200848767 九、發明說明： 【發明所屬之技術領域】 種能夠校正溫 本發明有關於雷射測距儀，特別有關 度漂移所產生之信號延遲的距離量測 【先前技術】 Μ” 隨著電子技術和半導體雷射器的發展，掌上型 r 已經商品化，且廣泛地應用在建築、交通田地形 =㈣时潢等方面。-般而言，此種測距儀係配備有 =射』以發出雷射光束’並且於掌上型雷射相位測距儀 中’係主要用於可視光譜中之光束，以便能夠對準量測點 (目標物）。測距儀内建之接收器藉由相較於發射器所發出 之光束與所接收到之光束間之時間差，即可求出與被測物 之間的距離。 一身又而㊁’測距儀中之摘測器係使用PIN光電二極體 或朋潰光電二極體（avalanche photodiode，APD)，將所對準 之被測物散射或反射回來之光束轉換成電性信號。藉由測 1相位變化來推算距離的測距儀會將所接收到的電性信號 且加此波頻率’以產生一個低頻量測信號，再將此低頻 里測彳s號之相位與參考信號之相位作比較，藉由兩者間之 相位差，即可獲知待測距離。然而，這種測距儀容易因外 在溫度的變化而影響測量精準度。 針對溫度產生之量測漂移，某些先前技術係揭露不同 之解決方法’但仍然無法完全地消除漂除或是電路太複雜 而難以應用於產品中。 0757-A22081 TWF(N2)；E01 〇6274；DENNIS 5 200848767 【發明内容】 本發明係提供一種距離量測系統，包括驅動單元，接 收具有第一頻率之第一調製信號；光發射單元，具有陽極 以及陰極，驅動單元係根據第一調製信號驅動光發射單 元，朝目標物發出第一光束；光混頻單元，用以根據具有 第二頻率之第二調製信號以及第一光束照射到目標物所反 射之光束’產生光混頻信號；電混頻早元’具有弟一輸入 端搞接光發射單元之陽極或陰極上具有第一頻率之一對應 f 信號，以及第二輸入端耦接第二調製信號，藉以產生電混 頻信號；以及處理單元，用以根據光混頻信號與電混頻信 號，進行相位差計算，以求出目標物與距離量測系統間之 距離。 本發明亦提供一種距離量測系統，包括頻率合成器， 用以產生第一調製信號與第二調製信號；驅動單元，耦接 該第一調製信號；雷射二極體，具有陽極以及陰極，驅動 單元係根據第一調製信號驅動雷射二極體，朝目標物發出 ( 光束；崩潰光電二極體，用以根據第二調製信號以及第一 光束照射到目標物所反射之光束，產生光混頻信號；以及 電混頻單元，具有第一輸入端耦接雷射二極體之陽極或陰 極，以及第二輸入端耦接第二調製信號與崩潰光電二極體 之陰極，藉以產生一電混頻信號。 本發明亦提供一種距離量測方法，包括藉由光發射單 元，根據具有第一頻率之第一調製信號，朝目標物發出光 束；藉由光混頻單元，根據具有第二頻率之第二調製信號 0757-A22081 TWF(N2) ；E0106274；DENNIS 6 200848767 以及該光束經由目標物所反射之光束，產生光混頻信號； 根據光發射單元之陰極上之具有第一頻率之第一對應信 號，以及由光混頻單元之陰極上具有第二頻率之第二對應 信號，產生電混頻信號；以及根據光混頻信號與電混頻信 號，進行相位差計算，以求出目標物與距離量測系統間之 距離。 為了讓本發明之上述和其他目的、特徵、和優點能更 明顯易懂，下文特舉一較佳實施例，並配合所附圖示，作 Γ詳細說明如下： 【實施方式】 元件與傳輸線路的任何變化都會產生延遲，使得距離 量測系統之量測值產生變化。舉例而言，雷射二極體與崩 潰二極體皆是會受溫度影響的光電元件，它們容易受到自 身發熱或環境溫度的影響，而產生溫度漂移。 第1圖係用以說明光發射二極體之輸出功率與溫度之 關係。舉例而言，於25°c時，臨界電流約為20mA，當溫 I 度增加至50°C時，臨界電流就會增加至約25mA，依此類 推。這是由於光發射二極體的光傳輸效率會隨著溫度增加 而下降。舉例而言，光發射二極體係可等效成並聯連接之 一電阻Rd與一電容Cd(如第2圖中所示），而其等效電容易 受到調製信號的影響。 由於光發射二極體的光輸出功率在某些應用下是需要 被固定的，所以其順偏電流將需要隨著溫度而改變。因此， 在某些驅動電路中會使用自動功率控制（automatic power 0757-A22081 TWF(N2)；E0106274；DENNIS 7 200848767 control ; APC)來驅動光發射二極體。另一方面，當順偏電 流變化時，光發射二極體之工作條件亦會著改變，而導致 调製頻率的相位延遲。 除此之外，崩潰光電二極體係為一特殊設計之PIN二 極體，所接收(Incoming)的光信號會引發雪崩崩潰，所以光 所產生的載子會藉由離子撞擊，引出其它的載子，以提供 一内部的增益。崩潰光電二極體的量化效率可以達到 100%，它可提供高增益（約可達10000倍）與高響應速度， ( 響應的時間可短至幾微微秒（或稱皮秒；picoseconds)。由 於距離愈遠，所接收到的信號之能量就愈弱，因此需要一 個具有大增益之接收器。由於崩潰光電二極體具有這些優 點，因此非常適用於雷射測距系統。 然而，崩潰光電二極體亦是/個會受溫度影響的元 件，溫度愈高，其内部的增益度愈低。為了維持對相同目 標物與相同量測距離，在不同溫度下仍然具有良好的信號 ,雜訊比(SNR)，其偏壓必需要隨著溫度來改變。第3圖說明 、溫度與崩潰光電二極體之反向偏壓間的關係，而第4圖係 說明隨著反向偏壓改變，崩潰光電二極體之電容值亦會跟 著改變。然而，當崩潰光電二極體之電容值隨反向偏塵改 變時，而導致不同之相位延遲。 本發明之距離量測系統係將混波器純於光發射二極 體與崩潰光電二極體之間，使得測量信號與參考信號經過 相同的通路，以便將溫度漂移的影響消除，藉以提昇測量 的準確性。 0757-A22081TWF(N2)；E0106274；DENNIS 8 200848767 第5圖所示為本發明之距離量測系統之示意圖。如圖 所示，本發明之距離量測系統100包括處理單元10、頻率 合成器20、驅動單元30、光發射單元40、光混頻單元50、 一電混頻單元50、濾波單元BPF1〜BPF3、電阻R1〜R2以 及電容C1〜C3。舉例而言，電容C1〜C3係作為耦合電容， 而電阻R1與R2要互相匹配，並且電容R3與R4係作為限 電流之用。 頻率合成器20係耦接處理單元10，用以根據來自處 " 理單元10之控制信號，產生具有第一頻率之第一調製信號 SM以及具有第二頻率之第二調製信號SL，一般而言兩者 之間係具有幾KHz之頻率差。 驅動單元30係用以根據第一調製信號SM，驅動光發 射單元40朝目標物200發出具有第一頻率之光束S1，而 光束S1照射到目標物200所產生之反射光束S1”輸入至光 混頻單元50。於本實施例中，光發射單元40係為一雷射 二極體（laser diode)具有一陽極輕接驅動單元30以及一陰 " 極藉由電阻R1與電容C1耦接至電混頻單元60。電阻R3 係具有一第一熬接至一接地端，以及一第二端輕接光發射 單元40之陰極以及電阻R1。 光混頻單元50，具有一陽極耦接濾波單元BPF1以及 一陰極耦接電阻R4以及電容C3，用以接收目標物200所 反射之光束S1”與調製信號SL”，用以產生一光混頻信號 S2。調製信號SL”係調製信號SM經由濾波單元BPF3所產 生，而電阻R4係耦接於光混頻單元50之陰極與反向偏壓 0757-A22081TWF(N2)；E0106274；DENNIS 9 200848767 VB之間。舉例而言，光混頻單元50係為一崩潰光電二極 體（APD)。 