Victor Company of Japan, Limited

Keisoku Giken Co., Ltd.

Keisou Giken Co., Ltd.

Jin Ogasawara

Seiichi Gohshi

Shinichiro Nakamura

Seiji Higurashi

Tetsuya Suwa

Tomoyuki Shindo

Keisuke Ohashi

For sharpening an input image by up-converting the input image in order to increase the number of pixels of an image and generating a frequency component higher than a frequency component contained in an input image signal representing the input image, the number of multipliers is reduced, thereby achieving significant downsizing of an apparatus and cost reduction. An image processing apparatus includes a path on a base image side for up-converting the input image signal and a path on a sharpening processing side for carrying out nonlinear arithmetic processing on the input image signal. The path on the sharpening processing side includes an up-converter at a subsequent stage of at least one filter, after which the nonlinear arithmetic processing is carried out. The at least one filter may be either a two-dimensional low pass filter for noise removal or a high pass filter for removing a DC component.

Image processing apparatus and image processing method

An image is sharpened by using a frequency component exceeding a Nyquist frequency. In particular, an image processing apparatusof the disclosure herein for generating an output image by sharpening an input image includes a first nonlinear processing unitconfigured to generate a first signal by carrying out nonlinear processing on an input image signal representing the input image, a sharpening processing blockconfigured to generate a second signal containing a frequency component higher than a frequency component contained in the first signal by carrying out sharpening processing on the first signal, and an adderconfigured to generate an output image signal representing the output image by adding the second signal to the input image signal.

An image is sharpened without generating, in frequency domain exceeding frequency component in horizontal and vertical direction, frequency component caused by sharpening carried out in horizontal and vertical direction in overlapping manner. An image processing apparatus includes: a vertical filter removing high frequency portion in vertical direction; a horizontal sharpening processing unit generating harmonic in horizontal direction containing frequency higher than frequency component in horizontal direction of the input signal; a horizontal filter removing high frequency portion in horizontal direction; and a vertical sharpening processing unit generating harmonic in vertical direction containing frequency higher than frequency component in vertical direction of the input signal, wherein a horizontal direction processing unit in which the vertical filter is disposed before the horizontal sharpening processing unit and a vertical direction processing unit in which the horizontal filter is disposed before the vertical sharpening processing unit are connected in series, or in parallel.

A locking-status judging circuit is composed of a comparator that compares a phase error signal with a reference signal for judging whether or not a digital PLL circuit locks on an input signal and outputs a signal '0 (zero)' or a signal '1 (one)', a selector that outputs a positive or negative number in response to the inputted signal whether it is &#x201c;0&#x201d; or &#x201c;1&#x201d;, a limiter that limits an accumulated number to be within a range of prescribed upper and lower limits, a feedback section that returns the accumulated number, an accumulator that adds the accumulated number and a positive or negative number from the selector and outputs a newly accumulated number, and a lock-state judging section that judges the digital PLL circuit whether it is in a lock-state or an unlock-state in response to an accumulated value of the newly accumulated number whether it is positive or negative.

Locking-status judging circuit for digital PLL circuit

A data recording and reproducing apparatus includes a rotary head for recording a signal on a tape-like recording medium while successively forming tracks thereon, and for reproducing a signal from the tape-like recording medium. Each of the tracks has a front margin area, an effective data area, and a rear margin area. A flag is generated which represents which of different speeds the rotary head rotates at. The generated flag is inserted into the signal before the signal is recorded on the tape-like recording medium by the rotary head. Thereby, the flag is recorded on the effective data area. A data rate of the signal recorded on the tape-like recording medium is maintained at a constant rate independent of which of the different speeds the rotary head rotates at. An amount of data recorded on the rear margin area is controlled in response to which of the different speeds the rotary head rotates at to cause the tracks to be equal in length independent of which of the different speeds the rotary head rotates at.

Data recording and reproducing apparatus

A drum servo system is provided with a rotation control device for controlling the rotation of a drum on the basis of a phase comparison signal obtained as a result of comparing the phase of an angle-of-rotation information signal obtained according to an angle of rotation of the drum with the phase of a control signal. The system also includes a detection device for determining the existence of a large data block or a small path block and outputting the result to a reference signal generator. The frequency of the reference signal is higher than that of the control signal, and is altered based on the output of the detection device. Frequency division is performed on the reference signal after it has been acted on by a phase locked loop, and the result is compared to the phase of the angle-of-rotation information signal in the rotation control device. Thus, a radical change in the control signal which occurs when the phase or frequency of the control signal is changed due to an abrupt external disturbance can preferably be absorbed in the comparison control device. Thereby, the rotation control device can always stably follow an abrupt change occurring in the control signal.

Drum servo system using a PLL with frequency divided reference clock

A clock signal selection circuit includes a delay for delaying a switching control signal to supply a delayed switching control signal. A first selection circuit changes its state between first and second states in response to the switching control signal. A second selection circuit changes its circuit condition between third and fourth states in response to the switching control signal and the output of first selection circuit. The second selection circuit outputs a second clock signal when operated in the third state and inhibits the second clock signal in the fourth state. The first selection circuit supplies the first clock signal when operated in the first state and inhibits the first clock signal from being supplied when operated in the second state in response to the switching control signal and the output of second selection circuit. A third selection circuit transmits the switching control signal to either the first or second selection circuit in response to the delayed control signal.

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Yokohama, Japan

Jin Ogasawara