JP4151211B2 - projector - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a projector (projection display device) that enables adjustment of projection illuminance.
[0002]
[Prior art]
FIG. 14 is a perspective view showing the appearance of a general projector. Here, the projector 501 has a rectangular parallelepiped shape including an upper case 503 that defines an upper surface thereof and an operation button 502 disposed thereon, a lower case 504 that defines a lower surface thereof, and a front case 505 that defines a front surface thereof. From 505, the tip of the projection lens 506 protrudes.
[0003]
A known optical system in such a projector has a configuration as shown in FIG. 15, for example.
That is, the illumination optical system 520 for making the illuminance distribution of the light from the light source 510 and the light source 510 uniform and making the polarization directions uniform enters the liquid crystal panels 550R, 550G, and 550B, and the illumination optical system 520 The color light separation optical system 530 that separates the emitted light beam W into red, green, and blue color light beams R, G, and B, and the color light beam separated by the color light separation optical system 530 corresponds to the blue light beam B. A relay optical system 540 that leads to the liquid crystal panel 550B, three liquid crystal panels 550R, 550G, and 550B as light modulation means for modulating each color light beam according to given image information, and color light combining optics that combines the modulated color light beams. A cross dichroic prism 560 as a system and a projection lens 506 for enlarging and projecting the combined light flux on the projection surface are provided.
[0004]
The illumination optical system 520 divides the light emitted from the light source 510 into a plurality of partial light beams by the first lens array 521, and causes the partial light beams to enter the polarization conversion element array 523 via the second lens array 522. After the polarization directions of the partial light beams are aligned by the conversion element array 523, they are superimposed on the image forming areas of the liquid crystal panels 550R, 550G, and 550B using the superimposing lens 524.
The illumination optical system 520 acts in this way to uniformly illuminate each of the liquid crystal panels 550R, 550G, and 550B with one kind of polarized light, brighten every corner when displaying an image on a projector or the like, and have high contrast in all areas. This contributes to providing a clear image.
[0005]
[Problems to be solved by the invention]
However, when using a device with high brightness in recent years and projecting with a smaller projection screen than previously set or with a smaller image size, more light than necessary is projected onto the projection surface. As a result, a phenomenon occurs in which the image is difficult to see due to being too dazzling. As a means to cope with this, it is conceivable to provide a variable aperture on the projection lens. However, if this is done, the size of the projection lens becomes large and the type of the projection lens is limited. The The present invention has been made in order to solve the above-described problems, and maintains the high brightness of the optical apparatus, and also reduces the projection brightness (or illuminance) without impairing the degree of freedom in designing other optical systems such as the projection optical system. It is an object of the present invention to provide a projector that makes it possible to adjust.
[0006]
[Means for Solving the Problems]
  The projector according to the present invention includes a light source, a light beam splitting element including a plurality of lenses for splitting light emitted from the light source into a plurality of partial light beams, a plurality of polarization separation films and a reflective film, A polarization conversion element array for adjusting the polarization direction;
  A light shielding material for adjusting the amount of light incident on the polarization separation film is disposed between the light beam splitting element and the polarization conversion element array,
  The light shielding member includes a plurality of light reflecting portions that block light and openings that allow light to pass through alternately. A movable light reflecting lid that is rotatably attached to each of the light reflecting portions corresponds to the light shielding portion. It swings to adjust the opening amount of each opening,
  The movable light reflecting lid so as to adjust the incident light amount according to projection informationIt is characterized by comprising a light shielding material operating means for operating.
  For example, a light shielding material operating means for operating the light shielding material so as to adjust the amount of incident light in accordance with the size of the projected image is provided.
  As a result, in a projector designed to project an image with a large and high brightness, even when projecting a small image, it is possible to achieve an appropriate illuminance without making the illuminance excessively dazzling. .
[0007]
A projection distance detector for detecting a projection distance to a projection surface on which an image is projected, and the light shielding material is adjusted so that the amount of incident light is adjusted according to the projection distance detected by the projection distance detector; It is characterized by comprising a light shielding material operating means for operating.
Since the projection distance is proportional to the size of the projected image, by adjusting the amount of incident light according to the change in the projection distance, the image is projected to be small in a projector designed to project an image with high brightness. Even in such a case, it is possible to obtain an appropriate illuminance without making the illuminance too bright.
