Abstract: When sequentially reading a plurality of documents in an image reading apparatus using, for example, an automatic document feeder, the temperature inside the apparatus rises and the refractive index of a lens or the like in an optical system changes, causing focus and magnification errors. To address this, focus and magnification adjustments are made by reading a chart when a document reading operation is not being performed. On the other hand, during a document reading operation, the temperature inside the apparatus, especially, the temperature of the lens, is measured, and the focus and magnification are adjusted based on the measured temperature.

Abstract: A light pattern controller generates a pattern of continuous wave, modulated and/or pulsed light onto a face of a collimating element. The light beam is collimated by the collimating element and extends to a focusing element which focuses the collimated light onto an illumination field. A controller controls the light pattern controller or the light source to determine a shape of the pattern on the face of the collimating element. The illumination field is imaged by an electronic or digital camera having first and second fields. Each field captures an image by integrating light received from the illumination field over an integration period. The controller controls the light pattern controller and the light source, and/or the camera to ensure an even amount of illumination from each element of the light pattern focused on the illumination field is integrated by each field of the camera. The controller also controls the frequency, phase angle and pulse width of the light source.

Abstract: Stereoscopic device including a lenticular lens layer and light sensor array, the lenticular lens layer includes a plurality of lenticular elements, the sight sensor array includes a plurality of light sensors, wherein selected ones of the light sensors detect light at a predetermined range of wavelengths and wherein at least selected others of the light sensors detect light at at least another predetermined range of wavelengths and wherein each of the lenticular elements is located in front of a selected group of the light sensors, thereby directing light from different directions to different light sensors within the selected group of the light sensors.

Abstract: Sampling points are generated selectively in a prescribed portion other than the pattern edge portion of a layout pattern used in a semiconductor manufacturing process based on an input that is data of the layout pattern. Simulation results of a pattern to be generated from the layout pattern are obtained for the respective sampling points. Pattern distortion amounts in the portion other than the pattern edge portion are detected by comparing the data of the layout pattern and the simulation results for the respective sampling points.

Abstract: Observer tracking is provided in an autostereoscopic 3D display, for instance of the type including an LCD panel 2 behind a parallax barrier. An infrared sensor such as a position sensitive detector is provided on the LCD panel. The parallax barrier extends over the detector so as to form an image of the observer or of a reflective target worn by the observer on the detector. The parallax barrier is moved so as to keep the image at a constant position on the detector. The viewing zone thus track the observer.

Abstract: The improved image inputting apparatus for reading the image recorded on a transmission original comprises: a light source; an image sensor for photoelectrically reading the light that has issued from the light source and which has been transmitted through the original; an imaging lens for permitting the transmitted light to be focused on the image sensor; a focusing device for automatically adjusting a focus of the imaging lens; and a control device for controlling the focusing device before starting the reading of a new image group such that only the first frame of the image group is subjected to one-step automatic focusing or two-step automatic focusing consisting of coarse and fine adjustments whereas the other frames are not subjected to focusing but image reading is performed adopting the focus state of the first frame or are subjected to automatic focusing comprising only fine adjustment.

Abstract: An automatic focus detection device for microscopes includes an optical system for forming an image of a sample; an image sensor for photoelectrically converting an optical image derived from the optical system; a device for storing image data such that an electric signal obtained from the image sensor is converted from analog to digital form and for processing the image data to compute contrast values; a device for comparing the contrast values; a device for moving an objective lens or a stage for the sample; and a device for storing the position of the objective lens or the stage.

Abstract: An optical apparatus or a control device to be used for a light flux deflecting apparatus is arranged to include at least two light flux deflecting portions and a control portion which control the driving actions of the at least two light flux deflecting portions in such a manner that, with the light flux deflecting portions applied as image shake preventing mechanisms to an optical apparatus using a plurality of light fluxes, such as a binocular, the arrangement effectively prevents such inconveniences as the necessity of using a plurality of control portions in controlling each of the light flux deflecting portions and giving a disagreeable feeling to the user due to a discrepancy arising in the amount of deflection between two light fluxes.

