CN1311230C - Quickly measuring method and device for lens transmittivity - Google Patents

Abstract

The present invention relates to a fire-new method and a device for measuring spectral transmittance by applying a fixed grating and a CCD photoelectric coupler. Spectra are emitted by adopting a xenon flash lamp with a D65 optical source of an international standard, which not only can solve the problem of heat generation of the light source, but also can reduce the power of a complete appliance. The spectra is received by the tight combination of an integrating sphere, a narrow slit, a concave mirror, the fixed grating and a linear array CCD, and the present invention can instantaneously receive all the spectra in measured wave bands at a time to rapidly complete the function of measurement. The measuring device and the measuring method accord with the ISO standard, and the present invention has the advantages of high measurement precision and accurate measuring results, microminiaturized structure, flexible configuration (can be independently used or used by matching with a computer). The present invention is especially suitable for lens manufacturing enterprises, lens retail stores, lens quality detecting organizations, etc.

Description

Lens Transmissivity Rapid Survey Method and Apparatus

Technical field

The present invention relates to a kind of measurement mechanism quick and precisely of the method and apparatus of measuring the eyeglass transmittance, particularly a kind of optical, mechanical and electronic integration.

Background technology

The lens quality of eyewear products such as the vision correction of myopia or long sight, eye protection is related to user's healthy protect, and country and industry all have higher requirement to the spectral transmittance of various eyeglasses.The method and apparatus that is used to measure transmittance at present can reduce two classes: (one) directly measures, utilize the combination of specific light source and color filter to obtain measuring band light beam, be unkitted sample and the beam intensity ratio that installs sample additional by irradiation, judgement sample is in the transmittance of this wave band fast; (2) spectrophotometer type is to utilize the spectrophotometer principle to obtain monochromatic light, is unkitted sample and the beam intensity ratio that installs sample additional by irradiation again and obtains measuring spectral transmittance in the wavelength band.Above-mentioned first kind method and apparatus is because the specific light source condition restriction, can not be accurately and the transmittance of quantitative measurment eyeglass, can only be used for observational measurement; The second class eyeglass transmittance measuring method and legacy equipment can only lining light microscopic sheets; Though but at present existing measuring tape has dioptric eyeglass, and its testing result meets eyeglass transmittance country and industry standard, and equipment volume is big, cost is high, and detection speed is slow, is difficult in the eyeglass industry and does business-like popularization and use.CN1375690A discloses a kind of method and apparatus of measuring light transmissivity, though it can solve the influence of the diopter of measurement eyeglass to measurement result, but still adopt an interference light filter section one section ground in limited wave band to measure, detection speed is slow, and can not realize the accurate measurement of specific wavelength transmittance, can't be extensive use of at the production and selling scene.

Summary of the invention

Purpose of the present invention designs a kind of method and apparatus that can accurately measure the eyeglass transmittance rapidly at the existing problem of present eyeglass transmittance measurement mechanism, provides the eyeglass manufacturing, the on-the-spot use of retail, with control and stabilized lenses quality.

The quick measuring method of eyeglass transmittance mainly is to use fixed grating spectral resolution is become colour light band, projects the CCD photoelectrical coupler and converts corresponding electric signal to, is handled obtaining different transmitted intensities by computer.

The method that the eyeglass transmittance is measured fast, it comprises following step of carrying out continuously:

A: it is the light beam of 280～780nm that the light wave that standard sources is sent obtains wavelength by unthreaded hole and color filter, and planoconvex lens focuses on the eyeglass to be measured;

B: tested light beam becomes directional light through concave mirror and shines on the fixed grating by behind the equal light action of integrating sphere, and it is inferior to make spectrum line up some levels according to certain rules behind diffraction;

C: select the spectrum of wherein light intensity is the strongest, resolution is a highest level time behind concave mirror optically focused, to become the light belt that puts in order by red, orange, yellow, green, blue, blue or green, purple and ultraviolet etc., project on the diverse location from top to bottom of line array CCD;

D: by CCD the light signal of whole pixels on it is transformed into electric signal, input CPU handles the intensity of calculating receiving spectrum by setup program after analog to digital conversion;

E: obtain the eyeglass transmittance with the ratio that does not install eyeglass spectral intensity to be measured additional by installing eyeglass to be measured additional.

