阅读说明：本技术 一种降低杂散光的方法及装置 (Method and device for reducing stray light ) 是由 袁琨 贡双虎 王坚 陈涛 曾亚澜 方欣宇 张宇梁 章晓寅 龚晓煜 闫卓 于 2020-07-08 设计创作，主要内容包括：本发明公开了一种降低杂散光的方法及装置,方法包括如下步骤：S1,将测量范围分段；S2,根据测量范围的分段,选取一组相应工作范围的滤光片,所述的滤光片具有截止范围,用于过滤其他测量范围的光谱能量；S3,光线通过各滤光片的过滤传输至传感器,传感器依次测量每段测量范围,计算得到测量范围的反射率；装置包括光源、滤光片、传感器,根据测量范围的分段,配合设置有一组相应工作范围的滤光片,所述的滤光片具有截止范围,用于过滤其他测量范围的光谱能量,滤光片设置在光源和传感器之间。(The invention discloses a method and a device for reducing stray light, wherein the method comprises the following steps: s1, segmenting the measuring range; s2, selecting a group of optical filters in corresponding working ranges according to the segmentation of the measuring ranges, wherein the optical filters have cut-off ranges and are used for filtering the spectral energy in other measuring ranges; s3, transmitting light to the sensor through the filtering of each optical filter, sequentially measuring each section of measuring range by the sensor, and calculating to obtain the reflectivity of the measuring range; the device comprises a light source, an optical filter and a sensor, wherein a group of optical filters corresponding to working ranges are arranged in a matched mode according to the segmentation of the measuring ranges, the optical filters are provided with cut-off ranges and used for filtering spectral energy of other measuring ranges, and the optical filters are arranged between the light source and the sensor.)

1. A method of reducing stray light, comprising the steps of:

s1, segmenting the measuring range;

s2, selecting a group of optical filters (1) corresponding to the working range according to the segmentation of the measuring range, wherein the optical filters (1) have cut-off ranges and are used for filtering the spectral energy of other measuring ranges;

s3, the light is transmitted to the sensor (6) through the filtering of each optical filter (1), the sensor (6) sequentially measures each section of measuring range, and the reflectivity of the measuring range is calculated.

2. The method for reducing stray light according to claim 1, wherein a group of segmented light sources (2) with corresponding working ranges are selected according to the segmentation of the measuring ranges, optical filters (1) matched with the working ranges of the segmented light sources (2) are respectively arranged between the segmented light sources (2) and the object to be measured, the segmented light sources (2) are sequentially lighted, light rays of the segmented light sources (2) enter the sensor (6) through the optical filters (1) with the corresponding working ranges through the reflection of the object to be measured, the sensor (6) sequentially measures reflection signals of each segment of measuring ranges, combines the reflection signals and calculates the reflectivity of the measuring ranges.

3. A method as claimed in claim 1, wherein the light source is a full spectrum light source (7) in the measurement range, a set of said filters (1) is disposed between the full spectrum light source (7) and the sensor (6), the light from the full spectrum light source (7) enters the sensor (6) through the sequentially switched filters (1), the sensor (6) sequentially measures, calculates the reflectivity of each measurement range and combines to obtain the reflectivity of the measurement range.

4. A method of reducing stray light as claimed in claim 1, wherein edges of adjacent segmented measuring ranges overlap.

5. The device for reducing the stray light comprises a light source, a filter (1) and a sensor (6), and is characterized in that the filter (1) with a group of corresponding working ranges is arranged according to the segmentation of a measuring range in a matching manner, the filter (1) has a cut-off range and is used for filtering the spectral energy of other measuring ranges, and the filter (1) is arranged between the light source and the sensor (6).

6. The device for reducing stray light according to claim 5, wherein a set of segmented light sources (2) with corresponding working ranges are cooperatively arranged according to the segmentation of the measuring ranges, the light filters (1) matched with the working ranges of the segmented light sources (2) are respectively arranged between the segmented light sources (2) and the object to be measured, the segmented light sources (2) are sequentially lighted, light rays of the segmented light sources (2) enter the sensor (6) through the light filters (1) with the corresponding working ranges by reflection of the object to be measured, and the sensor (6) sequentially measures each segment of the measuring ranges.

