JP2010239291A - Imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an imaging apparatus capable of acquiring a spectrum of illumination light in a photographic environment in simple configuration, and attaining an appropriate white balance control using the spectrum, or capable of appropriately controlling colors. <P>SOLUTION: The present invention relates to an imaging apparatus comprising an imaging device for obtaining image data by performing photoelectric conversion on light that is imaged through an optical system, comprising: an optical distance change unit for changing an optical distance of partial light incident through the optical system; a spectral unit for separating light of which the optical distance has been changed, and making it incident to a part of the imaging device; an image processing unit for producing spectrum data based on the image data obtained by performing the photoelectric conversion on the light incident through the spectral unit by means of the imaging device; and an adjustment unit for adjusting the image data obtained by the imaging device on the basis of the spectrum data. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an imaging apparatus including an imaging element.

  2. Description of the Related Art In recent years, an imaging system including an imaging element such as a charge coupled device (CCD) or a complementary metal-oxide semiconductor (CMOS) provided in a video camera or a digital camera has been widely used. In these imaging systems, for the purpose of knowing the illumination light of the imaging environment and the spectral characteristics of the subject, an imaging system having a spectral spectrum acquisition means for acquiring light by wavelength decomposition has been proposed in recent years.

  For example, the spectroscopic camera described in Patent Document 1 includes a continuous wavelength filter on a part of the front surface of an image sensor, and separates part of light from a subject by an optical spectrometer. The separated light is imaged by an imaging optical system, and the position of the mask is changed to take out light at an arbitrary position in the imaged image and enter the continuous wavelength filter through an optical fiber. The transmitted light and the remainder of the light separated by the optical spectrometer are simultaneously incident on the image sensor, and a subject image and a spectral spectrum at an arbitrary position of the subject can be acquired.

  In addition, the camera system described in Patent Document 2 includes an illumination unit that illuminates a subject, and a spectroscopic unit that measures spectral characteristics of reflected light from a subject incident through a photographing optical system. The illumination unit performs illumination of the subject. The spectral characteristic of the subject is calculated based on the measurement result obtained by the spectroscopic means, and the spectral characteristic of the photographing light source is calculated using this and the spectroscopic measurement result obtained when the subject is not illuminated by the illumination means. Based on the spectral characteristics of the photographing light source, white balance correction is performed on the photographed image to realize easy and appropriate white balance control.

JP-A 64-009326 Japanese Patent Laid-Open No. 2002-320231

  However, the spectroscopic camera described in Patent Document 1 has a complicated configuration such as the use of an optical fiber, and can acquire the spectral spectrum of the subject, but it is not possible to acquire the spectral spectrum of the illumination light in the shooting environment. There is a problem that it is difficult to obtain or estimate the spectrum of illumination light. In the camera system described in Patent Document 2, a spectral spectrum of a subject under a specific illumination whose spectral spectrum is known in advance is acquired, and an illumination light spectral spectrum in an actual photographing environment is acquired based on the acquired spectral spectrum. ing. For this reason, it is necessary to obtain a spectral spectrum twice under specific illumination and under actual illumination, and the procedure is complicated, and the processing load is increased because the spectral spectrum of imaging illumination is obtained by calculation.

  The present invention has been made in view of such circumstances, and obtains a spectral spectrum of illumination light in a shooting environment with a simple configuration, and enables appropriate white balance control using this, or provides a color. An object of the present invention is to provide an imaging apparatus that can be appropriately controlled.

  The present invention is an image pickup apparatus including an image pickup device that obtains image data by photoelectrically converting light imaged through an optical system, and changes an optical distance of a part of light incident through the optical system. Based on the changing unit, the spectroscopic unit that splits the light whose optical distance has been changed, and makes the light incident on a part of the image sensor, and the image data obtained by photoelectrically converting the light incident through the spectroscopic unit by the image sensor An image processing unit that generates the spectral data; and an adjustment unit that adjusts the image data obtained by the imaging device based on the spectral data.

  The present invention is characterized in that the optical distance changing unit changes the optical distance of the light by transmitting the light into a member of an optical material having a predetermined refractive index.

