JP2894247B2 - Blanking processing circuit for digital television video signal - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blanking processing circuit for a digital television video signal, and more particularly, to a blanking processing circuit for a digital television video signal for performing a blanking edge waveform processing.

[0002]

2. Description of the Related Art A conventional blanking circuit of this type is known as a circuit for performing waveform processing of a blanking edge.

As a blanking processing circuit, a circuit has been proposed in which roll data is generated by multiplying data at one point immediately before and after blanking by a coefficient of a blanking slope .

[0004]

The object of the invention is to be Solved However, this Hisage
The idea is that role data can be created accurately
Therefore, good blanking processing cannot be performed.

[0005]

Accordingly, an object of the present invention is to store roll data.
It is an object of the present invention to provide a blanking processing circuit for a digital television video signal which can be obtained more accurately .

[0007]

According to the first aspect of the present invention, (a) four data are respectively stored immediately before and after blanking of a digital television video signal.
A data detection unit for sampling at a predetermined sampling period ; and (b) data obtained by these samplings.
First data determination unit that determines data that is larger than the pedestal data and is close to blanking among the data
And (c) of the data obtained by sampling
A second data determination unit for determining data smaller than the pedestal data and close to blanking;
Coefficient for blanking inclination is used in the data of the first data judgment unit
By multiplying by the slope time compensation of the blanking edge.
A first multiplication unit that produces first roll data of the minute,
(E) Blanking inclination for data in the second data determination unit
The slope of the blanking edge by multiplying
Second multiplication producing second roll data for time correction
And parts, and a delay section for delaying the digital television video signal by processing time caused by the first and second multiplication unit (to), except ramp time of (g) blanking edge
The digital television video signal delayed by the delay unit
Select the first row during the blanking edge ramp time.
Digital data delayed by the delay unit
If the first roll data is smaller than the vision video signal,
Digital television set that has been delayed by the delay section.
2nd roll data is larger than version video signal
In this case, select the second roll data and
Revision video signal is larger than second roll data
If it is smaller than the first roll data,
A data selector for selecting a delayed digital television video signal is used to select a digital television video signal.
A ranking processing circuit is provided.

That is, according to the first aspect of the present invention, the data detector detects the polarity of the pedestal level from the data immediately before or immediately after the blanking to the pedestal level.
Creating data of a sexual predetermined time blanking slope,
The data is appropriately selected to perform the waveform processing of the blanking edge of the input digital television video signal. Therefore, it in case the circuit of the present invention was multistage interconnection
Can have, data blanking edges determined in the first stage, when processed in following stages becomes in the range of the limit value of the slope data, digital television video signal input is any processed And the blanking edge does not become steep during multistage coupling .

[0009]

[0010]

[0011]

[0012]

[0013]

[0014]

[0015]

Hereinafter, the present invention will be described in detail with reference to examples.

[0017]

FIG. 1 is a block diagram showing an embodiment of the present invention. In the figure, a blanking processing circuit for a digital television video signal includes a data detection unit 11 and
The apparatus includes a first role data creation unit 12, a second role data creation unit 13, a delay unit 14, and a data selection unit 15.

Here, the input terminal T _i is connected to the data detector 11.
And it is connected to the delay unit 14, a digital television picture signal V _i applied to the input terminal T _i is adapted to be supplied to the data detection unit 11 and the delay unit 14. Further, the data detection unit 11 supplies the sampling pulse S
_p is supplied. The output of the data detection unit 11 is connected to a first roll data creation unit 12 and a second roll data creation unit 13, and the four data extracted immediately before and immediately after the start of blanking are output to the fourth roll data creation unit 13, respectively. The first role data creation unit 12 and the second
Can be supplied to the roll data creation unit 13. The blanking slope coefficient _Sk is input to the first roll data creation unit 12 and the second roll data creation unit 13.

The output of the first role data creation unit 12 and the output of the second role data creation unit 13 are connected to a data selection unit 15 and the created role data is sent to the data selection unit 15. It can be supplied. The output of the delay unit 14 is connected to the data selector 15, the first roll of the input video signal V _i ·
Data creator 12 and second role / data creator 1
Only processing time at 3 to form a video signal V _d which is delayed so as to supply to the data selector 15. The data selector 15 is input roll data output control signal C _r, the delay signal, the first roll data, or one of the second roll data selected digital television video signal V _o so that the can be output to the output terminal T _o as.

Here, the first roll data creation section (first means) 12 determines data which is larger than the pedestal data and close to the blanking period among the four data from the data detection section. First data determination unit 121
And a first multiplying unit 122 that multiplies the data of the first data determining unit 121 by a coefficient for blanking inclination to generate first roll data.

Further, a second role data creation unit (second
Means 13), among the four data from the data detection unit 11, the second data determination unit 131 that determines data smaller than the pedestal data and close to the blanking period.
And a second multiplication unit 132 that multiplies the data of the second data determination unit 131 by a coefficient for blanking inclination to generate second roll data.

