BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram of a prior art UV detection device.
FIG. 2 is a diagram of resistance variation of a photosensitive resistor shown in FIG. 1.
FIG. 3 is a diagram of a ray-intensity detection device in accordance with a first embodiment of the present invention.
FIG. 4 is a diagram of a decision module in accordance with the present invention.
FIG. 5 is a diagram of a mobile communications device capable of detecting intensity of rays in accordance with a second embodiment of the present invention.
DETAILED DESCRIPTION
Please refer to FIG. 3, which illustrates a ray-intensity detection device 300 according to a first embodiment of the present invention. The ray-intensity detection device 300 is utilized for detecting intensity of specific rays, and comprises a housing 302, a filter lens 306, a photosensor 308, and a decision module 310. The housing 302 includes a hole 304 used for installing the filter lens 306. The filter lens 306 filters rays having wavelengths within a specific range, such as UV rays and infrared rays. As shown in FIG. 3, the photosensor 308 is installed at a position corresponding to the hole 304 inside the housing 302. The photosensor 308 can receive rays passing through the filter lens 306, and generate a corresponding current I. The decision module 310 determines ray intensity according to the current I generated by the photosensor 308. For example, if the intensity of UV rays is needed to be detected, a wavelength range of rays capable of passing through the filter lens 306 can be set as 200 nm to 400 nm since the wavelength range of UV rays is 200 nm to 400 nm. Therefore, only UV rays can pass through the filter lens 306. On the other hand, the photosensor 308 can generate currents corresponding to intensities or wavelengths of received rays. As a result, the present invention can determine intensity of UV rays according to the current I with the decision module 310.
Therefore, in the ray-intensity detection device 300, the filter lens 306 can filter specific rays, and the photosensor 308 can generate the current I accordingly. Then, the decision module 310 determines the intensity of rays according to the value of the current I. Notice that, there is no limitation of implementations of the decision module 310 as long as the intensity of rays can be determined according to the current I. For example, please refer to FIG. 4, which is a diagram of a decision module 400 according to an embodiment of the present invention. The decision module 400 is utilized for realizing the decision module 310 shown in FIG. 3, and includes a resistor 402, a voltage controlled oscillator (VCO) 404, a frequency decision unit 406, and a ray-intensity decision unit 408. When the current I generated by the photosensor 308 passes through the resistor 402, the resistor 402 generates a corresponding voltage V to the VCO 404. The VCO 404 outputs an oscillation signal Vsin to the frequency decision unit 406, and varies the oscillation frequency of the oscillation signal Vsin according to the voltage V. The frequency decision unit 406 determines the frequency of the oscillation signal Vsin, and outputs a result to the ray-intensity decision unit 408. Then, according to the frequency of the oscillation signal Vsin, the ray-intensity decision unit 408 can determine the intensity of rays according to a preset table. Therefore, operations of the decision module 400 can be concluded as follows: the resistor 402 generates the voltage V according to the current I generated by the photosensor 308 in FIG. 3, the VCO 404 generates the oscillation signal Vsin with a frequency corresponding to the value of voltage V, the frequency of the oscillation signal Vsin is then obtained through the frequency decision unit 406, and finally, the intensity of rays can be determined by the ray-intensity decision unit 408 according to the frequency of the oscillation signal Vsin.
Therefore, the ray-intensity detection device 300 shown in FIG. 3 can determine ray intensity precisely with the high-sensitivity VCO 404 of in the decision module 400. That is, the present invention can detect ray intensity without using photosensitive resistors, and thus decrease detection time. In addition, the ray-intensity detection device 300 can further comprise an output module 320, an alarm module 330, or a calibration module 340. The output module 320 is used for outputting corresponding signals through a screen 322 or an indicating light 324 according to the result of the decision module 310 (or the decision module 400). The alarm module 330 is used for outputting an alarm signal when ray intensity determined by the decision module 310 (or the decision module 400) is greater than a preset value. The calibration module 340 is used for calibrating the decision module 310 (or the decision module 400).
Please refer to FIG. 5, which is a diagram of a mobile communications device 500 capable of detecting the intensity of rays according to a second embodiment of the present invention. The mobile communications device 500 can be any mobile communications device, such as a mobile phone or a personal digital assistant. The mobile communications device 500 includes a housing 502, a mobile communications module 504, an image reception device 506, a filter lens 510, and a decision module 512. The housing 502 includes a hole for installing the image reception device 506. The image reception device 506 includes a lens 508, a photosensor 507, and an image processing circuit 509. The lens 508 is installed on the hole of the housing 502, and is utilized for generating images on the photosensor, which generates currents corresponding to red, blue, or green lights accordingly. The image processing circuit 509 then outputs an image according to the currents generated by the photosensor. The filter lens 510 can be switched on the lens 508 to filter rays having wavelengths within a specific range, such as UV rays, infrared rays, etc. For example, if the intensity of UV rays is going to be detected, a wavelength range of rays capable of passing through the filter lens 510 can be set as 200 nm to 400 nm since the wavelength range of UV rays is 200 nm to 400 nm. As a result, only UV rays can pass through the filter lens 510 after the filter lens 510 is switched on the lens 508. Therefore, rays focused on the photosensor are UV rays. Then, the decision module 512 determines the intensity of UV rays according to the current generated by the photosensor. The decision module 512 can be realized as the decision module 400 shown in FIG. 4. In the decision module 400, the VCO 404 and the frequency decision unit 406 can be replaced by circuits in a transceiver of the mobile communications device 500.
Moreover, the mobile communications module 504 comprises a central processing unit (CPU) 514 and a storage device 516. The storage device 516 stores program code 518 executed by the CPU 514. The program code 518 comprises steps for detecting the intensity of rays with the decision module 512 when the filter lens 510 is switched on the lens 508. Besides, according to the result of the decision module 512, the program code 518 can further include steps for outputting corresponding signals (such as sound, flash, or numbers), and adjusting brightness of a screen 519 of the mobile communications device 500 for saving power. Furthermore, the program code 518 can include steps for outputting an alarm signal when the result of the decision module 512 is greater than a preset value, or transmitting the information (such as exposure time and amount) to a health management center through the mobile communications module 504 for providing statistic data and reference information. Certainly, the mobile communications device 500 can also include a built-in or extra calibration module 540 for calibrating precision of the decision module 512.
As mentioned above, owing to the invisibility of UV rays, people may suffer from too much exposure to UV rays on a cloudy day or even indoors. In addition, some lamps also emit UV rays, so UV threats are everywhere in our daily life. So, if UV rays can be detected anytime and anywhere, people can protect themselves at the right moment, so as to prevent UV threats. However, the prior art cannot precisely and instantaneously detect the intensity of UV rays due to the long recovery time of the photosensitive resistor. In comparison, the present invention detects the intensity of UV rays using a filter lens for filtering specific rays, a photosensor for generating current corresponding to intensity of the specific ray, and a high-sensitivity voltage controlled oscillator. In addition to the intensity of UV rays, the intensities of other rays can also be detected (such as infrared rays) bye switching appropriate filter lens.
Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.
Patent Application
20080083879
