CN1065396C

CN1065396C - Detecting system for wide screen television

Info

Publication number: CN1065396C
Application number: CN96102537A
Authority: CN
Inventors: 王振中
Original assignee: Acer Computer Co Ltd
Current assignee: Qisda Corp
Priority date: 1996-02-17
Filing date: 1996-02-17
Publication date: 2001-05-02
Anticipated expiration: 2016-02-17
Also published as: CN1157531A

Abstract

The present invention relates to a screen detection system for detecting blanking areas at the upper end and the lower end of a wide screen television. The present invention comprises a comparator, a synchronization circuit, a blanking period detector and a display limit generator, wherein the comparator compares an image signal with a critical value of blanking and generates a positive value signal when the image signal is larger than the critical value of blanking, the synchronization circuit separates vertical synchronization signals from horizontal synchronization signals in the image signal and generates a period signal after each horizontal synchronization signal, the blanking period detector detects the output of the comparator within each period signal and generates a blanking signal when positive value signals do not exist in the output, and the display limit generator determines an upper display limit and a lower display limit according to the distributing situations of blanking signals.

Description

The screen detection system of panavision

The present invention is a kind of screen detection system that is applied in the panavision, refers to a kind of screen detection system that is used for detecting screen upper and lower end blanking zone especially.

Because 16: 9 panavisions are more and more universal, 4: 3 image frames of traditional NTSC system are presented at the consistency problem that panavision on is produced at 16: 9 also come into one's own day by day.In 4: 3 image frame of tradition, regular meeting has the program of 16: 9 image frames to broadcast, for example movie program.Please refer to Figure 1A to Fig. 1 C, Figure 1A shows 4: 3 image frames 10 that include 16: 9 image frames.Picture 10 is made of three zones: be used for showing zone 11 and upper and lower two blanking zones (blankareas) 12 and 13 of 16: 9 image frames, these two blanking zones often are used to show some information, mark or advertisement or the like.Show in the zone 11 one be used for comparing positive circular 14.Figure 1B utilizes existing image display technology that 4: 3 pictures 10 shown in Figure 1A are amplified and straight 16: 9 pictures 15 that convert to via level.The

zone

12 and 13 that in picture 15 Central Plains is picture 10 all is retained, and forms serious oval distortion but be positioned at positive circular 14 of zone 11 because of the level amplification.Fig. 1 C then is 16: 9 pictures that another kind of existing image display technology produced, and remove and reserve area 11 only fully in its

zone

12,13 with original picture 10.This method can be presented at zone 11 on 16: 9 screens really, but can be with 12 and 13 excisions of upper and lower side zone so that can't show any information or image.

Main purpose of the present invention is applied to screen detection system in the panavision flexibly removing in the upper and lower side blanking zone that in image frame occurs at 4: 3 of tradition for providing a kind of, and can not excise any image frame or information.

The object of the present invention is achieved like this, a kind of screen detection system of panavision promptly is provided, be used to detect the blanking zone that is positioned at an image frame upper and lower end in the picture signal of input, this panavision includes 1: 9 screens and an on-screen display system are used for being positioned at a upper end in will the picture signal of input and show that the limit and a lower end show that the image frame between the limit is presented on this screen; This screen detection system includes: (a) comparator is used for this picture signal relatively and a predetermined blanking critical value, if this picture signal then produces one on the occasion of signal greater than this blanking critical value; (b) synchronous circuit is used for separating the vertical and horizontal synchronizing signal in this picture signal, and produces the one-period signal after each horizontal-drive signal; (c) a blanking cycle detector is used for detecting the output of this comparator in each periodic signal, if this comparator does not have on the occasion of signal output among the one-period signal, then this blanking cycle detector can produce a blanking signal; (d) one shows limit generator, is used for deciding this upper end demonstration limit and deciding this lower end to show the limit according to being next to second vertical synchronizing signal blanking signal distribution scenario before according to being next to first vertical synchronizing signal blanking signal distribution scenario afterwards.

For making structure of the present invention, feature and effect can further be understood and understanding, and this paper cooperates preferred embodiment and accompanying drawing to describe in detail as the back:

Brief Description Of Drawings

Figure 1A is 4: 3 image frames of a tradition;

Figure 1B is for amplifying Figure 1A picture level in 16: 9 pictures that get;

Fig. 1 C is for removing 16: 9 pictures that produce with the zone up and down of Figure 1A picture;

Fig. 2 is the system block diagrams of panavision of the present invention and screen detection system thereof;

Fig. 3 is the sequential chart of Fig. 2;

Fig. 4 shows limit generator employed program when the decision upper and lower side shows the limit in the calcspar of Fig. 2;

Fig. 5 is for showing the employed another kind of program of limit generator.

