JP2006261861A - Imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an imaging apparatus which optimizes a spectral sensitivity and can emphasize the separability of melanin and hemoglobin components further in order to utilize the spectral reflection more efficiently and correctly in a medical diagnosis or a cosmetic diagnosis. <P>SOLUTION: The imaging apparatus capable of performing a color photography has an imaging element which has peak sensitivities in each of about 480 nm and about 550 nm of peak sensitivities, and has the spectral sensitivity having a narrow-band in each peak sensitivity. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an imaging system for photographing a skin portion such as a face or an arm for medical or cosmetic diagnosis.

  In medical diagnosis or beauty diagnosis, it has been proposed to optically analyze skin (skin) portions such as a face and an arm. On the other hand, the creation of a reference database for skin color is progressing based on the spectral characteristics analysis of skin color. In view of this, there is a technique of photographing the skin (skin) with an imaging system and analyzing the spectral reflectance based on such a database. In particular, for skin parts such as the face and arms, many proposals have been made on methods for enhancing the ability to detect stains, aza, and subcutaneous blood vessels by depositing melanin pigments to facilitate diagnosis.

  For example, as a change in skin color with aging, color unevenness (pigmentation) derived from melanin such as spots and buckwheat. Since melanin has maximum absorption in the ultraviolet region, using a light source containing ultraviolet light and using an ultraviolet filter that passes 420 nm or less, an image in which pigmentation appears significantly compared to an image under an incandescent light source Can be obtained. That is, there is a possibility of detecting pigmentation that is not detected by normal inspection.

Furthermore, skin has various colors depending on the structure and distribution of multiple pigments. Basically, it originates from color components derived from melanin pigments (such as spots and moles) and blood (such as hemoglobin). Separation has been found among color components (blood vessel images, etc.), and is used for image analysis such as independent component analysis.
Special Issue on Spectral Image Processing-Current Status and Issues of Research 65th Vol.

  The present invention has been made in view of the above circumstances, and the problem is that, in medical diagnosis or cosmetic diagnosis, in order to use spectral reflectance more efficiently and accurately, spectral sensitivity is optimized, and melanin and hemoglobin are obtained. An object of the present invention is to provide an imaging system capable of further enhancing the separation from components.

The above-mentioned subject concerning the present invention is attained by the following composition.
(1) An image pickup apparatus capable of color photographing, having an image pickup element having peak sensitivities in the vicinity of 480 nm and 550 nm, and the image pickup element having a narrow-band spectral sensitivity including each peak sensitivity.

(2) The imaging apparatus according to (1), wherein the peak sensitivity of the imaging element is in a range of 480 nm ± 20 nm and 550 nm ± 20 nm, respectively.

(3) The imaging apparatus according to (1) or (2), wherein the spectral sensitivity of the imaging element is a half width of 70 nm or less.
(4) The imaging apparatus according to any one of (1) to (3), wherein the imaging element has a peak sensitivity in the vicinity of red light (R).

  According to this imaging device, from the difference value between red (R) and the detected value at the peak sensitivity of 550 nm ± 20 nm, the color component derived from the melanin pigment (stain, mole, macular in the digestive organ, etc.) and blood The derived color components (blood vessel images and the like) can be separated and specified, and they can be highlighted according to the name of the lesion to be diagnosed.

  Furthermore, by obtaining the difference value from the blood vessel image and the difference value between the detection values having peak sensitivities at 480 nm ± 20 nm and 550 nm ± 20 nm, it can be used for detecting the ratio between the reduced form and the oxidized form of hemoglobin. It is possible to specify the amount of oxygen in the blood, and is useful for diagnosis of cyanosis, for example.

(5) The imaging apparatus according to any one of (1) to (4), wherein the imaging element includes a light receiving element provided for each peak sensitivity and a light receiving unit of each light receiving element. And a filter having the spectral sensitivity characteristic corresponding to each peak sensitivity.

(6) The imaging apparatus according to any one of (1) to (4), wherein the imaging apparatus includes the spectral sensitivity characteristic filter provided to be movable at a position facing the light receiving unit of the imaging element. apparatus.

