JP2003307705A - Illumination optical system and projector using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a projector which enables the adjustment of illuminance and coloring and enables a black-and-white display brighter than a full color display. <P>SOLUTION: The projector 1 is provided with a discharge lamp 60, a color wheel 70 which receives the light from the discharge lamp 60 and respectively fractionates the same into the rays of light having at least wavelengths of R, G and B, a DMD 50 which optically modulates the lights R, G, B fractionated by the color wheel, a projection means 100 which projects the light modulated by the DMD (digital mirror device) 50 and a color wheel driving part 40 which makes the position of the color wheel 70 changeable. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a projector, and more particularly to a DMD (Digital Mirror D).
DLP (Digital Lig)
ht Processing: DLP relates to a projector of the Texas Instruments (registered trademark) system.

[0002]

2. Description of the Related Art A DLP type projector irradiates a DMD made of a semiconductor element with light and magnifies and projects the reflected light with a lens to display an image in color. Patent Document 1 previously filed by the present applicant discloses an outline of a DLP type projector. As shown in FIG. 1 of Patent Document 1, white light from a light source is reflected by an elliptical mirror 52, and the reflected light is sequentially RGB by a disk-shaped color hole 53 in which R / G / B color filters are arranged.
The color is changed and the light is incident on the DMD 56. DMD56
Are driven in time division in synchronization with RGB, and the light reflected according to the image data is displayed on the screen 58 via the projection lens 57. The projection of such a color image is
Since a single color wheel is used for color display, it is called a so-called single plate type.

A color wheel used in the DLP system has R / G / B color filters arranged on the outer periphery thereof and is rotated at a constant speed. The white light emitted from the light source is reflected by the elliptical mirror 52 and then passes through the rotating color wheel. At this time, the white light is R / G / B (/
The color filter W) separates or converts light having R, G, and B wavelengths. The R, G, and B lights are time-divisionally illuminated on the DMD, where optical modulation is performed and a projection image is displayed on the screen.

[0004]

[Patent Document 1] Japanese Patent No. 3,121,843

[0005]

However, since the conventional projector has a structure in which a color wheel is inserted between the light source and the DMD and light passes therethrough, the loss of light is inevitable and the projection sometimes occurs. The image displayed may not have sufficient brightness. In order to increase the brightness, it is sufficient to increase the output of the light source, but then, the heat generated from the light source also increases and the output of the cooling fan for cooling the light also increases, resulting in a larger projector.

Further, the color wheel is indispensable for displaying a color image. On the other hand, when displaying a graph, a character, etc. in black and white (or in gradation display), the color wheel is used. On the contrary, the brightness may be sacrificed.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve the above conventional problems and to provide a projector capable of displaying brighter when displaying in black and white. A further object of the present invention is to provide a projector capable of selecting full color display and monochrome display with a single device. A further object of the present invention is to provide a projector capable of selecting modes such as illuminance and color of a projected image. Further, the object of the present invention is to let the light from the light source be R,
An object of the present invention is to provide a compact projector in which an optical element such as a color wheel for separating into G and B can be moved and a plurality of illuminances and hues can be selected. A further object of the present invention is to provide an illumination optical system having a plurality of irradiation modes with a single color wheel and a projector using the same. A further object of the present invention is to provide an illumination optical system capable of improving the brightness of white with a low-cost color wheel and a projector using the same.

[0008]

A projector according to the present invention comprises a light source, a light source, and a separating means capable of injecting light from the light source and separating the light into light having at least R, G, and B wavelengths. Modulation means for optically modulating the emitted light,
Projection means for projecting the modulated light and position changing means for changing the position of the sorting means are provided.

Preferably, the separating means is at least R,
An optical element for separating (or converting) light of G and B wavelengths is included, the optical element is divided into a plurality of groups, and one group is selected from the plurality of groups according to the position of the light source separating means. It The optical element includes, for example, a rotated disc-shaped color wheel, and the color wheel has a plurality of sets of color filters arranged to separate light of at least R, G, and B wavelengths. Further, the color wheel can be positioned at a plurality of positions by the position changing means, and emits R, G, and B lights by the corresponding set of color filters among the plurality of sets at the selected position.

