CN116698363A - Lens detection method and related equipment - Google Patents

Abstract

The invention discloses a method for detecting a lens and related equipment, wherein the method comprises the steps of obtaining the lens to be detected; according to a preset expected direction, placing the lens to be detected at a corresponding detection position; controlling a pre-connected polarized light source to emit light to the detection position, then passing through the lens to be detected, and collecting the light passing through the lens to be detected to obtain output light information; and determining the lens direction corresponding to the lens to be inspected according to the output light ray information. The invention can rapidly and conveniently realize the detection of the lens without damaging the lens.

Description

Lens detection method and related equipment

Technical Field

The invention relates to the technical field of optical detection, in particular to a lens detection method and related equipment.

Background

XR headsets are top products of current high performance display devices, where the concept of the meta-universe is even more so, incomparable. XR devices are classified into VR (virtual reality) devices, AR (augmented reality) devices, and MR (mixed reality) devices, which are all very close to a person, and thus comfort needs to be considered in the actual optical path design, while the optical path needs to be designed so that the image is located on the retina. XR devices are currently increasingly pursuing "slimmer" and so more and more solutions are focused on achieving short-distance focusing of the optical path using optical films rather than conventional lens groups, and therefore optical films are an important part of achieving high quality XR devices.

In recent years, more and more XR headsets have been designed with lenses selected to be symmetrical, non-circular, "shaped" for the left and right eye pieces for better ergonomic design. The design can better adapt to the curvature of eyes and reduce visual fatigue in use. However, the design of the shaped sheet may cause trouble in distinguishing the left and right eye sheets in actual production. The existing left eye piece and the right eye piece are designed in an axisymmetric mode with the same shape. The left eye piece (or right eye piece) can be overlapped with the right eye piece (left eye piece) by rotating 90 degrees around a certain fixed point. Therefore, the current method for distinguishing the left eye piece and the right eye piece is to use a marking and code spraying mode to track the original film one by one before actually cutting the eye pieces. This approach is slow and inefficient, and once the marking process is missed or the marking is wrong, the cut eye pieces cannot be distinguished. Therefore, an inspection method needs to be developed, and the inspection method is high in efficiency and speed on the basis of not damaging the eye pieces.

Disclosure of Invention

The invention aims to solve the technical problems that the accuracy and the efficiency of the existing detection mode for the lens are low, and provides a detection method for the lens and related equipment aiming at the defects of the prior art.

In order to solve the technical problems, the technical scheme adopted by the invention is as follows:

acquiring a lens to be inspected;

according to a preset expected direction, placing the lens to be detected at a corresponding detection position;

controlling a pre-connected polarized light source to emit light to the detection position, then passing through the lens to be detected, and collecting the light passing through the lens to be detected to obtain output light information;

and determining the lens direction corresponding to the lens to be inspected according to the output light ray information.

Optionally, the output light information is an image to be detected; the determining the lens direction corresponding to the lens to be inspected according to the output light ray information comprises:

obtaining a standard image obtained by detecting a preset standard lens, and calculating a detection deviation value corresponding to the detection image according to the standard image;

and determining the lens direction corresponding to the lens to be detected according to the detection deviation value.

Optionally, the obtaining a standard image detected by a preset standard lens, and calculating, according to the standard image, a detection deviation value corresponding to the detection image includes:

according to the preset standard lens shape, extracting the standard image to obtain a standard lens area;

according to the shape of the preset lens to be inspected, extracting the image of the detection image to obtain a lens area to be inspected;

and calculating the color deviation and/or the light intensity deviation between the standard lens area and the lens area to be detected to obtain a detection deviation value.

Optionally, the standard lens comprises a linear polarizer, a polarized reflecting plate attached to the linear polarizer, and a 1/4 wave plate attached to the polarized reflecting plate at one side away from the linear polarizer.

Optionally, the acquiring the standard image detected by the preset standard lens, and before calculating the detection deviation value corresponding to the detection image, includes:

obtaining a standard lens;

and controlling a pre-connected linear polarized light source to pass through the standard lens according to the standard direction corresponding to the standard lens, and photographing the standard lens to obtain a standard image.

