200540556 (1) 九、發明說明 【發明所屬之技術領域】 本發明係關於在數位相機等所使用的光圈裝置。更詳 細爲：關於抑制驅動時之驅動聲音的發生，最適合動畫（ 電影）模式攝影之光圈裝置。 【先前技術】 B 近年來，數位相機廣爲普及，其功能相當多功能化。 而且，於靜像專用之數位靜像攝影機附加有動畫攝影功能 。一般以靜像攝影機進行靜像攝影時，是先使扇形快門簾 幕（光圈扇形快門簾幕）移動而形成特定的光圈狀態。然 後，於使扇形快門簾幕停止於該位置之狀態下進行攝影。 可是，於進行動畫攝影時，周圍的亮度時時刻刻在變化， 所以需要因應此而調整光圈。因而，在動畫模式中，成爲 一面使扇形快門簾幕移動一面進行攝影。 # 在前述之動畫模式中，聲音也可以同時錄音。可是， 如以數位靜像攝影機進行動畫攝影時，則會發生光圈控制 之驅動聲音。此驅動聲音被相機所附有之麥克風所取得， 於再生錄影時，會有成爲噪音而被再生之問題。 因此’例如專利文獻1係提出：降低光圈之驅動時的 影響之數位相機。此數位相機係設置控制電動機之控制手 段’以使得光圈機構的驅動聲音於錄音之類比聲音訊號的 取樣週期間進入。如係此種數位靜像攝影機，電動機驅動 被控制爲光圈機構的驅動聲音發生於某取樣時間點和下一 -5- 200540556 (2) 取樣時間點之間。因此，可以防止光圈驅動機構之驅動聲 音被同時收錄。 [專利文獻1]日本專利特開200心23 5 02號公報 【發明內容】 [發明所欲解決之課題] 但是，專利文獻1所揭示之技術，係進行驅動電動機 # 使得驅動聲音於聲音訊號的取樣週期間進入之複雜的控制 。此控制並非在取樣週期之間來驅動電動機，而是使驅動 電動機時所發生之驅動聲音在取樣週期之間進入之控制’ 因此，控制邏輯變得複雜。另外，於專利文獻1之技術中 ，在需要以動畫模式驅動光圈機構之時序和聲音訊號之時 序週期爲一致時，爲了抑制驅動聲音進入，成爲不驅動電 動機。因此，在專利文獻1所提出之技術中，有時無法對 應周圍的亮度變化而驅動光圈機構。 • 因此，本發明之目的在於提供··攝影時，即使驅動扇 形快門簾幕，也可以抑制驅動聲音的發生之裝置。 [解決課題之手段] 前述目的可以藉由一種光圈裝置來達成，其係具備： 開閉形成於基板之開口的扇形快門簾幕、及驅動前述扇形 快門簾幕之電磁致動器、及控制前述電磁致動器的驅動之 控制手段；前述控制手段係實行一種驅動控制，該驅動控 制爲包含：在直到形成目的光圈狀態之位置爲止，而使前 -6 - 200540556 (3) 述扇形快門簾幕在移動的中途，使藉由前述電磁致動器之 前述扇形快門簾幕的驅動暫時停止之暫停步驟。如依據本 發明，以控制手段實行之驅動控制包含使藉由電磁致動器 之扇形快門簾幕的驅動暫時停止之暫停步驟的簡單構成方 式，和連續使電磁致動器驅動的情形相比，可以抑制所產 生的噪音。 另外，前述暫停步驟可以作成暫時切斷對前述電磁致 # 動器之通電。如此一來，可以抑制線圈之發熱或消耗電力 〇 另外，前述驅動控制可以包含：進行對前述電磁致動 器之通電的驅動步驟、和使前述暫停步驟交互地重複之間 歇驅動控制。即以使驅動和暫停之步驟交互地實行之間歇 驅動來移動扇形快門簾幕，能夠形成目的之光圈狀態。 另外，前述控制手段於在使對前述電磁致動器的通電 切斷後之際，較好爲在進行起始設定後，再度驅動該電磁 # 致動器。如此，於再度驅動時，如進行起始設定，即使發 生由於使電磁致動器停止時之位置偏差，也可將其去除。 如是具備如前述之光圈裝置的數位相機，可以抑制電磁致 動器的驅動聲音之影響而進行動畫攝影。 [發明效果] 如以上說明般，依據本發明，可以提供以包含使藉由 電磁致動器之扇形快門簾幕的驅動暫時停止之暫停步驟的 簡單之驅動控制，得以抑制驅動聲音的發生之光圈裝置。 -7- 200540556 (4) 另外，暫停步驟爲使對電磁致動器之通電暫時切斷之情形 ，可達成防止線圈的發熱及低消耗電力化。 【實施方式】 以下，依據圖面，針對本發明之一實施形態之光圈裝 置做說明。第1圖係顯示光圈開口爲全開之狀態下的光圈 裝置1之主要部份構造圖。另外，第2圖係顯示將光圈開 P 口設爲最小之光圈MN時之光圈裝置1圖。另外，第3圖 係將光圈裝置1所包含之1片的扇形快門簾幕（光圈扇形 快門簾幕）取出而顯示之圖。 第1圖中，光圈裝置1係具備形成有圓形的光圈開口 2 HL之基板2。可往箭頭RM方向轉動之光圈環5係被配 置於和基板2面平行。但是，第1圖所示之狀態係光圈環 5的位置爲位於旋轉至順時鐘方向之端部，因此，由第1 圖之狀態往反時鐘方向旋轉。此光圈環5係在中央部具有 • 環開口 5HL。此環開口 5HL和基板2的光圈開口 2HL係 略微同一形狀，光圈環5係被配置於基板2上，而使開口 彼此相互重疊。 本光圈裝置1係具備5片之扇形快門簾幕10-1〜10-5 ，其係伴隨前述光圈環5之旋轉動作而搖動，如此來變更 光圈開口 2HL之開度。5片之扇形快門簾幕10-1〜10-5之 各個係對於光圈開口 2HL之中心點CP，爲採取相互點對 稱之姿勢，藉由光圈環5而同樣地搖動，且協同動作而形 成特定光圈。 -8- 200540556 (5) 於基板2上係在圓周方向，以等間隔立設有3根固定 軸3-1〜3-5。前述5片之扇形快門簾幕10之各個係以此固 定軸3-1〜3-5爲支撐軸而搖動。另一方面，於光圏環5, 也在圓周方向，以等間隔立設有卡合銷6-1〜6-5。這些卡 合銷6-1〜6-5係卡合於形成在扇形快門簾幕10-1〜10-5 之特定形狀的凸輪溝1 1 · 1〜Π -5。藉此，根據光圈環5轉 動，各卡合銷6移動，於各凸輪溝1 1內滑動，因此，各 # 扇形快門簾幕1 0爲描繪特定軌跡而搖動。 第2圖係顯示由第1圖所示之全開狀態的光圈，使光 圈環5往反時鐘方向旋轉，設成最小光圈狀態之情形圖。 第2圖中，爲了容易確認被縮小之開口，係顯示劃上剖面 線之小的光圈開口 2MN之位置。另外，第3圖係顯示將 包含於本光圈裝置1之一片的扇形快門簾幕10-1取出， 光圈環5爲由第1圖之狀態旋轉爲第2之狀態時而搖動之 樣子圖。依據此第3圖，得以確認：卡合銷6- 1因光圈環 • 5之旋轉而往反時鐘方向移動時，則以固定軸3 -1爲中心 ，扇形快門簾幕1 0-1往順時鐘方向搖動。其它之扇形快 門簾幕10-2〜10-5也同樣地動作，因此，如第2圖所示般 ，可以縮小光圈開口 2HL。 再度參考第1圖來說明本光圈裝置1之驅動系統的構 造。如前述般，於改變光圈時，光圈環5被轉動。光圈環 5係具備突出於半徑方向之突出部5PR。於此突出部5PR 的前端係形成有齒排5 G A。此齒排5 G A係和藉由作爲電 磁致動器之步進電動機20的轉子部2 1所驅動的齒輪1 5 -9 - 200540556 (6) 嚙合。步進電動機20係藉由成爲控制手段之控制部25而 被控制驅動。因此，在本光圈裝置1被組裝於相機使用之 情形’控制部25係由相機側接受特定的光圈訊號，依據 此而控制步進電動機20，光圈環5被轉動，各扇形快門簾 幕1 〇被移動至應形成目的光圈之特定位置。另外，如第1 圖所示般，前述控制部25係藉由切換對於捲繞於配置於 步進電動機20內之定子的2個驅動線圈CA、CB所供給 # 之電流而進行步進電動機20的驅動控制。 