CN115876321A - Composite color filter array applied to chromaticity detection and manufacturing method - Google Patents

Abstract

The invention relates to a composite color filter array applied to chromaticity detection and a manufacturing method thereof. The invention can be used on a novel colorimeter, and corresponding color characteristics can be obtained in different pixel areas on a detector through a channel by forming the filter array by the three-primary-color filter and the contrast test area, so that the volume and the cost of equipment are reduced.

Description

Composite color filter array applied to chromaticity detection and manufacturing method

Technical Field

The invention relates to the technical field of optical filters, in particular to a composite color optical filter array applied to chromaticity detection and a manufacturing method thereof.

Background

Colors have three characteristics, namely lightness (also called brightness, purity), hue (also called dominant or complementary dominant wavelength), and chroma purity (also called saturation). To quantify the color, the use of tristimulus values is a viable approach. In order to measure the tristimulus values of the object color, three basic stimuli X, Y, Z are used, corresponding to red (R), green (G), blue (B), and the color can be quantitatively expressed by measuring the tristimulus values. The principle of the colorimeter is that according to the tri-stimulus value of the CIE spectrum, each wavelength of the spectrum is weighted in each channel, and therefore color characteristics are obtained; color filters meeting the CIE spectral standard are respectively adopted in each channel to realize the weighting function.

In the existing chromaticity detection technology, three groups of channels are used for respectively obtaining three excitation values, and then color characteristics are obtained quantitatively through the three excitation values. Based on above-mentioned technical scheme, need the multiunit passageway to realize, can cause the test instrument volume great like this, the heat dissipation scheduling problem relatively poor.

Disclosure of Invention

In order to achieve the above objects and other advantages and in accordance with the purpose of the invention, a first object of the present invention is to provide a composite color filter array for chromaticity detection, which sequentially includes a microlens array, a filter array, and a photosensitive chip along a light incident direction, wherein the microlens array includes a plurality of lens units, the filter array includes a plurality of filters, the photosensitive chip includes a plurality of pixel units, the lens units correspond to the filters, the filters correspond to the pixel units, the lens units collect incident light, and the collected incident light is focused to the corresponding pixel units through the corresponding filters.

Further, the filter array comprises a red filter, a green filter and a blue filter.

Further, the filter array also comprises a contrast test area.

Further, the contrast test area comprises an infrared filter, a dark area and a bright area; the bright area is an area without a filter, and the dark area is an area which is cut off from a visible light area and is not transparent to light.

Further, the microlens array includes six lens units, each of the lens units corresponding to one filter in the filter array.

Furthermore, the number of the pixel units in the photosensitive chip is a multiple of 6, and the number of the pixel units in each filter area is the same.

Furthermore, the filter films on the red filter, the green filter and the blue filter are formed by mutually overlapping a medium material with a high refractive index and a medium material with a low refractive index;

the high-refractive-index dielectric material is at least one mixture of Ta2O5, tiO2 and Nb2O 5;

the medium material with low refractive index is at least one mixture of SiO2, al2O3 and MgF 2.

Further, the infrared filter is a band-pass filter with a center wavelength of 940nm formed by mutually overlapping Si and SiO2 materials, and the angle offset of the band-pass filter under the 30Deg incident angle is less than 20nm.

A second object of the present invention is to provide a method for manufacturing a composite color filter array for chromaticity detection, comprising the steps of:

and shielding the non-film-coated area by adopting a photoresist exposure development or tool fixture mode, coating the preset area, and sequentially and repeatedly realizing the film coating of the plurality of optical filters.

Further, the method of adopting photoresist exposure development or tooling fixture to shield the non-film coating area, coating the preset area, and sequentially and repeatedly realizing the film coating of the plurality of optical filters comprises the following steps:

when the red filter is prepared, other areas are covered by a jig or photoresist;

when the green filter is prepared, other areas are covered by a jig or photoresist;

when the green filter is prepared, other areas are covered by a jig or photoresist;

when the infrared filter is prepared, masking other areas by using a jig or photoresist;

when a dark area is prepared, other areas are covered by a jig or photoresist;

when the bright area is prepared, other areas are covered by a jig or photoresist.

