JPH10210385A - Display - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control the luminance in a prescribed and that in another area, independently of each other. SOLUTION: Basically, a luminance control circuit 11 is provided for producing plural luminance control signals and selectively switching them. Then a 1st voltage generation circuit 15 is added to variably set a 1st luminance control signals V1 which controls the luminance in a prescribed area of a display screen with a 2nd voltage generation circuit 16 which variably sets a 2nd luminance control signal V2 to control the luminance in an area, other than the prescribed area. Then the circuit 11 includes a selection circuit 13 which fetches the position information signals X (XH, XL), which synchronize with the horizontal scanning period of a video signal and also show period corresponding to the prescribed area and another of the display screen at different voltage levels, selects one of 1st and 2nd luminance control signals based on the signals X, and outputs the selected luminance control signals to a video processing circuit 4. Thus, the luminance in a prescribed area and that of another area are controlled independently of each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display-related technique, and more specifically, to a brightness control technique for changing the brightness of an arbitrary area of a display screen.

[0002]

2. Description of the Related Art Conventionally, in a display using, for example, a cathode ray tube, the brightness of an arbitrary area (for example, a window for displaying a moving image) on a display screen is increased, and the maximum luminance of an image such as a moving image displayed in the area is increased. , Thereby improving the image quality. Image brightness control is generally performed by varying the voltage level of a brightness adjustment signal input to a video processing circuit that adjusts the amplitude of a video signal. Therefore, in order to increase the luminance of an arbitrary area of the display screen, as described in JP-A-60-39685, JP-A-2-22695, etc., position information indicating an arbitrary high-luminance area of the display screen is used. According to the signal,
This can be realized by increasing the voltage level of the luminance adjustment signal input to the video processing circuit.

In other words, a brightness control signal for adjusting the voltage level of a video signal corresponding to a predetermined area to be higher in accordance with the timing of horizontal scanning is created. For example, a luminance adjustment signal V ₁ for adjusting a brightness of a predetermined area, while setting the two variable voltage signal of the sub-brightness control signal V ₂ to adjust the brightness of the area other than the predetermined area, represents the position of a predetermined region Therefore, it has a time axis synchronized with the horizontal scanning cycle of the video signal, and position information in which the signal level of the period corresponding to the predetermined region and the signal level of the period corresponding to the other region are changed to high H and low L, respectively. Set the signal X ( _{XH, XL} ). When a luminance control signal V is generated by adding them, a luminance control signal V (H) corresponding to a predetermined area and a luminance control signal V (L) corresponding to another area are expressed by the following equations, respectively. Becomes This is input to the video processing circuit and V
(H), the amplitude of the video signal is adjusted according to V (L).

V (H) = V ₁ + V ₂ + X _H (1) V (L) = V ₁ + V ₂ + X _L (2)

[0005]

However, in the above-mentioned prior art, there is a problem that the luminance in a predetermined area and the luminance in other areas cannot be adjusted independently. In other words, the formula (1), is (2) As is apparent from, the higher the voltage level of V ₁ in an attempt to increase the brightness of the predetermined area, higher levels of other regions brightness control signal V (L) Would.

Further, in the case of a general cathode ray tube display, in order to limit the beam current, an automatic beam current limiting signal (hereinafter, referred to as an ABL signal) having a voltage level that changes according to the detected average beam current is output, and the luminance is output. The control is performed such that the ABL signal is subtracted from the control signal to lower the luminance as a whole. With this control, the brightness of the predetermined area is increased to some extent, but the brightness of the other areas is reduced, and in some cases, V (L) becomes almost zero level, and images other than the predetermined area are lost. There's a problem.

Therefore, a first object of the present invention is to make it possible to independently adjust the luminance of a predetermined area and the luminance of another area.

A second object of the present invention is to prevent the image from being lost even if the level of the luminance control signal is limited by the average beam current, in addition to the first object.

[0009]

In order to solve the above-mentioned first problem, the present invention basically comprises providing a luminance control circuit for generating a plurality of luminance adjustment signals and selectively switching between them. It is characterized by.

