A projection lens has a lens barrel holding a lens. In a case where an image forming panel is disposed to be shifted with respect to an optical axis of the projection lens, in a second part on a side to which the image forming panel is shifted with respect to the optical axis of the projection lens, there is a great increase in temperature, and in a first part on the opposite side, there is a small increase in temperature. A lens barrel heating optical section has a first mirror, condensing lenses, and a second mirror. The lens barrel heating optical section emits the redundant light, which is reflected by the color wheel, toward the first part of the lens barrel. By heating the first part through redundant light, temperature distribution in the circumferential direction becomes uniform, and deterioration in performance of the projected image is suppressed.

An image projection apparatus includes a light source to emit light, an image generation unit including an image generation element to generate an image using the light emitted from the light source, an optical unit to guide the light emitted from the light source to the image generation unit, and to enlarge and project the image generated by the image generation unit, a drive unit to change any one of a position of the image generation element and a position of at least a part of the optical unit at specific timing, and a cooling device to cool one or more parts disposed in the image projection apparatus. An operation sound generated by the cooling device while the cooling device is being operated has a given frequency characteristic settable according to a drive frequency of the drive unit.

A projector includes a light source, a filter unit, an auxiliary light source and a combiner. The light source produces a first beam of light having light in a plurality of ranges of wavelengths, corresponding to a plurality of colors. The filter unit is positioned in the optical path of the first light beam. The filter unit is configured in a first configuration during a first time interval and in a second configuration during a second time interval. When the filter unit is configured in the second configuration, the auxiliary light source produces a second beam of light. The combiner combines the first beam of light and the second beam of light. The combined beams of light are directed to a spatial light modulator.

A projector used a projection lens to enlarge and project image light generated by image generator. When it is assumed that the on-optical-axis position of a lens surface where the maximum of light ray passage ranges (effective diameter) is minimized in the projection lens is a minimum diameter position, a stop is provided on a lens shifted from the minimum diameter position toward the light exiting side. The lens on which the stop is provided is a lens (for example, fourth lens closest to minimum diameter position) that satisfies 0.8φ.sub.1≦φ.sub.2≦φ.sub.1, where φ.sub.1 represents the light flux diameter on a surface where the on-axis light flux diameter is maximized, and φ.sub.2 is the diameter of the stop.

A projection display apparatus of the present disclosure includes a solid state light source discharging blue light in a first wavelength range; a wheel having a transmission part transmitting blue light and a first light-emitting body emitting light in response to irradiation with blue light; a second light-emitting body emitting light in a second wavelength range closer to the longer wavelengths than the first wavelength range is and adjacent to the first wavelength range, in response to irradiation with blue light that has passed through the transmission part; a light uniformizing element uniformizing the blue light and the light emitted from the first and second light-emitting body; a light modulation element modulating the light uniformized by the light uniformizing element; and projection unit projecting the light modulated by the light modulation element.

A projector, an image projection method, and a recording medium storing a program. The projector includes a color wheel configured to divide light by time into light rays of a plurality of colors including at least a first color and a second color, the light forming an image to be projected, an image generator configured to generate the image including a plurality of pixels from the light rays divided by time by the color wheel, a shifting member configured to shift the plurality of pixels of the image formed by the first color and the second color, with varying shifting speeds, a color-wheel controller configured to control the color wheel, a shifting controller configured to control the shifting member, and a timing controller configured to generate a first timing signal for controlling timings of the color wheel and a second timing signal for controlling timings of the shifting member.

A projection device according to the present disclosure includes a sensor unit (for example, a camera), a detection unit, a controller and a projection unit. The sensor unit detects an object. The detection unit detects a moving object (for example, a person), a first object, and a second object based on a signal output from the sensor unit. The controller generates a projection image such that a first image corresponding to the first object is projected on a first projection region and a second image corresponding to the second object is projected on a second projection region. In this case, the first image is determined based on a position of the moving object, and the second image is determined without depending on a position of the moving object. The projection unit projects the projection image.

A projector includes alight source unit including a light source, a luminescent wheel having light source segments receiving light from the light source to emit different wavelength ranges of light, a color wheel separate from the luminescent wheel that has a first transmission area transmitting light, in visible light, existing in a certain range of wavelengths and a second transmission area transmitting light existing in a range of wavelengths broader than that of the light transmitted through the first transmission area and on to which the different wavelength ranges of light from the luminescent wheel are shone, and a control module controlling not only the luminescent wheel and the color wheel so that they are synchronized with each other but also the light source so that the light emitted from the light source is sequentially shone on to the light source segments.

A projector includes a DMD that forms an image, a projection lens that projects the image formed by the DMD on a projected surface, and a display control unit that controls an image forming operation of the DMD. The display control unit forms a frame image by sequentially forming a plurality of images using a combined pixel which is configured of a plurality of pixels, and with respect to temporally continuous two images, the display control unit forms one image at a position that is shifted by a distance that corresponds to the pixel pitch of the DMD in a predetermined direction relative to the other image.

A projection display apparatus of the present disclosure includes a solid state light source that emits blue light in a first wavelength range; a wheel having a light-emitting body that emits emission light in a second wavelength range closer to the longer wavelengths than the first wavelength range is and adjacent to the first wavelength range, in response to irradiation with the blue light; a light uniformizing element that uniformizes the blue light and the emission light; a light modulation element that modulates light uniformized by the light uniformizing element; and a projection unit that projects the light modulated by the light modulation element. An end of the light-emitting body that the blue light enters has a dichroic coating that partly reflects the blue light and transmits emission light.