Abstract: An optically-based overfill detection probe is provided that has a prism with a substantially quadrilateral cross-sectional shape, such that internal reflection angles are less than ninety degrees. The prism is made of a fluoropolymer, preferably TEFLON® PFA, and uses an infrared optical signal. The prism material has a high resistance to chemical solvents, has high signal transmission in the infrared (IR) wavelength range, is less prone to condensation and frost than plastic or glass, and enables the production of prisms at significantly less cost than glass. The substantially quadrilateral cross-sectional shape of the prism, in itself, has the advantage of allowing angles of incidence much less than ninety degrees on internal prism surfaces, thus reducing signal loss from surface irregularities.

Abstract: An optical device for measuring a level of a fluid in a container wherein a light conducting body having a top surface and a bottom surface is positioned within the container and into the fluid. A first end of the light conducting body and an oppositely disposed second end, preferably having stepped end surfaces, reflect and refract light in a predetermined manner based upon the fluid level in the container. A resulting brightness of the top surface is therefore inversely proportional to the level of the fluid. Such an optical device is particularly suited toward application to a vehicle fuel tank.

Abstract: An apparatus and method for measuring the viscosity of Newtonian and non-Newtonian fluids over a range of shear rates, especially low shear rates, by monitoring two rising columns of fluid (Newtonian or non-Newtonian) that pass through respective capillaries having different lengths. Furthermore, a specialized column monitor is provided that uses multiple interrogation sources (e.g., lasers) and a single detector (e.g., a charge-coupled device (CCD) array) to continuously monitor both columns of fluid substantially simultaneously. In particular, the system includes a Y-connector to form two flow paths and wherein each flow path includes a tube that includes a riser tube, a capillary tube of predetermined dimensions and a valve in each for controlling the fluid flow in each path.

Abstract: An apparatus including an enclosure having an interior surface and an exterior surface; a first radiation sensor coupled to the interior surface being configured to produce a first signal dependent on the radiation sensed by the first radiation sensor; a second radiation sensor coupled to the interior surface being configured to produce a second signal dependent on the radiation sensed by the second radiation sensor; and a bus accessible from the exterior surface, the bus being coupled to the first radiation sensor and the second radiation sensor.

Abstract: An optical gauge for measuring the level of a liquid in a container comprises an elongate, tubular member with a central bore. A light source is positioned for projecting radiant energy into the bore along a length of the tubular member. An elongate light collector is spaced from the light source and extends along the length of the tubular member for receiving radiant energy from the light source. The light collector has opposite ends and is formed such that radiant energy incident on a length of the light collector is transmitted to the light collector ends. A light blocking member is located within the bore and extends between the light source and at least a portion of the elongate light collector for blocking at least a portion of the radiant energy from the light collector.

Abstract: A device for converting a position of a float member in a rotameter in to an electrical output. Light from a light source is collimated into parallel light rays, at either or both opposing sides of a rotameter tube to greatly enhance accuracy of readings. The lightrays passing through the tube are detected by a linear optical array. A range of movement capable of being read by the linear optical array is extended by use of either a fiber optical array or a movable illumination device and linear optic array. The collimator(s) may be a linear array of one or two rows of cylindrical lenses sandwiched between a pair of plates. The linear optic array maybe arranged on opposite sides of the rotameter tube or may be on the same side there of. A light guide is used in the latter arrangement to guide light from the light source to a side of the rotameter tube opposite the linear optic array which may be a charge-coupled device(CCD).

Abstract: The present invention is a fluid level sensing system which has a single light source for providing light rays and a single light receiving device for receiving the light rays. The fluid level sensing system also has a fluid container which has a plurality of controlled surfaces arranged on the fluid container. Each controlled surface exhibits a first reflected light characteristic if fluid within the fluid container is in contact with the controlled surface and a second reflected light characteristic if the fluid is not in contact with the controlled surface. The controlled surfaces are disposed on the fluid container so that the light rays from the single light source impinge upon each of the controlled surfaces to produce either the first or the second reflected light characteristics and are thereby detected by the light receiving device to determine the fluid level in the fluid container.