Specifically, a video processing circuit having a function of adjusting the amplitude of a video signal according to a luminance control signal, and a display screen on which an image corresponding to the video signal output from the video processing circuit is displayed And a brightness control circuit for outputting a brightness control signal for controlling the brightness of the display image on the display screen to a video processing circuit, the first brightness adjustment signal for adjusting the brightness of a predetermined area of the display screen. And a second voltage generation circuit variably setting a second brightness adjustment signal for adjusting the brightness of an area other than the predetermined area. A position information signal synchronous with the horizontal scanning cycle and representing a period corresponding to a predetermined area and another area of the display screen at different voltage levels is fetched, and first and second signals are obtained based on the position information signal. Characterized by comprising a selection circuit for outputting to a video processing circuit selects one of the brightness control signal. Thereby, the brightness of the predetermined area can be independently adjusted by the first voltage generation circuit, and the area other than the predetermined area can be independently adjusted by the second voltage generation circuit.

In this case, the display screen is a cathode ray tube, and a beam current detection circuit for detecting a beam current of the cathode ray tube and outputting an ABL signal (automatic beam current limiting signal) of a voltage level corresponding to the average beam current is provided. ,
By providing a multiplier for multiplying the ABL signal by the luminance control signal output from the selection circuit, it is possible to limit the beam current while maintaining the relative relationship between the luminance in a predetermined area and the luminance in other areas. Therefore, the second problem can be solved. In this case, the ABL signal has a value smaller than “1”.

A third voltage generation circuit for variably setting a third luminance adjustment signal for adjusting the luminance of the display screen;
It is preferable to provide a low-level selection circuit that selects and outputs the low value of the luminance adjustment signal and the ABL signal, and multiplies the output of the low-value selection circuit with the luminance control signal by a multiplier. That is, when the predetermined area is small, the beam current does not increase so much even if the luminance is set high.
Although it is possible to adjust the brightness to a considerably high level without much restriction by the signal, there is a problem that the brightness balance of the entire display screen is rather deteriorated. In this regard, the third brightness adjustment signal is variably set, and the smaller of the ABL signal and the third brightness adjustment signal can limit the average brightness of the entire image. Can be appropriately adjusted.

Instead of the above-mentioned means, a first voltage generating circuit for variably setting a first brightness adjustment signal for adjusting the brightness of an area other than a predetermined area of the display screen, and adjusting a bias of the brightness of the display screen. A second voltage generation circuit for variably setting a second brightness adjustment signal to be provided, wherein the brightness control circuit includes an adder for adding the first brightness adjustment signal to a position information signal in a predetermined area; And a multiplier for multiplying the output by the second luminance adjustment signal.

Also in this case, a low value selection circuit for comparing the second luminance adjustment signal with the ABL signal of the cathode ray tube and selecting and outputting a low value is provided. The output of the low value selection circuit is used as an output of the adder. Preferably, the output is multiplied to generate a brightness control signal.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on embodiments. (First Embodiment) FIG. 1 is a block diagram showing a first embodiment of a display according to the present invention. In FIG. 1, a color video signal including a red video signal R, a green video signal G, and a blue video signal B is input to a video processing circuit 4 via input terminals 1, 2, and 3, respectively. The video signal processed by the video processing circuit 4 is applied to the cathode of the cathode ray tube 6 via the video output circuit 5. The horizontal synchronization signal and the vertical synchronization signal of the video signal are supplied to the horizontal deflection circuit 9 and the vertical deflection circuit 1 via input terminals 7 and 8, respectively.
Input to 0. The horizontal deflection circuit 9 and the vertical deflection circuit 10 allow a sawtooth-shaped deflection current synchronized with the synchronization signal to flow through the deflection coil 11 of the cathode ray tube 6.

On the other hand, the brightness control circuit 12 is provided with a selection circuit 13, and the selection circuit 13 has a predetermined area (for example, a window) on the display screen whose brightness is to be higher than other areas from the input terminal 14. ), The position information signal X having information for specifying the position, and the variable voltage generation circuits 15 and 16.
High brightness adjusting signal V ₁ and the sub-brightness control signal V ₂ is input from. The position information signal X has a time axis synchronized with the horizontal scanning cycle of the video signal, and has different voltage levels (for example, different periods) corresponding to a predetermined area and another area of the display screen.
H, X _H, expressed in binary signal) of L, consisting of X _L. Then, the selection circuit 13 selects the high-brightness adjustment signal V ₁ during the period T of X _H corresponding to the predetermined area according to the position information signal X (X _H , X _L ), and selects X corresponding to the other area. _L period of selecting the sub-brightness control signal V _2, and outputs to the video circuit 4 so as brightness control signal. FIG.
The high voltage output circuit 19 supplies high voltage power to the anode of the cathode ray tube 6, and the power supply circuit 20 supplies power to each circuit of the display.

