JP2006133640A - Projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a projector whose light utilization efficiency is not remarkably reduced even in a configuration assuring the smooth satisfactory display of a moving picture. <P>SOLUTION: The projector comprises: a flat illuminating device 100 in which each of the first small lenses 122 of the first lens array 120 is compressed to 50% in a y-axis direction; liquid crystal devices 400R, 400G, and 400B; a projecting optical system 600; and a rotary prism 770 used to scan an illuminating optical flux in the Y-axis direction on an image forming area of each of the liquid crystal devices in synchronization of frequency used for writing on the image plane of the liquid crystal device. When the opposite angle size of the image forming area of each liquid crystal device is L(mm), the F value of the projection optical system 600 is represented by following relational formula (1): 0.0526L+0.53≤F value ≤0.050L+0.88. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a projector.

FIG. 8 is a diagram for explaining a conventional projector. FIG. 8A is a diagram showing an optical system of a conventional projector, and FIGS. 8B and 8C are diagrams for explaining problems of such a conventional projector.
In the projector 900A, since the liquid crystal devices 400R, 400G, and 400B used as the electro-optic modulation device are hold type display devices having luminance characteristics as shown in FIG. 8B, they are shown in FIG. 8C. Unlike the case of the CRT which is an impulse type display device having such luminance characteristics, there is a problem that a smooth moving image display cannot be obtained due to a so-called tailing phenomenon. (Refer nonpatent literature 1.).

FIG. 9 is a diagram for explaining another conventional projector. FIG. 9A is a diagram showing an optical system of another conventional projector, and FIGS. 9B and 9C are diagrams for showing an optical shutter used in such another conventional projector. It is.
In the projector 900B, as shown in FIG. 9A, optical shutters 420R, 420G, and 420B are disposed on the light incident side of the liquid crystal devices 400R, 400G, and 400B, and light is intermittently blocked by these optical shutters. This solves the problem described above. That is, the so-called tailing phenomenon is alleviated so that a smooth and high-quality moving image display can be obtained (for example, see Patent Document 1).
"Image quality of video display on hold type display" (Technical Report of IEICE, EID99-10, pages 55-60 (1999-06)) JP 2002-148712 A (FIGS. 1 to 7)

  However, in such other conventional projectors, there is a problem in that the light use efficiency is significantly reduced because light is intermittently blocked by the optical shutter.

  The present invention has been made to solve such problems, and an object of the present invention is to provide a projector in which the light use efficiency is not significantly reduced even when a smooth and high-quality moving image display is obtained. And

The projector according to the present invention includes a light source device that emits a substantially parallel illumination light beam toward the illuminated region side, and a plurality of first small lenses that divide the illumination light beam emitted from the light source device into a plurality of partial light beams. From the first lens array, a second lens array having a plurality of second small lenses corresponding to the plurality of first small lenses of the first lens array, and the plurality of second small lenses of the second lens array An illuminating device having a superimposing lens for superimposing each emitted partial light beam in an illuminated region, an electro-optic modulator that modulates light from the illuminating device according to image information, and the electro-optic modulator A projection optical system that projects the modulated light, and each first small lens in the first lens array converts an illumination light beam emitted from the illumination device into an image forming unit of the electro-optic modulation device. Compressed in the other direction so that the illumination area has a cross-sectional shape that illuminates a part of the image forming area in the other direction in either one of the vertical and horizontal directions in the area. And a projector further comprising scanning means for scanning the illumination light beam along the other direction on the image forming area of the electro-optic modulator in synchronization with the screen writing frequency of the electro-optic modulator. When the diagonal dimension of the image forming area in the electro-optic modulation device is L (mm), the F value of the projection optical system is expressed by the following relational expression (1). .
0.0526L + 0.53 ≦ F value ≦ 0.050L + 0.88 (1)

  Therefore, according to the projector of the present invention, the entire image forming area is illuminated in one of the vertical and horizontal directions in the image forming area of the electro-optic modulation device, and a part of the image forming area is illuminated in the other direction. The illumination light beam having such a cross-sectional shape (that is, a cross-sectional shape compressed in the other direction) can be scanned along the other direction on the image forming region in synchronization with the screen writing frequency of the electro-optic modulator. Therefore, in the image forming area of the electro-optic modulation device, the light irradiation area and the light non-irradiation area are sequentially scrolled alternately. As a result, the tailing phenomenon is alleviated and a smooth and high-quality moving image display can be obtained.

  According to the projector of the present invention, the illumination light beam having the cross-sectional shape compressed in the other direction as described above is realized by using the first lens array in which the planar shape of the first small lens is compressed in the other direction. Therefore, unlike the case where an optical shutter is used, the illumination light beam emitted from the light source device can be led to the image forming area of the electro-optic modulation device without waste, and the light use efficiency is greatly reduced. Nothing will happen.

