TWI492555B - Low power wireless short range transmission system - Google Patents

Description

Low power wireless short-distance transmission system

The present invention is generally directed to low power wireless short range transmission and, more particularly, to a low power signal generation system for wireless short range transmission.

In the past few years, wireless short-range transmission systems have been more commonly used in devices such as remote controls or wireless keyboards to transmit signals to other devices within a short distance. The transmission range of wireless short-distance transmission systems is generally less than 15 meters. For example, a remote control or a wireless keyboard typically includes a set of keys, a key matrix, a controller, a transmitter, and a light emitting diode (LED) for transmitting infrared ("IR") signals. "), or an antenna for transmitting radio frequency ("RF") signals. For example, FIG. 1 is a block diagram of a conventional wireless keyboard 10. Referring to FIG. 1, the wireless keyboard 10 can include a set of keys (not shown), a key matrix 11 and a wireless short-range transmission system. The wireless short-range transmission system includes a controller 12, a quartz oscillator 13, a transmitter 14 (TX), and an antenna 15. The controller 12 is coupled to the key matrix 11, the quartz oscillator 13 and the transmitter 14. The quartz oscillator 13 is further coupled to the transmitter 14, and the transmitter 14 is further coupled to the antenna 15. The controller 12 can include a modulator 12-1 for generating a modulated signal. In operation, the controller 12 can transmit signals to or receive signals from the key matrix 11. For example, the controller 12 is configured to scan the key matrix 11 to find a signal indicating that "one or more keys are pressed", and respectively transmit a start signal ACT1 and a modulation signal MOD to the quartz oscillator 13 And the transmitter 14. In response to the enable signal ACT1, the quartz oscillator 13 can generate a reference signal REF having the desired frequency and return the reference signal REF to the transmitter 14. The transmitter 14 can include a phase-lock loop frequency synthesizer ("PLL" frequency synthesizer) 14-1 and a power amplifier ("PA") 14-2. Transmitter 14 may generate a modulated signal based on reference signal REF received from quartz oscillator 13, another enable signal ACT2, and modulation signal MOD received from controller 12. The modulated signal is then converted to an RF signal and transmitted via antenna 15.

2 is a timing diagram illustrating the operation of the controller 12 from the key matrix 11 after receiving a signal representing "a key is pressed" by the crystal oscillator 13, the phase lock loop 14-1, and the power amplifier 14- 2 and the signal generated by the transmitter 14. First, the controller 12 can activate the quartz oscillator 13 to generate a reference signal REF having a desired frequency. Once the quartz oscillator 13 has stabilized, the controller 12 can activate the phase locked loop frequency synthesizer 14-1 and the power amplifier 14-2. For example, the phase locked loop frequency synthesizer 14-1 may be first activated by a start signal ACT2 and based on the frequency of the reference signal REF to generate a carrier signal. Once the phase locked loop frequency synthesizer 14-1 has stabilized, the power amplifier 14-2 receiving the carrier signal from the phase locked loop frequency synthesizer 14-1 can be "turned on" by a modulation signal MOD from the controller 12. Or "off", thereby generating a modulated signal and converting it into an RF signal for transmission via antenna 15.

However, a conventional keyboard having a wireless short-range transmission system similar to the above-described operational form may consume a large amount of power. For example, suppose the information is transmitted in kilobits per second (Kilobit per second, "kbps"), while the logic high is the same as the low logic bit time (ie, the duty cycle is 50%), and the logic high and logic low voltage 2 volts (V) and 0 V, respectively, in addition, the currents of the driving quartz oscillator 13, the phase locked loop frequency synthesizer 14-1 and the power amplifier 14-2 are 50 microamperes (μA) and 5 milliamperes (mA), respectively. With 5 mA. In addition, for wireless short-range transmission, under the assumption of a very low bit error rate, and compared to the length of time of the command, the phase-locked loop frequency synthesizer is locked during the lock period. In the case of a relatively short time period, the current consumed during the phase locked loop frequency synthesizer lock period can be ignored. Therefore, the average current used to transmit a logic high bit (1) and a logic low bit (0) will be approximately 8000 μA (ie (500 μA + 5 mA + 5 mA) x 0.5 + (500 μA + 5 mA) x 0.5). Therefore, the energy efficiency will be approximately 16,000 nanojoule per bit ("nJ/bit") (ie 8000 μAx 2 V/1 kbps). Many energy-saving improvements have been proposed in the past by designing different phase-locked loop frequency synthesizers to produce more energy efficient phase locked loop frequency synthesizers (eg, low power phase locked loop frequency synthesizers). However, the phase locked loop frequency synthesizer 14-1 is continuously turned on during the entire period in which the signal to be transmitted is being generated via the transmitter 14. In other words, the phase locked loop frequency synthesizer 14-1 in such a wireless short range transmission system consumes energy during the period in which the logic "0" and "1" are generated. Therefore, the use of energy efficient phase locked loop frequency synthesizers to save energy is still limited. Accordingly, it is desirable to provide a wireless short range transmission system in which more energy is saved by increasing the data rate and reducing the operating time of the phase locked loop frequency synthesizer while the phase locked loop frequency synthesizer is still operating.