然後，特別是本光圈裝置1所具備之控制部25，係含 有在動畫模式下使扇形快門簾幕移動時，爲了抑制驅動聲 音的發生，而驅動步進電動機20之優異的特徵。以下， 說明藉由此控制部25之步進電動機20的控制。於動畫模 式中，攝影之畫像係時時刻刻在改變。例如，於攝影中， 畫像變暗之情形，需要使扇形快門簾幕1 0往使光圈變大 側移動。進而，之後，於攝影畫像變明亮時，反之，需要 # 使扇形快門簾幕1 〇往使光圈變小側移動。如此，在動畫 模式中，目的光圈（攝影較好之光圈）之狀態係時時刻刻 地在改變。然後，扇形快門簾幕1 0連續地被移動而陸續 形成如此改變之合適的光圈狀態。因此，習知上，如先前 指出的，驅動噪音因而產生。 第4圖係顯示爲了形成目的光圈狀態而使位於某位置 之扇形快門簾幕10移動時，使步進電動機20之線圈CA 、CB激磁之形式例。即此第4圖可以視爲係顯示控制部 25對於線圈CA、CB所供給之電流的控制形式例。另外， -10- 200540556 (7) 此第4圖所示之Αν係表示特定之光圈値。具體爲：如光 圈打開爲1 Αν時，則開口面積設定成爲約2倍，反之，如 光圈縮小1 Αν時，則開口面積設定成爲約1 /2倍。 第4圖中，上段係顯示往小口徑變更（使光圏値變小 )之情形，即由第1圖之狀態朝第2圖之狀態而使各扇形 快門簾幕1 〇移動之情形的激磁形式例。另外，於下段係 顯示與此相反，使光圈往大口徑變更（使光圈値變大）之 # 情形，即由第2圖之狀態朝第1圖之狀態而使各扇形快門 簾幕1 〇移動之情形的激磁形式例。第4圖所示之上下段 ，兩者都是顯示將目的之光圈狀態由原來狀態變更爲 2/3Αν之情形的例子。 此第4圖中應著眼的是，在最初變更1/3 Αν之光圈値 的動作（驅動步驟）、和接著使變更1 /3 Αν値之動作之間 ，暫停步驟S Τ被插入之點。在此暫停步驟S Τ中，對於兩 線圈CA、CB之通電被斷絕。即在此暫停步驟ST中，步 • 進電動機20的驅動被停止。以至少包含1次之第4圖所 示之暫停步驟ST之激磁形式來驅動線圈CA、CB，而使 各扇形快門簾幕1 〇移動時，則可以大幅抑制噪音的發生 〇 第5圖係如習知般連續通電，於和第4圖相同之範圍 內，使各扇形快門簾幕10移動時之線圈CA、CB之激磁 形式圖。即此第5圖係不包含第4圖之暫停步驟ST，扇 形快門簾幕10被移動而使2/3Av之光圈値連續地變更。 但是，於第5圖中，於相當各1/3 Αν之光圈値之範圍，以 -11 - 200540556 (8) 及暫停步驟S T被插入之地方’被賦予符號s P，以便能確 認和第4圖之不同而加以圖示。 本申請案發明人等確認到：如第4圖般而設置暫停步 驟S T時，則和如習知般連續通電而使扇形快門簾幕1 〇移 動之情形（參考第5圖）相比，可以減輕約5分貝之驅動 噪音。第6圖係顯示其曲線。橫軸係顯示暫停步驟S τ之 停止時間，縱軸係顯示噪音減少値。如曲線所示般，如取 # 暫停步驟S T爲比較長時間，噪音値雖因而降低，但是， 暫停步驟S T如取太長時間，則扇形快門簾幕之移動過於 花時間。在本實施形態中，暫停步驟S T係設置約8 0〜 9 0ms之停止時間。如此一來，能以和習知光圏裝置的光 圈之驅動時間沒有大差異的時間而使光圈扇形快門簾幕驅 動，噪音也可以變小。即在本光圈裝置1中，在變更光圏 時，以插入使步進電動機20的驅動暫時停止之暫停步驟 之簡單的控制，和習知相比，可以抑制約35%之噪音發生 • 。另外，在暫停步驟中，不加以通電，因此，可以抑制線 圈的發熱。另外，消耗電力也降低。 另外，在第4圖中，雖顯示關於使光圈値做2/3 Αν變 更之情形，係將1次之暫停步驟ST插入1/3 Αν値之光圈 動作之間的例子，但是，此係其之一例。在變更之光圈値 變大的情形，可2次以上設定暫停步驟S Τ，重複地進行 間歇驅動。另外，1此之動作所變更之光圈値可以適當地 變更，進而，也可將目的光圈不分割爲同樣等分而以不同 値做設定。另外，在暫停步驟s τ中，對於步進電動機2 0 -12- 200540556 (9) 之通電係被斷絕，因此，步進電動機20之位置會有從以 起初之起始激磁所被停止之起始設定改變之情形。因此， 如第4圖所示般，在進入下一 1/3 Αν動作時（再驅動時） ，較好係於進行再度之起始激磁PR後，才實質地驅動步 進電動機20。另外，在第4圖中，暫停步驟雖顯示係使通 電成爲OFF(關閉）之例子，但是，也可在暫停步驟中，持 續通以保持脈衝，而使步進電動機20暫時停止。 φ 另外，第4圖雖以1-2相激磁來驅動步進電動機20 之情形爲其一例而顯示，但是，以2相激磁來驅動步進電 動機20之情形，不用說同樣可以抑制驅動聲音的發生。 以上說明之光圈裝置1只是簡單地控制步進電動機20，即 使是扇形快門簾幕1 〇連續移動之情形，也可以抑制驅動 聲音的發生。因此，如係組裝有此種光圈裝置之數位相機 ，則在動畫模式下，也可以抑制噪音發生，能夠攝影動畫 〇 Φ 以上，雖針對本發明之較好的一實施形態而詳細說明 ，但是，本發明並不限定於特定之實施形態，於申請專利 範圍所記載之本發明的要旨範圍內，可以做種種之變形、 變更。 【圖式簡單說明】 第1圖係顯示使光圈開口全開時之狀態的光圈裝置之 主要部份構造圖。 第2圖係使光圈開口成爲最小的光圈]y[N時之光圈裝 -13- 200540556 (10) 置圖。 第3圖係取出光圈裝置所包含之1片的扇形快門簾幕 而顯示之圖。 第4圖係顯示使光圏裝置所包含之步進電動機的線圈 激磁之形式例圖。 第5圖係顯示如習知般連續通電，使扇形快門簾幕在 和第4圖相同之範圍移動時之線圈的激磁形式圖。 第6圖係表示暫停步驟S T之停止時間和噪音減少値 之關係圖。 【主要元件之符號說明】 1 :光圈裝置， 2 :基板， 2HL :光圈開口， 3-1〜3-5:固定軸， 5 :光圈環， 6-1〜6-5:卡合銷， 1 0 :扇形快門簾幕’ 1 1 .1〜1卜5 :凸輪溝， 1 5 :齒輪’ 2 0 :步進電動機’ 2 1 :轉子部’ 2 5 :控制部’ S T :暫停步驟， -14- 200540556 (11) P R :起始激磁， C A、C B :驅動線圈’ CP :中心點， 5 P R :突出部， 5 G A :齒排200540556 (1) IX. Description of the invention [Technical field to which the invention belongs] The present invention relates to an aperture device used in a digital camera and the like. More details: Regarding suppressing the occurrence of driving sound during driving, it is the most suitable aperture device for shooting in movie (movie) mode. [Previous technology] B In recent years, digital cameras have become widespread and their functions have become quite versatile. In