JP2005148020A - Multi-spectrum imaging device, and multi-spectrum lighting apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a small multi-spectrum imaging device capable of illuminating an irradiated side uniformly. <P>SOLUTION: The multi-spectrum imaging device is provided with: two or more luminescence units 22b which are packaged, including LED emitting lights different in wavelength, and so disposed that they may be turned to the opposite side of the irradiated side of an object 4 along the direction of a periphery on LED substrate 22 in a ring shape; a light diffusing element 26 comprising a diffuse reflection flat surface 26b and a torus reflective surface 26c which are reflected while diffusing the lights from these luminescence units 22b; a multi-spectrum lighting apparatus which has an optical sheet 27 which diffuses further the light from this light diffusing element 26; and an image pick-up optical system 21 and a CCD 13 in order that a multi-spectrum imaging device which carries out image formation and picturization of the catoptric light from the irradiated side illuminated by this multi-spectrum lighting apparatus. Thus, the multi-spectrum imaging device analyzes the image pick-up output of the CCD 13, and measures the color component of the irradiated side. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a multispectral imaging apparatus and a multispectral illumination apparatus adapted to irradiate light of different wavelengths in order to measure color components.

  Conventionally, various illumination devices for illuminating an object have been proposed in order to observe or image the surface of an object and analyze it.

  As a light source for such illumination, a bulb lamp has been widely used conventionally, but in recent years, light emitting diodes (LEDs) have been gradually used depending on the field. This LED has advantages such as low power consumption and long life as compared with a bulb lamp, and further has characteristics such as light emission in a narrow wavelength band and high color reproducibility.

  As one of the technologies that have been developed in recent years by taking advantage of the advantages and characteristics of these LEDs, a plurality of LEDs that emit light of different wavelengths are used to irradiate the object with light from these LEDs and reflect the reflected light. A technique for measuring the color of the object by receiving light and measuring the intensity is mentioned.

  For example, in the specification of Japanese Patent No. 3218601, LED light of three primary colors is emitted sequentially, and the irradiated surface is directly irradiated so that each color overlaps at the center, and the light reflected from the irradiated surface is photo-photographed. Light is received by a diode or the like, and a colorimetric value is obtained based on the intensity of reflected light.

  The LED as described above has a small light emission amount from one element, and it is necessary to increase the light emission amount by arranging a plurality of LEDs or the like in order to construct an illumination device for use in colorimetry. However, since the object may be illuminated unevenly by simply illuminating a plurality of LEDs side by side, it is necessary to apply some contrivance to illuminate uniformly.

  Japanese Patent Laid-Open No. 9-270885 discloses an illumination optical system incorporated in a colorimeter or the like using a ring-shaped light source including a fiber bundle bundled in a ring shape. A technique is described in which emitted light is reflected by a conical first mirror surface and further reflected by a concave second mirror surface to irradiate an object. The light is incident on the fiber bundle by condensing light from a point light source composed of a xenon lamp or the like.

Furthermore, various examples are also described in JP-A-5-307007, JP-A-7-244716, JP-A-11-249578, JP-A-2000-131037, JP-A-2002-57081, and the like. Has been.
Japanese Patent No. 3218601 JP-A-5-307007 JP-A-7-244716 Japanese Patent Laid-Open No. 9-270885 JP-A-11-249578 JP 2000-131037 A JP 2002-57081 A

  Since the colorimetric device described in the specification of the above patent 3218601 directly irradiates the irradiation surface with light of the three primary colors, whether or not unevenness in the amount of light on the irradiation surface occurs is determined by the LED light distribution. It is optically determined by the characteristics and the irradiation distance. In order to obtain an optically uniform amount of irradiation light, it is necessary to form a light beam having high directivity regardless of the irradiation distance, but it is difficult to achieve such light distribution characteristics using only LEDs. Therefore, the technique for narrowing the measurable area as described in this specification, that is, the technique for narrowing the area of the irradiation area where the light emitted from the LEDs corresponding to the three primary colors overlaps, measures a wide area. I can't. Further, in the configuration as described in the specification, since the specularly reflected light from the irradiation surface may be incident on the photodiode, it is not always possible to accurately measure the color.

  On the other hand, what is described in Japanese Patent Laid-Open No. 9-270885 is a technique using a point light source such as a lamp, and therefore an elliptical mirror for condensing light from the lamp on the end face of the fiber bundle. Such an illumination optical system is required, and the apparatus becomes large. Furthermore, when a lamp is used as the light source, the amount of light may change with time, and the life of the lamp itself is not necessarily long.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a small multispectral illumination apparatus and multispectral imaging apparatus that can uniformly illuminate a surface to be irradiated.

  In order to achieve the above object, a multispectral imaging apparatus according to a first invention includes a multispectral illumination apparatus that irradiates an irradiated surface with light of different wavelengths, and an irradiated surface illuminated by the multispectral illumination apparatus. A multi-spectral imaging device that measures the color component of the irradiated surface by analyzing the component of the reflected light acquired through the imaging optical system. The multispectral illumination device diffuses light from the light sources and a plurality of light sources that emit light of different wavelengths arranged in a ring shape so as to emit light in a direction opposite to the irradiated surface. A first reflecting surface for reflecting the light and a second reflecting surface for reflecting the light from the first reflecting surface, and the light reflected by the second reflecting surface is irradiated with the light. Irradiate the surface It is one that is configured to have a light diffusing element.

  A multispectral imaging device according to a second invention is the multispectral imaging device according to the first invention, wherein the second reflecting surface is formed in a rotationally symmetric torus shape and includes a rotationally symmetric axis. It is a reflective surface whose shape when it is cut with a substantially circular arc.

  Furthermore, the multispectral imaging device according to the third invention is the multispectral imaging device according to the second invention, wherein the multispectral illumination device further directs the light emitted from the light diffusing element toward the irradiated surface. And having a substantially cylindrical light guide element having a tapered shape with a reduced diameter toward the irradiated surface, the inner peripheral surface side being configured as a reflective surface that reflects light It is configured.

  A multispectral imaging device according to a fourth invention is the multispectral imaging device according to the second invention, wherein the multispectral illumination device further guides the light emitted from the light diffusing element toward the irradiated surface. It is configured to have a tapered substantially cylindrical member that is reduced in diameter toward the irradiated surface and is arranged in a double manner with different diameters. The peripheral surface side and the outer peripheral surface side of the cylindrical member on the inner diameter side are configured to have light guide elements each configured as a reflective surface that reflects light.

  A multispectral imaging apparatus according to a fifth invention is the multispectral imaging apparatus according to the second invention, wherein the light diffusing element has a distance from the light source to the first reflecting surface ranging from 8.5 mm to 14 mm. And the radius of curvature of the substantially arc when the second reflecting surface is cut by a plane including the rotational symmetry axis is in the range of 8.5 mm to 10.5 mm. It is a thing.

  A multispectral imaging device according to a sixth invention is the multispectral imaging device according to the fifth invention, wherein the multispectral illumination device further guides the light emitted from the light diffusing element toward the irradiated surface. It has a substantially cylindrical light guide element that has a tapered shape that decreases in diameter toward the surface to be irradiated and that has an inner peripheral surface side that is configured as a reflective surface that reflects light. It is a thing.

  A multispectral imaging device according to a seventh invention is the multispectral imaging device according to the fifth invention, wherein the multispectral illumination device further guides the light emitted from the light diffusing element toward the irradiated surface. It is configured to have a tapered substantially cylindrical member that is reduced in diameter toward the irradiated surface and is arranged in a double manner with different diameters. The peripheral surface side and the outer peripheral surface side of the cylindrical member on the inner diameter side are configured to have light guide elements each configured as a reflective surface that reflects light.