Measure the device of eyeglass transmittance, it comprises the spectral emissions device, and spectrum receiving trap and MICROCOMPUTER PROCESSING control and display device is characterized in that: form the spectral emissions device by standard sources, unthreaded hole, catoptron, color filter and collector lens; Form the spectrum receiving trap by integrating sphere, catoptron, fixed grating, color filter and line array CCD sensor; Form the computer processing control apparatus by data acquisition and analog to digital conversion circuit, CPU processor, input button and display; Standard sources by unthreaded hole and catoptron after optical filter enters specimen holder by condenser, the light wave that transmits exposes to line array CCD by integrating sphere, catoptron, fixed grating, color filter and converts electric signal to, becomes digital signal input CPU processor with analog to digital conversion through data acquisition again.

Theoretical foundation of the present invention is CCD all has induction to the light of various wavelength, each pixel in the last numerous pixels of CCD can both be differentiated the light wave that receives, use some level time spectrum that the fixation reflex grating diffration becomes the spectral resolution of all-wave light source arrangement, getting the inferior diffraction spectrum of certain one-level projects on the diverse location of CCD by the tactic colour light band of the length of its wavelength, because CCD can receive and distinguish the power that receives different wavelengths of light, and convert corresponding electric signal to according to this different wave length order and power thereof, this electric signal can pass through digitized processing, tries to achieve various transmittance by Computer Processing.

Because the applied line array CCD photoelectrical coupler of the present invention pixel is numerous, its window is a quartz glass, and each pixel can both receive the lightwave signal power of 280-780nm separately, and resolution is very high.So the section gap of desirable 10nm (visible region), 5nm (ultraviolet region) detects, and satisfies relative national standards and code requirement.Microprocessor in the checkout equipment of the present invention can be weighted integration and calibration, has the Automatic Program calculation function fast and accurately by establishment, and operation result is shown on the display screen in real time, or by online to realize more high precision and to show more clearly with PC.

The present invention adopts the fixed grating of polychromator structure, does not have the gearing of rotating shutter in the monochromator structure to rotate the course of work that detects one by one with different spectrum by grating, so can realize the microminiaturization and the fast detecting of checkout equipment.

Description of drawings

Fig. 1 is an optical schematic diagram of the present invention;

Fig. 2 is an electrical schematic diagram of the present invention;

Fig. 3 is a kind of embodiment synoptic diagram of the present invention, vertical eyeglass transmittivity.

Fig. 4 is horizontal eyeglass transmittance meter.

Fig. 5 is the lensmeter with transmittance measurement function.

Among the above-mentioned figure, 1, light source; 2, unthreaded hole; 3, plane mirror; 4, color filter 1; 5, convex lens; 6, eyeglass to be measured; 7, eyeglass grip slipper; 8, integrating sphere; 9, fixed grating; 10, concave mirror; 11, color filter 2; 12, line array CCD sensor; 13, data acquisition and analog to digital conversion circuit; 14, display screen; 15, microprocessor CPU; 16, function button; 17, mini-printer; 18, external computing machine; 19, support; 20, eyeglass inserts mouth; 21, eyeglass inserts a mouthful switch; 22, function indication frame; 23, transmittance meter box.

Embodiment

Below in conjunction with description of drawings structure of the present invention, measurements and calculations method.

