Input device with photosensitive elements and method for inputting information thereby

A method for inputting information by an input device with photosensitive elements uses laser light to illuminate a target and two photosensitive elements to sense the time at which beams reflected by the target and then reflected respectively by rotatable first and second mirrors, and determines an included angle between a virtual connecting line of the target and the first mirror and a virtual connecting line of the first mirror and the second mirror and an included angle between a virtual connecting line of the target and the second mirror and the virtual connecting line of the first and second mirrors depending on the time, thereby calculating a coordinate of the target and taking it as relative input information, capable of saving the time for obtaining the target's coordinate and the production cost of the input device.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an information input device, and more particularly to an input device used for detecting a target's coordinate and taking it as input information.

2. Description of Related Art

A several information input devices detect a target coordinate and takes it as the input information of characters, patterns and symbols corresponding thereto, or takes it as input information of an interactive game machine.

Taiwan Patent No. 1303770 discloses an information input device, including a microprocessor electrically connected to an image capturing device; a mirror is placed in front of a lens of the image capturing device, thereby allowing the image capturing device captures a reference image reflected by the mirror. When the microprocessor detects the image capturing device capturing that a user touches the reference image of at least one input zone of an image, and then generate a corresponding input signal according to the image capturing device capturing that the user touches the input image of the input zones.

Taiwan Patent Publishing No. 200813785 discloses an image position interpretation device, utilizing first and second reflecting mirrors to respectively reflect a target image to at least one lens of a image capturing device, and the target image is respectively captured as first and second images by the lens. A microprocessor processes the first and second images to obtain a corresponding coordinate value in the scope of an input operating face, where a horizontal optical axis of at least one image capturing device is parallel to the input operating face.

U.S. Pat. No. 7,202,860 discloses a coordinate input device working with at least display screen and desk-top surface as the pointing areas thereof, including a pair of cameras positioned in an upper left position and an upper right position of a display screen of a monitor lying close to a plane extending from the display screen of the monitor and views both a side face of an object in contact with a position on the display screen and a predetermined desk-top coordinate detection area to capture the image of the object within the field of view. The coordinate input device also includes a control circuit which calculates the coordinate value of a pointing tool, pointing to a position within a coordinate detection field, based on video signals output from the pair of cameras, and transfers the coordinate value to a program of a computer.

SUMMARY OF THE INVENTION

To increase the speed of the detection and calculation of a target's coordinate and reduce the production cost of an input device, the present invention is proposed.

The main object of the present invention is to provide an input device with photosensitive elements and a method for inputting information thereby, utilizing laser light to illuminate a target, and sensing two beams respectively formed by reflecting a beam reflected from a target through rotatable first and second reflectors so as to obtain two included angles respectively formed between a virtual connecting line of the first reflector and the target and a virtual connecting line of the first reflectors and second reflectors, and between a virtual connecting line of the second reflector and the target and the virtual connecting line of the first and second reflectors thereby calculating a coordinate of the target and taking it as relative input information, ensuring that a target's coordinate acquiring speed can be increased.

Another object of the present invention is to provide an input device with photosensitive elements and an method for inputting information thereby, using two cheaper photosensitive instead of a rather expensive image capturing module, thereby saving the production cost of the input device.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention proposes an input device with photosensitive elements and a method for inputting information by means thereof; it uses laser light, visible light or infrared light or the like to illuminate a target, and utilizes two photosensitive elements to detect respectively the times at which a beam reflected from a target is reflected by rotatable first reflector and second reflector, thereby determine rotating a angles of the first reflector and second reflector and further calculating to obtain a target's coordinate and taking it as corresponding input information.

Referring toFIGS. 1,2and3, an input device1having photosensitive elements of the present invention includes a light reflecting or emitting structure10, a first reflector11, a second reflector12, a first motor13, a second motor14, a light emitting module15, a microprocessor16, a first photosensitive element17and a second photosensitive element18. The light emitting module15can be replaced with a first light emitting module151and a second light emitting module152. A rotating shaft131of the first motor13is coupled to the first reflector11, thereby driving the first reflector11to rotate. A rotating shaft141of the second motor14is coupled to the second reflector12, thereby driving the second reflector12to rotate. The microprocessor16is in wired or wireless connection with the first motor13, second motor14, first photosensitive element17and second photosensitive element18, and can detect signals emitted from the aforementioned photosensitive elements. The light emitting module15can emit planar light to illuminate a target2and the light reflecting or emitting structure10. The light emitted from the first light emitting module151and the second light emitting module152illuminates respectively the target2and the light reflecting or emitting structure10by means of the reflection of the first reflector11and the second reflector12. The target2is positioned between the light reflecting or emitting structure10and the first reflector11, second reflector12. The light emitted from the light reflecting or emitting structure10is weaker than the light emitted respectively from the first light emitting module151and the second light emitting module152, but stronger than the light reflected from the target2. The first motor13and the second motor14may also be respectively replaced with repeatedly first and second oscillating mechanisms

