200933599 九、發明說明： 【發明所屬之技術領域】 本發明是有關於一種發光二極體相關的技術，且特別 是有關於一種視覺暫留圖像顯示裝置以及其掃描方法。 【先前技術】 自工業革命以來，人類大量使用石化燃料、濫伐森 林、使用含氯、氟之碳化物及熱絡之農工活動等，造成二 ©氧化碳、甲烷、氧化亞氮、氟氯碳化物、六氟化硫（SF6 )、 全氟碳化物（PFCs )、氫氟碳化物（HFCs )等易吸收長波 輕射氣體（即「溫室氣體（Greenhouse Gas, GHG )」）大 幅增加’形成地球溫暖化現象，造成地球「溫室效應」現 象產生。由於全球溫暖化可能危及並導致地球氣候之極端 異常，造成自然生態環境之惡化等重大衝擊，因此，各國 皆以推動降低能源消耗作為重點工作。 第1圖是習知的數位相框之裝置圖。請參考第丨圖，BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light-emitting diode related art, and more particularly to a visual persistence image display device and a scanning method thereof. [Prior Art] Since the industrial revolution, humans have used a large amount of fossil fuels, deforestation, the use of chlorine and fluorine-containing carbides, and the agro-industrial activities of the hot network, resulting in carbon monoxide, methane, nitrous oxide, and chlorofluorocarbonation. Long-wave light-emitting gases such as sulphur hexafluoride (SF6), perfluorocarbons (PFCs), and hydrofluorocarbons (HFCs), which are known as "greenhouse gas (GHG)", have increased dramatically The phenomenon of warming has caused the phenomenon of the "greenhouse effect" of the earth. As global warming may endanger and cause extreme anomalies in the Earth's climate, causing major impacts such as the deterioration of the natural ecological environment, all countries are focusing on promoting energy consumption reduction. Figure 1 is a diagram of a conventional digital photo frame. Please refer to the figure,
的控制。 的裝置為光敏電阻 光敏電阻的主要構成化學物 目前普遍使用於光源偵測器 (Light Dependent Resistor)。光鸟 6 200933599 質是琉化隔（CdS)或是碼化錯（cdSe)。光敏電阻受光照 後’其電阻值會變小。光敏電阻的CdS或CdSe沉積膜面 積越大’其受光照後的阻值變化也越大，故通常將沉積膜 做成弓字形，以增大其面積。第2圖為習知光敏電阻 的結構示意圖。 然而’光敏電阻的價格十分昂貴。另外，歐盟公告的 「電子電機設備有害物質限用指令」（R〇HS)，已經明文規 疋禁止含有鉛、汞、鎘、六價鉻、多溴聯苯及多溴聯苯醚 ©的電子電機設備輸入歐盟’並且，&因應歐盟新規定，經 濟部標準檢驗局亦訂定了「有害物質指定試驗室特定規 範」。因此，含有硫化隔（Cds)或是硒化鎘（cdSe)的光敏電 阻顯然已經不符合各國的規範。另外，雖然製造光敏電阻 的廠商有提出不含鎘的光敏電阻，但是其價格相對的貴上 許多。 【發明内容】 〇 冑鑒於此’本發明之一目的就是在提供一種檢測環境 免度方法’用以檢測環境的亮度，並符合環保法規。 本發明之另-目的就是在提供一種省電方法，用以根 據環境亮度調整顯示器的亮度，以達到在不同環境光源取 付最適當的視覺效果’並且節省電力。 ’、 本發明之又-目的就是在提供一種顯示裝置，丘 用一發光二極體同時作為婭妆但_ 達到節省成本的功,Γ作^以及環境光源檢測，以 為達上述或其他目的，本發明提出一種檢測環境亮度 200933599 方法，此方法包括下列步驟：提供一發光二極體；提供第 一電壓到發光二極體的第一端，並提供第二電壓到發光二 極體的第二端，其中發光二極體呈現逆向偏壓；設定發光 二極體的第二端為高阻抗狀態；以及根據發光二極體之第 二端的電壓對時間的變化量，決定環境的亮度。 本發明提出一種省電方法。此方法包括下列步驟：提 供一顯示裝置；在顯示裝置中，提供一發光二極體；提供 一第一電壓到發光二極體的第一端，並提供一第二電壓到 ©發光二極體的第二端，其中發光二極體呈現逆向偏壓；設 .定發光二極體的第二端為高阻抗狀態；以及根據發光二極 體之第二端的電壓對時間的變化量，決定顯示裝置的亮 度。 依照本發明的較佳實施例所述之檢測環境亮度方法 以及省電方法，上述發光二極體的第一端為陰極；發光二 極體的第二端為陽極；上述第一電壓為一電源電壓；上述 第二電壓為一接地電壓。且根據發光二極體之第二端的電 〇壓對時間的變化量，決定環境的亮度之步驟包括：根據發 光二極體的第二端的電壓充電到一預定電壓的時間，決定 環境的儿度。另外，根據發光二極體之第二端的電壓對時 間的變化量，決定顯示裝置的亮度之步驟包括：根據發光 二極體的第二端的電壓充電到一預定電壓的時間，決定顯 示裝置的亮度。 依’展本發明的較佳實施例所述之檢測環境亮度方法 以及省電方法，上述發光二極體的第一端為陽極；上述發 光一極體的第二端為陰極；上述第一電壓為一接地電壓； 8 200933599 上述第二電壓為一電源電壓。且根據發光二極體之第二山 的電壓對時間的變化量，決定環境的亮度之步驟包括 據發光二極體的陰極的電壓放電到一預定電壓的時間，= 定環境的亮度。另外，根據發光二極體之第二端的電麈對 時間的變化量，決定顯示裝置的亮度之步驟包括：根據發 光二極體的陰極的電壓放電到一預定電壓的時間，決 示裝置的亮度。 ' · 本發明提出一種顯示裝置。此裝置包括輸入裝置、面 ©版、發光二極體以及控制電路。控制t路輕接輸入展置、 面板以及發光二極體。當透過輸入裝置進行進行操作時， 控制電路控制發光二極體發出對應的光線。當上述發光二 極體不發光時，控制電路利用上述發光二極體偵測環境^ 依照本發明的較佳實施例所述之檢測環境亮度方法 以及省電方法，當上述發光二極體不發光時：控制電路根 據上述發光二極體之一端的電壓對時間的變化量，決定環 ^ &免度。在更進—步的實施例中，當上述發光二極體不發 光時’上述控制電路執行以下動作：提供上述發光二極體 的陽極一接地電壓；提供上述發光二極體的陰極一電源電 壓之後控制電路設定上述發光二極體的陰極到高阻抗狀 態，根據上述發光二極體的陰極的電塵放電到一預定電愿 的時間，判斷環境亮度。