JP2007241023A - Scintillation removal apparatus and projector - Google Patents

Abstract

A scintillation removing apparatus capable of effectively removing scintillation with a configuration suitable for practical use, and a projector including the scintillation removing apparatus.
SOLUTION: A diffusion unit 23 that diffuses light by transmission or reflection, a vibration generation unit 34 that generates vibration using a piezoelectric element, and a support unit 32 that supports the diffusion unit 23 in a oscillating state. The diffusing unit 23 receives the vibration from the vibration generating unit 34 and changes the phase of the light by transmitting or reflecting the light.
[Selection] Figure 3

Description

  The present invention relates to a scintillation removing apparatus and a projector, and more particularly to a technique of a scintillation removing apparatus for removing scintillation generated in image display by a projector.

  When an image is displayed with light modulated in accordance with an image signal, scintillation in which bright spots and dark spots are randomly distributed may occur due to light interference. The scintillation gives a viewer a glimmering flickering feeling and causes an adverse effect on image viewing. Since laser light has high coherence, scintillation is particularly likely to occur when a laser is used as a light source. Conventionally, a technique for reducing scintillation in a projector has been proposed in Patent Document 1, for example.

JP 2003-98476 A

  The technique proposed in Patent Document 1 uses a moving diffuser provided between a laser light source and a spatial light modulator. However, even if the moving diffuser is simply moved by the motion imparting means, scintillation may not be removed effectively, whereas Patent Document 1 does not touch on the details of the structure of the motion imparting means. In addition, the configuration using the electric motor, the vibration motor, and the linear actuator exemplified as the motion imparting means is considered to have poor responsiveness capable of moving the moving diffuser at high speed, and problems with vibration, noise, power consumption, etc. Therefore, practical application is considered extremely difficult. From such a problem, it is desired that scintillation can be effectively removed by a configuration suitable for practical use. The present invention has been made in view of the above, and provides a scintillation removal apparatus capable of performing effective scintillation removal with a configuration suitable for practical use, and a projector including the scintillation removal apparatus. Objective.

  In order to solve the above-described problems and achieve the object, according to the present invention, a diffusion unit that diffuses light by transmission or reflection, and a vibration generation unit that generates vibration using a piezoelectric element, The diffusing unit can provide a scintillation removing device characterized in that the vibration from the vibration generating unit is applied and the phase of the light is changed by transmitting or reflecting the light.

  The piezoelectric element used for the vibration generating unit can be easily driven at a high speed as compared with an electric motor or the like used in the prior art. By using the piezoelectric element, it is possible to easily realize high responsiveness that moves the diffusion portion at high speed. When the piezoelectric element is used, since the mechanism of the vibration generating unit can be configured with a small number of parts, the vibration generating unit can be made small and simple, and excellent quietness, power saving, and durability can be easily realized. Moreover, since the frequency which vibrates a spreading | diffusion part can be reduced according to the aspect which deform | transforms a piezoelectric element, high silence, low power consumption, and high reliability can be ensured. By changing the phase of light, light interference can be reduced and scintillation can be reduced. As a result, a scintillation removal apparatus capable of performing effective scintillation removal with a configuration suitable for practical use can be obtained.

  Moreover, as a preferable aspect of the present invention, it is desirable to have a support portion that supports the diffusion portion so as to vibrate. By supporting the diffusion portion by the support portion, it is possible to reduce the shift of the diffusion portion in the optical axis direction. Thereby, the phase of the light can be changed without degrading the quality of the image.

  Moreover, as a preferable aspect of the present invention, it is desirable that the support portion has an elastic body. Thereby, a spreading | diffusion part can fully be vibrated.

  Moreover, as a preferable aspect of the present invention, it is desirable that the vibration generating unit has an abutting portion that abuts against the diffusing portion and applies vibration to the diffusing portion by driving the abutting portion. Thereby, the vibration generated using the piezoelectric element can be applied to the diffusion portion.

  Moreover, as a preferable aspect of the present invention, it is desirable that the vibration generating portion is expanded and contracted in one direction by the piezoelectric element to displace the contact portion along the one direction. Thereby, vibration can be imparted to the diffusion portion.

  Moreover, as a preferable aspect of the present invention, the vibration generating unit performs a bending motion that expands and contracts in the first direction by the piezoelectric element and swings in the second direction substantially orthogonal to the first direction. It is desirable to displace the contact portion along a substantially elliptical or substantially circular track. Thereby, vibration can be imparted to the diffusion portion. In addition, it is possible to reduce the frequency at which the diffusing unit vibrates to below the audible limit. Therefore, it is possible to effectively reduce the occurrence of scintillation with a configuration excellent in silence, power saving, and reliability.

  As a preferred aspect of the present invention, the piezoelectric element is formed so that the width decreases as it goes in a specific direction in one direction, and the contact portion is a tip in a specific direction in the vibration generating portion. It is desirable to be provided in the part. By forming the piezoelectric element so that the width decreases as it goes in a specific direction, the displacement of the contact portion due to the deformation of the piezoelectric element can be increased. As a result, the vibration generating unit can be driven efficiently, and a configuration excellent in quietness and power saving can be obtained.

  As a preferred aspect of the present invention, the piezoelectric element has a plurality of electrodes for applying a voltage, and the piezoelectric element is provided along a first direction and a second direction substantially orthogonal to the first direction. The plurality of electrodes are preferably provided in parallel with respect to at least one of the first direction and the second direction. By appropriately adjusting the voltages applied to the plurality of electrodes provided in the same plane, the deformation of the piezoelectric element can be increased. As a result, the vibration generating unit can be driven efficiently, and a configuration excellent in quietness and power saving can be obtained.

  Moreover, as a preferable aspect of the present invention, it is desirable to have a plurality of vibration generating units. By applying vibration to the diffusing section by the plurality of vibration generating sections, it becomes possible to complicate the change in the phase of light from the diffusing section. The occurrence of scintillation can be effectively reduced by changing the phase of light in a complex manner.

  Moreover, as a preferable aspect of the present invention, it is desirable that the vibration generating unit adjusts the displacement at each position on the diffusing unit by applying vibration to the diffusing unit in accordance with a control signal for controlling the vibration generating unit. For example, a pattern in which scintillation is likely to occur can be identified from an image signal for displaying an image. In this case, by generating a control signal for controlling the vibration generating unit based on the image signal, it is possible to change the phase of the light according to the degree at which scintillation is likely to occur at a location and timing where scintillation is likely to occur. It becomes. When a piezoelectric element is used, the displacement for each position on the diffusion portion can be adjusted relatively easily. The occurrence of scintillation can be efficiently reduced by changing the phase of light at a location and timing where scintillation is likely to occur. Thereby, generation | occurrence | production of scintillation can be effectively reduced by the structure excellent in silence, power saving property, and reliability.

  Moreover, as a preferable aspect of the present invention, it is desirable to have a vibration expansion mechanism that expands the vibration generated by the vibration generation unit. By using the vibration magnifying mechanism, it is possible to efficiently apply vibration to the diffusion portion. Further, even when the vibration width by the vibration generating unit is small, the phase of light can be changed sufficiently. Since the vibration applied to the diffusing portion can be enlarged, the vibration generating portion can be further reduced in size. Thereby, generation | occurrence | production of scintillation can be effectively reduced by the structure excellent in silence, power saving property, and reliability.

