Solid state image pick-up apparatus

Claim 2

The solid-state image pickup apparatus as claimed in claim 1 wherein said second digital processing means (42) comprises a half band filter supplied with the digital luminance signal (Y) and the two digital color difference signals (C R , C B ) from said first digital processing means (41) for providing a digital luminance signal (Y) having a rate equal to f s1 , said half band filter having a passband in a range of from 0 to bf s2 for the digital luminance signal (Y) and a passband in a range of from 0 to f s2 /2 for the digital color difference signals (C R , C B ), and a rate converting filter supplied with outputs of said half band filter for down-sampling the digital luminance signal (Y) at a rate equal to f s2 and for down-sampling the two color difference signals (C R , C B ) at a rate equal to f s2 /2, for suppressing higher order sideband components close to N · 2f s1 , N being a natural number.

Claim 3

A solid-state image pickup apparatus comprising at least one solid-state image sensor (IG, IR, IB, 2) driven at a rate equal to f s1 , analog-to-digital converting means (3) for digitizing image pickup signals outputted by said solid-state image sensor (IG, IR, IB)at a rate equal to f s1 at a predetermined phase, first digital processing means (41) operated at a clock rate related to said rate of f s1 for generating, from said image signals digitized by said analog-to-digital converting means (3), at least a digital luminance signal (Y) having a data rate related to said rate of f s1 and two digital color difference signals (C R , C B ) having a data rate related to said rate of f s1 , second digital processing means (42, 5) for converting said digital luminance signal (Y) having a data rate related to said rate of f s1 and two digital color difference signals (C R , C B ) having a data rate related to said rate of f s1 into a digital luminance signal (Y(2f s1 )) having a data rate related to a rate of f s2 and two digital color difference (C R /C B (f s2 )) signals having a data rate related to a rate of f s2 , respectively, said second digital processing means (42, 5) having a half band filter having a passband of f s2 /2 for said digital luminance signal (Y) from said first digital processing means (41) having a data rate related to said rate of f s1 , with a data rate being 2f s1 , and a passband of f s2 /4 for said digital luminance signal (Y) from said first digital processing means (41) having a data rate related to said rate of f s1 , with a data rate being f s1 , and a rate converting filter (5) for performing rate conversion of from 2f s1 to f s2 on the digital luminance signals (Y) supplied via said half band filter and down-sampling a low order linear phase finite length impulse response sufficient to suppress higher order sideband components in the vicinity of n · 2f s1 , where n is an positive integer, at a down-sampling rate of f s2 for outputting down-sampled impulse response, said rate converting filter (5) also performing rate conversion of from f s1 to f s2 /2 or f s2 /4 on the digital luminance signals (Y) supplied via said half band filter and down-sampling a low order linear phase finite length impulse response sufficient to suppress higher order sideband components in the vicinity of n · f s1 , where n is an positive integer, at a down-sampling rate of f s2 /2 or f s2 /4 for outputting down-sampled impulse response.

Claim 4

The solid-state image pickup apparatus s claimed in claim 3 wherein said half band filter has characteristics of compensating roll-off characteristics of said rate converting filter.

Claim 5

The solid-state image pickup apparatus as claimed in claim 4 wherein said rate converting filter (5) has at least one zero point at n · 2f s1 for said digital luminance signal (Y) and at n · f s1 for said two digital color difference signals (C R , C B ), said rate converting filter (5) also having each two zero points in the vicinity thereof.

Claim 6

The solid-state image pickup apparatus s claimed in any of claims 3 to 5 wherein said rate converting filter (5) comprises a plurality of multipliers (155A, 155B, 155C).

Claim 7

The solid-state image pickup apparatus as claimed in any of claims 3 to 6 wherein said half band filter comprises a product of partial filters each constituted by integer coefficients.