  A multispectral imaging device according to an eighth invention is the multispectral imaging device according to the fifth invention, wherein the multispectral illumination device further controls light disposed on the emission surface side of the plurality of light sources. The optical sheet is configured.

  A multispectral imaging apparatus according to a ninth invention is the multispectral imaging apparatus according to the eighth invention, wherein the optical sheet controls the light by a predetermined diffusivity.

  A multispectral imaging device according to a tenth aspect of the invention is the multispectral imaging device according to the eighth aspect of the invention, wherein the optical sheet controls the light so that only light within a predetermined emission angle range is emitted. It is.

  A multispectral imaging device according to an eleventh aspect of the invention is the multispectral imaging device according to the first aspect of the invention, wherein the multispectral illumination device further controls light disposed on the exit surface side of the light diffusing element. The optical sheet is configured.

  A multispectral imaging apparatus according to a twelfth aspect of the invention is the multispectral imaging apparatus of the eleventh aspect, wherein the optical sheet controls the light by a predetermined diffusivity.

  A multispectral imaging device according to a thirteenth invention is the multispectral imaging device according to the eleventh invention, wherein the optical sheet controls the light so that only light within a predetermined emission angle range is emitted. It is.

  A multispectral imaging device according to a fourteenth invention is the multispectral imaging device according to the third invention, wherein the multispectral illumination device further controls light disposed on the exit surface side of the light guide element. The optical sheet is configured.

  A multispectral imaging apparatus according to a fifteenth invention is the multispectral imaging apparatus according to the fourteenth invention, wherein the optical sheet controls the light by a predetermined diffusivity.

  A multispectral imaging device according to a sixteenth invention is the multispectral imaging device according to the fourteenth invention, wherein the optical sheet controls the light so that only the light within a predetermined emission angle range is emitted. It is.

  A multispectral imaging device according to a seventeenth aspect of the invention is the multispectral imaging device according to the fourth aspect of the invention, in which the multispectral illumination device further controls light disposed on the exit surface side of the light guide element. The optical sheet is configured.

  A multispectral imaging device according to an eighteenth aspect of the invention is the multispectral imaging device according to the seventeenth aspect of the invention, wherein the optical sheet controls the light by a predetermined diffusivity.

  A multispectral imaging device according to a nineteenth aspect is the multispectral imaging device according to the seventeenth aspect, wherein the optical sheet controls the light so that only the light within a predetermined emission angle range is emitted. It is.

  A multispectral imaging device according to a twentieth aspect of the invention is the multispectral imaging device according to the first aspect of the invention, wherein the light diffusing element is a reflecting surface on which the first reflecting surface is painted white.

  A multispectral imaging device according to a twenty-first invention is the multispectral imaging device according to the first invention, wherein the light diffusing element is a reflecting surface on which the second reflecting surface is subjected to an aluminum coating process.

  A multispectral imaging device according to a twenty-second aspect of the invention is the multispectral imaging device according to the first aspect of the invention, wherein the multispectral illumination device is disposed on the exit surface side of the light diffusing element and only has light in one polarization direction. A first polarizing plate for transmitting light, and a second polarizing plate disposed on the incident surface side of the imaging optical system and transmitting only light in another polarization direction orthogonal to the one polarization direction And is further configured.

  A multispectral illumination device according to a twenty-third aspect of the invention is a light source from a plurality of light sources that emit light of different wavelengths arranged in a ring shape so as to emit light in the direction opposite to the surface to be irradiated; A first reflecting surface for reflecting while diffusing light and a second reflecting surface for reflecting light from the first reflecting surface, and the light reflected by the second reflecting surface is A light diffusing element that irradiates the surface to be irradiated.

  A multispectral illumination device according to a twenty-fourth invention is the multispectral illumination device according to the twenty-third invention, wherein the second reflecting surface is formed in a rotationally symmetric torus shape and cut along a plane including a rotationally symmetric axis. The reflection surface has a substantially arc shape.

  A multispectral illumination device according to a twenty-fifth aspect of the invention is the multispectral illumination device according to the twenty-fourth aspect of the invention, which guides light emitted from the light diffusing element toward the irradiated surface. The light guide element further includes a substantially cylindrical light guide element having a tapered shape with a reduced diameter toward the irradiation surface and an inner peripheral surface side configured as a reflection surface that reflects light.

  A multispectral illumination device according to a twenty-sixth invention is the multispectral illumination device according to the twenty-fourth invention, wherein the light emitted from the light diffusing element is guided toward the irradiated surface. A tapered substantially cylindrical member that is reduced in diameter toward the irradiation surface is arranged in a double manner with different diameters, and the inner peripheral surface side of the outer diameter side cylindrical member and the inner diameter side tube And a light guide element that is configured as a reflective surface that reflects light.

  According to the multispectral illumination device and the multispectral imaging device of the present invention, it is possible to uniformly illuminate the irradiated surface and to reduce the size.

  Embodiments of the present invention will be described below with reference to the drawings.

  1 to 6 show a first embodiment of the present invention. FIG. 1 is a diagram showing a usage pattern of a multispectral imaging apparatus, FIG. 2 is a block diagram showing a configuration of the multispectral imaging apparatus, and FIG. The figure which shows the internal structure of the imaging device centering on a multispectral illuminating device from the side and the front view which shows the structure of an LED board, FIG. 4 is the figure which shows the structure of a multispectral illuminating device from the side, and the effect | action of a reflective surface. FIG. 5 is a diagram showing the illumination spectrum by the LED and the spectral sensitivity of the CCD, and FIG. 6 is a diagram showing characteristic data when the constituent factors of the light diffusing element are changed.

  The multispectral imaging apparatus using the multispectral illumination apparatus of this embodiment is used for, for example, an application for accurately measuring the color of an automobile as an object.

  As shown in FIG. 1, the system of the multispectral imaging device is electrically connected to the imaging device 1 by, for example, mounting the imaging device 1 for imaging an object 4 such as an automobile and mounting the imaging device 1 after imaging. A cradle 2 that is connected to receive photographing data and also has a function of charging the photographing apparatus 1 and a personal computer that is connected to the cradle 2 and receives and analyzes the photographing data received through the cradle 2. And a computer (hereinafter referred to as a PC as appropriate) 3.

  Using such an imaging device 1 of a multispectral imaging device, for example, the surface of an automobile is imaged, and the imaging device 1 after imaging is connected to the cradle 2, whereby imaging data is taken into the PC 3. By analyzing in the PC 3, for example, it is possible to distinguish whether the color of the automobile is a color painted with a regular paint or a color painted with another paint. As a result, it is possible to determine the state of the automobile without any specialized knowledge regarding painting of the automobile.

  Next, the configuration of such a multispectral imaging apparatus will be described with reference to FIG.

  The photographing apparatus 1 is configured by extending a hood 6 from a main body 5. On the outer surface of the main body 5, a power switch 7 for turning on the power of the photographing apparatus 1 and an instruction input for photographing operation are input. A shutter button 8 for performing the operation, a contact 9 for electrically connecting to the cradle 2, and an LCD unit 10 for confirming a photographed image and displaying various information related to the photographing apparatus 1. A focus ring 11 for manually adjusting a focal position of an imaging optical system 21 to be described later is provided.

  In the interior from the hood 6 to the main body 5, LEDs 23a to 23h serving as light sources for illuminating the object 4, the LED substrate 22 to which these LEDs 23a to 23h are attached, and the LEDs 23a to 23h emit light. The illumination optical unit 24 for irradiating the illuminated surface of the object 4 with uniform illumination light as the uniform illumination light, and the light reflected from the illuminated surface of the illuminated object 4 are connected to the CCD 13 described later. An imaging optical system 21 for imaging is arranged.