[0008]
A zoom ratio detector for detecting a zoom ratio of a projection lens having a zoom function, and operating the light-shielding member so as to adjust the amount of incident light in accordance with the zoom ratio detected by the zoom ratio detector; A light-shielding material operating means is provided.
Since the zoom ratio of the projection lens is proportional to the size of the projected image, if the incident light amount is adjusted according to the zoom ratio of the projection lens, the image can be displayed on a projector designed to project an image with high brightness. Even when a small projection is performed, it is possible to obtain an appropriate illuminance without making the illuminance excessively dazzling.
In this case, the zoom ratio detector may be a rotation angle sensor that detects the rotation angle of the zoom ratio adjustment drive shaft or a linear movement amount sensor that detects the linear movement amount of the zoom ratio adjustment drive shaft. it can.
[0009]
In addition, an illuminance detector that detects the illuminance on the projection screen on which the image is projected, and the light shielding material that operates the light shielding material so as to adjust the incident light amount according to the illuminance detected by the illuminance detector. An operating means is provided.
According to this, since the illuminance itself on the projection screen can be grasped, the illuminance can be adjusted more appropriately.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described based on examples.
FIG. 1 is a schematic plan view showing an optical system configuration of a projector (projection display device) incorporating an illumination optical system according to an embodiment of the present invention. This optical system includes three main parts, a light source unit 20, an optical unit 30, and a projection lens 40.
[0013]
The optical unit 30 includes an integrator optical system 300 to be described later, a color light separation optical system 380 having dichroic mirrors 382 and 386, and a reflection mirror 384, a relay optical system having an incident side lens 392, a relay lens 396, and reflection mirrors 394 and 398. 390, three field lenses 400, 402, and 404, three liquid crystal panels 410R, 410G, and 410B, and a cross dichroic prism 420 that is a color light combining optical system.
The light source unit 20 is disposed on the incident surface side of the first lens array 320 of the optical unit 30, and the projection lens 40 is disposed on the exit surface side of the cross dichroic prism 420 of the optical unit 30.
[0014]
FIG. 2 is an explanatory diagram showing an illumination optical system that illuminates three liquid crystal panels that are illumination areas of the projector shown in FIG. The illumination optical system includes a light source 200 provided in the light source unit 20 and an integrator optical system 300 provided in the optical unit 30. The integrator optical system 300 includes a first lens array 320, a second lens array 340, a light shielding plate 350 and a polarization conversion element array 360 described later, and a superimposing lens 370.
[0015]
The light source 200 includes a light source lamp 210 and a concave mirror 212. Radial rays (radiated light) emitted from the light source lamp 210 are reflected by the concave mirror 212 and emitted in the direction of the first lens array 320 as a substantially parallel light bundle.
Here, a halogen lamp, a metal halide lamp, or a high-pressure mercury lamp can be used as the light source lamp 210, and a parabolic mirror is preferably used as the concave mirror 212.
[0016]
FIG. 3 is a front view (A) and a side view (B) showing the external appearance of the first lens array 320. In the first lens array 320, small lenses 321 having a rectangular outline are arranged in a matrix of N × 2 columns (here, N = 4) in the x direction and M rows (here, M = 10) in the y direction. The outer shapes of the small lenses 321 viewed from the z direction in FIG. 2 are set so as to be substantially similar to the shapes of the liquid crystal panels 410R, 410G, and 410B. For example, if the aspect ratio (ratio of horizontal and vertical dimensions) of the image forming area of the liquid crystal panel is 4: 3, the aspect ratio of each small lens 321 is also set to 4: 3.
[0017]
The second lens array 340 has a function of guiding the plurality of partial light beams emitted from the first lens array 320 so as to be condensed on the polarization separation film 366 of the polarization conversion element array 360, and the first lens array The number of small lenses 341 is the same as the number of lenses constituting 320.
