JPS5843667A - Display device - Google Patents

Abstract

PURPOSE:To execute display of a zebra pattern by a simple constitution, by displaying a level of a digital signal when a prescribed host bit has coincided with a specific code, in a device which has digitized a video signal. CONSTITUTION:Prescribed host 5 bits in a luminance signal Y among, for instance, 8 bits which is supplied to a terminal 1 are supplied to a code detecting circuit 11, and whether they coincide with a prescribed code or not is decided. In case of coincidence, its bits y3, y4 are converted to codes y3', y4' of bits decided in advance, of a digital signal, by a code converting circuit 12. Subsequently, among 8 bits of the luminance signal Y, a signal of y3', y4' are substituted for the bits y3, y4, and are outputted from a terminal 8. Accordingly, even in case of a device which is digitized a video signal, display of a zebra pattern can be executed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for displaying a so-called zebra pattern in which a predetermined level range of an Eirin signal is displayed in a light and dark striped pattern, for example in a vinyl finder of a television camera. The present invention provides a device suitable for digitizing and processing images.

In the so-called IRI unit, where the pedestal level is 0 and the white peak level is 100, the brightness of human skin is approximately 6.
It is not considered that the value is close to s~ysIR1K. The zebra pattern compensation is superimposed on range 11 of 6s to 75IR1ii in the image signal taken at
l! As shown, the aperture etc. are adjusted.

In that case, in the conventional anada signal, the luminance signal 4#Y supplied to the terminal (1)K is
It is supplied to the IDc regeneration circuit (2) for DC regeneration.

This signal is supplied to a wind lamp comparator (3) consisting of three comparison circuits and an AND circuit that detect @IIRI or more and 75IR1ii or less, and a signal in the range of C6S to 711ILl is taken out.This comparison output is sent to an AND circuit (4).
At the same time, it is supplied to the AND circuit (4) through one terminal (5) of a Kutsk signal Ttl of a predetermined phase for displaying a zebra pattern. With this AND output, 11 I
A switch (6) to which a signal of level 11 is supplied is controlled. The signal from this switch (6) and the luminance signal 4#Y are added together in an adder circuit (7), and the IC is taken out from the terminal (8).

This extracted video signal is the vinyl finder (II
6s of the projected image
It is possible to display a zebra pattern on the axis of ~7iIR1.

In this way, a zebra pattern can be displayed in line 5 in the analog signal.

There is also a demand for displaying a zebra pattern similar to that of a star in television cameras that digitize and process video signals. However, in that case, the window comparator (3) as described above may be configured with a digital circuit, or
If you try to mix signals using a digital addition circuit, etc.
The circuit is extremely complicated and costs a lot of money.

In view of these points, the present invention is intended to enable a zebra pattern to be displayed even on a digital television camera with a simple configuration.

In the case of digitizing the video signal using ζ, it has been proposed to quantize the signal from the sync step level to the white beater level by dividing it into 200 units.

The present invention is based on such quantization-11 quasi-1. An embodiment of the present invention will be described below with reference to the drawings.

The following table shows the correspondence between lR11i units and the above-mentioned quantization values. Note that the lower row of quantized values is expressed as a decimal value.

Minimum value 6s and maximum value 1 of zebra pattern display with F and ζ
s is simply a number standard.

It's not an absolute value.

On the other hand, when detecting a range as described above using binary values, all lower arbitrary bits of the minimum value in a predetermined range are rOJ
So, if all the lower bits of the same maximum value are "1", then
There is no need to compare that part, and if you can determine whether the higher level pin 1) is a specific food or not, bar 1) 5.

There is no practical problem even if it is done as follows.

In this case, the binary values of 9$ and 100111 are respectively 5-iaet 500111, that is, the lower 3 bits of the minimum value in the display range are ``OO・'' , the lower 3 bits of the maximum value are r 111 J
It is. Therefore, in the detection of this range, the top f)l hit is "10011 J or r too too
If it is determined that it is j', it is possible to detect the range from 1 to 7.

Furthermore, in this example, the smell sentence, zebra pattern [1[1m
``er 1 @ J (approximately 1111 m) wo addition f4.
J or l” 10100 When added to the value of J,
10O1laarar + 0・010(10
11 companies 1・■11s5...Enjoyment...(!)
10nIzaa + 00・toooo.