Claim 8

A solid-state image pickup apparatus comprising a solid-state image sensor (IG, IR, IB, 2) for providing an image pickup signal at a predetermined rate f s1 , analog-to-digital converting means (3) coupled to said solid- state image sensor (IG, IR, IB, 2) for digitizing said image pickup signal at a clock rate equal to said rate f s1 to form digital image pickup signals, first digital processing means (41) supplied with the digital image pickup signals from said analog-to-digital converting means (3) for providing at least a digital luminance signal (Y) having a rate equal to 2f s1 and two digital color difference signals (C R , C B ) each having a rate equal to f s1 , signal processing means (6) supplied with said digital luminance signal (Y) and the two digital color difference signals (C R , C B ) for generating output signals, recording/reproducing means (7) interfaced with a clock rate related to f s2 , second digital processing means (42, 5) coupled to said first digital processing means (41), said second digital processing means (42, 5) and said recording/reproducing means (7) converting the data rate of said digital luminance signals (Y) and the two color difference signals (C R , C B ) supplied from said first digital processing means (41) to a rate related to f s2 for generating rate-converted digital luminance signal (Y(f s2 )) and the rate-converted color difference signals (C R /C B (f s2 )), said second digital processing means (42, 5) supplying the rate-converted digital luminance signal (Y(f s2 )) and the rate-converted digital color difference signals (C R /C B (f s2 )) to said recording/reproducing means (7), said second digital processing means (42, 5) converting the data rate of the digital luminance signal (Y) and the color difference signals (C R , C B ) supplied thereto from said recording/reproducing means (7) to a data rate related to f s1 for generating rate-converted digital luminance signal (Y) and rate-converted color difference signals (C R , C B ), said second digital processing means (42, 5) supplying the rate-converted digital luminance signal (Y) and rate-converted color difference signals (C R /C B ) to said signal processing means (7).

Claim 9

The solid-state image pickup apparatus as claimed in claim 8 wherein for the recording mode, the digital luminance signal (Y) and the two color difference signals (C R , C B ) generated by said first digital processing means (41) are outputted via said signal processing means (6) and supplied via said second digital processing unit (42, 5) to said recording/reproducing unit (7), and wherein for the playback mode, the digital luminance signal (Y) and the two digital color difference signals (C R , C B ) of a data rate related to the rate of f s2 , supplied from said recording/reproducing (7) means, are supplied via said second digital processing unit to said signal processing unit (6), via which the signals supplied from said recording/reproducing means (7) are outputted as playback signals.

Claim 10

The solid-state image pickup apparatus as claimed in claims 8 or 9 wherein said signal processing unit (6) comprises digital-to-analog converting means (6/Y, 6/C R , 6/C B ).

Claim 11

The solid-state image pickup apparatus as claimed in any of claims 8 to 10 wherein, for the recording mode, said first digital processing unit (41) produces the digital luminance signal (Y) at a data rate of 2f s1 and said second digital processing means (42, 5) performs rate conversion of from 2f s1 to f s2 on the digital luminance signal (Y) having the data rate of 2f s1 .

Claim 12

The solid-state image pickup apparatus as claimed in claim 11 wherein, for the playback mode, said second digital processing unit (42, 5) performs rate conversion of from f s2 to 2f s1 on the digital luminance signal (Y) of the rate equal to f s2 supplied from said recording/reproducing means (7).

Claim 13

The solid-state image pickup apparatus as claimed in claim 11 wherein, for the playback mode, said second digital processing unit (42, 5) performs rate conversion of from f s2 to 2f s2 on the digital luminance signal (Y) of the rate equal to f s2 supplied from said recording/reproducing means (7).

Claim 14

The solid-state image pickup apparatus as claimed in claim 13 wherein said signal processing means (6) comprises digital-to-analog converting means (6/Y, 6/C R , 6/C B ) for converting, for the recording mode, the digital luminance signal (Y) at a data rate of 2f s1 , produced by said first digital processing means (41), into analog signals, which are outputted, said digital-to-analog converting means (6/Y, 6/C R , 6/C B ) converting, for the playback mode, the digital luminance signal (Y) at a data rate of 2f s2 , produced by said second digital processing means (42, 5), into analog signals, which are outputted.

Claim 15

The solid-state image pickup apparatus as claimed in any of claims 8 to 14 wherein, for the recording mode, said first digital processing unit (41) produces the digital luminance signal (Y) at a data rate of 2f s1 and two digital color difference signals (C R , C B ), each at the rate of f s1 , and wherein said second digital processing means (42, 5) performs rate conversion of from 2f s1 to f s2 on the digital luminance signal (Y) at the data rate of 2f s1 and rate conversion of substantially from f s1 to f s2 /2 on said two color difference signals (C R , C B ).

Claim 16

The solid-state image pickup apparatus as claimed in claim 15 wherein, for the playback mode, said second digital processing unit (42, 5) performs rate conversion of from f s2 to 2f s1 on the digital luminance signal (Y) having the rate equal to f s2 and rate conversion of substantially from f s2 /2 to f s1 on the two digital color difference signals (C R , C B ) having the rate equal to f s2 /2.

Claim 17

The solid-state image pickup apparatus as claimed in claim 15 wherein, for the playback mode, said second digital processing unit (42, 5) performs rate conversion of from f s2 to 2f S2 on the digital luminance signal (Y) having the rate equal to f s2 and rate conversion of substantially from f s2 /2 to f s1 on the two digital color difference signals (C R , C B ) having the rate equal to f s2 /2.