Abstract: A focus state detection device includes a field mask aperture having a shape created from the overlapping portions of two areas. The first area is formed by the outermost perimeter of the cross-section of light rays passing through the field mask plane toward each of the arrays of photoelectric conversion devices from each of point of the conjugal images of the arrays of photoelectric conversion devices at the primary imaging plane. The second area is formed by line segments that are the projection onto the field mask plane of the boundary lines at the surface of each re-imaging lens on the side toward the arrays of photoelectric conversion devices. The use of this shape causes light to be directed within the boundary lines of the outer perimeter of each of the re-imaging lenses. Through the use of this shape, the creation of stray light and internal reflection in the focus state detection optical system are suppressed, and stable focus state detection precision is enabled.

Abstract: There is disclosed a focus detecting device adapted for use in a camera or the like and provided with; a phototaking optical system for forming an image of the object on a reference plane; a focus detecting optical system for separating, from the light beam passing through the phototaking optical system, at least a pair of light beams passing through spatially different areas on a first predetermined plane axially spaced by a first distance from the reference plane, thereby forming images of the object; a photoelectric converting device composed of plural photosensor elements and adapted to generate object image signals corresponding to the intensity distribution of the object images formed by the focus detecting optical system; a phototaking optical system information device for generating information on the shape of exit pupil at fully-open diaphragm of the phototaking optical system and on a second distance from the reference plane to the exit pupil; a focus detecting optical system information device for

Abstract: A focus detecting system for detecting focus state of an image forming optical system relative to an object, includes a beam splitter assembly for forming at least three coplanar two-dimensional images of a scene, each image having a different focus setting. An area array image sensor senses the images at the image forming plane. Signal processing electronics determine the sharpness of the three images and calculates an optimum focus setting for the optical system by deterring the variances of the three images and calculating a position of maximum variance corresponding to a best focus setting of the optical system.

Abstract: There is disclosed a focus detecting device adapted for use in a camera or the like and provided with; a phototaking optical system for forming an image of the object on a reference plane; a focus detecting optical system for separating, from the light beam passing through the phototaking optical system, at least a pair of light beams passing through spatially different areas on a first predetermined plane axially spaced by a first distance from the reference plane, thereby forming images of the object; a photoelectric converting device composed of plural photosensor elements and adapted to generate object image signals corresponding to the intensity distribution of the object images formed by the focus detecting optical system; a phototaking optical system information device for generating information on the shape of exit pupil at fully-open diaphragm of the phototaking optical system and on a second distance from the reference plane to the exit pupil; a focus detecting optical system information device for

Abstract: Disclosed is a focus detecting device for use in a camera comprising a phototaking optical system for forming an image of the object on a reference plane. A focus detecting optical system separates light passing through the phototaking system from at least a pair of light beams passing through spatially different areas on a first predetermined plane axially spaced by a first distance from the reference plane, and thereby forming images of the object. A photoelectric converting device generates object image signals corresponding to the intensity distribution of the object images formed by the focus detecting optical system. A phototaking optical information device generates information on the shape of exit pupil at fully-open diaphragm of the phototaking system and on a second distance from the reference plane to the exit pupil. A focus detecting optical information device generates information on the areas on the first predetermined plane and on the first distance.

Abstract: A focus detection device is provided that can quickly detect small displacements with high precision in the optical image on arrays of photosensitive elements. The device includes a pair of arrays of photosensitive elements made of rectangular photosensitive elements arranged in a single line and positioned so that the boundary lines D between adjacent photosensitive elements are orthogonal to the direction in which the photosensitive elements are aligned. The boundary lines D are also inclined at a preset angle from the direction corresponding to vertical or horizontal lines in the image field. When the arrays of photosensitive elements and components peripheral to these arrays are solidly attached to a rectangular substrate, the arrays of photosensitive elements are positioned so that the direction in which the photosensitive elements are aligned is parallel to the sides of the perimeter of the substrate.

