BACKGROUND OF THE INVENTION

1. Field of the Invention

[0001] The present invention relates to eyewear. More specifically, the present invention relates to eyewear including electrochromic lenses with automatic and manual control of lens tint.

2. Description of the Related Art

[0002] Sunglasses are eye glasses with lenses that are tinted to protect the eyes of one wearing them from unwanted ultraviolet (UV) radiation, sunlight, or glare. Although some styles of sunglasses have interchangeable lenses, most sunglasses include lenses with a fixed or permanent tint. On the other hand, eye glasses with adaptive or transition lenses are also popular.

[0003] Some styles of adaptive eye glasses have photochromic lenses that are self- adjustable and usable as sunglasses. A photochromic lens changes its degree of tint or light absorbing property based on the level of ambient light or UV radiation. That is, a photochromic lens will darken as the degree of ambient UV increases and will begin to clear in the absence of UV light. Eye glasses with these photochromic lenses are cost effective and convenient because it saves one with a prescription from having to carry two sets of eye glasses (one clear and one tinted) and from switching back and forth each time they go outside and back indoors.

[0004] However, photochromic lenses have long reaction times and are relatively slow to change the degree of tint. For example, it may take several minutes for a photochromic lens to change from clear to full dark and vice versa. Someone moving from bright sunlight outside into a building or a driver passing into a tunnel, while wearing photochromic glasses would remain "in the dark" for some time with full-dark tint. Also, the photochromic reaction further slows down in colder temperatures. Thus, photochromic lenses will take even longer than normal to transition during winter or cooler weather. Additionally, photochromic lenses do not darken as well inside cars. Auto glass has UV protection, which can prevent UV light from causing photochromic lenses to transition. Under these conditions, the transitioning of photochromic lenses is slow and entirely outside the control of the wearer. Also, the degree of light transmission cannot be manually adjusted, depending only on the degree of ambient UV radiation.

[0005] Electrochromic lenses were developed in an attempt to overcome these problems of photochromic lenses. Electrochromic materials change color or opacity in response to an applied voltage, which may be a small DC voltage. Electrochromic materials can include liquid crystals, metal oxides, polymers, or other materials that respond to an applied voltage with a change in color or opacity. As the color change is persistent and energy need only be applied to affect a change, electrochromic materials are used to control the amount of light and heat allowed to pass through a glass surface as a switchable filter. Electrochromic glass has been used in applications such as skylights, windows for architecture or airplanes, flash suppression for welding helmets, electronic information displays, ski goggles, motorcycle helmet visors, automotive mirrors, and "smart" sunglasses. In these applications, switching between various tinted states can be done by a manual switch or automatically controlled using feedback from an ambient light sensor.

[0006] Existing eyewear with electrochromic lenses allows for faster response and manual voltage control of the tint, but have not been commercially successful as it is not always practical or safe to manage tint control manually. For example, manual control is cumbersome as one cannot see the control mechanism while wearing the glasses. Additionally, touch control does not always work well when the wearer is also wearing gloves.

[0007] Light-sensor based solutions have attempted to solve these problems but have failed because these solutions rely solely on ambient light to set the tint of the lenses. For example, a light sensor located on the eye glass frame may be blocked or covered by the bill of a hat or a roof of a motor vehicle. When inside a motor vehicle, light sensors cannot distinguish if a wearer is looking outside, at the dash board, or reading a map.

[0008] In autonomously driven vehicles with in-car entertainment, drivers and passengers can have multiple head positions for driving, watching scenery, viewing an entertainment console, reading, or operating a mobile device while traveling. Wearing sunglasses at nighttime is in vogue for celebrities especially while attending concerts or stage shows or while dining out. In these situations, the wearer might want to look down to check the time, read a menu, etc. In these situations, a reading by the ambient light sensor can misrepresent the actual use or instantaneous needs of wearer's electrochromic eyeglasses and cause an inappropriate tint on the lenses.

SUMMARY OF THE INVENTION

[0009] To overcome the problems described above, preferred embodiments of the present invention provide eyewear including electrochromic lens(es) with automatic and manual control of the shade or tint.