  The present invention is an imaging apparatus including a first imaging device that obtains image data by photoelectrically converting light imaged through an optical system, and obtains spectral data by photoelectrically converting the dispersed light. 2 that separates the light incident through the image sensor and the optical system into two, makes one light incident on the first image sensor, and makes the other light incident on the second image sensor Between the light separation unit and the second image sensor so that the distance from the light separation unit is different from the distance between the light separation unit and the first image sensor. Based on spectral spectrum data obtained by photoelectrically converting the light incident through the spectroscopic unit using the second image sensor. Obtained by the first image sensor. Characterized in that an adjusting unit for adjusting the image data.

  The present invention is characterized in that the spectroscopic section is composed of a transmission type dielectric multilayer filter.

  The present invention is characterized in that the adjustment unit adjusts image data by adjusting a gain of the imaging element.

  According to the present invention, it is possible to acquire a spectral spectrum of illumination light in a shooting environment without performing complicated calculations, in addition to simple configuration, and to perform more accurate white balance control and appropriate colors. The effect that control becomes possible is acquired.

1 is a block diagram illustrating a configuration example of an imaging apparatus according to a first embodiment of the present invention. It is a figure which shows the relationship between the imaging optical system in an imaging device, an imaging part, and a to-be-photographed object. It is a figure which shows the relationship between the depth of field and focus depth in an imaging device. It is explanatory drawing which shows the positional relationship of the imaging optical system shown in FIG. 1, an imaging part, an optical distance change part, and a spectroscopy part. It is the enlarged view to which the imaging part shown in FIG. 4, the optical distance change part, and the spectroscopy part were expanded. It is explanatory drawing which shows the range of the light which injects into the spectroscopy part shown in FIG. It is a figure which shows the structure of the spectroscopy part shown in FIG. It is explanatory drawing which shows the principle of a Fabry-Perot interferometer. It is explanatory drawing which shows an example of the arrangement position of the spectroscopy part shown in FIG. It is explanatory drawing which shows an example of the arrangement position of the spectroscopy part shown in FIG. It is a figure which shows the angle characteristic of the spectroscopy part shown in FIG. It is a figure which shows the angle characteristic of the spectroscopy part shown in FIG. It is a figure which shows the spectral spectrum of the fluorescent lamp acquired using the spectroscopy part shown in FIG. It is a figure which shows the spectral spectrum of the fluorescent lamp acquired using the spectroscopy part shown in FIG. It is a figure which shows the modification structural example of the imaging device shown in FIG. It is a block diagram which shows the example of 1 structure of the imaging device by the 2nd Embodiment of this invention. It is explanatory drawing which shows the positional relationship of the imaging optical system shown in FIG. 16, a light separation part, an imaging part, and a spectroscopy part.

<First Embodiment>
Hereinafter, an imaging device according to a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a configuration of an imaging apparatus according to the first embodiment of the present invention. The imaging apparatus 100 includes an interchangeable lens unit 101 and a main body unit 102. The interchangeable lens unit 101 includes an imaging optical system 103 configured by an optical lens. The main body unit 102 includes an imaging unit 104, an optical distance changing unit 105, a spectroscopic unit 106, an image processing unit 107, a data holding unit 108, and a white balance adjustment unit 109 that is an adjustment unit that adjusts image data. In FIG. 1, in order to distinguish an optical path from an electric signal line, an optical path of light is indicated by a thick white arrow, and a flow of an electric signal or data is indicated by a thin arrow.

  The imaging unit 104 is configured with a CCD imaging device, performs photoelectric conversion, and outputs imaging data. The optical distance changing unit 105 is made of an optical member such as glass and changes the optical distance (optical path length) of the light emitted from the imaging optical system 13. The spectroscopic unit 106 includes a transmissive dielectric multilayer filter, and decomposes the light whose optical distance has been changed by the optical distance changing unit 105 for each wavelength band. The light split by the spectroscopic unit 106 enters the imaging unit 104 and is output from the imaging unit 104 as spectral spectrum data. The imaging unit 104 outputs the image data obtained by imaging the imaging target and the spectral data spectrally separated by the spectroscopic unit 106. Here, the data composed of the image data and the spectral data is referred to as imaging data. The image processing unit 107 performs image processing on imaging data output from the imaging unit 104. The data holding unit 108 is configured by a memory, an SD card, or the like, and holds image data after image processing output from the image processing unit 107. The white balance adjustment unit 109 performs gain adjustment for each pixel of the imaging unit 104 based on the image data and spectral spectrum data output from the image processing unit 107.

