Abstract:
An input device for screen navigation. The input device includes a light source for emitting light onto a surface over which the input device move, a power port for receiving electric power to operate the input device, and an optical module. The input device includes, a voltage regulator formed on a substrate for regulating the voltage of electric power to the desired level, an optical imaging module formed on the substrate for capturing successive images of the surface and producing imaging signals corresponding to the captured images, a motion determining circuit formed on the substrate for producing a motion signal of the input device based on the successive imaging signals, and a modulating circuit formed on the substrate for modulating the motion signal. The input device also includes a RF module for transforming the modulated motion signal into a RF signal to be transmitted to a receiver for screen navigation.

Description:
BACKGROUND OF INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to an optical mouse, and more specifically, to an optical mouse having a module capable of increasing voltage to a predetermined voltage level and measuring movement with respect to a surface.  
         [0003]     2. Description of the Prior Art  
         [0004]     Compared with a traditional mechanical mouse, an optical mouse receives continuous plane images promptly and compares the images with each other to determine the moving direction and distance for an optical mouse. The principle of optical sensing in an optical mouse and the method for dealing with continuous image data are both well known in the prior art, and will not be discussed further here. Because there is no mechanical moving parts which may be abraded or stuck in an optical mouse, an optical mouse is reliable.  
         [0005]     Please refer to  FIG. 1 .  FIG. 1  is a bottom view of the optical mouse  10  according to the prior art. As the  FIG. 1  shows, there is a flat surface  12 , which has a hole  14 , on the bottom of the optical mouse  10 . The flat surface  12  is made from material with a low attrition factor with the aim of pushing the optical mouse  10  by outside force. The optical mouse  10  emits light with a light-emitting diode (not shown in  FIG. 1 ) to the surface through the hole  14 , scans and seizes plane images rapidly, and contrasts the difference between before seizing images and after. The displacement of the optical mouse  10  is counted by an optical sensing chip (not shown in  FIG. 1 ) installed inside the optical mouse  10  as the content of seized images changes, and then the displacement data will be transformed into axial displacement signals and transmitted to a computer (not shown in figures) through a cable line  16  (or transmitted wirelessly) which may have one of several standard adapters, such as a communication port (COM port), PS/2 port, USB, etc. An optical mouse in the prior art counts the moving direction and distance in the optical reflection and produces relative moving signals. No further description is given here, for the principle of optical reflection in an optical mouse is well known among skilled technicians.  
         [0006]     For the time being, some manufacturers provide a voltage regulator in an optical mouse with the aim of increasing working voltage to drive the operation of related circuits in an optical mouse without increasing extra batteries. Generally speaking, there are two methods of controlling output voltage for a normal DC/DC voltage regulator, one is PWM (Pulse Width Modulation), and the other is PFM (Pulse Frequency Modulation). Regardless of whether PWM or PFM is used, both of them require an oscillator for the PWM or PFM control circuit to adjust the output voltage, thereby generating the output voltage with various irregular-frequency ripples as the magnitude of load current. As far as the optical sensor which demands higher quality of power source is concerned, the ripple voltage serves as noise, reducing the quality of images, or causing errors in the identification of moving traces. Consequently, integrating an appropriate and cheap voltage regulator into an optical sensor is always the goal of the manufacturer.  
         [0007]     In general, a wireless optical mouse not only comprises the above-mentioned voltage regulator and optical sensing chips but also a micro-controller or a hardware circuit of a modulating circuit used for transforming motion signals into RF signals. However, when the wireless optical mouse adopting 27 MHz as a carrier frequency launches high-power signals through the antenna in a radiant manner, the launched signals may radiantly spread to the micro-controller or the optical sensor, resulting in incorrect operation of the micro-controller or incorrect error identification performed by the optical sensor. For this reason, it is necessary to arrange a shield layout or to EMI-proof components or materials on the printed circuit board for preventing EMI from being a problem.  
       SUMMARY OF INVENTION  
       [0008]     It is therefore an objective of the claimed invention to provide an optical mouse which combines and integrates a voltage regulator and an optical module into one single chip, so that the optical mouse not only increases the input voltage to the working voltage which the optical mouse requires, but also integrates the hardware circuit of the modulating circuit into one single chip so as to take valid measures to solve the problems of diverse signals in power sources or radio-frequency disturbance.  
