation device is disposed in the third optical path. In addition, the third color light can be favorably imaged at the arrangement position of the third light modulation device.

  As described above, by replacing the conventional relay optical system with the imaging optical device including the first optical element, the second optical element, and the two dispersion correction optical elements, the light source device is provided. The light beams emitted from the optical modulators are formed in the first optical path, the second optical path, and the third optical path without forming images at other positions except for the arrangement positions of the optical modulators. It is possible to form an image well at each installation position, and when a relay optical system is used, a good projection image can be obtained without causing uneven color due to uneven intensity in the surface of the light emitted from the light source. Can be formed.

In the projector according to the aspect of the invention, the imaging optical device may be disposed on the optical path rear side of the second color separation unit in the third optical path, and the first optical element and the second optical element may The imaging position of the third color light is changed, and the third color light is dispersed in the central axis direction according to the wavelength region of the third color light together with the first optical element and the second optical element. It is preferable that a third optical element that can form an image in the vicinity of the position where the third light modulation device is disposed is provided.
Here, as the third optical element, if the third color light can be imaged in the vicinity of the arrangement position of the third light modulation device together with the first optical element and the second optical element, positive refraction is possible. Either a lens having power or a lens having negative refractive power may be adopted.
According to the present invention, since the imaging optical device includes the third optical element, the second color light and the third color light are converted to the second light modulation device and the third color light using the second optical element. Compared to the configuration in which the light is imaged near the position where the light modulator is disposed, the third color light is easily imaged near the position where the third light modulator is disposed. Therefore, the degree of freedom in designing the projector is improved, and the projector can be optimized according to the required performance.

In the projector according to the aspect of the invention, the geometric optical path length of the first optical path is r1, the geometric optical path length of the second optical path is r2, and the geometric optical path length of the third optical path is r3. And the imaging optical device is disposed on the upstream side of the optical path of the color separation optical device, and the first color light among the light beams emitted from the light source device is set to r1 <r2 <r3. A first optical element that forms an image at an arrangement position of the first light modulation device, and an optical path preceding the image forming position of the second color light by the first optical element in the second optical path A second optical system configured to change an imaging position of the second color light by the first optical element and form an image of the second color light at an installation position of the second light modulation device. And the first optical element on the downstream side of the optical path of the second color separation means in the third optical path. And an imaging position of the third color light by the first optical element and the second optical element, which is disposed on the optical path upstream side of the imaging position of the third color light by the second optical element. And a third optical element that forms an image of the third color light at an arrangement position of the third light modulation device.
Here, as the first optical element, a lens with small chromatic dispersion that forms an image of light of each wavelength at the same position as used in a normal optical system can be employed. As the second optical element, it is possible to employ a lens having a small chromatic dispersion and a negative refractive power that forms an image of light of each wavelength at the same position as used in a normal optical system. As the third optical element, it is possible to employ a lens having a small chromatic dispersion and a negative refractive power that forms an image of light of each wavelength at the same position as used in a normal optical system.

In the present invention, the arrangement position of the first light modulation device is formed by the first optical element in the first optical path without forming an image at any position other than the arrangement position of the first light modulation device. Thus, the first color light can be imaged.
In addition, since the geometric optical path length r1 of the first optical path and the geometric optical path length r2 of the second optical path are set to have a relationship of r1 <r2, the first optical element emits the first color light. When the image is formed at the position where the first light modulator is disposed, the second color light is imaged on the upstream side of the light path of the position where the second light modulator is disposed. Here, since the second optical element is disposed on the optical path preceding stage from the imaging position of the second color light by the first optical element in the second optical path, the second optical element by the first optical element The second color light can be imaged at the arrangement position of the second light modulation device by changing the image formation distance of the color light to be long.
Therefore, the second optical element causes the second light element to form the second light in the second optical path without forming an image at a position other than the arrangement position of the second light modulation device. The second color light can be imaged at the arrangement position of the modulation device.

Further, since the geometric optical path length r2 of the second optical path and the geometric optical path length r3 of the third optical path are set in a relationship of r2 <r3, the first optical element and the second optical element When the second color light is imaged at the arrangement position of the second light modulation device, the third color light is imaged on the upstream side of the optical path at the arrangement position of the third light modulation device. . Here, since the third optical element is disposed on the optical path preceding stage from the imaging position of the third color light by the first optical element and the second optical element in the third optical path, By changing the imaging distance of the third color light by the optical element and the second optical element to be long, the third color light can be imaged at the arrangement position of the third light modulation device.
Therefore, the first optical element, the second optical element, and the third optical element form an image at a position other than the position where the third light modulation device is disposed in the third optical path. The third color light can be imaged at the position where the third light modulation device is disposed.

  As described above, instead of the conventional relay optical system, an image forming optical device composed of the first optical element, the second optical element, and the third optical element is provided, so that the light source device can The emitted light beam is not imaged in the first optical path, the second optical path, and the third optical path at positions other than the arrangement positions of the respective optical modulation apparatuses, and the arrangement of the respective optical modulation apparatuses is performed. Each image can be formed at the set position.

[First embodiment]
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, a first embodiment of the invention will be described with reference to the drawings.
[Configuration of projector]
FIG. 1 is a plan view schematically showing the projector 1 in the first embodiment.
The projector 1 modulates the light beam emitted from the light source according to the image information to form an optical image, and enlarges and projects it on the screen. As shown in FIG. 1, the projector 1 includes an exterior case 2, an optical device 3, and a projection lens 4.
Although not shown in FIG. 1, in the exterior case 2, in a space other than the optical device 3 and the projection lens 4, a cooling unit that cools the inside of the projector 1 and power to each component in the projector 1 are supplied. It is assumed that a power supply unit to be supplied, a control board for driving and controlling the optical device 3, the cooling unit, and the like are arranged.

The exterior case 2 is made of synthetic resin or the like, and is formed in a substantially rectangular parallelepiped shape that accommodates and arranges the optical device 3 and the projection lens 4 inside. Although not shown, the outer case 2 includes an upper case that configures the top, front, back, and side surfaces of the projector 1, and a lower that configures the bottom, front, side, and back surfaces of the projector 1, respectively. The upper case and the lower case are fixed to each other with screws or the like.
The exterior case 2 is not limited to being made of synthetic resin, but may be formed of other materials, for example, metal.

The optical device 3 optically processes a light beam emitted from a light source to form an optical image (color image) corresponding to image information. As shown in FIG. 1, the optical device 3 has a substantially L shape in plan view that extends along the back surface of the outer case 2 and extends along the side surface of the outer case 2. The detailed configuration of the optical device 3 will be described later.
The projection lens 4 is configured as a combined lens in which a plurality of lenses are combined. The projection lens 4 enlarges and projects an optical image (color image) formed by the optical device 3 on a screen (not shown).

[Configuration of optical device]
As shown in FIG. 1, the optical device 3 includes a light source device 10, an illumination optical device 20, a color separation optical device 30, an electro-optical device 40, and an imaging optical device 50. The optical elements constituting the device 20, the color separation optical device 30, and the imaging optical device 50 are accommodated in an optical component housing 60 in which a predetermined illumination optical axis A is set.
The light source device 10 illuminates the electro-optical device 40 by emitting light beams emitted from the light source lamp in a certain direction. As shown in FIG. 1, the light source device 10 includes a light source lamp 11, an ellipsoidal reflector 12, and a parallelizing concave lens 13. Then, the light beam emitted from the light source lamp 11 is emitted as focused light to the front side of the apparatus by the ellipsoidal reflector 12, collimated by the parallelizing concave lens 13, and emitted to the illumination optical apparatus 20. Here, as the light source lamp 11, a halogen lamp, a metal halide lamp, or a high-pressure mercury lamp is frequently used. Further, instead of the ellipsoidal reflector 12 and the collimating concave lens 13, a parabolic reflector may be used. The central axis of the light beam emitted from the light source device 10 coincides with the illumination optical axis A.

The illumination optical device 20 makes the intensity distribution of the light beam emitted from the light source device 10 substantially uniform in a plane orthogonal to the illumination optical axis A. As shown in FIG. 1, the illumination optical device 20 includes a first lens array 21, a second lens array 22, and a polarization conversion element 23.
The first lens array 21 divides the light beam emitted from the light source lamp 11 into a plurality of partial light beams, and includes a plurality of small lenses arranged in a matrix in a plane orthogonal to the illumination optical axis A. Configured.
The second lens array 22 is an optical element that condenses a plurality of partial light beams divided by the first lens array 21 described above, and a surface orthogonal to the illumination optical axis A as in the first lens array 21. A plurality of small lenses are arranged in a matrix.