7. The device for reducing stray light according to claim 5, wherein the light source is a full spectrum light source (7) in a measurement range, a filter switching device is disposed between the full spectrum light source (7) and the sensor (6), the filter switching device includes a filter (1) for sequentially switching the filters (1) in different working ranges, light from the full spectrum light source (7) enters the sensor (6) through the sequentially switched filters (1), and the sensor (6) sequentially measures each measurement range.

8. A device for reducing stray light according to claim 7, wherein said filter switching means is a set of shutters (5) having light transmission openings (8) corresponding to the filters (1), and the light transmission openings (8) are set to a full transmission state and a filtering state covering the filters (1) by switching of the shutters (5).

9. A device for reducing stray light according to claim 8, wherein a set of filters (1) with different working ranges are arranged to cooperate with said shutter (5), and said light-transmitting openings (8) are alternately covered by switching of said shutter (5).

10. The apparatus according to claim 7, wherein the filter switching device is a filter rotating wheel, the filter rotating wheel is cooperatively provided with a plurality of filters (1), and the filters (1) are sequentially switched between the full spectrum light source (7) and the sensor (6) by rotating.

Technical Field

The invention relates to the technical field of optical color measurement, in particular to a method and a device for reducing stray light.

Background

Stray light is generated in the optical measurement process, and the generation reasons of the stray light are mainly three: stray light generated by an imaging light path, stray light generated by a non-imaging light path and stray light generated by an instrument.

The stray light levels of different spectrum sensors are different, so that color data measured by each spectrum sensor are different, which is called as inter-station difference, and the stray light condition of each spectrum sensor needs to be measured and corrected.

The difference exists between the color value measured by the same spectrum sensor from the surface of the measured sample and the real color value of the surface of the measured sample, the difference is called indicating value error, the key factor influencing the indicating value error is stray light in a light splitting light path, and the stray light is embodied as that light with a specific wavelength is not focused at the position of the array sensor when the light with the specific wavelength is normally imaged, so that the detection precision of the energy with the specific wavelength is influenced, and the detection precision of the energy with other wavelengths is also influenced.

Disclosure of Invention

In order to solve the defects of the prior art and achieve the purposes of reducing stray light and improving detection precision, the invention adopts the following technical scheme:

a method of reducing stray light comprising the steps of:

s1, segmenting the measuring range;

s2, selecting a group of optical filters in corresponding working ranges according to the segmentation of the measuring ranges, wherein the optical filters have cut-off ranges and are used for filtering the spectral energy in other measuring ranges;

and S3, transmitting the light to the sensor through the filtering of each optical filter, sequentially measuring each section of measuring range by the sensor, and calculating to obtain the reflectivity of the measuring range.

Spectral energy of other measurement ranges is respectively filtered through optical filters in different working ranges, so that the formation of stray light in the unsegmented measurement process is reduced, and the indication error is reduced; meanwhile, segmented measurement can be completed without a plurality of sensors, so that the cost is saved, and the inter-station difference among different sensors is reduced.

According to the subsection of the measuring range, a group of subsection light sources corresponding to the working range are selected, optical filters matched with the working range of the subsection light sources are respectively arranged between the subsection light sources and the measured object, the subsection light sources are sequentially lightened, light rays of the subsection light sources pass through the optical filters corresponding to the working range and enter the sensor through the reflection of the measured object, the sensor sequentially measures reflection signals of each section of the measuring range, and the reflection signals are combined to calculate the reflectivity of the measuring range. The spectrum energy output by the segmented light source is the segmented spectrum energy, and the spectral energy is filtered by the corresponding segmented filter, so that the segmented filtering effect is improved.

The light source is a full spectrum light source in a measuring range, a group of optical filters is arranged between the full spectrum light source and the sensor, light rays of the full spectrum light source enter the sensor through the optical filters which are sequentially switched, the sensor sequentially measures, and the reflectivity of each section of measuring range is calculated and combined to obtain the reflectivity of the measuring range. Only one light source is needed, and segmented measurement can be completed through switching of the optical filter, so that cost is saved, and measurement efficiency is improved.

The edges of adjacent segmented measurement ranges overlap each other. Because the boundary value is easy to be interfered, a margin is left, which is beneficial to the accuracy of subsequent calculation.

