JP2005049111A - Angle detector and projector equipped therewith - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an angle detector for automatically detecting its relative inclination angle to a screen in order to correct a trapezoidal distortion of a projected image on a screen, and for automatically measuring the reflectivity of the screen to adjust the luminance and/or color of the projected image, and also to provide a projector. <P>SOLUTION: This angle detector comprises: a range finding part 3 for finding distances to a plurality of different measuring positions 1A to 1G on a straight line extending on the screen 1; an angle computing part 53 for calculating the relative inclination angle of the finding part to the screen on a plane vertical to the screen including the straight line based on the result of range finding; a reflectivity measurement means 32j for measuring the reflectivity of the screen; and a correction means 54 for adjusting at least either of the luminance and color of the image projected correspondently to the reflectivity of the screen measured by the measurement means. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

ここで、Ｌ（）：基準部３１ｃ側センサーデータ
Ｓａ ：基準部３１ｃ側受光素子最小Ｎｏ．
Ｗｎ ：部分群の受光素子数
ｔ ；整数（一般的に１〜４）
ノイズの影響を解除するためには、差分の絶対値が所定値（ノイズキャンセルレベル）以下の場合は、総和に加えない。
なお、ラインセンサ３１ｃの一列に配列された受光素子（画素）にはそれぞれ一連の通し番号（画素番号）がふってある。
【００６７】
次ぎに図１３を参照して、別の方法によるパッシブ型ライン式測距装置３を用いて傾斜角度θ１の計算方法を説明する。図１３に示すように、パッシブ型ライン式測距装置３の基線長方向（プロジェクタ２の水平方向）に対するスクリーン１の傾斜角度をθ１とし、図５で説明した方法により、ラインセンサ３１ｃの測距演算領域３１ｃ７の測距方向に沿って測距演算して算出されたスクリーン１までの距離がＬ１、測距演算領域３１ｃ３の測距方向に沿って測距演算して算出されたスクリーン１までの距離がＬ２とする。予め知られている測距演算領域３１ｃ３の測距方向と基線長方向に垂直な方向とがなす角度をβとし、同じく予め知られている測距演算領域３１ｃ７の測距方向と基線長方向に垂直な方向とがなす角度をγとする。傾斜角度θ１は、次式で計算される。
【００６８】
θ１＝ａｒｃｔａｎ（Ｌ２ｃｏｓβ−Ｌ１ｃｏｓγ）／（Ｌ１ｓｉｎγ＋Ｌ２ｓｉｎβ）
【００６９】
次ぎに、図１４を図３と併せて参照して本発明の１つの実施の形態を説明する。図１４に示すように、図３の反射率測定部３２ｊはメモリ領域３２ｂに記憶されたラインセンサ３１ｃ、３１ｄからの測光値１４を、予めメモリ部１０に記憶されていたスクリーン１の基準の反射率３６パーセントの場合の基準値１５と比較演算して、実質的に低い場合はスクリーン１の反射率が５％、実質的に等しい場合はスクリーン１の反射率が３６％、実質的に高い場合はスクリーン１の反射率が８０％のいずれかであると判定する。図１４に示すように、スクリーン１の反射率に応じて、スクリーン１上の投影色の見え方１６が異なる。すなわち、スクリーン１が基準の反射率３６％である場合に赤として見える投影色は、スクリーン１の反射率が低い（５％）場合は、暗い赤として見え、スクリーン１の反射率が高い（８０％）場合は、淡い赤として見える。このため、図３の輝度及び色合い補正部５４は反射率測定部３２ｊで得られたスクリーン１の反射率に応じて、スクリーン１上に投影色の色合いを調整するために、投影画像生成部６に補正を行う。例えば、もし、スクリーン１の反射率が基準の３６％よりも低い５％の場合は、投影色の色合いの鮮度及び／又は輝度を上げる。もし、スクリーン１の反射率が基準の３６％よりも高い８０％の場合は、投影色の色合いの鮮度及び／又は輝度を下げることにより補正する。このようにして、プロジェクタ２はスクリーン１が高い反射率を有する場合、壁のように低い反射率を有する場合等に応じて最適な輝度と色合いの画像の投射が可能となる。
【００７０】
以上説明した本発明の実施の形態において、測定対象としてスクリーン平面を用いたが、スクリーンに限らず、どんな平面的物体の測定対象についても本発明の角度検出装置は適用できる。例えば、測定対象の平面的物体としては、工作機械により加工される被加工物であって良く、これら被加工物に対して加工道具を正対させるため、被加工物と加工道具の相対的な傾斜角度を検出するためにも、本発明の角度検出器は適用できる。また、スクリーン１までの距離測定を行うためにパッシブ型ライン式測距装置を用いたが、距離測定手段はこれに限るものではなく、パッシブ型であれば適宜変更可能である。また、本発明において、スクリーン１の角度検出と反射率測定とをパッシブ型ライン式測距装置を併用して行ったが、反射率測定専用のセンサを別途設けても良い。
【００７１】
【発明の効果】
請求項１に記載された本発明によれば、測定対象上の１つの位置までの距離測定がたとえノイズ等又は製造誤差に起因して正しくできない場合でもその影響を少なくすることができ、信頼性の高い角度検出ができる。さらに、測定対象の反射率が異なる場合でも、最適な画像の投射が可能となる。この結果、測定対象として反射率が高いスクリーンから反射率の低い壁等のさまざまなものを使用する場合においても、最適な画像の投射が可能である。
【００７２】
請求項２に記載された本発明によれば、このスクリーンの傾斜角度を検出してスクリーン上の画像の歪みを補正するために使用でき、さらに、このスクリーンの反射率に応じて最適な輝度又は色合いの画像の投射ができる。
【００７３】
請求項３に記載された本発明によれば、プロジェクタがスクリーンの相対的な傾斜角度に起因する画像の歪みを自動的に正確に補正することができ、且つ、スクリーンの反射率に応じてスクリーン上に投射される画像の輝度又は色合いを自動的に調節して補正できるため、プロジェクタの投射画像の画質を向上できる。
【図面の簡単な説明】
【図１】本発明の１つの実施の形態による角度検出器を有するプロジェクタの構成を示す概略ブロック図。
【図２】図１に示したプロジェクタの概略正面図。
【図３】本発明の１つの実施の形態による角度検出器の機能ブロック図。
【図４】本発明の１つの実施の形態による角度検出器に含まれる測距装置の測距操作を説明する図。
【図５】本発明の１つの実施の形態による角度検出器に含まれる測距装置の測距操作を説明する別の図。
【図６】本発明の１つの実施の形態による角度検出器に含まれる測距装置の一対のラインセンサの概略を示すブロック図。
【図７】本発明の１つの実施の形態による角度検出器に含まれる測距装置による複数位置の距離測定を説明する別の図。
【図８】本発明の１つの実施の形態による角度検出器に含まれる測距装置による角度検出方法を説明する図。
【図９】本発明の１つの実施の形態による角度検出器に含まれる測距装置による角度検出方法を説明する別の図。
【図１０】本発明の１つの実施の形態による角度検出器に含まれる測距装置による角度検出方法を説明する別の図。
【図１１】本発明の１つの実施の形態による角度検出器に含まれる測距装置による角度検出方法を説明する別の図。
【図１２】本発明の１つの実施の形態による角度検出器に含まれる測距装置の測距演算領域のコントラスト重心位置を求める方法を説明する別の図。
【図１３】本発明の１つの実施の形態による角度検出器に含まれる測距装置による角度検出方法を説明する別の図。
【図１４】本発明の１つの実施の形態によるスクリーン反射率測定及びスクリーン反射率に応じた投射画像の輝度又は色合いの調節を示す表。
【符号の説明】
１ スクリーン
１Ａ〜１Ｇ 測定位置
２ プロジェクタ
３ 測距装置
４ 測距装置
５ 制御回路
３１ 撮像部
３１ａ レンズ
３１ｂ レンズ
３１ｃ ラインセンサ
３１ｄ ラインセンサ
３１ｃ１〜３１ｃ７ 測距演算領域
３２ 演算部
３２ｊ 反射率測定部３２ｊ
５１ 相互信頼性判定部
５３ 角度演算部
５４ 輝度及び色合い補正部
ｋ 基線長
θ１ 水平面内でスクリーン１が基線長ｋ方向となす傾斜角度[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an angle detection device using a passive line-type distance measuring device and a projector including the same.
