JP2009162988A - Projector, and image display method in projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To display a moving image of high visibility while reducing the amount of data. <P>SOLUTION: The projector has: a first image forming means 100 composing each color light modulated by three optical modulators and emitting it as a first image light; a second image forming means 200 composing each color light modulated by three optical modulators and emitting it as second image light; a polarizing-composing optical system 300 composing the first and second image light; and a projecting optical system 400 projecting the composed image light. Four optical modulators out of six optical modulators in total provided at the first and second image forming means, are optical modulators corresponding to green light sources G1-G4, and two optical modulators are optical modulators corresponding to a red light source R and a blue light source B. The four optical modulators corresponding to the light sources and green light are controlled so that each color light modulated by the four optical modulators corresponding to the green light is sequentially emitted with a lag of predetermined time within each frame of the image data. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a projector and an image display method in the projector.

Since projectors can easily display large screen images, they are used in a wide range of fields as projection devices for presentations and movies. On the other hand, recently, a digital camera or the like as an image input device has become higher in resolution and can acquire a high-definition image. A projector as an image output device that displays an image acquired by such a high-resolution image input device has a problem that the resolution is lower than that of a digital camera or the like.

As a means for solving this, there is known a method in which two projectors are used to stack-project the same image on one screen (projection surface) by shifting pixels by, for example, ½ pixel. The brightness of the image light thus stacked and projected is almost doubled, and the resolution is doubled in the vertical and horizontal directions of the projected image, so that a bright and high-definition image can be displayed.

However, when performing the stack projection as described above, it is not easy to correctly superimpose the projection images from the two projectors while shifting the pixels. If the image light from the two projectors is not correctly superimposed, the image quality of the projected image is degraded.

As a projector capable of solving such a problem, a projector having two systems of image forming means and one projection optical system has been proposed. 2 image forming means and 1
A projector having two projection optical systems includes a polarization combining optical system that combines image lights emitted from two image forming units (referred to as a first image forming unit and a second image forming unit), and polarization combining optics. A projection optical system for projecting image light synthesized by the system onto a screen as a projection surface.

In such a projector, the image light emitted from the first image forming unit and the image light emitted from the second image forming unit are set in advance so as to be shifted by 1/2 pixel, and are fixed in that state. Then, it is possible to shift the pixels with high accuracy.

Further, a projector using liquid crystal as a light modulation element has some problems in the response speed of liquid crystal, and there is room for improvement in terms of the visibility of moving images. As a technique for improving the visibility of a moving image, for example, a technique for improving the visibility of a moving image by generating an intermediate image from image data to be displayed and displaying the image at a high frame rate has been proposed. (For example, refer to Patent Document 1).

Japanese Patent Laid-Open No. 2003-69691

The technique (referred to as the prior art) disclosed in Patent Document 1 described above is a technique that generates high-frame-rate image data by generating an intermediate image, thereby enabling a smooth moving image display. .

However, when generating an intermediate image for RGB image data when generating the intermediate image, it is necessary to generate an intermediate image for each of the RGB image data, and the amount of computation for generating the intermediate image is extremely large. Also, there is a problem that the amount of data becomes enormous.

Therefore, an object of the present invention is to provide a projector and an image display method in the projector that can display a highly visible moving image while suppressing the amount of moving image data.

The projector according to the present invention includes three light modulation elements that modulate color light from a light source based on image data, and synthesizes the respective color lights modulated by the three light modulation elements and emits them as first image light. A first image forming unit and three light modulation elements that modulate color light from a light source based on image data. The color lights modulated by the three light modulation elements are combined and emitted as second image light. A second image forming unit, a polarization combining optical system for combining the first image light and the second image light emitted from the first image forming unit and the second image forming unit, and a combination by the polarization combining optical system An image having a projection optical system that projects the image light on the projection surface, a function of controlling a total of six light modulation elements provided in the first image forming unit and the second image forming unit, and a function of controlling the light source Display control unit A projector, wherein among the six light modulation elements, four light modulation elements are light modulation elements corresponding to green light, and the remaining two light modulation elements are light modulation elements corresponding to red light and blue light, The image display control unit includes the light source and the green light so that each color light modulated by the four light modulation elements corresponding to the green light is sequentially emitted with a predetermined time shift in each frame of the image data. The four light modulation elements corresponding to are controlled.

The projector of the present invention is a projector having two systems of image forming means (first image forming means and second image forming means) and one projection optical system. In the projector having such a configuration, Among these light modulation elements, four light modulation elements are used as light modulation elements corresponding to green light, and the remaining two light modulation elements are used as light modulation elements corresponding to red light and blue light. The light source and the four light modulation elements are controlled so that the respective color lights modulated by the four light modulation elements are emitted with a predetermined time shift in each frame of the image data. By performing such control, it is possible to increase the frame rate of image data corresponding to green sensitive to human eyes, and display a moving image with high visibility.

