201211671 六、發明說明： [0001] 【發明所屬之技術領域】 本發明涉及一種光學設備及其 圖像失真校正方法 係關於一種投影儀及其梯形失真校正方法 【先前技術】 ’尤其 [0002] Ο 當使用投影儀將圖像畫面投射到投影 找* (例如替墓1> 踏面）上顯科，往往由於投影儀與投純域 或 置關係使得顯示於投影區域上之圖德 、位 叫1豕置面產生梯形 。通常’使用者藉由手動調節投影儀與投影區域：、 位置來校正梯形失真，例如藉由操作投影儀上之 對 失 不 行梯形失真魅，或者使用遙控器遠料控完成t進 真校正。這種手浦作㈣校正._失真之方式相對 方便，而且不能保證完全消除梯形失真現專從而盔、·、 能獲得最佳之畫面投影效果。 ’’、、决 【發明内容】201211671 VI. Description of the Invention: [0001] The present invention relates to an optical device and an image distortion correction method thereof relating to a projector and a trapezoidal distortion correction method thereof [Prior Art] 'Special [0002] Ο When using a projector to project an image onto a projection to find a * (for example, a tomb 1 > tread), the map is displayed on the projection area due to the relationship between the projector and the pure field. The surface creates a trapezoid. Usually, the user corrects the trapezoidal distortion by manually adjusting the projector and the projection area: position, for example, by operating the projector on the trapezoidal distortion, or using the remote control to complete the t-correction. This kind of hand-pull (4) correction. _ distortion is relatively convenient, and can not guarantee the complete elimination of keystone distortion, and now the helmet, ·, can get the best picture projection effect. ‘’, 决 决 【Contents】
圃冑於以上内有必要提供一種投影儀及其梯形失真校 正方法，能夠對投影儀於畫面投影過程中產生之梯形2 真進行自動校正，以便獲得最佳晝面之投影效果。〆 [0004]所述之投影儀包括投射鏡頭、驅動單元、儲存單元、攝 像單元及梯形校正單元。該梯形校正單元包括：初妗化 模組，用於從儲存單元内讀取一幅内白外黑之正方形圖 片，及控制投射鏡頭於所述投射區域内投射該内白外黑 之正方形圖片；行校正模組，用於控制投射鏡頭於每一 梯形行校正等級下向投射區域投射正方形圖片，藉由攝 像單元於每一梯形行校正等級下從投射區域内攝取影像 099130947 表單編號A0101 第3頁/共20頁 0992054263-0 201211671 ，及藉由比較每一幅影像之每一行白色圖元點之開始位 置來對梯形失真進行梯形行校正；列校正模組，用於用 於控制投射鏡頭於每一梯形列校正等級下向投射區域投 射正方形圖片，藉由攝像單元於每一梯形列校正等級下 從投射區域内攝取影像，及藉由比較每一幅影像之每一 列白色圖元點之開始位置來對梯形失真進行梯形列校正 0 [0005] 所述之投影儀的梯形校正方法包括步驟：從儲存單元内 讀取一幅内白外黑之正方形圖片，並控制投射鏡頭於使 用者選定之投射區域内投射該内白外黑之正方形圖片； 控制投射鏡頭於每一梯形行校正等級下向投射區域投射 正方形圖月；藉由攝像單元於每一梯形行校正等級下從 投射區域内攝取影像；藉由比較每一幅影像之每一行白 色圖元點之開始位置來對梯形失真進行梯形行校正；控 制投射鏡頭於每一梯形列校正等級下向投射區域投射正 方形圖片；藉由攝像單元於每一梯形列校正等級下從投 射區域内攝取影像；藉由比較每一幅影像之每一列白色 圖元點之開始位置來對梯形失真進行梯形列校正。 [0006] 相較於習知技術，本發明所述之投影儀及其梯形失真校 正方法能夠對投影儀於畫面投影過程中產生之梯形失真 進行自動校正，以便獲得最佳晝面之投影效果。 【實施方式】 [0007] 如圖1所示，係本發明投影儀100較佳實施例之架構圖。 於本實施例中，該投影儀100包括梯形校正單元1、投射 鏡頭2、驅動單元3、攝像單元4、儲存單元5及微處理器6 099130947 表單編號A0101 第4頁/共20頁 0992054263-0 201211671 。當投影儀100藉由投射鏡頭2投射圖像畫面（例如圖2八 所示之正方形圖片）到投影區域（例如螢幕或牆面）上 時，往往由於投影儀與投影區域之相對位置關係使得 顯示於投影區域上之圖像晝面會產生梯形失真（例如圖 託所示之梯形圖片）。所述之梯形校正單元1用於對投射 鏡頭2於晝面投影過程中產生之梯形失真進行自動校正， 例如將圖2B所示之梯形圖片校正還原為2A所示之正方形 圖片，以便獲得最佳畫面之投影效果。 0 [〇〇〇8]所述之投射鏡頭2是指一種具有校正梯形失真功能之光學 控制鏡頭，能夠對梯形失真圖像（例如圖肫所示之梯形 圖片）進行梯形失真校正，其;包括梯形行校正及梯形列 权正。於本實施例中，投射鏡頭,2之‘形行校正及列校正 均包括10至+ 10共20個校正等級’例如-]_〇至_9為第一 等級、-9至-8為第二等級、….、9至1〇為第二十等級。 其中’最小校正等級為第一等級.，最大校正等級為第二 十等級。 ：* 〇 [漏]所述之驅動單每I蠢^-輕驅動馬達，其用於控制投射鏡頭 2於校正梯形等級範圍内移動來調節投射鏡頭2之梯形校 正等級’從而自動對投射鏡頭2投射於投影區域内圖像畫 面產生之梯形失真進行校正。 [0010] 所述之攝像單元4為一種具有攝像功能之攝像裝置，例如 攝像頭。該攝像單元4用於從投射區域内之投影晝面攝取 影像，並將該影像發送給梯形校正單元1進行梯形失真校 正0 099130947 表單編號A0101 第5頁/共20頁 0992054263-0 201211671 [0011] [0012] [0013] 所迷之镏存單元5為 己憶體（ρι_ Memory)或者為外部儲存卡。該铸存單一 投射於投影區域内之固定形状图像， 用於儲存所需 头I括但不限於 正方形圖片、矩形圖片、菱形圖片或 、’ U闺片。於太眘 施例中’以正方形圖片为例进行说明， ^ 通正方形圖片係 為一幅内白外黑，例如圖2 A所示之正方形圖片 ’、 所述之梯形校正單元1包括初始化模組〜 行才父正模纟且1 ? 及列校正模組13。本發明所稱之模組可為由多個電子元 器件構成之硬體電路，也可為由—系列計算指人纟成7^ 電腦程式程式段。於未實施例申，所述之模組a 夠被微處理器6所執行並且能夠完成固定功能之^ 段，其儲存於所述之儲存單元5中。 所述之初始化模組11用於於投影儀100加電開機時藉由驅 動單元3啟動投射鏡頭2將梯形行校正等級移動至最小行 校正等級，或者將梯形列校正等級移動至最小列校正等 級之位置’例如行校在等級[-10至-9 ]處，或者列校正等 級[-10至-9]處。