Abstract: According to this invention, a method and apparatus for setting a gap to a predetermined distance between a mask and a wafer facing each other, are arranged as follows. First and second diffraction grating are formed on a mask and a wafer. The first diffraction grating is one-dimensional type and has parallel bars extending in a predetermined direction. The second diffraction grating is one-dimensional type and has parallel bars extending in a direction perpendicular to the predetermined direction. The second diffraction grating may be two-dimensional type having cross-bars. Laser beam is radiated from a light source onto the first diffraction grating. The light beams diffracted and transmitted through the first diffraction grating are transferred to the second diffraction grating. The light beams diffracted and reflected by the second diffraction grating are transferred to the first diffraction grating. The light beams are diffracted and transmitted through the first diffraction grating.

Abstract: A working distance alignment optical system for use in an ophthalmological instrument includes a target projecting optical system for projecting a target to a cornea of an eye to be tested, and a target image observing optical system for observing an image of the target in the cornea from the diagonal direction with respect to the target projecting optical system. The working distance alignment optical system is characterized in that at least one of the target projecting optical system and the target image observing optical system is provided with an optical element whose optical working surface is a toric surface.

Abstract: A shape measuring apparatus is disclosed.

Abstract: An autolensmeter for inspecting refracting power of optical systems is herein disclosed, which comprises a collimater lens for projecting light from a light source onto an optical system to be examined as a parallel luminous flux, a mask means having a mask pattern for selectively transmitting the luminous flux from the optical system and a photodetecting means for receiving the luminous flux partially transmitted through the mask pattern, disposed at a non-image forming position of the optical system, characterized in that an optical element is arranged in close vicinity of the mask pattern so that the light source and the photodetecting means are in an optical conjugate relationship with each other.

Abstract: An infusion instrument comprises an infusion device for supplying intracular irrigating through an input end thereof, an infusion passage thereof and an insertion end thereof into an eyeball, an illumination unit including a light source for illuminating an inside portion of the eyeball, and a light transmitting element having a first end connected to the light source and a second end for transmitting a light from the light source to the eyeball. At least the second end of the light transmitting element is arranged in the infusion passage.

Abstract: An apparatus for stabilizing the wavelength/output power of a semiconductor laser is disclosed.

Abstract: A non-contact type tonometer is disclosed. It includes a fluid discharging device for discharging a fluid from a nozzle towards an eye to be tested and transfiguring the eye, an eye pressure measuring device for measuring the eye pressure of the eye based on the pressure of the fluid, and an alignment detecting device for detecting the aligning state of the nozzle of the fluid discharging device. It further includes an eye pressure value correcting device for correcting an actually measured eye pressure value obtained by the eye pressure measuring device based on an alignment error information of the nozzle with respect to the eye using the alignment detecting device.

Abstract: A slit apparatus has a rotatable base plate and a rotatable cam driving plate which are rotated about the same axis of rotation, but independently. The base plate is provided with slit blades for forming a slit therebetween. The slit blades are rotated together with the base plate and therefore the direction of the slit is changed. The cam driving plate is provided with a cam plate for changing slit width. The slit width is changed by rotation of the cam driving plate. A slit direction adjusting knob for driving the base plate is arranged to be coaxial with a slit width adjusting knob for driving the cam driving plate.

Abstract: A retinal camera of the present invention has an illumination optical system for projecting an illumination light to a retina of an eye to be tested and a photographing optical system for photographing a retinal image of the eye to be tested. The illumination optical system is provided in a position substantially conjugate to the retina with a filter member. The filter member is formed as such that transmittance is relatively increased as it goes toward the peripheral portion from the central portion. When the retina of the eye to be tested is illuminated by this illumination optical system, an illumination light quantity per unit area at the peripheral portion side becomes larger than a illumination light quantity per unit area of the central portion side of an illumination light to be formed on the retina.

Abstract: The invention provides a binocular indirect ophthalmoscope in which light reflected from an eye under test is split and guided to left and right oculars (7, 8). Left and right mirrors (10, 11) for directing the split light to the left and right oculars being laterally movable about the optical axes (01, 02) of the oculars and toward and away from each other. The mirrors are arranged to follow the mutual approaching and receding of the oculars but the oculars will not follow the mutual approaching and receding of the mirrors, whereby the distance between these mirrors can be adjusted separately from the distance between the optical axes of the oculars.Such arrangement allows the operator to shift the light beams for observation (OFL, OFR) to appropriate positions where they are not interrupted by the iris, and thus allows sufficient and widely ranging stereoscopic observation, irrespective of the size of the pupil diameter of the eye under test or OF the direction of observation.

Abstract: A corneal configuration measuring apparatus is disclosed. It comprises target projecting means for projecting target beams from a plurality of targets towards a cornea of an eye to be tested, light receiving means, measuring optical system for projecting the target beams reflected on the cornea towards the light receiving means and forming target reflection images on the light receiving means, and variable power optical system for varying imaging power of the target reflection images to be formed on the light receiving means.

