A large field of view expandable field of view instrument

Abstract

The present invention discloses a large-field-of-view expandable viewer, which is composed of multiple viewers spliced ​​together. The multiple viewers are spliced ​​together to reduce the design difficulty of a single viewer and reduce manufacturing costs. The viewer's field of view detection range can be expanded in any direction and at any angle according to the actual inspection needs of the product. The principle of pupil convergence is fully considered so that the inspected product can clearly see the graticule lines within the field of view. The range is 900 mil, the graticule line interval is 10 mil, and after adjustment and calibration, the graticule line inclination angle is guaranteed to be less than 10", and the full-field measurement error is no more than 0.82%.

Description

Technical Field

[0001] The invention belongs to the field of calibration instruments and optoelectronic technology, in particular to a large-field-of-view and expandable-field-of-view instrument. Background Art

[0002] The field of view (FOV) is a key performance indicator for optoelectronic products, and is typically tested using a FOV meter. Conventional FOV meters typically have a detectable FOV range of ±20°, with graticule values ​​typically exceeding 5°. Parameters such as zero position accuracy, graticule line accuracy, and reticle tilt cannot be corrected. To achieve high-precision, large-FOV, and high-quality inspection of optoelectronic products, it is necessary to design a FOV meter with this capability.

[0003] When the measurable field of view angle increases to above ±20°, the design difficulty of a single-field viewer increases significantly, and the expansion range is limited. The aperture of the optical system and the range of the reticle also increase, and the processing and manufacturing costs increase significantly. Therefore, it is necessary to explore a feasible and low-cost method to achieve an unlimited expansion range of the field viewer while maintaining high quality and precision. Summary of the Invention

[0004] The object of the present invention is to provide a large-field-of-view expandable viewer, which adopts a multi-viewer splicing method to reduce the design difficulty of a single viewer and reduce the manufacturing cost.

[0005] The technical solutions for achieving the purpose of the present invention are:

[0006] A large field of view expandable viewer is composed of multiple viewers; one of the viewers is used as a reference viewer, and the pupil distance of the nth group of viewers should meet

[0007] Where p1′ is the exit pupil distance of the reference viewer, θ n is the included angle between the optical axes of the nth group of viewfinders and the reference viewfinder.

[0008] Compared with the prior art, the present invention has the following significant advantages:

[0009] (1) The present invention adopts a multi-field viewer splicing method to reduce the design difficulty of a single field viewer and reduce the manufacturing cost; it can realize the expansion of the field view detection range of the field viewer in any direction and any angle according to the actual detection needs of the product;

[0010] (2) Fully consider the principle of pupil connection so that the inspected product can clearly see the scaled lines within the field of view at the same time; the field meter has a measuring range of 900 mil and a scaled line interval of 10 mil. After adjustment and calibration, ensure that the scaled line inclination angle is less than 10", and the full field of view measurement error is no more than 0.82%. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 This is a structural schematic diagram of a large-field-of-view and expandable-field-of-view instrument according to the present invention;

[0012] Figure 2 This is a schematic diagram of the structure of the grating mechanism of a large-field-of-view expandable viewer according to the present invention;

[0013] Figure 3 This is a schematic diagram of a graticule of a large-field-of-view expandable viewer according to the present invention;

[0014] Figure 4 This is a schematic diagram of the graticule lines of a large-field-of-view and expandable-field-of-view instrument according to the present invention;

[0015] Figure 5 This is a schematic diagram of the calibration results of the graticules of the large-field-of-view and expandable-field-of-view instrument described in the present invention. DETAILED DESCRIPTION

[0016] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0017] The large field of view in this embodiment can be expanded to include a field of view instrument, such as Figure 1 As shown, taking the dual-viewer assembly as an example, it includes a first graticule mechanism 1, a first lens group 2, a second graticule mechanism 3, a second lens group 4, and a support housing 5. The first graticule mechanism and the first lens group are placed horizontally to form the first viewer; the second graticule mechanism and the second lens group are mounted above the support housing 5 to form the second viewer. The optical axes of the first and second viewers form a 28° angle, and the exit pupils of the first and second lens groups are located near the intersection of the optical axes. This allows the inspected product to clearly see the graticule lines within the field of view, ensuring observation quality.

