JP2005215128A - Display apparatus - Google Patents

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JP2005215128A
JP2005215128A JP2004019587A JP2004019587A JP2005215128A JP 2005215128 A JP2005215128 A JP 2005215128A JP 2004019587 A JP2004019587 A JP 2004019587A JP 2004019587 A JP2004019587 A JP 2004019587A JP 2005215128 A JP2005215128 A JP 2005215128A
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display device
temperature
noise reduction
liquid crystal
circuit
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JP4595333B2 (en
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Haruyasu Hirakawa
晴康 平川
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Panasonic Holdings Corp
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Matsushita Electric Industrial Co Ltd
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Abstract

<P>PROBLEM TO BE SOLVED: To suppress noise increase and sharpness deterioration in a liquid crystal panel due to a temperature change, and to make it difficult for users to recognize an image quality change, such as the noise increase and the sharpness deterioration, when overdrive operation is switched, in a display apparatus equipped with a noise reduction circuit, such as a liquid crystal television. <P>SOLUTION: In the liquid crystal display apparatus in which display response characteristics are improved by a grayscale correction circuit 41, in which a grayscale for driving the liquid crystal is determined by an inputted video signal, a frame delayed video signal and a control signal inputted from outside, a noise reduction circuit capable of controlling noise reduction amount from the outside, a control means for controlling the noise reduction circuit 11 and the grayscale correction circuit and a temperature-sensing means are provided and the noise reducing circuit is controlled according to a temperature-sensing result, by the temperature sensing and the controlling of the grayscale correction circuit. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

本発明は、液晶テレビなどノイズ低減回路を備えた表示装置に関するものである。   The present invention relates to a display device including a noise reduction circuit such as a liquid crystal television.

近年テレビは、画質への要求の高まりやデジタル回路の集積化の進展により、従来の２次元処理のノイズ低減回路に加え、フレーム巡回型のノイズ低減回路を搭載する事が多くなっている。一般にノイズ低減回路はそのノイズ低減効果（以下ＮＲのゲインとする）を制御可能である。   In recent years, televisions are increasingly equipped with a frame-circulating noise reduction circuit in addition to a conventional two-dimensional processing noise reduction circuit due to increasing demands for image quality and progress in integration of digital circuits. In general, the noise reduction circuit can control the noise reduction effect (hereinafter referred to as NR gain).

フレーム巡回型のノイズ軽減回路はフレーム相関のないノイズに対して大きなノイズ低減効果を有するものの、同じくフレーム相関のない動画部分において鮮鋭感の劣化や尾引きなどの現象を発生する要因となるため、動き検出結果に応じてＮＲのゲインが適正になるよう調整される。   Although the frame recursive noise reduction circuit has a large noise reduction effect for noise without frame correlation, it also causes phenomena such as sharpness deterioration and tailing in moving image parts without frame correlation, The NR gain is adjusted to be appropriate according to the motion detection result.

同様に非巡回型の２次元処理によるノイズ低減回路においても、フィルタ特性の調整やコアリングの閾値調整にて、ＮＲのゲインを調整する事が可能であるが、ノイズ軽減効果を大きくしようとすると画像の鮮鋭感の劣化に繋がるため、設計者はノイズ軽減効果と画質への影響などを鑑みてＮＲのゲインを適正に調整している。またユーザーによる調整や映像信号のＡＧＣ回路のゲインなどの情報を用いて制御する場合もある。   Similarly, in a noise reduction circuit using non-recursive two-dimensional processing, it is possible to adjust the NR gain by adjusting the filter characteristics and adjusting the coring threshold value. In order to reduce the sharpness of the image, the designer appropriately adjusts the NR gain in consideration of the noise reduction effect and the influence on the image quality. In some cases, control is performed using information such as adjustment by the user and gain of the AGC circuit of the video signal.

