JP2013051467A - Imaging apparatus and imaging method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an imaging apparatus which obtains a high-definition image by using a low-cost imaging element of a low pixel density.SOLUTION: An imaging apparatus comprises: an imaging element 21 imaging a subject 5; a light-shielding film 26 formed on a light-receiving surface of the imaging element 21; a drive part 3 moving the imaging element 21 in a stepwise fashion to a plurality of imaging positions each displaced from another by a unit smaller than one pixel; a storage part 7 acquiring imaging information obtained by imaging of the imaging element 21; and a control part 4 calculating pixel information of the subject 5 by a unit smaller than one pixel on the basis of a difference in the imaging information calculated at each imaging position. The storage part 7 stores the calculated pixel information in association with a position of the subject.

Description

  The present invention relates to an imaging apparatus and an imaging method for imaging an image.

Conventionally, the shape of a product, a mold, a jig, or the like is measured, and a manufacturing apparatus or the like is adjusted based on the measurement result. In such an operation, an imaging device equipped with a high-resolution solid-state imaging device is used. Examples of the solid-state imaging device include a CCD (Charge Coupled Device) imaging device, a CMOS (Complementary Metal Oxide Semiconductor) imaging device, and the like.
Patent Document 1 discloses a solid-state imaging device that vibrates a light receiving surface in order to obtain a high resolution using an imaging device having a limited number of pixels.

Japanese Unexamined Patent Publication No. 60-18958

  Incidentally, the resolution of the imaging device generally increases in accordance with the number of effective pixels of the imaging device. However, in order to improve the number of effective pixels of the image sensor, it is usually necessary to increase the pixel density of the light receiving elements included in the image sensor, which is costly. On the other hand, for the purpose of improving resolution without increasing the number of light receiving elements, an imaging element with a narrow imaging range with a high pixel density of the light receiving elements is used, and the subject to be imaged is divided into a plurality of parts, There is a method in which shooting is repeated multiple times for each portion of the subject while moving. In this case, since it is necessary to connect the obtained images while confirming the relative positional relationship, the relative positional relationship between the images to be connected must be calculated. When the moving distance of the image sensor increases, it is necessary to calculate a correlation between pixels in consideration of a positional shift caused by the movement, and there is a problem that an error is easily generated here.

  The solid-state imaging device disclosed in Patent Document 1, for example, in an interline transfer method, transfers signal charges accumulated in the photosensitive part to a vertical CCD register during a signal blanking period and reads out during the next field effective period However, details for improving the resolution are not shown.

  In view of the above-described problems, an object of the present invention is to provide an imaging apparatus and an imaging method that obtain an image with high resolution using an imaging element with low pixel density and low cost.

  A first aspect of the present invention is a pixel information acquisition region (for example, a pixel information acquisition region P (described later) that converts incident light from a subject (for example, a later-described subject 5) to acquire pixel information for one pixel. 1, 1) to P (i, j)) arranged in the vertical and horizontal directions (for example, an image sensor 21 described later), and a light shielding film formed on the light receiving surface of the image sensor (For example, a light shielding film 26 to be described later), and a row of one end of a width less than one pixel in the vertical direction and a column of one end of a width less than one pixel in the horizontal direction in the plurality of pixel information acquisition regions. The light-shielding film covering at least one region and the image sensor are moved in stages to a plurality of image capture positions (for example, a basic position [1] to a move position [4] described later) shifted by units smaller than one pixel. A drive unit (for example, drive unit 3 to be described later) and the image sensor; An imaging information acquisition unit (for example, a storage unit 7 described later) that acquires imaging information (for example, an output value described later) obtained by imaging of the imaging element every time the driving unit moves to the imaging position, and the imaging A pixel information calculation unit (for example, to be described later) that calculates pixel information (for example, a pixel value to be described later) of the subject 5 in units smaller than one pixel based on the difference in the imaging information acquired for each imaging position by the information acquisition unit. A control unit 4), and an image information storage unit (for example, a storage unit 7 to be described later) that stores the pixel information calculated by the pixel information calculation unit as image information in association with the position of the subject. An imaging device (for example, an imaging device 10 to be described later) is provided.

According to the first aspect of the present invention, it is possible to obtain an image with high resolution using an image sensor with low pixel density and low cost.
Further, since the light shielding film is formed on the light receiving surface of the image sensor, diffracted light to the light shielding area of the image sensor is less likely to be generated from light incident near the boundary between the light receiving area of the image sensor and the light shielding film. Further, stray light that directly enters the light-shielding area of the image sensor from the vicinity of the boundary between the light-receiving area of the image sensor and the light-shielding film is less likely to occur. For this reason, it is possible to reduce the influence of noise in the light shielding area of the image sensor.

  The second aspect of the present invention is a pixel information acquisition region (for example, a pixel information acquisition region P (to be described later) that converts incident light from a subject (for example, a later-described subject 5) to acquire pixel information for one pixel. 1, 1) to P (i, j)) arranged in the vertical and horizontal directions (for example, an image sensor 21 described later), and a light shielding film formed on the light receiving surface of the image sensor (For example, a light shielding film 26 to be described later), and a row of one end of a width less than one pixel in the vertical direction and a column of one end of a width less than one pixel in the horizontal direction in the plurality of pixel information acquisition regions. An imaging method for imaging a subject using an imaging device (for example, imaging device 10 described later) including a light shielding film that covers at least one region, and a driving unit (for example, driving unit 3 described later), The image sensor is shifted by a unit smaller than one pixel. The imaging element is driven by the step of moving to an imaging position (for example, a basic position [1] to a moving position [4], which will be described later) and an imaging information acquisition unit (for example, a storage unit 7 to be described later). A step of acquiring imaging information (e.g., an output value described later) obtained by imaging of the imaging element each time the unit moves to the imaging position, and a pixel information calculation unit (e.g., a control unit 4 described later) A step of calculating pixel information (for example, a pixel value described later) of the subject in units smaller than one pixel based on a difference in imaging information acquired for each imaging position by the imaging information acquisition unit; and an image information storage unit (for example, Storing the pixel information calculated by the pixel information calculation unit in association with the position of the subject as image information by a storage unit 7) described later. It is to provide an imaging method comprising.

  According to the second aspect of the present invention, the same effect as that of the above-described imaging apparatus can be obtained.

  According to the present invention, it is possible to acquire a high-pixel image using an image sensor with low pixel density and low cost. Therefore, an image with high resolution can be acquired without spending money on the equipment.

1 is a schematic diagram of an imaging apparatus according to a first embodiment of the present invention. It is a block diagram which shows the structure of the image pick-up element which comprises the imaging device of FIG. It is the schematic of the imaging part which comprises the imaging device of FIG. It is a figure which shows the relationship between the image pick-up element which comprises the imaging device of FIG. 3, and a light shielding film. It is a figure explaining the relationship between an image sensor and a light shielding part. It is a figure which shows an example of the image pick-up element in which the light shielding film was formed. It is a figure which shows the pattern with respect to the to-be-photographed object which can be produced | generated by driving the image pick-up element of FIG. It is a figure which shows the relationship between the pixel information acquisition area | region which forms the edge part of the image pick-up element of FIG. 6, and a light shielding film. It is a figure which shows the image information area | region of a to-be-photographed object. It is a figure which shows the relationship between the output value in the basic position [1] of the some pixel information acquisition area | region of the image pick-up element of FIG. 7, and a light shielding film. It is a figure which shows the relationship between the output value in the movement position [2] of the some pixel information acquisition area | region which comprises the uppermost part of the image pick-up element of FIG. 7, and a light shielding film. It is a figure which shows the relationship between the output value in the movement position [3] of the some pixel information acquisition area | region which comprises the leftmost part of the image pick-up element of FIG. 7, and a light shielding film. It is a figure which shows the relationship between the output value in the movement position [4] of the several pixel information acquisition area | region which comprises the uppermost part of the image pick-up element of FIG. 7, and a light shielding film. It is a figure which shows the pixel information of the to-be-photographed object acquired by the image pick-up element of FIG. It is a flowchart of the process which acquires the image information which the imaging device of FIG. 2 performs.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[First Embodiment]
The outline of the imaging apparatus according to the first embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 is a schematic diagram of an imaging apparatus according to the first embodiment of the present invention, and FIG. 2 is a block diagram showing a configuration of an imaging element of the imaging apparatus according to the present embodiment.