[0002]
[Prior art]
When a projector such as a liquid crystal projector is used, there is a problem that distortion called trapezoidal distortion occurs in an image projected on the screen due to the relative positional relationship between the projection optical axis of the projector and the screen plane projected by the projector. . This trapezoidal distortion is caused when the projector projects the image from the front of the screen so that the position of the projector is shifted from the center of the screen so as not to disturb the viewer. As a result of which the top of the screen is farther (or closer) from the projector than the bottom of the screen. It also occurs when the right side of the screen is farther (or closer) from the projector than the left side of the screen.
[0003]
Conventionally, in order to automatically correct this trapezoidal distortion, an inclination angle indicating how much the screen plane is inclined from a state perpendicular to the projector projection optical axis is automatically detected and detected. Depending on the tilt angle, an electrical correction method for generating an image having a trapezoidal distortion opposite to the projected image in the video circuit inside the projector and projecting it, and a projection lens (condenser lens) of the projector's projection optical system An optical correction method for adjusting the tilt is used.
In order to automatically detect the relative inclination angle of how much the projection optical axis of the projector is inclined from the state perpendicular to the screen plane, as a conventional angle detection device, the one disclosed in Patent Document 1 is disclosed. is there. What is described in this patent document 1 is that each of the distances to the screen is measured by two active distance measuring sensors that are spaced apart from each other by a predetermined distance above and below the front surface of the projector main body 1, A simple inclination angle is obtained.
[0004]
Further, as disclosed in Patent Document 2, in a conventional liquid crystal projector, the ambient light of the projector is detected by external photometry means, and the projector brightness and color information is generated from the ambient light, and based on this information. Some have image improvement means for correcting the hue of the projected image.
[0005]
[Patent Document 1]
JP 2000-122617 A (see paragraph 0044 and FIG. 2)
[Patent Document 2]
Japanese Patent Laid-Open No. 2000-66166
[Problems to be solved by the invention]
However, the conventional angle detection device described in Patent Document 1 is configured to measure two distances to obtain a relative tilt angle in which the projection optical axis of the projector is tilted from a direction perpendicular to the screen plane. Therefore, if one or both of the two distance measurements are not correctly measured due to noise or the like, the tilt angle detection accuracy deteriorates and the trapezoidal distortion cannot be corrected correctly. It was.
On the other hand, in the projector of the prior art described in Patent Document 2, the ambient light around the projector is measured and the hue of the image projected by the projector is corrected. Therefore, the hue of the projected image is adjusted according to the reflectance of the screen. It cannot be corrected. As a result, even if the hue of the projected image is simply corrected based on the ambient light, the reflectance of the screen or the like varies depending on what is used, and the image projected by the projector changes with this, so that an optimal image can be projected. There was a problem that could not.
[0007]
The object of the present invention is to detect the tilt angle as accurately as possible even if one distance cannot be measured accurately due to noise or the like, and measure the reflectivity of the screen and project according to the reflectivity. An object of the present invention is to provide an angle detection device and a projector including the same, which can solve one of the conventional problems by correcting one of luminance or hue of an image.
[0008]
[Means for Solving the Problems]
According to the first aspect of the present invention, a projection unit that projects an image on a measurement target, a pair of lenses that are spaced apart by a base line length on the same plane, and a predetermined distance from the pair of lenses. A line sensor that is arranged so as to be spaced apart and extend in the baseline length direction and on which the measurement object is imaged via the pair of lenses, and the baseline length and the above based on the output from the line sensor A passive line-type distance measuring device comprising: a calculation unit that calculates distances to a plurality of different positions on the measurement object in a plurality of different ranging directions on a plane including a line sensor; and the calculation unit An inclination angle calculation unit for calculating an inclination angle of the measurement object with respect to the same plane on a plane including the base line length and the line sensor, based on the plurality of distances that are the calculation results of Reflectance measuring means for measuring the reflectance of the measurement object based on the output from the sensor, and brightness of an image projected by the projection means according to the reflectance of the measurement object measured by the reflectance measurement means Or an angle detecting device including a correcting means for adjusting at least one of the hues.
[0009]
According to such a configuration of the present invention, the distance to a plurality of positions linearly arranged on the measurement target is measured by the passive line-type distance measuring device, and the line-type distance measuring device is based on the measured distance. On the plane including the base line length and the line sensor, it is possible to calculate a relative inclination angle that the measurement object forms with respect to the same plane of the line-type distance measuring device. As a result, even when the distance measurement to one position on the measurement object cannot be performed correctly due to noise or the like or manufacturing error, the influence can be reduced, and highly reliable angle detection can be performed. Further, the reflectance of the measurement object is measured based on the output from the line sensor, and at least one of the brightness or the hue of the image projected by the projection unit is adjusted based on the measured reflectance of the measurement object. By providing the correction means, it is possible to project an optimum image even when the reflectance of the measurement object is different. As a result, even when various objects such as a low-reflectance wall or a screen having a high reflectance are used as the measurement target, an optimal image can be projected.
[0010]
According to the second aspect of the present invention, there is provided the angle detection device according to the first aspect, wherein the measurement object is a screen.
