JP2021060325A - Two-colour temperature measuring sensor and temperature measurement device using the same - Google Patents

Abstract

To provide a two-colour temperature measuring sensor allowing a light blocking mask provided between filter elements to be formed easily and highly accurately.SOLUTION: A two-colour temperature measuring sensor comprises: a mosaic sensor 3 obtained by arranging a plurality of light receiving elements capable of recording multiwavelength image in a mosaic pattern; and a two-colour mosaic filter 2 obtained by arranging two types of filter elements 2R, 2G transmitting therethrough light fluxes in two wavelength regions different from one another such that the light transmissive wavelength regions of the plurality of filter elements adjacent to each other in a mosaic pattern differ from each other. Both of the mosaic sensor and the two-colour mosaic filter are overlapped one on top of another so that one light receiving element included in the mosaic sensor and one filter element included in the two-colour mosaic filter overlap with each other. The size of one filter element is greater than that of one light receiving element, and part of the periphery of the one filter element overlaps with the periphery of the adjacent filter element.SELECTED DRAWING: Figure 2

Description

The present invention relates to a two-color temperature measurement sensor and a temperature measurement device using the same, and is particularly suitable for measuring temperature distribution information of an object by using a two-color temperature method using a multi-wavelength single plate camera. is there.

Conventionally, a camera that uses a color camera to form temperature information of an object in an imaging means by an imaging system and measures the temperature information of the object by using a two-color temperature method using an output signal from the imaging means is known. (Patent Documents 1 and 2).

In Patent Document 1, radiation in the infrared region is received by an image sensor (infrared sensor), and the distribution of its intensity is expressed as an image in shades. Of the color cameras, the single-panel color camera uses one imaging means, and R, G, B mosaic-shaped color filters are attached to the light incident side of each pixel (light receiving element), and R, G, R, G, from each pixel. The signal of B is calculated. The CCD or C-MOS imaging device [imaging means] used in a single-panel color camera arranges a plurality of pixels two-dimensionally, and opposes R, G, and B mosaic color filters corresponding to each pixel. It is arranged.

Patent Document 2 has a mosaic filter in which a plurality of filter elements that pass light fluxes in two different wavelength regions are arranged in a mosaic pattern, and the mosaic filter is provided on the light incident side of the image sensor. Then, the temperature information of a predetermined region of the object is obtained from the output signal from the image sensor.

Japanese Unexamined Patent Publication No. 2001-157214 Japanese Patent Application No. 2015-165555

If an infrared camera is used to measure the temperature of an object, the temperature distribution of each part of the object can be known.

At this time, the radiation in two wavelengths (wavelength range) of the object is measured, the ratio of the two is calculated, and the temperature of the blackbody showing the same value is set as the temperature of the object (Ratio Temperature, two-color temperature). ) Measurement can accurately measure the temperature of an object as long as the radiation rates at both wavelengths are the same. The single-plate color camera is characterized in that no error occurs due to the principle of specific temperature measurement even if the environmental temperature changes. At this time, as shown in FIG. 7, if a mosaic filter 70 in which a plurality of filter elements 71 and 72 that pass light fluxes in two different wavelength regions are arranged in a mosaic pattern is used, the first wavelength region 71a of the mosaic filter is used. In addition to the original radiation, a part of the light that has passed obliquely through the second wavelength region 72a of the mosaic filter is incident on the light receiving element (sensor) 71b after being reflected by the light receiving element 72b, and is mixed and optically. Cross talk occurs. As a result, when measuring the temperature, the S / N may decrease and the detection accuracy may decrease.

In order to prevent this, it is preferable to provide a light-shielding mask between the adjacent filter elements of the plurality of filter elements.

However, it is difficult to accurately form the light-shielding mask at this time on the surface of the light-receiving element, and the number of steps increases, which causes an increase in cost.

