Abstract: A projection system, comprising a light modulation device, a light source system and a light offset device. The light source system is used for emitting one or more illumination sub-beams. The light modulation device is used for modulating illumination light according to image data to form image light, the image light being used for displaying an image corresponding to the image data. The light offset device is used for transferring one illumination sub-beam to each zone of a micro-mirror unit by means of a time sequence such that the micro-mirror unit modulates the illumination sub-beam by means of a time sequence to form image light of a pixel corresponding to each zone, wherein each zone corresponds to one pixel of an image.

Abstract: A display includes a display substrate having an active display area including a plurality of first display subpixels. A transceiver circuit is arranged to drive the display in a first mode of operation or in a second mode of operation. The first display subpixels include micro light-emitting diodes and/or resonant-cavity light emitting devices. In the first mode of operation, the transceiver circuit provides a forward bias to the first display subpixels, such that the first display subpixels are operable to emit light. In the second mode of operation, the transceiver circuit provides a reverse bias to the first display subpixels, such that the first display subpixels are operable to detect light.

Abstract: A first holding member holds a first optical system and a first mirror, and has a first junction surface. A second holding member holds a second optical system and a second mirror, and has a second junction surface. A junction portion is configured such that, in a state where the first junction surface and the second junction surface are aligned with each other, the second holding member is capable of being shifted in a direction of both the junction surfaces and rotated around an optical axis, and makes it possible to perform optical axis alignment. An emission-side optical axis of the first optical system and an incidence-side optical axis of the second optical system are aligned with each other, and thus a U-shaped optical path is formed by the first and second optical systems.

Abstract: A projector according to the present disclosure includes a light source apparatus including a light source section including first, second, third, and fourth light emitters sequentially arranged in a row along a first direction that intersects a light exiting direction, a first optical section that shifts light outputted from the second light emitter in a second direction and shifts the light outputted from the second light emitter to a position adjacent to light outputted from the third light emitter, and a second optical section that shifts the light outputted from the third light emitter in the second direction and shifts the light outputted from the third light emitter to a position adjacent to the light outputted from the second light emitter; a light modulator that modulates light outputted from the light source apparatus; and a projection optical apparatus.

Abstract: A light emitting apparatus includes a first light source, a first angle converter, a second angle converter, and a diffuser that is provided on a light incident or exiting side of the first angle converter and diffuses the first light. The first angle converter includes a first light incident section on which the first light is incident, a first light exiting section via which the first light exits out of the first angle converter, and a first reflection section that reflects the first light incident via the first light incident section toward the first light exiting section. The second angle converter includes a second light incident section on which the first light having exited is incident, a second light exiting section via which the first light exits, and a second reflection section that reflects the first light incident via the second light incident section toward the second light exiting section.

Abstract: The present disclosure relates to a projection optical system and an image projection device capable of projecting a more uniform and brighter image. The image projection device includes a laser light source for outputting a laser beam, a scanning unit for performing scanning with the laser beam two-dimensionally, and an optical component for enlarging a projection angle of view of an image projected by performing the scanning at a predetermined magnification relative to a scanning angle of view of the scanning performed by the scanning unit. The optical component is designed so that a ratio of the magnification for enlargement to change the scanning angle of view into the projection angle of view at an edge part of an image to the magnification for enlargement of view at a central part of the image is greater than 1. The present technique is applicable to laser scanning type image projection devices, for example.

Abstract: An image display apparatus according to an aspect of the present technology includes a light source, an image generator, and a projection optical system. The image generator modulates light emitted from the light source and generates image light. The projection optical system includes a lens system and a concave reflective surface. The lens system is configured on a basis of a reference axis at a position on which the generated image light is incident, and has a positive refracting power as a whole. The concave reflective surface is configured on a basis of the reference axis, and reflects the image light emitted from the lens system toward a projection target. In addition, the concave reflective surface reflects at least one or more light beams included in the image light incident on the concave reflective surface, toward a direction that intersects with a direction along the reference axis at an angle of 80 degrees or more.

Abstract: A projection optical apparatus includes a first lens group including a first optical axis, a first optical path deflector, a second optical path deflector, a second lens group including a second optical axis, a first lens barrel, a second lens barrel and a frame. The frame includes a frame main body and a cover frame. The frame main body includes a lens barrel attachment part including first and second openings, and first and second side parts facing each other and extending in a direction along a plane containing the first optical axis and a third optical axis between the first optical path deflector and the second optical path deflector. The cover frame is disposed at an opposite side to a lens barrel attachment part side with respect to the first and second optical path deflectors, and includes an outer circumferential part fixed to the the first and second side parts.

