JP2003114123A - Light direction sensor and light direction sensor signal processing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compact light direction sensor capable of detecting the direction of a light source with high accuracy through the use of a two-dimensional photoelectric converting element. SOLUTION: In the light direction sensor, the direction of the light source is detected by detecting the contrast, etc., of a projected image generated by projecting a slit, etc., onto the two-dimensional photoelectric converting element by light from the light source. The light direction sensor is provided with a constitution capable of utilizing properties when a diagram in a plane is projected onto a plane to efficiently process the complicated projected image. By a method such as the correction of the inclination between a photosensitive surface of the two-dimensional photoelectric converting element and the slit, etc., the compact and highly accurate light direction sensor is implemented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical direction sensor mounted on a spacecraft such as an artificial satellite, a space probe, a space station or the like.

[0002]

2. Description of the Related Art Hitherto, as a light direction sensor requiring high accuracy such as a sun sensor used for attitude control of a satellite, a one-dimensional photoelectric conversion element 40 and a slit 42 shown in FIG. Light direction sensors having a structure arranged in the background have been used. This is called a conventional light direction sensor. Unit element 4 of one-dimensional photoelectric conversion element 40
1 can be regarded as being arranged in a line on a straight line, and this straight line is set as the x _d axis of the photoelectric conversion element surface reference coordinate system 46a.
At this time, the conventional method in which the light direction sensor detects the information about the direction of the light source is that the light flux 44 that has passed through the slit 42.
However, the signal processing / element drive unit 43 detects the position hitting the one-dimensional photoelectric conversion element 40, and the position x _p at which the light intensity is maximum and the distance L between the slit 42 and the one-dimensional photoelectric conversion element 40.
₂ is used, the angle θ _x formed by the plane including the direction of the light source and the direction 48 of the slit 42 and the plane including y _s and parallel to x _d.
Is calculated as in Expression (1). tan θ _x = x _p / L ₂ Formula (1) Normally, two conventional light direction sensors are arranged orthogonal to each other, and the direction of the light source is specified in a three-dimensional space from the outputs of the two sensors. It was

In the conventional light direction sensor, since the slit 42 and the photoelectric conversion element 40 are both one-dimensional, the error caused by the inclination between the slit 42 and the one-dimensional photoelectric conversion element 40 is small and relatively easy. It was possible to make corrections, and the structure made it easy to achieve high accuracy. This principle will be described with reference to FIG. FIG. 1A is a schematic view of the conventional light direction sensor seen from above, and FIG. 1B is the same drawing as FIG.
It is the figure which looked at from the side. First, the one-dimensional photoelectric conversion element 4
Obviously, the inclination angle of 0 around the x _d axis has almost no influence on the position detection of the slit transmitted light. As shown in FIG. 6B, the tilt angle β ₁ about the y _d axis is as long as the light beam 57 is provided as long as the reference position of the x _d axis of the one-dimensional photoelectric conversion element 40 is the origin O _d of the photoelectric conversion element surface reference coordinate system. It has no effect on the calculation of the incident angle θ _x . However, this O
_d is the slit 4 determined from the physical shape of the slit 42
It should be noted that the central axis z _{s of} 2 is displaced from the intersection point O _ds where the one-dimensional photoelectric conversion element 40 intersects by L ₂ tan β ₁ . On the other hand, from the same figure (A), the equation for obtaining the incident angle θ _x of the light flux when the tilt angle α ₁ around the z _d axis is taken into consideration can be expressed by the equation (2). tan θ _x = x _p · cos α ₁ / L ₂ Equation (2) From Equation (1), α ₁ acts as a proportional coefficient when obtaining tan θ _x , so it is easy to correct the influence of α _1. is there.

On the other hand, although the two-dimensional photoelectric conversion element is not used in applications requiring high precision, even when the two-dimensional photoelectric conversion element is used, the direction of the light source of the light is changed by the principle shown in FIG. It can be specified as the direction of a straight line in the three-dimensional space. That is, assuming that the unit element 70 forms the image at the point M ₁ by passing the light emitted from the light source 61 on the two-dimensional photoelectric conversion elements 9 arranged orthogonally and passing through the pinhole 62a, the image at the point M ₁ is x. with _d coordinate _{x m} and _{y d} coordinate _{y m,} the distance _{r 1} from the origin _{O d} of the point _{M 1 r 1} = √
The incident angle θ of the light beam 63a can be expressed as (x _m ² + y _m ² ).
_d1 , azimuth angle φ _s1 , and azimuth angle φ _d1 of point M ₁ are given by equation (3).
It becomes a relation of (5). tanθ _d1 = _r 1 / _{L 3} Equation _{(3) tanφ d1 = y m} / x m Equation _{(4) tanφ s1 = (-} y m) / (- x m) (5) In equation (5), "-" y _m, to _{x m} was given the will,
It shows that the angle between φ _d1 and φ _s1 is shifted by 180 degrees. As shown by the equations (3) to (5), the method using one pinhole does not have the influence of the tilt unlike the conventional light direction sensor. That is, the pinhole 62
It suffices that the leg of the perpendicular drawn from a to the photoelectric conversion element surface 73a coincides with the origin O _{d of the} photoelectric conversion element surface reference coordinate system 46b. However, in the formulas (2) to (4), since it is assumed that the pinhole is small enough to be treated as a point, the case where this approximation does not apply, or the photoelectric conversion element surface 73a such as the surface of the object having the pinhole is used. When the surface not parallel to is used as the reference surface of the optical direction sensor, it is desirable to correct the inclination.

[0005]

However, in the method using the one pinhole 62a described above, in order to obtain the same performance as that of the conventional light direction sensor, the one-dimensional photoelectric conversion element surface 73a is formed in one direction in the photoelectric conversion element surface 73a. The first problem is that it is difficult to reduce the size because it requires the same number of elements as the number of conversion elements. Therefore, considering another pinhole 62b, when the straight line 74 passing through the pinhole 62a and the pinhole 62b is not parallel to the photoelectric conversion element surface 73a, the pinhole 62b is changed to the photoelectric conversion element surface 7a.
The position of the point N ₁ which is the foot of the perpendicular line lowered to 3a and the distance K from the pinhole 62b to the photoelectric conversion element surface 73a
_{Since 1} depends on the angle formed by the straight line 74 and the photoelectric conversion surface 73a, calculation for obtaining the distance K ₁ and the position of the point N ₁ becomes complicated. This is because when a plurality of pinholes, slits, etc. are used as the projection target in order to solve the first problem, the inclination of the two-dimensional photoelectric conversion element surface complicates the process of angle detection, and The second problem was that it took a lot of time. Furthermore, since the number of unit elements included in the two-dimensional photoelectric conversion element is orders of magnitude larger than the number of unit elements included in the one-dimensional photoelectric conversion element, when using the two-dimensional photoelectric conversion element, all units are included. It may take time to read out the signal of the element, and as a result, the time required to detect the light source direction may be longer than that in the case where the one-dimensional photoelectric conversion element is used. This property is the third problem to be solved depending on the use of the light direction sensor. An object of the present invention is to provide a small-sized light direction sensor that overcomes the first problem, the second problem, has accuracy equal to or higher than that of the conventional light direction sensor, and By overcoming the three problems, the application of this optical direction sensor is expanded.

[0006]

According to the present invention, in order to solve the above-mentioned problems, the optical direction sensor according to claim 1 has a two-dimensional photoelectric conversion in which a plurality of unit elements are two-dimensionally arranged. An element, a projected portion including a portion that transmits light and a portion that blocks light, and a signal processing portion that processes a signal output by the two-dimensional photoelectric conversion element, and the projected portion is light by a light source, The signal of at least a part of the unit elements included in the two-dimensional photoelectric conversion element, which is generated according to the light intensity distribution of the projection image formed by being projected on the two-dimensional photoelectric conversion element, is signaled by the signal processing unit. A two-dimensional photoelectric conversion element is a light direction sensor that processes and detects as a light intensity distribution signal including light intensity signals of a plurality of unit elements, and the two-dimensional photoelectric conversion element is a photosensitive portion of almost all unit elements of the two-dimensional photoelectric conversion element. Part or all of the photosensitive surface Area is a two-dimensional photoelectric conversion element that can be regarded as included in the photoelectric conversion element surface that is a virtual plane, and the projected portion is a boundary between the light transmitting portion and the light shielding portion of the projected portion. By providing a configuration in which a part or all of the boundary line is a projected portion that can be regarded as included in a projected surface that is a virtual plane, the first problem and the second problem described above are solved. Is what makes it possible. Details will be described below.

The light-shielding boundary lines in this specification are, for example, the edges of openings, slits, and pinholes. The opening is a portion that is surrounded by the light-shielding boundary and transmits light, and is, for example, 3h in FIG. The opening is mainly used for the purpose of detecting the position of a light-dark boundary which is a boundary between a bright portion and a dark portion formed by projecting the edge thereof. Therefore, when the edge is formed by a straight line, each straight line portion of the edge has a linear light-shielding shape. For example, 2c in FIG. 9 corresponds to this. The slit is a linear portion that is surrounded by the light-shielding boundary and transmits light. For example, the slit has a shape as shown in 23b in FIG. 10, its width is sufficiently small, and it is mainly a linear bright portion formed by projection. It is used to detect the position of a linear bright part. So, for example, if the slit is straight,
This slit has one linear light-shielding shape. The pinhole is a non-linear portion, which is surrounded by the light-shielding boundary and transmits light, has a sufficiently small area, and is mainly used for the purpose of detecting the position of a dot-shaped bright portion formed by projection. However, since it has a finite size, the projected surface can be defined even for one pinhole. Although the pinhole does not have a straight line portion, it can be regarded as a slit when the pinhole is arranged linearly to obtain the same effect as the slit. Further, contrary to the openings and the slits, there is a light shielding portion that shields light in the portion surrounded by the light shielding boundary line. The light-shielding portion, which has a certain width like the opening, is mainly used for detecting the position of the light-dark boundary. It is used for the purpose of detecting dark areas. Light-shielding dots, which are the opposite of pinholes, are also used mainly for the purpose of detecting points darker than the surroundings. It should be noted that the opening shape and the light shielding shape pattern of the projected portion and the purpose of using them are not limited to those described here, and various patterns may be arranged depending on the signal processing method, the characteristics of the light source, and the like. , Used in various ways. The two-dimensional photoelectric conversion element is, for example,
The unit element of the two-dimensional photoelectric conversion element is, for example, a CCD, a CMOS image sensor, or an infrared imaging element, and corresponds to, for example, these pixels. Of course, even if completely independent elements are two-dimensionally arranged, they are two-dimensional photoelectric conversion elements, and even when one-dimensional photoelectric conversion elements are arranged so that their unit elements are two-dimensionally arranged. It becomes a two-dimensional photoelectric conversion element.

The means for solving the above-mentioned first problem will be specifically described. An important point of the present invention is to perform a linear conversion by projecting a light-shielding boundary line included in a flat surface to be projected onto a photosensitive surface of a two-dimensional photoelectric conversion element included in a photoelectric conversion element surface which is also a flat surface. That is, the principle of is applied. That is, except for a special situation where the direction of light is parallel to the projection surface or the photoelectric conversion element surface, the light and darkness on the photoelectric conversion element surface formed by projecting the light-shielding boundary line in the projection surface. The shapes of the boundaries, the bright parts, the dark parts, etc. are almost the same as the original shapes of the light-shielding boundary lines projected onto the photoelectric conversion element surface, that is, linearly converted. Further, in this linear conversion, the shape feature of a certain figure and the positional relationship between the figures are saved. This will be described with reference to FIG. For example, it is assumed that the quadrangle ABCD is projected onto the plane P ′ by the linear transformation T and converted into the quadrangle A′B′C′D ′. The position vectors of points A, B, C, and D are ~ a, ~ b, ~, respectively.
c, ~ d, position vector ~ e = (~ a + ~ b + ~ c + ~
d) Let E be the point having / 4. Similarly, points A ', B',
The position vectors of C'and D'are ~ a ', ~ b', ~
Position vectors ~ e '= (~ a' + ~ as c ', ~ d'
A point having b ′ + ˜c ′ + ˜d ′) / 4 is defined as E ′. Then, ~ e '= (T ~ a + T ~ b + T ~ c + T ~ d) / 4 = T
Since ((~ a + ~ b + ~ c + ~ d) / 4) = T ~ e,
It can be seen that the point E is transformed by the linear transformation T into the point E ′ on the plane P ′. On the contrary, if the quadrangle ABCD is on the plane P, the point E ′ is converted to the point E by the linear transformation T ′ that projects the quadrangle A′B′C′D ′ to match the quadrangle ABCD. That is, it can be said that the point having the average vector of the position vectors of the four vertices of the quadrangle is the characteristic point stored by the linear transformation that projects the figure in the plane onto the plane. Here, as shown in FIG. 7, there is an opening 3g corresponding to a quadrangle ABCD on the projection surface, and a quadrangle A'B'C'D '.
When the light-dark boundary 81 corresponding to is on the photoelectric conversion element surface, from the respective positional relationships of points corresponding to A and A ′, B and B ′, C and C ′, and D and D ′, Instead of obtaining the direction and averaging the directions, first, the points F in FIG. 7 corresponding to the feature point of the projection portion corresponding to E and the point F ′ in FIG. 7 corresponding to the light intensity distribution feature point corresponding to E ′ It is only necessary to find the position and find the direction of the light source from only the positional relationship between these two points. In the former, the calculation to find the direction of the light source is 4
In contrast, the latter requires only one time, and the calculation time has been greatly shortened. Here, four square points are used for explanation, but the above-mentioned principle does not limit the number of points used for calculating the characteristic points. Therefore, this method is particularly effective when the number of points is very large. Clearly, it works. Further, when the projected surface and the photoelectric conversion element surface are tilted or the reference direction is twisted, a complicated correction calculation is required when calculating the relative position of the points, but the above-mentioned principle , The complicated calculation needs to be performed only once, so that the projected surface and the photoelectric conversion element surface are inclined,
Even if the reference direction is twisted, a highly accurate optical direction sensor can be realized. Thus, for example, in order to compensate for the small number of unit elements in one direction of the two-dimensional photoelectric conversion element, the projected portion is projected on the two-dimensional photoelectric conversion element, and the bright and dark boundaries of the projected image are formed at a plurality of locations. The signal detected by the above method can be efficiently processed, and the first problem described above is solved.

