CN114964735A - Device and method for detecting polarization performance of display screen polaroid - Google Patents

Abstract

The invention discloses a device and a method for detecting polarization performance of a display screen polarizer, wherein the device comprises a light source, a polarization component, a rotating component, a photoelectric sensor component and a processor; the polarization assembly comprises at least two standard polaroids with different polarization directions, and the photoelectric sensor assembly comprises photoelectric sensors which correspond to the standard polaroids one by one; the polarizing component is arranged on the rotating component; the light source is positioned at one side of the polarizing component and uniformly irradiates each standard polarizer; the photoelectric sensor assembly is positioned at the other side of the polarization assembly, and the projection of each photoelectric sensor on the light source is respectively positioned in the projection of each standard polarizer on the light source; the processor is respectively connected with each photoelectric sensor in a communication mode. The method can more quickly and accurately detect the polarization performance of the polarizer to be detected.

Description

Device and method for detecting polarization performance of display screen polaroid

Technical Field

The invention relates to the technical field of optical detection, in particular to a device and a method for detecting the polarization performance of a display screen polarizer.

Background

The polarizer is an important optical film, and is mainly applied to a display screen of an electronic product, and as an important component of the display screen, various optical performance indexes of the polarizer are very important, and directly affect the output effect of the display screen, so that the optical performance of the polarizer needs to be detected, and currently, the optical performance parameters mainly detected comprise light transmittance, polarization degree, polarization axis position and the like.

Wherein the (monomeric) light transmittance is defined as T ═ I/I ₀ ，I ₀ The light intensity of incident natural light is shown, I is the light intensity of transmitted light of the natural light after passing through the polaroid, and the light transmittance represents the transmission ratio of the polaroid to light energy. The degree of polarization (also called the polarization ratio) is defined as P ═ I _{In parallel} -I _{Is perpendicular to} )/(I _{In parallel} +I _{Is perpendicular to} )，I _{In parallel} And I _{Hanging device} Respectively representing the light intensity of transmitted light in the directions of a parallel polarizing axis and a vertical polarizing axis of the vibration direction after natural light passes through the polarizer, namely the polarization degree is the ratio of the difference of the transmitted light intensity of two optical axes (the polarizing axis and the absorption axis which are vertical to each other) of the polarizer to the sum of the transmitted light intensity; ideally, I _{Is perpendicular to} When the polarization rate is 0, the polarization rate is 100 percent; that is, the closer the degree of polarization is to 1, the better.

The optical performance of the prior polaroid is usually detected manually by adopting artificial naked eyes, so that the detection efficiency is low and the detection quality is unstable.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: the device and the method for detecting the polarization performance of the polaroid of the display screen can detect the polarization performance of the polaroid to be detected more quickly and accurately.

In order to solve the technical problems, the technical scheme adopted by the invention is as follows: a polarization performance detection device for a display screen polaroid comprises a light source, a polarization component, a rotating component, a photoelectric sensor component and a processor; the polarization assembly comprises at least two standard polaroids, the polarization directions of the standard polaroids are different, and the photoelectric sensor assembly comprises photoelectric sensors which correspond to the standard polaroids one by one; the polarizing component is arranged on the rotating component, and the rotating component is used for driving each standard polarizer to rotate; the light source is positioned on one side of the polarizing component and uniformly irradiates each standard polarizer; the photoelectric sensor assembly is positioned on the other side of the polarization assembly, and the projection of each photoelectric sensor on the light source is respectively positioned in the projection of each standard polarizer on the light source; the processor is respectively in communication connection with the photoelectric sensors.

The invention also provides a polarization performance detection method of the polarization performance detection device based on the display screen polaroid, which comprises the following steps:

before the polaroid to be tested is placed, obtaining an incident voltage value according to the voltage signals output by each photoelectric sensor;

placing the polaroid to be tested between the polarizing component and the photoelectric sensor component, and obtaining a transmission voltage value according to the voltage signal output by each photoelectric sensor;

determining the light transmittance of the polarizer to be tested according to the transmission voltage value and the incident voltage value;

rotating each standard polaroid by controlling the rotating assembly, and obtaining light intensity waveform curves corresponding to each standard polaroid in n periods according to the voltage signals output by each photoelectric sensor, wherein n is a preset value;

analyzing to obtain a final illumination intensity function according to the light intensity waveform curve corresponding to each standard polaroid;

and determining the polarization degree and the polarization axis position error angle of the polarizer to be tested according to the final illumination intensity function.

The invention has the beneficial effects that: when the polaroid to be detected is to be detected, the polaroid to be detected is placed between the polarizing component and the photoelectric sensor component, so that light emitted by the light source can sequentially penetrate through the standard polaroid and the polaroid to be detected, an included angle between the polarization direction of the standard polaroid and the polarization direction of the polaroid to be detected is changed by rotating the standard polaroid, in the process, a voltage signal acquired by the photoelectric sensor also periodically changes, an illumination intensity function of an illumination value and a rotation angle is constructed by analyzing the waveform of a signal acquired by the photoelectric sensor, iterative correction is carried out, and finally the polarization degree and axial deviation in the polarization performance parameters of the polaroid to be detected are determined according to the final illumination intensity function; meanwhile, by arranging a plurality of standard polaroids with different polarization directions, different positions of the polaroid to be tested can be tested, so that the problem of single-point test and limited coverage of test points is solved, and the accuracy of test results can be improved. The invention can more quickly and accurately detect the polarization performance of the polaroid to be detected.