  Light from the imaging target is incident through the imaging optical system 103, and most of the incident light is incident on the imaging unit 104. The imaging unit 104 performs photoelectric conversion and outputs it as imaging data. A part of the incident light passes through the optical distance changing unit 105 and then enters the spectroscopic unit 106. The spectroscopic unit 106 splits the light for each wavelength and enters the imaging unit 104. Since the imaging unit 104 acquires the intensity corresponding to each wavelength according to the pixel position, it is possible to obtain a spectral spectrum. The imaging unit 104 outputs the acquired imaging data to the image processing unit 107, and the image processing unit 107 separates the spectral spectrum data and the image data from the imaging data, and the image data is sent to the data holding unit 108 and the spectral spectrum data and the image data. Data is output to the white balance adjustment unit 109. The white balance adjustment unit 109 sets the gain of the imaging unit 104 from the image data and the spectral spectrum.

Next, a general image acquisition principle in the imaging apparatus 100 will be described with reference to FIG. FIG. 2 is a diagram illustrating a positional relationship between the subject 111, the imaging optical system 103, and the imaging unit 104. In FIG. 2, the imaging optical system 103 is expressed by a single convex lens for simplicity. The focal length of the imaging optical system 103 is f, the distance between the subject 111 and the imaging optical system 103 is a, the distance between the imaging optical system 103 and the imaging surface 112 in the imaging unit 104 is b, and the subject 111 is on the imaging surface of the imaging unit 104. It is assumed that an image is formed at. At this time, the distance a, the distance b, and the focal length f satisfy the expression (1).
1 / a + 1 / b = 1 / f (1)

  When this positional relationship is established, the subject 111 is imaged on the imaging unit 104, and a sharp and focused image can be obtained. However, it is not always necessary to strictly satisfy this relationship, and it is acceptable at a certain distance. FIG. 3 shows this. In the imaging surface 112, d in the figure indicates an allowable range of deviation of the imaging position. In general, d corresponds to the size of one pixel of a CCD image pickup device that is the image pickup unit 104. If the shift of the imaging position is equal to or less than the size of one pixel, a blur-free image can be obtained even if the imaging position is shifted. The distance that allows an image even if the imaging surface 112 indicated by e in the figure is moved is referred to as the depth of focus, and the distance c in the figure that indicates the position of the subject that forms an image in this range is referred to as the depth of field.

  Based on the above, the imaging apparatus 100 shown in FIG. 1 will be described with reference to FIG. An optical distance changing unit 105 and a spectroscopic unit 106 are arranged on the lower front surface of the imaging unit 104. FIG. 5 is an enlarged view for explaining details of the optical distance changing unit 105, the spectroscopic unit 106, and the imaging unit 104 shown in FIG. The optical distance changing unit 105 is an optical glass (for example, BK7) that is an optical material used in the visible light region. The refractive index of the optical glass using BK7 is about 1.51. As indicated by reference numeral A in FIG. 5, light incident at an angle with respect to the incident-side surface of the optical distance changing unit 105 (incident at an angle not perpendicular to the incident-side surface) is optical distance changing unit 105. The optical path indicated by the solid line is advanced by refraction with respect to the optical path when there is no optical path (optical path indicated by the wavy line).

  As a result, light that greatly exceeds d, which is a range per pixel in which a blur-free image can be obtained, enters the spectroscopic unit 106. That is, the focal plane of the light after passing through the spectroscopic unit 106 is formed at a position shifted from the original focal plane. For example, if light corresponding to an image as shown in FIG. 6A is incident on the imaging optical system 103, the light incident on the spectroscopic unit 106 is illustrated when the optical distance changing unit 105 is not present. Only the light corresponding to the portion indicated by the dotted line 6 (b) is obtained. On the other hand, when the optical distance changing unit 105 is provided, the light is refracted as described above, and the light of the entire area indicated by t is mixed and incident on the spectroscopic unit 106. When this light is incident on the imaging unit 104, it is possible to obtain a spectral spectrum of the light corresponding to the area t as shown in FIG. 6B.

