JPH06165204A - Multiplier and television device - Google Patents

Abstract

PURPOSE:To attain a satisfactory white balance extending from a cutoff level to a high right level by providing at least one theta compensating circuit provided corresponding to an original color signal, and operating the theta compensation of the corresponding original color signal by the theta compensating circuit. CONSTITUTION:This device is equipped with a color separation compensating circuit 12 constituted of a Red theta compensating circuit 12R which operates the thetacompensation of only a red original color signal R, Green theta compensating circuit 12G which operates the theta compensation of only a green original color signal G, and Blue theta compensating circuit 12B which operates the theta compensation of only a blue original color signal B. Each theta compensating circuit 12R, 12G, and 12B constituting the color separation theta compensating circuit 12 operates the theta compensation by a mutually different compensating characteristic according to the theta characteristic of a fluorescent substance in the corresponding color among the fluorescent substances for each color. Therefore, at least one thetacompensating circuit provided corresponding to the original color signal operates the theta compensation of the corresponding one original color signal, so that the thetacompensation optimal to each original color signal can be attained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an amplifier for amplifying a signal and a television device for reproducing a video signal.

[0002]

2. Description of the Related Art Conventionally, in television broadcasting, so-called γ correction is performed so that the output signal is proportional to the (1 / γ) th power of the input signal, as shown in the graph on the left side of FIG. . This is because the relationship between the input signal of the CRT (cathode ray tube) used in many television devices and the display brightness is such that the brightness is proportional to the γth power of the input signal as shown in the graph in the center of FIG. Non-linearity (γ characteristic)
Because it has. As a result of this γ correction, the display brightness on the CRT is ensured to be linear in proportion to the input signal, as shown in the graph on the right side of FIG. 7.

However, the γ characteristic of a CRT is
It will be different depending on the characteristics of the phosphor constituting the RT. Further, in a television device configured to have a display device other than the CRT, such as an LCD (liquid crystal display device), in place of the CRT, the light emission characteristic and the transmission characteristic for an input signal are different from the γ characteristic of the CRT. It has become a thing.

Therefore, conventionally, a television apparatus is provided with a γ compensation circuit, and the γ compensation circuit is configured to electrically compensate the linearity of the display luminance with respect to the input signal, as shown in FIG. Have been proposed.

By the way, the amplifier used also for amplifying the primary color signals sent to the CRT in the above television apparatus is configured as a variable gain amplifier as shown in FIG. That is, this amplifier has four transistors Q ₁ , Q ₂ , Q ₃ , and Q ₄ . A bias voltage V ₁ is applied to the input signal Vin. The transistor Q ₁ is of the NPN type and has an input signal Vin
Is input to the base terminal. This transistor Q ₁
The output terminal of the diode D ₁ is connected to the collector terminal, and the current source 2I ₁ is connected to the emitter terminal via the resistor R ₁ . A bias voltage V ₂ is applied to the input terminal of the diode D ₁ . In addition, the transistor Q
₂ is an NPN type, and the bias voltage V ₁ is applied to the base terminal. In this transistor Q ₂ , the output terminal of the diode D ₂ is connected to the collector terminal, and the current source 2I ₁ is connected to the emitter terminal via the resistor R ₁ . The bias voltage V ₂ is applied to the input terminal of the diode D ₂ .

The base terminal of the transistor Q ₃ is connected to the collector terminal of the transistor Q ₂ . The transistor Q ₃ has a collector terminal to which a bias voltage V ₃ is applied and an emitter terminal to which a current source 2I ₂ is applied.
Are connected. The base terminal of the transistor Q ₄ is connected to the collector terminal of the transistor Q ₁ . The transistor Q ₄ has a collector terminal to which a bias voltage V ₃ is applied via a resistor R ₂ and an emitter terminal to which the current source 2I ₂ is connected. The collector terminal of the transistor Q ₄ is connected to the capacitor C ₁
It is grounded via and is an output terminal from which the output signal Vout is taken out.

In this amplifier, the transistor Q
The input signal Vin is input to ₁ and the transistor Q
Assuming that a current of i ₁ flows due to the resistance R ₁ between ₁ and the transistor Q ₂ , i ₁ = Vin / R ₁ ... (Equation 1) holds. Therefore, the diodes D ₁ and D _{2 are}
The electric currents flowing in the respective lines are I ₁ + i ₁ and I ₁ -i ₁ . Further, due to the output current i ₂ defined as Vout = i ₂ · R ₂ , the currents flowing through the transistors Q ₃ and Q ₄ become I ₂ + i ₂ and I ₂ −i ₂ , respectively.