In FIG. 7, the direction of the light source can be expressed by equations (6) to (9). However, the coordinates (x _f , y _f , 0) of the photoelectric conversion element surface reference coordinate system of the point F ′
There shall correspond to at a projection surface coordinate system _{(x n, y n, -L} 4). ^{_{r s = √ (x n 2}} + y n 2) Equation _{(6) tanθ s2 = r s} / L 4 Equation _{(7) tanφ d2 = y n} / x n formula _{(8) tanφ s2 = (-} y n) / ( -x _n) equation (9) in equation _(9), y n, the _{x n} "-" I was given the will,
It shows that the angle between φ _d and φ _s is shifted by 180 degrees. Further, the point F1 which is a light intensity distribution feature point or the like has been described so far, but of course, the calculation of the information about the light source direction using the light intensity distribution feature point or the like is performed according to the use. You may implement with respect to a feature point etc. The positions of the projected portion feature points, etc., corresponding to the positions of the light intensity distribution feature points, etc., are positions determined by the known arrangement of the light-shielding boundary lines, and so are calculated in advance and stored in the light direction sensor. By setting it in advance, it becomes possible to shorten the calculation time of the light source direction and the like. Further, by converting the positions of the feature points of the projected portion to the positions in the photoelectric conversion element surface reference coordinate system and storing them, the calculation time of the light source direction can be further shortened. . In addition, projecting the light-shielding boundary line included in the projection surface that is a plane onto the photosensitive surface of the two-dimensional photoelectric conversion element that is included in the photoelectric conversion element surface that is also a plane is the equation of the plane or the plane as described later. By making it easier to use the rotation matrix, coordinate transformation, etc. inside, it becomes easier to calculate the tilt of the surface and the twist of the azimuth in the reference direction, and the processing time can be shortened. It also solves problems. That is, the optical direction sensor according to claim 1 simultaneously solves the first problem and the second problem to be solved, and compensates for the small number of unit elements in one direction of the two-dimensional photoelectric conversion element. In order to efficiently process the information obtained by detecting the brightness and the like of the projected image formed by projecting the projected portion on the two-dimensional photoelectric conversion element at a plurality of points, correct the tilt, and adjust the azimuth reference direction. It is an optical direction sensor having a configuration suitable both for easily performing the calculation for correcting the twist of.

According to a tenth aspect of the present invention, in the light direction sensor, the signal processing section performs signal processing of the light intensity distribution signal, so that the projected section is projected onto the two-dimensional photoelectric conversion element to form a projection. The position of a point or line that serves as a reference for the position of the light intensity distribution of part or the whole of the image, or
A light source is obtained by obtaining at least one position or the like of a light intensity distribution position reference point or the like, which is either a point or a line amount equivalent to the position of a light intensity distribution position of a part or the whole of the projected image. The function as a light direction sensor is enhanced by detecting the information regarding the direction of the light source corresponding to at least one of the information regarding the direction of the light source and the information used for detecting the information regarding the direction of the light source. For example, the position of the line or point that satisfies the predefined condition of the light-dark boundary with respect to the light intensity distribution of the projected image formed by projecting the light-shielding boundary line included in the projection surface onto the two-dimensional photoelectric conversion element. , Positions of lines and points that satisfy the condition of the predefined bright part, positions of lines and points that satisfy the condition of the predefined dark part, phase when a certain length is defined as one cycle, light intensity distribution and evaluation The amount and the like obtained by arithmetically processing the function and correspond to the position of the light intensity distribution position reference point or the like. The evaluation function includes, for example, a sine function and a cosine function, and if Fourier analysis of the light intensity distribution is performed using this, phase information equivalent to the position can be detected. The position of the light intensity distribution position reference point or the like is one of the information for detecting the information about the light source direction, and the relative position relationship with the position of the projected part position reference point or the like corresponding to the position etc. Information about the direction of the light source can be detected. The detection of the information regarding the direction of the light source may be performed in the light direction sensor or may be performed by the light direction sensor signal processing device. Note that the method of determining the position of the projected portion position reference point, etc. is, for example, if the corresponding light intensity distribution position reference point is related to the physical structure such as the light-dark boundary, the light-shielded boundary line The position and the like may be determined by using the projection target position reference point and the like. When the position of the light intensity distribution position reference point or the like is to be obtained by a calculation process using an evaluation function, for example, by performing a calculation process equivalent to this calculation process on the transmittance distribution of the projection target, It is possible to obtain the position of the part position reference point and the like. Of course, this method can also be applied to the case of obtaining the position of the projected portion position reference point or the like corresponding to the position of the other light intensity distribution position reference point or the like. For the position of the projection target position reference point or the like, a value obtained in advance may be used, or may be calculated each time depending on the direction, brightness, temperature, etc. of the light source.
The calculation is efficient if it is a correction calculation for a value that is obtained in advance.

The above-mentioned predefined condition is defined as, for example, a light-dark boundary as a line where the light intensity coincides with a certain threshold value I _Th1 in a portion where the light intensity changes as shown in FIG. A point on the light-dark boundary can be defined as a point that satisfies the same condition with respect to the light intensity distribution on a straight line intersecting with the light-dark boundary. In FIG. 8A, this position is shown as x _BD . Here, the threshold value itself is
It is not necessary to use a predetermined constant value, and it may be appropriately changed depending on the approximate light source direction, light brightness, noise level of the photoelectric conversion element signal, and the like. For example, applying the knife-edge diffraction equation, I _Th1 = (I _BR +3
I _DK ) / 4. Further, for example, a linear bright portion is defined as a set of points where the light intensity distribution on a straight line in a certain direction intersecting the line has a maximum value I _PK, and the bright point is defined as the bright point. It can be defined as the included point. In FIG. 8B, the position of the bright point is shown as x _PK .
Alternatively, the definition may be defined as the midpoint between two points that match a certain threshold value I _Th2 . The position of this point is (x _H1 + x _H2 ) / 2 in FIG. 8B. In this case as well, as described above, the threshold value itself does not need to use a predetermined constant value, and may be appropriately changed according to the light source direction, the brightness of light, the noise level of the photoelectric conversion element signal, and the like. Good. As a definition of the dot-shaped bright part, it is general to define the point where the light intensity distribution has a two-dimensional maximum. The position of the dark part is calculated in the opposite way to the light part. In addition, when obtaining the position of the light intensity distribution position reference line, for example, a light intensity distribution position reference line having the same shape as the light shielding boundary line is moved on the photoelectric conversion element surface, and the light intensity distribution on the line has a light-dark boundary. There is a method of searching for a position that satisfies the condition of. At this time, if the straight line portion of the light shielding boundary line is used, for example, the light intensity distribution position reference line remains parallel to the straight line portion of the light shielding boundary line,
The position can be detected relatively easily because it can be moved in a direction perpendicular to the straight line. Further, for the light intensity distribution consisting of, for example, the sum of a plurality of light intensity signals of the unit element of the two-dimensional photoelectric conversion element, for example, by obtaining the above-mentioned bright and dark boundary points,
It is also possible to find the position of the substantial light intensity distribution position reference line. Of course, not only the position of the light intensity distribution position reference point or the like but also the phase, distance, azimuth, etc. may be obtained. The position and the like may be information about one direction or information about two or more directions. In the case of two directions, it is common to fix the position in one direction and obtain only the other directions, obtain one direction at a time, or obtain two directions at the same time. It should be noted that in the following description, an example is mainly used in which it is assumed that a bright / dark boundary or a linear bright portion is detected, but it means that detection of positions such as other light intensity distribution position reference points is limited. Not something to do.

The light intensity distribution actually composed of the light intensity distribution signals detected by the light direction sensor is roughly as shown in FIGS.
It is a discontinuous light intensity distribution as shown in FIG. Figure 9
[Fig. 10] is a schematic view of a light intensity distribution and the like when one straight line light-shielding shape 2c is projected. Fig. 10 shows a case of a slit 23b and Fig. 11 shows a case of an opening 3i. As a simple method for obtaining the light-dark boundary points or the positions of the light points from these discontinuous light intensity distributions, the position x _{BD0 of the} unit element having the light intensity closest to the threshold value of the light-dark boundary is used as the light-dark boundary point. , the position x _PK0 of the unit element having the largest light intensity, there is a method or the position of the bright point. However, in this method, the position detection resolution does not become equal to or less than the unit element arrangement interval. When accuracy is insufficient with this, after making the light intensity distribution a continuous line by interpolation, approximation, filtering, etc., calculate the position of the light intensity that matches the threshold value, or calculate the centroid of the distribution. By obtaining the center of the light intensity distribution by using, the detection resolution of the position is made smaller than the interval of the arrangement of the unit elements, and the detection position is the position x of the bright / dark boundary point of the true light intensity distribution.
It is possible to approach the position of _BD1 or the bright spot x _PK1 . In addition, the reference position of the fitting function, which is the predicted curve or curved surface of the light intensity distribution, is gradually shifted to calculate the error from the actual light intensity value, and the position where the error is minimized is the most accurate fitting function. As a unique position, a method of obtaining the position of the light intensity distribution position reference point, or the like, or signal processing between at least one one-dimensional or two-dimensional evaluation function and the light intensity distribution of the same dimension, for example, multiplying both and integrating. There is also a method of detecting the position of the light intensity distribution position reference point or the like by performing processing such as performing. In addition, as shown in FIG. 11, the method of obtaining the light-dark boundary line in a pair is a method of setting the threshold value at the position (x _BD2 + x _BD3 ) / 2 of the obtained midpoint of the light-dark boundary point, and the threshold value. This is a method that has the advantage that it is unlikely to be affected by the value itself. The case of bright spots formed by projecting pinholes will not be described in detail, but the position detection resolution can be increased by performing centroid calculation.

As described above, the position of the light intensity distribution position reference point or the like is detected, and the information on the direction of the light source is obtained by the relative positional relationship with the position of the projected part position reference point or the like corresponding thereto. It is as described above that the can be detected. If the correspondence between points and their relative positions are known, the light source direction can be specified by the calculations shown in equations (6) to (9). Further, when the point on the photoelectric conversion element surface and the straight line on the projection surface can be matched, it can be seen that the light source exists in the plane including the point and the straight line. Since it is not possible to know the direction of the light source from this information alone, this information is information about the direction of the light source, not the direction of the light source itself. However, for example, if two points that are not parallel to each other on the projected surface can be associated with points on the photoelectric conversion element surface, then the light source exists in two planes that are not parallel. The direction of the intersecting straight line is the direction of the light source.

In the light direction sensor according to the eleventh aspect, by obtaining a plurality of positions of the light intensity distribution position reference point and the like, the accuracy of the direction of the light source to be detected by the averaging effect and the like is improved, and as described above. The direction of the light source can also be determined by the correspondence between lines and points. Further, the calculation of the positions of the light intensity distribution feature points and the like using the characteristics of the linear conversion is effective when a plurality of positions of the light intensity distribution position reference points and the like are detected. The effect of obtaining a plurality of positions such as points is very effective.

In the optical direction sensor according to a twelfth aspect, when a linear transformation is performed in which at least one figure existing in one plane is projected onto another plane, the linear transformation is saved. Shape feature of the figure and the light intensity distribution feature point corresponding to the feature point or feature line of the figure that can be defined using at least one of the figure and the positional relationship between the figure saved by the linear conversion At least one is defined for the light intensity distribution, and the position of the light intensity distribution feature point or the position of the light intensity distribution feature point, which is the same amount as the position, is defined as a plurality of light intensity distribution position references. By including the process of calculating using the position of points etc. in the process of detecting the information about the direction of the light source from the light intensity distribution signal, for example, the positions of many detected light intensity distribution position reference points etc. can be used. Light source The calculation of the information about the executable in a short time. The effectiveness of applying the linear transformation has already been described. The figure described in claim 12 also includes lines and points. For example, a point is converted into a point and a straight line is converted into a straight line by a linear conversion in which a figure in the plane is projected onto the plane. There are many other features that can be saved by this linear transformation.For example, by combining these properly according to the arrangement of the light-shielding boundary lines of the projected portion, the positions of effective light intensity distribution feature points etc. are defined, The position and the like can be calculated efficiently.

In the light direction sensor according to a fourth aspect of the present invention, the light-shielding boundary line includes a linear light-shielding shape which is a linear portion of the light-shielding boundary line, so that the position of the light intensity distribution position reference point or the like. The detection accuracy is improved, and the positions of the light intensity distribution feature points and the like are easily calculated. For example, the light intensity distribution in the direction intersecting with the straight line of the projected image formed by projecting the straight line portion of the light-shielding boundary line is almost the same at a position sufficiently distant from the end of the straight line portion. When a plurality of straight lines along the line are defined and the positions of the light intensity distribution position reference points are obtained for the light intensity distributions on the respective straight lines, it is expected that these points will be arranged on the straight line. Conversely, the part deviating from the straight line is the position detection error due to variations in sensitivity characteristics, dark current characteristics, etc. of each unit element of the two-dimensional photoelectric conversion element, signal processing noise, etc. This position detection error can be reduced by obtaining the approximate straight line from the reference point. If the inclination of the projected surface and the photoelectric conversion surface or the twist in the reference direction can be corrected, or if the inclination or the twist can be ignored, the straight line part of the light-shielding boundary line is the straight line of the image projected on the photoelectric conversion surface in advance. It is preferable that the direction of the part is obtained in advance and the direction of the above-mentioned approximate straight line is made to coincide with the direction obtained in advance. In this case, for example, the light source lies in a plane including both the calculated approximate straight line and the corresponding projected portion position reference line. Further, in consideration of the field of view of the light direction sensor, when the straight line portion of the light shielding boundary line is sufficiently long, if the direction of the line projected on the plane perpendicular to the direction of the light source is the same, There is a merit that the position of the projected image of the linear portion on the photoelectric conversion element surface can be regarded as the same.