  An imaging apparatus 10 illustrated in FIG. 1 includes an imaging unit 2 that includes an imaging element 21 that captures a subject 5 and converts it into an electrical signal, a driving unit 3 that drives the imaging element 21, an imaging element 21, an imaging unit 2, and driving. A control unit 4 that controls the unit 3, a storage unit 7 that stores image data of the subject 5 imaged by the imaging unit 2, and a display unit 8 that displays an image of the subject 5 based on the image data.

  In addition to the image sensor 21, the image pickup unit 2 includes an image pickup lens (not shown) that forms an image of light from the subject 5 on the image sensor 21 arranged at an image pickup position described later. The image sensor 21 disposed at the imaging position converts incident light from the subject 5 imaged by the imaging lens into an electrical signal. The imaging device 21 is a CCD (Charge Coupled Device) imaging device, a CMOS (Complementary Metal Oxide Semiconductor) imaging device, or the like provided with a plurality of light receiving elements that photoelectrically convert the subject 5 projected and imaged by the imaging lens. Composed. The imaging unit 2 has a function of an imaging unit.

  The drive unit 3 drives the image sensor 21 to an appropriate imaging position for imaging the subject 5. Details of the drive unit 3 will be described later.

  In the present embodiment, the control unit 4, the storage unit 7, and the display unit 8 are configured as a part of the computer 9. Although not shown, the control unit 4 includes a ROM (Read Only Memory) in which a program for the imaging device 10 to execute various functions and a program stored in the ROM to execute various types of the imaging device 10. A CPU (Central Processing Unit) that realizes functions and a RAM (Random Access Memory) that stores data necessary for the CPU to execute various processes are appropriately configured.

  The control unit 4 controls the drive unit 3 to move the image sensor 21 and arranges the image sensor 21 at the imaging position. Further, the control unit 4 processes the electrical signal output from the image sensor 21 to generate image data (image information), and stores the generated image data in the storage unit 7. Further, the control unit 4 displays an image captured by the image sensor 21 on the display unit 8 based on the generated image data. In addition, the control unit 4 performs arithmetic processing described later when processing the electrical signal output from the image sensor 21.

  The display unit 8 is configured by a liquid crystal display or the like. The storage unit 7 includes a RAM (Random Access Memory), a ROM (Read Only Memory), a hard disk, and the like.

[Configuration of image sensor]
Next, the basic configuration of the image sensor 21 will be described with reference to FIG. The image sensor 21 is composed of a plurality of light receiving elements arranged two-dimensionally. Each of the light receiving elements includes a light receiving surface having a predetermined area. Each of the light receiving elements performs photoelectric conversion upon receiving incident light on the light receiving surface, and generates a signal charge corresponding to one pixel according to the amount of light received per light receiving surface. The light receiving surface of each light receiving element is hereinafter referred to as a “pixel information acquisition region”. For this reason, the entire light receiving surface of the image pickup element 21 formed by arranging the light receiving elements in a two-dimensional manner is provided in a plurality of pixel information acquisition regions each generating a signal charge corresponding to one pixel for each light receiving element. Can be divided.

  As shown in FIG. 2, the total number of pixels of the image sensor 21 is determined by the number of pixel information acquisition regions that form the light receiving surface of the image sensor 21. For example, if i and j are arbitrary natural numbers, the number of pixel information acquisition areas arranged in the horizontal direction, i.e., the number of horizontal pixel i, the number of pixel information acquisition areas arranged in the vertical direction, i.e. If the number of vertical pixels is j, the total number of pixels of the image sensor 21 is i × j. The pixel information acquisition region corresponds to the light receiving surface of the light receiving element.

  That is, the image pickup device 21 includes light receiving elements U (1, 1), U (2, 1), U (3, 1),..., U (1, 2), U (1, 3),. ..., U (i, j). Light receiving elements U (1,1), U (2,1), U (3,1),..., U (1,2), U (1,3),. , J) form pixel information acquisition areas P (1,1), P (2,1), P (3,1),..., P (1,2). ), P (1,3),..., P (i, j).

  Here, although not shown in FIG. 2, a part of the image sensor 21 is covered with a light shielding film 26 formed so as to shield part of the light incident on the image sensor 21. That is, the light shielding film 26 is formed on a part of the light receiving surface of the image sensor 21.

  FIG. 4A shows the relationship between the imaging element 21 and the light shielding film 26 of the present embodiment. As shown in FIG. 4A, in the present embodiment, a light shielding film 26 is formed directly on a part of the light receiving area of the image sensor 21 to provide a light shielding area. In other words, the light shielding film 26 is formed inside the protective film 28 of the image sensor 21 by being attached to the surface of the image sensor 21. For this reason, normal absorption and reflection are performed on the light L1 incident on the light receiving area and the light L2 incident on the protective film 28. Further, diffracted light hardly enters the light shielding area of the image sensor 21 from light incident near the boundary between the light receiving area and the light shielding film 26. Further, stray light that directly enters the light-shielding area of the image sensor 21 from the vicinity of the boundary between the light-receiving area and the light-shielding film 26 is unlikely to occur. For this reason, the influence of noise in the light shielding area of the image sensor 21 can be reduced.

  For reference, FIG. 4B shows the relationship between the conventional image sensor 21 and the light shielding plate 6. The light shielding plate 6 is disposed above the protective film 28 that covers the image sensor 21. For this reason, there is a certain distance between the image sensor 21 and the light shielding plate 6. Therefore, the diffracted lights LS1 and LS2 generated by the light L3 incident on the boundary portion of the light shielding plate 6 become large and enter the light shielding area of the image sensor 21 to cause noise. Further, stray light L4 that directly enters the light-shielding area of the image sensor 21 from the boundary portion of the light-shielding plate 6 is generated, which causes noise.

  Thus, by providing the light shielding film 26 as shown in FIG. 4A in place of the light shielding plate 6, diffracted light and stray light that may be generated by light shielding are reduced.

  An example of forming a light shielding film on the image sensor will be described. For example, an image sensor has been used as shown in FIG. It is assumed that there are 493 effective pixel signals including the first field and the second field. In the first field, the first line and the 248th line of the effective pixel signal are not practically used because the pixel signal on one side of the field readout includes optical black. Further, the optical black of the horizontal 40 pixels located on the right side is also shielded so that light does not enter the light receiving area of the image sensor 21. The horizontal 40-pixel signal is used as the black reference for the video signal. Since the horizontal feed signal for 22 pixels located on the left side has a small dark current component, it has been used as a reference for checking the magnitude of the dark current contained in the pixel signal.