  In such a configuration, the multispectral illumination device includes the LED substrate 22, LEDs 23 a to 23 h, and the illumination optical unit 24. Further, the imaging optical system 21 is an optical system that can perform photographing at a close distance. Further, in the hood 6, the light incident on the imaging optical system 21 is only reflected light from the object 4 illuminated by the illumination light from the LEDs 23 a to 23 h and the illumination optical unit 24, and the other outside. It is for shielding light so as not to be affected by light. The focus ring 11 is for adjusting the imaging position of the optical image of the object 4 by the imaging optical system 21 so as to coincide with the imaging surface of the CCD 13. Here, the focus adjustment is performed using the focus ring 11, but of course, it may be configured such that automatic focus adjustment can be performed using a mechanism such as autofocus.

  In the main body 5, a CCD 13 having an RGB color filter for converting an optical subject image formed by the imaging optical system 21 into an electrical image signal, and an output from the CCD 13. A signal processing circuit 14 for performing various signal processing on the image signal to be processed, an LED controller 15 for controlling the LEDs 23a to 23h to emit light, and image data processed by the signal processing circuit 14 A memory 16 for storing or storing a processing program or data executed by a control circuit 18 to be described later, and a battery 19 for accumulating power supplied from the cradle 2 via the contact 9 A power supply circuit 17 for supplying power supplied from the battery 19 to each circuit in the photographing apparatus 1, and the CCD 3, signal processing circuit 14, LED controller 15, memory 16, power circuit 17 and electric circuit board 12 on which a control circuit 18 to be described later is mounted, the LCD unit 10, signal processing circuit 14, LED controller 15, memory 16, power supply A control circuit 18 is connected to the circuit 17 in a bidirectional manner via a bus or the like, and controls the entire photographing apparatus 1 including them.

  As shown in FIG. 3 and the like, which will be described later, the photographing apparatus 1 is provided with a grip portion 5b for gripping with a palm, and the shutter button 8 is an index finger of a hand that grips the grip portion 5b. The power switch 7 is disposed at a position where the power switch 7 can be operated with a thumb or the like of the hand holding the grip portion 5b, which is opposite to the shutter button 8, for example. The grip portion 5b is further provided with a contact 9, and the battery 19 is disposed inside. The LCD unit 10 is disposed at a position where the main body 5 is easily observed, for example, on the back side.

  The cradle 2 includes a contact 39 for connecting to the contact 9 of the photographing apparatus 1, an AC adapter 35 that converts an alternating current of a predetermined voltage supplied from an AC power source into an appropriate DC voltage, and the AC adapter 35. A power supply circuit 36 for supplying power supplied from each of the circuits to each internal circuit, and an A / D conversion circuit 34 for converting into digital data when the image data transmitted from the photographing apparatus 1 is analog data. An SRAM 33 for storing image data or a processing program executed by the CPU 31 (to be described later), data, and the like; an FPGA (Field Programmable Gate Array) 32 for performing image data compression processing; USB2I / F37, which is an interface for communicating with the PC3 by, for example, USB2, and the FPGA32, SRA 33, A / D conversion circuit 34, power supply circuit 36, USB 2 I / F 37 and the like are bidirectionally connected to each other via a bus or the like to control the entire cradle 2 including these and control the photographing apparatus 1 and PC 3 together. And a CPU 31 for controlling the communication.

  Further, the PC 3 has color analysis software 41 for determining the color of the object 4 by analyzing the image data received from the photographing apparatus 1 via the cradle 2 connected by, for example, the USB 2 as described above. In addition to being installed, a color database 42 that is referred to when the color analysis software 41 performs color analysis is stored.

  Next, the illumination optical unit and the LED will be described with reference to FIGS.

  As shown in FIG. 3B, the LED substrate 22 is configured as a donut-shaped substrate, and allows light reflected from the object 4 to enter the imaging optical system 21 therein. A circular hole 22a is formed. On the surface of the LED substrate 22 opposite to the object 4, a plurality of light emitting units 22 b that collectively store the LEDs 23 a to 23 h are arranged along the circumferential direction. In this example, the light emitting unit 22b is configured by packaging all the LEDs 23a to 23h that emit light in eight different wavelength ranges. In addition, although it comprised so that all LED23a-23h might be packaged here in arbitrary light emission units 22b, it does not restrict to this. Furthermore, although one LED is provided in each light emitting unit 22b, a plurality of LEDs may be provided corresponding to light in one wavelength region.

  The emission spectra of these LEDs 23a to 23h are as shown in FIG. 5, 450nm as the LED 23a is indicated by the curve Sa, 505nm as the LED 23b is indicated as the curve Sb, 525nm as the LED 23c is indicated as the curve Sc, LED23d is 560 nm as shown by curve Sd, LED23e is 575 nm as shown by curve Se, LED23f is 609 nm as shown by curve Sf, LED23g is 635 nm as shown by curve Sg, LED23h is 670 nm as shown by curve Sh Each has a central emission wavelength.

  For these emission spectra, the spectral sensitivity of the CCD 13 through the RGB color filter is as shown in FIG. 5 for each filter color, and is not completely separated and partially overlaps. However, it is almost as follows. That is, the spectral sensitivity through the B color filter substantially includes the light emission band of the LED 23a and partially includes the light emission band of the LED 23b as shown by the curve B. Further, the spectral sensitivity through the G color filter substantially includes the emission bands of the LED 23b, LED 23c, LED 23d, and LED 23e as shown by the curve G. Furthermore, as shown by the curve R, the spectral sensitivity through the R color filter substantially includes the emission bands of the LEDs 23f, LED23g, and LED23h.

  Further, as shown in FIGS. 3A and 4A, the illumination optical unit 24 diffuses light so as to make uniform illumination light while transmitting light emitted from the LEDs 23a to 23h. The diffusing element 26 and an optical sheet 27 for diffusing the light disposed on the emission end face side of the light diffusing element 26 are configured.

  The light diffusing element 26 is formed, for example, by forming a hollow box-like body in a substantially donut shape, and a circular hole 26a for arranging the imaging optical system 21 is formed at the center. The radius of the circular hole 26a is substantially the same as the radius of the circular hole 22a formed in the LED substrate 22. Furthermore, the light diffusing element 26 diffuses and reflects the light emitted from each light emitting unit 22b on the LED substrate 22 as shown in FIG. 26b, a torus reflecting surface 26c which is a second reflecting surface formed in a rotationally symmetric torus shape for reflecting the light reflected by the diffuse reflecting plane 26b on the outer diameter side, and the torus reflecting surface 26c. And an exit 26d for emitting the reflected light. The diffuse reflection plane 26b is, for example, a reflection surface coated with white paint, and the torus reflection surface 26c is, for example, a reflection surface coated with an aluminum coat.

  The imaging optical system 21 has, for example, a distance x from the surface closest to the object side to the surface of the object 4 among a plurality of lenses constituting the imaging optical system 21, and the imaging optical system 21 is The distance y from the most objective side surface to the most imaging side surface among the plurality of lenses constituting the lens is 28.6 mm, and the most imaging side of the plurality of lenses constituting the imaging optical system 21 is located. The distance z from the surface to the imaging surface of the CCD 13 is 6.42 mm.

  When the imaging optical system 21 is designed in this way, the distance L from the light emitting unit 22b to the diffuse reflection plane 26b of the light diffusing element 26 is 10 mm. The torus reflecting surface 26c is a reflecting surface having a substantially arc shape when cut by a plane including a rotationally symmetric axis (coincident with the optical axis of the imaging optical system 21), and the curvature of the approximately arc. The radius R is 9.5 mm.

  Such a design is based on experimental data as shown in FIG. FIG. 6 shows changes in luminance and luminance unevenness when the distance L and the radius of curvature R, which are constituent factors of the light diffusing element, are changed.