Drawings

Fig. 1 is a schematic structural diagram of a polarization performance detection apparatus for a polarizer of a display screen according to a first embodiment of the present invention;

FIG. 2 is a cross-sectional view taken along line A-A of FIG. 1;

FIG. 3 is a schematic diagram illustrating the polarization direction of the standard polarizer in the initial state according to a second embodiment of the present invention;

fig. 4 is a schematic diagram of the voltage signals collected by one rotation of the driving spindle according to the second embodiment of the present invention;

FIG. 5 is a flowchart of a polarization performance testing method according to a second embodiment of the present invention;

FIG. 6 is a flowchart of step S5 according to the second embodiment of the present invention;

fig. 7 is a waveform diagram of the final illumination intensity function according to the second embodiment of the present invention.

Description of reference numerals:

1. a light source; 2. a standard polarizer; 3. a rotating assembly; 4. a photoelectric sensor; 5. a processor; 6. a polaroid to be tested;

31. a rotating electric machine; 32. a driving rotating shaft; 33. a hollow shaft; 34. a first gear; 35. a second gear.

Detailed Description

In order to explain technical contents, objects and effects of the present invention in detail, the following detailed description is given with reference to the accompanying drawings in conjunction with the embodiments.

Referring to fig. 1, a device for detecting polarization performance of a polarizer of a display screen includes a light source, a polarization assembly, a rotation assembly, a photoelectric sensor assembly, and a processor; the polarization component comprises at least two standard polarizers, the polarization directions of the standard polarizers are different, and the photoelectric sensor component comprises photoelectric sensors which correspond to the standard polarizers one by one; the polarizing component is arranged on the rotating component, and the rotating component is used for driving each standard polarizer to rotate; the light source is positioned on one side of the polarizing component and uniformly irradiates each standard polarizer; the photoelectric sensor assembly is positioned on the other side of the polarization assembly, and the projection of each photoelectric sensor on the light source is respectively positioned in the projection of each standard polarizer on the light source; the processor is respectively in communication connection with the photoelectric sensors.

From the above description, the beneficial effects of the present invention are: the polarizing performance of the polarizer to be tested can be detected more quickly and accurately.

Furthermore, the polaroid to be tested is positioned between the polarizing component and the photoelectric sensor component, and the projection of the polaroid to be tested on the light source covers the projection of each standard polaroid on the light source.

According to the above description, it is ensured that the photoelectric sensor can acquire the optical signal after the light emitted by the light source sequentially passes through the standard polarizer and the polarizer to be tested.

Furthermore, the polarization directions of the standard polaroids are different by 180 degrees/m in sequence, and m is the number of the standard polaroids.

As can be seen from the above description, subsequent analytical calculations are facilitated.

Furthermore, the rotating assembly comprises a rotating motor, a driving rotating shaft and hollow shafts in one-to-one correspondence with the standard polaroids, the standard polaroids are respectively arranged in the hollow shafts in one-to-one correspondence and are located on the same radial plane, the hollow shafts are respectively in transmission connection with the driving rotating shaft, and the driving rotating shaft is connected with the rotating motor.

As can be seen from the above description, the rotating motor synchronously drives the driving shaft to rotate, and the driving shaft drives the hollow shaft to rotate, so that the standard polarizer in the hollow shaft rotates,

furthermore, the outer side surface of the driving rotating shaft is provided with a first gear, the outer side surface of the hollow shaft is provided with a second gear, and the first gear is in transmission connection with the second gear.

From the above description, the transmission ratio can be set to 1, so that the driveshaft rotates 1 revolution, and the hollow shaft also rotates one revolution.

The invention also provides a polarization performance detection method based on the polarization performance detection device of the display screen polaroid, which comprises the following steps:

before the polarizer to be tested is placed, obtaining an incident voltage value according to voltage signals output by each photoelectric sensor;

placing the polaroid to be tested between the polarizing component and the photoelectric sensor component, and obtaining a transmission voltage value according to the voltage signal output by each photoelectric sensor;

determining the light transmittance of the polarizer to be tested according to the transmission voltage value and the incident voltage value;

rotating each standard polaroid by controlling the rotating assembly, and obtaining light intensity waveform curves corresponding to each standard polaroid in n periods according to the voltage signals output by each photoelectric sensor, wherein n is a preset value;

analyzing to obtain a final illumination intensity function according to the light intensity waveform curve corresponding to each standard polaroid;

and determining the polarization degree and the polarization axis position error angle of the polarizer to be tested according to the final illumination intensity function.

According to the above description, the light transmittance in the polarization performance parameters of the polarizer to be tested can be obtained by obtaining and analyzing the voltage values output by the photoelectric sensors before and after the polarizer to be tested is placed; the method comprises the steps of obtaining a plurality of signal waveforms of illumination values and rotation angles by rotating a plurality of standard polaroids with different polarization directions, obtaining a final illumination intensity function by analyzing and processing the signal waveforms, and solving the polarization degree and axial position deviation in polarization performance parameters of the polaroid to be tested based on the final illumination intensity function.