(7) The imaging apparatus according to any one of (1) to (6), wherein the imaging element has a peak sensitivity near 420 nm.
Since the imaging device has a peak sensitivity of 420 nm or less, when the wavelength light of this band is irradiated, an image in which a melanin pigmentation portion having a strong spectral sensitivity in ultraviolet rays is emphasized can be obtained, and a normal inspection is performed. The possibility of detecting undetectable pigmentation can be obtained.

(8) The imaging apparatus according to any one of (1) to (7), wherein a condensing lens that condenses light from an imaging target onto the imaging element, and photoelectric conversion from the imaging element An image processing unit that receives a signal and controls driving of the imaging device, an illumination lamp that illuminates the imaging object, a light emission control unit that is connected to the image processing unit and controls emission of the illumination lamp, and the illumination lamp An imaging device comprising: an illumination lens that irradiates an imaging target with light from the image; and a flexible waterproof tube that waterproofs at least the condenser lens and the illumination lens up to the imaging target in a living body.

This embodiment is an endoscope type imaging apparatus, and an optical fiber and a lens part are usually introduced into the body, and many actual imaging elements are arranged in an image receiving apparatus outside the body. In the case of a device, the desired filter can also be provided at the tip, back or middle of the fiber that actually enters the body.
Thus, by the configuration of the endoscope type imaging device, for example, the present invention can be applied to a living body, and the macula in the digestive organ can be captured more clearly.

  According to the present invention, in order to use spectral reflectance more efficiently and accurately in medical diagnosis or beauty diagnosis, an imaging system that can optimize spectral sensitivity and further enhance the separation between melanin and hemoglobin component is provided. can do.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a block diagram showing an outline of an imaging apparatus according to the first embodiment of the present invention.
In the figure, an image receiving element CCD 13, which is a solid-state imaging element, is disposed on the rear side of the objective lens system 11. Further, an image signal processing unit 15, an image signal output unit 17, and a CCD drive processing unit 19 are arranged.

  The image light passing through the objective lens system 11 is converted into an image signal by the CCD 13. The individual pixels constituting the CCD 13 are distributed so that only the corresponding color is received by the filters corresponding to R (red), G (green), and B (blue). In the image signal processing unit 15 that receives a signal from the CCD 13, after adjustment such as amplification processing and white balance, a color difference signal and a luminance signal are formed, and the image signal output unit 17 displays an image. On the other hand, the CCD drive processing unit 19 controls the CCD 13 while synchronizing with the image signal processing unit 15.

FIG. 2 is a characteristic diagram showing the spectral sensitivity of the imaging apparatus according to the first embodiment of the present invention.
As shown in the figure, the CCD 13 pixels distributed for G (green) and B (blue) have peak sensitivity at 480 nm and 550 nm. For each peak sensitivity, G (green) and B (blue) are used so that the spectral sensitivity (indicated by a solid line) has a half-width of 50 nm, which is narrower than that in general photography (indicated by a dashed line). Each filter is set. As described above, by limiting the spectral sensitivity to the two peak sensitivities and the half-value width thereof, it is possible to cope with more accurate image diagnosis. The spectral sensitivity of R (red) light may be a half width equivalent to that for general photography.

  In actual diagnosis, for example, an image in which a blood vessel image is enhanced is obtained by highlighting a difference between detection values of R (red) and G (green). Furthermore, it is possible to obtain the ratio of the reduced type and the oxidized type of hemoglobin from the difference between the blood vessel image and the detected values of B (blue) and G (green).

  The peak sensitivity is allowed in the range of 480 nm ± 20 nm for B (blue) and 550 nm ± 20 nm for G (green). If it deviates from this, it becomes a color different from the color of the diagnostic standard, and accurate judgment cannot be made. As for the half-value width of each spectral sensitivity including each peak sensitivity, a half-value width of about 70 nm is an allowable range. If it is taken wider than this and approaches the general half-value width, it will be difficult to enhance the image for image diagnosis.

FIG. 3 is a block diagram of an imaging apparatus according to the second embodiment of the present invention.
In the figure, an image receiving element CCD 23 (a commonly used CCD that performs color image processing with a three-primary color filter such as a checkered pattern) is disposed behind the objective lens system 21 and is objective. A filter 22 is disposed on the optical axis between the lens system 21 and the CCD 23. Further, an image signal processing unit 25, an image signal output unit 27, and a CCD drive processing unit 29 are arranged.