在另一更進-步的實施例中，當 上述發光二極體不發光時，控制電路執行以下動作·提供 上述發光二極體的陰極一電源電壓；提供上述發光二極體 的陽極#地電壓，之後控制電路設定上述發光二極體的 200933599 陽極到间阻抗狀態；根據上述發光二極體的陽極的電壓充 電到一預定電壓的時間，判斷環境亮度。 本發明之精神是在於利用低成本的發光二極體，作為 檢測光源的元件。因此，當應用在產品上時，可以共用同 I發光二極體作為操作提示以及光源偵測用之外還可以 即省成本，並且符合環保法規。另外，當應用於顯示裝置 時-除了可以根據環境受度調整顯示器的亮度，以達到在 不同％境光源取得最適當的視覺效果外，還可以節省不必 ©要的功率消耗。 ▲為讓本發明之上述和其他目的、特徵和優點能更明顯 易*，下文特舉較佳實施例，並配合所附圖式，作詳細說 明如下。 【實施方式】 第3圖是根據本發明實施例所繪示的顯示裝置的電路 圖。請參考第3圖，此顯示裝置包括輸入裝置3〇i、面版 ❹302、發光二極體3〇3以及控制電路3〇4。輸入裝置gw 例如是按鈕。控制電路304耦接輸入裝置3〇1、面板3〇2 以及發光二極體303。在此實施例中，假設顯示裝置是一 數位相框，輸入裝置301是按鈕，面板3〇2是液晶顯示面 板。當使用者透過輸入裝置301對此顯示裝置進行操作 時，控制電路304控制發光二極體發出光線。也就是說， 使用者每次按鈕301，控制電路3〇4便會控制發光二極體 3〇3發光，提示使用者已經按下按鈕。因此當使用者按鈕 失敗盼，例如使用者按钮按的太輕，發光二極體3 0 3便不 10 200933599 - 會發光，使用者便可以知道按鈕失敗，並重新按鈕。當使 用者不進行操作時，發光二極體3〇3便不發光，控制電路 304便利用發光二極體303來偵測環境亮度，藉以調整液 晶顯示面板303的背光，以達到在不同環境光源取得最適 當的視覺效果，並且節省電力。由於本實施例中，共用發 光一極體303分別作為提示與測量環境光線，因此，還可 以達到節省成本，並且美觀產品設計。 - 值得一提的是，雖然上述實施例中已經對本發明的顯 ©示裝置描繪出了一個可能的型態，但發光二極體用以檢測 環境光線的方式可以不同，因此以下再舉幾個實施例，以 便本領域具有通常知識者能夠實施本發明。 第4圖是根據本發明實施例所繪示的檢測環境亮度方 法的流程圖。請參考第4圖。 步驟S401 :開始。 步驟S402:提供一發光二極體。 步驟S403 :提供一第一電壓到上述發光二極體的第 〇 一端，並提供一第二電壓到上述發光二極體的第二端，其 中上述發光二極體呈現逆向偏壓。第5圖是根據本發明實 施例所繪示的用發光二極體檢測光源的電路操作圖。請同 時參考第3圖與第5圖，假設第5圖的發光二極體為第3 圖的發光二極體303 ’且其陽極耦接控制電路304的D02 接腳’其陰極搞接控制電路304的D01接腳。當發光二極 體303不發光時，控制電路3〇4的D01接腳會先供應給發 光二極體303的陰極一電源電壓Vdd，控制電路3〇4的 D01接腳會供應發光二極體3〇3的陽極接地電壓gNd， 11 200933599 使發光—極體3 Ο 3處在逆向偏壓的狀態。 一般來說’發光一極體303在製造過程中，會有逆向 偏壓電容的存在，同時發光二極體303所存在的印刷電路 板亦存在有雜散電容，上述兩者的等效電容可以用€乂表 不。上述步驟S403是要將發光二極體303的陽極對地的 等效電容Cx的電壓放到接地電壓gnD。另外，雖然此實 施例是用發光二極體3 0 3的逆向偏壓電容以及印刷電路 板的雜散電谷之專效電容Cx作舉例，應當知道，上述等 ©效電容Cx為了生產時，電容變化量可以受到控制，甚至 可以刻意外加並聯10〜50pF的電容。在此不予贅述。 步驟S404 :設定上述發光二極體的第二端為高阻抗 狀態。當放電完成後，控制電路304將D02接腳設為高阻 抗。 步驟S405 :根據該發光二極體之第二端的電壓對時 間的變化量，判斷環境的亮度。接下來，控制電路3 〇 4會 偵測D02接腳上的電壓，也就是發光二極體3〇3的陽極的 〇電壓。由於發光二極體303會依照其所接收到的光線的強 弱，發光二極體303的陰極流向其陽極的電流大小會跟著 不同。第6圖是根據本發明實施例第5圖所繪示的波形 圖。喷參考第6圖，波形601是當發光二極體3〇3所接收 到的光線強度較弱時，其陽極的電壓對時間的變化曲線； 波开y 602疋虽發光二極體303所接收到的光線強度較強 時，其陽極的電壓對時間的變化曲線。由此波形便可以看 出，虽發光一極體303所接收到的光線越強，雜散電容 Cx的充電速率越快。因此，只要判斷出發光二極體3〇3 12 200933599 的陽極之電壓對時間的轡彳 了]扪變化量，便可以藉此 度。在此實施例中’提供了兩種做法：_哀兄的儿 1 · 檢測發光二極體3 m & its* a 3〇3的陽極之電壓到達某個 預定電壓的時間。 2.在一預定時間後，檢測發光二極體3〇3的陽 極之電壓值。 由於可以藉由上述步驟S4〇5判斷環境的亮度，因 此:可以達成根據環境亮度調整顯示器的亮度，以達到在 ©不同環i兄光源取得最適當的雜譽^ τ取遇田的視覺效果，並且節省電力。 步驟S406 :結束。 在述實施命J中，提出了藉由檢測發光二極體的 陽極之電壓對時間的變化量，爽 夏术判斷環境焭度或調整顯示 器亮度，以下另外提出一種藉由檢測發光二極體3〇3的陰 極之電壓對時間的變化量，夹剌 里术判斷％境焭度或調整顯示器 亮度的方法。 第7圖疋根據本發明實施例所繪示的用發光二極體 〇 303檢測光源的電路操作圖。第8圖是根據本發明實施例 第7圖所繪示的波形圖。請同時參考第了圖以及第8圖， 當發光二極體303不發光時，控制電路3〇4 & D〇2接腳會 供應給發光一極體303的陽極—接地電壓GND，控制電 路3 0 4的D 0 1接腳會供應發光二極體3 〇 3的陰極一電源電 壓Vdd使發光一極體3〇3處在逆向偏壓的狀態，並對發 光二極體303的陰極的雜散電容Cx充電。 波形80 1疋虽發光二極體3〇3所接收到的光線強度較 強時，其陰極的電壓對時間的變化曲線；波形8〇2是當發 13 200933599 光二極體303所接收到的光線強度較弱時，其陰極的電壓 對時間的變化曲線。由此波形便可以看出，當發光二極體 303所接收到的光線越強，雜散電容Cx的放電速率越快。 接下來，當雜散電容Cx充電到Vdd後，控制電路3〇4將 D01接腳設為高阻抗。接下來，控制電路3〇4同樣可以利 用D01接腳選擇以下兩種做法： 在此實施例中，提供了兩種做法： 1- 檢測發光二極體303的陰極之電壓被放電到 © 某個預定電壓的時間。 2_ 在一預定時間後，檢測發光二極體303的陰 極之電壓值。 、·示上所述，本發明之精神是在於利用低成本的發光二 極體，作為檢測光源的元件。因&，當應用在產品上時， :::共广發光二極體作為操作提示以及光源偵測用 之外，還可以節省成本’並且符合環保法規。另外，♦應 用於顯示裝置時，除了可以根據環境亮^ ❹ 度，以達到在不同環境光源取得最 ° ^ ° ，冗 可以節省不必要的功传取適當的視覺效果外，還 用以之詳細說明中所提出之具體實施例僅 明本發明之技術内容’而非將本發明狹義地限 —'迷實施例，在不超出本發明之精神及以 範圍之情況，所做之種種變化實施，巧々 圍。因此本發明之保護範圍當 '明之範 定者為准。 ㈣圍“見後附之申請專利範圍所界 14 200933599 - 【圖式簡單說明】 第1圖是習知的數位相框之裝置圖。 第2圖為習知光敏電阻的結構示意圖。 第3圖是根據本發明實施例所繪示的顯示裝置的電路 圖。 第4圖是根據本發明實施例所繪示的檢測環境亮度方 ' 法的流程圖。 - 第5圖是根據本發明實施例所繪示的用發光二極體檢 ©測光源的電路操作圖。 第6圖是根據本發明實施例第5圖所繪示的波形圖。 第7圖是根據本發明實施例所繪示的用發光二極體 303檢測光源的電路操作圖。 第8圖是根據本發明實施例第7圖所繪示的波形圖。 【主要元件符號說明】 10、302 :顯示面板 〇 11:外框 1 2 :光源偵測器 - 301 :輸入裝置 . 303 :發光二極體 3 04 :控制電路 D01、D02 :控制電路的接腳 Cx :雜散電容 15control. The device is a photoresistor. The main constituent chemicals of the photoresistor are currently commonly used in Light Dependent Resistor. Light Bird 6 200933599 Quality is CdS or Coded Error (cdSe). When the photoresistor is illuminated, its resistance will become smaller. The larger the area of the CdS or CdSe deposited film of the photoresistor, the greater the change in resistance after illumination, so the deposited film is usually formed into a bow shape to increase its area. Figure 2 is a schematic view showing the structure of a conventional photoresistor. However, the price of the photoresistor is very expensive. In addition, the EU Directive on Restriction of Hazardous Substances in Electrical and Electronic Equipment (R〇HS) has expressly banned the importation of electronic machinery equipment containing lead, mercury, cadmium, hexavalent chromium, polybrominated biphenyls and polybrominated diphenyl ethers into the European Union' , & In response to the new EU regulations, the Bureau of Standards and Excise of the Ministry of Economic Affairs has also established "Specific Specifications for Designated Laboratory of Hazardous Substances". Therefore, photoresistors containing sulfide spacers (Cds) or cadmium selenide (cdSe) are clearly not in compliance with national regulations. In addition, although manufacturers of photoresistors have proposed cadmium-free photoresistors, their prices are relatively expensive. SUMMARY OF THE INVENTION In view of the above, an object of the present invention is to provide a method for detecting environmental exemption </ RTI> for detecting the brightness of an environment and complying with environmental regulations. Another object of the present invention is to provide a power saving method for adjusting the brightness of a display according to ambient brightness to achieve the most appropriate visual effect in different ambient light sources' and to save power. ', the present invention is again - the purpose is to provide a display device, the hill with a light-emitting diode at the same time as Ya makeup but _ to achieve cost-saving work, ^ 以及 and environmental light source detection, in order to achieve the above or other purposes, this The invention provides a method for detecting ambient brightness 200933599, the method comprising the steps of: providing a light emitting diode; providing a first voltage to a first end of the light emitting diode and providing a second voltage to the second end of the light emitting diode The light emitting diode exhibits a reverse bias voltage; the second end of the light emitting diode is set to a high impedance state; and the brightness of the environment is determined according to the amount of change of the voltage of the second end of the light emitting diode with respect to