JPS6097786A - Television receiver - Google Patents
Television receiverInfo
- Publication number
- JPS6097786A JPS6097786A JP20624683A JP20624683A JPS6097786A JP S6097786 A JPS6097786 A JP S6097786A JP 20624683 A JP20624683 A JP 20624683A JP 20624683 A JP20624683 A JP 20624683A JP S6097786 A JPS6097786 A JP S6097786A
- Authority
- JP
- Japan
- Prior art keywords
- circuit
- signal
- supplied
- luminance
- correction
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N5/00—Details of television systems
- H04N5/44—Receiver circuitry for the reception of television signals according to analogue transmission standards
- H04N5/57—Control of contrast or brightness
- H04N5/58—Control of contrast or brightness in dependence upon ambient light
Landscapes
- Engineering & Computer Science (AREA)
- Multimedia (AREA)
- Signal Processing (AREA)
- Television Receiver Circuits (AREA)
Abstract
Description
【発明の詳細な説明】
産業上の利用分野
この発明はテレビジョン受像機に関し、特にその内面上
におけるコントラストを改善する技術に関する。DETAILED DESCRIPTION OF THE INVENTION Field of the Invention This invention relates to television receivers, and more particularly to techniques for improving contrast on their inner surfaces.
背景技術とその問題点
一般にテレビl!I血を外光のあるところご見ると、輝
度信号が黒レベルになるほど、二Sントラストが悪化す
ることが知られ′ζいる。Background technology and its problems Generally speaking, television l! It is known that when viewing blood in the presence of external light, the contrast becomes worse as the luminance signal becomes black.
第1図はそのコントラストの低1−について実験をした
結果をボずグラフで、横軸は輝度信号のレベル(瞬時レ
ベル)を示し、縦軸は受像管の管面から目に入射する先
の量、ずなわぢ受像管の発光による光と、外光の管面で
の反射による光との)Uの光量を不ず。Figure 1 is a box graph showing the results of an experiment with low contrast, where the horizontal axis shows the level (instantaneous level) of the luminance signal, and the vertical axis shows the intensity of the signal that enters the eye from the surface of the picture tube. The amount of light (U) of the light emitted by the picture tube and the light reflected from the outside light on the tube surface.
この第1図碇おいて、曲線L1は暗室時の特性で、輝度
信号のレベルと受像管の管面からの光の暖がljlにな
っているので、輝度信号レベルの黒から白までコントラ
ストが一定の良好な画面となる。In this anchor in Figure 1, curve L1 is the characteristic in a dark room, where the level of the luminance signal and the warmth of the light from the picture tube surface are ljl, so the contrast from black to white at the luminance signal level is The result is a consistently good screen.
一方、曲線L2は外光があるときの特性で、輝度信号が
黒レベルになるほどコントラストが悪くなって恋つぶれ
の現象を起こす。この現象は外光量が強くなるほど強く
なる。On the other hand, curve L2 is a characteristic when there is external light, and as the luminance signal becomes black level, the contrast worsens, causing a phenomenon of falling in love. This phenomenon becomes stronger as the amount of external light increases.
そこで、輝度信号系に、第2図の曲線Co、C1゜C2
,C3で不ずような人出力特性の非線形補正回路を設け
、外光があるときは、輝度信号の黒方向の振幅を伸長し
、白方向の振幅を圧縮するように補止し°ζ、第1図で
曲線L3で丞ずような特性を得てコントラストを改善す
るようにすることが考えられた。Therefore, in the luminance signal system, curves Co, C1°C2 in Fig. 2 are used.
, C3 is provided with a non-linear correction circuit for normal human output characteristics, and when there is external light, the amplitude of the luminance signal in the black direction is expanded and the amplitude in the white direction is compressed. It was considered that the contrast could be improved by obtaining a characteristic similar to that of the curve L3 in FIG. 1.
