WO2024051037A1 - Control method for spectro-colorimeter illumination system - Google Patents

Abstract

A control method for a spectro-colorimeter illumination system. The method comprises: S11: a synchronous control circuit controlling a first pulse drive circuit and a second pulse drive circuit to generate pulse drive signals at the same time, so as to drive the illumination of a full-spectrum LED and a multi-color LED, and the synchronous control circuit and a detector collection circuit driving the exposure of a detector; S12: when the pulse drive signals change from a high level to a low level, the synchronous control circuit and the detector collection circuit controlling the exposure of the detector to end, so as to obtain a spectral reflectivity curve under the current pulse drive signals; S13: repeating step S11 and step S12 multiple times, and increasing the time widths of the pulse drive signals upon each repetition, so as to obtain spectral reflectivity curves under the pulse drive signals at different times; and S14: fusing the spectral reflectivity curves under the pulse drive signals at different times, so as to obtain a complete spectral reflectivity curve of an object under test. By means of the control method for a spectro-colorimeter illumination system, a high signal-to-noise ratio reflectivity curve or a high-dynamic-range spectral reflectivity curve of an object can be effectively acquired.

Description

A control method for a spectrophotometer lighting system Technical field

The present invention relates to the technical field of color measurement, and in particular to a control method for a spectrophotometer lighting system.

Background technique

The currently used spectrophotometers undergo a whiteboard calibration to obtain the normalized spectral reflectance of the object. When the reflectivity of the object is moderate, the object color data obtained by obtaining the normalized reflectance spectrum curve has little error. However, when measuring dark objects, such as dark gray mobile phone panels, the reflectivity at each wavelength is low, causing the detector to The response is low, and photon noise, detector noise, etc. seriously affect the measurement results. Or when the reflectivity curve of an object has strong and weak absorption or reflection characteristics at the same time, because these high and low or strong and weak characteristics are obviously different, these high dynamic range reflectance data cannot be obtained through calibration or direct measurement, which also brings serious consequences. Colorimetric measurement error.

Contents of the invention

The technical problem to be solved by the present invention is to provide a control method for a spectrophotometer illumination system that can obtain a complete high dynamic range spectral reflectance curve of an object to be measured.

In order to solve the above problems, the present invention provides a control method for a spectrophotometer lighting system. The lighting system includes a full-spectrum LED, a multi-color LED, a first pulse drive circuit, a second pulse drive circuit, and a detector acquisition circuit. and a synchronous control circuit, the first pulse drive circuit is connected to the full-spectrum LED, the second pulse drive circuit is connected to the multi-color LED, both the first pulse drive circuit and the second pulse drive circuit pass The synchronous control circuit is connected to the detector acquisition circuit, and the detector acquisition circuit is connected to the detector; the control method includes:

S11. The synchronous control circuit controls the first pulse drive circuit and the second pulse drive circuit to simultaneously generate pulse drive signals to drive the full-spectrum LED and multi-color LED lighting. The synchronous control circuit and the detector collection circuit drive the The detector is exposed;

S12. When the pulse driving signal changes from high to low, the synchronization control circuit and the detector acquisition circuit control the detector exposure to end, and obtain the spectral reflectance curve under the current pulse driving signal;

S13. Repeat steps S11 and S12 multiple times, increasing the time width of the pulse driving signal each time to obtain spectral reflectance curves under pulse driving signals at different times;

S14. Fusion of spectral reflectance curves under pulse driving signals at different times to obtain a complete spectral reflectance curve of the object to be measured.

As a further improvement of the present invention, in step S14, the following formula is used to fuse the spectral reflectance curves under pulse driving signals at different times:

Among them, f _z is the complete high dynamic range spectral reflectance curve of the object to be measured; f _b1 , f _b2 ,..., f _bn are the spectral reflectance curves under the 1st, 2nd,..., n pulse driving signals respectively. ;a ₂ ,...,a _n are respectively the ratio of the width of the 2nd,...,nth pulse drive signal to the width of the 1st pulse drive signal; {·} is the valid data selected in each spectral reflectance curve.

As a further improvement of the present invention, n≥3.

As a further improvement of the present invention, in step S11, the synchronization control circuit and the detector collection circuit drive the detector for exposure before or at the same time as the pulse driving signal is sent.