Abstract: An optical sensor for monitoring a utility meter having a sweep hand indicator that moves over a meter surface of the utility meter. The optical sensor has a single infrared light emitter and two photo diodes detectors. The infrared light emitter is positioned at an angle with respect the meter surface and the sweep hand indicator of the utility meter so that the sweep hand indicator is illuminated from an angle to provide a shadow of the sweep hand indicator. The photo detectors detect changes in the intensity of light reflected on the sweep hand indicator and the background surface as well as the shadow of the sweep hand indicator. The two photo diode detectors are electrically coupled in series but in opposite directions relative to an output node, so as to cancel each other at the output node in normal operation. The passing of the sweep hand indicator changes the signal produced of each of the photo diode detectors at the output node, independently but in opposite directions.

Abstract: Apparatus and method for determining the level of a material in a vessel. In one embodiment, and optical emitter emits light onto a rotating mirror. The light reflects off of the rotating mirror and propagates into a vessel. At a first time, the light reflects back and is detected by a first detector. At a second time, the light is reflected back and is detected by a second detector. The distance to the surface of the material in the vessel can be determined using the difference between the first and second times. The volume of the material may also be determined based on this distance. Additional embodiments include rotating the light source itself, maintaining an inert gas near a surface of a window located between the steering mirror and an interior area of the vessel, tilting the steering mirror and first and second detectors to obtain a reflection at maximum intensity, and accounting for the tilt in calculating the volume.

Abstract: In a leak sensor including a light-transmitting part 16 constituted by a transparent or semitransparent material, the leak sensor irradiating the light-transmitting part 16 with probe light L in a state where the light-transmitting part 16 is provided so as to face into a region subjected to leak detection 26, and detecting a leaked liquid according to a change in quantity of light L* reflected by a boundary between the light-transmitting part 16 and the region subjected to leak detection 26; the leak sensor 10 comprises an attachment 28 for installing the leak sensor 18 in the region subjected to leak detection 26; the attachment 28 comprising a ground portion 30 grounded on the region subjected to leak detection 26; and mounting portions 36, 38, 40, rising from the ground portion 30, adapted to mount the leak sensor 18 in a state where the light-transmitting part 16 is parallel to the ground portion 30 and in a state where a predetermined space is formed therebetween.

Abstract: The tilt detecting device of the present invention comprises a light transmission type electric bubble tube, a light source for emitting detection light to the electric bubble tube, a photodetector element for detecting emitted light amount for detecting an amount of light emitted from the light source, and a tilt detection control unit for controlling the emitted light amount of the light source to a constant level based on photodetection signal from the photodetector element for detecting emitted light amount, and causes of error are eliminated.

Abstract: The indication that water is flowing in a fire protection sprinkler riser is often used as an initial indication that a fire has occurred in the protected building. The subject invention is an improved water flow switch, that uses a paddle with a reflective surface placed opposite an LED/Photodiode pair. When water begins to flow the force of the water against the paddle causes the paddle to rotate about a pivot. The pair are used to optically detect the rotation of the paddle. This approach eliminates many of the maintenance problems with the electro-mechanical flow switches currently available, as well as reducing the cost of manufacture. Furthermore, it makes possible the measurement of the rate of flow in the fire suppression sprinkler system, allowing the responding fire service to determine whether the fire is being controlled by the sprinkler system or not by observing the data at the fire alarm control panel, before fire fighters enter the fire compartment.

Abstract: A liquid supplying device comprising a liquid container for storing a liquid so as to supply an external device and a liquid level sensor for detecting the liquid level. As the liquid within the liquid container is gradually used up, liquid level drops. As soon as the remaining liquid in the container drops to a predetermined amount, the liquid level sensor emits a warning signal to the operator, and the operator can then replenish the liquid in the container.

Abstract: An optical sensor (40) that provides a monotonic level-dependent output signal that varies smoothly and at an easily detectable rate over the entire length of the sensor includes first and second spaced waveguides (45, 50) extending along an axis, with each extending between its respective first and second ends. The first waveguide does not have surfaces contacting the liquid along the first waveguide's length. The second waveguide has at least a longitudinally extending portion of an outer surface in optical contact with the liquid. One or more web portions (50a, 50b, 50c) extend along and between both waveguides so that some of the light traveling along the first waveguide is coupled through the web portion(s) into the second waveguide. Light is injected into an end of the first waveguide (52), allowed to travel along the first waveguide, with a portion leaking into the second waveguide. Light is detected (55), with the amount representing the level of liquid.