すなわち、補正前の輝度信号(横軸)をX、補正後の輝
度信号(縦軸)をyとすると、y=xγ(+≦γ≦1)
とすると共に、外光MLに対応して乗数γを制御し°乙
補止曲線を外光量が明るいほど曲線03側となるように
すれば外光があゲζも、あるいは、その外光量りが変化
しても良好なコントラストを得ることができるわけであ
る。That is, if the luminance signal before correction (horizontal axis) is X and the luminance signal after correction (vertical axis) is y, then y=xγ (+≦γ≦1)
At the same time, if we control the multiplier γ in accordance with the external light ML so that the brighter the external light amount is, the closer the compensation curve B is to the curve 03 side, the external light will increase ζ, or the external light amount will change. This means that good contrast can be obtained even if the contrast changes.
ところが、このように外光量の大きさのみで非線形補止
を行なうと、画面が暗いシーンでは非電に効果的であっ
たが、明るいシーンでは白っぽい感じになっcしまい逆
効果になることが判明した。However, when performing non-linear correction based only on the amount of external light, it was effective in reducing non-electromagnetic effects in dark scenes, but it turned out to have the opposite effect in bright scenes, giving a whitish appearance. did.
これは、自レベル時には外光の有無が管曲の明るさに大
きな影響を与えないのに、黒レベルがら白レベルまで一
怠的に非線形補正しCいるため、輝度信号レベルが必要
以上に大きくなっcしまうこと及び白レベルのコントラ
ストとし′(は小さくなってしまうことが原因である。This is because, although the presence or absence of external light does not have a large effect on the brightness of the tube at its own level, non-linear correction is performed from the black level to the white level, making the brightness signal level higher than necessary. This is because the contrast of the white level becomes small.
そごで、外光量の大きさのみごなく、人力信号の平均輝
度レベルを検出し”C1平均輝度レベルがll11いと
きには非線形補止を弱くする方法が考えられた。Therefore, a method was devised in which the average brightness level of the human input signal is detected, regardless of the amount of external light, and when the C1 average brightness level is low, the nonlinear correction is weakened.
第3図はその場合の例で、映像検波回路(11)からの
輝度信号Yがクランプ回路(12)に供給され°ζベデ
スタルクランゾされた後、非線形補正回路(13)に供
給される。この補正回路(13)は第2図にポしたよう
な補止特性を有する。Figure 3 shows an example of such a case, where the luminance signal Y from the video detection circuit (11) is supplied to the clamp circuit (12), subjected to Bedestal clamping, and then supplied to the nonlinear correction circuit (13). . This correction circuit (13) has correction characteristics as shown in FIG.
また、外光量りの検出素子例えばCd5(14)が設け
られ、これよりの光検出出力が検出回路(15)に供給
され、これより外光量の検出信号St、が得られる。こ
の場合、この検出fば号SLは第4図に示すような特性
の信号である。この信号SLは乗算回路(16)にイハ
給される。Further, a detection element for detecting the amount of external light, for example Cd5 (14), is provided, and the light detection output from this is supplied to a detection circuit (15), from which a detection signal St of the amount of external light is obtained. In this case, the detected f-signal SL is a signal with characteristics as shown in FIG. This signal SL is supplied to a multiplication circuit (16).
一方、クランプ回v8(12)からの輝度信号がAPL
検出回路(17)に供給されζこれより平均輝度レベル
の検出信号SPは第5図にネオような特性の信号である
。この信号Spも乗算回路(16)に供給される。On the other hand, the luminance signal from the clamp circuit v8 (12) is APL
The detection signal SP of the average luminance level supplied to the detection circuit (17) is a signal with characteristics as shown in FIG. This signal Sp is also supplied to the multiplication circuit (16).
したがって、乗算回路(16)からは信号SLと信号S
pとの乗算信号SMが得られ、この信号3Mが補止回路
(13)に供給されζその補正特性が制御される。この
場合、外光量りが大きくなるほど、補正量は大きくされ
るが、このとき、APLが大きくなるほど、つまり平均
輝度レベルが商くなるほど補正量は小さくされ、APL
がある程度以上大きければ外光量の変化に関係なく補正
量は零となるようにされる。Therefore, from the multiplication circuit (16), the signal SL and the signal S
A signal SM multiplied by p is obtained, and this signal 3M is supplied to the correction circuit (13) to control its correction characteristic. In this case, the larger the amount of outside light, the larger the correction amount is.At this time, the larger the APL, that is, the more the average luminance level becomes the quotient, the smaller the correction amount is.