[0018]
In the polarization conversion element array 360, as shown in FIG. 2, two polarization conversion element arrays 361 and 362 are arranged in a symmetrical direction with the optical axis in between. FIG. 4 is a perspective view showing an appearance of one polarization conversion element array 361. The polarization conversion element array 361 includes a polarization beam splitter array 363 composed of a plurality of polarization beam splitters, and a λ / 2 retardation plate 364 (λ is selectively disposed on a part of the light exit surface of the polarization beam splitter array 363. Light wavelength). The polarization beam splitter array 363 has a shape in which a plurality of columnar translucent members 365 each having a parallelogram cross section are sequentially bonded. Polarization separation films 366 and reflection films 367 are alternately formed on the interface of the translucent member 365. The λ / 2 retardation film 364 is selectively attached to a mapping portion in the x direction on the light exit surface of the polarization separation film 366 or the reflection film 367. In this example, a λ / 2 phase difference plate 364 is attached to a mapping portion in the x direction on the light exit surface of the polarization separation film 366.
[0019]
The polarization conversion element array 361 has a function of converting an incident light beam into one type of linearly polarized light (for example, s-polarized light or p-polarized light) and emitting it. FIG. 5 is a schematic diagram showing the operation of the polarization conversion element array 361. When non-polarized light (incident light having a random polarization direction) including an s-polarized component and a p-polarized component is incident on the incident surface of the polarization conversion element array 361, the incident light is first s by the polarization separation film 366. Separated into polarized light and p-polarized light. The s-polarized light is reflected almost perpendicularly by the polarization separation film 366, is further reflected by the reflection film 367, and then emitted. On the other hand, the p-polarized light passes through the polarization separation film 366 as it is. A λ / 2 phase difference plate 364 is disposed on the exit surface of the p-polarized light transmitted through the polarization separation film 366, and the p-polarized light is converted into s-polarized light and emitted. Therefore, most of the light that has passed through the polarization conversion element array 361 is emitted as s-polarized light. When the light emitted from the polarization conversion element array 361 is to be p-polarized light, the λ / 2 phase difference plate 364 is disposed on the emission surface from which the s-polarized light reflected by the reflective film 367 is emitted. Good. Further, as long as the polarization direction can be aligned, a λ / 4 retardation plate may be used, or a desired retardation plate may be provided on both the exit surfaces of the p-polarized light and the s-polarized light.
[0020]
Of the polarization conversion element array 361, one block including one polarization separation film 366 and one reflection film 367 adjacent to each other and further comprising one λ / 2 phase difference plate 364 is regarded as one polarization conversion element. 368. The polarization conversion element array 361 has a plurality of such polarization conversion elements 368 arranged in the x direction.
Since the polarization conversion element array 362 has the same configuration as the polarization conversion element array 361, the description thereof is omitted.
[0021]
Next, the light shielding plate 350 disposed between the second lens array 340 and the polarization conversion element array 360 and its operation mechanism will be described. Since the vicinity of the polarization conversion element array 360 is in the vicinity of the arc image of the light source, the vicinity of the polarization conversion element array 360 and the entrance pupil of the projection lens have a substantially conjugate relationship. Therefore, even if the light beam is cut off at this position by the light shielding plate 350 or the like, it is the same as the case where it is stopped by the aperture of the projection lens, and the brightness can be adjusted without causing uneven illumination.
[0022]
FIG. 6 is a front view illustrating an example of a light shielding plate that adjusts the amount of light incident on the polarization separation film 366. The light shielding plate 350 corresponds to the light incident surface of each light transmissive member 365 constituting the polarization conversion element array 360 (361, 362), and blocks light having substantially the same width as the light incident surface width. It is a plate-like body formed by alternately forming reflection portions 351 and openings 352 (or transparent portions) that allow light to pass therethrough. The light shielding plate 350 is held by a guide 353 and a known driving mechanism, for example, FIG. 7 is movable along the arrangement direction of the polarization separation film 366 and the reflection film 367 using a drive mechanism including a rack (not shown) formed on the bottom surface of the light shielding plate 350 shown in FIG. It is configured.
[0023]
FIG. 8 is a schematic diagram showing the operation of the light shielding plate 350, and a part of the light incident on the polarization separation film 366 of the polarization conversion element array 360 depends on the position of the light shielding plate 350 with respect to the polarization conversion element array 360. This shows a state in which the amount of light that is reflected and blocked by the light reflecting portion 351 and incident on the polarization separation film 366 is adjusted.
