JP2018000733A - Optical measuring device, optical measuring method and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately analyze a state of a body to be measured.SOLUTION: An optical measuring device includes an irradiation part for irradiating a measuring light which is a modulated light onto a body to be measured, a light receiving part for receiving at least one of an external light which is a light of the outside and the measuring light reflected by the body to be measured, and converting the measuring light and the external light to an electric signal, a separation part for separating a measurement signal which is a signal component of the modulated measuring light by reducing a signal component of the external light from the electric signal, and an analysis part for analyzing the measurement signal and evaluating a state of the body to be measured.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an optical measurement device, an optical measurement method, and a program.

  There is known an optical measurement device that receives light reflected by a measurement object such as a person and evaluates the state of the measurement object by analyzing an electric signal obtained by electrically converting the light. Such an optical measurement device removes noise and the like caused by the measurement object, and improves analysis accuracy.

  However, when the measurement light is irradiated to the measurement object from a distant light source, the optical measurement device receives the measurement light and the external light, so that the electrical signal includes a signal component of the external light, There is a problem that the state of the measurement object cannot be accurately analyzed and evaluated.

  The present invention has been made in view of the above, and provides an optical measurement device, an optical measurement method, and a program capable of reducing the influence of external light and accurately analyzing the state of a measurement object. To do.

  In order to solve the above-described problems and achieve the object, the optical measurement device of the present invention includes an irradiation unit that irradiates a measurement object, which is modulated light, and external light that is external light, By receiving at least one of the measurement light reflected by the measurement object and converting the measurement light and the external light into an electrical signal, and reducing the signal component of the external light from the electrical signal, A separation unit that separates the measurement signal that is the signal component of the modulated measurement light; and an analysis unit that analyzes the measurement signal and evaluates the state of the measurement target.

  According to the present invention, it is possible to reduce the influence of external light and to accurately analyze the state of the measurement object.

FIG. 1 is a diagram of an optical measurement device according to the first embodiment. FIG. 2 is an enlarged configuration diagram of the optical measurement device according to the first embodiment. FIG. 3 is a diagram illustrating an implementation example of the optical measurement device according to the first embodiment. FIG. 4 is a functional block diagram illustrating functions of the control unit of the optical measurement device. FIG. 5 is a block diagram schematically illustrating the hardware configuration of the control unit of the optical measurement device. FIG. 6 is a flowchart of an optical measurement process executed by the control unit of the optical measurement device. FIG. 7 is a graph of a plurality of electrical signals acquired by the separation unit at the irradiation time when the measurement light is periodically irradiated. FIG. 8 is a graph that complements the estimated signal estimated from the electrical signal of FIG. 7 at the non-irradiation time when the measurement light is not irradiated. FIG. 9 is a graph obtained by extracting a guess signal from the graph of FIG. FIG. 10 is a graph of a plurality of electrical signals in the state of only external light that is not irradiated with the measurement light acquired by the separation unit. FIG. 11 is a graph of the measurement signal obtained by reducing and separating the external light signal. FIG. 12 is an overall configuration diagram of the optical measurement device according to the second embodiment. FIG. 13 is an overall configuration diagram of the optical measurement device according to the third embodiment. FIG. 14 is an enlarged configuration diagram of the optical measurement device according to the third embodiment. FIG. 15 is a functional block diagram illustrating functions of a control unit according to the third embodiment. FIG. 16 is an overall configuration diagram of the optical measurement device according to the fourth embodiment. FIG. 17 is an overall configuration diagram of the optical measurement device according to the fifth embodiment. FIG. 18 is an overall configuration diagram of the optical measurement device according to the sixth embodiment. FIG. 19 is an enlarged configuration diagram of the optical measurement device according to the seventh embodiment. FIG. 20 is an enlarged configuration diagram of the irradiation unit. FIG. 21 is a front view of the checker pattern portion. FIG. 22 is a diagram of a measurement subject irradiated with measurement light from the irradiation unit. FIG. 23 is a graph of an electrical signal in the irradiation area of the checker pattern. FIG. 24 is a graph of an electric signal in the light shielding region of the checker pattern. FIG. 25 is a graph of the measurement signal after separation by the separation unit.

  Common constituent elements such as the following exemplary embodiments are denoted by common reference numerals, and redundant descriptions are omitted as appropriate.

<First Embodiment>
FIG. 1 is a diagram of an optical measurement device 10 according to the first embodiment. As shown in FIG. 1, the optical measurement device 10 may be disposed at a position where external light 84 that is external light such as light transmitted through the window WD and light from the illumination device LD is received, for example. .

  The optical measurement device 10 includes a measurement unit 12 and a control unit 14. The measurement unit 12 irradiates the measurement light 82 that is measurement light to the cheek or nose of the face of the measurement subject 80 that is an example of the living body of the measurement target, and the measurement light 82 that is reflected by the measurement subject 80. Is received and converted into an electric signal S0. The control unit 14 is, for example, a computer. The control unit 14 controls the measurement unit 12 to irradiate the measurement light 82 and evaluates the state of the measurement subject 80 based on the electric signal S0 converted by the measurement unit 12.