In the optical direction sensor according to a fifth aspect of the present invention, at least a part of the unit elements of the two-dimensional photoelectric conversion element are arranged on the lattice points of the lattice whose unit lattice is substantially a parallelogram, and the straight line thereof. At least one of the directions of the straight lines of the portion corresponding to the straight line portion of the linear light-shielding shape of the image formed by projecting the light-shielding shape on the two-dimensional photoelectric conversion element is the two-dimensional photoelectric conversion element. Since it is not parallel to any of the unit element placement directions, the error due to the influence of the unit element placement gap and the sensitivity unevenness inside the unit element, the detection algorithm for the position of the light intensity distribution position reference point, etc. It is possible to reduce accompanying errors and the like. Figure 1
3 will be described as an example. FIG. 13A shows a configuration similar to that of FIG. 11 in which the two-dimensional photoelectric conversion element 9 is rotated by a twist angle γ ₂ within the plane of the photoelectric conversion element. Focusing on the light-dark boundary 81e, in order to detect the position of the light-dark boundary 81e, when the light-dark boundary points are respectively detected by the unit element rows 85b, 85c to 85d to obtain an approximate straight line, It can be seen that the position of the light-dark boundary in the unit element is slightly different. That is, in the unit element row 85b, the light-dark boundary is on the left side of the unit element, and in the unit element row 85c, it is almost at the center,
In d, it is near the boundary between the unit elements. With such a configuration, in the light direction sensor of FIG. 13, it is possible to average the error of the unit element interval period that occurs when the position of the light-dark boundary point is obtained with a resolution of the unit element interval or less, and the position detection is performed. The accuracy of can be improved. Note that this type of error is an error that occurs even if unit elements having uniform sensitivity are arranged without a gap. For example, when performing centroid calculation, this type of error is known to occur as a centroid error. Has been. On the other hand, in an actual two-dimensional photoelectric conversion element, there is a structure inside the unit element, and thus the sensitivity is not uniform or there is a gap between the unit elements. With the configuration of FIG. 13A, it is possible to reduce the position detection error due to the uneven sensitivity in the unit element. FIG. 13B shows
6 is a diagram in which six unit elements each having a sensitive section 91 having a uniform sensitivity and a dead section 92 having no sensitivity are arranged. FIG. For the sake of clarity, it is assumed that the light intensity in the region on the left side of the light-dark boundaries 81g to 81j is "0" and the light intensity in the region on the right side is "1". At this time, if 81g moves slightly to the left and right,
Since the outputs of the three unit elements on the left change accordingly, changes in the position of the light-dark boundary can be detected, but when 81h moves slightly left and right, the three unit elements on the left also change Since the outputs of the three unit elements also do not change, it is not possible to know the change in position. On the other hand, 81i, 81j
When the arrangement direction of the unit elements and the light-dark boundary are inclined as described above, it is possible to ensure that some part of the light-dark boundary is applied to the sensitive part of the unit element. In other words, with this configuration, the sensitivity of the detection position with respect to the position change of the light-dark boundary can be made uniform, so that the position detection error due to the uneven sensitivity in the unit element can be reduced. When the unit elements are square and orthogonally arranged, the twist angle γ
₂ indicates that the number of unit element rows that intersect the straight line portion of one light-dark boundary and detect the light-dark boundary point is N _L , and the positional relationship between the unit element and the light-dark boundary in N _L changes by N _C cycles. When it does, it can be expressed as in Expression (10). ta
n γ ₂ = N _C / N _L (Equation 10) Since N _C needs to be 1 or more in order to sufficiently obtain the above-mentioned effect, N _L may change depending on a slight change in the twist angle or the light source direction. In consideration of the characteristics, it is desirable to set N _C to several cycles or more. For example, if N _L = 100 and N _C = 7, then γ ₂ = 4 degrees. Although the description has been given here by using the light-dark boundary, this configuration is used when a plurality of positions of the light intensity distribution position reference points are obtained for the light intensity distribution of a linear light-shielding image, or the light intensity distribution position reference line. When obtaining the position and the like, the same effect can be expected except when obtaining the position of the light-dark boundary. Further, the shape of the unit cell does not have to be a square, but may be a parallelogram.

In the optical direction sensor according to a sixth aspect of the present invention, the projected portion includes at least one pair of linear light-shielding shapes in which the directions of the linear light-shielding shapes are parallel to each other. The accuracy of detecting the direction of the projected light source is improved. Further, by utilizing the fact that two parallel straight lines become two parallel straight lines by linear conversion, it is possible to define one straight line parallel to them from a plurality of parallel lines, for example, a light intensity distribution feature point. It is also possible to use it to define positions such as the position of the projection target part and the position of the projection target feature point, etc., and to obtain the position of the light intensity distribution position reference point using the evaluation function, etc. It is easy to handle multiple lines together. For example, if the intervals between parallel lines are equal, it is desirable that the evaluation function be a function having the same period as this interval.

In the light direction sensor according to the seventh aspect of the present invention, the projected portion includes the linear light shielding shapes in which the directions of the linear light shielding shapes are not parallel to each other, so that the direction of the light source can be specified as the linear direction. did. To know the relative positions of the light intensity distribution position reference points and the like of the light intensity distribution of the image generated by projecting at least two non-parallel linear light-shielding shapes, and the corresponding position of the projected portion position reference line. As described above, the direction of the light source can be specified. In addition to this, for example, the line of the bright portion generated by projecting two non-parallel linear light-shielding shapes is obtained as an approximate straight line by the above-described method, and these intersections and the corresponding linear light-shielding shape of the projected portion are obtained. The direction of the light source can be specified by knowing the relative position of the straight line along the intersection. This method effectively uses the position detection of a plurality of points and the linear conversion. Of course, it is also effective when detecting the position of another light intensity distribution position reference point or the like.

In the optical direction sensor according to the second aspect, since the projection surface and the photoelectric conversion element surface are provided with a structure or mechanism capable of being adjusted so as to be substantially parallel, The photoelectric conversion element surface can be adjusted to be parallel. With this structure or mechanism,
If the projection surface and the photoelectric conversion element surface are adjusted so as to be parallel to each other, it becomes possible to detect the information regarding the direction of the light source with good accuracy without performing the calculation for correcting the inclination. The error reduction method described above is based on the unevenness of photoelectric conversion element characteristics for each unit element,
This is a method for reducing so-called high spatial frequency error caused by uneven sensitivity in the unit element, noise of the signal processing circuit, centroid and the like. On the other hand, an error caused by a tilt between the projection surface and the photoelectric conversion element surface, a twist in the azimuth reference direction, distortion of the photoelectric conversion element surface, thermal expansion, etc. is an error called a low spatial frequency error. In this specification, the low spatial frequency error included in the information about the direction of the light source is called a bias error. In order to reduce the bias error due to the inclination of the surface, it is effective to eliminate the inclination or correct the inclination. For example, the two-dimensional photoelectric conversion element 9 is held by a structure capable of adjusting the inclination as shown in FIG. By doing so, the projection surface and the photoelectric conversion element surface can be adjusted to be parallel to each other. That is, the two-dimensional photoelectric conversion element holder 12c and the two-dimensional photoelectric conversion element holder support plate 1 are adjusted by adjusting the thicknesses of the shims 89 in the three inclination adjusting portions 10b.
Since the inclination of 3b can be set almost arbitrarily within the range of a minute angle, for example, if both the two-dimensional photoelectric conversion element holder support plate 13b and the projected portion are fixed to the housing, the projected surface and the photoelectric conversion are The element surfaces can be adjusted substantially parallel to each other.
When the angle of inclination is large, it is desirable to appropriately shape the washers 88 and the spacers 90 so that the pressure applied to the fixing bolts 87 is not biased.

In the optical direction sensor according to a third aspect of the present invention, both or one of the projected portion and the photoelectric conversion element has a direction substantially the same as the normal line of the projected surface or the normal line of the photoelectric conversion element surface. By providing a structure or mechanism that can rotate with respect to the rotation axis of, the projected surface and the reference direction of the in-plane azimuth angle of the photoelectric conversion element surface are adjusted to be parallel, The accuracy of information about the direction of the light source can be obtained without calculating the correction of the twist of the reference direction, or the above-mentioned twist angle γ ₂ can be easily set. Specifically, for example, it is a structure in which part or all of the outer shape of the projection target or the one to which the projection target is attached is configured by an arc. The projected part here is
It includes optical glass having a light-shielding film.

In the light direction sensor according to the thirteenth aspect, in the process of detecting information about the direction of the light source from the light intensity distribution signal, at least information about the inclination between the projected surface and the photoelectric conversion element surface is used. By including a process of performing a tilt correction, which is a correction process related to the tilt, the bias error included in the information about the direction of the light source detected from the light intensity signal output from the light direction sensor that does not correct the tilt is included. I tried to reduce it. For example, information about the tilt can be obtained by measuring the tilt in advance using a measuring device such as a microscope or estimating the tilt from the value of the light source direction detected by the light direction sensor before tilt correction or the light intensity distribution signal. I can know. For example, a plane equation representing the photoelectric conversion element surface may be created from this information to correct the position in the out-of-plane direction on the photoelectric conversion element surface. This will be described with reference to FIG. The figure shows y _{d of the} photoelectric conversion element surface reference coordinate system.
Axis is parallel to the y _s axis of the projected surface reference coordinate system and the x _d axis is β ₂
It is the figure which showed the state which only tilted. To O _s as there is an ideal pinhole 62c, if the light beam 63c which has passed through this reaches _{M 3,} when not correcting the tilt beta _{2, M 3} is on _{x s} parallel _{x c} The incident angle θ _s4 is detected assuming that it is at the position of M ₄ . However, since the actual incident angle is θ _s3 , this difference causes an error due to the inclination. From FIG. 14, the relationship between θ _s4 and θ _s3 can be expressed by equation (11). tan θ _s4 = tan θ _s3 cos β ₂ + tan θ _s3 ta
_{n (θ s3 + β 2)} sinβ 2 Equation (11) in order to correct the error, in the case of using the plane equation, _{M 3} is _{M 5}
The incident angle θ _s5 is detected assuming that the position is. This method cannot reduce the error to 0, but it is one of the effective methods that can be easily performed. At this time, θ _s5 is given by the formula (1
Given in 2). tan θ _s5 = tan θ _s4 + / (1 + tan θ
_s4 tan β ₂ ) Expression (12) Note that, conversely to this example, the same correction may be performed on the position of O _s with the photoelectric conversion element surface as a reference. Further, the tilt correction is effective not only for reducing the bias error of the light direction sensor that has not been tilt adjusted, but also for further reducing the bias error of the light direction sensor that has been tilt adjusted.

According to a fourteenth aspect of the present invention, in the process of detecting information about the direction of the light source from the light intensity distribution signal, at least the azimuth reference direction on the projection surface and the photoelectric conversion element surface are detected. By using the information about the angle of twist with respect to the reference direction of the azimuth angle of the
The bias error included in the information about the direction of the light source detected from the light intensity signal output from the light direction sensor that does not correct the deviation of the azimuth angle from the reference direction is reduced. For example, measure the twist angle in advance using a measuring instrument such as a microscope, or estimate the twist angle from the light source direction output value of the light direction sensor before the twist angle correction, the light intensity signal, etc. You can know the information. Even if it is not measured in advance, the twist angle can be estimated, for example, from the direction along the linear light-shielding linear portion of the projected portion and the direction of the straight line that approximates the light-dark boundary of the image produced by projecting this. Is. Twist angle γ ₀
Is the same as the rotation around the origin of the reference coordinate system of each of the projected surface and the photoelectric conversion element surface, which are the reference positions of the azimuth angle, so that, for example, if the rotation matrix of the angle γ _{0 in} the plane is used, The position vector in the coordinate system can be corrected according to the other coordinate system. However, in this case, the inclination between the projection surface and the photoelectric conversion element surface is not taken into consideration, so care must be taken.

According to a fifteenth aspect of the present invention, in the optical direction sensor, a photoelectric conversion element surface reference coordinate system including two unit vectors in the photoelectric conversion element surface and a projection surface reference including two unit vectors in the projection surface. Assuming a coordinate system, the above-described tilt correction and twist correction algorithms described above are part or all of the process of coordinate conversion between the projected surface reference coordinate system and the photoelectric conversion element surface reference coordinate system, or By including a part or all of the process of coordinate conversion, the position or vector in the photoelectric conversion element surface reference coordinate system is converted to the position or vector in the projected surface reference coordinate system to Correcting the inclination between the surface and the photoelectric conversion element surface and / or correcting the twist in the reference direction of the in-plane azimuth of the projection surface and the photoelectric conversion element surface. Made possible. The coordinate conversion can be performed by moving the origin and rotating T ₃ around the origin in the three-dimensional space. The tilt angle between the projection surface and the photoelectric conversion element surface, the tilt direction, and the reference twist angle of the azimuth angle can be known by measuring in advance. From these information, rotation T ₃
Since the Euler angle of can be calculated, the coordinate of one coordinate system is converted into the coordinate of the other coordinate system based on this rotation T ₃ and the relative position information of the origins of both coordinate systems known by measuring in advance. be able to. With this method based on coordinate conversion, the inclination of the surface and the twist angle can be corrected accurately at the same time, so it can be considered that the error shown in equation (11) can be made almost zero. Therefore, the bias error included in the information regarding the direction of the light source can be significantly and efficiently reduced by the method based on the coordinate conversion.