Abstract: A liquid level sensor comprising a transparent waveguide containing fluorescent material that is excited by light of a first wavelength and emits at a second, longer wavelength. The upper end of the waveguide is connected to a light source at the first wavelength through a beveled portion of the waveguide such that the input light is totally internally reflected within the waveguide above an air/liquid interface in a tank but is transmitted into the liquid below this interface. Light is emitted from the fluorescent material only in those portions of the waveguide that are above the air/liquid interface, to be collected at the upper end of the waveguide by a detector that is sensitive only to the second wavelength. As the interface moves down in the tank, the signal strength from the detector will increase.

Abstract: A wireless fuel gauge assembly including a fuel tank containing fuel having a level defining a liquid-air boundary. A control determines a digital indication of the fuel level. The control is able to determine plural digital signals that provide incremental level readings. A transmitter then sends an RF signal indicative of the level. A receiver captures the RF signal and communicates to a fuel gauge.

Abstract: An optical switch operatively sensitive to a fluid pressure differential includes a house having an open end, a fiber optic input line, a fiber optic output line, and a fluid-proof diaphragm sealingly engaged with the housing. The diaphragm is formed from a thin elastic material resiliently stretchable between first and second switching states and supports an optical barrier within the housing for blocking the propagation of an optical signal between the fiber optic lines when the diaphragm is in one switching state and for permitting the propagation of the signal between the fiber optic lines when the diaphragm is in the other one of the switching states. For a given housing and a given diaphragm, different optical barriers may be employed to achieve different switching thresholds. As well differing optical barriers may be used to make the switch either a normally "on" switch or a normally "off" switch. Apparatus for monitoring the level of a liquid may include a plurality of such switches.

Abstract: An optical mass gauge sensor is disclosed comprising a vessel having an interior surface which reflects radiant energy at a wavelength at least partially absorbed by a fluid contained within the vessel, an illuminating device for introducing radiant energy at such wavelength into the vessel interior, and, a detector for measuring the energy per unit area of illumination within the vessel created by the radiant energy which is not absorbed by the fluid.

Abstract: A bubble detector includes a conduit (1) through which a first fluid having a first refractive index is intended to flow, a light source (3) which directs a light beam (4; 41, 42) through a transparent conduit wall-part (12), through the conduit cavity and out through a second transparent conduit wall-part, and a detector means (5; 51, 52, 53) adapted to receive the light beam (4, 41) after the beam has passed through the conduit and the first fluid therein. The two opposing transparent wall-parts (12, 11) of the conduit (1) are trans-illuminated by the light beam and are essentially planar and parallel. The light source (3) is adapted to direct the beam (4) at an oblique angle (.alpha.) to the proximal transparent wall-part (12) of the conduit (1), so that the light source will be broken into different paths (41, 42) depending on whether the beam passes the first fluid or a second conduit-carried fluid having a different refractive index, such as a bubble.

Abstract: An arrangement for detecting moisture conditions on a pane, particularly a windshield of a motor vehicle, wherein radiation emitted by a transmitter is coupled by a radiation guide into the pane and is coupled out of the pane onto a receiver. With respect to the production and the dimensions, the design is supported by the measures which provide that the beam entry surface and/or the beam exit surface is/are arranged on the parallel side of the radiation guide facing the circuit board, and that the optical axis of the transmitter or of the receiver is oriented to be perpendicular to the beam entry surface or the beam exit surface and that the radiation guide has at least one input-end or output-end deviating surface with which the radiation that entered the radiation guide is guided at a right angle into the interior of the radiation guide or the radiation which is to be oriented out of the radiation guide onto the receiver is guided at a right angle out of the interior of the radiation guide.