Further, image data to be given to three light modulation elements among four light modulation elements corresponding to green light generates an intermediate image from the image data of the frame and the image data of the next frame in each frame. It is preferable to provide the generated intermediate image. Note that various intermediate image generation techniques that are generally performed, such as generation based on a motion vector, can be employed for the generation of the intermediate image. Moreover, since the process which produces | generates an intermediate image should just be performed about green, compared with the case where the intermediate image is produced | generated about each RGB, the amount of calculations can be reduced significantly.

In the projector according to the aspect of the invention, it is preferable that the predetermined time is 1/4 of a time corresponding to each frame of the image data.
In this way, by setting each color light modulated by the four light modulation elements corresponding to the green light to be shifted by a time corresponding to a quarter frame in each frame of the image data, it corresponds to the green light. The frame rate of the image data can be four times that of the image data corresponding to red light and blue light. As described above, by increasing the frame rate of image data corresponding to green light sensitive to human eyes, it is possible to display a highly visible moving image.

In the projector according to the aspect of the invention, it is preferable that the light source is a solid light source that emits the red light, the green light, and the blue light.
By using a solid light source (for example, LED) that emits each color of RGB as the light source, the light source can be switched on and off quickly, so that the present invention can be easily realized. Further, it is possible to eliminate the need for a dichroic mirror, a relay lens, etc., and to obtain an effect that the configuration of the optical system can be simplified.

In the projector according to the aspect of the invention, the four light modulation elements corresponding to the green light are first to fourth.
When the light modulation element is used, the first image forming unit includes first and second light modulation elements among the first to fourth light modulation elements and a light modulation element corresponding to red light, The two-image forming unit is preferably composed of third and fourth light modulation elements and a light modulation element corresponding to blue light.
This is a configuration in which four light modulation elements corresponding to green light are assigned to each of the first image forming unit and the second image forming unit, and by such a configuration, The projector of the present invention can be realized.

In the projector of the present invention, the green light is used as two types of green light: a first green light having a wavelength band closer to blue light and a second green light having a wavelength band closer to yellow light. The first green light is applied to the first light modulating element of the first image forming means and the third light modulating element of the second image forming means, and the second light modulation of the first image forming means is provided. The second green light is preferably applied to the element and the fourth light modulation element of the second image forming unit.

Thus, by using two types of green light having different wavelength bands as green light, a general cross dichroic prism can be used as the combining optical system. In addition,
The wavelength band of the green light is about 500 nm to 565 nm. Among such wavelength bands, the green light in the wavelength band of 500 nm to 532 nm is the first green light, and the green light in the wavelength band of 533 nm to 565 nm is the second. An example is green light.

In the projector according to the aspect of the invention, the first green light and the second green light have a time in which the first green light and the second green light overlap within a time corresponding to each frame of the image data. It is preferable that the first to fourth light modulation elements are sequentially given with a time shift.

In this way, simultaneously turning on the green light source that emits the first green light and the green light source that emits the second green light prevents the human eyes from seeing green as two types of green. Because. That is, by using green light as two types of green light, it is possible to use a general cross dichroic prism as a composite optical system, while green is 2 in human eyes.
Since it may be visually recognized as a kind of green, in order to prevent this, a green light source that emits first green light and a green light source that emits second green light are turned on simultaneously. In this case, since there is a time during which images from the two light modulation elements corresponding to green light are projected in an overlapping manner, green can be displayed brightly, which is suitable for an image that emphasizes brightness. It becomes.

In the projector according to the aspect of the invention, the image display control unit may cause the first to fourth light modulators to start driving before the time when the first green light or the second green light starts to emit light. It is preferable to control the first to fourth light modulation elements.
This is because when the light modulation element is a light modulation element using liquid crystal, green light can be given to the light modulation element during the stable operation period of the liquid crystal. In this way, the image quality can be improved by providing green light during the stable operation period of the light modulation element.

In the projector according to the aspect of the invention, the four light modulation elements corresponding to the green light are first to fourth.
When the light modulation element is used, the first image forming means is constituted by first to third light modulation elements among the first to fourth light modulation elements, and the second image forming means is a fourth light modulation element. It is also preferable that the optical modulator is configured by an element, a light modulation element corresponding to the red light, and a light modulation element corresponding to the blue light.
This is a configuration in which three of the four light modulation elements corresponding to green light are assigned to the first image forming means, and the remaining one light modulation element is assigned to the second image forming means. Thus, the projector of the present invention can also be realized with such a configuration. In this case, each green light uses a monochromatic green light having a wavelength band of about 500 nm to 565 nm.

In the projector according to the aspect of the invention, the green light may be sequentially supplied to the first to fourth light modulation elements without overlapping each other within a time corresponding to each frame of the image data to be projected. preferable.
This is made possible by making each green light into a monochromatic green light having a wavelength band of about 500 nm to 565 nm. In addition, since the images corresponding to each green light are displayed without overlapping, a high-quality image can be displayed.