time. The invention proposes a power saving method. The method includes the steps of: providing a display device; providing a light emitting diode in the display device; providing a first voltage to the first end of the light emitting diode, and providing a second voltage to the light emitting diode a second end, wherein the light emitting diode exhibits a reverse bias; the second end of the fixed light emitting diode is in a high impedance state; and the display is determined according to the amount of change of the voltage of the second end of the light emitting diode to time The brightness of the device. According to a method for detecting ambient brightness and a power saving method according to a preferred embodiment of the present invention, the first end of the light emitting diode is a cathode; the second end of the light emitting diode is an anode; and the first voltage is a power source Voltage; the second voltage is a ground voltage. And the step of determining the brightness of the environment according to the amount of change in the electric pressure of the second end of the light-emitting diode to determine the brightness of the environment comprises: determining the degree of the environment according to the time when the voltage of the second end of the light-emitting diode is charged to a predetermined voltage. . In addition, the step of determining the brightness of the display device according to the amount of change of the voltage of the second end of the light-emitting diode to the time comprises: determining the brightness of the display device according to the time when the voltage of the second end of the light-emitting diode is charged to a predetermined voltage. . According to a method for detecting ambient brightness and a power saving method according to a preferred embodiment of the present invention, the first end of the light emitting diode is an anode; the second end of the light emitting body is a cathode; and the first voltage Is a ground voltage; 8 200933599 The above second voltage is a power supply voltage. And the step of determining the brightness of the environment according to the amount of change of the voltage of the second mountain of the light-emitting diode to the time comprises: discharging the voltage according to the voltage of the cathode of the light-emitting diode to a predetermined voltage, and determining the brightness of the environment. In addition, the step of determining the brightness of the display device according to the amount of change of the power of the second end of the light-emitting diode to the time includes: determining the brightness of the device according to the time when the voltage of the cathode of the light-emitting diode is discharged to a predetermined voltage . The present invention proposes a display device. The device includes an input device, a face © version, a light emitting diode, and a control circuit. Control t-channel light connection input display, panel and light-emitting diode. When operating through the input device, the control circuit controls the light emitting diode to emit corresponding light. When the light emitting