Abstract: Red, green, and blue laser light emitted from laser light sources 1-3 is transformed into substantially parallel beams by collimator lenses 4-6, collected by microlens arrays 7-9, and rendered uniform by rod integrators 10-12, whereupon it is used to illuminate spatial light modulation elements 16-18 and subjected to modulation. The modulated laser light exiting from the spatial light modulation elements 16-18 is recombined using a beam-combining prism 19 and subjected to pixel separation using a birefringent plate 20, which is rotationally driven by a birefringent plate rotary drive unit 26, after which it is projected upon a screen 22 using a projection optical system 21. The birefringent plate 20 spatially separates the modulated laser light using birefringence. When pixels are spatially separated by the birefringent plate, the pixel grid region is made smaller, the distribution of brightness on the screen is rendered uniform, and speckle noise is reduced.

Abstract: An image display apparatus includes: a first spatial light modulator (SLM) and a second modulator for modulating a first and a second illumination lights for displaying images; an SLM control unit for generating first control data and second control data for controlling the first and second SLMs respectively in accordance with the first and second control data, wherein each of the first control data and second control data is generated for each of a plurality of sub-frame periods divided from one frame period for displaying the images, and the start timing of one sub-frame period of the first control data is different from the start timing of one sub-frame period of the second control data.

Abstract: A composite optical element is provided. The composite optical element includes a plurality of optical elements, in which at least one of the optical elements is formed of an element modifying an optical path and the other optical elements are bonded to an incident surface and/or exit surface of the element modifying the optical path with a low refractive index material layer in between.

Abstract: A screen device of the present invention has a light collecting element array including a plurality of light collecting elements that collect incident light from a projector and a back surface sheet. The back surface sheet includes a first electrode plate, a second electrode plate, a photoconductive layer disposed between the first electrode plate and the second electrode plate, and an image recording layer disposed between the first electrode plate and the photoconductive layer. At the back surface sheet, a light reflecting portion is formed at a light collecting region to which the light collected by the light collecting elements is irradiated, and a light absorbing portion is formed at a non-light collecting region to which the light collected by the light collecting elements is not irradiated.

Abstract: A stereoscopic digital image projecting system has a light source system energizable to provide polarized illumination having a first polarization state and a beam splitting system alternately generating first and second light beams having different polarization states from the polarized illumination. A combining system has a polarization beam combiner that combines the first and second light beams into a combined light beam. A spatial light modulator is used to modulate the combined light beam in a manner consistent with stereoscopic image data to form a first modulated image from illumination in the combined light beam having the first polarization state and to form a second modulated image from illumination in the combined light beam having the second polarization state. Projection optics are configured to project the first and second modulated images onto a display surface.

Abstract: A total internal reflection prism comprises at least two subprisms. The at least two subprisms define an airgap of a uniform thickness following a one-dimensional curve.

Abstract: A mirror unit of the present invention includes a base member constituted of an upper plate portion, a lower plate portion, a connecting portion connecting the upper plate portion and the lower plate portion, and wall portions. A mirror holder for holding a mirror is pivotally supported between the upper plate portion and the lower plate portion. A recess is formed in the wall portions. An adjuster is mounted in the recess. Screw holes extend through the recess, and adjusting screws are engaged in the screw holes. Lifting amounts of plate portions of the adjuster can be adjusted by the adjusting screws. The tilt angle of the mirror is adjusted so that the mirror is properly tilted with respect to a light flux from either one of two lamps.

Abstract: A projection type image display apparatus includes: a light source; an illumination optical system that uniformly illuminates beams, which are emitted from the light source, on a surface of an image modulation element as a primary image plane; and a projection optical system that projects image information of the primary image plane modulated by the image modulation element on a screen as a secondary image plane in an enlarged manner. The projection optical system includes a first optical system having a positive refractive power and including a plurality of transmissive surfaces, and a second optical system having a positive refractive power and including a concave reflective surface. The first optical system has a first reflective surface disposed between any surfaces of the plurality of transmissive surfaces, and a second reflective surface disposed between the first optical system and second optical system.

