Matsushita Electric Industrial Co., Ltd.

Yasuki Matsumoto

Haruo Yamashita

Hideshi Ishihara

Hiroyuki Yamaguchi

Mitsurou Moriya

Yoshihiro Mushika

Shin-ichi Yamada

Mitsuro Moriya

Ryusuke Horibe

Yoshihiro Kanda

Shigeo Sakaue

Susumu Maruno

Shinichi Yamada

Tsumoru Fukushima

Yasuaki Edahiro

Yasuhiro Sugihara

Osamu Yamaguchi

Shunji Oohara

Motoyuki Kobayashi

The present invention has an objective of providing a digital data reproduction apparatus and a method for correcting a reproduced signal digitization level in which the signal quality of a reproduced signal from a recording medium is kept high while ensuring the reproduction stability. The digital data reproduction apparatus includes: reproduced signal digitization means for digitizing a reproduced signal; synchronization means for producing a clock whose phase is synchronized with a leading edge and a trailing edge of the digitized signal produced by the reproduced signal digitization means; and jitter detection means for integrating and thereby converting absolute values of phase errors between the digitized signal and the clock to a voltage value. The apparatus further includes digitization level correction means for correcting a reproduced signal digitization level so as to minimize a signal produced by the jitter detection means.

Digital data reproducing apparatus and reproduction signal binarization level correcting method

The gradation correction device includes a luminance signal convertor to generate a luminance signal from the input R, G, B signals, a correction coefficient calculator which calculates the ratio to the luminance signal of the luminance signal after gamma correction to the predetermined gradation characteristics, and a multipliers to multiply the output from the correction coefficient calculator by each of the R, G, and B input signals. When the gradation correction is applied, effective brightness adjustment can be applied with no change in hue and saturation and without exceeding the dynamic range of a device.

Gradation correction method and device

In the optical recording medium of the invention, land and groove tracks are arranged in a spiral manner, and a completion information region having identification reading completion information indicative of a rear end of an identification region is disposed between data regions. A pair of wobble pits are disposed immediately behind the identification reading completion information region, and therefore the wobble pits can accurately be detected by reading out the wobble pits on the basis of the identification reading completion information.

Anti-wobble optical medium and tracking method and apparatus

In the disclosed thermal gradation printing apparatus, heat elements in a line-type thermal head are divided into a plurality of groups, and an accumulated heat amount in the substrate of the thermal head for each group is estimated based on the pulse width data applied to each heat element considering the influences by heat accumulations in the main-scanning direction and in the sub-scanning direction. Based on the group division estimated accumulated heat amounts and the temperature of the body portion of the thermal head, a correction value for the pulse width data to be applied to each heat element. Moreover, the correction value is applied to the pulse width data for each heat element, so as to output the corrected pulse width data to the thermal head.

Thermal gradation printing apparatus

A printer for recording a multitone image in which pulse width correction data is generated based on a temperature output of a thermistor for detecting the temperature of a head mount of a thermal head and an output of a data cumulating circuit for cumulating pulse width data inputted to the thermal head; and an adding circuit which adds the pulse width data to an output obtained by conversion, from inputted tone data, made by a .gamma. correcting circuit, thus accomplishing a temperature compensation. The temperature compensation constants necessary for calculating pulse width correction data are also determined.

Printer utilizing temperature evaluation and temperature detection

An optical recording medium includes a groove track and a land track provided on a resin substrate. Each of the tracks is divided into a plurality of sectors for every turn. Each sector has an ID region, a servo region, and an information region. A pit in the ID region is formed so as to span across both the groove track and the land track. The first wobble pit and the second wobble pit are provided on both sides of the center line of each track, and they are spaced with each other in the direction of the track. Thus, since a larger width of the pit can be provided, production of the optical recording medium can be facilitated. Moreover, since the center of the track can be detected accurately by the first and second wobble pits, accurate tracking control can be performed.

Optical disk capable of recording information on both groove and land

Method and apparatus for forming color images on paper using a sublimation type thermal transfer full-color printer using three color inks of yellow, magenta, and cyan. A color input signal to be printed is subjected to a first color correction process. The first color correction process performs a color correction using linear and non-linear masking operations and produces first ink-density signals. The first ink-density signals are judged for reproducibility by the printer by determining whether the signals fit within a gamut of colors. If judged to be reproducible, the first ink-density signals are passed on to the printer. However, if the first ink-density signals are judged to be outside the gamut of colors, the signals are subjected to a second correction process. The second color correction process first obtains a target color for color reproduction by the printer. Next, the second process sets ink-density signals, obtains predicted colors realized by the ink-density signals, chooses an output ink-density signal such that an evaluation value calculated by the target color and the predicted color becomes minimal, and produces a second ink-density signal that results in optimal colors within the range of colors reproducible by the printer.