[0024]
In this case, the movement of the light shielding plate 350 can be performed by the following light shielding plate operating device.
(Example 1 of light shielding plate operation device)
FIG. 9 is a configuration diagram of the light shielding plate operating device. This apparatus determines the projection screen size on which an image is projected by the projector according to the size of the screen 600 to be used, and inputs the projection screen size input means 611 such as a keyboard for inputting the projection screen size to the projector, and a settable projection screen. A value input from a memory 612 that stores in advance a correlation between the size and the position of the light-shielding plate 350 from which the amount of incident light having an illuminance appropriate for the projection screen size is obtained, and the projection screen size input means 611 And a relation stored in the memory 612, a calculation unit 613 including a CPU for determining the most appropriate position of the light shielding plate 350 in the projection screen size and calculating a movement amount from the current position to the position, and a calculation unit 613 Based on the position and amount of movement determined in step 1, the motor and gears that actually operate the light shielding plate 350 Consisting comprises an optical plate controller 650.
Here, the memory 612 stores a settable projection screen size and the position of the light shielding plate 350 that determines the amount of incident light in the vicinity of the polarization separation film 366 that optimizes the illuminance of the projection screen at that size. The calculation unit 613 determines the position of the light shielding plate 350 corresponding to the projection screen size closest to the size input from the projection screen size input unit 611 as the optimum position.
Instead of inputting the projection screen size, the actually displayed projection screen size may be detected and the detected value may be used. For example, the optimal position of the light shielding plate 350 can be determined by calculating the projection screen size from the relationship between the projection distance and the zoom ratio described later. According to this, since the input operation of the projection screen size is omitted, the operability is improved.
[0025]
(Example 2 of light shielding plate operating device)
FIG. 10 is another configuration diagram of the light shielding plate operating device. This apparatus includes a projection distance detector 621 that detects a projection distance to the screen 600 on which an image is projected by the projector, a settable projection distance, and a position of a light-shielding plate 350 that has an illuminance appropriate for the projection distance. The most suitable position of the light-shielding plate 350 at the projection distance is determined from the memory 622 that stores the correlation in advance, the value obtained by the projection distance detector 621 and the relation stored in the memory 622, and the current position. And a light-shielding plate comprising a motor, a gear, and the like that actually operates the light-shielding plate 350 based on the position and amount of movement determined by the computing unit 623. A drive control unit 650 is provided.
Here, the memory 622 stores the settable projection distance and the position of the light shielding plate 350 that determines the amount of light incident on the polarization separation film 366 that optimizes the illuminance of the projection screen at the distance, in correlation with each other. The calculation unit 623 determines the position of the light shielding plate 350 corresponding to the projection distance obtained by the projection distance detector 621 as the optimum position.
Further, as described above, the projection distance detector 621 can be used to calculate the projection screen size by combining the detected value with a zoom ratio described later, and the optimum position of the light shielding plate 350 can be determined.
Note that the projection distance detector 621 can be configured using ultrasonic waves or the like as described in Japanese Patent Application Laid-Open No. 11-95324, for example.
[0026]
(Example 3 of light shielding plate operating device)
FIG. 11 is another configuration diagram of the light shielding plate operating device. This apparatus has a zoom ratio detector 631 that detects the zoom ratio of the projection lens 40 constituting the projector, and a correlation between the settable zoom ratio and the position of the light shielding plate 350 that provides an appropriate illuminance for the zoom ratio. The most suitable position of the light shielding plate 350 in the zoom ratio is determined from the memory 632 storing the relationship in advance, the value obtained by the zoom ratio detector 631 and the relationship stored in the memory 632, and the current position is A calculation unit 633 including a CPU for calculating a movement amount to a position, and a light shielding plate driving control including a motor, a gear, and the like that actually operates the light shielding plate 350 based on the position and the movement amount determined by the calculation unit 633. Part 650.
Here, the memory 632 stores a settable zoom ratio and the position of the light shielding plate 350 that determines the amount of light incident on the polarization separation film 366 that optimizes the illuminance of the projection screen at the zoom ratio. The calculation unit 633 determines the position of the light shielding plate 350 corresponding to the zoom ratio obtained by the zoom ratio detector 631 as the optimum position.