  As described above, there are pixels that are shielded from light as black correction, but they have not been used for intentionally controlling light reception in units corresponding to a fraction of one pixel. In the present embodiment, for example, a light shielding film 26 that shields incident light in a unit corresponding to a fraction of one pixel is formed in a portion of the image sensor that has been used for black correction and dark current measurement. To do. In this way, the peripheral portion of the image sensor that has not been noticed in the past is effectively utilized.

  An example of the image sensor 21 in which the light shielding film 26 is formed is shown in FIG. What is necessary is just to form the light shielding film 26 so that the image pick-up element 21 may be light-shielded in the unit corresponded to the arbitrary fraction of 1 pixel. Here, as an example of this embodiment, a case where pixel information is obtained by dividing one pixel into four parts will be described.

  In the image sensor 21, L-shaped light-shielding films 26 are formed on two vertical and horizontal sides that form the outermost end of the image sensor 21. Here, the upper and left sides are shielded from light, but any side may be shielded as long as the sides are vertical and horizontal. In the present invention, at least one of at least two sides in the vertical and horizontal directions may be used. That is, the light-shielding film of the present invention includes at least one region of a row of one end of a width less than one pixel in the vertical direction and a column of one end of a width less than one pixel in the horizontal direction in a plurality of pixel information acquisition regions. cover.

  The L-shaped light shielding film 26 shields the pixel information acquisition region P (1, 1) forming the leftmost upper end portion of the image sensor 21 from three quarters of the pixels, and the pixel information acquisition region P (2, 1). ), P (3, 1), P (1, 2), and P (1, 3) are shielded from light by a half (2/4) pixels. The remaining pixel information acquisition regions P (2,2), P (3,2), P (2,3), and P (3,3) are not shielded from light.

  Here, in order to facilitate understanding, only nine pixel information acquisition regions have been described, but the number of pixel information acquisition regions of the image sensor 21 is arbitrary. The light shielding film 26 may be formed so as to shield the image sensor 21 in the same pattern in units of subpixels. That is, in the case of FIG. 6, the light shielding film 26 may be formed so as to shield the left end portion and the upper end portion of the image sensor 21.

[Configuration of imaging unit]
Returning to FIG. 3, in the imaging apparatus 10 according to the present embodiment, the imaging unit 2 includes an imaging element 21. The driving unit 3 drives the imaging element 21 to a plurality of imaging positions based on the control of the control unit 4. Here, the imaging element 21 is disposed at an imaging point F that appropriately receives incident light and can image a subject. The drive unit 3 moves the image sensor 21 located at the imaging point F in units of subpixels in the directions X and Y of the surface perpendicular to the incident light (see FIG. 3B). That is, the drive unit 3 moves the image sensor 21 step by step to a plurality of image capture positions shifted by units smaller than one pixel. The drive mechanism of the drive unit 3 can be configured by a piezoelectric element actuator, a distance sensor, or the like.

  FIG. 7 shows a plurality of imaging positions with respect to the subject 5 that can be taken by the pixel information acquisition region by driving the imaging device 21 of FIG. 6 by the driving unit 3.

The imaging device 21 arranged at the imaging point F is moved by the drive unit 3 in the sub-pixel units in the directions X and Y of the plane perpendicular to the incident light from the subject 5 and set to a predetermined imaging position. The Various patterns can be formed by the drive unit 3 moving the image sensor 21 in the direction of the surface perpendicular to the incident light. A case will be described in which the imaging element 21 moves in units of subpixels in the directions X and Y of the surface perpendicular to the incident light to acquire imaging information corresponding to each of the patterns I to IV shown in FIG.
7A to 7D showing the position of the image pickup element 21 for each of the patterns I to IV, and the image pickup element 21 necessary for acquiring the image pickup information corresponding to the patterns I to IV. FIG. 7E shows a table of movement direction and movement amount (phase shift amount) with reference to the pattern I of FIG.

  As shown in FIGS. 7A and 7E, the imaging element 21 can acquire imaging information in the pattern I at the basic position. This position is defined as a basic position [1].

  Further, as shown in FIGS. 7B and 7E, the image sensor 21 moves from the basic position [1] along the X axis by a distance corresponding to a half pixel in the right direction on the paper surface. Thus, the imaging information in the pattern II can be acquired. This position is defined as a movement position [2].

  Further, as shown in FIGS. 7C and 7E, the image sensor 21 moves from the basic position [1] by a distance corresponding to one-half pixel along the Y axis in the downward direction on the paper surface. Thereby, the imaging information in the pattern III can be acquired. This position is defined as a movement position [3].

  Further, as shown in FIGS. 7D and 7E, the image pickup device 21 has a half pixel from the basic position along the X axis to the right of the paper and 2 below the paper along the Y axis. The imaging information in the pattern IV can be acquired by moving by a distance corresponding to 1 / pixel. This position is defined as a movement position [4].

  In this way, by moving the image pickup element 21 on which the light shielding film 26 is formed in units of subpixels in a direction perpendicular to the incident light, the image pickup element 21 obtains image pickup information shifted in units of subpixels. Can do.

  Similar to the case where the light shielding film 26 is used, by using another light shielding film, not only pixel information obtained by dividing one pixel into four parts but also pixel information obtained by dividing one pixel into an integer multiple of an arbitrary natural number is obtained. be able to. For example, if X and Y are arbitrary natural numbers, one pixel can be divided into X × Y. For example, a configuration of a light shielding film that obtains pixel information by dividing one pixel into nine may be employed.

[Imaging processing]
A process for efficiently imaging a subject using the imaging device 21 configured as described above will be described below with reference to FIGS. 8 to 14.

  In FIG. 8, pixel information that forms the light shielding film 26 formed on the image sensor 21 and the end of the image sensor 21 to be observed when the subject 5 is first imaged using the patterns I to IV of the image sensor 21. The positional relationship between the acquisition area and the subject 5 imaged on the image sensor 21 is shown.

  As shown in FIG. 8A, for example, in the image sensor 21, the light shielding film 26 is formed so as to partially shield at least two sides forming the outermost portion of the image sensor 21. On the right side of FIG. 8 (1), the relationship between the pixel information acquisition region P (1, 1) at the uppermost left end of the image sensor 21 and the light shielding film 26 is shown in more detail. A portion surrounded by a solid line of the image sensor 21 represents a pixel information acquisition region P (1, 1) at the upper left end of the image sensor 21. The pixel information acquisition region P (1,1) is configured to acquire and output pixel information corresponding to one pixel when receiving light incident on the upper left end of the image sensor 21. At the position shown in FIG. 8A, the light shielding film 26 shields light corresponding to three quarters of one pixel at each of the upper end portion and the left end portion of the light incident on the pixel information acquisition region P (1, 1). It is arranged so that. For this reason, the pixel information acquisition region P (1,1) actually outputs pixel information in sub-pixel units corresponding to a quarter of one pixel.

  Similarly, the L-shaped light-shielding film 26 is a pixel information acquisition region corresponding to two sides having the pixel information acquisition region P (1, 1) of the image sensor 21 of the subject 5 imaged on the image sensor 21. The pixel information acquisition regions other than P (1,1) are also arranged so that one half of one pixel is shielded from light in the vertical and horizontal directions. As a result, at the position shown in FIG. 8 (2), the light shielding film 26 similarly forms a pixel information acquisition region that forms two sides in the vertical and horizontal directions at the extreme end, that is, the pixel information acquisition region P at the upper end. (2,1), P (3,1),..., P (i, 1), and pixel information acquisition regions P (1,2), P (1,3),. For P (1, j), one half of one pixel is shielded from light incident on the upper end and the left end. Therefore, the pixel information acquisition regions P (2,1), P (3,1),..., P (i, 1), and the pixel information acquisition regions P (1,2), P (1,3) ,..., P (1, j) actually outputs pixel information in sub-pixel units corresponding to one half of one pixel.