Furthermore, as previously mentioned, wireless short-range transmission systems are commonly used in wireless keyboards. Wireless keyboards typically include two types of keys. Each key of the first type is associated with its own function. The keys of the first type described above include, for example, text keys generally set to the QWERTY style, function keys (F1, F2, etc.), lock keys, navigation keys (up, down, etc.), and edit keys (delete, Input, etc.). The second type of key is a modifier key that only works when pressed simultaneously with other keys. The second type of keys include, for example, Ctrl, Alt, and Shift. For example, to enter "A", the user will first press "Shift" and then press "a". As shown in FIG. 3, in the conventional wireless keyboard, when "Shift" is pressed, the keyboard transmits the "Shift" key code, and when "a" is pressed, the keyboard transmits the "A" key code. On the receiver side, for example, a computer, when receiving a "Shift" key code, it does not perform any action associated with the display, because "Shift" itself is a meaningless command. The receiver will only perform the action when it receives the key code of "A", for example, the character "A" is displayed on the display. In other words, the "Shift" key code transmitted by the wireless keyboard does not provide any meaningful function. Therefore, there is a need for a wireless keyboard that saves energy by omitting the transmission of data when only a second type of key (such as "Shift") is pressed alone. The above-mentioned energy-saving method is particularly effective for users who are not familiar with typing and need to press the "Shift" button for a long time. At the same time, for smaller devices, such as handheld devices, because it is more difficult to find the correct text key on a small keyboard of a handheld device, the user may hold the "Shift" button for a longer duration. Therefore, the ability to save energy in small devices is even more significant and important.

In addition, many conventional keyboards use infrared (IR) signaling devices to transmit signals, and the amount of current that operates the light-emitting diode (LED) source alone (excluding the current that operates the circuit) typically ranges from 40 to 100 mA. In addition, when an infrared signal device for signal transmission is used, since the IR signal device requires a line-of-sight operation, the wireless keyboard needs to be placed at an appropriate position with respect to the receiver. It is therefore desirable to provide a wireless keyboard with an environmentally friendly wireless short-range transmission system that is capable of transmitting signals at lower power without the need for direct line-of-sight operation.

An example of the present invention can provide a wireless short-range transmission system including a controller, a first oscillator, a transmitter and an antenna for transmitting the modulated signal. The transmitter includes a phase locked loop frequency synthesizer for receiving a reference signal from the first oscillator and a first modulated signal from the controller. The phase locked loop frequency synthesizer is configured to be turned on by the first modulated signal to generate a carrier signal based on the reference signal. The transmitter further includes a power amplifier for receiving a carrier signal from the phase locked loop frequency synthesizer and a second modulated signal. The power amplifier is configured to be turned on and off by the second modulation signal to generate a modulated signal based on the carrier signal, wherein the power amplifier is turned on after the phase locked loop frequency synthesizer is stabilized, and The phase locked loop frequency synthesizer is turned off as the power amplifier is turned off, or the phase locked loop frequency synthesizer is turned off after the power amplifier is turned off.

Some examples of the invention may also provide a wireless keyboard comprising the wireless short range transmission system described above, and a key matrix coupled to the controller.

Other objects, advantages and innovative features of the invention will be obtained from the following detailed description of the invention.

Reference will now be made in detail to the exemplary embodiments of the invention, Wherever possible, the same reference numerals will be used to refer to the Please note that these drawings are drawn in a simplified form and are not drawn to exact scale.

4 is a block diagram of a wireless short range transmission system 20 in accordance with a first embodiment of the present invention. Referring to FIG. 4, the wireless short-range transmission system 20 can include a controller 22, a quartz oscillator 13, a transmitter 24, and an antenna 15 for transmitting radio frequency (RF) signals. The controller 22 can include a modulator 22-1, and the transmitter 24 can include a phase locked loop (PLL) 24-1, a power amplifier (PA) 24-2, a frequency selection pin 24-3, and a Or a plurality of modulation pins 24-4. Controller 22 can be a microprocessor or a microcontroller. The modulator 22-1 may include an Amplitude Shift Keying ("ASK") modulator and an On-off Keying ("OOK") modulator. The phase locked loop frequency synthesizer 24-1 is an integer N type phase locked loop, which can be a digital phase locked loop frequency synthesizer or a analog phase locked loop frequency synthesizer.

In an example in accordance with the invention, the components of system 20 described above may be integrated into a wafer, and system 20 may be in the form of an integrated circuit ("IC"). In another example, system 20 can be part of an IC. Additionally, system 20 can be applied to a human interface device ("HID") such as a keyboard, a keyboard on a mobile phone, a joystick and a remote control.