また液晶パネルを用いた表示装置においては、動画の表示性能を改善するためフレーム遅延させた映像信号を用いて実際に液晶パネルに印加する電圧を決定する映像信号に変換する階調補正回路を用いて、オーバードライブ駆動をする事がある。その際、階調補正回路に数種の動作モードを持たせて、パネルの温度などに対応して動作モードを切り替えることにより、温度に対する動画表示品位の変化を抑える技術も実用化している。
特開平６−２２５１７８号公報 特開２００２−１０１０６号公報 特許第２７０８７４６号公報 In addition, in a display device using a liquid crystal panel, a tone correction circuit is used that converts a frame-delayed video signal into a video signal that determines the voltage actually applied to the liquid crystal panel in order to improve moving image display performance. Overdrive. At that time, a technique for suppressing a change in the quality of moving image display with respect to temperature by putting several kinds of operation modes in the gradation correction circuit and switching the operation modes according to the temperature of the panel has been put into practical use.
JP-A-6-225178 JP 2002-10106 A Japanese Patent No. 2708746

しかしながら従来の技術を、温度によって表示の応答時間が変化する表示デバイスを用いた表示装置に適用した場合、表示デバイスの温度によっては、応答時間が速くなる事により、ノイズが認識されやすい表示となったり、応答時間が遅くなる事により、画像の鮮鋭感が劣化したりするなどし、最良の画質を得られないという問題があった。   However, when the conventional technology is applied to a display device using a display device whose display response time changes depending on the temperature, depending on the temperature of the display device, the response time becomes faster, and thus the display becomes easier to recognize noise. In addition, there is a problem that the best image quality cannot be obtained because the sharpness of the image deteriorates due to the slow response time.

また温度に応じてオーバードライブ駆動を切り替えて使用する場合において、階調補正回路の動作モードを切り替えた瞬間に入力映像信号に対する映像表示の応答が突然変化するため、ノイズの増加や鮮鋭感の劣化など画質変化が認識されるという問題があった。   Also, when overdrive drive is switched according to temperature, the video display response to the input video signal changes suddenly at the moment when the operation mode of the gradation correction circuit is switched, which increases noise and deteriorates sharpness. There was a problem that image quality changes were recognized.

この課題を解決するために
第１の発明は、
表示デバイスと、入力映像信号のノイズを外部から制御して低減するノイズ軽減回路と、前記ノイズ低減回路を制御するための第１の制御手段と、表示デバイスの温度を検出する温度検出手段とを備え、
前記温度検出手段により得られる温度検出結果に応じて、前記第１の制御手段が前記ノイズ低減回路を制御することを特徴とする表示装置であり、
室温の変化や、表示装置の回路の発熱などにより表示の応答が変化しても、ＮＲのゲイン制御を行うことにより、ノイズの増加や、画像の鮮鋭感の劣化などを抑えた表示装置を実現できる。 In order to solve this problem, the first invention
A display device, a noise reduction circuit for controlling and reducing noise of an input video signal from the outside, a first control means for controlling the noise reduction circuit, and a temperature detection means for detecting the temperature of the display device. Prepared,
In accordance with the temperature detection result obtained by the temperature detection unit, the first control unit controls the noise reduction circuit,
Even if the response of the display changes due to a change in room temperature or heat generation of the circuit of the display device, the display device that suppresses the increase in noise and the deterioration of the sharpness of the image is realized by controlling the NR gain. it can.

また第２の発明は、
表示デバイスが液晶パネルである請求項１記載の表示装置であり、
液晶の応答が速くなり、ノイズが認識されやすくなる高温環境での使用や、液晶の応答が遅くなり、画像の鮮鋭感が劣化する低温環境での使用においても、ノイズの増加や画像の鮮鋭感劣化を抑えたノイズ表示装置を提供できる。 Also, the second invention is
The display device according to claim 1, wherein the display device is a liquid crystal panel.
Increased noise and sharpness of images even when used in high-temperature environments where the response of the liquid crystal becomes fast and noise is easily recognized, and when used in low-temperature environments where the response of the liquid crystal becomes slow and the sharpness of the image deteriorates. A noise display device in which deterioration is suppressed can be provided.

また第３の発明は、
温度検出手段が、液晶パネルの表面温度、もしくは表示装置内において液晶パネルの表面温度と相関して温度が推移する部分の温度を検出することを特徴とした請求項１または２記載の表示装置であり、液晶パネルの表面温度により変化する液晶の応答に応じて常に適切なＮＲのゲインでノイズ軽減回路を動作させることができるため、ノイズ軽減効果の不足によるノイズの増加や、過度のノイズ軽減回路の動作による画像の鮮鋭感劣化のない高画質な表示装置を提供できる。 Also, the third invention is
3. The display device according to claim 1, wherein the temperature detecting means detects a surface temperature of the liquid crystal panel or a temperature of a portion where the temperature changes in correlation with the surface temperature of the liquid crystal panel in the display device. Yes, the noise reduction circuit can always be operated with an appropriate NR gain according to the response of the liquid crystal that changes depending on the surface temperature of the liquid crystal panel. Thus, it is possible to provide a high-quality display device in which the sharpness of the image is not deteriorated by the above operation.

