1338162 _ ' 099年11月22日修正替換頁 < _ _ 六、發明說明： 【發明所屬之技術領域】 [0001] 本發明涉及一種數位相機之自動對焦裝置，尤其是涉及 電子裝置用數位相機之自動對焦裝置。 【先前技術】1338162 _ 'November 22, 099, the revised replacement page < _ _ 6. Description of the Invention: [Technical Field] [0001] The present invention relates to an autofocus device for a digital camera, and more particularly to a digital camera for an electronic device The autofocus device. [Prior Art]
[0002] —般電子裝置（如手機、PDA等）用數位相機之光學模組 大都為定焦設計類型因而無法實現變焦功能。而為拍攝 到更遠之物體需要改變物距，因而需要調整鏡頭之位置 ，傳統數位相機之對焦機構一般採用馬達及傳動機構帶 動鏡片移動進行對焦動作，其需要配置複雜的傳動機構 才能實施，無法使用在體積較小的電子裝置上。 [0003] 習知技術中，採用壓電元件驅動透鏡以實現湘機之聚焦 ，如美國專利第4, 601，539號，其揭示一種利用壓電元 件之透鏡驅動裝置（lens moving device using piezoelectric material)，該透鏡驅動裝置在鏡筒 之一端設壓電元件、另一端設彈性元件或兩端均設壓電 φ 元件，該壓電元件具使光線通過之中心通孔。當一定電 壓施加至壓電元件時，壓電元件產生機械形變推動透鏡 在鏡筒中移動實現聚焦功能，當無電壓施加在壓電元件 上時，在彈性元件之作用下透鏡恢復初始位置，或者， 電壓施加於另一壓電元件上，該壓電元件發生機械形變 推動透鏡反向移動回到初始位置。 [0004] 惟，習知技術之透鏡驅動裝置藉由壓電元件之作用使透 鏡之位置發生變化，以實現對焦功能，因該裝置需在鏡 筒之兩端設置壓電元件或一端設置壓電元件、另一端設 093139361 表單編號A0101 第3頁/共10頁 0993416819-0 1338162 [0005] [0006] [0007] [0008] [0009] 093139361 099年11月22日核正替換言 彈性元件，從而使該透鏡驅動裝置之結構複雜。 因此，提供一種結構簡單、利用壓電效應實現自動對焦 功能之裝置實為必須。 【發明内容】 本發明之目的在於提供一種結構簡單、壓電效應實現對 焦功能之自動對焦裝置。 為實現本發明之目的，本發明之技術方案係：一種自動 對焦裝置，包括鏡頭筒，其中鏡頭筒中含有第一鏡片組 、第二鏡片組及一透鏡，該第一鏡片組、第二鏡片組及 該透鏡之組合可實現對焦功能壓電元件安裝於鏡頭 筒内，該透鏡容置於該壓電沅件中Λ Μ電元件之電性連 接一可變電壓電路，該壓電:元件聲:圓環#結構，且内圈 上開設一環形凹槽，該透鏡容置於該環形凹槽内；該壓 電元件產生機械形變時，該透鏡之幾何外形發生徑向及 縱向拉伸之改變而使該透鐃之焦距發生相.應變化。 相較於習知技術，本發明之自動對焦裝置藉由壓電元件 之機械形變使透鏡之幾何形狀於縱向及徑向同時發生改 變，從而使第一鏡片組、第二鏡片組及透鏡之組合實現 焦距之改變以實現自動對焦功能，因而該自動對焦裝置 結構簡單。[0002] The optical modules of digital cameras (such as mobile phones, PDAs, etc.) are mostly fixed-focus design types and thus cannot be zoomed. In order to capture objects farther away, it is necessary to change the object distance. Therefore, the position of the lens needs to be adjusted. The focusing mechanism of the conventional digital camera generally uses a motor and a transmission mechanism to move the lens to perform a focusing operation, which requires a complicated transmission mechanism to be implemented. Used on smaller electronic devices. [0003] In the prior art, a piezoelectric element is used to drive a lens to achieve a focus of a Xiang machine. For example, US Patent No. 4,601,539 discloses a lens moving device using a piezoelectric material. The lens driving device is provided with a piezoelectric element at one end of the lens barrel, an elastic element at the other end, or a piezoelectric φ element at both ends, the piezoelectric element having a central through hole through which light passes. When a certain voltage is applied to the piezoelectric element, the piezoelectric element generates a mechanical deformation to push the lens to move in the lens barrel to achieve a focusing function. When no voltage is applied to the piezoelectric element, the lens returns to the initial position under the action of the elastic element, or The voltage is applied to another piezoelectric element that mechanically deforms to push the lens back into the initial position. [0004] However, the lens driving device of the prior art changes the position of the lens by the action of the piezoelectric element to achieve the focusing function, because the device needs to have a piezoelectric element at one end of the lens barrel or a piezoelectric element at one end. Element, the other end is set to 093139361 Form No. A0101 Page 3 / Total 10 Page 0993416819-0 1338162 [0005] [0007] [0008] [0009] 093139361 November 22, 099, the replacement of the elastic element, thereby The structure of the lens driving device is