  In each pixel of the imaging unit 104, when a color image is captured, one of RGB color filters is generally formed. In a pixel to which light after passing through the spectroscopic unit 106 is incident, if there is a sufficient number of pixels with respect to the dispersed light, the light may be received by each of RGB, and the intensity for each wavelength may be obtained from each value. The accuracy drops. In addition, when the number of pixels is not sufficient, for example, when long-wavelength (red) light is incident on the B filter, the light is cut by the filter, and the intensity of the wavelength component cannot be acquired. For this reason, in the pixel on the imaging unit 104 to which the light after passing through the spectroscopic unit 106 is incident, a color filter is formed so as to transmit in all the wavelength ranges from 380 nm to 780 nm that are visible, or the color filter is not provided. The configuration is as follows.

  In this way, the light that has passed through the spectroscopic unit 106 using the optical distance changing unit 105 is not focused on the imaging unit 104 that is the original focal plane, so that the spectral spectrum of the subject itself, that is, the spectral reflection of the object. When light that is a mixture of reflected light in a certain area instead of the characteristics is incident on the spectroscopic unit 106, it is possible to obtain a spectral spectrum of light that is close to the ambient light that irradiates the subject. Note that the spectral sensitivity characteristic for each wavelength of the imaging unit 104 needs to be held in advance, and the light intensity for each wavelength obtained by the imaging unit 104 needs to be corrected.

  Here, with reference to FIG. 7, the principle of spectroscopy will be described for the spectroscopic unit 106 formed of a dielectric multilayer filter. FIG. 7A is a top view of the spectroscopic unit 106. The thickness increases in the direction A in the figure. FIG. 7B is an enlarged view of a portion indicated by a dotted line in FIG. For simplicity of explanation, the thickness change is ignored in this figure. As shown in FIG. 7B, the spectroscopic unit 106 is configured such that the high refractive index layers 121 and the low refractive index layers 122 are alternately stacked, and the low refractive index layer is formed in two layers only near the center. Examples of the material used for each layer include zinc sulfide for the high refractive index layer 121 and cryolite for the low refractive index layer 122. The light incident on the spectroscopic unit 106 is transmitted through only a certain wavelength of light according to the same principle as the Fabry-Perot interferometer.

The Fabry-Perot interferometer is, as shown in FIG. 8, arranged with an interval t in which mirrors 123 are parallel, and an air layer therebetween. The surfaces facing the mirrors 123 have high reflection characteristics. As for the light incident at an angle θ from the left direction in the figure, only the light having the wavelength λ given by the equation (2) is intensified by interference and emitted in the right direction in the figure.
mλ = t cos θ (2)
Here, m is an integer. The remaining lights will cancel each other. Thus, it becomes possible to extract only light of a specific wavelength.

  The thickness of each layer of the spectroscopic unit 106 is λ / 4, where λ is the wavelength of light to be transmitted. The portion where the two low refractive index layers 122 at the center are aligned corresponds to the Fabry-Perot air layer, and the remaining layers serve as mirrors, so that only light of a specific wavelength λ can be extracted. As shown in Fig. 7 (a), the wavelength changes in the longitudinal direction (A direction in Fig. 7 (a)), so that the wavelength of the transmitted light varies depending on the position. It becomes. Note that the material and the number of layers of the multilayer filter are not limited thereto, and a metal film filter for infrared cut may be integrally formed.

  In FIG. 4, an example in which the spectroscopic unit 106 is arranged at the lower end of the imaging unit 104 is shown. However, the present invention is not limited to this position, and may be arranged at the upper end. Further, as shown in FIG. It may be arranged at both the lower end and the lower end. Moreover, you may arrange | position at a right end and a left end, and as shown in FIG. As described above, by providing the spectroscopic unit 106 and the optical distance changing unit 105 at the end of the image capturing unit 104, it is possible to simultaneously acquire a spectral spectrum that is close to the ambient light to be imaged as well as an image. Further, by arranging a plurality of arrangements such as left and right and up and down, it is possible to eliminate the influence of the subject included in the photographing target and obtain the spectrum spectrum of the ambient light with higher accuracy. For example, when there is only one spectroscopic unit 106 and the photographing target area incident on the spectroscopic unit 106 is covered with a blue subject, a spectral spectrum close to ambient light is acquired on the short wavelength side corresponding to blue. Although it is possible, the spectrum on the long wavelength side corresponding to red may not be obtained accurately, but by having a plurality, it is possible to reduce the influence of errors due to such object bias It is.