  First, as shown in FIG. 6A, as the distance L between the light emitting unit 22b and the diffuse reflection plane 26b increases, the luminance of the irradiated surface of the object 4 gradually decreases. On the other hand, as shown in FIG. 6B, the luminance unevenness of the illuminated surface of the object 4 also decreases as the distance L increases. Therefore, in order to reduce the luminance unevenness, the distance L may be increased. However, if the distance L is increased, the luminance is decreased. Therefore, it is necessary to balance at an appropriate position.

  On the other hand, when the radius of curvature R of the torus reflecting surface 26c changes, as shown in FIG. 6C, the luminance of the irradiated surface of the object 4 reaches the minimum value near the position where the radius of curvature R is 9.5 mm. In addition, as shown in FIG. 6D, it can be seen that the luminance unevenness of the irradiated surface takes the minimum value near the same position.

  Therefore, as a result of taking such experimental results into consideration, the light diffusing element 26 has a range in which the distance L is 8.5 to 14 mm and a radius of curvature R in the range of 8.5 to 10.5 mm. Desirably, the most efficient value among them is the value that the distance L is 10.0 mm and the radius of curvature R is 9.5 mm as the design value as described above.

  Further, as shown in FIG. 4B, the reflection by the diffuse reflection plane 26b is performed in a predetermined direction (for example, a direction symmetrical to the incident direction with respect to the normal line standing on the reflecting surface) when a light ray is incident. The reflection is such that the light is diffused while maintaining a certain degree of directivity around the light beam.

  Then, the light reflected by the torus reflecting surface 26c with the light collecting property is emitted from the emission port 26d, enters the optical sheet 27, is further diffused and uniformed, and then is directed to the object 4. Irradiated towards.

  Next, the operation of the multispectral imaging apparatus configured as described above will be described.

  The user turns on the power of the photographing apparatus 1 by operating the power switch 7 with the hood 6 side of the photographing apparatus 1 facing the photographing target portion of the object 4. Thereby, each circuit on the electric circuit board 12 receives power supply from the battery 19 and starts driving.

  When the operation starts according to the control program, the control circuit 18 performs control such that a current is supplied to the LED substrate 22 via the LED controller 15 after performing a predetermined initialization process or the like. Thereby, all LED23a-23h provided in the light emission unit 22b arranged along the circumference direction of LED board 22 which makes a donut shape turns on simultaneously, for example. The LEDs 23a to 23h can all be turned on at the same time as described above, but on the other hand, any one or two or more can be turned on. The lighting of all the LEDs 23a to 23h is used when, for example, the object 4 is observed in a color close to natural color via the LCD unit 10, and the individual lighting of the LEDs 23a to 23h is, for example, a color measurement of the object 4. Used when doing. Further, the current value supplied to the LEDs 23a to 23h can be changed, and particularly when observing with the LCD unit 10, the current value is changed to control the light quantity. It is preferable to reduce power consumption while observing the object 4 with an appropriate illuminance. Furthermore, since the LEDs 23a to 23h have different light emission efficiencies, the amount of light emitted is different even when the same current is supplied. Therefore, it is possible to obtain a necessary light amount with a minimum amount of power by energizing only the LED having high light emission efficiency. When performing focus adjustment by the focus ring 11 as described later, it is not always necessary to perform adjustment while observing with an accurate color, so it is necessary to perform an illumination method in which only an LED with high luminous efficiency is emitted. The power consumption may be reduced while obtaining a sufficient amount of light.

  In this way, when power is supplied to the LEDs 23a to 23h provided in the light emitting unit 22b, each of the LEDs 23a to 23h emits light of each wavelength with a predetermined emission angle. This light is irradiated as illumination light onto the object 4 through the light diffusing element 26 of the illumination optical unit 24.

  The user adjusts the focus by operating the focus ring 11 while observing the shooting target portion of the target object 4 through the screen of the LCD unit 10 to focus on the shooting target portion. Then, when the image is in focus, pressing the shutter button 8 starts an image capturing operation for colorimetry of the portion to be imaged.

  That is, when the control circuit 18 detects that the shutter button 8 has been pressed, it instructs the LED controller 15 to perform the light emission operation in the measurement mode. In response to this instruction, the LED controller 15 sequentially turns on / off the eight LEDs 23a to 23h arranged in the light emitting unit 22b on the LED substrate 22 to which current is supplied at intervals of 1/30 seconds. To repeat. Thereby, for example, the LEDs 23a of the light emitting units 22b arranged in the circumferential direction are turned on all at once, and then they are turned off all at once, and then the LEDs 23b of the light emitting units 22b arranged in the circumferential direction are then turned on. Are turned on all at once, and so on. At this time, since the LEDs 23a to 23h have different luminous efficiencies for each of the wavelengths as shown in FIG. 6, the LED controller 15 supplies a current corresponding to the LED to be turned on. In this way, by controlling the current value, the amount of light necessary for photographing is emitted.

  Light emitted from the LEDs 23a to 23h at a predetermined angle is incident on the light diffusing element 26 and is first reflected by the diffuse reflection plane 26b. The diffuse reflection plane 26b is a surface on which fine white paint particles for faithfully diffusing and reflecting light of all wavelengths with a reflectance independent of the wavelength are applied to the inner surface. Due to the reflection action of the diffuse reflection plane 26b, the diffusion of the transmitted light is surely promoted.

  The light reflected by the diffuse reflection plane 26b is further reflected with directivity according to the radius of curvature R by the torus reflection surface 26c, which is the second circumferentially curved reflection surface.

  This light is further diffused by the optical sheet 27 and then irradiated to the object 4 as uniform illumination light. At this time, since the external light is blocked by the hood 6, the object 4 is almost illuminated only by the illumination light from the LED.

  The irradiated light is reflected by the object 4, enters the imaging optical system 21, and forms an image on the imaging surface of the CCD 13 having a color filter.

  The image data thus generated by photoelectric conversion by the CCD 13 is subjected to signal processing by the signal processing circuit 14 and then stored in the memory 16.

  Such an operation is performed in response to sequential turn-on / off of the LEDs 23a to 23h, and image data corresponding to each of the eight types of wavelengths is sequentially stored in the memory 16. Such eight types of image data may be fetched only once, but may be repeated a plurality of times in order to improve data reliability.

  When such a measurement operation using the photographing apparatus 1 is completed, the user places the photographing apparatus 1 on the cradle 2 and electrically connects the contact 9 and the contact 39.

  Then, the control circuit 18 of the photographing apparatus 1 and the CPU 31 of the cradle 2 communicate with each other, and the image data stored in the memory 16 is transferred from the photographing apparatus 1 to the cradle 2.

  The cradle 2 temporarily stores the received image data in the SRAM 33, processes it with the FPGA 32 or the like, and transmits it to the PC 3 via the USB 2 I / F 37.

  The PC 3 analyzes the received image data using the installed color analysis software 41. At this time, the analysis is performed with reference to the color database 42 stored in the PC 3. Thereby, the exact color of the subject is clearly analyzed in the PC 3, and the result is displayed on the monitor of the PC 3.

  Further, by connecting the photographing apparatus 1 to the cradle 2, the battery 19 of the photographing apparatus 1 is charged by receiving power supply from the AC adapter 35 of the cradle 2 via the contacts 9 and 39.

  According to the first embodiment, since the light diffusing element is provided in the multispectral illumination device, the light emitted from the plurality of LEDs is irradiated to the irradiated surface of the object as uniform illumination light having no unevenness in intensity. can do. Furthermore, since the diffuse reflection plane is provided in the light diffusing element, the illumination light can be made uniform efficiently. And since the torus reflective surface is provided in the light diffusing element, illumination light can be efficiently irradiated. In addition, since the optical sheet having the function of diffusing light is provided on the exit surface of the light diffusing element, the illumination light can be made more uniform.