addition, the digital still camera dedicated to still images has a movie shooting function. Generally, when still images are taken with a still camera, the fan-shaped shutter curtain (aperture fan-shaped shutter curtain) is first moved to form a specific aperture state. Then, photographing was performed with the fan shutter curtain stopped at that position. However, when performing movie shooting, the surrounding brightness changes from moment to moment, so it is necessary to adjust the aperture accordingly. Therefore, in the animation mode, photography is performed while moving the fan shutter curtain. # In the aforementioned animation mode, sound can also be recorded at the same time. However, if a digital still camera is used for movie shooting, the driving sound of the aperture control will occur. This driving sound is obtained by the microphone attached to the camera, and there is a problem that it becomes a noise and is reproduced when recording and reproducing. Therefore, for example, Patent Document 1 proposes a digital camera that reduces the influence of the diaphragm when it is driven. This digital camera is provided with a control means for controlling the motor so that the driving sound of the aperture mechanism enters during the sampling period of the analog sound signal for recording. In this type of digital still camera, the driving sound of the motor drive controlled by the aperture mechanism occurs between a sampling time point and the next sampling time point. Therefore, it is possible to prevent the driving sound of the diaphragm driving mechanism from being simultaneously recorded. [Patent Document 1] Japanese Patent Laid-Open No. 200 heart 23 5 02 [Summary of the Invention] [Problems to be Solved by the Invention] However, the technique disclosed in Patent Document 1 is to drive a motor # so that the driving sound is based on the sound signal. Complex controls entered during the sampling week. This control is not to drive the motor between the sampling periods, but to control the driving sound that occurs when the motor is driven between the sampling periods'. Therefore, the control logic becomes complicated. In addition, in the technology of Patent Document 1, when the timing of driving the aperture mechanism in the animation mode and the timing period of the sound signal are consistent, the motor is not driven in order to suppress the entry of the driving sound. Therefore, in the technique proposed in Patent Document 1, it is sometimes impossible to drive the aperture mechanism in response to changes in ambient brightness. • Therefore, an object of the present invention is to provide a device that can suppress the occurrence of driving sound even when a fan-shaped shutter curtain is driven during shooting. [Means for Solving the Problem] The foregoing object can be achieved by an aperture device, which includes a fan-shaped shutter curtain that opens and closes an opening formed on a substrate, an electromagnetic actuator that drives the fan-shaped shutter curtain, and controls the electromagnetic The