また第４の発明は、
表示デバイスと、入力映像信号の階調と１フレーム遅延させた前記入力映像信号の階調および外部から入力される制御信号に基づき階調データを決定する階調補正回路とを備えた液晶表示装置であって、前記入力映像信号のノイズを外部から制御して低減するノイズ軽減回路と、前記ノイズ低減回路を制御するための第１の制御手段とをさらに備え、
前記階調補正回路を制御する第２の制御手段の出力に対応して、前記第１の制御手段が前記ノイズ低減回路を制御する事を特徴とした表示装置であり、
表示装置の動画表示性能の改善等のために階調補正回路の動作を切り替えた際に認識されやすいノイズ量や画像鮮鋭感の変化を抑えることの出来る表示装置を提供するものである。 Also, the fourth invention is
A liquid crystal display device comprising: a display device; and a gradation correction circuit that determines gradation data based on a gradation of the input video signal, a gradation of the input video signal delayed by one frame, and a control signal input from the outside A noise reduction circuit for controlling and reducing noise of the input video signal from the outside, and a first control means for controlling the noise reduction circuit,
The display device is characterized in that the first control means controls the noise reduction circuit in response to an output of a second control means for controlling the gradation correction circuit,
It is an object of the present invention to provide a display device capable of suppressing changes in noise amount and image sharpness that are easily recognized when the operation of a gradation correction circuit is switched in order to improve the moving image display performance of the display device.

また第５の発明は、
表示デバイスと、入力映像信号の階調と１フレーム遅延させた前記入力映像信号の階調および外部から入力される制御信号に基づき階調データを決定する階調補正回路とを備えた液晶表示装置であって、前記入力映像信号のノイズを外部から制御して低減するノイズ軽減回路と、前記ノイズ低減回路を制御するための第１の制御手段と、表示デバイスの温度を検出する温度検出手段とをさらに備え、
前記階調補正回路を制御する第２の制御手段の出力および温度検出手段により得られる温度検出結果に応じて、前記第１の制御手段が前記ノイズ低減回路を制御する事を特徴とした表示装置であり、
液晶パネルの表面温度に対応して変化する液晶の応答に応じて常に適切なＮＲのゲインでノイズ軽減回路を動作させることができ、また表示装置の動画表示性能の改善等のために階調補正回路の動作を切り替えた際にもノイズ量や画像鮮鋭感の変化を抑えることの出来る表示装置を提供するものである。 In addition, the fifth invention,
A liquid crystal display device comprising: a display device; and a gradation correction circuit that determines gradation data based on a gradation of the input video signal, a gradation of the input video signal delayed by one frame, and a control signal input from the outside A noise reduction circuit for controlling and reducing noise of the input video signal from the outside, a first control means for controlling the noise reduction circuit, and a temperature detection means for detecting the temperature of the display device; Further comprising
A display device characterized in that the first control means controls the noise reduction circuit in accordance with an output of a second control means for controlling the gradation correction circuit and a temperature detection result obtained by the temperature detection means. And
The noise reduction circuit can always be operated with an appropriate NR gain according to the response of the liquid crystal that changes according to the surface temperature of the liquid crystal panel, and tone correction is performed to improve the video display performance of the display device. It is an object of the present invention to provide a display device that can suppress changes in noise amount and image sharpness even when the operation of a circuit is switched.

本発明によれば、温度により表示の応答が変化する表示デバイスを使用した表示装置において、表示デバイスの温度変化による応答特性の変化に伴うノイズの増加や鮮鋭感の劣化を抑え、また表示の応答を改善するためにオーバードライブ回路の動作を切り替えた際の、画質変化を抑えることが可能である。   According to the present invention, in a display device using a display device whose display response changes depending on the temperature, an increase in noise and sharpness deterioration due to a change in response characteristics due to a temperature change of the display device is suppressed, and a display response is suppressed. It is possible to suppress a change in image quality when the operation of the overdrive circuit is switched to improve the image quality.