According to the twentieth aspect of the present invention, the light direction sensor has a plurality of signal processing methods performed in the signal processing section, or is provided with an element control section for controlling the operation of the two-dimensional photoelectric conversion element, and the element control section performs the operation. By providing a plurality of element control methods or a plurality of both signal processing methods and element control methods, it is possible to detect information regarding the direction of the light source with a plurality of different accuracies. As a result, for example, after outputting the information about the direction of the light source with the first accuracy, it is possible to output the information about the direction of the light source with the second accuracy, which is better than the first accuracy.
This function is effective, for example, when the information on the light source direction is used for a plurality of purposes. For example, the sun direction information used to control the attitude of a satellite is output at a normal speed with a high degree of accuracy, and the sun direction information used to determine the attitude has been sufficiently processed to improve its accuracy. It becomes possible to output it later as information. That is, this optical direction sensor overcomes the third problem to be solved. The plurality of element control methods are, for example, changing the selection of the unit element that performs signal processing or changing the frequency or timing of the control signal input to the two-dimensional photoelectric conversion element. In addition, in the signal processing method, a plurality of signal processing methods can be performed by switching the amplification factor of the amplifier in the analog processing, the transmission frequency band of the filter, and the comparator threshold voltage. It is also possible to select whether to once store in the memory. In addition, the number and type of positions such as the light intensity distribution position reference point to be detected, the target area, etc. may be changed, the detection method may be changed, and the calculation method of the position of the light intensity distribution characteristic point, etc. may be changed. Various methods are possible by changing the inclination correction and the twist correction method. Among these methods, it is preferable to combine and use the most suitable method according to the required accuracy and the allowable calculation time.

In the optical direction sensor according to claim 19, a process of element control in which the first information, which is already detected information about the direction of the light source, is performed after the time when the first information is detected. By using information and the like regarding the direction of the light source as the second information by using both and / or one of the signal processing steps, for example, from the first information, the linear light-shielding shape is a photoelectric conversion element surface. Calculating the approximate position projected on, and limiting the unit element that performs signal processing or the signal output by the unit element, or changing the control method of the two-dimensional photoelectric conversion element based on this calculation result. With this, it is possible to efficiently obtain information about the direction of the light source. For example, when the light direction sensor periodically detects information about the direction of the light source, the previously obtained information may be used for signal processing or the like performed later in the same detection cycle. Information about the direction of the light source detected in a cycle may be used for signal processing in a subsequent cycle.

According to another aspect of the present invention, in the light direction sensor, the first projected portion in which the linear light-shielding shapes are sparsely arranged in the projected portion and the linear portion compared to the first projected portion are arranged. By including the second projected portion in which the light-shielding shapes are densely arranged, for example, to detect the information regarding the direction of the light source in the projected portion due to the accuracy of the information regarding the direction of the light source that is required. It was possible to select the part to be used. In other words, information about the general direction of the light source is detected from the linear light-shielding shapes of the first projected portions that are sparsely arranged and the light intensity distribution of the image that is formed by projecting them, and the densely arranged In addition, it is configured such that highly accurate information about the light source direction and the like can be detected from the linear light-shielding shape of the second projected portion and the light intensity distribution of the image formed by projecting it.

In the optical direction sensor according to the eighteenth aspect, the light-shielding boundary line includes a linear light-shielding shape which is a linear portion of the light-shielding boundary line, and the linear light-shielding shape is sparsely arranged. Using the signal of the unit element included in the first area on the two-dimensional photoelectric conversion element on which the first projected portion is projected, while detecting the information about the direction of the light source and the like with the first accuracy, the By using the signal of the unit element included in the second area on the two-dimensional photoelectric conversion element on which the second projected portion in which the linear light-shielding shape is densely arranged is projected, the information about the direction of the light source is described. By detecting with the second accuracy, which is better than the first accuracy, it is possible to detect information about the direction of the light source with different accuracy.

According to the twenty-first aspect of the invention, the light direction sensor has a function of detecting information on the brightness of light from the signal of the two-dimensional photoelectric conversion element. You can know information about distance. This brightness information can also be used as information for determining whether or not light from a planned light source strikes the light direction sensor, for example.

According to the twenty-second aspect, the light direction sensor has a function of detecting information on the brightness of light from the signal of the two-dimensional photoelectric conversion element, and at least information on the brightness of the light is used, Predict the shape of the light intensity distribution of the whole or a part of the projected image formed by projecting the projected portion on the two-dimensional photoelectric conversion element, and use the predicted light intensity distribution shape as the light intensity distribution position reference point, etc. It is possible to improve the accuracy of detecting information about the direction of the light source by using it for signal processing to find the position of. For example, the shape and size of the light source, and the relationship between the distance from the light source to the projection target and the information about the brightness of the light detected from the signal of the two-dimensional photoelectric conversion element are known, or the light direction sensor is already known. When it is known by using the direction of the detected light source, etc., the distance from the light source to the projection part is obtained from the detected brightness information, and the distance and the shape and size of the light source are used to calculate the distance. It is possible to predict the whole or a part of the shape of the light intensity distribution of the projected image formed by projecting the projected portion on the three-dimensional photoelectric conversion element. For example, if the visual diameter of the light source becomes large, it is expected that the length of the light-dark boundary portion where the brightness changes from dark to light at the light-dark boundary and the width of the light portion generated by the slit projection become longer. It is possible to change the number and positions of the unit elements used for detecting the bright and dark boundary points and the bright points, the signal processing method, and the like by using the predicted information. For example, in the signal processing of the detected position, V _DK 9, but it is important accurately obtain the V _{D K} of V _BR and 10, the position and the number of unit elements used to determine these values Is preferably changed according to the width of the bright-dark boundary portion or the width of the bright portion. It is also effective to change the position and number of unit elements used for the centroid calculation, the filter, and the interpolation calculation, the shape of the fitting function and the evaluation function, and the period. Further, regarding the filter, it is desirable to change the setting of the transmission band regardless of whether it is a digital filter or an analog filter. Note that such a change in the signal processing method may be made by judging from the shape of the light intensity distribution itself, regardless of the brightness information.

In the light direction sensor according to the twenty-third aspect, the light direction sensor has one or more temperature sensors for measuring the temperature of one or more parts of the light direction sensor to improve the accuracy of the information regarding the direction of the light source. The accuracy of detecting the information about the direction of the light source is increased by outputting the information about the temperature for performing the signal processing and the information about the direction of the light source whose accuracy is improved by the information about the temperature, or both. Made it possible. That is, if the two-dimensional photoelectric conversion element thermally expands, even the same unit element exists at a position different from that before the thermal expansion, and if the length corresponding to L ₄ in FIG. 7 changes. Information about the direction of the light source changes. Similarly, when the projected portion is thermally expanded, the distance and position of the linear light-shielding shape are changed, so that the information on the direction of the light source is affected. It is desirable to measure the temperature that determines the thermal expansion of at least these three points in order to correct the information related to the direction of the light source due to temperature, but it is known in advance that there is almost no temperature difference, or if the temperature difference can be predicted Even if the number of measurement points is reduced, effective correction can be performed.

According to the twenty-fourth aspect of the present invention, the light direction sensor has a function of controlling the two-dimensional photoelectric conversion element in synchronization with a timing signal input from the outside, so that information about the direction of the light source or the light intensity distribution. It was made possible to externally know when the signal corresponds to the direction of the light source at the time, and to control when the information on the direction of the light source at the time is detected from the outside. For example, the light intensity distribution signal of the image formed on the two-dimensional photoelectric conversion element by the light hitting the projection target is detected at a time after a delay time known in advance with respect to the timing signal input from the outside. The two-dimensional photoelectric conversion element may be controlled. When the direction of the light source changes with the passage of time, it is not enough to simply detect the direction of the light source, and it is preferable to output information in the form of a light source direction at a certain time. Because the uncertainty of the time multiplied by the rate of change over time in the light source direction,
This is because the measured light source direction becomes uncertain. Further, when the light direction sensor is used as a control sensor, it contributes to the reduction of control error by outputting information about the direction of the light source or the light intensity distribution signal in synchronization with the control cycle. Is possible.

In the optical direction sensor according to the twenty-fifth aspect, in addition to having a function of controlling the two-dimensional photoelectric conversion element in synchronization with a timing signal generated inside, the light direction sensor detects the information about the direction of the light source. Information about at least one of the time when the light that generated the light intensity distribution signal used hits the two-dimensional photoelectric conversion element and the time when the light that generated the detected light intensity distribution signal hits the two-dimensional photoelectric conversion element By outputting the information, it becomes possible to know from outside the information about the direction of the light source and the like corresponding to the direction of the light source. For example, the time information may be generated using an internal clock and the time may be calibrated externally. The importance of time information is as described above.

In the light direction sensor according to the sixteenth aspect, the light direction sensor
Detects information about the direction of the light source from the intensity distribution signal
Process, at least the photosensitive surface of the two-dimensional photoelectric conversion element
The strain on the photoelectric conversion element surface of the
Use the function described in the standard or information equivalent to this function
The process of performing distortion correction, which is the correction process related to that distortion.
By including, from the photoelectric conversion element surface of the photosensitive surface
It is possible to correct the deviation, so-called distortion. For example, two-dimensional
The distortion of the photosensitive surface of the photoelectric conversion element with respect to the photoelectric conversion element surface
Even if it is so large that it cannot be ignored, the two-dimensional photoelectric
The photosensitive area of the unit element included in the narrow area of the replacement element is enclosed.
The tangled photosensitive surface may be regarded as a flat surface. This plane
Is a plane even if it is different from the photoelectric conversion element surface
There is no change in the light intensity of the image formed in that area.
The position of the light intensity distribution feature points, etc. on the cloth can be accurately detected.
I can know. This position is the two-dimensional photoelectric conversion element
Since the position is on the photosensitive surface of the child, the photosensitive surface is a photoelectric conversion element.
A function described in the plane reference coordinate system or an equivalent function
By using information, from the photoelectric conversion element surface of the photosensitive surface
Deviation can be known and the amount of distortion can be known, and correction is performed.
be able to. For example, the function used for correction is the light on the photosensitive surface.
The strain on the surface of the electric conversion element is measured in advance and, for example,
z_d= F (x_d, Y_d) Function format
For example, the calculated light intensity distribution feature point (x_f, Y_f) Photoelectric conversion
The three-dimensional coordinates in the element plane reference coordinate system are (x _f, Y_f, F
(X_f, Y_f)) Can be used to correct distortion.
It This distortion correction has the effect of reducing the bias error.
The fruit is obtained. This distortion correction is based on the light intensity distribution position reference.
It can also be effectively applied to positions such as points.

In the light direction sensor according to the seventeenth aspect, the information about the direction of the light source is detected by using the signal of the unit element included in the specific area of the two-dimensional photoelectric conversion element, which is narrower than the two-dimensional photoelectric conversion element. By doing so, the bias error included in the information regarding the direction of the light source and the like is reduced. That is, the bias error can be reduced by calculating the information about the direction of the light source using only the signal of the unit element included in the area of the two-dimensional photoelectric conversion element having a good flatness on the photosensitive surface. In addition to reducing the influence of strain, it is expected that the bias error due to the stability of the unit element characteristics due to the use of the unit elements in the same region is reduced.
Needless to say, it is desirable that the surface enclosing the photosensitive portion of the unit element included in the region having good flatness is the photoelectric conversion element surface.

In the light-direction sensor according to the ninth aspect, the plurality of linear light-shielding shapes included in the projection surface include a light-shielding portion formed along a straight line in the projection surface and a non-light-shielding portion. The appearance pattern is a pattern that does not have periodicity, or is a combination pattern of a periodic pattern and a pattern having a larger period than the periodic pattern, so that both high accuracy and a wide measurement range can be achieved. it can. For example, in order to improve the accuracy, a large number of slits are arranged at equal intervals on the projected part, and some of the slits cause linear bright parts, that is, bright lines, in the two-dimensional photoelectric conversion element. Since the correspondence between the individual bright lines and the slits is not fixed, the information about the angle in the light source direction is an integer multiple of a constant angle determined by the slit arrangement cycle and the relative position between the photoelectric conversion element surface and the projection surface. Uncertainties will occur. However, if the interval between the slits is changed, for example, at one place, the periodicity of the slit arrangement is lost, and the uncertainty described above disappears. This will be described with reference to FIG.
9A is a schematic view of the light direction sensor viewed from above, and FIG. 9B is a cross-sectional view of the light direction distribution of the projected image.
5a is added. As can be seen in FIG.
This optical direction sensor is characterized in that only the central slit interval 93a has a different length from the other slit intervals 93b. The distribution shape 95a obtained by projecting the projected portion 1i of the light direction sensor has a bright line interval 94a corresponding to the long slit interval 93a, and other slit intervals 93a.
Since it is different from the interval 94b of the bright line corresponding to b, the correspondence between the slit interval 93a and the interval 94a of the bright line can be specified, and there is no uncertainty as described above, and the light source can be distributed over a wide range. The direction of can be determined. At this time, since the number of slits is hardly changed, the high precision is maintained. This is also effective when detecting the position of another light intensity distribution position reference point or the like, such as in the case of a bright / dark boundary due to the opening. The periodicity of light-shielding and non-light-shielding patterns can be eliminated by mixing, for example, one opening or slits of different widths in the row of slits, and vice versa. You may mix slits and openings with different widths. In addition, in the method of eliminating the periodicity of the row of slits, in the method of mixing the openings and the slits with a wide width, when identifying the light-dark boundary generated by the projection of the openings and the bright portion generated by the projection of the wide slits. Since the light intensity information can be used when identifying the, the identification is facilitated. This principle will be described with reference to FIGS. When one of the slits 23c arranged at equal intervals is changed to a wide slit 23d, the light intensity 81k of the bright portion generated by projecting this becomes larger than the light intensity of the other bright portions, so the threshold value between them is set. By comparing the light intensities using 97, the position of the bright portion corresponding to the slit 23d can be specified. However, since the light intensity of the bright portion changes depending on the direction of the light source, it is desirable to change the threshold value 97 accordingly. Although the slits are arranged one-dimensionally in each of the examples of FIGS. 15 and 16, the same is true when the slits are arranged two-dimensionally. In order to effectively detect the feature points in a narrow area, such as the optical direction sensor according to the twenty-third and twenty-fourth aspects, it is preferable to dispose a slit or the like as shown in FIG. In this example, since the area including the 20 slits 23e is one feature point detection unit 98, a large number of projected part feature points 100 at the center can be set, and the narrow area 99 of the two-dimensional photoelectric conversion element can be set to A feature point detection unit 98 around a feature point of any projected portion can be inserted. Therefore, since the position of the light intensity distribution feature point can be detected from the light intensity distribution of the image projected on the narrow area 99 of the two-dimensional photoelectric conversion element, the information on the direction of the light source can be obtained from the relative positional relationship between these two feature points. Can be detected. The discontinuity of the information about the direction of the light source due to the change of the feature point of the projected part used for detecting the information about the direction of the light source may be, for example, the direction of the light source, and This can be solved by using the intensity distribution feature points and calculating the weighted average so that continuity is not impaired. This method of eliminating discontinuity is also effective for a one-dimensional array. In addition, when the positions of light intensity distribution feature points and the like are calculated using the entire two-dimensional photoelectric conversion element using the slit array of FIG. 17, the size of the visual field of the light direction sensor is taken into consideration. It is desirable that the scale of the entire projected portion 1k is larger than that of the two-dimensional photoelectric conversion element 9. The slit 23f
Is a slit wider than the slit 23e, so that the slit 23e in FIG.
This is for obtaining the same effect as d. In addition, as shown in FIG. 17, the projected portion feature point 100 has, for example, the slit 2
This can be defined by a method in which five quadrangles are formed from four center lines of 3e and the average of the coordinates of the vertices of the quadrangle is calculated. It is obvious that the corresponding light intensity distribution feature points can be detected by the same method. Of course, the number of slits included in the detection unit is arbitrary, and an opening, a light shield, or the like may be used instead of the slit.