control means for driving the actuator; the aforementioned control means implements a type of drive control including: until the position of the objective aperture state is formed, the former -6-200540556 (3) the fan-shaped shutter curtain described above During the movement, the step of temporarily stopping the driving of the fan-shaped shutter curtain by the electromagnetic actuator is temporarily stopped. According to the present invention, the drive control performed by the control means includes a simple configuration of a pause step for temporarily stopping the drive of the fan shutter curtain by the electromagnetic actuator, as compared with the case where the electromagnetic actuator is continuously driven. The generated noise can be suppressed. In addition, the foregoing pause step may be performed to temporarily cut off the power to the electromagnetic actuator. In this way, it is possible to suppress heat generation or power consumption of the coil. In addition, the drive control may include a drive step of energizing the electromagnetic actuator and an intermittent drive control of repeatedly repeating the pause step. That is, moving the fan-shaped shutter curtain with intermittent driving in which the driving and pausing steps are performed alternately, can form the desired aperture state. In addition, the control means preferably drives the electromagnetic #actuator again after the initial setting is made after the power to the electromagnetic actuator is turned off. In this way, if the initial setting is made during re-driving, even if a position deviation occurs when the electromagnetic actuator is stopped, it can be removed. In the case of a digital camera having the aperture device as described above, it is possible to perform movie shooting while suppressing the influence of the driving sound of the electromagnetic actuator. [Effects of the Invention] As described above, according to the present invention, it is possible to provide an aperture that can suppress the occurrence of driving sound by a simple driving control including a pause step of temporarily stopping the driving of the fan-shaped shutter curtain by the electromagnetic actuator. Device. -7- 200540556 (4) In addition, the pause step is to temporarily cut off the energization of the electromagnetic actuator, which can prevent the heating of the coil and reduce the power consumption. [Embodiment] An aperture device according to an embodiment of the present invention will be described below with reference to the drawings. Fig. 1 is a structural diagram of a main part of the aperture device 1 in a state where the aperture opening is fully opened. In addition, FIG. 2 is a diagram showing the aperture device 1 when the aperture opening P port is set to the minimum aperture MN. In addition, FIG. 3 is a diagram showing one fan-shaped shutter curtain (iris fan-shaped shutter curtain) included in the aperture device 1 and displayed. In FIG. 1, the diaphragm device 1 includes a substrate 2 having a circular diaphragm opening 2 HL. The iris ring 5 