Claim 18

The solid-state image pickup apparatus as claimed in claim 17 wherein said signal processing means (6) comprises digital-to-analog converting means (6/Y, 6/C R , 6/C B ) for converting, for the recording mode, the 2f s1 rate digital luminance signal and the f s1 rate two digital color chrominance signals (C R , C B ), produced by said first digital processing means (41), into analog signals, which are outputted, said digital-to- analog converting means (6/Y, 6/C R , 6/C B ) converting, for the playback mode, the 2f s2 rate digital luminance signal (Y) and the two f s2 rate digital color chrominance signals (C R , C B ), produced by said second digital processing means (42, 5), into analog signals, which are outputted.

Claim 19

The solid-state image pickup apparatus as claimed in claims 17 or 18 wherein said second digital processing unit (42, 5) comprises a filter operated for the recording mode at a clock rate of 2f s1 and functioning as a Nyquist filter for the clock rate of 2f s1 for 2f s1 rate digital luminance signals Y (2f s1 ) generated by said first digital processing unit (41), said filter being operated for the reproducing mode at clock rates of 2f s2 and f s2 for digital luminance signals (Y) and digital color difference signals (C R , C B ), respectively, and presenting the same frequency characteristics as those for the recording mode, and rate converting filter (5) connected to said filter for performing rate conversion of substantially from 2f s1 to f s2 and rate conversion of substantially from f s1 to f s2 /2 on digital luminance signals (Y) supplied via said filter and on two digital color difference signals (C R , C B ) for the recording mode, respectively, said filter being used both for the playback mode and for the recording mode.

Claim 20

A solid-state image pickup apparatus comprising a solid-state image sensor (IG, IR, IB, 2) for providing an image pickup signal at a predetermined rate f s1 , analog-to-digital converting means (3) coupled to said solid-state image sensor (IG, IR, IB, 2) for digitizing said image pickup signal at a clock rate equal to said rate f s1 for outputting digital image pickup signal, first digital processing means (41) supplied with said digital image pickup signal for providing at least a digital luminance signal (Y) having a rate equal to 2f s1 and two digital color difference signals (C R , C B ) having a rate equal to f s1 , signal processing means (6) supplied with said digital luminance signal (Y) and said color difference signals (C R , C B ) for generating an output signal, recording/reproducing means (7) interfaced with a clock rate elated to f s2 , second digital processing means (42, 5) connected to said first digital processing means (41), said signal processing means (6) and said recording/reproducing means (7), said second digital processing means (42, 5) converting the data rate of said digital luminance signal (Y) supplied from said first digital processing means (41) to a rate equal to f s2 for outputting a converted digital luminance signal (Y(f s2 )) and supplying said converted digital luminance signal (Y(f s2 )) to said recording/reproducing means (7) for the recording mode, said second digital processing means (42, 5) converting the data rate of said digital luminance signal (Y) supplied from said recording/reproducing means (7) to a rate equal to 2f s2 for outputting a converted digital luminance signal (Y(2f s2 )) and supplying said converted digital luminance signal (Y(2f s2 )) to said signal processing means (6) for the playback mode.

Claim 21

The solid-state image pickup apparatus as claimed in any of claims 1 to 20 wherein said second digital processing unit (42, 5) is capable of setting a plurality of rate conversion ratios.

Claim 22

The solid-state image pickup apparatus as claimed in any of claims 1 to 21 wherein said second digital processing unit (42, 5) comprises a filter functioning as a Nyquist filter for the clock rate of f s2 for 2f s1 rate digital luminance signals (Y) generated by said first digital processing unit (41), for outputting 2f s1 rate digital luminance signals (Y), and a rate converting filter (5) for performing rate conversion of from 2f s1 to f s2 on said 2f s1 rate digital luminance signals (Y), said filter having constant characteristics and said rate converting filter (5) having a variable rate converting ratio.

Claim 23

The solid-state image pickup apparatus as claimed in any of claims 1 to 22 wherein said signal processing means (6) comprises a digital-to-analog converting circuit (6/Y, 6/C R , 6/C B ) for converting the digital luminance signal (Y) and the two digital color difference signals (C R , C B ) generated by said first digital processing means (41) into an analog luminance signal and analog color difference signals, and an analog encoder (62) supplied with said analog luminance signal and analog color difference signals generated by said digital-to-analog converting circuit.

Claim 24

The solid-state image pickup apparatus as claimed in claim 23 comprising a delay compensation circuit in a luminance signal channel of said first digital processing means (41) for compensating the group delay caused by a low-pass filter adapted for bandwidth-limiting on the analog color difference signals in said analog encoder (62).