本発明の請求項１、請求項２および請求項３に記載の発明は、
表示デバイスと、入力映像信号のノイズを外部から制御して低減するノイズ軽減回路と、前記ノイズ低減回路を制御するための第１の制御手段と、表示デバイスの温度を検出する温度検出手段とを備え、
前記温度検出手段により得られる温度検出結果に応じて、前記第１の制御手段が前記ノイズ低減回路を制御することを特徴とする表示装置である。 The invention according to claim 1, claim 2 and claim 3 of the present invention,
A display device, a noise reduction circuit for controlling and reducing noise of an input video signal from the outside, a first control means for controlling the noise reduction circuit, and a temperature detection means for detecting the temperature of the display device. Prepared,
The display device is characterized in that the first control unit controls the noise reduction circuit in accordance with a temperature detection result obtained by the temperature detection unit.

本発明の請求項４に記載の発明は、
表示デバイスと、入力映像信号の階調と１フレーム遅延させた前記入力映像信号の階調および外部から入力される制御信号に基づき階調データを決定する階調補正回路とを備えた液晶表示装置であって、前記入力映像信号のノイズを外部から制御して低減するノイズ軽減回路と、前記ノイズ低減回路を制御するための第１の制御手段とをさらに備え、
前記階調補正回路を制御する第２の制御手段の出力に対応して、前記第１の制御手段が前記ノイズ低減回路を制御する事を特徴とした表示装置である。 The invention according to claim 4 of the present invention is
A liquid crystal display device comprising: a display device; and a gradation correction circuit that determines gradation data based on a gradation of the input video signal, a gradation of the input video signal delayed by one frame, and a control signal input from the outside A noise reduction circuit for controlling and reducing noise of the input video signal from the outside, and a first control means for controlling the noise reduction circuit,
The display device is characterized in that the first control means controls the noise reduction circuit in response to an output of a second control means for controlling the gradation correction circuit.

本発明の請求項５に記載の発明は、
表示デバイスと、入力映像信号の階調と１フレーム遅延させた前記入力映像信号の階調および外部から入力される制御信号に基づき階調データを決定する階調補正回路とを備えた液晶表示装置であって、前記入力映像信号のノイズを外部から制御して低減するノイズ軽減回路と、前記ノイズ低減回路を制御するための第１の制御手段と、表示デバイスの温度を検出する温度検出手段とをさらに備え、
前記階調補正回路を制御する第２の制御手段の出力および温度検出手段により得られる温度検出結果に応じて、前記第１の制御手段が前記ノイズ低減回路を制御する事を特徴とした表示装置である。 The invention according to claim 5 of the present invention is
A liquid crystal display device comprising: a display device; and a gradation correction circuit that determines gradation data based on a gradation of the input video signal, a gradation of the input video signal delayed by one frame, and a control signal input from the outside A noise reduction circuit for controlling and reducing noise of the input video signal from the outside, a first control means for controlling the noise reduction circuit, and a temperature detection means for detecting the temperature of the display device; Further comprising
A display device characterized in that the first control means controls the noise reduction circuit in accordance with an output of a second control means for controlling the gradation correction circuit and a temperature detection result obtained by the temperature detection means. It is.

以下に、本発明の請求項１、請求項２および請求項３に記載された発明の実施の形態について、図１、図２および図３を用いて説明する。   Embodiments of the present invention described in claims 1, 2, and 3 of the present invention will be described below with reference to FIGS. 1, 2, and 3.

図１において、１１は入力された映像信号に対し、制御信号に基づいてノイズを低減した映像信号を出力するノイズ低減回路である。１２は温度検出手段１３から得られる温度検出結果に対応して前記ノイズ低減回路の制御信号を発生する第１の制御手段である。ノイズ低減回路１１の出力は、映像処理回路１４にて、ＲＧＢ信号へ変換やガンマ補正され、液晶パネル１５に出力される。   In FIG. 1, reference numeral 11 denotes a noise reduction circuit that outputs a video signal in which noise is reduced based on a control signal with respect to an input video signal. Reference numeral 12 denotes first control means for generating a control signal for the noise reduction circuit corresponding to the temperature detection result obtained from the temperature detection means 13. The output of the noise reduction circuit 11 is converted into an RGB signal or gamma corrected by the video processing circuit 14 and output to the liquid crystal panel 15.