  Furthermore, according to the present invention, it is possible to provide a projector that displays an image using light that has passed through the scintillation removing apparatus. By using the above scintillation removal apparatus, effective scintillation removal can be easily performed. As a result, a projector capable of displaying an image in which scintillation is effectively reduced can be obtained.

  Further, as a preferred aspect of the present invention, there is a homogenizing unit that uniformizes the intensity distribution of the light flux from the light source unit, and the scintillation removing device is provided in at least one of the vicinity of the entrance side and the exit side of the homogenizing unit. It is desirable that This makes it possible to reduce scintillation without degrading the image quality, and display a high-quality image.

  Further, as a preferred aspect of the present invention, a projection lens that projects light modulated in accordance with an image signal is provided, and the scintillation removal device is provided in the image plane in the projection lens or in the vicinity of the image plane. desirable. This makes it possible to reduce scintillation without degrading the image quality, and display a high-quality image.

  Further, as a preferred aspect of the present invention, it is desirable to have a screen on which light modulated according to an image signal is incident, and it is desirable that the scintillation removing device is provided in at least one of the vicinity of the entrance side and the vicinity of the exit side of the screen. . This makes it possible to reduce scintillation without degrading the image quality, and display a high-quality image.

  Embodiments of the present invention will be described below in detail with reference to the drawings.

  FIG. 1 shows a schematic configuration of a rear projector 10 according to a first embodiment of the present invention. The rear projector 10 projects light on one surface of the screen 14 and observes an image by observing light emitted from the other surface of the screen 14. The optical engine unit 11 supplies light modulated according to the image signal.

  FIG. 2 shows a schematic configuration of the optical engine unit 11. The light source unit 20R for red (R) light is a semiconductor laser that supplies red laser light. The R light from the R light source unit 20 </ b> R is diverged by the diverging lens 21 and then collimated by the collimator lens 22. The light from the collimator lens 22 passes through the two integrator lenses 24 and 25 after passing through the diffusion unit 23 of the scintillation removing apparatus.

  The first integrator lens 24 and the second integrator lens 25 have a plurality of lens elements arranged in an array. The first integrator lens 24 divides the light beam from the R light source unit 20R into a plurality of light beams. Each lens element of the first integrator lens 24 condenses the light beam from the R light source 20R in the vicinity of the lens element of the second integrator lens 25. The lens element of the second integrator lens 25 forms an image of the lens element of the first integrator lens 24 on the spatial light modulator.

  The light that has passed through the two integrator lenses 24 and 25 is converted into polarized light having a specific vibration direction, for example, s-polarized light by the polarization conversion element 26. The superimposing lens 27 superimposes the image of each lens element of the first integrator lens 24 on the spatial light modulator. The first integrator lens 24, the second integrator lens 25, and the superimposing lens 27 constitute a uniformizing unit that uniformizes the intensity distribution of light from the R light source unit 20R on the spatial light modulator. The field lens 28 collimates the R light from the superimposing lens 27 and enters the R light spatial light modulator 29R.

  The spatial light modulator 29R for R light is a transmissive liquid crystal display device that modulates R light according to an image signal. A liquid crystal panel (not shown) provided in the spatial light modulator 29R for R light encloses a liquid crystal layer for image display between two transparent substrates. The s-polarized light incident on the liquid crystal panel is converted into p-polarized light by modulation according to the image signal. The spatial light modulator 29R for R light emits R light converted into p-polarized light by modulation. The R light modulated by the spatial light modulator 29R for R light is incident on the cross dichroic prism 30 which is a color synthesis optical system.

  The green (G) light source unit 20G is a semiconductor laser that supplies green laser light. The G light from the G light source unit 20G passes through the optical elements from the diverging lens 21 to the field lens 28 as in the case of the R light, and then enters the G light spatial light modulator 29G. The spatial light modulation device 29G for G light is a transmissive liquid crystal display device that modulates G light according to an image signal. The s-polarized light incident on the G light spatial light modulator 29G is converted into p-polarized light by modulation in the liquid crystal panel. The spatial light modulation device 29G for G light emits G light converted into p-polarized light by modulation. The G light modulated by the spatial light modulator 29 G for G light is incident on the cross dichroic prism 30.

  The blue (B) light source unit 20B is a semiconductor laser that supplies blue laser light. The B light from the B light source unit 20B passes through the optical elements from the diverging lens 21 to the field lens 28 as in the case of the R light, and then enters the B light spatial light modulator 29B. The B light spatial light modulation device 29B is a transmissive liquid crystal display device that modulates the B light according to an image signal. The s-polarized light incident on the B light spatial light modulation device 29B is converted into p-polarized light by modulation in the liquid crystal panel. The B light spatial light modulator 29B emits B light converted into p-polarized light by modulation. The B light modulated by the B light spatial light modulator 29 </ b> B enters the cross dichroic prism 30.

  The cross dichroic prism 30 has two dichroic films 30a and 30b arranged so as to be substantially orthogonal to each other. The first dichroic film 30a reflects R light and transmits G light and B light. The second dichroic film 30b reflects B light and transmits R light and G light. The cross dichroic prism 30 combines the R light, the G light, and the B light incident from different directions and emits them in the direction of the projection lens 12.

  As the light source unit, a wavelength conversion element that converts the wavelength of laser light from the semiconductor laser, for example, a second-harmonic generation (SHG) element may be used. Further, instead of the semiconductor laser, a semiconductor laser pumped solid state (DPSS) laser, a solid laser, a liquid laser, a gas laser, or the like may be used for the light source unit.

  Returning to FIG. 1, the projection lens 12 projects the light from the optical engine unit 11 in the direction of the mirror 13. The mirror 13 is provided on the back surface of the housing 15. The mirror 13 bends the light from the projection lens 12 in the direction of the screen 14 by reflection. The mirror 13 has a substantially flat planar shape. The mirror 13 can be configured by forming a reflective film on a parallel plate. As the reflective film, a highly reflective member layer, for example, a metal member layer such as aluminum, a dielectric multilayer film, or the like can be used.

  The screen 14 is formed on the front surface which is the surface on the viewer side of the housing 15. The screen 14 is a transmissive screen that transmits light that has passed through the projection lens 12 and the mirror 13. The screen 14 has an angle conversion unit (not shown) that converts light incident obliquely from the mirror 13 into the direction of the observer. A Fresnel lens can be used as the angle conversion unit. The screen 14 may be provided with, for example, a lenticular lens array or a microlens array that diffuses light, a diffusion plate in which a diffusion material is dispersed, or the like.

  FIG. 3 illustrates the configuration of the scintillation removal apparatus 35. The diffusion unit 23 includes a rectangular diffusion plate 31 and a diffusion plate frame 36 provided around the diffusion plate 31. The diffusion plate 31 diffuses light from the light source unit by transmission. The diffusion plate 31 is configured by dispersing a diffusion material in a transparent member. The diffusing unit 23 is supported in the optical engine casing 33 by supporting units 32 provided at the four corners of the diffusing plate frame 36, respectively. The diffusion unit 23 is supported by the support unit 32 in a state where the diffusion unit 23 can vibrate without contacting the optical engine housing 33. The optical engine housing 33 accommodates each part of the optical engine unit 11. The support portion 32 is an elastic body made of an elastic member such as a rubber member or a spring.