If is larger than a certain level, the correction amount is set to zero regardless of changes in the amount of external light.
そして、このように補止された輝度信号がピクチャーコ
ントロール回路(18)及び映像出力回路(19)を介
し”ζ受像管(20)に供給される。ここで、ピクチャ
ーコントロール回路(18)では映像出力回路(19)
からの管曲の明るさに応じたABL信号によって輝度信
号振幅が度えられる。またピクチャーボリューム(18
νP)が使用者によっ゛ζ操作されることにより同様に
輝度信号振幅が変えられるものである。The brightness signal supplemented in this way is then supplied to the ζ picture tube (20) via the picture control circuit (18) and the video output circuit (19). Output circuit (19)
The brightness signal amplitude is increased by the ABL signal corresponding to the brightness of the tube curve. Also picture volume (18
Similarly, the brightness signal amplitude can be changed by manipulating νP) by the user.
以−ヒのように、人力輝度信号のAPLを検出し、AP
Lが商いときには補正を弱めるようにすることにより、
明るいシーンで画面が白っぽくなるのが改善される。As shown below, the APL of the human brightness signal is detected and the AP
By weakening the correction when L is quotient,
Improves screen appearance in bright scenes.
ところが、第3図の例では、?ili止回路の後段に、
上記のように輝度信号の振幅を制御するピクチャーコン
トロール回路が入るため、ABL等によりこのコントロ
ール回路で補正された信号の振幅が変えられてしまうこ
とにより人力信号のAPLと管面の明るさとの対応がな
くなってしまい、管面はlllいのにコントラスト補止
が働かないというような不都合が生しる。However, in the example in Figure 3, ? After the ili stop circuit,
As mentioned above, since there is a picture control circuit that controls the amplitude of the luminance signal, the amplitude of the signal corrected by this control circuit is changed by ABL etc., so the correspondence between the APL of the human input signal and the brightness of the screen surface is changed. This results in inconveniences such as the contrast correction not working even though the tube surface is very dark.
発明の目的
この発明は上記欠点を改善し°乙いかなる外光条件でも
、いかなるシーンでもコントラストの良好な画面が得ら
れるようにしたものCある。Purpose of the Invention The present invention improves the above-mentioned drawbacks and makes it possible to obtain a screen with good contrast in any scene under any outside light conditions.
発明の概要
この発明は、へ1月、を検出−4る代わりに受像管の管
曲の平均輝度を検出し、外光量が大きくζも管面の平均
輝度が+Iliりれば非線形補止を少なくJるようにコ
ントロールすることにより、いがなる外光条件でも、ま
た、いがなるシーンでも最適な肉質が得られるようにし
たものである。Summary of the invention This invention detects the average luminance of the tube curve of the picture tube instead of detecting -4, and performs nonlinear correction if the amount of external light is large and the average luminance of the tube surface increases +Ili. By controlling the amount of meat to a minimum, optimal meat quality can be obtained even under harsh external light conditions and in harsh scenes.
実施例
第6図はこの発明の一実施例のゾロツク図で、この例に
おいては、映像検波回路(21)からの輝度信号はピク
チャーごlントロール回II (22> ニ供給され、
映像出力回路(24)からの受像管(25)の管面の輝
度に応したABL信号によりこの輝度信号振幅が制御さ
れる。このピクチャーコントロール回路(22)からの
出方信号は第2図の特性のような補正特性の非線形補正
回路(23)に供給される。そし゛乙後述するように非
線形補正された後、映像出力回路(24)を通じて受像
管(25)に供給される。(22VR)は使用者が辿F
調節するためのピクチャーボリュームである。Embodiment FIG. 6 is a diagram of an embodiment of the present invention. In this example, the luminance signal from the video detection circuit (21) is supplied to the picture control circuit II (22),
The amplitude of this brightness signal is controlled by an ABL signal from the video output circuit (24) that corresponds to the brightness of the tube surface of the picture tube (25). The output signal from this picture control circuit (22) is supplied to a nonlinear correction circuit (23) having a correction characteristic as shown in FIG. Then, after being subjected to non-linear correction as described below, it is supplied to the picture tube (25) through the video output circuit (24). (22VR) is traceable by the user.