Abstract: A focus detecting apparatus is provided including an image reforming optical system which splits a bundle of rays incident upon a detecting zone, which is provided on a predetermined focal surface, and reforms an image. The predetermined focal surface is substantially conjugate with a focal plane of a taking lens. The focus detecting apparatus further includes a line sensor which receives the reformed image, a detector which detects a focus state of the taking lens in accordance with an output of the line sensor, and a driver which moves the detecting zone on the predetermined focal surface.

Abstract: An optical microscope including a revolver for mounting a plurality of objective lenses having different magnifications, a stage for holding a specimen to be inspected and being movable in a plane perpendicular to an inspection optical axis, a television camera for picking-up an image of the specimen by means of an objective lens which is indexed into the inspection optical axis, and a television monitor for displaying an image of the specimen on a display screen. In order to select an objective lens having a desired magnification and to move the stage with respect to the inspection optical axis automatically, a desired region is denoted on the image displayed on the display screen by operating a mouse. Then, a necessary magnification is calculated in accordance with a division ratio obtained by dividing an area of the desired region by a full area of the display screen.

Abstract: An image pickup device which, in placing a phase type optical low pass filter in front of a taking lens, is able to cope with the varying focal distances of the taking lens only by a single piece of phase type optical low pass filter and which is also able to obtain a large quantity of information to be used for focusing detection in the auto focusing (AF) operation. The image pickup device is composed of a taking lens having a variable focal distance, a solid state image pickup element on which an object light image is formed through the taking lens, a phase type optical low pass filter which is disposed in front of the taking lens in a freely rotatable manner, and a device for rotating the phase type optical low pass filter according to the focal distances of the taking lens so as to be able to remove a given spatial frequency component corresponding to the pixel pitch of the solid state image pickup element.

Abstract: A distance distribution measuring method includes the steps of disposing an image pickup on the optic axis of a projection optical system, forming on the image pickup the images of objects existing in multiple directions through the projection optical system, progressively varying the spacing in the direction of the optic axis between the projection optical system and the image pickup, extracting substantially in-focus one of the object images on the image pickup for each amount of spacing along with the step of varying the spacing, and finding the distance to an object corresponding to each object image extracted at the step of extracting, on the basis of the amount of spacing when the object image is extracted, thereby obtaining the distances to the objects existing in the multiple directions and measuring the distance distribution.

Abstract: An automatic focusing apparatus of a camera according to the present invention includes: a focus detector which detects repeatedly focus conditions of a photographic lens and outputs successively focus signals corresponding to the focus conditions; a drive unit for driving the photographic lens for focus adjustment; a predictor for predicting an in-focus detector; a control unit for controlling the drive unit to drive the photographic lens toward the in-focus point predicted by the predictor; an auxiliary light projector for projecting auxiliary light onto an object to enable detecting operation of the focus detector; and a forbidding device for forbidding the control of drive by the control unit while the auxiliary light is projected by the auxiliary light projector.

Abstract: A focus detecting device for detecting the focus adjusted state of an imaging optical system with respect to an object body comprises first and second photoelectric element arrays each including a plurality of photoelectric elements arranged in one direction, a focus detecting optical system for forming first and second optical images of the body on or near the first and second arrays by first and second light beams passed through different first and second areas, respectively, of the exit pupil of the imaging optical system, the first array producing a series of first output signals having a distribution pattern associated with the illumination intensity distribution pattern of the first image, the second array producing a series of second output signals having a distribution pattern associated with the illumination intensity distribution pattern of the second image, focus detection apparatus for producing a focus detection signal representative of the focus adjusted state of the imaging optical system, on t

Abstract: A photoelectric conversion apparatus has a plurality of photoelectric conversion cells. Each cell includes a semiconductor transistor having a control electrode area which in turn includes a plurality of main electrode areas for reading signals. The potential of the control electrode area is controlled to store carriers produced by optical pumping in the control electrode area, to read, from the main electrode area, a signal controlled by the storage voltage produced due to the storage, and to perform a refreshing operation to nullify the carriers stored in the control electrode area. A device is provided for performing a peak detection on the basis of signals from the main electrode area. At least one of the photoelectric conversion cells is shielded from light.

