JPH0411464A - Contour compensation circuit - Google Patents

Abstract

PURPOSE:To attain contour compensation in which preshoot and overshoot are balanced multiplying a contour signal extracted from an original signal and an original signal so as to match the phase of the contour signal extracted from the original signal and the original signal at 1st and 2nd multiplier circuits and adding the result. CONSTITUTION:A contour signal (b) is extracted from an inputted television signal (a) by a contour signal extraction circuit 2 and inputted to a 1st multiplier circuit 5, from which a signal (j) delayed by a delay time tp required for multiplication is obtained. On the other hand, a television signal (c) is inputted to a 2nd multiplier circuit 7 configurated similarly to that of the circuit 5, from which a signal (i) delayed by a delay time tp required for multiplication is obtained. An adder signal 6 adds the television signal (i) and the signal (j) of the same phase as the signal (i). Thus, an inexpensive contour compensation circuit is realized, from which a contour compensation television signal (k) with well-balanced preshoot and overshoot is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a contour compensation circuit (No. Li) exclusively for division.

[Prior art] Figure 3 is a block circuit diagram of a conventional contour compensation circuit.
) is an input terminal for a television signal, (2) is a contour signal extraction circuit, (3) is an input terminal for a signal A that controls contour signal compensation, and (4) is an input terminal for a signal B that controls contrast. (5) is a first multiplication circuit that determines the amplitude of the contour compensation signal by multiplying the contour signal extracted by the contour signal extraction circuit (2) by the contour compensation amount control signal A; (6) is the contour signal extraction circuit; An adder circuit 2 (7) that adds the delay-compensated television signal C output from the circuit (2) and the output signal d of the first multiplier circuit adds the output signal e of the adder circuit (6) and the contrast control signal B. A second multiplier circuit (8) is an output terminal of the second multiplier circuit (7), which determines the amplitude of the television signal by multiplying by .

Next, the operation will be explained. For example, if the television signal a shown in Fig. 4 (a) is input to the input terminal (+1) by human input, the contour signal extraction circuit (2) extracts the contour signal b (shown in Fig. 4 (bl)). , and television 43C (shown in Figure 4(C)) delayed by the delay time caused by this extraction. Although it is possible to obtain an edge-compensated television signal by adding C, it is necessary to externally control the amount of edge compensation depending on the user's preference, etc. Therefore, the edge signal ) and the input terminal (3)
When multiplying by the manually inputted contour compensation amount control signal A,
xAx (contour signal b) (K is a constant) is calculated. The contour compensation signal d passed through the first multiplier circuit (5) is delayed by the time required for operation W, as shown in FIG.
It becomes a signal d like dl. In the adder circuit (6), the television signal C and the contour compensation signal d whose phase is delayed by tP are added, so that the signal e, which has more overshoot than the brished signal, is added as shown in FIG. can get.

In addition, it is generally necessary to externally control the brightness (contrast) of the screen depending on the appearance of the display such as a preview, the user's preference, and the brightness of the installation location. The contour-compensated television signal e is given the second power p(
01 path (7) and is multiplied by a contrast control signal Hj B manually input from the input terminal (4).

2 XBX ((original signal) + +x△×(contour signal)) (K is a constant) The following calculation is performed to obtain a contour-compensated television signal.

[Problems to be Solved by the Invention] Since the conventional contour compensation circuit is configured as described above, it is possible to prevent overshift and overflow caused by adding one contour compensation quantity and the original signal without matching their phases. The problem is that the unbalanced shot makes the display screen look unnatural, and this unnaturalness becomes especially noticeable on high-definition displays, resulting in an unsightly screen.

In order to solve this problem, a configuration may be used in which the original signal is delayed by a delay element, but this may cause problems such as signal deterioration due to the characteristics of the delay element.

This invention was made in order to solve the above-mentioned problems, and it is possible to match the phase of the contour compensation signal and the original signal without providing a new delay element, and it is possible to equalize the preshoot and overshoot. The purpose of this invention is to obtain a contour compensation circuit with good matching.

[Means for Solving the Problems] The contour compensation circuit according to the present invention includes a first multiplier that determines the amplitude of the contour signal extracted from the original signal by the contour extraction circuit, and a first multiplier that determines the amplitude of the original signal. a third multiplier circuit that multiplies the contour signal by the first multiplier; a first multiplier circuit that multiplies the contour signal by the first multiplier; , a second multiplier circuit having a propagation delay time equal to that of the first multiplier circuit, and an adder circuit that adds the output signals of the first and second multiplier circuits.