該初始化模組11還用於從儲存單元5内 讀取一幅内白外黑之正方形圖片，及控制投射鏡頭2於使 用者選定之投射區域内投射該正方形圖片。 [〇〇14] 所述之行校正模組12用於控制投射鏡頭2於每一梯形行校 正等級下向投射區域内投射正方形圖片，藉由攝像單元4 於每一梯形行校正等級下從投射區域内攝取影像，及藉 由比較每一幅影像之每一行白色圖元點之開始位置來對 梯形失真進行梯形行校正。於本實施例中，所述之影像 均是由黑色圖元點和白色圖元點組成之内白外黑影像’ 099130947 表單編號A0101 第6頁/共20頁 0992054263-0 201211671 其中黑色圖元點之RGB值0-50，白色圖元點之RGB值 5〇、255。於正常室内光線下，當黑色圖元點之RGB值高 於5〇時，人眼就不宜分辨出影像之黑色圖元點，此時圖 元點之RGB值就認為是白色圖元點之開始位置，例如圖2B 所示之PI、P2、P3、…Pn點。其具體之梯形行校正方 法，請參照圖3所示說明。 [0015] 所述之列校正模組13用於控制投射鏡頭2於每一梯形列校 正等級下向投射區域内投射正方形圖片’藉由攝像單元4 於每一梯形列校正等級下從投射區域内攝取影像，及藉 由比較每一幅影像之每一列白色圖元點之開始位置來對 梯形失真進行梯形列校正。其具體之梯形列校正方法， 請參照圖4所示說明。 ，一 :: [0016] 如圖3所示，係本發明投影儀梯形失真之梯形行校正方法 較佳實施例之流程圖。於本實施例中，該梯形行校正方 法能夠自動對投射鏡頭2於畫面投影過程中產生之梯形失 真進行梯形行校正。 w，： [0017] 步驟S30，初始化模組11從儲存單元5内讀取—幅内白外 黑之正方形圖片（例如圖2A所示之正方形圖片），並藉 由投射鏡頭2於使用者選定之投射區域内投射該内白外累 之正方形圖片’此時投射鏡頭2投射出之正方形圖片 生梯形失真，例如圖2B所示之梯形圖片。 [0018]步驟S31，初始化模組11藉由驅動單元3驅動投射鏡頭2將 梯形行校正等級移動至最小行校正等級，例如行校正等 級[-10至-9]處。 099130947 表單編號A0101 第7頁/共20頁 〇992〇54263-〇 201211671 [0019] 步驟S32，行校正模組12藉由攝像單元4從投射區域攝取 第一影像，並將該第一影像之每一行白色圖元點之開始 位置（即，第一影像之每一行首先出現白色圖元點之RGB 值，例如圖2B戶斤示之PI、P2、P3、".Pn點之RGB值）放 入第一行陣列。 [0020] 步驟S33，行校正模組12於第一行陣列中找出白色圖元點 之開始位置最大值與最小值，並將最大值減去最小值計 算出該最大值與最小值之第一差值。 [0021] 步驟S34，行校正模組12控制驅動單元3驅動投射鏡頭2將 梯形行校正等級增加一個行校正等級，例如將梯形行校 正等級移動至行校正等級[-9至-8]處。 [0022] 步驟S35，行校正模組12藉由攝像單元4從投射區域内攝 取第二影像（即，第二影像之每一行首先出現白色圖元 點之RGB值，例如圖2B所示之PI、P2、P3、“.Pn點之 RGB值），並將該第二影像每一行白色圖元點之開始位置 放入第二行陣列。 [0023] 步驟S36，行校正模組12於第二行陣列中找出白色圖元點 之開始位置最大值與最小值，並將最大值減去最小值計 算出該最大值與最小值之第二差值。 [0024] 步驟S37，行校正模組12判斷第二差值是否大於第一差值 。若第二差值大於第一差值，步驟S38，行校正模組12將 第二差值作為第一差值儲存於儲存單元5中，而後執行步 驟S34。若第二差值小於第一差值，步驟S39，行校正模 組1 2控制驅動單元3驅動投射鏡頭2將梯形行校正等級回 099130947 表單編號A0101 第8頁/共20頁 0992054263-0 201211671 [0025] [0026]In the above, it is necessary to provide a projector and its trapezoidal distortion correction method, which can automatically correct the trapezoidal 2 generated by the projector during the screen projection process, so as to obtain the best projection effect. The projector according to [0004] includes a projection lens, a driving unit, a storage unit, a photographing unit, and a trapezoidal correction unit. The trapezoidal correction unit comprises: a preliminary decoding module, configured to read a square image of white and black outside from the storage unit, and control the projection lens to project the square image of the inner white and outer black in the projection area; The line correction module is configured to control the projection lens to project a square picture to the projection area at each trapezoidal line correction level, and the image is taken from the projection area by the camera unit at each trapezoidal line correction level. 099130947 Form No. A0101 Page 3 / Total 20 pages 0992054263-0 201211671, and trapezoidal line correction of trapezoidal distortion by comparing the starting position of each white line point of each image; column correction module for controlling the projection lens A square picture is projected onto the projection area under a trapezoidal column correction level, and the image is taken from the projection area by the camera unit at each trapezoidal column correction level, and by comparing the start position of each column of the white element point of each image To perform trapezoidal column correction on trapezoidal distortion 0 [0005] The ladder correction method of the projector includes the steps of: reading from a storage unit a square image of white and black outside the frame, and controlling the projection