Here, the V _BE of the transistor is V _BE = V
_From the equation of _T · ln (Ic / Is), the V of each of the transistors Q ₁ , Q ₂ , Q ₃ , and Q ₄ is calculated.
When the _BE and _{V B1, V B2, V B3} , V B4, the following _{as, V B1 + V B4 = V} B2 + V B3 V T · ln (I 1 + i 1 / Is) + V T · ln (I 2 -i _{2 / Is) = V T ·} ln (I 1 -i 1 / Is) + V T · ln (I 2 + i 2 / Is) (I 1 + i 1) (I 2 -i 2) = (I 1 -i 1 ) (I ₂ + i ₂ ) i ₁ · I ₂ = i ₂ · I ₁ i ₂ = i ₁ · I ₂ / I ₁ ······ (Equation 2) Substituting into Equation 1, i ₂ = (Vin / R ₁ ) · I ₂ / I ₁ . When Vout is calculated, Vout = i ₂ · R ₂ = Vin · I ₂ · R ₂ / (I ₁ · R ₁ ) = A · Vin ······· (Equation 3) Output characteristics can be obtained. Here, A is defined as an input / output characteristic. In this amplifier, when it is desired to change the gain, the current i ₂ may be changed.

[0009]

By the way, in a television device provided with a γ compensation circuit as described above, in particular, a so-called three-tube type video projector device and an LCD provided as a display device, FIG. As shown
The γ curves for the three primary colors of R (red), G (green), and B (blue) may not match each other. In such a case, even if the same γ compensation is performed for the above three primary colors, as shown in FIG. 10, it is not possible to secure the linearity of the display luminance for each primary color with respect to the input signal. Therefore, as shown in the graph on the right side of FIG. 10 showing the characteristics of the display luminance after γ-compensation with respect to the input signal, the white balance is adjusted at the cutoff adjustment point (point B) and the highlight adjustment point (point C). Even if the display brightness of each primary color is adjusted to be good, in the intermediate brightness part,
Good white balance cannot be obtained.

Further, in the above-mentioned amplifier, there is a possibility that a good output signal may not be obtained in terms of frequency characteristic (f characteristic) and S / N ratio (signal noise ratio). That is, the frequency characteristic of the output signal is dominated by the parasitic capacitance C ₁ connected to the collector terminal of the transistor Q ₄ . This parasitic capacitance C ₁ is equal to the additional resistance R ₂ and f _CO =
A low-pass filter having a cutoff frequency of 1 / (2πC ₁ R ₂ ) is formed, which becomes a factor of deteriorating the frequency characteristic.

Regarding the S / N ratio, it is necessary to consider shot noise due to the emitter current and thermal noise due to the base resistance as the noise of the transistor. That is, these respective noise sources are equivalently equivalent to the output terminals (cathodes) of the respective diodes D ₁ and D ₂ as shown in FIG.
And the base terminal of each of the transistors Q ₃ and Q ₄ above, and S /
The N ratio is deteriorated.

Therefore, the present invention is proposed in view of the above-mentioned circumstances, and R (red), G (green), B
It is an object of the present invention to provide a television device capable of realizing a good white balance over a highlight level rather than a cutoff level by performing good γ compensation for the three primary colors (blue).

It is another object of the present invention to provide an amplifier which has good frequency characteristics and S / N ratio and is suitable for application to a television device.

[0014]

In order to solve the above-mentioned problems and achieve the above-mentioned object, an amplifier according to the present invention comprises an amplifier for amplifying an input signal, the input signal and a signal amplified by the amplifier. And an adding section for adding and outputting.

Further, the television device according to the present invention is
At least one γ compensation circuit provided corresponding to the primary color signal is provided, and the γ compensation circuit performs γ compensation for the corresponding one primary color signal.

Further, the television apparatus according to the present invention comprises at least one amplifier provided corresponding to the primary color signal, and the amplifier receives the corresponding one primary color signal and amplifies the primary color signal. And an adding section for adding and outputting the primary color signals and the primary color signals amplified by the amplifying section, and amplifying one corresponding primary color signal.