  For this reason, the projector according to the present invention is a projector in which the light use efficiency is not significantly reduced even when smooth and high-quality moving image display is obtained.

  By the way, according to the analysis of the present inventor, when irradiating the electro-optic modulator with an illumination light beam having a cross-sectional shape compressed in the other direction in the projector whose tailing is relaxed as described above, in a normal projector, It has been found that the maximum incident angle of the illumination light beam with respect to the image forming region of the electro-optic modulation device is larger than that in the case of irradiating the electro-optic modulation device with a normal illumination light beam. For this reason, in such a projector with reduced tailing, when the projection optical system used in a normal projector is used as it is, the illumination light beam modulated by the electro-optic modulation device can be efficiently taken in. It was not possible, and it turned out that light utilization efficiency may fall.

  However, according to the projector of the present invention, the F value of the projection optical system is a projection optical system having a smaller F value than the conventional projection optical system represented by the above relational expression (1). The illumination light beam modulated by the modulation device can be efficiently introduced, and the light use efficiency is not reduced due to the use of the illumination light beam having a cross-sectional shape compressed in the other direction.

  That is, when the F value is set to a value equal to or less than “0.050L + 0.88”, most of the illumination light beam modulated by the electro-optic modulation device can be taken in, and the cross-sectional shape compressed in the other direction The light utilization efficiency is not lowered due to the use of the illumination light beam having On the other hand, if the F value is reduced to “0.0526L + 0.53”, most of the illumination light beam modulated by the electro-optic modulation device can be included, and therefore the F value is set to “0.0526L + 0.53”. It is not necessary to make the value less than. In general, as the F value of the lens is decreased, the manufacturing cost of the lens tends to increase. Therefore, by using the projection optical system represented by the above relational expression (1) as the projection optical system, the price performance is improved. A projector having an excellent ratio can be configured.

  The projector of the present invention is particularly effective when the electro-optic modulation device is a liquid crystal device in which a microlens is not provided for each pixel.

In order to increase the light use efficiency of the illumination light beam in the projector, a projector using a liquid crystal device in which a microlens is provided for each pixel is known as an electro-optic modulation device. In such a projector, the angle of the light emitted from the microlens is large, so that a projection optical system having a small F value (original) with a small F value can be used. .
On the other hand, in a projector using a liquid crystal device in which a microlens is not provided for each pixel as an electro-optic modulation device, there is no reason as described above, so that the F value is usually relatively large (relatively dark). A projection optical system is used.

  For this reason, when a projection optical system normally used in a projector having a liquid crystal device in which a microlens is not provided for each pixel is used for a projector with reduced tailing, the projector has a cross-sectional shape compressed in the other direction. There is a case where the illumination light flux cannot be efficiently introduced and the light use efficiency is lowered. However, even in such a case, by making the F value of the projection optical system smaller than that of the conventional projection optical system represented by the relational expression (1) as in the projector of the present invention, An illumination light beam having a cross-sectional shape compressed in the other direction can be efficiently introduced, and the light use efficiency is reduced due to the use of the illumination light beam having a cross-sectional shape compressed in the other direction. Also disappear.

  In the projector according to the aspect of the invention, it is preferable that the illumination light beam emitted from the illumination device is an illumination light beam having a cross-sectional shape that illuminates 50% or less of the image forming region in the other direction.

  In such a case, since the maximum incident angle of the illumination light beam with respect to the image forming area of the electro-optic modulation device is particularly large, the conventional projection optical system in which the F value of the projection optical system is expressed by the above relational expression (1). A particularly large effect can be obtained by making it smaller.

  In the projector according to the aspect of the invention, the scanning unit may be disposed between the illumination device and the electro-optic modulation device at a position optically conjugate with the electro-optic modulation device and rotated perpendicular to the illumination optical axis. A rotating prism having an axis and configured to sequentially scroll a light irradiation area and a light non-irradiation area on the electro-optic modulation device in synchronization with a screen writing frequency of the electro-optic modulation device. It is preferable to have.

  With this configuration, it is possible to realize a smooth scroll operation of the light irradiation region and the light non-irradiation region in the image forming region of each electro-optic modulation device in the full color projector.

  In the projector according to the aspect of the invention, a color separation light guide optical system for separating an illumination light beam emitted from the illumination device into a plurality of color lights between the illumination device and the electro-optic modulation device, and the electro-optics As a modulation device, a plurality of color light beams emitted from the color separation light guide optical system are modulated by a plurality of electro-optic modulation devices that modulate image light corresponding to each color light, and the plurality of electro-optic modulation devices. It is preferable to further include a cross dichroic prism that combines the respective color lights.

  With this configuration, a projector in which the light use efficiency is not significantly reduced even when smooth and high-quality moving image display can be obtained is a full-color projector with excellent image quality (for example, a three-plate type). Will be able to.

