CN2715275Y

CN2715275Y - Light refraction and total reflection experiment device

Info

Publication number: CN2715275Y
Application number: CN 03207925
Authority: CN
Inventors: 周文
Original assignee: Individual
Current assignee: Individual
Priority date: 2003-08-25
Filing date: 2003-08-25
Publication date: 2005-08-03
Anticipated expiration: 2013-08-25

Abstract

The light refraction and total reflection experiment device of the utility model relates to an educational apparatus of physical test in secondary schools. The light refraction and total reflection experiment device is composed of a graduation screen 1, a chassis 2, a glass block in shape of a semi-column 3, a support bracket 4, an indicating needle 5, and a modified laser pen 6. The chassis 2, the support bracket 4, and the indicating needle 5 are coaxial and are connected by a screw 7, and the glass block 3 is fixed on the support bracket 4. The laser pen 6 is fixed on the rotatable indicating needle 5, and the graduation screen 1 and the chassis 2 are vertically twisted into a semi-disk. An angle of incidence, an angle of refraction and an angle of non-slip point can be directly read on the graduation screen 1. According to the angles, observing the phenomena of refraction and total reflection, explaining the refraction related notion and law, validating the law of refraction, and solving for a refractive index have good effect through being applied in classrooms.

Description

The refraction of light and total reflection tester

Affiliated technical field

The utility model relates to a kind of physical experiment teaching in middle schools instrument.

Background technology

Usually when the refraction of demonstrating light and total reflection phenomenon, semicircle glass block is fixed on the optical disk, allow light incide the circle centre position on glass block plane along the optical disk face, rotate optical disk, just can see incident ray and refracted ray in theory, relative normal is read the size at incident angle and refraction angle again.But in practical operation, tend to because the optical disk face is not very smooth, light is not necessarily parallel fully with card, its rotation axis and card with also can not be absolute vertical, be the comparison difficulty so will see the track of incident ray and refracted ray simultaneously, the measurement at incident angle and refraction angle not only error is big, and can not read simultaneously, experiment is preferably in darker place, and requirement of experiment is than higher, be difficult for accomplishing fully, use inconvenience, generally also can only explain the usefulness of demonstration, effect is undesirable.

Summary of the invention

In order to overcome above deficiency, the visuality of experiment is strengthened, can see the track of incident ray and refracted ray simultaneously, the measurement at incident angle and refraction angle is clear accurately, reduces the environmental requirement of experiment, and is easy to operate, both can explain demonstration for the teacher, can allow student's hands-on, cost is not high simultaneously yet, and I have made " refraction of light and total reflection tester ".The technical scheme that its technical matters that solves the utility model adopts is:

1, instrument (Fig. 1) is made up of scale screen 1, chassis 2, half-cylindrical glass block 3, support 4, pointer 5 and improved laser pen 6, does as a whole very easy to usely, hands and gets final product.The iron plate of scale screen 1, chassis 2, support 4, the thick 1mm of pointer 5 usefulness is made, and wherein scale shields 1, chassis 2 is orthogonal stranded, chassis 2, semicircle glass block 3 concentrics.Half-cylindrical glass block 3 diameter 80mm, thick 12mm.Laser pen 6 is fixed on the pointer 5, and pointer 5 is installed on the center of circle on chassis 2 with support 4, wherein laser pen 6 pointers 5 rotatable 180 degree that are bordering on.Allow laser beam inject, on scale screen 1, directly read incident angle (vertical angle equate), observe incident light and refract light by normal and laser pen 6 pointers 5 perpendicular to cylindroid.Incident light, refract light, normal and can rotate variation all in the plane that is parallel to chassis 2 in this plane.Laser beam can be observed refraction effect in view of the above through can directly reading the refraction angle after the refraction of semicircle glass on scale screen 1, explanation refraction related notion, rule, checking refraction law.When the refraction angle equals 90, also can observe total reflection phenomenon, directly read critical angle by laser pen 6 pointers 5, obtain refractive index.

2, the making of laser pen 6: form by electronic teacher pointer 10 (in the multimedia presentation, be used to indicate the hand-held device of explanation content, the light beam of generation is thin and bright) and little metal cap folder 11.Directly be enclosed within 10 of electronic teacher pointers with one " P " font, the little metal cap folder 11 of wide about 2mm (I press from both sides 11 with " P " font smooth metal cap on the cap of a pen) and upward get final product (as Fig. 6).Require light beam to incide on the bent side of circle near tangential direction " P ", allow the direct incident of a part of light beam, another part light beam is by the bent offside reflection of circle, to become a light belt bar (as Fig. 6) that broadens gradually after segment beam is reflected, the light belt bar after the utilization reflection shows the track of incident light and refract light at the reflected light on projecting plane.

The use the beneficial effects of the utility model are:

Both can also can be used for student experiment in group by the hand-held demonstration explanation of teacher, the teacher of junior middle school can be suitable for through the classroom with reference to the explanation demonstration, and effect is material benefit (the cost of manufacture dozens of yuan of tester) again pretty good, is embodied in:

1, by observing the explanation notion:

Incident ray (laser pen 6 is to the center of circle), the refraction point (center of circle, be the position that beam direction changes), refracted ray (center of circle is to scale screen 1), normal (the vertically pointer 5 of glass), critical angle (when the refraction angle is 90 when spending, the incident angle of pointer 5 indications is critical angle), refractive index etc.