  Since the illumination optical system can be configured relatively compactly, it is possible to configure a multispectral imaging apparatus that is small in size, has good operability, and can perform accurate color measurement.

  FIG. 7 shows a second embodiment of the present invention, and is a perspective view showing a configuration of an illumination optical unit using a light diffusing element, a side sectional view, and a side view showing an action of an optical sheet. In the second embodiment, the same parts as those of the first embodiment are denoted by the same reference numerals and the description thereof is omitted, and only different points will be mainly described.

  As shown in FIGS. 7A and 7B, light emitted from the LEDs 23a to 23h provided in the light emitting unit 22b with a predetermined emission angle passes through the first optical sheet 28 having a diffusion function. Via the light diffusing element 26.

  As shown in FIG. 7C, the first optical sheet 28 has a plane of incidence 28a and a plane of emission 28b, and diffuses light emitted from the light emitting unit 22b. After the emission angle is widened, the light is emitted into the light diffusing element 26.

  The light incident on the light diffusing element 26 with a sufficient spread is repeated in the same manner as in the above-described first embodiment, and further, the diffusion is promoted by reflection a plurality of times, and finally becomes close to the integrated light. Irradiated as uniform illumination light toward the irradiated surface of the object 4.

  The illumination optical unit according to the second embodiment includes the first optical sheet 28 and the light diffusing element 26 as described above.

  According to the second embodiment, even if an optical sheet is provided on the incident side instead of providing the optical sheet on the emission side of the light diffusing element 26, the same effects as those of the first embodiment described above can be obtained. Can do.

  FIG. 8 is a perspective view showing a configuration of an illumination optical unit using a light diffusing element and a light guide element, a side sectional view, and a side view showing the action of an optical sheet, showing Embodiment 3 of the present invention. is there. In the third embodiment, the same parts as those in the first and second embodiments are denoted by the same reference numerals, description thereof is omitted, and only different points will be mainly described.

  As shown in FIGS. 8A and 8B, the light emitted from the LEDs 23a to 23h provided in the light emitting unit 22b with a predetermined emission angle is a second optical sheet having a directivity control function. The light is diffused into the light diffusing element 26 through 28A.

  The second optical sheet 28A has a surface subjected to louver processing for controlling the directivity of light, and as shown in FIG. 8C, the light emitted from the light emitting unit 22b has a predetermined angle. The light is converted into light having directivity (so that only light within a predetermined emission angle range is emitted) and emitted into the light diffusing element 26.

  The light incident on the light diffusing element 26 at a predetermined incident angle repeats the diffusion promotion by reflection at a number of times equal to or higher than that in the first embodiment, and finally becomes close to the integrated light. The light is emitted with a predetermined spread angle.

  The light emitted from the light diffusing element 26 enters the light guide element 29, which is a cylindrical member having a tapered shape whose diameter is reduced toward the distal end side (the object 4 side), from the incident side opening 29a. . The light guide element 29 is disposed so as to be coaxial with the central axis of the light diffusing element 26 and the central axis of the LED substrate 22, and the inner peripheral surface having a tapered shape is coated with aluminum to reflect the surface. 29c. The reflection surface 29c is configured to have a reflection characteristic of 80% or more with respect to each wavelength of the light emitted from the LEDs 23a to 23h, and the amount of light is reduced as much as possible even when the light is reflected. There is no such thing.

  By repeating the light guide reflection by the reflecting surface 29c a plurality of times, the light diffusion angle is increased as the taper is reduced in diameter. Thus, when the light is emitted from the emission-side opening 29b of the light diffusing element 26, the light finally becomes a state close to complete diffused light, and is irradiated onto the irradiated surface as uniform illumination light with no unevenness in the amount of light.

  The illumination optical unit according to the third embodiment includes the second optical sheet 28A, the light diffusion element 26, and the light guide element 29 as described above.

  Further, the outside light is blocked by the hood 6, but the hood 6 may be omitted by providing the light guide element 29 with the function of the hood 6. Is possible.

  According to the third embodiment, the same effects as those of the first and second embodiments can be obtained by using an optical sheet or a tapered light guide element. By using an optical sheet having a directivity control function, it becomes possible to obtain optical characteristics that cannot be achieved by other optical systems alone.

  9 to 11 show Embodiment 4 of the present invention. FIG. 9 is a side view showing the internal configuration of the photographing apparatus, a side sectional view showing the multispectral illumination apparatus in an enlarged manner, and FIG. FIG. 11 is a perspective view and a side sectional view showing a configuration of an illumination optical unit using a light diffusing element and a light guide element, and FIG. 11 is a view for explaining correction of illumination unevenness by an optical sheet. In the fourth embodiment, parts similar to those of the first to third embodiments are denoted by the same reference numerals, description thereof is omitted, and only different points will be mainly described.

  As shown in FIGS. 9A and 9B, a second optical sheet 51 having a directivity control function is provided in the vicinity of the exit 26d of the light diffusing element 26. FIG.

  Similar to the second optical sheet 28A of the third embodiment described above, the second optical sheet 51 has a surface subjected to louver processing for controlling the directivity of light, and is emitted from the light diffusing element 26. Conversion is performed so that light having a spread in a state close to the integrated light emitted from the mouth 26d becomes light having directivity of a predetermined angle.

  Light that is emitted from the second optical sheet 51 and spreads at a predetermined angle with directivity enters the hollow light guide element 52.

  The hollow light-guiding element 52 is configured by concentrically doublingly arranging tapered cylindrical members whose diameter decreases toward the distal end side, with different diameters. Are arranged so as to be coaxial with the central axis of the LED substrate and the central axis of the LED substrate 22.

  That is, as shown in FIG. 10A and FIG. 10B, the hollow light guide element 52 is disposed on the inner diameter side and the tapered cylindrical member 52a disposed on the outer diameter side. A cylindrical member 52b having a tapered shape, and an inner peripheral surface side of the cylindrical member 52b has a hollow opening 52g for allowing reflected light from the object 4 to pass through the imaging optical system 21. It has become. The space between the two cylindrical members 52a and 52b is an optical path through which illumination light passes, and the interval between the optical paths is configured to become narrower toward the distal end side. In such an arrangement, the inner peripheral surface side of the cylindrical member 52a is a reflective surface 52c on which an aluminum coat is applied, and the outer peripheral surface side of the cylindrical member 52b is a reflective surface 52d on which an aluminum coat is applied. These reflection surfaces 52c and 52d are configured to have a reflection characteristic of 80% or more with respect to each wavelength of light emitted from the LEDs 23a to 23h, and the amount of light is reduced as much as possible even when light is reflected. There is nothing to do.

  The light incident from the second optical sheet 51 to the ring-shaped incident port 52e of the hollow light guide element 52 is finally reflected into the diffused light by being reflected a plurality of times by the reflecting surfaces 52c and 52d. In a close state, the light is emitted as light having directivity with respect to the irradiated surface from the ring-shaped emission port 52 f of the hollow light guide element 52.

  The light emitted from the hollow light guide element 52 enters the third optical sheet 53. As shown in FIG. 11, the third optical sheet 53 has gradation characteristics that correct illumination unevenness when the third optical sheet 53 is not provided. Is provided with a circular opening 53 a for allowing the reflected light from the object 4 to pass through the imaging optical system 21, similar to the hollow opening 52 g of the hollow light guide element 52.

  That is, as shown in FIG. 11 (A), when the illumination light from the hollow light guide element 52 is directly irradiated onto the surface to be irradiated of the object 4, illumination unevenness with a distribution as shown in FIG. It may occur on the irradiated surface. Therefore, the third optical sheet 53 having a gradient characteristic (on the irradiated surface) as shown in FIG. 11D that can correct this illumination unevenness is hollow as shown in FIG. By disposing the light guide element 52 on the front end side, uniform illumination without uneven illumination as shown in FIG. 11E can be performed.