The operation of this embodiment will be described. First, the digital television video signal V _i applied to the input terminal T _i is applied to the data detection unit 11 and the delay unit 14. The data detection unit 11, based on the sampling pulse S _p, the input digital television picture signal V
from each _i blanking immediately before and immediately after the end taken out four data, to form the detection data S _a to the pedestal level is subtracted from these data. The detection data _Sa is input to the first role data creation unit 12 and the second role data creation unit 13.

[0023] In the first roll data creation unit 12, the first data determination unit 121 determines the closest data to the blanking positive polarity to the detection data S _a, first data this as S _b supplied to the first multiplier unit 122. If there is no positive polarity data,
The pedestal data and the first data S _b. The first multiplication unit 122 multiplies the first data S _b by a blanking slope coefficient S _k to form positive roll data S _d for the blanking edge slope time correction .

On the other hand, in the second roll data creation unit 13, the detection data S
It determines closest data to the blanking with a negative polarity with respect to _a, and supplies a second data S _c to the second multiplying unit 132. In the case where the negative polarity data does not exist, the pedestal data and second data S _c. Second multiplier 6
In, the second data S _c, by multiplying the blanking inclination factor K, to form a negative role data S _e slope time of the blanking edge correction <br/> min.

The digital television video signal V
_i is the delay unit 14, the delayed digital television picture signal V _d first roll data creation unit 12 and the second roll data processed only takes time of the creation unit 13 is delayed. In the data selection unit 15, the role
The data output control signal C _r, except blanking inclined portion selects and outputs the delayed digital television video signal V _d, and an input digital television video signal V _d which is delayed by a blanking inclined portion, a positive role data (first roll data) S _d, and selects and outputs one of the negative role data (second roll data) S _e.

In the data selector 15, the delayed input digital television video signal _Vd and the positive roll
And data S _d, in a negative role data S _e, to compare such as: size, determines the output signal.

(I) If S _d > V _d > S _e , the signal output from the data selector 15 is a delayed digital television video signal V _d . (Ii) If S _d <V _d , the signal output from the data selection unit 15 is the positive roll data S _d . (Iii) If V _d <S _e , the signal output from the data selector 15 is the negative roll data S _e .

The data output from the data selection unit 15
Digital television video signal V _oIs the output terminal T_oOr
Output from

[0029]

In this embodiment, a first roll data creation unit 12, a second roll data creation unit 13, a delay unit 14, and a data selection unit 15 are provided. Since the limit value of the ranking inclination is provided, even if there is a color signal at a blanking edge, there is no possibility of being converted into a luminance signal .

[0031]

As described above, the invention according to claim 1 is described above.
According to the, you blanking immediately prior to the start by the data detection unit
And four data immediately after completion according to the sampling cycle
It was created by each. And based on these data
And the first of the blanking edge inclination time correction
Creating the second role data . For this reason, books
Inventive digital television video signal blanking
Even if the processing circuits are connected in multiple stages, if the data of the blanking edge determined in the first stage is processed in the subsequent stages, it will be within the range of the limit value of the inclination data and the input digital television video signal Is output without any processing, and the blanking edge does not become sharp at the time of multi-stage coupling. Also, in the present invention , the first and second units, the delay unit and the data selection unit are used for the first and second units.
The limit value of the blanking inclination is provided . others
Because, even if there is a color signal in the blanking edge is outside limit range color signal by the limit data, within the limit range can output a color signal of an input digital television video signal.

[0032]

[0033]

[0034]

[0035]

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a digital television video signal blanking processing circuit of the present invention.

[Explanation of symbols]

11 data detection unit 12 first roll data creation unit 13 second roll data creation unit 14 delay unit 15 the data selection section T _i input terminal T _o output terminal

Claims (1)

(57) [Claims] And 1. A data detector for sampling the digital television video signal blanking immediately before start and end, respectively four data immediately after a predetermined sampling period, or of the data obtained by these sampling
Et al., Larger than the pedestal data, and blanking
A first data determination unit that determines data close to the following, and among the data obtained by the sampling,
小 さ く Smaller than destal data and close to blanking
A second data determination unit that determines the blanking data and a blanking edge slope time compensation by multiplying the data of the first data determination unit by a blanking slope coefficient.
A first multiplication unit for producing first minute roll data, and a coefficient for blanking gradient added to the data of the second data determination unit
By multiplying by the slope time compensation of the blanking edge.
A second multiplying unit for producing second minute roll data, a delaying unit for delaying a digital television video signal by a processing time generated in the first and second multiplying units, and a blanking edge ramp time Otherwise, the delay is delayed by the delay unit.
Select the extended digital television video signal and
The first roll date is used in the ranking edge ramp time.
The digital television set delayed by the delay unit.
If the first roll data is smaller than the
Selected and delayed by the delay unit
If the second roll data is larger than the video signal
In this case, select the second roll data and
The vision video signal is larger than the second roll data
The delay unit if it is smaller than the first roll data
To select the digital television video signal delayed by
And a data selection unit for the digital television video signal.