ノイズ低減回路１１は、効果を大きくしようとすると、画像の鮮鋭感に低下や動画の尾引きやぼやけなどを伴うため、ノイズ低減の効果と画質への影響を鑑みてそのゲインが設定されている。一方で液晶パネルは、その表面温度によって表示に対する応答特性が変化する。図２に液晶の応答特性の例を示す。液晶は、図２（ａ）に示すように温度が高い場合応答が速くなり、温度が低くなると遅くなるので、動画の鮮鋭感に大きく影響する。また図２（ｂ）は１フレーム期間だけ表示階調が変化するような映像信号を入力した際の液晶の表示応答特性を示すものである。このようにフレーム間に相関のないノイズや動画に関しては、液晶の応答特性が表示画像に大きく影響する。すなわちノイズ低減回路の調整を行う際に設計者が意図した温度より温度が高い場合にはノイズが目立つようになり、温度が低くなるとノイズは目立たなくなるものの動画領域に対する鮮鋭感が劣化しボケた映像となる。図３（ａ）はそれを模式的に示したものである。   In order to increase the effect, the noise reduction circuit 11 is accompanied by a decrease in the sharpness of the image, tailing or blurring of the moving image, and the gain is set in consideration of the effect of noise reduction and the influence on the image quality. . On the other hand, the response characteristics of the liquid crystal panel change depending on the surface temperature. FIG. 2 shows an example of response characteristics of the liquid crystal. As shown in FIG. 2A, the response of the liquid crystal becomes faster when the temperature is high, and becomes slower when the temperature is low, which greatly affects the sharpness of the moving image. FIG. 2B shows the display response characteristics of the liquid crystal when a video signal whose display gradation changes only for one frame period is input. As described above, with respect to noise and moving images having no correlation between frames, the response characteristics of the liquid crystal greatly affect the display image. In other words, when adjusting the noise reduction circuit, if the temperature is higher than the temperature intended by the designer, the noise will become noticeable, and if the temperature becomes lower, the noise will become inconspicuous, but the sharpness of the video area will deteriorate and the image will be blurred It becomes. FIG. 3 (a) schematically shows this.

そこで温度検出手段１３による温度検出結果に応じて、第１の制御回路１２が、ノイズ低減回路に設定するＮＲのゲインを調整する事で画質の最適化が図れる。具体的には温度が高くなった場合にＮＲのゲインを上げノイズの増加を抑え、温度が低くなりノイズが目立たなくなった場合にはＮＲのゲインを下げ鮮鋭感を向上させる。   Therefore, the image quality can be optimized by adjusting the NR gain set in the noise reduction circuit by the first control circuit 12 in accordance with the temperature detection result by the temperature detection means 13. Specifically, the NR gain is increased to suppress the increase in noise when the temperature becomes high, and the NR gain is lowered to improve the sharpness when the temperature becomes low and the noise becomes inconspicuous.

なお温度によるノイズ低減回路の制御は、表示装置内の温度や、室温などの検出でも当然効果は期待できるが、請求項３記載の発明のように液晶パネルの温度に対応して制御するものであれば、図３（ｂ）に示すように広範囲な温度に対し安定した画質を得る事が出来る表示装置を提供できる。   The control of the noise reduction circuit by temperature can be expected to be effective even by detecting the temperature in the display device or the room temperature, but it is controlled according to the temperature of the liquid crystal panel as in the invention of claim 3. If so, a display device capable of obtaining stable image quality over a wide range of temperatures as shown in FIG. 3B can be provided.

以下に、本発明の請求項４に記載された発明の実施の形態について、図４、図５、図６および図７を用いて説明する。   Hereinafter, an embodiment of the invention described in claim 4 of the present invention will be described with reference to FIGS. 4, 5, 6 and 7.