Optionally, the detection light passes through the standard lens and the lens to be detected simultaneously, and the standard lens and the lens to be detected are photographed simultaneously.

A computer readable storage medium storing one or more programs executable by one or more processors to perform the steps in the method of inspecting a lens as described in any of the above.

A terminal device, comprising: a processor, a memory, and a communication bus; the memory has stored thereon a computer readable program executable by the processor;

the communication bus realizes connection communication between the processor and the memory;

the processor, when executing the computer readable program, performs the steps in the method for inspecting a lens as described in any one of the above.

The beneficial effects are that: according to the scheme, the detection of the lens direction can be realized through polarized light illumination and shooting, and the effect of rapid detection is realized. By detecting light, the lens direction of the lens to be detected can be accurately judged, and the rapid, efficient and accurate detection and screening can be realized on the basis of not damaging the eye lens by detecting the light of the lens to be detected.

Drawings

Fig. 1 is a flowchart of a method for detecting a lens according to the present invention.

Fig. 2 is a diagram showing the trend of circularly polarized light in a polarizer having a polarization reflection function.

Fig. 3 is an optical axis position of a lens to be inspected in a correct position according to the method for inspecting a lens of the present invention.

Fig. 4 is an optical axis position of a lens to be inspected when the lens is at an error position in the method for inspecting a lens provided by the present invention.

Fig. 5 is a schematic structural diagram of a terminal device provided by the present invention.

Detailed Description

The invention provides a method for detecting a lens, which is used for making the purpose, technical scheme and effect of the invention clearer and more definite, and the invention is further described in detail below by referring to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention.

As used herein, the singular forms "a", "an", "the" and "the" are intended to include the plural forms as well, unless expressly stated otherwise, as understood by those skilled in the art. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. It will be understood that when an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element or intervening elements may also be present. Further, "connected" or "coupled" as used herein may include wirelessly connected or wirelessly coupled. The term "and/or" as used herein includes all or any element and all combination of one or more of the associated listed items.

It will be understood by those skilled in the art that all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs unless defined otherwise. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the prior art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

The invention provides a method for detecting a lens, which is described by taking a common server as an execution main body for convenience of explanation, wherein the server can be installed on automatic equipment and connected with other automatic elements to control the behavior of the automatic equipment, and the method for detecting the lens comprises the following steps:

s10, acquiring a lens to be inspected.

Specifically, the lens to be inspected is a lens for which it is necessary to detect whether the lens direction is a left or a right spectacle lens.

As shown in fig. 2, the key film in the current XR device is a "polarizer with polarization reflection function", and the film is formed by laminating three layers of functional films, including three films, namely a linear polarizer, a polarization reflector and a 1/4 wave plate. If the incident light is right-handed circularly polarized light, the 1/4 wave plate is used for converting the incident right-handed circularly polarized light into P polarized light, and the converted P polarized light is reflected by the polarized reflecting plate with P reflection and S transmission and then is converted into right-handed polarized light by the 1/4 wave plate again. If left circularly polarized light is incident, the light is converted into S polarized light by the 1/4 wave plate, and the S polarized light is directly transmitted through the polarized reflecting plate. The transmitted S-polarized light will be absorbed by the elliptical component of the S-polarized light as it passes through the linear polarizer. Therefore, the 1/4 wave plate has the function of converting circularly polarized light into linearly polarized light, the polarizing reflecting plate has the function of screening linearly polarized light in different vibration directions, and the linear polaroid has the function of eliminating stray light so that emergent light is purer.

As shown in FIG. 2, the direction of the light path is from right to left, LP2 is a linear polarizer, PBS is a polarizing reflector, and QWP2 is a 1/4 wave plate. In this example, the direction of the absorption axis of LP2 is parallel to the direction of the P-ray reflection axis of the PBS, and the slow axis of QWP2 is 45 ° to the directions of the absorption axes of LP2 and PBS.

