WO2017114122A1

WO2017114122A1 - Glass surface stress meter

Info

Publication number: WO2017114122A1
Application number: PCT/CN2016/109031
Authority: WO
Inventors: 李俊峰
Original assignee: 南通杰福光学仪器科技有限公司; 北京杰福科技有限公司
Priority date: 2015-12-29
Filing date: 2016-12-08
Publication date: 2017-07-06
Also published as: CN106932130A

Abstract

A glass surface stress meter comprises an illumination unit comprising a light source (101); a testing prism (200); and an image forming unit. The testing prism (200) comprises a testing surface (200a) used to attach to a surface of glass to be tested (30). A testing light enters the testing prism (200) from the illumination unit is entirely reflected at an attachment location between the testing surface (200a) and the surface of the glass to be tested (30). The image formation is arranged to receive an outgoing light of the testing prism (200) to form a test image. The illumination unit further comprises a converging lens (104) formed and arranged to converge light rays from the light source (101) to or near the testing surface (200a) of the testing prism (200). The glass surface stress meter converges the light rays from the light source (101) to or near the testing surface of the testing prism (200) by employing the converging lens (104), facilitating to enhance testing precision.

Description

Glass surface stress meter

Technical field

The present disclosure relates to an optical detecting device, and in particular to a glass surface stress meter.

Background technique

Glass sheets are common materials in everyday life and industrial production. In order to measure the quality of the glass sheet and ensure the safety of the glass sheet, it is often necessary to measure the stress in the glass sheet. In order to detect the stress of the glass plate, it is stipulated in the national standard and the like that the surface stress of the glass is measured by means of birefringence to characterize the stress level inside the glass. At present, there are two main methods for determining the surface stress of glass in practical use: differential surface refractometry (DSR) and surface grazing angle (GASP). Among them, the DSR method uses a small number of optical components, and the price of the detection instrument is relatively low, and is widely used by various detection organizations.

However, the existing DSR-type glass surface stress meter is not without defects. In particular, Figures 1a and 1b show partial schematic views of optical detection of a prior art DSR-type glass surface stress meter. As shown in Figs. 1a and 1b, the light emitted from the light source 1 is divergent, and the divergent light is irradiated onto the detecting surface 2a of the detecting prism 2, and is reflected at the interface between the detecting prism and the glass surface. In the case of detecting the curved glass 3 (for example, a windshield for an automobile), as shown in FIG. 1a, the incident light at the curved glass and the prism contact point 3a does not necessarily include the light having the total reflection angle, and thus the detection error Larger. For the detection of the flat glass 4, as shown in Fig. 1b, there is a problem that the range of the refractive index of the glass to be detected is narrow. In addition, if the above-mentioned conventional glass surface stress meter has scratches or stains on the detecting surface 2a, scratches or stains have a great influence on the detection result, resulting in a large detection error.

Summary of the invention

The present invention has been made in view of the above-described deficiencies in the prior art.

According to the present invention, there is provided a glass surface stress meter comprising: a lighting unit, The illumination unit includes a light source, a detection prism having a detection surface for bonding with a surface of the glass to be inspected for detection, and detection light incident from the illumination unit to the detection prism on the surface of the detection surface and the glass to be inspected The junction between them is totally reflected; and the imaging unit is arranged to receive the outgoing light from the detection prism and form a detection image, wherein the illumination unit further comprises a concentrating mirror formed and arranged to Light from the source is focused onto or near the detection surface of the detection prism.

Preferably, the light source is a white LED light source.

Preferably, the illumination unit further includes at least one of a pupil and a filter between the light source and the concentrating mirror.

According to some embodiments, the illumination unit may further comprise a mirror that directs light from the concentrating mirror to the detection prism. According to further embodiments, the detection prism may include a reflective surface that reflects the detection light entering the detection prism and directs it to the detection surface.

The focal length of the condensing mirror is preferably no more than 25 mm.