The polarization conversion element 23 aligns the polarization directions of the partial light beams divided by the first lens array 21 with linear polarization in substantially one direction.
Although not shown, the polarization conversion element 23 has a configuration in which polarization separation films and reflection mirrors that are inclined with respect to the illumination optical axis A are alternately arranged. The polarization separation film transmits one polarized light beam among the P-polarized light beam and S-polarized light beam included in each partial light beam, and reflects the other polarized light beam. The other polarized light beam reflected is bent by the reflecting mirror and emitted in the emission direction of the one polarized light beam, that is, the direction along the illumination optical axis A. Any of the emitted polarized light beams is polarized and converted by a phase difference plate provided on the light beam exit surface of the polarization conversion element 23, and the polarization directions of almost all the polarized light beams are aligned. By using such a polarization conversion element 23, it is possible to align the light beam emitted from the light source lamp 11 with a polarized light beam in approximately one direction, and therefore, the utilization efficiency of the light source light used in the electro-optical device 40 can be improved. .

The color separation optical device 30 converts a plurality of partial light beams emitted from the illumination optical device 20 into three color lights having different wavelength regions of the short wavelength side, the long wavelength side, the short wavelength side, and the intermediate wavelength of the long wavelength side. To separate. As shown in FIG. 1, the color separation optical device 30 includes a dichroic mirror 31 serving as a first color separation unit and a dichroic mirror 32 serving as a second color separation unit.
These dichroic mirrors 31 and 32 are optical elements in which a wavelength selection film that reflects a light beam in a predetermined wavelength region and transmits a light beam of another wavelength is formed on a translucent substrate. The dichroic mirror 31 arranged in the front stage of the optical path is a mirror that reflects blue light as the first color light having a short wavelength side, for example, a wavelength region of about 400 to 500 nm, and transmits a light beam in another wavelength region. . The dichroic mirror 32 arranged at the latter stage of the optical path reflects green light as the second color light having an intermediate wavelength, for example, a wavelength region of about 500 nm to 580 nm, and a long wavelength side, for example, a wavelength region of about 580 to 750 nm. It is a mirror which permeate | transmits the red light as 3rd color light which has.

The electro-optical device 40 modulates an incident light beam according to image information to form a color image. The electro-optical device 40 includes a liquid crystal panel 42 as three light modulation devices, an incident-side polarizing plate 43 and an emitting-side polarizing plate 44 that are respectively disposed in the upstream and downstream optical paths of the liquid crystal panel 42, and a cross dichroic prism. 45.
The incident-side polarizing plate 43 receives light of each color whose polarization direction is aligned in approximately one direction by the polarization conversion element 23, and is substantially the same as the polarization axis of the light beam aligned by the polarization conversion element 23 among the incident light beams. Only polarized light in the direction is transmitted, and other light beams are absorbed. This incident side polarizing plate 43 is stuck on translucent board | substrates, such as sapphire glass or quartz crystal, for example.

The liquid crystal panel 42 includes a blue light liquid crystal panel 42B as a first light modulation device, a green light liquid crystal panel 42G as a second light modulation device, and a red light liquid crystal as a third light modulation device. Liquid crystal panel 42R. These liquid crystal panels 42 have a configuration in which a liquid crystal, which is an electro-optical material, is hermetically sealed in a pair of transparent glass substrates. The alignment state of the certain liquid crystal is controlled, and the polarization direction of the polarized light beam emitted from the incident side polarizing plate 43 is modulated.
The exit-side polarizing plate 44 has substantially the same configuration as that of the incident-side polarizing plate 43, and out of the light beams emitted from the image forming area of the liquid crystal panel 42, the polarization axis orthogonal to the transmission axis of the light beam in the incident-side polarizing plate 43. Is arranged so as to transmit only the light flux having a light and absorb the other light flux.
The cross dichroic prism 45 is an optical element that forms a color image by synthesizing an optical image modulated for each color light emitted from the emission side polarizing plate 44. The cross dichroic prism 45 has a square shape in plan view in which four right angle prisms are bonded together, and two dielectric multilayer films are formed on the interface where the right angle prisms are bonded together. These dielectric multilayer films reflect each color light emitted from the liquid crystal panels 42R and 42B via the emission side polarizing plate 44, and transmit the color light emitted from the liquid crystal panel 42G and passed through the emission side polarizing plate 44. In this manner, the color lights modulated by the liquid crystal panels 42R, 42G, and 42B are combined to form a color image.

  Although the specific configuration of the imaging optical device 50 will be described later, the light beam emitted from the illumination optical device 20 is used to transmit red, green, and blue light in three optical paths from the dichroic mirror 31 to each liquid crystal panel 42. The images are formed at the positions where the liquid crystal panels 42 are disposed without being imaged at positions other than the positions where the liquid crystal panels 42 are disposed.

The optical component housing 60 is made of, for example, a synthetic resin molded product, and although not specifically illustrated, a container-like component that houses and arranges the optical components 10 to 50 at a predetermined position with respect to the illumination optical axis A. The storage member and a lid-like member that closes the opening of the component storage member.
In the present embodiment, the geometric optical path length of the first optical path Bop (FIG. 1) on the illumination optical axis A along which blue light follows from the dichroic mirror 31 to the liquid crystal panel 42B is r1, and from the dichroic mirror 31 to the liquid crystal panel 42G. The geometrical optical path length of the second optical path Gop (FIG. 1) on the illumination optical axis A followed by green light is r2, and the third on the illumination optical axis A followed by red light from the dichroic mirror 31 to the liquid crystal panel 42R. When the geometric optical path length of the optical path Rop (FIG. 1) is r3, the optical components 10 to 50 are housed and arranged in the optical component casing 60 so that r1 = r2 <r3. .

[Configuration of imaging optical device]
As shown in FIG. 1, the imaging optical device 50 includes a superimposing lens 51 as a first optical element, a first auxiliary lens 52 as a second optical element, and a second as a third optical element. Auxiliary lens 53, three reflection mirrors 54, 55, and 56, three achromatic lenses 57R, 57G, and 57B as dispersion correction optical elements, and three field lenses 58.

FIG. 2 is a diagram schematically illustrating chromatic dispersion by the superimposing lens 51.
As shown in FIG. 1, the superimposing lens 51 is disposed between the illumination optical device 20 and the dichroic mirror 31, and collects a plurality of partial light beams that have passed through the illumination optical device 20 to form an image on each liquid crystal panel 42. It is an optical element to be superimposed on the area. In the present embodiment, the superimposing lens 51 is constituted by a lens having a large chromatic dispersion as compared with a lens that forms an image of light of each wavelength at the same position as used in a normal optical system. Therefore, the refractive index of the superimposing lens 51 varies depending on the wavelength (color), and the focal length of each color light via the superimposing lens 51 is as shown in FIG. The focal length of the blue light B, the focal length of the green light G, and the focal length of the red light R increase in this order. Here, the superimposing lens 51 is designed to form an image of the blue light B in the vicinity of the position where the liquid crystal panel 42B is disposed in the light flux emitted from the illumination optical device 20. Therefore, the distance from the superimposing lens 51 to the imaging plane (imaging distance) is blue light B <green light G <red light R. In FIG. 2, blue light B indicates light having an intermediate wavelength in the short wavelength side, for example, a wavelength region of about 400 to 500 nm, and green light G indicates an intermediate wavelength, for example, an intermediate wavelength in the wavelength region of about 500 to 580 nm. The red light R indicates light having an intermediate wavelength in the long wavelength side, for example, a wavelength region of about 580 to 750 nm.

  As shown in FIG. 1, the first auxiliary lens 52 is disposed between the dichroic mirror 31 and the dichroic mirror 32 in the second optical path Gop, and changes the imaging distance of green light and red light by the superimposing lens 51. To do. In the present embodiment, the first auxiliary lens 52 is composed of a lens having a positive refractive power. Specifically, the geometrical optical path length r1 of the first optical path Bop and the geometrical optical path length r2 of the second optical path Gop are set to be the same, and the superimposing lens 51 arranges the blue light into the arrangement position of the liquid crystal panel 42B. Since it is designed to form an image in the vicinity, the green light that has passed through the superimposing lens 51 forms an image on the downstream side of the optical path at the position where the liquid crystal panel 42G is disposed. Here, the first auxiliary lens 52 is changed so that the imaging distance of the green light by the superimposing lens 51 is shortened, and the green light is imaged near the position where the liquid crystal panel 42G is disposed.