Abstract: A light source apparatus which emits light from phosphor by exciting light and in which an efficiency of brightness is improved is provided. The light source apparatus has a light source which emits exciting light; and a metal member to which the exciting light is input, wherein the metal member has a concave portion in a portion to which the exciting light is input, and phosphor to generate phosphor light from the exciting light is coated in the concave portion. The concave portion may have a taper shape. The phosphor may be coated on at least two surfaces of the concave portion. The phosphor may be coated on an area which is equal to or less than the half of a depth of the concave portion. A glass member having a taper shape may be formed at an opening portion of the concave portion.

Abstract: Disclosed is an optical projection system for projecting an enlarged image on a projection surface. The optical projection system includes an image forming element, a coaxial optical system and a concave mirror. The coaxial optical system and the concave mirror are arranged in this order on an optical path from the image forming element to the projection surface. The coaxial optical system includes lens groups and an aperture stop that share an optical axis. The lens groups include a first lens group and other lens groups. The first lens group has negative refractive power and independently moves in an optical axis direction for adjusting the focus of the optical projection system. The aperture stop is arranged at a position closer to the image forming element than the first lens group that is arranged closest to the concave mirror among the lens groups having the negative refractive power.

Abstract: An image forming system is described that includes a light source that provides a light beam and an anamorphic refractive optical element. A first outer surface of the anamorphic element faces the light source and includes a toric surface. The light beam is incident upon the first outer face and then an incident surface of the anamorphic element. The anamorphic element directs the light beam to an image forming device. An illumination system is also described where an anamorphic element includes a toric surface and a facet surface.

Abstract: A laser projector includes a green laser, a two-wavelength laser, a PBS, a collimator lens, a two-axis galvanometer mirror, a group of lenses, and a screen. The green laser emits a green laser beam. The two-wavelength laser emits red and blue laser beams. The PBS is provided at the position where respective optical paths of laser beams emitted from respective lasers cross each other to cause these optical paths to coincide with each other.

Abstract: Provided is a light emitting device of an electronic device, provided with a DLP (Digital Light Processing) projector and a display unit, which is configured in such a manner that the light generated by the operation of the DLP projector can be re-used as a backlight light of the display unit. The disclosed light emitting device includes a first mirror for projecting a light of the DLP projector on a flat area provided ahead of the first mirror in an intermediate operation state of the first mirror; a light concentration mirror for converging the light projected on the flat area, the light concentration mirror being provided at a position adjacent to the flat area; and an optical fiber for transferring the light converged by the light concentration mirror to the display unit and enabling re-use of the transferred light as a light for a backlight of the display unit.

Abstract: A laser illuminating device and an image display device are provided to enable a removal of speckle noises in a diffraction field and an image field, to uniformly illuminate an illumination plane, and to realize miniaturization. The laser illuminating device 100 includes a laser light source 3 and a first lens 1 including a plurality of microlenses 10, each having a predetermined numerical aperture in an in-plane direction, and each of the microlenses 10 being adapted to expand laser light emitted from the laser light source 3 to thereby superimpose the laser light transmitted through each of the microlenses 10. The laser illuminating device 100 also includes a second lens 2 having an effective diameter larger than an effective diameter of the first lens 1, and compensating for a divergence angle of the laser light expanded by each of the plurality of the microlenses 10.

Abstract: An aspheric mirror has an aspheric reflective surface symmetrical with respect to an optical axis that goes through the reflective surface and a reference plane provided in the reflective surface. The optical axis may go through the reflective surface at a non-center position on the reflective surface. The reference plane may be perpendicular to the optical axis. The reference plane may be flat enough for a beam to be reflected from the reference plane in almost specular reflection when emitted to the reference plane.

Abstract: A fixed-focus lens disposed between an object side and an image side is provided. The fixed-focus lens includes a reflector, a curved reflector, a first lens group, and a second lens group disposed in sequence from the object side to the image side. The first lens group includes two aspheric lenses. The second lens group includes a spherical lens and an aspheric lens, wherein the aspheric lens of the second lens group is closest to the image side in the second lens group. Besides, an effective focal length (EFL) of the fixed-focus lens is f, an EFL of the second lens group is f2, and a clear aperture of the aspheric lens of the second lens group is D. The fixed-focus lens satisfies one of following conditions: 0.04<f/f2<0.078 and 0.05<f/D<0.18. An apparatus integrating optical projection and image detection is provided.

