JP2003166880A - Imaging device having temperature measuring means - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an imaging device having a temperature measuring means capable of taking a color photograph of an object, and measuring a specific temperature (temperature) of the object highly accurately. <P>SOLUTION: This device has an objective system for forming an image of an analyte, a branch optical system for branching light flux from the objective system into four or more optical paths, imaging means for acquiring image information of spectral images having mutually different spectral characteristics through the branch optical system, and a color image processing circuit for acquiring a color image from three spectral images and a temperature image processing circuit for acquiring a temperature distribution on the analyte from two spectral images, among the spectral images acquired by each imaging means. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image pickup apparatus having temperature measuring means, and more particularly to video shooting and an object (subject).
It is suitable for measuring the temperature of the object, displaying it, and measuring the temperature distribution of the object with high accuracy.

[0002]

2. Description of the Related Art Conventionally, there are various imaging systems which form an image of an object on the surface of an imaging means by an imaging system, process an output signal from the imaging means and display a color image (color image) on the display means. Proposed.

A color image has three primary colors, red (R), green (G), and blue (B), which the human eye perceives. Photographed so that primary color signals can be obtained, and reproduced in three primary colors.

A photographing method for obtaining three primary color signals from an image is as follows:
A method of using three dedicated image pickup means for R, G, B, and three colors like a three-plate color camera, and one image pickup means like a single-plate color camera, and each pixel has a light incident side. There are two types of methods in which R, G, B mosaic color filters are mounted and R, G, B signals are calculated from each pixel.

On the other hand, conventionally, infrared cameras have been widely used in the medical and industrial fields as a device for measuring the temperature distribution of an image (object) obtained by a photographing system and displaying it on a display means. In the infrared camera, the radiation in the infrared region is received by the image sensor (infrared sensor), and the intensity distribution is expressed as an image in shades, or it is expanded into colors and expressed as pseudo colors. .

[0006]

If an infrared camera is used as a means for measuring the temperature of an object, the temperature distribution of each part of the object field (object) can be known, but the infrared camera measures the "radiation temperature". Since it is difficult to know the true temperature (absolute temperature), it is impossible to obtain a color image at the same time.

As is well known, in order to know the true temperature from the radiation temperature of an object, it is necessary to make a correction by the emissivity or the transmittance of the object to be measured. However, since the emissivity shows different values depending on the object, the measurement wavelength, and the environment in which the object is placed, it is extremely difficult to know it accurately.

On the other hand, the radiation of two wavelengths (wavelength range) of the object to be measured is measured, the ratio between the two is calculated, and the temperature of the black body showing the same value is taken as the temperature of the object. The (Ratio Temperature, two-color temperature) measurement can accurately measure the temperature of an object as long as the emissivity at both wavelengths is the same. As long as the condition that the emissivity is the same, the specific temperature measuring method does not need to be corrected by emissivity or correction by transmittance.

When measuring the temperature of an object by using the specific temperature measuring method, in a three-image sensor type camera (three-plate type color camera), outputs from three sensors (imaging means) for receiving lights of different color lights. The relative emission ratio is obtained from the signal, and the specific temperature is obtained from this.

For example, when a self-luminous image is photographed by a video camera having three spectral wavelength bands and the temperature is to be obtained from the calculated value of the relative radiation ratio, the noise of the sensor becomes a great obstacle. If there is noise, an error will occur in the calculation of the relative radiation ratio, and the correct specific temperature cannot be obtained. Noise is generated at various places after the light is received and converted into an electric signal by the sensor, and it is very difficult to completely remove it. In specific temperature measurement, the temperature is measured not by the intensity of radiation but by the ratio of two radiations.Therefore, even if there is no radiation, if a small noise is in the measurement wavelength range, it is calculated as radiation and an incorrect temperature is calculated. Data may be output. Further, even if there is radiation, if the radiation data is weak, the amount of noise with respect to the radiation data is large and the so-called S / N ratio becomes poor, and an erroneous value may be output as temperature data.

According to the present invention, the color temperature of the object is measured and the specific temperature (temperature) of the object is measured with high accuracy, and the temperature information is displayed together with the image (color image) of the object on the display means. It is an object of the present invention to provide an imaging device having a temperature measuring means having a function capable of accurately displaying the temperature distribution of an object.