[0011]
According to such a configuration of the present invention, it can be used to detect the tilt angle of the screen and correct the distortion of the image on the screen, and further, an image having an optimum brightness or color can be obtained according to the reflectance of the screen. Adjust and project.
[0012]
According to the third aspect of the present invention, there is provided a projector for projecting an image onto a screen, wherein the angle detecting device according to the second aspect and the inclination angle calculated by the angle detecting device are on the screen. An image distortion correction unit that corrects the image distortion is provided.
[0013]
According to this configuration of the present invention, the projector can automatically and accurately correct image distortion caused by the relative tilt angle of the screen, and is projected on the screen according to the reflectance of the screen. The brightness or hue of the image to be adjusted can be automatically adjusted and corrected, and the image quality of the projected image of the projector can be improved.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
[0015]
FIG. 1 is a schematic block diagram of a projector 2 that includes an angle detection device according to the present embodiment and electrically corrects trapezoidal distortion of an image projected on the screen 1 based on the detected tilt angle of the screen 1. The angle detection device according to the present embodiment detects a tilt angle of the projector 2 with respect to the screen 1 in a horizontal plane and a vertical plane, and therefore, a plurality of positions arranged in the horizontal and vertical directions on the plane of the screen 1 from the projector 2. A first passive line-type distance measuring device 3 and a second passive line-type distance measuring device 4 are provided. The passive distance measuring device receives an image projected on the screen 1 and measures the distance without emitting or transmitting light by itself. The line-type distance measuring device has a line sensor in which a plurality of photodetector cells are arranged in a straight line.
[0016]
FIG. 2 is a plan view showing the front of the projector 2 shown in FIG. Note that the angle detection device according to the present embodiment is not limited to the one provided in the projector, and is not limited to the one that detects the angle of inclination with the screen. It can be applied to relative tilt angle detection. The projector 2 is an example of an application in which the angle detection device of the present invention is used.
[0017]
As shown in FIG. 2, the first passive line-type distance measuring device 3 of FIG. 1 is separated by a first base line length k (FIG. 4) extending in the horizontal direction on the plane constituting the front of the projector 2. And an imaging unit 31 having a pair of lenses 31a and 31b. Similarly, the second passive line-type distance measuring device 4 extends in the vertical direction perpendicular to the horizontal direction of the imaging unit 31 on the same plane that constitutes the front surface of the projector 2 and has a second baseline length k ′ (not shown). ) Includes an imaging unit 41 including a pair of lenses 41a and 41b that are spaced apart from each other. As shown in FIG. 2, a projection lens (which may include a condenser lens or the like) 8 constituting projection optical means is further provided on the same plane constituting the front surface of the projector 2. Irradiate the light that projects the image.
[0018]
Please refer to FIG. 1 again. If the projection optical axis projected from the projection lens 8 onto the screen 1 is in a positional relationship perpendicular to the plane of the screen 1, the upper and lower sides (or left and right) of the screen 1 have the same distance from the projection lens 8. No trapezoidal distortion occurs in the image above 1. However, in actuality, as described above, the projector 2 is shifted downward or upward from the center of the screen so as not to disturb the viewer when illuminating from the front of the screen 1. The projection optical axis irradiated to the screen 1 from the projection lens 8 is inclined from the positional relationship perpendicular to the plane of the screen 1.
[0019]
For this reason, the distance from the projection lens 8 is different between the upper and lower sides of the screen 1, and thus a trapezoidal distortion occurs in the image projected on the screen 1. As described above, in order to correct the trapezoidal distortion, the inclination of the optical axis of the projection lens 8 is optically corrected, or a portion that is projected to be small (large) due to the trapezoidal distortion is greatly enlarged (smallly reduced). An electrical correction in which the image processing to be performed is performed by an electric circuit is considered as described in Patent Document 1.
[0020]
However, in order to automatically perform these corrections, first, the inclination angle at which the optical axis of the projection lens 8 is inclined from the vertical direction of the plane of the screen 1, that is, the plane of the screen 1 with respect to the plane constituting the front of the projector 2. It is necessary to automatically and accurately measure the inclination angle of the plane.
[0021]
As will be described in detail below, the angle detection device of the present invention includes first and second passive type line-type distance measuring devices 3 and 4, and is horizontally (first passive) on the screen 1 from the front of the projector 2. The distance to a plurality of positions along the vertical direction (corresponding to the base line length k ′ direction of the second passive line type distance measuring device 4) and the vertical direction (corresponding to the base line length k ′ direction of the second line type distance measuring device 4) is measured. Thus, the inclination angle of the plane of the screen 1 with respect to the plane constituting the front of the projector 2 can be accurately measured in the horizontal plane and the vertical plane.
[0022]
The first and second passive type line-type distance measuring devices 3 and 4 have calculation units 32 and 42, respectively, and output signals from the imaging units 31 and 41 are input, respectively. Output signals from the arithmetic units 32 and 42 are input to the control circuit 5 including the configuration of the present invention. The control circuit 5 controls the first and second passive line-type distance measuring devices 3 and 4, and also inputs a projected image from a device such as a personal computer (not shown) to output image information. And the display drive part 7 which outputs an image to the projection lens 8 is controlled. The control circuit 5 calculates the relative tilt angles of the screen 1 in the horizontal direction and the vertical direction, respectively, with respect to the plane constituting the front of the projector 2 based on the outputs from the calculation units 32 and 42 according to the present invention. Next, the control circuit 5 controls the projection image generation unit 6 and / or the display driving unit 7 so as to correct the trapezoidal distortion based on the calculated tilt angle, so that the screen 1 is moved up and down and / or left and right. Enlarge or reduce the projected image. However, as described above, trapezoidal distortion optical correction or electrical correction itself is known (see, for example, Patent Document 1) and will not be described further. The control circuit 5 and the arithmetic units 32 and 42 can be configured by one microprocessor (CPU) 9.
[0023]
The projector 2 includes a memory unit 10 and stores data and commands necessary for the configuration of the present invention. The projector 2 supplies the data and commands to the control circuit 5 and the arithmetic units 32 and 42 as needed, or the control circuit 5. Data is received from the arithmetic units 32 and 42 and the like. The memory unit 10 includes two types of memory devices such as a non-volatile flash memory and a volatile RAM, and instructions necessary for the present invention and long-term data are stored in the non-volatile memory device. Data that is only used temporarily is stored in a volatile memory device. The nonvolatile memory device of the memory unit 10 includes projection data according to data indicating the relationship between the reflectance of the screen 1 used in the present invention and the output from the line sensor and the reflectance of the screen 1 in advance. A correction amount of luminance and / or hue of an image projected from the system onto the screen 1 is stored. Then, as will be described later, these stored data are used by the control circuit 5 to optimally adjust the image quality of the image projected on the screen 1 according to the measured reflectance of the screen 1. At least one of the luminance or the hue of the image projected from the projection lens 8 onto the screen 1 is corrected via the projection image generator 6.
