A system for visually determining the distance to an object includes a lens that is adapted to be sighted upon an object, said lens being divided equally in a first direction with each half covered by polarizing masks arranged at right angles to each other, a flat light transmission analyzer positioned in the vicinity of the focal plane of the lens and dividing the field of view thereof in a second direction displaced 90.degree. with respect to said first direction, each half of the analyzer bei...

Apparatus for sensing and automatically adjusting the focus of a photographic variable size copying machine. An optical system identical to that of the camera is mechanically coupled to operate in parallel therewith. A photoelectric sensing system located in the plane of the photographic plate receiving light through the optical system from a light source in the plane of the negative carrier is activated by inaccuracy of focus. Signals of the photoelectric system are applied to control motor dri...

Correspondingly located portions of images projected on separate planes are compared for coincidence by correspondingly located photosensitive elements on each of the planes. The photosensitive elements on each corresponding image location on each plane are connected in separate circuits. An electrical potential is applied across these separate circuits. This produces a first aggregate current flow at image coincidence and a second easily distinguishable aggregate current flow at image non-coinc...

The present invention provides a low-cost focus detector that can carry out a focus detection over a wide field of view and can secure a sufficient light-receiving quantity to have an improved S/N ratio and an improved focus detection precision. A camera has a condenser lens disposed near a predetermined focusing surface of an image pick-up lens. At the rear of the condenser lens, a brightness diaphragm having a pair of apertures is disposed. Further, at the rear of the brightness diaphragm, a t...

A focus detector includes a movable reflecting mirror and a stationary reflecting mirror which reflect incident light admitted through a pair of independent windows for the purpose of comparison. A drive for the movable mirror drives it with different speeds during its movement in a forward and a reverse direction. The comparison takes place when the movable mirror is driven at a lower speed. The drive includes a non-symmetrical eccentric cam, a motor for rotating the eccentric cam, and a suppor...

A focus detector amplifies a plurality of sets of output signals from a plurality of photoelectric transfer element arrays by the most preferable amplifying mode and focuses a focus of an optical lens system on a desired object among a plurality of objects corresponding to the photoelectric transfer element arrays by selecting a method for deciding a defocus among a nearest position priority method, a lateral direction priority method and a reliability priority method responding to a condition o...

The present invention aims to perform high-accuracy focus control in an optical disk drive, even if a solid immersion lens (SIL) or a solid immersion mirror (SIM) is set between an objective lens and the optical disk in order to increase a numerical aperture, by accurately detecting a change of the distance between an SIL or SIM and an optical disk. The present invention comprises light detection means (8) for detecting the light incoming to an SIL (2) or an SIM from an objective lens (1) at an ...

A focus detector amplifies a plurality of sets of output signals from a plurality of photoelectric transfer element arrays by the most preferable amplifying mode and focuses a focus of an optical lens system on a desired object among a plurality of objects corresponding to the photoelectric transfer element arrays by selecting a method for deciding a defocus among a nearest position priority method, a lateral direction priority method and a reliability priority method responding to a condition o...

An improved focus ring is configured for use in a plasma processing chamber. The focus ring is configured to overlap at least a portion of a substrate-holding chuck that is powered by radio frequency (RF) power during plasma operation to act as an electrode. The focus ring includes an upper surface that is exposed to a plasma region within the plasma processing chamber during the plasma operation. The focus ring further includes a chuck-overlapping portion that overlaps the portion of the substr...

A focus detector used in an AF-SLR camera has a plurality of focusing sensors disposed not only in the center but also in a region distant from the center of the frame. A first focusing sensor group of the focusing sensors which are disposed in a first region where light flux passing through a pupil of a lens having an F-number larger than a predetermined F-number such as F2.8 is always used without reference to the F-number of the lens. A second focusing sensor group of focusing sensors which a...