Preferably, the glass surface stress meter further includes a light shielding cover, the illumination unit, the detection prism, and the imaging unit are housed in the light shielding cover, and the light shielding cover is formed with a detection hole, and the detection surface of the detection prism is from the The detection hole is extended. More preferably, the detection hole is located at the bottom of the light shielding cover, and a light shielding seal is disposed around the detection hole between the light shielding cover and the detecting prism. The distance from which the detection surface of the detection prism protrudes from the detection aperture is preferably adjustable.

Preferably, the imaging unit includes a first mirror, a lens group, a second mirror, an analysis mirror, and a photosensitive element disposed in sequence along the optical path, and the light shielding cover may be disposed through the light shielding cover to the first mirror Adjustments for position adjustment.

Preferably, the glass surface stress meter further comprises: a data processing unit disposed in the light shielding cover, the photosensitive element is electrically connected to the data processing unit; and formed on or supported by the surface of the light shielding cover a display unit on the cover, the display unit being electrically connected to the data processing unit for displaying the detected image.

Preferably, the imaging unit further includes a third mirror and a visual observation unit, the third mirror being disposed between the second mirror and the analysis mirror, which is capable of being in the first position and Rotating between two positions, in the first position, the third mirror directs light from the second mirror to the analysis mirror, and in the second position, the third mirror will come from the second The light of the mirror is directed to the visual observation unit, and the visual observation unit is exposed from the light shielding cover.

The glass surface stress meter according to the present invention concentrates light from a light source onto or near the detection surface of the detection prism by providing a condensing mirror, which contributes to an improvement in detection accuracy.

DRAWINGS

Other features, objects, and advantages of the present application will become more apparent from the detailed description of the accompanying drawings.

1a is a partial schematic view of a prior art glass surface stress meter for detecting curved glass;

Figure 1b is a partial schematic view of a prior art glass surface stress meter for detecting flat glass;

2a is a partial schematic view of a glass surface stress meter for detecting a curved glass according to an embodiment of the present invention;

2b is a partial schematic view of a glass surface stress meter for detecting a flat glass according to an embodiment of the present invention;

3 is a schematic structural view of a glass surface stress meter according to a first embodiment of the present invention;

4 is a schematic structural view of a glass surface stress meter according to a modification of the first embodiment;

Figure 5 is a schematic structural view of a glass surface stress meter according to another modification of the first embodiment;

Figure 6 is a schematic view showing the structure of a glass surface stress meter according to a second embodiment of the present invention.

detailed description

The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It is understood that the specific embodiments described herein are merely illustrative of the invention, and are not intended to be limiting.

2a and 2b respectively show partial schematic views of a glass surface stress meter for detecting curved glass and flat glass according to an embodiment of the present invention. As shown, the glass surface stress meter according to the present invention adds a concentrating mirror 12 for concentrating the light beam after the light source 11. The light emitted by the light source 11 passes through the convergence of the condensing mirror 12, optionally through the inverse of the mirror 13 Shot, incident detection prism 20. The light is focused on or near the detecting surface 20a of the detecting prism 20. The glass surface stress meter according to the present invention is placed on the glass such that the detecting surface 20a of the detecting prism 20 is attached to the glass surface. A suitable index matching medium, such as a matching solution or gel, can be applied between the detection prism 20 and the glass surface. Light from the light source is focused by the concentrating mirror to the abutment (e.g., contact point 30a with the curved glass) such that light is totally reflected at the junction between the detection surface and the surface of the glass being inspected. The totally reflected light carries information on the glass birefringence capability of the glass surface stress and can be detected by subsequent imaging units.

In accordance with the present invention, a concentrating mirror in a glass surface stress meter converges light from a source, typically a diverging beam, onto or near the detection surface of the detection prism. When detecting curved glass, focus the beam on where the detection surface fits the glass surface. This ensures that the light incident on the illuminating surface contains as many rays as possible with an incident angle satisfying the total reflection condition, and the accuracy of the stress detection result is improved. When detecting flat glass, the glass surface stress meter according to the present invention can better adapt to the case where the refractive index change caused by the glass surface stress is large. In addition, this helps to reduce the influence of scratches or smudges on the detection surface of the detecting prism on the detection result.

