CN102681668B - Low power wireless keyboard - Google Patents

Abstract

The invention provides a wireless keyboard, which comprises a plurality of keys, a transmitter, an antenna and a controller. The plurality of keys includes a set of keys of a first type and a set of keys of a second type. Each of the plurality of first type keys is associated with one of a plurality of predetermined functions. The controller is configured to receive a first signal from the plurality of keys, the first signal indicating that at least one of the plurality of keys has been selected; determining whether a selected at least one of said plurality of keys is one of said first type of keys; and if the selected at least one of the plurality of keys is one of the first type of keys, activating the transmitter to transmit a second signal via the antenna, wherein the second signal carries information of one of the plurality of predetermined functions associated with the selected at least one of the plurality of keys.

Description

Low Power Wireless Keyboard

technical field

The present invention relates generally to wireless transmission, and more particularly to a low power wireless keyboard.

Background technique

Over the past few years, wireless short-range transmission systems have become more commonly used in devices such as remote controls or wireless keyboards. For example, a remote control or a wireless keyboard usually includes a set of keys, a key matrix, a controller, a transmitter, and a light emitting diode ("LED") for transmitting infrared (Infrared, "IR") signals. ), or an antenna for transmitting radio frequency (Radio frequency, "RF") signals. For example, FIG. 1 is a block diagram of a conventional conventional wireless keyboard 10 . Referring to FIG. 1, the wireless keyboard 10 may include a group of keys (not shown), a key matrix 11 and a wireless short-distance transmission system. The wireless short-distance transmission system includes a controller 12 , a crystal 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 . A quartz oscillator 13 is further coupled to the transmitter 14 , and the transmitter 14 is further coupled to the antenna 15 . The controller 12 may include a modulator 12-1 for generating a modulated signal. In operation, the controller 12 can transmit signals to the key matrix 11 or receive signals from the key matrix 11 . For example, the controller 12 is configured to scan the key matrix 11, and then find the signal representing "one or more keys are pressed", and transmit an activation signal ACT1 and a modulation signal MOD to the crystal oscillator 13 respectively. and the conveyor 14 . In response to the enable signal ACT1 , the crystal oscillator 13 can generate a reference signal REF with a desired frequency, and send the reference signal REF back to the transmitter 14 . The transmitter 14 may include a phase-lock loop frequency synthesizer (Phase-lock loop, “PLL” frequency synthesizer) 14-1 and a power amplifier (Power amplifier, “PA”) 14-2. The transmitter 14 can generate a modulated signal based on the reference signal REF received from the crystal oscillator 13 , another enable signal ACT2 , and the modulation signal MOD received from the controller 12 . The modulated signal is then converted into an RF signal and transmitted via the antenna 15 .

FIG. 2 is a timing diagram illustrating that after the controller 12 receives a signal representing "a key is pressed" from the key matrix 11, the process is performed by the crystal oscillator 13, the phase-locked loop 14-1, and the power amplifier. 14-2 and the signal generated by the transmitter 14. First, the controller 12 can start the quartz oscillator 13 to generate the reference signal REF with 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 can be activated by an activation signal ACT2 first, and then generate a carrier signal based on the frequency of the reference signal REF. 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 the antenna 15.

However, a conventional keyboard with a wireless short-range transmission system operating similarly to the above may consume a large amount of power. For example, suppose information is transmitted at 1 kilobit per second ("kbps"), and the bit time for logic high and logic low is the same (that is, the duty cycle is 50%), and the voltage of logic high and logic low 2 volts (V) and 0 V, respectively. In addition, the currents driving the 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 5mA. In addition, for wireless short-distance transmission, under the assumption of very low bit error rate (bit error rate), and, compared to the time length of the command, the phase lock loop frequency synthesizer lock period In the case of a relatively short length of time, the current consumed during the lock period of the phase lock loop frequency synthesizer is negligible. Therefore, the average current for delivering 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). Thus, the energy efficiency will be approximately 16000 nanojoules per bit ("nJ/bit") (ie, 8000 μA x 2V/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 on during the entire time period that the signal to be transmitted is being generated via the transmitter 14 . In other words, the phase-locked loop frequency synthesizer 14 - 1 in this wireless short-distance transmission system will consume energy during the period of generating logic "0" and "1". Therefore, the energy savings from using an energy-efficient phase-locked-loop frequency synthesizer is still limited. Therefore, there is a need to provide a wireless short-distance transmission system in which more energy can be saved by increasing the data rate and reducing the operation time of the PLL frequency synthesizer while the PLL frequency synthesizer is still operating.