Controller 22 is coupled to quartz oscillator 13 and transmitter 24. When the controller 22 receives a trigger to activate the quartz oscillator 13 or transmits the modulated signal, the controller 22 can start the quartz oscillator 13 with a start signal ACT1, so that the crystal oscillator 13 generates a reference signal REF. The reference signal REF is then transmitted to the transmitter 24 via the frequency selection pin 24-3. The controller 22 can be configured to determine whether the quartz oscillator 13 has stabilized by receiving a feedback signal (not shown) from the quartz oscillator 13 or having a counter (not shown) to count for a predetermined period of time. The predetermined period of time is approximately the time required to stabilize the quartz oscillator 13, and this time can be determined experimentally. Once the controller 22 has determined that the quartz oscillator 13 has stabilized, the controller 22 may cause the phase locked loop frequency synthesizer 24-1 to generate a carrier signal based on the reference signal REF and cause the transmitter to be as described below with reference to FIG. The method produces a modulated signal. Additionally, because controller 22 is a digital circuit, it requires a clock signal to operate. In an example, controller 22 can include an internal oscillator (not shown) for generating the clock signal. Additionally, controller 22 can receive the clock signal from external quartz oscillator 13. Moreover, in another embodiment, the transmitter 24 can include another frequency selection pin (not shown) to receive a signal from the controller 22 and to transmit the received signal to the phase locked loop. The frequency synthesizer 24-1 is used to fine tune the frequency of the carrier signal generated by the phase locked loop frequency synthesizer 24-1.

FIG. 5 is a timing diagram illustrating signals generated by the crystal oscillator 13, the phase locked loop frequency synthesizer 24-1, the power amplifier 24-2, and the transmitter 24 shown in FIG. 4 after the controller 22 receives the trigger. . First at time t1, the controller activates the quartz oscillator 13 to generate a reference signal REF which is transmitted to the phase locked loop frequency synthesizer 24-1 of the transmitter 24. Once the controller 22 determines that the quartz oscillator 13 has stabilized, the controller 22 can transmit a first modulation signal MOD1 generated by the modulator 22-1 to the phase locked loop frequency synthesizer 24- via the modulation pin 24-4. 1. The phase locked loop frequency synthesizer 24-1 is activated by the first modulation signal MOD1 and can generate a carrier signal based on the frequency of the reference signal REF. This carrier signal is then transmitted to power amplifier 24-2. As shown in FIG. 5, the phase locked loop frequency synthesizer 24-1 is activated at time point t2 and is stable at time point t3. The time required to stabilize the phase locked loop frequency synthesizer 24-1 is approximately 100 microseconds (μs). This time can vary depending on the design of the phase locked loop frequency synthesizer. The controller 22 can count the stabilization of the phase locked loop frequency synthesizer 24-1 by receiving a feedback signal (not shown) from the phase locked loop frequency synthesizer 24-1 or having a counter (not shown). A predetermined period of time (e.g., 100 μs) is used to determine whether the phase locked loop frequency synthesizer 24-1 has stabilized. Once the controller 22 determines that the phase locked loop frequency synthesizer 24-1 has stabilized, the power amplifier 24-2 is turned on and off in response to, for example, the rising edge and the falling edge of the second modulation signal MOD2, respectively, based on the carrier signal. A modulated signal is generated with the second modulation signal MOD2. Thus, as illustrated in FIG. 5, the power amplifier output can have the same waveform as the second modulation signal MOD2.

In an example, the phase locked loop frequency synthesizer 24-1 and the power amplifier 24-2 can be turned off by the falling edge of the second modulation signal MOD2. In another example, the phase locked loop frequency synthesizer 24-1 can be turned off after the power amplifier 24-2 has been turned off. The first modulation signal MOD1 and the second modulation signal MOD2 may be two signals having the same frequency and amplitude but different phases. In an example in accordance with the present invention, the transmitter 24 can include a phase delay circuit (not shown) that receives a single modulated signal from the controller 22 and produces a first modulated signal MOD1 and a second modulation Signal MOD2. For example, the phase delay circuit can include a buffer for causing a delay of the received modulated signal, thereby generating a second modulated signal MOD2, wherein the phase of the second modulated signal MOD2 is different from the received Modulation signal. In another example according to the present invention, both modulation signals MOD1 and MOD2 are generated by the modulator 22-1 and transmitted to the phase locked loop frequency synthesizer 24-1 via different modulation pins 24-4. With power amplifier 24-2.

The phase locked loop frequency synthesizer 24-1 can include a voltage controlled oscillator ("VCO") and a frequency divider that is the most power consuming component of the phase locked loop frequency synthesizer 24-1. Therefore, the phase locked loop frequency synthesizer 24-1 can be turned off by turning off the VCO. Once the VCO is turned off, the frequency divider will also be turned off. In response to the first modulation signal from controller 22, the VCO can generate a carrier signal for power amplifier 24-2. The modulated signal can then be converted to a radio frequency signal and transmitted via an antenna 15 coupled to the transmitter 24.