lens to project a square image of the inner white and black in the projection area selected by the user; controlling the projection lens to project a square moon to the projection area at each trapezoidal line correction level; Acquiring images from the projection area by the camera unit at each trapezoidal line correction level; trapezoidal line correction of trapezoidal distortion by comparing the start positions of each line of white element points of each image; controlling the projection lens at each Projecting a square image to the projection area under a trapezoidal column correction level; capturing an image from the projection area by the camera unit at each trapezoidal column correction level; by comparing the start position of each column of white element points of each image Trapezoidal column correction for keystone distortion. Compared with the prior art, the projector and the trapezoidal distortion correction method of the invention can automatically correct the trapezoidal distortion generated by the projector during the screen projection process, so as to obtain the optimal projection effect of the surface. [Embodiment] FIG. 1 is a block diagram of a preferred embodiment of a projector 100 of the present invention. In the embodiment, the projector 100 includes a trapezoidal correction unit 1, a projection lens 2, a driving unit 3, an imaging unit 4, a storage unit 5, and a microprocessor. 6 099130947 Form No. A0101 Page 4 / Total 20 Page 0992054263-0 201211671. When the projector 100 projects an image image (for example, a square picture shown in FIG. 2) onto the projection area (for example, a screen or a wall surface) by the projection lens 2, the display is often caused by the relative positional relationship between the projector and the projection area. The image plane on the projection area produces trapezoidal distortion (for example, the trapezoidal picture shown in Figure). The trapezoidal correction unit 1 is used for automatically correcting trapezoidal distortion generated during projection of the projection lens 2, for example, reducing the trapezoidal image correction shown in FIG. 2B to a square image as shown in FIG. 2A for optimal use. The projection effect of the picture. 0 [〇〇〇8] The projection lens 2 is an optical control lens with a correction keystone function capable of performing keystone correction on a trapezoidal distortion image (for example, a trapezoidal picture shown in FIG. Trapezoidal line correction and trapezoidal column weighting. In the present embodiment, the projection lens, 2's line correction and column correction include 10 to + 10 total 20 correction levels 'for example -] _ 〇 to _9 for the first level, -9 to -8 for the first The second level, ...., 9 to 1 is the twentieth level. Where the 'minimum correction level is the first level. The maximum correction level is the twentieth level. :* 〇[Leak] The driving list is an I-stap-light drive motor for controlling the projection lens 2 to move within the range of the corrected trapezoidal level to adjust the trapezoidal correction level of the projection lens 2 to automatically project the projection lens 2 The trapezoidal distortion generated by the image projected in the projection area is corrected. [0010] The imaging unit 4 is an imaging device having an imaging function, such as a camera. The camera unit 4 is configured to take an image from a projection plane in the projection area, and send the image to the trapezoid correction unit 1 for keystone correction. 