Compared with the prior art, the invention has the beneficial effects that:

the invention provides a composite color filter array applied to chromaticity detection, which can be used on a novel colorimeter.

The foregoing description is only an overview of the technical solutions of the present invention, and in order to make the technical solutions of the present invention more clearly understood and to implement them in accordance with the contents of the description, the following detailed description is given with reference to the preferred embodiments of the present invention and the accompanying drawings. The detailed description of the present invention is given in detail by the following examples and the accompanying drawings.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the invention without limiting the invention. In the drawings:

fig. 1 is a first schematic diagram of a composite color filter array for chromaticity detection in example 1;

FIG. 2 is a first schematic diagram of the filter array of embodiment 1;

FIG. 3 is a second schematic diagram of the filter array of embodiment 1;

FIG. 4 is a schematic diagram of a second color filter array applied to chromaticity detection in example 1;

fig. 5 is a flowchart of example 2 showing a process of manufacturing the composite color filter array for chromaticity detection.

In the figure: 1. a microlens array; 2. an optical filter array; 21. a blue filter; 22. a red filter; 23. a green filter; 24. an infrared filter; 25. a dark region; 26. a bright area; 3. and a photosensitive chip.

Detailed Description

The present invention will be further described with reference to the accompanying drawings and the detailed description, and it should be noted that any combination of the embodiments or technical features described below can be used to form a new embodiment without conflict.

In the following description, suffixes such as "module", "component", or "unit" used to denote elements are used only for facilitating the explanation of the present invention, and have no specific meaning in itself. Thus, "module", "component" or "unit" may be used mixedly.

At present, there are two main technical schemes for colorimetric measurement: the first method is a method for measuring color by using a photoelectric colorimeter, which is similar to a densimeter in principle, directly displays tristimulus values and converts the tristimulus values into color space scales; weighting each wavelength of the spectrum in each channel of the colorimeter according to the tristimulus values of the CIE spectrum by adding a set of color filters; the test instrument corresponding to the scheme has larger volume, and the size needs to be further reduced to achieve the aim of complete portability.

The second method is a method of measuring color using a spectrophotometer, which measures point by point in the visible spectrum, i.e., measures at discrete points, measures one point every 5 or 10nm, and integrates to obtain color. The spectrophotometer is large in size and is only suitable for detection in a laboratory.

In order to solve the problems in the prior art, the invention provides a composite optical filter array applied to chromaticity detection, so as to realize the weighted average of tristimulus values on a spectrum on a single channel and realize the functions of light intensity calibration and wavelength calibration, on one hand, the number of channels is reduced, and the chromaticity value can be obtained only by a single channel; on the other hand, the light intensity calibration and the wavelength calibration are realized, so that the test precision is improved.

Example 1

A composite color filter array 2 applied to chromaticity detection comprises a micro lens array 1, a filter array 2 and a photosensitive chip 3 sequentially along a light incidence direction, as shown in figures 1 and 4, wherein the micro lens array 1 comprises a plurality of lens units, the filter array 2 comprises a plurality of filters, each different filter is used for passing light rays with preset wavelengths corresponding to the filters in incident light rays, the photosensitive chip 3 comprises a plurality of pixel units, the lens units correspond to the filters, the filters correspond to the pixel units, the lens units collect incident light rays, and the collected incident light rays are focused to the corresponding pixel units through the corresponding filters. The photosensitive chip 3 is used for converting the collected optical image signal into a point type, so as to obtain and store spectral image data, and is mainly a Charge-coupled Device (CCD).

The filter array 2 comprises three primary color filters, namely a red filter 22, a green filter 23, and a blue filter 21. The filter films on the three-primary-color filter are formed by mutually overlapping high-refractive-index dielectric materials and low-refractive-index dielectric materials, are realized through a coherent effect, and are mainly used for weighting the red, green and blue tristimulus values.

The medium material with high refractive index is at least one mixture of Ta2O5, tiO2 and Nb2O 5;

the dielectric material with low refractive index is at least one mixture of SiO2, al2O3 and MgF 2.