This is the picture volume for adjustment.
そして、映像出力回路(24)がらのABL信号が管面
の平均輝度検出回路(26)にイハ給される。The ABL signal from the video output circuit (24) is then fed to the average luminance detection circuit (26) on the tube surface.
この検出回路(26)は例えば抵抗(26R)とコンデ
ンサ(26C)との積分回路がらなり、これよりの管面
平均輝度検出電圧sBは、第7図にボずように輝度が高
いほどその絶対値が小さくなるように出力されるように
される。This detection circuit (26) consists of, for example, an integrating circuit consisting of a resistor (26R) and a capacitor (26C), and the tube surface average brightness detection voltage sB from this circuit increases as the brightness increases, as shown in Figure 7. The output is made so that the value becomes smaller.
こうして得られた管面の平均輝度検出電圧は乗算回路(
29)に供給される。The average luminance detection voltage of the tube surface obtained in this way is calculated by the multiplier circuit (
29).
一方、外光量の検出素子(27)からの信号が検出回路
(28)に供給され°乙これより第4図に小ずような特
性の外光量の検出信号St、が得られ、これが乗算回路
(29)に供給さJl、る。On the other hand, the signal from the external light amount detection element (27) is supplied to the detection circuit (28), and from this, an external light amount detection signal St having characteristics as shown in FIG. (29) is supplied to Jl,ru.
したがって、乗算回118(29)からは信号sBと信
号St、との乗算信号SM’が得られ、この信号SN’
が制御電圧とし°C補正回路(23)に供給される。Therefore, a multiplication signal SM' of the signal sB and the signal St is obtained from the multiplication circuit 118 (29), and this signal SN'
is supplied as a control voltage to the °C correction circuit (23).
この場合、補1F回路(23)はその制御車jLの絶対
値が大きいほど非線形性が強くなるように補正される。In this case, the complementary 1F circuit (23) is corrected so that the greater the absolute value of the controlled vehicle jL, the stronger the nonlinearity becomes.
よっ°ζ、この制御により、外光9が強くても管面平均
輝度が商ければ非線形補+Eは弱くなるようにされる。Therefore, with this control, even if the external light 9 is strong, if the tube surface average luminance is equal to the average brightness, the nonlinear complement +E is made weak.
なお、この例におい′Cはクランプ回路は設&Jられて
いないが、これは管面平均輝度検出電圧を既に直流電圧
になっているA B L電圧から検出しCいるためであ
る。In this example, a clamp circuit is not provided, but this is because the tube surface average brightness detection voltage is detected from the ABL voltage, which is already a DC voltage.
第8図はこの発明の他の例で、この例においζは、AB
L電圧の代わりにピクチャーコントロール回路(22)
の出力電比が管面平均輝度検出回路(26)に43(給
される。他は第6図例と同様である。FIG. 8 shows another example of this invention, in which ζ is AB
Picture control circuit (22) instead of L voltage
The output voltage ratio of 43 is supplied to the tube surface average brightness detection circuit (26).Others are the same as in the example shown in FIG.
ただ、この例の場合、映像検波回路(21〕 とピクチ
ャーコントロール回路(22)との間にクランプ回路(
31)が設りられる。この例は、へBLL信号によりピ
クチ+−コントロールb!J路(22ンの出力は一定の
ABL量になるように制御されていることを利用した例
である。However, in this example, a clamp circuit (
31) will be established. This example uses the BLL signal to control picture+-b! This is an example that takes advantage of the fact that the output of J road (22) is controlled to have a constant ABL amount.
なお、第6図及び第8図の例で、ピクチャーコントロー
ル回路(22)において、コントロールボリュームを使
用者が絞っ°ζ使用し°(いる場合に、外光が入ると、
管面の平均輝度検出電圧の絶対値が商くなっているので
、補止回IIJt(23)の人力信号の振幅が小さくな
っていることと相俟つ゛ζコントラスI・アソグの機能
とし“ζも働くものである。In the examples shown in FIGS. 6 and 8, if the user is using the control volume at the picture control circuit (22) and using external light,
Since the absolute value of the average brightness detection voltage on the tube surface is a quotient, this is combined with the fact that the amplitude of the human input signal in compensation circuit IIJt (23) is small. It also works.