[0017]

Since the amplifier according to the present invention comprises the amplifying section for amplifying the input signal and the adding section for adding and outputting the input signal and the signal amplified by the amplifying section, the necessary gain is obtained. To obtain the gain, the gain in the amplification section can be reduced, and the frequency characteristic and the S / N ratio can be improved.

Further, in the television device according to the present invention, at least one γ-compensation circuit provided corresponding to the primary-color signals performs γ-compensation on the corresponding primary-color signal, and therefore, for each primary-color signal. Even if the γ characteristics are different, optimal γ compensation can be performed for each primary color signal, and good white balance can be realized over the highlight level rather than the cutoff level.

Further, in the television device according to the present invention, the at least one amplifier provided corresponding to the primary color signal has an amplifier for receiving the corresponding one primary color signal and amplifying the primary color signal. A signal and an adder that adds and outputs the primary color signals amplified by the amplifier, and performs amplification for one corresponding primary color signal. Therefore, good frequency characteristics and S / N ratio are obtained for each primary color signal. Can be amplified, and good white balance can be realized over the highlight level rather than the cutoff level.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, the television device has a tuner 2 that receives broadcast radio waves such as VHF, UHF, and BS via an antenna 1. Broadcast radio waves received by the tuner 2 are
Is converted into an intermediate frequency by the video detection circuit 3 and sent to the video detection circuit 3 to be demodulated into a composite video signal by the video detection circuit 3. This composite video signal is sent to the video switch 4. This video switch 4
In addition to the composite video signal, a video signal sent from a recording / reproducing device such as a video tape recorder or a video disc player is input to the video input terminal via the video input terminal.

Each video signal input to the video switch 4 is selected by the video switch 4, and the selected video signal is sent to the Y / C separation circuit 5. The Y / C separation circuit 5 separates the transmitted video signal into a luminance signal Y and a chroma signal C, sends the luminance signal Y to the luminance signal processing circuit 6, and sends the chroma signal C to the color demodulation circuit 7. send. The brightness signal Y is sent to the RGB matrix circuit 8 after being subjected to signal processing such as sharpness processing and DC transmission rate conversion in the brightness signal processing circuit 6. The chroma signal C is output to BY, R by the color demodulation circuit 7.
-Y color difference signals are converted and sent to the RGB matrix circuit 8.

The RGB matrix circuit 8 generates red, green and blue three primary color signals R, G and B from the transmitted luminance signal Y and color difference signals BY and RY, and sends them to the γ compensation circuit 9. . The γ compensation circuit 9 is a circuit that performs uniform γ compensation on each of the primary color signals.

The γ-compensation is performed to ensure such linearity when the linearity of the display luminance of the display device such as a CRT with respect to the input signal cannot be ensured only by so-called γ correction in television broadcasting. It is an electrical process. That is, the γ characteristic of CRT is this CR
Since it depends on the characteristics of the phosphor forming T and the like, the linearity of the display luminance with respect to the input signal cannot be ensured unless γ compensation is performed.

Then, the respective primary color signals which have been gamma-compensated by the gamma compensation circuit 9 are amplified by a CRT drive circuit 10 and sent to a CRT 11 which is a video display device.

Then, in the television apparatus according to the present invention, as shown in FIG. 2, in place of the γ compensation circuit 9, γ compensation is performed only for the red primary color signal R.
A color-specific γ compensation circuit 12 including a dγ compensation circuit 12R, a Green γ compensation circuit 12G that performs γ compensation only on the green primary color signal G, and a Blue γ compensation circuit 12B that performs γ compensation only on the blue primary color signal B is provided. . Each γ compensation circuit 1 that constitutes the γ compensation circuit 12 for each color
2R, 12G, and 12B, as shown in the center graph in FIG. 11, have different compensation characteristics depending on the γ characteristics of the phosphors of the corresponding colors among the phosphors of the respective colors that form the CRT 11. Perform γ compensation.