which can be turned in the direction of the arrow RM is arranged parallel to the two surfaces of the substrate. However, the state shown in FIG. 1 is that the position of the aperture ring 5 is located at the end rotated to the clockwise direction. Therefore, the state shown in FIG. 1 is rotated to the counterclockwise direction. This aperture ring 5 has a ring opening 5HL in the center. The ring opening 5HL and the aperture opening 2HL of the substrate 2 are slightly the same shape. The aperture ring 5 is arranged on the substrate 2 so that the openings overlap each other. The aperture device 1 is provided with five fan-shaped shutter curtains 10-1 to 10-5, which is shaken in accordance with the rotation of the aperture ring 5 described above, and thus the opening of the aperture opening 2HL is changed. Each of the five fan-shaped shutter curtains 10-1 to 10-5, with respect to the center point CP of the aperture opening 2HL, adopts a point-symmetrical posture, and is similarly shaken by the aperture ring 5, and cooperates to form a specific aperture. -8- 200540556 (5) Three fixed shafts 3-1 to 3-5 are erected on the substrate 2 in a circumferential direction at regular intervals. Each of the aforementioned five-piece fan-shaped shutter curtain 10 is shaken with the fixed shafts 3-1 to 3-5 as support shafts. On the other hand, in the optical ring 5, engaging pins 6-1 to 6-5 are also erected at equal intervals in the circumferential direction. These engaging pins 6-1 to 6-5 are engaged with cam grooves 1 1 · 1 to Π -5 having a specific shape formed in a sector shutter curtain 10-1 to 10-5. Thereby, according to the rotation of the aperture ring 5, each of the engaging pins 6 moves and slides in each of the cam grooves 11. Therefore, each of the # fan-shaped shutter curtains 10 shakes to draw a specific trajectory. Fig. 2 is a diagram showing a situation where the aperture ring 5 is rotated in the counterclockwise direction from the fully-opened aperture shown in Fig. 1 to the minimum aperture state. In Fig. 2, in order to easily confirm the reduced opening, the position of the small aperture opening 2MN drawn with a hatching is shown. In addition, FIG. 3 is a diagram showing a state where the fan-shaped shutter curtain 10-1 included in one of the aperture devices 1 is taken out, and the aperture ring 5 is shaken when the aperture ring 5 is rotated from the state shown in FIG. 1 to the second state. Based on this figure 3, it can be confirmed that when the engaging pin 6-1 moves in the counterclockwise direction due to the rotation of the aperture ring 5, the fixed axis 3-1 is used as the center, and the fan-shaped shutter curtain 10-1 goes straight. The clock is shaking. The other shutter curtains 10-2 to 10-5 also operate in the same manner. Therefore, as shown in Fig. 2, the aperture opening 2HL can be reduced. Referring to FIG. 1 again, the structure of the drive system of the aperture device 1 will be described. As described above, when the aperture is changed, the aperture ring 5 is rotated. The aperture ring 5 is