  The vibration generating unit 34 is a gap between the diffusing unit 23 and the optical engine casing 33 and is provided in the vicinity of one corner of the diffusing plate frame 36. The vibration generator 34 is arranged in a state where the contact portion 48 is in contact with the diffusion plate frame 36 of the diffusion portion 23. The vibration generator 34 generates vibration using a piezoelectric element. The diffusion unit 23 is subjected to vibration from the vibration generation unit 34 and transmits light, thereby changing the phase of light from the light source unit.

  FIG. 4 illustrates the configuration of the vibration generator 34. The vibration generator 34 has a substantially flat strip shape. The vibration generating unit 34 includes two plate-like piezoelectric elements 41 and 43. A flat substrate 42 is provided between the two piezoelectric elements 41 and 43. For example, the substrate 42 is made of an insulating member. The piezoelectric elements 41 and 43 and the substrate 42 are all provided along the x direction that is the first direction and the y direction that is the second direction substantially orthogonal to the first direction. The contact part 48 is formed in the end part of the x direction which is a strip-shaped longitudinal direction among the board | substrates 42. As shown in FIG.

  A first electrode 44 is formed on the surface of the first piezoelectric element 41 opposite to the substrate 42 side. A second electrode 46 is formed on the surface of the first piezoelectric element 41 on the substrate 42 side. Both the first electrode 44 and the second electrode 46 are attached so as to cover the entire surface of the first piezoelectric element 41. A first electrode 45 is formed on the surface of the second piezoelectric element 43 opposite to the substrate 42 side. A second electrode 47 is formed on the surface of the second piezoelectric element 43 on the substrate 42 side. Both the first electrode 45 and the second electrode 47 are attached so as to cover the entire surface of the second piezoelectric element 43.

  The piezoelectric elements 41 and 43 have an advantage that high-speed driving can be easily performed as compared with an electric motor or the like used in the prior art. Piezoelectric elements 41 and 43 are lead zirconate titanate (PZT (trademark)), crystal, lithium niobate, barium titanate, lead titanate, lead metaniobate, polyvinylidene fluoride, lead zinc niobate, lead scandium niobate. Etc. can be used. Each of the electrodes 44 to 47 can be configured using a conductive member, for example, a metal member such as silver or aluminum.

  FIG. 5 illustrates a configuration for generating vibration by the vibration generator 34. The driving unit 50 supplies a voltage to the electrodes 44 to 47 of the vibration generating unit 34. The first electrode 44 of the first piezoelectric element 41 and the first electrode 45 of the second piezoelectric element 43 are connected so as to have the same potential. The second electrode 46 of the first piezoelectric element 41 and the second electrode 47 of the second piezoelectric element 43 are connected so as to have the same potential. In the drawing, the two second electrodes 46 and 47 are shown as one body, and the illustration of the substrate 42 is omitted.

  Supplying alternating current signals whose phases are inverted from the drive unit 50 so that the potentials of the first electrodes 44 and 45 and the potentials of the second electrodes 46 and 47 become + V, −V, or −V and + V, respectively. Thus, the piezoelectric elements 41 and 43 expand and contract. In this case, since it is possible to increase the potential difference between the two electrodes as compared with the case where 0 V is applied to one of the electrodes, that is, the case where it is connected to the ground, the degree of deformation of each of the piezoelectric elements 41 and 43 can be increased. Can be bigger. The substrate 42 may be composed of a conductive member. In this case, the second electrodes 46 and 47 can be omitted, and a voltage can be applied to the substrate 42 instead of the second electrodes 46 and 47.

  As the piezoelectric elements 41 and 43 expand and contract in response to an AC signal from the driving unit 50, the vibration generating unit 34 expands and contracts in the x direction, which is the longitudinal direction of the strip shape, as shown in the side configuration of FIG. Generate vibration. The vibration generating unit 34 is expanded and contracted in the x direction, which is one direction, by the piezoelectric elements 41 and 43, thereby displacing the contact portion 48 along the x direction, which is one direction, as shown in the plan configuration of FIG. 7. Let The vibration generating unit 34 imparts vibration to the diffusing unit 23 by reciprocating the contact portion 48 in the x direction. In addition, by forming an abutting portion with the diffusing portion 23 in the abutting portion 48 in a circular arc shape, a part of the abutting portion 48 can be obtained regardless of a change in the positional relationship between the vibration generating portion 34 and the diffusing portion 23. It is possible to always come into contact with the diffusion portion 23. Further, by bringing a narrow region of the contact portion 48 into contact with the diffusing portion 23, it is possible to reliably propagate the vibration of the vibration generating portion 34 to the diffusing portion 23.

  Returning to FIG. 3, the scintillation removing device 35 uses the vibration applied by the vibration generating unit 34 and the elasticity of the support unit 32 to indicate a portion of the diffusing unit 23 close to the vibration generating unit 34 with a double arrow. Go back and forth. Since vibration is applied to a position close to one corner, the entire diffusing unit 23 vibrates so as to reciprocate with a slight displacement. The scintillation removing apparatus 35 changes the phase of light by vibrating the diffusing unit 23 and transmitting light to the diffusing unit 23 in this way. By changing the phase of light from the light source unit at high speed, the rear projector 10 can reduce the occurrence of scintillation.

  If the scintillation removing device 35 can sufficiently change the phase of the light, the vibration generating unit 34 may be moved to a position different from the above description, for example, the center position of one side of the rectangular shape of the diffusing unit 23. It is good also as arranging. Moreover, the vibration generation part 34 should just be able to propagate the vibration generated by a deformation | transformation of the piezoelectric elements 41 and 43 to the spreading | diffusion part 23, and is not restricted to the structure which provides the board | substrate 42 and the contact part 48. FIG.

  Since the limit of human visual acuity is 1/60 second, scintillation is easily recognized when there is a moment when the direction in which the diffusing unit 23 is displaced changes for 1/60 second or longer. It is desirable that the scintillation removing device 35 displaces the diffusing unit 23 at least 60 times per second by vibration from the vibration generating unit 34. As a result, it is possible to change the phase state of light more quickly than a human recognizes a moving object, and it is possible to sufficiently reduce the occurrence of scintillation. By using the piezoelectric elements 41 and 43, the vibration generating unit 34 can easily realize high responsiveness to the extent that the diffusing unit 23 is displaced 60 times or more per second.

  In an electric motor or the like used in the conventional technique, a relatively large mechanism is required for high-speed driving that displaces the diffusion unit 23 60 times or more per second. The larger the mechanism, the more unnecessary vibration, noise, increased power consumption, lower durability, and the more difficult it is to install in the optical system. On the other hand, when the piezoelectric elements 41 and 43 are used, since the mechanism of the vibration generating unit 34 can be configured with a small number of parts, it is possible to make the vibration generating unit 34 small and simple. Since the vibration generating unit 34 can be reduced in size, the vibration generating unit 34 can be disposed in a narrow space between the optical engine casing 33 and the diffusing unit 23. Further, the vibration generating unit 34 can easily suppress the dimension in the optical axis direction to approximately the same as the thickness of the diffusing unit 23.