  As shown in FIG. 1, the second auxiliary lens 53 has an optical path that is closer to the rear side of the optical path of the dichroic mirror 32 in the third optical path Rop than the imaging position FB of red light by the superimposing lens 51 and the first auxiliary lens 52. The imaging distance of red light by the superimposing lens 51 and the first auxiliary lens 52 is disposed on the front stage side and is changed. The imaging position FB is determined from the geometric optical path lengths r1 and r2 of the first optical path Bop and the second optical path Gop from the dichroic mirror 31 in the third optical path Rop by chromatic dispersion of the superimposing lens 51. It is formed at a position of a longer distance. In the present embodiment, the second auxiliary lens 53 is composed of a lens having negative refractive power. Specifically, the second auxiliary lens 53 is changed so that the imaging distance of the red light by the superimposing lens 51 and the first auxiliary lens 52 is increased, and the red light is connected in the vicinity of the position where the liquid crystal panel 42R is disposed. Let me image.

  The reflection mirrors 54, 55, and 56 are general mirrors that reflect a light beam and guide it to a predetermined position. Among these, as shown in FIG. 1, the reflection mirror 54 is disposed in the first optical path Bop, and reflects the blue light reflected by the dichroic mirror 31 toward the liquid crystal panel 42B. As shown in FIG. 1, the reflection mirrors 55 and 56 are disposed in the third optical path Rop, respectively, and reflect the red light transmitted through the dichroic mirror 32 to guide it to the liquid crystal panel 42R.

As shown in FIG. 1, the three achromatic lenses 57B, 57G, and 57R include a rear stage side of the optical path of the reflection mirror 54 in the first optical path Bop, a rear stage side of the optical path of the dichroic mirror 32 in the second optical path Gop, and a third one. Are arranged on the rear side of the optical path Rop of the reflecting mirror 56, and the image forming positions of the three color lights of blue, green and red are made to coincide with the positions of the liquid crystal panels 42B, 42G and 42R.
FIG. 3 is a diagram schematically showing an imaging position of blue light in a state where the achromatic lens 57B is not provided in the first optical path Bop. In FIG. 3, for convenience of explanation, the polarization conversion element 23, the dichroic mirror 31, the reflection mirror 54, the field lens 58, and the incident side polarizing plate 43 are omitted. In FIG. 3, the locus of the shortest wavelength color light B1 of the blue light B is indicated by a solid line, the locus of the intermediate wavelength color light B0 is indicated by a broken line, and the locus of the longest wavelength color light B2 is indicated by a two-dot chain line.
As shown in FIG. 2, the superimposing lens 51 is composed of a lens having a large chromatic dispersion compared to a lens that forms an image of light of each wavelength at the same position as used in a normal optical system. Similarly, the imaging distances differ depending on the wavelengths of the three color lights via the superimposing lens 51, and the imaging distances differ depending on the wavelengths in each color light. For example, the blue light separated by the dichroic mirror 31 has a wavelength region of about 400 to 500 nm as described above. Therefore, the blue light imaging position FBx by the superimposing lens 51 is coupled with the longest wavelength color light B2 of about 500 nm from the imaging position FB1 where the shortest wavelength color light B1 of about 400 nm forms an image, as shown in FIG. It has a predetermined width (range) up to the image formation position FB2. That is, the imaging position FBx indicates a range from the imaging position FB1 to the imaging position FB2.

FIG. 4 is a diagram schematically showing an illumination area of blue light in a state where the achromatic lens 57B is not provided.
As described above, when the blue light image formation position FBx has a predetermined width, as shown in FIG. 3, the image formation position FB0 of the color light B0 having an intermediate wavelength of about 450 nm is set on the liquid crystal panel 42B. Even if it is set so as to match the arrangement position, the imaging position of the colored light in the other wavelength region is shifted from the arrangement position of the liquid crystal panel 42B.
In such a state, among the blue light image formation position FBx, the intermediate wavelength color light B0 whose image formation position coincides with the arrangement position of the liquid crystal panel 42B is the small lenses L1, L2, and L2 of the first lens array 21. Images of L3 and the like (FIG. 3) are superimposed on the liquid crystal panel. On the other hand, among the blue light image formation positions FBx, other color lights whose image formation positions do not coincide with the arrangement positions of the liquid crystal panel 42B are small lenses L1, L2, L3, etc. of the first lens array 21 ( The image in FIG. 3) is not superimposed on the liquid crystal panel 42.
Therefore, as shown in FIG. 4, the blue light has an intermediate wavelength color light B0 whose image formation position coincides with the arrangement position of the liquid crystal panel 42B, and the illuminance is uniform in the substantially central part of the entire illumination area ABx of the blue light. The other color light that forms the illumination area AB0 and whose imaging position does not coincide with the arrangement position of the liquid crystal panel 42B diffuses at the arrangement position of the liquid crystal panel 42B, and illuminates the entire illumination area ABx of blue light with non-uniform illumination. Thus, an illumination area AB1 with non-uniform illuminance is formed at the outer edge portion of the illumination area AB0.
For this reason, when performing optical design, as shown in FIG. 4, it is necessary to set the uniform illumination area AB0 to substantially coincide with the image forming area Ar of the liquid crystal panel 42B. However, with this setting, the non-uniform illumination area AB1 becomes a non-use area that is not used in the liquid crystal panel 42B. As a result, the illuminance of light irradiated on the liquid crystal panel 42B becomes low, and the projected image Brightness is lost.

FIG. 5 is a diagram schematically illustrating a state in which the color dispersion of the blue light by the superimposing lens 51 is corrected by providing the achromatic lens 57B in the first optical path Bop. In FIG. 5, for convenience of explanation, the first lens array 21, the second lens array 22, the polarization conversion element 23, the dichroic mirror 31, the reflection mirror 54, the field lens 58, and the incident are substantially the same as in FIG. 2. The side polarizing plate 43 is omitted.
FIG. 6 is a diagram schematically showing an illumination area ABx ′ of blue light in a state where the achromatic lens 57B is provided in the first optical path Bop.
When the achromatic lens 57B is provided in the first optical path Bop, as shown in FIG. 5, correction is made so as to reduce the deviation in the optical path length direction of the imaging position due to frequency dispersion due to chromatic dispersion of the superimposing lens 51. As a result, the width of the blue light image formation position FBx approaches 0 and matches the arrangement position of the liquid crystal panel 42B. That is, the achromatic lens 57B is designed according to the optical characteristics (axial chromatic aberration) of the superimposing lens 51.
Then, by bringing the width of the blue light imaging position FBx close to 0 and matching the imaging position FBx with the arrangement position of the liquid crystal panel 42B, as shown in FIG. 6, the blue light illumination area ABx ′ is uniform. It is substantially the same size as the illumination area AB0 and substantially coincides with the image forming area Ar of the liquid crystal panel 42B.

  Note that the two achromatic lenses 57G and 57R respectively disposed in the second optical path Gop and the third optical path Rop also have the same function as the achromatic lens 57B disposed in the first optical path Bop described above. Have. That is, although not specifically shown, the achromatic lens 57G disposed in the second optical path Gop corrects the width of the green light image formation position due to the color dispersion of the superimposing lens 51 to be close to zero. The green light image formation position is matched with the arrangement position of the liquid crystal panel 42G. Further, the achromatic lens 57R disposed in the third optical path Rop corrects the width of the red light image formation position due to the chromatic dispersion of the superimposing lens 51 to be close to 0, and changes the red light image formation position to the liquid crystal. It matches with the position of the panel 42R.

  The three field lenses 58 are respectively disposed between the three achromatic lenses 57R, 57G, and 57B and the three incident-side polarizing plates 43, and are emitted from the three achromatic lenses 57R, 57G, and 57B. The principal ray of the light beam is converted into a light beam substantially parallel to the illumination optical axis A.