Abstract: An apparatus and method for optical sensing of liquid level in cooking vessels are disclosed. The apparatus comprises: a first sensor (P1) for detecting a liquid and generating a first signal indicating a vessel level of the detected liquid above a desired liquid level (110) in the cooking vessel (102); a second sensor (P2) for detecting the liquid and generating a second signal indicating the vessel level of the detected liquid below the desired liquid level (110) in the cooking vessel (102); a third sensor (P3) for detecting the liquid and generating a third signal indicating the vessel level of the detected liquid (110) at the bottom of the cooking vessel (102); and a controller (108) for receiving the signals and for determining the vessel level in the cooking vessel (102).

Abstract: Improved apparatus and methods for forming a layer of material over a surface of a previously-formed cross-section of a three-dimensional object in anticipation of forming a next cross-section of the object out of the layer. A volume of material, including at least some excess material, is placed over the surface, and the excess material is swept off by placing the excess material in the predetermined path of a sweeping member, the path being substantially in a plane spaced from a working surface of material. The member may be directed to sweep the excess material away through a successive number of sweeps, which may vary for each cross-section, at least a velocity which may vary for each sweep. Additionally, the clearance between the member and the surface of the previous cross-section may vary for each sweep. A "winged" member is also provided, comprising two legs extending from a base, and a "Trident" embodiment is also provided, comprising three legs extending from a base.

Abstract: A optically-based fluid overfill prevention probe has an anti-reflective guard which prevents light external to a prism of the probe from reaching a photodetector of the probe. The probe has a light source which couples light into a prism that is detected by a photodetector when it is internally reflected within the prism. When the prism is contacted by fluid in a container being monitored, the light from the light source exits the prism, and is no longer detected by the photodetector. To avoid the light exiting the prism from being accidentally reflected back into the prism in a direction which would allow it to be detected by the photodetector, the anti-reflective guard is located within a viewing radius of the photodetector, and blocks light external to the prism which might otherwise be detected by the photodetector.

Abstract: A fluid monitor determines the quality, intensity and/or level of a fluid by transmitting a beam of light through the fluid and evaluating any changes to the shape of the beam as a result of being transmitted through the fluid. The monitor includes a light source and a lens which generate an incident beam of light having a predefined cross sectional shape. The beam is transmitted through a volume of the fluid, which modifies the shape of the beam as a function of the fluid quality, intensity and/or level. The beam can be polarized before being transmitted through the fluid or after beam transmission. The polarized beam is directed to a detector which evaluates the horizontal and vertical components of the beam and provides a shape signal to a detection circuit. The detection circuit processes the shape signal received from the detector to determine the quality, intensity and/or level of the fluid based on any variations from the predefined shape of the incident beam.

Abstract: A sensor for detecting environmental media and pressure comprises two types of optical fibers. An intrinsic fiber containing a portion of the fiber with the jacket removed is sensitive to its surroundings as some light traveling through the fiber will escape. The change in light intensity is received by a light detector, and this information is interpreted to correspond to a certain media, a change in media, or a phase change in media. An extrinsic fiber with a membrane and mirror located at one end is placed vertically in the media. Pressure from the media changes the position of the membrane and the mirror, resulting in a change in the intensity of the light reflected back through the fiber to the light detector. The pressure can then be used to determine the volume of the media in the container. Pressure determination can be continuous. In addition, both types of sensors can be networked, allowing information from one sensor to influence the gathering of information from the other.

Abstract: A low ink sensing system is combined with an ink cartridge detection system to enable a more efficient ink jet printer. An ink container which supplies ink to an associated printhead is modified by the incorporation of two light directing elements, in the preferred embodiment, a faceted prism and a roof mirror, into a transparent wall of the container housing. The cartridge, comprising the ink container and associated printhead, is mounted on a scan carriage. Periodically, the carriage is conveyed to a sensing station comprising a pair of light sources and a commonly used photosensor. A first light source is energized and a beam of light is directed to a location where the roof mirror, would be positioned if the cartridge is present. If the cartridge is absent, lack of a reflected return signal is sensed, indicating a cartridge has not been inserted. Print operation is halted until a cartridge is inserted.