As shown in Figure 1, standard D65 light source 1, by unthreaded hole 2, reflective mirror 3 and optical filter 4, obtain the broadband light beam that measurement range is 280nm-780nm, behind planoconvex lens 5 optically focused, enter integrating sphere 8 by eyeglass 6 to be measured, disperse by narrow slit on the integrating sphere 8, reflection by concave mirror 10 becomes directional light and shines on the fixation reflex grating 9 again, because grating diffration effect, make the beam reflection of wide spectrum become some level time spectrum of arranging according to certain rules, to wherein light intensity is the strongest, the inferior diffraction spectrum of a level that resolution is the highest becomes by red behind concave mirror 10 optically focused, orange, yellow, green, blue, blue or green, purple, tactic light belt such as ultraviolet, color chips 11 disturbs with the secondary of eliminating light belt after filtration again, projects the diverse location from top to bottom of line array CCD sensor 12.

As shown in Figure 2, the light signal that whole pixels are received on the line array CCD sensor becomes electric signal, and the data after changing with AD through the signal amplification are by the DSP processing and show measurement result; As Fig. 3,4,5 is that three kinds of eyeglass spectral transmittance measuring equipment are multi-form.

Fig. 3 and Fig. 4 are eyeglass transmittance meter, and the spectral emissions device is made up of standard D65 xenon flash lamp 1, unthreaded hole 2, reflective mirror 3, color filter 4 and convex lens 5.Standard sources by D65 sends to plane mirror 3, again by unthreaded hole 2 and color filter 4, arrives eyeglass 6 to be measured through convex lens 5 backs by unthreaded hole 2 again.Eyeglass grip slipper 7 is clamped in eyeglass 6 to be measured on the light path.The spectrum receiving trap is made up of with line array CCD sensor 12 integrating sphere 8, concave mirror 10, fixed grating 9, color filter 11, the wavelength that sees through eyeglass to be measured be the broadband light beam of 280nm-780nm enter integrating sphere 8 all behind the light from the integrating sphere narrow slit disperse, the directional light that is reflected into by concave mirror 10 shines on the fixed grating 9 again, wideband light wave through optical grating diffraction is arranged as some level time spectrum according to certain rules, and wherein primary spectrum is on incident line array ccd sensor 12 behind the color filter 11.Circuit part is made up of data acquisition circuit, A/D change-over circuit, CPU processor and input and output.The dosing crystal display except that showing output, also can be joined mini-printer 17 and serial output and PC networking prison and show usefulness.Above-mentioned spectral emissions device, spectrum receiving trap are located in the support 19 of sealing.

Fig. 3 is vertical eyeglass transmittance meter, Fig. 4 is horizontal eyeglass transmittance meter, all can be used for measuring light transmittance τ V, the weighted mean transmittance τ SUVB of the weighted mean transmittance τ SUVA of solar ultraviolet A and solar ultraviolet B, eyeglass 6 to be measured is inserted mouthful 20 insertions and is clamped aligning by specimen holder 7 by eyeglass, by parameters such as button 16 input spectrum scopes, can measure different spectral transmittance etc. or output measurement result etc.

Install the ratio of eyeglass to be measured and the spectral intensity that does not install eyeglass to be measured additional additional, calculate spectral transmittance τ v, testing results such as solar ultraviolet A band transmittance τ SUVA and solar ultraviolet B wave band transmittance τ SUVB and eyeglass chromaticity coordinate.

1, spectral transmittance is calculated as follows:

2, ultraviolet waves A (315nm-380nm spectral region) average transmittance is calculated as follows:

${\mathrm{\τ}}_{\mathrm{UVA}}=\frac{1}{(380-315)\mathrm{nm}}\·{\∫}_{315\mathrm{nm}}^{380\mathrm{nm}}\mathrm{\τ}\left(\mathrm{\λ}\right)\·d_{\mathrm{\λ}}\×100\%---\left(2\right)$

3, solar ultraviolet A (315nm-380nm) wave band transmittance τ (λ) is calculated as follows with the weighted mean transmittance of ES λ (λ) and S (λ):