According to the present invention, in order to solve the above-mentioned problems, a light direction sensor signal processing device according to a twenty-sixth aspect is provided with a signal processing unit, and the light direction sensor according to the first aspect outputs. Information about the direction of the light source that corresponds to at least one of the information about the direction of the light source and the information used to detect the direction of the light source, and / or the signal used to detect the information about the direction of the light source. By using one, to detect the information about the direction of the light source, and to correct the information about the direction of the light source, or both,
Information about the direction of the light source can be detected. That is, when only the light direction sensor according to claim 1 cannot detect the information about the direction of the light source or the content of the information about the direction of the light source or the accuracy of the information is insufficient, for example, the case of claim 26 By using the light direction sensor signal processing device described in (1), it is possible to detect information regarding the direction of the light source having required accuracy and content. With this light direction sensor signal processing device, for example, the light direction sensor according to claim 1 does not necessarily need to detect information relating to the direction of the light source, so that the circuit necessary for the detection can be omitted, and It is possible to reduce the size and power consumption. This effect is very effective, for example, in a spacecraft where there are few places where the light direction sensor can be mounted or where the light direction sensor is mounted in a place where heat dissipation is difficult.

The light direction sensor signal processing device according to the twenty-seventh to thirty-eighth aspects performs advanced signal processing on the light intensity distribution signal detected by the light direction sensor, information on the direction of the light source, and the like, and outputs the light source signal from the light source. It detects and corrects the information about the direction with good accuracy, and the solution means by these features and the effect by the solution means are already explained as the features of the optical direction sensor as described above. On the street.

[0039]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described based on examples.

[0040]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the optical direction sensor according to the present invention will be described with reference to FIGS. 1 (A), (B), (C) and FIG. 1A, 1B, and 1C are views showing an optical direction sensor according to a first embodiment of the present invention, in which FIG. 1A is a top view and FIG. ) Is a cross-sectional view taken along the line BB, and FIG. 6C is a cross-sectional view taken along the line CC of FIG. FIG. 18 shows FIG. 1 (B).
It is a schematic diagram of a configuration of a signal processing unit of. The main configuration of the first embodiment of the present invention is the projected portion 1a, the linear light-shielding shape 2
a, 2b, openings 3a, 3b, 3c, 3d, 3e, housing 8a, two-dimensional photoelectric conversion element 9, tilt adjustment section 10a, two-dimensional photoelectric conversion element holder 12a, two-dimensional photoelectric conversion element holder support plate 13a, Element control unit 18, signal processing unit 1
9a and a mirror surface 24. The projected portion is formed by, for example, coating the surface of the optical glass 16 with a light-shielding material to form a light-shielding film, and then removing the film of the light-transmitting portion by etching or the like. Alternatively, the surface of the optical glass 16 may be printed with a light-shielding ink. The surface 16 of the optical glass preferably has high flatness. If the light-shielding film or the like does not reflect light well, a metal such as aluminum or gold may be vapor-deposited on part of the optical glass in advance to form the mirror surface 24. In the present embodiment, it is assumed that the linear light-shielding shape 2a is projected and the light-dark boundary formed on the two-dimensional photoelectric conversion element 9 is detected. Therefore, the width W of the opening 3a is the visual diameter of the light source. 2ω,
When the maximum incident angle is θ _max and the distance between the projection target 1 and the two-dimensional photoelectric conversion element 9 is L ₁ , W ₀ = 2L ₁ ta
The value is made sufficiently larger than nω / cos θ _max so that at least the entire light source can be seen from above the two-dimensional photoelectric conversion element 9 through the opening 3a. The same applies to the width of the opening of the linear light-shielding shape 2b. Further, when the view diameter of the light source is small, it is more affected by diffraction. Therefore, it is necessary to find the optimum value of the width of the opening from the values of the wavelength of the light to be detected, the wavelength width, the distance L ₁ and the distance to the light source. There is.
That is, if the width of the opening is increased, it is expected that the detection accuracy of one bright / dark boundary is improved, but the number of the linear light-shielding shapes 2b is reduced, so that the averaging effect cannot be expected so much. On the contrary, when the number of the linear light-shielding shapes 2b is increased and the averaging effect is expected, the width of the opening is reduced, and there is a concern that the accuracy of detecting the bright-dark boundary at one location may decrease due to the influence of diffraction. That's what it means. The value of the distance L ₁ may be determined according to the viewing angle and the required accuracy. Figure 1
Then, in order to make the shape of the opening easier to understand, it is drawn larger than it actually is. For example, the second region 5a in which the openings are densely arranged is smaller than the photosensitive portion of the two-dimensional photoelectric conversion element 9. However, the second region 5a is set to the two-dimensional photoelectric conversion element 9
It is not an essential requirement of the present invention to make the size smaller than the photosensitive part, and by setting the projected part as the projected part 1k in FIG. 17, high accuracy can be obtained over the entire visual field. This is one of the preferred embodiments. The projected portion 1a is not a line directly visible from the upper surface, but is drawn as a solid line for easy understanding.

The two-dimensional photoelectric conversion element 9 is, for example, in the area C.
It is a CD, a CMOS image sensor, or an infrared imaging device. It is desirable to cover the portion of the two-dimensional photoelectric conversion element 9 other than the photosensitive portion with a mask plate 11 whose surface reflectance is reduced in order to reduce stray light. The two-dimensional photoelectric conversion element 9 is the mask plate 1
1 is fixed to the two-dimensional photoelectric conversion element holder 12a together with the two-dimensional photoelectric conversion element holder 12a, and the two-dimensional photoelectric conversion element holder 12a is fixed to the housing 8a.
Therefore, it is supported via the three inclination adjusting units 10a. The tilt adjusting section 10a is, for example, the tilt adjusting section 10 shown in FIG.
The shim 89 is used to eliminate the inclination between the photoelectric conversion element surface of the two-dimensional photoelectric conversion element 9 and the projection surface of the projection unit 1 by using the shim 89, and is used for making parallel adjustment. The tilt can be adjusted by, for example, measuring the tilt direction and angle of the photoelectric conversion element surface based on the mirror surface 24 and the alignment cube 6 in advance, and adjusting the thickness of the shim 89 to cancel this. Good. After this adjustment, the twist angle γ ₁ between the direction of the arrangement of the unit elements of the two-dimensional photoelectric conversion element 9 and the direction of the linear light-shielding shape 2a is adjusted, so that the optical glass 16
It is desirable that the notch be formed with a notch or a protrusion so that it can be easily rotated. The element control unit 18 synchronizes with a timing signal input from the outside of the light direction sensor,
For example, the time of exposure of the two-dimensional photoelectric conversion element 9 and the time of outputting a signal are adjusted. The element control unit 18 first causes the signal of the unit element 70 in the peripheral portion of the two-dimensional photoelectric conversion element 9 to be output, and the signal processing unit 19a processes the signal. Details of an example of the configuration of the signal processing unit are shown in FIG. The output signal of the two-dimensional photoelectric conversion element 9 is amplified and filtered by the analog signal processing unit 28 and then A / D converted by the A / D conversion unit 29.
It is D-converted and output to the microcontroller 30a. At least a part of the unit element 70 in the peripheral portion is at least one of the opening 3a or the opening 3c included in the first projected portion 4a according to claim 8 or 18.
And the opening 3 also included in the first projected portion 4a.
Since at least one of b or the opening 3d is included in the first region projected according to claim 18, the light intensity distribution signal of the unit element 70 in the peripheral portion is used to For example, the light intensity distribution of the image formed by projecting the openings 3a and 3b can be detected. In the micro controller 30a, the light intensity distribution signal is subjected to digital signal processing by using the RAM 33a in accordance with the program stored in the ROM 34a, and for example, the position of the light-dark boundary point of the image of the opening 3a and the image of the opening 3b are displayed. Calculate the position of the light-dark boundary point. Using this calculation result, for example, it is possible to calculate a rough position of a point at which a line approximating the center of each image of the opening 3a and the opening 3b corresponding to the light intensity distribution position reference point intersects on the photoelectric conversion element surface. You can 20. This rough position corresponds to the information regarding the direction of the light source derived with the first accuracy described in claim 18, and the like.
This is the information corresponding to the first information described in (1). This rough position is converted into a position in the photoelectric conversion element surface reference coordinate system in consideration of inclination correction and twist correction of the position of the projected portion feature point which is a corresponding point of the projected portion stored in the ROM 34a in advance. It is used to calculate the direction of the light source along with the position. The calculated direction of the light source is output to the outside of the light direction sensor as a first output after being converted into a desired format by the signal output unit 32a. The calculation of the direction of the light source is also one of the processes executed by the microcontroller 30a according to the program stored in the ROM 34a.

The microcontroller 30a calculates the direction of the light source from this rough position, and at the same time, claims on the two-dimensional photoelectric conversion element 9 on which the second projected portion 5a according to claim 8 or 18 is projected. The position range of the unit element 70 included in the second region described in 18 is obtained and output to the element control unit 18 via the sequence control unit 38, and the element control unit 18 outputs the unit element included in the position range. 70 signal is output. This signal is the analog signal processing unit 2
8. After passing through the A / D converter, it is inputted to the microcontroller 30a as a digitized light intensity distribution signal together with the signals of the temperature sensors 17a, 17b, 17c. The microcontroller 30a digitally processes this light intensity distribution signal to detect the positions of the light-dark boundary points on the photoelectric conversion element surface at a plurality of points, and the process of calculating the position of the light intensity distribution feature point shown in FIG. Equivalent process, that is, 12 straight lines approximating the center of the image of the opening 3e from the bright / dark boundary of the image of the pair of linear light-shielding shapes 2b are determined, and 3 quadrangles are determined from these 12 straight lines. The position of the light intensity distribution feature point can be detected with higher accuracy than the first information described above through the process of calculating the average or weighted average of the coordinate values of those 12 vertices and the process of distortion correction according to claim 16. calculate. As the position of the projected part feature point corresponding to this, for example, a highly accurate position obtained by correcting the stored position using the first output value in the direction of the light source is used. Claims 13 and 14 are used in this correction process.
The process of tilt correction and twist correction described in 1) may be included. From the positions of the light intensity distribution characteristic points and the positions of the projected portion characteristic points detected with high accuracy, the direction of the light source is calculated with higher accuracy than the above-mentioned first output, and the direction of the light source is calculated outside the light direction sensor. Is output as. The second output corresponds to the information on the direction of the light source derived with the second accuracy described in claim 18, that is, the second information described in claim 19. In this light direction sensor, the coordinate system serving as the reference for the direction of the light source can be switched to the projected surface reference coordinate system. In this case, a process of converting the position of the light intensity distribution feature point obtained in the photoelectric element surface reference coordinate system to the position in the projection surface reference coordinate system by the tilt correction and the twist correction according to claim 13 and 14 is performed. To do. This tilt correction is a simple correction using a plane equation,
The twist correction is a correction that uses a matrix that represents the rotation of the position vector in the plane. It should be noted that the above-mentioned correction of the feature point position of the projected portion means, for example, when light passes through the opening at an incident angle θ from a plane perpendicular to the long side direction of the opening, the thickness of the light shielding film is defined as t. Then, the effective aperture width becomes smaller by t · tan θ, and this difference is corrected. There is also a method of deriving high-accuracy information about the direction of the light source without correction, for example, only by the light-shielding boundary line on the side where the light flux is not blocked by the thickness and the light-dark boundary of the projected image.