Abstract: An apparatus for measuring liquid level in a container, the apparatus having a flexible measurement scale attached at one end to a weight for retainment at the bottom of the container and at the opposite end to a receiver at the top of the container. A float moves along the flexible scale, and has a configuration and density designed to place a portion of the float below the level of the liquid to be measured and a portion above the liquid level. The portion above the liquid level contains transmitter apparatus for applying energy to one side of the scale, and detection apparatus on the other side for detecting energy transmitted through the scale and converting it to a liquid level in the container.

Abstract: A light emitting photonic structure has a transparent substrate, such as sapphire, supporting a layer of group IV semiconductor material, such as silicon, having at least one porous region from which light is emitted as a response to a stimulus. An example of such a photonic structure is described in U.S. patent application Ser. No. 08/118,900. The photonic structure can be used to assess the presence of various fluids. The photonic structure is disposed to be contacted by the fluid to be sensed should it be present. The light emitting region of the photonic structure is stimulated by an appropriate source, and the light emitted by the photonic source is detected by a detector. The light emitting region of the photonic structure will emit a certain luminescence in air and should the light emitting region be contacted by other fluid or fluids, this luminescence can be affected and the corresponding change in luminescence can be detected thus the presence of these fluids can be sensed.

Abstract: Improved apparatus and methods for forming a layer of material over a surface of a previously-formed cross-section of a three-dimensional object in anticipation of forming a next cross-section of the object out of the layer. A volume of material, including at least some excess material, is placed over the surface, and the excess material is swept off by placing the excess material in the predetermined path of a sweeping member, the path being substantially in a plane spaced from a working surface of material. The member may be directed to sweep the excess material away through a successive number of sweeps, which may vary for each cross-section, at least a velocity which may vary for each sweep. Additionally, the clearance between the member and the surface of the previous cross-section may vary for each sweep. A "winged" member is also provided, comprising two legs extending from a base, and a "Trident" embodiment is also provided, comprising three legs extending from a base.

Abstract: A liquid level gauge utilizes a liquid tight plastic envelope carrying an elongate p-c board that has a light source mounted so as to direct light laterally thereof, and a light sensor also mounted so as to receive light from a direction which is lateral of the board. The gauge further has a lens configuration which is part of the envelope, for providing a largely solid, reflective path for light which emanates at the light source and is to be received at the light sensor. The lens is capable of aiding in the establishment, at the exterior of the envelope, of a path which diverges from the solid reflective path when the exterior of the envelope is surrounded by liquid that has an index of refraction which is different from the index of refraction of the material of which the lens and envelope are constituted. Assembly is significantly simplified as compared with prior, known gauge constructions.

Abstract: A liquid sensing apparatus for a fuel tank comprises a first optical sensor for producing an output having a first state that corresponds to the first optical sensor being exposed to air and a second state that corresponds to the first optical sensor being exposed to fuel; and a circuit for detecting the first and second optical sensor output states. The sensor circuit also has self test capability for testing both active and passive components. The sensor circuits can be accessed using a two wire only interface, and thermal stability can be achieved with the electronic circuit as shown.

Abstract: A liquid gauging system for a liquid container, the system comprising sensor means for producing a first electromagnetic signal that corresponds to liquid quantity in the container, and remote interrogation means for receiving the first electromagnetic signal and producing a system output that corresponds to the liquid quantity; the sensor means being energized by a second electromagnetic signal transmitted by the remote interrogation means.

Abstract: In a preferred embodiment, a liquid level sensor for use in a hot, pressurized liquid, including: an outer housing suitable for immersion in the liquid; an inner housing disposed within the outer housing and containing therein electronic/electrical components; detection apparatus disposed within the outer housing and the inner housing to detect level of the liquid; a space defined between the outer housing and the inner housing; and means to permit the liquid which migrates through a wall of the outer housing into the space and which is vaporized therein to pass to the ambient surroundings, so as to preclude migration of the liquid through a wall of the inner housing.