  In the first embodiment described above, since the projector 1 includes the imaging optical device 50, the light beam emitted from the light source device 10 and passing through the illumination optical device 20 is converted into the first optical path Bop and the second optical path Gop. In the third optical path Rop, the liquid crystal panels 42B, 42G, and 42G, 42G, 42G, 42D, 42G, 42G, 42G, 42G, 42D, 42D, 42G, 42G, 42D Each image can be formed at the position 42R. For this reason, even if the light emitted from the light source has uneven intensity in the plane (a direction orthogonal to the illumination optical axis A), the intensity distribution on the screen for each color light can be set to be substantially the same. Therefore, when the relay optical system is used, it is possible to satisfactorily prevent the occurrence of color unevenness caused by in-plane intensity unevenness in the light emitted from the light source.

  The geometric optical path length r3 of the third optical path Rop of red light is set to be longer than the geometric optical path lengths r1 and r2 of the first optical path Bop and the second optical path Gop. Therefore, the imaging optical device 50 includes the superimposing lens 51 having a large chromatic dispersion as compared with a lens that forms an image of light of each wavelength at the same position as used in a normal optical system. Each liquid crystal is emitted from the light source device 10 through the illumination optical device 20 without being imaged at other positions except for the positions where the liquid crystal panels 42B, 42G, and 42R are disposed in the optical paths Bop, Gop, and Rop. A configuration in which images are formed at the positions where the panels 42B, 42G, and 42R are arranged can be easily realized.

Here, the superimposing lens 51 is designed to form blue light in the vicinity of the position where the liquid crystal panel 42 is disposed, out of the light flux emitted from the light source device 10 and passing through the illumination optical device 20. Further, since the imaging optical device 50 includes the achromatic lens 57B disposed in the first optical path Bop, the image forming position of the blue light by the superimposing lens 51 is corrected so as to approach 0. The blue light imaging position is matched with the arrangement position of the liquid crystal panel 42B, that is, the blue light illumination area ABx ′ (uniform illumination area AB0) is matched with the image forming area Ar of the liquid crystal panel 42B. The light utilization efficiency can be improved.
Therefore, by the superimposing lens 51 and the achromatic lens 57B, the blue light is emitted at the arrangement position of the liquid crystal panel 42B without forming an image in the first optical path Bop other than the arrangement position of the liquid crystal panel 42B. Can be imaged satisfactorily.

Further, since the imaging optical device 50 includes the first auxiliary lens 52 and the achromatic lens 57G disposed in the second optical path Gop, the imaging distance of green light by the superimposing lens 51 is shortened. The green light is imaged in the vicinity of the position where the liquid crystal panel 42G is disposed, and the width of the green light image forming position by the superimposing lens 51 is corrected so as to be close to 0, thereby adjusting the green light image forming position to the liquid crystal. It is possible to match the position of the panel 42G. That is, similarly to the blue light, the light use efficiency of green light can be improved.
Accordingly, the superimposing lens 51, the first auxiliary lens 52, and the achromatic lens 57G allow the liquid crystal to be imaged in the second optical path Gop at a position other than the position where the liquid crystal panel 42G is disposed. The green light can be favorably imaged at the arrangement position of the panel 42G.

Further, the imaging optical device 50 includes a second auxiliary lens 53 disposed on the upstream side of the optical path from the imaging position FB of red light by the superimposing lens 51 and the first auxiliary lens 52 in the third optical path Rop. Since the achromatic lens 57R is provided, the red light image formation distance by the superimposing lens 51 and the first auxiliary lens 52 is changed to be long, and the red light is connected in the vicinity of the position where the liquid crystal panel 42G is disposed. In addition, the width of the image formation position of the red light by the superimposing lens 51 is corrected to be close to 0, and the image formation position of the red light can be matched with the arrangement position of the liquid crystal panel 42R. That is, the light use efficiency of red light can be improved in the same manner as the blue light and green light.
Accordingly, the superimposing lens 51, the first auxiliary lens 52, the second auxiliary lens 53, and the achromatic lens 57R are used in the third optical path Rop, except for the position where the liquid crystal panel 42R is disposed. Thus, red light can be favorably imaged at the position where the liquid crystal panel 42R is disposed.

  As described above, instead of the conventional relay optical system, the superimposing lens 51, the first auxiliary lens 52, the second auxiliary lens 53, and the three achromatic lenses 57B, 57G, and 57R are provided. A light beam emitted from the light source device 10 and passing through the illumination optical device 20 is imaged at other positions in the optical paths Bop, Gop, Rop except for the positions where the liquid crystal panels 42B, 42G, 42R are disposed. Each of the liquid crystal panels 42B, 42G, and 42R can be imaged satisfactorily, and when the relay optical system is used, color unevenness caused by in-plane intensity unevenness occurs in the light emitted from the light source. Therefore, a good projection image can be formed.

  In addition, since the superimposing lens 51 is composed of a lens having a large chromatic dispersion compared to a lens that forms light of each wavelength at the same position as used in a normal optical system, the superimposing lens 51 is refracted. A lens with a high rate can be used. For this reason, the squeezing angle of the incident light beam in the superimposing lens 51 is increased, and the illuminance on each image forming area on the liquid crystal panels 42R, 42G, and 42B can be increased. Therefore, in addition to the effects of the achromatic lenses 57R, 57G, and 57B, it is possible to form a projected image with better brightness. Further, in the case where the brightness is not changed, the luminance of the light source device 10 can be lowered, and the power consumption can be reduced.

[Second Embodiment]
Next, 2nd Embodiment of this invention is described based on drawing.
FIG. 7 is a plan view schematically showing the projector 1A in the second embodiment.
In the following description, the same structure and the same members as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted or simplified.
In the projector 1A of the present embodiment, as shown in FIG. 7, in the imaging optical device 50A, the first auxiliary lens 52 and the three achromatic lenses 57R, 57G, and 57B described in the first embodiment are omitted. ing. Further, in the imaging optical device 50A, the superimposing lens 51 described in the first embodiment is a superimposing lens with small chromatic dispersion that images light of each wavelength at the same position as used in a normal optical system. 51A. The configuration is the same as that of the first embodiment except that the first auxiliary lens 52 and the three achromatic lenses 57R, 57G, and 57B are not provided, and the superimposing lens 51 is changed to the superimposing lens 51A.

The superimposing lens 51A as the first optical element forms an image of the blue light in the light beam emitted from the illumination optical device 20 at the position where the liquid crystal panel 42B is disposed with the width of the image forming position being substantially zero. Designed to. Since the geometric optical path length r1 of the first optical path Bop and the geometric optical path length r2 of the second optical path Gop are set to be the same, by designing the superimposing lens 51A as described above, the superimposing lens By 51A, among the light beams emitted from the illumination optical device 20, the green light is also imaged at the arrangement position of the liquid crystal panel 42G in a state where the width of the image formation position is close to zero.
The second auxiliary lens 53 is disposed on the optical path downstream side of the dichroic mirror 31 in the third optical path Rop and on the optical path upstream side of the red light imaging position FB ′ by the superimposing lens 51A. Note that the imaging position FB ′ is such that the superimposing lens 51A is composed of a lens having a small chromatic dispersion, so that the first optical path Bop and the second optical path Gop from the dichroic mirror 31 in the third optical path Rop. It is formed at a position substantially equal to each geometrical optical path length r1, r2. The second auxiliary lens 53 changes the red light imaging distance by the superimposing lens 51A so as to increase the image of the red light at the position where the liquid crystal panel 42R is disposed.

In the second embodiment described above, the imaging optical device 50A includes the superimposing lens 51A having a small chromatic dispersion as compared with the first embodiment. Therefore, the superimposing lens 51A alone has the same geometric optical path length. The blue light and the green light that follow the first optical path Bop and the second optical path Gop having r1 and r2 can be imaged at the respective arrangement positions of the liquid crystal panels 42B and 42G.
In addition, the imaging optical device 50A is a second auxiliary lens disposed on the optical path upstream side of the imaging position FB ′ of the red light by the superimposing lens 51A on the downstream side of the optical path of the dichroic mirror 32 in the third optical path Rop. 53, the red light by the superimposing lens 51A can be changed so that the imaging distance of the red light becomes long, and the red light can be imaged at the position where the liquid crystal panel 42R is disposed.
Therefore, in place of the conventional relay optical system, a light beam emitted from the light source device 10 and passing through the illumination optical device 20 is provided by arranging an imaging optical device including the superimposing lens 51A and the second auxiliary lens 53. Without being imaged at the positions other than the positions of the liquid crystal panels 42B, 42G, 42R in the optical paths Bop, Gop, Rop, respectively, at the positions of the liquid crystal panels 42B, 42G, 42R. An image can be formed.
Further, since the first auxiliary lens 52 and the achromatic lenses 57R, 57G, and 57B described in the first embodiment can be omitted, the lenses 52, 57R, 57G, and 57B are supported in the optical component casing 60. There is no need to form a member. Therefore, the omission of the lenses 52, 57R, 57G, and 57B and the omission of the supporting member make it possible to reduce the cost, size, and weight of the projector 1.