  FIG. 2 is an enlarged configuration diagram of the optical measurement device 10 according to the first embodiment. As shown in FIGS. 1 and 2, the measurement unit 12 includes an irradiation unit 20 and a light receiving unit 22.

  The irradiation unit 20 irradiates the measurement subject 80 with the modulated light as the measurement light 82. The irradiation unit 20 includes a modulation unit 23, a light source unit 24, and an irradiation optical member 26.

  The modulation unit 23 irradiates the light source unit 24 with the modulated light as measurement light 82. For example, the modulation unit 23 modulates the intensity of the measurement light 82 with time (for example, pulse modulation) and irradiates it. Specifically, the modulation unit 23 periodically irradiates the measurement light 82 and does not irradiate the measurement light 82 for the remaining time. The modulation unit 23 is an example of a light intensity time modulation unit.

  The light source unit 24 is an illumination device capable of emitting light (for example, white light), an LED (Light Emitting Diode), a semiconductor laser, or the like. The light source unit 24 irradiates the measurement subject 80 with the measurement light 82 modulated according to the instruction from the modulation unit 23 via the irradiation optical member 26.

  The irradiation optical member 26 is disposed on the light irradiation side of the light source unit 24. The irradiation optical member 26 is a collimation optical member such as a convex lens, for example. The irradiation optical member 26 irradiates the measurement subject 80 with the measurement light 82 irradiated by the light source unit 24 close to parallel light. The irradiation optical member 26 may make the measurement light 82 substantially parallel light or parallel light.

  The light receiving unit 22 receives at least one of the measurement light 82 and the external light 84, converts the measurement light 82 and the external light 84 into an electric signal S <b> 0, and transmits it to the control unit 14. An example of the light receiving unit 22 is an imaging device such as a digital camera that captures an image of a subject such as the measurement subject 80 and generates image data. The light receiving unit 22 includes a light receiving lens 28 and a light receiving member 30.

  The light receiving lens 28 is, for example, a convex lens. The light receiving lens 28 receives the measurement light 82 reflected by the measurement subject 80. The light receiving lens 28 condenses the received measurement light 82 onto the light receiving member 30.

  The light receiving member 30 is disposed on the opposite side of the measurement subject 80 as viewed from the light receiving lens 28. The light receiving member 30 is an imaging element such as a digital camera having a CCD (Charge Coupled Device) sensor or a CMOS (Complementary Metal Oxide Semiconductor) sensor, for example. The light receiving member 30 electrically converts the light received from the light receiving lens 28 into one or a plurality of electric signals S0 having an intensity corresponding to the luminance level, and transmits the electric signal S0 to the control unit 14. For example, the light receiving member 30 transmits the pixel value (for example, RGB value) of each pixel included in the image data of one frame of the moving image or the image data of the still image to the control unit 14 as the electric signal S0. In this case, the light receiving unit 22 preferably has an autofocus function. Thereby, the light receiving member 30 can generate the electric signal S0 in a state where the measurement target region such as the face of the measurement subject 80 is in focus. Of the signal components included in the electrical signal S0, the signal component of the measurement light 82 is defined as a measurement signal S1. Of the signal components included in the electric signal S0, the signal component of the external light 84 is referred to as an external light signal S2. Note that the electrical signal S0 transmitted when the light receiving member 30 receives only the external light 84 is substantially equal to the external light signal S2.

  FIG. 3 is a diagram illustrating an implementation example of the optical measurement device 10 according to the first embodiment. The optical measuring device 10 shown in FIG. 3 is provided inside the automobile CA. For example, the optical measurement device 10 is provided in front of the driver who is the person to be measured 80. The optical measuring device 10 irradiates the measurement subject 80 with the measurement light 82 to analyze and evaluate the state of the measurement subject 80. The optical measurement device 10 is preferably arranged at a position where the measurement light 82 is not blocked by the handle SW.

  FIG. 4 is a functional block diagram illustrating functions of the control unit 14 of the optical measurement device 10. As illustrated in FIG. 4, the control unit 14 includes an instruction unit 36, a calculation unit 32, and a storage unit 34.

  The arithmetic unit 32 is an arithmetic processing device such as a processor including a CPU (Central Processing Unit). The calculation unit 32 includes an instruction unit 36, a separation unit 38, and an analysis unit 40. The calculation unit 32 has functions of an instruction unit 36, a separation unit 38, and an analysis unit 40, for example, by reading an optical measurement program stored in the storage unit 34. A part or all of the instruction unit 36, the separation unit 38, and the analysis unit 40 may be configured by hardware such as an ASIC (Application Specific Integrated Circuit).

  The instruction unit 36 transmits an irradiation instruction for irradiating the light source unit 24 with the modulated measurement light 82 to the modulation unit 23.