[0018] The first division is composed of Figure 2 The schematic diagram includes a scale barrel 31, a pressure ring 32, a spacer 33, a ground glass 34, a scale plate 35, and a scale focusing barrel 36. The ground glass 34 and the scale plate 35 are separated by the spacer 33. The pressure ring 32 presses the spacer 33, the ground glass 34, and the scale plate 35 to fix them on the scale frame barrel 31. The outer ring of the scale barrel 31 has a V-shaped groove and is sleeved in the scale focusing barrel 36. The screws on the scale focusing barrel 36 are aligned with the characteristic V-shaped groove (311) on the outer ring of the scale barrel 31, so that the scale barrel 31 can only rotate and does not move axially, avoiding changes in the optical interval. The scale focusing barrel 36 is connected to the support housing 5 through a thread, and the precise focus of the lower scale mechanism 3 is achieved by screwing.

[0019] The second graticule mechanism is similar in structure to the first, except that the surface of the graticule closest to the second lens group is concave, and the entire graticule has negative optical power. The first and second lens groups have different focal lengths, and the graticule size and line spacing are different.

[0020] The scale lines on the first dividing mechanism at different distances from the optical axis are calculated according to the formula y1=f1′tanw1, where y1 is the distance between the scale lines and the optical axis of the first lens group, f1′ is the focal length of the first lens group, and ω1 is the corresponding field of view angle; the first lens group 2 has positive focal power as a whole and is composed of a first cemented lens, a third lens 21, a fourth lens 22, a fifth lens 23, and a sixth lens 24 arranged in sequence, wherein the first cemented lens is a first lens 25 with negative focal power and a second lens 26 with positive focal power cemented together, and has negative focal power as a whole, the third lens 21 has positive focal power, the fourth lens 22 has positive focal power, the fifth lens 23 has positive focal power, and the sixth lens 24 has negative focal power. The scale lines on the second dividing mechanism at different distances from the optical axis are calculated according to the formula y2=f′2tan(w2-θ 21 ), where y2 is the distance between the graticule and the optical axis of the second lens group, f′2 is the focal length of the second lens group, ω2 is the corresponding field of view, and θ 21 is the included angle between the optical axes of the second lens group and the first lens group. In this embodiment, θ 21 =28°; the second lens group 4 has positive focal power as a whole, and is composed of a second cemented lens, a ninth lens 41, and a third cemented lens, wherein the second cemented lens is composed of a seventh lens 42 with positive focal power and an eighth lens 43 with negative focal power, and has negative focal power as a whole, the ninth lens 41 has positive focal power, and the third cemented lens is composed of a tenth lens 44 with negative focal power and an eleventh lens 45 with positive focal power, and has positive focal power as a whole.

[0021] In order to ensure that all the field of view scale lines cannot be seen clearly at the same time due to the difference in the exit pupil position of each field of view instrument during measurement, the exit pupil distance of the horizontally or vertically placed reference field of view instrument (first field of view instrument) is set to p'1, ​​and the angle θ with the optical axis of the reference field of view instrument is set to n The exit pupil distance of the nth group of field instruments should meet the requirements Ensure observation quality; determine the reticle range and line accuracy of each field of view instrument, and ensure that the lines are continuous and without overlap;

[0022] After coarsely adjusting the parallax of the first and second viewfinders using the front mirror, fine-tune the parallax using the pentaprism and the theodolite. Lock the graticule focusing tube 36 and place the leveled theodolite near the intersection of the optical axes of the first and second viewfinders. Observe the graticule of the first viewfinder. After locking the theodolite's horizontal adjustment mechanism, use the theodolite's vertical adjustment mechanism to scan up and down, measuring the horizontal change in the graticule of the first viewfinder. When the angle change is greater than 10", rotate the graticule tube 31. Repeat the vertical adjustment of the theodolite to scan up and down, measuring the horizontal change in the graticule of the first viewfinder, until the angle change is less than or equal to 10". Tighten the upper graticule mechanism 1 with the screws on the graticule focusing tube 36. Repeat these adjustment steps for the second viewfinder.