A device for reducing stray light comprises a light source, a light filter and a sensor, wherein a group of light filters corresponding to working ranges are arranged in a matched mode according to the segmentation of a measuring range, the light filters are provided with cut-off ranges and used for filtering spectral energy of other measuring ranges, and the light filters are arranged between the light source and the sensor. Spectral energy of other measurement ranges is respectively filtered through optical filters in different working ranges, so that the formation of stray light in the unsegmented measurement process is reduced, and the indication error is reduced; meanwhile, segmented measurement can be completed without a plurality of sensors, so that the cost is saved, and the inter-station difference among different sensors is reduced.

According to the subsection of the measuring range, a group of subsection light sources corresponding to the working range are arranged in a matched mode, light filters matched with the working range of the subsection light sources are arranged between the subsection light sources and the measured object respectively, the subsection light sources are sequentially lightened, light rays of the subsection light sources enter the sensor through the light filters corresponding to the working range and reflected by the measured object, and the sensor sequentially measures each section of measuring range. The spectrum energy output by the segmented light source is the segmented spectrum energy, and the spectral energy is filtered by the corresponding segmented filter, so that the segmented filtering effect is improved.

The light source is a full-spectrum light source in a measuring range, a light filter switching device is arranged between the full-spectrum light source and the sensor in a matching mode, the light filter switching device comprises light filters and is used for switching the light filters in different working ranges in sequence, light of the full-spectrum light source enters the sensor through the light filters which are switched in sequence, and the sensor measures each section of measuring range in sequence. Only one full-spectrum light source is needed, segmented measurement can be completed through switching of the optical filter, cost is saved, and meanwhile measurement efficiency is improved.

The optical filter switching device is a group of shutters which are provided with light transmission openings and correspond to the optical filters, and the light transmission openings are switched by the shutters to form a full transmission state and a filtering state covering the optical filters.

Two optical filters with different working ranges are matched with the shutter, and the light-transmitting openings are covered by the switching of the shutter in turn. When the measuring range is divided into two sections, only one shutter is needed to switch the two sections of the optical filters, and when multiple sections are involved, the number of the shutters can be reduced, and the efficiency is improved.

The optical filter switching device is an optical filter rotating wheel, a plurality of optical filters are arranged on the optical filter rotating wheel in a matching mode, and the optical filters are sequentially switched between the full-spectrum light source and the sensor through rotation.

The invention has the advantages and beneficial effects that:

spectral energy of other measurement ranges is respectively filtered through optical filters in different working ranges, so that the formation of stray light in the unsegmented measurement process is reduced, and the indication error is reduced; meanwhile, segmented measurement can be completed without a plurality of sensors, so that the cost is saved, and the inter-station difference among different sensors is reduced.

Drawings

FIG. 1 is a top sectional view of an apparatus according to an embodiment of the present invention.

FIG. 2 is a graph of transmittance of three filters according to the present invention.

FIG. 3 is a graph comparing measured reflectance data with real reflectance data for segments with filters added in the present invention.

FIG. 4 is a cross-sectional view of a second embodiment of the apparatus of the present invention.

Fig. 5a is a schematic diagram of a shutter structure according to a second embodiment of the present invention.

Fig. 5b is a first state diagram of the shutter according to the second embodiment of the present invention.

FIG. 5c is a second state diagram of the shutter according to the second embodiment of the present invention.

Fig. 6a is a graph of the signals measured by five spectral sensors (C12666 MA) on the stray light detection device.

Fig. 6b is a graph of the signals (X-axis magnification) measured by five spectral sensors (C12666 MA) on the stray light detection device.

FIG. 7 is a graph comparing measured reflectance data to actual reflectance data.

In the figure: 1. the device comprises a filter 2, a segmented light source 3, an integrating sphere 4, a measuring port 5, a shutter 6, a sensor 7, a full-spectrum light source 8, a light transmitting port 9, a first filter 10 and a second filter.

Detailed Description

The following detailed description of embodiments of the invention refers to the accompanying drawings. It should be understood that the detailed description and specific examples, while indicating the present invention, are given by way of illustration and explanation only, not limitation.