  The spectroscopic unit 106 composed of a dielectric multilayer filter has an angle characteristic, and when parallel light is incident, it becomes possible to accurately disperse the incident light, and an optical system is arranged so that the normally incident light is converted into parallel light. To do. When light having an angle instead of parallel light is incident, wavelength shift or the like occurs and an error occurs in the spectral spectrum. 11 and 12 are diagrams showing how the light transmitted through the spectroscopic unit 106 changes depending on the angle. As shown in FIG. 11, an imaging unit 104 and a spectroscopic unit 106 are arranged, and light is incident at an angle θ. As in FIG. 7, it is assumed that the wavelength of transmitted light becomes longer as it goes in the direction A, and when light comes from the direction of the arrow shown in the figure, the right direction and vice versa. The case where light comes from the left direction with respect to the normal line of the spectroscopic unit 106 as the direction is defined as the left direction.

  FIG. 12 shows changes in the spectral spectrum obtained by the imaging unit 104 after passing through the spectral unit 106 at each angle. Here, it is assumed that light having a single wavelength having a wavelength of about 558 nm is incident on the spectroscopic unit 106. The vertical axis represents the light intensity normalized with 1 being 0 degree, and the horizontal axis represents the wavelength. In the case of the left direction, it can be seen that the wavelength is shifted to the long wavelength side, and in the case of the right direction, it is shifted to the short wavelength side. Moreover, it turns out that intensity | strength is reducing large as an angle becomes large. This is due to the characteristic that the transmission position shifts to the short wavelength side with respect to the light refraction at the spectroscopic unit 106 which is a dielectric multilayer filter and the light having the angle of the multilayer filter.

  As described above, the error increases with respect to light having an angle. However, if it is within ± 10 degrees, the intensity is also changed within 10%, and the wavelength shift is relatively small. Here, it is data in which light of only 0 degrees, 10 degrees, and 20 degrees is incident, but in actuality, for example, light within 0 to 10 degrees is incident within ± 10 degrees, so the fluctuation of the peak position is not much. Due to the wavelength shift for each angle, a slightly broad spectrum is obtained.

  FIG. 13 shows a spectrum obtained by obtaining a spectrum of a general fluorescent lamp within ± 10 degrees. FIG. 13A shows a spectral spectrum inherent to a fluorescent lamp, and FIG. 13B shows a spectral spectrum obtained with a dielectric multilayer filter within ± 10 degrees. However, the sensitivity characteristics of the image sensor and the transmission characteristics of the filter are corrected. Referring to FIG. 13, it can be seen that a nearly accurate spectral spectrum can be obtained although there is a slight increase in the half-value width and a slight error in intensity at the peak portion. Although the spectroscopic unit 106 is disposed inside the imaging device 100, the light inside the imaging device 100 is light with a limited angle due to the light receiving angle characteristics of the imaging unit 104. Therefore, by arranging the spectroscopic unit 106 at a position after passing through the imaging optical system as in the present embodiment, light with a limited angle is incident and a spectroscopic spectrum can be obtained. Depending on the characteristics of the imaging unit 104, light exceeding ± 10 degrees may be incident, but the peak position and the like can be grasped although the error increases. Therefore, with such a configuration, a special optical system that collimates the light incident on the spectroscopic unit 106 is not required, and the spectral spectrum of ambient light using a dielectric multilayer film filter with a simple configuration can be obtained. Acquisition is possible.

  The image processing unit 107 processes imaging data output from the imaging unit 104. In the imaging data, image data to be imaged and spectral spectrum data are mixed. The image processing unit 107 separates the image data and the spectral spectrum, holds the image data in the data holding unit 108, and outputs the separated image data and spectral spectrum data to the white balance adjustment unit 109. At this time, the image processing unit 107 performs demosaicing, image compression in the JPEG format, and the like.