[0024]
Next, the configuration of the projector 2 according to the present embodiment will be described using functional blocks with reference to FIG. For the sake of brevity, only the configuration of the first passive line-type distance measuring device 3 will be described, but the second passive line-type distance measuring device 4 is similarly configured. Below the pair of lenses 31a and 31b, which are spaced apart by a base line length k (FIG. 4) in the horizontal direction on the plane constituting the front of the projector 2, the focal length f (FIG. 4) from these lenses 31a and 31b. The line sensors 31c and 31d are arranged along the base line length k (FIG. 4). The line sensors 31c and 31d are a pair of line CCDs or other line type image pickup elements having a predetermined number, for example, 104 photodetection elements (pixels) arranged in a straight line. An electrical signal corresponding to the light amount of the image on the screen 1 formed on the pixels of the line sensors 31c and 31d by the lenses 31a and 31b is output in series from the imaging unit 31 via the output unit 31e. . The electric signals from the line sensors 31c and 31d change according to the reflectivity of the screen 1 because the image on the screen 1 is projected from the projection lens 8. That is, if the reflectance of the screen 1 is large, the electrical signal from the line sensors 31c and 31d is large, and if the reflectance of the screen 1 is small, the electrical signal from the line sensors 31c and 31d is small.
[0025]
The A / D conversion unit 32a converts the analog electrical signal output from the output unit 31e of the imaging unit 31 into a digital signal. The digitized output signals from the line sensors 31c and 31d are stored as video data signal strings IL and IR, respectively, in the memory area 32b for subsequent processing. Accordingly, a pair of video data signal strings IL and IR each consisting of 104 data strings are stored in the memory area 32b. The memory area 32 b may be provided in the memory unit 10. The line sensor output signal data in the memory area 32b is also supplied to the reflectance measuring unit 32j as reflectance measuring means. The reflectance measurement unit 32j is configured to calculate the line sensor output data when the reference reflectance of the screen 1 stored in advance in the memory unit 10 is, for example, 36%, and the line sensor output signal data from the memory region 32b. The reflectance of the screen 1 is obtained based on the magnitude relationship, and it is determined whether the reflectance of the screen 1 corresponds to a plurality of reflectances, for example, 5%, 36%, or 80%. As described above, since the angle detection and the reflectance measurement of the screen 1 are performed by the passive line type distance measuring device, the configuration of the projector 2 can be simplified.
[0026]
The filter processing unit 32c removes the DC component from the line sensor output signal (filtering), and changes the video data signal strings IL and IR into useful signals including only the spatial frequency component corresponding to the image. As will be described later with reference to FIGS. 4 and 5, the correlation calculation unit 32 d performs a partial video data group iLm (for example, 26 pixel groups spatially close from the video data signal sequences IL and IR. The reference part) and iRn (reference part) are selectively extracted, and the partial video data groups iLm and iRn are compared with each other in order to calculate the degree of coincidence of the data. For example, the comparison is repeated while fixing one partial video data group iLm as a reference part and even one pixel at a time in the IR using the other partial video data group iRn as a reference part. The maximum correlation degree detection unit 32e detects two partial video data groups iLm and iRn having the highest data matching degree in the pair of video data signal sequences IL and IR.
[0027]
The interpolation calculation unit 32f determines the position interval of the partial video data groups iLm and iRn having the highest degree of coincidence obtained by the maximum correlation degree detection unit 32e by a known interpolation method more accurately than the position interval in pixel pitch units. Interpolate to intervals. Based on the position interval interpolated by the interpolation calculation unit 32f, the phase difference detection unit 32g makes a relative shift between a pair of images of the same distance measuring object imaged on the pair of line sensors 31c and 31d. Calculate the quantity (phase difference).
[0028]
As will be described later with reference to FIG. 12, the contrast centroid calculating unit 32h obtains the contrast centroid of the images formed on the line sensors 31c and 31d. The reliability determination unit 32i determines the reliability of the relative shift amount (phase difference) between the positions imaged on the calculated line sensors 31c and 31d. For example, if the object whose distance is to be measured is correctly imaged on both line sensors 31c and 31d, the degree of coincidence obtained in the maximum correlation degree detection unit 32e is equal to or greater than a predetermined value. Should be. Therefore, even if the degree of coincidence obtained in the maximum correlation degree detection unit 32e is relatively highest, if the degree of coincidence is less than a predetermined value, the reliability judgment unit 32i determines that the reliability is low. Eliminate results. If the degree of coincidence obtained by the maximum correlation degree detection unit 32e is equal to or greater than a predetermined value, the data is reliable and CONF_FLG1 = OK is set. The above-described configurations of the imaging unit 31 and the calculation unit 32 are well known, and are described in, for example, Patent Document 3 and Patent Document 4, and thus further description thereof is omitted.
[0029]
[Patent Document 3]
Japanese Patent No. 3230759 [Patent Document 4]
Japanese Patent Publication No. 4-77289 [0030]
The projector 2 further includes a control circuit 5 according to the embodiment of the present invention, and a mutual reliability determination unit 51 for determining the reliability of the distance measurement results of a small group of several spatially adjacent measurement positions. Then, an average value calculation unit 52 for obtaining an average value of the distance measurement results determined to be reliable by the mutual reliability determination unit 51, and an inclination angle from the distance measurement result obtained from the average value calculation unit 52 An angle calculation unit 53 is included for performing calculation for the purpose. Based on the tilt angle of the screen 1 calculated by the angle calculation unit 53, a correction amount for correcting the trapezoidal distortion is given to the projection image generation unit 6 and / or the display drive unit 7. Thereby, the trapezoidal distortion on the screen 1 is corrected. The control circuit 5 further includes a luminance and hue correction unit 54 as correction means, and corrects the luminance and hue of the projected image in accordance with the reflectance of the screen 1 obtained by the reflectance measurement unit 32j. The projection image generation unit 6 is adjusted. Thus, the image data output from the projection image generation unit 6 in which the brightness and the hue are adjusted is projected onto the screen 1 through the display drive unit 7 and the lens 8. Note that the memory unit 10 is connected to a microprocessor (CPU) 9 and stores and provides instruction codes and data necessary for the present embodiment.