[Third embodiment]
Next, 3rd Embodiment of this invention is described based on drawing.
FIG. 8 is a plan view schematically showing a projector 1B according to the third embodiment.
In the following description, the same structure and the same members as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted or simplified.
In the projector 1B of the present embodiment, as shown in FIG. 8, in the color separation optical device 30B, the dichroic mirror 31 described in the first embodiment transmits blue light among the incident light beams and transmits other color light (green). A dichroic mirror 31B that reflects light, red light). Further, the positions of the dichroic mirror 31B and the reflection mirror 54 are switched, and the dichroic mirror 31B and the reflection mirror 54 reflect the other color light (green light and red light) separated by the dichroic mirror 31B toward the reflection mirror 54. Then, the reflection mirror 54 is disposed so as to be reflected toward the dichroic mirror 32. In addition, the shape of the optical component casing 60B is changed, and the light source device 10 and the illumination optical device 20 are arranged so that the optical path that the blue light emitted from the light source device 10 and separated by the dichroic mirror 31B follows is linear. And the superimposing lens 51 are arranged. The geometrical optical path length r1 of the first optical path Bop on the illumination optical axis A on which the blue light follows from the dichroic mirror 31B to the liquid crystal panel 42B, and the illumination optical axis on which the green light follows from the dichroic mirror 31B to the liquid crystal panel 42G. The geometrical optical path length r2 of the second optical path Gop on A and the geometrical optical path length r3 of the third optical path Rop on the illumination optical axis A on which the red light follows from the dichroic mirror 31B to the liquid crystal panel 42R are r1. The relationship is set so that <r2 <r3. Further, in the imaging optical device 50B, the first auxiliary lens 52 described in the first embodiment is configured by a first auxiliary lens 52B having a negative refractive power. The point that the dichroic mirror 31 is changed to the dichroic mirror 31B, the point that the dichroic mirror 31B and the reflection mirror 54 are arranged as described above, the point that the shape of the optical component housing 60B is changed as described above, the first auxiliary lens The configuration is the same as that of the first embodiment except that 52 is changed to the first auxiliary lens 52B.

Similar to the first embodiment, the superimposing lens 51 in the present embodiment forms an image of blue light in the vicinity of the position where the liquid crystal panel 42 </ b> B is disposed, among the light beams emitted from the illumination optical device 20.
The first auxiliary lens 52B as the second optical element is disposed on the upstream side of the optical path from the image formation position FG of green light by the superimposing lens 51 in the second optical path Gop. The imaging position FG is formed at a position longer than the geometric optical path length r1 of the first optical path Bop from the dichroic mirror 31B in the second optical path Gop due to chromatic dispersion of the superimposing lens 51. Is. Then, the first auxiliary lens 52B is changed so as to increase the imaging distance of the green light by the superimposing lens 51, and the green light is imaged in the vicinity of the arrangement position of the liquid crystal panel 42G.
In the present embodiment, the second auxiliary lens 53 is located on the optical path downstream side of the dichroic mirror 32 in the third optical path Rop and on the upstream side of the optical path position FB ″ of the red light by the superimposing lens 51 and the first auxiliary lens 52B. It is arranged on the side. The imaging position FB ″ is formed at a distance longer than the geometric optical path length r2 of the second optical path Gop from the dichroic mirror 31B in the third optical path Rop due to chromatic dispersion of the superimposing lens 51. Is. Then, the second auxiliary lens 53 is changed so as to increase the imaging distance of the red light by the superimposing lens 51 and the first auxiliary lens 52B, as in the first embodiment, and the red light is changed to the liquid crystal panel. An image is formed near the arrangement position of 42R.
As in the first embodiment, the achromatic lenses 57R, 57G, and 57B in the present embodiment correct the width of the image formation position of each color light due to the color dispersion of the superimposing lens 51 to be close to 0, and The image formation position is made to coincide with the arrangement position of each liquid crystal panel 42R, 42G, 42B.

In the third embodiment described above, compared to the first embodiment, the geometric optical path length r1 of the first optical path Bop, the geometric optical path length r2 of the second optical path Gop, and the third optical path Rop. Even when the geometrical optical path length r3 is set to satisfy the relationship r1 <r2 <r3, the superimposing lens 51, the first auxiliary lens 52B, and the second auxiliary lens are used instead of the conventional relay optical system. By disposing the imaging optical device 50B including the lens 53 and the three achromatic lenses 57R, 57G, and 57B, the light beam emitted from the light source device 10 and passing through the illumination optical device 20 is sent to each optical path Bop, It is possible to easily realize a configuration in which images are formed at the arrangement positions of the liquid crystal panels 42B, 42G, and 42R without forming images at positions other than the arrangement positions of the liquid crystal panels 42B, 42G, and 42R in Gop and Rop. .
In addition, since the imaging optical device 50B includes the first auxiliary lens 52B and the second auxiliary lens 53, each color light is moved to the vicinity of the position where the liquid crystal panels 42R, 42G, and 42B are disposed by using only the superimposing lens 51. Compared with the configuration for forming an image, the configuration is such that green light and red light are easily formed in the vicinity of the respective arrangement positions of the liquid crystal panels 42G and 42R. Therefore, the degree of freedom in designing the projector 1B is improved, and the projector 1B can be optimized according to the required performance.

[Fourth embodiment]
Next, 4th Embodiment of this invention is described based on drawing.
FIG. 9 is a plan view schematically showing a projector 1C according to the fourth embodiment.
In the following description, the same structure and the same members as those in the third embodiment are denoted by the same reference numerals, and detailed description thereof is omitted or simplified.
In the projector 1C of this embodiment, as shown in FIG. 9, in the imaging optical device 50C, the superimposing lens 51 described in the third embodiment is replaced with the superimposing lens 51A having a small chromatic dispersion described in the second embodiment. Consists of. In the imaging optical device 50C, the first auxiliary lens 52B described in the third embodiment is configured by the first auxiliary lens 52C having a large chromatic dispersion and a negative refractive power. Further, in the imaging optical device 50C, the achromatic lens 57B disposed in the first optical path Bop among the three achromatic lenses 57R, 57G, and 57B described in the third embodiment is omitted. Except for changing the superimposing lens 51 to the superimposing lens 51A, changing the first auxiliary lens 52B to the first auxiliary lens 52C, and not providing the achromatic lens 57B, the same configuration as in the third embodiment. It is.

Similar to the second embodiment, the superimposing lens 51A forms an image of blue light at the position where the liquid crystal panel 42B is disposed in a state where the width of the image forming position is substantially zero among the light beams emitted from the illumination optical device 20. Designed to let you.
The first auxiliary lens 52C as the second optical element is disposed on the upstream side of the optical path from the imaging position FG ′ of green light by the superimposing lens 51A in the second optical path Gop. Note that the imaging position FG ′ is such that the superimposing lens 51A is formed of a lens with small chromatic dispersion, so that the geometric optical path length r1 of the first optical path Bop from the dichroic mirror 31B in the second optical path Gop. Is formed at a position approximately equal to the distance. Then, the first auxiliary lens 52C changes the green light image formation distance by the superimposing lens 51 so as to increase the green light image in the vicinity of the position where the liquid crystal panel 42G is disposed. The first auxiliary lens 52C is composed of a lens having a large chromatic dispersion as compared with a lens that forms an image of light of each wavelength at the same position as used in a normal optical system. In substantially the same manner as the superimposing lens 51 described in the embodiment, the imaging distances of the green light and the red light through the first auxiliary lens 52C are different, and the imaging positions of the respective color lights have a predetermined width. . Here, the achromatic lens 57G disposed in the second optical path Gop is formed of green light by the color dispersion of the first auxiliary lens 52C in substantially the same manner as in the first and third embodiments. The position width is corrected so as to be close to 0, and the image formation position of the green light is matched with the arrangement position of the liquid crystal panel 42G.