${\mathrm{\τ}}_{\mathrm{SUVA}}=\frac{{\∫}_{315\mathrm{nm}}^{380\mathrm{nm}}\mathrm{\τ}\left(\mathrm{\λ}\right)\·E_{\mathrm{S\λ}}\left(\mathrm{\λ}\right)\·S\left(\mathrm{\λ}\right)\·d_{\mathrm{\λ}}}{{\∫}_{315\mathrm{nm}}^{380\mathrm{nm}}{E}_{\mathrm{S\λ}}\left(\mathrm{\λ}\right)\·S\left(\mathrm{\λ}\right)\·d_{\mathrm{\λ}}}\×100\%---\left(3\right)$

4, the spectral transmittance τ (λ) of solar ultraviolet B (280nm-315nm) wave band is calculated as follows with the weighted mean transmittance of ES λ (λ) and S (λ):

${\mathrm{\τ}}_{\mathrm{SUVB}}=\frac{{\∫}_{280\mathrm{nm}}^{315\mathrm{nm}}\mathrm{\τ}\left(\mathrm{\λ}\right)\·E_{\mathrm{S\λ}}\left(\mathrm{\λ}\right)\·V\left(\mathrm{\λ}\right)\·S\left(\mathrm{\λ}\right)\·d_{\mathrm{\λ}}}{{\∫}_{280\mathrm{nm}}^{315\mathrm{nm}}{E}_{\mathrm{S\λ}}\left(\mathrm{\λ}\right)\·S\left(\mathrm{\λ}\right)\·d_{\mathrm{\λ}}}\×100\%---\left(4\right)$

The spectral transmittance of τ (λ)-eyeglass

Average human eye spectral luminous efficiency function (defining among the ISO/CIE10527) under V (λ)-daylight

The spectral distribution function (defining among the ISO/CIE10526) of SD65 λ (λ)-standard sources D65

The spectral distribution function of ES λ (λ)-solar radiation

The relative spectral efficiency function of S (λ) UV radiation

5. the mensuration of eyeglass chromaticity coordinate

Calculate the chromaticity coordinate of color, must try to achieve the tristimulus values X of color earlier, Y, Z.The tristimulus values computing formula of International Commission on Illumination (CIE) colorimeter system is:

$\left\{\begin{array}{c}X=k{\∫}_{\mathrm{\λ}}S\left(\mathrm{\λ}\right)\mathrm{\τ}\left(\mathrm{\λ}\right)\stackrel{\‾}{x}\left(\mathrm{\λ}\right)\mathrm{d\λ},\\ Y=k{\∫}_{\mathrm{\λ}}S\left(\mathrm{\λ}\right)\mathrm{\τ}\left(\mathrm{\λ}\right)\stackrel{\‾}{y}\left(\mathrm{\λ}\right)\mathrm{d\λ}\\ Z=k{\∫}_{\mathrm{\λ}}S\left(\mathrm{\λ}\right)\mathrm{\τ}\left(\mathrm{\λ}\right)\stackrel{\‾}{z}\left(\mathrm{\λ}\right)\mathrm{d\λ}\end{array}\right.---\left(1\right)$

In the formula, the scope of integration in visible light wave range, i.e. 380～780nm.Come approximate integration with summation in the actual computation, formula (1) can be exchanged into following formula:

$\left\{\begin{array}{c}X=k\underset{\mathrm{\λ}}{\mathrm{\Σ}}S\left(\mathrm{\λ}\right)\mathrm{\τ}\left(\mathrm{\λ}\right)\stackrel{\‾}{x}\left(\mathrm{\λ}\right)\mathrm{\Δ\λ},\\ Y=k\underset{\mathrm{\λ}}{\mathrm{\Σ}}S\left(\mathrm{\λ}\right)\mathrm{\τ}\left(\mathrm{\λ}\right)\stackrel{\‾}{y}\left(\mathrm{\λ}\right)\mathrm{\Δ\λ}\\ Z=k\underset{\mathrm{\λ}}{\mathrm{\Σ}}S\left(\mathrm{\λ}\right)\mathrm{\τ}\left(\mathrm{\λ}\right)\stackrel{\‾}{z}\left(\mathrm{\λ}\right)\mathrm{\Δ\λ}\end{array}\right.---\left(2\right)$

Wherein, S (λ) is the relative spectral power distribution of lighting source; τ (λ) is the spectral transmittance of eyeglass; X (λ), y (λ), z (λ) are CIE specified standard colourity observer's spectral tristimulus values, and k is called transformation coefficient or adjusts the factor, its effect is that the Y value of selected standard illuminants is adjusted to 100, and its value can be tried to achieve by formula (3).