[0010] According to a preferred embodiment of the present invention, eyewear includes an electrochromic lens, a gyro sensor that outputs a gyro signal corresponding to an angle of the eyewear with respect to a fixed horizontal plane that is perpendicular to a vertical axis, and control circuitry that controls a tint level of the electrochromic lens. The eyewear has multiple control modes, and the control circuitry automatically controls the tint level of the electrochromic lens based on the gyro signal in an automatic mode.

[0011] The eyewear can further include a light sensor that outputs a light signal corresponding to ambient light, wherein the control circuitry automatically controls the tint level based on the light signal. The gyro signal can additionally correspond to a speed of the eyewear.

[0012] The eyewear can further include a hinge switch that turns on and off the control circuitry. The eyewear can further include a tactile switch that when activated causes the control circuitry to disable automatic control of the tint level and allows a user to manually control the tint level in a manual mode. The control circuitry can disable the manual mode and enables the automatic mode after a preset period. The manual mode can include darkening and lightening the tint level.

[0013] The tint can be darkened as the angle of the eyewear with respect to the fixed horizontal plane increases, and the tint can be lightened as the angle of the eyewear with respect to the fixed horizontal plane decreases. The eyewear can further include a frame, two temples, and two electrochromic lenses. The control circuity can be powered by a battery that is charged using a thermoelectric generator. The battery can be charged using an external heating device located adjacent to the thermoelectric generator. The control circuity can include a storage device that stores configuration data and a look up table. The configuration data can include programmable operation parameters.

[0014] The above and other features, elements, characteristics, steps, and advantages of the present invention will become more apparent from the following detailed description of preferred embodiments of the present invention with reference to the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figs. 1 and 2 show examples of eyewear according to a preferred embodiment of the present invention.

[0016] Fig. 3 shows a functional block diagram of eyewear according to a preferred embodiment of the present invention.

[0017] Fig. 4 shows a circuit block diagram of eyewear according to a preferred embodiment of the present invention.

[0018] Fig. 5 shows an example of viewing zones according to a preferred embodiment of the present invention.

[0019] Fig. 6 is a chart showing interaction of operating modes according to a preferred embodiment of the present invention.

[0020] Figs. 7-9 are a flow charts for operating modes according to preferred embodiments of the present invention.

[0021] Fig. 10 shows a TEG module that can be used with the eyewear shown in Fig. 1.

[0022] Fig. 11 shows a thermoelectric generator using the TEG module shown in Fig. 10.

[0023] Fig. 12 shows a TEG module included in a temple of eyewear.

[0024] Fig. 13 shows optional locations of TEG modules included in eyewear.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS [0025] Eyewear can include one or two electrochromic lenses with an automatic control mode and a manual control mode. The automatic control mode will change the tint of the electrochromic lens(es) based on input from multiple sensors. The manual control mode will allow the wearerto change the tint of the electrochromic lens(es) in multiple steps using a control input.

[0026] Fig. 1 shows an example of eyewear 100 that includes a frame 110, two temples 120 attached to the frame 110, and two electrochromic (EC) lenses 130 in the frame 110. Although illustrated as eye glasses, the eyewear of preferred embodiments of the present invention can be goggles, a visor, a face shield, or any other suitable structure. Although eyewear with two lenses can be used, it is also possible to use eyewear with a single lens. Fig. 1 also shows a user control device in the form of a tactile switch 140 on the outside of the frame 120 that a wearer can activate to change operating modes, as described below. The tactile switch 140 can be a push-button switch, a rotary switch, a slide switch, a touch pad, a touch/proximity sensor, or any other suitable device that a wearer can access to switch between and to control the operating modes. The tactile switch 140 can be a device that a wearer can activate while wearing gloves.

[0027] Fig. 2 is a perspective view of a frame 210 where one of the two temples 220 further includes a control board 250 mounted inside of the temple 220 and a hinged switch 252. The control board 250 is used to mount electronics of control circuitry used to control the eyewear's operating modes. The control board 250 can include electronics on a substrate such as a printed circuit board, ceramic, resin, or any other suitable material. Optionally, the control circuitry can be made of a single encapsulated module. Optionally, the control circuitry can be mounted directly into a cavity in the temple 220. Optionally, the control circuitry can be mounted in the frame 210 or can be distributed in the frame 210 and one or both temples 220. Light sensor 253 can be located at any suitable location on the frame 210 in front of the EC lenses, and light sensor 254 can be located at any suitable location on either the frame 210 or one of temples 220 behind the EC lenses.