Abstract: An optical image transmitted through a photographing lens is incident on a light-receiving unit of a two-dimensional matrix. An output from the light-receiving unit is input to a first arithmetic logic unit, and the first arithmetic logic unit calculates actual object brightness values in consideration of an aperture value of an aperture. An output from the first arithmetic logic unit is supplied to a multiplexer and a neural network. The neural network determines a main part of the object from a pattern of brightness values of the respective photoelectric transducer elements and outputs a position signal of the main part. The multiplexer selectively passes the brightness value of the photoelectric transducer element corresponding to the main part of the object from the outputs generated by the first arithmetic logic unit. An output from the multiplexer is supplied to a second arithmetic logic unit.

Abstract: An image sensing device capable of being utilized in an automatic focus detecting system includes a pair of sets of light sensing elements that are spaced from each other. These light sensing elements can have a variable accumulation time of storing electric charges depending upon the intensity of the light level incident thereon. Since the automatic focus detection system must be managed within the parameters of photography, a first and second light measuring element is uniquely positioned adjacent each of the sets of light sensing elements. The outputs of these light measuring elements can control the charge accumulation period.

Abstract: A focus detecting device is provided with first and second line sensors and first and second image forming lenses which are located behind a predetermined focal plane of the objective lens to receive the object lights for forming first and second images on the first and second line sensors, respectively. The image signal generated by the first line sensor is divided into a plurality of block signals each consisting of a predetermined number of picture element outputs and each block signal is compared with groups of picture element outputs of the second line sensor, with the groups shifted sequentially, to find a group which best coincides therewith and the distance between the first and second images on the line sensors is calculated in accordance with the shift position of the group thus determined, for calculation of the amount and direction of defocus of the object image on the focal plane.

Abstract: An automatic focusing divice for a camera is disclosed. The automatic focusing device has sensing means for sensing light intensity distributions within narrow and wide areas of a field of view of an objective lens, respectively and can be operated in either operation mode of one-shot AF mode and continuous AF mode. When the one-shot AF mode is designated, said narrow area which is narrower than said wide area is automatically selected for focus condition detection and, when the continuous AF mode is designated, said wide area is automatically selected.

Abstract: A condenser lens disposed behind a film equivalent plane, a pair of light splitting elements disposed behind the condenser lens, and a focal point detecting apparatus. The radius of curvature of a front surface of the condenser lens at the film equivalent plane side is larger than that of a rear surface of the condenser. A path length L from the film equivalent plane to the rear surface of the condenser lens is set in a range of 3.2 mm>L>3.6 mm on the assumption that the path length L is not substantially expanded by a refractive material. The pair of light splitting elements are disposed in symmetricy with respect to a meridian plane of the condenser lens. The focal point detecting apparatus is adapted to detect a focal point by finding a relative positional displacement of an objective image which is reimaged by the pair of light splitting elements.

Abstract: A focus detection system for detecting a focus state of an object lens, includes an optical device for forming first and second light distributions corresponding to first and second images having light fluxes passing through the different parts of a pupila of the object lens. The positional relationship between the two light distributions varies in accordance with the focus state of the object lens. First and second sensors sense the first and second light distributions. A signal processor for processing output signals from the first and second sensors detect the focus state of the object lens in accordance with the positional relationships between the two light distributions. The signal processor processes the signals from the first and second sensors in accordance with a predetermined formula to obtain the positional relationship between the two images to determine a degree of coincidence of the two light distributions.

Abstract: A device for detecting the focal deviation value for focusing an optical apparatus includes a pair of optical lenses for receiving light from the focal object, which produces a pair of images that travel along two spatially isolated optical paths. These images are detected by a pair of photoelectric transducer arrays or photodiode arrays, which produce a pair of image signals that represents the distribution of light intensity in each image. Each image signal is composed of a plurality of image signal values. These signal values are used by a correlation evaluator, which extracts pairs of partial image signals corresponding to a predetermined number of consecutive image signal values, evaluates the correlation between any pair of extracted partial image signals, detects the position of the pair of extracted partial image signals and produces a corresponding focal deviation value for focusing the optical apparatus. The number of signal values in each image signal is not more than 1.