The zoom ratio detector 631 also has a rotation angle sensor (for example, an optical encoder, a potentiometer, etc.) that detects the rotation angle of the zoom ratio adjustment drive shaft, as described in JP-A-11-95324. Rotation (or straight line) of the projection lens 40 using a linear movement amount sensor (such as one that detects the linear movement amount based on a change in resistance value or capacitance) that detects the linear movement amount of the zoom ratio adjusting drive shaft. The amount of movement can be detected and the zoom ratio can be determined.
[0027]
(Example 4 of light shielding plate operating device)
FIG. 12 is another configuration diagram of the light shielding plate operating device. This apparatus includes an illuminance detector 641 that detects the illuminance of a display image on the screen 600 by the projector, a memory 642 that stores appropriate image display illuminance in advance, a value obtained by the illuminance detector 641, and a memory Taking the difference from the appropriate value stored in 622 and reducing the difference, that is, if the detected illuminance is greater than the appropriate value, the amount of incident light on the polarization separation film 366 of the polarization conversion element array 360 is calculated. If the detected illuminance is smaller than the appropriate value so as to decrease, the value obtained by the illuminance detector 641 and the memory 642 while moving the light shielding plate 350 so as to increase the amount of light incident on the polarization separation film 366. The calculation unit 643 including a CPU that outputs a signal for stopping the light shielding plate 350 when the difference from the appropriate value stored in the range falls within a predetermined range, and the calculation unit 643 Motor for actually operating the light shielding plate 350 in response to the output signal, formed by blackout plate controller 650 consisting of a gear.
Note that the illuminance detector 641 can be configured using an optical sensor or the like as described in, for example, Japanese Patent Laid-Open No. 8-235501.
[0028]
In Examples 1 to 4 of the light shielding plate operating devices described above, a variable aperture light shielding plate 450 shown in FIG. 13 may be used instead of the light shielding plate 350. Similar to the light shielding plate 350, the light shielding plate 450 is formed by alternately forming light reflecting portions 451 that block light and openings 452 (or transparent portions) that allow light to pass through. Further, a movable light reflecting lid 453 for adjusting the opening amount of the opening 452 is attached to the light reflecting portion 451 so as to be swingable (or rotatable). The movable light reflecting lid 453 is supported by an elastic support member 454 such as a spring, and is normally at a position where the opening 452 is fully opened. However, a rotational force A acts on a rotating shaft 455 integral with the movable light reflecting lid 453. Then, the movable light reflecting lid 453 swings along the arrow B in accordance with the rotational force to change the opening amount of the opening 452 to adjust the amount of light incident on the polarization separation film 366. Therefore, the swing (or rotation) of the movable light reflecting lid 453 in the light shielding plate 450 corresponds to the movement of the light shielding plate 350.
Further, in the light shielding plate 450, instead of swinging (or rotating) the movable light reflecting lid 453, it is possible to easily adjust the opening amount of the opening 452 by sliding left and right.
[0029]
Such light shielding plates 350 and 450 can be made using a sheet metal having an opening in the light passage portion or a light transmissive plate material in which a reflection film is deposited on the light shielding portion. In particular, when made of a metal material such as aluminum having a high light reflectivity (preferably a reflectivity of 80% or more), it is excellent in heat resistance and can be used for a long time under high luminance.
[0030]
Next, the operation of the projector configured as described above will be described.
As shown in FIG. 2, the unpolarized light emitted from the light source 200 is divided into a plurality of partial light beams 202 by a plurality of small lenses 321 of the first lens array 320 constituting the integrator optical system 300, and the second lens array. A plurality of small lenses 341 collect light in the vicinity of the polarization separation film 366 of the two polarization conversion element arrays 361 and 362, and the amount of light directed to the vicinity of the polarization separation film 366 is adjusted according to the position of the light shielding plate 350. . Thus, the plurality of partial light beams incident on the two polarization conversion element arrays 361 and 362 are converted into one type of linearly polarized light and emitted as described above. A plurality of partial light beams emitted from the two polarization conversion element arrays 361 and 362 are superimposed on liquid crystal panels 410R, 410G, and 410B, which will be described later, by a superimposing lens 370.