That is, in this television device, the γ characteristic of each color phosphor in the CRT 11 is
As shown in FIG. 9, even if they do not match each other, FIG.
As shown in the center graph in the middle, γ compensation can be performed for each of the above three primary colors by individual compensation characteristics. Therefore, as shown in the graph on the right side in FIG. 11, for the input signal of the display luminance in the CRT 11 for each primary color signal. It is possible to secure linearity. Therefore, as shown in the graph on the right side of FIG. 11 showing the characteristics of the display luminance after γ compensation with respect to the input signal, each primary color is adjusted so that the white balance becomes good at the cutoff adjustment point and the highlight adjustment point. By adjusting the display brightness of the signal, good white balance can be obtained even in the intermediate brightness part.

The television device according to the present invention is
As shown in FIGS. 3 and 4, both the γ compensation circuit 9 and the color-specific γ compensation circuit 12 may be provided. In this case, the color-by-color compensation circuit 12 may be interveningly connected between the γ compensation circuit 9 and the CRT drive circuit 10 as shown in FIG. 3, and as shown in FIG. ,
An intervening connection may be made between the RGB matrix circuit 8 and the γ compensation circuit 9. Also in these cases, γ-compensation can be performed for the above three primary colors by individual compensation characteristics.

Further, as shown in FIGS. 5 and 6, the television apparatus according to the present invention has the above-mentioned primary color signals R,
A gamma compensation circuit that performs gamma compensation may be provided for only one or two of G and B. Further, in this case, as shown in FIG. 5, it is not necessary to use the γ compensation circuit 9 that uniformly performs the γ compensation on each of the primary color signals, and as shown in FIG. 6, the γ compensation circuit 9 is used together. You may.

That is, in the example shown in FIG. 5, each of the primary color signals R,
Of G and B, the red primary color signal R and the green primary color signal G are sent to the CRT drive circuit 10, and only the blue primary color signal B is sent to the Blue γ compensation circuit 12B. This B
The lue γ compensation circuit 12 B performs γ compensation on only the blue primary color signal B and sends it to the CRT drive circuit 10. Further, in the example shown in FIG.
Among the primary color signals R, G, B uniformly gamma-compensated by, the red primary color signal R and the green primary color signal G are sent to the CRT drive circuit 10, and only the blue primary color signal B is
It is sent to the lueγ compensation circuit 12B. The Blue γ compensation circuit 12B further performs γ compensation on only the blue primary color signal B and sends it to the CRT drive circuit 10.

The television device according to the present invention is
The present invention is not limited to the one having the CRT 11 as shown in the above-mentioned embodiment, and an LCD can be used instead of the CRT 11.
Alternatively, the CRT 11 may be replaced by a so-called three-tube type video projector having a three-tube monochromatic projector.

The amplification of each of the primary color signals in the CRT drive circuit 10 of the television device according to the present invention is carried out separately for each primary color signal by the amplifier according to the present invention. That is, the CRT drive circuit 1
0, three sets of the amplifiers are provided corresponding to the respective primary color signals.

As shown in FIG. 12, the amplifier has an amplifying section 13 which is supplied with the input signal Vin which is the primary color signal and which amplifies the input signal Vin. And
In this amplifier, the input signal Vin is also sent to the adder 14. The adder 14 is supplied with the amplified signal amplified and output from the amplifier 13. The adder 14 adds the input signal Vin and the amplified signal to each other and outputs as an output signal Vout.

In this amplifier, assuming that the gain in the amplifying section 13 is B, the output signal Vout is represented by Vout = (1 + B) · Vin. be able to.

Then, this amplifier is as shown in FIG.
The first to seventh seven transistors Q₁, Q₂, Q
₃, Q_Four, Q_Five, Q₆, Q₇Can be configured using
Wear. The input signal Vin has a first bias voltage V
₁Is applied. The first transistor Q₁Is NP
It is N-type and the input signal Vin is input to the base terminal.
It This first transistor Q₁To the collector terminal
1 diode D₁The output end of is connected to the emitter terminal
The 12th resistor R₁Through the first current source 2I ₁Connected
Has been done. The first diode D₁At the input end of
Second bias voltage V₂Is being applied. Also, above
Second transistor Q₂Is an NPN type,
Bias voltage of 1₁Is applied to the base terminal. this
Second transistor Q₂Is the second die on the collector terminal
Aether D₂Is connected to the output terminal of the
Resistance R₁Via the first current source 2I₁Is connected
ing. The second diode D₂At the input end of
Second bias voltage V₂Is being applied.