diode does not emit light, the control circuit utilizes the light emitting diode detecting environment. According to the method for detecting ambient brightness and the power saving method according to the preferred embodiment of the present invention, when the light emitting diode does not emit light Time: The control circuit determines the degree of freedom of the ring according to the amount of change of the voltage of one end of the above-mentioned light-emitting diode with respect to time. In a further embodiment, when the light emitting diode does not emit light, the control circuit performs the following actions: providing an anode-ground voltage of the light-emitting diode; providing a cathode-power voltage of the light-emitting diode Thereafter, the control circuit sets the cathode of the light-emitting diode to a high-impedance state, and determines the ambient brightness according to the time during which the discharge of the cathode of the light-emitting diode discharges to a predetermined power. In another further embodiment, when the light emitting diode does not emit light, the control circuit performs the following actions: providing a cathode-power voltage of the light emitting diode; providing the anode of the light emitting diode The voltage is then controlled by the control circuit to set the 200933599 anode to the inter-impedance state of the above-mentioned light-emitting diode; and the ambient brightness is determined according to the time when the voltage of the anode of the light-emitting diode is charged to a predetermined voltage. The spirit of the present invention is to utilize a low-cost light-emitting diode as an element for detecting a light source. Therefore, when applied to a product, it is possible to share the same light-emitting diode as an operation prompt and light source detection, which is also cost-effective and complies with environmental regulations. In addition, when applied to a display device - in addition to adjusting the brightness of the display according to the degree of environmental exposure, in order to achieve the most appropriate visual effect in different % of the light source, it is also possible to save the power consumption that is not necessary. The above and other objects, features, and advantages of the present invention will become more apparent. [Embodiment] FIG. 3 is a circuit diagram of a display device according to an embodiment of the invention. Referring to FIG. 3, the display device includes an input device 3〇i, a faceplate 302, a light-emitting diode 3〇3, and a control circuit 3〇4. The input device gw is, for example, a button. The control circuit 304 is coupled to the input device 3〇1, the panel 3〇2, and the light emitting diode 303. In this embodiment, it is assumed that the display device is a digital photo frame, the input device 301 is a button, and the panel 3〇2 is a liquid crystal display panel. When the user operates the display device through the input device 301, the control circuit 304 controls the light emitting diode to emit light. That is to say, each time the button 301 is pressed by the user, the control circuit 3〇4 controls the