Distance measuring method and distance measuring device

Abstract

The application discloses a ranging method and a ranging device, and belongs to the technical field of ranging. The ranging method and the ranging device can adjust the focal length of a liquid lens module by adjusting the current or voltage of the liquid lens module, and obtain the current or voltage of the liquid lens module when a target object is clearly imaged on an eyepiece module. Based on the corresponding relationship between the current or voltage of the liquid lens module and the working distance of the liquid lens module, the working distance corresponding to the obtained current or voltage of the liquid lens module is inquired, and the inquired working distance is the distance between the target object and the ranging lens. Compared with the prior art, the steps are simple, the structure is compact, the volume is small, the cost is low, the response time of the liquid lens module is short, rapid focusing can be realized, and the ranging speed is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of distance measurement, in particular to a distance measurement method and a distance measurement device. BACKGROUND

[0002] There are two traditional distance measurement methods: pulse method and phase method. The pulse method measures the distance by emitting laser from a distance measurement device, reflecting on the measured object and being received by the distance measurement device again. The distance measurement device records the time of the laser round trip. Half of the product of the speed of light and the round trip time is the distance between the distance measurement device and the measured object. The pulse method is generally only suitable for long distance measurement. The phase method measures the distance by modulating the laser beam and measuring the phase delay generated by the modulated light when it returns to the measured object once. Then the distance represented by the phase delay is converted according to the wavelength of the modulated light.

[0003] Existing bar code scanning devices are mostly used for short distance. If the bar code scanning device uses the pulse method to measure the distance, the reflection time is too short to accurately calculate the distance in a short distance. Although the phase method is suitable for short distance high precision measurement, the instrument structure is complex, the cost is high, and the volume is large, which is not suitable for focusing cooperation of the bar code reading module. SUMMARY

[0004] The purpose of the present application is to provide a distance measurement method and a distance measurement device, which are simple in steps, compact in structure, small in volume, low in cost and high in distance measurement speed.

[0005] To achieve the above purpose, the following technical solutions are provided:

[0006] In one aspect, a distance measurement method is provided, which measures the distance between a target object and a distance measurement lens. The distance measurement lens includes an objective lens module, an eyepiece lens module, and a liquid lens module connected between the objective lens module and the eyepiece lens module. The distance measurement method includes the following steps:

[0007] Adjusting the focal length of the objective lens module and the eyepiece lens module, and adjusting the current or voltage input into the liquid lens module to adjust the focal length of the liquid lens module;

[0008] Determining whether the target object is clearly imaged on the eyepiece lens module, and if so, obtaining the current or voltage input into the liquid lens module;

[0009] Based on the corresponding relationship between the current or voltage input into the liquid lens module and the working distance of the liquid lens module, the working distance corresponding to the obtained current or voltage input into the liquid lens module is queried. The queried working distance is the distance between the target object and the distance measurement lens.

[0010] As an alternative to the ranging method, the step of adjusting the current or voltage supplied to the liquid lens module to adjust the focal length of the liquid lens module comprises:

[0011] detecting the temperature of the liquid lens module;

[0012] querying the diopter of the liquid lens module corresponding to the detected temperature of the liquid lens module based on the correspondence between the temperature of the liquid lens module and the diopter of the liquid lens module;

[0013] adjusting the current or voltage supplied to the liquid lens module so that the diopter of the liquid lens module is equal to the queried diopter.

[0014] In another aspect, a ranging device is provided, comprising:

[0015] a ranging lens comprising an objective lens module, an eyepiece lens module, and a liquid lens module connected between the objective lens module and the eyepiece lens module;

[0016] a regulation unit comprising an identification module, an adjustment module, and a control module, the identification module being capable of determining whether a target object is clearly imaged on the eyepiece lens module; the adjustment module being used to adjust the current or voltage supplied to the liquid lens module; the control module being capable of recording the current or voltage supplied to the liquid lens module when the target object is clearly imaged on the eyepiece lens module, and the control module being further capable of querying the working distance corresponding to the recorded current or voltage supplied to the liquid lens module based on the correspondence between the current or voltage supplied to the liquid lens module and the working distance of the liquid lens module, the queried working distance being the distance between the target object and the ranging lens.