The polarizer with polarized reflection function comprising the three-layer film structure is used for both the left and right eye pieces, but the left and right eye pieces are axisymmetric in shape due to the ergonomic design, so that the confusion phenomenon is easy to occur after the left and right eye pieces are rotated by 90 degrees. As shown in fig. 3, the black double-arrow line in the left and right eye pieces indicates the absorption axis of the linear polarizer, and the gray double-arrow line indicates the slow axis of the 1/4 wave plate, and the absorption axes of the two pieces are on the same horizontal line when the left and right eye pieces are in the correct positions. Because the shape of the left eye piece and the right eye piece are symmetrical, the left eye piece and the right eye piece can be respectively changed in position and properly rotated, and the left eye piece and the right eye piece can also be arranged in the lens module. However, if the left and right eye plates are in the wrong position (as shown in fig. 4), then the absorption axis direction is completely wrong with the 1/4 wave plate slow axis direction, resulting in the opposite visual effect.

S20, placing the lens to be inspected at a corresponding detection position according to a preset expected direction.

Specifically, before performing the inspection, the lens to be inspected first needs to be placed at a preset inspection position. The position is preset, and the specific position depends on the estimated lens direction of the lens to be inspected. For left and right lenses, the intended directions include left eye directions and right eye directions. An expected direction is preset, namely, a direction corresponding to the lens to be detected is expected. The detection position is a position for placing the lens to be detected, the detection position is positioned on a light path of the inspection platform for emitting polarized light from the detection light source, for example, the detection light source is arranged at the bottom, the detection light source emits light from bottom to top, and the detection position is above the detection light source; or the side is provided with a detection light source, the detection light source emits light from left to right, and the detection position is on the right side of the detection light source. The detection light source is a polarized light source.

S30, controlling a detection light source connected in advance to emit light to the detection position, then enabling the light to pass through the lens to be detected, and collecting the light passing through the lens to be detected to obtain output light information.

Specifically, the detection light source is controlled to emit polarized light to the detection position and then enters the lens to be detected, and an acquisition element can be arranged on a light path of the detection light source passing through the lens to be detected, wherein the acquisition element can acquire output light information output through the lens to be detected.

Further, the collecting element may employ a photosensitive element. For the difference between the lens position to be inspected and the misplaced lens position to be inspected, if the difference between the output light rays is smaller, more refined detection is required, in this embodiment, the acquisition element adopts a camera, so the steps may include: and controlling a detection light source connected in advance to emit polarized light rays to the detection position, then entering the lens to be detected, and photographing the lens to be detected to obtain a detection image.

S40, determining the lens direction corresponding to the lens to be inspected according to the output light ray information.

Specifically, the collecting element can judge whether the lens direction of the lens to be detected is the same as the expected direction according to the intensity and the color of the collected output light, and if the lens direction is the same as the expected direction, no color deviation and/or light intensity deviation exists; if not, there is a color deviation and/or a light intensity deviation.

For the acquisition element is the camera, when the output light information is the image to be examined, confirm the process of lens direction includes:

s41, obtaining a standard image obtained by detecting a standard lens, and calculating a detection deviation value corresponding to the detection image.

Specifically, the standard lens refers to a lens to be inspected when the lens module is in a correct position, and includes a left-eye standard lens and a right-eye standard lens. The standard lens comprises a linear polaroid, a polarized reflecting sheet attached to the linear polaroid, and a 1/4 wave plate attached to the polarized reflecting sheet at one side far away from the linear polaroid.

The standard image is obtained by photographing the standard lens under the same conditions including a detection light source, a photographing angle and the like. When the detection deviation value between the standard image and the detection image is calculated, the brightness and the color of the two images can be directly compared. And extracting the image of the standard image according to the preset standard lens shape, and extracting the image of the detection image according to the preset lens shape to be detected, so as to respectively obtain a standard lens area and a lens area to be detected. And calculating to obtain a detection deviation value according to the color deviation and/or the light intensity deviation between the standard lens area and the lens area to be detected.

In obtaining the color deviation or the light intensity deviation, image processing software such as OpenCV may be used to perform image extraction and color comparison, calculate the color difference of each pixel in the two areas, and sum the difference values, thereby obtaining the total amount of color deviation. When comparing the light intensity deviations, the light intensity difference for each pixel in the two regions may be calculated and the difference values summed to obtain the total amount of light intensity deviation. And finally, adding the total color deviation and the total light intensity deviation or summing weights to obtain a detection deviation value between the two images.