  The image light that has passed through the objective lens system 21 passes through the filter 22 and is converted into an image signal by the CCD 23. The filter 22 cuts the spectral sensitivity wrinkle portion of the image light that has passed through the objective lens system 21 such that the half-value width is 50 nm with respect to the peak sensitivity of B (blue) and G (green). That is, B (blue) has a spectral sensitivity within a peak sensitivity of 480 nm and a half width of 50 nm, and G (green) has a spectral sensitivity of a peak sensitivity of 550 nm and a half width of 50 nm. In the image signal processing unit 25, after adjustment such as amplification processing and white balance, a color difference signal and a luminance signal are formed, and an image is displayed in the image signal output unit 27. On the other hand, the CCD drive processing unit 29 controls the CCD 23 while synchronizing with the image signal processing unit 25.

FIG. 4 is a characteristic diagram showing the spectral sensitivity of the imaging apparatus according to the second embodiment of the present invention.
As indicated by the solid line, the filter 22 has a spectral sensitivity of B (blue) within a peak sensitivity of 480 nm and a half-value width of 50 nm, and a spectral sensitivity of G (green) is reduced to a peak sensitivity of 550 nm and half of the spectral sensitivity. The spectral sensitivity 淵 portions of B (blue) and G (green) are attenuated with respect to the image light that has passed through the objective lens system 11 so that the value width is within 50 nm.
In this way, by limiting the spectral sensitivity to the two peak sensitivities and the half-value width, the spectral sensitivity 淵 part is attenuated from the sensitivity part (one-dot chain line) that appears when there is no filter 22 to the sensitivity part indicated by the solid line, It is possible to cope with more accurate image diagnosis.

FIG. 5 is a schematic characteristic diagram showing the transmittance characteristic of the filter 22 when the spectral sensitivity of FIG.
The distribution shown here is not absolute. In the case of the second embodiment, any distribution may be used as long as it provides at least a peak sensitivity of 480 nm and its half-value width of 50 nm, and a peak sensitivity of 550 nm and a half-value width of 50 nm. Therefore, in FIG. 4 and FIG. 5, the R (red) region also gives sensitivity. This is necessary when the display image is to be expressed in a natural hue, but is not absolutely necessary. Note that the half width need not be specified. Further, since infrared rays may be a problem, a filter for a longer wavelength portion may be inserted.

This filter 22 can be exchanged, and the peak sensitivity and half-value width can be set appropriately. For example, the three primary color filters are also eliminated, and a filter that transmits the ultraviolet region (420 nm or less) and gives a peak sensitivity of 420 nm ± 20 nm and its half-value width of 50 nm, and a peak sensitivity of 550 nm and a half-value width of 50 nm is disposed. Thus, a processed image that particularly emphasizes melanin having strong absorption in the ultraviolet region can be used.
Furthermore, instead of the filter 22, a plurality of filters are switched and photographed, and other wavelengths are combined with a focus on giving a peak sensitivity of 480 nm and its half-value width of 50 nm and a peak sensitivity of 550 nm and a half-value width of 50 nm. It is also possible to obtain an image.

FIG. 6 is a conceptual diagram of a third embodiment in which the present invention is an endoscope type imaging apparatus.
In this figure, an objective lens 31, a CCD 33 on its optical axis, and an illumination lens 49 of another optical axis are arranged at the distal end portion 30a of the endoscope 30. The endoscope operation unit 30b at the rear end of the endoscope 30 includes an illumination lamp 43, a light emission control unit 41 that drives the illumination lamp 43, and a condenser lens 45. The light collected by the condenser lens 45 is guided to a light guide 47 (usually an optical fiber) provided in the inner longitudinal direction of the distal end portion 30a, and is irradiated to the object through the illumination lens 49. . Reflected light from the object is captured by the objective lens 31 and subjected to photoelectric conversion by the CCD 33. The CCD 33 is connected to the CCD drive unit 35 provided in the endoscope operation unit 30 b, and the image signal is processed by the image signal processing unit 37.

  The imaging apparatus of the present invention is integrated into the objective lens 31 and the CCD 33 at the distal end portion 30a of the endoscope 30, and the CCD driving unit 35 and the image signal processing unit 37 of the endoscope operation unit 30b. When the first embodiment of the present invention is applied, the CCD 33 is provided with a filter having peak sensitivity at 480 nm and 550 nm for B (blue) G (green), and has a spectral sensitivity with a half band width of 50 nm which is a narrow band. Can be set.

