Photochromic spectacles

1. Technical Field

The present disclosure relates to photochromic spectacles powered by solar cell films thereof.

2. Description of Related Art

Photochromic spectacles are used for protecting the wearer's eyes against unwanted external light stimulation. However, typical photochromic spectacles need additional batteries to provide power, and this makes the photochromic spectacles bulky.

Therefore, it is desired to provide photochromic spectacles which can overcome the above mentioned problems.

FIG. 1 is an isometric view of photochromic spectacles including a pair of lenses, according to a first embodiment.

FIG. 2 is an enlarged, schematic cross-sectional view of one lens of FIG. 1 , the lens including an electrochromic film.

FIG. 3 is a schematic cross-sectional view of the electrochromic film of FIG. 2 .

FIG. 4 is a schematic cross-sectional view of one lens of photochromic spectacles according to a second embodiment.

FIG.5 is a functional block of the photochromic spectacles of FIG. 1 .

FIGS. 1-3 show photochromic spectacles 100 according to a first embodiment. The photochromic spectacles 100 are battery-free, and include a frame 10 , two lenses 20 arranged in the frame 10 , two arms 30 , a driving circuit 40 and a control switch 50 .

The lenses 20 each have a flat or curved surface, and can be vision corrective lenses or non-corrective lenses. Each lens 20 includes a substrate 21 , an electrochromic film 22 , and a solar cell film 23 . The substrate 21 is made of resin. In this embodiment, the electrochromic film 22 is sandwiched between the solar cell film 23 and the substrate 21 .

Referring to FIG. 3 , the electrochromic film 22 includes a first transparent conductive layer 221 , an ion storage layer 222 for providing positive ions, an electrolyte layer 223 , an electrochromic layer 224 and a second transparent conductive layer 225 layered in that sequence. The first transparent conductive layer 221 and the second transparent conductive layer 225 are made of transparent conductive glass, such as indium tin oxide. The ion storage layer 222 is a lithium metal layer for providing lithium ions. The electrolyte layer 223 transmits the positive ions provided by the ion storage layer 222 , for example, H + , Li + , or Na + . The electrolyte in the electrolyte layer 223 is LiClO 4 or LiBF 4 , in one example. The electrochromic layer 224 may be made of organic electrochromic material or inorganic electrochromic material. The organic electrochromic material can be selected from organic low molecular compound or organic polymer, such as polyaniline, viologen, phenazine, or the like. The inorganic electrochromic layer can be made of tungsten trioxide (WO 3 ) or a metal oxide. In this embodiment, the electrochromic layer 224 is made of WO 3 . If the electrochromic layer 224 is made of organic electrochromic material, the speed of chemical reaction is fast and the transition state is also fast accordingly.

The solar cell film 23 is a transparent film and arranged as an outer layer of the lenses 20 . The thickness of the solar cell film 23 is typically about 5 μm˜150 μm. The outer layer can be understood as the layer farthest from the wearer's eye when the spectacles are worn. The solar cell film 23 is configured for absorbing infrared light and ultraviolet light, and converting the infrared and ultraviolet light into electrical power. A size of a major face of the solar cell film 23 is substantially equal to a corresponding size of the substrate 21 . The solar cell film 23 is a dye-sensitized solar cell or a photosensitive plastic polymer battery. The dye-sensitized solar cell includes a transparent conductive glass, a color dye, and an electrolyte formed between the transparent conductive glass and the color dye. A light transmission rate of the dye sensitized solar cell is determined by a color of the color dye and a color of the electrolyte.

Because the solar cell film 23 is arranged as the outer layer of the lens 20 , the solar cell film 23 absorbs more sunlight to generate the needed power, and also helps prevent an excessive amount of ultraviolet light reaching the wearer's eye.

The driving circuit 40 is arranged on the frame 10 and electrically connected with the electrochromic film 22 and the solar cell 23 , as shown in FIG.5 . The driving circuit 40 includes a printed circuit board (PCB) 41 , a rechargeable battery 42 , and a central processing unit (CPU) chip 43 . The battery 42 and the CPU chip 43 are both arranged on the printed circuit board 41 . The battery 42 is used for storing the electric power generated by the solar cell film 23 . The driving circuit 40 is configured for providing the electric power generated by the solar cell film 23 to the electrochromic film 22 . The two arms 30 are connected with the frame 10 . The control switch 50 is arranged on one of the arms 30 and configured for switching the driving circuit 40 to provide or not provide power to the electrochromic film 22 .

The photochromic spectacles 100 are transparent indoors. When the photochromic spectacles 100 are used outdoors under strong sunlight, the solar cell film 23 absorbs the infrared light and the ultraviolet light from the sun, converts the light energy to electrical power, and stores the power in the battery. When a predetermined voltage difference is applied between the first transparent conductive layer 221 and the second transparent conductive layer 225 , the electrochromic film 22 gradually darkens and in this way the wearer's eyes are protected from ultraviolet light. Typically, the change from the transparent state to the dark state takes about ten seconds. When the voltage polarity is reversed, the electrochromic film 22 changes from dark to transparent. Thus, the color or translucency of the electrochromic film 22 can be changed between transparent and dark, and this realizes the function of a desired discoloration of the photochromic spectacles 100 .

Referring to FIG. 4 , a lens 201 of photochromic spectacles according to a second embodiment also includes a substrate 21 , a solar cell film 23 and an electrochromic film 22 . The substrate 21 is sandwiched between the solar cell film 23 and the electrochromic film 22 . The photochromic spectacles of the second embodiment having two of the lenses 201 are similar to the photochromic spectacles 100 of the first embodiment.

It is to be understood that even though numerous characteristics and advantages of the present embodiments have been set forth in the foregoing description, together with details of the structures and functions of the embodiments, the disclosure is illustrative only, and changes may be made in detail, especially in the matters of shape, size, and arrangement of parts within the principles of the disclosure to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.