complicated. Therefore, it is necessary to provide a device having a simple structure and realizing an autofocus function by using a piezoelectric effect. SUMMARY OF THE INVENTION An object of the present invention is to provide an autofocus device that has a simple structure and a piezoelectric effect to achieve a focus function. For the purpose of the present invention, the technical solution of the present invention is an autofocus device comprising a lens barrel, wherein the lens barrel includes a first lens group, a second lens group and a lens, and the first lens group and the second lens group And the combination of the lens can realize the focusing function, the piezoelectric element is mounted in the lens barrel, and the lens is received in the piezoelectric element, and the electrical component is electrically connected to a variable voltage circuit, the piezoelectric component: a ring # structure, and an annular groove is formed in the inner ring, the lens is received in the annular groove; when the piezoelectric element is mechanically deformed, the geometric shape of the lens changes in radial and longitudinal directions. The focal length of the lens should be changed. Compared with the prior art, the autofocus device of the present invention changes the geometry of the lens in the longitudinal direction and the radial direction by mechanical deformation of the piezoelectric element, so that the combination of the first lens group, the second lens group and the lens The focal length is changed to achieve the autofocus function, and thus the autofocus device has a simple structure.
【實施方式】 請參閱第一圖、第二圖所示，本發明之自動對焦裝置100 包括鏡頭筒10、壓電元件14。 該鏡頭筒10内設有第一鏡片組11、第二鏡片組12及透鏡 表單編號Α0101 第4頁/共10頁 0993416819-0 [0010] 1338162 _ • . I 099年11月22日梭正替換頁 1 3，該透鏡1 3位於第一鏡片組1 1與第二鏡片組1 2之間， 透鏡13與第一鏡片組11、第二鏡片組12亦可係其他位置 關係。 [0011] 該壓電元件14係圓環結構，其外徑略小於鏡頭筒10之内 徑’且沿圓週整體凹陷形成一凹槽140，該透鏡13用膠水 固定於該凹槽140内。該壓電元件14亦可用膠水固定於鏡 頭筒10内壓電元件14内圓環、外圓環分別具有與電壓 產生電路20相連接之正電極、負電極，以使電壓施加於 φ 壓電元件14上β [0012] 其中，該壓電元件14具機電轉換功能，可將施加其上之 電能轉換為相應之機械能，因而該壓電元件14於電場之 作用下可發生一定形狀之機械形變，該壓電元件14可為 壓電陶瓷。因’壓電元件14之機械形變與施加其上電場 強度Ε係正比例關係，可用下述簡單公式表示壓電元件14 之形變量與電場強度忍之比例關係：公丑，^為壓 φ 電元件14在某一電場強度丑時之形變量，y為壓電元件 14之壓電常數。由上述公式可知：如要使壓電元件14發 生一定形變公時可施加^倍數之電場。 [0013] 當給壓電元件14施加一與極化方向相同（或相反）電場 時，由於電場方向與極化方向相同（或相反），起著極 化強度增大（或減小）之作用，使壓電元件14引起沿極 化方向增長（或縮短）之機械形變。 093139361 表單編號A0101 第5頁/共1〇頁 0993416819-0 竹 38162 [0014] 099年11月22日梭正替換*S 該透鏡1 3之形狀於外力作用下可發生縱向及徑向之改變 ’其可由PMMA (polymethyl methacrylate，即聚甲 基丙烯酸曱酯）、PC (phosphatidyl choline，為磷 δ旨膽鹼，磷肌酸）或PDMS (polydimethyl s i1oxane ，即聚二曱基矽氧烷，又稱矽膠）等材料製成。 [⑻ 15] [0016] 組裝時’首先將透鏡13壓縮固定於壓電元件14之凹槽140 中，其次將第一鏡片組11、壓電元件14及第二鏡片組12 分別放入鏡頭筒10中’於透鏡13之初始狀態下與第一鏡 片組Π、第二鏡片組12進行對焦操作，最後，用膠水固 定壓電元件14、第一鏡片組11與第二鏡片組12。 在使用時’對焦誤差檢測器龙圖，未示)½測到誤差信號 .'.C 時，電壓產生電路20輸出電:；！.；^如至壓:電元件14上，壓 電元件14於該電壓作用下產生機械形變，由初始狀態沿 極化方向增長之機械形變，該形變量使容置在其中透鏡 13之幾何外形發生徑向及縱向拉伸之改變，透鏡13形狀 之改變引起其本身之焦距發生相應變化。[Embodiment] Referring to the first and second figures, the autofocus device 100 of the present invention includes a lens barrel 10 and a piezoelectric element 14. The lens barrel 10 is provided with a first lens group 11, a second lens group 12, and a lens form number Α0101. Page 4/10 pages 0993416819-0 [0010] 1338162 _ • I. November 22, 2009, the shuttle is being replaced. The lens 13 is located between the first lens group 1 1 and the second lens group 1 2 , and the lens 13 and the first lens group 11 and the second lens group 12 may be in other positional relationship. [0011] The piezoelectric element 14 is a ring-shaped structure having an outer diameter slightly smaller than the inner diameter of the lens barrel 10 and integrally recessed along the circumference to form a groove 140, and the lens 13 is fixed in the groove 140 by glue. The piezoelectric element 14 can also be fixed to the inner ring of the piezoelectric element 14 in the lens barrel 10 by glue, and the outer ring has a positive electrode and a negative electrode connected to the voltage generating circuit 20, respectively, so that a voltage is applied to the φ piezoelectric element. 