図４において１１は入力された映像信号に対し、制御信号に基づいてノイズを低減した映像信号を出力するノイズ低減回路である。ノイズ低減回路１１の出力は、映像処理回路１４にて、ＲＧＢ信号へ変換やガンマ補正などの信号処理がなされ、階調補正回路３１に入力される。階調補正回路４１は応答速度の改善のため導入されており、俗にオーバードライブ回路と言われているものである。図５に階調補正回路４１の構成例を示す。入力された映像信号（第１の階調データ）と前記第１の階調データを１フレーム遅延した第２の階調データから液晶に印加される電圧に対応する第３の階調データに変換する。図６（ａ）に示す応答特性に対し、階調補正回路４１の動作により、図６（ｂ）の様に階調データを変換して液晶パネルに出力する事により、それぞれの温度における応答時間の最適化を図るものである。ＲＡＭ等により構成されるルックアップテーブル５１の回路規模の問題から、第２の制御回路４２により切り替えられるオーバードライブのモード数は通常数種類である。本実施の形態では３０℃における応答を最適化したモードと４０℃における応答を最適化したモードを３５℃にて切り替えている。図７（ａ）は、画面で認識されるノイズの量を模式的に示したものであり、高温においてノイズ量が多くなり、かつ階調補正回路４１の動作モードを切り替える温度の前後でノイズ量が大きく変わる。そこで第２の制御回路４２の出力により、低温用の動作モード時にＮＲのゲインを大きめに、もしくは、高温用の動作モード時にＮＲのゲインが小さめになるように、第１の制御回路を１２がノイズ低減回路１１を制御する事により、図７（ｂ）に示すように階調補正回路４１の動作切り替え時のノイズ量の変化や画像鮮鋭感の変化を抑え、それがユーザーに認識されにくくする事が可能となる。   In FIG. 4, reference numeral 11 denotes a noise reduction circuit that outputs a video signal in which noise is reduced based on a control signal with respect to an input video signal. The output of the noise reduction circuit 11 is subjected to signal processing such as conversion to RGB signals and gamma correction in the video processing circuit 14 and is input to the gradation correction circuit 31. The gradation correction circuit 41 is introduced for improving the response speed and is commonly called an overdrive circuit. FIG. 5 shows a configuration example of the gradation correction circuit 41. The input video signal (first gradation data) and the second gradation data obtained by delaying the first gradation data by one frame are converted into third gradation data corresponding to the voltage applied to the liquid crystal. To do. With respect to the response characteristics shown in FIG. 6 (a), the gradation correction circuit 41 operates to convert the gradation data as shown in FIG. 6 (b) and output it to the liquid crystal panel. Is to optimize. Due to the problem of the circuit scale of the look-up table 51 composed of a RAM or the like, the number of overdrive modes switched by the second control circuit 42 is usually several. In the present embodiment, the mode that optimizes the response at 30 ° C. and the mode that optimizes the response at 40 ° C. are switched at 35 ° C. FIG. 7A schematically shows the amount of noise recognized on the screen. The amount of noise increases at a high temperature and before and after the temperature at which the operation mode of the gradation correction circuit 41 is switched. Will change drastically. Therefore, the output of the second control circuit 42 has the first control circuit 12 set so that the NR gain is increased in the low temperature operation mode or the NR gain is decreased in the high temperature operation mode. By controlling the noise reduction circuit 11, as shown in FIG. 7B, a change in the amount of noise and a change in image sharpness at the time of switching the operation of the gradation correction circuit 41 are suppressed, making it difficult for the user to recognize it. Things will be possible.

以下に、本発明の請求項５に記載された発明の実施の形態について、図７および図６を用いて説明する。   An embodiment of the invention described in claim 5 of the present invention will be described below with reference to FIGS.

図７に本実施の形態のブロック図を示す。実施の形態２と比較し、第１の制御回路１２は階調補正回路４１の切り替え信号である第２の制御回路出力に加え、温度検出手段１３により得られる温度検出データからノイズ低減回路１１を制御する。   FIG. 7 shows a block diagram of the present embodiment. As compared with the second embodiment, the first control circuit 12 uses the noise reduction circuit 11 from the temperature detection data obtained by the temperature detection means 13 in addition to the second control circuit output which is the switching signal of the gradation correction circuit 41. Control.