[0023] In this embodiment, the vertical field of view of the visual field instrument is extended to 900mil (1mil=0.06°), the measurement range is -300mil to 600mil, and the line interval is 10mil. The vertical measurement range of the first visual field instrument is ±300mil, and the vertical measurement range of the second visual field instrument is ±200mil. The first visual field instrument is placed horizontally, the pupil distance is 150mm, and the optical axis center design angle between the second visual field instrument and the first visual field instrument is 28°. According to the formula The pupil distance of the second field of view instrument was determined to be 170mm during the design phase. The field of view angles of the first and second field of view instruments overlap by 4°. To ensure that the lines are continuous and distinguishable and to avoid confusion, the lines on the first field of view instrument's reticle are between -300mil and 250mil, and the lines on the second field of view instrument's reticle are between 260mil and 600mil. The vertical field of view detection range is -300mil to 600mil (54°). Figure 4 shown.

[0024] Use the leveled theodolite to calibrate the scales of the first and second field instruments, and obtain the following: Figure 5 The results are shown. From 300mil to 250mil, the measurement error per 50mil is no more than 0.065mil, or no more than 0.13%; in the transition region, from 250mil to 300mil, the measurement error is no more than 0.411mil, or no more than 0.82%; and from 300mil to 600mil, the measurement error per 50mil is no more than 0.135mil, or no more than 0.27%.

Claims

1. A large field of view and expandable field of view instrument, characterized in that: It is composed of multiple field monitors; One of the viewfinders is used as the reference viewfinder, and the pupil distance of the nth group of viewfinders should meet Where p1′ is the exit pupil distance of the reference viewer, θ n is the angle between the optical axes of the nth group of viewfinders and the reference viewfinder; The exit pupil positions of the multiple viewfinders are located near the intersection of the optical axes.

2. The large field of view and expandable field of view instrument according to claim 1, characterized in that: All field meters are equipped with lens groups and dividing mechanisms.

3. The large field of view and expandable field of view instrument according to claim 2, characterized in that: The grading mechanism includes a grading cylinder, a pressure ring, a spacer, a frosted glass, a grading plate, and a grading focusing cylinder; The frosted glass and the graticule plate are separated by a spacer ring, and the pressure ring presses the spacer ring, the frosted glass, and the graticule plate to fix them on the graticule frame tube; the outer ring of the graticule tube has a V-shaped groove, which is sleeved in the graticule focusing tube, and the screws on the graticule focusing tube are aligned with the V-shaped groove on the outer ring of the graticule tube so that the graticule tube can only rotate and does not move axially. The graticule focusing tube is connected to the support shell through a thread, and the focusing of the graticule mechanism is achieved by screwing.

4. The large field of view and expandable field of view instrument according to claim 1, characterized in that: It consists of two sets of field meters, and the optical axes of the two field meters form an angle of 28°.

5. The large field of view and expandable field of view instrument according to claim 1 or 4, characterized in that: The lens group of the reference viewfinder has positive optical power and is composed of a first cemented lens, a third lens, a fourth lens, a fifth lens, and a sixth lens arranged in sequence. The first cemented lens is composed of a first lens with negative optical power and a second lens with positive optical power cemented together, and the whole has negative optical power. The third lens has positive optical power, the fourth lens has positive optical power, the fifth lens has positive optical power, and the sixth lens has negative optical power.

6. The large field of view and expandable field of view instrument according to claim 4, characterized in that: The second group of viewfinders has positive optical power and is composed of a second cemented lens, a ninth lens, and a third cemented lens; the second cemented lens is composed of a seventh lens with positive optical power and an eighth lens with negative optical power, and the whole has negative optical power. The ninth lens has positive optical power. The third cemented lens is composed of a tenth lens with negative optical power and an eleventh lens with positive optical power.

7. The large field of view and expandable field of view instrument according to claim 4, characterized in that: The basic viewfinder reticle has lines between -300mil and 250mil, and the secondary viewfinder reticle has lines between 260mil and 600mil.

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