Please refer to Fig. 2.Fig. 2 is the system block diagrams of panavision of the present invention and screen detection system thereof.Fig. 2 shows that this panavision includes:

(1) 1 16: 9 screens 22;

(2) one on-screen display systems 21 are used for showing that with being positioned at a upper end in the picture signal by the input of VIDEO port the limit and a lower end show that the image frame between the limit is presented on this screen;

(3) one screen detection systems 23 are used for detecting the blanking zone that is positioned at an image frame upper and lower end in the picture signal of being imported by the VIDEO port and produce a upper end and show that the limit and a lower end show the limit, and this screen detection system 23 includes:

(a) comparator 24 is used for this picture signal relatively and a predetermined blanking critical value THD, if when the amplitude of this picture signal is higher than this blanking critical value THD then produce one on the occasion of signal at the COMP port;

(b) synchronous circuit 25 is used for and will vertically reaches horizontal-drive signal by separating in this picture signal and by the output of V.SYNC port and H.SYNC port, and this synchronous circuit 25 can produce the one-period signal to the PERIOD port after each horizontal-drive signal;

(c) a blanking cycle detector 26 is used for detecting this output of comparator 24 in each periodic signal, if this comparator 24 does not have on the occasion of signal output in the one-period signal, then this blanking cycle detector 26 can produce a blanking signal to the BLANK port;

(d) a demonstration limit generator 27 is used for deciding the upper end demonstration limit and deciding the lower end to show the limit according to being next to second vertical synchronizing signal blanking signal distribution scenario before according to being next to first vertical synchronizing signal blanking signal distribution scenario afterwards.

Please refer to Fig. 3.Fig. 3 is the sequential chart of panavision shown in Figure 2.The picture signal of being imported by the VID-EO port of Fig. 2 includes vertical synchronizing signal 33, a plurality of horizontal-drive signals 34, and be positioned at each horizontal-drive signal 34 video signal 30 afterwards.If some video signals 30 contain real image, then the amplitude of this video signal 30 can be higher than

A predetermined blanking critical value THD (dotted line is represented).If but it does not contain any image, then its amplitude can be lower than this blanking critical value THD.Comparator 24 can be compared by picture signal and this blanking critical value THD that the VIDEO port is imported, if picture signal greater than this blanking critical value THD, then comparator 24 can produce one on the occasion of signal in the COMP port, for example signal 31.Synchronous circuit 25 can be with vertical synchronizing signal 33 and horizontal-drive signal 34 by separating in the picture signal to produce corresponding vertical synchronizing signal 35 at the V.SYNC port and to produce horizontal-drive signal 36 at the H.SYNC port.In addition, synchronous circuit 25 can produce one-period signal 37 after each horizontal-drive signal 36, and the COMP port of blanking cycle detector 26 meetings detection comparator 24 within each periodic signal 37 does not have image to exist if be detected then can produce a blanking signal 38 in its BLANK port on the occasion of signal to be illustrated in this video signal probably.Certainly, if the time span of periodic signal 37 more near its corresponding video signal length then the accuracy of this detection is also just high more.Show that limit generator 27 will utilize the output of blanking cycle detector 26 and synchronous circuit 25 to decide upper and lower end to show that the limit gets rid of upper and lower

end blanking zone

12 and 13 shown in Figure 1A for on-screen display system 21.

The function that shows limit generator 27 can be finished with a microprocessor, it can judge and produce the upper end and show the limit according to being next to blanking signal distribution scenario after first vertical synchronizing signal, and judges and produce the lower end demonstration limit according to being next to blanking signal distribution scenario before second vertical synchronizing signal.Fig. 4 shows that with Fig. 5 two kinds of different programs decide upper and lower end to show the limit.

Fig. 4 shows limit generator 27 employed program 40 when the decision upper and lower end shows the limit in the calcspar of Fig. 2.Program 40 can be calculated the number that is next to the blanking signal that occurs continuously after first vertical synchronizing signal and show the limit to produce the upper end, and the number that is next to the blanking signal of the continuous appearance before second vertical synchronizing signal shows the limit to produce the lower end.The identification accurately of this method be arranged in an image frame upper and lower end of picture signal the blanking zone so that on-screen display system 21 when showing that this picture signal is in screen 22, can accurately the blanking zone that is positioned at upper and lower end be removed.In program 40, the number of horizontal-drive signal is to represent with H between two vertical synchronizing signals, and variable i is represented paid-in horizontal-drive signal number, and the detected blanking signal number of parameter j representative.Program 40 comprises following steps:

Step 41 is waited for first vertical synchronizing signal;

Step 42 is set i=O; J=O;

Step 43 is set i=i+1 after receiving a horizontal-drive signal;

Whether step 44 detects blanking signal, if do not have then to step 46;

Step 45 is set j=j+1, and to step 43;

Step 46 utilizes the comparison value of j and H to produce the upper end demonstration limit;

Step 47 is set j=O;

Step 48 is set i=i+1 after receiving a horizontal-drive signal;

Step 49 if i=H then to step 53;

Whether step 50 detects blanking signal, if having then to step 52;

Step 51 is set j=O, to step 48;

Step 52 is set j=j+1, to step 48;

Step 53 utilizes the comparison value of j and H to produce the lower end demonstration limit;

Step 54 finishes.