Abstract: In a method for aligning first and second objects relative to each other, according to this invention, the first and second objects are arranged opposite to each other, and are aligned in a direction perpendicular to their opposing direction. A grating pattern is formed, as an alignment mark, on the first object, and a checkerboard-like grating pattern is formed, also as an alignment mark, on the second object. A light beam emitted from an alignment light source is radiated onto the checkerboard-like grating pattern of the second object. The light beam diffracted by the checkerboard-like grating pattern is guided onto the grating pattern of the first object. The light beam diffracted by the grating pattern of the first object is detected by a detector. Since the light beam emitted from the light source is diffracted by the checkerboard-like grating pattern, a relative position of the first and second objects can be detected, irrespective of the distance therebetween.

Abstract: First and second objects are moved relative and parallel to each other, in order to be aligned. More specifically, a first mark formed on the first object has first and second light-passing sections. A second mark formed on the second object has first and second light-reflecting sections. A light beam from a light source is directed to and reflected by the first and second light-reflecting sections of said second mark and transferred onto said first mark. An image of said first light-reflecting section is projected onto the first mark, so that the first light-passing section has a first overlapping region which overlaps a part of the inner of said first light-reflecting section. An image of said second light-reflecting section is projected onto the first mark, so that said second light-passing section has a second overlapping region which overlaps a part of the image of said second light-reflecting section.

Abstract: An automatic perimeter comprising stimulus presentation unit for presenting stimuli to examine a patient's eyesight, an examination program memory for memorizing a plurality of examination programs which present stimuli under different presentation conditions, a selector for selecting a first examination program for the first examination, and a presentation controller for controlling said stimulus presentation unit so that stimulus presentation for said first examination is carried out under a presentation program selected by a selecting command if the selecting command is applied to the selector and carried out under a predetermined presentation program if the selecting command is not applied to the selector.

Abstract: A coordinates measuring method in which the image information of the same point are derived as first, second and third information when viewed from at least three different directions, a first corresponding point is determined by deriving the correlation between the first and second information, and a second corresponding point is determined by deriving the correlation between the second and third information, and mismatching is decided when the first and second coordinates are not substantially coincident with each other.

Abstract: A tonometer comprising an eye pressure measuring device including a fluid discharge device for discharging a fluid toward an eye to be tested, a pulse wave phase detecting device for detecting a phase cycle of pulse wave due to pulse fluctuation of the eye to be tested, a pulse wave phase area establishing device for establising whether or not an eye pressure measurement was carried out in any phase area of the pulse wave, according to an output pulse caused by a fluid discharge during the eye pressure measurement and an output of the pulse wave phase detecting device, and a recognizing device for recognizing a measured eye pressure value corresponding to a phase area of the eye pressure measuring time according to the output of the pulse wave phase area establishing device.

Abstract: An ophthalmological measuring apparatus is disclosed. It comprises a projecting systems for projecting a target image to the cornea and retina of an eye to be tested, respectively, a measuring optical system for being introduced a corneal reflecting beam of light and a retina reflecting beam of light from the eye, a light receiving portion for receiving the corneal reflecting beam of light and the retina reflecting beam of light through the measuring optical system and photoelectrically transferring the same, an image displaying device for displaying an image of the anterior portion of the eye based on a signal from the light receiving portion, and a calculating device for calculating and measuring a corneal configuration and an eye refractive power of the eye to be tested based on the signals of the corneal reflecting beam of light and the retina reflecting beam of light detected by the light receiving portion.

Abstract: A gaze-fixing device for a surgical microscope which is capable of providing a marking without an error at the time of a radial keratotomy operation. The device comprises a gaze-fixing target which can be disposed on the observation optical axis of a microscope, and light quantity-reducing means for reducing the quantity of illumination light applied from an illumination light source for illuminating an eye to be operated on.

Abstract: A surface inspection apparatus is equipped with a transfer machine which includes a first storage unit for storing a plurality of wafers therein, a first transfer portion for receiving the wafers from the first storage unit one by one and transferring them along a horizontal plane, a first receiver moving vertically between a lower position and an upper position for receiving the wafers from the first transfer portion when the first receiver moves from its lower position to its upper position and moving them up and down, a chuck moving to a predetermined position under the wafers received by the first receiver when the first receiver is at or near its upper position and receiving the inspected elements from the first receiver when the first receiver moves from its upper position to its lower position, the chuck holding the wafers in their fixed condition and moving them in a given direction along a horizontal plane while they are inspected, a second receiver moving vertically between a lower position and an u

Abstract: An operation microscope in which the optical axis of the illumination optical system is in alignment with the optical axis of the objective lens of the observation optical system and the illumination rays pass along the optical axis of the objective lens. Due to this construction, it is possible to sufficiently illuminate the deep parts of diseased tissue in, for example, a cataract operation, and very easy to confirm whether or not any part of the lens remains in the capsula lentis after the removal of the lens of the eye.