Further, the analyzing according to the light intensity waveform curve corresponding to each standard polarizer to obtain the final illumination intensity function specifically comprises:

calculating to obtain a final amplitude value according to a voltage value corresponding to a peak point and a voltage value corresponding to a valley point of a light intensity waveform curve corresponding to each standard polaroid;

calculating to obtain an initial phase according to the angle value corresponding to the peak point and the angle value corresponding to the valley point of the light intensity wave curve corresponding to each standard polaroid;

taking the final amplitude value as an initial offset value, and generating an initial illumination intensity function according to the final amplitude value, the initial phase and the initial offset value, wherein the illumination intensity function is a cosine function;

taking the initial illumination intensity function as a current illumination intensity function, and obtaining intersection points of light intensity waveform curves corresponding to the standard polaroids;

calculating to obtain a substituted voltage value corresponding to each intersection point through a current illumination intensity function according to the angle value of each intersection point;

calculating voltage difference values corresponding to the intersection points according to the voltage values of the intersection points and the substituted voltage values corresponding to the intersection points, and calculating the average value of the voltage difference values to obtain the average value of the voltage difference values;

judging whether the average value of the voltage difference values is smaller than a preset threshold value or not;

if so, taking the current illumination intensity function as a final illumination intensity function;

if not, calculating to obtain a new offset value according to the offset value in the current illumination intensity function and the average value of the voltage difference values;

and updating the current illumination intensity function according to the new deviation value, taking the new illumination intensity function as the current illumination intensity function, and continuously executing the step of obtaining the intersection points of the light intensity waveform curves corresponding to the standard polaroids.

From the above description, the final amplitude value and the initial phase in the final illumination intensity function are obtained by comprehensively analyzing the amplitude value and the phase deviation value of the light intensity waveform curve corresponding to each standard polarizer; and determining a more accurate deviation value by performing iterative analysis on the deviation value, thereby obtaining a final illumination intensity function.

Further, the step of calculating, according to the voltage value corresponding to the peak point and the voltage value corresponding to the valley point of the light intensity waveform curve corresponding to each standard polarizer, to obtain a final amplitude value specifically includes:

respectively calculating the average value of voltage values corresponding to all peak points of a light intensity waveform curve corresponding to a standard polaroid and the average value of voltage values corresponding to all valley points to obtain the peak voltage average value and the valley voltage average value of the light intensity waveform curve corresponding to the standard polaroid;

calculating to obtain an amplitude value of the light intensity waveform curve corresponding to the standard polaroid according to the peak voltage average value and the trough voltage average value of the light intensity waveform curve corresponding to the standard polaroid;

and calculating the average value of the amplitude values of the light intensity waveform curves corresponding to the standard polaroids to obtain the final amplitude value.

As can be seen from the above description, the final amplitude value is obtained by calculating and integrating the amplitude values of the light intensity waveform curves corresponding to the standard polarizers.

Further, the calculating according to the angle value corresponding to the peak point and the angle value corresponding to the valley point of the light intensity waveform curve corresponding to each standard polarizer specifically includes:

obtaining included angle angles between the polarization direction of each standard polarizer before rotation and the ideal polarization direction of the polarizer to be tested, and obtaining initial included angle angles corresponding to each standard polarizer;

determining the angle value of an ideal wave peak point and the angle value of an ideal wave valley point of a light intensity wave curve corresponding to each standard polaroid according to the initial included angle corresponding to each standard polaroid;

calculating a phase deviation value of a light intensity waveform curve corresponding to a standard polaroid according to an angle value corresponding to a peak point of the light intensity waveform curve corresponding to the standard polaroid, an angle value corresponding to a trough point, an angle value of an ideal peak point and an angle value of an ideal trough point;

and calculating an average value according to the phase deviation value of the light intensity waveform curve corresponding to each standard polaroid to obtain an initial phase.

As can be seen from the above description, the initial phase is obtained by calculating and integrating the phase shift values of the light intensity waveform corresponding to each standard polarizer.

Further, the determining the polarization degree and the polarization axis error angle of the polarizer to be measured according to the final illumination intensity function specifically includes:

determining the polarization degree of the polarizer to be tested according to the amplitude value and the deviation value in the final illumination intensity function;

and determining the polarization axis position error angle of the polarizer to be tested according to the initial phase in the final illumination intensity function.

As can be seen from the above description, the degree of polarization can be calculated based on the peak value and the trough value of the final illumination intensity function, and the peak value and the trough value can be calculated according to the amplitude value and the offset value, so the degree of polarization can be calculated according to the amplitude value and the offset value; meanwhile, the initial phase can be directly used as the axial deviation of the polaroid to be measured.

Example one

Referring to fig. 1-2, a first embodiment of the present invention is: a polarization performance detection device for a display screen polarizer can be applied to detecting the polarization performance of a mobile phone screen polarizer.