  By the illumination light that has passed through the third optical sheet 53, the object 4 is uniformly illuminated without unevenness, and the reflected light from the object 4 is reflected by the circular opening 53a, the hollow opening 52g, and the circular hole 26a. Are sequentially imaged on the CCD 13 by the imaging optical system 21.

  The illumination optical unit according to the fourth embodiment includes the light diffusing element 26, the second optical sheet 51, the hollow light guide element 52, and the third optical sheet 53 as described above.

  In the above description, the second optical sheet 51 is disposed between the light diffusing element 26 and the hollow light guide element 52, and the third optical sheet 53 is disposed on the distal end side of the hollow light guide element 52. However, the present invention is not limited to this, and can be arranged at an appropriate position. Further, the optical characteristics of the second optical sheet 51 and the third optical sheet 53 are not limited to the above-described characteristics, and those having appropriate characteristics can be used. By adjusting the arrangement and characteristics in this way, it is possible to improve the efficiency and uniformity of illumination and control the directivity, and it is possible to configure an illumination optical system that matches the desired characteristics. Become.

  The external light is blocked by the hood 6, and the hood 6 is omitted by providing the hollow light guide element 52 with the function of the hood 6. Is also possible.

  According to the fourth embodiment, it is possible to obtain substantially the same effects as the first to third embodiments described above by combining a hollow light guide element or a plurality of optical sheets with a light diffusing element.

  FIG. 12 shows a fifth embodiment of the present invention, and is a perspective view showing a configuration of an illumination optical unit using a light diffusing element and a polarizing plate, a side sectional view, and a state of light reflection on an object. It is an expanded sectional view shown. In the fifth embodiment, parts similar to those in the first to fourth embodiments described above are denoted by the same reference numerals, description thereof is omitted, and only different points will be mainly described.

  The light emitted from the light emitting unit 22b is generally light having both a P-polarized component and an S-polarized component, and is reflected by the light diffusing element 26 as shown in FIG. As explained, it is emitted as diffused light that can uniformly irradiate the irradiated surface of the object 4.

  As shown in FIG. 12B, a first polarizing plate 61 is disposed in the vicinity of the exit 26d of the light diffusing element 26. The first polarizing plate 61 passes only the S-polarized component of the light emitted from the light emitting unit 22b.

  The S-polarized light that has passed through the first polarizing plate 61 enters the light shielding frame 63. The light shielding frame 63 is a cylindrical member formed in a tapered shape with a diameter decreasing toward the tip side, and is arranged to be coaxial with the central axis of the light diffusing element 26 and the central axis of the LED substrate 22. In addition, the inner peripheral surface 63a having a tapered shape is provided with a black coating that absorbs light with a high absorption rate independent of the wavelength.

  With this configuration, light that is unnecessary for irradiating the irradiated surface of the object 4 out of the light emitted from the light diffusing element 26 is absorbed by the inner peripheral surface 63 a of the light shielding frame 63. Therefore, it does not reach the irradiated surface.

  In this way, when the object 4 is irradiated with S-polarized light, two types of reflection occur. First, the first reflection is regular reflection performed on the surface of the object 4. When this regular reflection occurs, the S-polarized light reaching the surface of the object 4 is reflected while maintaining the S-polarization based on the reflectance characteristics of the surface.

  Next, the second reflection is a reflection performed inside the object 4 as shown in FIG. S-polarized light incident on the inside of the object 4 from the surface is scattered by the particles 4 a constituting the object 4. This scattering results in reflected light including the color component of the irradiated surface, and this reflected light includes both the P-polarized component and the S-polarized component. The light reflected in this way goes again to the imaging optical system 21 side.

  A second polarizing plate 62 that blocks the S-polarized light component and allows only the P-polarized light component to pass is disposed on the object 4 side of the image sensor 21. Thereby, the S-polarized light by the first reflection (regular reflection) and the S-polarized component of the light by the second reflection are blocked, and these lights do not reach the imaging optical system 21. .

  On the other hand, the P-polarized component of the light due to the second reflection passes through the second polarizing plate 62 and enters the imaging optical system 21 and forms an image on the CCD 13. Thus, the CCD 13 photoelectrically converts light that does not contain a regular reflection component and outputs an image signal.

  Therefore, the color analysis software 41 of the PC 3 can accurately analyze the color component.

  The illumination optical unit according to the fifth embodiment includes the light diffusing element 26, the first polarizing plate 61, the second polarizing plate 62, and the light shielding frame 63 as described above.

  Further, the outside light is blocked by the hood 6. However, the hood 6 can be omitted by providing the hood 6 with the function of the hood 6. It is.

  According to the fifth embodiment, the same effects as those of the first to fourth embodiments described above can be obtained, the specular reflection component can be efficiently removed, and accurate color measurement can be performed.

  Since the inner peripheral surface of the light shielding frame is painted black, when the inner peripheral surface is not black painted, the light reflected from the S-polarized light to the P-polarized light by the light shielding frame is correctly reflected by the object. The reflected light can be prevented from entering the imaging optical system, and more accurate color measurement can be performed.

  In addition, this invention is not limited to the Example mentioned above, Of course, a various deformation | transformation and application are possible within the range which does not deviate from the main point of invention.

[Appendix]
According to the embodiment of the present invention as described in detail above, the following configuration can be obtained.

(1) A multispectral illumination device that irradiates the irradiated surface with light of different wavelengths, and an imaging optical system that forms an image of reflected light from the irradiated surface illuminated by the multispectral illumination device. A multispectral imaging device for measuring a color component of the irradiated surface by analyzing a component of reflected light acquired through an imaging optical system,
The multispectral illumination device is
A plurality of light sources that emit light of different wavelengths arranged in a ring shape so as to emit light in a direction opposite to the irradiated surface;
A first reflection surface for reflecting the light from the light source while diffusing, and a second reflection surface for reflecting the light from the first reflection surface, the second reflection A light diffusing element that irradiates the irradiated surface with light reflected by the surface;
A multispectral imaging device characterized in that the multispectral imaging device is configured.

(2) The second reflecting surface is formed in a rotationally symmetric torus shape, and is a reflecting surface having a substantially arc shape when cut by a plane including a rotationally symmetric axis. The multispectral imaging device according to appendix (1).

(3) The light diffusing element is configured such that a distance from the light source to the first reflecting surface is in a range from 8.5 mm to 14 mm, and the second reflecting surface is set to an axis of rotational symmetry. The multispectral imaging device as set forth in appendix (2), wherein the radius of curvature of the substantially arc when cut by a plane including is in the range of 8.5 mm to 10.5 mm .

(4) The multispectral imaging according to any one of appendices (1) to (3), wherein the light diffusing element is a reflective surface in which the first reflective surface is white-coated. apparatus.

(5) The multi-spectrum according to any one of appendices (1) to (4), wherein the light diffusing element is a reflective surface on which the second reflective surface is subjected to an aluminum coating treatment. Imaging device.

(6) The multispectral illumination device further guides light emitted from the light diffusing element toward the irradiated surface, and has a tapered shape that reduces the diameter toward the irradiated surface. None, any one of appendix (1) to appendix (5), characterized in that the inner peripheral surface side is configured to have a substantially cylindrical light guide element configured as a reflective surface that reflects light. The multispectral imaging device according to claim 1.

