Seiko Epson Corporation

Seiko Epson Corporaition

Takeshi Sowa

Yujiro Nomura

Ryuta Koizumi

Nozomu Inoue

Ken Ikuma

Yoichi Mitsui

Takashi Suzuki

Takatomo Fukumoto

Kyu Takada

Yuichiro Iwama

Masayuki Kanazawa

Osamu Nakajima

Etsuko Ito

A projector includes a light source, light modulation device, first driver, and second driver. The first driver is configured to drive the light modulation device to alternately provide a first polarity period and a second polarity period. The second driver is configured to drive the light source so that timings of switching related to a drive current coincide between the first polarity period and the second polarity period. The timings of switching are different from each other between a first period and a second period. The first period contains one first polarity period and one second polarity period adjacent to the one first polarity period. The second period is adjacent to the first period and contains another first polarity period than the one first polarity period and another second polarity period than the one second polarity period. The another second polarity period is adjacent to the another first polarity period.

Projector and method of driving projector

A projector includes a discharge lamp and a discharge lamp drive section. The discharge lamp drive section is configured to selectively perform a first drive in which first drive power is supplied and a second drive in which second drive power higher than the first drive power is supplied in a first posture, and supply drive power not lower than third drive power and not higher than fourth drive power in a second posture in which optical axis intersects with horizontal plane, the third drive power is drive power with which one of the electrodes in the second posture is set to temperature corresponding to first temperature in the first drive in the first posture, and the fourth drive power is drive power with which one of the electrodes in the second posture is set to temperature corresponding to second temperature in the second drive in the first posture.

Projector

An exposure head includes a light emitting element and a imaging optical system having a first region and a second region and contrived such that a slope of a long dimension of a spot diagram formed by light emitted from the light emitting element that passes through the first region is different from a slope of a long dimension of a spot diagram formed by light emitted from the light emitting element that passes through the second region.

Exposure head and image forming apparatus with light emitting element emitting light forming first and second diagrams having angle

Disclosed is an exposure head including a light emitting element array including light emitting elements disposed in a first direction, a light blocking member including an aperture stop through which lights emitted from the light emitting elements pass, and an image forming optical system that makes an image by using the lights having passed through the light blocking member. An absolute value of a magnification in the first direction of the image forming optical system is equal to or more than 0.7 times and is equal to or less than 0.8 times.

Exposure head and image forming apparatus

An exposure head, includes: a lens array that includes lenses that are arranged in a first direction and in a second direction orthogonal to the first direction; and a light emitting element substrate that is provided with light emitting elements that emit lights to be imaged by the lenses, wherein a relationship defined by a following formula: 1&#x3c;L/Lis satisfied, where the symbol Ldenotes a length of the lens in the first direction and the symbol Ldenotes a length of the lens in the second direction.

Lens array, an exposure head and an image forming apparatus

An image forming apparatus includes an image carrier having a curvature in a first direction; and an exposure head including a first light emitting element that emits a light having a wavelength &#x3bb;and a light having a wavelength &#x3bb;, a first optical system that converges each of the light emitted from the first light emitting element onto the image carrier, a second light emitting element, and a second optical system that converges a light emitted from the second light emitting element onto the image carrier, wherein a position at which the first optical system converges each of the light and a position at which the second optical system converges the light are different from each other with respect to the first direction.

A line head includes first to third light-emitting elements arranged in a first direction; and an optical system that forms images by light emitted from the first to third light-emitting elements on an imaging surface to form images of the light-emitting elements, in which the first light-emitting element is arranged between the second light-emitting element and the third light-emitting element in the first direction; the optical system has a first lens surface that has refractive power and is arranged so as to satisfy a relation of H&#x3e;0.5D, where H is a distance in the first direction between the geometrical centers of the images of the second and third light-emitting elements, and D is the maximum width in the first direction of a light passing region of the first lens surface through which light emitted from the second and third light-emitting elements passes; and, light emitted from the first and second light-emitting elements do not overlap with each other on a cross section of the first lens surface taken along the first direction so as to include an optical axis of the optical system.

Line head and image forming apparatus

An image forming apparatus includes a latent image carrier on which a latent image is formed; and a line head. The line head includes light-emitting elements arranged in a first direction; an aperture diaphragm; and an optical system that images light emitted from the light-emitting elements on a latent image carrier. The aperture diaphragm and the optical system are arranged in a second direction that is orthogonal to or substantially orthogonal to the first direction; and among the lenses included in the optical system, a lens located at the position closest to the aperture diaphragm is a multifocal lens.