As shown in fig. 1, the device comprises a light source 1, a polarization component, a rotation component 3, a photoelectric sensor component and a processor 5; the polarization component comprises at least two standard polaroids 2, the polarization directions of the standard polaroids 2 are different, and the photoelectric sensor component comprises photoelectric sensors 4 which correspond to the standard polaroids 2 one to one. In the present embodiment, the polarizer assembly includes two standard polarizers 2, and correspondingly, the photo-sensor assembly includes two photo-sensors 4.

The polarizing component is arranged on the rotating component 3, and the rotating component 3 is used for driving each standard polarizer 2 to rotate. In this embodiment, referring to fig. 2, the rotating assembly 3 includes a rotating motor 31, an active rotating shaft 32 and hollow shafts 33 corresponding to the standard polarizers 2 one by one, each standard polarizer 2 is disposed in each hollow shaft 33 one by one and located on the same radial plane, each hollow shaft 33 is in transmission connection with the active rotating shaft 32, and the active rotating shaft 32 is connected with the rotating motor 31. Specifically, the outer side surface of the driving rotating shaft 32 is provided with a first gear 34, the outer side surface of the hollow shaft 33 is provided with a second gear 35, and the first gear 34 and the second gear 35 are in transmission connection.

Preferably, the hollow shafts 33 are evenly distributed around the central axis of the active shaft 32. The transmission ratio of the driving rotating shaft to the hollow shaft 33 is 1, so that the rotating angle of the hollow shaft is the rotating angle of the driving rotating shaft, and the subsequent accurate control of the rotating angle of the standard polarizer is facilitated.

As shown in fig. 1, a light source 1 is located at one side of the polarizer assembly and uniformly irradiates each standard polarizer 2; preferably, the light source 1 is a surface light source, and uniformly irradiates the same radial plane where the two standard polarizers 2 are located.

The photoelectric sensor assembly is located at the other side of the polarization assembly, and the projections of the photoelectric sensors 4 on the light source 1 are respectively located in the projections of the standard polarizer 2 on the light source 1, further, the photoelectric sensors 4 are respectively located on the extension lines of the central axes of the hollow shafts 33, so that the photoelectric sensors 4 can acquire optical signals penetrating through the standard polarizer 2 in the hollow shaft 33.

When the performance of the polarizer 6 to be tested is to be tested, the polarizer 6 to be tested is placed between the polarization assembly and the photoelectric sensor assembly, and the projection of the polarizer 6 to be tested on the light source 1 covers the projection of each standard polarizer 2 on the light source 1, that is, the size of the polarizer 6 to be tested can cover the driving rotating shaft 32 and each hollow shaft 33, so that the light emitted by the light source 1 can be irradiated onto the polarizer 6 to be tested after passing through the standard polarizers 2 in each hollow shaft 33, and further the polarizer 6 to be tested is subjected to polarization, at this moment, the photoelectric sensor 4 collects optical signals after the light source 1 passes through the corresponding standard polarizer 2 and the polarizer 6 to be tested, and then converts the collected optical signals into electric signals.

The processor 5 is in communication connection with each of the photoelectric sensors 4, and is configured to obtain electrical signals output by each of the photoelectric sensors 4, and analyze the electrical signals to obtain polarization performance parameters of the polarizer 6 to be tested.

Furthermore, the detection device may further include a support member and a clamping member (not shown in the figure), where the support member may be a bracket or a support pillar, and when the polarizer to be detected is to be detected, the polarizer to be detected may be placed on the support member and fixed by the clamping member, so as to ensure stability of the polarizer to be detected in the detection process.

Further, the polarization directions of the standard polarizers are different, preferably, the polarization directions of the standard polarizers are different by 180 °/m in sequence, and m is the number of the standard polarizers. For example, in the embodiment, the number of the standard polarizers is two, and the included angle between the polarization directions of the two standard polarizers is 90 °. In an alternative embodiment, if the number of the standard polarizers is three, the polarization directions of the three standard polarizers sequentially differ by 60 °, and if the polarization direction of one of the standard polarizers is 0 degree, the polarization directions of the other two standard polarizers are 60 degrees and 120 degrees, respectively. In another optional embodiment, if the number of the standard polarizers is four, the polarization directions of the four standard polarizers sequentially differ by 45 °, and if the polarization direction of one of the standard polarizers is 0 degree, the polarization directions of the other three standard polarizers are respectively 45 degrees, 90 degrees, and 135 degrees. And so on.

In this embodiment, make the light that the light source sent can see through standard polaroid and the polaroid that awaits measuring in proper order, through rotatory standard polaroid for the contained angle between the polarization direction of standard polaroid and the polarization direction of polaroid that awaits measuring changes, at this in-process, the voltage signal that the photoelectric sensing ware was gathered also is periodic variation, and follow-up signal waveform through gathering the photoelectric sensing ware analyzes and revises, can detect out the polarisation performance of polaroid that awaits measuring. And through setting up the different standard polaroids of a plurality of polarization directions, can test the different positions of the polaroid that awaits measuring to solve the single-point test, the limited problem of test point coverage can improve the accuracy of test result.

Example two

Referring to fig. 3 to 7, this embodiment is a polarization performance detection method of a polarization performance detection apparatus for a polarizer of a display panel according to a first embodiment.