[0017] As an alternative to the ranging device, the liquid lens module comprises a liquid lens and a temperature detection member, the temperature detection member being used to detect the temperature of the liquid lens, and the temperature detection member being in communication connection with the regulation unit.

[0018] As an alternative to the ranging device, the regulation unit is a computer.

[0019] As an alternative to the ranging device, the liquid lens module comprises a liquid lens and two transparent protective plates connected to both sides of the liquid lens, respectively.

[0020] As an alternative to the ranging device, the liquid lens module further comprises a housing corresponding to each of the two transparent protective plates, both of the housings being connected to the liquid lens, and the transparent protective plates being fixedly arranged in the corresponding housings.

[0021] As an alternative to the distance measuring device, the objective lens module comprises a plurality of first lenses arranged in order from the object side to the image side.

[0022] As an alternative to the distance measuring device, the eyepiece module comprises a plurality of second lenses arranged in order from the object side to the image side.

[0023] Compared with the prior art, the present application has the following advantages:

[0024] The distance measuring method and distance measuring device of the present application can adjust the focal length of the liquid lens module by adjusting the current or voltage of the liquid lens module, and obtain the current or voltage of the liquid lens module when the target object is clearly imaged in the eyepiece module. Based on the corresponding relationship between the current or voltage of the liquid lens module and the working distance of the liquid lens module, the working distance corresponding to the obtained current or voltage of the liquid lens module is queried, and the queried working distance is the distance between the target object and the distance measuring lens. Compared with the prior art, the steps are simple, the structure is compact, the volume is small, the cost is low, and the liquid lens module has a short response time, which can realize fast focusing and improve the distance measuring speed. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 The figure is a structural schematic diagram of the distance measuring lens in the embodiment of the present application.

[0026] Figure 2 The figure is a state schematic diagram of the liquid lens module under the first diopter in the embodiment of the present application.

[0027] Figure 3 The figure is a state schematic diagram of the liquid lens module under the second diopter in the embodiment of the present application.

[0028] Figure 4 The figure is a state schematic diagram of the liquid lens module under the third diopter in the embodiment of the present application.

[0029] Figure 5 The figure is a working distance schematic diagram of the distance measuring lens that can be measured by the liquid lens module under the first diopter in the embodiment of the present application.

[0030] Figure 6 The figure is a working distance schematic diagram of the distance measuring lens that can be measured by the liquid lens module under the second diopter in the embodiment of the present application.

[0031] Figure 7 The figure is a working distance schematic diagram of the distance measuring lens that can be measured by the liquid lens module under the third diopter in the embodiment of the present application.

[0032] Figure 8 The figure is a structural schematic diagram of the liquid lens module in the embodiment of the present application.

[0033] Reference signs:

[0034] 1, objective module; 11, first lens; 2, eyepiece module; 21, second lens; 3, liquid lens module; 31, liquid lens; 32, transparent protective plate; 33, shell. DETAILED DESCRIPTION

[0035] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings can be arranged and designed in various different configurations.

[0036] Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative labor are within the scope of protection of the present application.

[0037] It should be noted that: similar reference numerals and letters represent similar items in the following drawings, therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0038] In the description of the present application, it should be noted that the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship when the product of the present application is usually placed, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", "third" and the like are only used for differentiation in description, and cannot be understood as indicating or implying relative importance. In the description of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0039] In the description of the present application, it should also be noted that, unless otherwise specified and limited, the terms "arranged", "connected" should be understood broadly, for example, it can be fixedly connected, or detachably connected, or integrally connected; it can be mechanically connected, or electrically connected. For those of ordinary skill in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0040] In the present application, unless otherwise explicitly specified and limited, the first feature is "on" or "under" the second feature can include that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the first feature "on", "above" and "over" the second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the first feature is higher in horizontal height than the second feature. The first feature "under", "below" and "underneath" the second feature includes that the first feature is directly below and obliquely below the second feature, or only indicates that the first feature is lower in horizontal height than the second feature.