The invention also provides a control method for a spectrocolorimeter lighting system. The lighting system includes a full-spectrum LED, a multi-color LED, a first pulse drive circuit, a second pulse drive circuit, a detector acquisition circuit and a synchronous control circuit. , the first pulse drive circuit is connected to the full-spectrum LED, the second pulse drive circuit is connected to the multi-color LED, both the first pulse drive circuit and the second pulse drive circuit are controlled through the synchronization The circuit is connected to the detector acquisition circuit, and the detector acquisition circuit is connected to the detector; the control method includes:

S21. The synchronous control circuit controls the first pulse drive circuit and the second pulse drive circuit to simultaneously generate periodic pulse drive signals to drive the full-spectrum LED and multi-color LED lighting. The synchronous control circuit and detector collect The circuit drives the detector to expose, the exposure time is greater than or equal to the width of a single pulse driving signal, and the spectral reflectance curve under the current exposure time is obtained;

S22. Repeat step S21 multiple times, adjusting the exposure time each time to obtain spectral reflectance curves under different exposure times;

S23. Fusion of spectral reflectance curves under different exposure times to obtain a complete spectral reflectance curve of the object to be measured.

As a further improvement of the present invention, in step S22, step S21 is repeated multiple times, and the exposure time is adjusted each time it is repeated so that each exposure time corresponds to a different number of single pulse driving signal widths.

As a further improvement of the present invention, in step S23, the following formula is used to fuse the spectral reflectance curves under different exposure times:

Among them, f _z is the complete high dynamic range spectral reflectance curve of the object to be measured; f _d1 , f _d2 ,..., f _dm are respectively the spectral reflection under the exposure time corresponding to the number pulse of 1, 2,..., m rate curve; {·} is the valid data selected in each spectral reflectance curve.

As a further improvement of the present invention, m≥3.

As a further improvement of the present invention, in step S22, the exposure time is adjusted by increasing the time span or selecting a different time span each time it is repeated.

Beneficial effects of the present invention:

The control method of the spectrocolorimeter lighting system of the present invention can effectively obtain a high signal-to-noise ratio reflectance curve of a low reflectivity object, and can effectively obtain a high dynamic range spectral reflectance curve when the object has large differences in high and low absorption or high and low reflection spectral characteristics. Thus, high-precision chromaticity values, such as Lab, Luv and other color space coordinates, are obtained, which improves the measurement accuracy of the spectrophotometer.

The above description is only an overview of the technical solution of the present invention. In order to have a clearer understanding of the technical means of the present invention, it can be implemented according to the content of the description, and in order to make the above and other objects, features and advantages of the present invention more obvious and understandable. , the following is a detailed description of the preferred embodiments, together with the accompanying drawings.

Description of the drawings

Figure 1 is a schematic diagram of a spectrophotometer illumination system in an embodiment of the present invention;

Figure 2 is a flow chart of a control method of a spectrophotometer illumination system in an embodiment of the present invention;

Figure 3 is a schematic diagram of spectral reflectivity curve fusion under pulse driving signals at different times in an embodiment of the present invention;

Figure 4 is a schematic diagram of a control method of a spectrophotometer illumination system in another embodiment of the present invention;

Figure 5 is a schematic diagram of spectral reflectance curve fusion under different exposure times in another embodiment of the present invention.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and specific examples, so that those skilled in the art can better understand and implement the present invention, but the examples are not intended to limit the present invention.

The control method of the spectrocolorimeter lighting system in the embodiment of the present invention is used to control the spectrocolorimeter lighting system. Referring to Figure 1, the lighting system includes a full-spectrum LED, a multi-color LED, a first pulse drive circuit, a second Pulse drive circuit, detector collection circuit and synchronous control circuit, the first pulse drive circuit is connected to the full spectrum LED, the second pulse drive circuit is connected to the multi-color LED, both the first pulse drive circuit and the second pulse drive circuit pass The synchronous control circuit is connected to the detector collection circuit, and the detector collection circuit is connected to the detector; wherein, the integrating sphere uniformly lights the full-spectrum LED2 and the multi-color LED3, and the uniformized light is incident on the object to be measured, and is detected by the detector after reflection. The detector has linear radiation response characteristics at each wavelength, and CCD or CMOS detectors can be selected.

As shown in Figure 2, the control method of the spectrophotometer illumination system in the embodiment of the present invention includes the following steps:

Step S11, the synchronous control circuit controls the first pulse drive circuit and the second pulse drive circuit to simultaneously generate pulse drive signals to drive full-spectrum LED and multi-color LED lighting, and the synchronous control circuit and detector acquisition circuit drive the detector for exposure; Among them, the synchronous control circuit and the detector acquisition circuit drive the detector to expose before or at the same time that the pulse driving signal is sent. The synchronous control circuit ensures that the pulse driving signal width for driving full-spectrum LEDs and multi-color LEDs is consistent.

Step S12: When the pulse driving signal changes from high to low, the synchronization control circuit and the detector acquisition circuit control the detector to end the exposure, and obtain the spectral reflectance curve under the current pulse driving signal.