Abstract: A projection apparatus includes an illumination system, a light valve, a projection lens, and a first reflective unit. The illumination system provides an illumination light beam. The light valve is disposed on a transmission path of the illumination light beam and capable of converting the illumination light beam into an image light beam. The illumination light beam is transmitted to the light valve vertically. The projection lens is disposed on a transmission path of the image light beam. The first reflective unit disposed on the transmission path of the image light beam is located between the light valve and the projection lens. The first reflective unit is capable of reflecting the image light beam from the light valve to the projection lens. The image light beam reflected by the first reflective unit to the projection lens is perpendicular to the illumination light beam transmitted to the light valve.

Abstract: A projection display apparatus includes a housing member that houses a light source, an imager that modulates light emitted from the light source, and a projection unit that projects light emitted from the imager onto a projection plane, wherein the projection unit has a concave mirror that reflects the light emitted from the imager to the projection plane side, and the housing member pivotally supports the concave mirror along a circumference of a virtual circle formed by a virtual extension line of the concave mirror.

Abstract: A projection type image display apparatus includes an image display element, a projection unit including a first lens group and a second lens group formed with a plural number of lenses, a reflection mirror configured to reflect light emitted from the second lens group thereon after the light passes through the first lens group so as to project the light on a screen obliquely, and a mechanism configured to enable movement of at least one lens of the second lens group in a direction of an optical axis. The first lens group is fixed with respect to a bottom portion of the mechanism and is configured to compensate for an aberration of an optical system thereof. The second lens group is configured to enable movement of at least one lens of the second lens group with respect to the first lens group and the bottom portion of the mechanism.

Abstract: An image projection apparatus according to the present invention includes a light source for outputting laser light and a mirror section for reflecting and projecting the laser light having been output from the light source, and displays an image with at least a portion of the projected laser light. The image projection apparatus includes a detection section for detecting at least a portion of the laser light returning from a projection direction of the laser light, and a calculation section for determining an image displayable region based on the detected light. The mirror section reflects at least a portion of the laser light returning from the projection direction of the laser light so as to be led into the detection section.

Abstract: An optical micro-projection system comprising the following components: at least one laser light source (200, 400, 402, 600); at least one movable mirror (102, 103, 203) for deviating light from said light source to allow generation of images on a projection surface (104, 301, 303, 306, 603); a self mixing module for measurement of the distance (604) between the projection source and a projection surface, said self mixing module comprising:—at least one photodiode (401, 601) for monitoring the light emission power of the laser light source;—an optical power variation counter for counting optical power variations (605); successive displacements of said mirror allowing the self mixing module providing successive projection distance measurements of a plurality of points of said projection surface. A projection method for optical micro-projection system and a distance measurement method are also provided.

Abstract: Method to display an image using four or more primaries having different spectral distributions that are distributed into three groups of primaries, wherein, in a visual color space, all primaries belonging to the same group have the same visual color and are metamehc. Each image being got from a combination of three primary images and each primary image being associated with each visual color of a group, the different primaries of each group are spatially or sequentially distributed over the primary image associated with this group, then allowing an efficient anti-copy protection based on metamerization of images, without any supplemental video processing.

Abstract: A projection display is provided with a light engine including a damped piezo-electric smooth picture actuating device. The light engine comprises a mirror and an actuator for positioning the mirror. The actuator includes a tilting means that couples the actuator to the mirror. The tilting means has damping material attached thereto. The damping material may be a polymeric material.

Abstract: A display device includes: a reflection property control layer which is disposed in the front face of a display screen, whereby reflection properties are switched for each predetermined region; and a control unit configured to switch the reflection properties of the reflection property control layer depending on an input image, with the control means detecting a gloss region from the input image, and switching the reflection properties of a predetermined region according to the relevant detection result.

Abstract: A light emitting diode package including a carrier, at least one LED chip, and a light guide element. The LED chip is disposed on the carrier. The light guide element including a light transmissive body, a light integration part, a reflective film, and a support part is disposed on the carrier and located above the LED chip. The light integration part connected to the light transmissive body and disposed between the light transmissive body and the LED chip has a light incident surface facing the LED chip and at least one side surface. The side surface connects the light transmissive body and the light incident surface. The reflective film is disposed on the side surface. The support part leaning on the carrier is connected to the light transmissive body and surrounds the light integration part. The light transmissive body, the light integration part, and the support part are integrally formed.

