A projector includes an image forming panel 14 on which an image is formed, and a projection lens 15 which projects the image of the image forming panel 14. In a projector in which the center of the image forming panel 14 is fixed with being shifted in a direction opposite to a direction in which a central position of the projected image of the image forming panel 14 is deviated with respect to an optical axis L of the projection lens 15, a lens barrel 31 of the projection lens 15 includes heater 33 for heating a lens barrel portion on a side opposite to a direction, in which the image forming panel 14 is shifted, on the image forming panel 14 side from the diaphragm position 32 where an F-Number of the projection lens is determined. Cooler may be provided in place of the heater.

A projector 10 includes an image forming panel 14 on which an image is formed, and a projection lens 15 which projects the image of the image forming panel 14 onto a screen 20. The center of the image forming panel 14 is fixed with being shifted in a direction opposite to a direction, in which a central position of a projection surface of the screen 20 is deviated with respect to an optical axis L of the projection lens 15. A lens barrel 31 of the projection lens 15 has an opening 34 as a heat release structure which is formed in a portion of a lens barrel 31 in a direction, in which the image forming panel 14 is shifted, on the image forming panel 14 side from a diaphragm position 32 where an F-Number of the projection lens 15 is determined.

Methods and systems for acquiring and/or projecting images from and/or to a target area are provided. Such a method or system can includes an optical fiber assembly which may be driven to scan the target area in a scan pattern. The optical fiber assembly may provide multiple effective light sources (e.g., via a plurality of optical fibers) that are axially staggered with respect to an optical system located between the optical fiber and the target area. The optical system may be operable to focus and/or redirect the light from the multiple light sources onto separate focal planes. A composite image may be generated based on light reflected from and/or projected onto the separate focal planes. The composite image may have an extended depth of focus or field spanning over a distance between the separate focal planes while maintaining or improving image resolution.

An optical element adjusting apparatus configured to support an optical element includes an adjusting base, a fixed base and locking elements. The adjusting base includes a first through hole disposed on a center of gravity of the adjusting base, a second through hole and a third through hole. An extension direction of a first straight line passing through the first through hole and the second through hole is different from an extension direction of a second straight line passing through the first through hole and the third through hole. The fixed base includes coupling holes corresponding to the first, second, third through holes. The locking elements pass though the first, second, third through holes respectively and are coupled to the coupling holes to couple the adjusting base to the fixed base. The adjusting base includes a support side away from the fixed base to support the optical element.

A projection system includes a first lens group to an n-th lens group with n being 6 or 7 sequentially arranged from a enlargement side. The first lens group includes a first-first lens group and a first-second lens group sequentially arranged from the enlargement side. The two lens groups are separated from each other by a variable distance for image plane correction. The first lens group and the n-th lens group are fixed and the second lens group to the (n−1)-th group are moved when the magnification is changed. The following conditional expression is satisfied: 2<BF/fw<2.8, where fw represents the focal length of the projection system operating at the wide angle end, and BF represents the air conversion length of the back focal distance of the projection system.

A blur compensation system includes: a mirror on which light of an image from a predetermined position is incident and which reflects light of a specific wavelength such that an incidence angle and an emission angle of the light of the specific wavelength are different from each other; a mirror that is disposed at a position on which the light of an image which is reflected by the mirror is incident and reflects the light of the specific wavelength such that an incidence angle and an emission angle of the light of the specific wavelength are different from each other; and a lens that is disposed on an optical axis of the light of an image between the mirror and the mirror and changes a direction of the light of an image which is reflected by the mirror such that light of a wavelength other than the specific wavelength out of the light of an image which is reflected by the mirror is emitted in the same direction as the light of the specific wavelength from an emission position of the light of the specific wavelength in the mirror.

In order to provide a projection lens barrel and a projection display device that are capable of correcting the optical characteristics of a plurality of lens groups, a projection lens barrel, comprising a lens optical system causing light from an image display element to be formed as a projected image on a screen, also comprises correction mechanisms that move each of at least two lens groups along an optical axis and correct the optical characteristics to be corrected, said lens groups each having different optical characteristics for correction in order to suppress reduction in image quality of a projected image caused by changes in optical characteristics caused by temperature changes in the projection lens barrel.

An object of the present invention is to provide a projection type image display apparatus in which an imaging lens can be replaced according to a focal length of a projection lens. In order to achieve the above object, a projection type image display apparatus includes: a light source; a lighting optical system configured to guide light from the light source to a display element; a projection lens mounting portion in which a projection lens configured to project the light transmitting through or being reflected by the display element is mountable, and that is configured to allow one replaceable projection lens of a plurality of replaceable projection lenses to be selectively mounted in the projection type image display apparatus; and an imaging lens mounting portion configured to allow one imaging lens of a plurality of replaceable imaging lenses to be selectively mounted in the projection type image display apparatus.

A suspension system including a set of optics which adjust the size and focus of the projection image originating at a Digital Micro-Mirror Device mirror set. The suspension and adjustment system for these optics may be mounted between the Digital Micro-Mirror Device housing and the optics carrier. This system has the capability to both adjust the resulting size and focus of the image at the same distance to a wall, as well as adjust for out-of-plane issues which often result in skewed images. This results in an adjustable focal and image size differing from the manufacturer's intended throw pattern and allowing broader use of the projector to make smaller images at the same throw distance.

A laser projection apparatus includes a laser source, an optical engine and a projection lens. The optical engine includes a light pipe, a lens assembly, a reflector, a prism assembly and a digital micromirror device. An optical axis of the illumination beam transmitted by the light pipe and the lens assembly is a first optical axis. An optical axis of an illumination beam reflected by the reflector to the prism assembly is a second optical axis. The first optical axis is perpendicular to the second optical axis, and both the first optical axis and the second optical axis are parallel to the beam receiving face of the digital micromirror device.