Victor Company of Japan, Limited

Masaru Osada

Shintaro Nakagaki

Itsuo Takanashi

Ichiro Negishi

Hiroshi Ichimura

Takashi Kuriyama

Wataru Katase

Kaoru Kitami

Ichiro Shishido

Tadayoshi Miyoshi

Horosi Ichimura

Makotoi Iwahara

A picture element data density conversion apparatus, enabling arbitrary amounts of data density reduction to be independently selected for the horizontal (i.e. main) and vertical (i.e. secondary) scanning directions of a picture field, executes processing along a continuous path in which horizontally successive input values along each line of the field are first periodically selected and horizontal weighted averaging between specific pairs of these selected values is executed, then periodic selection of successive lines of the horizontal weighted average values thus obtained is executed, and vertical weighting averaging between vertically corresponding pairs of values in the selected line pairs is performed, to obtain density-reduced output data.

Picture element data density conversion apparatus

A first set of different color signals represented in a colorimetric system is converted into a second set of different color signals represented in another colorimetric system. Predetermined main parts of the second set of the color signals are determined in response to predetermined first portions of the first set of the color signals. Calculation coefficients are determined in response to the first portions of the first set of the color signals. Predetermined subordinate parts of the second set of the color signals are calculated from predetermined second portions of the first set of the color signals and the calculation coefficients according to an interpolation. The determined main parts of the second set of the color signals and the calculated subordinate parts of the second set of the color signals are combined into a whole of the second set of the color signals. The calculation coefficients are designed so that, if the color signals in the first set vary by equal values, achromatic color data which results from the calculation lies on an achromatic color axis in a color space defined with respect to the readout data of the main parts of the second set of the color signals, and that the sum of squared errors of color conversion is minimized.

Method and apparatus for processing color signals to convert between

A color separation stripe filter in a color image pickup apparatus in which a color image is focused on a photo-electric conversion target through the filter to be converted to an electrostatic image so as to generate a color multiplexed signal. The filter comprises a plurality of recurrent groups of three different color stripes successively arranged at periodic intervals. The first color stripe has a characteristic showing a peak transmission factor in a red color region, the second color stripe has a characteristic showing a peak transmission factor in a green color region which is substantially equal to the peak transmission factor of the first color stripe, and the third color stripe has a characteristic showing a negative peak transmission factor at a wavelength between 500 nm and 530 nm so as to produce first and second peak transmission factors in a blue region and said green region. The first peak transmission factor is substantially equal to each of the peak transmission factors of the first and second color stripes and the second peak transmission factor existing in the green color region to be 50% to 80% of each of the peak transmission factors of the first and second color stripes, a curve of the characteristic of the third color stripe in the green region being substantially similar in configuration to that of the second color stripe.

Color stripe filter in color image pickup apparatus

An image pickup device comprises an image pickup tube and an index generator having a light shield box; a light emitting diode held in the light shield box; a stripe screen provided on the photosensitive layer of the image pickup tube and shading compensation filter having transmittance pattern which equalizes illuminance variation on the stripe pattern of the stripe screen caused by the light emitting diode so that illuminance at any point of the stripe pattern becomes uniform. The image pickup tube generates picture signal together with index signal which is derived from the projected stripe pattern image on peripheral portion of the photosensitive layer through the shading compensation filter which equalizes index signal output level to make timing derived from the index signal accurate. A method of providing shading compensation filter is disclosed where a sheet of negative film is placed on the opening of the light shield box, exposed to the light emitting diode. Then the sheet of film is developed by chemical process.

Image pickup device with index signal generator

A color filter has a plurality of succesively arranged recurrent groups of different color stripes. An image pickup tube has a photoelectrical conversion target exposed to light passing through the color filter and an index signal generation pattern. The image pickup tube outputs a signal containing a color signal component determined by a carrier which is modulated with the individual color stripes of each recurrent group of the color filter. The output signal from the image pickup tube also contains an index signal component which depends on the index pattern. A first memory holds at least part of the index signal component. The index signal component held by the memory is periodically updated. A second memory holds a portion of the output signal from the image pickup tube which was obtained under conditions where a predetermined color light illuminates the photoelectrical conversion target via the color filter. A reference signal is generated in accordance with the index signal component read from the first memory and with the signal portion read from the second memory. A color signal is detected from the output signal of the image pickup tube by use of the reference signal.

Color imaging apparatus including control system for stabilizing phase

A color filter has recurrent groups of different color stripes. An image pickup tube has a photoelectrical conversion target exposed to light passing through the color filter and an index signal generation pattern. The image pickup tube outputs a signal containing a color signal component and an index signal component which depends on the index pattern. The index signal component has a phase representing a present start position of each scanning line. A memory holds a portion of the output signal from the image pickup tube corresponding to an initial frame period which occurs under conditions where a predetermined color light is applied to the photoelectrical conversion target via the color filter. A reference signal reflects a signal read out from the memory. A color component is detected from the output signal of the image pickup tube by use of the reference signal. The reference signal contains an index signal component which has a phase representing a start position of each scanning line during the initial frame period. A closed-loop phase control system allows the present start position of each scanning line to remain essentially equal to the start position of the corresponding scanning line during the initial frame period. A phase or level shifter is interposed in a loop of the closed-loop phase control system.

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Yokosuka, Japan

Masaru Osada