  The projector of the present invention will be described below based on the embodiments shown in the drawings.

Embodiment 1
FIG. 1 is a diagram for explaining a projector 1000 according to the first embodiment. FIG. 1A is a view of the optical system of the projector 1000 as viewed from above, and FIG. 1B is a view of the optical system of the projector 1000 as viewed from side.
In the following description, the three directions orthogonal to each other are defined as the z-axis direction (illumination optical axis 100ax direction in FIG. 1A) and the x-axis direction (parallel to the paper surface in FIG. And a direction perpendicular to the paper surface in FIG. 1A and perpendicular to the z-axis.

  As shown in FIG. 1, the projector 1000 according to Embodiment 1 separates the illumination device 100 and the illumination light flux from the illumination device 100 into three color lights of red, green, and blue and guides them to the illuminated area. The separation light guide optical system 200, three liquid crystal devices 400R, 400G, and 400B as electro-optic modulation devices that modulate each of the three color lights separated by the color separation light guide optical system 200 according to image information, and these A cross dichroic prism 500 that combines the color lights modulated by the three liquid crystal devices 400R, 400G, and 400B, and a projection optical system 600 that projects the light combined by the cross dichroic prism 500 onto a projection surface such as a screen SCR. It is a projector.

  The illumination device 100 includes a light source device 110 that emits an illumination light beam that is substantially parallel to the illuminated region side, and a plurality of first small lenses 122 that divide the illumination light beam emitted from the light source device 110 into a plurality of partial light beams. The first lens array 120, the second lens array 130 having the plurality of second small lenses 132 corresponding to the plurality of first small lenses of the first lens array 120, and the alignment of the polarization directions emitted from the light source device 110. A polarization conversion element 140 that aligns the unilluminated light flux with one type of linearly polarized light, and a superimposing lens 150 for superimposing the partial light fluxes emitted from the polarization conversion element 140 in the illuminated area.

  The light source device 110 includes an ellipsoidal reflector 114, an arc tube 112 having a light emission center in the vicinity of the first focal point of the ellipsoidal reflector 114, and a collimation that converts the focused light reflected by the ellipsoidal reflector 114 into substantially parallel light. And a lens 118. The arc tube 112 is provided with an auxiliary mirror 116 as a reflecting means for reflecting the light emitted from the arc tube 112 toward the illuminated area toward the ellipsoidal reflector 114.

  As the color separation light guide optical system 200, as shown in FIG. 1A, an equal optical path length optical system having the same optical path length from the illumination device 100 to the liquid crystal devices 400R, 400G, and 400B is used. The color separation light guide optical system 200 separates the illumination light beam emitted from the illumination device 100 into a plurality of color lights, and guides each color light to the liquid crystal devices 400R, 400G, and 400B.

The liquid crystal devices 400 </ b> R, 400 </ b> G, and 400 </ b> B modulate the incident illumination light beam according to image information to form a color image, and are the illumination target of the illumination device 100. Although not shown, an incident-side polarizing plate is interposed between the color separation light guide optical system 200 and each of the liquid crystal devices 400R, 400G, and 400B, and crosses each of the liquid crystal devices 400R, 400G, and 400B. Between the dichroic prism 500, an exit side polarizing plate is interposed. The incident-side polarizing plate, the liquid crystal devices 400R, 400G, and 400B and the exit-side polarizing plate modulate light of each color light incident thereon.
The liquid crystal devices 400R, 400G, and 400B are a pair of transparent glass substrates in which a liquid crystal that is an electro-optical material is hermetically sealed. For example, incident side polarization is performed according to a given image signal using a polysilicon TFT as a switching element. The polarization direction of one type of linearly polarized light emitted from the plate is modulated.
As the liquid crystal devices 400R, 400G, and 400B, a wide vision liquid crystal device having a planar shape of “longitudinal dimension along the y-axis direction: lateral dimension along the x-axis direction = 9: 16 rectangle” is used. .

The cross dichroic prism 500 is an optical element that forms a color image by synthesizing optical images modulated for the respective color lights emitted from the emission-side polarizing plate. The cross dichroic prism 500 has a substantially square shape in plan view in which four right angle prisms are bonded together, and a dielectric multilayer film is formed in a substantially X shape at the interface where the right angle prisms are bonded together. One of the approximately X-shaped dielectric multilayer films reflects red light, and the other dielectric multilayer film reflects blue light. By these dielectric multilayer films, the red light and the blue light are bent and aligned with the traveling direction of the green light, so that the three color lights are synthesized.
The color image emitted from the cross dichroic prism 500 is enlarged and projected by the projection optical system 600 to form a large screen image on the screen SCR.

  In the projector 1000 according to the first embodiment, the configuration of the first lens array 120 (and the configuration of the second lens array 130 corresponding thereto), the use of the scanning unit including the rotating prism 770, and the configuration of the projection optical system 600 are used. It is characterized by.