Preferably, the projector has position detecting means for detecting the position of the separating means, and controls the modulating means in accordance with the position information of the separating means detected by the position detecting means. Further, it is preferable that the projector controls the position changing means based on the position information of the separating means detected by the position detecting means to position the separating means.

The projector is, for example, a DLP type projector, the light source includes a discharge lamp and a reflector that reflects light from the discharge lamp, and the modulation means is a DMD.
Including a semiconductor mirror element. Furthermore, it is preferable that the light source includes a light tunnel that substantially uniformizes and emits the light from the reflector, and the position changing means moves the separating means in parallel to the longitudinal direction of the exit diameter of the light tunnel.

Further, the projector according to the present invention is provided with a light source, a sorting means which is capable of splitting light from the light source into light having at least R, G and B wavelengths, and optically modulating the sorted light. Modulation means, projection means for projecting the modulated light, and variable means for varying the incident amount of the light incident from the light source to the sorting means.

Preferably, the variable means includes a moving means for moving the sorting means. Then, when the separating means is moved to the first position by the moving means, a part of the light from the light source is incident on the separating means, and the separating means is moved to the second position by the moving means. At this time, it is possible to prevent the light from the light source from entering the sorting means. The separating means includes, for example, a rotated color wheel, and color filters for separating light of at least R, G, and B wavelengths are arranged on the color wheel.

Preferably, the projector has a position detecting means for detecting the position of the separating means, and controls the modulating means based on the position information of the separating means detected by the position detecting means. Further, the projector controls the moving means based on the position information of the sorting means detected by the position detecting means.

Further, the projector has mode selecting means for selecting a mode of an image projected from the outside,
When the mode is selected, the variable means maximizes the amount of light incident on the sorting means, and when the mode selecting means selects the second mode, the variable means minimizes the amount of light incident on the sorting means. And The minimum is, for example, zero, and a black and white image is displayed by the projection means at this time.

Further, in the projection method of the present invention, a light source, a sorting means which is capable of splitting light from the light source into light having at least R, G, and B wavelengths, and the split light is optically modulated. In a projector having a modulating means for projecting and a projecting means for projecting modulated light, a step of selecting a mode of an image to be projected, and the sorting means are positioned at a predetermined position according to the selected mode. And a step of modulating the light from the light source and projecting the light by the projection means. This mode includes an image projection mode.

As described above, the present invention includes at least R, G, and B.
Since the position of the separating means for separating the light having the wavelength of is changed (or moved), it is possible to obtain a projection image with the optimum illuminance and color tone desired by the user,
Further, in the case of monochrome display, the light from the light source can be supplied to the modulating means such as the DMD without passing through the separating means, so that it is possible to provide a significantly bright projection image without loss due to the separating means.

Further, the illumination optical system according to the present invention has a rotation driving means, a filter member connected to the rotation driving means, and a light source for making light incident on the filter member, and the filter members have different colors. It has an arrangement part and emits light in different irradiation modes. Preferably, the different color arranging unit has a region in which filter regions for emitting red (R), blue (G), and green (B) light are continuously arranged, and a white region in addition to each of these filter regions. And a filter region for emitting light. More preferably, the filter member is composed of a filter region that emits red, blue, and green colors and a filter region that emits white light, and has a color arrangement portion having a different area ratio of the region that emits white light. The different irradiation modes are a mode that prioritizes color contrast and a mode that prioritizes luminance due to white light. Different irradiation modes can be realized by changing the incident position of the light from the light source on the filter member. By applying such an illumination optical system to a projector, it is possible to project a projection image in a display mode according to the user's request.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the main configuration of a DLP type projector according to an embodiment of the present invention. The projector 1 receives an image signal 11 and converts it into RGB digital image data having the same number of pixels as the DMD, and controls driving of the DMD 50 based on the digital image data from the preprocessing unit 10 and a lamp drive circuit. 30 and a control unit 20 that controls the color wheel drive unit 40 and the like. Lamp drive circuit 3
0 controls activation of the discharge lamp 60 as a light source and AC driving of the discharge lamp after activation. The color wheel drive unit 40 includes a moving mechanism that rotates the color wheel 70 to convert the light from the discharge lamp 60 into RGB and further moves the color wheel 70 in the horizontal direction. The position detection sensor 80 detects the position of the color wheel 70 and outputs the detection result to the control unit 20. DMD5
In the case of 0, the lights sequentially converted into RGB from the color wheel 70 are irradiated through the illumination optical system 90, and the switching mirror corresponding to each pixel is rotated to reflect the RGB lights. The projection optical system 100 magnifies and projects the reflected light from the DMD 50 to display an image on the screen.