(7) The multispectral illumination device further guides light emitted from the light diffusing element toward the irradiated surface, and has a tapered shape that decreases in diameter toward the irradiated surface. The substantially cylindrical member is configured to be doubled with different diameters, and the inner peripheral surface side of the cylindrical member on the outer diameter side and the outer peripheral surface side of the cylindrical member on the inner diameter side transmit light. The multispectral imaging apparatus according to any one of appendices (1) to (5), wherein the multispectral imaging device is configured to include light guide elements each configured as a reflective surface to reflect.

(8) The multispectral illumination apparatus further includes an optical sheet for controlling light disposed on an emission surface side of the plurality of light sources. The multispectral imaging device according to any one of 1) to appendix (7).

(9) The multispectral illuminating device further includes an optical sheet for controlling light disposed on the exit surface side of the light diffusing element. The multispectral imaging device according to any one of 1) to appendix (7).

(10) The multispectral illumination device further includes an optical sheet for controlling the light disposed on the light exit surface side of the light guide element. 6) or the multispectral imaging device according to appendix (7).

(11) The multispectral imaging apparatus according to any one of appendices (8) to (10), wherein the optical sheet controls the light by a predetermined diffusivity.

(12) The optical sheet performs any one of the supplementary notes (8) to (10), wherein the light is controlled so as to emit only light within a predetermined emission angle range. A multispectral imaging device according to claim 1.

(13) The multispectral imaging apparatus according to (9) or (10), wherein the optical sheet has a gradation for reducing non-uniformity of illumination on the irradiated surface.

(14) The multispectral illumination device is:
A first polarizing plate disposed on the exit surface side of the light diffusing element and transmitting only light in one polarization direction;
A second polarizing plate disposed on the incident surface side of the imaging optical system and transmitting only light in another polarization direction orthogonal to the one polarization direction;
The multispectral imaging apparatus according to any one of supplementary notes (1) to (5), further comprising:

(15) The multispectral illumination device further covers an outer peripheral side of an optical path in which light emitted from the light diffusing element travels toward the irradiated surface, and has a small diameter toward the irradiated surface. As described in the appendix (14), which is configured to have a substantially cylindrical light-shielding frame that is formed into a tapered shape and has a black coating that absorbs light on the inner peripheral surface side. Multispectral imaging device.

(16) a plurality of light sources that emit light having different wavelengths, which are arranged in a ring shape so as to emit light in a direction opposite to the irradiated surface;
A first reflection surface for reflecting the light from the light source while diffusing, and a second reflection surface for reflecting the light from the first reflection surface, the second reflection A light diffusing element that irradiates the irradiated surface with light reflected by the surface;
A multispectral illumination device comprising:

(17) The second reflecting surface is formed in a rotationally symmetric torus shape, and is a reflecting surface having a substantially arc shape when cut by a plane including a rotationally symmetric axis. The multispectral illumination device according to appendix (16).

(18) The light diffusing element is configured such that a distance from the light source to the first reflecting surface is in a range of 8.5 mm to 14 mm, and the second reflecting surface is arranged on a rotationally symmetric axis. The multispectral illumination device as set forth in appendix (17), characterized in that the radius of curvature of a substantially arc when cut by a plane including a diameter is in the range of 8.5 mm to 10.5 mm .

(19) The multispectral illumination according to any one of appendix (16) to appendix (18), wherein the light diffusing element is a reflective surface in which the first reflective surface is white coated. apparatus.

(20) The multispectral according to any one of appendix (16) to appendix (19), wherein the light diffusing element is a reflective surface on which the second reflective surface is subjected to an aluminum coating treatment. Lighting device.

(21) The light emitted from the light diffusing element is guided toward the irradiated surface, has a tapered shape with a diameter decreasing toward the irradiated surface, and the inner peripheral surface reflects the light. The multispectral illumination device according to any one of supplementary notes (16) to (20), further comprising a substantially cylindrical light guide element configured as a reflecting surface.

(22) Light that is emitted from the light diffusing element is guided toward the irradiated surface, and the diameter of the tapered substantially cylindrical member that decreases in diameter toward the irradiated surface is varied. The inner peripheral surface side of the cylindrical member on the outer diameter side and the outer peripheral surface side of the cylindrical member on the inner diameter side are each configured as a reflective surface that reflects light. The multispectral illumination device according to any one of supplementary notes (16) to (20), further comprising a light guide element.

(23) From the supplementary note (16) to the supplementary note (22), further comprising an optical sheet for controlling the light disposed on the emission surface side of the plurality of light sources. The multispectral illumination device according to any one of the above.

(24) From the supplementary note (16) to the supplementary note (22), further comprising an optical sheet for controlling the light disposed on the exit surface side of the light diffusing element. The multispectral illumination device according to any one of the above.

(25) According to appendix (21) or appendix (22), further comprising an optical sheet for controlling the light disposed on the light exit surface side of the light guide element The multispectral illumination device described.

(26) The multispectral illumination device according to any one of appendices (23) to (25), wherein the optical sheet performs the light control by a predetermined diffusivity.

(27) Any one of Supplementary Notes (23) to (25), wherein the optical sheet performs control of the light so as to emit only light within a predetermined emission angle range. A multispectral illumination device according to claim 1.

(28) The multispectral imaging apparatus according to appendix (24) or appendix (25), wherein the optical sheet has a gradation for reducing non-uniformity of illumination on the irradiated surface.

(29) a first polarizing plate disposed on the exit surface side of the light diffusing element and transmitting only light in one polarization direction;
A second polarizing plate disposed on the incident surface side of the imaging optical system and transmitting only light in another polarization direction orthogonal to the one polarization direction;
The multispectral illumination device according to any one of supplementary notes (16) to (20), further comprising:

(30) The light emitted from the light diffusing element covers an outer peripheral side of an optical path that travels toward the irradiated surface, and has a tapered shape that decreases in diameter toward the irradiated surface. The multispectral illumination device as set forth in appendix (29), further comprising a substantially cylindrical light-shielding frame having a black coating that absorbs light on the surface side.

  The present invention can be suitably used when performing illumination in an apparatus for measuring the color of an object.

The figure which shows the usage condition of the multispectral imaging device in Example 1 of this invention. FIG. 3 is a block diagram showing a configuration of a multispectral imaging apparatus in the first embodiment. In the said Example 1, the figure which shows the internal structure of the imaging device centering on a multispectral illuminating device from a side, and the front view which shows the structure of an LED board. In the said Example 1, the figure which shows the structure of a multispectral illuminating device from a side, and the side view which shows the effect | action of a reflective surface. In the said Example 1, the diagram which shows the illumination spectrum by LED, and the spectral sensitivity of CCD. In the said Example 1, the diagram which shows the characteristic data when the component factor of a light-diffusion element is changed. In Example 2 of this invention, the perspective view which shows the structure of the illumination optical unit using a light-diffusion element, a side sectional view, and the side view which shows the effect | action of an optical sheet. The perspective view which shows the structure of the illumination optical unit using the light-diffusion element and light guide element in Example 3 of this invention, a sectional side view, and a side view which shows the effect | action of an optical sheet. The figure which shows the internal structure of the imaging device in Example 4 of this invention from a side, and the sectional side view which expands and shows a multispectral illuminating device. In the said Example 4, the perspective view and side sectional drawing which show the structure of the illumination optical unit using a light-diffusion element and a light guide element. In the said Example 4, the figure for demonstrating correction | amendment of the illumination nonuniformity by an optical sheet. The perspective view which shows the structure of the illumination optical unit using the light-diffusion element and polarizing plate in Example 5 of this invention, a side sectional view, and the expanded sectional view which shows the mode of the reflection of the light in a target object.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Imaging device 2 ... Cradle 3 ... Personal computer (PC)
4 ... object 5 ... main body 6 ... hood 7 ... power switch 8 ... shutter button 9 ... contact 12 ... electric circuit board 13 ... CCD
DESCRIPTION OF SYMBOLS 14 ... Signal processing circuit 15 ... LED controller 16 ... Memory 17 ... Power supply circuit 18 ... Control circuit 19 ... Battery 21 ... Imaging optical system 22 ... LED board (a part of multispectral illumination device)
22a ... circular hole 22b ... light emitting unit (light source, part of multispectral illumination device)
23a to 23h ... LED (light source, part of multispectral illumination device)
24. Illumination optical unit (part of multi-spectral illumination device)
26: Light diffusing element 26a: Circular hole 26b: Diffuse reflection plane (first reflection surface)
26c ... Torus reflecting surface (second reflecting surface)
26d ... Outlet 27 ... Optical sheet 28 ... First optical sheet 28A ... Second optical sheet 29 ... Light guide element 29c ... Reflecting surface 31 ... CPU
35 ... AC adapter 39 ... contact 41 ... color analysis software 42 ... color database 51 ... second optical sheet 52 ... hollow light guide element (light guide element)
52a ... cylindrical member (outer diameter side)
52b ... cylindrical member (inner diameter side)
52c ... reflective surface 52d ... reflective surface 52g ... hollow opening 53 ... third optical sheet 53a ... circular opening 61 ... first polarizing plate 62 ... second polarizing plate 63 ... light shielding frame 63a ... inner peripheral surface
Agent Patent Attorney Susumu Ito

