Oki Data Corporation

Oki Electric Industry Co., Ltd.

Hisashi Tsukagoshi

Norio Nakajima

Yoshihisa Aikoh

Minoru Teshima

Katsuya Kamimura

A circuit board holds a line of light emitting elements mounted thereon. The light emitting elements are at a predetermined height from the surface of the circuit board. A rod lens array longitudinally extends and forms images of the light emitting elements on a photoconductive body such that the images and the light emitting elements form pairs of conjugate points with respect to the rod lens array. A holder holds the rod lens array relative to the light emitting elements. Supporting members are mounted to the holder at locations along a length of the rod lens array and hold the rod lens array relative to the circuit board so that the images form a substantially straight line on the photoconductive body. Each of supporting member supports a part of the rod lens array relative to the circuit board. The supporting member has a first reference portion and a second reference portion, the first reference portion abutting a lower surface of the rod lens array and the second reference portion abutting the surface of the circuit board on which the light emitting elements are carried. The supporting member of different heights may be assembled to the holder along the length of the rod lens array so that any warp and/or distortion of the base is accommodated, thereby allowing images of light emitting elements are on a very straight line.

Optical printhead

An LED print head is for use in an LED printer. The LED print head has an LED circuit board on which a plurality of LED chips are mounted in line, and a lens assembly having rod lenses for focusing light emitted from the LED chips on a surface of a photosensitive drum in the LED printer. A first member or slider engages either the LED circuit board or the lens assembly and is adapted to displace stepwise to cause either the LED circuit board or the lens assembly to flex stepwise relative to the surface of the photosensitive drum. A second member or slider engages said first member to movably hold said first member. The LED circuit board or lens assembly is flexed so that a point on the photosensitive drum and the surface of the corresponding LED form a pair of conjugate points with respect to the corresponding rod lens.

Led print head and method of adjusting the focus thereof

The present invention is a light emission intensity width compensating method of an optical print head having a large number of light emitting devices, comprising the steps of measuring a light emission intensity distribution of each of the light emitting devices of the optical print head, slicing the distribution corresponding to a reference light emission intensity value, calculating a light emission intensity width of the reference light emission intensity value for each of the light emitting devices, designating a compensation value of drive energy so that each of the light emission intensity widths becomes equal, and causing each light emitting device to emit light corresponding to the compensation value of the drive energy. In addition, the present invention is an apparatus corresponding to the light emission intensity compensating method. The compensation values of the drive energy are stored in a storing means of the apparatus. When data is printed, the light emitting devices of the optical print head are lit corresponding to the compensation value of the drive energy. Thus, the drive energy is varied corresponding to the light emission intensity width. Consequently, a dot image can be printed free of uneven density.

Growing community of inventors

Tokyo, Japan

Hisashi Tsukagoshi