FIG. 2 shows details of the optical system shown in FIG. The discharge lamp 60 as a light source is integrally attached to the elliptical mirror 61, and for example, a xenon arc short lamp, a metal halide lamp, an ultra-high pressure mercury lamp or the like is used. The elliptic mirror 61 is preferably a dichroic mirror or a cold mirror that reflects visible light from the discharge lamp 60 and transmits infrared light, and also for blocking leaked visible light and absorbing infrared light. It is desirable to coat a black inorganic pigment on the outside of the elliptical mirror.

The light tunnel 62 is an optical transmission medium having a constant length and a rectangular cross section, and emits a light beam having a uniform light intensity distribution. The convergent light beam reflected by the elliptical mirror 61 is incident from the entrance of the light tunnel 62 at a predetermined incident angle, and the incident light is multiply reflected on the inner wall having a high refractive index in the light tunnel and propagates to the exit.
The emission aperture of the light emitted from the light tunnel 62 has a long side to short side ratio of 4: 3 (or 16: 9).

The color wheel 70 is rotated at a constant speed by the color wheel driving section 40, and is arranged in such a positional relationship that the light emitted from the light tunnel 62 is incident substantially vertically. The light incident on the color wheel 70 is
The light is sequentially converted (or sorted) into light having R, G, and B wavelengths. The illumination optical system 90 includes a condenser lens 91.
The R, G, and B lights that have passed through the color wheel 70 and include a pair of reflecting mirrors 92 are converted into parallel rays by the condenser lens 91 to illuminate the DMD 50. DMD50
Is the rotation of the color wheel 70, that is, R, G, B
The mirrors that are driven at the timings synchronized with the conversion to R, and that configure each pixel reflect the R, G, and B lights based on the RGB digital image data. The R, G, and B lights reflected in the ON state by the DMD 50 are enlarged and projected by the projection optical system 100, thereby forming an image on the screen.

FIG. 3 shows a plan view of the color wheel. The color wheel 70 has RGB color filters arranged in the shape of a thin glass disk, and selects the wavelength of light transmitted therethrough. In the present embodiment, the color wheel 70 is concentrically divided into three types (three sets) of color filters. The first type color filter 71 has R / G / B color filters arranged within a first radius R1 from substantially the center thereof, and the second type color filter 72 has a first radius R1 and a first radius R1. An R / G / B / W color filter is arranged between the second radius R2 (> the first radius) and the third type color filter 73 has a second radius R2 and a third radius R3 ( > 2nd radius) and R / G
Arrange / B / W color filters. First, second,
A reference boundary line 74 is determined in each of the third color filters 71, 72, 73. The boundary between R and B of the first color filter 71, the second color filter 72
Boundary of W and B, and W and B of the third color filter 73
The reference line 74 is defined so that the boundary of the line becomes a straight line.

The color wheel 70 is rotated by the color wheel drive unit 40 and is movable in the horizontal direction. The moving direction is parallel to the long side defining the exit diameter 63 of the light tunnel 62 while maintaining a substantially vertical relationship with the light tunnel 62. As a result, the light emitted from the light tunnel 62 is relatively moved in the radial direction of the color wheel 70.
0, first, second, and third color filters 71, 72,
Any one of 73 is selected. That is, when the color wheel 70 is in the first position, the light emitted from the light tunnel 62 is emitted from the first color filter 71 within the first radius R1.
When the color wheel 70 is in the second position, the light emitted from the light tunnel 62 passes through the second color filter 72, and when the color wheel 70 is in the third position, passes through the third color filter 73. .