From Malus' law: a beam of light having an intensity of I ₀ After passing through the analyzer, the light intensity of the transmitted light (without considering the absorption) is: i ═ I ₀ cos ² And alpha, wherein I is the light intensity of the transmitted light, and alpha is the included angle between the polarization direction of the linearly polarized light and the polarization direction of the polaroid.

Since cos ² α ═ (cos2 α +1)/2, and therefore derivation of the above equation yields:

I＝I ₀ (cos2α+1)/2＝(I ₀ /2)cos2α+I ₀ /2

therefore, the illumination intensity y of the light emitted from the light source after passing through the polarizer (standard polarizer) and the analyzer (polarizer to be tested) can be expressed by cosine function, i.e. the illumination intensity function can be expressed as

Where ω is 2 and the period T is 2 pi/ω is pi, i.e. the illumination intensity function can be expressed as

x is the angle between the polarization direction of the standard polarizer and the polarization direction of the polarizer to be tested, A represents the amplitude,

indicating the initial phase and B the offset.

Because the whole display screen polaroid may not be uniform, or when the display screen polaroid to be detected is placed in the detection device, part of the part tilts, the polarization performance parameters of different positions on the polaroid to be detected may be inconsistent. Therefore, if only one standard polarizer is arranged, only the illumination intensity change of light emitted by the light source after passing through a certain position on the standard polarizer and the polarizer to be tested can be measured, that is, only the polarization performance of the certain position on the polarizer to be tested can be tested, so that the detection result is incomplete and inaccurate.

Therefore, the invention analyzes the illumination intensity change corresponding to each standard polarizer by setting at least two standard polarizers to determine a more accurate illumination intensity function, and then calculates the polarization degree and the polarization axis position (namely the polarization axis position error angle) in the polarization performance parameters based on the illumination intensity function.

In this embodiment, the polarizing assembly includes two standard polarizers, that is, the polarizing assembly includes a standard polarizer a and a standard polarizer b, and an included angle between polarization directions of the two standard polarizers is 90 °.

Assuming that the polarization directions of the standard polarizer a and the standard polarizer b are as shown in fig. 3 (the dotted line in the figure represents the polarization direction) in the initial state, when the polarizer to be tested is placed, the ideal polarization direction of the polarizer to be tested is consistent with the polarization direction of the standard polarizer a, and the polarization direction of the standard polarizer a is 0 ° and the counterclockwise direction is the positive direction. At this time, if the active rotating shaft rotates counterclockwise by one circle, that is, 360 °, the two hollow shafts rotate clockwise by one circle, the voltage signals output by the two photoelectric sensors are as shown in fig. 4, the abscissa axis represents the rotation angle of the active rotating shaft, the ordinate axis represents the voltage value, V _a Is a wave curve corresponding to the standard polarizer a, V _b Is the corresponding wave curve of the standard polarizer b.

Theoretically, the amplitudes of the corresponding wave curves of the two standard polarizers should be consistent, however, due to various factors, there may be a difference in practice, and the amplitude a in the illumination intensity function may be subsequently determined according to the amplitude of the corresponding wave curve of each standard polarizer.

Meanwhile, theoretically, the rotation angles corresponding to the peak point and the valley point of the two wave curves should be multiples of 90 °, however, because the polarizer to be tested has axis deviation, the two wave curves in fig. 4 have deviation on the abscissa axis, and then the above-mentioned illumination intensity function can be obtained according to the deviationInitial phase of

And the error angle is used as the polarizing axis position error angle of the polaroid to be measured.

For the light transmittance in the polarization performance parameter, the calculation formula is T ═ I/I ₀ ，I ₀ Indicating the intensity of incident natural light, and I indicates the intensity of transmitted light after the natural light passes through the polarizer. In this example, I ₀ The light intensity of the light emitted by the light source after passing through the standard polarizer may be used, and the light intensity of the light emitted by the light source after passing through the standard polarizer and the polarizer to be tested may be used as the I. Therefore, the light transmittance can be calculated by obtaining the voltage values output by the photoelectric sensors before and after the polarizer to be tested is placed.

Therefore, as shown in fig. 5, the polarization performance detection method of the present embodiment includes the following steps (before performing detection, turning on the light source):

s1: before the polaroid to be tested is placed, voltage signals output by each photoelectric sensor are obtained, and an incident voltage value is obtained;

s2: placing the polaroid to be tested between the polarizing component and the photoelectric sensor component, and acquiring voltage signals output by each photoelectric sensor to obtain a transmission voltage value;

s3: and calculating the light transmittance of the polaroid to be tested according to the transmission voltage value and the incident voltage value.

Specifically, each of the photoelectric sensors corresponds to an incident voltage value and a transmission voltage value, in this embodiment, an average value of the incident voltage values corresponding to the photoelectric sensors may be calculated first, an average value of the transmission voltage values corresponding to the photoelectric sensors may be calculated, and finally, the average value of the transmission voltage values is divided by the average value of the incident voltage values, so as to calculate the light transmittance of the polarizer to be measured.

In other embodiments, the transmittance corresponding to each photoelectric sensor may be calculated according to the incident voltage value and the transmission voltage value corresponding to each photoelectric sensor, and then the average value is taken as the final transmittance.