14上β [0012] wherein the piezoelectric element 14 has an electromechanical conversion function, which can convert the electrical energy applied thereto into a corresponding mechanical energy, and thus the piezoelectric element 14 can undergo a mechanical deformation of a certain shape under the action of an electric field. The piezoelectric element 14 can be a piezoelectric ceramic. Since the mechanical deformation of the piezoelectric element 14 is proportional to the electric field strength applied thereto, the following simple formula can be used to express the proportional relationship between the shape variable of the piezoelectric element 14 and the electric field strength: ugly, ^ is the voltage φ electrical component 14 is the shape variable of a certain electric field strength ugly, and y is the piezoelectric constant of the piezoelectric element 14. It can be seen from the above formula that an electric field of a multiple can be applied if a certain deformation of the piezoelectric element 14 is to be made. [0013] When an electric field of the same (or opposite) direction as the polarization direction is applied to the piezoelectric element 14, since the direction of the electric field is the same as (or opposite to) the polarization direction, the polarization intensity is increased (or decreased). The piezoelectric element 14 is caused to cause mechanical deformation that increases (or shortens) in the polarization direction. 093139361 Form No. A0101 Page 5 of 1 Page 0993416819-0 Bamboo 38162 [0014] On November 22, 099, the shuttle is replacing *S. The shape of the lens 13 can change longitudinally and radially under the action of external force. It can be composed of PMMA (polymethyl methacrylate), PC (phosphatidyl choline, phosphorus δ choline, phosphocreatine) or PDMS (polydimethyl s i1oxane), also known as polydimethyl fluorene oxide. Made of silicone rubber and other materials. [(8) 15] [0016] When assembling, the lens 13 is first compression-fixed in the groove 140 of the piezoelectric element 14, and then the first lens group 11, the piezoelectric element 14, and the second lens group 12 are respectively placed in the lens barrel. In the initial state of the lens 13, the first lens group Π and the second lens group 12 are focused, and finally, the piezoelectric element 14, the first lens group 11, and the second lens group 12 are fixed by glue. When used, the 'focus error detector dragon map, not shown' 1⁄2 detects the error signal . '.C, the voltage generating circuit 20 outputs electricity:;! For example, to the voltage: the electrical component 14, the piezoelectric component 14 undergoes mechanical deformation under the action of the voltage, and the mechanical deformation of the initial state increases along the polarization direction, and the deformation variable accommodates the geometric shape of the lens 13 therein. A change in the radial and longitudinal stretching occurs, and the change in the shape of the lens 13 causes a corresponding change in the focal length of itself.