  The separation unit 38 acquires the electric signal S0 including the external light signal S2 and the measurement signal S1 from the light receiving member 30. The separation unit 38 separates the measurement signal S1 by reducing the external light signal S2 from the electrical signal S0. For example, the separation unit 38 separates the measurement signal S1 from the electrical signal S0 that changes according to the time modulation of the intensity of the measurement light 82. Here, when acquiring the image data as the electrical signal S0, the separation unit 38 sets a partial region in the image data as the measurement region, and uses only the electrical signal S0 in the measurement region to measure the measurement signal S1. May be separated. An example of the measurement region is a region in which the state of the measurement subject 80 such as the cheek, nose, and eyes of the measurement subject 80 can be evaluated. The separation unit 38 outputs the measurement signal S1 to the analysis unit 40.

  The analysis unit 40 acquires the measurement signal S1 from the separation unit 38. The analysis unit 40 analyzes the acquired measurement signal S1 and evaluates the state of the measurement subject 80. The analysis unit 40 notifies the measurement target 80 of the evaluation result via the notification unit 42 such as an image display device or a sound output device. The notification unit 42 may have the configuration of the optical measurement device 10 or a configuration different from the optical measurement device 10.

  The storage unit 34 stores a program such as an optical measurement program and parameters necessary for executing the program.

  FIG. 5 is a block diagram schematically illustrating a hardware configuration of the control unit 14 of the optical measurement device 10. As shown in FIG. 5, the control unit 14 of the optical measurement device 10 according to the present embodiment includes a CPU (Central Processing Unit) 50, a RAM (Random Access Memory) 52, a ROM (Read Only Memory) 54, and an HDD. The computer includes a (Hard Disk Drive) 56, an I / F 58, and a bus 60. The CPU 50, RAM 52, ROM 54, HDD 56 and I / F 58 are connected via a bus 60. Further, a modulation unit 23 such as an LCD (Liquid Crystal Display) and a light receiving member 30 are connected to the I / F 58.

  The CPU 50 is a calculation means such as a processor. The CPU 50 governs overall control of the optical measurement device 10. The RAM 52 is a volatile storage medium capable of reading and writing information at high speed, and is used as a work area when the CPU 50 processes information. The ROM 54 is a read-only nonvolatile storage medium and stores programs such as firmware.

  The HDD 56 is a nonvolatile storage medium capable of reading and writing information, and stores an OS (Operating System), various control programs, application programs, and the like. The I / F 58 connects and controls the bus 60 and various hardware and networks.

  The optical measurement program executed by the optical measurement apparatus 10 according to the present embodiment has a module configuration including the above-described units (the instruction unit 36, the separation unit 38, and the analysis unit 40). As the actual hardware, the CPU 50 reads the optical measurement program from the ROM 54 and executes it, whereby the above-described units are loaded onto the main storage device. Thus, the instruction unit 36, the separation unit 38, and the analysis unit 40 are generated on the main storage device, and these functions are realized in the computer.

  For example, the optical measurement program executed by the optical measurement device 10 of the present embodiment is provided by being incorporated in advance in the ROM 54 or the like. The optical measurement program executed by the optical measurement apparatus 10 of the present embodiment is a file in an installable format or an executable format, and is a CD-ROM, flexible disk (FD), CD-R, DVD (Digital Versatile). It may be configured to be recorded on a computer-readable recording medium such as a disk).

  Furthermore, the optical measurement program executed by the optical measurement device 10 of the present embodiment is stored on a computer connected to a network such as the Internet and provided by being downloaded via the network. Also good. Moreover, you may comprise so that the program for optical measurement performed with the optical measuring device 10 of this Embodiment may be provided or distributed via networks, such as the internet.

  FIG. 6 is a flowchart of an optical measurement process executed by the control unit 14 of the optical measurement device 10. The calculation part 32 of the control part 14 performs the optical measurement process which is an example of the optical measurement method by reading the program for optical measurement.

  As shown in FIG. 6, in the light measurement process, the instruction unit 36 transmits an irradiation instruction to the modulation unit 23, modulates the intensity with time, and periodically turns on and off the measurement light 82 to the light source unit 24. Irradiate (S102). The lighting cycle of the light source unit 24 is, for example, twice the cycle of generating the electrical signal S0 of the light receiving member 30. When the light receiving member 30 generates moving image data as the electric signal S0, the lighting cycle of the light source unit 24 is twice the moving image frame rate. Therefore, the light source unit 24 emits the measurement light 82 at a rate of one frame out of every two frames of the moving image. Next, the separation unit 38 receives only the measurement signal S1 and the external light signal S2 including the measurement signal S1 and the external light signal S2 from the light receiving member 30 that has received the measurement light 82 and the external light 84 reflected by the measurement subject 80. Are obtained alternately (S104).

  The separation unit 38 determines whether or not the number of times of acquiring the electrical signal S0 satisfies a predetermined number of times of acquisition (S106). The number of acquisitions is stored in the storage unit 34, for example. The separation unit 38 repeats steps S102 and S104 until the separation unit 38 determines that the number of acquisitions of the electrical signal S0 satisfies the acquisition number (S106: No).