S4: and rotating each standard polaroid by controlling the rotating assembly, and obtaining light intensity wave curves corresponding to each standard polaroid in n periods according to the voltage signals output by each photoelectric sensor, wherein n is a preset value.

In this embodiment, the standard polarizer is slowly rotated at a constant speed for one circle, that is, 360 °, to obtain a light intensity waveform curve of two periods.

S5: and analyzing to obtain a final illumination intensity function according to the light intensity waveform curve corresponding to each standard polarizer.

Specifically, as shown in fig. 6, the present step includes the steps of:

s501: and calculating to obtain a final amplitude value according to the voltage value corresponding to the peak point and the voltage value corresponding to the valley point of the light intensity waveform curve corresponding to each standard polaroid.

In this embodiment, the amplitude values of the light intensity waveform curves corresponding to the standard polarizers are calculated respectively, and then the average value is calculated as the final amplitude value.

Specifically, for a light intensity waveform curve corresponding to a standard polarizer, calculating an average value of voltage values corresponding to each peak point of the standard polarizer to obtain a peak voltage average value, calculating an average value of voltage values corresponding to each valley point of the standard polarizer to obtain a valley voltage average value, calculating a difference value between the peak voltage average value and the valley voltage average value, and dividing the difference value by 2 to obtain an amplitude value of the light intensity waveform curve corresponding to the standard polarizer; and finally, averaging the amplitude values of the light intensity waveform curves corresponding to the standard polaroids to obtain a final amplitude value A.

S502: and calculating to obtain an initial phase according to the angle value corresponding to the peak point and the angle value corresponding to the valley point of the light intensity wave curve corresponding to each standard polaroid.

Specifically, the included angle between the polarization direction of each standard polarizer before rotation and the ideal polarization direction of the polarizer to be tested is obtained to obtain the initial included angle corresponding to each standard polarizer, and the angle value of the ideal peak point and the angle value of the ideal valley point of the light intensity waveform curve corresponding to each standard polarizer are determined according to the initial included angle corresponding to each standard polarizer.

For example, in this embodiment, since the light intensity waveform curve corresponding to each standard polarizer has two periods, the light intensity waveform curve corresponding to each standard polarizer has two peak points and two valley points. From the property of the cosine function, in general, the angle values of two adjacent peak points are different by one period, namely 180 °, the angle values of two adjacent valley points are different by one period, and the angle values of the peak point and the valley point in the same period are different by half a period, namely 90 °.

Before rotation, namely in an initial state, an included angle between the polarization direction of the standard polarizer a and the ideal polarization direction of the polarizer to be tested is 0 degrees, namely the initial included angle corresponding to the standard polarizer a is 0 degrees, then the angle values of ideal wave peak points of a light intensity wave curve corresponding to the standard polarizer a are 0 degrees and 180 degrees, and the angle values corresponding to ideal wave trough points are 90 degrees and 270 degrees. Similarly, in the initial state, the included angle between the polarization direction of the standard polarizer b and the ideal polarization direction of the polarizer to be tested is 90 °, the angle values of the ideal peak points of the light intensity waveform curve corresponding to the standard polarizer b are 90 ° and 270 °, and the angle values of the ideal valley points are 0 ° and 180 °.

And then acquiring the actually obtained angle values corresponding to each peak point and each valley point in the light intensity waveform curve corresponding to each standard polaroid, and calculating the phase deviation value of the light intensity waveform curve corresponding to each standard polaroid by combining the angle values of the ideal peak point and the ideal valley point of the light intensity waveform curve corresponding to each standard polaroid.

For example, suppose that the angle value corresponding to two peaks of the light intensity waveform corresponding to the standard polarizer a is divided into θ _{a peak 1} And theta _{Peak 2 of a} The angle value corresponding to two valley points is divided into theta _{a grain 1} And theta _{a grain 2} Then the phase deviation value of the corresponding light intensity wave form curve of the standard polarizer a

Similarly, the angle value corresponding to two peak points of the light intensity wave curve corresponding to the standard polaroid b is assumed to be divided into theta _{b peak 1} And theta _{b peak 2} The angle value corresponding to two valley points is divided into theta _{b valley 1} And theta _{b valley 2} The phase deviation value of the corresponding light intensity wave curve of the standard polaroid b

Finally, calculating an average value according to the phase deviation value of the light intensity waveform curve corresponding to each standard polaroid to obtain an initial phase; i.e. initial phase

S503: using the final amplitude value A as the initial offset value B ₁ Instant B ₁ A, and according to the final amplitude value A and the initial phase

And an initial offset value B ₁ Generating an initial illumination intensity function

Since the initial light intensity function has a minimum value of 0, but in practical cases the minimum voltage value is substantially not 0, the offset value is iteratively corrected by the subsequent steps.

S504: and taking the initial illumination intensity function as the current illumination intensity function.

S505: and acquiring intersection points of the light intensity wave curves corresponding to the standard polaroids, and calculating to obtain a substituted voltage value corresponding to each intersection point through the current illumination intensity function according to the angle value of each intersection point.

Namely, the angle values of the intersection points are respectively substituted into the current illumination intensity function, and the calculated voltage value is used as a substituted voltage value.