  By making the vibration generating unit 34 small and simple, the scintillation removing device 35 can easily realize excellent silence and power saving. Since the mechanism of the vibration generating unit 34 can be configured with a small number of parts, high durability can be easily realized. By changing the phase of light, light interference can be reduced and scintillation can be reduced. Thereby, there is an effect that scintillation can be effectively removed by a configuration suitable for practical use. Further, by using the scintillation removing device 35, the rear projector 10 can display an image in which scintillation is effectively reduced.

  When the scintillation removing device 35 is disposed in the vicinity of the incident side of the first integrator lens 24 (see FIG. 2) constituting the uniformizing unit, the light diffused by the diffusing unit 23 can be imaged on the screen 14. is there. It is also possible to maintain the shape of the illumination area on the spatial light modulator. For this reason, by arranging the scintillation removing device 35 in the vicinity of the incident side of the first integrator lens 24, it is possible to reduce the scintillation without degrading the image quality and display a high-quality image. . The support portion 32 vibrates the diffusion portion 23 in a plane substantially orthogonal to the optical axis, and desirably supports the diffusion portion 23 so as to minimize the shift of the diffusion portion 23 in the optical axis direction. . Thereby, the phase of the light from the light source unit can be changed without degrading the image quality.

  As shown in FIG. 6, when the vibration generating unit 34 expands and contracts in the x direction, a rotational moment around the center of gravity of the vibration generating unit 34 is generated in the vibration generating unit 34 due to an imbalance in the weight balance of the vibration generating unit 34. . The vibration generating unit 34 may perform bending motion that swings in the y direction as shown in FIG. 8 due to the rotational moment as well as expansion and contraction in the x direction shown in FIG. 6. Assuming that the x direction for expanding and contracting the vibration generating unit 34 is a first direction, the y direction for swinging the vibration generating unit 34 is a second direction substantially orthogonal to the first direction. Assuming that the vibration caused by expansion and contraction in the x direction shown in FIG. 6 is called longitudinal vibration and the vibration caused by bending motion shown in FIG. 8 is called bending vibration, the longitudinal vibration and bending vibration are combined, as shown in FIG. The vibration generating part 34 can displace the contact part 48 along a substantially elliptical orbit.

  FIG. 10 shows an example of the relationship between the vibration frequency and impedance of the vibration generator 34. Which of the longitudinal vibration mode and the bending vibration mode of the vibration generator 34 is dominant is determined by the frequency of the drive signal supplied to the piezoelectric elements 41 and 43. The resonance frequency f1 that is the minimum value of the impedance in the longitudinal vibration mode and the resonance frequency f2 that is the minimum value of the impedance in the bending vibration mode are different from each other. The piezoelectric elements 41 and 43 are driven using a drive signal having a frequency f2 ′ between a frequency f3 at which the impedance becomes a maximum value between the resonance frequencies f1 and f2 and a minimum value f2 of the impedance in the bending vibration mode. Thus, bending vibration can be induced together with the longitudinal vibration of the piezoelectric elements 41 and 43.

  By repeatedly moving the abutting portion 48 along the substantially elliptical orbit, the vibration generating portion 34 can impart vibrations that are displaced along the ellipse to the diffusing portion 23. By imparting to the diffusing unit 23 vibration that is displaced along an ellipse, the diffusing unit 23 can be continuously displaced without causing the moment when the diffusing unit 23 stops. The scintillation removal device 35 can continuously change the phase of light by displacing the diffusion unit 23 continuously.

  By continuously changing the phase of the light, it is possible to sufficiently reduce the occurrence of scintillation even if the frequency at which the diffusing unit 23 is vibrated is reduced compared to the case where the diffusing unit 23 is reciprocally vibrated in one direction. It becomes. The inventors have confirmed that the scintillation can be sufficiently reduced by displacing the diffusing portion 23 so as to draw a substantially ellipse, even if the frequency at which the diffusing portion 23 is vibrated is lowered to a value lower than 60 Hz. Furthermore, the quietness which was excellent by making the frequency which vibrates the spreading | diffusion part 23 into the numerical value lower than 20 Hz used as an audible limit is realizable. Thereby, the scintillation removal apparatus 35 can be set as the structure further excellent in silence, power saving property, and reliability.

  By setting the frequency f2 'of the drive signal to a value close to the resonance frequency f2 of the bending vibration mode, a large bending vibration of the vibration generating unit 34 is induced, and the contact portion 48 draws a large elliptical locus. When the contact part 48 is displaced on a large elliptical locus, the driving efficiency of the scintillation removing device 35 can be improved, and quietness, power saving performance and reliability can be improved. The vibration generating unit 34 may displace the contact part 48 along a substantially circular orbit. The mode of displacing the contact portion 48 is not limited as long as scintillation can be effectively removed, and can be appropriately set according to the vibration width of longitudinal vibration and the vibration width of bending vibration.

  As described above, by using the piezoelectric elements 41 and 43, the scintillation removing device 35 can displace the diffusion unit 23 in a two-dimensional direction with a simple configuration using the single vibration generation unit 34. For this reason, scintillation can be effectively reduced with a simple configuration. Moreover, since the frequency which vibrates the spreading | diffusion part 23 can be reduced suitably according to the deformation | transformation aspect of the piezoelectric elements 41 and 43, high silence, low power consumption, and high reliability can be ensured easily.

  FIGS. 11-14 demonstrates the modification of a vibration generation part. In the vibration generating unit 51 shown in FIG. 11, the contact part 48 is arranged at a position near the corner on the diffusion unit 23 side in the rectangular shape of the vibration generating unit 51. It is possible to increase the displacement amount due to the deformation of the piezoelectric elements 41 and 43 as the position is farther from the center of the vibration generating unit 51. By providing the contact portion 48 at a position near the rectangular corner that is the farthest from the center of the vibration generating portion 51, the amount of displacement of the contact portion 48 can be increased. As a result, the vibration generating unit 51 can be driven efficiently, and a configuration excellent in quietness and power saving can be obtained.

  Furthermore, the vibration generating unit 51 may include a balance unit 52 having substantially the same shape as the contact unit 48. The balance part 52 is formed at a position symmetrical to the contact part 48 with respect to the rectangular center position of the vibration generating part 51. By providing the balance portion 52, the vibration generating portion 51 can induce a large bending vibration and further increase the displacement amount of the contact portion 48.

  The vibration generating unit 53 shown in FIG. 12 has a shape such that the width in the y direction becomes smaller toward the plus x direction. A positive x direction, which is a specific direction among the x directions that are one direction, is a direction from the vibration generating unit 53 toward the diffusion unit 23. The abutting portion 48 is provided at the front end portion in the plus x direction of the vibration generating portion 53. By forming the piezoelectric elements 41 and 43 so that the width decreases as going in a specific direction, it is possible to increase the amount of displacement of the tip portion on the side with the smaller width. By providing the contact portion 48 at the tip of the vibration generating portion 53, the amount of displacement of the contact portion 48 due to deformation of the piezoelectric elements 41 and 43 can be increased. Thereby, it is possible to drive the vibration generating unit 53 efficiently, and to have a configuration excellent in quietness and power saving.