  Next, the imaging process of this embodiment will be described. In the present embodiment, the drive unit 3 is controlled so that the imaging element 21 is shifted in stages by units (one-fourth of one pixel) less than the remaining one pixel covered by the light shielding film 26. The process of moving to the imaging position and photographing the subject 5 is repeated step by step until each pixel is imaged in a unit (one quarter of one pixel) that is less than the remaining one pixel covered by the light shielding film 26. The subject 5 is imaged. That is, in the present embodiment, the subject 5 is imaged four times with a default.

<Process focusing on the pixel information acquisition area at the end>
First, in order to facilitate understanding, an operation for setting each predetermined imaging position so as to use the patterns I to IV of the imaging element 21 that images the subject 5, and output values from the patterns I to IV of the imaging element 21 Will be described by focusing on the pixel information acquisition region P (1, 1) at the end and the subject 5. In the present embodiment, four different pieces of imaging information are obtained by the patterns I to IV of the imaging element 21.

In the following processing, attention is focused on a small area of subpixels of the pixel information acquisition area P (1, 1) defined as one-fourth of one pixel at the upper left end. Thereby, the pixel information of the subject 5 is calculated in units smaller than one pixel based on the difference between the four pieces of imaging information acquired for each imaging position of the patterns I to IV of the imaging element 21.
FIG. 9 shows an image information area of the subject 5 imaged by the image sensor 21. As shown in FIG. 9, the subject 5 to be imaged is partitioned by an image information area g (m, n) for each quarter of one pixel. Here, m and n are integers starting from 0, and the total number m and n is twice the number of i and j in the pixel information acquisition region P (i, j). Note that when m or n in the image information area g (m, n) is 0, this is an area outside the imaging range of the subject 5.
The drive unit 3 captures images in the pixel information acquisition region P (1,1) at the endmost portion and captures image information regions g (1,1), g (2,1), g (1,2), g (2 , 2) while moving the imaging device 21 to a predetermined imaging position, the pixel information areas in the vertical direction and the horizontal direction in units corresponding to a quarter of one pixel using the light shielding film 26. Switch.

  As a result, in the horizontal direction, until one line of image information areas arranged in the vertical direction continuous to the image information area g (1, 1) in the subject 5 at the extreme end captures an area corresponding to one pixel, Further, in the vertical direction, imaging is performed until a row of image information areas arranged in the horizontal direction continuous to the image information area g (1, 1) in the subject 5 at the endmost portion captures an area corresponding to one pixel. The element 21 is moved to a predetermined position so as to be the patterns I to IV. Therefore, the light-shielding film 26 is changed until the subject 5 at the upper left end in the vertical and horizontal directions is imaged for one pixel in a unit corresponding to a quarter of one pixel.

  First, the image sensor 21 uses the pixel information acquisition region P (1, 1) in a state in which a region corresponding to three-fourths of subpixels of one pixel at the uppermost left upper end is shielded by the light shielding film 26. 1, 1) is imaged. The position of the image sensor 21 with respect to the subject 5 at this time is defined as a basic position [1].

FIG. 10 is a diagram showing the relationship between the position of the image sensor 21 and the subject 5 at the basic position [1], focusing on the pixel information acquisition region P (1, 1) at the upper left end. In this way, imaging is performed in a state where the upper and left portions of the pixel information acquisition region P (1,1) at the uppermost left end portion are respectively shielded by the light shielding film 26 in a region corresponding to three quarters of one pixel. .
The output value of the pixel information acquisition region P (1, ¹⁾ is stored in the storage unit 7 as a ^{(1, 1)} . Further, the output value a ^(1,1) of the pixel information acquisition region P (1,1) at this time is used as the pixel value A ⁽¹ ) of the image information region g (1,1) of the upper leftmost region of the subject 5. ^{, 1)} is stored in the storage unit 7.
At this time, imaging is performed in a state where the upper part of the pixel information acquisition region P (2, 1) is light-shielded by the light-shielding film 26 in a region corresponding to one-half of one pixel. The output value of the pixel information acquisition region P (2, ¹⁾ is stored in the storage unit 7 as a ^{(2, 1)} . In the same manner, imaging is performed in a state where the upper part of the pixel information acquisition region P (i, 1) corresponds to a half of one pixel is shielded by the light shielding film 26. The output value of the pixel information acquisition region P (i ^{, 1)} is stored in the storage unit 7 as a ^{(i, 1)} .
At this time, imaging is performed in a state where the left portion of the pixel information acquisition region P (1,2) corresponds to a half of one pixel is shielded by the light shielding film 26. The output value of the pixel information acquisition region P ( ^1,2) is stored in the storage unit 7 as a ^(1,2) . In the same manner, imaging is performed in a state where the left portion of the pixel information acquisition region P (1, j) is light-shielded by the light-shielding film 26 in a region corresponding to one-half of one pixel. The output value of the pixel information acquisition region P (1 ^{, j)} is stored in the storage unit 7 as a ^{(1, j)} .
Further, at this time, the pixel information acquisition region other than the pixel information acquisition region P (i, 1) and the pixel information acquisition region P (1, j) is also imaged. The output value of the pixel information acquisition region P (i ^{, j)} is stored in the storage unit 7 as a ^{(i, j)} .

  Subsequently, the position of the image sensor 21 is shifted from the basic position [1] to the right by a distance corresponding to one half of one pixel with respect to the subject 5 and imaged. In other words, the image sensor 21 has the image information area g (() in the pixel information acquisition area P (1, 1) in a state where the area corresponding to three-fourths of subpixels of the uppermost leftmost pixel is shielded by the light shielding film 26. 2, 1) is imaged. The position of the image sensor 21 with respect to the subject 5 at this time is defined as a movement position [2].

In FIG. 11, the image information area of the subject 5 imaged on the image sensor 21 is shifted by a distance h corresponding to one-half pixel in the right direction from the basic position [1]. It is a figure which shows the relationship between the image pick-up element 21 and the to-be-photographed object 5 at the time of moving like this.
The output value b ^(1, 1) of the pixel information acquisition region P (1, 1) at this time is stored in the storage unit 7. The output value b ^(1,1) of the pixel information acquisition region P (1,1) at this time is stored as the pixel value B ^(1,1) of the upper left image information region g (2,1) of the subject 5 7
At this time, imaging is performed in a state where the upper part of the pixel information acquisition region P (2, 1) is light-shielded by the light-shielding film 26 in a region corresponding to one-half of one pixel. The output value of the pixel information acquisition region P (2, ¹⁾ is stored in the storage unit 7 as b ^{(2, 1)} . In the same manner, imaging is performed in a state where the upper part of the pixel information acquisition region P (i, 1) corresponds to a half of one pixel is shielded by the light shielding film 26. The output value of the pixel information acquisition region P (i ^{, 1)} is stored in the storage unit 7 as b ^{(i, 1)} .
At this time, imaging is performed in a state where the left portion of the pixel information acquisition region P (1,2) corresponds to a half of one pixel is shielded by the light shielding film 26. The output value of the pixel information acquisition region P ( ^1,2) is stored in the storage unit 7 as b ^(1,2) . In the same manner, imaging is performed in a state where the left portion of the pixel information acquisition region P (1, j) is light-shielded by the light-shielding film 26 in a region corresponding to one-half of one pixel. The output value of the pixel information acquisition region P (1 ^{, j)} is stored in the storage unit 7 as b ^{(1, j)} .
At this time, the pixel information acquisition area other than the pixel information acquisition area P (i, 1) and the pixel information acquisition area (1, j) is also imaged. The output value of the pixel information acquisition region P (i ^{, j)} is stored in the storage unit 7 as b ^{(i, j)} .

further,
a ^(2,1) -B ^(1,1) = A ^(2,1)
A storage unit as a pixel value A ^(2,1) of the third image information area g (3,1) in the right direction from the upper left end of the subject 5 obtained by photographing this value A ^(2,1) 7 is stored.
In addition to this,
b ^(2,1) -A ^(2,1) = B ^(2,1)
A storage unit as a pixel value B ^(2, 1) of the fourth image information area g (4, 1) in the right direction from the upper left end of the subject 5 obtained by photographing this value B ^{(2, 1)} 7 is stored.