The present invention is a two-color temperature measurement sensor capable of easily and highly accurately forming a light-shielding mask provided between filter elements and capable of measuring the temperature information of an object with high accuracy by the two-color temperature method, and a temperature measuring device using the same. The purpose is to provide.

The two-color temperature measurement sensor of the present invention includes a mosaic sensor in which a plurality of light receiving elements capable of recording multi-wavelength images are arranged in a mosaic pattern, and two types of filter elements that pass light rays in two different wavelength ranges. It has a two-color mosaic filter in which a plurality of filter elements adjacent to each other in a mosaic pattern are arranged so that the light passing wavelength ranges are different from each other, and both the mosaic sensor and the two-color mosaic filter constitute one that constitutes the mosaic sensor. A two-color temperature measurement sensor in which a light receiving element and one filter element constituting the two-color mosaic filter are overlapped with each other so as to overlap each other.
The size of the one filter element is also large, and one part of the peripheral portion of one filter element overlaps with the peripheral portion of another adjacent filter element. ..

At this time, the arrangement pitch of the light receiving elements of the mosaic sensor and the arrangement pitch of the filter elements of the two-color mosaic filter are the same. Further, the two-color mosaic filter has a first wavelength mosaic filter and a second wavelength mosaic filter, and the pitch of the filter element of the first wavelength mosaic filter and the filter element of the second wavelength mosaic filter is the same. The pitch of the filter element of the first wavelength mosaic filter and the filter element of the second wavelength mosaic filter is twice the arrangement pitch of the light receiving element.

According to the present invention, it is possible to obtain a two-color temperature measurement sensor capable of accurately measuring the temperature distribution of an object by using specific temperature measurement using a single plate type camera, and a temperature measuring device using the same.

Schematic diagram of the main part of the temperature measuring device of the present invention Cross-sectional view of the main part of the two-color temperature measurement sensor according to the present invention. Top view of the main part of the mosaic filter according to the present invention Top view of the main part of the mosaic sensor according to the present invention (A), (B) Top view of the main part of the mosaic filter according to the present invention Explanatory drawing of spectral transmittance of mosaic filter which concerns on this invention Explanatory drawing of optical crosstalk

The temperature measuring device of the present invention uses a single-plate multi-wavelength camera. The single-panel multi-wavelength camera has features such as a simple structure, easy manufacturing, and a good balance of output signals from each light receiving element in response to changes in the sensor environment.

In FIG. 1, reference numeral 11 denotes a temperature measuring device. The temperature measuring device 11 processes the output signal from the two-color temperature measuring sensor 13 formed on the two-color temperature measuring sensor 13 by the photographing lens 12 with the signal processing means 14. The temperature measuring means 15 obtains the temperature information of a predetermined region of the object from the output signal from the signal processing means 14.

The temperature measuring means 15 has two colors from the signal extraction unit 15a that extracts the output signal from the predetermined light receiving element for one filter element among the output signals from the signal processing means 14, and the output signal extracted by the signal extraction unit 15a. It has a specific temperature measuring unit 15b that obtains temperature information of an object by using a temperature method. The temperature information of the object is displayed on the display means 16 based on the output signal from the temperature measuring means 15. The output signal from the temperature measuring means 15 can also be used for controlling the heating furnace and the like.

FIG. 2 is a cross-sectional view of a main part of the two-color temperature measurement sensor 13 that constitutes the temperature measuring device of the present invention.

FIG. 3 is a plan view of a main part of the two-color mosaic filter 2 that constitutes the temperature measuring device of the present invention.

The two-color temperature measurement sensor 13 has a mosaic sensor 1 and a two-color mosaic filter 2.

FIG. 4 is a plan view of a main part of the mosaic sensor 1.

5A and 5B are plan views of the main parts of the first wavelength mosaic filter 2λ1 and the second wavelength mosaic filter 2λ2 included in the two-color mosaic filter 2.

In FIG. 4, reference numeral 1 denotes a mosaic sensor in which a plurality of light receiving elements 1a capable of recording a multi-wavelength image are arranged in a mosaic pattern.