Then, the third transistor Q ₃ is
The base terminal is connected to the collector terminal of the second transistor Q ₂ . This third transistor Q ₃ is
The collector terminal and the base terminal of the fifth transistor Q ₅ are connected to the collector terminal, and the emitter terminal is connected to the second current source 2I ₂ . The fifth transistor Q
The _fifth emitter terminal, via a third resistor R _3, the third
Bias voltage V ₃ is applied. In addition, the fourth
The transistor Q ₄ has a base terminal connected to the collector terminal of the first transistor Q ₁ . The transistor Q ₄ has a collector terminal to which a third bias voltage V ₃ is applied via a _second resistor R ₂ , and an emitter terminal to which the second current source 2I ₂ is connected.

The amplifying section 13 is constituted by such a constitution including the _{first to} fourth transistors Q ₁ , Q ₂ , Q ₃ , Q ₄ .

Then, the above-mentioned fifth transistor Q_FiveThe
The source terminal is the sixth transistor Q. ₆Connect to the base terminal of
Has been continued. This sixth transistor Q₆Emi
To the third bias voltage V
₃Is applied, the collector terminal receives the output signal Vout
It is an output terminal that is output. Also, this sixth tiger
Register Q₆To the collector terminal of the fifth resistor R_FiveThrough
Then, the seventh transistor Q₇The emitter terminal of is connected
Has been. This 7th transistor Q₇Is the base terminal
Is supplied with the above input signal Vin, and the collector terminal is grounded
Has been done.

As described above, the seventh transistor Q ₇
The adding unit 14 is configured to include the above.
That is, in this amplifier, the output current i ₂ of the amplification section 13 flows through the fifth resistor R ₅ by the current mirror circuit composed of the fifth and sixth transistors Q ₅ and Q ₆ . The fifth resistor R ₅ functions as a load resistor, like the resistor R ₂ in the conventional amplifier shown in FIG. Therefore, the gain of the amplifying section 13 is obtained by replacing R ₂ in the above (Equation 3) with R ₅ . Then, the input signal Vin passes through the buffer of the seventh transistor Q ₇ , is output at the same level, passes through the fifth resistor R ₅ , is added to the output of the amplifying unit 13, and is output as the output signal. It becomes Vout.

By the way, comparing the above-mentioned (Expression 3) showing the output signal Vout in the above-mentioned conventional amplifier with the above-mentioned (Expression 3) showing the output signal Vout in this amplifier, when Vout is made equal, A = 1 + B B = A-1 ... (Equation 5) is established. Therefore, the gain of the amplifier unit 13 of the amplifier according to the present invention may be reduced by -1 as compared with the conventional amplifier. For example, if the gain of the amplifier as a whole is 2, the gain of the amplification section 13 becomes 1.

Therefore, in the amplifier according to the present invention, the resistance value of the second resistor R ₂ which is a factor for determining the gain can be lowered, and the cutoff frequency f _CO = 1 / ( 2πC ₁ R ₁ ) can be increased. That is, the frequency characteristic is improved.

Considering the S / N ratio, the noise source in the amplifier according to the present invention is equivalently shown in FIG.
As shown in FIG. 3, noise sources V _N1 , V _N2 , V are respectively provided at the output terminals of the first and second diodes D ₁ , D ₂ and the base terminals of the third and fourth transistors Q ₃ , Q _{4. N3} , _VN4
Will exist. These noise sources V _N1 , V _N2 ,
When a geometric mean value of V _N3, V _N4 and V _N, the noise level in the output signal Vout and _{V N0, V N0 = V N} · R 2 / 2r E ···········・ (Equation 6) Here, r _E is the third and fourth transistors Q
₃ and Q ₄ are the emitter resistance values. Here, _assuming that the noise level in the amplifier according to the present invention is V _N0 ′, since the gain B of the amplification unit 13 is A (gain of conventional amplifier) −1, from the above (Equation 6), V _N0 '= _VN0 (A-1) / A ... (Equation 7) That is, the noise level has been reduced.

In the amplifier according to the present invention, since the adder unit 14 is composed of a resistance matrix, no noise is generated in the adder unit 14, and the noise level of the entire amplifier is the above-mentioned V _N0 ′. Become. Therefore,
In the amplifier according to the present invention, the output signal Vout is
The noise level is reduced when is constant, and the S / N ratio is improved.