Claims (26)

A multispectral illumination device that irradiates the irradiated surface with light of different wavelengths; and an imaging optical system that forms an image of reflected light from the irradiated surface illuminated by the multispectral illumination device. A multispectral imaging device that measures the color component of the irradiated surface by analyzing the component of the reflected light acquired via
The multispectral illumination device is
A plurality of light sources that emit light of different wavelengths arranged in a ring shape so as to emit light in a direction opposite to the irradiated surface;
A first reflection surface for reflecting the light from the light source while diffusing, and a second reflection surface for reflecting the light from the first reflection surface, the second reflection A light diffusing element that irradiates the irradiated surface with light reflected by the surface;
A multispectral imaging device characterized in that the multispectral imaging device is configured.   2. The reflection surface according to claim 1, wherein the second reflection surface is formed in a rotationally symmetric torus shape, and the shape when cut by a plane including a rotational symmetry axis forms a substantially arc. A multispectral imaging device according to claim 1.   The multispectral illumination device further guides light emitted from the light diffusing element toward the irradiated surface, and has a tapered shape with a reduced diameter toward the irradiated surface. The multispectral imaging apparatus according to claim 2, wherein the multispectral imaging apparatus is configured to include a substantially cylindrical light guide element having a circumferential surface configured as a reflective surface that reflects light.   The multispectral illumination device further guides light emitted from the light diffusing element toward the irradiated surface, and has a substantially cylindrical shape with a taper that decreases in diameter toward the irradiated surface. Reflection in which light is reflected by the inner peripheral surface side of the cylindrical member on the outer diameter side and the outer peripheral surface side of the cylindrical member on the inner diameter side. The multispectral imaging apparatus according to claim 2, wherein the multispectral imaging apparatus is configured to include light guide elements each configured as a surface.   The light diffusing element is configured such that a distance from the light source to the first reflecting surface is in a range from 8.5 mm to 14 mm, and the second reflecting surface is a plane including a rotationally symmetric axis. The multispectral imaging apparatus according to claim 2, wherein the radius of curvature of the substantially arc when cut by is within a range of 8.5 mm to 10.5 mm.   The multispectral illumination device further guides light emitted from the light diffusing element toward the irradiated surface, and has a tapered shape with a reduced diameter toward the irradiated surface. The multispectral imaging apparatus according to claim 5, wherein the multispectral imaging apparatus is configured to include a substantially cylindrical light guide element having a circumferential surface configured as a reflective surface that reflects light.   The multispectral illumination device further guides light emitted from the light diffusing element toward the irradiated surface, and has a substantially cylindrical shape with a taper that decreases in diameter toward the irradiated surface. Reflection in which light is reflected by the inner peripheral surface side of the cylindrical member on the outer diameter side and the outer peripheral surface side of the cylindrical member on the inner diameter side. The multispectral imaging apparatus according to claim 5, wherein the multispectral imaging apparatus is configured to have light guide elements each configured as a surface.   6. The multispectral illumination device according to claim 5, further comprising an optical sheet for controlling light disposed on an emission surface side of the plurality of light sources. Multispectral imaging device.   The multispectral imaging apparatus according to claim 8, wherein the optical sheet controls the light by a predetermined diffusivity.   The multispectral imaging apparatus according to claim 8, wherein the optical sheet performs control of the light so as to emit only light within a predetermined emission angle range.   2. The multispectral illumination apparatus according to claim 1, further comprising an optical sheet for controlling light disposed on an emission surface side of the light diffusing element. Multispectral imaging device.   The multispectral imaging apparatus according to claim 11, wherein the optical sheet controls the light by a predetermined diffusivity.   The multispectral imaging apparatus according to claim 11, wherein the optical sheet controls the light so as to emit only light within a predetermined emission angle range.   4. The multispectral illumination apparatus according to claim 3, further comprising an optical sheet for controlling light disposed on an exit surface side of the light guide element. Multispectral imaging device.   The multispectral imaging apparatus according to claim 14, wherein the optical sheet controls the light by a predetermined diffusivity.   15. The multispectral imaging apparatus according to claim 14, wherein the optical sheet controls the light so as to emit only light within a predetermined emission angle range.   5. The multispectral illumination apparatus according to claim 4, further comprising an optical sheet for controlling light disposed on an exit surface side of the light guide element. 6. Multispectral imaging device.   The multispectral imaging apparatus according to claim 17, wherein the optical sheet controls the light by a predetermined diffusivity.   The multispectral imaging apparatus according to claim 17, wherein the optical sheet controls the light so as to emit only light within a predetermined emission angle range.   The multispectral imaging apparatus according to claim 1, wherein the light diffusing element is a reflecting surface on which the first reflecting surface is painted white.   2. The multispectral imaging apparatus according to claim 1, wherein the light diffusing element is a reflecting surface on which the second reflecting surface is subjected to an aluminum coating process. The multispectral illumination device is
A first polarizing plate disposed on the exit surface side of the light diffusing element and transmitting only light in one polarization direction;
A second polarizing plate disposed on the incident surface side of the imaging optical system and transmitting only light in another polarization direction orthogonal to the one polarization direction;
The multispectral imaging apparatus according to claim 1, further comprising: A plurality of light sources that emit light of different wavelengths arranged in a ring shape so as to emit light in a direction opposite to the irradiated surface;
A first reflection surface for reflecting the light from the light source while diffusing, and a second reflection surface for reflecting the light from the first reflection surface, the second reflection A light diffusing element that irradiates the irradiated surface with light reflected by the surface;
A multispectral illumination device comprising:   24. The second reflecting surface is formed in a rotationally symmetric torus shape, and is a reflecting surface having a substantially arc shape when cut by a plane including a rotationally symmetric axis. A multispectral illumination device according to claim 1.   A light-reflecting surface that guides light emitted from the light diffusing element toward the irradiated surface, has a tapered shape with a diameter decreasing toward the irradiated surface, and reflects light on the inner peripheral surface side The multispectral illumination apparatus according to claim 24, further comprising a substantially cylindrical light guide element configured as described above.   Light that is emitted from the light diffusing element is guided toward the irradiated surface, and a tapered substantially cylindrical member that is reduced in diameter toward the irradiated surface is doubled with different diameters. The light guide is configured as a reflection surface that reflects light, and the inner peripheral surface side of the cylindrical member on the outer diameter side and the outer peripheral surface side of the cylindrical member on the inner diameter side. The multispectral illumination apparatus of claim 24, further comprising an element.

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