In this embodiment, the light receiving area of the light receiving element 1a is 20μ × 20μ, and the plurality of light receiving elements 1a are arranged in a mosaic pattern (two-dimensionally) with a pitch Pa of 20μ.

The two-color mosaic filter 2 has a first wavelength mosaic filter 2λ1 and a second wavelength mosaic filter 2λ2.

FIG. 5A is a plan view of a main part of the first wavelength mosaic filter 2λ1.

The first wavelength mosaic filter 2λ1 has a configuration in which a plurality of first wavelength filters 2G are arranged in a mosaic pattern.

As shown in FIG. 6, the main light transmission wavelength range 2Gt of the first wavelength filter 2G has a wavelength of 785 nm to 815 nm, and the size of the light passing region is 24 μ × 24 μ.

A plurality of first wavelength filters 2G are arranged in a mosaic pattern with a pitch P2G of 40 μ (2 × 20 μ).

FIG. 5B is a plan view of a main part of the second wavelength mosaic filter 2λ2.

The second wavelength mosaic filter 2λ2 has a configuration in which a plurality of second wavelength filters 2R are arranged in a mosaic pattern.

As shown in FIG. 6, the main light transmission wavelength range 2Rt of the second wavelength filter 2R has a wavelength of 950 nm to 990 nm, and the size of the light passing region is 24 μ × 24 μ.

A plurality of second wavelength filters 2R are arranged in a mosaic pattern with a pitch P2R of 40 μ (2 × 20 μ).

The configuration of the two-color temperature measurement sensor 13 is as follows.

The first wavelength mosaic filter 2λ1 and the second wavelength mosaic filter 2λ2 are superposed.

At this time, as shown in FIGS. 5A and 5B, the center point 2G1 between the first wavelength filters 2G is overlapped so as to coincide with the center point 2R1 of the second wavelength filter 2R.

Further, the mosaic sensor 1 and the two-color mosaic filter 2 are superimposed. At this time, the center point 1a1 of the light receiving element 1a of the mosaic sensor 1 is configured to overlap the center point 2G1 of the first wavelength filter G1 (or the center point 2R1 of the second wavelength filter 2R).

At this time, the overlapping region of the outer peripheral portion of the first wavelength filter 2G and the outer peripheral portion of the second wavelength filter 2R has a length of 2μ at the outer peripheral portion.

Therefore, the effective area of the light receiving element 1a is 16μ × 16μ (256μ ² ). When there is no filter, it is 20μ × 20μ (400μ ² ). Therefore, the light utilization efficiency of the light receiving element 1a is 0.64.

As shown in FIGS. 2 and 3, as shown in FIGS. 2 and 3, a part of the outer peripheral portion of the first wavelength filter 2G of the first wavelength mosaic filter 2λ1 and the second wavelength filter 2R of the second wavelength mosaic filter 2λ2. Part of the outer circumference overlaps.

Then, as shown in FIG. 2, all the light incident on the overlapping regions is blocked and does not enter the mosaic sensor 1. This reduces the occurrence of crosstalk.

In the temperature measuring device of this embodiment, of the light (400 nm to 1000 nm) incident on the two-color temperature measuring sensor 13, the light having a wavelength of 785 nm to 815 nm mainly passes through the first wavelength filter 2G and then enters the light receiving element 1aa.

Further, mainly light having a wavelength of 950 nm to 990 nm passes through the second wavelength filter 2R and then enters the light receiving element 1aa.

As shown in FIG. 2, the light incident on the overlapping region of the first wavelength filter 2G and the second wavelength filter 2R is blocked by the first wavelength filter 2G and the second wavelength filter 2R and does not enter the light receiving element 1a.

In this embodiment, the optical crosstalk is reduced by the above configuration. Then, the two-color temperature measurement is performed using the light detected by the light receiving element 1a to obtain the temperature information of the object, and the temperature information of the object is displayed on the display means 16.