Abstract: A projection apparatus includes a light source, a light valve, a light uniforming device, and a lens module. The light source provides an illumination beam. The light valve on a transmission path of the illumination beam converts the illumination beam into an image beam. The light valve has an active surface with a rectangular shape. The light uniforming device is between the light source and the light value. The lens module is between the light uniforming device and the light value. A refractive power of the lens module along a first direction is different from a refractive power of the lens module along a second direction. An f-number of the illumination beam along a direction parallel to a long side of the active surface of the light valve is greater than an f-number thereof along a direction parallel to a short side of the active surface of the light valve.

Abstract: A projection type display device that displays an image with projected light onto a target to he projected, including a first sensor (12) that detects reflected light of the projected light; a second sensor (13) that detects an infrared ray in a predetermined range in an optical path direction of the projected light; and a light amount deciding section (23) that decides an amount of the projected light based on the amount of reflected light detected by the first sensor (12) and an amount of change of the infrared ray detected by the second sensor (13).

Abstract: The present invention provides a display apparatus, comprising: an a light source for emitting illumination light for transmitting along illumination light path; a display device includes a plurality of pixels for modulating the illumination light for reflecting the illumination light along a projection light path after said illumination light is modulated by said display device; light path change actuator for changing the projection light paths; and a control circuit for controlling the light source, wherein the control circuit controls the light source in response to changes of the projection light path.

Abstract: The invention discloses a projecting system. The projecting system includes two sets of lens. The first set of lens has a first focal length for focusing an incident ray of light to form a first image. The second set of lens has a second focal length for projecting the first image to form a second image. The two sets of lens are separated by a lens-apex distance relative to the light path between the two sets of lens. The second focal length is smaller than or equal to the lens-apex distance. A difference between the second focal length and the lens-apex distance is smaller than or equal to a half of the first focal length.

Abstract: A reflector used in combination with a light emitting portion that emits light and disposed around a central axis on which the light emitting portion is disposed includes a curved reflection section having the substantially same shape as that of a surface of revolution around the central axis, the curved reflection section reflecting light from the light emitting portion, and a flat deflection section formed on a flat surface positioned closer to the central axis than the surface of revolution, the flat deflection section deflecting the light from the light emitting portion forward. The flat deflection section has a plurality of structural members formed on the flat surface.

Abstract: Disclosed are a display apparatus and a light control method thereof, in which the display apparatus including a display panel, a light source unit, an illumination unit to illuminate the display panel with light emitted from the light source unit, and a projection unit to project the light from the display panel in a predetermined direction includes: a light sensor which is provided between the light source unit and the illumination unit; and a light controller which corrects brightness of light sensed by the light sensor on the basis of reflective characteristics of the display panel. With this configuration, the quantity of light is prevented from decreasing so as to prevent the brightness of an image from decreasing.

Abstract: A display device (100) of the present invention has a first switch (3) and a second switch (4) on an upper surface of its casing, and includes a control circuit (18) for controlling the first switch (3) and the second switch (4) and a light source (19) inside the casing. The control circuit (18) performs control so that the light source (19) is turned on when the second switch (4) is pressed after a predetermined period of time has passed from when the first switch (3) was pressed. Thereby, the display device (100) of the present invention prevents entering of a person into a projection area before projection of video, and controls inadvertent start-up.

Abstract: A light source apparatus includes: a light source unit; a light guiding reflection mirror; a reflector; and a luminous body unit. The luminous body unit includes: a luminous body and a reflecting body. The plurality of light sources are disposed around a position corresponding to an axis on which the luminous body unit is disposed.

Abstract: An optical system unit having a light smoothing unit for emitting a light beam which is substantially parallel to an optical axis and a projector including the optical system unit are provided. The optical system unit includes a light source-side optical system, a display device for forming an image by reflected light and a projection-side optical system, whereby a light beam emitted from the light source unit is shone on to the display device via the light source-side optical system, an image is formed by the display device, and the image so formed is projected on to a screen via the projection-side optical system. The light smoothing unit of the light source-side optical system is such that at least one side of sides other than an incident side and an emitting side is disposed obliquely relative to a side which the at least one side confronts so that an area of the emitting side becomes larger than an area of the incident side.