電混頻單元60，具有一第一輸入端藉由電容C1與電 阻R1耦接至光發射單元40之陰極，以及一第二輸入端藉 由電容C2、C3與電阻R2耦接光混頻單元50之陰極，藉 以產生一電混頻信號S3。舉例而言，電混頻單元60係可 為一混波器（mixer)。 濾波單元BPF1係耦接光混頻單元50，用以接收光混 f 頻信號S2，輸出一信號S2” ；而濾波單元BPF2係耦接混 頻單元40，用以接收電混頻信號S3，輸出一信號S3”。舉 例而言，濾波單元BPF1〜BPF2係可為帶通濾波器用以得出 具有相位訊息之信號S2”與S3”。 處理單元10,用以根據信號S2”與S3”進行相位差計 算，以求出距離量測系統100與目標物200間之距離。在 某些實施例中，處理單元10係可為一數位信號處理器 (digital signal processor，DSP)，並且處理單元 10 與遽波單 ( 元BPF1與BPF2之會設置類比數位轉換單元，用以將來自 濾波單元BPF1與BPF2之信號S2”與S3”，轉換成數位信 號以便處理單元10進行相位差計算，以求出距離量測系統 100與目標物200間之距離估算值。 當溫度改變時，驅動單元30與光發射元件40之工作 條件就會產生漂移，所以光發射元件40所輸出之光束S1 與第一調製信號SM之間會有相位延遲。然而，光發射元 件40之陽極與陰極上之信號，同樣會影響到此漂移的影 0757-A22081TWF(N2)；E0106274；DENNIS 10 200848767 響，因此也會有產生相位延遲。舉例而言，節點N1上之 信號(例如電壓或電流）會與光束S1具有相同的頻率（例如 第一頻率）與相位延遲。 同樣地，當溫度改變時，光混頻單元（即崩潰光電二極 體）50之電容值會改變，造成之信號延遲會在調製信號 SL”（即節點N2上的信號）與光混頻信號S2上起相同的作 用。 換言之，由於電混頻單元60係耦接至光發射單元40 f 之陰極（即節點N1)與光混頻單元50之陰極，所以電混頻 單元60所接收到的調製信號中會同樣具有驅動單元30、 光發射單元40與光混頻單元50由於溫度而產生之信號延 遲。因此，光發射單元40與光混頻單元50所受的溫度影 響將可在混頻時同時抵消。 除此之外，在某些實施例中，電阻R1係可以連接於電 容C1與光發射單元40之陽極。換言之，電混頻單元60 係採用光發射單元40之陽極上與光束S1同樣具有第一頻 ( 率之對應信號來行進電混頻，以清除溫度造成之信號漂移。 本發明亦揭露一種距離量測方法，其動作係參考第5 圖說明如下。 首先，藉由光發射單元40，根據具有一第一頻率之一 第一調製信號SM，朝一目標物發出一光束S1。 接著，由光混頻單元50，根據具有一第二頻率之一第 二調製信號SL以及該光束S1經由該目標物所反射之光束 S1”，產生一光混頻信號S2。舉例而言，該第二調製信號 0757-A22081TWF(N2)；E0106274；DENNIS 11 200848767 SL可先通過一濾波單元BPF3去除雜訊後（即調製信號SL”) 再耦接至光混頻單元50與反射之光束S1”進行混頻產生光 混頻信號S2。 然後，根據光發射單元40之陰極上之具有該第一頻率 之一第一對應信號，以及由該光混頻單元50之陰極上具有 該第二頻率之一第二對應信號，產生一電混頻信號。 舉例而言，電混頻單元60之一第一輸入端係藉由電容 C1與電阻R1耦接至光發射單元40之陰極，並且其一第二 f 輸入端係藉由電容C2、C3與電阻R2耦接光混頻單元50 之陰極，藉以產生一電混頻信號S3。由於驅動單元30與 光發射元件40之工作條件會因為溫度改變而產生漂移，所 以光發射元件40所輸出之光束S1與第一調製信號SM之 間會有相位延遲。然而，光發射元件40之陽極與陰極上之 信號，同樣會影響到此漂移的影響，因此也會有產生相位 延遲。舉例而言，節點N1上之信號(例如電壓或電流）會與 光束S1具有相同的頻率（例如第一頻率）與相位延遲。 ( 同樣地，光混頻單元（即崩潰光電二極體）50之電容值 亦會隨著溫度改變而變化，造成之信號延遲會在調製信號 SL”（即節點N2上的信號）與光混頻信號S2上起相同的作 用。 換言之，由於電混頻單元60係耦接至光發射單元40 之陰極（即節點N1)與光混頻單元50之陰極，所以電混頻 單元60所接收到的調製信號（即第一對應信號與第二對應 信號）中會同樣具有驅動單元30、光發射單元40與光混頻 0757-A22081TWF(N2)；E0106274；DENNIS 12 200848767 單兀50由於溫度而產生之信號延遲。因此，光發射單元 40與光混頻單元5〇所受的溫度影響將可在混頻時同時抵 消0 除此之外，在某些實施例中，電阻R1係可以連接於電 谷C1與光發射單元4〇之陽極。換言之，電混頻單元㈧ 係採用光發射單元40之陽極上錢束S1同樣具有第—頻 率之義信號來行進電混頻，以清除溫度造成之信號漂移: 一最後，，據該光混頻信號S2與該電混頻信號S3，進 灯相位差冲异，以求出目標物2〇〇與距離量測系統⑽間 之距離。舉例而言，處理單幻0係根據光混頻信號S2”與 電混頻信號S3，，進行相位差計算，以求出距離量測系統_ 與目標物200間之距離。在某些實施例中，處理單元忉 係可為數位L遽處理器（digital p〇r，D ， 並且處理單元10與濾波單元卿1與BPF2之間會設置 比數位轉換單元，用以將來自濾波單元Bm與BPF2之1 ，頻，號S2”與電混齡號S3”，轉換成數位信號以便處理 早凡<丁相位差計算，以求出距離量測系統100鱼 物200間之距離估算值。 /、 ^ 由^電混頻單元所接收受溫度影響後之信號（ ㈣二2上之信號)進行混頻，因此由溫度變化所造成之相 ί 1：：^ 雖然本务明已以較佳實施例 \ 範圍内，當可料許更=2在傾離本㈣之精神和 /、潤飾，因此本發明之保護範圍200848767 IX. Description of the invention: [Technical field of the invention] The ability to calibrate the temperature of the present invention relates to laser range finder, especially to the measurement of the signal delay caused by the degree of drift [Prior Art] 随着" With the electronic technology With the development of semiconductor lasers, the handheld r has been commercialized and widely used in construction, traffic field topography = (four), and so on. In general, such rangefinders are equipped with = shots to issue The laser beam 'and in the handheld laser phase range finder' is mainly used for the beam in the visible spectrum to be able to align the measuring point (target). The built-in receiver of the