The operation of the embodiment constructed as described above will be described below. First, a video signal input to the input terminals 1, 2, 3 is converted into a signal having a required amplitude by the video processing circuit 4 and the video output circuit 5, and is applied to the cathode of the cathode ray tube 6. As a result, an electron beam is generated from the cathode, and the electron beam is scanned by a deflection coil 11 controlled by a horizontal deflection circuit 9 and a vertical deflection circuit 10, and an image corresponding to a video signal is displayed on a display screen.

Next, a brightness control circuit 1 which is a feature of the present invention.
Operation 2 will be described. The brightness control circuit 12 creates a brightness control signal V for adjusting the amplitude of the video signal based on the position information signal X, the high brightness adjustment signal V ₁ , and the sub brightness adjustment signal V ₂ , and outputs the brightness control signal V to the video processing circuit 4. . Thereby, the gain of the video processing circuit 4 is adjusted, and a video signal having an amplitude corresponding to the luminance control signal is output. As shown in FIG. 2A, the position information signal X is a signal having a time axis synchronized with the horizontal scanning cycle of the video signal, and during a period T corresponding to a predetermined area of the display screen, the voltage level is high. _H
And the voltage level is low X during the period corresponding to the other region.
_It is a binary signal that becomes _L. In addition, as shown in FIG. 2B, the high luminance adjustment signal V ₁ is the sub luminance adjustment signal V ₂
Set to a higher value. Then, the selection circuit 13
Based on the position information signal X is input, select V ₁ corresponding to the period T of X _H is a predetermined region to be higher luminance, corresponding to X _L is other area select V _2, The luminance control signal V (V ₁ , V ₂ ) having the waveform shown in FIG. Video processing circuit 4, the amplitude corresponding to the period T of the input video signal shown in the FIG. 2 (d), by increasing the output in response to the high luminance adjusting signal V ₁ as shown in shown in FIG. 2 (e) . As a result, the brightness of a predetermined area such as a window is displayed higher than the brightness of other areas.

As described above, according to the embodiment of FIG. 1, the high-brightness adjustment signal and the sub-brightness adjustment signal are independently variably set in correspondence with the predetermined area and the other area.
Since the brightness control signal is created by switching these in the selection circuit 13 based on the position information signal, the brightness of the predetermined area and the brightness of the other area can be independently and variably adjusted.

(Second Embodiment) FIG. 3 is a block diagram showing a display according to a second embodiment of the present invention. The circuit configuration of the brightness control circuit 12 is different from that of the embodiment of FIG. 1, and this embodiment solves the problem particularly when the limitation by the ABL signal related to the limitation of the beam current is applied. That is, as shown in FIG. 3, the point that a voltage generating circuit 21, a limiter circuit 22, and a multiplier 23 are provided is different from FIG. Other components are the same as those in FIG.

The voltage generating circuit 21 controls a maximum average luminance adjustment signal V ₃ for adjusting the maximum level of the average luminance of the entire display screen.
Is variably set, and the maximum average brightness adjustment signal V ₃
Are input to the limiter circuit 22. The high voltage output circuit 19 detects a beam current of the cathode ray tube 6 and inputs an ABL signal V ₄ having a voltage level corresponding to the detected beam current to the limiter circuit 21 in order to limit the beam current. Limiter circuit 22 compares the maximum average luminance adjustment signal V ₃ and the ABL signal V _4, and selects and outputs the signal of either smaller, is formed of a so-called low value selection circuit. The multiplier 23 multiplies the luminance control signal V output from the selection circuit 13 by the output of the limiter circuit 22 and outputs the luminance control signal V ′ subjected to the limiter processing to the video processing circuit 4.
Output.