Abstract: A method and system for finding an exact focus of a taking lens of a single lens camera or the like. The method detects the relative position between two images on the basis of light intensity distribution of the images from a pair of light sensor arrays that receive the images through light paths separated from each other in space. The relative position depends on whether a taking lens of a camera is in front-focus condition or in back-focus condition. Partial image data consisting of n data respectively are sampled from the two image data as verification data. A number of combinations of the data are used to calculate evaluation values indicative of the level of correlation between the respective verification data. Correct focus exhibits the highest correlation. The method overcomes the problem that the combination having the highest correlation may not be correctly determined due to abnormal shape or envelope of the plotted distribution of the evaluation value.

Abstract: A focus condition detecting device which eliminates a wasteful operation thereof to obtain optical results of detection in a shortest period of time and wherein it can be discriminated correctly depending upon data read from a lens regarding an exit pupil of the lens whether or not detection of a focus condition is possible. The device comprises an optical means which forms a plurality of pairs of light images from beams of light from pairs of areas of an exit pupil plane of an interchangeable lens. Relative displacements between the light images are detected by a plurality of focus condition detecting means. Data regarding optical characteristics of the lens are read from the lens, and in accordance with the data thus read, those ones of the focus condition detecting means for which detection of a focus condition is possible are selected from an optical relationship between the optical means and the exit pupil of the lens.

Abstract: A focus detecting system having a passive type automatic focusing function and an active type automatic focusing function. When the passive type automatic focusing function is used, focus detection is performed using light which is incident from a position close to an optical axis of a photographic lens, while in the case of using the active type automatic focusing function, focus detection is performed using light which has passed through a position far from the optical axis of a photographic lens. The focus detection value is corrected using a preset correction value to set the photographic lens in the best image position.

Abstract: The light sensor has a light transmitter (10, 12) which radiates the light along an axis (x.sub.0) of a transmitter system and two light receiving systems (12, 14) which pick up the light scattered back from an object (G) to be detected along a receiving system axis (x.sub.1, x.sub.2). A light sensitive element (16) has three detection zones (El.sub.T, E.sub.H, E2.sub.T) arranged in a row of which the outer zones (E1.sub.T and E2.sub.T) each receive light via one of the receiving systems (12, 14) from a sensing zone (T) and of which the central detection zone (E.sub.H) accepts light via both light receiving systems from the background region (H) of the field of view of the light sensor. An output signal which is used for object recognition is obtained by additive superposition of the signals of the detection zones (E1.sub.T, E2.sub.T) associated with the scanning region (T) and by difference formation with the signal from the detection zone (E.sub.H) associated with the background region (H).

Abstract: In a focus detection system in which light from an object is incident on at least two photosensor arrays via an optical system to form two images on the photosensor arrays, the relative displacement between the two images is determined in order to detect whether the optical system is in focus or not. A correction term which is formed by f(i.sub.0 +2) and f(i.sub.0 +1) or f(i.sub.0 -2) and f(i.sub.0 -1) is added to f(i.sub.0-1)-f(i.sub.0) or f(i.sub.0 +1)-f(i.sub.0), so that the amount of image deviation between the two images is obtained. Here i.sub.0 is the value of i when a function f(i) is minimized, the function f(i) expressing the inconsistency between the two images, corresponding to an amount of relative displacement i.times.p between the two images obtained discretely. The symbol p represents the pitch of the at least two photosensor arrays.

Abstract: A device for determining the contrast of a display screen as a function of the observation direction. This device comprises a first convergent objective (12) for forming the image (19) of the Fourier transform of an elementary surface (9) of a screen (6) in the image focal plane (Fi) of the first objective, a second convergent objective (14) for projecting the image of the transform on to an array (16) of detectors (18) arranged in matrix-like manner, each detector producing an electric signal proportional to the light intensity from the elementary surface in accordance with a given observation direction and a diaphragm (20) in the vicinity of the second objective and whose aperture defines a surface, which must be equal to that of the elementary surface, as well as a computer for processing the electric signal produced by each detector in order to determine said contrast.