0 099130947 Form No. A0101 Page 5 / Total 20 Page 0992054263-0 201211671 [0011] [0013] The cache unit 5 is a memory (ρι_Memory) or an external memory card. The deposit is a fixed shape image projected onto the projection area for storing the desired headers including but not limited to square images, rectangular images, diamond images, or 'U闺 slices. In the case of Yu Tai Shen, 'the square picture is taken as an example. ^ The square picture is a black and white, such as the square picture shown in Figure 2A. The trapezoidal correction unit 1 includes an initialization module. ~ The line is just the parent and the ?? and the column correction module 13. The module referred to in the present invention may be a hardware circuit composed of a plurality of electronic components, or may be a computer program segment by a series of calculations. In the non-embodiment, the module a is executed by the microprocessor 6 and can complete the fixed function, and is stored in the storage unit 5. The initialization module 11 is configured to move the trapezoidal line correction level to the minimum line correction level by the driving unit 3 when the projector 100 is powered on, or to move the trapezoidal column correction level to the minimum column correction level. The position 'for example, the line is at the level [-10 to -9], or the column correction level [-10 to -9]. The initialization module 11 is further configured to read a square image of white and black outside from the storage unit 5, and control the projection lens 2 to project the square image in a projection area selected by the user. [14] The line correction module 12 is configured to control the projection lens 2 to project a square picture into the projection area at each trapezoidal line correction level, and project from the projection unit 4 at each trapezoidal line correction level. The image is taken in the area, and trapezoidal line correction is performed on the trapezoidal distortion by comparing the start positions of the white element points of each line of each image. In this embodiment, the images are black and white images composed of black primitive points and white primitive points. 099130947 Form No. A0101 Page 6 / Total 20 Pages 0992054263-0 201211671 Where Black Feature Points The RGB value is 0-50, and the RGB values of the white primitive points are 5〇, 255. Under normal indoor light, when the RGB value of the black pixel point is higher than 5〇, the human eye should not distinguish the black pixel point of the image. At this time, the RGB value of the primitive point is considered to be the beginning of the white element point. The position, such as the PI, P2, P3, ... Pn points shown in Figure 2B. For the specific trapezoidal line correction method, please refer to the description shown in Figure 3. [0015] The column correction module 13 is configured to control the projection lens 2 to project a square picture into the projection area at each trapezoidal column correction level. The image capturing unit 4 is within the projection area at each trapezoidal column correction level. The image is taken and the trapezoidal distortion is corrected by trapping the start position of each column of white pixels in each image. For the