The phase locked loop frequency synthesizer 24-1 of the first embodiment of the present invention as shown in FIG. 4 does not continue to be "ON" during the entire period in which the modulated signal is being generated, and therefore, according to the present The wireless short-range transmission system 20 of the first example of the invention consumes very little energy and is more energy efficient than the wireless short-range transmission system in the conventional wireless keyboard. Specifically, it can be assumed again that the information is transmitted at 1 kbps, the logic high and logic low bit times are the same (ie, the duty cycle is 50%), the logic high and logic low voltages are 2V and 0V, respectively, and the operating quartz oscillator is operated. 13. The currents of the phase locked loop frequency synthesizer 24-1 and the power amplifier 24-2 are 500 μA, 5 mA, and 5 mA, respectively. In addition, the phase locked loop frequency synthesizer lock time is typically about 1/10 of the bit time. Therefore, since the lock time of the phase locked loop frequency synthesizer is short enough to be negligible with respect to the bit time length, the current consumed during the phase lock loop frequency synthesizer lock time can be ignored. In addition, when the signal transmitted by the transmitter 24 is logic low, the most energy consuming component phase locked loop frequency synthesizer 24-1 is turned off by the modulation signal MOD1/MOD2, and at the same time, the power amplifier 24-2 is also turned off. . Alternatively, the phase locked loop frequency synthesizer 24-1 is turned off after the power amplifier 24-2 has been turned off. Therefore, the average current for transmitting a "1" and a "0" bit is only 5500 μA, which is 2500 μA less than the current operated by the wireless short-distance transmission system in the conventional wireless keyboard 10 described above. Therefore, the energy efficiency of the first example of the present invention is approximately 11,000 nJ/bit, which is 5000 nJ/bit less than the energy efficiency of the wireless short-distance transmission system in the conventional wireless keyboard 10 described above. In addition, the present invention uses an RF signal to transmit the modulated signals, which is more energy efficient than using the IR signals to transmit the modulated signals, and the wireless keyboard according to the present invention does not require a direct line of sight. To operate. Thus, those skilled in the art will be able to appreciate that the first example of the present invention requires less energy to transmit information than conventional short-range wireless transmission systems.

Figure 6 is a block diagram of a wireless short range transmission system 30 in accordance with a second embodiment of the present invention. The second embodiment shown in Figure 6 is similar to the first embodiment shown in Figure 4, except that the second embodiment includes a transmitter 34; the transmitter 34 includes a fast lock phase locked loop frequency synthesis The device 34-1 is different from the phase locked loop frequency synthesizer 24-1 of the first embodiment. The fast lock phase locked loop frequency synthesizer 34-1 has a significantly shorter lock time than the phase locked loop frequency synthesizer 24-1 and can be a digital fast lock phase locked loop frequency synthesizer or an analogy Fast lock phase locked loop frequency synthesizer. The fast lock phase locked loop frequency synthesizer 34-1 can be, for example, an integer N type phase locked loop that is integrated with additional components to reduce the lock time. For example, it has been proposed to add a digital discriminator-assisted phase detector (DAPD) to an integer N-type phase-locked loop for the acceleration loop to reach a steady state. Another example of a fast lock phase locked loop frequency synthesizer 34-1 may be a fractional N type phase locked loop that has a more complex structure than the integer N type phase locked loop, but with a shorter lock time. When the lock time is short, the bit rate may increase, thereby increasing the energy efficiency of the wireless short-range transmission system 30 as described below with reference to FIG. The operation method of this second embodiment is the same or similar to the operation method of the first embodiment.

Figure 7 is a diagram showing signals generated by the crystal oscillator 13, the fast lock phase locked loop frequency synthesizer 34-1, the power amplifier 24-2, and the transmitter 34 shown in Figure 6 after the controller 22 receives the trigger. Timing diagram. As shown in FIG. 7, the lock time of the fast lock phase lock loop frequency synthesizer 34-1 is approximately 10 μs, which is 10 times shorter than the lock time of the phase lock loop frequency synthesizer 24-1. Therefore, the transmitter 34 of the second embodiment has a bit rate of 10 kbps which is 10 times higher than the bit rate of the transmitter 24 of the first embodiment. Therefore, according to the second embodiment of the present invention, the average current for transmitting a "1" and a "0" bit is also 5500 μA, but since the bit rate is increased due to a shorter locking time. Ten times, the energy efficiency of the second embodiment of the present invention is about 1100 nJ/bit, which is 10 times more energy efficient than the first embodiment. In other words, the second embodiment of the present invention uses less energy to transmit information.

Figure 8 is a block diagram of a wireless keyboard 40 in accordance with a third embodiment of the present invention. The wireless keyboard 40 includes a wireless short-range transmission system similar or identical to the wireless short-range transmission system according to the first and second embodiments shown in FIGS. 4 and 6. The wireless keyboard 40 further includes a key matrix 11 and a set of keys (not shown) connected to the key matrix 11. The controller 42 is configured to scan the key matrix 11 to find one or more signals representative of "one or more keys being pressed." If one or more signals representing "one or more keys are being pressed" are received by the controller 42, the controller 42 may cause the wireless short-range transmission system to be similar or identical to the first and second embodiments. A method of wireless short-range transmission system to generate and transmit a modulated signal.