Abstract: A glazing including an electrochromic component and a coating coupled to the electrochromic component. In an embodiment the coating includes a non-transparent element. In a further embodiment, the non-transparent element includes a plurality of non-transparent elements. In another aspect, a method of displaying an image includes providing an electrochromic component and a coating coupled to the electrochromic component and projecting the image onto the coating from a light emitting source.

Abstract: A light source module includes a plurality of light combining elements, a plurality of first light emitting elements, and a plurality of second light emitting elements. Each of the light combining elements has a first reflecting surface and a second reflecting surface. Each of the first light emitting elements emits a first illuminating beam, and one of the first reflecting surfaces reflects the first illuminating beam to be transmitted along a light combining direction. Orthographic projections of the light combining elements on a reference plane are connected in sequence, and the reference plane is perpendicular to the light combining direction. Each of the second light emitting elements emits a second illuminating beam, and one of the second reflecting surfaces reflects the second illuminating beam to be transmitted along the light combining direction. In addition, a projector having the light source module is also provided.

Abstract: An illumination device includes a light source, a micromirror array having micromirror actuators, switchable in each case between an on state and an off state, an optical unit, and an optical sensor unit. The light is guided onto the array and proportionally at a respective one of the actuators in an on tilt position is reflected to an illumination application, and in an off tilt position is reflected to the optical sensor unit. The device is configured such that a first actuator, which is in an on state in the on tilt position, is brought to the off tilt position for a first test interval, and a second actuator, which is in an off state in the off tilt position, remains in the off tilt position for the first test interval. A radiation power incident on the sensor unit during the first test interval is detected by the sensor unit.

Abstract: An illumination optical system of a projector apparatus includes a rod lens which equalizes illuminance of illumination light incident on a micromirror device from lamps, and a plurality of light-shielding plates that shields unnecessary light not incident on the rod lens among the illumination light. The plurality of light-shielding plates is disposed on the incidence side of the rod lens such that each light-shielding plate is provided at a predetermined gap in an optical axis direction of the rod lens. Openings of each light-shielding plate are formed such that a light-shielding plate disposed on an emission side has a smaller passage area of illumination light than on an incidence side.

Abstract: A laser light source is disclosed that includes a laser device, a first diffusion element, a fluorescence wheel, and a second diffusion element. The fluorescence wheel emits a fluorescent light when excited by the laser light, and before reaching the fluorescence wheel, the laser light emitted by the laser device is transmitted through the first diffusion element that is fixedly arranged. As the second diffusion plate rotates about its axis, the laser light from the first diffusion element and the fluorescent light from the fluorescence wheel transmit through the second diffusion plate.

Abstract: Provided and described herein are exemplary embodiments of apparatus, system, computer-accessible medium, procedure and method according to the present disclosure which can be used for providing laser steering and focusing for e.g., incision, excision and/or ablation of tissue in minimally-invasive surgery. For example, an exemplary apparatus is provided that can include at least one optical element which can be configured to refract and/or diffract light provided in a structure which can be configured to be inserted into a body, where at least one of the optical element(s) is structured to receive the light at a first angle and generate a refracted and/or diffracted light at a second angle which can be different from the first angle relative to an optical axis.

Abstract: A telescope includes a first reflector having a first concave cylindrical surface with a first radius and a second reflector having a second concave cylindrical surface with a second radius different from the first radius, and a fixing member configured to fix the first reflector and the second reflector in such a way that the first concave cylindrical surface and the second concave cylindrical surface face each other and a central axis of the first concave cylindrical surface and a central axis of the second concave cylindrical surface are orthogonal to each other.

Abstract: A light integrating system includes an integrator rod, a triangular prism, and first and second light sources misaligned with each other. The integrator rod has a light-integrating axis, first and second light-entrance surfaces, a first reflection inclined surface and a first light-exit surface. The triangular prism adjacent to the second light-entrance surface has a third light-entrance surface, a second light-exit surface, and a second reflection inclined surface. Light of the first light source is incident into the integrator rod through the first light-entrance surface and is reflected by the first reflection inclined surface to emit out of the first light-exit surface along the light-integrating axis. Light of the second light source is incident into the triangular prism through the third light-entrance surface and is reflected by the second reflection inclined surface to emit out of the first light-exit surface through the second light-exit surface and the second light-entrance surface sequentially.