specific trapezoidal column correction method, please refer to FIG. [0016] As shown in FIG. 3, it is a flow chart of a preferred embodiment of the trapezoidal line correction method for the trapezoidal distortion of the projector of the present invention. In the present embodiment, the trapezoidal line correction method can automatically perform trapezoidal line correction on the trapezoidal distortion generated by the projection lens 2 during the projection of the screen. w,: [0017] Step S30, the initialization module 11 reads from the storage unit 5 a square image of white and black outside the frame (for example, a square picture shown in FIG. 2A), and is selected by the user by the projection lens 2. The square image of the inner white and white is projected in the projection area. At this time, the square image projected by the projection lens 2 is trapezoidal distortion, for example, the trapezoidal picture shown in FIG. 2B. [0018] In step S31, the initialization module 11 drives the projection lens 2 by the driving unit 3 to move the trapezoidal line correction level to the minimum line correction level, for example, the line correction level [-10 to -9]. 099130947 Form No. A0101 Page 7 / Total 20 pages 〇992〇54263-〇201211671 [0019] Step S32, the line correction module 12 captures the first image from the projection area by the imaging unit 4, and each of the first images The starting position of a line of white primitive points (ie, the RGB value of the white element point first appears in each line of the first image, for example, the RGB values of the PI, P2, P3, ".Pn points shown in Figure 2B) Enter the first row of arrays. [0020] Step S33, the row correction module 12 finds the maximum value and the minimum value of the starting position of the white primitive point in the first row array, and subtracts the maximum value from the maximum value to calculate the maximum value and the minimum value. A difference. [0021] In step S34, the line correction module 12 controls the driving unit 3 to drive the projection lens 2 to increase the trapezoidal line correction level by one line correction level, for example, to move the trapezoidal line correction level to the line correction level [-9 to -8]. [0022] Step S35, the line correction module 12 captures the second image from the projection area by the camera unit 4 (that is, the RGB value of the white element point first appears in each line of the second image, for example, the PI shown in FIG. 2B. , P2, P3, “RGB value of .Pn point”, and put the starting position of each row of white primitive points of the second image into the second row array. [0023] Step S36, the row correction module 12 is in the second row. The maximum value and the minimum value of the starting position of the white primitive point are found in the row array, and the maximum value is subtracted from the minimum value to calculate the second difference between the maximum value and the minimum value. [0024] Step S37, the line correction module Determining whether the second difference is greater than the first difference. If the second difference is greater than the first difference, in step S38, the line correction module 12 stores the second difference as the first difference in the storage unit 5, and then Step S34 is performed. If the second difference is smaller than the first difference, in step S39, the line correction module 12 controls the driving unit 3 to drive the projection lens 2 to return the trapezoidal line correction level to 099130947. Form number A0101 Page 8 / Total 20 pages 0992054263 -0 201211671 [0025] [0026]