  The vibration generating unit 60 illustrated in FIG. 13 includes five first electrodes 55 to 59 arranged in parallel in the xy plane. One first electrode 57 is disposed so as to occupy a central strip-shaped region of the rectangular shape of the vibration generating unit 60 divided into three in the y direction. The two first electrodes 55 and 56 each occupy a region obtained by further dividing the strip-shaped region adjacent to the first electrode 57 disposed in the center into two equal parts, out of the rectangular shape of the vibration generating unit 60. Is arranged. The remaining two first electrodes 58 and 59 are arranged so as to occupy an area obtained by dividing the remaining strip-shaped area into two equal parts.

  Regarding the four first electrodes 55, 56, 58, 59 other than the central first electrode 57 in the vibration generating unit 60, the electrodes provided at symmetrical positions with respect to the rectangular center position of the vibration generating unit 60 are mutually connected. A voltage is applied so as to have the same potential. For example, AC signals whose phases are inverted are supplied so that the two first electrodes 55 and 59 and the two first electrodes 56 and 58 are + V, −V, or −V and + V, respectively. Thereby, a large bending vibration of the vibration generating part 60 can be induced, and the displacement amount of the contact part 48 can be increased.

  The first electrode is desirably arranged in the same manner for the first piezoelectric element 41 and the second piezoelectric element 43. Similarly to the first electrodes 55 to 59, five first electrodes are arranged for the second piezoelectric element 43. As shown in FIG. 14, the first electrodes 55, 57, 58 on the first piezoelectric element 41 side and the corresponding first electrodes 61, 62, 63 on the second piezoelectric element 43 side have the same potential. So that they are connected. In FIG. 14, three first electrodes on each of the first piezoelectric element 41 side and the second piezoelectric element 43 side are illustrated, but two first electrodes (not shown) are similarly connected. By causing the first electrodes corresponding to each other on the first piezoelectric element 41 side and the second piezoelectric element 43 side to have the same potential, a large bending vibration of the vibration generating unit 60 is induced, and the amount of displacement of the contact portion 48 is increased. be able to.

  The vibration generating unit 60 is not limited to the configuration in which the five first electrodes are arranged in parallel. A configuration in which a plurality of first electrodes are arranged in parallel in at least one of the x direction and the y direction may be used. As a result, AC signals whose phases are reversed in the xy plane on which the vibration generating unit 60 is arranged can be supplied, and the displacement of the vibration generating unit 60 can be increased.

  FIG. 15 illustrates a modified example of the support portion. The scintillation removing device 67 replaces the support portions 32 (see FIG. 3) provided at the four corners of the diffusion portion 23 with support portions 64 provided on the two opposite sides of the rectangular shape of the diffusion portion 23, respectively. Have. The support part 64 includes a rod-shaped member 65 and a connecting part 66. The rod-shaped member 65 is disposed along the side where the support portion 64 is provided in the rectangular shape of the diffusion portion 23. Both ends of the rod-shaped member 65 are fixed to the optical engine casing 33. With respect to portions other than both end portions of the rod-shaped member 65, an elongated gap is provided between the rod-shaped member 65 and the optical engine casing 33. The connecting portion 66 connects the central portion of the rod-like member 65 and the diffusion plate frame 36. About the part other than the center part of the rod-shaped member 65, a long and narrow gap is provided between the rod-shaped member 65 and the diffusion plate frame 36.

  The support part 64 supports the diffusion part 23 in a state in which a long and narrow gap is provided between the optical engine casing 33, the rod-like member 65, and the diffusion plate frame 36. When the diffusion unit 23 is pushed up by the vibration generation unit 34, the support unit 64 narrows the gap on the side opposite to the side where the vibration generation unit 34 is provided when viewed from the connection unit 66, and the vibration generation unit 34 is provided. Deform to widen the gap on the side. Thereafter, when the force that pushes up the diffusing portion 23 by the vibration generating portion 34 disappears, the support portion 64 is deformed so as to widen the gap on one side as viewed from the connecting portion 66 and narrow the gap on the other side by the biasing force. To do. In this way, the entire diffusing unit 23 vibrates so as to reciprocate with a slight displacement. The support portion 64 has an elastic structure that functions as an elastic body by the rod-like member 65 and the connecting portion 66.

  Even when the support portion 64 having such a configuration is used, the diffusion portion 23 can be supported and the diffusion portion 23 can be sufficiently vibrated. The support part 64 can be formed using not only an elastic member but another member, for example, a metal member constituting the diffusion plate frame 36, or the like. The position of the support portion 64 is not limited to the rectangular long side portion of the diffusing portion 23, and may be a short side portion. The shape of the support portion 64 is not limited to that shown in the drawing as long as it is an elastic structure that functions as an elastic body.

  16 to 19 illustrate a modification example regarding the arrangement of the vibration generating unit 34. In the scintillation removing device 68 shown in FIG. 16, the vibration generating unit 34 is disposed at a position where the contact portion 48 contacts one corner portion of the rectangular shape of the diffusion portion 23. Whether the contact portion 48 is in contact with the rectangular corner portion or the side portion of the diffusing portion 23 is appropriately selected from the viewpoint of efficiently applying vibration to the diffusing portion 23 according to the drive of the vibration generating portion 34. be able to.

  A scintillation removing device 69 shown in FIG. 17 has two vibration generating units 34 and 70. The two vibration generators 34 and 70 are disposed in the vicinity of the end of one side of the rectangular shape of the diffusing unit 23. The two vibration generators 34 and 70 have the same configuration. Regarding the application of vibration to the diffusing unit 23, the displacement of the diffusing unit 23 can be increased by reversing the phase between one vibration generating unit 34 and the other vibration generating unit 70. Thereby, generation | occurrence | production of scintillation can be reduced effectively.

  Regarding the application of vibration to the diffusing unit 23, the displacement of the diffusing unit 23 can be complicated by shifting the phase between one vibration generating unit 34 and the other vibration generating unit 70. Thereby, the phase change of the light from the diffusion unit 23 can be complicated, and the occurrence of scintillation can be effectively reduced. In addition, the number and position of a vibration generation part are not restricted to what is demonstrated. The scintillation removing device 69 can effectively reduce the occurrence of scintillation as long as it has a configuration in which a plurality of vibration generating units are provided.

  Furthermore, the vibration applied to the diffusing unit 23 may be appropriately controlled by one vibration generating unit 34 and the other vibration generating unit 70. By controlling the driving of the two vibration generators 34 and 70, the displacement for each position on the diffusion unit 23 can be adjusted. Thereby, for example, it is possible to control the scintillation removing device 69 so that the phase of the light is greatly changed in a portion where scintillation is likely to occur in the image. The portion where scintillation is likely to occur is a portion where the phases of light are easily aligned, for example, a portion where a single color is displayed in a wide range.

  A control signal generation unit 71 shown in FIG. 18 determines a position where the scintillation is likely to occur and the degree of occurrence from the image signal input to the rear projector 10, and generates a control signal for controlling the vibration generation units 34 and 70. . The drive unit 50 drives the vibration generation units 34 and 70 in accordance with the control signal from the control signal generation unit 71. The vibration generators 34 and 70 adjust the displacement for each position on the diffusion unit 23 due to the application of vibration to the diffusion unit 23 according to the control signal from the control signal generation unit 71. This makes it possible to change the phase of light at a location and timing at which scintillation is likely to occur, depending on the degree to which scintillation is likely to occur.