light-emitting diodes 3〇3 to emit light, prompting the user that the button has been pressed. Therefore, when the user button fails, for example, the user button is too light, the light-emitting diode 3 0 3 will not be illuminated, and the user can know that the button has failed and the button is pressed again. When the user does not operate, the LEDs 3 〇 3 do not emit light, and the control circuit 304 conveniently uses the LED 303 to detect the ambient brightness, thereby adjusting the backlight of the liquid crystal display panel 303 to achieve different ambient light sources. Get the most appropriate visuals and save power. In this embodiment, the common light-emitting diode 303 serves as a prompt and measurement ambient light, respectively, thereby achieving cost saving and aesthetic product design. - It is worth mentioning that although the above embodiment has shown a possible form of the display device of the present invention, the manner in which the light-emitting diode is used to detect ambient light may be different, so The embodiments are intended to enable those skilled in the art to practice the invention. FIG. 4 is a flow chart of a method for detecting ambient brightness according to an embodiment of the invention. Please refer to Figure 4. Step S401: Start. Step S402: providing a light emitting diode. Step S403: providing a first voltage to the first end of the light emitting diode and providing a second voltage to the second end of the light emitting diode, wherein the light emitting diode exhibits a reverse bias. Fig. 5 is a circuit operation diagram of a light-emitting diode detecting light source according to an embodiment of the present invention. Please refer to FIG. 3 and FIG. 5 simultaneously, assuming that the light-emitting diode of FIG. 5 is the light-emitting diode 303 ' of FIG. 3 and its anode is coupled to the D02 pin of the control circuit 304'. D01 pin of 304. When the LED 303 is not illuminated, the D01 pin of the control circuit 3〇4 is first supplied to the cathode of the LED 303, and the D01 pin of the control circuit 3〇4 is supplied with the LED. The anode grounding voltage gNd of 3〇3, 11 200933599 makes the light-emitting body 3 Ο 3 in a state of reverse bias. In general, the 'light-emitting diode 303 has a reverse bias capacitor during the manufacturing process, and the printed circuit board of the light-emitting diode 303 also has stray capacitance, and the equivalent capacitance of the two. Can use the table to not show. The above step S403 is to place the voltage of the equivalent capacitance Cx of the anode of the light-emitting diode 303 to the ground to the ground voltage gnD. In addition, although this embodiment is exemplified by the reverse bias capacitor of the light-emitting diode 310 and the capacitor Cx of the stray electric valley of the printed circuit board, it should be understood that the above-mentioned capacitors Cx are for production. The amount of capacitance change can be controlled, and even a capacitor of 10 to 50 pF can be accidentally added in parallel. I will not repeat them here. Step S404: setting the second end of the light emitting diode to a high