[0012]

According to another aspect of the present invention, there is provided an image pickup apparatus having temperature measuring means, an objective system for forming an image of a subject, and a branch for branching a light beam from the objective system into four or more optical paths. An optical system, an imaging means for obtaining image information of spectral images having different spectral characteristics through the branching optical system, and a color image for obtaining a color image from three spectral images of the spectral images obtained by each imaging means. It is characterized in that it has a processing circuit and a temperature image processing circuit for obtaining a temperature distribution relating to the subject from two spectral images.

According to a second aspect of the present invention, there is provided an image pickup apparatus having temperature measuring means, an objective system for forming an image of a subject, a branching optical system for branching a light beam from the objective system into a plurality of optical paths, and the branching optical system. An image pickup unit that obtains image information of a plurality of spectral images having different spectral characteristics through a system, and each pixel or a pixel group of two different spectral images existing at the same coordinate position among the spectral images obtained by the image pickup unit. A temperature image processing circuit for calculating the radiation intensity of the subject from the luminance and measuring the temperature of the subject by the ratio of the two radiation intensities, and the electricity of each pixel or pixel group obtained at different times. And an averaging circuit for averaging the output with respect to time.

According to another aspect of the present invention, there is provided an imaging apparatus having temperature measuring means, an objective system for forming an image of a subject, a branch optical system for branching a light beam from the objective system into a plurality of optical paths, and the branch optical system. An image pickup unit that obtains image information of a plurality of spectral images having different spectral characteristics through a system, and each pixel or a pixel group of two different spectral images existing at the same coordinate position among the spectral images obtained by the image pickup unit. The intensity of the radiation of the subject is calculated from the luminance, and the temperature image processing circuit that measures the temperature of the subject by the ratio of the two radiation intensities and the temperature distribution image of the calculation results obtained at different times are displayed. It is characterized by having an averaging circuit for averaging.

According to another aspect of the present invention, there is provided an imaging apparatus having temperature measuring means, an objective system for forming an image of a subject, a branch optical system for branching a light beam from the objective system into a plurality of optical paths, and the branch optical system. An image pickup unit that obtains image information of a plurality of spectral images having different spectral characteristics through a system, and each pixel or a pixel group of two different spectral images existing at the same coordinate position among the spectral images obtained by the image pickup unit. The intensity of radiation of the subject is calculated from the brightness, and the temperature image processing circuit that measures the temperature of the subject by the ratio of the intensity of both radiations, and the electrical output for the incident light incident on each image pickup unit. It is characterized by having a correction means for maintaining linearity.

According to another aspect of the present invention, there is provided an imaging apparatus having temperature measuring means, an objective system for forming an image of a subject, a branch optical system for branching a light beam from the objective system into a plurality of optical paths, and the branch optical system. An image pickup unit that obtains image information of a plurality of spectral images having different spectral characteristics through a system, and each pixel or a pixel group of two different spectral images existing at the same coordinate position among the spectral images obtained by the image pickup unit. A temperature image processing circuit for calculating the radiation intensity of the subject from the brightness and measuring the temperature of the subject by the ratio of the two radiation intensities, and a threshold value of the output signal from the imaging means or a threshold value or more. And a signal removing circuit for excluding the following output signals.

The invention of claim 6 is the invention of claim 2, 3, 4 or 5.
In the invention, the color image relating to the subject and the temperature information relating to the subject are simultaneously obtained from the spectral images obtained by the plurality of imaging means.

According to a seventh aspect of the invention, in the invention according to any one of the first to sixth aspects, spectral wavelength selecting means having different characteristics are provided on the light incident sides of the plurality of image pickup means. Is characterized by.

The invention of claim 8 is characterized in that, in the invention of any one of claims 1 to 7, the branching optical system has a plurality of dichroic mirrors having different spectral characteristics.

According to a ninth aspect of the present invention, in the invention according to any one of the first to eighth aspects, the branch optical system emits a light beam in a blue color,
The temperature image processing circuit is branched into optical paths of green, red, and infrared, and the temperature image processing circuit obtains an infrared spectral image obtained by the imaging means and one spectral image of blue, green, and red obtained by the imaging means. Is used to obtain the temperature information of the subject.

According to a tenth aspect of the present invention, in the invention according to any one of the first to ninth aspects, the temperature image processing circuit obtains temperature information of a predetermined region of the subject by using a two-color temperature method. It is characterized by being.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic view of the essential portions of a first embodiment of the present invention.