[0031]
Next, the operation principle (external light triangular distance measuring method) of the passive line type distance measuring devices 3 and 4 will be described with reference to FIG. The first passive line-type distance measuring device 3 includes a pair of lenses 31a and 31b that extend in the horizontal direction on the plane that constitutes the front surface of the projector 2 and are separated from each other by a base length k, and from the base length k to the lenses 31a and 31b. It includes a pair of line sensors 31c and 31d that are separated by a focal length f of 31b and extend along the same horizontal direction as the baseline length k direction. The first passive type line-type distance measuring device 3 measures the distance between a plurality of positions on the plane of the screen 1 located in a plane (horizontal plane) including the baseline length k and the line sensors 31c and 31d, In a plane (horizontal plane) including k and the line sensors 31c and 31d, a relative inclination angle between the front of the projector 2 and the plane of the screen 1 is calculated.
[0032]
On the other hand, the second passive line-type distance measuring device 4 includes a pair of lenses 41a and 41b spaced apart by a base line length k ′ (not shown) extending in the vertical direction on a plane constituting the front surface of the projector 2. A pair of line sensors 41c (not shown) extending from the baseline length k '(not shown) by the focal length f of the lenses 41a and 41b and extending along the same vertical direction as the baseline length k' (not shown). And 41d (not shown). The second passive line type distance measuring device 4 is a screen located in a plane (vertical surface) including a base line length k ′ (not shown) and line sensors 41c (not shown) and 41d (not shown). A distance between a plurality of positions on one plane is measured, and a plane length (vertical plane) including a base line length k ′ (not shown) and line sensors 41c (not shown) and 41d (not shown) is measured. The relative inclination angle between the front of the projector 2 and the plane of the screen 1 is calculated.
[0033]
For the sake of brevity, only the first passive line-type distance measuring device 3 will be described here, and the description of the second passive line-type distance measuring device 4 will be omitted, but the operating principle is the same. Therefore, the same description can be applied to the second passive line type distance measuring device 4 only by replacing the horizontal direction with the vertical direction.
[0034]
In FIG. 4A, a pair of lenses 31 a and 31 b are arranged apart from each other by a predetermined baseline length k extending in the horizontal direction on a plane constituting the front surface of the projector 2. A pair of line sensors 31c and 31d, which are separated from the pair of lenses 31a and 31b by their focal length f and extend in the base length k direction (horizontal direction), are below the plane that forms the front of the projector 2. Has been placed. The line sensors 31c and 31d are arranged so that the central portions thereof are substantially positioned on the optical axes 31ax and 31bx of the lenses 31a and 31b, respectively, and the corresponding lenses 31a and 31b are respectively provided on the line sensors 31c and 31d. As a result, an image 1A at a certain position on the screen 1 for distance measurement is formed.
[0035]
In FIG. 4A, the measurement position 1A on the screen 1 is imaged on the line sensors 31c and 31d through the optical paths A and B in different directions and through the respective lenses 31a and 31b. .
[0036]
If it is assumed that the measurement position 1A exists at an infinite position, the measurement position 1A is on the line sensors 31c and 31d at the focal length f from the pair of lenses 31a and 31b. An image is formed at reference positions 31cx and 31dx intersecting the axes 31ax and 31bx.
[0037]
Next, when the measurement position 1A approaches from the infinity position along the direction A on the optical axis 31ax of the lens 31a and reaches the position of FIG. 4A, that is, the distance LC, the measurement position 1A is on the line sensor 31c. In FIG. 4, the image is still formed on the reference position 31cx, but on the line sensor 31d, the image is formed at a position shifted by α from the reference position 31dx by the lens 31b.
[0038]
From the principle of triangulation, the distance LC to the measurement position 1A is obtained by LC = kf / α. Here, the base line length k and the focal length f are known values that are known in advance, and the distance LC can be measured by detecting the shift amount α from the reference position 31dx on the line sensor 31d. This is the principle of operation of a passive line type distance measuring device for external light triangulation. The detection of the shift amount α and the calculation of LC = kf / α are executed by the calculation unit 32 in FIG.
[0039]
That is, the detection of the shift amount α from the reference position 31dx of the line sensor 31d is performed for the partial video data groups iLm and iRn extracted from the pair of video data signal sequences IL and IR output from the pair of line sensors 31c and 31d, respectively. The calculation unit 32 detects the correlation calculation. This correlation calculation is well known (for example, see Patent Document 3).
[0040]
For this reason, detailed description of the correlation calculation is omitted, and only the following general description is given. As shown in FIG. 4 (b), the correlation calculation is performed by using the line sensors 31c and 31d as the line sensors 31c and 31d for the partial video data groups iLm and iRn to be overlapped. This is a calculation that is detected while relatively shifting. In FIG. 4B, the position of the partial video data group iLm from one line sensor 31c is fixed to the reference position 31cx and used as the reference portion. The partial video data group iRn from the other line sensor 31d is shifted one pixel at a time as a reference portion, and the partial video data group iRn having the highest degree of coincidence with the reference portion is searched. The distance between the position on the line sensor 31d that generates the partial video data group iRn having the highest degree of coincidence and the reference position 31dx of the line sensor 31d is the shift amount α.
[0041]
Since each of the line sensors 31c and 31d is composed of a pair of line CCDs in which a predetermined number of photodetector cells (pixels) are arranged on a straight line having a predetermined length as will be described later, the shift amount α is a partial image. It can be easily obtained from the pixel position and pixel pitch in the video data signal sequence IR of the data group iRn. In this way, the distance LC to the measurement position 1A in the same direction A as the optical axis 31ax of the lens 31a can be measured by detecting the shift amount α.
[0042]
Next, the principle of measuring the distances LR ′ and LR to the measurement position 1B in a direction different from that in FIG. 4 will be described with reference to FIG. As shown in FIG. 5A, the measurement position 1B passes through the optical path C and the optical path D in different directions, and is imaged on the line sensors 31c and 31d via the respective lenses 31a and 31b.
[0043]
If it is assumed that the measurement position 1B exists at an infinite position in the direction C to be measured, the center of the image of the measurement position 1B formed on the pair of line sensors 31c and 31d by the pair of lenses 31a and 31b The reference positions 31cy and 31dy are separated from each other by the base line length k. Next, when the measurement position 1B at the infinity position approaches along the distance measurement direction C and reaches the position shown in FIG. 5A, the image of the measurement position 1B formed by the lens 31a on the line sensor 31c. However, the position on the line sensor 3dc of the image of the measurement position 1B formed by the lens 31b is shifted by α ′ from the reference position 31dy.
[0044]
From the principle of triangulation, the distance LR to the measurement position 1B is LR = kf / (α′cos β). The angle β is an inclination angle of the distance measuring direction C with respect to the vertical line of the base length k, that is, the optical axis 31ax of the lens 31a, and is an angle determined by determining the measuring direction C. Since the base line length k, the focal length f, and cos β are known values, the distance LR can be measured by detecting the shift amount α ′.