When deriving the second output, the signals of the temperature sensors 17a, 17b and 17c are used to determine the temperatures of the projected portion 1a, the two-dimensional photoelectric conversion element 9 and the casing 8a. It is possible to detect and correct the scale change due to thermal expansion of each part. In order to reduce the angle detection error due to temperature, the material of the tilt adjusting unit 10a, for example, as shown in FIG.
It is also effective to make the material of the spacer 90 different from that of the housing 8a and set the thermal expansion of the spacer 90 to cancel the angle detection error due to temperature as much as possible. In order to reduce the bias error in the angle detection error due to temperature, the materials of the optical glass 16, the housing 8a, the mask plate 11, the two-dimensional photoelectric conversion element holder 12a, and the two-dimensional photoelectric conversion element holder support plate 13a can be used. As far as possible, it is preferable to use a material having a linear expansion coefficient close to the linear expansion coefficient of the material of the case of the two-dimensional photoelectric conversion element 9. Further, it is preferable that the bandpass filter 14 and the ND filter 15 can be selected similarly. An opening 3f for detecting the brightness is provided at the center of the projected portion 1a.
The width is larger than other apertures in order to reduce the influence of diffraction and accurately measure brightness. Of course, the actual signal output depends on the direction of the light source, and the influence of the inclination of the light flux and the change of the light attenuation rate due to the change in the length passing through the ND filter 15 and the bandpass filter 14 are taken into consideration. There is a need. For example, when the sun is targeted, the shape and the relationship between the brightness and the distance are known. Therefore, the visual diameter of the sun is obtained from the brightness information, etc. For example, the light intensity distribution on the boundary of light and dark on 9 can be predicted. For example, the predicted distribution shape is used in digital signal processing as a fitting function used in signal processing in which the positions of bright and dark boundary points are detected with a resolution equal to or lower than the arrangement interval of unit elements. As a method of not using this fitting function, for example, there is a method of smoothing with a digital filter, obtaining an interpolation curve, or using an evaluation function, as already described in the section of solving means. Also,
The light direction sensor of the present embodiment has both a function of performing measurement at the timing of input from the outside and a function of measuring at the timing of internal generation and outputting the time information together. It is possible to switch which mode to operate by. Furthermore, since the program for performing the measurement only in a specific area of the two-dimensional photoelectric conversion element is already built in, the function can be exhibited by replacing the projected portion with 1k in FIG. Similarly, programs corresponding to several kinds of projected parts can be built in, and a function capable of immediately dealing with them can be provided. In addition,
In the present embodiment, FIG. 18 is presented as a configuration example of the signal processing unit 19a, but this configuration is not an essential requirement of the present invention and may be any configuration capable of performing the signal processing shown in the present invention. In addition, the two-dimensional photoelectric conversion element 9, the element control unit 18,
The signal processing unit 19a is not necessarily physically separated from the others. For example, one IC chip includes the two-dimensional photoelectric conversion element 9, the element control unit 18, and the analog signal processing 28 and the A / D of the signal processing unit 19a. The conversion unit 29 may be included, and the RAM 33a may be included.

The bandpass filter 14 determines the wavelength and the band width in consideration of, for example, the wavelength of the light of the target light source and the sensitivity characteristic of the two-dimensional photoelectric conversion element 9. ND filter 1
Reference numeral 5 is for adjusting the intensity of light incident on the two-dimensional photoelectric conversion element, and it is desirable that it can be easily replaced.
For example, when the intensity of light from the light source is high and the heat absorbed by the filter causes unevenness in the refractive index due to deformation of the ND filter 15 and unevenness in temperature, resulting in poor detection accuracy in the light source direction. A reflection type ND filter film can be vapor-deposited on the surface of the ND filter 15 on the light source side to significantly reduce heat absorption due to light absorption. When used in the space environment, it is desirable that these optical materials have radiation resistance. As a countermeasure against stray light, the inside surface of the housing 8a is made black and a light-shielding line is cut at a portion where light is applied. Further, from the viewpoint of reducing stray light, it is desirable to take measures such as covering the upper portion of the mirror surface 24 with a light shielding material after the adjustment is completed. When this is difficult, the mirror surface 24 may be arranged near the housing so that the light does not easily reach. As a result, the center of the projected portion 1a,
If the parallelism of the mirror surface is not enough, the mirror surface 2
4 is provided at the edge of the projected portion 1a, or the entire edge is a mirror surface, and the direction of the surface at the center of the projected portion 1a is estimated from the surface directions at a plurality of positions in the mirror surface. Is also possible. In addition, in the case where the two-dimensional photoelectric conversion element 9 has poor characteristics or the shape of the projected portion 1a is defective, the positions of those elements are set in advance in the R of the signal processing portion.
It is desirable to have a function of storing the data in the OM 33a and correcting it during arithmetic processing or excluding it from the target of arithmetic processing.

FIGS. 2A, 2B, 2C and 2D are views showing an optical direction sensor according to a second embodiment of the present invention. FIG. 2A is a top view and FIG. 7B is a sectional view taken along the line BB of FIG. 7A, and FIG. 8C is a sectional view taken along the line C-C of FIG. FIG. 3D is an optical direction sensor that performs digital signal processing for detecting information regarding the direction of the light source from the light intensity distribution signal output from the optical direction sensor and correcting information regarding the direction of the light source. 3 is a schematic diagram of a signal processing device 26. FIG. FIG. 19 is a block diagram showing the functional arrangement of a light direction sensor signal processing apparatus according to the third embodiment of the present invention, which is shown in FIG.
Is a detailed version of. Since the light direction sensor of the second embodiment of the present invention and the light direction sensor signal processing device of the third embodiment of the present invention are mainly used in combination, they will be described together. In this embodiment, in order to make the light direction sensor 25b smaller, the analog signal processing unit and the A / D conversion unit in the signal processing unit 1a are left, and the others are separated from the light direction sensor signal. Signal processing unit 19 in the processing device
Included in c. Further, the inclination adjusting portion 10a is eliminated, and the two-dimensional photoelectric conversion element holder 12 is directly fixed to the housing 8. Further, in the first embodiment, the projected portion 1a is formed on the surface of the optical glass 16, but in the present embodiment, the projected portion 1b is formed on the surface of the bandpass filter 14 so that the optical direction sensor 25b can be further improved. It is small. Although the mounting method of the alignment cube 6 has also changed, this method has an advantage that the surface opposite to the surface having the light source can be used. The shape and arrangement of the opening of the projected portion 1b is the first.
However, this is not related to miniaturization. Slits 23a are radially arranged on the projected portion 1b, but this is an example of the shape and arrangement of the openings. In this embodiment, for example, an intersection of radial straight lines that approximates the bright line of the radial image formed by projecting the slits 23a arranged radially or a point that approximates this intersection is defined as a light intensity distribution characteristic point. And the information on the direction of the light source can be calculated from the position of the corresponding projected portion feature point. Further, the projected portion 1b of the present embodiment does not have an opening portion to be the large opening portion 3f at the center, but the brightness can be detected by widening the width of the opening portion 3a.

The light direction sensor 25b outputs the light intensity distribution signal to the light direction sensor signal processing device 26 via the cable 22. The signal input to the light direction sensor signal processing device 26 as a digital light intensity distribution signal is a signal input unit 31.
Then, the data is converted so as to match the internal data bus 36b and output to the microcontroller 30b. The subsequent operation method as the light direction sensor and the light direction sensor signal processing device is basically the same as the embodiment of the first embodiment, but the element control method uses the above-mentioned first accuracy information. At the time of calculation, a light intensity distribution signal composed of light intensity signals of all the unit elements 70 of the two-dimensional photoelectric conversion element 9 is output and stored in the RAM 33b, and according to the calculation accuracy,
Instead of selecting the unit element 70, the method is to change the address of the RAM 33b accessed by the microcontroller 30b. Further, in this embodiment, the amount of the tilt to be corrected becomes large because the tilt adjusting unit 10a is not provided. Therefore, the method of coordinate conversion according to claim 15 having high accuracy is used for the tilt correction and the twist correction. In this coordinate conversion, the position of the light intensity distribution feature point in the photoelectric conversion element surface reference coordinate system is converted into the position in the projection surface reference coordinate system.

In the second and third embodiments, the light direction sensor 1
Although one light direction sensor signal processing device is provided for each table, for example, a light direction sensor signal processing device that can process the output of a plurality of light direction sensors is provided, and the light direction sensor signal is output to the plurality of light direction sensors. One processing device may be provided.
As a countermeasure against a failure, a plurality of light direction sensor signal processing devices may be provided for a plurality of light direction sensors. The light direction sensor signal processing device does not necessarily need to be dedicated to the light direction sensor, and for example, the device for digital signal processing can be included in the attitude control computer of the artificial satellite. However, in that case, the attitude control computer is also a light direction sensor signal processing device. In addition, except for the function of the optical direction sensor signal processing device that performs tilt correction, twist correction, distortion correction, etc., tilt correction, twist correction, distortion correction, etc. are performed separately from the optical direction sensor signal processing device. It may be performed by the direction sensor signal processing device. Even in a general-purpose computer, by incorporating a signal processing program, it becomes a light direction sensor signal processing device, can perform signal processing of the light direction sensor, and can detect information regarding the direction of the light source. The configuration of FIG. 19 is an example of the configuration of the present invention and is not an essential requirement.

Both the first embodiment and the second embodiment have the openings 3a and the like arranged in a cross shape, but this is not an essential requirement of the present invention, and a light-shielding boundary line or slit in the plane to be projected is provided. Arrangement is arbitrary. However, depending on its shape and arrangement, the signal processing as described in the embodiments may not be directly applicable. In addition, the first embodiment, the second
In each of the embodiments, each has one bandpass filter 14, one ND filter 15, and one alignment cube 6,
These are also not indispensable requirements of the present invention, and may be plural or may be omitted. Similarly, the mask plate 11 may be omitted, or the two-dimensional photoelectric conversion element holder 12a or 12b may be omitted.
May be integrated with. The two-dimensional photoelectric conversion element holder support plate 13a may be integrated with the housing 8a, and the two-dimensional photoelectric conversion element holder 12b may be integrated with the housing 8b. Both of the housings 8a and 8b have a cylindrical shape, but since this shape is not an essential requirement of the present invention, they may be, for example, a polygonal prism, a truncated cone, a polygonal pyramid, or a composite shape thereof. Further, although the structure for mounting is not shown in the housings 8a and 8b, this is, for example, a mounting foot with holes for mounting screws or a tap for mounting screws processed in the housing. Good. Considering the stability of mounting, it is desirable that there are three or more structures for mounting. In addition,
When using the products of the present invention in a space environment, consideration must be given to radiation.

In each of the first and second embodiments, one two-dimensional photoelectric conversion element 9 outputs information that can specify the direction of the light source in the three-dimensional space. For example, one two-dimensional photoelectric conversion element is used. The configuration may be such that the direction of the light source is specified in a plane and two two-dimensional photoelectric conversion elements are combined to provide information that can specify the direction of the light source in a three-dimensional space. This corresponds to a configuration in which the one-dimensional photoelectric conversion element of the conventional light direction sensor is replaced with a two-dimensional photoelectric conversion element, but it can be made smaller than the conventional light direction sensor. The merit of the configuration in which the two two-dimensional photoelectric conversion elements are combined is that the signal processing becomes simple and the information of the first accuracy described above can be output quickly. For example, in a two-dimensional photoelectric conversion element, the signal reading order is often fixed, and signals are sequentially read from one of the four sides of the two-dimensional photoelectric conversion element or from two opposite sides.
The information calculated by processing the signals of the elements at the edges of the side is obtained when reading of almost all the elements is completed.
If two two-dimensional photoelectric conversion elements are arranged at a right angle,
By combining the information obtained by performing signal processing on the signals of the elements read out early from the two two-dimensional photoelectric conversion elements, it becomes possible to output the information capable of specifying the direction of the light source in the three-dimensional space early. This merit is effective when it is used as a control sensor, for example, where real-time output information is required. Examples of projected parts having this configuration are the projected parts 1i and 1j shown in FIGS. 15 and 16, both of which are included in the preferred embodiments of the present invention. With this configuration, since the entire two-dimensional photoelectric conversion element can be used for detection in one direction, high accuracy can be expected.

[0050]

Since the light direction sensor of the present invention is constructed as described above, it has the following excellent effects. In the light direction sensor according to the first aspect, by using the two-dimensional photoelectric conversion element, the light direction sensor can be significantly downsized. Since the above-mentioned conventional light direction sensor uses a one-dimensional photoelectric conversion element and has a considerable number of unit elements to achieve high accuracy, the length of the one-dimensional photoelectric conversion element is five.
It is about cm. Further, since the conventional light direction sensor mainly detects only the rotation angle about the slit as the central axis, in order to specify the direction of the light source as the direction of the straight line in the three-dimensional space, the conventional light direction sensor is used. It was necessary to use more than one. In this case, the size of the surface facing the light source in the conventional light direction sensor needs to be at least about 8 cm × 12 cm. On the other hand, since the size of the two-dimensional photoelectric conversion element is about 1 cm × 1 cm, the light direction sensor according to claim 1 considers the size of the projection target part, the filter described in the embodiment, and the like. Can also be accommodated in a size of about 4 cm × 4 cm, and the area of the surface facing the light source is 1/6 that of the conventional light direction sensor. The miniaturization reduces the mass and the area required for mounting, and also makes it difficult for the temperature difference to occur, which makes it less likely to be affected by thermal strain caused by the temperature difference. This effect is particularly remarkable in the optical direction sensor mounted on the spacecraft.

The features of the optical direction sensor according to claim 1 and the optical direction sensor according to claims 4 to 6 are suitable for reducing a high spatial frequency error due to detection of a position such as a light intensity distribution position reference point. The detection of the position of the light intensity distribution position reference point or the like, which is the feature of the light direction sensor according to claim 10 or the detection of the position of the light intensity distribution feature point, etc., is performed efficiently and with high accuracy. This is a possible configuration. Thereby, the high spatial frequency error of the light direction sensor according to the present invention can be made equal to or less than the high spatial frequency error of the conventional light direction sensor. For example, there are a light direction sensor according to the present invention and a conventional light direction sensor having the same visual field range, both of which use a CCD as a photoelectric conversion element, and assuming that the pixels of the CCD have the same size, Due to the difference in length, it is assumed that, for example, a detection angle of 1 ° at the center of the visual field corresponds to 8 pixels in the light direction sensor according to the present invention and 40 pixels in the conventional light direction sensor. It is disadvantageous for the light direction sensor according to the present invention to assume that the magnitude of the high spatial frequency error associated with the detection of the position of one light intensity distribution position reference point is proportional to the pixel size. Provisionally, the magnitude of the error is set to 2 pixels in accordance with this condition. Under this condition, the error of the light direction sensor according to the present invention when the detection angle is set becomes five times the error of the conventional light sensor. However, the light direction sensor according to the present invention obtains a plurality of positions of the light intensity distribution position reference point and the like, thereby increasing the detection accuracy of the position of the light intensity distribution characteristic point and the like, and thereby the error converted into the detection angle is obtained. Can be reduced. For example, when 100 positions of the light intensity distribution position reference point or the like are obtained and the positions of the light intensity distribution characteristic point or the like are calculated from them, the positions are included in the 100 positions of the light intensity distribution position reference point or the like. If it can be considered that the high spatial frequency error is an independent error, the high spatial frequency error included in the positions of the light intensity distribution feature points, etc. is calculated by taking the average of these, and one high light intensity distribution position reference point is obtained. It can be considered that it becomes approximately one-tenth of the high spatial frequency error included in the positions such as. That is, the error of the detection angle of the light direction sensor according to the present invention is 0.025 degrees, which is half the error of the conventional light direction sensor of 0.05 degrees.