Fig. 5 is for showing limit generator 27 employed another kind of programs 60.Program 60 can the whole predetermined upper area 12 of scanning and lower end area 13 appear among any one zone to have judged whether any information or image.If have any information or image to occur then whole upper area 12 will show with lower end area 13.If but detected video signal major part all is a blanking signal in upper end or lower end area, then should can not shown by whole removal in the zone.Whether have information or image to occur in upper end or lower end area is to be decided by detected blanking signal sum in this zone.If the sum of blanking signal surpasses some predetermined ratios for example 98% o'clock, then the border of zone 11 and upper area 12 or lower end area 13 will be set to the upper end demonstration limit or the lower end demonstration limit among Figure 1A, to remove whole upper area 12 or lower end area 13.The method of this calculating percentage can be avoided when the minority noise appears in upper end or the lower end area, and the position that this noise occurs can by the wrong upper end of regarding as image or the lower end shows the limit.In program 60, the predetermined upper and lower end demonstration limit is represented with TL and BL respectively, the number of horizontal-drive signal then is to represent with H between two vertical synchronizing signals, variable t and b represent that respectively the upper and lower end that will determine shows the limit, variable i is represented paid-in horizontal-drive signal number, and variable j represents paid-in blanking signal number.Program 60 comprises following steps;

Step 61 is waited for first vertical synchronizing signal;

Step 62 is set i=j=O; T=TL (predetermined upper end shows the limit);

Step 63 is set i=i+1 after receiving a horizontal-drive signal;

Whether step 64 detects blanking signal, if do not have then to step 66;

Step 65 is set j=j+1;

Step 66 if i＜TL then to step 67;

If step 67 is (j/TL)＞=98%, then to step 69,

Step 68 is set t=O (top of image frame);

Step 69 is set j=O, b=BL (predetermined lower end shows the limit);

Step 70 is set i=i+1 after receiving a horizontal-drive signal;

Step 71 is as if i＜BL, then to step 70;

Step 72 is set i=i+1 after receiving a horizontal-drive signal;

Whether step 73 detects blanking signal, if do not have then to step 75;

Step 74 is set j=j+1;

Step 75 if i＜H then to step 72;

Step 76 [if j/ (H-BL)]＞=98% to step 78;

Step 77 is set b=H (bottom of image frame);

Step 78 finishes.

The above only is preferred embodiment of the present invention, and all equivalences of doing according to the present patent application change and modify, and all should belong to the protection range of patent of the present invention.

Claims

1, a kind of screen detection system of panavision, be used to detect the blanking zone that is positioned at an image frame upper and lower end in the picture signal of input, this panavision includes 1: 9 screens and an on-screen display system are used for being positioned at a upper end in will the picture signal of input and show that the limit and a lower end show that the image frame between the limit is presented on this screen; This screen detection system includes:

(a) comparator is used for this picture signal relatively and a predetermined blanking critical value, if this picture signal then produces one on the occasion of signal greater than this blanking critical value;

(b) synchronous circuit is used for separating the vertical and horizontal synchronizing signal in this picture signal, and produces the one-period signal after each horizontal-drive signal;

(c) a blanking cycle detector is used for detecting the output of this comparator in each periodic signal, if this comparator does not have on the occasion of signal output among the one-period signal, then this blanking cycle detector can produce a blanking signal;

(d) one shows limit generator, is used for deciding this upper end demonstration limit and deciding this lower end to show the limit according to being next to second vertical synchronizing signal blanking signal distribution scenario before according to being next to first vertical synchronizing signal blanking signal distribution scenario afterwards.

2, screen detection system as claimed in claim 1, this demonstration limit generator are made aforesaid upper end according to the number that is next to the afterwards continuous blanking signal of first vertical synchronizing signal and are shown the limit.

3, screen detection system as claimed in claim 1, this demonstration limit generator are made aforesaid lower end according to the number that is next to the preceding continuous blanking signal of second vertical synchronizing signal and are shown the limit.

4, screen detection system as claimed in claim 1, if when being positioned at ratio that first vertical synchronizing signal and a predetermined upper end show blanking signal number and the horizontal-drive signal number of being received during this between the limit greater than a predetermined ratio, the upper end demonstration limit that this demonstrations limit generator can be scheduled to is set at the aforesaid upper end demonstration limit.

5, screen detection system as claimed in claim 4, this predetermined ratio is 98%.

6, screen detection system as claimed in claim 1, if when being positioned at ratio that a predetermined lower end shows blanking signal number and the horizontal-drive signal number of being received during this between the limit and second vertical synchronizing signal greater than a predetermined ratio, the lower end demonstration limit that this demonstrations limit generator can be scheduled to is set at the aforesaid lower end demonstration limit.

7, screen detection system as claimed in claim 6, this predetermined ratio is 98%.