発明の効果
この発明によれば、輝度信号のA P Lを検出する代
わりに管面の平均輝度を検出し、それと外光量の大きさ
とに応じ′ζ非線形補正をするようにしたので、目で見
たときの管面の明るさに対応した最適なコントラスI−
補正ができるものである。Effects of the Invention According to the present invention, instead of detecting the APL of the luminance signal, the average luminance of the tube surface is detected, and non-linear correction is performed according to that and the amount of external light. Optimal contrast I- corresponding to the brightness of the tube surface when viewed
This can be corrected.
第1図は外光存在1ζにおけるテレビジョン受像機のコ
ントラスト低−トについ゛この実験結果を示す図、第2
図はそのコントラスト低トの補止方法を説明するための
図、第3図は従来のテレビジョン受像機の一例のブロッ
ク図、第4図及び第5図はその説明のための図、第6し
1はこの発明の一実施例のブロック図、第7図はその説
明のだめの図、第8図はこの発明の他の例のブロック図
ζある。
(23)は非線形補止回路、(26)は受像管の管面の
平均輝度検出回路、(27)は外光量検出素子、(29
)は補止回路(23)の制御電圧を得る乗算回路である
。Figure 1 is a diagram showing the results of this experiment regarding the low contrast of a television receiver in the presence of external light 1ζ.
3 is a block diagram of an example of a conventional television receiver, FIGS. 4 and 5 are explanatory diagrams, and 6 1 is a block diagram of one embodiment of the present invention, FIG. 7 is a diagram for explaining the same, and FIG. 8 is a block diagram ζ of another embodiment of the present invention. (23) is a nonlinear compensation circuit, (26) is an average brightness detection circuit for the tube surface of the picture tube, (27) is an external light amount detection element, (29)
) is a multiplication circuit that obtains the control voltage of the supplementary circuit (23).
Claims (1)
る回路と、この制御回路の後段に設けられ、上記輝度信
号に対し゛ζ非線形的にその出力レベルを制御する非線
形補正回路と、外光量検出回路と、上記管面の平均輝度
を検出する検出回路とを有し、上記非線形補正回路は上
記外光量の大きさにより制御されるもこの外光量による
制御が上記検出回路の出力により抑えられるようにされ
て、J−記受像管の管面の明るさに対応した最適なコン
トラスト補正がなされるようにされたテレビジョン受像
機。A circuit for controlling the amplitude of a luminance signal in accordance with the brightness of the tube surface of a picture tube, and a nonlinear correction circuit provided at a subsequent stage of this control circuit for nonlinearly controlling the output level of the luminance signal. , has an external light amount detection circuit and a detection circuit that detects the average brightness of the tube surface, and the nonlinear correction circuit is controlled by the magnitude of the external light amount. A television receiver in which optimum contrast correction is performed corresponding to the brightness of the tube surface of a J-recording picture tube.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP20624683A JPS6097786A (en) | 1983-11-02 | 1983-11-02 | Television receiver |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP20624683A JPS6097786A (en) | 1983-11-02 | 1983-11-02 | Television receiver |
Publications (1)
Publication Number | Publication Date |
---|---|
JPS6097786A true JPS6097786A (en) | 1985-05-31 |
Family
ID=16520155
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP20624683A Pending JPS6097786A (en) | 1983-11-02 | 1983-11-02 | Television receiver |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS6097786A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2005295513A (en) * | 2004-03-05 | 2005-10-20 | Matsushita Electric Ind Co Ltd | Image signal processing method, image signal processing apparatus and image displaying apparatus |
-
1983
- 1983-11-02 JP JP20624683A patent/JPS6097786A/en active Pending
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2005295513A (en) * | 2004-03-05 | 2005-10-20 | Matsushita Electric Ind Co Ltd | Image signal processing method, image signal processing apparatus and image displaying apparatus |
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