  The white balance adjustment unit 109 estimates the color temperature of the light source from the spectral spectrum data based on the image data and spectral spectrum data output from the image processing unit 107, and sets the gain for each pixel on the imaging unit 104 accordingly. decide. Since the spectral spectrum of the light source is integrated with the color matching function in the XYZ color system, the XYZ value is calculated, and the correlated color temperature can be obtained from this value. For this color temperature, for example, when the color temperature is high, R Processing is performed such as increasing the gain, decreasing the B gain, and decreasing the R gain and increasing the B gain when the color temperature is low. The gain for each color temperature can be applied in any one of a plurality of methods such as holding in advance in a table or calculating based on a calculation formula. Further, an average may be taken by comparing with the color temperature obtained from the image data. This is effective when there is a large bias in the color of the subject in the area from which the spectrum was acquired.

  Here, the color temperature is used, but when calculating from image data, the image is divided into a plurality of areas, the average of each area is calculated for each RGB, and the average value for each RGB of the area assumed to be white is calculated. There is a method to calculate and adjust the gain so that the RGB balance is almost the same, refer to the table using the color temperature from the spectral spectrum, calculate the gain, gain from the image and gain from the spectral spectrum The gain used for control may be determined using the average value of.

  As described above, this is effective when there is a large deviation in the color of the subject in the area where the spectrum is acquired. Also, the color temperature is not limited, and the characteristics of the RGB color filter of the image receiving unit 104 that receives light that does not pass through the spectroscopic unit 106 are retained, and the RGB color filters and the obtained spectral filters are obtained. Each value of RGB is calculated by integrating the spectrum. Then, these values may be compared to check the RGB balance, and the values of R and B may be adjusted so that all RGB values are the same. In this case, it means that control is performed so that RGB is the same after including all processing such as correction processing of gamma characteristics. In addition, RGB may not be completely the same for the purpose of leaving the atmosphere of the light source, and appropriate control changes depending on the situation.

  Moreover, the database regarding a light source may be provided and a light source may be determined by collating with the output spectrum data. As shown in FIG. 13, there is no problem in determining the light source as long as spectral spectra that are substantially the same can be acquired, but there is also a method of estimating the light source from the position of the peak wavelength when the error is large. FIG. 14 shows a spectral spectrum of a fluorescent lamp having a spectral spectrum different from that of the fluorescent lamp shown in FIG. The spectral spectrum is normalized using the maximum value. In the fluorescent lamp of FIG. 14A, there is no peak near 480 nm as shown in FIGS. 13A and 14B, and the light source can be specified. Further, comparing the spectral spectra of the fluorescent lamps of FIGS. 13 (a) and 14 (b), although the peak wavelength is substantially the same, the peak intensity around 430 nm with respect to the largest peak (near 540 nm) is greatly different. It can be seen that the discrimination is possible by looking at the ratio. As described above, it is possible to estimate the light source by using the position of the peak wavelength and its intensity ratio, and to estimate the ambient light that illuminates the imaging area even when the acquired light source spectral spectrum has a large error Is possible. When the light source cannot be identified, the gain for white balance adjustment may be determined only from the image data.

  Note that here, a single-lens digital camera is assumed, and the interchangeable lens unit 101 and the main body unit 102 are described separately. However, the imaging optical system 103 is provided in the main body unit 102 like a compact digital camera or a video camera. It may be done. In FIG. 2, for simplicity of explanation, a simple example in which the imaging optical system 103 is configured by one convex lens is shown, but it may be generally configured by a plurality of lenses. In addition, the interchangeable lens unit 101 may include a mechanism for focus adjustment.