The filter array 2 also includes a contrast test area. Specifically, the contrast test area includes an infrared filter 24, a dark area 25, and a bright area 26; the bright region 26 is a region without a filter, and may be uncoated or coated with a visible light region AR film, and the dark region 25 is a region cut off in the visible light region and opaque, and may be coated with a Cr film. The infrared filter 24 is a band pass filter with a center wavelength of 940nm formed by mutually overlapping Si and SiO2 materials, in this embodiment, a 940TOF film is used, and an angle offset of the band pass filter at an incident angle of 30Deg is less than 20nm. In this embodiment, 940 the TOF film is used for ranging positioning, and the bright 26 and dark 25 regions are used for calibration of the baselines, 100% T and 0%. In this embodiment, six regions in the optical filter array 2 are square regions, and cover corresponding pixel regions according to the requirement of a detector algorithm.

In order to correspond to the filters in the filter array 2, the microlens array 1 includes six lens units, each corresponding to one filter in the filter array 2.

Fig. 2 shows the distribution of the filter array 2. Wherein, the filters with weighted average of RGB tristimulus values are positioned in a row of positions, 940TOF filters, dark areas 25 (Cr films) and bright areas 26 (AR films) are positioned in a row of positions, and a 3 x 2 array structure is formed.

Fig. 3 shows another distribution of the filter array 2. The filter array 2 has an array structure of 1 × 6, and six regions including a red filter 22, a green filter 23, a blue filter 21, a 940TOF filter, a dark region 25 (Cr film), and a bright region 26 (AR film) are sequentially arranged.

It should be understood that the filters on the filter array 2 may be combined in various ways according to different arrangement positions.

The number of the pixel units included in the light sensing chip 3 may be determined according to the resolution and the size to be acquired, and is not limited herein, but it should be confirmed that the number of the pixel units is a multiple of 6, which satisfies that the number of the pixel units of the optical filter is the same in six optical filter regions.

Incident light reaches the focusing effect through the micro lens array 1, six lens units on the micro lens array 1 respectively correspond to six areas on the optical filter array 2, the light passes through different optical filters with different transmission characteristics in the optical filter array 2, and the light is converged on the photosensitive chip 3, so that different spectral characteristics are obtained.

After collecting the spectrum of the light passing through the red filter 22 on the filter array 2, carrying out the weighted average of the red stimulus color of the CIE;

after the light rays passing through the green filter 23 on the filter array 2 are subjected to spectrum collection, the weighted average of the green stimulus color of the CIE is carried out;

after collecting the spectrum of the light passing through the blue filter 21 on the filter array 2, performing the weighted average of the blue stimulus color of the CIE;

collecting a spectrum of light passing through a 940TOF filter on the filter array 2, and taking the obtained spectrum as wavelength determination data;

after a spectrum is collected for light passing through a dark area 25 (Cr film) on the filter array 2, the obtained spectrum is taken as 0% baseline data;

after collecting a spectrum of light passing through the bright region 26 (AR film) on the filter array 2, the obtained spectrum was taken as a baseline of 100%.

After obtaining the weighted average spectrum of the tristimulus colors, dividing the spectrum by the baseline data (100% -0%) to obtain the tristimulus colors of white light, wherein the white light refers to a light source with uniform light intensity of all wave bands. The 940TOF filter mainly functions to cut off visible light (400 nm-920 nm) and (960 nm-1100 nm), transmit the spectrum of an infrared band (920-960 nm), and obtain the distance between the test instrument and a test sample by delaying the spectrum of 940nm wavelength of the infrared spectrum.

The composite color filter array 2 applied to chromaticity detection provided by the invention has six regions, and filters with preset wavelengths are respectively prepared, so that wavelength calibration, light intensity calibration and determination of tristimulus colors of a CIE standard can be realized in one channel. The test precision of the colorimeter is improved, the size of the device is reduced, and power consumption is reduced.

Example 2

When the optical filter array 2 is manufactured, since the spectral properties corresponding to the optical filters in the respective regions are different, the optical filters need to be manufactured separately. A method for manufacturing a composite color filter array 2 for chromaticity detection, as shown in fig. 5, includes the following steps:

and shielding the non-film-coated area by adopting a photoresist exposure development or tool fixture mode, coating the preset area, and sequentially and repeatedly realizing the film coating of the plurality of optical filters. Specifically, the method comprises the following steps:

s101, when the red filter 22 is prepared, other areas are covered by a jig or photoresist;

s102, when the green filter 23 is prepared, other areas are covered by a jig or photoresist;

s103, when the green filter 23 is prepared, other areas are covered by a jig or photoresist;

s104, masking other areas by using a jig or photoresist when the infrared filter 24 is prepared;

s105, when the dark area 25 is prepared, other areas are covered by a jig or photoresist;

and S106, when the bright region 26 is prepared, when the scheme of plating a film such as an AR film on the bright region 26 is adopted, other regions are covered by a jig or photoresist.