         [0009]     According to the claimed invention, an input device for screen navigation, comprises a light source for emitting light onto a surface over which the input device move, a power port for receiving electric power to operate the input device, an optical module, and a RF module. The optical module comprises a substrate, a voltage regulator, formed on the substrate, for regulating the voltage of electric power to the desired level, an optical imaging module, formed on the substrate, for capturing successive images of the surface and producing imaging signals corresponding to the captured images, a motion determining circuit, formed on the substrate and electrically coupled with the optical imaging module, for producing a motion signal of the input device based on the successive imaging signals, and a modulating circuit, formed on the substrate and electrically coupled with the motion determining circuit, for modulating the motion signal. The RF module is electrically coupled with the modulating circuit and used for transforming the modulated motion signal into a RF signal to be transmitted to a receiver for screen navigation.  
         [0010]     According to the claimed invention, an input device for screen navigation comprises a light source for emitting light onto a surface over which the input device move, a power port for receiving electric power to operate the input device, and an optical module. The optical module comprises a substrate, a voltage regulator, formed on the substrate, for regulating the voltage of electric power to the desired level, an optical imaging module, formed on the substrate, for capturing successive images of the surface and producing imaging signals corresponding to the captured images, a motion determining circuit, formed on the substrate and electrically coupled with the optical imaging module, for producing a motion signal of the input device based on the successive imaging signals, a modulating circuit, formed on the substrate and electrically coupled with the motion determining circuit, for modulating the motion signal, and a RF module, formed on the substrate and electrically coupled with the modulating circuit, for transforming the modulated motion signal into a RF signal to be transmitted to a receiver for screen navigation.  
         [0011]     According to the claimed invention, an input device for screen navigation, comprises a light source for emitting light onto a surface over which the input device move, a power port for receiving electric power to operate the input device, an optical module, a modulating circuit, and a RF module. The optical module comprises a substrate, a voltage regulator, formed on the substrate, for regulating the voltage of electric power to the desired level, an optical imaging module, formed on the substrate, for capturing successive images of the surface and producing imaging signals corresponding to the captured images, and a motion determining circuit, formed on the substrate and electrically coupled with the optical imaging module, for producing a motion signal of the input device based on the successive imaging signals. The modulating circuit is electrically coupled with the motion determining circuit and used for modulating the motion signal. The RF module is electrically coupled with the modulating circuit and used for transforming the modulated motion signal into a RF signal to be transmitted to a receiver for screen navigation.  
         [0012]     These and other objectives of the claimed invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment, which is illustrated in the various figures and drawings. 
     
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0013]      FIG. 1  is a bottom view of the optical mouse of the prior art.  
         [0014]      FIG. 2  is an inside component diagram of the optical mouse of the present invention.  
         [0015]      FIG. 3  is a perspective drawing of the optical mouse in  FIG. 2  positioned on a surface.  
         [0016]      FIG. 4  is a functional block diagram of the optical mouse transmitting RF signals to a computer host according to the present invention.  
         [0017]      FIG. 5  is a circuit diagram of the voltage regulator in  FIG. 4 .  
         [0018]      FIG. 6  is a timing diagram of inductor voltage V L  and capacitor current I c  of voltage regulator in  FIG. 5 .  
         [0019]      FIG. 7  shows a second embodiment of the optical module according to the present invention.  
         [0020]      FIG. 8  shows a second embodiment of the optical module according to the present invention. 