  That is, the first small lens 122 in the first lens array 120 transmits the illumination light beam emitted from the illumination device 100 in the horizontal direction along the x-axis direction in the vertical and horizontal directions in the image forming regions of the liquid crystal devices 400R, 400G, and 400B. A plane compressed in the vertical direction so that the entire image forming area is illuminating light flux having a cross-sectional shape that illuminates 50% of the image forming area in the vertical direction along the y-axis direction. It has a shape.

  The rotating prism 770 is disposed between the illumination device 100 and the liquid crystal devices 400R, 400G, and 400B, and extends in the vertical direction on the image forming area in synchronization with the screen writing frequency of the liquid crystal devices 400R, 400G, and 400B. It has a function of scanning the illumination light beam.

Furthermore, the projection optical system 600 has an F value represented by the following relational expression (1) when the diagonal dimension of the image forming region in the liquid crystal devices 400R, 400G, and 400B is L (mm). .
0.0526L + 0.53 ≦ F value ≦ 0.050L + 0.88 (1)

  For this reason, according to the projector 1000 according to the first embodiment, among the vertical and horizontal directions in the image forming areas of the liquid crystal devices 400R, 400G, and 400B, the entire image forming area in the horizontal direction along the x-axis direction is the y-axis. In the vertical direction along the direction, the illumination light flux having a cross-sectional shape that illuminates a part of the image forming region (that is, the cross-sectional shape compressed in the vertical direction) is used as the screen writing frequency of the liquid crystal devices 400R, 400G, 400B Since the image forming area can be scanned along the y-axis direction in synchronization with the image forming area, the light irradiation area and the light non-irradiation area are sequentially formed in the image forming area of the liquid crystal devices 400R, 400G, and 400B. It will be scrolled. As a result, the tailing phenomenon is alleviated and a smooth and high-quality moving image display can be obtained.

  Further, according to the projector 1000 according to the first embodiment, the illumination light beam having the cross-sectional shape compressed in the vertical direction as described above is used to compress the planar shape of the first small lens 122 in the vertical direction as the first lens array 120. Unlike the case of using an optical shutter, the illumination light beam emitted from the light source device 110 can be guided to the image forming areas of the liquid crystal devices 400R, 400G, and 400B without waste. Thus, the light use efficiency is not greatly reduced.

  For this reason, the projector 1000 according to the first embodiment is a projector in which the light use efficiency is not significantly reduced even when smooth and high-quality moving image display is obtained.

  Hereinafter, the first lens array 120, the rotating prism 770, and the projection optical system 600 in the projector 1000 according to the first embodiment will be described in detail.

1. First Lens Array FIG. 2 is a diagram for explaining the structure of the first lens array 120. 2 (a) is a front view of the first lens array 120, FIG. 2 (b) is a front view of the liquid crystal device 400R, and FIG. 2 (c) is a diagram in which the illumination light beam is irradiated to FIG. 2 (b). Area L is added. 2B and 2C also illustrate the image forming region 402R of the liquid crystal device 400R. Further, the liquid crystal device 400G and the liquid crystal device 400B are the same as those of the liquid crystal device 400R, and thus description thereof is omitted.

  As shown in FIG. 2A, the first lens array 120 has a structure in which the first small lenses 122 are arranged in four rows in the horizontal direction and 14 rows in the vertical direction. Further, the first small lens 122 in the first lens array 120 has a planar shape of “vertical dimension along the y-axis direction: lateral dimension along the x-axis direction = 9: 32 rectangle”. For this reason, the first lens array 120 illuminates the illumination light beam emitted from the illumination device 100 over the entire image formation region in the lateral direction along the x-axis direction in the image formation regions of the liquid crystal devices 400R, 400G, and 400B. In the longitudinal direction along the y-axis direction, an illumination light beam having a cross-sectional shape that illuminates 50% of the image forming area can be obtained.

2. Rotating Prism FIG. 3 is a diagram showing the relationship between the rotation of the rotating prism 770 and the illumination state on the liquid crystal devices 400R, 400G, and 400B. FIG. 3A is a cross-sectional view of the rotating prism 770 when viewed along the rotation axis 772. FIG. 3B is a view of the rotating prism 770 when viewed along the illumination optical axis 100ax. FIG. 3C is a diagram showing an irradiation state of the illumination light beam on the image forming areas of the liquid crystal devices 400R, 400G, and 400B.

  As shown in FIGS. 3A and 3B, the image P of the virtual center point of the first lens array 120 on the illumination optical axis 100ax is rotated by the rotating prism 770 as the rotating prism 770 rotates. It is scrolled up and down around the axis 772. As a result, as shown in FIG. 3C, when the rotating prism 770 rotates, the light irradiation region and the light non-irradiation region are sequentially scrolled in the image forming regions of the liquid crystal devices 400R, 400G, and 400B. .