The operation of the embodiment configured as described above is as follows.
This will be described with reference to the waveform diagrams of the signals of the respective units shown in FIG. In FIG. 4, (a) is a horizontal period waveform of the position information signal X for specifying the position of the predetermined area to be increased in brightness, which is the same as FIG. 2 (a). (B) a solid high luminance adjusting signal V ₁ of the waveform to adjust the brightness of the high brightness region, the broken line sub luminance adjustment signal V ₂ of the waveform, (c) the brightness control signal V output from the selection circuit 13 waveform, (d) is the highest average luminance adjustment signal V ₃ of waveform, (e) is a waveform of the ABL signal V ₄ outputted from the high voltage output circuit 19 is adjusted by the voltage generating circuit 21. (F) and (g) are the waveforms of the limiter-processed luminance control signal V ′ output from the multiplier 23, (h) is the waveform of the video signal input to the input terminals 1, 2, 3, and (i) (J) is an output waveform of the video processing circuit 4.

The selection circuit 13 of the luminance control circuit 12
And outputs a luminance control signal V having the waveform shown in FIG. Here, in order to independently vary the luminance of the predetermined area to be increased in luminance and the luminance of the other areas, the high luminance adjustment signal V ₁ is adjusted by the voltage generation circuit 15, and the auxiliary luminance adjustment signal is adjusted by the voltage generation circuit 16. performed by adjusting the V _2. On the other hand, the limiter circuit 22, the maximum average luminance adjustment signal V ₃ shown in FIG. 4 (d), comparing the ABL signal V ₄ shown in FIG. 4 (e), the luminance limit lower of the voltage signal V _L Output as That is, the luminance of the entire display screen, so as to limit the voltage highest average luminance adjustment signal V ₃ or set by generating circuit 21, or to any lower level ABL signal V ₄ to limit the beam current. Next, the brightness control signal V output from the selection circuit 13 is multiplied by the brightness control signal V _L obtained by limiting the maximum value output from the limiter circuit 22 by the multiplier 23, and the brightness control signal V _L subjected to the limiter processing is multiplied. 'And outputs it to the video processing circuit 4. FIG. 4F shows the ABL signal V ₄
Is a luminance control signal V 'when the restriction by
In Figure 4 (g) is a luminance control signal V 'when worked limited by ABL signal V _4. The luminance control signal V ′ controls the gain of the video processing circuit 4, and the amplitude of the input video signal (FIG. 4 (h)) is converted as shown in FIG. 4 (i) or (j). Are output to the video output circuit 5. Here, comparing (f) and (g) of FIG.
In (g), the maximum value of the output of the multiplier 23 is reduced in (g) due to the restriction by the ABL signal.
Since the voltage ratio of V ₁ and V ₂ is a luminance adjustment signal and the predetermined region to be higher brightness other area has not changed, the relative relationship between the brightness of both regions is maintained. The video processing circuit 4 uses the luminance control signal V 'thus created.
To control the input video signal (h)
Is controlled as shown in (i), and the brightness is controlled as shown in (j) even when the average beam current of the cathode ray tube 6 increases and the limitation by the ABL circuit operates.

As described above, according to the present embodiment, in addition to the effect of the embodiment of FIG. 1, there is no problem that video information in a region other than a predetermined region to be increased in luminance is lost. The effect that reproducibility does not deteriorate is obtained.

(Third Embodiment) FIG. 5 is a block diagram showing a display according to a third embodiment of the present invention. This embodiment is different from the embodiment of FIG. 3 in that the voltage generation circuit 15 for generating the high brightness adjustment signal V ₁ is omitted, and the sub-brightness adjustment signal V ₂ and the position information signal X are replaced with the selection circuit 13.
Is added to generate the luminance adjustment signal V. The other points are the same as those of the embodiment of FIG. 3, and therefore, the same reference numerals are given and the description is omitted.

Here, the operation of the present embodiment will be described with reference to the signal waveform diagrams of the respective parts shown in FIG. Adder 2
4 is a position information signal X ( _XH , _XL ) shown in FIG.
And the sub-brightness adjustment signal V ₂ shown in FIG. 4B are added to obtain a luminance having a high voltage level in the waveform T shown in FIG. The control signal V is output. That is, in the period T, V = X
A luminance control signal V having a waveform of _H + V ₂ and V = X _L + V ₂ in other periods is output to the multiplier 23. The operation of the limiter circuit 22 is the same as that of the embodiment of FIG. 6D and 6E show the voltage levels of the maximum average luminance adjustment signal V ₃ and the ABL signal V ₄ , respectively. The multiplier 23 multiplies the luminance control signal V output from the adder 24 by the luminance limit signal _VL which is the output of the limiter circuit 22 and limits the maximum value.
A luminance control signal V ′ subjected to the limiter processing is created and output to the video processing circuit 4. FIG. 6F shows the ABL signal V
₄ 'a, (g) in FIG. 6 is the brightness control signal V when worked limited by ABL signal V _4' by the luminance control signal V when the limit is not work is. This brightness control signal V ′
Thus, the video signal (FIG. 6 (h)) input to the video processing circuit 4 is converted into (i) or (j) in FIG.
Output to the video output circuit 5. As is clear from FIG. 6, the present embodiment also provides the same effects as the embodiment of FIG.