It is also possible to replace the objective lens 31 with the tip 30a so that a filter (not shown) can be installed. With this configuration, the second embodiment of the present invention can be applied.
In the case of the endoscope type imaging apparatus of the present invention, a desired filter can be provided also at the front end, rear end or intermediate portion of the fiber that actually enters the body.
Thus, by the configuration of the endoscope type imaging device, for example, the present invention can be applied to a living body, and the macula in the digestive organ can be captured more clearly.

In the case of the present invention, since the spectral sensitivity in a narrow band is given to the peak sensitivity, it may depend on the spectral characteristics of the illumination light source. It is possible to adjust the difference in characteristics with a chart or the like.
Furthermore, in any of the above embodiments, peak sensitivity is allowed in the range of 480 nm ± 20 nm for B (blue) and 550 nm ± 20 nm for G (green). If it deviates from this, it becomes a color different from the color of the diagnostic standard, and accurate judgment cannot be made. As for the half-value width of each spectral sensitivity including each peak sensitivity, a half-value width of about 70 nm is an allowable range. If it is taken wider than this and approaches the general half-value width, it will be difficult to enhance the image for image diagnosis.

1 is a block diagram showing an outline of an imaging apparatus according to a first embodiment of the present invention. The characteristic view which shows the spectral sensitivity of the imaging device by 1st embodiment of this invention. The block diagram of the imaging device by 2nd embodiment of this invention. The characteristic view which shows the spectral sensitivity of the imaging device by 2nd embodiment of this invention. FIG. 5 is a schematic characteristic diagram showing the transmittance characteristic of the filter 22 when the spectral sensitivity of FIG. The conceptual diagram of 3rd Embodiment which used this invention as the endoscope type imaging device.

Explanation of symbols

11 Objective lens 13 CCD
15 Image signal processing unit 17 Image signal output unit 19 CCD drive processing unit B Spectral sensitivity G of blue light image sensor Spectral sensitivity R of green light image sensor Spectral sensitivity 21 of red light image sensor Objective lens 22 Filter 23 CCD
25 Image signal processing unit 27 Image signal output unit 29 CCD drive processing unit 30 Endoscope 30a Endoscope tip 30b Endoscope operation unit 31 Objective lens 33 CCD
35 CCD drive unit 37 Image processing device 41 Light emission control unit 43 Illumination lamp 45 Condensing lens 47 Light guide 49 Illumination lens

Claims (8)

In an imaging device capable of color photography,
An image pickup apparatus having an image pickup device having a peak sensitivity in the vicinity of 480 nm and in the vicinity of 550 nm, and the image pickup device having a narrow-band spectral sensitivity including each peak sensitivity. The imaging apparatus according to claim 1,
An imaging apparatus in which the peak sensitivity of the imaging element is in the range of 480 nm ± 20 nm and 550 nm ± 20 nm, respectively. The imaging device according to claim 1 or 2,
An imaging apparatus in which the spectral sensitivity of the imaging element is a half-value width of 70 nm or less. The imaging device according to any one of claims 1 to 3,
An imaging apparatus in which the imaging element has peak sensitivity in the vicinity of red light (R). An imaging apparatus according to any one of claims 1 to 4, wherein
The imaging device includes: a light receiving element provided for each peak sensitivity; and a filter fixed to a light receiving portion of each light receiving element to obtain the spectral sensitivity characteristic. An imaging apparatus according to any one of claims 1 to 4, wherein
An image pickup apparatus having a filter for obtaining the spectral sensitivity characteristic movably provided at a position facing the light receiving portion of the image pickup element. The imaging device according to any one of claims 1 to 6,
An imaging apparatus in which the imaging element has a peak sensitivity near 420 nm. An imaging apparatus according to any one of claims 1 to 7,
A condensing lens for condensing light from the imaging object on the imaging device;
An image processing unit that receives a photoelectric conversion signal from the image sensor and controls driving of the image sensor;
An illumination lamp that illuminates the imaging object;
A light emission control unit connected to the image processing unit to control light emission of the illumination lamp;
An illumination lens for irradiating the imaging target with light from the illumination lamp;
An imaging apparatus comprising: a flexible waterproof tube that waterproofs at least the condenser lens and the illumination lens up to the imaging object in a living body.

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