3. Projection Optical System As described above, the projection optical system 600 has the F value represented by the above-described relational expression (1) when the diagonal dimension of the image forming region in the liquid crystal devices 400R, 400G, and 400B is L (mm). have.

  FIG. 4 is a diagram illustrating a state in which the illumination light beam is incident on the image forming areas of the liquid crystal devices 400R, 400G, and 400B. FIG. 4A is a diagram illustrating the case of the projector 1000 according to the first embodiment, and FIG. 4B is a diagram illustrating the case of the projector 1000a according to the comparative example. The projector 1000a (not shown) according to the comparative example is a normal projector that does not have a trailing relaxation function.

According to the analysis of the present inventor, the liquid crystal devices 400R, 400G, and 400B are irradiated with an illumination light beam having a cross-sectional shape that is compressed in the other direction in a projector whose tailing is relaxed, such as the projector 1000 according to the first embodiment. In the case (see FIG. 4A), the liquid crystal devices 400R, 400G, and 400B are irradiated with an uncompressed illumination light beam in a normal projector such as the projector 1000a according to the comparative example (FIG. 4B). It was found that the maximum incident angle of the illumination light beam with respect to the image forming regions of the liquid crystal devices 400R, 400G, and 400B is larger than that of the above).
For this reason, when the projection optical system used in a normal projector such as the projector 1000a according to the comparative example is used as it is for the projector whose tailing is reduced like the projector 1000 according to the first embodiment, It can be seen that the illumination light flux that has passed through the liquid crystal devices 400R, 400G, and 400B cannot be efficiently introduced, and the light utilization efficiency may decrease.

  However, according to the projector 1000 according to the first embodiment, the F value of the projection optical system is smaller (brighter) than the normal projection optical system represented by the relational expression (1). The illumination light flux modulated by the devices 400R, 400G, and 400B can be introduced only efficiently, and the light utilization efficiency is reduced due to the use of the illumination light flux having a cross-sectional shape compressed in the other direction. Disappear.

  FIG. 5 is a diagram showing the relationship between the diagonal dimension L of the image forming area of the liquid crystal device and the F value of the projection optical system. In the figure, the A region is a region having an F value of “0.050L + 0.88” or more, and the B region satisfies a relational expression of “0.0526L + 0.53 ≦ F value ≦ 0.050L + 0.88”. The C region is a region where the F value is less than “0.0526L + 0.53”.

  Tables 1 to 3 are tables showing the relationship between the diagonal dimension L of the image forming area of the liquid crystal device and the F value of the projection optical system. Table 1 is a table showing a relationship when the projection optical system 600 in the projector 1000 according to the first embodiment captures a sufficiently large amount of illumination light. Table 2 shows the relationship between the projection optical system 600 in the projector 1000 according to the first embodiment. It is a table | surface which shows the relationship when only most of illumination light beams are taken in, and Table 3 is a table | surface which shows the relationship when the projection optical system in the projector 1000a which concerns on a comparative example takes in most part of illumination light beams. In Tables 1 to 3, the incident angle 1 indicates the maximum incident angle of the sufficient amount of light when the projection optical system 600 captures a sufficient amount of the illumination light beam, and the incident angle 2 indicates that the projection optical system is illuminated. The maximum incident angle of most of the light when only most of the light flux is included is shown.

  That is, as shown in FIG. 5 and Table 1, when the F value is set to “0.050L + 0.88” or less (B region or C region), illumination modulated by the liquid crystal devices 400R, 400G, and 400B Most of the light beam can be captured, and the light use efficiency is not lowered due to the use of the illumination light beam having a cross-sectional shape compressed in the other direction. On the other hand, as shown in FIG. 5 and Table 2, when the F value is reduced to “0.0526L + 0.53”, most of the illumination light flux modulated by the liquid crystal devices 400R, 400G, and 400B can be captured. Therefore, it is not necessary to set the F value to a value less than “0.0526L + 0.53” (C region). In general, as the F value of the lens is reduced, the manufacturing cost of the lens tends to increase. Therefore, as the projection optical system 600, the projection optical system represented by the above relational expression (1) (F value is in the B region). A projector having an excellent price / performance ratio can be configured.

In the projector 1000 according to the first embodiment, a liquid crystal device in which a microlens is not provided for each pixel is used as the electro-optic modulation device.
When such a liquid crystal device is used, a projection optical system having a relatively large F value (relatively dark) is usually used. For this reason, when such a normal projection optical system having a relatively large F value is used in the projector 1000 according to the first embodiment, it is possible to efficiently incorporate the illumination light beam having a cross-sectional shape compressed in the other direction. This is not possible, and the light use efficiency may be reduced. However, even in such a case, like the projector 1000 according to the first embodiment, the F value of the projection optical system is smaller than the F value of the conventional projection optical system represented by the above relational expression (1). As a result, an illumination light beam having a cross-sectional shape compressed in the other direction can be efficiently introduced, and light is generated by using the illumination light beam having a cross-sectional shape compressed in the other direction. Usage efficiency will not be reduced.