Abstract: A vehicle circumference monitoring apparatus includes: an image acquisition section that acquires captured image data output from an imaging section that is provided in a vehicle and images a circumference of the vehicle; a state acquisition section that acquires vehicle state data output from a vehicle state detection section that is provided in the vehicle and detects at least a roll state of the vehicle; a setting section that sets a center of rotation to rotate a display image depending on the roll state if the display image is displayed on a display device based on the captured image data; an image adjustment section that rotates a display state of the display image about the center of rotation that is set depending on the roll state; and an output section that outputs the display image to the display device.

Abstract: A micromirror array has the form of a sheared rectangle. In an arrangement in an illumination optical unit, one side is aligned perpendicular to a scanning direction.

Abstract: An image display apparatus and an image display unit. The image display apparatus and the image display unit includes a light source configured to emit light, an illumination optical system including a luminous body forming device configured to form a secondary luminous body, the illumination optical system guiding the light emitted from the light source, an optical modulation element including a plurality of reflection planes to modulate the light guided by the illumination optical system, and a projection optical system including a projection lens system and a barrel storing the projection lens system, the projection optical system projecting the light modulated by the optical modulation element onto a projection plane. The barrel satisfies an equation ?<0.71H+8.5, where ? denotes an outside diameter of a front end of the barrel on a light entering side and H denotes distance between the reflection planes and the front end of the barrel.

Abstract: A reflector can have a conical shape. The shape can tapers from a wide base to an apex. The apex can include an aperture, a mirror, and a set of one or more optical elements. A mirror is location in a cavity and is positioned within an overhang enclosure of the device in a plane approximately parallel to a circular cross section of the conical shape. The mirror can reflect environmental light that is reflected by the reflector into the aperture or reflect light emitting from the aperture onto the reflector. Stray light reflected by the mirror is absorbed by the cavity walls. A set of one or more optical elements can be positioned at least partially within a volumetric region of the reflector. The one or more optical elements focus light passing through the aperture to an image sensor.

Abstract: An illumination optical system is provided that is configured to guide light emitted from a light source to an image generation unit that is arranged to be movable in a direction perpendicular to incoming light and is configured to generate an image by reflecting the incoming light. The illumination optical system includes a first lens that is arranged to be movable in a direction perpendicular to an optical axis of the first lens, a second lens that is arranged to be movable in a direction that changes a face-to-face distance between the first lens and the second lens, and a lens position control unit configured to displace the first lens and the second lens.

Abstract: A projection lens includes, in order from a magnification side to a reduction side, a first lens group having a negative refractive power, a reflector to bend an optical path, a second lens group having a positive refractive power, and an aperture stop disposed within the second lens group. The second lens group has a positive refractive power on the magnification side of the aperture stop, and a negative refractive power on the reduction side of the aperture stop. Conditional formula (A) is satisfied: (A) Ot/Y?<6.1, where Ot is a distance along the optical axis between a maximum-magnification-side surface of the first lens group and a surface of a lens adjacent to a reduction-side surface of the reflector, and Y? is a maximum height of the image displayed on the display surface of the image display element.

Abstract: A light source unit includes one or more solid-state light sources and a light collecting optical system. The one or more solid-state light sources are arranged on a rear side of an output portion and each output light in a predetermined wavelength range along the same direction as an optical-axis direction. The output portion includes a light emitter that is excited by the light in the predetermined wavelength range with a predetermined direction as the optical-axis direction to emit visible light in a wavelength range longer than the predetermined wavelength range. The output portion is also capable of outputting light containing the light in the predetermined wavelength range and the visible light from the light emitter along the optical-axis direction. The light collecting optical system collects the light in the predetermined wavelength range.

Abstract: A light source unit includes a fluorescent member configured to emit, when irradiated with excitation light, fluorescence light having a wavelength different from a wavelength of the excitation light, and a controller configured to adjust a conversion efficiency from the excitation light to the fluorescence light of the fluorescent member so that a gradient T satisfies 0.35G?T?0.8G in a fluorescence characteristic of the fluorescent member when a horizontal axis represents a normalized light intensity of the excitation light so that a maximum light intensity of the excitation light incident on the fluorescent member is normalized to 1, and a vertical axis represents the light intensity of the fluorescence light from the fluorescence member irradiated with the normalized light intensity of the excitation light, where G represents a gradient in the fluorescence characteristic when the normalized light intensity of the excitation light is 0.3.