The long side defining the emission aperture 63 of the light tunnel 62 is defined by the first radius R1, the distance between the first and second radii R1 and R2 of the color wheel 70, the second and third radii R2, It is smaller than the distance between R3. Further, the spoke time angle formed by the corner of the emission aperture 63 of the light tunnel 62 and the reference line 74 when the color wheel 70 is in the first, second, and third positions needs to be obtained in advance. For example, when the color wheel 70 is in the first position, the angle formed by the line connecting the corner of the emission aperture 63 and the center of the color wheel 70 and the reference line 74 is θ1.
Similarly, when the color wheel 70 is in the second position, θ2 is set, and when it is in the third position, θ3 is set. As is clear from the figure, the angles increase in the order of θ1, θ2, and θ3. Spoke time angles θ1, θ2, θ3 are DMD
Is important in driving. This is because when light passes through a rotating color filter, light of pure R, G, and B wavelengths cannot always be obtained at the boundary of RGB (W), and a kind of color turbidity in which wavelengths are mixed occurs. Therefore, it is desirable to control the DMD in consideration of this and obtain optimum brightness and optimum color. For example, when the color wheel 70 is rotated in the first position, each boundary of RGB (spoke time angle θ1) per one rotation of the color wheel.
At R, G + G + G + B + B + R = 2RG
B, it is possible to use this boundary period as white. On the other hand, it is also possible to ignore these spoke time angles altogether and turn off the DMD mirror.

R / G / B constituting the first, second, and third type color filters 71, 72, 73.
The ratio of the area occupied by / W determines the brightness and color tone of the image projected by the projector, and is thus determined in advance according to the specifications and application of the projector (for example, home projector, business projector).

The position detection sensor 80 is used for the color wheel 7.
The position of 0 is detected and the detection result is sent to the control unit 20. As described above, the control unit 20 controls the DMD 50 at the timing synchronized with the position of the color wheel 70, that is, the configuration of the selected color filter. Further, the control unit 20 controls the color wheel drive unit 40 based on the position detection result from the position detection sensor 80 to move the color wheel 70 to the selected position (first, second, third position). It may be done. As the position detection sensor 80, a known sensor can be used,
For example, a sensor in which a switch is mechanically or optically opened / closed according to the position of the color wheel 70, or a potentiometer or a magnetic sensor whose magnetism or resistance is variable in response to the position of the color wheel 70 can be used. .

The color wheel drive unit 40 includes a stepping motor for rotating the color wheel 70, and further includes a moving mechanism for moving the color wheel 70 in the horizontal direction. A linear motor or the like may be used as a drive source for horizontal movement, or may be manually moved. In the case of using a linear motor, the color wheel 70 may be moved linearly or may be moved in multiple stages. In the case of manual movement, it is desirable to include a positioning mechanism for accurately positioning the color wheel in the first, second and third positions.

As described above, in the present embodiment, a plurality of types (a plurality of sets) of color filters are prepared for the color wheel, and the types can be appropriately selected, so that the brightness and color of various modes are based. Images can be projected and displayed.

Next, a second embodiment of the present invention will be described. This embodiment has a basic configuration in common with the first embodiment, but as shown in FIG. 4A, R / G /
A color wheel 110 in which B / W filters are arranged is used, and this is moved to four positions. The figure (b) is
The relative positional relationship between the color wheel 110 and the emission aperture 63 of the light tunnel 60 is shown.

The color wheel 110 is in the first position (first
Mode), the exit diameter 63 of the light tunnel 62 is set to the color wheel 11 as shown in FIG.
All of the light that is inside the outer periphery 111a of 0 and is emitted from the emission aperture 63 passes through the color filter. When the color wheel 110 moves parallel to the longitudinal direction of the emission aperture 63 and is in the second position (second mode), part of the emission aperture 63 is outside the outer circumference 111b of the color wheel 110. When the color wheel 110 further moves to the third position (third mode), most of the emission aperture 63 is outside the outer circumference 111c of the color wheel 110. When the color wheel 110 is in the fourth position (fourth mode), the exit aperture 63 is located completely outside the outer circumference 111d of the color wheel, and the light tunnel 62 is
Virtually no light is incident on the color wheel 110. Therefore, although a color image cannot be displayed, a particularly bright black-and-white image can be projected and displayed instead.