Method and apparatus for forming color images by converting a color

In a tracking control apparatus of a recording and reproducing apparatus for an optical disk, information is recorded in groove tracks and land tracks of the optical disk and address information is recorded in an address area arranged to each of the groove tracks and the land tracks, a control signal corresponding to a positional deviation between a light beam spot and a track is derived on the basis of light reflected from the optical disk, and hence an address period in which the light beam spot traces the address area is derived. When the light beam spot traces the land track, a tracking operation is performed by a control signal which is invert in polarity to that of groove track, and when the light beam spot traces the address area, the tracking control is performed by a signal of the same polarity as that of the groove track.

Tracking control apparatus

An improved image signal processing method and apparatus which can reduce the color noises of high level with a simple construction without deterioration of the apparent resolution of the color signal, and wherein the color noise components in the horizontal direction is diffused in the vertical direction, in a region where the change in the brilliance distribution is less, by the detection of the correlation in the vertical direction of the brilliance. The smoothing processing with respect to the color signal is prohibited with respect to the abrupt edge portion so as to preserve the edge portion of the color, with an superior effect that the S/N improvement of the high level can be effected without deterioration of the color resolution in the vertical direction of the image.

Image signal processing method and apparatus

A color image forming method and an apparatus to be used for executing the method are provided which are capable of effecting more faithful color reproduction with respect to a target color, and also, a color correction factor determining method to be used in the above method and apparatus. The color image forming apparatus to which the color image forming method is applied is arranged to subject three primary color luminance signals (R, G, B) to linear matrix calculation by a luminance matrix device for conversion into second luminance signals (R', G', B') to correct deviation of wavelength of the spectral absorbing characteristic of the ink, and to subject each color of the second luminance signals (R', G', B') to complementary color conversion into three primary color density signals (D.sub.R, D.sub.G, D.sub.B) by a complementary color converting device, and further, to subject the three primary color density signals (D.sub.R, D.sub.G, D.sub.B) to color correcting calculation by a color correcting device for conversion into ink density signals (C, M, Y), so as to correct color turbidity due to the unnecessary component of the ink. Additionally, the correction factor determining method determines the luminance matrix factor used for the luminance matrix calculation and the color correction factor used for the color correcting calculation by minimizing conditions of a color difference to be perceived by man.

Color image forming method and an apparatus employed therefor, and a

A thermal head drive unit comprises electric power supply means for supplying electric power to heat-generating resistor elements arranged in a line in a thermal head. Head drive means is provided for electrically driving the heat-generating resistor elements in a lump by supplying electric power continuously variably in time to the heat-generating resistor elements depending on input gradation data. Head drive control means controls the head drive means in such a manner that, in a one-line recording time period composed of a power supply time during which electric power is supplied to the heat-generating resistor elements and an intermission time during which no electric power is supplied to the heat-generating resistor elements in disregard of the gradation data, the intermission time occupies a part not more than approximately 40% in the one-line recording time period.

Thermal head drive unit

In order to realize a method of color correction which is capable of performing the UCR compensating for the non-linearity of the superposed densities and the non-linear color correction meeting the non-linearity of the superposed densities at high accuracy with a configuration in substantially the same scale as the conventional linear UCR and linear masking techniques, there is provided a color correction method comprising first conversion means for converting the C, M, Y density information by a monotonously incremental non-linear function with a similarly monotonously incremental derivative, matrix means, and second conversion means for converting the same density information by a monotonously incremental non-linear function with a monotonously decremental derivative. In another aspect, there is provided four-color reproduction means comprising first conversion means for converting the C, M, Y information by a monotonously incremental non-linear function with a similarly monotonously incremental derivative, second conversion means, for effecting the conversion with a monotonously incremental non-linear function with a monotonously decremental derivative, and black separation means, subtraction means and matrix means interposed between the first and second conversion means for controlling the densities of the four inks to implement color recording.

Color image forming apparatus

A gradation correction apparatus for processing R, G, and B input signals includes a luminance signal conversion device for obtaining the original luminance signal, which is before gamma conversion, from the input signals, a luminance gamma conversion device for gamma converting the original luminance signal to the desired gradation characteristics to obtain a gamma converted luminance signal, a correction coefficient calculation means for obtaining a ratio of the gamma converted luminance signal to the original luminance signal, a first RGB operation means for multiplying the ratio by each of the R, G, and B input signals for obtaining primary gradation-corrected R, G, and B signals; a color difference signal operation means for producing a difference between each of the R, G, and B input signals and the original luminance signal; a second RGB operation means for adding the gamma converted luminance signal to each of the difference for obtaining secondary gradation-corrected R, G, and B signals; and an RGB determination means for obtaining final gradation-corrected R, G, B signals based on the primary and secondary gradation-corrected R, G, and B signals.

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Hirakata, Japan

Yasuki Matsumoto