Dainippon Screen Mfg. Co., Ltd.

Yoshikazu Kataoka

Eiichi Tamaki

Takahide Hirawa

Yoshimi Hashimoto

Zenji Wakimoto

Takeshi Sugata

A light from a laser light source () is collected at a position of a slit () in a vertical direction by a first optical system () to form an intermediate image which is long in a horizontal direction corresponding to an arrangement direction of light modulator elements. An undesired light such as side lobes which appear on the both sides of the intermediate image in the vertical direction is blocked by a slit () and the intermediate image is reformed by a second optical system (), to direct a liner illumination light onto the spatial light modulator (). Thus, in a state where moving ribbons are sagged and first order diffracted lights are emitted in a light modulator element, it is possible to prevent a zeroth order light from being emitted from both end portions of ribbons, to thereby enhance contrast of the signal light.

Apparatus for generating spatially modulated light and image recording apparatus

A projection optical system has first to fourth lens groups () to () provided in this order from a SLM, a mirror () having an opening is provided between the first lens group () and the second lens group (), and an aperture plate () is provided between the third lens group () and the fourth lens group (). Zeroth order light which is signal light from the SLM passes through each opening of the mirror () and the aperture plate () to be guided to a recording medium, and a part of first order diffracted light is reflected by the mirror () to be guided outside and received by an external light-block water-cooling jacket. The rest of the first order diffracted light is blocked by the aperture plate (), and heat generated by light blocking is removed by a cooling mechanism connected to the aperture plate ().

Image recording apparatus

In an image recording apparatuswhich records an image on a recording mediumby moving an optical headwhile rotating the recording mediumheld by a holding drum, a photodetectorhaving a plurality of photodetector elementsis provided in a range of movement of the optical head. In correcting beam intensity, the optical headis positioned so precisely that the photodetectorcan receive the signal light beams. This constitution makes it possible to detect signal light beams from the light modulator with high S/N ratio as compared with a conventional case where one photodetector element sequentially receives the signal light beams, and therefore possible to correct the beam intensities with high accuracy.

Method for correcting the beam intensity in an image recording apparatus using a multi-channel light modulator

An optical head of an image recording apparatus is provided with a light-source water-cooling jacket for cooling a light source and a device water-cooling jacket for cooling the Grating Light Valve and a light-shield water-cooling jacket . The optical head is also provided with a mirror for reflecting a light form the light source in a non-recording status and mirrors for reflecting non-signal light beams from the light valve , and the lights from these mirrors are directed to the light-shield water-cooling jacket . Further, a refrigerant from a chiller unit goes through the light-source water-cooling jacket , the device water-cooling jacket and the light-shield water-cooling jacket in this order. With this constitution, it is possible to efficiently cool all the heat sources and in the optical head.

Image recording apparatus using the grating light valve

A laser beam emitted from a laser light source passes through an illumination lens and is thereafter incident upon a total internal reflection prism. The total internal reflection prism bends the laser beam, which is applied to a Grating Light Valve&trade;. The laser beam divided into a number of beams and modulated by the light valve is incident upon a focusing lens. The normal to the light valve forms an angle &thgr;xz with the optical axis of an illumination optical system including the total internal reflection prism and an illumination lens. The normal to the light valve also forms the angle &thgr;xz with the optical axis of a focusing optical system.

Laser imager having reduced interference between internal optical reflections

A lens system operable with two or three colors comprises a front lens system disposed on the object side relative to a stop and a rear lens system disposed on the image side relative to the stop. The front lens system includes first to third lens groups, while the rear lens system includes fourth to sixth lens groups. Each of the front and rear lens systems includes two meniscus lenses. The meniscus lenses have a concave surface and a negative power. Accordingly, average image points with respect to two or three wavelengths substantially coincide with each other, while the image fields coincide with each other within the range from the vicinity of the optical axis to image peripheral portion.

Lens system with four meniscus lenses made of anomalous dispersion glass

An apochromatic lens system is corrected for chromatic aberration at three wavelengths. The apochromatic lens system includes a plane glass and a plane lens which are interchangeable with each other. When the plane glass is disposed on the optical axis of the lens system, the plane glass cooperates with the lens system to correct for chromatic aberration at first and second wavelengths. When the plane lens is disposed on the optical axis instead of the plane glass, the plane lens cooperates with the lens system to correct for chromatic aberration at the first wavelength and at a third wavelength.

Apochromatic lens system

An apochromat optical system for a photoengraving process comprises a first lens group which includes a first lens having a positive power, a second lens made of Kultz flint glass having a negative power and a third lens in the form of a meniscus having a positive power. The first to third lenses are successively disposed in order starting from the object side. A second lens group includes the substantially same configuration of lenses as in the first lens group. The lenses of the first and second lens groups are approximately symmetrical with respect to the stop. Accordingly, the system has a high aperture ratio and small curvature of a saggital and meridional image field which can reduce an astigmatic difference in a peripheral part of an image.

Growing community of inventors

Kyoto, Japan

Yoshikazu Kataoka