Step S13: Repeat steps S11 and S12 multiple times, increasing the time width of the pulse driving signal each time to obtain spectral reflectance curves under pulse driving signals at different times.

Step S14: Fusion of spectral reflectance curves under pulse driving signals at different times to obtain a complete spectral reflectance curve of the object to be measured.

Specifically, the following formula is used to fuse the spectral reflectance curves under pulse driving signals at different times:

Among them, f _z is the complete high dynamic range spectral reflectance curve of the object to be measured; f _b1 , f _b2 ,..., f _bn are the spectral reflectance curves under the 1st, 2nd,..., n pulse driving signals respectively. ;a ₂ ,...,a _n are respectively the ratio of the width of the 2nd,...,nth pulse drive signal to the width of the 1st pulse drive signal; {·} is the valid data selected in each spectral reflectance curve. The sub-wavelength ranges corresponding to these effective data positions are combined to form a complete measurement wavelength range. The so-called effective means to remove the saturated signal and low signal-to-noise ratio curve in the spectral curve. Further, n≥3.

Referring to Figure 3, optionally, assume that the width of the first pulse drive signal is Ts, the width of the second pulse drive signal is a times Ts, the width of the second pulse drive signal is b times Ts, and b>a> 1. c is a multiple of the exposure time, c>b indicates that the exposure time is longer than the driving pulse time width. When the difference in the spectral curves of objects is relatively large, as shown on the far right side of Figure 3. The first shortest pulse illumination can obtain the signal near the high reflectivity characteristic band position without saturating the signal. When the pulse drive width is sequentially increased, the signal at the low reflectivity characteristic band will appear, but the signal near the high reflectivity characteristic band will be saturated. When the pulse driving time width is further increased, the saturation wavelength width at the high reflectivity characteristic band continues to expand, and the lower reflectivity characteristic spectrum band is measured. Finally, the effective spectral data obtained under pulse-driven illumination at each time are combined to obtain a complete high-dynamic spectral curve. The middle of Figure 3 shows the spectral reflectance curve under three different time pulse driving signals, and the right side of Figure 3 shows the complete spectral reflectance curve of the object under test obtained by fusion.

As shown in Figure 4, the control method of the spectrocolorimeter illumination system in another embodiment of the present invention includes the following steps:

Step S21: The synchronous control circuit controls the first pulse drive circuit and the second pulse drive circuit to simultaneously generate periodic pulse drive signals to drive the full-spectrum LED and multi-color LED lighting. The synchronous control circuit and detector The acquisition circuit drives the detector to expose, and the exposure time is greater than or equal to the width of a single pulse driving signal to obtain the spectral reflectance curve under the current exposure time.

Step S22, repeat step S21 multiple times, and adjust the exposure time each time to obtain spectral reflectance curves under different exposure times; optionally, adjust the exposure by increasing the time span or selecting different time spans each time it is repeated. time.

Step S23: Fusion of spectral reflectance curves under different exposure times to obtain a complete spectral reflectance curve of the object to be measured.

Optionally, in step S22, step S21 is repeated multiple times, and the exposure time is adjusted each time it is repeated, so that each exposure time corresponds to a different number of single pulse driving signal widths. Can be easily calculated.

Further, in step S23, the following formula is used to fuse the spectral reflectance curves under different exposure times:

Among them, f _z is the complete high dynamic range spectral reflectance curve of the object to be measured; f _d1 , f _d2 ,..., f _dm are respectively the spectral reflection under the exposure time corresponding to the number pulse of 1, 2,..., m rate curve; {·} is the valid data selected in each spectral reflectance curve. Preferably, m≥3.

Referring to Figure 5, optionally, assuming that the width of a single pulse driving signal is Ts, the first detector exposure time is Ts+k ₁ , the second detector exposure time is 2Ts+k ₂ , and the third detector exposure time is 3Ts+k ₃ , k ₁ , k ₂ , and k ₃ are redundant times when the exposure time is longer than the illumination pulse, and k ₁ , k ₂ , and k ₃ can remain consistent. The middle of Figure 5 shows the spectral reflectance curve obtained under three exposure times, and the right side of Figure 5 shows the complete spectral reflectance curve of the object under test obtained by fusion.

The control method of the spectrocolorimeter lighting system of the present invention can effectively obtain a high signal-to-noise ratio reflectance curve of a low reflectivity object, and can effectively obtain a high dynamic range spectral reflectance curve when the object has large differences in high and low absorption or high and low reflection spectral characteristics. Thus, high-precision chromaticity values, such as Lab, Luv and other color space coordinates, are obtained, which improves the measurement accuracy of the spectrophotometer.