Thus, A ^{(i, 1)} is
As a ^{(i, 1)} −B ^(i−1,1) = A ^{(i, 1)} ,
B ^{(i, 1)} is
b ^{(i, 1)} −A ^{(i, 1)} = B ^{(i, 1)}
As a pixel value ^A of the value ^{A (i, 1)} from the leftmost upper portion of the object 5 which is obtained by photographing in the right direction m = 2i-th information area ^{g (m, 1) (i} , 1) Store in the storage unit 7. Further, the pixel value B ^{(i, 1)} of the m = 2i-1st image information area g (m, 1) in the right direction from the upper left end of the subject 5 obtained by photographing this value B ^{(i, 1) . 1)} is stored in the storage unit 7.

  Subsequently, the position of the image sensor 21 is shifted from the basic position [1] downward by a distance corresponding to one half of one pixel with respect to the subject 5 and imaged. In other words, the image sensor 21 has the image information area g (() in the pixel information acquisition area P (1, 1) in a state where the area corresponding to three-fourths of subpixels of the uppermost leftmost pixel is shielded by the light shielding film 26. 1, 2). The position of the image sensor 21 with respect to the subject 5 at this time is defined as a movement position [3].

In FIG. 12, the image sensor 21 is thus shifted downward from the basic position [1], and the image information area of the subject 5 imaged on the image sensor 21 is shifted by a distance h corresponding to a half pixel. It is a figure which shows the relationship between the image pick-up element 21 and the to-be-photographed object 5 at the time of moving like this.
The output value c ^(1,1) of the pixel information acquisition region P (1,1) at this time is stored in the storage unit 7. The output value c ^(1,1) of the pixel information acquisition region P (1,1) at this time is stored as the pixel value C ^(1,1) of the upper left image information region g (1,2) of the subject 5. 7 is stored.
At this time, imaging is performed in a state where the upper part of the pixel information acquisition region P (2, 1) is light-shielded by the light-shielding film 26 in a region corresponding to a half of one pixel. The output value of the pixel information acquisition region P (2, ¹⁾ is stored in the storage unit 7 as c ^{(2, 1)} . In the same manner, imaging is performed in a state where the upper part of the pixel information acquisition region P (i, 1) corresponds to a half of one pixel is shielded by the light shielding film 26. The output value of the pixel information acquisition region P (i ^{, 1)} is stored in the storage unit 7 as c ^{(i, 1)} .
At this time, imaging is performed in a state where the left portion of the pixel information acquisition region P (1,2) corresponds to a half of one pixel is shielded by the light shielding film 26. The output value of the pixel information acquisition region P ( ^1,2) is stored in the storage unit 7 as c ^(1,2) . In the same manner, imaging is performed in a state where the left portion of the pixel information acquisition region P (1, j) is light-shielded by the light-shielding film 26 in a region corresponding to one-half of one pixel. The output value of the pixel information acquisition region P (1 ^{, j)} is stored in the storage unit 7 as c ^{(1, j)} .
Further, at this time, the pixel information acquisition region other than the pixel information acquisition region P (i, 1) and the pixel information acquisition region P (1, j) is also imaged. The output value of the pixel information acquisition region P (i ^{, j)} is stored in the storage unit 7 as c ^{(i, j)} .

further,
a ^(1,2) −C ^(1,1) = A ^(1,2)
Pixel value ^{A (1, 2)} as the storage unit of the value ^{A (1, 2)} in a downward direction from the leftmost upper portion of the object 5 which is obtained by photographing a third information area g (1, 3) 7 is stored.
In addition to this,
c ^(1,2) −A ^(1,2) = C ^(1,2)
Storage unit as the pixel value ^{C (1, 2)} in the downward direction from the leftmost upper end fourth information area g (l, 4) of the object 5 which is obtained by photographing the value ^{C (1, 2)} 7 is stored.

Thus, A ^{(1, j)} is
As a ^{(1, j)} -C ^{(1, j-1)} = A ^{(1, j)} ,
C ^{(1, j)} is
c ^{(1, j)} −A ^{(1, j)} = C ^{(1, j)}
The value ^{A (1, j)} as the pixel value ^{A (1, j)} in the downward direction from the leftmost upper end n = 2j-th information area g of the object 5 which is obtained by photographing (1, n) and Store in the storage unit 7. Further, the pixel value C ^(1, n) of the n = 2i−1-th image information area g (1, n) downward from the upper left end of the subject 5 obtained by photographing this value C ^{(1, j) . j)} is stored in the storage unit 7.

  Further, the position of the image pickup device 21 is shifted from the basic position [1] in the lower right direction by a distance corresponding to one half of one pixel with respect to the subject 5 and picked up. In other words, the image sensor 21 has the image information area g (() in the pixel information acquisition area P (1, 1) in a state where the area corresponding to three-fourths of subpixels of the uppermost leftmost pixel is shielded by the light shielding film 26. 2, 2). The position of the image sensor 21 relative to the subject 5 at this time is defined as a movement position [4].

FIG. 13 shows a distance h in which the image information area of the subject 5 imaged on the image sensor 21 is equivalent to a half pixel, respectively, with the image sensor 21 in the lower right direction from the basic position [1]. It is a figure which shows the relationship between the image pick-up element 21 and the to-be-photographed object 5 when moving so that it may shift.
The output value of the pixel information acquisition region P (1, 1) at this time is stored in the storage unit 7 as d ^{(1, 1)} . The output value d ^(1,1) of the pixel information acquisition area P (1,1) at this time is stored as the pixel value D ^(1,1) of the upper left image information area g (2,2) of the subject 5 7
At this time, imaging is performed in a state where the upper part of the pixel information acquisition region P (2, 1) is light-shielded by the light-shielding film 26 in a region corresponding to one-half of one pixel. The output value of the pixel information acquisition region P ( ^2,1) is stored in the storage unit 7 as d ^(2,1) . In the same manner, imaging is performed in a state where the upper part of the pixel information acquisition region P (i, 1) corresponds to a half of one pixel is shielded by the light shielding film 26. The output value of the pixel information acquisition region P (i ^{, 1)} is stored in the storage unit 7 as d ^{(i, 1)} .
At this time, imaging is performed in a state where the left portion of the pixel information acquisition region P (1,2) corresponds to a half of one pixel is shielded by the light shielding film 26. The output value of the pixel information acquisition region P ( ^1,2) is stored in the storage unit 7 as d ^(1,2) . In the same manner, imaging is performed in a state where the left portion of the pixel information acquisition region P (1, j) is light-shielded by the light-shielding film 26 in a region corresponding to one-half of one pixel. The output value of the pixel information acquisition region P (1 ^{, j)} is stored in the storage unit 7 as d ^{(1, j)} .
Further, at this time, the pixel information acquisition region other than the pixel information acquisition region P (i, 1) and the pixel information acquisition region P (1, j) is also imaged. The output value of the pixel information acquisition region P (i ^{, j)} is stored in the storage unit 7 as d ^{(i, j)} .