The image pickup apparatus of this embodiment is an object (subject).
Of the image (color image) obtained by using a three-plate image pickup means (two-dimensional image sensor), and a temperature for measuring the temperature (ratio temperature, ratio temperature, specific temperature, two-color temperature) of a predetermined region of the object It has a measuring means (ratio temperature measuring means).

In this embodiment, a color image and a temperature distribution chart of the object to be measured (object to be measured) are obtained at the same time.

In FIG. 1, a light beam from an object (object to be measured) OB enters an objective lens (objective system) 1. The incident image from the objective lens 1 is reflected by the first mirror 2 such as a dichroic mirror having a spectral characteristic to reflect light (image) in the near infrared region having a wavelength longer than red, and a bandpass filter (spectral wavelength selecting means). It is incident on the first sensor 4 through 3 and is received.

The light (image) in the blue region of the light (image) in the visible light region having a shorter wavelength than the near infrared light that has passed through the first mirror 2 is reflected by the second mirror 5 such as a dichroic mirror, and is bandpassed. The second sensor 7 through the filter 6
Incident on. The red light in the green and red light (image) that has passed through the second mirror 5 is reflected by the third mirror 8 such as a dichroic mirror, and enters the third sensor 10 through the bandpass filter 9.

The green light (image) passing through the third mirror 8 passes through the bandpass filter 11 and the fourth sensor 12
Incident on. The first, second, and third mirrors 2, 5, and 8 constitute a branching optical system that branches an incident image into four spectral images having different spectral characteristics. The first, second, third and fourth sensors 4, 7, 10 and 12 constitute an image pickup means. The color image processing circuit 13 includes the second, third and fourth sensors 7, 1
Red, green, and blue signals are obtained from the outputs from 0 and 12, and these signals are combined to display a color image on the color image monitor 1.
Output to 4. The temperature image processing circuit 15 obtains an output relating to a red image from the third sensor 10 and an output relating to a near infrared image from the first sensor 4, and outputs each portion of the subject image by the two-color temperature method pixel by pixel. Temperature is calculated, and the temperature distribution regarding the object OB is displayed on the temperature pixel monitor 16 in pseudo color. In addition, the signal from the color image monitor 14 is used to superimpose and display the measured temperature value on the color image.

Among the temperatures of the object to be measured, the high temperature is measured by an optical method. In contrast to the monochromatic method that measures the temperature of the measured object by measuring the radiation of a single wavelength or the single wavelength range, the two-color method that measures the temperature of the measured object from the measurement of the radiation of the two wavelengths or the two wavelength ranges Is characterized by being less susceptible to the emissivity of the object to be measured and allowing more accurate temperature measurement. In the present embodiment, this temperature measurement is performed together with the image capturing, and the temperature can be measured from the color image.

In the present embodiment, the subject is divided into four spectral images having different spectral characteristics (different wavelength regions), but it is divided into four or more spectral images and a pseudo color is obtained by combining the respective spectral images. You may make it obtain an image. The temperature image processing circuit 15 and the temperature image monitor 16 constitute one element of temperature measuring means for measuring the temperature information of the object OB.

Next, in the present embodiment, a so-called specific temperature (two-color method) measuring principle for measuring the temperature of an object (object to be measured) to be photographed by the image pickup system using the temperature image processing circuit will be described. To do.

In general, the electromagnetic radiation from an object increases as the temperature of the object increases (a) the amount of radiation increases (luminance increases in the visible light range). (B) The wavelength at which the maximum radiation is generated is short. (In the visible light range, the color changes from red to pale.)

The spectral radiation characteristics of a black body at each temperature are shown in FIG. The radiation curve of this FIG. 2 corresponds to temperature in a 1: 1 relationship. That is, the curves are all different depending on the temperature. Thus, the temperature of the black body can be known by measuring the curve, that is, the spectral distribution characteristic of the radiation of the black body at a certain temperature.

The ratio temperature (two-color temperature) is a method of specifying this curve, in which radiation at two wavelengths is measured and the ratio thereof is calculated. This value is unique to each blackbody temperature, and since there is only one numerical value, the temperature can be known from this. It is called the dichroic temperature because it compares the brightness of two wavelengths.

Since a general object is not a black body, the radiation amount when the object is at the same temperature as the black body is smaller than that of a black body. The ratio of the two radiation doses is called emissivity ε,
ε is always 1 or less.