In the projector according to the aspect of the invention, the image display control unit may perform the first to fourth light modulations so that the first to fourth light modulation elements start driving before the time when the green light starts to emit light. It is preferable to control the element.
This is also because, as described above, when the light modulation element is a light modulation element using liquid crystal, green light can be given to the light modulation element during the stable operation period of the liquid crystal. In this way, the image quality can be improved by providing green light during the stable operation period of the light modulation element.

In the projector according to the aspect of the invention, it is preferable that the light modulation element is a light modulation element using liquid crystal.
In the projector according to the present invention, when a light modulation element (liquid crystal panel) using liquid crystal is used, a more remarkable effect can be obtained.

An image display method in a projector according to the present invention includes three light modulation elements that modulate color light from a light source based on image data, and each color light modulated by the three light modulation elements is emitted as first image light. A first image forming unit that modulates the color light from the light source based on the image data, and emits each color light modulated by the three light modulation elements as the second image light. 2 image forming means, a polarization combining optical system for combining the first image light and the second image light emitted from the first image forming means and the second image forming means, and the polarization combining optical system. Image display control having a projection optical system for projecting image light onto a projection surface, a function for controlling a total of six light modulation elements provided in the first image forming means and the second image forming means, and a function for controlling the light source Have a part and That an image display method in the projector, the 6
Of the two light modulation elements, four light modulation elements are used as light modulation elements corresponding to green light, and the remaining two light modulation elements are used as light modulation elements corresponding to red light and blue light. The light sources and the four lights corresponding to the green light are sequentially emitted so as to be shifted by a predetermined time in each frame of the image data in the respective frames of the image data. The modulation element is controlled.

In a projector having two systems of image forming means (first image forming means and second image forming means) and one projection optical system, the image display method in the projector according to the invention is adopted, thereby the projector according to the invention. And the effects described in the projector of the present invention can be obtained. The image display method in the projector of the present invention preferably has the same characteristics as the projector of the present invention.

Hereinafter, embodiments of the present invention will be described.
[Embodiment 1]
FIG. 1 is a diagram schematically illustrating an optical configuration of a projector according to the first embodiment. The projector according to the first embodiment is a projector having two image forming units (referred to as image forming units) and one projection optical system. As shown in FIG. 1, the two image forming units 100 and 200 are used. (Referred to as the first image forming unit 100 and the second image forming unit 200) and the respective image lights emitted from the first image forming unit 100 and the second image forming unit 200 (referred to as first image light and second image light). ) And a projection optical system 400 that projects the image light synthesized by the polarization synthesis prism 300 onto a screen SCR as a projection surface.

The first image forming unit 100 includes first to third light source devices 110 to 130 as light source devices, and the second image forming unit 200 serves as fourth to sixth light source devices 210 to 23 as light source devices.
0. First to third light source devices 110 to 130 and fourth to sixth light source devices 210 to 2
A solid light source (LED) is used as the light source 30.

The first light source device 110 in the first image forming unit 100 includes a plurality of red light sources R configured by a plurality of red LEDs that emit red light and a plurality of red LEDs that correspond to the plurality of red LEDs that configure the red light source R. The condenser lens 111, the rod integrator 112, and the condenser lens 113 provided on the output side of the rod integrator 112 are included.

In addition, the second light source device 120 includes a first green light source G1 composed of a plurality of green LEDs that emit green light, and a plurality of collections provided corresponding to the plurality of green LEDs that constitute the first green light source G1. It has an optical lens 121, a rod integrator 122, and a condenser lens 123 provided on the output side of the rod integrator 122.

The third light source device 130 includes a second green light source G2 composed of a plurality of green LEDs that emit green light, and a plurality of light sources provided corresponding to the plurality of green LEDs constituting the second green light source G2. It has an optical lens 131, a rod integrator 132, and a condensing lens 133 provided on the output side of the rod integrator 132.

The first image forming unit 100 includes light modulation elements 150R, 150G1, and 150G2 corresponding to the first to third light source devices 110 to 130, and light modulation elements 150R and 150G.
It further has a synthesis optical system 160 that synthesizes each color light modulated by 1,150G2. The synthesizing optical system 160 uses a cross dichroic prism and has a light modulation element 150R.
A function of reflecting the red light modulated by the optical modulation element, transmitting the green light modulated by the light modulation element 150G1, reflecting the green light modulated by the light modulation element 150G2, and combining the respective color lights. Yes.

The fourth light source device 210 in the second image forming unit 200 is provided corresponding to the blue light source B composed of a plurality of blue LEDs emitting blue light and the plurality of blue LEDs constituting the blue light source B. A plurality of condenser lenses 211, a rod integrator 212, and a condenser lens 213 provided on the output side of the rod integrator 212 are provided.

The fifth light source device 220 includes a third green light source G3 composed of a plurality of green LEDs that emit green light, and a plurality of light sources provided corresponding to the plurality of green LEDs constituting the third green light source G3. It has an optical lens 221, a rod integrator 222, and a condenser lens 223 provided on the output side of the rod integrator 222.