range finder is compared The distance between the beam emitted by the transmitter and the received beam can be used to determine the distance from the object to be measured. The PIN photodiode is used in the finder of the two-way range finder. Or avalanche photodiode (APD), which converts the reflected or reflected beam of the object to be converted into an electrical signal. The rangefinder that estimates the distance by measuring the phase change will Received electrical The signal is added to the frequency of the wave to generate a low-frequency measurement signal, and the phase of the s-number is compared with the phase of the reference signal, and the phase difference between the two is used to obtain the distance to be measured. However, such rangefinders are susceptible to measurement accuracy due to changes in external temperature. Some prior art techniques have revealed different solutions for temperature-induced measurement drifts' but still cannot completely eliminate drift or circuits. It is too complicated to be used in a product. 0757-A22081 TWF(N2); E01 〇 6274; DENNIS 5 200848767 SUMMARY OF THE INVENTION The present invention provides a distance measuring system including a driving unit that receives a first frequency having a first frequency a modulation signal; a light emitting unit having an anode and a cathode, wherein the driving unit drives the light emitting unit according to the first modulation signal to emit a first light beam toward the target; and the optical mixing unit is configured to use the second modulated signal having the second frequency And the first light beam is irradiated to the light beam reflected by the target object to generate an optical mixing signal; the electric mixing frequency is early elemental One of the first frequency corresponding to the f signal on the anode or the cathode, and the second input end coupled to the second modulation signal to generate an electrical mixing signal; and a processing unit for the optical mixing signal and the electrical mixing signal Performing a phase difference calculation to determine the distance between the target and the distance measuring system. The present invention also provides a distance measuring system including a frequency synthesizer for generating a first modulated signal and a second modulated signal; And coupling the first modulated signal; the laser diode has an anode and a cathode, and the driving unit drives the laser diode according to the first modulation signal, and emits the light toward the target (beam; collapsing photodiode for Generating an optical mixing signal according to the second modulated signal and the first beam illuminating the beam reflected by the target; and the electric mixing unit having the first input coupled to the anode or cathode of the laser diode, and the second The input end is coupled to the second modulation signal and the cathode of the crash photodiode to generate an electrical mixing signal. The present invention also provides a distance measuring method, comprising: emitting, by a light emitting unit, a light beam toward a target according to a first modulated signal