[0031]
In FIG. 1, a color light separation optical system 380 includes first and second dichroic mirrors 382 and 386 and has a function of separating light emitted from the illumination optical system into red, green, and blue color light. is doing. The first dichroic mirror 382 transmits the red light component of the light emitted from the superimposing lens 370 and reflects the blue light component and the green light component. The red light transmitted through the first dichroic mirror 382 is reflected by the reflection mirror 384, passes through the field lens 400, and reaches the liquid crystal panel 410R for red light. The field lens 400 converts each partial light beam emitted from the superimposing lens 370 into a light beam parallel to the central axis (principal ray). The field lenses 402 and 404 provided in front of the other liquid crystal panels 410G and 410B operate in the same manner.
[0032]
Further, of the blue light and green light reflected by the first dichroic mirror 382, the green light is reflected by the second dichroic mirror 386 and reaches the green light liquid crystal panel 410 </ b> G through the field lens 402. On the other hand, the blue light passes through the second dichroic mirror 386, passes through the relay optical system 390, that is, the incident side lens 392, the reflection mirror 394, the relay lens 396, and the reflection mirror 398, and further passes through the field lens 404. The light reaches the light liquid crystal panel 410B. The reason why the relay optical system 390 is used for blue light is that the optical path length of the blue light is longer than the optical path lengths of the other color lights, thereby preventing a decrease in light use efficiency due to light diffusion or the like. It is to do. That is, this is to transmit the partial light beam incident on the incident side lens 392 to the field lens 404 as it is.
[0033]
The three liquid crystal panels 410R, 410G, and 410B have a function as an electro-optical device that modulates incident light according to given image information (image signal). Thereby, each color light incident on the three liquid crystal panels 410R, 410G, and 410B is modulated according to the given image information to form an image of each color light. A polarizing plate (not shown) is provided on the light incident surface side and the light emitting surface side of the three liquid crystal panels 410R, 410G, and 410B. The liquid crystal panel and the polarizing plate are collectively referred to as a liquid crystal light valve. .
[0034]
The three colors of modulated light emitted from the three liquid crystal panels 410R, 410G, and 410B are incident on the cross dichroic prism 420. The cross dichroic prism 420 has a function as a color light combining optical system that forms a color image by combining three colors of modulated light. In the cross dichroic prism 420, a dielectric multilayer film that reflects red light and a dielectric multilayer film that reflects blue light are formed in an approximately X shape at the interface of four right-angle prisms. These dielectric multilayer films combine three colors of modulated light to form combined light for projecting a color image. The combined light generated by the cross dichroic prism 420 is emitted in the direction of the projection lens 40. The projection lens 40 has a function of projecting the combined light on the projection screen, and displays a color image on the projection screen.
[0035]
In the projector of the present embodiment as described above, an image can be displayed on the projection screen with an appropriate illuminance that is easy for the viewer to see according to the projection image size, the projection distance, the zoom ratio of the projection lens, or the projection illuminance. It becomes possible.
[0036]
In the above embodiment, an example in which the present invention is applied to a projection display device using a transmissive liquid crystal panel has been described. However, the present invention is applicable to a projection display device using a reflective liquid crystal panel. Can also be applied. Further, as will be described later, the electro-optical device is not limited to a liquid crystal panel. Here, “transmission type” means that the electro-optical device such as a liquid crystal panel transmits light, and “reflection type” means that the electro-optical device such as a liquid crystal panel reflects light. Means type. In a projection display device employing a reflective electro-optical device, a dichroic prism is used as a color light separating means for separating light into three colors of red, green, and blue, and modulated three-color light. May also be used as color light combining means for combining and emitting in the same direction.
[0037]
The electro-optical device for light modulation is not limited to a liquid crystal light valve using a liquid crystal panel, and may be a device using a micromirror, for example.
Also, the prism that is a color light combining optical system is not limited to a dichroic prism in which two types of color selection surfaces are formed along the adhesion surface of four triangular prisms, but a dichroic prism with a single color selection surface, or a polarization It may be a beam splitter. In addition, the prism may be such that a light selection surface is disposed in a substantially hexahedral light-transmitting box and the liquid is filled therewith.
[0038]
Further, as the projection display device, there are a front projection display device that performs projection from the direction in which the projection image is observed and a rear projection display device that performs projection from the side opposite to the direction in which the projection image is observed. The configurations described in the above embodiments can be applied to any of them.
