JPH02159272A - Protective glasses - Google Patents

Abstract

PURPOSE:To obtain protective glasses free from erroneous operation by equipping the glasses with an ultraviolet ray detection means for detecting ultraviolet rays having a predetermined wavelength or less to output the detection result and a light shield means for limiting the incidence of light to the eye of a wearer according to the output from the ultraviolet detection means. CONSTITUTION:Protective glasses 1 are constituted of a liquid crystal type light shield part 2 and an ultraviolet detection part 3 and ultraviolet detection elements 3a, 3b are provided to the ultraviolet detection part 3 and emit signals, for example, when light having a wavelength of 270nm or more is incident in predetermined quantity or more. Further, a filter 3c for shielding a part of light is provided to the front surface of the element 3b. When welding work is carried out, the ultraviolet detection elements 3a, 3b detect ultraviolet rays to generate detection signals and the application of voltage to liquid crystal films 2a, 2b is eliminated and the protective glasses 1 become the most light-impermeable state and an eye is not damaged. When ultraviolet rays generated from other worker are incident to an eye and the protective glasses 1 become a light shielding state, a pitch-dark dangerous state is developed. In this case, the ultraviolet rays incident to the ultraviolet detection element 3b are attenuated by the filter 3c and the element 3b detects no ultraviolet rays and ultraviolet rays are attenuated to a degree imparting no damage to an eye.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to protective eyewear.

[Prior art]

For example, when electric welding such as arc welding or acetylene welding is used to weld iron plates or the like using a burner, a large amount of infrared rays, visible light, and ultraviolet rays are generated from the welded portion.

Since these light rays are harmful to human eyes, welders use protective goggles for welding work to protect their eyes during welding work.

However, such protective goggles for welding work have very low light transmittance so that they can completely protect the eyes, and they cannot see anything other than the welding part. Therefore, if you are wearing these protective goggles for welding work, you will have to rely on your intuition to get the welding rod close to the welding part without being able to see at all until welding starts. , making the work extremely difficult. Therefore, many workers began welding without using protective goggles. Therefore,
There was a risk of eye injury due to the light emitted from the welded parts, especially ultraviolet rays.

Therefore, in order to prevent such accidents from occurring, various measures have been devised. For example, a visible light sensor made of cadmium sulfide (CdS) detects strong visible light emitted from a welding part, and then mechanically welds a protective surface placed above the welder's head in response to the detection output signal. It can be moved to the front of the worker's face to prevent light from the welding part from entering the eyes directly, and lead sulfide (PbS) can be moved to the front of the worker's face.
) can be used to detect the strong infrared rays emitted from the welded part, and based on the detection results, the light transmittance of the liquid crystal can be changed to block the light.

[Problem to be solved by the invention]

Welding operations are usually performed under illumination (eg, tungsten bulbs, fluorescent lights) or sunlight. Tungsten light bulbs and fluorescent lamps emit light with an emission spectrum of about 300 nm or more, and sunlight that reaches the ground has an emission spectrum of about 270 nm or more. FIG. 3 shows the relationship between the wavelengths of these lights and the wavelengths of light emitted from the welded portion. As can be seen from Fig. 3, welding workplaces are filled with so-called visible light and infrared light. Therefore, when the visible light sensor and infrared sensor described earlier are operated in such an environment, even though the intensity of these lights from the welded part is high,
There is a strong possibility that the visible light sensor or infrared sensor may detect light from a source other than the welded part, causing the light shielding mechanism of the protective face, safety glasses, etc. to malfunction.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and provide protective eyewear that does not malfunction by using an ultraviolet sensor that detects ultraviolet light from a welded portion.

[Means to solve the problem]

In order to achieve the above-mentioned problems, the protective glasses of the present invention include an ultraviolet detection means for detecting ultraviolet light of a predetermined wavelength or less and outputting the detection result, and an ultraviolet light detection means for detecting ultraviolet light at a wavelength below a predetermined wavelength and outputting the detection result to the wearer's eyes according to the output from the ultraviolet detection means. and a light shielding means for restricting the incidence of light.

[Effect]

The protective goggles of the present invention are configured as described above, and are provided with means for detecting only ultraviolet rays of a predetermined wavelength or less, and the light blocking means of the protective glasses are driven in accordance with the output of this detecting means. This makes it possible to prevent malfunctions.