[0041] Embodiments of the present application are described in detail below with reference to examples shown in the accompanying drawings, in which the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application and cannot be understood as a limitation of the present application.

[0042] As shown in the drawings, Figures 1-8 The present embodiment provides a ranging method for measuring the distance between a target object and a ranging lens; the ranging lens comprises an objective lens module 1, an eyepiece lens module 2 and a liquid lens module 3 connected between the objective lens module 1 and the eyepiece lens module 2; the ranging method comprises the following steps:

[0043] S1, adjusting the focal length of the objective lens module 1 and the eyepiece lens module 2, and adjusting the current or voltage input into the liquid lens module 3 to adjust the focal length of the liquid lens module 3;

[0044] S2, judging whether the target object is clearly imaged on the eyepiece lens module 2, if yes, obtaining the current or voltage input into the liquid lens module 3;

[0045] S3, based on the corresponding relationship between the current or voltage input into the liquid lens module 3 and the working distance of the liquid lens module 3, querying the working distance corresponding to the obtained current or voltage input into the liquid lens module 3, and the queried working distance is the distance between the target object and the ranging lens.

[0046] It can be understood that by adjusting the current or voltage input into the liquid lens module 3, the hydrophilicity of the oil-water intersection film in the liquid lens module 3 can be changed, so that the film is deformed, thereby adjusting the curvature of the liquid lens module 3, and then changing its diopter, and finally achieving the purpose of adjusting the focal length of the liquid lens module 3, so as to realize clear imaging of different depths of field in cooperation with the objective lens module 1 and the eyepiece lens module 2.

[0047] The ranging method of the embodiment can adjust the focal length of the liquid lens module 3 by adjusting the current or voltage input to the liquid lens module 3, and obtain the current or voltage input to the liquid lens module 3 when the target object is clearly imaged in the ocular lens module 2, query the working distance corresponding to the obtained current or voltage input to the liquid lens module 3 based on the correspondence between the current or voltage input to the liquid lens module 3 and the working distance of the liquid lens module 3, and the queried working distance is the distance between the target object and the ranging lens. Compared with the prior art, the steps are simple, and the response time of the liquid lens module 3 is in the order of milliseconds (about 25 ms), which greatly improves the focusing speed and in turn improves the ranging speed.

[0048] It should be noted that the correspondence between the current or voltage input to the liquid lens module 3 and the working distance of the liquid lens module 3 can be obtained by calibration through multiple tests, and the specific method and steps belong to the prior art and will not be described here.

[0049] Optionally, the step of adjusting the current or voltage input to the liquid lens module 3 to adjust the focal length of the liquid lens module 3 comprises:

[0050] S11, detecting the temperature of the liquid lens module 3;

[0051] S12, querying the refractive power of the liquid lens module 3 corresponding to the measured temperature of the liquid lens module 3 based on the correspondence between the temperature of the liquid lens module 3 and the refractive power of the liquid lens module 3;

[0052] S13, adjusting the current or voltage input to the liquid lens module 3 so that the refractive power of the liquid lens module 3 is equal to the queried refractive power.

[0053] It should be noted that the temperature of the liquid lens module 3 itself is different, and the refractive power thereof is also different, in other words, there is a linear relationship between the temperature of the liquid lens module 3 itself and the refractive power thereof. The state diagram of the liquid lens module 3 under three refractive powers is shown in Figures 2-4 Correspondingly, the focal length of the liquid lens module 3 under different refractive powers is different, as shown in Figures 5-7 The measurable working distance is different.

[0054] Before adjusting the focal length of the liquid lens module 3, the temperature of the liquid lens module 3 is detected first, then the refractive power of the liquid lens module 3 corresponding to the measured temperature of the liquid lens module 3 is queried, and the current or voltage input to the liquid lens module 3 is adjusted so that the refractive power of the liquid lens module 3 is equal to the queried refractive power, thereby the liquid lens module 3 can achieve fast and accurate focusing and ensure clear focusing.