2, understand law by measurement:

Same plane: normal is in the plane that is parallel to chassis 2, and laser pen 6 (incident ray) rotates in this plane, can see that refracted ray also rotates in this plane.

Both sides: laser pen 6 (incident ray) is when pointer 5 (normal) left side, and refracted ray is on the right side; Otherwise incident ray is when the right side, and refracted ray is in the left side.

Ratio: all can on screen, directly read because of incident angle and refraction angle, can allow student's ratio than the ratio at incident angle and refraction angle and with the ratio of the sine at incident angle and refraction angle be a constant.

Special case: when the incident light vertical irradiation, incident ray and refracted ray are on same straight line, and direction does not change

3, by calculating verification result:

Calculate the ratio of the sine at the ratio at incident angle and refraction angle and incident angle and refraction angle respectively, obtain refractive index.

4, use by operation:

Instrument itself can be used as the utility unit of measuring refractive index.

Description of drawings

Further specify below in conjunction with accompanying drawing and the utility model.

Fig. 1 is a structural drawing of the present utility model, comprising: scale screen 1, chassis 2, half-cylindrical glass block 3, support 4, pointer 5, laser pen 6 and screw 7;

Fig. 2, Fig. 3 are the construction drawings on scale screen 1 and chassis 2, and both are orthogonal stranded, and its diameter d is 200mm, shields high 64mm, and there is one " 0 " finedraw 8 centre, about respectively mark 0 to 90 degree scale mark;

Fig. 4 is a support 4, is " ten " word structure, not only is used for fixing half-cylindrical glass block 3 but also can be used as glass and the interface of air, also can replace normal, and the bottom interposition is equipped with a circular hole 9;

Fig. 5 is that pointer 5 is used in reference to and is shown into firing angle, is used for fixing laser pen 6 after the bottom bend;

Fig. 6 is the making schematic diagram of laser pen 6, and laser pen 6 is made up of electronic teacher pointer 10 and little " P " font metal cap folder 11, and little metal cap folder 11 directly is enclosed within on the electronic teacher pointer 10;

Chassis 2 among Fig. 3, Fig. 4, Fig. 5, support 4, pointer 5 are fixed on 2 centers of circle, chassis with screw 7 by circular hole 9 is coaxial, wherein pointer 5 can rotate around the axis, the two ends of support 4 are stuck in the break joint on scale screen 1 and chassis 2, a diameter 3mm circular hole 9 is stayed in the bottom of support 4, be used for laser pen 6 transmissive, point to 0 degree finedraw, 8 places of scale screen 1.

Embodiment

1. allow light beam point to the center of circle and inject (direction of propagation of light beam is constant during by cylinder, reflection loss is very little) perpendicular to the face of cylinder, light beam passes circular hole 9 vertical glass by 0 finedraw 8, the 2 plane rotating pointers 5 on the chassis, the position and the motion conditions of observing the ruddiness spot on the center of circle and the scale screen 1.

2. hour reflection and refraction take place simultaneously at center of circle glass interface place when incident angle, determine incident light and refract light, can be observed incident light and refract light in the rotation process and rotate on same plane, incident light and refract light are always in the normal both sides.

3. on index dial, directly read incident angle (vertical angle equate) by normal and laser pen 6 pointers 5.

4. light beam can directly be read the refraction angle on index dial after the refraction of semicircle glass.

5. when the refraction angle equals 90, directly read critical angle by laser pen 6 pointers 5, and can observe total reflection phenomenon.

6. adjust the position and the incident angle of laser pen 6, on glass bottom surface, 2 interfaces, chassis, observe the track of light.

When implementing, light beam should be aimed at the center of circle (being the axle center of Fig. 3, Fig. 4, Fig. 5) of semicircle glass, otherwise looses and fuzzy at the hot spot of scale screen 1, and the refraction angle is readability standard not also, and error increases.Pointer 5 should sway in the plane that is parallel to chassis 2 as far as possible, both can also can be demonstrated by the part student by demonstration explanation limit, teacher limit record, and another part record makes the satisfactory success of experiment.

Claims

1. the refraction of a light and total reflection tester, form by scale screen (1), chassis (2), half-cylindrical glass block (3), support (4), pointer (5) and laser pen (6), it is characterized in that: chassis (2), support (4), the coaxial center screw (7) of using of pointer (5) connect, glass block (3) is fixed on the support (4), scale screen (1) vertical with chassis (2) stranded be semi-disc.

2. according to right 1 described tester, it is characterized in that: laser pen (6) is fixed on the rotary pointer (5), and pointer (5) serves as that axle rotates in the plane, chassis with screw (7).

3. according to right 1 described tester, it is characterized in that: laser pen (6) is made up of electronic teacher pointer (10) and little " P " font metal cap folder (11), and little metal cap folder (11) directly is enclosed within on the electronic teacher pointer (10).

4. according to right 1 described tester, it is characterized in that: one " 0 " degree finedraw (8) is arranged in the middle of the scale screen (1), respectively mark 0 to 90 degree scale mark about it, support is " ten " structure, and the bottom interposition is equipped with a circular hole (9).