S506: and calculating voltage difference values corresponding to the intersection points according to the voltage values of the intersection points and the substituted voltage values corresponding to the intersection points, and calculating the average value of the voltage difference values to obtain the average value of the voltage difference values.

For example, in this embodiment, the light intensity waveform corresponding to the standard polarizer a and the light intensity waveform corresponding to the standard polarizer b have 4 intersections, and the intersections are assumed to be (θ) ₁ ，V ₁ )、(θ ₂ ，V ₂ )、(θ ₃ ，V ₃ ) And (theta) ₄ ，V ₄ ) Will theta ₁ 、θ ₂ 、θ ₃ And theta ₄ The substituted voltage values calculated by substituting x into the current illumination intensity function are respectively y ₁ 、y ₂ 、y ₃ And y ₄ Then, the average value of the voltage difference Δ B is ((y) ₁ -V ₁ )+(y ₂ -V ₂ )+(y ₃ -V ₃ )+(y ₄ -V ₄ )/4。

S507: and judging whether the average value of the voltage difference values is smaller than a preset threshold value, namely whether the delta B is smaller than the epsilon, if so, executing a step S508, and if not, executing a step S509.

S508: the current light intensity function is taken as the final light intensity function, and the waveform of the final light intensity function is shown in fig. 7.

S509: calculating to obtain a new offset value, namely a new offset value B according to the offset value in the current illumination intensity function and the average value of the voltage difference values _i+1 ＝B _i +ΔB。

S510: updating the current light intensity function based on the new offset value, i.e. the new light intensity function is

And the new illumination intensity function is taken as the current illumination intensity function, and the step S505 is executed again.

S6: and determining the polarization degree and the polarization axis position error angle of the polarizer to be tested according to the final illumination intensity function.

In particular, assume the final illumination intensityFunction is as

Directly converts the initial phase therein

And the error angle is used as the polarizing axis position error angle of the polaroid to be measured. Further, since the initial phase is not modified in the iteration process of steps S505 to S510, the polarization axis position error angle of the polarizer to be tested can be determined when the initial phase is calculated in step S502.

For the degree of polarization, it is defined as P ═ I (I) _{In parallel} -I _{Is perpendicular to} )/(I _{In parallel} +I _{Is perpendicular to} ) Here I _{In parallel} The maximum voltage value that can be regarded as a function of the final illumination intensity, i.e. A + B, I _{Is perpendicular to} It can be regarded as the minimum voltage value of the final illumination intensity function, i.e., -a + B, and therefore, the polarization degree P of the polarizer to be tested is ((a + B) - (-a + B))/((a + B) + (-a + B)) ═ a/B.

In the embodiment, the light transmittance in the polarization performance parameters of the polarizer to be tested is calculated by acquiring and analyzing the voltage values output by the photoelectric sensors before and after the polarizer to be tested is placed; the method comprises the steps of obtaining a plurality of signal waveforms of illumination values and rotation angles by rotating a plurality of standard polaroids with different polarization directions, obtaining a final illumination intensity function by analyzing and processing the signal waveforms, and solving the polarization degree and axial deviation in polarization performance parameters of the polaroid to be detected based on the final illumination intensity function, so that the polarization performance of the polaroid to be detected can be detected more quickly, accurately and conveniently.

In summary, the polarization performance detection device and the polarization performance detection method for the display screen polarizer provided by the invention can detect the polarization performance of the polarizer to be detected more quickly, accurately and conveniently, and are beneficial to improving the measurement capability of the industry and promoting the industrial development of related instruments.

The above description is only an embodiment of the present invention, and not intended to limit the scope of the present invention, and all equivalent changes made by using the contents of the present specification and the drawings, or applied directly or indirectly to the related technical fields, are included in the scope of the present invention.

Claims (10)

1. The device for detecting the polarization performance of the display screen polaroid is characterized by comprising a light source, a polarization component, a rotating component, a photoelectric sensor component and a processor; the polarization assembly comprises at least two standard polaroids, the polarization directions of the standard polaroids are different, and the photoelectric sensor assembly comprises photoelectric sensors which correspond to the standard polaroids one by one;

the polarizing component is arranged on the rotating component, and the rotating component is used for driving each standard polarizer to rotate; the light source is positioned on one side of the polarizing component and uniformly irradiates each standard polarizer; the photoelectric sensor assembly is positioned on the other side of the polarization assembly, and the projection of each photoelectric sensor on the light source is respectively positioned in the projection of each standard polarizer on the light source; the processor is respectively in communication connection with the photoelectric sensors.

2. The device for detecting the polarization performance of a display screen polarizer according to claim 1, wherein the polarizer to be detected is located between the polarization component and the photoelectric sensor component, and the projection of the polarizer to be detected on the light source covers the projection of each standard polarizer on the light source.

3. The device for detecting the polarization performance of a display screen polarizer according to claim 1, wherein the polarization directions of the standard polarizers are sequentially different by 180 °/m, wherein m is the number of the standard polarizers.

4. The device for detecting the polarization performance of a display screen polarizer according to claim 1, wherein the rotating assembly comprises a rotating motor, an active rotating shaft and hollow shafts corresponding to the standard polarizers one by one, the standard polarizers are respectively arranged in the hollow shafts one by one and located on the same radial plane, the hollow shafts are respectively in transmission connection with the active rotating shaft, and the active rotating shaft is connected with the rotating motor.