[Effect]

The contour compensation circuit in this invention has a contour 4rj "'I
The original signal is compensated by passing it through the second multiplier circuit for the same amount of time that is delayed by the propagation delay time of the first multiplier circuit, and then added, so that the contour compensation signal and the original signal are A contour compensation signal whose A1'l phase matches that of the signal is obtained.

[Embodiment of the Invention] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 1st
In the figure, the same components as those of the conventional example shown in FIG. 3 are given the same reference numerals, and the explanation thereof will be omitted.

(lO) is a third multiplier that multiplies the contour compensation amount control signal A, which is the first multiplier, by the contrast control signal, which is the second multiplier, and multiplies the multiplier signal A-, which is the third multiplier. B is input to the first multiplication circuit (5) and multiplied by the contour signal S.

On the other hand, the contrast control signal B is inputted to the second multiplication circuit (7), multiplied by the delay-compensated television signal C, and the amplitude-adjusted television signal 1 and the first multiplication circuit (5) are multiplied by the delay-compensated television signal C. ) is the output of contour compensation (;'I bow'
J and are added in the adder circuit (6), and this addition No. 46 k
is output as a contour-compensated television signal.
・Next, the operation will be explained. The human-generated television signal a (shown in Figure 2 (al)) is processed by the contour signal extraction circuit (
2), the contour signal b (shown in FIG. 2 (bl)) is extracted as in the conventional example. This contour signal b is input to the first multiplication circuit (5), and the delay time tp required for multiplication is on the other hand, the television signal C (shown in FIG. 2(c)) is delayed by a signal such as fjl in FIG. Two multiplication circuits (
7) and is delayed by the delay times t and p required for multiplication, resulting in a signal i as shown in FIG. 2(i). Addition circuit (
6), since the television signal l and the contour compensation signal j having the same phase are added, the contour compensated television signal k with balanced preshoot and overshoot (see FIG. 2( k) is obtained.

In the 12th multiplication circuit (7), (+'>S□;B for controlling the contrast is manually input, K2XHX (K2 is a constant)... (1 ) is being performed.

Further, the first multiplication circuit (5) is supplied with the contrast control signal B to the contour compensation control signal and the third multiplication circuit (10
), the operation p of 3XΔXB (Kl is a constant) is performed and the multiplied signal A-B is manually inputted, and K3XAXBX (contour signal b) - (2
1 operation is being performed.

The adder circuit (6) has completed the addition of 1 to the two signals i shown below, and KM XBX (television signal C) +, xAx
Bx (contour signal b) = BX (K2 x <television word C)
+XAX (contour signal b)) -...(3) is output.

Equation (3) controls the amplitude of the contour compensation (+'t 3 J) using the contour compensation control signal 1, and controls the amplitude of the contour compensated television circle ( This means controlling the amplitude of +1'5 +, and it is possible to control contour compensation and contrast as in the conventional example.

〔Effect of the invention〕

According to this invention, since the contour signal extracted from the original signal and the phase of the redundant signal are combined by multiplication in the first and second multiplier circuits and then added together, the pre-shoot This has the effect of providing an inexpensive contour compensation circuit that can perform contour compensation with a well-balanced balance between the contour and the overshad.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a contour compensation circuit according to an embodiment of the present invention, FIG. 2 is a signal waveform diagram for explaining this embodiment, and FIG. 3 is a block diagram showing a conventional contour compensation circuit. The circuit diagram and FIG. 4 are signal waveform diagrams for explaining this conventional example. (2)...Contour signal extraction circuit, (5), (71,
No)...Multiplication circuit, (6)...Addition circuit. In addition, the same symbols and symbols in each figure indicate the same or equivalent parts, respectively.

Claims (1)

[Claims] (1) A contour signal extraction circuit that sends out a contour signal extracted from a television signal and the original signal delayed by the delay time caused by this extraction; a first multiplier that determines the amount of compensation for the contour signal; and a first multiplier that determines the amount of compensation for the contour signal; a third multiplier circuit that multiplies the contour signal by a second multiplier that determines the amplitude of the signal; and a third multiplier circuit that multiplies the contour signal by a third multiplier obtained by the third multiplier circuit to adjust its amplitude. a second multiplication circuit that multiplies the original signal by the first coefficient to determine its amplitude and delays the output signal by the same amount as the first multiplication circuit; an adder circuit for adding the output signal of the multiplier circuit and the output signal of the second multiplier circuit.