[0028] The hinged switch 252 can include a hinge used to connect the temple 220 to the frame 210 and to allow the temple 220 to rotate relative to the frame 210, between a collapsed or storage position and an open or deployed position. The hinged switch 252 can also include a switch that can be activated by rotation to turn off and on the control circuitry such that the switch is off or open when the temple 220 is in the closed position and on or closed when the temple 220 is in the open position. The hinged switch 252 can be located on either side of the frame 210. Optionally, two hinged switches 252 can be used, one each on both sides of the frame 210, and can be dual-purposed or redundant.

[0029] Fig. 3 shows a functional block diagram of the eyewear 300. Fig. 3 shows that the eyewear 300 can include a main control board 310, an EC lens 330, a touch/proximity sensing board 340, sensors 350, a battery 362, and a thermoelectric generator (TEG) 364. The TEG 364 generates a voltage from a difference, for example, between the wearer's body temperature and the ambient temperature and stores energy in the battery 362 via a charging circuit 312. Optionally, the battery 362 can be charged by plugging into an external power source. The transparency or tint of the EC lens 330 can be controlled by a microcontroller unit (MCU) 314 that executes algorithms of a control process and by an H-bridge driver 316 that switches the polarity of the voltage that drives the electrochromic lens 330. As previously mentioned, a tactile switch as a touch/proximity sensor 342, a touch pad 344, or the like can be used by the wearer to control operation of the eyewear 300. Sensors 350 can include hinge switch 352, gyro sensor 354, and light sensor 356. The hinge switch 352 can detect the opened and closed position of the temple. The gyro sensor 354 can be mounted at any location on the eyewear 300 and can be used to sense the wearer's head movement. The light sensor 356 can be in front of and/or behind the EC lens 330 to measure the ambient light level.

[0030] Fig. 4 shows a circuit block diagram of the eyewear, with the broad arrows representing a power plane and the narrow arrows representing control functions. Fig. 4 shows that the TEG 464 generates a voltage to the charging circuit 412 that in turn stores energy in the battery 462, which powers the control circuitry of the eyewear. Power to the control circuitry is turned off and on by the hinge switch 452, as previously discussed. When power is turned on, the MCU 410 reads configuration data stored in a radio-frequency identification (RFID) device 472 or other memory. The configuration data is a way to personalize the wearer's experience by adjusting and saving operating parameters at the time of sale or during a future update. The configuration data can include parameters that control the tint transition rate, number of tint levels, the inclusion or not of different operating modes, the amount of time elapsed before the eyewear switches to an automatic mode from a manual mode, etc., as further described below. Once initialized, the MCU 410 reads data from the various sensors 450 and senses any input from the user control 440 provided by the tactile switch to determine which operating mode to execute. If needed, the MCU 410 can access data in a look up table (LUT) 474 stored on the RFID 472 or a different storage device to determine what polarity to set the H bridge driver 416 and what voltage to drive the EC lenses 430 to set the tint of the eyewear. There can be at least three levels of tint, but any number of tint levels is possible. [0031] Operating modes of the eyewear take into account different viewing zones of the eyewear as worn by a wearer to adjust the tint of the eyewear. Although more viewing zones are possible, Fig. 5 shows an example of three different viewing zones. The viewing zones 510, 520, and 530 are based on the viewing angle 560 as measured from a horizontal axis 540 that is perpendicular to a vertical axis 550 with a vertex at a virtual point of rotation 570 on the wearer's 500 head. Fig. 5 shows that Zone 1510 is on the horizontal axis 540 and represents the wearer 500 viewing forward scenes such as a landscape, a road, a stage, a bright sky, etc. In such conditions, the tint of the EC lenses of the eyewear would likely be at the darkest level.