  In the present embodiment, the second auxiliary lens 53 has an optical path on the third optical path Rop on the downstream side of the optical path of the dichroic mirror 32 and on the red light imaging position FB ′ ″ by the superimposing lens 51A and the first auxiliary lens 52C. It is arranged on the front side. The imaging distance FB ′ ″ is longer than the geometric optical path length r2 of the second optical path Gop from the dichroic mirror 31B in the third optical path Rop due to chromatic dispersion of the first auxiliary lens 52C. It is formed at a distance position. Then, similarly to the third embodiment, the second auxiliary lens 53 is changed so as to increase the imaging distance of the red light by the superimposing lens 51A and the first auxiliary lens 52C, and the red light is changed to the liquid crystal panel 42R. The image is formed in the vicinity of the arrangement position of. The achromatic lens 57R disposed in the third optical path Rop is similar to the first embodiment and the third embodiment in that the red light imaging position by the color dispersion of the first auxiliary lens 52C. The image forming position of the red light is made to coincide with the arrangement position of the liquid crystal panel 42R.

In the fourth embodiment described above, the first auxiliary lens 52C can be used in a normal optical system even when the superimposing lens 51A is configured with a lens having a small chromatic dispersion as compared with the third embodiment. By using a lens having a large chromatic dispersion compared to a lens that forms an image of light of each wavelength at the same position, a light beam emitted from the light source device 10 and passing through the illumination optical device 20 is converted into each optical path Bop, It is possible to easily realize a configuration in which images are formed at the arrangement positions of the liquid crystal panels 42B, 42G, and 42R without forming images at positions other than the arrangement positions of the liquid crystal panels 42B, 42G, and 42R in Gop and Rop. .
Further, since the imaging optical device 50B includes the second auxiliary lens 53, the liquid crystal panels 42G and 42R are provided with green light and red light using only the chromatic dispersion of the first auxiliary lens 52C. Compared with the configuration in which the image is formed in the vicinity of the position, the red light is easily imaged in the vicinity of the arrangement position of the liquid crystal panel 42R. Therefore, the degree of freedom in designing the projector 1C is improved, and the projector 1C can be optimized according to the required performance.

[Fifth Embodiment]
Next, a fifth embodiment of the present invention will be described with reference to the drawings.
FIG. 10 is a plan view schematically showing a projector 1D according to the fifth embodiment.
In the following description, the same structure and the same members as those in the third embodiment are denoted by the same reference numerals, and detailed description thereof is omitted or simplified.
In the projector 1D of this embodiment, as shown in FIG. 10, in the imaging optical device 50D, the superimposing lens 51 described in the third embodiment is replaced with the color described in the second embodiment and the fourth embodiment. The superimposing lens 51A has a small dispersion. In the imaging optical device 50D, the three achromatic lenses 57R, 57G, and 57B described in the third embodiment are omitted. The configuration is the same as that of the third embodiment except that the superimposing lens 51 is changed to the superimposing lens 51A and the achromatic lenses 57R, 57G, and 57B are not provided.

Similar to the second and fourth embodiments, the superimposing lens 51 </ b> A uses blue light of the light beam emitted from the illumination optical device 20 to form the liquid crystal panel 42 </ b> B in a state where the width of the imaging position is close to zero. It is designed to form an image at the arrangement position.
The first auxiliary lens 52B in the present embodiment is disposed on the optical path upstream side of the green light imaging position FG ′ by the superimposing lens 51A in the second optical path Gop. Note that the imaging position FG ′ is such that the superimposing lens 51A is formed of a lens with small chromatic dispersion, so that the geometric optical path length r1 of the first optical path Bop from the dichroic mirror 31B in the second optical path Gop. Is formed at a position approximately equal to the distance. Then, the first auxiliary lens 52B changes so as to increase the image formation distance of the green light by the superimposing lens 51A, and forms an image of the green light at the position where the liquid crystal panel 42G is disposed.
In the present embodiment, the second auxiliary lens 53 is located behind the optical path position FB ″ ″ of the red light by the superimposing lens 51A and the first auxiliary lens 52B on the downstream side of the optical path of the dichroic mirror 32 in the third optical path Rop. It is disposed on the upstream side of the optical path. In the image forming position FB ″ ″, since the superimposing lens 51A and the first auxiliary lens 52B are composed of lenses with small chromatic dispersion, the second position from the dichroic mirror 31B in the third optical path Rop. The optical path Gop is formed at a position substantially equal to the geometric optical path length r2. Then, the second auxiliary lens 53 changes the red light image formation distance by the superimposing lens 51A and the first auxiliary lens 52B to increase the image of the red light at the position where the liquid crystal panel 42R is disposed.

  In the fifth embodiment described above, since the imaging optical device 50D includes the superimposing lens 51A having a small chromatic dispersion as compared with the third embodiment, the superimposing lens 51A causes the first optical path Bop to be The blue light can be imaged at the arrangement position of the liquid crystal panel 42B without image formation at other positions except the arrangement position of the liquid crystal panel 42B.

Further, since the first auxiliary lens 52B is disposed on the upstream side of the optical path with respect to the imaging position FG ′ of the green light by the superimposing lens 51A in the second optical path Gop, the imaging distance of the green light by the superimposing lens 51A Thus, the green light can be imaged at the position where the liquid crystal panel 42G is disposed.
Therefore, by the superimposing lens 51A and the first auxiliary lens 52B, in the second optical path Gop, an image is formed at a position other than the position where the liquid crystal panel 42G is disposed at the position where the liquid crystal panel 42G is disposed. Green light can be imaged.

Further, since the second auxiliary lens 53 is disposed on the upstream side of the optical path from the imaging position FB ″ ″ of the red light by the superimposing lens 51A and the first auxiliary lens 52B in the third optical path Rop, The red light by the superimposing lens 51A and the first auxiliary lens 52B can be changed so that the imaging distance of the red light becomes longer, and the red light can be imaged at the position where the liquid crystal panel 42R is disposed.
Accordingly, the superimposing lens 51A, the first auxiliary lens 52B, and the third auxiliary lens 53 do not form an image at other positions in the third optical path Rop except for the position where the liquid crystal panel 42R is disposed. The red light can be imaged at the arrangement position of the liquid crystal panel 42R.

As described above, instead of the conventional relay optical system, the image forming optical device 50D configured by the superimposing lens 51A, the first auxiliary lens 52B, and the second auxiliary lens 53 is disposed, whereby the light source device. The liquid crystal panels 42B, 42B, and 42B are formed without forming images of the light beams emitted from 10 through the illumination optical device 20 at positions other than the positions where the liquid crystal panels 42B, 42G, 42R are disposed in the optical paths Bop, Gop, Rop. A configuration in which images are formed at the positions 42G and 42R can be easily realized.
Further, since the achromatic lenses 57R, 57G, and 57B described in the third embodiment can be omitted, it is not necessary to form a member that supports the lenses 57R, 57G, and 57B in the optical component casing 60. Therefore, the omission of the lenses 57R, 57G, and 57B and the omission of the supporting member make it possible to reduce the cost, size, and weight of the projector 1.

Although the present invention has been described with reference to preferred embodiments, the present invention is not limited to these embodiments, and various improvements and design changes can be made without departing from the scope of the present invention. It is.
In the first embodiment, the first auxiliary lens 52 constituting the imaging optical device 50 is disposed between the dichroic mirrors 31 and 32. However, the present invention is not limited to this, and the dichroic in the second optical path Gop is used. You may arrange | position in the optical path back | latter stage side of the mirror 32. FIG. At this time, the second auxiliary lens 53 may be disposed on the upstream side of the optical path from the red light image formation position by the superimposing lens 51.