The above embodiments are only preferred embodiments to fully illustrate the present invention, and the protection scope of the present invention is not limited thereto. Equivalent substitutions or transformations made by those skilled in the art on the basis of the present invention are within the protection scope of the present invention. The protection scope of the present invention shall be determined by the claims.

Claims (9)

A control method for a spectrophotometer lighting system, characterized in that the lighting system includes a full-spectrum LED, a multi-color LED, a first pulse drive circuit, a second pulse drive circuit, a detector acquisition circuit and a synchronous control circuit, The first pulse drive circuit is connected to the full-spectrum LED, the second pulse drive circuit is connected to the multi-color LED, and both the first pulse drive circuit and the second pulse drive circuit pass through the synchronous control circuit. It is connected to a detector acquisition circuit, and the detector acquisition circuit is connected to the detector; the control method includes: S11. The synchronous control circuit controls the first pulse drive circuit and the second pulse drive circuit to simultaneously generate pulse drive signals to drive the full-spectrum LED and multi-color LED lighting. The synchronous control circuit and the detector collection circuit drive the The detector is exposed; S12. When the pulse driving signal changes from high to low, the synchronization control circuit and the detector acquisition circuit control the detector exposure to end, and obtain the spectral reflectance curve under the current pulse driving signal; S13. Repeat steps S11 and S12 multiple times, increasing the time width of the pulse driving signal each time to obtain spectral reflectance curves under pulse driving signals at different times; S14. Fusion of spectral reflectance curves under pulse driving signals at different times to obtain a complete spectral reflectance curve of the object to be measured. The control method of a spectrophotometer illumination system as claimed in claim 1, characterized in that, in step S14, the following formula is used to fuse the spectral reflectance curves under pulse driving signals at different times:

Among them, f _z is the complete high dynamic range spectral reflectance curve of the object to be measured; f _b1 , f _b2 ,..., f _bn are the spectral reflectance curves under the 1st, 2nd,..., n pulse driving signals respectively. ;a ₂ ,...,a _n are respectively the ratio of the width of the 2nd,...,nth pulse drive signal to the width of the 1st pulse drive signal; {·} is the valid data selected in each spectral reflectance curve. The control method of a spectrocolorimeter illumination system as claimed in claim 2, wherein n≥3. The control method of a spectrocolorimeter illumination system according to claim 1, characterized in that, in step S11, the synchronous control circuit and the detector acquisition circuit drive the detector before or at the same time as the pulse drive signal is sent. device exposure. A control method for a spectrophotometer lighting system, characterized in that the lighting system includes a full-spectrum LED, a multi-color LED, a first pulse drive circuit, a second pulse drive circuit, a detector acquisition circuit and a synchronous control circuit, The first pulse drive circuit is connected to the full-spectrum LED, the second pulse drive circuit is connected to the multi-color LED, and both the first pulse drive circuit and the second pulse drive circuit pass through the synchronous control circuit. It is connected to a detector acquisition circuit, and the detector acquisition circuit is connected to the detector; the control method includes: S21. The synchronous control circuit controls the first pulse drive circuit and the second pulse drive circuit to simultaneously generate periodic pulse drive signals to drive the full-spectrum LED and multi-color LED lighting. The synchronous control circuit and detector collect The circuit drives the detector to expose, the exposure time is greater than or equal to the width of a single pulse driving signal, and the spectral reflectance curve under the current exposure time is obtained; S22. Repeat step S21 multiple times, adjusting the exposure time each time to obtain spectral reflectance curves under different exposure times; S23. Fusion of spectral reflectance curves under different exposure times to obtain a complete spectral reflectance curve of the object to be measured. The control method of a spectrocolorimeter illumination system as claimed in claim 5, characterized in that, in step S22, step S21 is repeated multiple times, and the exposure time is adjusted each time it is repeated, so that each exposure time corresponds to a different number of Single pulse drive signal width. The control method of a spectrophotometer illumination system as claimed in claim 6, characterized in that, in step S23, the following formula is used to fuse the spectral reflectance curves under different exposure times:

Among them, f _z is the complete high dynamic range spectral reflectance curve of the object to be measured; f _d1 , f _d2 ,..., f _dm are respectively the spectral reflection under the exposure time corresponding to the number pulse of 1, 2,..., m rate curve; {·} is the valid data selected in each spectral reflectance curve. The control method of a spectrocolorimeter illumination system as claimed in claim 7, wherein m≥3. The control method of a spectrocolorimeter illumination system as claimed in claim 5, wherein in step S22, the exposure time is adjusted by increasing the time span or selecting different time spans each time it is repeated.

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