〔Example〕

Embodiments according to the present invention will be described below with reference to the drawings.

Elements with the same symbol have the same function! IIw
The explanation of L is omitted.

FIG. 1 shows a schematic configuration of an embodiment of a protection Ui mirror according to the present invention.

As shown in FIG. 1, the protection 1a mirror 1 of this embodiment is composed of a liquid crystal light shielding section 2 that emits light at the speed of incident light, and an ultraviolet detection section 3 for detecting ultraviolet rays. Furthermore, this protection g! The i-mirror 1 is provided with a mounting part 4 configured to allow an operator to wear the glasses on a container. Figure 2 (
Figure a) shows the internal structure of the liquid crystal type light shielding part. As shown in this figure, the liquid crystal type light shielding part 2 is constructed by overlapping liquid crystal films 2a and 2b in double layers.
The light transmittance is low when the applied voltage is less than a predetermined voltage, and the light transmittance is high when the applied voltage is higher than the predetermined voltage. This liquid crystal film can be individually applied with a voltage. And such a liquid crystal film is 1/
It can react in about 1000 seconds. Like this 2
Two liquid crystal pA2 a-.

2b is used so that the light transmittance of the light shielding part 2 can be adjusted in three stages as described later.

On the other hand, the ultraviolet detection section 3 has two
Two ultraviolet detection elements 3as3b are provided, and the ultraviolet detection elements 3a and 3b have a wavelength of, for example, 270 nm.
It is configured to output a signal when a predetermined amount or more of the following light is incident.

Examples of such sensors include an ultraviolet phototube with a Cs-1 photocathode and a spectral sensitivity of 200 nm or less, and a UVt manufactured by Hamamatsu Photonics with a spectral sensitivity of 250 nm or less.
There is ron (registered trademark).

Of the ultraviolet light generated during welding, those with a wavelength of 200 nm or less are easily absorbed by air and attenuated. Therefore, it is more preferable to use a UVtron sensitive to ultraviolet light having a wavelength of 200 nm to 250 nm. FIG. 3 shows the spectral sensitivity characteristics of this trvtron. However, this ultraviolet detection element is not limited to this UVtron, and other ultraviolet detection sensors can also be used.

Furthermore, this ultraviolet detection section 3 includes this ultraviolet detection element 3a.
, 3b is provided with a filter 3C that blocks part of the incident light in front of the light detection section of one of the elements 3b, and by the action of this filter 3C, the sensitivity of the ultraviolet detection element 3b is changed to the sensitivity of the other ultraviolet detection element 3a. It is lower than that. By providing a filter only on the front surface of one ultraviolet detection element 3b in this way, three-stage detection becomes possible.

This ultraviolet detection section 3 includes an ultraviolet detection element 3a.

A light-shielding tube 7 for limiting the direction of incidence of ultraviolet rays on the ultraviolet rays 3b is provided on the front surface of the ultraviolet detecting element 3a s 3b. This light shielding tube 7
The ultraviolet detection element 3 a s 3 b detects only the ultraviolet rays in the direction that enters the worker's eyes when wearing the protective goggles.
Make the shape so that it can be detected.

The reason for having this configuration is that, for example, if a worker wearing protective goggles is blocked by ultraviolet rays that do not directly enter the eyes, the area in front of the eyes will suddenly become completely dark, which can be extremely dangerous. It is a danger. Therefore, the protective goggles are prevented from entering the light-blocking state in a state that does not cause any harm to the eyes of the worker wearing the protective goggles.

Furthermore, the protective glasses 1 include the ultraviolet detection element 3a described above.
, 3b, a control section 8 that controls voltage application to the liquid crystal film 2a s2b, and a power supply section 9 that supplies electricity to the control section 8, the light shielding section 2, and the ultraviolet detection section 3 are connected to the mounting section 4. It is set in. The control section 8 is electrically connected to the ultraviolet detection elements 3as and 3b and the electric terminals of the liquid crystal films 2a and 2b.

Next, the operation of the protective eyewear 1 of the above embodiment will be explained.