The fourth embodiment of the present invention is a wireless keyboard having the same components as the wireless keyboard 40, except that the transmitter 44 of the fourth embodiment may be the same or similar to the transmitter 14, as shown in FIG. One of the conveyor 24 shown in Figure 4 or the conveyor 34 shown in Figure 6. The operation method of the fourth embodiment is the same as or similar to the operation method of the third embodiment except that the controller 42 of the fourth embodiment is configured to activate the quartz oscillator 13 and the transmitter in response to the selection signal received from the key matrix 11. 44. For example, the controller 42 of the fourth embodiment can be configured to determine whether the received one or more signals correspond to one or more of the keys of the first or second type, It is thereby determined whether the quartz oscillator 13 and the transmitter 44 are to be activated to transmit information. Each of the keys of the first type is associated with its own function. The first type of keys include, for example, text keys that are normally set to the QWERTY style, function keys (F1, F2, etc.), lock keys, navigation keys (up, down, etc.), and edit keys (delete, input, and many more). The second type of key is a modifier key that can only function when pressed simultaneously with other keys. Examples of the second type of keys include Ctrl, Alt, and Shift.

If the received signals correspond to one of the keys of the first form, the controller 42 will trigger the quartz oscillator 13 and the transmitter 44 in the same or similar manner to the first and second embodiments. . However, if the received signals correspond only to one of the keys of the second type, the controller 42 will not transmit any signals to activate the quartz oscillator 13 or the transmitter 44. In contrast, the controller 42 is employed in a manner that will wait for subsequent signals from the key matrix 11. When the controller 42 waits for a subsequent signal, the controller 42 can completely turn off its own power supply, or turn off some of its components. In the alternative of the fourth embodiment, when the signal representing that a key has been pressed is received by the controller 42, the quartz oscillator 13 is first activated, and during subsequent operations, the transmitter 44 is only in the The received one or more signals are determined to be corresponding to one or more of the keys of the first or second type before being activated.

9 is a flow chart of a method in which the controller 42 can execute and determine whether the digital controller 42 has received one or more signals representing one or more keys being pressed from the key matrix 11. A signal must be transmitted to activate the transmitter 44. In step 111, the controller 42 scans the key matrix 11. In step 112, controller 42 determines if two or more keys are being pressed. If two or more keys are being pressed, the controller 42 proceeds to step 113 to determine if there is a key code corresponding to the combination of the two or more pressed keys. For example, the combination of "Shift" and "a" corresponds to the key code "A", however, the combination of "Alt" and "Shift" may not correspond to any key code. If there is a key code corresponding to the combination of the two or more pressed keys, the controller 42 performs the start-up quartz oscillator 13 and the transmitter 44, or when the quartz oscillator 13 has been activated, only Transmitter 44 is activated and the data is transmitted via transmitter 44 in step 115. The controller 42 can activate the quartz oscillator 13 and the transmitter 44 and transmit via the transmitter 44 in accordance with any of the methods described above with respect to the first and second examples illustrated in Figures 4 through 7. The key code of the combination of the two or more pressed keys. On the other hand, if the controller 42 determines in step 113 that there is no key code corresponding to the combination of the two or more pressed keys, the controller 42 does not activate the transmitter 44.

In step 112, if the controller 42 determines that only one of the keys is being pressed, the controller 42 proceeds to step 114 to determine whether the pressed key is one of the keys of the first or second type. If the pressed key is the first type of key, the controller 42 may proceed to step 115. Otherwise, if the pressed key is a second type of key, the controller 42 will not activate the transmitter 44. Finally, controller 42 can remain in an idle state or turn off its own power until another signal from key matrix 11 is received.

10 is a timing diagram of signals illustrating the signals received by controller 42 from key matrix 11 and the timing of signals transmitted by transmitter 44. As shown in FIG. 10, when a "Shift" key of one of the keys of the second type is pressed, no data is being transmitted by the conveyor 44. Then, when the "Shift" key is pressed simultaneously with the "a" key, and it is determined that the combination of the two keys corresponds to "A", the transmitter 44 sends the key code of "A". In an example, when the controller 42 receives a signal representative that "one or more keys are being pressed", the controller 42 may transmit the first enable signal ACT1 to the quartz oscillator 13, thereby causing the quartz oscillator 13 to generate a reference. Signal REF. Controller 42 can then scan key matrix 11 to determine which keys are being pressed. For example, if the "Shift" key signal from the key matrix 11 and the "a" key signal are simultaneously received by the controller 42, after the quartz oscillator 13 has stabilized, the controller 42 can transmit one of the key codes representing "A". The signal is modulated to transmitter 44.

The circuitry of the wireless keyboard 40 typically includes a printed circuit board ("PCB") and an IC die. The manufacture of the wireless keyboard 40 typically includes the steps of fabricating an IC on a wafer in a fab, testing the wafer, packaging the IC, and soldering the IC to the PCB. The PCB board is usually designed according to the application of the PCB board. Figure 11 illustrates a procedure for fabricating a wireless keyboard 40 in accordance with an example of the present invention. When the IC is being designed, the first number of pins are designated as keys associated with the first type, and the second number of pins are designated as keys associated with the second version. Then, the IC is fabricated in a fab according to the design concept of the IC. Based on the pin designation of the IC fabricated in the fab, the customer can design a low power keyboard or keypad with a first type of key or a second type of key on a printed circuit board (PCB). The customer's PCB can then be manufactured accordingly. Therefore, the controller 42 in the wireless keyboard 40 manufactured according to the above method will be able to determine whether the signal received from the key matrix 11 represents a key of the first type or a key of the second type, and is associated with the map according to the above. The method of 9 determines whether or not to transmit a signal via the transmitter 44.