[0045]
The distance LR ′ from the same plane (baseline length k direction) constituting the front surface of the projector 2 on which the lenses 31a and 31b are arranged to the measurement position 1B is obtained by LR ′ = LR cos β = kf / α ′. That is, the distance LR ′ can be obtained from the baseline length k and the focal length f, which are known values, by detecting the shift amount α ′. That is, in order to measure the distance LR ′, the angle β is not necessary.
[0046]
In order to detect the shift amount α ′, the above-described correlation calculation is performed. As shown in FIG. 5B, the position is fixed with the partial video data group iLm corresponding to the reference position 31cy from one line sensor 31c as a reference portion, and the partial video data group iRn from the other line sensor 31d is fixed. The reference part iRm having the highest degree of coincidence with the data of the reference part iLm is found by shifting the positions one pixel at a time as the reference part and superimposing each other.
[0047]
Each of the line sensors 31c and 31d is composed of a pair of line CCDs in which a predetermined number of photodetector cells (pixels) are arranged in a predetermined length on a straight line, as will be described later. It can be easily obtained from the position (pixel number) in the video data signal sequence IR of the video data group iRn, the position (pixel number) in the video data signal sequence IL of the partial video data group iLm, and the pixel pitch.
[0048]
In the correlation calculation method described above, the partial video data group iLm from one line sensor 31c is fixed as a reference part, and the partial video data group iRn from the other line sensor 31d is used as a reference part, and the position is set to one pixel. We decided to inspect each other for the high degree of coincidence. However, when the distance measuring direction is the direction from the intermediate position between the lenses 31a and 31b, the partial video data is moved while moving the positions of the partial video data groups iLm and iRn in the opposite directions on the line sensors 31c and 31d. You may make it test | inspect the height of a mutual agreement between group iLm and iRm.
[0049]
Next, one line sensor 31c of the pair of line sensors 31c and 31d will be described in detail with reference to FIG. The other line sensor 31d is configured similarly to the line sensor 31c. As shown in FIG. 6, the line sensor 31c is configured by a large number, for example, a linear CCD (charge coupled device) in which 104 photodetector cells (pixels) are linearly arranged, or other linear imaging device. Yes. The 104 photodetector cells (pixels) are assigned pixel numbers in order from the left end to the right end in FIG. These photodetector cells (pixels) have seven ranging calculation areas 31c1 (1-26), 31c2 (13-38), 31c3 (27-52), 31c4 (39) by groups of 26 adjacent units. -64), 31c5 (53-78), 31c6 (65-90) and 31c7 (79-104). However, the number in parentheses is the photodetector cell (pixel) number. In each of the distance measurement calculation areas 31c1 to 31c7, the first half is included in the front-end adjacent distance calculation calculation area and the second half is included in the rear-range adjacent distance calculation calculation area. The distance calculation areas 31c1 to 31c7 overlap each other by half with the distance measurement calculation areas adjacent to each other.
[0050]
Signals from the photodetector cells (pixels) in the distance measurement calculation areas 31c1 to 31c7 correspond to the respective partial video data groups iLm of the video data signal sequence IL of the line sensor 31c in FIGS. Each of the center positions a (13), b (26), c (38), d (52), e (64), f (78), and g (90) of each of the ranging calculation areas 31c1 to 31c7 (however, The parentheses are pixel numbers), which is a reference position for determining the distance measuring direction. As a result, the distance measuring device 3 using the line sensors 31c and 31d of the present embodiment measures the distances to seven spaced positions on the screen 1 in the same plane (horizontal plane) as the reference line k. Can do. However, the actual ranging direction can be corrected by the contrast centroid position in the ranging calculation area as will be described later by the contrast centroid calculating unit 32h in FIG. In FIG. 6, reference positions a ′, b ′, c ′, d ′, e ′, f ′, and g ′ corresponding to the other line sensor 31d are shown, and the measurement in the line sensor 31c is performed as a reference portion. It is used when calculating the amount of deviation when performing correlation calculation with the distance calculation area.
[0051]
A plurality of different positions on the screen 1 for distance measurement according to the present invention need not be limited to seven, and may be appropriately set to an appropriate number, for example, 11, the number of pixels of the line sensors 31c and 31d or a distance measurement calculation area. This is possible by appropriately selecting the number of.
[0052]
For example, eleven ranging calculation areas may be provided in units of 27 photodetector cell (pixel) groups using 162 line detector CCD (pixel) line CCDs. Each area is used by overlapping with a distance measurement calculation area in which 13 to 14 pixels out of 27 pixels are adjacent to each other. In this example, one of eleven positions along the reference line direction (horizontal direction) on the screen 1 can be selected.
[0053]
Next, a description will be given with reference to FIG. FIG. 7 shows a state in which the mutual positional relationship of the screen 1 of the projector 2 is set to a predetermined positional relationship in order to perform the initial adjustment of the line type distance measuring devices 3 and 4. That is, initial adjustment of the line-type distance measuring devices 3 and 4 from the projector 2 with the screen 1 in advance parallel to the baseline lengths k and k ′ so that the projection optical axis from the projector 2 is perpendicular to the screen 1. The image suitable for is projected. In the initial adjustment, for example, the lenses 31a and 31b have aberration. For this reason, when different measurement positions along the base line length k direction on the screen 1 are imaged on the line sensors 31c and 31d, they are not imaged on a straight line but actually distorted. In the initial adjustment, a correction coefficient for correcting the distortion due to the lens aberration is calculated, stored in the memory unit 10, and used by the subsequent calculation units 32 and 42. The line-type distance measuring device 3 measures the distances on the screen 1 in the seven distance measuring directions using the seven distance calculating areas 31c1 to 31c7 on the line sensor 31c. For the sake of brevity, 1C, 1E, 1G on the screen 1 in three distance measurement directions corresponding to the three distance measurement calculation areas 31c3, 31c5, 31c7 on the line sensor 31c among the seven directions in FIG. Only the position of is shown.
[0054]
The line-type distance measuring device 3 measures an inclination angle with respect to the base line length k direction of the plane of the screen 1 on the horizontal plane, and the line type distance measuring device 4 is inclined in the direction of the base line length k ′ (not shown) of the screen 1 plane within the vertical plane. Measure the angle. For the sake of brevity, only the measurement of the inclination angle with respect to the base line length k direction of the plane of the screen 1 on the horizontal plane by the line type distance measuring device 3 will be described. However, the description of the present embodiment is similarly applied to the measurement of the tilt angle in the vertical plane of the screen 1 by the line type distance measuring device 4.
[0055]
Next, a method of measuring the tilt angle of the screen 1 using the passive line type distance measuring device 3 will be described with reference to FIGS. For simplification of description, two distance measurement directions C and G of the two distance calculation calculation areas 31c3 and 31c7 of the line sensor 31c are used, and 2 on the plane of the screen 1 in the two distance measurement directions C and G are used. Two distances LR ′ and LL ′ to the two measurement positions 1C and 1G are measured by the method described in FIG. In the present embodiment, only two distances LR ′ and LL ′ are measured. Actually, however, distances to seven (or eleven) measurement positions on the screen 1 in seven (or eleven) distance measurement directions are measured. Measured.