  In addition, although the CCD image pickup device is used as the image pickup unit 104 here, the image pickup unit 104 is not limited to this and may be a CMOS or another image pickup device. The number of pixels in the area of the image capturing unit 104 that receives the light after passing through the spectroscopic unit 106 and the spectroscopic unit 106 is 400 pixels, where the spectroscopic unit 106 has a resolution from 380 nm to 780 nm. It is desirable to have the above number of pixels. Thereby, it becomes possible to acquire a spectral spectrum with high accuracy. However, when the accuracy of the required spectral spectrum is low, the present invention is not limited to this, and a lower resolution may be used. Also in the processing of the image processing unit 107, the compressed image format is not limited to JPEG, and may be other formats such as processing with RAW data or bitmap format, and data with means for determining exposure. It is not limited to the functions listed here, such as delivery. When storing only RAW data, the gain of the imaging unit 104 is processed later on a personal computer or the like, so the white balance adjustment unit 109 may not change the gain.

  Although the optical distance changing unit 105 is used here, since the refraction unit 106 itself undergoes refraction and the like, the focal position after transmission only by the spectroscopic unit 106 is shifted from the light receiving surface of the image sensor 104, or the focal point. It is also possible not to have. If the function of the optical distance changing unit 105 is integrated with the spectroscopic unit in this way, the optical distance changing unit 105 becomes unnecessary, and the present invention can be realized with a simpler configuration.

  Further, the configuration shown in FIG. 4 may be modified as shown in FIG. In FIG. 15, the optical distance changing unit 105 does not exist, but another imaging unit 131 different from the imaging unit 104 is provided. If the distance between the imaging optical system 103 and the imaging unit 104 is a, and the distance between the imaging optical system 103 and the imaging unit 131 is b, the distances a and b are different distances. Thus, by providing another imaging unit 131 and disposing the spectroscopic unit 106 on the front side, it is possible to shift the imaging unit 104 from the imaging unit 104 that is the focal plane of the imaging optical system 103, and the same as the configuration described above. Spectral spectrum data can be acquired.

  In addition, here, the adjustment unit is used as a white balance adjustment unit, and the obtained spectral spectrum of ambient light or the information of the determined light source is used for white balance adjustment, but may be used for color control. For example, a table that defines each color conversion matrix information corresponding to the light source is provided, and color conversion is performed by switching this matrix according to the light source, thereby matching the appearance of the real thing and the color under each light source, or coloring by each light source. It is possible to perform control such as finishing the image with high brightness.

<Second Embodiment>
Next, an imaging apparatus according to the second embodiment of the present invention will be described. In addition, the same code | symbol is attached | subjected about what functions the same as the imaging device 100 by 1st Embodiment, and the detailed description is abbreviate | omitted. FIG. 16 is a diagram illustrating a configuration example of an imaging apparatus according to the second embodiment of the present invention. The imaging apparatus 200 according to the present embodiment includes an interchangeable lens unit 101 and a main body unit 201. In FIG. 16, in order to distinguish the optical path from the electric signal line, the light optical path is indicated by a thick white arrow, and the flow of an electric signal or data is indicated by a thin arrow.

  The interchangeable lens unit 101 includes an imaging optical system 103 constituted by a lens. The main unit 201 includes an image pickup unit 104 that is a CCD image pickup device that acquires an image, a light separation unit 202 that is an optical member including a half mirror, and a transmission type dielectric multilayer filter that decomposes incident light for each wavelength. A spectroscopic unit 106, an image capturing unit 131 that receives light transmitted through the spectroscopic unit 106 and acquires a spectral spectrum, an image processing unit 107 that performs image processing on imaging data output from the image capturing unit 104, and a data storage unit 108 that stores image data The white balance adjustment unit 109 adjusts the gain of the imaging unit 104 based on the image data output from the image processing unit 107 and the spectral data output from the imaging unit 131.

  Light from the imaging target is incident through the imaging optical system 103 in the imaging apparatus 200 and is divided into two by the light separation unit 202. One is incident on the imaging unit 104 and is acquired as image data through photoelectric conversion. The other light enters the spectroscopic unit 106, where it is split for each wavelength and enters the imaging unit 131. Since the imaging unit 131 acquires the intensity corresponding to each wavelength in accordance with the pixel position, it is possible to obtain a spectral spectrum. The spectral data acquired here is sent to the white balance adjustment unit 109. The imaging unit 104 sends the acquired imaging data to the image processing unit 107, and the image processing unit 107 sends the image data to the data holding unit 108 and the white balance adjustment unit 109. The white balance adjustment unit 109 sets a gain for each pixel on the imaging unit 104 from the image data and the spectral spectrum. In the following, details of parts different from the first embodiment will be described.