The sixth light source device 230 includes a fourth green light source G4 composed of a plurality of green LEDs emitting green light and a plurality of light sources provided corresponding to the plurality of green LEDs constituting the fourth green light source G4. It has an optical lens 231, a rod integrator 232, and a condensing lens 233 provided on the output side of the rod integrator 232.

The second image forming unit 200 includes light modulation elements 250B, 250G3, and 250G4 corresponding to the fourth to sixth light source devices 210 to 230, and light modulation elements 250B and 250G.
It further has a synthesis optical system 260 that synthesizes each color light modulated by 3,250G4. The synthesizing optical system 260 uses a cross dichroic prism, and the light modulation element 250B.
The blue light modulated by the light modulation element 250G3 is reflected, the green light modulated by the light modulation element 250G3 is reflected, the green light modulated by the light modulation element 250G4 is transmitted, and the respective color lights are combined. Yes.

In FIG. 1, a case where a rod integrator is used as an integrator is illustrated, but a lens integrator may be used. In addition, the light modulation elements 150R and 150G
1, 150G2 and light modulation elements 250B, 250G3, 250G4 are light modulation elements (liquid crystal panels) using liquid crystals.

By the way, although the wavelength band of green light is about 500 nm to 565 nm, in the projector according to the first embodiment, green light having a wavelength band of about 500 nm to 565 nm is converted into a wavelength band (500 nm to Two types of green light: green light (wavelength band of 532 nm) (referred to as first green light) and green light (referred to as second green light) in a wavelength band (wavelength band of 533 nm to 565 nm) closer to yellow light use.

In this way, by using the green light as two types of green light, the first green light and the second green light, the combining optical system 160 of the first image forming unit 100 and the second image forming unit 2 are used.
The 00 combining optical system 260 can use a general cross dichroic prism.

In the projector according to the first embodiment, the light modulation element 150G1 of the first image forming unit 100 and the light modulation element 250G3 of the second image forming unit 200 include 500 nm to 5 nm.
First green light having a wavelength band of 32 nm is applied, and the light modulation element 150G2 of the first image forming unit 100 and the light modulation element 250G4 of the second image forming unit 200 are 533n.
It is assumed that the second green light having a wavelength band of m to 565 nm is set.

FIG. 2 is a configuration diagram for explaining functions of the projector according to the first embodiment. As shown in FIG. 2, the projector according to the first embodiment includes an image data input unit 610 that inputs image data corresponding to an image to be displayed, and various interface signals (such as user instructions and settings).
I / F signal input unit 620 capable of inputting (I / F signal), a data storage unit 630 for storing various data necessary for projection processing such as image data to be displayed, and correction processing. A parameter storage unit 640 for storing the various parameters, a function for generating and correcting image data given to each light modulation element, and a total of six provided in the first image forming hand unit 100 and the second image forming unit 200. An image having various functions for performing overall processing such as a function for controlling one light modulation element and a function for controlling each light source (red light source R, blue light source B, first to fourth green light sources G1 to G4). The light modulation elements 150R, 150G1, and 150G2 of the first image forming unit 100 are controlled by the display control unit 660 and the image display control unit 660.
And light modulation element driving units 651R, 651G1, 651G2, 651B, 651G3, 65 for driving the light modulation elements 250B, 250G3, 250G4 of the second image forming unit 200.
1G4 and each light source (red light source R, blue light source B, first light source) under the control of the image display controller 660.
To a fourth light source G1 to G4).

The image display control unit 660 includes four light modulation elements 150G1, 15 corresponding to green light.
It also has a function of controlling the drive timing of the light modulation element so as to shift the drive timing of 0G2, 250G3, 250G4 by a predetermined time and a function of generating an intermediate image.

FIG. 3 is a diagram for explaining the relationship between the operation of the light source and the driving of the light modulation element in the projector according to the first embodiment. 3A shows the operation of the first green light source G1 corresponding to the light modulation element 150G1, FIG. 3B shows the operation of the second green light source G2 corresponding to the light modulation element 150G2, and FIG.
) Shows the operation of the third green light source G3 corresponding to the light modulation element 250G3, and FIG. 3D shows the operation of the fourth green light source G4 corresponding to the light modulation element 250G4. 3E shows the operation of the red light source R corresponding to the light modulation element 150R, and FIG. 3F shows the operation of the blue light source B corresponding to the light modulation element 250B.

In FIGS. 3A to 3F, the gray area indicates that the light source is turned on, and the white area indicates that the light source is turned off. 3A to 3D, the green light uses the first green light having a wavelength band of 500 nm to 532 nm and the second green light having a wavelength band of 533 to 565 nm. Are divided into dark gray (first green light) and light gray (second green light).