The wireless keyboard 40 in accordance with the present invention can operate in at least one of two modes: an activation mode when the user is transmitting information using the wireless keyboard 40, and a standby mode when the user is not using the wireless keyboard 40. . When the wireless keyboard 40 is operating in the startup mode, the controller 42 repeatedly performs the method described in FIG. 9 until a predetermined period of time has elapsed during which the controller 42 does not receive the key matrix 11 from. Any signal. After the predetermined period has elapsed, the wireless keyboard 40 switches to the standby mode. When the wireless keyboard 40 is in the standby mode, the power of all of the components in the wireless keyboard can be turned off. When it is in the standby mode, the controller 42 receives the signal from the key matrix 11, and the controller 42 switches to the startup mode and begins the procedure described in FIG.

Figure 12 is a block diagram of a wireless keyboard 50 in accordance with a fifth embodiment of the present invention. The wireless keyboard 50 is similar to the wireless keyboard 40 according to the fourth embodiment of the present invention, except that the wireless keyboard 50 further includes a memory 46 in which some information has been pre-stored with respect to the keys relative to the The mapping information of the address of the memory, and the information indicating that each key is the first type of key or the second type of key. The controller 52 is configured to determine whether the received one or more signals correspond to the first based on the one or more signals received from the key matrix 11 and information pre-stored in the memory 46. One or more of the types of keys or the second type of keys.

FIG. 13 is a diagram illustrating an example of the memory 46 and the relationship between the information stored in the memory 46 and the keys on the keyboard 50. Each key on keyboard 50 is mapped to a single address in memory 46. The content on each address represents whether the key corresponding to the address is one of the first type of key or the second type of key. For example, "0" can represent the first type of key, and "1" can represent the second type of key.

Figure 14 illustrates a procedure for fabricating a wireless keyboard 50 in accordance with an example of the present invention. In the design phase, the position of each key on the PCB is determined by the customer or application method, and the PCB is manufactured according to the position determined above. Since the winding for each key is made according to the kind of each key at the stage of designing the PCB, it becomes complicated and limited due to the complexity of the winding and the complicated structure of the winding; Therefore, when the IC is being designed, all the keys are designed to transmit signals. And, the IC is manufactured in a fab according to the concept of IC design. Information about the location and type of each key can be recorded into memory 46 during wafer testing, IC packaging, or after the IC is soldered to the PCB. The wireless keyboard can be manufactured according to the above-described program, and the keyboard can be customized according to the application method and the needs of the customer. For example, the wiring of the keyboard of the palm-sized device may be different from the wiring of a desktop or laptop. Therefore, the positions of the keys on each keyboard can be different. With the above procedure, the IC can be specially designed to enable all of the keys to transmit signals. Once the customer or application of the keyboard has been determined, the non-transmission characteristics of the second type of keys can be recorded by the wafer during testing, during IC packaging, or after the IC is soldered to the PCB. This memory is implemented in the memory. Therefore, it is possible to provide a wireless keyboard having different sizes and energy efficiency.

In describing a representative example of the present invention, the present specification has been presented as a particular sequence of steps for operating the method and/or program of the present invention. However, to some extent, the method or program does not rely on the specific order of steps set forth herein, and the method or program should not be limited to the particular order of the steps described. As will be appreciated by those skilled in the art, other sequences of steps are also possible. Therefore, the specific order of steps set forth in this specification should not be construed as limiting the scope of the claims. In addition, the scope of the patent application of the method and/or procedure of the present invention should not be limited to the performance of the steps in the order presented, and those skilled in the art can immediately understand that the order can be changed and still maintain the spirit of the present invention. Within the scope.

Those skilled in the art should be aware that changes can be made to the above examples without departing from the broad inventive concepts. Therefore, it is understood that the invention is not limited to the specific examples of the invention, and is intended to cover the modifications of the invention and the scope of the invention as defined by the appended claims.

10. . . wireless keyboard

11. . . Key matrix

12. . . Controller

12-1. . . Modulator

13. . . Quartz oscillator

14. . . Transmitter

14-1. . . Phase locked loop frequency synthesizer

14-2. . . Power amplifier

15. . . antenna

20. . . Wireless short-distance transmission system

twenty two. . . Controller

22-1. . . Modulator

twenty four. . . Transmitter

24-1. . . Phase locked loop

24-2. . . Power amplifier

24-3. . . Frequency selection pin

24-4. . . Modulated pin

30. . . Wireless short-distance transmission system

34. . . Transmitter

34-1. . . Fast lock phase lock loop

40. . . wireless keyboard

42. . . Controller

44. . . Transmitter

46. . . Memory

50. . . wireless keyboard

52. . . Controller

T1. . . Time point

T2. . . Time point

T3. . . Time point

111-115. . . step

The foregoing summary of the preferred embodiments of the invention, as well as For the purposes of illustration of the present invention, various drawings are illustrated in the drawings. However, it should be understood that the invention is not limited to the precise arrangements and devices disclosed. In each figure:

1 is a block diagram of a conventional wireless keyboard 10.