5. The device for detecting the polarization performance of a polarizer of a display screen according to claim 4, wherein a first gear is disposed on the outer side surface of the driving rotating shaft, a second gear is disposed on the outer side surface of the hollow shaft, and the first gear and the second gear are in transmission connection.

6. The method for detecting the polarization performance of the device for detecting the polarization performance of a display screen polarizer according to any one of claims 1 to 5, comprising the following steps:

before the polarizer to be tested is placed, obtaining an incident voltage value according to voltage signals output by each photoelectric sensor;

placing the polaroid to be tested between the polarizing component and the photoelectric sensor component, and obtaining a transmission voltage value according to the voltage signal output by each photoelectric sensor;

determining the light transmittance of the polarizer to be tested according to the transmission voltage value and the incident voltage value;

rotating each standard polaroid by controlling the rotating assembly, and obtaining light intensity waveform curves corresponding to each standard polaroid in n periods according to the voltage signals output by each photoelectric sensor, wherein n is a preset value;

analyzing to obtain a final illumination intensity function according to the light intensity waveform curve corresponding to each standard polaroid;

and determining the polarization degree and the polarization axis position error angle of the polarizer to be tested according to the final illumination intensity function.

7. The polarization performance detection method according to claim 6, wherein the final illumination intensity function obtained by analyzing according to the light intensity waveform curve corresponding to each standard polarizer is specifically:

calculating to obtain a final amplitude value according to a voltage value corresponding to a peak point and a voltage value corresponding to a valley point of a light intensity waveform curve corresponding to each standard polaroid;

calculating to obtain an initial phase according to the angle value corresponding to the peak point and the angle value corresponding to the valley point of the light intensity wave curve corresponding to each standard polaroid;

taking the final amplitude value as an initial offset value, and generating an initial illumination intensity function according to the final amplitude value, the initial phase and the initial offset value, wherein the illumination intensity function is a cosine function;

taking the initial illumination intensity function as a current illumination intensity function, and obtaining intersection points of light intensity waveform curves corresponding to the standard polaroids;

calculating to obtain a substituted voltage value corresponding to each intersection point through a current illumination intensity function according to the angle value of each intersection point;

calculating voltage difference values corresponding to the intersection points according to the voltage values of the intersection points and the substituted voltage values corresponding to the intersection points, and calculating the average value of the voltage difference values to obtain the average value of the voltage difference values;

judging whether the average value of the voltage difference values is smaller than a preset threshold value or not;

if so, taking the current illumination intensity function as a final illumination intensity function;

if not, calculating to obtain a new offset value according to the offset value in the current illumination intensity function and the average value of the voltage difference values;

and updating the current illumination intensity function according to the new deviation value, taking the new illumination intensity function as the current illumination intensity function, and continuously executing the step of obtaining the intersection points of the light intensity waveform curves corresponding to the standard polaroids.

8. The polarization performance detection method according to claim 7, wherein the calculating of the final amplitude value according to the voltage value corresponding to the peak point and the voltage value corresponding to the valley point of the light intensity waveform curve corresponding to each standard polarizer specifically includes:

respectively calculating the average value of voltage values corresponding to all wave crest points and the average value of voltage values corresponding to all wave trough points of a light intensity waveform curve corresponding to a standard polaroid to obtain the wave crest voltage average value and the wave trough voltage average value of the light intensity waveform curve corresponding to the standard polaroid;

calculating to obtain an amplitude value of the light intensity waveform curve corresponding to the standard polaroid according to the peak voltage average value and the trough voltage average value of the light intensity waveform curve corresponding to the standard polaroid;

and calculating the average value of the amplitude values of the light intensity waveform curves corresponding to the standard polaroids to obtain the final amplitude value.

9. The polarization performance detection method according to claim 7, wherein the calculating of the initial phase according to the angle value corresponding to the peak point and the angle value corresponding to the valley point of the light intensity waveform curve corresponding to each standard polarizer specifically comprises:

obtaining included angle angles between the polarization direction of each standard polarizer before rotation and the ideal polarization direction of the polarizer to be tested, and obtaining initial included angle corresponding to each standard polarizer;

determining the angle value of an ideal wave peak point and the angle value of an ideal wave valley point of a light intensity wave curve corresponding to each standard polaroid according to the initial included angle corresponding to each standard polaroid;

calculating a phase deviation value of a light intensity waveform curve corresponding to a standard polaroid according to an angle value corresponding to a peak point of the light intensity waveform curve corresponding to the standard polaroid, an angle value corresponding to a trough point, an angle value of an ideal peak point and an angle value of an ideal trough point;

and calculating an average value according to the phase deviation value of the light intensity waveform curve corresponding to each standard polaroid to obtain an initial phase.

10. The polarization performance detection method according to claim 6, wherein the determining the polarization degree and the polarization axis position error angle of the polarizer to be tested according to the final illumination intensity function specifically comprises:

determining the polarization degree of the polarizer to be tested according to the amplitude value and the deviation value in the final illumination intensity function;

and determining the polarization axis position error angle of the polarizer to be tested according to the initial phase in the final illumination intensity function.

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