provided with a protruding portion 5PR protruding in the radial direction. A tooth row 5 G A is formed at the front end of the protruding portion 5PR. This gear train 5 G A is meshed with a gear 1 5 -9-200540556 (6) driven by a rotor portion 21 of a stepping motor 20 as an electromagnetic actuator. The stepping motor 20 is controlled and driven by a control unit 25 serving as a control means. Therefore, in the case where the aperture device 1 is assembled in a camera, the control unit 25 receives a specific aperture signal from the camera side, and controls the stepping motor 20 based on this, the aperture ring 5 is rotated, and each fan-shaped shutter curtain 1 〇 Moved to a specific position where the intended aperture should be formed. As shown in FIG. 1, the control unit 25 performs the stepping motor 20 by switching the current supplied to the two driving coils CA and CB wound around the stator disposed in the stepping motor 20. Drive control. In particular, the control unit 25 included in the aperture device 1 includes an excellent feature of driving the stepping motor 20 in order to suppress the occurrence of driving sound when the fan shutter curtain is moved in the animation mode. The control of the stepping motor 20 by the control unit 25 will be described below. In the animation mode, the portraits of photography are constantly changing. For example, in photography, when the image becomes dark, it is necessary to move the fan-shaped shutter curtain 10 to the side where the aperture becomes larger. Furthermore, after that, when the photographic image becomes bright, on the contrary, it is necessary to # move the fan-shaped shutter curtain 10 to the side where the aperture becomes smaller. In this way, in the animation mode, the state of the target aperture (the aperture for better photography) is constantly changing. Then, the fan-shaped shutter curtain 10 is continuously moved to successively form the appropriate aperture state thus changed. Therefore, conventionally, as previously noted, driving noise is generated. FIG. 4 shows an example of a form in which the coils CA and CB of the stepping motor 20 are excited when the fan-shaped shutter curtain 10 located at a certain position is moved to form a desired aperture state. That is, this fourth figure can be regarded as an example of the control form of the display controller 25 with respect to the currents supplied by the coils CA and CB. In addition, -10- 200540556 (7) Aν shown in FIG. 4 indicates a specific aperture 値. Specifically, if the aperture is opened to 1 Αν, the opening area is set to about 2 times, and conversely, if the aperture is reduced to 1 Αν, the opening area is set to about 1/2 times. In FIG. 4, the upper stage shows the excitation when the small-caliber change (making the light beam smaller) is changed, that is, the state of each of the fan-shaped shutter curtains is moved from the state of FIG. 1 to the state of FIG. 2. Form example. In addition, in the lower section, the opposite situation is shown. The situation where the aperture is changed