Fig. 5 shows that Zone 2520 is at an angle down from the horizontal axis 540 and represents the wearer 500 with the eyewear 580 viewing downward scenes such as instrumentation or an illuminated dashboard when driving. The position of the eyewear 580 in Zone 2520 is tilted downward with respect to the position of the eyewear 580 in Zone 1510. In Zone 2520, the tint of the EC lenses of the eyewear 580 would likely be at a mid-level. Zone 2520 is defined by a plane that is tilted with respect to the horizontal plane of Zone 1510. Fig. 5 shows that Zone 3 530 is located below Zone 2520 and represents the wearer 500 with the eyewear viewing downward scenes such as reading material, a watch, a menu, a mobile device, etc. . The position of the eyewear 580 in Zone 3 530 is tilted downward with respect to the position of the eyewear 580 in Zone 2 520. In Zone 3 530, the tint of the EC lenses of the eyewear would likely be at the lightest level. Zone 3 530 is defined by a plane that is tilted with respect to the plane of Zone 2510.

[0032] Fig. 6 is a chart showing interaction of the eyewear's different operating modes. Although other modes are possible, Fig. 6 shows that the eyewear can include a Power Save Mode 610, a Mode Detect Mode 620, a Drive Mode 630, a Read Mode 640, and a Manual Mode 650. As described in detail below, the different arrows represent switching from one mode to a different mode.

[0033] In the Power Save mode 610, the hinge switch is open and the power is off so that all of the control circuitry in the eyewear is powered down. The tint of the EC lenses will be at the state they were in when the hinge switch was most recently opened and the power is off. When the hinge switch is turned on, the eyewear powers up into the Mode Detect Mode 620, represented by the gray arrow shown in Fig. 6, which is the default state when all sensors are active. The tint of the EC lenses will be at the state they were in when the power was most recently turned off. Upon power up in the Mode Detect Mode 620, the MCU reads the gyro sensor and the light sensor. The gyro sensor detects continuous movement of the wearer's head and computes the wearer's speed. The MCU compares this computed speed against a gyro sensor table in the LUT. If the speed is above a preset value, then the MCU activates the Drive Mode 630, represented by the blue arrow from the Mode Detect Mode 620 to the Drive Mode 630 in Fig. 6. The light sensors can be located in front of and behind the EC lenses and measures the amount of ambient light. For example, as shown in Fig. 2, light sensor 253 can be located in front of the EC lenses, and light sensor 254 can be located behind the EC lenses. The MCU compares a value based on the amount of sensed ambient light with a predetermined value in the LUT. If the sensed ambient light is below a preset value, the MCU activates the Read Mode 640, represented by the blue arrow from the Mode Detect Mode 620 to the Read Mode 640 in Fig. 6. If the speed is below the preset value and the ambient light is above the preset value, then the eyewear will remain in the Mode Detect Mode 620 until parameters change causing activation of another mode.

[0034] The Drive Mode 630 is an automatic control mode where the MCU continuously reads the light sensor and the gyro sensor and adjusts the tint of the EC lenses based on the light sensor and the gyro sensor outputs. The gyro sensor output can include data indicating the angle and acceleration in all axes. The Read mode 640 is an automatic mode where the MCU continuously reads the gyro sensor and adjusts the tint of the EC lenses based on the gyro sensor output. When eyewear is powered up, the wearer can switch the eyewear into the Manual Mode 650 at any time (red arrows), where the MCU ignores all sensor data. [0035] If at any time, the battery is out of charge or the control electronics cease to function, the tint of the EC lenses will remain at the state they were in when the battery runs out of charge.

[0036] Fig. 7 is a flow chart showing operation of the Drive Mode 630. In the Drive Mode 630, the control circuitry can continuously execute four separate control loops by reading the ambient light sensor, the gyro sensor, the hinge switch, and the tactile switch and can send a pulse-width modulation (PWM) signal to the H Bridge driver to supply voltage to the EC lenses to set the tint level. The PWM signal can include two parameters where the on-off ratio determines the tint transition rate and the length determines the level of tint. For example, in operation, when a wearer of the eyewear is driving an automobile and enters a road tunnel or a low light area, the visibility of the wearer is suddenly diminished. The eyewear can quickly and automatically adjust the light passing through the EC lenses of the eyewear. Also, while driving, if the wearer looks down to the vehicle dashboard, his watch, or a map, the EC lenses can automatically adjust to a lighter tint to increase readability.