Abstract: A sensor device for detecting the degree of wetting and/or contamination of windows, especially windshields of motor vehicles, which device has a radiation source (12) emitting a radiation into the window (10) from the inside of the window (10), and a radiation measuring device detecting the radiation reflected many times by total reflection in the window (10) between outer surface (17) and inner surface (18). A heating device (33) is arranged on at least one contact surface between the sensor device and the window (10) or in the window. As a result, the measurement path (19) of the window (10) is deliberately heated with a low energy requirement, so that no measurement impairment is to be feared as a result of condensation on the inner surface (18) of the window and a mirrored reflection surface on this inside is not necessary.

Abstract: A failsafe apparatus for verifying a volume of aspirated reagent before it is provided to dilute a sample in an automated assay instrument. A pump draws reagent through a tube having a reagent probe disposed at one end. An optical flow detector includes an optical source disposed proximate the tube to illuminate the interior of the tube, and a photodetector oriented ninety degrees about the circumference of the tube from the source to detect reflected illumination from the contents of the tube. The photodetector provides one voltage level with gas/air within the tube, and a second level with a liquid within the tube. A circuit in communication with the detector discriminates between the two levels. The rate at which aspirate is pumped and the volume of the tube from a probe tip inlet to the detector are known constants. Therefore, a given volume of aspirate takes a predictable amount of time to pass from tip to detector.

Abstract: An apparatus and method is disclosed for sensing a full level condition for a large basket. A signal generator produces an oscillating signal which is applied to energy emitters that are capable of transmitting electrical energy along defined paths and across the width of the large basket. The transmitted electrical energy is received by a plurality of receivers which output an electrical signal which is representative of the signal applied to the energy emitters when material which is being loaded into said basket does not interfere with the energy being transmitted along the defined paths. A logic circuit analyzes the signals output from the receivers and produces a status signal indicating whether material which is being loaded into the large basket has interfered with the energy being transmitted along the defined paths.

Abstract: An optical liquid level sensor for distinguishing between the presence of oil and vapor within a compressor crankcase. The sensor has a light transmitting window positioned to interface the crankcase interior and a planar side facing the crankcase exterior. A light source and a light sensor are both positioned adjacent the exterior face of the window. The sensor has a first condition when the prismatic face is immersed in oil and a second condition when the prismatic face is immersed in vapor. An electronic circuit having a dual MOSFET switch for alternating current is mounted adjacent the light source and sensor. The circuit provides power to the source and monitors the sensor. When the sensor is in the first condition, the circuit closes the switch. When the sensor detects the second condition, the circuit starts a timer and continuously tests the condition of the sensor. If the first condition is detected, the timer resets to its initial value.

Abstract: An array of four infrared LEDs and an array of four phototransistor receivers with each LED and phototransistor mounted inside a light baffle. The LEDs are positioned in a substantially vertical array just outside one side wall of the cassette. The vertical line on which the LEDs are arranged is substantially parallel to the direction in which the fluid/air interface moves within the cassette. The LEDs are aimed upwardly at an angle of approximately 20.degree. from horizontal. A corresponding substantially vertical array of four phototransistor receivers is mounted outside the cassette opposite the LEDs such that each of the receivers is aimed at its corresponding LED.

Abstract: A liquid level monitor uses a tube to confine a float to a vertical path with a canister containing a lower liquid and an upper liquid which meet at a liquid boundary, the level of which is to be monitored. Light from a light-emitting diode is conveyed to a vertical position of the tube by an optical fiber. A second optical fiber is arranged in a diametrically opposed position of the tube to detect light transmitted across the tube from the first optical fiber. The float is more transmissive than either liquid. When the level of the boundary falls to the level of the optical fibers, received light increases. The second optical fiber conveys this return light to a photodetector, the output of which can be used to trigger an alarm indicating that the boundary level is low.

Abstract: A brewed beverage maker, such as a coffee maker, is provided having an automatic concentration control system. An optical feedback system is employed for controlling the concentration of brewed beverages such as coffee and tea. In preferred embodiments, this invention employs a light beam that is passed through the beverage as the beverage is being made to determine the concentration of the beverage. A control system compares the measured concentration to a desired concentration and controls the flow of water through a filter basket containing coffee, tea or the like.

Abstract: 057238701Apparatus for detecting fluid level in a container, comprises a housing adapted to be disposed in the container; a float with an associated magnetic element, the float position corresponding to fluid level in the container; a magnetostrictive sensor disposed inside the housing; and a stick gauge disposed inside the housing; the magnetostrictive sensor and the stick gauge each being operable to determine the float position.