having a first frequency; and performing a second modulation according to the second frequency by the optical mixing unit Signal 0757-A22081 TWF(N2); E0106274; DENNIS 6 200848767 and the beam reflected by the beam through the target, producing an optical mixing signal; according to a first corresponding signal having a first frequency on the cathode of the light emitting unit, and Generating an electric mixing signal by a second corresponding signal having a second frequency on a cathode of the optical mixing unit; and performing phase difference calculation according to the optical mixing signal and the electric mixing signal to obtain a target and distance measurement The distance between the systems. The above and other objects, features and advantages of the present invention will become more apparent and understood. Any change in the delay will result in a change in the measured value of the distance measurement system. For example, both the laser diode and the collapse diode are temperature-dependent optoelectronic components that are susceptible to self-heating or ambient temperature and cause temperature drift. Figure 1 is a diagram showing the relationship between the output power of a light-emitting diode and temperature. For example, at 25 ° C, the critical current is about 20 mA. When the temperature I increases to 50 ° C, the critical current increases to about 25 mA, and so on. This is because the light transmission efficiency of the light-emitting diode decreases as the temperature increases. For example, a light-emitting diode system can be equivalent to a resistor Rd connected in parallel with a capacitor Cd (as shown in Figure 2), and its equivalent power is susceptible to the modulation signal. Since the light output power of the light-emitting diode needs to be fixed in some applications, its forward bias current will need to change with temperature. Therefore, automatic power control (automatic power 0757-A22081 TWF(N2); E0106274; DENNIS 7 200848767 control; APC) is used in some drive circuits to drive the light-emitting diode. On the other hand, when the forward current changes, the operating conditions of the light-emitting diode also change, resulting in a phase delay of the modulation frequency. In addition, the crash photodiode system is a specially designed PIN diode. The optical signal received by Incoming will cause avalanche collapse, so the carrier generated by the light will cause other loads by ion impact. Sub to provide an internal gain. The collapsing photodiode has a quantization efficiency of 100%, which provides high gain (up to 10,000 times) and high response speed (the response time can be as short as a few picoseconds (or picoseconds). The farther the distance is, the weaker the energy of the received signal is, so a receiver with a large gain is needed. Because of the advantages of the collapsed photodiode, it is very suitable for laser ranging systems. The polar body is also a component that is affected by temperature. The higher the temperature, the lower the gain inside. In order to maintain the same target and the same measurement distance, there is still a good signal