  When determining that the number of times the electrical signal S0 has been acquired is the number of acquisition times (S106: Yes), the separation unit 38 reduces the external light signal S2 from the electrical signal S0 and separates the measurement signal S1 (S108).

  The process in which the separation unit 38 separates the measurement signal S1 from the electrical signal S0 executed in step S108 will be described with reference to FIGS.

  FIG. 7 is a graph of a plurality of electrical signals S0 acquired by the separation unit 38 at the irradiation time when the measurement light 82 is periodically irradiated. FIG. 8 is a graph obtained by complementing the estimated signal S0d estimated from the electrical signal S0 of FIG. 7 at the non-irradiation time when the measurement light 82 is not irradiated. FIG. 9 is a graph obtained by extracting the estimation signal S0d from the graph of FIG. FIG. 10 is a graph of a plurality of electrical signals S0 in the state of only the external light 84 that is not irradiated with the measurement light 82 acquired by the separation unit 38. FIG. 11 is a graph of the measurement signal S1 obtained by reducing and separating the external light signal S2. 7 to 11, the horizontal axis indicates time including irradiation time and non-irradiation time. The vertical axis indicates the signal intensity, which is the intensity of the measurement signal S1, the external light signal S2, and the electric signal S0. An example of the irradiation time at which the measurement light 82 is irradiated is the time at which the light receiving member 30 generates an odd-numbered frame of the frame rate of the moving image data when the moving image data is generated as the electric signal S0. An example of the non-irradiation time when the measurement light 82 is not irradiated is the time when the light receiving member 30 generates even-numbered frames of the frame rate of the moving image data when the moving image data is generated as the electric signal S0.

  The separation unit 38 acquires the electrical signal S0 illustrated in FIG. 7 including the measurement signal S1 and the external light signal S2 at the irradiation time when the measurement light 82 is irradiated. The separation unit 38 estimates the estimation signal S0d illustrated in FIG. 8 at the non-irradiation time when the measurement light 82 is not irradiated from the electrical signal S0 in FIG. For example, the separation unit 38 calculates the average of two electrical signals S0 that are temporally adjacent or adjacent to each other with an odd number of the frame rate shown in FIG. 7 at a non-irradiation time that is intermediate between the irradiation times of the two electrical signals S0. Calculated as the estimated signal S0d.

Here, when i is an integer, the frame number (2i + 1) is an odd number and corresponds to the irradiation time when the measurement light 82 is irradiated. On the other hand, the frame number (2i) is an even number and corresponds to a non-irradiation time when the measurement light 82 is not irradiated. When the electrical signal S0 of the frame number (2i + 1) is expressed as an electrical signal S0 (2i + 1) and the estimated signal S0d of the frame number (2i) is expressed as an estimated signal S0d (2i), the relationship between the electrical signal S0 and the estimated signal S0d Can be expressed by the following equation (1).
S0d (2i + 2) = (S0 (2i + 1) + S0 (2i + 3)) / 2 (1)
FIG. 9 shows an estimation signal S0d estimated by the separation unit 38 based on the equation (1).

As illustrated in FIG. 10, the separation unit 38 acquires, from the light receiving member 30, the electric signal S <b> 0 at the non-irradiation time when the measurement light 82 is not irradiated (that is, the even number of the frame rate). Since the electrical signal S0 at the non-irradiation time is acquired in a state where only the external light 84 is applied, it can be considered that the electrical signal S0 is composed only of the external light signal S2. The separation unit 38 separates the measurement signal S1 by the electrical signal S0 including only the estimation signal S0d illustrated in FIG. For example, the separation unit 38 calculates a difference Δ obtained by subtracting the electrical signal S0 (= external light signal S2) shown in FIG. 10 at the same time from the estimated signal S0d shown in FIG. Here, when i is an integer, the estimated signal S0d of the frame number (2i + 2) shown in FIG. 9 is expressed as the estimated signal S0d (2i + 2), and the electric signal S0 of the frame number (2i + 2) shown in FIG. This is expressed as a signal S0 (2i + 2). In this case, the above-described difference Δ can be expressed by the following equation (2).
Δ = S0d (2i + 2) −S0 (2i + 2)
= (S0 (2i + 1) + S0 (2i + 3)) / 2-S0 (2i + 2) (2)

  Since the difference Δ can be almost regarded as the measurement signal S1, the separation unit 38 calculates and separates the difference Δ as the measurement signal S1 in which the external light signal S2 is reduced. Thereby, the separation unit 38 separates the measurement signal S1 from the electrical signal S0 including the measurement signal S1 and the external light signal S2. Accordingly, the separation unit 38 separates the measurement signal S1 from the electrical signal S0 of FIGS. 7 and 10 acquired in a state where the intensity of the measurement light 82 is time-modulated.

  Returning to FIG. 6, the analysis unit 40 analyzes the acquired measurement signal S1 (S110). For example, the analysis unit 40 analyzes a pulse wave signal or the like that appears in the measurement signal S1 by the measurement light 82 reflected from the cheek or nose region of the measurement subject 80, and determines the fatigue state or stress state of the measurement subject 80. evaluate.

