Abstract: A particle measuring device having a light source, scanning means for optically scanning a light from the light source in a direction intersecting the direction of passage of particles to be examined in a portion to be examined through which the particles to be examined pass, means for making the shape of the scanning light applied to the particles to be examined into a shape longer than the length of the particles to be examined in the direction of passage of the particles to be examined, and light receiving means for receiving the light from the portion to be examined.

Abstract: An image recording method having a first step of recording an image on a first area of a recording medium by the major scanning by a light beam scanning optical system and a first subsidiary scanning in which the recording medium is moved relative to the light beam scanning optical system in a direction intersecting the major scanning, and a second step of recording an image on a second area of the recording medium by the major scanning and a second subsidiary scanning in which the recording medium is moved relative to the light beam scanning optical system so that the first area again crosses the scanning area of the light beam scanning optical system.

Abstract: In a device for controlling the flow rate of a hydraulic operating fluid from a pump to a hydraulic motor for driving an engine cooling fan in a vehicle by modifying either the cross sectional opening area of a variable flow constriction means in the fluid conducting passage while maintaining a constant pressure difference across the flow constriction means by a pressure control valve responsive to the pressure difference across the flow constriction means or the pressure difference by selectively partly leaking the pressure transmitted from the downstream side of the flow constriction means to a rear side of the pressure control valve, a cold state relief means is provided to temporarily relieve the rear side of the pressure control valve at cold start of the engine to avoid abnormally high fluid pressure being supplied to the motor due to delayed response of the pressure control valve under high viscosity of the operating fluid at low temperature.

Abstract: In an opthalmic photographing apparatus, capable of photographing the fundus of an eye to be examined at a variable magnification, being provided with a ring slit in an illuminating optical path at a position substantially conjugate with the front-eye-part and being further provided with a baffle at a position substantially conjugate with the crystalline lens, the slit width of a ring slit image projected onto the eye to be examined and further the size of a baffle image are variable with a magnification change.

Abstract: A light is applied to particles to be examined in a cell, the scattered light from the particles to be examined is converted to an afocal light, a beam splitter is provided in the afocal light beam, and photometering and observation of the cell are efficiently effected in two optical paths branched off by the beam splitter.

Abstract: An eye fundus camera including a photographic system for photographing the fundus of an eye and forming an imaging optical path having an illuminating system for illuminating the eye fundus and forming an illuminating light path, a barrier filter releasably seated in the imaging optical path, and an exciter releasably seated in the illuminating optical path. The apparatus also includes a diaphragm arranged in the illuminating optical path for changing the illuminated field on the eye fundus, an optical device in the imaging optical path for changing the magnification of the photographic system, or an apertured plate in the same path to change the photographic field, and a drive connection device responsive to insertion of the barrier filter and exciter into the path for enlarging the diaphragm and for reducing the magnification of the photographic system, or increasing the size of the opening in the apertured plate.

Abstract: An image recording apparatus has a feed system for feeding a recording sheet from a feed magazine to a drum, a drum system for winding the recording sheet therearound and rotating to align the recording position with a predetermined position on the circumferential surface of the drum, a scanning system for main-scanning the recording sheet at the recording position of the sheet with an optically modulated beam, and a storage system for storing the recording sheet on which an image has been formed. The drum is rotated in opposite directions during feed and storage of the sheet.

Abstract: An image recording method having a first step of recording an image on a first area of a recording medium by the major scanning by a light beam scanning optical system and a first subsidiary scanning in which the recording medium is moved relative to the light beam scanning optical system in a direction intersecting the major scanning, and a second step of recording an image on a second area of the recording medium by the major scanning and a second subsidiary scanning in which the recording medium is moved relative to the light beam scanning optical system so that the first area again crosses the scanning area of the light beam scanning optical system.

Abstract: In an opthalmic photographing apparatus, capable of photographing the fundus of an eye to be examined at a variable magnification, being provided with a ring slit in an illuminating optical path at a position substantially conjugate with the front-eye-part and being further provided with a baffle at a position substantially conjugate with the crystalline lens, the slit width of a ring slit image projected onto the eye to be examined and further the size of a baffle image are variable with a magnification change.

Abstract: An eye-fundus camera provides change-over and selection between automatic focusing and manual focusing. The eye-fundus camera includes a projector, a photo-sensor array, a focus controller and an illuminator. The projector projects a first focus mark and a second focus mark on the fundus of an eye to be examined. The photo-sensor array detects the first focus mark reflected from the fundus and the output from the sensor array is introduced into the controller to adjust the focus of the camera. The illuminator illuminates the fundus uniformly with light within a first wavelength range. The first focus mark is with light within the first wavelength range and within a second wavelength range other than the first one whereas the second focus mark is formed only of light within the first wavelength range. The eye-fundus camera further comprises a wavelength selecting mirror which cuts off light of the first wavelength range among rays of light incident upon the photo-sensor array.