     
    
     DETAILED DESCRIPTION  
       [0021]     Please refer to  FIG. 2  showing an assembly diagram  20  of the optical mouse  10 . As shown in  FIG. 2 , the optical mouse  10  further includes a lens module  30  installed above a hole  33  on a bottom surface  31 , a circuit board  40  installed above the lens module  30 , an optical module  42  installed above the circuit board  40 , a LED  44  (or a laser diode) installed above the circuit board  40 , and an optical mask  46  installed above the circuit board  40 . The optical module  42  is used for capturing images of the working surface that the optical mouse  10  has passed by to analyze and judge the displacement of the optical mouse  10 . The LED  44  is used as a light source of the optical module  42 , and the optical mask  46  is used to prevent light from the LED  44  from directly entering into the optical module  42 . The lens module  30  includes a lens  32 , a first reflection surface  34  and a second reflection surface  36 . The circuit board  40  includes an aperture  48  positioned above the lens  32 , and the optical module  42  is installed above the aperture  48  of the circuit board  40 . The first reflection surface  34  protrudes out of the aperture  48  so that it is located between the LED  44  and the optical module  42 .  
         [0022]     Please refer to  FIG. 2  in conjunction with  FIG. 3 , which shows the optical mouse  20  shown in  FIG. 2  positioned on a working surface  50 . As shown in  FIG. 3 , the LED  44  is opposite to the first reflection surface  34  and generates a ray  27 . The ray  27  will progress toward the first reflection surface  34  and be reflected downwards by the first reflection surface  34  to the second reflection surface  36 . After being reflected by the second reflection surface  36 , the ray  27  passes through the hole  33  on the bottom surface  31  and irradiates a working surface  50  under the optical mouse  20 . The working surface  50  modulates the characteristics of the ray  27  and reflects the ray  27  to the lens  32  to be a reflected ray  28 . The reflected ray  28  will be converged and focused on the optical module  42  by the lens  32 , and the optical module  42  determines the movement of the optical mouse  50  according to the change of the reflected ray  28 . However, if the working surface  50  is highly transparent or is a special color (e.g. a piece of glass or a glossy surface), the ray  27  incident on the working surface  50  cannot be completely reflected to the optical module  42 , so that the optical module  42  cannot receive continuous images of the working surface  50 , and the cursor of the optical mouse  20  cannot be in the right place.  
         [0023]     Please refer to  FIG. 2  with  FIG. 4 .  FIG. 4  is a functional block diagram in which the optical mouse  20  transmits RF signals to a computer host  80  according to the present invention. The optical mouse  20  also comprises a power port  64  and a RF module  66 . The power port  64  is for use in installing batteries to generate an input voltage. The optical module  42  comprises a substrate  71 , a DC/DC voltage regulator  72 , an optical imaging module  74 , a motion determining circuit  76  and a modulating circuit  78 . The voltage regulator  72  connects to the power port  64  to increase the input voltage to a working voltage. And the working voltage generated by the voltage regulator  72  will be provided to the optical imaging module  74 , the motion determining circuit  76 , the modulating circuit  78  and the RF module  66  to drive the operation of the circuits (for clarity, the connection between the voltage regulator  72  and other circuits is not shown in  FIG. 4 .). Please take notice that the DC/DC voltage regulator  72 , the optical imaging module  74 , the motion determining circuit  76  and modulating circuit  78  are all formed on the same substrate  71 .  
         [0024]     While the optical mouse  20  is moving on the surface  50 , the light  27  generated by the light-emitting diode  44  is reflected by the surface  50 , and then the reflected light  28  enters into the optical imaging module  74 . The optical imaging module  74  will generate sensing signals corresponding to emitted light and transmit the sensing signals to the motion determining circuit  76 . The motion of the optical mouse  20  causes a change of sensing signal generated by the optical imaging module  74 , so that the motion determining circuit  76  electrically connected to the optical imaging module  74  will determine the current motion vector and velocity of the optical mouse  20  according to the changed sensing signals. The modulating circuit  78  connected to the motion determining circuit  76  will transform the motion signals of the motion vector and velocity generated by the motion determining circuit  76  into the wireless signals. Finally, the RF module  66  electrically connected to the modulating circuit  78  will transform the wireless signals generated by the modulating circuit  78  into RF signals and transmit them to a computer host  80 . The computer host  80  includes a receiving module  82  and a control circuit  84 . The receiving module  82  is used for receiving the RF signals transmitted from the RF module  66 , transforming them into a demodulated signal and then transmitting the demodulated signal to the control circuit  84 . Finally, the control circuit  84  will determine the motion vector and velocity of the optical mouse  20  based on the transformed demodulated signal. Thus, the computer host  80  can be operated according to the motion vector and velocity of the optical mouse  20 . Besides that, the computer host  80  also comprises a display screen  88  for displaying the moving traces of the optical mouse  20  in the display screen  88  according to the motion vector and the velocity of the optical mouse  20  determined by the control circuit  84 . The RF module  66  is able to transform the received wireless signals into a RF signal, which is carried by a carrier having frequency of 27 MHz or 2.4 GHz.  