(Fourth Embodiment) FIG. 7 shows a block diagram of a fourth embodiment of the display according to the present invention. This embodiment is different from the embodiment of FIG.
, A basic brightness control signal V is created by multiplying the high brightness adjustment signal V ₁ by the position information signal X, and the sub brightness adjustment signal V ₂ is added by an adder 26. The addition to the highest average luminance adjustment signal V ₃ and the addition of an adder 27 on the output side of the multiplier 23 add the output of the limiter circuit 22 to the luminance control signal V ′ subjected to the limiter processing to have a DC bias. I had to do it.

The operation of the embodiment configured as described above is as follows.
The operation will be described with reference to the operation waveform diagrams of the respective units shown in FIG. 8 (a) shows the output of the adder _{26 (V 2 + V 3)} , (b), (c) respectively show examples of the ABL signal limiting the beam current is large V ₄ 'smaller ABL signal V ₄ ,
(D) is a luminance control signal V (= X
_H × V ₁ ). Output of the adder 26 (V ₂ + V ₃ )
Corresponds to a luminance adjustment signal for limiting the maximum luminance. 5E and 5G show the luminance control signal V ′ output from the multiplier 23, and the former shows the output (V ₂
+ V ₃ ), the latter being ABL
A case where limited by signal V _4. (F) and (h) show the luminance control signal V ″ output from the adder 27. The former shows the case where the output (V ₂ + V ₃ ) of the limiter circuit 22 is added to (e). The latter is a case where the output V ₄ of the limiter circuit 22 is added. By the luminance control signal V ″, the video signal (FIG. 8 (i)) input to the video processing circuit 4 is obtained as shown in FIG. It is converted to (j) or (k) and output to the video output circuit 5.
As is clear from FIG. 8, this embodiment also provides
The same effect as that of the embodiment can be obtained.

[0029]

As described above, according to the display of the present invention, the brightness of a predetermined area and the brightness of another area can be independently adjusted. By independently adjusting the luminance, there is an effect that the image quality can be improved.

Further, even when the restriction by the ABL signal is applied, there is no problem that image information is lost in an area other than the predetermined area to be increased in brightness, so that an image with good tone reproducibility is provided. There is an effect that can be.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a first embodiment of a display according to the present invention.

FIG. 2 is a signal waveform diagram of each section for explaining the operation of the embodiment of FIG. 1;

FIG. 3 is a block diagram showing a second embodiment of the display according to the present invention.

FIG. 4 is a signal waveform diagram of each section for explaining the operation of the embodiment of FIG. 3;

FIG. 5 is a block diagram showing a third embodiment of the display according to the present invention.

FIG. 6 is a signal waveform diagram of each unit for explaining the operation of the embodiment of FIG. 5;

FIG. 7 is a block diagram showing a fourth embodiment of the display according to the present invention.

8 is a signal waveform diagram of each section for explaining the operation of the embodiment of FIG. 7;

[Explanation of symbols]

4 video processor circuit 6 CRT 12 brightness control circuit 13 selecting circuits 15, 16, 21 voltage generation circuit 19 high-voltage output circuit 22 limiter circuit 23, 25 Multiplier 24, 26, 27 adders X, X _H, X _L position information signal V, V ', V "brightness control signal V ₁ high brightness control signal V ₂ sub luminance adjustment signal V ₃ highest average luminance adjustment signal V _4, V _4' ABL signal

Claims (7)

