CN201237850Y - Optical grating Moire fringe tester - Google Patents

Abstract

The utility model provides a measuring apparatus to detect the properties of moire fringes of optical grating, belonging to a teaching apparatus. The measuring apparatus mainly consists of a track 1, a slider 2, a raising platform 3, a CCD4, an auxiliary optical grating 5, a main optical grating 6, a calibrated dial 7, a screw mandrel 8, a centigrade handwheel9, a homogenizer plate 10 and an LED 11; wherein, the main optical grating 6 and the auxiliary optical grating 5 can be dismounted flexibly; the auxiliary optical grating 5 can be rotated freely, and the included angle between the main optical grating 6 and the auxiliary optical grating 5 can be read via the calibrated dial 7. The screw mandrel 8 and the centigrade handwheel 9 can drive the slider to move straightly along the track 1. The measuring apparatus can be used to observe moire fringes with naked eyes, is not only capable of detecting the relationship between the relative displacement of the optical gratings and the number of moire fringes passed by, but also capable of detecting the relationship between the changes of the included angle of the optical gratings and the changes of the widths of the moire fringes. The structure of the measuring apparatus is completely open, and the operational process is transparent.

Description

Grating Moire fringe tester

Technical field:

The utility model belongs to instruments used for education, particularly a kind of measuring instrument that detects grating Moire fringe characteristic.

Background technology:

Present grating Moire fringe instruments used for education are many to be research object with the high precision grating, and such grating can't with the naked eye be seen the Moire fringe phenomenon clearly under the natural light condition, and this will limit the vividness and the iconicity of teaching.Simultaneously, the linear displacement characteristic that present grating Moire fringe instruments used for education mainly relatively move based on research key light grid and indication grating, the relation of the variation of key light grid and indication grating variable angle and Moire fringe width is not given and support, this will bring defective to the experimental teaching of Moire fringe, be unfavorable for user's fully understanding the feature of Moire fringe.

Summary of the invention:

The purpose of this utility model:, provide a kind of grating Moire fringe characteristic tester that is used to impart knowledge to students in order to overcome the deficiency of present Moire fringe instruments used for education.This instrument not only can observe with the naked eye Moire fringe under the natural light condition, and structure is open fully, can measure the variation of grating angle and the relation of Moire fringe wide variety more accurately.

The related grating Moire fringe tester of the utility model mainly is made of track, slide block, lifting table, CCD, secondary grating, key light grid, index plate, screw mandrel, centigrade handwheel, equal tabula rasa, LED; It is interior and detachable that the key light grid are placed on the track bar-shaped trough, slide block is placed in directly over the track, contact with track upper surface, can make slide block do rectilinear motion in orbit by screw mandrel and centigrade handwheel, lifting table is fixed on the slide block, and lifting table can make CCD fixed thereon move up and down, and index plate is fitted in shoe surface, secondary grating is placed in the slide block groove, can rotate freely.

Advantage of the present utility model: can with the naked eye observe Moire fringe clearly, and can detect the relation of grating variable angle and Moire fringe wide variety.Key light grid and indication grating are dismountable simultaneously, structure is open fully, this convenient and practical person installs the grating of different pitch, thereby the grating that can be observed different pitch forms the Moire fringe phenomenon, by specific energy is had more deep understanding to the characteristic of Moire fringe.Package unit is simple in structure, easy to understand and operation.

Description of drawings:

Fig. 1 is a structure front elevation of the present utility model

Fig. 2 is the side view of this test instrument

Fig. 3 is the vertical view of this experiment instrument

Fig. 4 is secondary optical grating construction figure

1. tracks among the figure, 2. slide block, 3. lifting table, 4.CCD, 5. secondary grating, 6. key light grid, 7. index plate, 8. screw mandrel, 9. centigrade handwheel, 10. equal tabula rasa, 11.LED.