  The analysis of the measurement signal S1 by the analysis unit 40 and the evaluation of the state of the measurement subject 80 will be specifically described. In general, disturbances in human autonomic nerves cause fluctuations in the pulse interval. For example, in a stress state, a sympathetic nerve that is a human autonomic nerve is activated, but a parasympathetic nerve is inactivated. On the other hand, in the relaxed state, the parasympathetic nerve is activated and the sympathetic nerve is inactivated. Since there is such a balance relationship, when the stress state continues, the balance of the autonomic nerve is disturbed, and the parasympathetic nerve is not activated even in the relaxed state. As a result, the disturbance of the autonomic nerve appears as a change in fluctuation of the pulse interval. In addition, it is known that when spectrum analysis is performed focusing on fluctuations in the pulse interval, there is a tendency to have a low frequency peak and a high frequency peak. Here, the low-frequency fluctuation component (hereinafter referred to as LF component) mainly represents the function of the sympathetic nerve, and the high-frequency fluctuation component (hereinafter referred to as HF component) mainly represents the function of the parasympathetic nerve. Further, it is known that the HF component decreases and the LF / HF increases in the stress state and the fatigue state. Since the amount of hemoglobin in a person's blood changes depending on the pulse, the amount of light reflected from the skin region changes minutely according to changes in the pulse and the amount of hemoglobin.

  Accordingly, the electrical signal S0 obtained by converting the intensity (or luminance) of the light reflected by the cheek or nose of the person 80 to be measured is changed in synchronization with the pulse. To do. Therefore, the analysis unit 40 can analyze a pulse wave signal indicating a pulse by analyzing the measurement signal S1. Specifically, the analysis unit 40 can calculate the pulse rate of the person to be measured 80 by counting the number of peaks per minute of the measurement signal S1. Moreover, the analysis part 40 can calculate the fluctuation of the pulse of the measurement subject 80 by calculating the difference between the peak intervals of the measurement signal S1. The analysis unit 40 can digitize the state of the person 80 to be measured such as fatigue and stress by performing spectral analysis of fluctuations in the pulse interval from the pulse wave signal. For example, the analysis unit 40 extracts the LF frequency signal and the HF frequency signal by filtering based on the measurement signal S1 which is a pulse wave signal acquired from the separation unit 38, respectively. The analysis unit 40 calculates the LF signal by integrating the spectrum of the LF band (for example, integrating 0.04 Hz to 0.15 Hz). The analysis unit 40 calculates the HF signal by integrating the spectrum of the HF band (for example, integrating 0.15 Hz to 0.4 Hz). The analysis unit 40 evaluates the state of the measurement subject 80 such as fatigue and stress by calculating a ratio that is highly correlated with the degree of fatigue such as LF / HF or LF / (LF + HF). For example, the analysis unit 40 evaluates a healthy state if LF / HF is 2.5 or less, and evaluates a fatigue state if 3.0 or more.

  The analysis unit 40 notifies the measurement subject 80 of the evaluation result based on the analysis of the measurement signal S1 via the notification unit 42 (S112). The analysis unit 40 notifies the measurement subject 80 of the evaluation result by, for example, an image or sound.

  As described above, since the optical measurement device 10 reduces the external light signal S2 from the external light 84 and separates the measurement signal S1, the influence of the external light 84 is reduced and the state of the person 80 to be measured is more accurate. Can be analyzed and evaluated well.

Second Embodiment
FIG. 12 is an overall configuration diagram of the optical measurement device 110 according to the second embodiment. As illustrated in FIG. 12, the control unit 14 of the optical measurement device 110 according to the second embodiment is provided separately from the measurement unit 12.

<Third Embodiment>
FIG. 13 is an overall configuration diagram of the optical measurement device 210 according to the third embodiment. FIG. 14 is an enlarged configuration diagram of the optical measurement device 210 according to the third embodiment. As illustrated in FIGS. 13 and 14, the measurement unit 212 of the optical measurement device 210 includes an irradiation unit 220 and a light receiving unit 222.

  The irradiation unit 220 irradiates the measurement subject 80 with the measurement light 82 that is modulated by imparting polarization characteristics. The irradiation unit 220 includes a light source unit 24, an irradiation optical member 26, and a polarization modulation unit 225. The irradiation unit 220 of the third embodiment does not have the modulation unit 23.

  For example, the polarization modulator 225 is disposed on the irradiation side of the irradiation optical member 26. An example of the polarization modulator 225 is a polarization filter. After being irradiated from the light source unit 24, the polarization modulation unit 225 modulates the measurement light 82 that has been transmitted through the irradiation optical member 26 by applying a polarization characteristic to the measurement light 82, and irradiates the measurement subject 80 with the polarization. For example, the polarization modulator 225 modulates the measurement light 82 into linearly polarized light (for example, S-polarized light). The polarized measurement light 82 is transmitted through the body from the epidermis of the face of the person to be measured 80 and reaches the capillaries, and is reflected while being affected by the light absorption of hemoglobin. To the outside of the body. Note that the polarization characteristics of the measurement light 82 are slightly disturbed by egg laying in the human body of the person 80 to be measured, but the initial polarization component remains.