[0037] In the left-side control loop of Fig. 7, the MCU compares the light sensor data with the ambient light table in the LUT and controls the EC lenses to adjust the tint transition rate. If both the ambient light and the pass-through light, i.e., the light passing through the EC lenses, are above a preset value, the EC lens tint is gradually switched to the darkest level. If the ambient light level drops by an amount more than a preset value within a preset time interval, the tint of the EC lenses is instantaneously switched to the lightest level. If the ambient light level is less than a preset value, the tint of the EC lenses is gradually switched to the lightest level. For example, instantaneous switching can be about one second, and gradually switching can take five seconds. Other options are possible, and the tint transition rate can be included as programmable configuration data.

[0038] In the middle control loop of Fig. 7, the MCU reads the gyro sensor to detect the speed and the viewing angle corresponding to a preset viewing angle range for each viewing zone described with respect to Fig. 5 and compares the detected viewing angle with predetermined viewing angle values in the LUT. If the viewing angle corresponds to "Zone 1," then the MCU controls the EC lenses to change to darkest level. If the viewing angle corresponds to "Zone 2," then the MCU controls the EC lenses to change to the middle level. If the viewing angle corresponds to "Zone 3," then the MCU controls the EC lenses to change to the lightest level. The MCU uses the gyro sensor data to automatically detect and enter the Drive Mode 630. Once in the Drive Mode 630, the MCU uses the ambient light sensor following the left-side control loop of Fig. 7. In a case where the gyro sensor data indicates the viewing angle is Zone 3, but the sensed ambient light is below the present value, the MCU will follow the control loop on the left side of Fig. 7.

[0039] In the right-side control loop of Fig. 7, the MCU reads the state of the hinge switch. If the hinge switch is transitioned to open or off, then the control circuitry is immediately powered down and returns to the Power Save Mode 610, as represented by the yellow arrow from the Drive Mode 630 to the Power Save Mode 610. In such a case, the tint of the EC lenses will be retained. In right-side control loop shown on the right at the bottom of Fig. 7, the MCU reads an interrupt caused by the wearer activating the tactile switch and switches operation to the Manual Mode 650 as represented by the red arrow from the Drive Mode 630 to the Manual Mode 650 shown in Fig. 6.

[0040] Fig. 8 is a flow chart showing operation of the Read Mode 640. In the Read Mode 640, the control circuitry can continuously execute three separate control loops by reading the gyro sensor, the hinge switch, and the tactile switch and sends a pulse-width modulation (PWM) signal to the H Bridge driver to supply voltage to the EC lenses to set the tint level. In the left-side control loop of Fig. 8, the MCU reads the gyro sensor to detect the viewing angle corresponding to a preset viewing angle range for each viewing zone described with respect to Fig. 5 and compares the detected viewing angle with predetermined viewing angles in the LUT.

If the viewing angle corresponds to "Zone 1," then the MCU controls the EC lenses to change to the darkest level. If the viewing angle corresponds to "Zone 2," then the MCU controls the EC lenses to change to the middle level. If the view angle corresponds to "Zone 3," then the MCU controls the EC lenses to change to the lightest level. When the wearer of the eyewear is in a low ambient light area, such as watching a concert, or just for stylishness, then the wearer may read a program, a menu, their watch, etc. In such cases, the eyewear quickly and automatically adjusts the tint of the EC lenses to allow more light to pass through and increase readability in a head-down viewing angle.

[0041] In the right side, top control loop shown of Fig. 8, the MCU reads the state of the hinge switch. If the hinge switch is transitioned to open or off, then the control electronics are powered down and returned to the Power Save Mode 610, as represented by the yellow arrow from the Read Mode 640 to the Power Save Mode 610. In the right side, bottom control loop of Fig. 8, the MCU reads an interrupt caused by the wearer activating the tactile switch and switches operation to the Manual Mode 650 as represented by the red arrow from the Read Mode 640 to the Manual Mode 650 shown in Fig. 6.

[0042] Fig. 9 is a flow chart showing operation of the Manual Mode 650. As previously mentioned, a wearer can cause the control electronics to enter the Manual Mode 650 at any time by activating the tactile switch. As shown in the control loop on the left side of Fig. 9, the MCU is in a waiting state that detects an interrupt caused by activation of the tactile switch. Once in the Manual Mode 650, the MCU disables all automatic control modes, including the Drive Mode 630 and the Read Mode 640, and allows the wearer to change the tint of the EC lenses in multiple steps using the tactile switch.