to a large diameter (the aperture 値 becomes larger) is #, that is, the fan shutter curtains are moved from the state in FIG. 2 to the state in FIG. 1. Example of the excitation form. The upper and lower sections shown in Figure 4 both show examples of changing the objective's aperture state from the original state to 2 / 3Αν. In this fourth figure, the point at which the step S T is inserted is paused between the operation (driving step) of changing the aperture 値 of 1/3 Αν and the operation of changing 1/3 Αν 値 initially. In this pause step ST, the power to the two coils CA, CB is cut off. That is, in this pause step ST, the driving of the stepping motor 20 is stopped. The coils CA and CB are driven by the excitation form including the pause step ST shown in FIG. 4 at least once, and when each sector shutter curtain 10 is moved, the occurrence of noise can be greatly suppressed. The conventional continuous energization, in the same range as in Fig. 4, makes the fan-shaped shutter curtain 10 when the coils CA, CB excitation form diagram. That is, the fifth picture does not include the pause step ST of the fourth picture, and the fan shutter curtain 10 is moved to continuously change the aperture 値 of 2 / 3Av. However, in FIG. 5, the symbol s P is assigned to -11-200540556 (8) and the place where the pause step ST is inserted in a range corresponding to the aperture Α of each 1/3 Αν. The difference is illustrated. The inventors of the present application have confirmed that when the pause step ST is provided as shown in FIG. 4, compared with the case where the fan-shaped shutter curtain 10 is moved by continuously applying power as in the conventional case (refer to FIG. 5), Reduces driving noise by about 5 dB. Figure 6 shows the curve. The horizontal axis shows the stop time of the pause step S τ, and the vertical axis shows the noise reduction 値. As shown in the graph, if # Pause step ST is taken for a relatively long time, the noise may be reduced, but if Pause step ST is taken for a long time, the movement of the fan shutter curtain takes too much time. In this embodiment, the pause step S T sets a stop time of about 80 to 90 ms. In this way, the aperture fan shutter curtain can be driven at a time that is not significantly different from the driving time of the aperture of the conventional optical device, and the noise can be reduced. That is, in the aperture device 1, when changing the light beam, a simple control that inserts a pause step for temporarily stopping the driving of the stepping motor 20 can suppress about 35% of noise generation compared with the conventional one. In addition, since no power is applied during the pause step, the heating of the coil can be suppressed. In addition, power consumption is also reduced. In addition, in FIG. 4, the case where the aperture 値 is changed by 2/3 Αν is shown as an example in which the one-time pause step ST is inserted between the aperture operations of 1/3 Αν 値. However, this is the case An example. In the case where the aperture 变更 to be changed becomes