2 is a timing diagram illustrating signals generated by the quartz oscillator 13, the phase locked loop frequency synthesizer 14-1, the power amplifier 14-2, and the transmitter 14 in the conventional wireless keyboard of FIG.

3 is a timing diagram illustrating signals transmitted by the wireless short-range transmission system of the conventional wireless keyboard of FIG. 1.

4 is a block diagram of a wireless short range transmission system 20 in accordance with a first example of the present invention.

FIG. 5 is a timing chart illustrating signals generated by the crystal oscillator 13, the phase locked loop frequency synthesizer 24-1, the power amplifier 24-2, and the transmitter 24 shown in FIG.

Figure 6 is a block diagram of a wireless short range transmission system 30 in accordance with a second example of the present invention.

Fig. 7 is a timing chart showing signals generated by the crystal oscillator 13, the fast lock phase locked loop frequency synthesizer 34-1, the power amplifier 24-2, and the transmitter 34 shown in Fig. 6.

Figure 8 is a block diagram of a wireless keyboard 40 in accordance with third and fourth examples of the present invention.

Figure 9 is a flow diagram of a method performed by controller 42 as shown in Figure 8 for determining if transmitter 44 must be activated.

Figure 10 is a timing diagram illustrating the signals received by the controller 42 from the key matrix 11 and the signals transmitted by the transmitter 44 in accordance with the fourth example of the present invention as shown in Figure 8.

Figure 11 illustrates a procedure for manufacturing a wireless keyboard as shown in Figure 8.

Figure 12 is a block diagram of a wireless keyboard 50 in accordance with a fifth example of the present invention.

FIG. 13 is a diagram illustrating an example of the memory 46 shown in FIG. 12 and the relationship between the information stored in the memory 46 and the keys on the keyboard.

Figure 14 is a diagram for explaining a procedure for manufacturing a wireless keyboard as shown in Figure 12 .

13. . . Quartz oscillator

15. . . antenna

20. . . Wireless short-distance transmission system

twenty two. . . Controller

22-1. . . Modulator

twenty four. . . Transmitter

24-1. . . Phase locked loop

24-2. . . Power amplifier

24-3. . . Frequency selection pin

24-4. . . Modulated pin

Claims (19)