  In projector 1000 according to the first embodiment, as described above, the illumination light beam emitted from illumination device 100 is an illumination light beam having a cross-sectional shape that illuminates 50% of the image forming region in the other direction. In such a case, since the maximum incident angle of the illumination light beam with respect to the image forming regions of the liquid crystal devices 400R, 400G, and 400B is particularly large, the F value of the projection optical system 600 is represented by the above relational expression (1). A particularly large effect can be obtained by making it smaller than the projection optical system.

  The first lens array 120, the rotating prism 770, and the projection optical system 600 in the projector 1000 according to the first embodiment have been described in detail above. However, the projector 1000 according to the first embodiment also has the following characteristics. .

The projector 1000 according to the first embodiment further includes a polarization conversion element 140 that emits the illumination light beam from the light source device 110 so as to be aligned with one type of linearly polarized light.
The polarization conversion element 140 transmits one linear polarization component of the polarization component included in the illumination light beam from the light source device 110 as it is, and reflects the other linear polarization component in a direction perpendicular to the illumination optical axis 100ax. And the other linearly polarized light component reflected by the polarization separation layer in a direction parallel to the illumination optical axis 100ax, and the other linearly polarized light component reflected by the reflective layer is converted into one linearly polarized light component. And a retardation plate.
For this reason, since the illumination light beam from the light source device 110 can be converted into one kind of linearly polarized light having one polarization axis by the action of the polarization conversion element 140, as in the projector 1000 according to the first embodiment. When an electro-optic modulation device that uses one type of linearly polarized light, such as a liquid crystal device, is used as the electro-optic modulation device, the illumination light beam from the light source device 110 can be used effectively.

In the projector 1000 according to the first embodiment, as shown in FIG. 1A, an illumination light beam emitted from the illumination device 100 is converted into a plurality of color lights between the illumination device 100 and the liquid crystal devices 400R, 400G, and 400B. In accordance with image information corresponding to each color light, a color separation light guide optical system 200 for separating and guiding the light to an illuminated area, and a plurality of color lights emitted from the color separation light guide optical system 200 as a liquid crystal device A plurality of liquid crystal devices 400R, 400G, and 400B that modulate the light, and a cross dichroic prism 500 that combines the respective color lights modulated by the liquid crystal devices 400R, 400G, and 400B.
For this reason, even if smooth and high-quality moving image display is obtained, a projector in which the light use efficiency is not significantly reduced can be a three-plate full-color projector with excellent image quality.

  In the projector 1000 according to the first embodiment, the antireflection film is formed on the light transmission surface of the rotating prism 770. For this reason, since the light transmittance in the rotating prism 770 is improved, a decrease in light utilization efficiency can be minimized, and the stray light level is reduced and the contrast is improved.

[Embodiment 2]
FIG. 6 is a diagram illustrating an optical system of the projector 1002 according to the second embodiment. 6A is a view of the optical system of the projector 1002 as viewed from above, and FIG. 6B is a view of the optical system of the projector 1002 as viewed from side.

The projector 1002 according to the second embodiment basically has a configuration similar to that of the projector 1000 according to the first embodiment. However, as shown in FIG. The configuration of the separation light guide optical system is different.
In other words, in the projector 1002 according to the second embodiment, the color separation light guide optical system 202 has the same direction in which the light irradiation region and the light non-irradiation region are scrolled on the liquid crystal devices 400R, 400G, and 400B. Therefore, a double relay optical system is used.

  As described above, the projector 1002 according to the second embodiment is different from the projector 1000 according to the first embodiment in the configuration of the color separation light guide optical system, but as in the case of the projector 1000 according to the first embodiment, the liquid crystal device. Of the vertical and horizontal directions in the 400R, 400G, and 400B image forming areas, the entire image forming area in the horizontal direction along the x-axis direction, and a part of the image forming area in the vertical direction along the y-axis direction. An illumination light beam having a cross-sectional shape that illuminates (that is, a cross-sectional shape compressed in the vertical direction) is scanned along the y-axis direction on the image forming area in synchronization with the screen writing frequency of the liquid crystal devices 400R, 400G, and 400B. Therefore, in the image forming area of the liquid crystal devices 400R, 400G, and 400B, the light irradiation area and the light non-irradiation area are in order. It will be scrolled alternately. As a result, the tailing phenomenon is alleviated and a smooth and high-quality moving image display can be obtained.