  The light receiving unit 222 includes a light detecting unit 229, the light receiving lens 28, and the light receiving member 30.

  For example, the light detection unit 229 is disposed closer to the measurement subject 80 than the light receiving lens 28. The light analyzer 229 is, for example, a polarization filter. The vibration direction of polarized light transmitted through the light analyzing unit 229 is associated with the vibration direction of polarized light transmitted through the polarization modulation unit 225. For example, the vibration direction of polarized light transmitted through the light analyzing unit 229 is substantially the same as the vibration direction of polarized light transmitted through the polarization modulation unit 225. Accordingly, the light analyzer 229 selectively transmits the measurement light 82 modulated to light having the polarization characteristic provided by the polarization modulator 225 (for example, linearly polarized light). On the other hand, the light analyzer 229 is non-polarized light that does not have polarization characteristics such as light (for example, sunlight) incident from the window WD or the like in the vicinity of the optical measurement device 110 and light from the illumination device LD. Blocks and reduces much of the light 84. Here, the width of the rotation angle in the vibration direction of the polarized light transmitted by the light analyzer 229 is preferably about ± 0.5 °. As a result, the light analyzer 229 cuts a large amount (for example, 99.7% = 359 × 100/360) of the external light 84 different from the polarization direction of the polarization modulator 225. As a result, the light detecting unit 229 supplies the light receiving member 30 with almost no external light 84 via the light receiving lens 28 and almost including the measurement light 82.

  FIG. 15 is a functional block diagram illustrating functions of the control unit 214 according to the third embodiment. As illustrated in FIG. 15, the calculation unit 232 of the control unit 214 according to the third embodiment includes an instruction unit 36 and an analysis unit 40. That is, the calculation unit 232 does not have the separation unit 38. The instruction unit 36 outputs an irradiation instruction for causing the light source unit 24 to irradiate the measurement light 82. Since the light receiving member 30 receives almost the light composed of the measurement light 82, the analysis unit 40 hardly includes the external light signal S2 due to the external light 84 even if there is no separation unit 38, and the electrical signal almost includes the measurement signal S1. S0 is acquired from the light receiving member 30. Therefore, the analysis unit 40 analyzes the electrical signal S0 acquired from the light receiving member 30 as the measurement signal S1, and evaluates the measurement subject 80.

  As described above, the optical measurement device 210 according to the third embodiment irradiates the measurement subject 80 with polarized light as the measurement light 82 and selectively receives the measurement light 82 separated from the external light 84 and generates it. The state of the person 80 to be measured is evaluated by analyzing the electric signal S0 that can be regarded as the measured signal S1. Thereby, the optical measuring device 210 can reduce the influence of the external light 84 and can analyze and evaluate the state of the person to be measured 80 with higher accuracy.

<Fourth embodiment>
FIG. 16 is an overall configuration diagram of an optical measurement device 310 according to the fourth embodiment. As shown in FIG. 16, the control unit 214 of the optical measurement device 310 of the fourth embodiment is provided separately from the measurement unit 212.

<Fifth Embodiment>
FIG. 17 is an overall configuration diagram of an optical measurement device 410 according to the fifth embodiment. As shown in FIG. 17, the optical measurement device 410 includes an irradiation unit 420 and a light receiving unit 222. The irradiation unit 420 includes a modulation unit 23, a light source unit 24, an irradiation optical member 26, and a polarization modulation unit 225.

  The irradiation unit 420 irradiates the measurement light 82 modulated by the light source unit 24 in accordance with an instruction from the modulation unit 23. The irradiation optical member 26 irradiates the polarization modulator 225 with the measurement light 82 as substantially parallel light. The polarization modulator 225 modulates the measurement light 82 into polarized light and irradiates the measurement subject 80.

  In the light receiving unit 222, the light detecting unit 229 transmits the measurement light 82 that is polarized light, and substantially blocks light other than the measurement light 82. The light receiving member 30 receives the light that has substantially become the measurement light 82 and transmits the electrical signal S0 to the separation unit 38.

  The separation unit 38 outputs the measurement signal S1 obtained by further reducing and separating the external light signal S2 from the electrical signal S0 that can be regarded as the measurement signal S1 to the analysis unit 40. The analysis unit 40 analyzes the measurement signal S1 acquired from the separation unit 38.

  As described above, the optical measurement device 410 according to the fifth embodiment further includes an external light signal from the electrical signal S0 that can be regarded as the measurement signal S1 generated by selectively receiving the measurement light 82 separated from the external light 84. The state of the person under measurement 80 is evaluated by analyzing the electric signal S0 separated from S2. Thereby, the optical measuring device 410 can further reduce the influence of the external light 84 and analyze and evaluate the state of the person to be measured 80 with higher accuracy.