[0039]
【The invention's effect】
According to the present invention, even when a small image is projected using a projector designed to project an image with a large and high brightness, the illuminance is set to an appropriate illuminance without causing the illuminance to be excessively bright. Is possible.
[Brief description of the drawings]
FIG. 1 is a plan view showing an optical system of a projector according to an embodiment of the invention.
FIG. 2 is an explanatory diagram of an illumination optical system constituting the optical system of FIG.
FIGS. 3A and 3B are a front view and a side view of a first lens array constituting an illumination optical system. FIGS.
FIG. 4 is a perspective view showing an appearance of a polarization conversion element array.
FIG. 5 is a schematic diagram showing an operation of a polarization conversion element array.
FIG. 6 is a front view showing an example of a light shielding plate that adjusts the amount of light incident on a polarization separation film.
7 is an explanatory view showing a driving mechanism of the light shielding plate of FIG. 6. FIG.
FIG. 8 is a schematic diagram showing the operation of the light shielding plate of FIG. 6;
FIG. 9 is a block diagram showing a configuration of a light shielding plate operating device.
FIG. 10 is a block diagram showing a configuration of a light shielding plate operating device.
FIG. 11 is a block diagram showing a configuration of a light shielding plate operating device.
FIG. 12 is a block diagram showing a configuration of a light shielding plate operating device.
FIG. 13 is a configuration diagram illustrating another example of a light-shielding plate driving mechanism.
FIG. 14 is a perspective view showing an external appearance of a general projector.
FIG. 15 is a configuration diagram showing an optical system of a known projector.
[Explanation of symbols]
320 First lens array
340 Second lens array
350 Shading plate
351 Light reflection part of light shielding plate
352 Opening of shading plate
353 Guide
360, 361, 362 polarization conversion element array
366 Polarized light separation membrane
367 Reflective film
370 Superimposing lens
410R, 410G, 410B LCD panel
430 spur gear
450 Shading plate
451 Light reflection part of light shielding plate
452 Opening of shading plate
453 Movable light reflective lid
600 screens
611 Projection screen size input means
621 Projection distance detector
631 Zoom ratio detector
641 Illuminance detector
650 Shading plate drive controller

Claims (7)

Polarized light having a light source, a light beam splitting element composed of a plurality of lenses for splitting light emitted from the light source into a plurality of partial light beams, a plurality of polarization separation films and a reflective film, and adjusting the polarization direction of the partial light beams A conversion element array,
A light shielding material for adjusting the amount of light incident on the polarization separation film is disposed between the light beam splitting element and the polarization conversion element array,
The light shielding member includes a plurality of light reflecting portions that block light and openings that allow light to pass through alternately. A movable light reflecting lid that is rotatably attached to each of the light reflecting portions corresponds to the light shielding portion. It swings to adjust the opening amount of each opening,
A projector comprising: a light shielding material operating means for operating the movable light reflecting lid so as to adjust the incident light amount according to projection information. The projector according to claim 1, further comprising a light shielding material operating unit that operates the movable light reflecting lid so as to adjust the amount of incident light according to a size of a projected image. A projection distance detector that detects the projection distance to the projection surface on which the image is projected,
The projector according to claim 1, further comprising: a light shielding material operating unit that operates the movable light reflecting lid so as to adjust the amount of incident light in accordance with a projection distance detected by the projection distance detector. A zoom ratio detector for detecting the zoom ratio of a projection lens having a zoom function,
The projector according to claim 1, further comprising: a light shielding material operating unit that operates the movable light reflecting lid so that the incident light amount is adjusted according to a zoom ratio detected by the zoom ratio detector.   5. The projector according to claim 4, wherein the zoom ratio detector is a rotation angle sensor that detects a rotation angle of a zoom ratio adjusting drive shaft.   5. The projector according to claim 4, wherein the zoom ratio detector is a linear movement amount sensor that detects a linear movement amount of a zoom ratio adjusting drive shaft. An illuminance detector that detects the illuminance on the projection screen on which the image is projected,
The projector according to claim 1, further comprising a light shielding material operating unit that operates the movable light reflecting lid so that the incident light amount is adjusted according to the illuminance detected by the illuminance detector.

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