The method for producing the two-color temperature measurement sensor 13 in the present invention is as follows.
Step 1 The first wavelength mosaic filter 2λ1 is produced by a multilayer film deposition method or the like.
Step 2 The second wavelength mosaic filter 2λ2 is separately produced.
Step 3 The film surfaces of the first wavelength mosaic filter 2λ1 and the second mosaic filter 2λ2 are bonded together in a mosaic pattern.
Step 4 The mosaic filter 2 is attached to the mosaic sensor 1. In this method, the first wavelength mosaic filter may be formed on one surface of the filter base material, and the second wavelength mosaic filter may be formed on the other surface.

It can also be manufactured by the following method.
Step 1 In each mosaic region of the second wavelength mosaic filter 2λ2 of the substrate material, a mask material is installed in a portion smaller than each side of the sensor pixel by a predetermined amount.
Step 2 A first wavelength mosaic filter 2λ1 is produced on the front surface of the substrate by a multilayer film deposition method or the like.
Step 3 Remove the mask in the second wavelength mosaic filter 2λ2 region.
Step 4 A mask material is installed in each mosaic region of the first wavelength of the substrate material in a portion smaller by a predetermined amount from each side of the sensor pixel.
Step 5 A second wavelength mosaic filter 2λ2 is produced on the front surface of the substrate by a multilayer film deposition method or the like.
Step 6 Remove the mask on the mosaic filter in the first wavelength region.
Step 7 Attach the mosaic filter to the mosaic sensor.

According to the present invention, the following effects can also be obtained.
-The ambient temperature of the image sensor, etc. by configuring a filter in a mosaic pattern on a single sensor for the purpose of using it for two-color temperature method, bio-measurement, etc. Image sensors that avoid the effects of the environment can be easily created.
-It is not necessary to create a mask to prevent optical crosstalk.
-It can be created in fewer steps than an image sensor with a two-wavelength mosaic filter.
-It is possible to create an image sensor with a multi-wavelength mosaic filter, not limited to two wavelengths, in a shorter time and at lower cost.
・ The defective rate can be reduced by reducing the number of processes.
・ High sensitivity is possible by configuring a mosaic filter that includes multiple pixels.

I Mosaic sensor 2 Two-color mosaic filter 11 Temperature measuring device 12 Shooting lens 13 Two-color temperature measuring sensor 14 Signal processing means 15 Temperature measuring means 16 Display means

Claims (4)

A mosaic sensor in which a plurality of light receiving elements capable of recording a multi-wavelength image are arranged in a mosaic pattern, and a filter element in which a plurality of two types of filter elements that pass light rays in two different wavelength ranges are arranged in a mosaic pattern. It has a two-color mosaic filter arranged so that the light passing wavelength ranges are different from each other, and both the mosaic sensor and the two-color mosaic filter are provided with one light receiving element constituting the mosaic sensor and the two-color mosaic filter. It is a two-color temperature measurement sensor that is superposed so that one of the constituent filter elements overlaps with each other.
The size of the one filter element is also large, and one part of the peripheral portion of one filter element overlaps with the peripheral portion of another adjacent filter element. Two-color temperature measurement sensor. The two-color temperature measurement sensor according to claim 1, wherein the arrangement pitch of the light receiving elements of the mosaic sensor and the arrangement pitch of the filter elements of the two-color mosaic filter are the same. The two-color mosaic filter has a first wavelength mosaic filter and a second wavelength mosaic filter, and the pitch of the filter element of the first wavelength mosaic filter and the filter element of the second wavelength mosaic filter is the same, and the pitch of the second wavelength mosaic filter is the same. The two-color temperature measurement sensor according to claim 2, wherein the pitch of the filter element of the one-wavelength mosaic filter and the filter element of the second wavelength mosaic filter is twice the arrangement pitch of the light receiving element. A temperature measuring device comprising an imaging system for forming image information of an object in an imaging means and a two-color temperature measuring sensor according to any one of claims 1 to 3.

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