In the optical direction sensor according to the second, thirteenth, and fifteenth aspects, the bias error due to the inclination between the projection surface and the photoelectric conversion element surface can be significantly reduced. For example, the inclination of the projected surface and the surface on which the photoelectric conversion element is attached are
By improving the machining accuracy, it can be suppressed to about 0.1 degree or less, but the inclination between the surface on which the two-dimensional photoelectric conversion element is attached and its photosensitive surface, that is, the photoelectric conversion element surface is
It is determined by an error in manufacturing the two-dimensional photoelectric conversion element. For example, in the case of an area CCD with a window glass, the inclination of the photoelectric conversion element surface of the window glass and the CCD is 0.6 at maximum.
It will be about degree. The angle error when the tilt is not corrected can be calculated by the equation (11). For example, when the angle detection error when the tilt is 0.7 degrees is calculated, it is 0.
It becomes 35 degrees, which is a bias error of the light direction sensor. The maximum bias error of the conventional light direction sensor is 0.
Considering that it is about 05 degrees, the accuracy is insufficient without correcting the inclination. The optical direction sensor according to the sixth aspect has an inclination adjusting structure as shown in FIG. 12, for example, so that the inclination can be adjusted with an accuracy of about 0.04 degrees.
This is done by setting the gap between the tilt adjusting parts 10b to 30 mm and the shim 8
It is an approximate value when the thickness of 9 can be changed in units of 20 μm. The bias error of the detection angle of the light direction sensor in which the parallelism between the photoelectric conversion element surface and the projection surface is improved by this tilt adjustment structure is 0.02 degrees, which should be smaller than the error of the conventional light direction sensor described above. Is possible. Further, if the inclination is corrected as in the optical direction sensor according to the thirteenth or fifteenth aspect, the same accuracy can be expected without the inclination adjusting structure. In particular, the method using coordinate conversion can be said to be an epoch-making method that can accurately correct the twist angle and the tilt at the same time.

[Brief description of drawings]

FIG. 1 is a view showing a first embodiment of a light direction sensor according to the present invention.

FIG. 2 is a view showing a second embodiment of the optical direction sensor according to the present invention.

FIG. 3 is a perspective view showing the operation principle of a conventional light direction sensor.

FIG. 4 is a schematic diagram showing an operation principle of a conventional light direction sensor.

FIG. 5 is a perspective view showing the principle of light direction detection using a two-dimensional photoelectric conversion element and a pinhole.

FIG. 6 is a schematic view showing a quadrangle on a plane and a quadrangle projected on the plane.

FIG. 7 is a perspective view showing an example of the operation principle of the light direction sensor according to the present invention.

FIG. 8 is a schematic diagram showing a light intensity distribution of a projected image.

FIG. 9 is a schematic diagram illustrating a principle of detecting a light-dark boundary position from a projected image of an opening.

FIG. 10 is a schematic diagram illustrating a principle of detecting a light / dark boundary position from a projected image of a slit.

FIG. 11 is a schematic diagram showing the principle of detecting a light-dark boundary position from a projected image of an opening.

FIG. 12 is a view showing a tilt adjusting structure.

FIG. 13 is a schematic diagram showing an effect of setting a twist angle.

FIG. 14 is a schematic diagram showing an error angle due to a tilt between a photoelectric conversion element surface and a projection surface.

FIG. 15 is a schematic diagram showing an effect when the distance between the slit rows is changed at one place.

FIG. 16 is a schematic view showing an effect when the width of the slit is widened at one place.

FIG. 17 is a schematic diagram showing an example of slit arrangement suitable for a high-accuracy light direction sensor.

FIG. 18 is a schematic diagram illustrating a signal processing unit according to the first embodiment of this invention.

FIG. 19 is a schematic diagram showing a third embodiment of the present invention.

[Explanation of symbols]

1a, 1b, 1c, 1d, 1e, 1f, 1g, 1i, 1
j, 1k Projected portions 2a, 2b, 2c, 2d, 2e Linear light shielding shapes 3a, 3b, 3c, 3d, 3e, 3f, 3g, 3h, 3
i Opening 4a First region (portion in which linear light-shielding shape of projected portion 1a is sparsely arranged) 4b First region (portion in which linear light-shielding shape of projected portion 1b is sparsely arranged) 5a Second region (portion in which the linear light-shielding shapes of the projected portion 1a are densely arranged) 5b Second region (portion in which the linear light-shielding shapes of the projected portion 1b are densely arranged) 6 Alignment cube 7 Alignment Mounting bases 8a, 8b of the cube 6 Housing 9 Two-dimensional photoelectric conversion elements 10a, 10b Tilt adjusting unit 11 Mask plates 12a, 12b, 12c Two-dimensional photoelectric conversion element holders 13a, 13b Two-dimensional photoelectric conversion element holder support plate 14 Band pass Filter 15 ND filter 16 Optical glass 17a, 17b, 17c Temperature sensor 18 Element control section 19a, 19b, 19c, 19d Signal processing section 22 Cable 23a, 3b, 23c, 23d, 23e, 23f
Slit 24 Mirror surfaces 25a, 25b Light direction sensor 26 Light direction sensor signal processor 28 Analog signal processor 29 A / D converters 30a, 30b Microcontroller 31 Signal input 32a, 32b Signal output 33a, 33b RAM 34a, 34b ROM 35 Power supply section 36a, 36b Data bus 37 Light direction sensor control section 38 Sequence control section 40 One-dimensional photoelectric conversion element 41 Unit element of one-dimensional photoelectric conversion element 42 Slit 43 Signal processing / element drive section 44 Luminous flux 46a, 46b Photoelectric conversion Element plane reference coordinate system (x _d -y
_d− z _d ) 48 Direction of slit 42 y _s 52a, 52b Projected surface reference coordinate system (x _s −y _s −z
_s ) 53 Bright portion 57 by light flux 57 Light flux passing through slit 42 (center) 61 Light sources 62a, 62b, 62c Light flux passing through pinholes 63a, 63b, 63c pinhole (center) 65 Light flux passing through opening (center) ) 67 Orthogonal projection of the luminous flux 63a on the x _d -y _d plane 70 Unit element 73a of the two-dimensional photoelectric conversion element 9 Photoelectric conversion element surface (x _d -y _d plane of the photoelectric conversion element surface reference coordinate system) 74 Pinhole 62a A straight line 81a connecting the pinhole 62b and a light / dark boundary 81b formed by projecting the opening 3g. A light / dark boundary 81c formed by projecting the opening 3h. A light / dark boundary 81d formed by projecting the linear light-shielding shape 2c. 23b is projected to form bright portions 81e, 81f, 81g, 81h, 81i, 81j Bright / dark boundary 81k Slit 23d is projected Light intensity 85a, 85b, 85c, 85d of the light portion formed by the unit element row used for detecting the bright and dark boundary points 87 Fixing bolt 88 Washer 89 Shim 90 Spacer 91 Sensitive portion (there is sensitivity in the unit element 70 Part) 92 Insensitive part (a part of the unit element 70 having sensitivity) 93a, 93b Slit intervals 94a, 94b Bright line intervals 95a, 95b Light intensity distribution 96 of the projected image of the slit array 97 Slit passing light beam (center) 97 light Intensity threshold 98 Feature point detection unit 99 Narrow region of two-dimensional photoelectric conversion element 100 Projected part feature points A, B, C, D Vertex of quadrangle E before linear conversion E of quadrangle before linear conversion A ', B' , C ′, D ′ The vertex E of the quadrangle after the linear transformation E ′ The feature point F of the quadrangle after the linear transformation The projected portion feature point for the opening 3 g (E in FIG. 6)
F ') The light intensity distribution characteristic point for the light-dark boundary 81 (Fig.
E) of I) Light intensity (axis) I _BR Light intensity of the part where the light hits I _DK Light intensity of the part where the light does not hit I _PK Maximum value of the light intensity I _Th1 Threshold light intensity at the light-dark boundary I _{Th2 Bright} check Output threshold light intensity K ₁ pinhole 62b, distance L ₂ slit 42 between two-dimensional photoelectric conversion element 9 and photoelectric conversion element surface reference coordinate system 4
6a xd axis distance L ₃ pinhole 62a and photoelectric conversion element surface 73a
Distance _M 1 of length _{L 5} points _{O d} and the point _{O s} point of distance _{L 4} F 'and of the projection _plane, M 2, _{M 3} pin brightest point _M 4 by Hall light beam passing _{therethrough,} the virtual point of M 5 _{M 3} N Two-dimensional photoelectric conversion element 9 from _1- pinhole 62b
Foot of the perpendicular line O _d The origin of the photoelectric conversion element surface reference coordinate system O _ds z _s and the intersection point of x _d O _s Origin point S of the projected surface reference coordinate system The foot of the perpendicular line drawn to the projected surface V Light intensity signal output (axis) V _BR Light intensity signal output of the part where the light hits V _DK Light intensity signal output of the part that does not hit the light V _Th1 Threshold light intensity signal output at the light-dark boundary V _PK Maximum value of the light intensity signal output x position (x axis) x _BD light / dark boundary point position x _BD0 light _/ dark boundary point position (unit element position) x _BD1 light / dark boundary point position x _BD2 light / dark boundary point position x _BD3 light _/ dark boundary point position x _H1 bright position of x _PK0 bright point position x _PK bright point hem position x _H2 bright part of the Department of the hem (position of the unit element) x _PK1 bright point position x _c photoelectric conversion element surface at a virtual position axis (x ) x _d photoelectric conversion element surface at a position axis (x) _{x d} coordinate _{x m} light intensity of _{x f} point F 'is the point of maximum _{y d} coordinate y of _d coordinates _{x p} light intensity position axis in _{x d} coordinate _{x s} a projection surface of a point of maximum (x) position axis in _{y d} photoelectric conversion element surface (y) _{y f} point F ' _m y _d coordinate of the point where the light intensity is maximum y _s Position axis on the projected surface (y) z _d z axis in the photoelectric conversion element surface reference coordinate system z _s z axis in the projected surface reference coordinate system ₁ Twist angle of one-dimensional photoelectric conversion element β ₁ Angle of inclination of one-dimensional photoelectric conversion element β ₂ Angle of inclination of two-dimensional photoelectric conversion elements γ ₁ , γ ₂ Twist angle θ _s2 Incident angle (reference plane to be projected) θ _s3 Incident angle (Projected surface reference) θ _s4 , θ _s5 Detected incident angle (Projected surface reference) θ _d1 Incident angle (photoelectric conversion element surface reference) θ _x Incident angle (one-dimensional photoelectric conversion element) φ _d1 , φ _d2 Azimuth angle (Photoelectric conversion element surface reference) φ _s1 azimuth (photoelectric conversion element surface reference) φ _s2 azimuth (projection surface reference)

Claims (38)