In the above-described embodiment, the first auxiliary lens 52 and the achromatic lens 57G, and the second auxiliary lens 53 and the achromatic lens 57R are configured separately, but may be configured integrally. Good.
For example, the achromatic lens 57G is omitted, and the first auxiliary lens 52 is configured to have the function of the achromatic lens 57G. In such a configuration, the color dispersion of the green light and the color dispersion of the red light by the superimposing lens 51 can be corrected, so that the achromatic lens 57R can also be omitted.
Further, for example, as described above, the first auxiliary lens 52 is disposed on the downstream side of the optical path of the dichroic mirror 32 in the second optical path Gop. The achromatic lens 57G is omitted, and the first auxiliary lens 52 is configured to have the function of the achromatic lens 57G.
Further, for example, the achromatic lens 57R is omitted, and the second auxiliary lens 53 is configured to have the function of the achromatic lens 57R.
If comprised as mentioned above, the member which supports the 1st auxiliary | assistant lens 52 and the achromatic lens 57G in the optical component housing | casing 60 can be shared. In addition, the members that support the second auxiliary lens 53 and the achromatic lens 57R can be shared. For this reason, the number of parts can be reduced, and the projector 1 can be reduced in size and weight.
In the third embodiment and the fourth embodiment as well, the second auxiliary lens 53 and the achromatic lens 57R may be configured integrally.

In the third embodiment, a configuration in which the first auxiliary lens 52B and the third auxiliary lens 53 constituting the imaging optical device 50B are omitted may be employed. At this time, the imaging distance of each color light that differs depending on the chromatic dispersion of the superimposing lens 51 is set in accordance with the geometric optical path lengths r1, r2, and r3 of each optical path Bop, Gop, and Rop, and each color light is set. The liquid crystal panels 42B, 42G, and 42R are imaged in the vicinity of the arrangement positions.
In the fourth embodiment, a configuration in which the second auxiliary lens 53 constituting the imaging optical device 50C is omitted may be employed. At this time, the image formation distances of the green light and the red light, which differ depending on the chromatic dispersion of the first auxiliary lens 52C, are set according to the geometric optical path lengths r2 and r3 of the optical paths Gop and Rop. Light and red light are imaged in the vicinity of the arrangement positions of the liquid crystal panels 42G and 42R, respectively.

In each embodiment, the optical path of the light beam emitted from the light source device 10 and emitted from the projection lens 4 is not limited to the optical path described in each embodiment. In the first embodiment and the second embodiment, any optical path may be used if the geometric optical path lengths r1, r2, and r3 of the optical paths Bop, Gop, and Rop are in the relationship of r1 = r2 <r3. It does not matter. In the third embodiment to the fifth embodiment, any geometrical optical path length r1, r2, r3 of each optical path Bop, Gop, Rop has any relationship as long as r1 <r2 <r3. It may be an optical path.
For example, in the first embodiment and the second embodiment, the dichroic mirror 31 is configured by a mirror that transmits blue light and reflects other color light (green and red light). Then, the light source device 10, the illumination optical device 20, and the superimposing lens 51 are positioned on the lower side in FIG. 1 or 2 with respect to the dichroic mirror 31, and the light flux emitted from the light source device 10 is as shown in FIG. It arrange | positions so that it may go upwards inside.
Further, for example, in the third to fifth embodiments, the dichroic mirror 31B is configured by a mirror that reflects blue light and reflects other color light (green and red light). Then, the light source device 10, the illumination optical device 20, and the superimposing lenses 51 and 51A are positioned above the dichroic mirror 31B in FIG. 8 to FIG. 10, and the light flux emitted from the light source device 10 is shown in FIG. It arrange | positions so that it may go to the downward direction in FIG.

  In each of the above embodiments, the light of each color via the liquid crystal panels 42R, 42G, and 42B is synthesized by the cross dichroic prism 45. However, the present invention is not limited to this, and the dichroic mirror 31 described in each of the above embodiments. A configuration similar to 31B and 32, in which each of the color lights via the liquid crystal panels 42R, 42G, and 42B is synthesized using a plurality of dichroic mirrors that transmit predetermined color light and reflect other color light, may be employed. .

In the first embodiment, in the imaging optical device 50, only the superimposing lens 51 is formed by a lens having a large chromatic dispersion as compared with a lens for imaging light of each wavelength at the same position as used in a normal optical system. However, the first auxiliary lens 52 and / or the second auxiliary lens 53 may be configured by a lens having a large chromatic dispersion.
Similarly, in the third embodiment, in the imaging optical device 50B, a lens having a large chromatic dispersion is used as compared with a lens that images light of each wavelength at the same position as used in a normal optical system. Although only the superimposing lens 51 is configured, the first auxiliary lens 52B and / or the second auxiliary lens 53 may be configured by a lens having a large chromatic dispersion.
Further, similarly in the fourth embodiment, in the imaging optical device 50C, a lens having a large chromatic dispersion is used as compared with a lens for imaging light of each wavelength at the same position as used in a normal optical system. Although only the first auxiliary lens 52C is configured, the second auxiliary lens 53 may be configured with a lens having a large chromatic dispersion.

In each of the above embodiments, the superimposing lenses 51 and 51A, the first auxiliary lenses 52, 52B and 52C, and the second auxiliary lens 53 are configured by a single lens. A combination lens may be used.
In each of the above embodiments, the imaging optical device 50 has an imaging position in the vicinity of any of the liquid crystal panels 42R, 42G, and 42B, but is imaged on any of the liquid crystal panels 42R, 42G, and 42B. It is most preferable that the image is formed at least within an allowable range of the depth of field of the projection lens 4.

In each of the above embodiments, a transmissive liquid crystal panel having a different light incident surface and light emitting surface is used. However, a reflective liquid crystal panel having the same light incident surface and light emitting surface may be used.
In each of the embodiments, the liquid crystal panel is used as the light modulation device. However, a light modulation device other than liquid crystal, such as a device using a micromirror, may be used. In this case, polarizing plates on the light beam incident side and the light beam emission side can be omitted.
In each of the above embodiments, only an example of a front type projector that projects from the direction of observing the screen has been described. However, the present invention also applies to a rear type projector that projects from the side opposite to the direction of observing the screen. Applicable.

Although the best configuration for carrying out the present invention has been disclosed in the above description, the present invention is not limited to this. That is, the invention has been illustrated and described primarily with respect to particular embodiments, but may be configured for the above-described embodiments without departing from the scope and spirit of the invention. Various modifications can be made by those skilled in the art in terms of materials, quantity, and other detailed configurations.
Therefore, the description limited to the shape, material, etc. disclosed above is an example for easy understanding of the present invention, and does not limit the present invention. The description by the name of the member which remove | excluded the limitation of one part or all of such is included in this invention.

  The projector of the present invention is useful as a projector used in home theaters and presentations because it can prevent color unevenness in the projected image.

FIG. 2 is a plan view schematically showing the projector in the first embodiment. The figure which shows typically chromatic dispersion by the superimposition lens in the said embodiment. The figure which shows typically the image formation position of the blue light in the state which does not provide the achromatic lens in the said embodiment in the 1st optical path. The figure which shows typically the illumination area | region of the blue light in the state which does not provide the achromatic lens in the said embodiment. The figure which shows typically the state which corrected the color dispersion of the blue light by a superimposition lens by providing the achromatic lens in the said embodiment in the 1st optical path. The figure which shows typically the illumination area of the blue light in the state which provided the achromatic lens in the said embodiment in the 1st optical path. The top view which shows typically the projector in 2nd Embodiment. The top view which shows typically the projector in 3rd Embodiment. The top view which shows typically the projector in 4th Embodiment. The top view which shows typically the projector in 5th Embodiment.

Explanation of symbols

  1, 1A, 1B, 1C, 1D ... projector, 10 ... light source device, 30 ... color separation optical device, 31 ... dichroic mirror (first color separation means), 32 ... dichroic Mirror (second color separation means), 42R, 42G, 42B ... Liquid crystal panel (light modulation device), 50, 50A, 50B, 50C, 50D ... Imaging optical device, 51, 51A ... Superimposition Lens (first optical element), 52, 52B, 52C ... first auxiliary lens (second optical element), 53 ... second auxiliary lens (third optical element), 57R, 57G 57B... Achromatic lens (dispersion correction optical element), A... Illumination optical axis, Bop... First optical path, Gop... Second optical path, Rop.