at different temperatures, the noise ratio (SNR), the bias voltage must be changed with temperature. Figure 3 illustrates the relationship between temperature and the reverse bias of the colliding photodiode, while Figure 4 illustrates the change with reverse bias. The capacitance value of the collapsing photodiode will also change. However, when the capacitance value of the collapsing photodiode changes with the reverse dust, it causes different phase delays. The distance measuring system of the present invention will be mixed. The wave is pure between the light-emitting diode and the colliding photodiode, so that the measurement signal and the reference signal pass through the same path to eliminate the influence of temperature drift, thereby improving the accuracy of the measurement. 0757-A22081TWF(N2) E0106274; DENNIS 8 200848767 Figure 5 is a schematic diagram of the distance measuring system of the present invention. As shown, the distance measuring system 100 of the present invention includes a processing unit 10, a frequency synthesizer 20, a driving unit 30, and light. The transmitting unit 40, the optical mixing unit 50, an electric mixing unit 50, the filtering units BPF1 to BPF3, the resistors R1 to R2, and the capacitors C1 to C3. For example, the capacitors C1 to C3 are used as coupling capacitors, and the resistors R1 and R2 is matched to each other, and capacitors R3 and R4 are used as current limiting. Frequency synthesizer 20 is coupled to processing unit 10 for generating a first frequency having a first frequency based on a control signal from unit " The modulation signal SM and the second modulation signal SL having the second frequency generally have a frequency difference of several KHz therebetween. The driving unit 30 is configured to drive the light emission according to the first modulation signal SM. The unit 40 emits a light beam S1 having a first frequency toward the object 200, and the reflected light beam S1" generated by the light beam S1 to the target object 200 is input to the optical mixing unit 50. In the present embodiment, the light emitting unit 40 is A laser diode has an anode lightly connected driving unit 30 and a cathode electrode coupled to the electric mixing unit 60 via a resistor R1 and a capacitor C1. The resistor R3 has a first connection to a ground terminal, and a second end lightly connected to the cathode of the light emitting unit 40 and the resistor R1. The optical mixing unit 50 has an anode coupling filter unit BPF1 and a cathode coupling resistor R4 and a capacitor C3 for receiving the target. The light beam S1" and the modulation signal SL" reflected by the object 200 are used to generate an optical mixing signal S2. The modulation signal SL" is generated by the filtering unit BPF3, and the resistor R4 is coupled between the cathode of the optical mixing unit 50 and the reverse bias voltage 0757-A22081TWF(N2); E0106274; DENNIS 9 200848767 VB. For example, the optical mixing unit 50 is a crash photodiode (APD). The electric mixing unit 60 has a first input coupled to the cathode of the light emitting unit 40 via a capacitor C1 and a resistor R1. And a