[Claims] 1. A light direction sensor having a function of emitting light by itself or receiving light emitted from a light source that reflects light, and detecting a signal used to detect information regarding the direction of the light source. A two-dimensional photoelectric conversion element in which a plurality of unit elements are two-dimensionally arranged, a projected portion including a portion that transmits light and a portion that blocks light, and a signal output by the two-dimensional photoelectric conversion element is processed. The two-dimensional photoelectric conversion element is generated according to a light intensity distribution of a projection image formed by being projected on the two-dimensional photoelectric conversion element by the light, the signal processing section A signal of at least a part of the unit elements included in the signal processing unit, the optical direction sensor for detecting as a light intensity distribution signal including light intensity signals of the plurality of unit elements, The two-dimensional photoelectric conversion element However, a part or all of the photosensitive surface enveloping the photosensitive portions of substantially all the unit elements of the two-dimensional photoelectric conversion element is a two-dimensional photoelectric conversion element that can be considered to be included in the photoelectric conversion element surface that is a virtual plane. Then, it is considered that the projected portion is such that a part or all of a light-shielding boundary line which is a boundary between a light-transmitting portion and a light-shielding portion of the projected portion is included in the projected surface which is a virtual plane. The light direction sensor, which is a projection unit. 2. The surface to be projected and the photoelectric conversion element surface,
The light direction sensor according to claim 1, further comprising a structure or a mechanism that can be adjusted so as to be substantially parallel. 3. The projection target and / or the two-dimensional photoelectric conversion element, or both, with respect to a rotation axis in a direction substantially the same as the normal line of the projection surface or the normal line of the photoelectric conversion element surface. The optical direction sensor according to claim 1 or 2, further comprising a structure or a mechanism capable of rotating the optical direction. 4. The light direction sensor according to claim 1, wherein the light-shielding boundary line includes a linear light-shielding shape that is a linear portion of the light-shielding boundary line. 5. A unit element of at least a part of the two-dimensional photoelectric conversion element is arranged on a lattice point of a lattice whose unit lattice is a substantially parallelogram, and the linear light shielding shape is the two-dimensional photoelectric conversion element. At least one of the directions of the straight lines of the portion corresponding to the straight line portion of the linear light-shielding shape of the image formed by being projected on the conversion element is the direction of arrangement of the unit elements of the two-dimensional photoelectric conversion element. The optical direction sensor according to claim 4, wherein the optical direction sensor is not parallel to any of the above. 6. The light direction sensor according to claim 4, wherein the projected portion includes at least one pair of the linear light shielding shapes in which the directions of the linear light shielding shapes are parallel to each other. 7. The light according to claim 4, wherein the projected portion includes the linear light shielding shapes in which directions of the linear light shielding shapes are not parallel to each other. Direction sensor. 8. A first projected portion in which the linear light-shielding shapes are sparsely arranged in the projected portion, and the linear light-shielding shapes are densely arranged in comparison with the first projected portion. The optical direction sensor according to claim 4, further comprising a second projected portion that is formed. 9. A pattern of appearance of a light-shielding portion and a non-light-shielding portion formed along a straight line in the projection surface by a plurality of the linear light-shielding shapes included in the projection surface is periodic. 9. The light direction according to claim 4, wherein the light direction is a pattern having no property, or a combination pattern of a periodic pattern and a pattern having a period larger than the periodic pattern. Sensor. 10. The light processing of the light intensity distribution signal in the signal processing unit, whereby part or all of the light of the projection image formed by projecting the projected unit onto the two-dimensional photoelectric conversion element is performed. The light intensity distribution is either the position of a point or a line serving as the position of the position of the intensity distribution, or the amount equivalent to the position of the point or the line serving as the position of the position of the light intensity distribution of a part or the whole of the projection image. At least one position such as a position reference point is obtained, and information about the direction of the light source corresponding to at least one of the information about the direction of the light source and the information used for detecting the information about the direction of the light source is obtained. The light direction sensor according to claim 1, wherein the light direction sensor detects the light direction. 11. The light direction sensor according to claim 10, wherein a plurality of positions of the light intensity distribution position reference point and the like are obtained to detect information and the like regarding the direction of the light source. 12. A feature of the shape of a graphic stored by the linear conversion when performing a linear conversion in which at least one graphic existing in a certain plane is projected onto another another plane, and A light intensity distribution feature point or the like corresponding to a feature point or a feature line of the graphic that can be defined by using at least one of the graphic and the positional relationship between the graphic stored by the linear conversion, with respect to the light intensity distribution. Define at least one of the positions of the light intensity distribution feature points or the positions of the light intensity distribution feature points having the same amount as the positions, and use the positions of the plurality of light intensity distribution position reference points and the like. 11. The process of calculating according to claim 10 is included in the process of detecting information or the like regarding the direction of the light source from the light intensity distribution signal.
Or the optical direction sensor according to item 11. 13. A tilt correction process using at least information about the tilt between the projected surface and the photoelectric conversion element surface in the process of detecting information about the direction of the light source from the light intensity distribution signal. 13. The method according to claim 10, further comprising the step of performing the inclination correction.
The optical direction sensor according to claim 1. 14. A reference direction of an azimuth angle on at least the projected surface and a reference direction of an azimuth angle on the photoelectric conversion element surface in the process of detecting information about the direction of the light source from the light intensity distribution signal. 10. A process of performing a twist correction, which is a correction process relating to the twist, using information about a twist angle with respect to is included.
3. The light direction sensor according to any one of 3 above. 15. A unit vector 2 in the plane of the photoelectric conversion element.
Assuming a photoelectric conversion element surface reference coordinate system including two and a projection surface reference coordinate system including two unit vectors in the projection surface, the process of the correction is performed with the projection surface reference coordinate system. 15. The process according to claim 13 or 14, which includes a part or all of a process of coordinate conversion with the photoelectric conversion element surface reference coordinate system, or a process equivalent to part or all of the process of coordinate conversion. The optical direction sensor described. 16. In the process of detecting information about the direction of the light source from the light intensity distribution signal, at least distortion of the photosensitive surface of the two-dimensional photoelectric conversion element with respect to the photoelectric conversion element surface is converted into a photoelectric conversion element. 16. A process of performing distortion correction, which is a correction process relating to the distortion, using a function described in a surface reference coordinate system or information equivalent to the function, and the process according to claim 10, wherein the process is performed. The optical direction sensor described. 17. The information relating to the direction of the light source is detected by using a signal of the unit element included in a specific region of the two-dimensional photoelectric conversion element which is narrower than the two-dimensional photoelectric conversion element. The light direction sensor according to claim 10. 18. The light-shielding boundary line includes a linear light-shielding shape that is a linear portion of the light-shielding boundary line, and the first projected portion in which the linear light-shielding shape is sparsely arranged is projected. Using the signals of the plurality of unit elements included in the first region on the two-dimensional photoelectric conversion element, the information regarding the direction of the light source and the like are detected with the first accuracy, and the linear light-shielding shape Using the signals of the plurality of unit elements included in the second area on the two-dimensional photoelectric conversion element onto which the second projected portion arranged densely is projected, information about the direction of the light source, etc. 18. The light direction sensor according to claim 10, wherein the detection is performed with a second accuracy that is better than the first accuracy. 19. A device control process and / or a signal processing process in which first information, which is already detected information about the direction of the light source, etc., is performed after the time when the first information is detected. 19. The light direction sensor according to claim 10, wherein the light direction sensor detects the direction of the light source or the like as the second information by using the other direction. 20. A plurality of signal processing methods performed in the signal processing section, or a plurality of element control methods performed in the element control section with an element control section controlling operation of the two-dimensional photoelectric conversion element. 20. The optical direction sensor according to claim 1, further comprising a plurality of both the signal processing method and the element control method. 21. The light direction according to claim 1, further comprising a function of detecting information on the brightness of the light from a signal of the two-dimensional photoelectric conversion element. Sensor. 22. A function of detecting information on the brightness of the light from a signal of the two-dimensional photoelectric conversion element, and at least information on the brightness of the light is used to display on the two-dimensional photoelectric conversion element. Signal processing for predicting the shape of the light intensity distribution of the whole or a part of the projected image formed by the projection of the projected portion and obtaining the predicted light intensity distribution shape such as the position of the light intensity distribution position reference point 20. The light direction sensor according to claim 10, wherein the light direction sensor is used as a light source. 23. One or more temperature sensors for measuring the temperature of one or more parts of the light direction sensor, wherein the information on the temperature detected by the temperature sensor and the information on the temperature are used. 23. The light direction sensor according to claim 1, wherein the light direction sensor outputs both or one of the obtained information about the direction of the light source and the like. 24. The optical direction sensor according to claim 1, which has a function of controlling the two-dimensional photoelectric conversion element in synchronization with a timing signal input from the outside. 25. The light intensity distribution signal used for detecting information about the direction of the light source and the like, which has a function of controlling the two-dimensional photoelectric conversion element in synchronization with a timing signal generated internally. The time when the generated light hits the two-dimensional photoelectric conversion element, and the information about at least one of the time when the light that generated the detected light intensity distribution signal hits the two-dimensional photoelectric conversion element is output. The light direction sensor according to any one of claims 1 to 24, which is characterized in that. 26. To detect information about the direction of the light source and information about the direction of the light source output by a light direction sensor that emits light by itself or receives light emitted from a light source that reflects light. The signal processing unit is provided with a signal processing unit that includes information about the direction of the light source corresponding to at least one of the information used and both or either of the signals used for detecting the information about the direction of the light source. The optical direction sensor signal processing device for performing both or one of detecting information related to the direction of the light source and correcting the information related to the direction of the light source. A light direction sensor, a two-dimensional photoelectric conversion element in which a plurality of unit elements are two-dimensionally arranged, a projected portion including a portion that transmits light and a portion that blocks light, A two-dimensional photoelectric conversion element, and a signal processing unit that processes a signal output from the two-dimensional photoelectric conversion element, wherein the projected portion is projected by the light on the two-dimensional photoelectric conversion element. The signal of at least a part of the unit elements included in the two-dimensional photoelectric conversion element generated by performing signal processing in the signal processing unit, as a light intensity distribution signal including light intensity signals of the plurality of unit elements. In the light direction sensor for detecting, the two-dimensional photoelectric conversion element, a part or all of the photosensitive surface enveloping the photosensitive portions of substantially all the unit elements of the two-dimensional photoelectric conversion element is a virtual plane. A two-dimensional photoelectric conversion element that can be regarded as included in a certain photoelectric conversion element surface, wherein the projected portion is a part of a light-shielding boundary line which is a boundary between a light-transmitting portion and a light-shielding portion of the projected portion or Everything is virtual Said optical directional sensor signal processing unit, characterized in that the said light direction sensor is a projection portion which can be regarded as being included in the projection surface in a plane 27. A feature of having a function of detecting information on the brightness of the light from a signal of the two-dimensional photoelectric conversion element, and the light direction sensor is provided in one or more parts of the light direction sensor. In the case of having one or more temperature sensors for measuring temperature, both the information regarding the temperature detected by the temperature sensor and the information regarding the direction of the light source obtained by using the information regarding the temperature, or the like, or One of the features of outputting one of them, the feature of having a function of controlling the two-dimensional photoelectric conversion element in synchronization with a timing signal input from the outside, and the feature of having the function of controlling the two-dimensional photoelectric conversion element in synchronization with the timing signal generated internally. The light having the function of controlling the three-dimensional photoelectric conversion element and generating the light intensity distribution signal used for detecting information about the direction of the light source is the two-dimensional And the time that had hit the photoelectric conversion element,
27. At least one of the features of outputting information on at least one of the times when the light that has generated the detected light intensity distribution signal has hit the two-dimensional photoelectric conversion element is provided. The optical direction sensor signal processing device according to. 28. A feature of the shape of a figure stored by the linear transformation when a linear transformation is performed in which at least one figure existing in one plane is projected onto another one plane, and A light intensity distribution feature point or the like corresponding to a feature point or a feature line of the graphic that can be defined by using at least one of the graphic and the positional relationship between the graphic stored by the linear conversion, with respect to the light intensity distribution. At least one is defined and the position of the light intensity distribution feature point or the position of the light intensity distribution feature point or the like having the same amount as the position is used by using the information used to detect the information regarding the direction of the light source. 28. The process of detecting the information about the direction of the light source, etc. is included in the process of calculating by calculating.
The optical direction sensor signal processing device according to. 29. At least information regarding the inclination between the projection surface and the photoelectric conversion element surface is included in either the step of detecting the information regarding the direction of the light source or the step of correcting the information regarding the direction of the light source. 29. The optical direction sensor signal processing device according to claim 26, further comprising a step of performing a tilt correction, which is a correction process relating to the tilt, by using the process. 30. At least one of the reference direction of the azimuth angle on the projection surface and the photoelectric conversion element, in either the process of detecting the information regarding the direction of the light source or the process of correcting the information regarding the direction of the light source. 30. The process according to claim 26, further comprising a step of performing a twist correction, which is a correction process for the twist, using information about a twist angle with respect to a reference direction of an azimuth angle on a surface.
An optical direction sensor signal processing device according to paragraph. 31. A unit vector 2 in the plane of the photoelectric conversion element.
Assuming a photoelectric conversion element surface reference coordinate system including two and a projection surface reference coordinate system including two unit vectors in the projection surface, the process of the correction is performed with the projection surface reference coordinate system. 31. A part or all of the process of coordinate conversion with the photoelectric conversion element surface reference coordinate system, or a process equivalent to part or all of the process of coordinate conversion is included. The optical direction sensor signal processing device described. 32. In the process of detecting information about the direction of the light source, at least distortion of the photosensitive surface of the two-dimensional photoelectric conversion element with respect to the photoelectric conversion element surface is described in a photoelectric conversion element surface reference coordinate system. 32. A process of performing distortion correction, which is a correction process for the distortion, using a function or information equivalent to the function, according to claim 26.
The optical direction sensor signal processing device according to claim 1. 33. Information or the like regarding the direction of the light source is detected by using a signal of the unit element included in a specific region of the two-dimensional photoelectric conversion element, which is narrower than the two-dimensional photoelectric conversion element. 33. The light direction sensor signal processing device according to claim 26. 34. A device control process and / or a signal processing process, in which the first information, which is already detected information relating to the direction of the light source, is performed after the time when the first information is detected. 34. The light direction sensor signal processing device according to claim 26, wherein the light direction sensor signal processing device is used by detecting the information about the direction of the light source or the like as the second information by using the other. 35. In the element control section, there is provided a plurality of signal processing methods performed in the signal processing section of the light direction sensor signal processing apparatus, or an element control section for controlling operation of the two-dimensional photoelectric conversion element is provided. 27. A plurality of element control methods to be performed, or a plurality of both the signal processing method and the element control method.
35. The light direction sensor signal processing device according to any one of items 34 to 34. 36. A signal processing of the light intensity distribution signal in the signal processing unit, whereby part or all of the light of the projection image formed by projecting the projected unit onto the two-dimensional photoelectric conversion element is performed. The light intensity distribution is either the position of a point or a line serving as the position of the position of the intensity distribution, or the amount equivalent to the position of the point or the line serving as the position of the position of the light intensity distribution of a part or the whole of the projection image. At least one position such as a position reference point is obtained, and information about the direction of the light source corresponding to at least one of the information about the direction of the light source and the information used for detecting the information about the direction of the light source is obtained. 36. The light direction sensor signal processing device according to claim 26, wherein the light direction sensor signal processing device detects. 37. The light direction sensor signal processing device according to claim 36, wherein a plurality of positions and the like of the light intensity distribution position reference point are obtained to detect information and the like regarding the direction of the light source. 38. A function for detecting information on the brightness of the light from a signal of the two-dimensional photoelectric conversion element is provided, and at least information on the brightness of the light is used on the two-dimensional photoelectric conversion element. Signal processing for predicting the shape of the light intensity distribution of the whole or a part of the projected image formed by the projection of the projected portion and obtaining the predicted light intensity distribution shape such as the position of the light intensity distribution position reference point The optical direction sensor signal processing device according to claim 36 or 37, characterized in that the optical direction sensor signal processing device is used.