further,
c ^(2,1) -D ^(1,1) = C ^(2,1)
This value C ^(2,1) is taken as the pixel value C ^(2,1) of the third image information region g (3,2) in the right direction and the second in the downward direction from the leftmost upper end of the photographed subject 5. Store in the storage unit 7.

further,
b ^(1,2) −D ^(1,1) = B ^(1,2)
This value B ^(1,2) is taken as the pixel value B ^(1,2) of the second image information area g (2,3) in the second right direction and the third in the lower direction from the upper left end of the subject 5 that has been photographed. Store in the storage unit 7.

further,
d ^(2,1) -C ^(2,1) = D ^(2,1)
This value D ^(2,1) is taken as the pixel value D ^(2,1) of the fourth image information area g (4,2) in the right direction and the second in the downward direction from the leftmost upper end portion of the photographed subject 5. Store in the storage unit 7.

further,
d ^(1,2) −B ^(1,2) = D ^(1,2)
This value D ^(1,2) is used as the pixel value D ^(1,2) of the second image information area g (2,4) in the second right direction and the fourth in the lower direction from the upper left end of the photographed subject 5. Store in the storage unit 7.

further,
a ^(2,2) -(D ^(1,1) + B ^(2,1) + C ^(1,2) ) = A ^(2,2)
This value A ^{(2, 2)} is taken as the pixel value A ^{(2, 2)} of the third image information area g (3, 3) in the third direction in the right direction and the third in the lower direction from the upper left end of the photographed subject 5. Store in the storage unit 7.

Similarly,
b ^(2,2) -(C ^(2,1) + D ^(2,1) + A ^(2,2) ) = B ^(2,2)
This value B ^{(2, 2)} is taken as the pixel value B ^{(2, 2)} of the fourth image information area g (4, 3) in the right direction and the third in the lower direction from the upper left end of the photographed subject 5. Store in the storage unit 7.

Similarly,
c ^(2,2) -(B ^(1,2) + D ^(1,2) + A ^(2,2) ) = C ^(2,2)
This value A ^{(3, 4)} is taken as the pixel value C ^{(2, 2)} of the third image information region g (3, 4) in the right direction and the fourth in the downward direction from the upper left end of the photographed subject 5. Store in the storage unit 7.

Similarly,
d ^(2,2) -(A ^(2,2) + B ^(2,2) + C ^(2,2) ) = D ^(2,2)
This value D ^{(2, 2)} is taken as the pixel value D ^{(2, 2)} of the fourth image information region g (4, 4) in the right direction and the fourth in the downward direction from the upper left end of the photographed subject 5. Store in the storage unit 7.

In this way, the pixel values are a ^{(i, j)} , b ^{(i, j)} , c ^{(i, j)} , d ⁽ so as to leave the corresponding pixel values in the image information area g (m, n) to be obtained. ^It can be calculated by subtracting other pixel values on the upper and left sides from any of ^{i, j)} .
That is, the 2i−1th image information area g (2i−1,2j−1) in the right direction and the 2j−1th direction in the downward direction from the upper left end of the subject 5 where the pixel value A ^{(i, j)} is captured. ^Is stored in the storage unit 7 as a pixel value A ^{(i, j)} .
That is, the pixel value A ^{(i, j)} = a ^{(i, j)} − (D ^{(i−1, j−1)} + B ^{(i−1, j} ) of the image information area g (2i−1,2j−1). ⁾ + C ^{(i, j-1)} ).

Pixel value ^{B (i, j)} 2i-1-th to the right from the leftmost top end of the object 5 was taken, the pixel value ^{B (i} the downward 2j-th information area g (2i, 2j-1) ^{, J)} are stored in the storage unit 7.
That is, the pixel value B ^{(i, j)} = b ^{(i, j)} − (C ^{(i, j−1)} + D ^{(i, j−1)} + A ^{(i ) of} the image information region g (2i, 2j−1). ^{, J)} ).

Pixel values ^{C (i, j)} 2i th in the right direction from the leftmost upper portion of the object 5 was taken, the pixel value ^{C (i} the downward 2j-1-th picture information area g (2i-1,2j) ^{, J)} are stored in the storage unit 7.
That is, the pixel value C ^{(i, j)} = c ^{(i, j)} − (B ^{(i−1, j)} + D ^{(i−1, j)} + A ^{(i ) of} the image information area g (2i−1,2j). ^{, J)} ).

Pixel value ^{D (i, j)} 2i th in the right direction from the leftmost upper portion of the object 5 was taken, the pixel value ^{D (i, j)} of the 2j-th information area g downward (2i, 2j) as Store in the storage unit 7.
That is, the pixel value of the image information area g (2i, 2j) = d ^{(i, j)} − (A ^{(i, j)} + B ^{(i, j)} + C ^{(i, j)} ).

In this way, by moving the image sensor 21 to a predetermined imaging position, that is, the patterns I to IV, the image sensor 21 is moved from the basic position [1] to the movement position [2] to the movement position [3]. The imaging information can be obtained by shifting to [4]. Based on the difference in the imaging information, the pixel information of the subject 5 can be calculated as the pixel value of the sub-pixel corresponding to a quarter as described above. Then, the pixel information of the subject 5 calculated as the pixel value of the sub-pixel equivalent to a quarter is stored as image information in association with the position of the subject 5. That is, it is possible to obtain image information with approximately four times the resolution using the pixel information acquisition area P (i, j) for one pixel.
As described above, the sub-pixel information of all the pixels of the subject 5 can be separated from the information obtained in a state where the uppermost part and the leftmost part are partially shielded by the light shielding film 26 of the image sensor 21 as shown in FIG. it can.

  With reference to FIG. 15, a flow of processing in which the imaging apparatus 10 according to the present embodiment acquires image information of the subject 5 will be described. The following processing is performed under the control of the control unit 4.

  First, the control unit 4 controls the drive unit 3 to set the position of the image sensor 21 (step S101). Specifically, the control unit 4 controls the driving unit 3 to place the imaging element 21 at the imaging point F at which the subject 5 can be imaged.

Subsequently, the image pickup device 21 is moved in a predetermined direction by a predetermined amount and imaged (step S102).
Specifically, the control unit 4 controls the drive unit 3 so that the image sensor 21 captures the subject 5 in sub-pixel units in the directions X and Y of the surface perpendicular to the incident light. An image is taken from a predetermined imaging position (from the basic position [1] to the movement position [4] via the movement position [2] to the movement position [3]).

Subsequently, an output value (imaging information) from the imaging element 21 resulting from the imaging is input (step S103).
Specifically, the control unit 4 controls the imaging unit 2 to perform imaging, and each pixel information acquisition region P (1,1), P (2,1), P (3,1) of the imaging element 21. ,..., P (1,2), P (1,3),..., P (i, j) are input and output values (imaging information) are input to the storage unit 7. Remember.

Subsequently, a pixel value is calculated (step S104).
Specifically, the control unit 4 controls the pixel information acquisition regions P (1,1), P (2,1), P (3,1),. ), P (1,3),..., P (i, j) output values (imaging information) at a plurality of imaging positions, and pixel values of sub-pixels that are pixel information of each subject 5 Is calculated and stored in the storage unit 7.