As shown in FIGS. 3A to 3D, in the projector according to the first embodiment, the first green light source G1 and the second green light source G2 of the first image forming unit 100 and the second green light source G2 of the second image forming unit 200 are used. The 3 green light source G3 and the fourth green light source G4 are sequentially turned on every time corresponding to a quarter frame obtained by dividing one frame of the image data into four (this is set as Δt time), and the lighting state is 2 Continue for a time corresponding to / 4 frame (2Δt time). Therefore, the first green light source G1, the second green light source G2, the third green light source G3, and the fourth green light source G4 are each a green light source (first green light source G1 and The third green light source G3) and the green light sources emitting the second green light (the second green light source G2 and the fourth green light source G4) are turned on by overlapping by Δt time.

For example, regarding the second frame F2, in the time corresponding to the first quarter frame obtained by equally dividing the second frame F2 into four (referred to as Δt1 time), the first green light source G1.
And the fourth green light source G4 are turned on simultaneously, and the time corresponding to the second quarter frame (Δt
2 hours), the first green light source G1 and the second green light source G2 are turned on simultaneously.
In addition, in Δt time (Δt3 time) corresponding to the third quarter frame,
The second green light source G2 and the third green light source G3 are turned on at the same time, and the third green light source G3 and the fourth green light source G4 in the Δt time (Δt4 time) corresponding to the fourth quarter frame.
And light up simultaneously.

As described above, the green light source that emits the first green light and the green light source that emits the second green light are simultaneously turned on in order to prevent the human eyes from seeing green as two types of green. It is. That is, by using two types of green light (first green light and second green light), a general cross dichroic prism can be used as a composite optical system. Since it may be visually recognized as a kind of green, in order to prevent this, a green light source that emits first green light and a green light source that emits second green light are turned on simultaneously.

FIGS. 3E and 3F show the operations of the red light source R and the blue light source B, and the red light source R and the blue light source B perform continuous lighting. The image display control unit 660 performs the light source on / off control as shown in FIGS. That is, the image display control unit 660 is set with the timing of turning on / off each light source, and the light source driving unit 670 turns on or off a predetermined light source based on the set content.

3 (g) to 3 (l) show the driving time of each light modulation element, and FIG. 3 (g)
Is the drive time of the light modulation element 150G1, FIG. 3 (h) is the drive time of the light modulation element 150G2, FIG. 3 (i) is the drive time of the light modulation element 250G3, and FIG. 3 (j) is the drive time of the light modulation element 250G4. FIG. 3 (k) shows the driving time of the light modulation element 150R, FIG. 3 (l) shows the driving time of the light modulation element 250B, and the portions shown in gray are the time during which each light modulation element is driven. Is shown. The drive timing control for each light modulation element as shown in FIGS. 3G to 3L is performed by the image display control unit 660. That is, the image display control unit 660 has a drive timing for driving each light modulation element, and the light modulation element driving units 651R, 651B, 651G1 to 651G4 correspond to the light modulation elements based on the set contents, respectively. Drive.

As shown in FIGS. 3G to 3L, the light modulation elements 150G1 and 150G corresponding to green light.
2 and the light modulation elements 250G3 and 250G4 are driven so as to correspond to the lighting of the first to fourth green light sources G1 to G4. At this time, the lighting time of the first to fourth green light sources G1 to G4 (2Δt
The time including the time Δt before and after (time) is defined as the driving time. Therefore, in this case, the driving time of the light modulation elements 150G1 and 150G2 and the light modulation elements 250G3 and 250G4 corresponding to green light is 4Δt time (time corresponding to one frame). Each color light modulated by 150G2 and the light modulation elements 250G3 and 250G4 is emitted for 2Δt time.

As described above, the time including the time Δt before and after the lighting time (2Δt time) of the first to fourth green light sources G1 to G4 is used as the driving time of each light modulation element. This is because the light source emits light during the stable operation period of the liquid crystal. Such control is performed by the image display control unit 660. That is, the image display control unit 660
Are set such that the light modulation elements 150G1 and 150G2 and the light modulation elements 250G3 and 250G4 start driving before the time when the first to fourth green light sources G1 to G4 start to emit light, respectively. Based on the setting contents, the light modulation element driving units 651G1 to 651G.
4 respectively control the corresponding light modulation elements 150G1, 150G2, 250G3, 250G4.

The projector according to the first embodiment is configured as shown in FIGS. 1 and 2, and the light source and the light modulation element are driven as shown in FIG. 3, so that the frame rate of image data corresponding to green light can be set. The image data corresponding to red light and blue light can be set to 4 times.

In addition, the light modulation elements 150G1, 150G2, 250G3, 250G4 corresponding to the green light
Of these, if the frame (referred to as the nth frame) of the frames originally included in the image data is given to the light modulation element 150G1, the other light modulation element 150G2
, 250G3, 250G4 are preferably given, for example, three intermediate images generated from the nth frame and the (n + 1) th frame of the image data. For the generation of the intermediate image, various commonly used intermediate image generation techniques such as an intermediate image generation technique based on a motion vector can be employed. Such an intermediate image generation process is performed by the image display control unit 660.