[0017] 透鏡13之焦距改變可使其與第一鏡片組11、第二鏡片組 12之組合光學系統之焦距發生變化，其三者之焦距與組 合之光學系統之焦距有如下關係：[0017] The focal length of the lens 13 can be changed to change the focal length of the combined optical system of the first lens group 11 and the second lens group 12. The focal lengths of the three lenses are related to the focal length of the combined optical system as follows:
其中，/係組合光學系統之等 效焦距、乂係第一鏡片組11之焦距、 /係第二鏡片組 12之焦距、 Λ 係透鏡13之焦距 093139361 表單编號Α0101 第6頁/共10頁 0993416819-0 1338162 t 〆 /099年11月22日按正替换頁 各I.、决差檢測器檢測到一對焦信號時，電壓源20保持 銳1电壓值不皮，可使得壓電元件14保持當前之機械形 夂里從而透鏡13之幾何形狀固定，透鏡13之焦距固定 ，因而透鏡13之焦距發生變化從而使第—鏡片組u、第 一鏡片組13及透鏡13之光學模組實現對焦功能。 [0019]當該光學模組欲恢復原始狀態時，斷開電壓產生電路2〇 對壓電元件14之電壓輸出，該壓電元件14產生反向之機 械形變恢復初始狀態’從而可使透鏡13之幾何形狀恢復 • 原始尺寸。 陶]综上所述，本發明符合發明專利要件，爰依法提出專利 申請。惟，以上所述者僅料發明之較佳實施例，舉凡 熟悉本發明技藝之人士，在援依本發明創作精神所作之 等效修飾或變化，皆應包含於以下之中請專利範圍内。 【圖式簡單說明】 _第-圖係本發明自動對焦裝置之源始狀態示意圖。 φ [_第二圖係本發明自動對焦裝置之對焦狀態示意圖。 【主要元件符號說明】 [0023] 自動對焦裝置：1〇〇 [0024] 鏡頭筒：10 [0025] 第一鏡片組：11 [0026] 第二鏡片組：12 [0027] 透鏡：13 [0028] 壓電元件：14 093139361 表單編號A0101 第7頁/共10頁 0993416819-0 1338162 099年11月22日修正薄换试 [0029] 凹槽：140 [0030] 電壓產生電路：20Wherein, the equivalent focal length of the /-combined optical system, the focal length of the first lens group 11 of the tether, the focal length of the second lens group 12, and the focal length of the tether lens 13 093139361 Form No. 1010101 Page 6 of 10 0993416819-0 1338162 t November 22, 2009, according to the positive replacement page I., the difference detector detects a focus signal, the voltage source 20 maintains the sharp 1 voltage value is not skinned, so that the piezoelectric element 14 can be maintained In the current mechanical shape, the geometry of the lens 13 is fixed, the focal length of the lens 13 is fixed, and the focal length of the lens 13 is changed to achieve the focusing function of the optical modules of the first lens group u, the first lens group 13 and the lens 13. . When the optical module is to be restored to the original state, the voltage generating circuit 2 turns off the voltage output of the piezoelectric element 14, and the piezoelectric element 14 generates a reverse mechanical deformation recovery initial state 'to thereby enable the lens 13 Geometry recovery • Original size. Tao] In summary, the present invention complies with the requirements of the invention patent and submits a patent application according to law. However, the above-mentioned preferred embodiments of the present invention are intended to be equivalent to those skilled in the art, and equivalent modifications or variations made by the spirit of the present invention should be included in the following patent claims. [Simple Description of the Drawings] _The first figure is a schematic diagram of the source state of the autofocus device of the present invention. φ [_Second diagram is a schematic diagram of the focus state of the autofocus device of the present invention. [Main component symbol description] [0023] Autofocus device: 1〇〇 [0024] Lens barrel: 10 [0025] First lens group: 11 [0026] Second lens group: 12 [0027] Lens: 13 [0028] Piezoelectric element: 14 093139361 Form No. A0101 Page 7 of 10 0993416819-0 1338162 November 22, revised correction test [0029] Groove: 140 [0030] Voltage generation circuit: 20
0993416819-0 093139361 表單編號A0101 第8頁/共10頁0993416819-0 093139361 Form No. A0101 Page 8 of 10