Abstract: In a focus detection system for detecting focus condition of an objective lens, there is disposed a pair of photo sensor arrays each having a plurality of photo cells lined up in one diection to receive a first image and second image passed through respectively a lens system and the photo sensor arrays produce first original signal groups and second original signal groups each signal groups corresponding to light intensity of the images projected thereto. A processing device processes the original signal groups in such a manner that the first original signal groups are respectively divided into a plurality of blocks, and one of the blocks of the first original signal groups is selected and it is detected that in what group in the selected block best coincidence occurs.

Abstract: A focus detection device which repeatedly calculates correlations between first and second image signals representing light intensity distributions on first and second image sensor arrays by shifting one of the image signals relative to the other to find an amount of shift affording the highest correlation includes shift range restriction means for restricting the shift range for the present correlation calculation in accordance with the amount of shift found through the last correlation calculation to afford the highest correlation. The shift range restriction is inhibited when the result of the last correlation calculation was not reliable indicating an infeasible condition of the focus detection.

Abstract: A focus detection apparatus includes:a first optical device for forming light distributions, associated with an object image, whose relative positional relationship chnages along a first direction in accordance with a focusing state of the objective lens;a second optical device for forming light distributions, associated with the object image, whose relative positional relationship changes along a second direction in accordance with the focusing state of the objective lens;a first sensing unit, having a plurality of photosensors, for forming an electrical signal associated with the focusing state of the objective lens in order to sense the light distributions formed by the first optical device; anda second sensing unit, having a plurality of photosensors, for forming an electrical signal associated with the focusing state of the objective lens in order to sense the light distribution formed by the second optical device.

Abstract: An automatic focusing device for a camera is disclosed.The automatic focusing device has focus detection means for detecting defocus amount of the image, object movement detection means for detecting movement of the object based on defocus data detected by the focus detection means and correction means for correcting the detected defocus amount according to the detected movement of the object.The objective lens of the camera is driven according to the corrected defocus amount for focus adjustment.

Abstract: A focus detecting device has a plurality of focus detection blocks, which blocks reproduce images of an object once produced by an objective lens as a pair of images on first and second CCD line sensors arrayed in a line, by means of a condenser lens, a pair of re-imaging lenses, and an aperture mask having a pair of aperture openings provided in the proximity of the re-imaging lenses, which blocks detect the positions of the paired images formed on the CCD line sensors, and detects the focus condition of the objective lens. In the focus detecting device, a light shield member to prevent the incidence of harmful light on the CCD line sensors is provided between at least the condenser lens and the CCD line sensors.

Abstract: An automatic focusing device for use in a video camera comprises a first and a second light-receiving element, a first and a second integration circuit integrating output signals of the first and second light-receiving elements respectively and each having a function of proportional current integration and a function of fixed current integration, a first and a second comparator comparing integration output voltages of the first and second integration circuits with the same threshold voltage respectively, a microcomputer producing a focusing signal by detecting the period of time from a time when one of the integration output voltages of the first and second integration circuits reaches the level of the threshold voltage to a time when the other integration output voltage reaches the level of the threshold voltage, and a detection circuit detecting that one of the integration output voltages of the first and second integration circuits reaches the level of the threshold voltage on the basis of the comparator o

Abstract: A focus detecting device having a field lens disposed near the predetermined imaging plane of an objective and a secondary imaging optical system disposed rearwardly of the field lens, whereby a pair of object images based on light beams passing through different portions of the pupil of the objective are formed and the respective object images are detected by photoelectric conversion element rows disposed rearwardly of the secondary imaging optical system to thereby discriminate the focus state of the objective from the amount of relative deviation of the object images is characterized in that a refracting portion for refracting the light beam in the direction of arrangement of the photoelectric conversion elements is provided in the secondary imaging optical system.