As described above, according to the projector according to the first embodiment, the frame rate of image data corresponding to green light can be four times that of image data corresponding to red light and blue light. Further, when generating an intermediate image, the generation process of the intermediate image may be performed for green, so that the amount of calculation can be significantly reduced as compared with the case of performing for each color of RGB. In addition, since the frame rate of the image data corresponding to the green light most sensitive to human eyes is increased, the effect of improving the visibility of the moving image can be further enhanced.

In the projector according to the first embodiment, since the green light is two types of green light (first green light and second green light) having different wavelength bands, a general cross dichroic prism is used as the combining optical system. can do. When the green light source is turned on, the first green light and the second green light are turned on at the same time, so that the human eyes can be prevented from being viewed as two types of green. it can.

[Embodiment 2]
FIG. 4 is a diagram schematically illustrating an optical configuration of the projector according to the second embodiment. Similarly to the projector according to the first embodiment, the projector according to the second embodiment is a projector having two image forming units and one projection optical system. However, in the case of the projector according to the first embodiment, the first image formation is performed. All the light sources on the unit 100 side are green light sources (first green light source G1).
, A second green light source G2 and a third green light source G3), and the light source on the second image forming unit 200 side is a red light source R, a green light source (fourth green light source G4), and a blue light source B as in a normal projector.
Is different. In the projector according to the second embodiment, the light source is preferably an individual light source such as an LED. In the projector according to the second embodiment, the green light emitted from each green light source is monochromatic green light having a wavelength band of about 500 nm to 565 nm.

Thus, in the projector according to the second embodiment, the first image forming unit 100 is used.
Since all are green light sources, the light modulation elements provided in the first image forming unit 100 are referred to as light modulation elements 150G1, 150G2, and 150G3. The second image forming unit 2
Since 00 is a red light source R, a fourth green light source G4, and a blue light source B, the light modulation elements provided in the second image forming unit 200 are light modulation elements 250R, 250G4, and 250B.

In the projector according to the second embodiment, on the first image forming unit 100 side, as a combining optical system, a combining optical system (combining optical system 170) having a configuration in which two half mirrors 170a and 170b are combined in an X shape. ). Accordingly, the respective color lights modulated by the first green light source G1, the second green light source G2, and the third green light source G3 in the first image forming unit 100 are transmitted or reflected by the half mirrors 170a and 170b and emitted. .
If the transmittance of each half mirror is 50%, the respective color lights emitted from the first green light source G1, the second green light source G2, and the third green light source G3 are transmitted to the half mirror 170a and the half mirror 170b. Therefore, the light quantity is 25% with respect to the light quantity of each light source.

On the other hand, on the second image forming unit 200 side, since the color light emitted from the light source is red light, green light, and blue light, a general cross dichroic prism can be used as the combining optical system 260.

FIG. 5 is a configuration diagram for explaining functions of the projector according to the second embodiment. In FIG. 5, the same parts as those in FIG. In the projector according to the second embodiment, the light modulation elements in the first image forming unit 100 are the light modulation elements 150G1, 150G2, and 150G3 corresponding to green light, and the light modulation elements in the second image forming unit 200 are red. Light modulation elements 250R and 250G corresponding to light, green light and blue light
4,250B. As the light modulation element driving unit, as shown in FIG. 5, the first image forming unit 100 is provided with light modulation element driving units 651G1, 651G2, and 651G3, and the second image forming unit 200 is provided with light modulation. Element driver 651R, 651G
4,651B is provided.

FIG. 6 is a diagram for explaining the relationship between the operation of the light source and the driving of the light modulation element in the projector according to the second embodiment. 6A shows the operation of the first green light source G1 corresponding to the light modulation element 150G1, FIG. 6B shows the operation of the second green light source G2 corresponding to the light modulation element 150G2, and FIG.
) Indicates the operation of the third green light source G3 corresponding to the light modulation element 150G3, FIG. 6D corresponds to the operation of the fourth green light source G4 corresponding to the light modulation element 250G4, and FIG. 6E corresponds to the light modulation element 250R. FIG. 6F shows the operation of the blue light source B corresponding to the light modulation element 250B. In FIGS. 6A to 6F, a gray area indicates that the light source is turned on, and a white area indicates that the light source is turned off.

In the projector according to the second embodiment, the green light source G of the first image forming unit 100 is used.
1, G2, G3 and the green light source G4 of the second image forming unit 200 are sequentially turned on every time (Δt time) corresponding to ¼ frame, and the lighting state is maintained for Δt time. Thus, in the projector according to the second embodiment, since the green light is one type,
The first to fourth green light sources G1 to G4 sequentially repeat the operation of maintaining the lighting state for Δt time every Δt time.

The light source on / off control as shown in FIGS. 6A to 6F is performed by the image display control unit 660 on the light source driving unit 670 as in the projector according to the embodiment.