Abstract: A method for measuring or controlling the volume of a liquid segment confined within a tube and having a leading edge and a trailing edge. The tube is exposed to radiation at an angle and radiation refracted from the inner surface of the tube is measured at the leading and trailing edges of the segment while the liquid segment is moving through the tube.

Abstract: Device for the detection of liquid surfaces including a light source sending light onto a liquid surface, an oscillation element which is moved toward the liquid surface and causes the liquid surface to oscillate upon contact with the surface. The surface contact is detected by a light detector which picks up the radiation reflected by the liquid. Upon contact with the liquid, the light sent out by the light source is modulated by the oscillations of the liquid surface. The so modulated signal can be selectively identified by the detector.

Abstract: A liquid level detecting mechanism for detecting the liquid level in a vessel for storage of liquid, includes a light emitting unit and a light receiving unit disposed opposite to the vessel for storage of liquid or a chamber communicating with the vessel. The light receiving unit detects the liquid level in the vessel in accordance with the quantity of received light from the light emitted from the light emitting unit, and members in contact with liquid which are arranged between the light emitting unit and the light receiving unit, the members being formed of a material having high wettability relative to the liquid.

Abstract: An optical liquid sensing system for sensing liquids in contact with an optical sensing component is provided. The sensing system comprises an optical sensor connected to a control module by a fiber optic cable having two fiber optic strands, the first for receiving light emitted by the control module, and the second for receiving light reflected from a distal reflector. The strands terminate in a longitudinally oriented common ferrule within the optical sensor. The optical sensor is generally cylindrical and includes a distal reflector opposite and in a spaced relationship to the ferrule. A group of apertures is defined in the circumferential wall of the housing so as to permit entry of liquid into the housing and to draw liquid proximally located to the sensor into the housing via capillary action.

Abstract: A dry particle-size distribution measuring apparatus capable of conducting a measurement using a small quantity of sample. An optical system, a sample detector, a controller, an operating portion, and a sample-supplying portion which intermittently supplies a sample are provided. The optical system has a laser beam source emitting a laser beam, a collecting lens, and a detector which detects scattered or transmitted light. The sample supply-detecting means has a light transmitter and a light receiver provided between the sample-supplying portion and the optical system. The controlling and operating portion has a CPU which receives a detected signal from the detector and measures the particle-size distribution on the basis of the scattered or transmitted light data from the sample.

Abstract: A developing apparatus includes a developer container for containing a developer; a light transmitting portion, in the developer container, for optically detecting the developer; a rotatable wiping sheet for wiping the light transmitting portion; wherein the wiping sheet has a low rigidity portion at a rotational axis side beyond an end of the wiping sheet.

Abstract: The liquid level sensor includes a modulated laser diode and collimating optics for collimating the diode output to produce an optical measurement signal beam transmitted to the fluid boundary through a diffuser to diverge the beam. A detector detects reflections of the beam from the fluid boundary to produce an output signal which is amplified and inverted to drive the modulator. The frequency of the modulation, which depends on the distance to the fluid boundary, is measured and the distance is derived from that measurement.

Abstract: Apparatus for detecting fluid level in a container, comprises a housing adapted to be disposed in the container; a float with an associated magnetic element, the float position corresponding to fluid level in the container; a magnetostrictive sensor disposed inside the housing; and a stick gauge disposed inside the housing; the magnetostrictive sensor and the stick gauge each being operable to determine the float position.

Abstract: An inexpensive ink tank having an ink remaining amount detection section which can be used with ink of any color is disclosed. An optical ink detection section formed from a light transmitting material has an inclined interface and is formed integrally with the ink tank. Incident light from a light source is refracted, when ink is present in the ink tank, at the interface to make refraction light and does not emerge to a visual observation portion. When no ink is present, the incident light is totally reflected by the interface to make total reflection light, which can be visually observed at the visual observation portion. A roughened face is formed at the visual observation portion so that light emerging to the visual observation portion may be scattered to facilitate visual observation.