  In step S <b> 104, when the control unit 4 calculates the pixel values of the sub-pixels that are all the pixel information of the subject 5, the calculated all pixel values are associated with the position information of the corresponding subject 5 in the storage unit 7. And stored as image information of the subject 5 (step S105). Further, an image is displayed based on the calculated all pixel values as necessary. Specifically, the control unit 4 controls the display unit 8 to display an image of the subject 5 based on all the pixel information of the subject 5 stored in the storage unit 7. This completes the image information acquisition process.

The imaging device 10 according to the present embodiment has an imaging element 21 that has a pixel information acquisition region P (i, j) that is a light receiving surface having a predetermined area and is partially shielded in an L shape from an object 5. Imaging is performed by moving light in four patterns I to IV. Accordingly, a step (step S103) of acquiring output values (imaging information) in different patterns I to IV from the light receiving element U (i, j) of the image pickup element 21 and a light receiving element U (i of the image pickup element 21). , J), a pixel value (pixel information) corresponding to the amount of light received in an area smaller than the light receiving area of each light receiving element (i, j) of the image pickup device 21 is calculated from a plurality of output values (image pickup information). An imaging method including a step (step S104) and a step (step S105) of storing the pixel value (pixel information) calculated in step S104 as image information in association with the position of the subject 5 is executed.
In such an imaging method, the image sensor 21 having the light shielding film 26 is displaced, so that the pixel value (A ⁽² ) of the image information region g (m, n) of the subject 5 is further reduced based on the output value of the image sensor 21. ^{i, j)} , B ^{(i, j)} , C ^{(i, j)} , D ^{(i, j)} ) can be obtained, and the pixel density of the light receiving element U (i, j) must be increased. There is no. That is, using an image sensor with low pixel density and low cost, it is possible to acquire a four times higher pixel image in this embodiment. Therefore, an image with high resolution can be acquired without spending money on the equipment.

  In addition, since the light-shielding film 26 is formed on the light-receiving surface of the image sensor 21, diffracted light to the light-shielding area of the image sensor 21 is emitted from light incident near the boundary between the light-receiving area of the image sensor 21 and the light-shield film 26. Does not occur. Further, stray light that directly enters the light shielding area of the image sensor 21 from the vicinity of the boundary between the light receiving area of the image sensor 21 and the light shielding film 26 does not occur. For this reason, the influence of noise in the light shielding area of the image sensor 21 can be reduced.

  In the present embodiment, the process of photographing the subject 5 by shifting the pixel area by a distance corresponding to one half of one pixel using the image sensor 21 is performed in the image information area g (1, 1 A case has been described in which the subject 5 is repeatedly photographed until the imaging information (output value) corresponding to one pixel is acquired. That is, the case where the subject 5 is photographed with the accuracy of the sub-pixel obtained by dividing one pixel into four has been described as an example. However, the distance for shifting the pixel region using the imaging element having the light shielding film is not limited to a distance corresponding to a half of one pixel. Further, the direction in which the pixel region is shifted may be different between the vertical direction and the horizontal direction. Assuming that X and Y are arbitrary natural numbers, the subject 5 is imaged by shifting the subject 5 in the vertical and horizontal directions at a distance corresponding to 1 / X of 1 pixel and 1 / Y of 1 pixel, respectively. When the information area g (1, 1) is repeated until the imaging information (output value) corresponding to one pixel is acquired, that is, one pixel is divided into an integer number obtained by multiplying X by Y. The same procedure can be used when shooting with high accuracy.

  As described above, the imaging apparatus 10 according to the present embodiment has the pixel information acquisition region P (i, j) for one pixel, and part of the light receiving elements U (i, j) is incident light from the subject 5. The image pickup device 21 in which a light shielding film 26 that partially shields light is selectively formed is provided. Here, i is a natural number of 1 or more, and j is an arbitrary natural number of 1 or more. With this configuration, the imaging apparatus 10 according to the present embodiment has the image information region g (m, n) equal to the remainder of the portion shielded by the light shielding film 26 of the pixel information acquisition region P (1, 1) at the leftmost end. An output value capable of calculating the pixel value can be obtained. Therefore, the imaging apparatus 10 can obtain a fine output value that reflects the degree of the light shielding state, which is different from the output value in the state where the light receiving surface is not shielded.

  Furthermore, the imaging device 10 according to the present embodiment detects the light receiving element U (i, j) from the difference between a plurality of pieces of imaging information obtained by imaging the pixel information acquisition region P (i, j) with the four patterns I to IV. ) And a storage unit that stores the pixel value calculated by the control unit 4 in association with the position of the subject 5. 7 can be further provided. Therefore, the imaging apparatus 10 according to the present embodiment has a pixel corresponding to the amount of light received in an area smaller than the light receiving surface of the light receiving element U (i, j) due to the difference between a plurality of pieces of imaging information in which the patterns I to IV are different. It is possible to calculate a value and store the calculated pixel value in association with the position of the subject 5. Therefore, the imaging apparatus 10 can acquire finer image information of the subject 5 based on the pixel value corresponding to an area smaller than each light receiving surface of the light receiving element U (i, j).

  Furthermore, according to the imaging apparatus 10 of the present embodiment, different patterns I to IV in which the position of the imaging element 21 on which the light shielding film 26 is formed are displaced by a distance smaller than the dimension of the light receiving element U (i, j). The drive part 3 to which it moves is provided. With this configuration, the imaging apparatus 10 according to the present embodiment can be displaced by a distance smaller than the dimension of the light receiving element U (i, j) of the imaging element 21, and therefore an output value (imaging information) corresponding to the displacement. ), It is possible to obtain finer image information of the subject 5.

  Therefore, finer image information of the subject 5 can be obtained without increasing the pixel density of the light receiving element and without having to connect the images. That is, a high pixel image can be acquired using a low pixel image sensor. Therefore, the imaging apparatus 10 according to the present embodiment can acquire an image with high resolution by a low-cost method that does not cost equipment.

In step S104, the imaging apparatus 10 according to the present embodiment determines, for example, imaging information (a ^{(i, j)} , b ^{(i, j)} , c ^{(i, j )} from differences in imaging information depending on the patterns I to IV. ⁾ , D ^{(i, j)} ) to the left and upper pixel information (pixel values A ^{(i, j)} , B ^{(i, j)} , C ^{(i, j)} , D ^{(i, j))} Etc.) is subtracted to execute an imaging method including a step of obtaining a target pixel value.

  In the present embodiment, the case where the subject 5 is photographed with the accuracy of subpixels obtained by dividing one pixel into four parts has been described. However, the present invention is not limited to this. In the present embodiment, the image sensor 21 having the light-shielding film 26 shields an area corresponding to one-half of one pixel in the vertical direction and the horizontal direction from the uppermost left end with respect to the two sides of the subject 5. In this state, the subject 5 is photographed by repeating the photographing process by shifting the image sensor 21 in the vertical direction and the horizontal direction for each distance corresponding to one-half of one pixel. It is not limited.

For example, if X and Y are arbitrary natural numbers, they correspond to X-1 of X for one pixel and Y-1 of Y for one pixel in the vertical and horizontal directions, respectively, with respect to the two sides of the subject 5. A process of taking an image by using an image pickup device in a state where a region to be shielded is shaded and shifting in the vertical direction and the horizontal direction for each distance corresponding to 1 / X of 1 pixel and 1 / Y of 1 pixel. Alternatively, the subject 5 may be photographed by repeating an integer obtained by multiplying Y by Y. Thereby, it is possible to take an image with the accuracy of subpixels obtained by dividing one pixel by an integer obtained by multiplying X by Y by the same method.
In the imaging apparatus according to this embodiment, the number of pixels per pixel divided by the light-shielding film can be changed to arbitrarily increase the resolution of the image to be captured or the number of pixels constituting the image to be captured.