impedance state. When the discharge is complete, control circuit 304 sets the D02 pin to a high impedance. Step S405: Determine the brightness of the environment according to the amount of change in the voltage of the second end of the light-emitting diode. Next, the control circuit 3 〇 4 detects the voltage on the D02 pin, that is, the 〇 voltage of the anode of the LED 3〇3. Since the light-emitting diode 303 is in accordance with the intensity of the light it receives, the magnitude of the current flowing from the cathode of the light-emitting diode 303 to its anode will be different. Fig. 6 is a waveform diagram shown in Fig. 5 of the embodiment of the present invention. Referring to Fig. 6, waveform 601 is a curve of the voltage of the anode with respect to time when the light intensity received by the light-emitting diode 3〇3 is weak; the wave opening y 602 疋 is received by the light-emitting diode 303 When the intensity of the light is strong, the voltage of the anode changes with time. From this waveform, it can be seen that although the light received by the light-emitting body 303 is stronger, the charging rate of the stray capacitance Cx is faster. Therefore, it is possible to determine the amount of change in the voltage of the anode of the light-emitting diode 3〇3 12 200933599 with respect to time. In this embodiment, two methods are provided: _ 哀 Brother 1 · Detects the time when the voltage of the anode of the light-emitting diode 3 m & its* a 3〇3 reaches a predetermined voltage. 2. After a predetermined time, the voltage value of the anode of the light-emitting diode 3〇3 is detected. Since the brightness of the environment can be determined by the above step S4〇5, it is possible to adjust the brightness of the display according to the ambient brightness, so as to achieve the visual effect of obtaining the most appropriate knowledge of the different sources. And save electricity. Step S406: End. In the description of the implementation of the life J, it is proposed to detect the amount of change in the voltage of the anode of the light-emitting diode with respect to time, to determine the environmental temperature or to adjust the brightness of the display, and additionally to provide a detection of the light-emitting diode 3 The amount of change in the voltage of the cathode of 〇3 with respect to time, the method of judging the degree of 焭 焭 or adjusting the brightness of the display. FIG. 7 is a circuit operation diagram of detecting a light source by a light-emitting diode 303 according to an embodiment of the invention. Fig. 8 is a waveform diagram shown in Fig. 7 of the embodiment of the present invention. Please refer to the same figure and FIG. 8 at the same time. When the light-emitting diode 303 does not emit light, the control circuit 3〇4 & D〇2 pin is supplied to the anode-ground voltage GND of the light-emitting body 303, and the control circuit The D 0 1 pin of 3 0 4 supplies the cathode of the light-emitting diode 3 〇3, and the power supply voltage Vdd causes the light-emitting body 3〇3 to be in a reverse bias state, and the cathode of the light-emitting diode 303 The stray capacitance Cx is