It should be noted that the above preparation processes are not in sequence.

It should also be noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrases "comprising a," "8230," "8230," or "comprising" does not exclude the presence of additional identical elements in the process, method, article, or apparatus comprising the element.

All the embodiments in the present specification are described in a progressive manner, and the same and similar parts among the embodiments are referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the apparatus embodiment, since it is substantially similar to the method embodiment, the description is relatively simple, and reference may be made to the partial description of the method embodiment for relevant points.

The foregoing is merely an example of the present specification and is not intended to limit one or more embodiments of the present specification. Various modifications and alterations to one or more embodiments described herein will be apparent to those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of one or more embodiments of the present specification should be included in the scope of claims of one or more embodiments of the present specification. One or more embodiments of this specification.

Claims (10)

1. A composite color filter array applied to chromaticity detection is characterized in that: include microlens array, light filter array, sensitization chip along light incident direction in proper order, the microlens array contains a plurality of lens units, the light filter array contains a plurality of light filters, sensitization chip contains a plurality of pixel units, the lens unit with the light filter corresponds, the light filter with the pixel unit corresponds, the lens unit assembles the incident light, and the incident light that assembles focuses on corresponding pixel unit through corresponding light filter.

2. A composite color filter array for use in colorimetric detection as claimed in claim 1, wherein: the filter array comprises a red filter, a green filter and a blue filter.

3. A composite color filter array for use in colorimetric detection as claimed in claim 2, wherein: the filter array also includes a contrast test area.

4. A composite color filter array for use in colorimetric detection as claimed in claim 3, wherein: the contrast test area comprises an infrared filter, a dark area and a bright area; the bright area is an area without a filter, and the dark area is an area which is cut off in a visible light area and is not transparent.

5. The composite color filter array for chrominance detection according to claim 4, wherein: the micro lens array comprises six lens units, and each lens unit corresponds to one filter in the filter array.

6. The composite color filter array for chromaticity detection according to claim 4, wherein the number of pixel units in the light-sensing chip is a multiple of 6, and the number of pixel units in each filter area is the same.

7. A composite color filter array for use in colorimetric detection as claimed in claim 2, wherein: the filter films on the red filter, the green filter and the blue filter are formed by mutually overlapping a medium material with high refractive index and a medium material with low refractive index;

the high-refractive-index dielectric material is at least one mixture of Ta2O5, tiO2 and Nb2O 5;

the dielectric material with low refractive index is at least one mixture of SiO2, al2O3 and MgF 2.

8. The composite color filter array for chrominance detection according to claim 4, wherein: the infrared filter is a band-pass filter which is formed by mutually overlapping Si and SiO2 materials and has the central wavelength of 940nm, and the angle offset of the band-pass filter under the 30Deg incident angle is less than 20nm.

9. The method of claim 1, wherein the method comprises the steps of:

and shielding the non-film-coated area by adopting a photoresist exposure development or tool fixture mode, coating the preset area, and sequentially and repeatedly realizing the film coating of the plurality of optical filters.

10. The method of claim 9, wherein the step of forming the color filter array further comprises: the method comprises the following steps of adopting a photoresist exposure development or tooling jig mode to shield a non-film coating area, coating a preset area, and sequentially and repeatedly realizing the film coating of a plurality of optical filters:

when the red filter is prepared, other areas are covered by a jig or photoresist;

when the green filter is prepared, other areas are covered by a jig or photoresist;

when the green filter is prepared, other areas are covered by a jig or photoresist;

when the infrared filter is prepared, masking other areas by using a jig or photoresist;

when a dark area is prepared, other areas are covered by a jig or photoresist;

when the bright area is prepared, other areas are covered by a jig or photoresist.

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