         [0025]     Please refer to the  FIG. 5  with reference to  FIG. 6 .  FIG. 5  is a circuit diagram of the voltage regulator  72  in  FIG. 4 .  FIG. 6  is a timing diagram of inductor voltage V L  and capacitor current I c  of voltage regulator  72  in  FIG. 5 . In the present embodiment, the voltage regulator  72  is a DC/DC converter, but in fact, any voltage regulators able to raise input voltage are all in the scope of the present invention. A MOS  90  serves as a switch of which the gate is connected to a control voltage Vc. The control voltage is a square wave with a duty circle Ts, and D represents the ratio of the square wave on the period corresponding to positive voltage level to the whole cycle Ts. When a positive voltage level of the control voltage Vc is applied, the MOS  90  turns on, and at this moment, the Vg will charge the inductor  92  and restore energy in the inductor  92 . On the other hand, when a zero voltage level of the control voltage Vc is applied, the MOS  90  turns off. At this moment, the voltage across the inductor  92  will reverse due to Lenz law, and the input voltage Vg through the diode  94  results in the output voltage V being higher than the input voltage Vg.  FIG. 6  is a timing diagram of inductor voltage VL and capacitor current I c  as the control voltage Vc changes. It leads to the following equation from  FIG. 6 :  
           ∫   0   Ts     ⁢       V   L     ⁡     (   t   )         =     VgDTs   +       (     Vg   -   V     )     ⁢     (     1   -   D     )     ⁢   Ts           
         VgDTs   +       (     Vg   -   V     )     ⁢     (     1   -   D     )     ⁢   Ts       =   0       
       therefore   ,     V   =     Vg     1   -   D             
 
         [0026]     In other words, the magnitude of the voltage V is determined based on the conducting cycle of the control voltage Vc. The voltage level of the input voltage Vg can be raised to a working voltage V according to the conducting cycle D by using the voltage regulator  72 . For instance, suppose that the power port  64  is designed to set up a 1.5V battery, but the required working voltage of the circuit in the optical mouse  20  is 3V. The input voltage generated by the power port is 1.5V but the 1.5V input voltage can be increased to a working voltage of 3V by means of the voltage regulator  72 . As a result, the circuits in the optical mouse  20  work regularly with only one 1.5V battery.  
         [0027]     Please refer to  FIG. 7 , which shows a second embodiment of the optical module according to the present invention. Elements that have the same function as that illustrated in  FIG. 4  are provided the same item numbers used in  FIG. 7 . Differing from the optical module depicted in  FIG. 4 , the voltage regulator  72 , the optical imaging module  74 , the motion determining module  76 , the modulating module  78  and the RF module  66  are formed on the substrate  101 , and packaged as a single chip, i.e. the optical module  102 .  
         [0028]     Please refer to  FIG. 8 , which shows a third embodiment of the optical module according to the present invention. Elements that have the same function as that illustrated in  FIG. 4  are provided the same item numbers used in  FIG. 8 . Differing from the optical module depicted in  FIG. 4 , the voltage regulator  72 , the optical imaging module  74 , and the motion determining module  76  are formed on the substrate  111 , and packaged as a single chip, i.e. the optical module  112 .  
         [0029]     In the prior art, the voltage regulator and the modulating circuit exercised are individual chips. However, the present invention optical mouse integrates the voltage regulator and the modulating circuit into one single chip. Consequently, the voltage regulator is able to increase the input voltage generated by the power port appropriately. Besides that, noises of power sources or interference of RF circuits can be improved because both the voltage regulator and the modulating circuit are packaged into a single chip.  
         [0030]     Those skilled in the art will readily observe that numerous modifications and alterations of the device 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.