A wireless short-distance transmission system, comprising: a controller; a first oscillator; a transmitter comprising: a frequency selection pin and at least one modulation pin; and a phase locked loop frequency synthesizer via The frequency selection pin receives a reference signal from the first oscillator and receives a first modulation signal from the controller via a first pin of the at least one modulation pin, wherein the phase locked loop frequency The synthesizer is configured to be turned on by the first modulation signal to generate a carrier signal based on the reference signal, and the phase locked loop frequency synthesizer turns on and off in response to an ASK/OOK modulation signal; and a power amplifier Receiving the carrier signal and the second modulated signal from the phase locked loop frequency synthesizer, wherein the power amplifier is configured to be turned on and off by the second modulated signal, thereby generating based on the carrier signal a modulated signal, wherein the power amplifier is turned on after the phase locked loop frequency synthesizer is stabilized, and the phase locked loop frequency synthesizer The power amplifier is turned off, or turned off after the power amplifier has been turned off; and an antenna is used to transmit the modulated signal. The system of claim 1, wherein the power amplifier receives the second modulation signal from the controller via a second pin of the at least one modulation pin; and the controller includes an amplitude key shift ( ASK) and one of the on-off keying (OOK) modulators for generating the first modulation signal and the second modulation signal, wherein the frequency of the first modulation signal and the second modulation signal Same as amplitude but different in phase. The system of claim 1, wherein the controller comprises an amplitude key shift modulator and an open key control modulator One of the signals for generating the first modulation signal; and the transmitter further includes a phase delay circuit for receiving the first modulation signal and generating the second modulation signal, wherein the first modulation signal The frequency and amplitude of the second modulated signal are the same, but the phases are different. The system of claim 1, wherein the controller is configured to: transmit a start signal to the first oscillator to activate the first oscillator; and transmit the first modulated signal to the at least one modulated pin Activating the phase locked loop frequency synthesizer in one of: (i) when the controller receives a first feedback signal from the first oscillator representative that the first oscillator has stabilized, and (ii) After a first predetermined period of time, the first predetermined period of time is a time for stabilizing the first oscillator; and transmitting the second modulated signal to the power amplifier when one of: (i) when the controller The phase locked loop frequency synthesizer receives a second feedback signal representative of that the phase locked loop has stabilized, and (ii) after a second predetermined period of time, the time during which the phase locked loop synthesizer is stabilized. The system of claim 1, wherein the controller comprises a microprocessor and a microcontroller; the phase locked loop frequency synthesizer comprises a digital phase locked loop frequency synthesizer, a analog phase a locked loop frequency synthesizer, a digital fast lock phase locked loop (PLL), and one of a type of fast lock phase locked loop (PLL), wherein the phase locked loop frequency synthesizer further includes a second oscillator, And the phase locked loop synthesizer is turned on or off by turning the second oscillator on or off; and the modulated signal is converted into a radio frequency signal for transmission. A wireless keyboard comprising: a controller; a first oscillator; a transmitter comprising: a frequency selection pin and at least one modulation pin; a phase locked loop frequency synthesizer, via which the reference pin receives a reference from the first oscillator And receiving, by the first pin via the at least one modulation pin, a first modulation signal from the controller, wherein the phase locked loop frequency synthesizer is configured to be turned on by the first modulation signal Generating a carrier signal based on the reference signal, and the phase locked loop frequency synthesizer turns on and off according to an ASK/OOK modulation signal; a power amplifier for receiving the carrier from the phase locked loop frequency synthesizer a signal and a second modulation signal, wherein the power amplifier is configured to be turned on and off by the second modulation signal, thereby generating a modulated signal based on the carrier signal, wherein the power amplifier is in the phase The locked loop frequency synthesizer is turned on after being stabilized, and the phase locked loop frequency synthesizer is turned off with the power amplifier, or the power amplifier has been Turning off after turning off; and an antenna for transmitting the modulated signal; and a key matrix coupled to the controller. The wireless keyboard of claim 6, further comprising: a plurality of keys coupled to the key matrix, wherein the plurality of keys comprise a set of keys of the first type and a set of keys of the second type. Each of the first type of keys is associated with one of a plurality of predetermined functions; wherein the controller is further configured to: receive from the key matrix to represent at least one of the plurality of keys that have been selected a first signal determining, based on the first signal, whether at least one of the plurality of selected keys is one of the keys of the first type, and if the plurality of keys are selected At least one of the keys of the first type of key, i.e., activated for transmitting via the antenna The transmitter of the modulated signal, wherein the modulated signal carries information of one of the plurality of predetermined functions associated with at least one of the plurality of selected ones of the plurality of keys. The wireless keyboard of claim 7, wherein the controller is further configured to: determine whether at least one of the plurality of keys selected comprises two or more keys, and if the plurality of keys At least one of the selected ones includes two or more keys, the controller being further configured to determine whether the combination of the two or more keys corresponds to one of the plurality of predetermined functions, and if so When the combination of two or more keys is associated with one of the plurality of predetermined functions, the transmitter for transmitting the modulated signal via the antenna is activated, wherein the modulated signal carries and Information relating to one of the plurality of predetermined functions associated with the combination of two or more keys. A wireless keyboard as claimed in claim 8 wherein each of the second type of keys is only one of the plurality of keys of the second type and the plurality of keys At least one of the other ones is associated with one of the plurality of predetermined functions. For example, the wireless keyboard of claim 9th, wherein the first type of keys includes letters, numbers, symbols, punctuation keys, enter, backspace, tab, and caps lock (Caps Lock) At least one of the keys, and the set of second keys includes at least one of a control (Ctrl), a shift (Shift), and an alt (alt) key. The wireless keyboard of claim 7, further comprising: a memory coupled to the controller for storing each of the plurality of keys to be the first type Predetermined information of one of the keys or one of the second types of keys, wherein the controller determines at least one of the plurality of keys based on the first signal and the predetermined information Whether it is one of the first type of keys. The wireless keyboard of claim 11, wherein the memory comprises a plurality of memory locations, each memory location being identified by a memory address, the memory being configured to store the plurality of keys associated with the memory And a predetermined mapping information of the plurality of memory locations, each of the plurality of memory locations storing a flag representing the corresponding key as the first type of key or the second type of key . A wireless short-range transmission system, the system comprising: an oscillator for generating a reference clock signal; a controller for transmitting a first modulation signal and a signal subsequent to the first modulation signal a second modulation signal; a phase locked loop frequency synthesizer that is turned on in response to the first modulation signal and is turned off in response to a falling edge of the second modulation signal, the phase locked loop frequency synthesizer being based The reference clock signal generates a carrier signal; and a power amplifier for generating a modulated signal based on the carrier signal, the power amplifier being turned on in response to a rising edge of the second modulated signal, and responsive Closed at the falling edge of the second modulation signal. The system of claim 13 wherein the controller is configured to transmit the first modulated signal when the oscillator is stable. A system of claim 13 wherein the controller is configured to transmit an enable signal to activate the oscillator and then transmit the first modulated signal after a predetermined period of time. The system of claim 13, wherein the controller is configured to transmit the second modulation signal when the phase locked loop frequency synthesizer is stable. The system of claim 13, wherein the controller is configured to transmit the second modulated signal after the phase locked loop frequency synthesizer becomes stable for a predetermined period of time. The system of claim 13, wherein the controller is coupled to a keyboard matrix coupled to a set of keys of the first type, each of which is associated with one of a plurality of functions, and a second set of Keys, each of which acts as the Wait for the first type of key and the other type of one of the keys to modify the key. The system of claim 18, wherein the controller is configured to determine whether at least one of the keys of the first type is selected and cause transmission of a modulated signal, the bearing and the Information relating to one of the plurality of predetermined functions associated with at least one of the selected types of keys.