  When the piezoelectric elements 41 and 43 are used, the displacement for each position on the diffusion portion 23 can be adjusted relatively easily. The occurrence of scintillation can be efficiently reduced by changing the phase of the light according to the degree at which scintillation is likely to occur at locations and timings where scintillation is likely to occur. Thereby, generation | occurrence | production of scintillation can be effectively reduced by the structure excellent in silence, power saving property, and reliability. Note that the control of the vibration generating unit is not limited to using a plurality of vibration generating units, and may be performed when using a single vibration generating unit.

  A scintillation removing device 72 shown in FIG. 19 is obtained by changing the position of the vibration generating unit 34 in the scintillation removing device 67 shown in FIG. The scintillation removing device 72 arranges the vibration generating unit 34 by bringing the contact portion 48 into contact with a position close to the connection portion of the rod-like member 65 with the optical engine housing 33. When the position close to the fulcrum that is the connection part with the optical engine casing 33 in the rod-shaped member 65 is pushed up by the vibration generator 34, the connection part with the connecting part 66 that is far from the fulcrum of the rod-shaped member 65 is enlarged. Can be displaced. In the present modification, the support portion 64 functions as a vibration expansion mechanism that expands the vibration applied to the diffusion portion 23.

  By using the vibration magnifying mechanism, it is possible to efficiently apply vibration to the diffusion unit 23. Further, even when the vibration width by the vibration generator 34 is small, the phase of light can be changed sufficiently. Since the vibration applied to the diffusing unit 23 can be enlarged, the vibration generating unit 34 can be further reduced in size. Thereby, generation | occurrence | production of scintillation can be effectively reduced by the structure excellent in silence, power saving property, and reliability. Since the piezoelectric elements 41 and 43 generate a large force but have a small amount of displacement in many cases, a synergistic effect can be obtained by combining a vibration magnifying mechanism. The vibration magnifying mechanism is not limited to the case of the support part 64 as long as it is configured to be able to expand the vibration generated by the vibration generating part 34.

  FIG. 20 illustrates the structure of the diffusion plate 31 provided in the diffusion unit 23. In order to obtain a large diffusion effect with a small vibration of the diffusion portion 23, it is desirable that the diameter d of the diffusion material particles 73 dispersed in the transparent member 74 is as small as possible, for example, about 0.01 mm to 0.1 mm. Further, it is desirable that the diffusing material particles 73 are randomly dispersed in the transparent member 74. In order to reduce the focus shift, it is desirable that the diffusion plate 31 has a thin shape. The diffusion plate 31 may be a plate member such as a glass plate or a sheet-like member. Further, the diffusion plate 31 may be a rubbing glass plate or a film provided with a diffusion surface having a diffusion function, as long as it has a function of diffusing light.

  FIG. 21 explains the displacement of the diffusing material grains 73. When the diffusing material grains 73 reciprocate in the linear direction indicated by the double-pointed arrows, if the diffusing portion 23 is displaced 60 times per second, the diffusing-material grains 73 correspond to the length of the double-headed arrows in 1/60 seconds. Suppose you move a distance. When the distance to which the diffusion material particles 73 are moved by vibration is too short, the occurrence of scintillation may not be sufficiently reduced due to a small change in the phase of light. The distance by which the diffusion material particles 73 are moved is preferably longer than both the diameter d of the diffusion material particles 73 and the distance s between the center positions of the adjacent diffusion material particles 73 shown in FIG. However, the distance to which the diffusion material particles 73 are moved needs to be long enough to drive the diffusion unit 23 at high speed.

  When the diffusion material particles 73 are continuously moved along a substantially elliptical or substantially circular orbit, the occurrence of scintillation can be sufficiently reduced even when the frequency at which the diffusion material particles 73 are moved is lower than 60 Hz. The inventors have confirmed that when the diffusing material particles 73 are moved at a speed of about 5 mm / s or more, the scintillation can be sufficiently removed by setting the diameter d of the diffusing material particles 73 to about 0.5 mm. At this time, the haze value of the diffusion plate 31 is about 10 to 20%. The haze value of the screen 14 can be about 80%.

  FIG. 22 illustrates the configuration of the projection lens 80 which is a characteristic part of the second embodiment of the present invention. The projection lens 80 can be applied to the rear projector 10 of the first embodiment. The present embodiment is characterized by having a scintillation removing device 85 provided in the projection lens 80 in place of the scintillation removing device 35 provided in the optical engine unit 11 (see FIG. 2).

  By collimating the light incident on the projection lens 80 by the two lenses 83 and 84, the image 81 of the spatial light modulator is formed in the projection lens 80. The diffusing unit of the scintillation removing device 85 is provided in an image plane in the projection lens 80 where an intermediate image is formed. The scintillation removal apparatus 85 can be configured in the same manner as the scintillation removal apparatus 35 (see FIG. 3) of the first embodiment. The scintillation removing device 85 is housed in the lens barrel 82. The light transmitted through the diffusing section forms an image on the screen 14 by the exit side lens 86.

  By adopting a configuration in which an intermediate image is formed on the diffusing portion, the light diffused by the diffusing portion can be imaged on the screen 14 as indicated by a broken line in the figure. Therefore, scintillation can be reduced without degrading the image quality, and a high-quality image can be displayed. The projection lens 80 is not limited to the configuration having the three lenses 83, 84, 86. Any number of lenses may be provided in the projection lens 80 as long as an image can be formed by the diffusion unit of the scintillation removing device 85.

  FIG. 23 illustrates a configuration of a projection lens 90 according to a modification of the present embodiment. The present modification is characterized by having a scintillation removing device 93 provided in the vicinity of the reflecting portion 94 in the projection lens 90. The reflector 94 is disposed at a position where the image 81 of the spatial light modulator is formed by the two lenses 83 and 84. Between the lens 84 and the reflection part 94, a reflection type polarizing plate 91, a λ / 4 phase plate 92, and a diffusion part of a scintillation removing device 93 are provided.

  The reflective polarizing plate 91 is disposed at an angle of approximately 45 degrees with respect to the principal ray of light from the lens 84. The reflective polarizing plate 91 transmits polarized light in the first vibration direction and reflects polarized light in the second vibration direction that is substantially orthogonal to the first vibration direction. As the reflective polarizing plate 91, for example, a wire grid type polarizing plate can be used. The wire grid type polarizing plate can use a configuration in which wires made of metal, for example, aluminum, are provided in a grid pattern on a substrate made of an optically transparent glass member. The wire grid type polarizing plate transmits polarized light whose vibration direction is substantially perpendicular to the wire and reflects polarized light whose vibration direction is substantially parallel to the wire. By arranging the wire grid type polarizing plate so that the wire is substantially perpendicular to the vibration direction of the polarized light, only the polarized light having a specific vibration direction can be transmitted. As the reflective polarizing plate 91, a polarization beam splitter having a polarization separation film may be used in addition to the wire grid polarizing plate.