Claims (11)

A light source device and a wavelength region that is disposed on a central axis of a light beam emitted from the light source device and has a different wavelength region of a short wavelength side, a long wavelength side, a short wavelength side, and an intermediate wavelength of the long wavelength side. A projector comprising: a color separation optical device that separates into three color lights; and three light modulation devices that are arranged on the central axis and modulate the three color lights according to image information, respectively.
The color separation optical device separates a light beam emitted from the light source device into a first color light having a wavelength region on the short wavelength side and a color light having a wavelength region other than the wavelength region on the short wavelength side. The color light having a wavelength region other than the wavelength region on the short wavelength side separated by the first color separation unit, the second color light having the intermediate wavelength region, and the long wavelength Second color separation means for separating into third color light having a wavelength region on the side,
Each optical path from the first color separation means to each light modulation device has a geometrical shape of the first light path from the first color separation means to the first light modulation device corresponding to the first color light. An optical path length, and a geometric optical path length of the second optical path from the first color separation means to the second light modulation device corresponding to the second color light through the second color separation means. On the other hand, the geometrical optical path length of the third optical path from the first color separation means to the third light modulation device corresponding to the third color light via the second color separation means becomes longer. Is set to
The light beam emitted from the light source device is imaged at each of the light modulation device arrangement positions without being imaged at any position other than the light modulation device arrangement position in each light path. A projector comprising an image optical device. The projector according to claim 1, wherein
When the geometric optical path length of the first optical path is r1, the geometric optical path length of the second optical path is r2, and the geometric optical path length of the third optical path is r3, r1 = r2 < r3 relationship is set,
The imaging optical device includes:
A state in which the first color light is distributed in the central axis direction according to the wavelength region of the first color light among the light beams emitted from the light source device, disposed on the optical path upstream side of the color separation optical device. Thus, the second color light and the third color light can be imaged in the vicinity of the arrangement position of the first light modulation device, and the second color light and the third color light according to each wavelength region of the second color light and the third color light. In a state of being dispersed in the central axis direction, an image can be formed in the vicinity of each imaging position having an imaging distance longer than the imaging distance of the first color light in the second optical path and the third optical path. 1 optical element;
An image forming position of the second color light by the first optical element is changed in the second optical path, and the second color light is connected in the vicinity of an installation position of the second light modulation device. A second optical element capable of imaging;
In the third optical path, the third color light is coupled by the first optical element alone or by both the first optical element and the second optical element on the downstream side of the second color separation means. Disposed on the front side of the optical path from the image position, and changes the imaging position of the third color light by only the first optical element or by both the first optical element and the second optical element, A third optical element capable of forming an image of the third color light in the vicinity of the arrangement position of the third light modulation device;
The first optical path, the second color separation means in the second optical path, the second color separation means on the downstream side of the optical path, and the third optical path on the optical path downstream of the second color separation means, respectively, The dispersion in the central axis direction corresponding to each wavelength region of the three color lights by one optical element is corrected, and the image forming positions of the three color lights are respectively matched with the arrangement positions of the three light modulators. A projector comprising: a dispersion correcting optical element that causes the optical element to move. The projector according to claim 2,
The second optical element is disposed on the rear side of the optical path of the second color separation unit in the second optical path, and the second color separation unit in the second optical path of the dispersion correction optical element. And a dispersion correction optical element disposed on the rear side of the optical path of the projector. In the projector according to claim 2 or 3,
The third optical element is configured integrally with a dispersion correction optical element disposed on the downstream side of the optical path of the second color separation means in the third optical path of the dispersion correction optical element. Projector. The projector according to claim 1, wherein
When the geometric optical path length of the first optical path is r1, the geometric optical path length of the second optical path is r2, and the geometric optical path length of the third optical path is r3, r1 = r2 < r3 relationship is set,
The imaging optical device includes:
Of the light beams emitted from the light source device, disposed on the front side of the optical path of the color separation optical device, the first color modulation device and the second light are converted into the first color light and the second color light. A first optical element that forms an image at each arrangement position of the modulation device;
The first optical element is disposed on the optical path downstream side of the second color separation means in the third optical path and on the optical path upstream side with respect to the imaging position of the third color light by the first optical element. And a third optical element that changes the image formation position of the third color light according to, and forms the image of the third color light on the arrangement position of the third light modulation device. projector. The projector according to claim 1, wherein
When the geometric optical path length of the first optical path is r1, the geometric optical path length of the second optical path is r2, and the geometric optical path length of the third optical path is r3, r1 <r2 < r3 relationship is set,
The imaging optical device includes:
A state in which the first color light is distributed in the central axis direction according to the wavelength region of the first color light among the light beams emitted from the light source device, disposed on the optical path upstream side of the color separation optical device. Thus, the second light can be formed in the vicinity of the position where the first light modulator is disposed, and the second color light is dispersed in the central axis direction according to the wavelength region of the second color light. An image can be formed in the vicinity of the arrangement position of the modulation device, and the arrangement position of the third light modulation device in a state where the third color light is dispersed in the central axis direction according to the wavelength region of the third color light. A first optical element capable of imaging in the vicinity;
The first color path, the second color separation means in the second light path, the second color separation means on the rear side of the optical path, and the third light path in the second color separation means on the rear side of the optical path, respectively. The dispersion in the central axis direction corresponding to each wavelength region of the three color lights by one optical element is corrected, and the image forming positions of the three color lights are respectively set at the arrangement positions of the three light modulators. A projector comprising a dispersion correcting optical element for matching. The projector according to claim 6, wherein
The imaging optical device is disposed in the second optical path, changes an imaging position of the second color light by the first optical element, and outputs the second color light together with the first optical element. And a second optical element capable of forming an image in the vicinity of an arrangement position of the second light modulation device in a state of being dispersed in the central axis direction according to the wavelength region of the second color light. Projector. In the projector according to claim 6 or 7,
The imaging optical device is disposed on the rear side of the optical path of the second color separation means in the third optical path, changes the imaging position of the third color light by the first optical element, and It is possible to form an image in the vicinity of the position where the third light modulation device is disposed in a state where the third color light and the first optical element are dispersed in the central axis direction according to the wavelength region of the third color light. A projector comprising a third optical element. The projector according to claim 1, wherein
When the geometric optical path length of the first optical path is r1, the geometric optical path length of the second optical path is r2, and the geometric optical path length of the third optical path is r3, r1 <r2 < r3 relationship is set,
The imaging optical device includes:
A first optical that is disposed on the optical path upstream side of the color separation optical device and forms an image of the first color light at a position where the first light modulation device is disposed, among light beams emitted from the light source device. Elements,
The second optical path is disposed on the upstream side of the second optical path from the imaging position of the second color light by the first optical element, is emitted from the first optical element, and passes through the first color separation means. Of the colored light having the wavelength region on the short wavelength side, the second light modulation device is disposed in a state where the second colored light is dispersed in the central axis direction according to the wavelength region of the second colored light. It is possible to form an image in the vicinity of the position, and it is possible to form an image in the vicinity of the arrangement position of the third light modulation device in a state where the third color light is dispersed in the central axis direction according to the wavelength region of the third color light. A second optical element,
The second color separation means in the second optical path on the rear side of the optical path and the third optical path on the rear side of the optical path of the second color separation means, respectively. The dispersion in the central axis direction corresponding to each wavelength region of the second color light and the third color light is respectively corrected, and the imaging positions of the second color light and the third color light are determined as the second light. A projector comprising: a modulation device; and a dispersion correction optical element that matches each arrangement position of the third light modulation device. The projector according to claim 9, wherein
The imaging optical device is disposed on the rear side of the optical path of the second color separation means in the third optical path, and the third color light is coupled by the first optical element and the second optical element. The image position is changed, and the third color light is dispersed in the optical axis direction according to the wavelength region of the third color light together with the first optical element and the second optical element. A projector comprising a third optical element capable of forming an image in the vicinity of an arrangement position of the light modulation device. The projector according to claim 1, wherein
When the geometric optical path length of the first optical path is r1, the geometric optical path length of the second optical path is r2, and the geometric optical path length of the third optical path is r3, r1 <r2 < r3 relationship is set,
The imaging optical device includes:
A first optical that is disposed on the optical path upstream side of the color separation optical device and forms an image of the first color light at a position where the first light modulation device is disposed, among light beams emitted from the light source device. Elements,
An image forming position of the second color light by the first optical element is changed on the first stage of the optical path from the image forming position of the second color light by the first optical element in the second optical path. A second optical element that forms an image of the second color light on an arrangement position of the second light modulation device;
In the third optical path, on the downstream side of the second color separation means in the optical path, on the upstream side of the optical path from the imaging position of the third color light by the first optical element and the second optical element. The imaging position of the third color light by the first optical element and the second optical element is changed, and the third color light is imaged at the arrangement position of the third light modulation device. And a third optical element.

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