<Sixth Embodiment>
FIG. 18 is an overall configuration diagram of an optical measurement device 510 according to the sixth embodiment. As shown in FIG. 18, the control unit 14 of the optical measurement device 510 is provided separately from the measurement unit 412.

<Seventh embodiment>
FIG. 19 is an enlarged configuration diagram of the optical measurement device 610 according to the seventh embodiment. As illustrated in FIG. 19, the irradiation unit 620 of the measurement unit 612 of the optical measurement device 610 includes a light source unit 24, an irradiation optical member 26, a polarization modulation unit 225, and a checker pattern unit that is an example of a light intensity region modulation unit. 627. The checker pattern unit 627 is disposed on the measurement subject 80 side (that is, the irradiation side) of the polarization modulation unit 225.

  FIG. 20 is an enlarged configuration diagram of the irradiation unit 620. FIG. 21 is a front view of the checker pattern portion 627.

  The checker pattern unit 627 modulates the intensity (or luminance) of the measurement light 82 in a region. As illustrated in FIGS. 20 and 21, the checker pattern unit 627 includes a transmission part 627 a and a light shielding part 627 b. The transmission part 627a and the light shielding part 627b are alternately arranged in two directions (for example, the vertical direction and the horizontal direction).

  The transmission unit 627 a transmits the measurement light 82 emitted from the light source unit 24. For example, the transmission part 627a is made of a transparent material that can transmit light.

  The light shielding unit 627 b blocks the measurement light 82 emitted from the light source unit 24. The light shielding part 627b is made of a material colored in black or the like that can block light. The light shielding unit 627b may be a polarizing filter that blocks the polarized light when the measurement light 82 is polarized light.

  FIG. 22 is a diagram of the person to be measured 80 irradiated with the measurement light 82 of the irradiation unit 620. As shown in FIG. 22, the checker pattern unit 627 receives the measurement light 82 from the light source unit 24 and receives an irradiation region 90 a having a high intensity of the measurement light 82 and a light shielding region 90 b having a low intensity of the measurement light 82 (inside the dotted circle). The checker pattern 90 including the reference) is irradiated on the measurement subject 80. The separation unit 38 separates the measurement signal S1 of the measurement light 82 from the external light signal S2 of the external light 84 based on the light intensity of the irradiation region 90a and the light intensity of the light shielding region 90b.

  FIG. 23 is a graph of the electric signal S0a of the irradiation region 90a of the checker pattern 90. The electrical signal S0a is, for example, an integral value of the electrical signal of the irradiation region 90a. FIG. 24 is a graph of the electric signal S0b of the light shielding region 90b of the checker pattern 90. The electric signal S0b is, for example, an integrated value of the electric signal in the light shielding region 90b. FIG. 25 is a graph of the measurement signal S1 after separation by the separation unit 38.

  For example, the separation unit 38 separates the electrical signal S0a of the irradiation region 90a and the electrical signal S0b of the light shielding region 90b from the image of the checker pattern 90 based on the region change of the intensity of the electrical signals S0a and S0b of the checker pattern 90. To do.

  Thereby, the separation unit 38 extracts the electric signal S0a of the irradiation region 90a shown in FIG. 23 from the image of the checker pattern 90. The electric signal S0a illustrated in FIG. 23 includes a measurement signal S1 based on the measurement light 82 and an external light signal S2 based on the external light 84. The separation unit 38 extracts the electric signal S0b of the light shielding region 90b shown in FIG. 24 from the image of the checker pattern 90. The electric signal S0b shown in FIG. 24 is an electric signal S0b of the light shielding region 90b that is not irradiated with the measurement light 82, and therefore can be regarded as an external light signal S2 by the external light 84.

  The separation unit 38 calculates the electric signal S0c shown in FIG. 25 by subtracting the electric signal S0b of the light shielding region 90b shown in FIG. 24 from the electric signal S0a of the irradiation region 90a shown in FIG. The electric signal S0c shown in FIG. 25 can be regarded as the measurement signal S1 because the electric signal S0b that can be regarded as the external light signal S2 is subtracted from the electric signal S0a including the measurement signal S1 and the external light signal S2. . Thereby, the separation unit 38 separates the electric signal S0c from the electric signal S0a as the measurement signal S1. In other words, the separation unit 38 separates the measurement signal S1 from the electrical signal S0a based on the change in the intensity of the electrical signals S0a and S0b that change in accordance with the change in the intensity of the measurement light 82 in the checker pattern 90. . The separation unit 38 outputs the electrical signal S0c shown in FIG. 25 to the analysis unit 40 as the measurement signal S1. The analysis unit 40 analyzes the measurement signal S1 to analyze the state of the person being measured 80.

  The function, shape, number, arrangement, and the like of the configuration of each embodiment described above may be changed as appropriate. You may combine each embodiment suitably.

  In the above-described embodiment, the optical measurement device 10 or the like installed in the automobile CA has been described as an example. However, the optical measurement device 10 or the like may be installed other than the automobile.