An optical system of a line head images light emitted from first and second light emitting elements and includes a rotationally symmetric lens having a lens face. A first region of the lens face includes an intersection point of the lens face with the symmetry axis of the lens, and a second region surrounding a periphery of the first region. The shape of a boundary portion between the first and second regions has the relationship 0.5&#x3c9;&#x3c;&#x394;&#x3b8;, wherein &#x3c9; is a first direction angle that a first chief ray emitted by the first light emitting element makes with a second chief ray emitted by the second light emitting element, and &#x394;&#x3b8; is an angle that a tangent line to the first region at the boundary portion makes with a tangent line to the second region at the boundary portion in a first direction cross-section including the symmetry axis.

An image forming apparatus includes a line head that performs exposure on a latent image carrier to form a latent image. The line head includes first and second light-emitting elements arranged in a first direction; and an optical system that images light emitted from the first and second light-emitting elements. When a difference between the maximum and minimum values of a longitudinal aberration of the optical system is G, a distance in the first direction between centers of geometry of the first and second light-emitting elements is P, and an optical magnification of the optical system is &#x3b2;, a relation of G&#x3e;|&#x3b2;|&#xb7;Pis satisfied.

An exposure head, includes: a lens array that includes a light transmissive substrate whose length in a first direction is greater than a length thereof in a second direction orthogonal to the first direction, a first lens that is arranged on the light transmissive substrate, and a second lens that is arranged on the light transmissive substrate at the first direction of the first lens, the first lens and the second lens being connected in the first direction; and a head substrate that is provided with a first light emitting element that emits a light toward the first lens and a second light emitting element that emits a light toward the second lens.

Exposure head and an image forming apparatus

An exposure head, includes: a substrate that is provided with a first light emitting element, a second light emitting element that is arranged at one side of the first light emitting element in a first direction and a third light emitting element that is arranged at the one side of the second light emitting element in the first direction, the first light emitting element and the second light emitting element being arranged at a first distance from each other in the first direction, the second light emitting element and the third light emitting element being arranged at a second distance, which is different from the first distance, from each other in the first direction; and an imaging optical system that images light from the first, the second and the third light emitting elements.

A line head includes: a positive lens system having two lenses with positive refractive power; an image-side lens array in which the image-side lens of the two lenses is arrayed in a plural number in first and second directions; an object-side lens array in which the object-side lens of the two lenses is arrayed in a plural number in the first and second directions; a light emitter array in which a plurality of light-emitting elements are arrayed on an object side of the positive lens system for the one positive lens system; and an aperture plate that forms an aperture diaphragm disposed on the object side of the positive lens system so that an image side is telecentric or approximately telecentric. Assuming that the row number of lenses arrayed in the second direction of the image-side lens array is m, a gap between effective regions of the two image-side lenses adjacent to each other in the first direction is &#x3b1;, an image-side angle of aperture (half angle) of the positive lens system is &#x3b8;, a width (full width) of a plurality of light-emitting element images in the first direction, which are images on image surfaces of the plurality of light-emitting elements arrayed for the one positive lens system, is W, a focal length of the image-side lens is f, and a distance from an image-side principal plane of the image-side lens to the image surface is S, the following conditions, f&#x2266;(mW&#x2212;&#x3b1;)/(2&#x3b8;), W&#x2267;2S&#x3b8;/(m&#x2212;1)+&#x3b1;/(m&#x2212;1), are satisfied.

Line head and image forming apparatus using the same

A line head, includes: a lens array that includes a first lens, a second lens and a light transmissive substrate on which the first lens and the second lens are arranged in a first direction; and a light emitting element substrate on which light emitting elements are arranged in the first direction, wherein the first lens is formed such that, in a cross section in the first direction including an optical axis of an imaging optical system comprised of the first lens, a curvature of the first lens at an outer peripheral portion has a sign opposite to that of a curvature of the first lens on the optical axis or has a smaller absolute value than the curvature of the first lens on the optical axis.

Line head and an image forming apparatus

A line head includes a positive lens system having two lenses, image-side and object-side lens arrays, a light emitter array on an object side of the positive lens system, and an aperture plate that forms an aperture diaphragm. Where the row number of lenses arrayed in a second direction is 'm', a gap between effective regions of two image-side lenses adjacent to each other in a first direction is '&#x3b1;', an image-side angle of aperture is &#x2018;&#x3b8;i&#x2019;, a width of light-emitting elements images in the first direction is &#x2018;Wi&#x2019;, a focal length of the image-side lens is &#x2018;f&#x2019; and a distance from an image-side principal plane of the image-side lens to an image surface is &#x2018;Si&#x2019;, the following conditions are satisfied: f&#x2266;(mWi&#x2212;&#x3b1;)/(2&#x3b8;i), Wi&#x2267;2Si&#x3b8;i/(m&#x2212;1)+&#x3b1;/(m&#x2212;1).

Growing community of inventors

Matsumoto, Japan

Takeshi Sowa