For standard lenses, the means for acquiring a standard image include: obtaining a standard lens; according to the standard direction corresponding to the standard lens, namely the absorption axis direction, the lens is placed at the corresponding standard position; and controlling the detection light source connected in advance to emit light to the standard position, and photographing a standard lens through which the light passes, so that a standard image is obtained. It should be noted that the standard position is a fixed reference position, for example, the horizontal left direction is the standard direction, and then the standard lens is placed at the standard position according to the known absorption axis direction of the standard lens and placed parallel to the standard direction.

Standard images may be pre-stored in a database from which they are retrieved when required. Because the light change is realized after the detection light source passes through the lens, the change of the detection light source also affects the detection result, in order to ensure the consistency of the result, the shooting conditions corresponding to the standard image and the detection image are the same, the same shooting conditions comprise that the detection light passes through the standard lens and the lens to be detected simultaneously, and the standard lens and the lens to be detected are photographed simultaneously, so that the reliability of the result is reduced due to the difference of the detection light. The standard lens and the lens to be inspected can be simultaneously placed on the light path of the inspection light source, so that the inspection light passes through the lens to be inspected and the standard lens.

S42, determining the lens direction corresponding to the lens to be inspected according to the detection deviation value.

Specifically, the detected deviation value can describe the difference between the standard image and the detected image, and if the difference exists, the expected direction is not consistent with the lens direction of the lens to be detected, so that the lens direction is determined.

In a mode of determining the lens to be inspected, presetting a deviation threshold, and determining the expected direction as the lens direction corresponding to the lens to be inspected when the detected deviation value is smaller than the preset deviation threshold; and when the detected deviation value is greater than or equal to the deviation threshold value, determining the direction opposite to the expected direction as the lens direction.

However, in lens inspection, there may be a large difference between the inspection image and the standard image due to a lens quality defect, and the directions of the lenses to be inspected are not the same, so in order to better determine that the difference between the inspection image and the standard image is caused by the directions of the lenses, in another method for determining the lenses to be inspected, a deviation threshold is preset, and when the inspection deviation value is smaller than the preset deviation threshold, the expected direction is determined to be the direction of the lenses to be inspected. And when the detection deviation value is greater than or equal to the deviation threshold value, adjusting the placement angle corresponding to the lens to be detected according to the direction opposite to the expected direction. For example, a left lens is initially envisioned, but the detected deviation value is greater than or equal to the deviation threshold, the angle of placement of the lens to be inspected is adjusted to be the same as the right lens (e.g., adjusted by 90 °). And then, controlling the polarized light to pass through the lens to be inspected, and photographing the lens to be inspected to obtain a rechecked image. And obtaining a standard image obtained by detecting the standard lens, and calculating a re-detection deviation value corresponding to the re-detection image. The step is the same as the acquisition of the detection image, and therefore, the description is omitted. And finally, determining the lens direction corresponding to the lens to be inspected according to the detection deviation value. For example, if the detected deviation value is smaller than a preset deviation threshold value, it is indicated that the difference between the detected image and the standard image is large due to the lens direction, so that it is determined that the lens direction corresponding to the lens to be detected is not opposite to the expected direction. However, if the detected deviation value is still greater than or equal to the deviation threshold value, it is indicated that there are other problems in the lens to be inspected, and based on this, for the lens to be inspected whose lens direction is different from the expected direction, the lens direction and quality of the lens to be inspected can be further determined.

This solution has several advantages. First, the inspection mode is very simple, and only the left eye piece and the right eye piece are distinguished through obvious color change. This way of inspection is not environmentally demanding and can therefore be performed in different environments. Secondly, the inspection mode is very friendly to the inspected film material and cannot damage the inspected film material. In addition, the standard lens has the characteristic of reusability, so the standard lens can be used for multiple times and can be applied to detection of lenses to be detected with different optical axis angles. Not only saves the cost, but also reduces the waste, and can be applied to large-scale production.

