Abstract: A memory control circuit for controlling a memory bus and a memory includes buffers, counters, data transfer circuits, and a bus arbiter having a state machine. Each of the data transfer circuits transmits a request signal demanding start of the data transfer on the basis of at least one of the count values of the counters. If the data transfer circuit associated with the current state transmits the request signal, the bus arbiter transmits an acknowledge signal granting start of the data transfer. Each of the data transfer circuits starts the data transfer at receipt of the acknowledge signal, and stops the data transfer being executed on the basis of either number of pieces of data transferred after the receipt of the acknowledge signal or the count value of at least one of the counters.

Abstract: The invention is an endface polishing method and an endface polishing apparatus improving polishing accuracy of an optical fiber and making polishing time and polishing work shorten. Polishing is performed making a boundary line center axis while observing the boundary line of brightness and darkness formed at outer circumference face of an optical fiber by irradiating substantial parallel light from the predetermined direction crossing at the right angle to the axis of the optical fiber in an endface polishing method polishing a tip end of the optical fiber held by a jig by a polishing member attached at a polishing disk in an apparatus providing the polishing disk supported by a main body of the apparatus and the jig holding the optical fiber.

Abstract: An end face polishing machine having a polishing board supported on a machine body, and an optical fiber retaining jig, and adapted to polish a free end portion of an optical fiber retained by the jig, to the shape of a wedge by a polishing member fixed to the polishing board, the machine including an inspection unit adapted to take a picture image of a free end portion of the optical fiber retained by the jig, and ascertain the position of a core on an end face of the optical fiber.

Abstract: An end face polishing apparatus that allows a rod-shaped member to be polished with improved precision and the polishing process to be simplified is provided. In an end face polishing apparatus that polishes a rod-shaped member mounted at a polishing fixture by pressing the rod-shaped member against a lapping member on a lapping board that is supported at the main body of the apparatus to rotate and rock, the polishing fixture is pressed through an abutting part against a supporting portion provided at the apparatus main body, and the abutting part is located more on the side of the lapping board than the center of gravity of the polishing fixture.

Abstract: An optical fiber connector assembly has a holding member and a housing having a cavity for receiving the holding member. The holding member has a first surface, a second surface, grooves formed in the first surface for holding respective ferrules each supporting an optical fiber element, and through-holes for respectively receiving therethrough the optical fiber elements and for communicating the grooves with the second surface. The housing has a base surface, through-holes extending through the base surface, and side surfaces defining with the base surface a cavity for receiving the holding member so that the through-holes of the holding member are communicated with the through-holes of the housing for receiving therethrough the optical fiber elements.

Abstract: An end face polishing apparatus with improved polishing precision regardless of the length of ferrules when end faces of the ferrules are polished is provided. In an end face polishing apparatus polishing a rod-shaped member mounted at a polishing fixture by pressing the rod-shaped member against a lapping member on a lapping machine provided on a surface plate that is supported at the main body of the apparatus to rotate and rock, there are a plurality of rod-shaped guide members provided at the polishing fixture radially outwardly projecting and a tubular member capable of supporting the polishing fixture through the guide members on the surface plate. In this way, the guide members at the polishing fixture and the tubular member abut against each other so that the movement of the polishing fixture in the pressing direction is restricted.

Abstract: End face polishing apparatus and method that allow the eccentricity of curvature of an end face of a rod-shaped member to be reduced and the cost to be reduced by efficient use of a lapping sheet, so that the polishing efficiency is improved. In an end face polishing apparatus that polishes a rod-shaped member mounted at a polishing fixture by pressing the rod-shaped member against a lapping member mounted at a polishing plate rotatably and rock-ably supported at the main body of the apparatus, the polishing fixture is secured to a first virtual disk having a prescribed diameter and the lapping member is driven to move relative to the polishing fixture so that the first virtual disk moves along the circumference of a second virtual disk as it rotates, and the second virtual disk moves along the circumference of a third virtual disk as it rotates.