In this way, by changing the ratio of the exit diameter of the light tunnel 62 applied to the color wheel in multiple steps, it is possible to change the illumination of the DMD 50, and thus the illuminance and color of the projected image. Then, when the color wheel 110 is in the fourth position, the white light from the discharge lamp 60 illuminates the DMD 50, and the projected image is completely black and white. At this time, since there is no loss of light due to the color wheel 110, it is possible to display a black and white image on the screen, which is considerably brighter than in full color. For example, when importance is attached to brightness rather than color (graphs, sentences, etc.), there is an advantage of selecting such a monochrome mode.

The preferred modes of using the color wheel according to the present embodiment are as follows. a) When color is important: Selection of the first mode b) When there is some color and illuminance is desired: Second,
Selection of the third mode c) When only illuminance is desired: Selection of the fourth mode When selecting the fourth mode, compared to when selecting the first mode,
It is possible to obtain about 3 times the illuminance.

In the first and second embodiments described above, it is possible to provide the projector with selecting means for selecting a mode. According to the preference of the user, for example, in the first embodiment, by selecting a desired color filter from a plurality of sets of color filters, different shades and illuminances can be displayed. In the above embodiment, color and black and white (or gradation display) may be selected. In this case, when the selection mode is selected (or the selection mode is input) by the user, the control unit 20 refers to the position information from the position detection sensor 80 according to the selection mode, and controls the color wheel drive unit 40. The color wheels 70 and 110 may be driven and positioned. Alternatively,
Color wheel 70, 1
The position of 10 may be changed, but in this case, the mode selection and the color wheel positioning selection are performed at the same time.

Further, FIG. 5 shows a color wheel according to a third embodiment of the present invention. The color wheel shown in FIGS. 4 and 5 described above generally forms a color filter on a glass substrate by sputtering or vapor deposition, but this method requires a mask process each time a color filter of each color is formed. Therefore, the number of manufacturing steps is complicated and the manufacturing cost is relatively high. In the color wheel of the third embodiment, glass of each color that transmits light in the R, G, and B bands is prepared, a filter member of a predetermined size is cut out from the glass, and the end surface of the cut filter member is cut. Bonded with an adhesive to form one integrated color filter. The color wheel formed by such a method can be manufactured at a lower cost than the conventional one.

FIG. 5A is a plan view of the color wheel according to the third embodiment, and FIG. 5B is a plan view showing the structure of the filter member. The color wheel 200 according to the present embodiment includes a support member 201 and three filter members 202, 20 attached to the outer periphery of the support member 201.
4, 206. The support member 201 is an annular member having an opening 201a formed in the center thereof, and is made of a metal such as aluminum or iron. Alternatively, other than this, a glass member or a plastic member can be used. A motor rotor (not shown) is coupled to the opening 201a of the support member 201. Color wheel 20
Zero is rotated about the central axis of the support member 201 when the motor is rotationally driven.

Part of the back surface of the color filter members 202, 204, 206 is fixed to the outer peripheral portion of the front surface of the support member 201. For example, it is adhered by an adhesive. In this example, the filter member 202 mainly selects light of the wavelength of the red (R) component, the filter member 204 mainly selects light of the wavelength of the green (G) component, and the filter member 206.
Mainly selects light having a wavelength of the blue (B) component. The filter members 202, 204, 206 are made of glass, for example. Since glass generally has high light transmittance, loss of light absorption can be reduced, and since heat resistance is high, the diameter of light incident on the color wheel can be reduced. By appropriately selecting the substance contained in the glass, it is possible to provide a filter function according to the light passing therethrough.

Each filter member 202, 204, 206
Is cut into a predetermined shape from glass having a constant plate thickness (in this example, the plate thickness is 1 mm). Each filter member 202, 20
4, 206 are 120 with respect to the central axis of the support member 202.
They have an interior angle of degrees and each has the same shape. That is, the filter members 202, 204, 206 have front and back surfaces, inner and outer peripheral surfaces concentric with the opening 201a of the support member 201, radially extending from the central axis of the opening 201a, and inner and outer peripheral surfaces. The end surface 208 of one filter member is bonded to the end surface 208 of another filter member with an adhesive.