second input terminal is coupled to the cathode of the optical mixing unit 50 by the capacitors C2, C3 and the resistor R2, thereby generating an electrical mixing signal S3. For example, the electric mixing unit 60 can be a mixer. The filter unit BPF1 is coupled to the optical mixing unit 50 for receiving the optical mixed frequency signal S2 and outputting a signal S2"; and the filtering unit BPF2 is coupled to the mixing unit 40 for receiving the electrical mixing. The signal S3 outputs a signal S3". For example, the filtering units BPF1 B BPF2 can be band pass filters for obtaining signals S2" and S3" having phase information. The processing unit 10 is configured to be based on the signal S2" S3" performs phase difference calculation to find the distance measurement system 100 and The distance between the objects 200. In some embodiments, the processing unit 10 can be a digital signal processor (DSP), and the processing unit 10 and the chopping unit (the elements of the BPF1 and BPF2 are set analogy) a digital conversion unit for converting the signals S2" and S3" from the filtering units BPF1 and BPF2 into digital signals for processing unit 10 to perform phase difference calculation to determine the distance between the distance measuring system 100 and the target 200 When the temperature is changed, the operating conditions of the driving unit 30 and the light-emitting element 40 are shifted, so that there is a phase delay between the light beam S1 output from the light-emitting element 40 and the first modulation signal SM. However, the light emission The signal on the anode and cathode of component 40 will also affect the shadow of this drift 0757-A22081TWF (N2); E0106274; DENNIS 10 200848767, so there will also be phase delay. For example, the signal on node N1 ( For example, voltage or current) will have the same frequency (eg, first frequency) and phase delay as beam S1. Similarly, when the temperature changes, the optical mixing unit (ie, collapse) The capacitance of the photodiode 50 will change, causing the signal delay to have the same effect on the modulated signal SL" (i.e., the signal at node N2) and the optical mixing signal S2. In other words, due to the electrical mixing unit 60 It is coupled to the cathode of the light emitting unit 40 f (ie, the node N1) and the cathode of the optical mixing unit 50. Therefore, the modulated signal received by the electrical mixing unit 60 also has the driving unit 30 and the light emitting unit 40. The signal of the optical mixing unit 50 due to temperature is delayed. Therefore, the temperature effects experienced by the light emitting unit 40 and the optical mixing unit 50 can be simultaneously cancelled at the time of mixing. In addition, in some embodiments, resistor R1 can be coupled to capacitor C1 and the anode of light emitting unit 40. In other words, the electric mixing unit 60 employs the same frequency as the light beam S1 on the anode of the light emitting unit 40 to travel the electric mixing frequency to remove the signal drift caused by the temperature. The present invention also discloses a distance quantity. The measurement method is