FIG. 6G shows the driving time of the light modulation element 150G1, and FIG. 6H shows the light modulation element 150G.
6 (i) shows the driving time of the light modulation element 150G3, FIG. 6 (j) shows the driving time of the light modulation element 250G4, FIG. 6 (k) shows the driving time of the light modulation element 250R, and FIG. l) indicates the drive time of the light modulation element 250B, and the gray portion indicates the time during which each light modulation element is driven.

6 (g) to 6 (l), the green light sources G1, G2 and G are the same as in FIGS. 3 (g) to 3 (l).
3, the driving time is the time including the Δt time before and after the lighting time of G4 (Δt time in this case). Therefore, the light modulation elements 150G1, 150G2, 150G3 corresponding to the green light
In this case, the driving time of the light modulation element 250G4 is 3Δt.
Each color light modulated by 50G1, 150G2, 150G3 and the light modulation element 250G4 is emitted for Δt time. The timing control for driving each light modulation element as shown in FIGS. 6G to 6L is performed based on the setting contents of the image display control unit 660 as in the projector according to the embodiment. 651R, 651B, 651G1 to 651G4 are performed by driving the corresponding light modulation elements, respectively.

The projector according to the second embodiment is configured as shown in FIGS. 4 and 5, and the light source and the light modulation element are driven as shown in FIG. The image data corresponding to red light and blue light can be set to 4 times.

Note that, similarly to the projector according to the first embodiment, the light modulation element 150G1 corresponding to green light.
, 150G2, 150G3, and 250G4, if the nth frame originally included in the image data is given to the light modulation element 150G1, the other light modulation elements 150G2 and 150G2 are provided.
150G3 and 250G4 are preferably provided with three intermediate images generated from the nth frame and the (n + 1) th frame of the image data.

As described above, in the projector according to the second embodiment, as in the projector according to the first embodiment, the frame rate of image data corresponding to green light is four times that of image data corresponding to red light and blue light. It is possible to increase the visibility of moving images. In addition, since the process for generating the intermediate image may be performed for green, the amount of calculation can be significantly reduced as compared with the case of performing for each color of RGB. In addition, since the frame rate of the image data corresponding to green that is most sensitive to human eyes is increased, the effect of improving the visibility of moving images can be further increased.

In the case of the projector according to the second embodiment, as can be seen from FIG. 6, for green light, the same effect as the black image insertion can be obtained, and an effect that a smoother image display can be realized can be expected. .

In the projector according to the second embodiment, the two half mirrors 1 each color light modulated by the three light modulation elements 150G1 to 150G3 in the first image forming unit 100 are used.
Although the case where it radiates | emits by the synthetic | combination optical system 170 which has 70a, 170b was illustrated, green light is made into several wavelength bands (three wavelength bands in the projector which concerns on Embodiment 2) similarly to the projector which concerns on Embodiment 1. FIG. The divided three types of green light can be combined by a cross dichroic prism. In this case, since three types of green light are generated, it is preferable that the three types of green light be simultaneously applied to the light modulation element in order to prevent the human eye from viewing the three types of green light. .

The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention. For example, in each of the above-described embodiments, the light source is LE.
Although an example using D is shown, a laser (semiconductor laser) or the like may be used. Alternatively, each color light of RGB obtained by performing spectroscopy from a white light source may be applied to a corresponding light modulation element.

Further, in each of the above-described embodiments, from the viewpoint that it is preferable that the light source emits light during the stable operation period of the liquid crystal, the light modulation element of the light modulation element is equivalent to a time corresponding to 1/4 frame before and after the light emission time of each light source. Although the driving time is set, the time corresponding to 1/4 frame may be set only on the front side of the light emission start of each light source, not before and after. Further, in order to provide a further margin, a time longer than the time corresponding to ¼ frame may be set.

Further, in each of the above-described embodiments, an example in which a transmissive liquid crystal panel is used as the light modulation element has been described. The light modulation element is
Not only a light modulation element using liquid crystal but also a micromirror type light modulation element.

FIG. 2 is a diagram schematically illustrating an optical configuration of the projector according to the first embodiment. FIG. 3 is a configuration diagram for explaining functions of the projector according to the first embodiment. FIG. 6 is a diagram for explaining a relationship between the operation of the light source and the driving of the light modulation element in the projector according to the first embodiment. FIG. 6 is a diagram schematically illustrating an optical configuration of a projector according to a second embodiment. FIG. 6 is a configuration diagram for explaining functions of a projector according to a second embodiment. FIG. 6 is a diagram for explaining the relationship between the operation of a light source and driving of a light modulation element in a projector according to a second embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... 1st image forming unit, 110-130 ... 1st-3rd light source device, 15
0R, 150G1, 150G2, 150G3... Light modulation element, 160, 260... Synthesis optical system (cross dichroic prism), 170... Synthesis optical system (synthesis optical system using half mirror), 250R, 250B , 250G3, 250G4... Light modulation element,
200 ... second image forming unit, 210 to 230 ... fourth to sixth light source devices, 300
... Polarization combining prism, 400 ... Projection optical system, 660 ... Image display control unit, 65
1R, 651B, 651G1 to 651G4: Light modulation element driving unit, 670: Light source driving unit, G1 to G4: First to fourth green light sources, R: Red light source, B: Blue light source