Abstract: There is provided a light source device including at least one light source configured to emit light, a diffusion plate configured to diffuse and reflect the light emitted from the light source, and a partial transmission member which is provided between the light source and the diffusion plate and has a transmission region which allows the light to pass through and a reflection region which reflects the light and is except the transmission region.

Abstract: According to an embodiment of the invention, an image projection apparatus includes: a light source device; a first circuit board including an image display device configured to form an image using light, a connector, and an electrically conductive portion near the connector; a retaining member made of metal; an optical illuminating unit held by the retaining member and configured to guide the light to the image display device; an optical projecting unit configured to project the image onto a projection surface; a second circuit board configured to be electrically connected to the connector; a metal plate fixed and electrically connected to the retaining member; and an elastic metal member arranged on the metal plate. The first circuit board is fixed to the retaining member. The elastic metal member is in contact with the electrically conductive portion. The second circuit board is fixed and electrically connected to the metal plate.

Abstract: An image projection method includes: reflecting, by a concave mirror, light having transmitted through one or more lenses after forming an intermediate-focused image of the light; and projecting an image onto a projection plane through reflecting the light reflected by the concave mirror by a plane mirror that has an aspect ratio of 1.9 or more.

Abstract: Provided is an image projection apparatus, such as a projector, including a light source; an image generating element such as a DMD that receives light from the light source and forms an image; an image generating unit that irradiates the image generating element with the light from the light source; a first optical system including multiple transmission refractive optical elements; a second optical system arranged on an optical path of outgoing light of the first optical system and including a reflection optical element; and a projection optical system that enlarges and projects an image conjugate to the image generated by the image generating element as a projected image. The light source, the image generating unit, and the first optical system are arranged side by side in series in a direction parallel with the projected image plane.

Abstract: Some embodiments include methods for correcting optical alignment of components in a camera module for a multifunction device. In some embodiments, components of a camera module for use in a multifunction device are assembled on a test station. Some embodiments include a method that includes capturing a single test image, calculating from the spatial frequency response data an optical tilt between the optical axis of a lens and an optical axis of the image sensor of the camera module, and mechanically adjusting an alignment of the lens and the optical axis of the image sensor of the camera module to reduce the optical tilt. In some embodiments, the capturing is performed using the components of the camera module, and the single test image contains visually encoded spatial frequency response data for characterizing the components of the camera module.

Abstract: An image displaying apparatus including a light source, an image displaying element configured to control exiting of incident light to display an image, an illumination optical system configured to illuminate the image displaying element with light exiting from the light source, and a projection optical system configured to project an image displayed on a display surface of the image displaying element, to provide an enlarged display. The projection optical system includes a lens optical system, a first mirror configured to reflect light transmitted through the lens optical system, and a second mirror configured to reflect light reflected from the first mirror toward the surface to be projected onto, and one of the mirrors is arranged at a position conjugate to the image displaying element, and wherein an optical surface of the one mirror is arranged to face vertically downward.

Abstract: A method for providing a feedback circuit for a three dimensional projector. First and second input devices and a sensor for determining the rotational speed of the second input device are provided. A control device for controlling the rotational speed of the second input device and a phase locked loop (PLL) are provided. A phase reference signal is created based on the signal rate of the first input device. A phase signal is created based on the rotational speed of the second input device. The PLL compares the phase reference signal and the phase feedback signal to determine whether the first input device and the second input device are synchronized. A signal is sent to the control device for the second input device to change the rotational speed of the second input device in response to determining that the first input device and the second input device are not synchronized.

Abstract: A projection device having an image beam and an off-state light is provided, which includes a camera module, a condensing element, a digital micromirror device (DMD) and a shading element, wherein the DMD allows the image beam to enter the camera module, and the shading element is configured between the DMD and the condensing element to block the off-state light.

Abstract: Embodiments relate generally to computer-based image processing, and more particularly, to systems, computer-readable media, methods, integrated circuits, and apparatuses to facilitate operation of a projection system with relatively high dynamic range output by, among other things, providing subsets of light patterns along an optical path during respective first and second temporal fields associated with respective first and second illuminants. The projection system can synthesize color for projectable images by combining or otherwise using the subsets of light patterns with an array of color elements to produce projectable images with color in at least the visible spectrum.