Abstract: Disclosed is a high-pressure discharge lamp (100) that reduces the occurrence of cracks even under high mercury vapor pressure. The high-pressure discharge lamp (100) is provided with a glass arc tube (102) including a light-emitting part (103) and a sealing part (104) connected to the light-emitting part (103), the light-emitting part (103) enclosing a discharge space, and a pair of electrodes (101), one end of each of the electrodes (101) facing one end of the other electrode (101) in the discharge space, and another end of each electrode (101) being embedded in the sealing part (104) and connected to a metal foil (105), at least one embedded section of the pair of electrodes (101) including at least one projection (101c).

Abstract: An image forming system is described that includes a light source that provides a light beam and an anamorphic refractive optical element. A first outer surface of the anamorphic element faces the light source and includes a toric surface. The light beam is incident upon the first outer face and then an incident surface of the anamorphic element. The anamorphic element directs the light beam to an image forming device. An illumination system is also described where an anamorphic element includes a toric surface and a facet surface.

Abstract: This invention realizes an illumination optical system with a small etendue that has a longer lifetime and a high degree of brightness. The invention includes: a laser light source that generates excitation light having a first wavelength; a phosphor wheel including a blue fluorescent light generation region that generates fluorescent light having a second wavelength by means of the excitation light, and a green fluorescent light generation region that generates fluorescent light having a third wavelength by means of the excitation light; an LED light source that generates light having a fourth wavelength; and a dichroic mirror that reflects fluorescent light having the second wavelength and fluorescent light having the third wavelength and allows light having the fourth wavelength to pass therethrough, to thereby emit each of the lights in the same direction.

Abstract: A projector includes: a light source; a light modulation device which modulates a light emitted from the light source and forms image light; a projection device which magnifies and projects the image light; and an exterior casing, wherein on a light exiting surface for the image light of the exterior casing, a first opening is formed and a projection direction change unit which opens and closes the first opening is provided, and the projection direction change unit has: a cover which has a second opening for passing the image light from the projection device and which is provided rotatably in an off-plane direction with respect to the light exiting surface and thus opens and closes the first opening; a shutter which is movably provided along an inner surface of the cover and thus opens and closes the second opening; and a reflection mirror which is provided on an inner surface of the shutter and reflects the image light from the projection device.

Abstract: A beam alignment chamber extending in a length direction comprising a base having a front edge, and two side edges, first and second opposed side walls connected to the base, and extending along the length of the base, a front wall located at the front edge of the base having an output opening. The beam alignment chamber further comprises a plurality of arrays of light sources disposed to direct light beams through the first or second side walls, and a plurality of reflectors mounted on the base, each having independent yaw and pitch adjustments, each reflector being paired with a corresponding array of light sources, the base-mounted reflectors being disposed to direct the light beams along the length of the beam alignment chamber through the output opening forming an aligned two-dimensional array of parallel light beams.

Abstract: Disclosed is a projection optical system including a projection surface configured such that an image conjugate to an object is projected, plural optical elements having a refractive power, and a deflecting element having no refractive power configured to deflect an optical path of a light beam and to pass the light beam having a deflected optical path between the plural optical elements, wherein a normal line of the projection surface at a center of the projection surface does not pass through the plural optical elements or between the plural optical elements.

Abstract: A position adjustment device for an integration rod includes a fixed plate, two resilient members, and two adjusting screws. The first resilient member is positioned between the fixed plate and the rod for exerting an elastic force on the rod in a first direction, and the second resilient member is positioned between the fixed plate and the rod for exerting an elastic force on the rod in a second direction different from the first direction. The first adjusting screw is inserted through the part of the housing and has a first end surface that presses against one side surface of the rod opposite the first resilient member. The second adjusting screw is inserted through the part of the housing and has a second end surface that presses against one side surface of the rod opposite the second resilient member. The first and the second end surface are arc surfaces.

Abstract: An image display device using a semiconductor laser as a light source, includes a green laser light source device that converts a wavelength of infrared laser light and outputs green laser light; a spatial light modulator that modulates the green laser light input from the green laser light source device based on an image signal; an optical element that is provided in a path between the green laser light source device and the spatial light modulator, and reflects the green laser light to direct it to the spatial light modulator; an optical element support device that supports the optical element; and a case to which the green laser light source device, the spatial light modulator and the optical element support device are attached. The optical element support device rotates about at least one rotation axis in a state of holding the optical element to displace an optical axis of the green laser light.

