TWI383132B - System and method for measuring field of view of an optical system - Google Patents

Description

Optical viewing angle measuring system and measuring method thereof

The invention relates to a measuring system for optical viewing angle and a measuring method thereof, in particular to an optical viewing angle measuring system for a lens and a measuring method thereof.

With the advent of the digital age, portable electronic devices such as mobile phones with camera functions are increasingly used, and they are moving toward light, thin, short, and small, and people are increasingly demanding the quality of photographs. Therefore, performance testing of camera lenses is essential. The detection of the camera's optical field of view (FOV) is a key test item in camera lens performance testing. The optical viewing angle refers to the maximum angle between the subject and the image sensor that can be captured.

Referring to FIG. 1 and FIG. 2 , when the camera optical angle of view is measured, the lens 501 captures an image 201 from the test image 20 and forms an image 201 ′ on the image sensor 503 . The length of the diagonal AC of the image 201 is d. The length of the diagonal A'C' of the image 201' is d'. The distance between the lens 501 and the test picture 20 is s. The image sensor 503 is located on the image plane of the lens 501, and the distance from the image sensor 503 is the focal length f of the lens 501. The maximum optical viewing angle of the camera is θ, which can be derived from the following formula:

For measuring the optical angle of view of the camera, it is only necessary to measure the length d' of the diagonal line A'C' of the image 201' and the distance f between the image sensor 503 and the image 201', and the above formula (1) can be applied. Calculating θ, that is, the optical angle of view of the camera; or, by measuring the length d of the diagonal line AC of the image 201 and the distance s between the lens 501 and the test picture 20, θ can be calculated using the formula (2).

An automatic measurement system has been used in the industry to measure the optical angle of the camera. As shown in FIG. 3, a camera optical angle automatic measurement system includes a camera module 50, a data input module 30, and a data processing module 40. The camera module 50 includes a lens 501 and an image sensor 503. The lens 501 captures an image 201 on the test image 20 and forms an image 201' on the image sensor 503. The image sensor 503 of the camera module 50 is connected to the data processing module 40, and converts the sensed image signal into an electronic image signal for transmission to the data processing module 40. The data processing module 40 automatically acquires the pixel value Pd occupied by the diagonal line A'C' of the image 201'. The data input module 30 is configured to input the actual length Ld of the pixel of the image sensor 503 and the distance f of the lens 501 to the image sensor 503 to the data processing module 40. The data processing module 40 can calculate θ according to the following formula (1).

However, when the measurement is performed by the above-described camera optical angle automatic measurement system, the data processing module 40 automatically captures the border of the image 201' to obtain the pixel value Pd of the diagonal line A'B' of the image 201'. Because the images taken during each measurement are often different in size, there are many The same size pattern, so that the system is easy to produce misjudgment during the process of crawling, thus affecting the quality of the measurement. In addition, since the image sensor 503 of the different camera modules 50 is different, the actual length value Ld of the pixels is different, so each time the different camera modules are measured, the actual length of the different pixels must be manually input. The value Ld, this will result in a lot of time and labor waste.

In view of this, it is necessary to provide an optical viewing angle measuring system that improves measurement quality and saves measurement time.

In addition, it is also necessary to provide a measurement method for improving the optical quality of the measurement quality and saving the measurement time.

An optical viewing angle measuring system for measuring an optical viewing angle of an optical system including a lens and an image sensor, the optical viewing angle measuring system comprising a test picture, the test picture is provided with a color rendering block; and a data input module, It is used for inputting the side length value a of one of the aforementioned color blocks and the distance between the test picture and the lens s; a data processing module connected to the data input module for receiving the optical system for the test picture The electronic image signal of the captured image is obtained, and the pixel number Pd occupied by the diagonal of the captured image and the pixel number Pa of the side of one side of the color block are calculated and the optical angle of view value θ is calculated. .

An optical viewing angle measuring method for measuring an optical viewing angle of an optical system including a lens and an image sensor, the optical viewing angle measuring method comprising the steps of: providing a test picture with a color developing block; The data processing module inputs an edge length value a of one side of the color developing block and an input step of the distance between the test picture and the lens of the optical system; and obtains a side length value a and a test picture of one side of the color developing block by the data input module a step of spacing s from the lens of the optical system; taking an image of the color image block from the test image by the lens of the optical system, and obtaining the diagonal of the captured image by the data processing module The pixel number Pd and the pixel number Pa of the side length of the color block are determined by the following formula The step of calculating the optical viewing angle value θ of the optical system is calculated.