Embodiments of the invention are described in detail below.

3 is a schematic view showing the structure of a glass surface stress meter according to a first embodiment of the present invention. The illustrated glass surface stress gauge includes a lighting unit, a detection prism 200, and an imaging unit.

As shown in FIG. 3, the glass surface stress meter according to the present invention may further include a cover 400, and the cover is preferably a light shielding cover. The light shielding housing 400 houses the above-described illumination unit, detection prism, and imaging unit that shields stray light from the outside to define the shape of the stress gauge.

As shown in FIG. 3, the illumination unit includes a light source 101, a diaphragm 102, a color filter 103, a condensing mirror 104, and a mirror 105 which are sequentially disposed.

For the convenience of energy saving and power supply voltage, the light source 101 used by the lighting unit is preferably an LED light source. In the present embodiment, an aperture 102 is provided for adjusting the light intensity. If the light intensity of the light source 101 is appropriate, the diaphragm may not be used. The color filter 103 may be, for example, an interference filter for purifying light emitted from the light source to improve detection accuracy. If the monochromaticity of the light source 101 satisfies the requirement of detection accuracy, the filter 103 may not be used. In this embodiment, the light source 101 is, for example, an LED white light source, and passes through the aperture 102 and the filter. The mirror 103 adjusts and improves the characteristics of the light for detection, thereby ensuring the detection accuracy.

Condenser 104, as already discussed above with respect to Figures 2a and 2b, is formed and arranged to focus light from the source onto or near detection surface 200a of detection prism 200. The condensing mirror 104 can be constituted, for example, by a convex lens. The focal length of the condensing mirror and the object distance and the image distance are calculated by the optical path such that the light enters the prism and converges on or near the detecting surface of the detecting prism, so that the optical detecting surface is small. In order to reduce the volume of the entire device, the focal length of the concentrating mirror is preferably no more than 25 mm.

In the optical path before the light enters the detecting prism 200, the mirror 105 can be selectively disposed for folding the optical path, thereby reducing the overall volume of the stress meter. The invention is not limited to the use or non-use of the mirror 105.

The detecting prism 200 may be a triangular prism, a rectangular prism whose incident surface is a circular arc shape, or the like. The detecting prism 200 shown in Fig. 3 is a square prism. The detecting prism 200 has a detecting surface 200a for bonding to the surface of the glass to be inspected. By filtering the light emitted from the light source, the light incident on the prism can be made into a monochromatic light, which reduces the adverse effect of the spectral width of the light source on the measurement after the detection light is emitted from the glass-prism interface. The incident angle of the light source is determined by scientific calculation, and the use of the detection prism with the corresponding parameters avoids the operator's selection in multiple steps and affects the measurement accuracy.

A detection hole 401 may be opened in the light shielding cover 400, and the detection surface 200a of the detection prism protrudes from the detection hole 401. Preferably, the distance from which the detecting surface 200a of the detecting prism protrudes from the detecting hole 401 is adjustable. For example, the exterior of the light-shielding cover 400 may have adjustment means connected to the detection prism 200 for adjusting the distance of the detection prism from the light-shielding cover. Further, preferably, the detecting hole 401 is located at the bottom of the light shielding cover, and a light shielding seal (not shown) is disposed around the detecting hole 401 between the light shielding housing 400 and the detecting prism 200 to prevent stray light from entering the detecting prism via the detecting hole 401. .

The imaging unit includes a lens group 301, an analysis mirror 302, and a photosensitive element 303 which are sequentially disposed in accordance with the optical path.