Based on the above-mentioned method for detecting the lens, the present invention also provides a terminal device, as shown in fig. 5, which includes at least one processor (processor) 20; a display screen 21; and a memory (memory) 22, which may also include a communication interface (Communications Interface) 23 and a bus 24. Wherein the processor 20, the display 21, the memory 22 and the communication interface 23 may communicate with each other via a bus 24. The display screen 21 is configured to display a user guidance interface preset in the initial setting mode. The communication interface 23 may transmit information. The processor 20 may invoke logic commands in the memory 22 to perform the methods of the embodiments described above.

In addition, the logic commands in the memory 22 described above may be implemented in the form of software functional units and may be stored in a computer readable storage medium when sold or used as a stand alone product.

The memory 22, as a computer-readable storage medium, may be configured to store a software program, a computer-executable program, such as program commands or modules corresponding to the methods in the embodiments of the present disclosure. The processor 20 performs functional applications and data processing, i.e. implements the methods of the embodiments described above, by running software programs, commands or modules stored in the memory 22.

The memory 22 may include a storage program area that may store an operating system, at least one application program required for functions, and a storage data area; the storage data area may store data created according to the use of the terminal device, etc. In addition, the memory 22 may include high-speed random access memory, and may also include nonvolatile memory. For example, a plurality of media capable of storing program codes such as a usb disk, a removable hard disk, a Read-Only Memory (ROM), a random access Memory (Random Access Memory, RAM), a magnetic disk or an optical disk, or a transitory computer readable storage medium may be used.

In addition, the specific processes of loading and executing the plurality of command processors in the terminal device and the computer readable storage medium are described in detail in the above method, and are not stated here.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present invention, and are not limiting; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims (8)

1. A method of inspecting a lens, the method comprising:

acquiring a lens to be inspected;

according to a preset expected direction, placing the lens to be detected at a corresponding detection position;

controlling a pre-connected polarized light source to emit light to the detection position, then passing through the lens to be detected, and collecting the light passing through the lens to be detected to obtain output light information;

and determining the lens direction corresponding to the lens to be inspected according to the output light ray information.

2. The method for detecting a lens according to claim 1, wherein the output light information is an image to be detected; the determining the lens direction corresponding to the lens to be inspected according to the output light ray information comprises:

obtaining a standard image obtained by detecting a preset standard lens, and calculating a detection deviation value corresponding to the detection image according to the standard image;

and determining the lens direction corresponding to the lens to be detected according to the detection deviation value.

3. The method according to claim 2, wherein the obtaining a standard image obtained by detecting a preset standard lens, and calculating a detection deviation value corresponding to the detection image according to the standard image comprises:

according to the preset standard lens shape, extracting the standard image to obtain a standard lens area;

according to the shape of the preset lens to be inspected, extracting the image of the detection image to obtain a lens area to be inspected;

and calculating the color deviation and/or the light intensity deviation between the standard lens area and the lens area to be detected to obtain a detection deviation value.

4. The method for inspecting a lens according to claim 2, wherein the standard lens comprises a linear polarizer, a polarizing reflector attached to the linear polarizer, and a 1/4 wave plate attached to the polarizing reflector on a side away from the linear polarizer.

5. The method for detecting a lens according to claim 4, wherein the step of obtaining a standard image detected for a preset standard lens and calculating a detection deviation value corresponding to the detected image comprises:

obtaining a standard lens;

and controlling a pre-connected linear polarized light source to pass through the standard lens according to the standard direction corresponding to the standard lens, and photographing the standard lens to obtain a standard image.

6. The method according to any one of claims 2 to 5, wherein the detection light passes through the standard lens and the lens to be inspected at the same time, and the standard lens and the lens to be inspected are photographed at the same time.

7. A computer-readable storage medium storing one or more programs executable by one or more processors to perform the steps in the method of inspecting a lens according to any one of claims 1 to 6.

8. A terminal device, comprising: a processor, a memory, and a communication bus; the memory has stored thereon a computer readable program executable by the processor;

the communication bus realizes connection communication between the processor and the memory;

the processor, when executing the computer readable program, performs the steps of the method for inspecting a lens according to any one of claims 1 to 6.