Abstract: An automatic focusing device for a camera is disclosed. The automatic focusing device has sensing means for sensing light intensity distributions within narrow and wide areas of a field of view of an objective lens, respectively and can be operated in either operation mode of one-shot AF mode and continuous AF mode. When the one-shot AF mode is designated, said narrow area which is narrower than said wide area is automatically selected for focus condition detection and, when the continuous AF mode is designated, said wide area is automatically selected.

Abstract: Method and apparatus for detecting a focus condition of an optical system forms two images of an object, the images propagating along two different optical paths. The two images are received with a plurality of photosensitive elements. The photosensitive elements are disposed in a plurality of sections, each section having a plurality of elements, each element outputting a signal corresponding to received light. The element output signals from the first image are stored in a first memory while the element output signals from the second image are stored in a second memory. A processor calculates the image light contrast for each section from the stored element signals. Then, the section displaying the highest contrast is selected for use in the correlation process. The correlation process is carried out by correlating the stored first image element signals with the stored second image element signals from the selected section.

Abstract: An apparatus for detecting the focus state of an optical system has optical apparatus for forming first and second light distributions of an object. The relative positional relationship of the light distributions varies in accordance with the focus state of the optical system. A light receiving device has first and second ranges, each having a plurality of picture elements. The first and second ranges respectively receive the first and second light distributions. Operation circuitry manipulates the output signals from the first and second ranges by relatively mathematically moving them to calculate a value representing the focus state of the optical system. The operation circuitry selectively executes a first operation in which the number of signals corresponding to each other is varied, and a second operation in which the number of signals corresponding to each other is kept constant.

Abstract: In a focus detection system for detecting the focus condition of an objective lens, there is disposed a pair of photosensor arrays for generating a plurality of image signals. The peak signal of the plurality of image signals is detected and compared with a predetermined constant level. The amount of defocus of the objective lens is calculated in accordance with the plurality of image signals when the detected peak signal is over the predetermined constant level. It is determined that focus detection is impossible when the detected peak signal is below the predetermined constant level.

Abstract: An optical system for use in a focus detecting apparatus has a photographing lens for forming an image of an object, a condenser lens disposed behind, with respect to the photographic lens, a plane corresponding to a photographing film surface, and a pair of split optical elements located behind the condenser lens for splitting the image of the object. The split optical elements are symmetrical with respect to a meridional plane of the condenser lenses. Using a line sensor, a relative positional shift of the images is detected by the optical system to determine a focal position. The optical system has a sufficiently large spherical aberration that the diameter of the minimum circle of confusion at the maximum contrast position is larger than the width of one bit of the line sensor.

Abstract: A focus detecting system having a passive type automatic focusing apparatus and an active type automatic focusing apparatus. When the passive type automatic focusing apparatus is used, focus detection is made using light which is incident from a position close to an optical axis of a photographic lens, while in the case of using the active type automatic focusing apparatus, focus detection is made using light passed through a position far from the optical axis of a photographic lens. The focus detection value is corrected using a preset correction value to set the photographic lens in the best image position.

Abstract: A focus condition detecting device which generated first and second light intensity distribution signals representing light intensity distributions on first and second arrays arranged to receive lights having passed through different areas of the exit pupil of an objective lens is arranged so as to divide the first light intensity distribution signal into a plurality of blocks. Each of the portions of the first light intensity distribution signal belonging to the respective blocks is shifted relative to the second light intensity distribution signal by sequentially changing an amount of shift, so that correlations therebetween are calculated for finding the amount of shift providing the highest correlation.

Abstract: An autofocus system employing a slave lens which is so shaped or configured as to produce a strip of radiation on a pair of detectors used in the autofocus system thus enabling an attractive and useful arrangement for photographic or video camera apparatus.

Abstract: First and second light distributions having their relative positional relation varying in conformity with the focus adjusted state of an objective optical system and based on an object are received by a plurality of picture elements, and the range of use of the picture element row can be changed when a value indicative of the focus adjusted state is calculated by the use of the signals from the picture elements.