この構成により、液晶の応答時間の改善のため補正回路４１の動作モードを切り替えた際のノイズ量や画像の鮮鋭感の変化および
液晶パネルの温度変化による応答特性変化に伴うノイズ量の増加や鮮鋭感の劣化を無くし、７（ｃ）に示すように広範囲な温度条件において高画質な液晶表示装置を提供できる。 With this configuration, the noise amount when the operation mode of the correction circuit 41 is switched to improve the response time of the liquid crystal, the change in the sharpness of the image, and the increase in the amount of noise accompanying the change in the response characteristics due to the temperature change of the liquid crystal panel It is possible to provide a liquid crystal display device with high image quality under a wide range of temperature conditions as shown in 7 (c) without deterioration of feeling.

なお本実施の形態では第１の制御手段は、第２の制御手段の出力を入力とするものとしているが、階調補正回路の制御と連動すれば、制御手段は１つにまとめるなどしても良い。   In the present embodiment, the first control means receives the output of the second control means as an input. However, if the first control means is interlocked with the control of the gradation correction circuit, the control means are combined into one. Also good.

本発明のノイズ低減回路は、
温度により表示の応答が変化する表示デバイスを使用した表示装置において、表示デバイスの温度変化による応答特性の変化に伴うノイズの増加や鮮鋭感の劣化を抑え、また表示の応答を改善するためにオーバードライブ回路の動作を切り替えた際の、画質変化を抑えることが可能であり、液晶テレビをはじめとする表示装置全般に有用である。 The noise reduction circuit of the present invention is
In a display device using a display device whose display response varies with temperature, it is overloaded to suppress noise increase and sharpness degradation due to changes in response characteristics due to temperature changes of the display device, and to improve display response. It is possible to suppress changes in image quality when the operation of the drive circuit is switched, which is useful for display devices such as liquid crystal televisions in general.

本発明の実施の形態１を示すブロック図Block diagram showing Embodiment 1 of the present invention 温度に対する液晶の応答を示す図Figure showing liquid crystal response to temperature 従来技術と本発明における、温度に対するノイズ量を示す図The figure which shows the noise quantity with respect to temperature in the prior art and this invention 本発明の実施の形態２を示すブロック図The block diagram which shows Embodiment 2 of this invention 階調補正回路４１を示すブロック図Block diagram showing the gradation correction circuit 41 階調補正回路４１の動作を示す図The figure which shows operation | movement of the gradation correction circuit 41 従来技術と本発明における、温度に対するノイズ量を示す図The figure which shows the noise quantity with respect to temperature in the prior art and this invention 本発明の実施の形態３を示すブロック図Block diagram showing Embodiment 3 of the present invention

符号の説明Explanation of symbols

１１ ノイズ低減回路
１２ 第１の制御回手段
１３ 温度検出手段
１４ 映像処理回路
１５ 液晶パネル
４１ 階調補正回路
４２ 第２の制御手段
５１ ルックアップテーブル
５２ フレームメモリ DESCRIPTION OF SYMBOLS 11 Noise reduction circuit 12 1st control circuit 13 Temperature detection means 14 Video processing circuit 15 Liquid crystal panel 41 Gradation correction circuit 42 2nd control means 51 Look-up table 52 Frame memory

Claims (5)