[0027] [0028] Ο 退一個行校正等級，並將此時之行校正等級作為最佳行 校正等級。 如圖4所示，係本發明投影儀梯形失真之梯形列校正方法 較佳實施例之流程圖。於本實施例中，該梯形列校正方 法能夠自動對投射鏡頭2於晝面投影過程中產生之梯形失 真進行梯形列校正。 步驟S40，初始化模組11從儲存單元5内讀取一幅内白外 黑之正方形圖片（例如圖2Α所示之正方形圖片），並藉 由投射鏡頭2於使用者選定之投射區域内投射該内白外黑 之正方形圖片，此時投射鏡頭2投射出之正方形圖片會產 生梯形失真，例如圖2Β所示之梯形圖片。 步驟S41，初始化模組11藉由驅動單元3驅動投射鏡頭2將 梯形列校正等級移動至最小列校正等級，例如列校正等 級[_10至-9]處。 步驟S42，列校正模組13藉由攝像單元4從投射區域内攝 取第一影像，並將該第一影像之每一列白色圖元點之開 始位置（即，第二影像之每一行首先出現白色圖元點之 RGB值，例如圖2Β所示之LI、L2 ' L3、".Ln黑占之RGB值 )放入第一列陣列。步驟S43，列校正模組13於第一列陣 列中找出白色圖元點之開始位置最大值與最小值，並將 最大值減去最小值計算出該最大值與最小值之第一差值 〇 步驟S44，列校正模組13控制驅動單元3驅動投射鏡頭2將 梯形列校正等級增加一個列校正等級，例如將梯形列校 099130947 表單編號A0101 第9頁/共20頁 0992054263-0 [0029] 201211671 正等級移動至列校正等級[-9至-8]處。步驟S45，列校 正模組13藉由攝像單元4從投射區域内攝取第二影像，並 將該第二影像每一列白色圖元點之開始位置（即，第二 影像之每一行首先出現白色圖元點之RGB值，例如圖2B所 示之LI 、L2 、L3 、黑占之RGB值）放人第三歹'JP車歹。 步驟S46，列校正模組13於第二列陣列中找出白色圖元點 之開始位置最大值與最小值，並將最大值減去最小值計 算出該最大值與最小值之第二差值。 [0030] 步驟S47，列校正模組13判斷第二差值是否大於第一差值 。若第二差值大於第一差值，步驟S48，列校正模組13將 第二差值作為第一差值儲存於儲存單元5中，而後執行步 驟S44。若第二差值小於第一差值，步驟S49，列校正模 組13控制驅動單元3驅動投射鏡頭2將梯形列校正等級回 退一個列校正等級，並將此時之列校正等級作為最佳列 校正等級。 [0031] 以上所述僅為本發明之較佳實施例而已，且已達廣泛之 使用功效，凡其他未脫離本發明所揭示之精神下所完成 之均等變化或修飾，均應包含於下述申請專利範圍内。 【圖式簡單說明】 [0032] 圖1係本發明投影儀較佳實施例之架構圖。 [0033] 圖2係為投影儀於投影區域上之投射畫面時產生梯形失真 之示意圖。 [0034] 圖3係本發明投影儀的梯形失真校正之梯形行校正方法較 佳實施例之流程圖。 099130947 表單編號A0101 第10頁/共20頁 0992054263-0 201211671 [0035] 圖4係本發明投影儀的梯形失真校正之梯形列校正方法較 佳實施例之流程圖。 【主要元件符號說明】 [0036] 投影儀100 [0037] 梯形校正單元 [0038] 初始化模組 11 [0039] 行校正模組 12 [0040] 列校正模組 13 [0041] 投射鏡頭 2 [0042] 驅動單元 3 [0043] 攝像單元 4 [0044] 儲存單元 5 [0045] 微處理器 6 v.. 〇 Ο 099130947 表單編號Α0101 第11頁/共20頁 0992054263-0[0028] 退 Retreat a line correction level and use the line correction level at this time as the best line correction level. As shown in Fig. 4, it is a flow chart of a preferred embodiment of the trapezoidal column correction method for the trapezoidal distortion of the projector of the present invention. In the present embodiment, the trapezoidal column correction method can automatically perform trapezoidal column correction on the trapezoidal distortion generated by the projection lens 2 during the projection of the facet. In step S40, the initialization module 11 reads a square image of the inner white and black (for example, the square image shown in FIG. 2A) from the storage unit 5, and projects the projection lens 2 into the projection area selected by the user. In the white and black square picture, the square picture projected by the projection lens 2 will produce trapezoidal distortion, such as the trapezoidal picture shown in FIG. In step S41, the initialization module 11 drives the projection lens 2 by the drive unit 3 to move the trapezoidal column correction level to the minimum column correction level, for example, the column correction level [_10 to -9]. In step S42, the column correction module 13 captures the first image from the projection area by the imaging unit 4, and starts the position of the white pixel point of each column of the first image (that is, each line of the second image first appears white). The RGB values of the primitive points, such as LI, L2 'L3, ".Ln black RGB values shown in Figure 2, are placed in the first column array. Step S43, the column correction module 13 finds the maximum