When measuring the temperature of an object from the amount of radiation, it is very important to know the emissivity, but the emissivity differs depending on the shape of the material surface of the object and the like, and also depends on the temperature and the wavelength. Therefore, it is extremely difficult to perform accurate temperature measurement with a brightness thermometer or a total radiation thermometer (such as an infrared thermometer).

On the other hand, in the ratio thermometer, the emissivity is automatically canceled by selecting a wavelength band in which the emissivity of the substance to be measured at the two wavelengths is the same, and the ratio is affected. I try not to.

Next, the reason will be described with reference to FIG.

In the ratio thermometer, attention is paid to the luminances of the wavelengths L1 and L2 of the spectral radiation of general objects and black bodies.

When the wavelengths L1 and L2 are selected close to each other in the radiation distribution of a general object, it is considered that the emissivities ε of both are almost the same. As long as that relationship holds, the following relationships hold.

As shown in FIG. 3, when the luminances of the general object at wavelengths L1 and L2 are R1 and R2, and the luminances of the black body at wavelengths L1 and L2 are Rbb1 and Rbb2, respectively, R1 = ε × Rbb1 R2 = ε × Rbb2

[0041]

[Equation 1]

It becomes

That is, in a general object, both wavelengths L1 and L
As long as the premise that the emissivity ε at 2 is equal, the relation of the luminance is equal to the luminance of both wavelengths in the black body.

If glass, smoke, water, etc. exist between the object and the measuring system and their transmittances are equal to τ, the values obtained by the detecting means are the same at wavelengths L1 and L2. Since it is affected by the rate τ, when R1 = τ × ε × Rbb1 R2 = τ × ε × Rbb2,

[0045]

[Equation 2]

Therefore, the transmittance is not affected.

In the actual measurement, the luminance ratio R2 / R1 of the object to be measured is obtained and compared with the luminance ratio of the black body measured in advance. It becomes the temperature of.

As a result, the Ratio Temperature does not need to know the emissivity ε of the object, and a substance such as glass or smoke having the same transmittance at both wavelengths is interposed between the measuring object and the measuring instrument. However, accurate temperature measurement is possible.

Next, a mathematical description of Ratio Temperature according to the present invention will be given.

The ratio temperature is obtained by measuring the brightness temperature at two wavelengths and taking the ratio of the two.

Radiance (luminance temperature) Mλ at wavelength λ
Is determined by Planck's formula.

[0052]

[Equation 3]

Where c ₁ : first radiation constant = 2πc ² h
= 3.74041 × 10 ⁻¹⁶ [Wm ² ] λ: wavelength μm c ₂ : second emission constant = ch / k = 1.4368 × 10 ⁻²
[MK] T: absolute temperature (Kelvin) C: speed of light in vacuum h: Planck's constant k: Boltzmann's constant If the emissivity of the object is ε and the transmittance from the object to the measurement system is τ,

[0054]

[Equation 4]

It becomes

The two wavelengths measured are 0.4 μm in the visible range.
Two wavelengths within ˜0.7 μm are used. When the Wien's approximation formula is applied, formula (4) becomes formula (5).

[0057]

[Equation 5]

Now, assuming that the radiant energy in a narrow wavelength region with a width Δλ centered on the wavelength λ ₀ is M ₀ ,

[0059]

[Equation 6]

The radiant energy M ₀ from a general object is calculated from the equation (6).

[0061]

[Equation 7]

Where β ₀ : Proportional coefficient ε ₀ : Emissivity at wavelength λ ₀ τ ₀ : Spatial transmittance from the measuring point to the object at wavelength λ ₀ M ₁ is the radiant energy at wavelengths λ ₁ and λ ₂ . Assuming M ₂ , the two-wavelength ratio (relative emission ratio) R is

[0063]

[Equation 8]

It becomes

If the monochromatic lights λ ₁ and λ ₂ have sufficiently small Δλ, β ₁ and β ₂ are substantially equal to each other and β ₁ / β ₂ = 1.

Further, when the transmittance of the object interposed from the object to the measurement system does not fluctuate much with respect to the wavelength, τ ₁
/ Τ ₂ = 1. Applying this condition to equation (9),

[0067]

[Equation 9]

Here, the constants C3 and C4 are

[0069]

[Equation 10]

It becomes

As can be understood from the equation (10), the ratio of the radiation amounts of the two wavelengths (that is, the relative radiation ratio R = B / G = B / R = G
/ R) is proportional to the reciprocal of temperature.

