An autofocus for a confocal microscope is realized by means of a confocal microscopic device with scanned illumination of an object (5), means to produce a first wavelength selective division (e.g. chromatic color-length defect) of the illuminating light, means (6) to produce a second wavelength selective division of the light coming from the object, and means of detection (10) to detect the light distribution produced by the two means above-mentioned. Spectral division and detection of a wavelength selectively illuminated object image occur, and a control signal to adjust focal position is generated on the basis of determined deviations in frequency and/or intensity from a predefined reference value corresponding to the position of an object. The invention also relates to a method for detecting deviations between one first vertical profile and one second vertical profile, preferably to detect and/or control defects in semiconductor structures, wherein wavelength-selective illumination of a first object is carried out, the light arising from the first object is detected and electronically compared with a second object.

Confocal microscopic device

A telecentric rotary actuary in an optical storage system. A laser generates a laser beam which is focused by an objective lens onto an optical disk in order to write data to and read data from the optical disk. In performing a seek, a galvo rotates a mirror in order to reflect the laser beam to different radial displacements in reference to the optical disk. The position of the laser beam is detected, and a rotary actuator, to which the objective lens is attached, follows the movement of the laser beam. A telecentric optical system comprising a relay lens and an image lens is used to minimize an offset between the laser beam and the objective lens. The relay lens focuses the laser beam to a back focal point. The image lens optically conjugates the back focal point to a front focal point corresponding to the objective lens in order to demagnify any offset.

Telecentric rotary actuator in an optical recording system

An optical system is provided with a pair of forward optical components each having a shutter for controlling the amount of transmission of a light from an object, an optical member for laying the optical axes of the pair of forward optical components one upon the other, and a rearward optical component disposed so that the optical axis thereof may coincide with the optical axes laid one upon the other. The optical system alternately varies the amounts of transmission of the light transmitted through the shutters of the pair of forward optical components to thereby time-serially form a parallax image.

Optical system for photographing a stereoscopic image, zoom lens and image pickup optical system

A method and an apparatus is disclosed for extracting from a single shot, two pictures of an illuminated scene having a foreground zone and a background zone respectively. The first picture has a depth of field which is greater than the second picture. Subsequently the high frequency components are extracted from each of the pictures in order to reflect characteristics of each of the pictures which have the greatest amount of contrast or sharpness. The two high frequency signals are compared in order to obtain a depth of field signal based upon the differences between the two signals.

Method and device to obtain an element of information on depth in the field seen by picture-shooting device

A control device includes an image acquisition section and a focus control section. The image acquisition section acquires an image captured by an imaging section. The focus control section performs a focus control process that focuses the imaging section on an object based on the acquired image. The focus control section performs the focus control process based on an image for which occurrence of a bright spot is suppressed.

Control device, endoscope apparatus, and focus control method

A beam splitter, a first polarizing plate and a quarterwave plate are provided in that order on the optical axis of an image formation lens between an image formation plane and an objective lens. The first polarizing plate comprises a non-polarizing region for transmitting illuminating light and reflected light and a polarizing region provided to enclose the non-polarizing region for transmitting the illuminating light but limiting the reflected light which is rendered out of phase with the illuminating light by the quarterwave plate. Thus, the angular aperture of the illuminating light can be increased and an irradiated plane can be observed with no hindrance even if the same is inferior in flatness, while illuminance of the irradiated plane can be sufficiently ensured. At the same time, the angular aperture of the objective lens can be reduced, and the depth of focus Q is increased.

Reflection type optical apparatus

PURPOSE: To assure the large angular aperture of the luminous flux contributing to illumination and enable setting of an objective lens at a sufficiently small angular aperture by adding and disposing a polarizing plate having an annular polarization region and a quarter-wave plate successively between a beam splitter and the objective lens. CONSTITUTION: The polarizing plate 18 having the annular polarization region and the quarter-wave plate 19 are successively added and disposed between the beam splitter 17 and the objective lens 2. The illuminating light transmitted through the annular polarization region 18a of the plate 18 is polarized to linearly polarized light which is then polarized by the quarter-wave plate 19 to circularly polarized light. The circularly polarized light part is reversed in the rotating direction of the plane of the polarization thereof with respect to the progressing direction of the light by the reflection on the surface 5a to be irradiated. Only the incident luminous flux on the annular polarization region 18a of the plate 18 is shut off when the light passes the plate 19 again. Only the luminous flux past the central part 18b contributes to the imaging. The angular aperture 2θ of the objective lens 2 is thereby set sufficiently small and the angular aperture 2α of the illuminating light sufficiently large. COPYRIGHT: (C)1989,JPO&Japio

Shin-ichi Nagata

Papers

Reflection type optical apparatus

Reflection illuminating device