  Further, according to the projector 1002 according to the second embodiment, the illumination light beam having the cross-sectional shape compressed in the vertical direction as described above is used to compress the planar shape of the first small lens 122 in the vertical direction as the first lens array 120. Unlike the case of using an optical shutter, the illumination light beam emitted from the light source device 110 can be guided to the image forming areas of the liquid crystal devices 400R, 400G, and 400B without waste. Thus, the light use efficiency is not greatly reduced.

  For this reason, the projector 1002 according to the second embodiment is a projector in which the light use efficiency is not significantly reduced even when smooth and high-quality moving image display is obtained.

  Further, according to the projector 1002 according to the second embodiment, as in the case of the projector 1000 according to the first embodiment, the F value of the projection optical system is higher than that of a normal projection optical system represented by the above relational expression (1). Since the F value is small (bright), the illumination light flux modulated by the liquid crystal devices 400R, 400G, and 400B can be efficiently introduced as in the case of the projector 1000 according to the first embodiment. The light utilization efficiency is not reduced due to the use of the illumination light beam having a cross-sectional shape compressed in the direction.

[Embodiment 3]
FIG. 7 is a diagram illustrating an optical system of the projector 1004 according to the third embodiment. FIG. 7A is a view of the optical system of the projector 1004 as viewed from the top, and FIG. 7B is a view of the optical system of the projector 1004 as viewed from the side.

As shown in FIG. 7, the projector 1004 according to the third embodiment is different from the projector 1000 according to the first embodiment in the configuration of the electro-optic modulation device (and the configuration of the optical system subsequent to the illumination device). Yes.
That is, in the projector 1004 according to the third embodiment, the micromirror type modulation device 410 is used as the electro-optic modulation device.

  As described above, the projector 1004 according to the third embodiment differs from the projector 1000 according to the first embodiment in the configuration of the electro-optic modulation device (and the configuration of the optical system subsequent to the illumination device). Of the vertical and horizontal directions in the image forming area of the mold modulator 410, the entire image forming area is illuminated in the horizontal direction along the x-axis direction, and a part of the image forming area is illuminated in the vertical direction along the y-axis direction. The illumination light beam having a cross-sectional shape (that is, a cross-sectional shape compressed in the vertical direction) is scanned along the y-axis direction on the image forming region in synchronization with the screen writing frequency of the micromirror type modulation device 410. Therefore, in the image forming area of the micromirror type modulation device 410, the light irradiation area and the light non-irradiation area are sequentially scrolled. To become. As a result, as in the case of the projector 1000 according to the first embodiment, the tailing phenomenon is alleviated, and the projector can obtain a smooth and high-quality moving image display.

  Further, according to the projector 1004 according to the third embodiment, the illumination light beam having the cross-sectional shape compressed in the vertical direction as described above is compressed as the first lens array 120 and the planar shape of the first small lens 122 is compressed in the vertical direction. Since this is realized by using the first lens array, the illumination light beam emitted from the light source device 110 can be guided to the image forming area of the micromirror type modulation device 410 without waste unlike the case of using the optical shutter. As a result, the light use efficiency is not significantly reduced.

  For this reason, the projector 1004 according to the third embodiment is a projector in which the light use efficiency is not significantly reduced even when smooth and high-quality moving image display is obtained.

  Further, according to the projector 1004 according to the third embodiment, as in the case of the projector 1000 according to the first embodiment, the F value of the projection optical system 610 is obtained from a normal projection optical system represented by the relational expression (1). Since the F-number is small (bright), the illumination light beam modulated by the micromirror-type modulation device 410 can be efficiently taken in. Similarly to the projector 1000 according to the first embodiment, The light utilization efficiency is not reduced due to the use of the illumination light beam having a cross-sectional shape compressed in the direction.

  The projector of the present invention has been described based on each of the above embodiments. However, the present invention is not limited to each of the above embodiments, and can be implemented in various modes without departing from the scope of the invention. For example, the following modifications are possible.

(1) In the projectors 1000 to 1004 of the above embodiments, the planar shape of the first small lens 122 of the first lens array 120 is “vertical dimension: lateral dimension = 9: 32 rectangle”. The present invention is not limited to this, and for example, a “vertical dimension: horizontal dimension = 1: 4 rectangle” or a “vertical dimension: horizontal dimension = 3: 8 rectangle” is also preferable. Can be used.

(2) Although the projectors 1000 to 1004 of each of the above embodiments use the rotating prism 770 as scanning means, the present invention is not limited to this. For example, the galvanometer mirror, polygon mirror, DMD (digital micro Mirror device) (trademark of TI) can also be preferably used.

(3) The projectors 1000 to 1004 according to the above embodiments include, as the light source device 110, an ellipsoidal reflector 114, an arc tube 112 having a light emission center near the first focal point of the ellipsoidal reflector 114, and a collimating lens 118. However, the present invention is not limited to this, and a light source device having a parabolic reflector and an arc tube having an emission center near the focal point of the parabolic reflector is also preferably used. Can do.