Further, it is irrelevant to the emissivity of the object, and is not affected by the transmittance of anything such as a lens, glass, or gas that is interposed between the object and the measurement system.

According to the present embodiment, as described above, the specific temperature (temperature) of the object is measured with high accuracy based on the information obtained by the image pickup means while photographing the object. For example, the display means (temperature image monitor) 16 The temperature information is displayed together with the image of the object (color image), thereby accurately displaying the temperature distribution of the object.

In the temperature measurement of the test object by the two-color method, when the two wavelengths are set to longer wavelengths, for example, 0.7-1.5 μm, than two wavelengths are set to the short wavelength portion of the visible light range.
It is possible to further reduce the influence of the fine powder present between the subject and the objective lens 1. In addition, the solid-state sensor (imaging means) such as CCD is not limited to the visible light range but has a wavelength of 1 μm.
It has photosensitivity up to the near infrared of about m.

In consideration of these points, the present embodiment detects the wavelength range of 0.7 μm or more, which is removed in the normal image capturing, and simultaneously performs the image capturing and the more accurate temperature measurement. . The wavelength of the subject to be photographed as a color image is 0.45 μm for blue and 0.54 μ for green.
m, red color has a wavelength of about 0.62 μm as a central wavelength and a color image is obtained in a wavelength range of about 1 to 40 nm. Further, the temperature of the subject is measured by the two-color method using the red signal and a signal of any wavelength between 0.65 and 1.0 μm.

In this embodiment, an object to be measured (object) is formed by an image pickup system (objective lens) on an image sensor (image pickup means) such as CCD or C-MOS, and an image is obtained from an output signal from the image pickup means. At the same time, when the temperature distribution of the object to be measured is obtained, an output signal from the image pickup means based on each color light is appropriately set to secure a temperature calculated value with less error. The image sensor has a plurality of photodiodes on the image plane of the objective lens, for example, about 3 in the case of standard TV images.
50,000 (720 × 480) pixels are arranged, and the output from each photodiode is output as a pixel to a cathode ray tube or the like to reproduce an image. In the case of a color image, red, green, and blue light are split and received by three sensors, and one sensor shares red, green, and blue for each pixel and receives light, and each pixel is red by interpolation.
A device adapted to obtain green and blue light signals is applicable. In this color image, the intensity of radiation is calculated from the outputs of two wavelength regions of each pixel, for example, red and green light, the ratio of the two is calculated, and the fact that the ratio has a functional relationship with temperature is used. A two-color image temperature measurement system using the color method is used.

The two-color image temperature measuring system can obtain the image and temperature distribution of the object to be measured at the same time by utilizing this relationship. In this embodiment, in the two-color image temperature measuring system, the object to be measured is measured. Accurately measures the temperature of objects.

Next, a second embodiment of the present invention will be described.

In the second embodiment, an averaging circuit for averaging the time-lapse outputs of the same pixel several times is used as opposed to the CCD performing inaccurate output due to dark current noise or read noise. This reduces the error in measuring the temperature of the subject.

Next, a third embodiment of the present invention will be described.

In the third embodiment, the temperature information of the object is measured with high accuracy by using an averaging circuit for averaging the calculation results instead of adding to the sensor output.

Next, a fourth embodiment of the present invention will be described.

The fourth embodiment is characterized in that it has a correction means for correcting the temperature error caused by the non-linearity of the output from the image pickup means (sensor) and the auxiliary circuit with respect to the optical input. A radiation thermometer such as an infrared thermometer measures the intensity of radiation from a target object and measures the temperature by utilizing the fact that the radiation intensity has a functional relationship with the temperature. However, if the target object is a black body, the emissivity is 1, and since the emissivity is known, accurate temperature can be measured. However, since ordinary objects are not black bodies, it is necessary to correct the emissivity. .
Further, in the case of measurement, if there is a medium such as glass in the measurement optical path, it is necessary to correct the transmittance.