Preferably, the imaging unit may further comprise at least two mirrors. For example, as shown in FIG. 1, the imaging unit includes a first mirror 300a, a second mirror 300b, and a third mirror 300c. The first mirror 300a is placed between the detecting prism 200 and the lens group 301 and adjacent to the detecting prism 200 to reflect the light emitted from the detecting prism into the lens group 301. Second anti The reflecting surfaces of the mirror 300b and the third mirror 300c are oppositely disposed, and are disposed between the lens group 301 and the analyzing mirror 302 for guiding the light focused by the lens group 301 to the analyzing mirror 302, and then passing through the analyzing mirror. A photosensitive element 303 such as CCD/CMOS/PMT is imaged, and a step difference image of the surface stress of the reaction glass is exhibited on the photosensitive element. Preferably, the position of the first mirror 300a adjacent to the detecting prism 200 can be adjusted by the user via the adjusting member 300d, thereby adjusting the angle of the light entering the lens group 301, so that the critical angle of light passes through the lens group and is irradiated to the photosensitive member. On, a high quality step difference image is presented. The adjustment member 300d is preferably a screw to improve ease of use and adjustment accuracy.

The analysis mirror 302 can be realized, for example, by splicing two mutually perpendicular polarizing plates or by using one or more polarization beam splitting prisms.

A data processing unit (not shown) electrically connected to the photosensitive element 303 processes the step difference image to obtain a surface stress of the glass. The data processing unit can be implemented by a general purpose computer having data processing software, or by using a dedicated small data processor, such as a microcontroller, an FPGA, a CPLD, or the like. A small data processor can be integrated in the photosensitive element 303.

At this time, in order to intuitively let the user know the detection result, the glass surface stress meter may include a display unit formed on or protruding from the surface of the light shielding cover. The display unit may include a graphical image interface that displays the detection result, and controls a small data processor built into the detection device to perform physical or virtual keys such as initialization, clearing, calibration, fault detection, and the like. The display unit can be a touch display.

Alternatively, the third mirror 300c may be omitted, or the third mirror 300c may be a rotatable mirror.

Fig. 4 shows a glass surface stress meter according to a variant of the first embodiment, wherein the third mirror is arranged as a rotatable mirror. As shown in FIG. 4, the imaging unit further includes a visual observation unit 500. In this modification, the third mirror 300c is disposed between the second mirror 300b and the analysis mirror 302, and the visual observation unit 500 and the photosensitive unit 303 are conjugate with respect to the third mirror 300c. The third mirror 300c is rotatable between a first position and a second position. In the first position, the third mirror 300c directs light from the second mirror 300b to the analysis mirror 302, causing the photosensitive element 303 to perform image recording for electronic measurement, similar to the operation of the DSLR camera. In the second position, the third mirror 300c will be in the future The light from the second mirror 300b is guided to the visual observation unit 500 so that the result can be observed and manually calculated by the visual observation unit 45. The visual observation unit 500 is exposed from the light shielding cover 400.

Fig. 5 shows a glass surface stress meter according to another modification of the first embodiment, which is substantially the same as the glass surface stress meter according to the first embodiment, except that optionally included in the first embodiment The display unit formed on or protruding from the surface of the light-shielding cover is replaced by a separate display unit 600 supported on the light-shielding cover. Specifically, as shown in FIG. 5, the display unit 600 is supported on the light shielding cover 400 through the bracket 601, and is electrically connected to the aforementioned data processing unit. The display unit 600 may include a graphical image interface that displays the detection result, and controls a small data processor built into the detection device to perform physical or virtual keys such as initialization, clearing, calibration, fault detection, and the like. The display unit can be a touch display. Preferably, the display unit 600 is further integrated with a computing module for performing at least part of the data processing task.

It should be understood that the glass surface stress meter of the present invention is not limited to the particular function or configuration of the imaging unit described above. In particular, although the imaging unit includes the analysis mirror and the photosensitive element in the above first embodiment and its modifications, the glass surface stress meter according to the present invention may have any other suitable form of imaging unit. For example, the imaging unit may be simply implemented as a visual observation system for directly observing interference fringes generated by totally reflected light by the naked eye, may not include mirrors or include more or fewer mirrors, and the like.