When a worker wearing the protective goggles 1 of the above embodiment performs welding work, both of the ultraviolet detection elements 3as and 3b detect the ultraviolet rays due to the strong ultraviolet rays emitted from the welding part and generate a detection signal. Then, depending on this detection signal,
No voltage is applied to both of the two liquid crystal films 2a and 2b, and the protective glasses 1 are in a state where no light is transmitted through them. As a result, the welding operator can perform welding work while directly looking at the welded part without causing eye problems.

On the other hand, even when the welding worker wearing the protective goggles 1 does not directly look at the welding part, ultraviolet rays generated by other workers' welding work may enter the eyes. In such a case, if the safety goggles 1 reach the state where they block the most light, it will be pitch black in front of the eyes, and the worker who was doing work other than welding may not be able to continue working, resulting in a dangerous situation. be. In such a case, only the ultraviolet detection element 3a detects ultraviolet light and generates a signal. In other words, in such a state, very strong ultraviolet rays do not enter the ultraviolet detecting element, so the ultraviolet rays incident on the ultraviolet detecting element 3b are filtered through the filter 3C.
Therefore, the ultraviolet light detection element 3b does not detect the ultraviolet light. Therefore, in response to the detection signal only from the ultraviolet detection element 3a, voltage application to only one of the liquid crystal films 2a and 2b is eliminated. As a result, the protective eyewear 1 becomes an intermediate light transmitting state. Therefore, the ultraviolet light that enters the eyes of the worker wearing the protective goggles 1 is attenuated to the extent that it does not harm the eyes, and as a result, the eyes are protected and the worker's field of vision becomes slightly darker. can continue working while wearing safety glasses.

Further, when there is little or no ultraviolet rays incident on the eyes of the worker wearing the protective goggles 1, neither the ultraviolet detecting elements 3a nor 3b generates a detection signal, and the two liquid crystal films 2a% 2b A voltage equal to or higher than a predetermined voltage is applied. In this case, the light transmittance of the protective glasses ml is at its maximum, and the worker can perform normal work while wearing the protective glasses.

The present invention is not limited to the above embodiments, and various modifications may be made.

For example, in the protective glasses of the above embodiment, two ultraviolet detection elements are used to switch the light transmittance in three stages.
However, the light transmittance may be switched in three or more stages depending on the detection output level of the 12 ultraviolet detection elements.

In addition, the protective glasses of the above embodiment use two liquid crystal films to change the light transmittance to three levels, but a liquid crystal film or the like is used that can change the light transmittance to three or more levels depending on the applied voltage. In that case, there is no need to provide more than one.

Furthermore, in the protective glasses of the above embodiment, a light-shielding tube is provided as a means for restricting the incident direction of ultraviolet rays to be detected, and furthermore, three
Although the light transmission band changing mechanism is provided in stages, only one of them may be provided.

Furthermore, although the above embodiment describes protective eyewear that protects the eyes from ultraviolet rays generated during welding work, the present invention is not limited to such use, and can also be applied to sunglasses, etc., for example.

〔Effect of the invention〕

As described above, the protective glasses of the present invention can effectively protect the eyes from ultraviolet rays and the like, and can protect the eyes without malfunction.

In particular, by using it during welding work, the eyes of the welder can be effectively protected.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a schematic configuration of protective glasses according to the present invention,
FIG. 2 is a diagram showing the configuration of the light shielding part and ultraviolet detection part of the protective glasses shown in FIG. 1, and FIG. 3 is a diagram showing the spectrum of light existing in a welding workplace and the spectral sensitivity characteristics of UVtron. 1... Safety glasses, 2a, 2b... Liquid crystal film, 2...
Light-shielding part, 3... Ultraviolet detection part, 3a, 3b... Ultraviolet detection element, 4... Mounting part, 7... Light-shielding tube. Light shielding part Figure 1 (b) Ultraviolet detection part Figure 2

Claims (3)

[Claims] 1. Protection including an ultraviolet detection means that detects ultraviolet rays having a predetermined wavelength or less and outputs the detection result, and a light shielding means that limits the incidence of light to the wearer's eyes according to the detection output from the ultraviolet detection means. glasses. 2. 2. The protective eyewear according to claim 1, wherein the amount of light transmitted through the light blocking means is controlled based on the amount of ultraviolet rays detected by the ultraviolet detecting means. 3. The protective eyewear according to claim 1 or 2, wherein the ultraviolet detection means detects light having a wavelength of less than 270 nm.