charged. Waveform 80 1疋When the light intensity received by the light-emitting diode 3〇3 is strong, the voltage of the cathode changes with time; the waveform 8〇2 is the light received by the light source 303 of 200933599 The curve of the voltage of the cathode versus time when the intensity is weak. From this waveform, it can be seen that the stronger the light received by the light-emitting diode 303, the faster the discharge rate of the stray capacitance Cx. Next, when the stray capacitance Cx is charged to Vdd, the control circuit 3〇4 sets the D01 pin to a high impedance. Next, the control circuit 3〇4 can also select the following two methods by using the D01 pin: In this embodiment, two methods are provided: 1- detecting that the voltage of the cathode of the light-emitting diode 303 is discharged to © The time at which the voltage is predetermined. 2_ After a predetermined time, the voltage value of the cathode of the light-emitting diode 303 is detected. According to the above description, the spirit of the present invention resides in the use of a low-cost light-emitting diode as an element for detecting a light source. Because &, when applied to the product, the ::: common light-emitting diode can be used as an operation prompt and light source detection, and it can save cost' and comply with environmental regulations. In addition, ♦ when applied to the display device, in addition to the brightness of the environment, in order to achieve the most ° ^ ° in different ambient light sources, redundancy can save unnecessary power to take appropriate visual effects, but also used in detail The specific embodiments described in the specification are merely illustrative of the technical content of the present invention, and the invention is not limited to the invention, and various changes are made without departing from the spirit and scope of the invention. Cleverly wrapped around. Therefore, the scope of protection of the present invention is subject to the specifications of the specification. (4) Encircles “See Appendix 14 for the scope of patent application. 200933599 - [Simple description of the diagram] Figure 1 is a diagram of the device of a conventional digital photo frame. Figure 2 is a schematic diagram of the structure of a conventional photoresistor. A circuit diagram of a display device according to an embodiment of the present invention. FIG. 4 is a flow chart of a method for detecting an ambient brightness according to an embodiment of the present invention. - FIG. 5 is a diagram illustrating an embodiment of the present invention. FIG. 6 is a waveform diagram of a light source according to an embodiment of the present invention. FIG. 7 is a diagram showing a waveform according to an embodiment of the present invention. The circuit diagram of the body 303 detects the light source. Fig. 8 is a waveform diagram according to the seventh embodiment of the present invention. [Main component symbol description] 10, 302: display panel 〇11: outer frame 1 2: light source detection Detector - 301: Input device. 303: Light-emitting diode 3 04: Control circuit D01, D02: Pin Cx of control circuit: stray capacitance 15