value and the minimum value of the starting position of the white primitive point in the first column array, and subtracts the minimum value from the maximum value to calculate the first difference between the maximum value and the minimum value. In step S44, the column correction module 13 controls the driving unit 3 to drive the projection lens 2 to increase the trapezoidal column correction level by one column correction level, for example, the trapezoidal column 099130947, the form number A0101, the 9th page, the total 20 pages, 0992054263-0 [0029] 201211671 Positive level moves to the column correction level [-9 to -8]. In step S45, the column correction module 13 captures the second image from the projection area by the image capturing unit 4, and displays the starting position of each white pixel point of the second image (that is, the white image first appears in each line of the second image. The RGB values of the elements, such as the LI, L2, L3, and black RGB values shown in Figure 2B, are placed in the third 歹 'JP rut. Step S46, the column correction module 13 finds the maximum value and the minimum value of the starting position of the white primitive point in the second array, and subtracts the minimum value from the maximum value to calculate the second difference between the maximum value and the minimum value. . [0030] Step S47, the column correction module 13 determines whether the second difference is greater than the first difference. If the second difference is greater than the first difference, in step S48, the column correction module 13 stores the second difference as the first difference in the storage unit 5, and then performs step S44. If the second difference is smaller than the first difference, in step S49, the column correction module 13 controls the driving unit 3 to drive the projection lens 2 to roll back the trapezoidal column correction level by one column correction level, and optimize the column correction level at this time. Column correction level. The above are only the preferred embodiments of the present invention, and have been used in a wide range of ways, and other equivalent changes or modifications which are not departing from the spirit of the present invention should be included in the following. Within the scope of the patent application. BRIEF DESCRIPTION OF THE DRAWINGS [0032] FIG. 1 is a block diagram of a preferred embodiment of a projector of the present invention. [0033] FIG. 2 is a schematic diagram showing the trapezoidal distortion generated when the projector projects a projected image on the projection area. 3 is a flow chart of a preferred embodiment of a trapezoidal line correction method for trapezoidal distortion correction of a projector of the present invention. 099130947 Form No. A0101 Page 10 of 20 0992054263-0 201211671 [0035] FIG. 4 is a flow chart of a preferred embodiment of the trapezoidal column correction method for trapezoidal distortion correction of the projector of the present invention. [Main Component Symbol Description] [0036] Projector 100 [0037] Triangulation Correction Unit [0038] Initialization Module 11 [0039] Row Correction Module 12 [0040] Column Correction Module 13 [0041] Projection Lens 2 [0042] Drive unit 3 [0043] camera unit 4 [0044] storage unit 5 [0045] microprocessor 6 v.. 〇Ο 099130947 Form number Α 0101 page 11 / total 20 page 0992054263-0