[0056]
If the measurement positions 1C and 1G on the screen 1 are images suitable for passive distance measurement, the manufacturer's logo that is first projected onto the screen 1 via the projection lens 8 when the projector 2 is powered on. An image including a mark or the like may be used, and when the angle detection operation is periodically performed during the operation of the projector 2, the measurement positions 1C and 1G on the screen 1 are arbitrary images projected on the screen 1. It may be.
[0057]
The distance L between the reference positions c (38) and g (90) in the distance measurement directions C and G of the two distance measurement calculation areas 31c3 and 31c7 of the line sensor 31c is based on the pixel number and the pixel pitch in the parentheses. It is a value known in advance.
[0058]
When a point perpendicular to a straight line k1 parallel to the base line length k1 passing through the measurement position 1G from the measurement position 1C on the straight line k2 parallel to the base line length k is C ′, the distance between the measurement position 1C and the point C ′ Is equal to LR′−LL ′. When the tilt angle θ1 of the screen 1 is not so large, the magnitude of this LR′−LL ′ is defined as a point C ”with a point at a distance (LL ′ * L / f) from the measurement position 1G on the straight line k1 as C ″. Can be approximated to a distance 1C'-C "in the case of an intersection 1C 'between the line perpendicular to the straight line k1 from the screen 1 and the screen 1. Usually, the relative positional relationship between the screen 1 and the projector 2 by hand or the like in advance. Since the inclination angle θ1 is not so large, this approximation is appropriate in many cases. The triangle composed of the measurement position 1G, the point C ″, and the center of the lens 31a and the reference position The triangle formed by c and g and the center of the lens 31a has a similar relationship, and the two reference positions c (38) and g (90) of the two distance measurement calculation areas 31c3 and 31c7 on the line sensor 31c. Distance between , Since then corresponds to the distance between the measurement position 1G~ point C ", the value of the inclination angle θ1, using the relationship and trigonometric functions similar shape,
θ1 = arctan {(LR′−LL ′) / (LL ′ * L / f)}
It can be asked.
[0059]
Therefore, the control circuit 5 of the projector 2 can calculate the tilt angle θ1 in the base line length k direction of the screen 1 and the projector 2 in the horizontal plane by calculating the above equation. Based on the magnitude of the tilt angle θ1, the control circuit 1 in FIG. 1 can give an instruction to the projection image generation unit 6 and / or the display drive unit 7 to correct the trapezoidal distortion of the image. However, the inclination angle θ1 obtained from the above equation depends on the accuracy of the distance measurement results LR ′ and LL ′ to the measurement positions 1G and 1C. The present invention improves the accuracy and reliability of the distance measurement result, and enables accurate angle detection.
[0060]
In FIG. 8, the measurement distance is changed from the measurement position 1C and 1G to the base line length k direction in place of the lengths of the vertical lines LR ′ and LL ′. The length may be up to the measurement positions 1C and 1G. This case will be described with reference to FIG.
[0061]
If high accuracy is required for angle detection, each measurement is performed instead of the distance L between the reference values c (38) and g (90) of the two distance calculation calculation areas 31c3 and 31c7 used for angle detection. The distance of the contrast centroid position in the distance calculation areas 31c3 and 31c7 may be used.
[0062]
With reference to FIG. 12, distance measurement using the contrast centroid position by the contrast centroid calculating unit 32h of FIG. 3 will be described. As is well known, passive distance measurement includes an operation of detecting a place where the degree of coincidence is highest when a pair of images formed on two line sensors is overlapped. This is to detect whether the contrast states of the images match.
[0063]
Accordingly, in the passive distance measurement, if the designed distance measurement direction of one distance measurement calculation area 31cn is the arrow J direction as shown in FIG. 12, the image is formed on the distance measurement calculation area 31cn. When the image to be measured is an image in which the contrast position 1K exists only in the arrow K direction, the actual distance measurement direction is shifted from the arrow J direction to the arrow K direction. If the distance measurement target image formed on the distance measurement calculation area 31cn is an image in which the contrast position 1M exists only in the arrow M direction, the actual distance measurement direction is shifted from the arrow J direction to the arrow M direction. . Further, when the image of the distance measurement object formed on the distance measurement calculation area 31cn is an image in which the contrast positions 1K and 1M exist in the arrow K direction and the arrow M direction, the actual distance measurement direction is from the arrow J direction. It shifts to the contrast centroid position of the image formed on the measurement calculation area 31cn.
[0064]
Therefore, if the distance of the contrast centroid position in each distance measurement calculation area is used as a value corresponding to the distance between the two distance calculation calculation areas used for angle detection, a highly accurate distance L can be used. Angle detection accuracy is improved. In addition, the method of calculating | requiring a contrast gravity-center position is described in patent document 5, and is well-known.
[0065]
[Patent Document 5]
For reference to Japanese Patent Laid-Open No. 8-75985, Formula 1 for obtaining the contrast barycentric position in the present embodiment is shown below.
[0066]
[Expression 1]

Here, L (): reference part 31c side sensor data Sa: reference part 31c side light receiving element minimum No.
Wn: number t of light receiving elements in the subgroup; integer (generally 1 to 4)
In order to cancel the influence of noise, when the absolute value of the difference is equal to or less than a predetermined value (noise cancellation level), it is not added to the sum.
The light receiving elements (pixels) arranged in a line of the line sensor 31c have a series of serial numbers (pixel numbers).
[0067]
Next, with reference to FIG. 13, a method for calculating the tilt angle θ1 using the passive line type distance measuring apparatus 3 according to another method will be described. As shown in FIG. 13, the inclination angle of the screen 1 with respect to the base line length direction (horizontal direction of the projector 2) of the passive line-type distance measuring device 3 is θ1, and the distance measurement of the line sensor 31c is performed by the method described in FIG. The distance to the screen 1 calculated by the distance calculation along the distance measurement direction of the calculation area 31c7 is L1, and the distance to the screen 1 calculated by the distance measurement calculation along the distance measurement direction of the distance calculation calculation area 31c3. The distance is L2. The angle formed by the distance measurement direction of the distance measurement calculation area 31c3 known in advance and the direction perpendicular to the baseline length direction is β, and the distance measurement direction of the distance measurement calculation area 31c7 also known in advance is the same as the baseline length direction. Let γ be the angle between the vertical direction. The inclination angle θ1 is calculated by the following equation.