Abstract: A polishing system capable of producing and controlling a plurality of types of rod-shaped members is provided. The polishing system has a control machine capable of inputting and indicating pressure processing conditions having actual pressure measurements. The control machine includes a numbers indication part for indicating the number of the rod-shaped members, a type indication part for indicating connector types, a type indication part for indicating ferrule types, a process indication part for indicating a plurality of steps, and programmed pressure for inputting and indicating programmed pressure.

Abstract: In an edge correcting circuit of an image to be represented by a digitized image signal, a high-frequency signal extracting circuit (5) extracts a high-frequency signal of the image by calculation based on a signal of a target pixel, a signal of a pixel shifted from the target pixel by m (m being an integer not smaller than 2) pixels in the right or lower direction, and a signal of a pixel shifted from the target pixel by m pixels in the left or upper direction, an amplitude-restricting signal generator (6) determines an amplitude-restricting signal (Si) based on a minimum value or a maximum value of an absolute value of a difference between the signal of the target pixel and a signal of a pixel shifted from the target pixel by n (n being an integer not smaller than 1 and smaller than m) pixels in the right or lower direction, and an absolute value of a difference between the signal of the target pixel and a signal of a pixel shifted from the target pixel by n pixels in the left or upper direction, an amplitu

Abstract: A synchronizing signal processing circuit for use in a video apparatus such as a display apparatus and an information recording/reproducing is disclosed. The synchronizing signal processing circuit is capable of not only removing false synchronizing pulses included in incoming synchronizing signals and compensating for missing signals, but also causing its output to follow its input quickly after a phase of the incoming synchronizing signals has shifted abruptly.

Abstract: A luminance resolution enhancement circuit receives an (m+n) -bit image signal having an m-bit displayable component and an n-bit non-displayable component. An address generating element generates relative spatial and temporal coordinates of the pixel values in the image signal. For each pixel value, an average element calculates the average non-displayable component of the image signal in an averaging region including the pixel value, and a dithering element generates a dither signal responsive to the relative spatial and temporal coordinates of the pixel and the calculated average value. A processor additively combines the dither signal with the displayable component of the image signal, thereby generating an m-bit output image signal having a simulated luminance resolution exceeding m bits.

Abstract: An end surface polishing drive mechanism has a first rotational shaft mounted for undergoing rotation about a first axis and for undergoing revolving movement about a second axis. The first rotational shaft has a first end for connection to a polishing device to undergo rotation therewith and a second end. A second rotational shaft undergoes rotation about the second axis. A drive mechanism produces a driving force to rotationally drive the first and second rotational shafts and to revolve the first rotational shaft. A first gear is connected to the first rotational shaft for undergoing rotation and revolving movement therewith. A second gear is rotatably mounted on the second rotational shaft and is connected to the first gear for transmitting a drive force of the drive means to the first rotational shaft.

Abstract: An end-face lapping apparatus, comprises a rod member W supported on an apparatus main body by a support mechanism through a fixing jig board. A lapping board has a lapping member for lapping the rod member and is rotatably swingably supported on the apparatus main body by a drive mechanism. The drive mechanism causes the lapping board to rotate about a first rotating center and at the same time swivel rotating center about a second rotating center to thereby carry out lapping while urging the rod member W fitted in the fixing jig board against the lapping member of the rotatably swinging lapping board by the support mechanism. The end-face lapping apparatus has a relative position shift device for shifting the relative position of the lapping board and the fixing jig board. The rod member W is lapped at a different portion of the lapping member each time the relative position shift device shifts the relative position of the lapping board.