Under a condition without the light reflecting or emitting structure10, the microprocessor16can then detect to obtain the sensing signal outputting times of the first photosensitive element17and the second photosensitive element18when the first motor13, second motor14drive respectively the first reflector11and the second reflector12to rotate respectively to a specific angle thereby allowing beams21,22reflected from the target2to be respectively reflected to the first and second photosensitive elements17,18by the first and second reflectors11,12to cause the first and second photosensitive elements17,18to output sensing signals. Thereafter, the microprocessor16can then determine included angles θ1, θ2 respectively between a virtual connecting line S1of the target2and the first reflector11and a virtual connecting line S between the first reflector11and the second reflector12, and between a virtual connecting line S2of the target2and the second reflector12and the virtual connecting line S according to the rotating angles of the first and second motors13,14at that time, and then calculate a relative coordinate of the target2depending on the virtual connecting line S and the angles θ1, θ2, thereby taking it as input information corresponding to a position of the target2. The light emitting module15, first light emitting module151, second light emitting module152may respectively emit laser light, visible light or infrared light. The first and second photosensitive elements17,18may be a photosensitive element such as a photo detector, a photo diode, a photo receiver, a photo transistor and an object capable of the wired or wireless emission of light sensing signals.

The first light emitting module151and the second light emitting module152are respectively stacked with the first photosensitive element17and the second photosensitive element18. The beams emitting from the first light emitting module151and light emitting module152can be respectively reflected to the target2by the first reflector11and the second reflector12, then reflected to the first reflector11and second reflector12by the target2and further reflected to the first photosensitive element17and second photosensitive element18by the first reflector11and second reflector12owing to the far larger speed of light than the rotating speeds of the first reflector11and second reflector12when the first reflector11, second reflector12are rotated to a specific angle. Therefore, the first photosensitive element17and second photosensitive element18can still sense the beams21,22reflected from the target2.

Under a condition having the light reflecting or emitting structure10, the beams emitted from the first light emitting module151and second light emitting module152are respectively reflected to the light reflecting or emitting structure10by the first reflector11and second reflector12when they are not blocked by the target2, and then reflected respectively to the first reflector11and second reflector12by the light reflecting or emitting structure10, and further reflected to the first photosensitive element17and second photosensitive element18respectively by the first reflector11and second reflector12. Because the volume of the light reflecting or emitting structure10is larger and the light reflecting performance thereof is better than the target2or it can emit light brighter than the light reflected by the target2, the first photosensitive element17and second photosensitive element18can respectively sense continuous and brighter light and respectively emit stronger continuous signals. When the first reflector11, second reflector12are respectively rotated to a specific angle, causing the light emitted from the first light emitting module151and the second light emitting module152to be not respectively reflected to the light reflecting or emitting structure10but respectively reflected to the target2by the first reflector11and second reflector12and then reflected by the target2, or the light emitted from the light reflecting or emitting structure10is blocked by the target2, the first photosensitive element17and second photosensitive element18can only sense respectively weaker light. The microprocessor16outputs respectively the time at which the light is weakest depending on the first photosensitive element17and second photosensitive element18, and then calculate a relative coordinate of the target2as mentioned above depending on the rotating angles of the first motor13and second motor14at that time.

An input method for inputting information by an input device with photosensitive elements of the present invention includes the following steps:

Step1: sensing, obtaining respectively the time at which the weakest beams21,22are reflected from the rotatable first reflector11and second reflector12after the beams21,22reflected from the target2are further respectively reflected by the reflectors11,12.

Step2: determining rotating angles of the first reflector11and the second reflector12depending on that time to obtain respectively an included angle θ1 between a virtual connecting line S1of the first reflector11and the target2and a virtual connecting line S of the first reflector11and the second reflector12, and an included angle θ2 between a virtual connecting line S2of the second reflector12and the target2and the virtual connecting line S.

Step3: calculating a relative coordinate of the target2by means of the length of the virtual connecting line S and the angles θ1, θ2 and taking it as input information corresponding to the position of the target2.

The method for inputting information by an input device with photosensitive elements includes the corresponding technical content of the input device with photosensitive elements of the present invention described in the specification beside the aforementioned steps, the detail is omitted here.