  FIG. 17 is a diagram for explaining the details of the configuration of the imaging apparatus 200 according to the present embodiment. The light transmitted through the imaging optical system 103 is divided into two lights by the light separation unit 202. One light is incident on the imaging unit 104, and the other light is split by passing through the spectral unit 106 and incident on the imaging unit 131. At this time, as shown in FIG. 17, when the distance from the light separation unit 202 to the imaging unit 104 is a and the distance from the light separation unit 202 to the imaging unit 131 is b, the distances a and b are different from each other. To do. As a result, the focal plane of the light incident on the spectroscopic unit 106 and the imaging unit 131 is arranged at a position different from the light receiving surface of the imaging unit 131. Therefore, as in the first embodiment, a blurred image, that is, light in a certain area is incident, and light of the entire certain area is incident instead of a part of the spectral reflected light of the subject. It is possible to obtain a spectrum close to.

  The distance between a and b is an optical distance, and it is necessary to dispose the light receiving surface and the focal plane of the image sensor 131 so as not to coincide with each other in consideration of the influence of the spectroscopic unit 106. Since the white balance adjustment unit 109 has the same functions as those of the first embodiment except that the spectral spectrum data is input from the imaging unit 131, the description thereof is omitted.

  Note that a general digital camera or the like may have a configuration in which the direction of light is switched in order to check an object to be photographed with a viewfinder. Using this function, light is transmitted to the spectroscopic unit 106 and the imaging unit 104. You may make it guide. In this case, for example, a part of the light guided to the finder may be guided to the spectroscopic unit 106 by changing the optical distance.

  Although the embodiments of the present invention have been described above, each part, configuration diagram, and the like in the drawings of each embodiment are described with exaggeration and simplification for easy understanding. It is different from the ratio. The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims, and technical means disclosed in the different embodiments can be appropriately used. Embodiments obtained in combination are also included in the technical scope of the present invention.

  The present invention can be used in an imaging system such as a digital camera or a video camera using an imaging device.

  DESCRIPTION OF SYMBOLS 100, 200 ... Imaging device, 101 ... Interchangeable lens part, 102, 201 ... Main part, 103 ... Imaging optical system, 104, 131 ... Imaging part, 105 ... Optical distance change 106, spectroscopic unit, 107 ... image processing unit, 108 ... data holding unit, 109 ... white balance adjustment unit, 202 ... light separation unit

Claims (5)

An imaging apparatus including an imaging device that obtains image data by photoelectrically converting light imaged through an optical system,
An optical distance changing unit for changing an optical distance of a part of light incident through the optical system;
A spectroscopic unit that splits the light whose optical distance has been changed and makes it incident on a part of the imaging device;
An image processing unit that generates the spectral data based on imaging data obtained by photoelectrically converting light incident through the spectral unit by the imaging device;
An image pickup apparatus comprising: an adjustment unit that adjusts image data obtained by the image pickup device based on the spectral spectrum data.   3. The optical distance changing unit according to claim 1, wherein the optical distance of the light is changed by transmitting the light into a member of an optical material having a predetermined refractive index. 4. Imaging device. An imaging apparatus including a first imaging element that obtains image data by photoelectrically converting light imaged through an optical system,
A second imaging device that obtains spectral data by photoelectrically converting the dispersed light;
A light separating unit that separates light incident through the optical system into two parts, makes one light incident on the first image sensor, and makes the other light incident on the second image sensor;
A distance between the light separation unit and the second image sensor is provided so that a distance from the light separation unit is different from a distance between the light separation unit and the first image sensor. A spectroscopic unit that splits the light and makes it incident on the second image sensor;
An adjustment unit that adjusts image data obtained by the first image sensor based on spectral spectrum data obtained by photoelectrically converting light incident through the spectroscopic unit by the second image sensor; An imaging apparatus comprising:   The imaging device according to claim 1, wherein the spectroscopic unit is configured by a transmissive dielectric multilayer filter.   The imaging apparatus according to claim 1, wherein the adjustment unit adjusts image data by adjusting a gain of the imaging element.

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