Abstract: An end face polishing apparatus in which whereas a jig board mounted with a rod-like member is supported by an apparatus main body by a supporting mechanism, a polishing board mounted with a polishing member for polishing the rod-like member is supported by the apparatus main body rotatably and pivotably by a drive mechanism for polishing the rod-like member mounted to the jig board by the supporting mechanism by pressing the rod-like member to the rotating and pivoting polishing board, wherein the polishing member is mounted to the polishing board attachably thereto and detachably therefrom, further comprising an automatic interchanging device for interchanging the polishing member which is mounted to the polishing board and which has been used with the polishing member which is stored at a predetermined position and which is to be used by which the operational performance is promoted.

Abstract: An optical fiber connector for connecting an optical fiber cable to a ferrule comprises a tubular body having a first end portion for connection to a peripheral surface of a ferrule, a second end portion for connection to a peripheral surface of an optical fiber cable, a step portion interconnecting the first end portion to the second end portion, and a clamping portion for clamping the optical fiber cable to the ferrule. The clamping portion extends inwardly from a terminal end of the second end portion towards the central axis of the tubular body but does not project lengthwise from the terminal end of the second end portion in the direction of the central axis. The first end portion, the second end portion, the step portion and the clamping portion of the tubular body have approximately the same wall thickness.

Abstract: A ferrule for use in an optical connector enabling effective suppression of the increase in the insertion loss resulting from repeated attachments/detachments of the optical connector. In the ferrule for use in the optical connector, a plurality of grooves 17 are formed in a fitting surface 16A of a ferrule main body 11 located between the ferrule main body 11 and a connection sleeve SL. And, a ferrule 2 for use in an optical connector, a plurality of concentric annular grooves 27 are formed in a connection end surface 24 of the ferrule main body 21 having a connection end 22A of the optical fiber 22 exposed thereon.

Abstract: A sync signal generator circuit comprises a first counter which is reset each time it detects a reference edge of the input sync signal, a first register for holding a first value immediately before the first counter is reset, a reset signal generator for generating reset pulses, a second counter which is reset each time it receives a reset pulse, a second register for holding a second value immediately before the second counter is reset, and a sync pulse generator for generating an output sync signal on the basis of the reset pulses. The reset pulse is generated each time the counted value of the second counter matches a predetermined value or each time the first counter detects the reference edge while an absolute value of a difference between the counted value of the second counter and the second value held in the second register is not greater than a permissible value of period fluctuations.

Abstract: A circuit for detecting a valid range of a video signal, has a detection window signal generator for generating a detection region window signal which has a low level during at range of time containing a point of time when the vertical sync signal changes its level or another point of time when the horizontal sync signal changes its level, and a valid range detector for detecting the valid range, during which the video signal has a level equal to or greater than a threshold and the detection region window signal has a high level.

Abstract: An end face polishing apparatus in which whereas a jig board mounted with a rod-like member is supported by an apparatus main body by a supporting mechanism, a polishing board mounted with a polishing member for polishing the rod-like member is supported by the apparatus main body rotatably and pivotably by a drive mechanism for polishing the rod-like member mounted to the jig board by the supporting mechanism by pressing the rod-like member to the rotating and pivoting polishing board, wherein the polishing member is mounted to the polishing board attachably thereto and detachably therefrom, further comprising an automatic interchanging device for interchanging the polishing member which is mounted to the polishing board and which has been used with the polishing member which is stored at a predetermined position and which is to be used by which the operational performance is promoted.

Abstract: A clamp ring for connecting a tensile strength member to the periphery of a rear end portion of a ferrule retaining part for holding a ferrule, in which an optical fiber of an optical fiber cable incorporating a coated optical fiber and the tensile strength member surrounding the coated optical fiber is inserted and fixed with an outer covering of the optical fiber cable stripped off from its terminal portion, the clamp ring comprising a first annular portion which fits on the periphery of the rear end portion of the ferrule retaining part, a second annular portion located in the back of the first annular portion, the second annular portion having a smaller diameter than the first annular portion, a step portion interconnecting the second annular portion and the first annular portion, and a clamping portion extending inward from the rear end of the second annular portion in such a way that the extreme end of the clamping portion secures the periphery of the optical fiber cable, in which the first annular port