-・・・・・・12) Proverb 1011・sss, becomes, ζt″e (1) In ni, 1 from the top,
4 bits are changed from rolJl to rl@Jk: Formula (112) and Vc are the same (only the 3.4th bit from the top changes from rl. to rllJk).

That's the number! In II, the high-order bit of the brightness signal Y#)^ supplied to the terminal (1) is supplied to the =-de-detection-path*lK, and this S bit is r1@011.
"J or f 101.0" to determine whether it is being fed. Furthermore, 3 or 4 bits from the top of the luminance signal Y) are supplied to the rich conversion garden road a21, and 1. ! -Discrimination IF from code detection circuit 1-! #, a command signal 2 displaying a zebra pattern, and a tart signal T are supplied to the wealth conversion circuit.

In this =-code conversion Il loop, during the period when command note 2 and tartuta signal IT are "1", the 3rd and 4th signals are r
From olJ to “1o” Aruiha “1o” to “11” =
−Convert. Then, of the luminance signal Y08 bits, the 3.4th bit from the top is replaced with a signal from the code conversion circuit a, and a signal is output to the terminal (8).

In other words, in the =- code detection circuit 01), when the signal of the upper 5 bits F is [ylyz yl y4 yl J, 11・11・7j'F4"71"Lly yl In ζζ, which performs a logical operation, the symbol (・) indicates and.

Furthermore, in the KW-code conversion circuit a2, y@'m Z * T @ LH+ yl14'm Z
*T*(Lt+Ls) Performs the logical operation of $y4. In ζζ, (+) indicates OR, and (e) indicates extal-sive OR.

Therefore, in this circuit, when the upper s bit of the luminance signal Y is r 10011 J, LA becomes "1" K, and r
When 10100 J, L8 becomes rlJ. SaraKyl
' becomes "1" when Ll is rlJ, and y4' becomes "1" or "
1'' to rOJl/C.

As a result, the level of the luminance signal Y is 65.1 to 7.
In the range of 4 IRI, a bright and dark zebra pattern of about 111 ILE is displayed.

ζ5 The level is displayed using a zebra pattern, but according to the present invention, it is possible to display a 4-turn zebra in a device that digitizes a video signal. In that case, it can be extremely easily configured using only a simple logic circuit, without requiring complicated window comparators, digital adder circuits, etc.

In the present invention, the circuit can be further simplified by defining the display range of the zebra pattern as follows.

In this case, MURI and MU! The two-way value of m is O-10100000 AF m 10101111. Therefore, when detecting the display range, the upper 4 bits are
It is sufficient to detect that it is 1010 J, and furthermore, the superposition of the zebra pattern is performed by detecting the 4th bit from the top from rOJ to r
All you have to do is convert it to lJ.

Therefore, in Fig. S, the upper four bits F of the luminance signal Y are supplied to the soot detection circuit (o'), and these four bits are [H].
10 Distinguish between J and Jin. That is, yl・3・y
Perform the logical operation of the instruction y4 Wx,1.

Further, the fourth bit y4 from the top of the luminance signal Y is supplied to the code conversion circuit (B), and the above-mentioned discrimination output L' and command signal 2. Code conversion circuit (Ig)
and converts the 4th bit ;- code from rOJ to "1". That is, the logical operation y4'Z@T@L'+74 is performed.

Then, a signal in which the fourth bit from the top of the luminance signal Y08 bits is replaced with a signal from the hood conversion circuit (XZ) is outputted to a terminal (8)K.

Therefore, in this circuit as well, the level of the luminance signal Y is 71
．． 4～1ull IILI Nohan 1iKTh I? , about 1
The light and dark zebra pattern of lIRI is displayed.

According to the present invention, it is possible to display a zebra pattern with an extremely simple configuration in a device that digitizes a video signal.

[Brief explanation of drawings]

Tuna ill is a configuration diagram of a conventional device, FIG. 17g2 is a configuration diagram of an example of the present invention, and FIG. 3 is a configuration diagram of another example. aυ is a code detection circuit, and Q3 is a code conversion circuit. Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] A display device configured to convert a predetermined bit of the digital signal from a =- code and display the level of the digital signal when a predetermined upper bit of the digital signal matches a specific - code.