large, the pause step S T can be set more than 2 times, and intermittent driving can be repeatedly performed. In addition, the aperture 値 changed by this operation can be changed as appropriate, and the target aperture can also be set with different 不 without dividing the target aperture into the same equal division. In addition, in the pause step s τ, the energizing system for the stepping motor 2 0 -12- 200540556 (9) is cut off. Therefore, the position of the stepping motor 20 will be from the time when the initial excitation is stopped. When the settings are changed. Therefore, as shown in FIG. 4, when the next 1/3 Aν operation is performed (during re-driving), it is preferable that the stepping motor 20 is substantially driven only after the re-starting excitation PR is performed. In addition, although the pause step is shown in FIG. 4 as an example of turning off the power, the step motor 20 may be temporarily stopped by continuously turning on the pulse during the pause step. φ In addition, in FIG. 4, the case where the stepping motor 20 is driven by 1-2 phase excitation is shown as an example, but the case where the stepping motor 20 is driven by 2 phase excitation is needless to say. occur. The diaphragm device 1 described above simply controls the stepping motor 20, and even if the fan-shaped shutter curtain 10 moves continuously, the occurrence of driving sound can be suppressed. Therefore, if the digital camera is equipped with such an aperture device, it is possible to suppress the occurrence of noise in the animation mode, and it is possible to shoot movies more than 0Φ. The invention is not limited to a specific embodiment, and various modifications and changes can be made within the scope of the gist of the invention described in the scope of the patent application. [Brief description of the drawing] Fig. 1 is a structural diagram of the main part of the aperture device showing the state when the aperture opening is fully opened. Figure 2 shows the aperture with the smallest aperture opening] y [N aperture setting -13- 200540556 (10). Fig. 3 is a view showing one fan-shaped shutter curtain included in the aperture device. Fig. 4 is a diagram showing an example of a form of exciting a coil of a stepping motor included in the photonic device. Fig. 5 is a diagram showing a form of excitation of a coil when a conventional shutter is continuously energized and the fan-shaped shutter curtain is moved in the same range as in Fig. 4; Fig. 6 is a graph showing the relationship between the stop time of the pause step S T and the noise reduction 値. [Symbol description of main components] 1: aperture device, 2: base plate, 2HL: aperture opening, 3-1 ~ 3-5: fixed shaft, 5: aperture ring, 6-1 ~ 6-5: engagement pin, 1 0: sector shutter curtain 1 1 .1 to 1 5 5: cam groove, 1 5: gear '2 0: stepper motor' 2 1: rotor section '2 5: control section' ST: pause step, -14 -200540556 (11) PR: initial excitation, CA, CB: drive coil 'CP: center point, 5 PR: protrusion, 5 GA: tooth row
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