In the dichroic temperature method, not the absolute amount of radiation at a single wavelength of an object, but the ratio of radiation at two wavelengths is calculated and the temperature is obtained because the ratio has a functional relationship with temperature. As shown in FIG. 3, the temperature can be measured accurately without being affected by the emissivity and the transmittance. In FIG. 3, when the temperature is obtained only from the measured value of the wavelength L1, an error occurs due to the influence of the emissivity and the like.
In the ratio of the measured values of, the emissivity is canceled and no error occurs.

However, even in the dichroic temperature method, the sensor circuit output with respect to the brightness (light intensity) needs to be a straight line (relationship of a linear function). If the radiation ratio is calculated when this is non-linear, the radiation ratio of the two wavelengths will differ depending on the radiation intensity, making temperature measurement impossible.

Let R1 be the brightness at the wavelength L1 and R2 be the brightness at the wavelength L2 in FIG.
/ L1 is equal to R2 / L2, but in FIG.
L1 does not equal R2 / L2. In other words, the two wavelength ratios differ depending on the intensity of radiation, and accurate temperature measurement cannot be performed.

The fact that the output from the sensor is non-linear is due to the basic characteristic, and if only the part where the linearity can be maintained is used, the dynamic range becomes narrow and the function as the image sensor is impaired. Therefore, in the present embodiment, as a method of solving this, a lookup table is used to calculate the intensity of the radiation by correcting the density output with respect to the luminance input in the two wavelength bands so that the density output becomes a straight line. , Seeking an accurate temperature regardless of the intensity of radiation.

Next, a fifth embodiment of the present invention will be described.

In the fifth embodiment, the noise ratio with respect to the signal becomes high at the input with low luminance, and if the temperature is obtained from the calculation of the radiation ratio based on such input, the measurement becomes inaccurate, so that it can be excluded. The applicant has proposed a possible temperature measurement method in Japanese Patent Laid-Open No. 2000-88259.

In the temperature measurement proposed in the same item, when the incident light on the photodiode of each pixel is saturated, the concentration output value is also saturated, and the value is used to obtain the temperature from the calculated radiation ratio. And get the wrong temperature value. Even if the output is not saturated, the density output near the saturation value may lack linearity and cause an error.

In the present embodiment, in order to prevent such temperature calculation error in the low brightness and high brightness regions, a lower limit threshold value and an upper limit threshold value are provided for the sensor output used for temperature calculation, and data exceeding the threshold value is provided by the signal removal circuit. The accuracy of temperature measurement of the subject is secured by avoiding the temperature calculation by-.

FIG. 5 is a schematic view of the essential portions of Embodiment 6 of the present invention.

The present embodiment shows a temperature measuring device using a computer, and the method of processing the output signals from the first to fourth sensors 4, 7, 10, 12 is different from that of the first embodiment shown in FIG. . In the present embodiment, the output signals from the first to fourth sensors 4, 7, 10, 12 are processed by a computer system such as a personal computer or a computer-embedded system based on an MPU to obtain a color image and temperature distribution of a subject. It has gained.

In FIG. 5, the first to fourth sensors 4,
The output signals from 7, 10, 12 are subjected to analog processing such as amplification by the amplifying means 21, and then input to an expansion board 22 called a capture board or an image board of a computer by an analog signal or a digital signal. C
In addition to a capture board, a memory 24, a hard disk 25, a video board 26, etc. are connected to the bus from the PU 23, which is the basic software such as the OS and image capture /
By the temperature measurement application software, a color image of the object OB and a temperature distribution image such as a pseudo-color image processed by calculation are displayed on the monitor 27 simultaneously or separately. A control signal may be output from the computer to the heat source for controlling the temperature source.

With this configuration, the same effect as that of the first embodiment is obtained.

[0096]

According to the present invention, the color temperature of the object is measured and the specific temperature (temperature) of the object is measured with high accuracy, and the temperature information is displayed on the display means together with the image (color image) of the object. As a result, it is possible to achieve an image pickup apparatus having a temperature measuring means having a function of accurately displaying the temperature distribution of an object.

[Brief description of drawings]

FIG. 1 is a block diagram of a main part of a first embodiment of the present invention.

FIG. 2 is an explanatory diagram of spectral characteristics of black body radiation.

FIG. 3 is an explanatory diagram of specific temperature measurement.

FIG. 4 is an explanatory diagram for correcting non-linearity of temperature measurement according to the present invention.

FIG. 5 is a block diagram of a main part of a second embodiment of the present invention.