Abstract: Illumination device includes a light source (101); an illumination optical system (102, 103, 104, 106, 107) that spatially splits each of the plurality of color light beams emitted from the light source, superimposes the split light beams of each of the plurality of color light beams, and emits the superimposed light beams to a display element (110); a reflective polarization plate (109) that is arranged between the illumination optical system (102, 103, 104, 106, 107) and the display element (110) and that transmits first polarized light and reflects second polarized light whose polarization state is different from that of the first polarized light toward the illumination optical system (102, 103, 104, 106, 107); a reflection element (105) that is arranged at a position where each of the plurality of color light beams is spatially split by the illumination optical system and that transmits the split light beams of each of the color light beams and reflects, of the split light beams of each of the color light

Abstract: A method for providing a feedback circuit for a three dimensional projector. First and second input devices and a sensor for determining the rotational speed of the second input device are provided. A control device for controlling the rotational speed of the second input device and a phase locked loop (PLL) are provided. A phase reference signal is created based on the signal rate of the first input device. A phase signal is created based on the rotational speed of the second input device. The PLL compares the phase reference signal and the phase feedback signal to determine whether the first input device and the second input device are synchronized. A signal is sent to the control device for the second input device to change the rotational speed of the second input device in response to determining that the first input device and the second input device are not synchronized.

Abstract: A display device includes: a display portion having a screen that can display an image; and an image forming substrate formed into a plate, wherein the image forming substrate are configured to be switchable between a first state where the screen is arranged to be inclined with respect to the first main surface such that light from the screen enters the image forming substrate from the first main surface side and forms the image on the second main surface side and a second state where the display portion and the image forming substrate are aligned in the thickness direction and are arranged along each other.

Abstract: A light source system for use in a projector is provided. The light source system comprises a main optical axis, a first sub-optical axis, a second sub-optical axis, at least one first optical module, at least one second optical module and a third optical module. The at least one first optical module comprises a first light source array and a second light source array for emitting a plurality of first beams and a plurality of second beams respectively. The at least one second optical module comprises a third light source array for emitting a plurality of third beams. The third optical module integrates the first beams, the second beams and the third beams into a main beam for projection along the main optical axis.

Abstract: A projector system that includes a first input device, a second input device, a control device, a sensor and a phase locked loop (PLL). A phase reference signal is created based on a signal rate of the first input device. A phase feedback signal is created based on the rotational speed of the second input device as it is measured by the sensor. The PLL compares the phase reference signal and the phase feedback signal to determine whether the first input device and the second input device are synchronized. A signal is sent to the control device for the second input device to change the rotational speed of the second input device in response to determining that the first input device and the second input device are not synchronized.

Abstract: A light source unit may include a cooling device; a luminescent substance; an excitation radiation source having a laser source; and an optical element arranged between the radiation source and the substance; wherein the cooling device constitutes a heat sink, wherein the substance is linked thermally to the heat sink; and wherein the optical element is designed as an integrating optical element and is coupled between the radiation source and the substance in such a manner that a part of the radiation emitted by the radiation source, entering in an acceptance angle range of the integrating optical element, is subjected to an internal reflection in the optical element before it exits the optical element and strikes the substance, and that a part of the radiation emitted by the substance enters the optical element and exits the optical element as effective radiation.

Abstract: A method of projecting an image is provided. The method includes the step of providing a first light source, the first light source emitting light at a first polarization. A second light source is provided adjacent the first light source, the second light source emitting light at a second polarization. A digital mirror device is provided (DMD), the DMD having a first axis. A mirror is provided optically disposed between the first light source, the second light source and the DMD, the mirror being adjacent the DMD. A first light is emitted from the first light source. The first light is reflected with the mirror onto the DMD. A second light is emitted from the second light source after the first light is emitted. The second light is reflected with the mirror onto the DMD.

Abstract: The invention relates to a rear project device, comprising a screen, projection optics, and an image module for generating an image, which is projected from the rear onto the screen by means of the projection optics, so that an observer located in front of the screen can perceive the image projected onto the screen. Furthermore, a method for such a rear projection apparatus is described. To this end, a Fresnel mirror, or an aspherical mirror, is used.