  In the above-described embodiment, an example in which the measurement light 82 is analyzed to evaluate the state of the person to be measured 80 is described. However, the optical measurement device 10 or the like analyzes the measurement light 82 to analyze a living body other than a person or You may evaluate the state of to-be-measured bodies other than a biological body.

  In the above-described embodiment, examples of the configuration for modulating the measurement light 82 include time modulation, region modulation, and polarization modulation, but are not limited thereto. For example, a phase time modulation unit that modulates the phase characteristic of the measurement light 82 with time may be provided in the optical measurement device 10 or the like.

DESCRIPTION OF SYMBOLS 10 ... Optical measuring device, 12 ... Measuring part, 14 ... Control part, 20 ... Irradiation part, 22 ... Light receiving part, 23 ... Modulation part, 24 ... Light source part, 26 ... Irradiation optical member, 30 ... Light receiving member, 36 ... Instruction 38: Separation unit, 40 ... Analysis unit, 42 ... Notification unit, 80 ... Measurement subject, 82 ... Measurement light, 84 ... External light, 90 ... Checker pattern, 110 ... Optical measurement device, 210 ... Optical measurement device, 212: Measurement unit, 214: Control unit, 220: Irradiation unit, 222: Light receiving unit, 225 ... Polarization modulation unit, 229 ... Light detection unit, 310 ... Optical measurement device, 410 ... Optical measurement device, 412 ... Measurement unit, 420 Irradiating unit, 510 ... optical measuring device, 610 ... optical measuring device, 612 ... measuring unit, 620 ... Morphism unit, 627 ... checker pattern portion, 627a ... transmitting unit, 627b ... shielding portion.

JP 2012-143316 A JP 2014-529439 A

Claims (11)

An irradiation unit for irradiating the measurement object, which is modulated light, to the measurement object;
A light receiving unit that receives external light that is external light and at least one of the measurement light reflected by the measurement target, and converts the measurement light and the external light into an electrical signal;
A separation unit that separates a measurement signal that is a signal component of the modulated measurement light by reducing a signal component of the external light from the electrical signal;
An analysis unit that analyzes the measurement signal and evaluates the state of the measurement object;
An optical measurement device comprising: The irradiation unit is
A light intensity time modulation unit for modulating the intensity of the measurement light with time,
A light intensity region modulation unit for modulating the intensity of the measurement light in a region;
A polarization modulator that modulates the measurement light by imparting a polarization characteristic; and
The optical measurement apparatus according to claim 1, further comprising at least one of a phase time modulation unit that modulates a phase characteristic of the measurement light with time. The irradiation unit is
A light source unit that emits the measurement light;
An irradiation optical member for bringing the measurement light emitted by the light source unit close to parallel light;
The optical measuring device according to claim 1, comprising: The irradiation unit includes a light intensity time modulation unit that modulates the intensity of the measurement light with time,
The optical measurement device according to claim 1, wherein the separation unit separates the measurement signal from the electrical signal acquired in a state where the intensity of the measurement light is time-modulated. The irradiation unit includes a light intensity region modulation unit that modulates the intensity of the measurement light in a region,
5. The optical measurement device according to claim 1, wherein the separation unit separates the measurement signal from the electrical signal in accordance with a region change in the intensity of the measurement light. The irradiation unit includes a polarization modulation unit that modulates the measurement light by imparting a polarization characteristic thereto,
The optical measurement device according to claim 1, wherein the light receiving unit includes a light detection unit that selectively transmits light having the polarization characteristic. The optical measurement device according to claim 1, wherein the analysis unit analyzes a state of a living body that is the measurement target. The optical measurement device according to claim 7, wherein the analysis unit analyzes a fatigue state of a living body that is the measurement target. An irradiating unit that irradiates a measurement object with measurement light modulated by imparting polarization characteristics; and
A measurement unit that selectively transmits and separates the measurement light from external light that is external light and light that includes the measurement light reflected by the measurement target; and the measurement that is transmitted by the detection unit A light receiving unit for converting light into an electrical measurement signal;
An analysis unit for analyzing the state of the measurement object based on the measurement signal;
An optical measurement device comprising: An irradiation unit for irradiating the measurement object, which is modulated light, to the measurement object;
Executed by an optical measurement device comprising: a light receiving unit that receives at least one of external light that is external light and the measurement light reflected by the measurement target, and converts the measurement light and the external light into an electrical signal. In the optical measurement method
Separating the measurement signal that is the signal component of the modulated measurement light by reducing the signal component of the external light from the electrical signal;
An analysis stage for analyzing the measurement signal and evaluating the state of the measurement object;
An optical measurement method comprising: An irradiation unit for irradiating the measurement object, which is modulated light, to the measurement object;
A computer of an optical measurement device comprising: a light receiving unit that receives at least one of external light that is external light and the measurement light reflected by the measurement target, and converts the measurement light and the external light into an electrical signal. In addition,
A separation function for separating a measurement signal which is a signal component of the modulated measurement light by reducing a signal component of the external light from the electrical signal;
An analysis function for analyzing the measurement signal and evaluating the state of the measurement object;
A program that realizes

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