A plurality of cutouts 211, 212, 213 are formed in the circumferential direction of the color wheel 200.
For example, when the cutout portion 211 is formed, as shown in FIG.
As shown in (b), the piece portions 211a and 213a of the outer peripheral portion are cut from both end surfaces of the filter member 206 (hatched area in the figure). Similarly, other filter members 202, 2
Also for 04, cut one part. Then, when the end surface 208 of each filter member is joined with an adhesive, notches 211, 212, and 213 are formed on the joining surface, and the notches become hollow regions. Notches 211 and 2
Reference numerals 12 and 213 allow the light applied thereto to be transmitted as they are. In other words, since white light from the lamp, which is a light source, is transmitted as it is, it can be regarded as a white (W) color filter. By positively forming the white filter region on the color wheel 200, the white light transmitted therethrough can be used to improve the brightness of the white color. The cutouts are preferably formed on the color wheel at equal intervals. This is because, when the color wheel is rotated, the weight balance of the color wheel is kept uniform, whereby aerodynamic characteristics can be maintained and noise can be reduced. However, the cutouts do not necessarily have to be evenly spaced in the circumferential direction, and the number and size of the cutouts can be appropriately changed according to the design requirements of the projector. Further, when the cutouts are not arranged at equal intervals in the circumferential direction, or when the size of each cutout is different, a weight may be added to maintain the balance of the color wheel. . For the weight, a metal or other plastic member can be attached by an adhesive.

Next, a fourth embodiment of the present invention will be described. FIG. 6 is a plan view of the color wheel according to the fourth embodiment. In the color wheel 300 according to the fourth embodiment, the R, G, and B color filter members 302, 304, and 306 are adhered to the outer peripheral portion of the support member 301 in which the opening 301a is formed in the center, and the end surface 3
10 are bonded to each other with an adhesive. In addition to the R, G, B color filter members 302, 304, 306,
A W (white) color filter member 308 is included between the filter members 302 and 306. The filter member 308 is cut out from glass that transmits white light. Each time the color wheel 300 makes one rotation, the white light can be transmitted for a period corresponding to the filter member 308, so that the brightness of the white light can be further improved as compared with the conventional color wheel. Further, the color wheel 300 has one notch 3 in a region continuous with the filter member 308.
Includes 14.

Although the preferred embodiments of the present invention have been described in detail as above, the present invention is not limited to the specific embodiments, and the scope of the gist of the present invention described in the claims. Within, various modifications and changes are possible. For example, in the third and fourth embodiments, the end faces of the filter member are bonded to each other with an adhesive, but by fixing a part of the back surface of the filter member to the support member with an adhesive, sufficient bonding is achieved. When strength is obtained, it is not always necessary to join the end faces of these filter members with an adhesive.

[0042]

According to the present invention, at least R, G, B
By changing the position of the separating means for separating the light having the wavelength of 5 by the position changing means, various R,
It is possible to separate the G and B lights, and thus it is possible to display a projected image with optimum illuminance and color. Further, it is possible to display a bright black-and-white image by eliminating the incidence of light on the separating means. As described above, in the present invention, in addition to changing the illuminance and color tone of full-color display in a single projector, it becomes possible to display a black and white image much brighter than full-color display,
A wide variety of display modes can be provided to the user.

[Brief description of drawings]

FIG. 1 is a block diagram showing a main configuration of a projector according to an embodiment of the present invention.

FIG. 2 is a plan view showing the configuration of the optical system shown in FIG.

FIG. 3 is a diagram showing a configuration of a color wheel.

FIG. 4 (a) shows a color wheel according to a second embodiment of the present invention, and FIG. 4 (b) is a diagram showing a relative positional relationship between the color wheel and the exit aperture.

5A and 5B are views showing a color wheel according to a third embodiment of the present invention, FIG. 5A is a plan view thereof, and FIG. 5B is a view showing a filter member.

FIG. 6 is a plan view showing a color wheel according to a fourth embodiment of the present invention.