Referring toFIGS. 2 and 3again, other structures of an input device3with photosensitive elements of a first preferred embodiment according to the present invention are the same as the input device1with photosensitive elements shown inFIG. 2expect without the first light emitting module151and the second light emitting module152shown inFIG. 1. The first photosensitive element11and second photosensitive element12of the present embodiment are respectively configured on the horizontal sides of the first reflector11and the second reflector12. The first reflector11is disposed with at least one reflecting face111, and the second reflector12is disposed with at least one reflecting face121; the reflecting face111of the first reflector11and the reflecting face121of the second reflector12are respectively parallel to the rotating shafts131,141.

Referring toFIGS. 2 and 4, other structures of an input device4with photosensitive elements of a second preferred embodiment according to the present invention are the same as the input device1with photosensitive elements shown inFIG. 2expect without the light emitting module15shown inFIG. 2. The first light emitting module151, second light emitting module152of the present embodiment are respectively stacked with the first photosensitive element17, second photosensitive element18. The first light emitting module151, second light emitting module152and the first photosensitive element17, second photosensitive element are respectively configured on the horizontal sides of the first reflector11and second reflector12. The reflecting face111of the first reflector11, the reflecting face121of the second reflector12are respectively parallel to the rotating shafts131,141.

Referring toFIGS. 2 and 5, other structures of a input device5with photosensitive elements of a third preferred embodiment according to the present invention are the same as the input device1with photosensitive elements shown inFIG. 2expect without the light emitting module15shown inFIG. 2. The first light emitting module151, second light emitting module152of the present embodiment are respectively stacked with the first photosensitive element17, second photosensitive element18. The first light emitting module151, second light emitting module152and the first photosensitive element17, second photosensitive element are respectively configured on the vertical sides of a first reflector11′ and second reflector12′. A reflecting face111′ of the first reflector11′, a reflecting face121′ of the second reflector12are respectively formed 45 degrees with the rotating shafts131,141. The first reflector11′, second reflector12′ may respectively be a prism.

Referring toFIGS. 4,6and7, the present invention also allows the microprocessor16to be connected to a timer161, thereby calculating respectively the rotating angles of the first reflector11and the second reflector12by means of a time difference between the times at which the largest sensing signal and the weakest sensing signal are emitted from the first photosensitive element17, second photosensitive element18without needing to obtain respectively the rotating angles of the first reflector11and second reflector12by means of the rotating angles of the first motor13and second motor14.

Taking the first reflector11, the first light emitting module151, the first photosensitive element17as an example and disposing the first reflector11with m equiangularly distributed reflecting faces111to explain a method for detecting a rotating angle of the first reflector11, the first photosensitive element17can sense the beam23emitted form the first light emitting module151and then reflected directly by one reflecting face111of the first reflector11in sequence to obtain respectively the strongest sensing signal Sh when the first reflector11is rotated; the microprocessor16records the times T(n), T(n+1) and etc at which the strongest sensing signal Sh is detected, where the time difference between the two adjacent time (T(n+1)−T(n)) is equal to the time needed for the 1/m cycle (360 degree/m) rotation of the first reflector11, where n, m are integer 1, 2, 3 . . . ; when the first photosensitive element17senses the light emitted from the first light emitting module151, reflected to the light reflecting or emitting structure10of the one reflecting face111of the first reflector11through the first reflector11and then reflected by the light reflecting or emitting structure10, or the light emitted from the light emitted from the light reflecting or emitting structure10and then reflected by one reflecting face111of the first reflector11between the adjacent times T(n) and time T(n+1), a weaker sensing signal S0can be obtained; it is because the light reflecting function of the target2is weaker than the light reflecting or emitting structure10or the light emitted from the light reflecting or emitting structure10is brighter than the light reflected from the target2, and the light emitted from the light reflecting or emitting structure10is blocked by the target2and cannot be reflected to the first photosensitive element17by the first reflector11; the microprocessor16records the time T(0) at which the weakest sensing signal S1is detected through the time provided by the timer161; because the rotation of the first reflector11is close to a uniform motion, a rotating angle θ of the first reflector11as a function of time T(0) relative to time T(n) can be calculated as (T(0)−T(n))/(T(n+1)−T(n)) multiplied by 360/m.