$k=\frac{100}{\underset{\mathrm{\λ}}{\mathrm{\Σ}}S\left(\mathrm{\λ}\right)\stackrel{\‾}{y}\left(\mathrm{\λ}\right)\mathrm{\Δ\λ}}---\left(3\right)$

After calculating the tristimulus values of color by formula (2), calculate chromaticity coordinate by formula (4) and be

$x=\frac{X}{X+Y+Z},y=\frac{Y}{X+Y+Z},$

$z=\frac{Z}{X+Y+Z},---\left(4\right)$

The colourity computing method that CIE recommends have two kinds of weighted ordinate method and selected ordinate methods, adopt weighted ordinate method in this research.

Eyeglass transmittance meter equipment is except can using separately, be equipped with display screen (14), function display box (22), function button (16) and support (19) and form the eyeglass lensmeter, shown in Figure 5, its flexibly communication port can also be used with PC, finish comprehensive detection to the various performances of eyeglass.

Claims (5)

1, the quick method of measuring of eyeglass transmittance is characterized in that comprising following step of carrying out continuously:

It is the light beam of 280～780nm that the light wave that a, standard sources are sent obtains wavelength by unthreaded hole (2) with color filter (4), and planoconvex lens (5) focuses on the eyeglass to be measured (6);

B, tested light beam become directional light through concave mirror (10) and shine on the fixed grating (9) after passing through the equal light action of integrating sphere (8), and it is inferior to make spectrum line up some levels according to certain rules behind diffraction;

C, select the spectrum of wherein light intensity is the strongest, resolution is a highest level time behind concave mirror optically focused, to become the light belt that puts in order by red, orange, yellow, green, blue, blue or green, purple and ultraviolet etc., project on the diverse location from top to bottom of line array CCD;

D, by CCD the light signal of whole pixels on it is transformed into electric signal, input CPU handles the intensity of calculating receiving spectrum by setup program after analog to digital conversion;

E, obtain the eyeglass transmittance with the ratio that does not install eyeglass spectral intensity to be measured additional by installing eyeglass to be measured additional.

2, measure the device of eyeglass transmittance, it comprises the spectral emissions device, spectrum receiving trap and MICROCOMPUTER PROCESSING control and display device is characterized in that: form the spectral emissions device by standard sources (1), unthreaded hole (2), catoptron (3), color filter (4) and collector lens (5); Form the spectrum receiving trap by integrating sphere (8), catoptron (10), fixed grating (9), color filter (11) and line array CCD sensor; Form the computer processing control apparatus by data acquisition and analog to digital conversion circuit, CPU processor, input button and display; Standard sources by unthreaded hole and catoptron after color filter enters specimen holder by condenser, the light wave that transmits exposes to line array CCD by integrating sphere, catoptron, fixed grating, color filter and converts electric signal to, becomes digital signal input CPU processor with analog to digital conversion through data acquisition again.

3,, it is characterized in that standard sources (1) is the D65 xenon flash lamp as the device of measurement eyeglass transmittance as described in the claim 2.

4, as the device of measurement eyeglass transmittance as described in the claim 2, it is characterized in that specimen holder is made up of eyeglass to be measured (6) and grip slipper (7).

5,, it is characterized in that spectral emissions device and spectrum receiving trap be located in the support (19) of sealing as the device of measurement eyeglass transmittance as described in the claim 2.

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