  The scintillation removing apparatus 93 can be configured similarly to the scintillation removing apparatus 35 of the first embodiment. The scintillation removing device 93 is housed in the lens barrel 82. The exit-side lens 86 is provided at a position where light that is incident on the reflective polarizing plate 91 from the reflecting portion 94 and whose optical path is bent by approximately 90 degrees due to reflection by the reflective polarizing plate 91 is incident.

  The p-polarized light which is linearly polarized light in the first vibration direction emitted from the spatial light modulator is transmitted through the reflective polarizing plate 91 and then converted into circularly polarized light by the λ / 4 phase plate 92. The circularly polarized light from the λ / 4 phase plate 92 passes through the diffusing unit of the scintillation removing device 93 and then enters the reflecting unit 94. The circularly polarized light reflected by the reflecting section 94 is transmitted through the diffusing section of the scintillation removing device 93 and then converted into s-polarized light that is linearly polarized light in the second vibration direction by the λ / 4 phase plate 92. The s-polarized light from the λ / 4 phase plate 92 is reflected by the reflective polarizing plate 91 and then enters the screen 14 through the exit side lens 86.

  The diffusing unit of the scintillation removing device 93 is disposed in the vicinity of the incident surface of the reflecting unit 94 that is an image plane on which an intermediate image is formed. By disposing the scintillation removing device 93 as close as possible to the reflecting portion 94, the light diffused by the diffusing portion can be imaged on the screen 14, as indicated by a broken line in the figure. Further, in this modification, the light diffusion degree can be increased by transmitting light twice through the diffusion unit of the scintillation removing apparatus 93. For this reason, even if the scintillation removing device 93 reduces the vibration width of the diffusing unit to half, it is possible to diffuse the light to the same extent as in the case of transmitting light to the diffusing unit once. Thereby, it can be set as the structure excellent in silence, power saving property, and reliability. Moreover, according to this modification, the light reflected by the diffusing section can be incident on the reflective polarizing plate 91 and reused, so that the light efficiency can be improved.

  Further, the scintillation removing apparatus 93 may be provided with a diffusing unit that diffuses light by reflection instead of the diffusing unit that transmits light and the reflecting unit 94. The diffusion unit that diffuses the light by reflection can change the phase of the light by reflecting the light while receiving the vibration from the vibration generating unit. The diffuser that reflects light can be configured using a highly reflective member having a reflective surface that has been subjected to a diffusion treatment such as unevenness. In this case as well, the occurrence of scintillation can be reduced as in the case of using a diffusing portion that transmits light.

  FIG. 24 shows a schematic configuration of the rear projector 100 according to the third embodiment of the present invention. The present embodiment is characterized by having a scintillation removing apparatus 101 provided in the vicinity of the incident side of the screen 14 in place of the scintillation removing apparatus 35 provided in the optical engine unit 11 (see FIG. 2). The same parts as those in the first embodiment are denoted by the same reference numerals, and redundant description is omitted.

  The diffusing unit of the scintillation removing apparatus 101 is disposed in the vicinity of the incident side of the screen 14 on which an image is formed. By disposing the scintillation removal apparatus 101 as close as possible to the screen 14, the influence of diffusion in the diffusion section on the image formation on the screen 14 can be reduced. This makes it possible to reduce scintillation without degrading the image quality, and display a high-quality image. The scintillation removal apparatus 101 may be provided in the vicinity of the emission side of the screen 14. The scintillation removal apparatus 101 can be provided in at least one of the vicinity of the entrance side and the vicinity of the exit side of the screen 14.

  FIG. 25 shows a schematic configuration of the rear projector 110 according to the fourth embodiment of the present invention. The rear projector 110 of this embodiment includes a micro mirror array device 108 that is a spatial light modulator. An ultra-high pressure mercury lamp 102 as a light source unit supplies light including R light, G light, and B light. Light from the ultrahigh pressure mercury lamp 102 passes through the condenser lens 103 and then enters the color wheel 104.

  In the color wheel 104, a rotating body configured by combining a dichroic film in an appropriate shape such as a spiral is rotated around a rotation axis substantially parallel to the optical axis. The dichroic film transmits light in a specific wavelength region and reflects light in other wavelength regions. Using a color wheel 104 using an R light transmitting dichroic film that selectively transmits R light, a G light transmitting dichroic film that selectively transmits G light, and a B light transmitting dichroic film that selectively transmits B light Thus, the light from the ultrahigh pressure mercury lamp 102 can be separated into R light, G light, and B light.

  The light from the color wheel 104 passes through the diffusion part of the scintillation removal apparatus 105 and then enters the rod integrator 106 that is a uniformizing part. The rod integrator 106 is formed of a transparent glass member having a rectangular parallelepiped shape. The light incident on the rod integrator 106 travels inside the rod integrator 106 while repeating total reflection at the glass member / air interface. As a result, the rod integrator 106 makes the intensity distribution of the light beam uniform. The rod integrator 106 is not limited to a glass member, but may be a hollow structure whose inner surface is a reflective surface. In the case of a rod integrator having an inner surface as a reflecting surface, light incident on the rod integrator travels inside the rod integrator while being repeatedly reflected on the reflecting surface. Further, the rod integrator may be configured to combine a glass member and a reflecting surface.

  The light from the rod integrator 106 enters the micromirror array device 108 through the collimator lens 107 and the aspherical mirror 109. The light reflected by the micromirror array device 108 in the direction of the projection lens 12 according to the image signal is projected onto the screen 14 by the projection lens 12.

  The diffusion part of the scintillation removal apparatus 105 is disposed in the vicinity of the incident side of the rod integrator 106. The scintillation removal apparatus 105 can be configured similarly to the scintillation removal apparatus 35 (see FIG. 3) of the first embodiment. A light source image is formed on the incident surface of the rod integrator 106. By disposing the scintillation removing device 105 as close as possible to the rod integrator 106, the light diffused by the diffusing section can be imaged on the screen 14.

  Therefore, scintillation can be reduced without degrading the image quality, and a high-quality image can be displayed. Note that the scintillation removal apparatus 105 may be provided in the vicinity of the emission side of the rod integrator 106. Since the light source image is also formed on the exit surface of the rod integrator 106, even when the scintillation removing device 105 is disposed in the vicinity of the exit side of the rod integrator 106, the light diffused by the diffusing unit is imaged on the screen 14. Can do. The scintillation removing apparatus 105 can be provided in at least one of the vicinity of the entrance side and the vicinity of the exit side of the rod integrator 106 that is a uniformizing unit.

  In the rear projector 110 of this embodiment, a scintillation removing device may be provided in the projection lens 12 or in the vicinity of the screen 14 in place of the vicinity of the incident side and the vicinity of the exit side of the rod integrator 106. The rear projector may be used by appropriately combining the scintillation removing apparatuses of the above embodiments.

  The rear projector uses a reflection type liquid crystal display (LCOS) as a spatial light modulation device or a projection device (for example, GLV (Grating Light Valve)) that controls the direction and color of light by utilizing the light diffraction effect. It may be used. When a reflective liquid crystal display device is used, the same configuration as that of the rear projector 110 (see FIG. 25) can be employed. The rear projector may be configured to use a light emitting diode element (LED) or the like instead of a laser or an ultrahigh pressure mercury lamp as a light source unit. Further, the rear projector may be a laser projector that scans a laser beam modulated in accordance with an image signal. In the case of a laser projector, a laser light source that supplies laser light modulated in accordance with an image signal and a scanning optical system that scans light from the laser light source are used instead of the optical engine unit 11.