[0068]
θ1 = arctan (L2cosβ−L1cosγ) / (L1sinγ + L2sinβ)
[0069]
Next, one embodiment of the present invention will be described with reference to FIG. 14 in conjunction with FIG. As shown in FIG. 14, the reflectance measuring unit 32 j in FIG. 3 uses the photometric value 14 from the line sensors 31 c and 31 d stored in the memory area 32 b as the reference reflection of the screen 1 stored in the memory unit 10 in advance. When compared with the reference value 15 when the rate is 36%, the reflectivity of the screen 1 is 5% when it is substantially low, and when the reflectivity of the screen 1 is substantially equal when it is substantially equal, it is 36%. Determines that the reflectance of the screen 1 is 80%. As shown in FIG. 14, the appearance 16 of the projected color on the screen 1 varies depending on the reflectance of the screen 1. That is, the projected color that appears as red when the screen 1 has a reference reflectance of 36% appears dark red when the reflectance of the screen 1 is low (5%), and the reflectance of the screen 1 is high (80 %) Appears as light red. Therefore, the brightness and hue correction unit 54 in FIG. 3 adjusts the hue of the projected color on the screen 1 in accordance with the reflectance of the screen 1 obtained by the reflectance measurement unit 32j. Make corrections. For example, if the reflectance of the screen 1 is 5%, which is lower than the standard 36%, the freshness and / or luminance of the projected color shade is increased. If the reflectance of the screen 1 is 80%, which is higher than 36% of the reference, correction is performed by lowering the freshness and / or luminance of the projected color. In this way, the projector 2 can project an image with optimum brightness and color according to the case where the screen 1 has a high reflectance, the case where the screen 1 has a low reflectance, or the like.
[0070]
In the embodiment of the present invention described above, the screen plane is used as the measurement target. However, the angle detection apparatus of the present invention can be applied to the measurement target of any planar object, not limited to the screen. For example, the planar object to be measured may be a workpiece to be processed by a machine tool, and the workpiece and the processing tool are relatively positioned so that the processing tool is opposed to the workpiece. The angle detector of the present invention can also be applied to detect the tilt angle. In addition, although a passive line type distance measuring device is used to measure the distance to the screen 1, the distance measuring means is not limited to this, and can be appropriately changed if it is a passive type. Further, in the present invention, the angle detection of the screen 1 and the reflectance measurement are performed in combination with the passive line type distance measuring device, but a sensor dedicated to the reflectance measurement may be separately provided.
[0071]
【The invention's effect】
According to the first aspect of the present invention, even if distance measurement to one position on the measurement object cannot be performed correctly due to noise or the like or manufacturing error, the influence can be reduced, and reliability can be reduced. High angle detection is possible. Furthermore, even when the reflectance of the measurement object is different, it is possible to project an optimal image. As a result, even when various objects such as a low-reflectance wall or a screen having a high reflectance are used as the measurement target, an optimal image can be projected.
[0072]
According to the invention as claimed in claim 2, it can be used to detect the tilt angle of this screen to correct the distortion of the image on the screen, and also to obtain the optimum brightness or Projects shaded images.
[0073]
According to the third aspect of the present invention, the projector can automatically and accurately correct the image distortion caused by the relative tilt angle of the screen, and the screen can be selected according to the reflectance of the screen. Since it is possible to automatically adjust and correct the brightness or hue of the image projected above, the image quality of the projected image of the projector can be improved.
[Brief description of the drawings]
FIG. 1 is a schematic block diagram showing a configuration of a projector having an angle detector according to one embodiment of the present invention.
FIG. 2 is a schematic front view of the projector shown in FIG.
FIG. 3 is a functional block diagram of an angle detector according to one embodiment of the present invention.
FIG. 4 is a diagram for explaining a ranging operation of the ranging device included in the angle detector according to the embodiment of the present invention.
FIG. 5 is another diagram illustrating a distance measurement operation of the distance measuring device included in the angle detector according to the embodiment of the present invention.
FIG. 6 is a block diagram showing an outline of a pair of line sensors of the distance measuring device included in the angle detector according to one embodiment of the present invention.
FIG. 7 is another diagram illustrating distance measurement at a plurality of positions by the distance measuring device included in the angle detector according to one embodiment of the present invention.
FIG. 8 is a diagram illustrating an angle detection method by a distance measuring device included in the angle detector according to one embodiment of the present invention.
FIG. 9 is another diagram illustrating an angle detection method by the distance measuring device included in the angle detector according to the embodiment of the present invention.
FIG. 10 is another diagram for explaining an angle detection method by the distance measuring device included in the angle detector according to the embodiment of the present invention.
FIG. 11 is another diagram illustrating an angle detection method by the distance measuring device included in the angle detector according to the embodiment of the present invention.
FIG. 12 is another diagram illustrating a method for obtaining the contrast centroid position of the distance measurement calculation area of the distance measuring device included in the angle detector according to the embodiment of the present invention.
FIG. 13 is another diagram illustrating an angle detection method by the distance measuring device included in the angle detector according to one embodiment of the present invention.
FIG. 14 is a table showing screen reflectivity measurement and adjustment of brightness or hue of a projected image according to screen reflectivity according to an embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Screen 1A-1G Measurement position 2 Projector 3 Distance measuring device 4 Distance measuring device 5 Control circuit 31 Image pick-up part 31a Lens 31b Lens 31c Line sensor 31d Line sensors 31c1-31c7 Distance calculation calculation area 32 Calculation part 32j Reflectivity measurement part 32j
51 Mutual Reliability Determination Unit 53 Angle Calculation Unit 54 Luminance and Tint Correction Unit k Baseline Length θ1 Inclination angle that the screen 1 makes in the baseline length k direction in the horizontal plane

Claims (3)

Projecting means for projecting an image on the measurement object;
A pair of lenses arranged on the same plane and spaced apart by a base line length, and the object to be measured via the pair of lenses disposed so as to be separated from the pair of lenses by a predetermined distance and extending in the base line length direction A line sensor on which the image is formed, and a plurality of different positions on the plurality of different distance measuring directions on the plane including the base line length and the line sensor based on an output from the line sensor. A passive line-type distance measuring device provided with a calculation unit for calculating the distance of
An inclination angle calculation unit that calculates an inclination angle of the measurement target with respect to the same plane on a plane including the base line length and the line sensor based on the plurality of distances that are calculation results of the calculation unit;
A reflectance measuring means for measuring the reflectance of the measurement object based on the output from the line sensor;
And angle correction means for adjusting at least one of luminance or hue of an image projected by the projection means according to the reflectance of the measurement object measured by the reflectance measurement means. apparatus. The angle detection device according to claim 1, wherein the measurement object is a screen. An projector for projecting an image onto a screen, the angle detection device according to claim 2, and an image distortion correction unit that corrects distortion of the image on the screen based on an inclination angle calculated by the angle detection device; Including a projector.

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