Compared with the prior art, the optical viewing angle measuring system does not need to provide different pixel actual length values Ld every time in the measurement process, and does not need the system to capture the image frame, thereby avoiding the misjudgment generated during the system capturing process. Phenomenon saves measurement time and improves measurement quality. The measuring method of the optical viewing angle automatically calculates the actual length value Ld of the pixel by the system during the measurement process, so that it is not necessary to provide different pixel actual length values Ld in each measurement process, and the measurement time is saved. Improve the quality of measurement.

Referring to FIG. 4, the optical viewing angle measuring system of the present invention will be described by taking an optical viewing angle of an optical system 52 as an example. A preferred embodiment of the optical viewing angle measurement system includes a test picture 22, a data input module 32, and a data processing module 42 coupled to the data input module 32.

The optical system 52 includes a lens 521 and an image sensor 523. The lens 521 is used for imaging on the image sensor 523. The image sensor 523 is electrically connected to the data processing module 42 to transmit an electronic image signal to the data processing module 42.

Referring to FIG. 5 and FIG. 6 together, a rectangular color developing block 220 having four vertices of M, N, P, and Q is disposed at a substantially central position of the test picture 22 of the optical viewing angle measuring system. The side length a of one of the strips NP of the color developing block 220 is known, for example, the side length a of the side NP can be measured by a vernier caliper. It can be understood that the color developing block 220 is not limited to a rectangle, and may also be a coloring block having a regular edge shape such as a triangle or a trapezoid. The color developing block 220 is black. It can be understood that the color developing block 220 is not limited to black, as long as the color thereof is clearly distinguishable from the background color of the test image 22, so as to be recognized by the system and the measuring personnel.

The data input module 32 of the optical viewing angle measuring system is configured to input relevant information required for optical viewing angle measurement to the data processing module 42, such as the side length a of the edge NP of the color generating block 220 and the distance s between the lens 521 and the test picture 22. .

The data processing module 42 is connected to the data input module 32 and the image sensor 523 of the optical system 52, and processes the received data and outputs the measurement result.

Referring to FIG. 5 and FIG. 6 together, the measurement principle of the optical viewing angle measuring system of the present invention is as follows: when measuring, the lens 521 of the optical system 52 captures the test picture 22, and the lens 521 viewing range must include the color rendering block 220 in The image 221 having the vertices A, B, C, and D is shown in FIG. 5, and the image 221 forms a vertex A', B', C', D' on the image sensor 523. The image 221 ′, the color rendering block 220 forms a color rendering block 220 ′ with vertices M′, N′, P′, Q′ on the image sensor 523 . After the image sensor 523 converts the sensed color block 220 ′ and the image 221 ′ into electronic signals for transmission to the data processing module 42 , the data processing module 42 automatically acquires the edge N′ of the chromogenic block 220 ′. The pixel number Pd occupied by P' and the diagonal number A'C' of the image 221'. Since the side length a of the edge NP of the color developing block 220 is known, the length d of the diagonal line AC can be obtained by the following formula:

At this time, only the distance s between the test picture 22 and the lens 521 of the optical system 52 is measured, and θ can be obtained by the following formula (4), as follows:

The measuring method of the optical viewing angle measuring system comprises the following steps: providing a test picture 22 having a color developing block 220; measuring a side length a of one side of the color developing block 220 and the test picture 22 and The distance between the lenses 521 of the optical system 52 is s; the edge length a value of the color developing block 220 and the distance s between the test picture 22 and the lens 521 of the optical system 52 are input to the data processing module 42 by the data input module 32. The lens 521 of the driving optical system 52 captures an image of the test picture 22, and the lens 521 has a framing range in which the color rendering block 220 is to be included; as shown in FIG. 5, the vertices A, B, C, and D are shown. For example, the image 221 forms an image 221 ′ of the vertices A′, B′, C′, and D′ on the image sensor 523 , and the color display block 220 forms a vertex on the image sensor 523 . The color image block 220' of the M', N', Q', P'; the image sensor 523 converts the sensed image 221' into an electronic signal for transmission to the data processing module 42, the data processing module 42 Obtaining the pixel number Pa occupied by the side N'P' of the color generating block 220' and the pixel number Pd occupied by the diagonal line A'C' of the image 221'; the data processing module 42 uses the formula (4) ) The optical viewing angle value of the optical system 52 is calculated.