  The scintillation removal apparatus of each embodiment is not limited to a rear projector, and may be applied to a front projection type projector or a screen used in combination with a front projection type projector. In this case, as in the case of the rear projector, scintillation can be effectively removed with a configuration suitable for practical use.

  As described above, the scintillation removal apparatus according to the present invention is suitable for removing scintillation that occurs in image display by a projector.

1 is a diagram illustrating a schematic configuration of a rear projector according to a first embodiment of the invention. The figure which shows schematic structure of an optical engine part. The figure explaining the structure of a scintillation removal apparatus. The figure explaining the structure of a vibration generation part. The figure explaining the structure for generating a vibration by a vibration generation part. The figure explaining the longitudinal vibration of a vibration generation part. The figure explaining the displacement of a contact part. The figure explaining the bending vibration of a vibration generation part. The figure explaining the displacement of a contact part. The figure which shows an example of the relationship between the vibration frequency and impedance of a vibration generation part. The figure which shows the modification which arrange | positions a contact part in the position close | similar to the angle | corner by the side of a spreading | diffusion part. The figure which shows the modification which has a shape where a width | variety becomes small as it goes to a specific direction. The figure which shows the modification which makes a some 1st electrode parallel. The figure explaining the structure for generating a vibration by the vibration generation part of a modification. The figure which shows the modification which deform | transformed the support part. The figure which shows the modification which makes a contact part contact | abut to one corner | angular part of the rectangular shape of a spreading | diffusion part. The figure which shows the modification which has two vibration generation parts. The figure which shows the structure for controlling a vibration generation part. The figure which shows the modification which has a vibration expansion mechanism. The figure explaining the structure of a diffusion plate. The figure explaining the displacement of a diffusion material grain. FIG. 6 is a diagram illustrating a configuration of a projection lens that is a characteristic part of Embodiment 2 of the present invention. FIG. 6 is a diagram illustrating a configuration of a projection lens according to a modification example of Example 2. FIG. 10 is a diagram illustrating a schematic configuration of a rear projector according to a third embodiment of the invention. FIG. 10 is a diagram illustrating a schematic configuration of a rear projector according to a fourth embodiment of the invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Rear projector, 11 Optical engine part, 12 Projection lens, 13 Mirror, 14 Screen, 15 Case, 20R R light source part, 20G G light source part, 20B B light source part, 21 Divergence lens, 22 Collimator Lens, 23 Diffuser, 24 First integrator lens, 25 Second integrator lens, 26 Polarization conversion element, 27 Superimposing lens, 28 Field lens, 29R R light spatial light modulator, 29G G light spatial light modulator, 29B Spatial light modulator for B light, 30 cross dichroic prism, 30a first dichroic film, 30b second dichroic film, 31 diffuser plate, 32 support section, 33 optical engine casing, 34 vibration generating section, 35 scintillation removal apparatus, 36 diffusion plate frame, 41 first piezoelectric element, 42 Substrate, 43 Second piezoelectric element, 44, 45 First electrode, 46, 47 Second electrode, 48 Contact portion, 50 Drive portion, 51 Vibration generating portion, 52 Balance portion, 53 Vibration generating portion, 55-59 First Electrode, 60 Vibration generating part, 61-63 First electrode, 64 Support part, 65 Bar-shaped member, 66 Connecting part, 67 Scintillation removing apparatus, 68 Scintillation removing apparatus, 69 Scintillation removing apparatus, 70 Vibration generating part, 71 Control signal generation , 72 scintillation removal device, 73 diffuser particle, 74 transparent member, 80 projection lens, 81 image, 82 lens barrel, 83, 84 lens, 85 scintillation removal device, 86 exit side lens, 90 projection lens, 91 reflection type Polarizing plate, 92 λ / 4 phase plate, 93 scintillation removing device, 94 reflector, 100 A projector, 101 scintillation removing apparatus, 102 an ultra-high pressure mercury lamp, 103 a condenser lens, 104 a color wheel, 105 scintillation removing apparatus, 106 rod integrator 107 collimator lens, 108 micromirror array device, 109 aspherical mirror, 110 a rear projector

Claims (15)

A diffuser that diffuses light by transmission or reflection; and
A vibration generating unit that generates vibration using a piezoelectric element,
The scintillation removing apparatus according to claim 1, wherein the diffusing unit is subjected to vibration from the vibration generating unit and changes the phase of light by transmitting or reflecting the light.   The scintillation removing apparatus according to claim 1, further comprising a support portion that supports the diffusion portion so as to vibrate.   The scintillation removing apparatus according to claim 2, wherein the support portion includes an elastic body.   The said vibration generation part has a contact part made to contact | abut to the said spreading | diffusion part, and gives a vibration to the said spreading | diffusion part by the drive of the said contact part. The scintillation removal apparatus described in 1.   The scintillation removing apparatus according to claim 4, wherein the vibration generating unit is expanded and contracted in one direction by the piezoelectric element to displace the contact portion along the one direction.   The vibration generating part expands and contracts in the first direction by the piezoelectric element and performs a bending motion that swings in a second direction substantially orthogonal to the first direction, thereby making the contact part substantially elliptical. The scintillation removing apparatus according to claim 4, wherein the scintillation removing apparatus is displaced along a shape or a substantially circular orbit. The piezoelectric element is formed such that the width decreases as it goes to a specific direction in one direction,
The scintillation removing apparatus according to any one of claims 4 to 6, wherein the contact portion is provided at a tip portion in the specific direction among the vibration generating portions. A plurality of electrodes for applying a voltage to the piezoelectric element;
The piezoelectric element is provided along a first direction and a second direction substantially orthogonal to the first direction,
The scintillation removal apparatus according to any one of claims 1 to 7, wherein the plurality of electrodes are provided in parallel with respect to at least one of the first direction and the second direction.   The scintillation removing apparatus according to claim 1, wherein the scintillation removing apparatus includes a plurality of the vibration generating units.   The said vibration generation part adjusts the displacement for every position on the said diffusion part by provision of the vibration to the said diffusion part according to the control signal which controls the said vibration generation part. The scintillation removing apparatus according to any one of the above.   The scintillation removal apparatus according to any one of claims 1 to 10, further comprising a vibration expansion mechanism that expands vibration generated by the vibration generation unit.   The projector which displays an image using the light which passed through the scintillation removal apparatus as described in any one of Claims 1-11. Having a homogenizing unit that uniformizes the intensity distribution of the light beam from the light source unit,
13. The projector according to claim 12, wherein the scintillation removing device is provided in at least one of the vicinity of the incident side and the vicinity of the output side of the uniformizing unit. A projection lens that projects light modulated in accordance with an image signal;
The projector according to claim 12, wherein the scintillation removing device is provided on an image plane in the projection lens or in the vicinity of the image plane. Having a screen on which light modulated according to an image signal is incident;
The projector according to claim 12, wherein the scintillation removing device is provided in at least one of the vicinity of the entrance side and the exit side of the screen.

Images