described below with reference to Fig. 5. First, a light beam S1 is emitted toward a target by a light emitting unit 40 according to a first modulation signal SM having a first frequency. The unit 50 generates an optical mixing signal S2 according to the second modulation signal SL having a second frequency and the light beam S1" reflected by the light beam S1. For example, the second modulation signal 0757- A22081TWF(N2); E0106274; DENNIS 11 200848767 SL can be first mixed by a filter unit BPF3 to remove noise (ie, modulation signal SL)) and then coupled to the optical mixing unit 50 and the reflected beam S1" for mixing to produce light mixing Frequency signal S2. Then, according to a first corresponding signal having a first frequency on the cathode of the light emitting unit 40, and having a second one of the second frequency on the cathode of the optical mixing unit 50 The signal is generated to generate an electrical mixing signal. For example, one of the first input terminals of the electric mixing unit 60 is coupled to the cathode of the light emitting unit 40 by a capacitor C1 and a resistor R1, and a second f input thereof The end is coupled to the cathode of the optical mixing unit 50 by the capacitors C2, C3 and the resistor R2, thereby generating an electric mixing signal S3. Since the operating conditions of the driving unit 30 and the light emitting element 40 may drift due to temperature changes, Therefore, there is a phase delay between the light beam S1 outputted by the light emitting element 40 and the first modulation signal SM. However, the signals on the anode and the cathode of the light emitting element 40 also affect the influence of the drift, and thus there is also A phase delay is generated. For example, a signal (eg, voltage or current) at node N1 will have the same frequency (eg, first frequency) and phase delay as beam S1. (Similarly, the optical mixing unit (ie, crash photodiode) The capacitance value of the polar body 50 also changes with temperature, and the signal delay causes the same effect on the modulation signal SL" (i.e., the signal on the node N2) and the optical mixing signal S2. Since the electrical mixing unit 60 is coupled to the cathode of the light emitting unit 40 (ie, the node N1) and the cathode of the optical mixing unit 50, the modulated signal received by the electrical mixing unit 60 (ie, the first corresponding signal and The second corresponding signal) will also have the signal delay of the driving unit 30, the light emitting unit 40 and the optical mixing 0757-A22081TWF (N2); E0106274; DENNIS 12 200848767 unit 50 due to the temperature. Therefore, the light emitting unit 40 The temperature influence on the optical mixing unit 5 将 can be offset by zero at the time of mixing. In addition, in some embodiments, the resistor R1 can be connected to the anode of the electric valley C1 and the light emitting unit 4 . In other words, the electric mixing unit (8) uses the signal beam S1 of the anode of the light emitting unit 40 to have the first-frequency meaning signal to travel the electric mixing to clear the signal drift caused by the temperature: First, according