[0055] Further, the correspondence between the temperature of the liquid lens module 3 and the diopter of the liquid lens module 3 can be calibrated through multiple tests, and the specific method and steps belong to the prior art, which will not be repeated here.

[0056] The embodiment also provides a ranging device for implementing the ranging method, the ranging device comprising a ranging lens and a control unit, the ranging lens comprising an objective lens module 1, an eyepiece lens module 2, and a liquid lens module 3 connected between the objective lens module 1 and the eyepiece lens module 2; the control unit comprising an identification module, an adjustment module, and a control module, the identification module being capable of judging whether the target object is clearly imaged on the eyepiece lens module 2; the adjustment module being used for adjusting the current or voltage input into the liquid lens module 3; the control module being capable of recording the current or voltage input into the liquid lens module 3 when the target object is clearly imaged on the eyepiece lens module 2, and the control module being also capable of querying, based on the correspondence between the current or voltage input into the liquid lens module 3 and the working distance of the liquid lens module 3, the working distance corresponding to the recorded current or voltage input into the liquid lens module 3, the queried working distance being the distance between the target object and the ranging lens.

[0057] The ranging device of the embodiment has a compact structure, a small volume, and a low cost, and meanwhile, the liquid lens module 3 has a short response time, so that the ranging speed can be improved.

[0058] Further, the correspondence between the temperature of the liquid lens module 3 and the diopter of the liquid lens module 3 and the correspondence between the temperature of the liquid lens module 3 and the diopter of the liquid lens module 3 can be embedded in the control unit in advance. In the embodiment, the control unit is a computer.

[0059] Alternatively, the liquid lens module 3 comprises a liquid lens 31 and a temperature detection member, the temperature detection member being used for detecting the temperature of the liquid lens 31, and the temperature detection member being in communication connection with the control unit. The temperature of the liquid lens 31 can be detected in real time by using the temperature detection member, so that the control unit can adjust the current or voltage input into the liquid lens 31 in real time according to the detection result of the temperature detection member, to realize fast and accurate focusing and ensure clear focusing.

[0060] Further, the temperature detection member can make the liquid lens 31 have a temperature compensation function, so that the liquid lens 31 can normally work at -20℃ to +65℃ and is not affected by the change of ambient temperature, the focusing clarity is improved, and the distance measurement precision is improved.

[0061] Alternatively, the liquid lens module 3 further comprises two transparent protective plates 32 connected to the two sides of the liquid lens 31 respectively. Exemplarily, the transparent protective plate 32 is glass. Specifically, the two transparent protective plates 32 are arranged on the front and back sides of the liquid lens 31 respectively, the transparent protective plates 32 are used for protecting the liquid lens 31, and the transparent protective plates 32 do not affect the light path.

[0062] Optionally, the liquid lens module 3 further comprises a shell 33 arranged corresponding to each of the two transparent protection plates 32, and the two shells 33 are connected to the liquid lens 31, and the transparent protection plate 32 is fixedly arranged in the corresponding shell 33. The shell 33 supports and fixes the transparent protection plate 32, and facilitates the disassembly and assembly of the transparent protection plate 32, so as to maintain the liquid lens 31 and the like.

[0063] Optionally, the objective lens module 1 comprises a plurality of first lenses 11 arranged in sequence from the object side to the image side. The focal lengths of the plurality of first lenses 11 can be the same or different, and can be set according to requirements. In the embodiment, the first lens 11 is provided with three, of course, in other embodiments, the number of first lenses 11 can also be set to one, two, four, or even more, and can be set according to requirements, which is not limited here.

[0064] Optionally, the eyepiece lens module 2 comprises a plurality of second lenses 21 arranged in sequence from the object side to the image side. The focal lengths of the plurality of second lenses 21 can be the same or different, and can be set according to requirements. In the embodiment, the second lens 21 is provided with three, of course, in other embodiments, the number of second lenses 21 can also be set to one, two, four, or even more, and can be set according to requirements, which is not limited here.