It can be understood that when the same test picture 22 and each optical system 52 are set at the same position during the test, the side length a value of the color block 220 and the distance s value of the lens 521 and the test picture 22 can be preset to the data processing mode. In group 42, the data can be automatically invoked when data processing module 42 processes the data. Therefore, when measuring different optical systems 52, it is not necessary to manually input the side length a value of the color developing block 220 and the distance s value of the lens 521 and the test picture 22 each time.

Since the measurement is performed by using the optical viewing angle measuring system, it is only necessary to provide the optical viewing angle measuring system with the side length a value of the color developing block 220 and the distance s value of the lens 521 and the test picture 22 or preset it to the system. Therefore, it is not necessary to provide the actual pixel length value Ld of the different image sensor 523 to the optical viewing angle measuring system each time. Therefore, the optical viewing angle measurement system provided avoids errors in the system capture process The phenomenon of the system saves the measurement time of the system and improves the quality of the system measurement.

In summary, the present invention complies with the requirements of the invention patent and submits a patent application according to law. The above descriptions are only the preferred embodiments of the present invention, and those skilled in the art will be able to include equivalent modifications or variations in the spirit of the present invention.

(known)

20‧‧‧Test pictures

201,201’‧‧‧ Images

30‧‧‧Data input module

40‧‧‧Data Processing Module

50‧‧‧ camera module

501‧‧‧ lens

503‧‧‧Image sensor

(this invention)

22‧‧‧Test pictures

220,220’‧‧‧ color blocks

221,221’‧‧‧ Images

32‧‧‧Data input module

42‧‧‧Data Processing Module

52‧‧‧Optical system

521‧‧‧ lens

523‧‧‧Image Sensor

1 is a schematic diagram showing the principle of measuring the optical angle of view of a conventional camera; FIG. 2 is a schematic diagram of an optical angle of view of a conventional camera image sensor; FIG. 3 is a structural block diagram of a conventional optical angle measuring system for a camera; FIG. 5 is a schematic diagram of a measurement principle of a preferred embodiment of the optical viewing angle measurement system of the present invention; FIG. 6 is an image sensing method of a preferred embodiment of the optical viewing angle measurement system of the present invention. Schematic diagram of the optical perspective of the device.

220,220’‧‧‧ color blocks

221,221’‧‧‧ Images

523‧‧‧Image Sensor

Claims (11)

An optical viewing angle measuring system for measuring an optical viewing angle of an optical system including a lens and an image sensor, comprising: a test picture having a color developing block; and a data input module for Inputting a side length value a of one of the color developing blocks and a distance s between the test picture and the lens; a data processing module connected to the data input module for receiving the optical system to capture the test picture The electronic image signal of the image is obtained by taking the pixel number Pd occupied by the diagonal of the captured image and the pixel number Pa of the side of one side of the color block and calculating the optical angle of view value θ, Wherein the data processing module is represented by the following formula The optical viewing angle value of the optical system is calculated. The optical viewing angle measuring system of claim 1, wherein the color developing block is disposed at a central position of the test picture. The optical viewing angle measuring system according to claim 1, wherein the color developing block is a color developing block having a regular edge shape. The optical viewing angle measuring system of claim 3, wherein the color developing block is a rectangular color developing block. The optical viewing angle measuring system of claim 3, wherein the color developing block is a triangular color developing block. The optical viewing angle measuring system of claim 3, wherein the color developing block is a trapezoidal color developing block. The optical viewing angle measuring system of claim 1, wherein the color developing block is a black color developing block. The optical viewing angle measuring system of claim 1, wherein the color of the color developing block is clearly distinguishable from the background color of the test picture. An optical viewing angle measuring method for measuring an optical viewing angle of an optical system including a lens and an image sensor, comprising the steps of: providing a test picture provided with a color developing block; and inputting a color developing block to the data processing module The edge value of one side is a and the distance between the test picture and the lens of the optical system s; an image of the color block is included in the test picture by the lens of the optical system; the data processing module acquires the picture The pixel number Pd occupied by the diagonal line and the pixel number Pa of the side of the color block, and by the following formula The step of calculating the optical viewing angle value θ of the optical system. The optical viewing angle measuring method according to claim 9, wherein the side length value a of the color developing block is preset in the data processing module. The optical angle of view measurement method of claim 9, wherein the distance s between the lens and the test picture is preset in the data processing module.