[Explanation of symbols]

1 Objective lens 2 first mirror 3 filters 4 first sensor 5 Second mirror 6 filters 7 Second sensor 8 third sensor 9 filters 10 Third sensor 11 filters 12 4th sensor 13 Color image processing circuit 14 color video monitor 15 Temperature image processing circuit 16 temperature image monitor

Claims (10)

[Claims] 1. An objective system for forming an image of a subject, and a branching optical system for branching a light beam from the objective system into four or more optical paths.
Imaging means for obtaining image information of spectral images having mutually different spectral characteristics through the branching optical system; and a color image processing circuit for obtaining a color image from three spectral images among the spectral images obtained by each imaging means, An image pickup apparatus having temperature measuring means, comprising: a temperature image processing circuit for obtaining a temperature distribution regarding a subject from two spectral images. 2. An objective system for forming an image of a subject, a branching optical system for branching a light beam from the objective system into a plurality of optical paths, and a plurality of spectral images having different spectral characteristics through the branching optical system. The radiation intensity of the subject is calculated from the brightness of each pixel or pixel group of two different spectral images existing at the same coordinate position in the spectral image obtained by the image capturing means and the spectral image obtained by the image capturing means. However, a temperature image processing circuit that measures the temperature of the subject based on the ratio of the two radiation intensities, and an averaging circuit that averages the electrical output of each pixel or pixel group obtained at different times with respect to time. An image pickup apparatus having a temperature measuring means characterized by comprising: 3. An objective system for forming an image of a subject, a branching optical system for branching a light beam from the objective system into a plurality of optical paths, and a plurality of spectral images having different spectral characteristics through the branching optical system. The radiation intensity of the subject is calculated from the brightness of each pixel or pixel group of two different spectral images existing at the same coordinate position in the spectral image obtained by the image capturing means and the spectral image obtained by the image capturing means. However, it has a temperature image processing circuit that measures the temperature of the subject based on the ratio of the two radiation intensities and an averaging circuit that averages the temperature distribution images of the calculation results obtained at different times. An imaging device having a characteristic temperature measuring means. 4. An objective system for forming an image of a subject, a branching optical system for branching a light beam from the objective system into a plurality of optical paths, and a plurality of spectral images having different spectral characteristics via the branching optical system. The radiation intensity of the subject is calculated from the brightness of each pixel or pixel group of two different spectral images existing at the same coordinate position in the spectral image obtained by the image capturing means and the spectral image obtained by the image capturing means. However, it has a temperature image processing circuit that measures the temperature of the subject based on the ratio of the two radiation intensities, and correction means that maintains the linearity of the electrical output with respect to the incident light that enters each imaging means. An image pickup apparatus having a temperature measuring means characterized by. 5. An objective system for forming an image of a subject, a branching optical system for branching a light beam from the objective system into a plurality of optical paths, and a plurality of spectral images having different spectral characteristics via the branching optical system. The radiation intensity of the subject is calculated from the brightness of each pixel or pixel group of two different spectral images existing at the same coordinate position in the spectral image obtained by the image capturing means and the spectral image obtained by the image capturing means. However, it has a temperature image processing circuit that measures the temperature of the subject based on the ratio of the two radiation intensities, and a signal removal circuit that excludes output signals from the imaging unit that are greater than or equal to a threshold value of the output signal. An imaging device having a temperature measuring means characterized by the above. 6. A color image relating to the subject and temperature information relating to the subject are simultaneously obtained from spectral images obtained by the plurality of image pickup means.
An imaging device having 3, 4 or 5 temperature measuring means. 7. The temperature measuring means according to claim 1, wherein spectral light selecting means having different characteristics are provided on the light incident sides of the plurality of image pickup means. An imaging device having a. 8. The image pickup apparatus having the temperature measuring means according to claim 1, wherein the branch optical system has a plurality of dichroic mirrors having different spectral characteristics. 9. The branching optical system branches a light beam into optical paths of blue, green, red, and infrared, and the temperature image processing circuit includes an infrared spectroscopic image obtained by the imaging means and an imaging means. 9. The temperature measuring means according to claim 1, wherein the temperature information of the subject is obtained using one of the obtained spectral images of blue, green and red. An imaging device having. 10. The temperature according to claim 1, wherein the temperature image processing circuit obtains temperature information of a predetermined region of the subject by using a two-color temperature method. An imaging device having measuring means.