Claims (12)

A first image forming unit that includes three light modulation elements that modulate color light from a light source based on image data, and synthesizes each color light modulated by the three light modulation elements to emit as first image light; ,
A second image forming unit that includes three light modulation elements that modulate the color light from the light source based on the image data, and synthesizes each color light modulated by the three light modulation elements and emits the second light as a second image light; ,
A polarization combining optical system that combines the first image light and the second image light emitted from the first image forming unit and the second image forming unit;
A projection optical system that projects the image light combined by the polarization combining optical system onto a projection surface;
An image display control unit having a function of controlling a total of six light modulation elements provided in the first image forming unit and the second image forming unit and a function of controlling the light source;
A projector having
Among the six light modulation elements, four light modulation elements are light modulation elements corresponding to green light, and the remaining two light modulation elements are light modulation elements corresponding to red light and blue light,
The image display control unit
The light sources and the four light modulations corresponding to the green light are sequentially emitted with a predetermined time shifted in each frame of the image data, respectively, in each frame of the image data, which is modulated by the four light modulation elements corresponding to the green light. A projector characterized by controlling an element. The projector according to claim 1, wherein
The projector according to claim 1, wherein the predetermined time is a quarter of a time corresponding to each frame of the image data. The projector according to claim 1 or 2,
The projector is characterized in that the light source is a solid light source that emits the red light, the green light, and the blue light. The projector according to any one of claims 1 to 3,
When the four light modulation elements corresponding to the green light are the first to fourth light modulation elements, the first
The image forming means includes first and second light modulating elements among the first to fourth light modulating elements and a light modulating element corresponding to red light, and the second image forming means includes the third and second light modulating elements. A projector comprising four light modulation elements and a light modulation element corresponding to blue light. The projector according to claim 4, wherein
The green light is used as two types of green light, a first green light having a wavelength band close to blue light and a second green light having a wavelength band close to yellow light, and the first image formation. The first green light is applied to the first light modulation element of the means and the third light modulation element of the second image forming means, and the second light modulation element and the second image of the first image forming means are provided. The projector according to claim 1, wherein the second green light is applied to the fourth light modulation element of the forming unit. The projector according to claim 5, wherein
The first green light and the second green light have a time during which the first green light and the second green light overlap within a time corresponding to each frame of the image data. A projector characterized in that the light modulation element is sequentially given to the light modulation element while shifting the time. The projector according to claim 5 or 6,
The image display control unit includes the first to fourth lights so that the first to fourth light modulators start driving before the time when the first green light or the second green light starts to emit light. A projector characterized by controlling a modulation element. The projector according to any one of claims 1 to 3,
When the four light modulation elements corresponding to the green light are the first to fourth light modulation elements, the first
The image forming means is composed of first to third light modulation elements among the first to fourth light modulation elements,
The second image forming means includes a fourth light modulation element, a light modulation element corresponding to the red light, and a light modulation element corresponding to the blue light. The projector according to claim 8, wherein
The projector is characterized in that the green light is sequentially given to the first to fourth light modulation elements without being overlapped at different times within a time corresponding to each frame of the image data to be projected. The projector according to claim 8 or 9,
The image display control unit controls the first to fourth light modulation elements such that the first to fourth light modulation elements start driving before the time when the green light starts to emit light. Characteristic projector. The projector according to any one of claims 1 to 10,
The projector according to claim 1, wherein the light modulation element is a light modulation element using liquid crystal. A first image forming unit that includes three light modulation elements that modulate color light from a light source based on image data, and that emits each color light modulated by the three light modulation elements as first image light; A second image forming unit that emits each color light modulated by the three light modulation elements as a second image light, and three light modulation elements that modulate the color light of the first color image based on the image data; A polarization combining optical system that combines the first image light and the second image light emitted from the forming unit and the second image forming unit, and projection optics that projects the image light combined by the polarization combining optical system onto a projection surface An image display method in a projector having a system and an image display control unit having a function of controlling a total of six light modulation elements provided in the first image forming unit and the second image forming unit and a function of controlling the light source There
Among the six light modulation elements, four light modulation elements are used as light modulation elements corresponding to green light, and the remaining two light modulation elements are used as light modulation elements corresponding to red light and blue light,
The image display control unit
The light sources and the four light modulations corresponding to the green light are sequentially emitted with a predetermined time shifted in each frame of the image data, respectively, in each frame of the image data, which is modulated by the four light modulation elements corresponding to the green light. An image display method in a projector, characterized by controlling an element.