Pioneer Electronic Corporation

Satoshi Kusano

Toshio Suzuki

Yuji Tawaragi

Noriko Obitsu

Shinichi Takahashi

Daisuke Ito

Tetsuo Akiyama

A line sensor having a plurality of photoelectric conversion elements is provided for producing image data dependent on an optical image of at every scanning line. Marker data of a green line is generated on demand. A changeover switch is provided for selectively switching the image data and the marker data, and a display memory is provided for storing the image data and marker data. A controller produces a first write signal for writing the marker data and a second write signal for writing the image data at every scanning line. A timing signal is generated for deciding timing for producing the first write signal and the second write signal. A monitor is provided for displaying the green line dependent on the stored marker data and an image dependent on the stored image data, superimposing on the green line.

Image scanning system

An image display device includes: a first memory for storing an image data; transmitting unit for reading out a portion of the image data stored in the first memory from a position of a transmitting side address and transmitting the read image data; a second memory for receiving the image data from the transmitting unit and storing the transmitted image data from a position of a receiving side address, the second memory renewing the stored image data endlessly by cyclicly changing the receiving side address and overwriting the transmitted image data; a display unit for reading out the image data stored in the display memory from a position of a display start address and displaying the read image data on a screen thereof; scroll information receiving unit for receiving scroll information including a scroll direction and a scroll amount inputted by an operator; and control unit for determining the display start address, the receiving side address and the transmitting side address in accordance with the scroll information, the second memory having a storage capacity larger than a data capacity of image displayed on one screen of the display unit.

Image display device

An optical disk player having a tracking servo apparatus and a focusing servo apparatus. By amplifying a focusing error at a predetermined gain and adding it to a tracking error, the rolling which occurs due to a mass balance distortion of a pickup is electrically suppressed. Thus, an adverse influence on the tracking servo by the rolling upon focusing driving can be prevented.

Optical disk player having beam correction means

An optical disk player provided with tilt servo unit. A quadrant type photodetector is used as disk tilt detecting means, and the push-pull output is issued as a disk tilt detecting signal. By simultaneous use of the photodetector of the pickup, there is no need to use special-purpose tilt sensor, and this contributes to compact design of the pickup and to the reduction of manufacturing cost.

Optical disk player having tilt servo control absent tilt sensor

A tracking servo system of disk player uses the time difference detection method for generating the tracking error signal. A time gate is provided for detecting the zero-crossing of the tracking error level in an on-track condition during a jumping operation. As the result, negative effects due to unstableness in timing of the zero-crossing can be eliminated.

Tracking servo system

An optical disk player using quadrant type photodetector as light receiving means. The phase difference output by the time difference detection method is issued as a tracking error, and a DC component of differential output by the push-pull method is issued as a tilt error, and zero cross of said differential output is detected. By using this detection output for the detection of zero-cross timing on off-track, stable operation of the tracking servo unit is ensured.

Optical disk player

A recording disk reproducing apparatus employing simplified digital servo control for lower-cost, more stable operational control of the apparatus. At least one of a focusing servo loop, a tracking servo loop, a spindle servo loop, and a time base servo loop employs digital conversion of an analog error signal for processing in a microprocessor. The analog-to-digital conversion circuitry has an input-output characteristic which varies in accordance with error signal level, enabling a reduction in the number of bits of A/D output necessary, and reducing cost.

Recording disk reproducing apparatus having high-resolution A/D converter

A servomechanism for a recording disk reproducing system which includes a switching device receptive of the analog error signals of a variety of servo systems for outputting the same analog error signals sequentially in a time division manner in response to sampling signals of predetermined frequency. The analog error signals passed through the switching means are converted into digital error signals and subjected to arithmetic processing. The processed digital error signals are reconverted into analog error signals and distributed to the respective controlled portions of the various servo systems in synchronism with the sampling signals. The frequency of the sampling signals is set on the basis of that of a reference signal contained in the signal read from the disk being played.

Servomechanism for recording disk reproducing system

A digital frequency and phase comparator for both detecting a frequency of a digital signal and the phase thereof relative to a reference signal, wherein polarity inversions of the output phase different signal and saturated characteristics of the circuit when the phase difference succeeds a predetermined value are eliminated. The inventive digital frequency and phase comparator includes a time counter, an input holding circuit for holding a first and a second count value of the time counter at two different input timings of an input signal, a first arithmetic device for determining one of the frequency and period of the inputs signal in response to the first and second count values held by the input timing holding device, and a second arithmetic device for determining a phase of the input signal relative to a reference signal in response to a selected one of the first and second count values held in the input timing holding device.

Growing community of inventors

Tokorozawa, Japan

Satoshi Kusano