Abstract: A light emitting unit array including a plurality of micro-light emitting diodes (?-LEDs) is provided. The micro-light emitting diodes are arranged in an array on a substrate, and each of the micro-light emitting diodes includes a reflection layer, a light emitting structure, and a light collimation structure. The light emitting structure is disposed on the reflection layer, and includes a first type doped semiconductor layer, an active layer, and a second type doped semiconductor layer that are stacked sequentially. At least a portion of the first type doped semiconductor layer, the active layer, and the second type doped semiconductor layer are sandwiched between the reflection layer and the light collimation structure.

Abstract: An illumination device includes a light source device including an ellipsoidal reflector with a reflecting concave surface and a light emitting tube having an emission center in the vicinity of a first focal position of the ellipsoidal reflector, and defining a first focal position and a second focal position of the ellipsoidal reflector in a cross-sectional plane in a first virtual plane including a center axis of the ellipsoidal reflector as F1 and F2, respectively, and defining a first focal position and a second focal position of the ellipsoidal reflector in a cross-sectional plane in a second virtual plane including a center axis of the ellipsoidal reflector and perpendicular to the first virtual plane as F1? and F2?, respectively, the ellipsoidal reflector has a rotationally asymmetrical concave shape having F1 and F1? at the same position, and F2 located between the F2? and the ellipsoidal reflector.

Abstract: A projector that can prevent laser light from entering eyes is provided. A process that controls the projector includes the steps of detecting turning-on of power to the projector; detecting an input for adjusting the reflection direction of a two-axis galvanometer mirror; sending an instruction to reduce output from respective lasers, to an FPGA; setting signal values of the lasers respectively controlled by laser control circuits, to small values; determining whether a certain period of time has elapsed since an operation input is no longer performed on an operation panel; standing by the process for a certain period of time when the certain period of time has not elapsed since an operation input is no longer performed; and returning the signal values to a normal level when the certain period of time has elapsed since an operation input is no longer performed.

Abstract: A projection assembly and projection method for accurately reproducing animated and live characters, objects, and effects. The projection assembly uses a high precision robotic mirror system to achieve very high levels of image resolution, brightness, and contrast. The assembly includes a projector receiving an input image stream, and a mirror assembly is positioned proximate to the projector outlet. The mirror assembly uses positionable mirrors to reflect the projected images onto a display surface at positions that define an animation pattern on the display surface for the projected image or character. The assembly includes a motor controller assembly positioning the mirrors based on position data defining the animation pattern. The projected images may be provided in a projection area that is a fraction of the size of the display surface, such that the resolution and output light of the projector are concentrated on the display surface within this projection area.

Abstract: A projection optical system satisfies a conditional formula: 0.01<{(tan ?f1?tan ?f2)?(tan ?n1?tan ?n2)}·(?2/?1)<0.

Abstract: A micro-scanner adapted for being miniaturized and an image projection apparatus using the same. The micro-scanner includes a scan mirror for scanning incident light to a screen while swinging about a rotary shaft; and upper and lower supports for rotatably supporting the top and bottom parts of the rotary shaft. The upper and lower supports having a driving unit for supplying driving force for rotating the scan mirror.

Abstract: A projector includes a light source, a light modulator that modulates the light flux emitted from the light source in accordance with an image signal to form image light, a projection optical apparatus that enlarges and projects the image light, a reflection section having a reflection surface disposed along the direction in which the projection optical apparatus outputs the image light, the reflection surface reflecting the image light, and an adjustment section that adjusts the inclination angle of the reflection section with respect to the direction in which the image light travels.

Abstract: In a projection type image display apparatus, for enlarging an image on a image display apparatus 1 by means of a projection lens 2, thereby projecting the enlarged image onto a screen 6, obliquely, being inclined thereto, between the projection lens 2 and a rear-surface mirror 5, there are disposed free shaped surface mirrors 3 and 4, each having a free shaped surface for compensating a trapezoidal distortion due to oblique projection of the enlarged image. The surface configuration of the free shaped surface mirror is so shaped as to satisfy a following equation: |L1?L2|>1.4·Dv if assuming that a distance for a light beam of an upper end of the enlarged image to reach the screen after being reflected upon a free shaped surface is “L1”, a distance for a light beam of a lower end of the enlarged image to reach the screen after being reflected upon the free shaped surface is “L2”, and a distance from an upper end of an image on the screen to a lower end thereof is “Dv”.