表示デバイスと、入力映像信号のノイズを外部から制御して低減するノイズ軽減回路と、前記ノイズ低減回路を制御するための第１の制御手段と、表示デバイスの温度を検出する温度検出手段とを備え、
前記温度検出手段により得られる温度検出結果に応じて、前記第１の制御手段が前記ノイズ低減回路を制御することを特徴とする表示装置。 A display device, a noise reduction circuit for controlling and reducing noise of an input video signal from the outside, a first control means for controlling the noise reduction circuit, and a temperature detection means for detecting the temperature of the display device. Prepared,
The display device, wherein the first control unit controls the noise reduction circuit in accordance with a temperature detection result obtained by the temperature detection unit. 表示デバイスが液晶パネルである請求項１記載の表示装置。 The display device according to claim 1, wherein the display device is a liquid crystal panel. 温度検出手段が、液晶パネルの表面温度、もしくは表示装置内において液晶パネルの表面温度と相関して温度が推移する部分の温度を検出する事を特徴とした請求項１または請求項２記載の表示装置。 3. The display according to claim 1, wherein the temperature detecting means detects a surface temperature of the liquid crystal panel or a temperature of a portion where the temperature changes in the display device in correlation with the surface temperature of the liquid crystal panel. apparatus. 表示デバイスと、入力映像信号の階調と１フレーム遅延させた前記入力映像信号の階調および外部から入力される制御信号に基づき階調データを決定する階調補正回路とを備えた液晶表示装置であって、前記入力映像信号のノイズを外部から制御して低減するノイズ軽減回路と、前記ノイズ低減回路を制御するための第１の制御手段とをさらに備え、
前記階調補正回路を制御する第２の制御手段の出力に対応して、前記第１の制御手段が前記ノイズ低減回路を制御する事を特徴とした表示装置。 A liquid crystal display device comprising: a display device; and a gradation correction circuit that determines gradation data based on a gradation of the input video signal, a gradation of the input video signal delayed by one frame, and a control signal input from the outside A noise reduction circuit for controlling and reducing noise of the input video signal from the outside, and a first control means for controlling the noise reduction circuit,
A display device, wherein the first control means controls the noise reduction circuit in response to an output of a second control means for controlling the gradation correction circuit. 表示デバイスと、入力映像信号の階調と１フレーム遅延させた前記入力映像信号の階調および外部から入力される制御信号に基づき階調データを決定する階調補正回路とを備えた液晶表示装置であって、前記入力映像信号のノイズを外部から制御して低減するノイズ軽減回路と、前記ノイズ低減回路を制御するための第１の制御手段と、表示デバイスの温度を検出する温度検出手段とをさらに備え、
前記階調補正回路を制御する第２の制御手段の出力および温度検出手段により得られる温度検出結果に応じて、前記第１の制御手段が前記ノイズ低減回路を制御する事を特徴とした表示装置。 A liquid crystal display device comprising: a display device; and a gradation correction circuit that determines gradation data based on a gradation of the input video signal, a gradation of the input video signal delayed by one frame, and a control signal input from the outside A noise reduction circuit for controlling and reducing noise of the input video signal from the outside, a first control means for controlling the noise reduction circuit, and a temperature detection means for detecting the temperature of the display device; Further comprising
A display device characterized in that the first control means controls the noise reduction circuit in accordance with an output of a second control means for controlling the gradation correction circuit and a temperature detection result obtained by the temperature detection means. .
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8896508B2 (en) 2009-05-12 2014-11-25 Seiko Epson Corporation Electro-optical device, driving method therefor, and electronic apparatus

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH04288589A (en) * 1990-09-03 1992-10-13 Toshiba Corp Liquid crystal display device
JP2001331154A (en) * 2000-05-23 2001-11-30 Matsushita Electric Ind Co Ltd Liquid crystal display device and liquid crystal display method
JP2002297104A (en) * 2001-03-29 2002-10-11 Fujitsu Ltd Control circuit for performing drive compensation for high speed response for liquid crystal display device
JP2003202845A (en) * 2001-10-31 2003-07-18 Mitsubishi Electric Corp Circuit and method for driving liquid crystal
US20030231158A1 (en) * 2002-06-14 2003-12-18 Jun Someya Image data processing device used for improving response speed of liquid crystal display panel
JP2004163873A (en) * 2002-06-14 2004-06-10 Mitsubishi Electric Corp Circuit and method for driving liquid crystal, and liquid crystal display device

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH04288589A (en) * 1990-09-03 1992-10-13 Toshiba Corp Liquid crystal display device
JP2001331154A (en) * 2000-05-23 2001-11-30 Matsushita Electric Ind Co Ltd Liquid crystal display device and liquid crystal display method
JP2002297104A (en) * 2001-03-29 2002-10-11 Fujitsu Ltd Control circuit for performing drive compensation for high speed response for liquid crystal display device
JP2003202845A (en) * 2001-10-31 2003-07-18 Mitsubishi Electric Corp Circuit and method for driving liquid crystal
US20030231158A1 (en) * 2002-06-14 2003-12-18 Jun Someya Image data processing device used for improving response speed of liquid crystal display panel
JP2004163873A (en) * 2002-06-14 2004-06-10 Mitsubishi Electric Corp Circuit and method for driving liquid crystal, and liquid crystal display device

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8896508B2 (en) 2009-05-12 2014-11-25 Seiko Epson Corporation Electro-optical device, driving method therefor, and electronic apparatus

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