Abstract: Provided is an image projection apparatus, such as a projector, including a light source; an image generating element such as a DMD that receives light from the light source and forms an image; an image generating unit that irradiates the image generating element with the light from the light source; a first optical system including multiple transmission refractive optical elements; a second optical system arranged on an optical path of outgoing light of the first optical system and including a reflection optical element; and a projection optical system that enlarges and projects an image conjugate to the image generated by the image generating element as a projected image. The light source, the image generating unit, and the first optical system are arranged side by side in series in a direction parallel with the projected image plane.

Abstract: A projection system is provided. The system includes a first light source emitting light at a first polarization. A second light source is provided adjacent the first light source, the second light source emitting light at a second polarization. A digital mirror device (DMD) is provided having a first axis. A mirror optically is disposed adjacent the DMD between the first light source, the second light source and the DMD. The first light source and second light source emit light that is reflected onto the DMD.

Abstract: An illumination unit includes a light source, an optical mixer to form secondary light sources from a light beam from the light source, and an illumination system to illuminate an optical modulator with the light beam from the optical mixer, including an optical element having an anamorphic surface, in which the optical element is rotated at a certain rotational angle about a rotational axis which is a normal line from a vertex of a surface of the optical element.

Abstract: A light source apparatus includes a light source unit that includes plural sets of a laser and a coupling lens corresponding to the laser, which are circumferentially provided to form a circle; and a reflecting unit placed within the circle and provided with plural reflecting surfaces corresponding to the lasers of the plural sets of the light source unit to be formed in a cone shape, the light irradiated from each of the lasers being injected into the corresponding reflecting surface via the corresponding coupling lens.

Abstract: A projection optical system substantially consists of a first optical system composed of a plurality of lenses and a second optical system composed of one reflection mirror having a convex aspherical surface arranged in this order from the reduction side and is configured, when an air space between the first optical system and the second optical system is taken as T12 and a displacement in a direction of the optical axial from a position of maximum effective height on the magnification side lens surface of the lens disposed on the most magnification side in the first optical system to the vertex of the lens surface is taken as Zf, to satisfy a conditional expression (1): 0.1<Zf/T12<1.0, in which an image formed on a conjugate plane on the reduction side is magnified and projected onto a conjugate plane on the magnification side.

Abstract: A videoconferencing unit for enhancing direct eye-contact between participants can include a curved fully reflective mirror to reflect the image of the near end to a camera. The curved mirror can be placed in front of the display screen near a location where images of faces/eyes of far end participants are to appear. In another example, the videoconferencing unit can include a disintegrated camera configuration that provides an air gap between a front lens element and a rear lens element. The front lens element can be located behind an aperture within the display screen. The air gap can provide an unobstructed path to light from projectors and therefore avoid any undesirable shadows from appearing on the display screen. In another example, the videoconferencing unit can include a combination of the disintegrated camera configuration and mirrors for providing direct eye contact videoconferencing.

Abstract: A digital light processing projector includes a light emitting diode (LED), a laser, a rotatable optical element, a reflector, a first filter, a second filter, a digital micro-mirror device (DMD), and a projection lens. The LED and the laser respectively emit a first and second homogeneous lights. The rotatable optical element converts a first portion of the second homogeneous light to a third homogeneous light, reflects the third homogeneous light, and transmits a second portion of the second homogeneous light. The reflector reflects the third homogeneous light. The first filter transmits the first homogeneous light, and reflects the second portion to the second filter. The second filter transmits the second portion and the first homogeneous light, and reflects the third homogeneous light to the DMD. The DMD modulates the first, second and third homogeneous lights to obtain optical images. The projection lens projects the optical images on a screen.

Abstract: A system is provided for projecting a three-dimensional image. The system includes a first light source, emitting a light of a first color and a second light source emitting light of a second color. At least one polarizing beam splitter (PBS) is disposed adjacent the first light and the second light source, and at least one imaging device is disposed adjacent the at least one PBS.

Abstract: The invention pertains to a projector comprising an optical engine, a projection lens, a means for light deviation, and an afocal lens system, wherein the projector has a total throw ratio between 0.7 and 0.8. Such a projector can be used to build a very compact and cost-effective back-projection system. The invention also pertains to a projection assembly comprising such a projector, followed by a means for light gradation and a front-surface mirror. The invention also pertains to a display system comprising at least one such projection and a display screen.