(4) In the above embodiments, the projector using the three liquid crystal devices 400R, 400G, and 400B has been described as an example. However, the present invention is not limited to this, and one, two, or four projectors are used. The present invention can also be applied to a projector using the above liquid crystal device.

(5) The present invention is applied to a rear projection projector that projects from a side opposite to the side that observes the projected image, even when applied to a front projection projector that projects from the side that observes the projected image. Is also possible.

FIG. 3 is a diagram for explaining a projector 1000 according to the first embodiment. FIG. 3 is a diagram for explaining a first lens array 120 used in the projector 1000 according to the first embodiment. The figure which shows the relationship between rotation of the rotation prism 770, and the illumination state on liquid crystal device 400R, 400G, 400B. The figure which shows a mode that an illumination light beam injects into the image formation area of liquid crystal device 400R, 400G, 400B. The figure which shows the relationship between the diagonal dimension L of the image formation area of a liquid crystal device, and F value of a projection optical system. FIG. 6 is a diagram showing an optical system of a projector 1002 according to a second embodiment. FIG. 10 shows an optical system of a projector 1004 according to a third embodiment. The figure shown in order to demonstrate the conventional projector. The figure shown in order to demonstrate another conventional projector.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Illuminating device, 100ax ... Illumination optical axis, 110 ... Light source device, 110ax ... Light source optical axis, 112 ... Arc tube, 114 ... Ellipsoidal reflector, 116 ... Auxiliary mirror, 118 ... Parallelizing lens, 120 ... First lens array 122 ... 1st small lens, 130 ... 2nd lens array, 132 ... 2nd small lens, 140 ... Polarization conversion element, 150 ... Superimposing lens, 160 ... Relay optical system, 170 ... Light-shielding device, 200, 202 ... Color separation Light guiding optical system, 400R, 400G, 400B ... liquid crystal device, 402R ... image forming region, 410 ... micromirror type modulation device, 500 ... cross dichroic prism, 600, 610 ... projection optical system, 770 ... rotating prism, 772 ... rotating Axis, 900A, 900B, 1000, 1002, 1004... Projector, L... Frequency, P ... image of the virtual center point of first lens array on the illumination optical axis, SCR ... screen

Claims (5)

A light source device that emits a substantially parallel illumination light beam toward the illuminated region, a first lens array having a plurality of first small lenses for dividing the illumination light beam emitted from the light source device into a plurality of partial light beams, A second lens array having a plurality of second small lenses corresponding to the plurality of first small lenses of the first lens array, and each partial light beam emitted from the plurality of second small lenses of the second lens array An illuminating device having a superimposing lens for superimposing the image on the illuminated area;
An electro-optic modulator that modulates light from the illumination device according to image information;
A projection optical system that projects light modulated by the electro-optic modulation device,
Each first small lens in the first lens array emits an illumination light beam emitted from the illuminating device, and covers the entire illuminated region in one of the vertical and horizontal directions in the image forming region of the electro-optic modulation device. The other direction has a planar shape compressed in the other direction so as to have an illumination light beam having a cross-sectional shape that illuminates a part of the image forming region,
A projector further comprising scanning means for scanning an illumination light beam along the other direction on an image forming region of the electro-optic modulator in synchronization with a screen writing frequency of the electro-optic modulator;
A projector, wherein the F value of the projection optical system is represented by the following relational expression (1), where L (mm) is a diagonal dimension of an image forming region in the electro-optic modulation device.
0.0526L + 0.53 ≦ F value ≦ 0.050L + 0.88 (1) The projector according to claim 1, wherein
The electro-optic modulator is a liquid crystal device in which a microlens is not provided for each pixel. The projector according to claim 1 or 2,
An illumination light beam emitted from the illumination device is an illumination light beam having a cross-sectional shape that illuminates 50% or less of an image forming region in the other direction. The projector according to any one of claims 1 to 3,
The scanning means is disposed at a position optically conjugate with the electro-optic modulation device between the illumination device and the electro-optic modulation device, and has a rotation axis perpendicular to the illumination optical axis. The light irradiation area and the light non-irradiation area on the electro-optic modulation device have a rotating prism configured to be sequentially scrolled in synchronization with a screen writing frequency of the electro-optic modulation device. projector. The projector according to any one of claims 1 to 4,
A color separation light guide optical system for separating an illumination light beam emitted from the illumination device into a plurality of color lights between the illumination device and the electro-optic modulation device;
As the electro-optic modulator, a plurality of electro-optic modulators that modulate a plurality of color lights emitted from the color separation light guide optical system according to image information corresponding to each color light, and
A projector further comprising: a cross dichroic prism that combines the respective color lights modulated by the plurality of electro-optic modulators.