That is, the drive unit 3 drives the image pickup device having the light shielding film to the image pickup positions from the basic position [1] to the movement position [4] by a unit corresponding to a quarter of one pixel.
The imaging element 21 performs imaging whenever it is driven to the imaging position by the drive unit 3. The storage unit 7 acquires imaging information (output value) based on the signal charge generated by the imaging element 21. The storage unit 7 constitutes an imaging information acquisition unit.
Further, the control unit 4 determines one of the subjects 5 based on a difference in imaging information acquired for each imaging position where the imaging element 21 is driven by the driving unit 3, that is, on a difference in signal charge generated by the imaging element 21 for each imaging position. Pixel information (pixel value) corresponding to the unit is calculated in units smaller than one pixel. The control unit 4 constitutes a pixel information calculation unit.
The control unit 4 stores the pixel information calculated in this way in the storage unit 7 as image information in association with the position of the subject 5. The storage unit 7 constitutes an image information storage unit.

  Although the light shielding film 26 has an L shape, the light shielding film 26 may have a shape other than the L shape as long as it is suitable for shielding at least two sides of the image sensor 21.

  As described above, according to the present invention, finer image information of a subject can be obtained without increasing the pixel density of the light receiving element and without having to connect the images. That is, a high pixel image can be acquired using a low pixel image sensor. Therefore, the imaging apparatus of the present invention can acquire a high-resolution image by a low-cost method that does not cost equipment.

  In the image pickup apparatus of the present invention, since it is only necessary to move an image sensor by a unit smaller than one pixel and perform imaging, the subject to be imaged is divided into a plurality of parts, and the subject portion is moved while moving the image sensor. Compared with the conventional method in which photographing is repeated several times each time, the processing is very simple. Therefore, according to the present invention, it is possible to obtain a high-resolution image by shortening the time required for moving the image sensor and shortening the total time required for imaging.

  In the present invention, pixels corresponding to a part of a subject based on signal charges (imaging information) generated by each pixel information acquisition region obtained by imaging each time an imaging element having a light shielding film is arranged at an imaging position. The information can be calculated in units smaller than one pixel, and the calculated pixel information can be stored as image information in association with the position of the subject.

  The image sensor in which the light-shielding film is formed in the present invention has the remaining one row in one pixel of the pixel information acquisition region in which the light-shielding film is arranged in the vertical direction of the image sensor and one of the pixel information acquisition regions arranged in the horizontal direction. Image at least one of the remaining one column of pixels in units corresponding to 1 / X of 1 pixel or 1 / Y of 1 pixel in the vertical and horizontal directions, where X and Y are predetermined natural numbers, respectively. What is necessary is just to drive an element.

  In the present invention, imaging is performed every time the imaging element configured as described above is arranged at an imaging position. Then, based on signal charges (imaging information) generated by the imaging elements at the plurality of imaging positions, the pixel information corresponding to a part of the subject is multiplied by Y of X for one pixel. It can be calculated in units.

  As described above, according to the present invention, image information can be acquired in units of sub-pixels by moving the image sensor on which the light-shielding film is formed in units smaller than one pixel.

  In the present invention, since the light shielding film is formed on the light receiving surface of the image sensor, diffracted light to the light shielding area of the image sensor is generated from the light incident near the boundary between the light receiving area of the image sensor and the light shielding film. hard. Further, stray light that directly enters the light-shielding area of the image sensor from the vicinity of the boundary between the light-receiving area of the image sensor and the light-shielding film is unlikely to occur. For this reason, it is possible to reduce the influence of noise in the light shielding area of the image sensor. Thereby, the accuracy of the imaging information obtained by the imaging device is improved, and more accurate image information can be acquired in units of subpixels.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the present invention. is there.
For example, in the above-described embodiment, the case where the subject is photographed with the accuracy of the sub-pixel obtained by dividing one pixel into four has been described, but the present invention is not limited to this.
For example, if M is an arbitrary natural number, only one incident light for 1 / M pixels is incident on one row or one column of a pixel information acquisition region for acquiring pixel information for one pixel of the image sensor, and the remaining incident light In the case of imaging by moving an image sensor having a light shielding plate that shields light, an area where incident light of 1 / M pixels is incident on the pixel information acquisition area P (1, 1) of the image sensor It is only necessary to acquire the imaging information by imaging the subject M times while moving the imaging element so as to be different within the range of the upper left pixel, and calculate pixel information corresponding to 1 / M pixels from the difference in the imaging information.

  Note that the present invention can be applied not only to an apparatus for measuring the position of a workpiece but also to an electronic apparatus generally provided with an image sensor. The series of processes described above can be executed by hardware or can be executed by software.

  When a series of processing is executed by software, a program constituting the software is installed on a computer or the like from a network or a recording medium. The computer may be a computer incorporated in dedicated hardware. The computer may be a computer capable of executing various functions by installing various programs, for example, a general-purpose personal computer.

  In the present specification, the step of describing the program recorded on the recording medium is not limited to the processing performed in time series along the order, but is not necessarily performed in time series, either in parallel or individually. The process to be executed is also included.

2 ... Imaging unit 3 ... Drive unit 4 ... Control unit (pixel information calculation unit)
5 ... Subject 7 ... Storage unit (imaging information acquisition unit, image information storage unit)
DESCRIPTION OF SYMBOLS 8 ... Display part 10 ... Imaging device 21 ... Imaging element 26 ... Light shielding film

Claims (2)

An image sensor having a plurality of pixel information acquisition regions arranged in the vertical direction and the horizontal direction to convert incident light from a subject to acquire pixel information for one pixel;
A light-shielding film formed on a light-receiving surface of the image sensor, wherein one row of one end in a width less than one pixel in the vertical direction and one end in a width less than one pixel in the horizontal direction in the plurality of pixel information acquisition regions A light-shielding film covering at least one region of the row;
A drive unit that moves the image sensor step by step to a plurality of image capture positions shifted by units smaller than one pixel;
An imaging information acquisition unit that acquires imaging information obtained by imaging of the imaging element each time the imaging element is moved to the imaging position by the driving unit;
A pixel information calculation unit that calculates pixel information of the subject in units smaller than one pixel based on a difference in imaging information acquired for each imaging position by the imaging information acquisition unit;
An image information storage unit that stores the pixel information calculated by the pixel information calculation unit as image information in association with the position of the subject;
An imaging apparatus comprising: An image sensor having a plurality of pixel information acquisition regions that are arranged in the vertical direction and the horizontal direction to convert incident light from a subject to acquire pixel information for one pixel, and a light shield formed on a light receiving surface of the image sensor A light-shielding film that covers at least one region of one row in a width less than one pixel in a vertical direction and one column in a width less than one pixel in a horizontal direction in the plurality of pixel information acquisition regions An imaging method for imaging a subject using an imaging device comprising:
Stepwise moving the image sensor to a plurality of imaging positions shifted by units smaller than one pixel by a driving unit;
Acquiring imaging information obtained by imaging of the imaging element each time the imaging element is moved to the imaging position by the driving unit by an imaging information acquisition unit;
Calculating pixel information of the subject in units smaller than one pixel based on a difference in imaging information acquired for each imaging position by the imaging information acquisition unit by a pixel information calculation unit;
Storing the pixel information calculated by the pixel information calculation unit in association with the position of the subject as image information by an image information storage unit;
An imaging method comprising:

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