Facsimile and static presentation processing – Facsimile – Specific signal processing circuitry
Patent
1987-03-12
1989-03-28
Chin, Tommy P.
Facsimile and static presentation processing
Facsimile
Specific signal processing circuitry
358181, H04N 5268, H04N 5272
Patent
active
048169153
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
The present invention relates particularly to an interlace control circuit for two-picture television receiver which displays two different images on one display screen.
BACKGROUND ART
Hitherto, the two-picture television receiver has been realized in various circuit types. The interlace control circuit is one of the arts necessary for realizing it. That is, in television broad-cast images, one image consists of one frame which is a combination of a first field and a second field; and in order to display two different images (frequencies and phases of their synchronization signals are different each other) on the same picture, it is necessary to make an agreement in field relation between these two. It is the interlace controlling circuit which realizes this.
First, elucidation is made on the interlace controlling circuit of a conventional two-picture television receiver. FIG. 1 is a schematic view of the two-picture television receiver. In the figure, numeral 31 is a televisions receiver, numeral 32 is a main-picture, numeral 33 is a sub-picture which is compressed and synthesized in one part of the main-picture 32.
FIG. 2 is a block diagram of the conventional two-picture television receiver. In the figure, numeral 41 is a cathode-ray tube (hereafter is abbreviated as CRT), numeral 42 is an input terminal whereto an image signal for the main-picture is applied to, and numeral 43 is an input terminal whereto an image signal for the sub-picture is applied. For instance, in a television receiver having two tuners, an image signal made by detecting output signal of the one tuner is applied to the one input terminal 42, an image signal made by detecting and processing output signal of the other signal is applied to the other input terminal 43. And, in a television receiver having one tuner and an input terminal, whereto an image signal output from external apparatus, for instance, video tape recorder or video disc player and so on is impressed, the one image signal is that from the tuner and the other one is from the above-mentioned external apparatus.
Numeral 44 is a circuit part for processing the image signal of the main-picture, numeral 45 is a circuit part for processing image signal of the sub-picture, numeral 46 is an output line of the main-picture processing circuit part 44, numeral 47 is an output line of the sub-picture operation circuit part 45, numeral 48 is a two-input-one-output switch, and numeral 49 is an output line for a signal to deflect CRT 41.
Hereafter, operation of the above-mentioned constitution is elucidated. When the switch 48 is connected to the terminal A, the image signal for the main-picture is conveyed to the CRT 41. When the switch 48 is connected to the terminal B, the image signal for the sub-picture is conveyed to the CRT 41. That is, the switch 48 is connected to the terminal B only when the CRT 41 is scanning by the deflection signal at the part of the sub-picture 33 of FIG. 1. In the sub-picture processing circuit part 45, mainly the following two processings are carried out against the sub-picture image signal inputted from the input terminal 43.
(1) To synchronize with deflection signal of the CRT 41.
(2) To compress the image into the size of the sub-picture 33.
For this purpose, a memory becomes necessary for the sub-picture processing circuit 45. There is prior art, for instance, disclosed in the Gazette of Japanese unexamined published patent application No. Sho 54-156420, which realizes such function by a circuit including two field memory parts.
Hereafter, the above-mentioned conventional sub-picture processing circuit part 45 is explained with reference to FIG. 3. In the drawing, numeral 43 is the input terminal of the image signal for the sub-picture, numeral 47a is the output terminal of the image signal of the sub-picture processing part 45, and numeral 49a is an input terminal of the image signal of the main-picture. Numeral 51 is a field polarity detection part of the sub-picture, numeral 52 is a detection part of the main-picture field
REFERENCES:
patent: 3652790 (1972-03-01), Eberhardt
patent: 4172264 (1979-10-01), Taylor
patent: 4249213 (1981-02-01), Imaide
patent: 4665433 (1987-05-01), Hinson
patent: 4665438 (1987-05-01), Miron
patent: 4673983 (1987-06-01), Sarugaki
patent: 4680630 (1987-07-01), Field
Imai Kiyoshi
Kawashima Kazumi
Chin Tommy P.
Matsushita Electric - Industrial Co., Ltd.
LandOfFree
Two-picture television receiver does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Two-picture television receiver, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Two-picture television receiver will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1663844