[0065] It should be noted that the above are only the preferred embodiments of the present application and the technical principles applied. Those skilled in the art will understand that the present application is not limited to the specific embodiments described herein, and those skilled in the art can make various obvious changes, re-adjustments and substitutions without departing from the scope of the present application. Therefore, although the present application has been described in more detail through the above embodiments, the present application is not limited to the above embodiments, and can include more other equivalent embodiments without departing from the concept of the present application, and the scope of the present application is determined by the appended claims.

Claims

1. A method of distance measurement, characterized in that, The distance between the target object and the ranging lens is measured by using a ranging lens; the ranging lens comprises an objective lens module (1), an eyepiece lens module (2) and a liquid lens module (3) connected between the objective lens module (1) and the eyepiece lens module (2); the ranging method comprises the following steps: The focal length of the objective lens module (1) and the eyepiece lens module (2) is adjusted, and the current or voltage input into the liquid lens module (3) is adjusted to adjust the focal length of the liquid lens module (3); It is judged whether the target object is clearly imaged on the eyepiece lens module (2), if yes, the current or voltage input into the liquid lens module (3) is obtained; Based on the corresponding relationship between the current or voltage input into the liquid lens module (3) and the working distance of the liquid lens module (3), the working distance corresponding to the obtained current or voltage input into the liquid lens module (3) is queried, and the queried working distance is the distance between the target object and the ranging lens; The step of adjusting the current or voltage input into the liquid lens module (3) to adjust the focal length of the liquid lens module (3) comprises: The temperature of the liquid lens module (3) is detected; Based on the corresponding relationship between the temperature of the liquid lens module (3) and the dioptric power of the liquid lens module (3), the dioptric power of the liquid lens module (3) corresponding to the measured temperature of the liquid lens module (3) is queried; The current or voltage input into the liquid lens module (3) is adjusted, so that the dioptric power of the liquid lens module (3) is equal to the queried dioptric power.

2. Ranging device, characterized in that The ranging device for implementing the ranging method of claim 1 comprises: A ranging lens comprising an objective lens module (1), an eyepiece lens module (2) and a liquid lens module (3) connected between the objective lens module (1) and the eyepiece lens module (2); A regulation unit comprising an identification module, an adjustment module and a control module, the identification module can judge whether the target object is clearly imaged on the eyepiece lens module (2); the adjustment module is used to adjust the current or voltage input into the liquid lens module (3); the control module can record the current or voltage input into the liquid lens module (3) when the target object is clearly imaged on the eyepiece lens module (2), and the control module can also query the working distance corresponding to the recorded current or voltage input into the liquid lens module (3) based on the corresponding relationship between the current or voltage input into the liquid lens module (3) and the working distance of the liquid lens module (3), and the queried working distance is the distance between the target object and the ranging lens.

3. The ranging device of claim 2, wherein, The liquid lens module (3) comprises a liquid lens (31) and a temperature detection member, the temperature detection member is used to detect the temperature of the liquid lens (31), and the temperature detection member is in communication connection with the regulation unit.

4. The ranging device of claim 2, wherein, The regulation unit is a computer.

5. The ranging device of claim 2, wherein, The liquid lens module (3) comprises a liquid lens (31) and two transparent protective plates (32) connected to both sides of the liquid lens (31) respectively.

6. The ranging device of claim 5, wherein, The liquid lens module (3) further comprises a housing (33) arranged in one-to-one correspondence with the two transparent protective plates (32), both of the housings (33) are connected to the liquid lens (31), and the transparent protective plate (32) is fixedly arranged in the corresponding housing (33).

7. The ranging device of claim 2, wherein, The objective lens module (1) comprises a plurality of first lenses (11) arranged in sequence from the object side to the image side.

8. The ranging device of claim 2, wherein, The eyepiece lens module (2) comprises a plurality of second lenses (21) arranged in sequence from the object side to the image side.

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