[Explanation of symbols]

10: Pre-processing unit 20: Control unit 30: Lamp drive circuit 40: Color wheel drive unit 50: DMD 60: Discharge lamp 70, 110: Color wheel 80: Position detection sensor

Claims (24)

[Claims] 1. A light source, a separating means for injecting light from the light source and separating the light into light having at least R, G, B wavelengths, and a modulating means for optically modulating the separated light. A projector comprising: a projection unit that projects the modulated light; and a position changing unit that changes the position of the sorting unit. 2. The separating means is at least R, G, B
2. The optical element according to claim 1, further comprising: an optical element for separating light of wavelengths, the optical element is divided into a plurality of sets, and one set is selected from the plurality of sets according to a position of the separating unit. projector. 3. The optical element according to claim 2, wherein the optical element includes a rotatable color wheel, and the color wheel has a plurality of sets of color filters for separating lights of at least R, G, and B wavelengths. projector. 4. The color wheel can be positioned at a plurality of positions by the position changing means, and R, G, B lights are emitted from a plurality of sets of corresponding color filters at a selected position. The projector according to claim 3. 5. The projector has a position detecting means for detecting the position of the separating means, and controls the modulating means in accordance with position information of the separating means detected by the position detecting means. The projector according to any one of 1 to 4. 6. The projector according to claim 1, wherein the projector controls the position varying means based on the position information of the sorting means detected by the position detecting means to position the sorting means. . 7. The projector according to claim 1, wherein the light source includes a discharge lamp and a reflector that reflects light from the discharge lamp, and the modulating unit includes a semiconductor mirror element. 8. The light source includes a light tunnel that substantially uniformly emits light from the reflector, and the position changing means moves the sorting means in parallel with a longitudinal direction of an emission aperture of the light tunnel. The projector according to claim 7, wherein the projector comprises: 9. A light source, a separating means for injecting light from the light source and separating the light into light having at least R, G, B wavelengths, and a modulating means for optically modulating the separated light. A projector comprising: projection means for projecting modulated light; and varying means for varying the amount of light incident from the light source to the sorting means. 10. The projector according to claim 9, wherein the variable unit includes a moving unit that moves the sorting unit. 11. The projector according to claim 10, wherein when the separating unit is moved to the first position by the moving unit, a part of the light from the light source is incident on the separating unit. 12. The projector according to claim 10, wherein the light from the light source does not enter the sorting unit when the sorting unit is moved to the second position by the moving unit. 13. The sorting means includes a rotated color wheel, at least R, G,
13. The projector according to claim 9, wherein color filters for separating the light of wavelength B are arranged. 14. The projector according to claim 9, further comprising position detection means for detecting a position of the classification means, and controlling the modulation means based on position information of the classification means detected by the position detection means. 14. The projector according to any one of 1 to 13. 15. The project according to claim 10, wherein the projector controls the moving means based on position information of the sorting means detected by the position detecting means. 16. The projector has a mode selection means for selecting a mode of an image projected from the outside, and when the first mode is selected, the variable means maximizes the amount of light incident on the classification means. The projector according to claim 9, wherein 17. The projector according to claim 16, wherein when the second mode is selected by the mode selection unit, the variable unit minimizes the amount of light incident on the sorting unit. 18. The projector according to claim 17, wherein the minimum is zero, and a black and white image is projected by the projection means. 19. A light source, a separating means which is capable of separating light from the light source into light having at least R, G and B wavelengths, and a modulating means which optically modulates the separated light. A projection method of a projector having a projection means for projecting modulated light, the step of selecting a mode of an image to be projected, the step of positioning the classification means at a predetermined position according to the selected mode A step of modulating light from the light source and projecting the light by the projection means. 20. The image projection method according to claim 19, wherein the mode includes a monochrome image projection mode. 21. A rotary drive means, a filter member connected to the rotary drive means, and a light source for making light incident on the filter member, the filter member having different color arrangement portions, and different irradiation. An illumination optical system that emits light in modes. 22. The different color arrangement part includes a region in which filter regions for emitting red, blue, and green light are continuously arranged, and a filter region for emitting white light in addition to each of these filter regions. 22. The illumination optical system according to claim 21, wherein the illumination optical system is provided with. 23. The filter member is composed of a filter region that emits red, blue, and green colors and a filter region that emits white light, and has a color arrangement portion having a different area ratio of the region that emits white light. The illumination optical system according to claim 21. 24. A projector using the illumination optical system according to claim 21.