Abstract: A prepit detecting apparatus which uses an optical recording medium having information recording tracks on which information is recorded and guide tracks each of which guides a light beam to the information recording track and on which prepits for saving pre-information are formed such that the light beam is applied to the information track of the optical recording medium, the prepit detecting apparatus comprising: light receiving means divided into a first divided light receiving portion and a second divided light receiving portion divided along an optically parallel division line in a direction of tangent of the information tracks and arranged to receive reflected light of the light beam with which the optical recording medium has been irradiated; and a difference calculator for calculating the difference between a first read signal output from the first divided light receiving portion and a second read signal output from the second divided light receiving portion so that the prepit is detected in response

Abstract: When first and second read signals generated on the basis of the outputs of electrical signals from a light receiving portion are input to an amplitude correcting circuit, the first and second read signals are added to generate an addition signal. Then the amplitudes of the first and second read signals are corrected for the each RF signal component corresponding to each recording pit, which is contained in the first and second read signals on the basis of the addition signal. Finally, the difference between the first and second read signals is computed to generate a difference signal so that a pre-pit signal will be detected on the basis of the difference signal.

Abstract: A prepit detecting apparatus which uses an optical recording medium having information recording tracks on which information is recorded and guide tracks each of which guides a light beam to the information recording track and on which prepits for saving pre-information are formed such that the light beam is applied to the information track of the optical recording medium, the prepit detecting apparatus comprising: light receiving means divided into a first divided light receiving portion and a second divided light receiving portion divided along an optically parallel division line in a direction of tangent of the information tracks and arranged to receive reflected light of the light beam with which the optical recording medium has been irradiated; and a difference calculator for calculating the difference between a first read signal output from the first divided light receiving portion and a second read signal output from the second divided light receiving portion so that the prepit is detected in response

Abstract: A prepit detecting apparatus which uses an optical recording medium having information recording tracks on which information is recorded and guide tracks each of which guides a light beam to the information recording track and on which prepits for saving pre-information are formed such that the light beam is applied to the information track of the optical recording medium, the prepit detecting apparatus comprising: light receiving means divided into a first divided light receiving portion and a second divided light receiving portion divided along an optically parallel division line in a direction of tangent of the information tracks and arranged to receive reflected light of the light beam with which the optical recording medium has been irradiated; and a difference calculator for calculating the difference between a first read signal output from the first divided light receiving portion and a second read signal output from the second divided light receiving portion so that the prepit is detected in response

Abstract: A prepit detection unit for detecting prepits in an optical recording and reproducing apparatus for recording and reproducing information on a recordable, optical record medium including preinformation such as address information in a prepit form. In the prepit detection unit, for first and second divisional RF signals output from a pickup being divided into a first divisional light reception part and a second divisional light reception part by a division line optically parallel to the tangential direction of an information track for receiving reflected light from the optical record medium, mark sections and space sections are clamped by potential correction circuits and a difference is found by a radial push-pull circuit.

Abstract: When first and second read signals generated on the basis of the outputs of electrical signals from a light receiving portion are input to an amplitude correcting circuit, the first and second read signals are added to generate an addition signal. Then the amplitudes of the first and second read signals are corrected for the each RF signal component corresponding to each recording pit, which is contained in the first and second read signals on the basis of the addition signal. Finally, the difference between the first and second read signals is computed to generate a difference signal so that a pre-pit signal will be detected on the basis of the difference signal.

Abstract: A prepit detection unit for detecting prepits in an optical recording and reproducing apparatus for recording and reproducing information on a recordable, optical record medium including preinformation such as address information in a prepit form. In the prepit detection unit, for first and second divisional RF signals output from a pickup being divided into a first divisional light reception part and a second divisional light reception part by a division line optically parallel to the tangential direction of an information track for receiving reflected light from the optical record medium, mark sections and space sections are clamped by potential correction circuits and a difference is found by a radial push-pull circuit.

Abstract: A prepit detection unit for detecting prepits in an optical recording and reproducing apparatus for recording and reproducing information on a recordable, optical record medium including preinformation such as address information in a prepit form. In the prepit detection unit, for first and second divisional RF signals output from a pickup being divided into a first divisional light reception part and a second divisional light reception part by a division line optically parallel to the tangential direction of an information track for receiving reflected light from the optical record medium, mark sections and space sections are clamped by potential correction circuits and a difference is found by a radial push-pull circuit.

Abstract: An information detecting device detects information recorded in a form of pre-pits on a storage medium which is recorded with movement control information recorded by wobbling information tracks at a frequency corresponding to the movement control information and the recording control information recorded by forming the pre-pits on neighboring tracks of the information track.

Abstract: The present invention provides a recycle slide gate plate, said slide gate plate being connected to a lower portion of a molten metal container and used for sliding a plate to control a flow of molten metal drained from the molten metal container, comprising an upper plate and/or a lower plate obtained by polishing a sliding surface of a slide gate plate used at least one time, at a predetermined smoothness tolerance, a tubular ring fixed to a through hole obtained by cutting out a molten metal outlet portion of the upper plate and/or the lower plate having a projecting portion on a side opposite to a sliding surface of the upper plate and/or the lower plate, said projecting portion having a total height of a sum of a height dimension substantially equal to a height of a projecting portion of a new plate before use and a thickness dimension to be reduced by polishing out the sliding surface, the projecting portion being provided with a molten metal outlet hole formed inside the projecting portion, and a cushi

Abstract: The reading position of a first reading head jumps when it is located in a vertical blanking period section of a video disc and the reading position of a second reading head jumps when it is located outside a predetermined portion of the vertical blanking period section in which a PCM audio signal is recorded. An output of the first reading head that is produced by reading sections other than the vertical blanking period section is employed as a video reading signal, and an output of the second reading head that is produced by reading the vertical blanking period section is employed as an audio reading signal.

Abstract: Disclosed herein are a refractory repairing material for repairing a brick comprising a mixture of 70 to 80 wt % of alumina having not more than 1 mm of grain size, which comprises 25 to 30 wt % of the above amount with a grain size not passing through a 325 mesh and 45 to 50 wt % of the above amount with a grain size passing through a 325 mesh; 1 to 7 wt % of carbonaceous material having a grain size passing through a 60 mesh; 1 to 5 wt % of magnesia having a grain size passing through a 325 mesh; and 10 to 25 wt % of aluminum phosphate, and a method of repairing a plate-like brick.

Abstract: Disclosed herein are a refractory repairing material for repairing a brick comprising a mixture of 70 to 80 wt % of alumina having not more than 1 mm of grain size, which comprises 25 to 30 wt % of the above amount with a grain size not passing through a 325 mesh and 45 to 50 wt % of the above amount with a grain size passing through a 325 mesh; 1 to 7 wt % of carbonaceous material having a grain size passing through a 60 mesh; 1 to 5 wt % of magnesia having a grain size passing through a 325 mesh; and 10 to 25 wt % of aluminum phosphate, and a method of repairing a plate-like brick.