Referring toFIGS. 6,7and8, a method for detecting a rotating angle of the first reflector11according to the present invention includes the following steps:

Step31: allowing the microprocessor16to record the two times T(n), T(n+1) at which the strongest sensing signal Sh respectively emitted from the first photosensitive element17is detected by means of the time provided by the timer161, where the two strongest sensing signals are generated from the sensing of the beam23emitted from the first light emitting module151and then reflect directly by one reflecting face111of the first reflector11; a time difference (T(n+1)−T(n)) is equal to the time needed for the 1/m cycle (360/m) rotation of the first reflector11;

Step32: allowing the microprocessor16to record time T(0) at which the weakest sensing signal51emitted from the first reflector11is detected by means of the time provided by the timer161, where the weakest sensing signal S1is generated from the sensing of the beam24emitted from the first light emitting module151, reflected to the target2by the first reflector11, reflected to one reflecting face111of the first reflector11and then reflected by the reflecting face111by the photosensitive element17between the adjacent times T(n) and T(n+1);

Step33: allowing the microprocessor16to calculate (T(0)−T(n))/(T(n+1)−T(n)) multiplied by 360/m, thereby obtaining a rotating angle θ of the first reflector11as a function of time T(0) relative to time T(n), and determining the rotating angle of the first reflector11depending on the rotating angle θ.

Referring toFIGS. 4,6,7and8, the method for detecting the rotating angle of the first reflector11of the present invention is also applied to the detection of a rotating angle of the second reflector12; defining times corresponding to T(n), T(n+1), T(0) for calculating the rotating angle of the second reflector respectively as T(p). T(p+1), T(q), (T(q)−T(p))/(T(p+1)−T(p)) multiplied by 360/r can be calculated to obtain a rotating angle of the second reflector12as a function of time T(q) relative to time T(p), and the rotating angle of the second reflector12can be determined depending on the rotating angle mentioned above, where p, r respectively are an integer 1, 2, 3 . . . , the second reflector12is disposed with r equiangularly distributed reflecting faces121, and r may also be equal to m.

Referring toFIG. 5again, in the input device4with photosensitive elements the third embodiment of the present invention, because the first light emitting module151, the second light emitting module152and the first photosensitive element17, the second photosensitive element18are respectively disposed on the vertical sides of the first reflector11′, the second reflector12′, and the reflecting face111′ of the first reflector11′, the reflecting face121′ of the second reflector12′ are respectively formed 45 degrees with the beams25,26emitted respectively from the first light emitting module151, the second light emitting module152, the first photosensitive element17, the second photosensitive element18are unable to sense the beams emitted respectively from the first light emitting module151, the second light emitting module152and reflected directly by the reflecting face111′ of the first reflector11′, the reflecting face121′ of the second reflector12′ to send the strongest signals; the reflected beams must be respectively sensed through a first mirror191, a second mirror192shown in the figure. Because the first mirror191, second mirror192respectively have a better light reflecting effect than the target2, in the present embodiment, the first photosensitive element17, the second photosensitive element18are used to sense respectively the beams emitted respectively from the first light emitting module151, the second light emitting module152, reflected respectively to the first mirror191, the second mirror192by the reflecting face111′ of the first reflector11′, the reflecting face121′ of the second reflector12′, reflected respectively to the reflecting face111′ of the first reflector11′, the reflecting face121′ of the second reflector12′ by the first mirror191, the second mirror192and then reflected by the reflecting face111′ of the first reflector11′, the reflecting face121′ of the second reflector12′, thereby obtaining the strongest sensing signal. Therefore, the strongest signal in the present embodiment is obtained by means of the method mentioned above.

The detection method of the rotating angles of the first reflector11and the second reflector12of the present invention includes the technical content related to the detection of the rotating angles of the first reflector11and the second reflector12of the present invention in the specification besides the operating steps mentioned above; the detailed is omitted here.

The present invention does not need to rely on the rotating angles of precise, expensive stepper motors to not only obtain the rotating angles of the first reflector11and the second reflector12but differentiate between the rotating angles of the first reflector11and the second reflector12more precisely and obtain the position of the target2more accurately. For example, the present invention uses cheaper motors of 60 revolutions per sec to drive the first reflector11with only one reflecting face111to rotate such that the facilities cost thereof is cheaper. Furthermore, the present invention provides a timer161with a system timing clock oscillation frequency of 72 million times such that each turn of the motor is divided into 72,000,000/60=1,200,000 divisions; and 360 degrees=360*60*60=1,290,200 seconds. Therefore, the angle can be divided by each unit time interval (1/72 million second) is 1,290,000/1,200,000=1.08 seconds; it is very accurate. Besides, the accuracy of the angle detection can be increased if a timer161with a larger oscillation frequency is used.

The input device with photosensitive elements and the method for inputting information thereby according to the present invention only uses two cheaper photosensitive elements instead of expensive image capturing modules such that the production cost of the device can be reduced. Furthermore, the included angles between the virtual connecting lines S of a target and the first, second reflectors can respectively obtained easily through the rotating angles of the rotating shafts of the motors to calculate to obtain the coordinate of the target simply and fast instead of a complex, time-consuming operation.