Embodiment

Fig. 1 is the structural representation of grating Moire fringe tester, as shown in Figure 1, grating Moire fringe tester mainly is made of track 1, slide block 2, lifting table 3, CCD4, secondary grating 5, key light grid 6, index plate 7, screw mandrel 8, centigrade handwheel 9, equal tabula rasa 10, LED11; It is interior and detachable that key light grid 6 are placed on track 1 bar-shaped trough, slide block 2 is placed in directly over the track 1, contact with track 1 upper surface, can make slide block 2 on track 1, do rectilinear motion by screw mandrel 8 and centigrade handwheel 9, lifting table 3 is fixed on the slide block 1, and lifting table 3 can make CCD4 fixed thereon move up and down, and index plate 7 is fitted in slide block 1 surface, secondary grating 5 is placed in slide block 1 groove, can rotate freely.

Further specify principle of work, testing process and the detection effect of grating Moire fringe tester below in conjunction with Fig. 3.The slide block 2 that at first will have secondary grating 5 is placed on the track 1 that key light grid 6 are housed, and opening power is lighted LED11, and can see light and dark Moire fringe this moment on secondary grating 5 surfaces, and CCD4 reads in monitor with this striped appearance, thereby makes things convenient for the user to observe.When the research Moire fringe moves concerning of number and grating relative displacement, at first write down slide block 2 current on track 1 residing position, folk prescription is to rotating centigrade handwheel 9 then, make slide block 2 rectilinear motions, on monitor, read mobile Moire fringe and count N, write down slide block 2 and move the present position, back, can verify that then relative displacement and Moire fringe move the relation of number.When the concerning of research grating angle and Moire fringe width, the secondary grating 5 on the turning block 2 changes the angle of secondary grating 5 and key light grid 6 from small to large, and corner dimension can be read from index plate 7.Revolution is crossed an angle, then reads the width of current Moire fringe on display, and this width then is actual current Moire fringe width divided by the CCD enlargement factor, thereby can verify the relational expression of grating angle and Moire fringe width.This tester is to the characteristic measurement such as the table 1 of grating Moire fringe, shown in the table 2.

1) measure relatively move displacement S and Moire fringe of grating and move the relation of number N, its experiment the results are shown in Table 1

Table 1

N	0	10	20	30	40	50	60	70
									S(mm)	0	4.940	9.915	14.924	19.917	24.947	29.973	35.007
N	80	90	100	110	120	130	140
									S(mm)	40.025	45.020	50.350	55.345	60.335	65.415	70.040

(pitch W=0.5mm)

2) relation of mensuration two grating grid line angle theta and Moire fringe width B.Its measurement result sees Table 2

Table 2

θ (degree)	28	24	20	16	12	8	4
								B1(mm)	1.40	1.70	1.95	2.65	3.65	5.35	10.50
B2(mm)	1.50	1.90	2.35	2.60	3.90	5.35	11.00
								B3(mm)	1.85	1.75	2.00	2.65	3.75	6.00	11.45
B4(mm)	1.60	2.00	2.40	3.05	3.95	6.00	10.65
								Mean value B (mm)	1.59	1.84	2.18	2.74	3.81	5.68	10.90

(pitch W=0.5mm)

From the measurement result of table 1 table 2 as can be known, this instrument can be measured the variation of grating angle and the relation of Moire fringe wide variety more accurately, meets design requirement.

Claims (1)

1, a kind of grating Moire fringe tester is made of track (1), slide block (2), lifting table (3), CCD (4), secondary grating (5), key light grid (6), index plate (7), screw mandrel (8), centigrade handwheel (9), equal tabula rasa (10), LED (11); It is characterized in that: it is interior and detachable that key light grid (6) are placed on track (1) bar-shaped trough, slide block (2) is placed in directly over the track (1), contact with track (1) upper surface, can make slide block (2) on track (1), do rectilinear motion by screw mandrel (8) and centigrade handwheel (9), lifting table (3) is fixed on the slide block (2), lifting table (3) can make CCD fixed thereon (4) move up and down, index plate (7) is fitted in slide block (1) surface, secondary grating (5) is placed in slide block (1) groove, can rotate freely.

Images