[Claims] A video processing circuit having a function of adjusting an amplitude of a video signal according to a luminance control signal; a display screen on which an image corresponding to a video signal output from the video processing circuit is displayed; A brightness control circuit for outputting the brightness control signal for controlling the brightness of the display image on the display screen to the video processing circuit; a first brightness adjustment signal for adjusting the brightness of a predetermined area of the display screen A first voltage generation circuit that variably sets the brightness and a second voltage generation circuit that variably sets a second brightness adjustment signal that adjusts the brightness of an area other than the predetermined area, wherein the brightness control circuit comprises: A position information signal synchronized with a horizontal scanning cycle of a video signal and representing a period corresponding to a predetermined region and another region of the display screen at different voltage levels is taken in, and based on the position information signal, The Te first and second
A selection circuit for selecting one of the luminance control signals and outputting the selected signal to the video processing circuit. 2. The display according to claim 1, wherein the display screen is a CRT, and a beam current detection circuit for detecting a beam current of the CRT and outputting a beam current signal having a voltage level corresponding to the beam current. Prepared,
A display, comprising: a multiplier for multiplying the beam current signal by a luminance control signal output from the selection circuit. 3. The display according to claim 2, wherein a third voltage generation circuit variably sets a third luminance adjustment signal for adjusting the luminance of the display screen, and the third luminance adjustment signal and the beam. A low-level selection circuit for selecting and outputting a low value of the current signal, wherein the multiplier multiplies the output of the low-value selection circuit by the brightness control signal by the multiplier. 4. A video processing circuit having a function of adjusting the amplitude of a video signal according to a luminance control signal, a display screen on which an image corresponding to the video signal output from the video processing circuit is displayed, A brightness control circuit that outputs the brightness control signal for controlling the brightness of the display image on the display screen to the video processing circuit, wherein a brightness of an area other than a predetermined area of the display screen is adjusted. A first voltage generation circuit that variably sets a luminance adjustment signal; and a second voltage generation circuit that variably sets a second luminance adjustment signal that adjusts a bias of the luminance of the display screen. Fetching a position information signal synchronized with a horizontal scanning cycle of the video signal and representing a period corresponding to a predetermined area and another area of the display screen at different voltage levels; Wherein a first adder for adding the luminance adjusting signal, a display, characterized in that shall become and a multiplier for multiplying said second luminance adjusting signal to the output of the adder No.. 5. The display according to claim 4, wherein the display screen is a cathode ray tube, and a beam current detection circuit for detecting a beam current of the cathode ray tube and outputting a beam current signal of a voltage level corresponding to the beam current. Prepared,
The brightness control circuit selects a low value of the second brightness adjustment signal and the low value of the beam current signal and outputs the low value. An output of the low value selection circuit is output from the adder by the multiplier. A display characterized by multiplying by. 6. A cathode ray tube having a video processing circuit having a function of adjusting the amplitude of a video signal according to a luminance control signal, and a display screen on which an image corresponding to the video signal output from the video processing circuit is displayed. A brightness control circuit that outputs the brightness control signal for controlling the brightness of a display image on the display screen to the video processing circuit; a beam current signal having a voltage level corresponding to the beam current, detecting a beam current of the cathode-ray tube And a beam current detection circuit for outputting a first brightness adjustment signal for adjusting a brightness of a predetermined area of the display screen in a display configured to limit a level of the brightness control signal based on the beam current signal. A first voltage generation circuit that variably sets a voltage, and a second voltage generation circuit that variably sets a second luminance adjustment signal that adjusts luminance of an area other than the predetermined area. And a third voltage generation circuit variably setting a third brightness adjustment signal for adjusting a bias of brightness of the display screen, wherein the brightness control circuit is synchronized with a horizontal scanning cycle of the video signal, and A first multiplier that takes in a position information signal representing a period corresponding to a predetermined region and another region of the display screen at different voltage levels, and multiplies the position information signal by the first luminance adjustment signal; A first adder for adding the second and third brightness adjustment signals, a low value selection circuit for comparing the output of the adder with the beam current signal and outputting a low value, and the low value selection circuit And a second multiplier for multiplying the output of the first multiplier by the output of the first multiplier, and a second adder for adding the output of the low value selection circuit to the output of the multiplier. A display, characterized in that: 7. A display comprising a brightness control circuit for displaying brightness of a predetermined area of a display image at a brightness different from that of another area, wherein the brightness control circuit has a function of independently adjusting the brightness of each area. A display characterized by becoming.