[0043] Once the Manual Mode 650 has been entered, the MCU determines which section of the tactile switch has been activated. If the darkening section of the tactile switch has been activated, the MCU will send a signal to the H Bridge to darken the tint of the EC lenses. The MCU may wait for a period, for example, two seconds, before sending a signal to transition the EC lenses to the next darkest tint. If the wearer continues to activate the darkening section of the tactile switch, the MCU will continue to step-wise transition the EC lenses to the darkest tint.

[0044] Likewise, if the lightening section of the tactile switch has been activated, the MCU will send a signal to the H Bridge to lighten the tint of the EC lenses. The MCU may wait for a period, for example, two seconds, before sending a signal to transition the EC lenses to the next lightest tint. If the wearer continues to activate the lightening section of the tactile switch, the MCU can continue to step-wise transition the EC lenses to the lightest tint. [0045] As shown in the middle control loop of Fig. 9, a countdown timer starts as soon as the MCU in interrupted by activation of the tactile switch. The countdown time is preset based on a predetermined configuration stored in the RFID or other storage device. Once the countdown time expires, the Manual Mode 650 is disabled and the control circuitry returns to the Mode Detect Mode 620 as represented by the green arrow from the Manual Mode 650 to the Mode Detect Mode 620 shown in Fig. 6. Optionally, rather than wait for the entire countdown, the MCU can be programmed to allow the wearer to directly enter one of the automatic mode via activation of the tactile switch or the like.

[0046] In the top, right-side control loop shown at the right side at the top of Fig. 9, the MCU reads the state of the hinge switch. If the hinge switch is transitioned to open or off, then the control circuitry is powered down and returned to the Power Save Mode 610, as represented by the yellow arrow from the Manual Mode 650 to the Power Save Mode 610 shown in Fig. 6.

[0047] Fig. 10 shows an example of a TEG module 1064 that can be used to generate electricity from the temperature difference between the wearer's body and the ambient temperature. The TEG module 1064 can include positive and negative terminals. The TEG module 1064 can be a micro-generation module that is capable outputting about 50 mV or more at a temperature difference of about 1.86°C or less. An output of about 50 mV can be used to change the tint of the EC lenses.

[0048] Fig. 12 is a representative cross section of a temple 1120 for eyewear that includes a TEG module 1164. As shown, the temple 1120 can include an outer portion 1122 that is thermally conductive and used to conduct heat away from the cool side of the TEG module 1164. The outer portion can include thermally conductive material such as a coiled metal such as aluminum, alloy, or another suitable material. Optionally, the thermally conductive material can be flat or plate shaped. The temple 1120 also can include an inner portion 1124 that contacts the wearer's head while the eyewear is worn. The inside portion can absorb heat from the wearer's head and transfer the heat to the hot side of the TEG module 1164. Additionally, as shown, the temple 112 can include a thermal insulator 1167 that thermally isolates the outer portion 1122 and the inner portion 1124 from each other to improve operation and efficiency of the TEG module 1164. The thermal insulator 1167 can include polyimide or any other suitable material.

[0049] Fig. 12 shows the TEG module 1264 located in the temple 1220 of the eyewear where the temple 1220 is in contact with the wearer's head, near the wearer's ear.

[0050] In addition to or instead of being located in the temple near the wearer's ear, it is also possible to locate the TEG module in the nosepiece of eyewear near the wearer's nose. Fig. 13 is a perspective view of eyewear that shows possible locations of TEG modules 1364 included in eyewear, as shown in temples 1320 and nosepiece 1335.

[0051] Optionally, an external heating pad can be provided that attaches to or is placed adjacent to a TEG module that uses the TEG module to charge the battery while the eyewear is not worn.

[0052] It should be understood that the foregoing description is only illustrative of the present invention. Various alternatives and modifications can be devised by those skilled in the art without departing from the present invention. Accordingly, the present invention is intended to embrace all such alternatives, modifications, and variances that fall within the scope of the appended claims.