6 shows a glass surface stress meter according to a second embodiment of the present invention, and the rest of the glass surface stress gauges according to the first embodiment are substantially the same, the main difference being that the mirror 105 is detected by the reflective surface in the prism 200. Replaced by 200b. Specifically, as shown in FIG. 6, after the light from the illumination unit enters the detecting prism 200, it is reflected at the reflecting surface 200b, thereby being guided to the detecting surface 200a of the detecting prism 200. The reflective surface 200b is preferably a lower bottom side of the detection prism 200. By integrating the mirror and the detecting prism, the space occupied by the entire optical path can be further shortened, miniaturization is achieved; at the same time, the mounting is simplified, and the detection due to the positional error of the mirror 105 with respect to the detecting prism is avoided. Reduced accuracy.

The present invention is not limited to the above embodiments, and various embodiments in the specification are for illustrative purposes only and do not limit the scope of the invention. Without departing from the scope of the invention In the case of the surrounding, various modifications and modifications can be made. Any omissions, substitutions or modifications made on the basis of the embodiments of the present invention will fall within the scope of the present invention.

Claims

A glass surface stress meter comprising:

a lighting unit comprising a light source;

a detecting prism having a detecting surface for adhering to a surface of the glass to be inspected for detection, and light incident from the illumination unit to the detecting prism is bonded at a position between the detecting surface and a surface of the glass to be inspected Total reflection; and

An imaging unit arranged to receive the outgoing light from the detection prism and form a detection image,

It is characterized in that

The illumination unit also includes a concentrating mirror formed and arranged to focus light from the source onto or near the detection surface of the detection prism.
The glass surface stress meter of claim 1 wherein said light source is a white LED light source.
The glass surface stress meter of claim 1 wherein said illumination unit further comprises at least one of a stop and a filter between said light source and said concentrating mirror.
The glass surface stress meter of claim 1 wherein said illumination unit further comprises a mirror that directs light from said concentrating mirror to said detecting prism.
A glass surface stress meter according to claim 1, wherein said detecting prism further comprises a reflecting surface that reflects light entering the detecting prism and guides it to said detecting surface.
The glass surface stress meter of claim 1 wherein said concentrating mirror has a focal length of no greater than 25 mm.
The glass surface stress meter according to any one of claims 1 to 4, further comprising a light shielding cover, wherein the illumination unit, the detecting prism and the image forming unit are housed in the light shielding cover, and the light shielding cover is formed There is a detection hole from which the detection surface of the detection prism protrudes.
The glass surface stress meter according to claim 7, wherein said detecting hole is located at a bottom of said light shielding cover, and between said light shielding cover and said detecting prism A light blocking seal is disposed around the detection hole.
A glass surface stress meter according to claim 7, wherein a distance from which the detecting surface of the detecting prism protrudes from the detecting hole is adjustable.
A glass surface stress meter according to claim 7, wherein said image forming unit comprises a first mirror, a lens group, a second mirror, an analysis mirror, and a photosensitive member which are sequentially disposed along the optical path, and which pass through the The light shielding cover may be provided with an adjustment member that adjusts the position of the first mirror.
The glass surface stress meter of claim 10, further comprising:

a data processing unit disposed within the light shielding housing, the photosensitive element being electrically coupled to the data processing unit; and

a display unit formed on a surface of the light shielding cover or supported on the light shielding cover, the display unit being electrically connected to the data processing unit for displaying the detection image.
A glass surface stress meter according to claim 10, wherein said imaging unit further comprises a third mirror and a visual observation unit, said third mirror being disposed between said second mirror and said analysis mirror Rotating between a first position in which the third mirror directs light from the second mirror to the analysis mirror, and a second position in which The third mirror directs light from the second mirror to the visual observation unit, the visual observation unit being exposed from the light shielding cover.