The amplifier according to the present invention can not only be used as a variable gain amplifier by making each of the current sources I ₁ and I ₂ variable, but also by fixing these current sources I ₁ and I ₂ to a gain. It can also be used as a constant amplifier.

[0044]

As described above, in the television apparatus according to the present invention, at least one γ compensation circuit provided corresponding to the primary color signal performs γ compensation for the corresponding primary color signal. Therefore, in this television device, even if the γ characteristic is different for each primary color signal, optimal γ compensation can be performed for each primary color signal, and it is better than the cutoff level over the highlight level. You can achieve excellent white balance.

Further, in the television apparatus according to the present invention, at least one amplifier provided corresponding to the primary color signal has an amplifier for receiving the corresponding primary color signal and an amplifying section for amplifying the primary color signal. A signal and an addition unit that adds and outputs the primary color signals amplified by the amplification unit,
Amplification is performed for one corresponding primary color signal. for that reason,
In this television device, good frequency characteristics and good S / N ratio amplification can be performed for each primary color signal, and good white balance can be realized from the cutoff level to the highlight level.

The amplifier according to the present invention comprises an amplifier for amplifying the input signal and an adder for adding and outputting the input signal and the signal amplified by the amplifier. Therefore, in this amplifier, the gain in the amplifying section can be reduced to obtain the required gain, and the frequency characteristic and the S / N ratio can be improved.

That is, according to the present invention, good gamma compensation can be performed for the three primary colors of R (red), G (green), and B (blue), so that a good white balance over the cutoff level to the highlight level is realized. It is possible to provide a television device that can be used.

Further, the present invention can provide an amplifier which has good frequency characteristics and S / N ratio, and which is suitable even when applied to a television device.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a television device.

FIG. 2 is a block diagram showing a configuration in the vicinity of a color-specific γ compensation circuit which is a main part of a television device according to the present invention.

FIG. 3 is a block diagram showing an example in which a color-specific γ compensation circuit, which is a main part of a television device according to the present invention, is arranged in a portion different from the example shown in FIG.

FIG. 4 is a block diagram showing a main part of an example in which the television apparatus according to the present invention is configured to use a conventional γ compensation circuit in combination.

FIG. 5 is a block diagram showing an example in which the television apparatus according to the present invention is configured by providing a γ compensation circuit for only one primary color signal.

FIG. 6 is a block diagram showing an example in which the television apparatus according to the present invention is configured by using a γ compensation circuit for only one primary color signal and a conventional γ compensation circuit.

FIG. 7 is a graph illustrating the principle of γ correction performed in broadcast radio waves.

FIG. 8 is a graph illustrating the principle of γ compensation performed in the television device.

FIG. 9 is a graph illustrating a difference in γ characteristic of each color phosphor in a CRT of a television device.

FIG. 10 is a graph illustrating a problem that occurs when γ compensation is uniformly performed on each primary color signal.

FIG. 11 is a graph illustrating the principle of γ compensation in the television device according to the present invention.

FIG. 12 is a block diagram showing a configuration of an amplifier according to the present invention.

FIG. 13 is an equivalent circuit diagram showing the position of a noise source in an amplifier.

FIG. 14 is a circuit diagram showing a configuration of an amplifier according to the present invention.

FIG. 15 is a circuit diagram showing a configuration of a conventional amplifier.

[Explanation of symbols]

 9 ... γ compensation circuit 10 CRT drive circuit 11 CRT 12 ...... gamma. Compensation circuit for each color 12R ..... Red.gamma. Compensation circuit 12G .................. Green.gamma. Compensation circuit 12B ..・ ・ ・ Blue γ compensation circuit 13 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Amplifying unit 14 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Adding unit

Claims (3)

[Claims] 1. An amplifier comprising: an amplifier for amplifying an input signal; and an adder for adding and outputting the input signal and the signal amplified by the amplifier. 2. A television device comprising at least one γ compensation circuit provided corresponding to a primary color signal, wherein the γ compensation circuit performs γ compensation for the corresponding one primary color signal. 3. An at least one amplifier provided corresponding to the primary color signal, wherein the amplifier receives the corresponding one primary color signal and amplifies the primary color signal and the primary color signal and the amplification section. A television device having an adding section for adding and outputting the primary color signals amplified by, and amplifying the corresponding one primary color signal.