to the optical mixing The signal S2 and the electric mixing signal S3 are different in phase contrast to obtain the distance between the target 2〇〇 and the distance measuring system (10). For example, the processing of the single magic 0 is based on the optical mixing signal S2" and the electrical mixing signal S3, the phase difference calculation is performed to find the distance between the distance measuring system _ and the target 200. In some embodiments The processing unit can be a digital L遽 processor (digital p〇r, D, and a ratio conversion unit is set between the processing unit 10 and the filtering unit 1 and BPF2 for using the filtering unit Bm and BPF2. 1, the frequency, the number S2" and the electric mixing age number S3", are converted into a digital signal to process the early < Ding phase difference calculation to obtain the distance estimation value of the fish object 200 from the distance measuring system 100. ^ The temperature-affected signal received by the ^ electric mixing unit (the signals on (4) 2 and 2) is mixed, so the phase caused by the temperature change is 1::^ Although the present invention has been described in the preferred embodiment \ Scope, when it can be expected to change = 2 in the spirit of the (4) and /, retouching, so the scope of protection of the present invention
0757-A22081TWF(N2)；E0106274；DENNIS 13 200848767 當視後附之申請專利範圍所界定者為準。 f 0757-A22081TWF(N2)；E0106274；DENNIS 14 200848767 【圖式簡單說明】 第1圖係用以說明光發射二極體之輸出功率與溫度之 關係。 第2圖係表示光發射二極體之等效電路圖。 第3圖說明溫度與崩潰光電二極體之反向偏壓間的關 係； 第4圖係說明反向偏壓與崩潰光電二極體之電容值的 關係。 第5圖所示為本發明之距離量測系統之示意圖。 【主要元件符號說明】 10 ··處理單元； 20 :頻率合成器； 30 :驅動單元； 40 ··光發射單元； 50 :光混頻單元； 6 0 ·電混頻早元， BPF1〜BPF3 :濾波單元； R1〜R4、Rd :電阻； C1 〜C3、Cd ··電容； 100 :距離量測系統； 200 :目標物；0757-A22081TWF(N2); E0106274; DENNIS 13 200848767 The terms defined in the appended patent application shall prevail. f 0757-A22081TWF(N2); E0106274; DENNIS 14 200848767 [Simple description of the diagram] Figure 1 is a diagram showing the relationship between the output power of a light-emitting diode and temperature. Fig. 2 is an equivalent circuit diagram showing a light-emitting diode. Figure 3 illustrates the relationship between temperature and the reverse bias of the colliding photodiode; Figure 4 illustrates the relationship between the reverse bias and the capacitance of the collapsed photodiode. Figure 5 is a schematic view of the distance measuring system of the present invention. [Main component symbol description] 10 ··Processing unit; 20: Frequency synthesizer; 30: Driving unit; 40 ··Light emitting unit; 50: Optical mixing unit; 6 0 · Electric mixing early, BPF1~BPF3: Filter unit; R1~R4, Rd: resistance; C1~C3, Cd ··capacitance; 100: distance measurement system; 200: target;
Nl、N2 :節點； VB :偏壓； SM、SL、SL，，：調製信號； 0757-A22081TWF(N2)；E0106274；DENNIS 15 200848767 si :光束； S1” ：反射光束； S 3 ·電混頻信號， S2 :光混頻信號； S2”、S3 :信號。Nl, N2: node; VB: bias voltage; SM, SL, SL,,: modulation signal; 0757-A22081TWF(N2); E0106274; DENNIS 15 200848767 si: beam; S1": reflected beam; S 3 · electric mixing Signal, S2: optical mixing signal; S2", S3: signal.
0757-A22081TWF(N2)；E0106274；DENNIS 160757-A22081TWF(N2); E0106274; DENNIS 16