In addition, as mentioned earlier, wireless short-range transmission systems are often used in wireless keyboards. Wireless keyboards generally include two types of keyboards. Each key of the first type is associated with its own function. The keys of the above-mentioned first type include, for example, text files, function keys (F1, F2, etc.), lock keys, navigation keys (up, down, etc.), and edit keys (delete, input, etc.) , etc.). The second type of key is a modifier key, which can only take effect when pressed simultaneously with other keys. Examples of the second type of key include Ctrl, Alt, and Shift. For example, to enter " A", the user will press "Shift" first, and then press "a". As shown in Figure 3, in the traditional wireless keyboard, when pressing "Shift", the keyboard will transmit the key code of "Shift", and When "a" is pressed, the keyboard sends the key code of "A". On the receiver side, such as a computer, usually when receiving the key code of "Shift", it does not execute the key code associated with the display. Any action, because "Shift" by itself is a meaningless command. The receiver will only perform an action when it receives a keycode of "A", for example, display the character "A" on the display. In other words, by The "Shift" keycode transmitted by the wireless keyboard does not provide any meaningful function. Therefore, there is a need for a wireless keyboard that passes when only a second type of key (such as "Shift") is pressed alone Omit data transmission, thereby saving energy. For users who are not familiar with typing and need to press the "Shift" key for a long time, the above energy-saving method is particularly effective. At the same time, for smaller devices, For example, handheld devices, because it is more difficult to find the correct text key on a small keyboard on a handheld device, and the user may hold down the "Shift" key for a longer duration. Therefore, the ability to save energy in small devices may even more significant and important.

Additionally, many conventional keyboards employ infrared (IR) signaling devices to transmit signals. The amount of current required to operate the light emitting diode (LED) light source alone (not including the current to operate the circuit) typically ranges from 40 to 100 mA. In addition, when using an infrared signaling device for signal transmission, since the IR signaling device requires line-of-sight operation, the wireless keyboard needs to be placed in an appropriate position relative to the receiver. Therefore, there is a need to provide a wireless keyboard with an environment-friendly wireless short-distance transmission system, which can transmit signals with lower power and does not require direct line of sight for operation.

Contents of the invention

The main purpose of the present invention is to provide a wireless keyboard to solve the above-mentioned problems in the prior art.

In order to achieve the above object, an example of the present invention provides a wireless keyboard, which includes a plurality of keys, a transmitter, an antenna and a controller. The plurality of keys includes a set of keys of a first type and a set of keys of a second type. Each of the first type of keys is associated with one of a plurality of predetermined functions. The controller is coupled to the plurality of keys and the transmitter. The controller is configured to receive a first signal from the plurality of keys, the first signal indicating that at least one of the plurality of keys has been selected; whether the selected at least one is one of the first type of keys; and if at least one of the selected at least one of the plurality of keys is one of the first type of keys, activating the transmitter to transmit a second signal through the antenna. The second signal carries information of one of the plurality of predetermined functions associated with the selected at least one of the plurality of keys.

Other objects, benefits and innovative features of the present invention will be understood from the following detailed examples of the present invention together with the accompanying drawings.

Description of drawings

The foregoing Summary of Preferred Examples of the invention, as well as the foregoing Detailed Description, are better understood when read in conjunction with the accompanying drawings. For the purpose of illustrating the present invention, presently preferred examples are shown in each drawing. It should be understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown. In each diagram:

FIG. 1 is a block diagram of an existing wireless keyboard 10;

FIG. 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. 1;

3 is a timing diagram illustrating signals generated by the wireless short-distance transmission system of the existing wireless keyboard of FIG. 1;

FIG. 4 is a block diagram of a wireless short-distance transmission system 20 according to a first example of the present invention;

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;

FIG. 6 is a block diagram of a wireless short-distance transmission system 30 according to a second example of the present invention;

FIG. 7 is a timing diagram illustrating signals generated by the quartz oscillator 13, the fast-locked phase-locked loop frequency synthesizer 34-1, the power amplifier 24-2, and the transmitter 34 shown in FIG. 6;

FIG. 8 is a block diagram of a wireless keyboard 40 according to third and fourth examples of the present invention;

FIG. 9 is a flowchart of a method executed by the controller 42 shown in FIG. 8 for determining whether the transmitter 44 must be activated;

FIG. 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 according to the fourth example of the present invention as shown in FIG. 8;

Figure 11 illustrates the procedure used to manufacture the wireless keyboard shown in Figure 8;

FIG. 12 is a block diagram of a wireless keyboard 50 according to a fifth example of the present invention;

FIG. 13 is a schematic 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;

FIG. 14 is a diagram illustrating a procedure for manufacturing the wireless keyboard shown in FIG. 12 .

Explanation of reference signs: 10: wireless keyboard; 11: key matrix; 12: controller; 12-1: modulator; 13: quartz oscillator; 14: transmitter; 14-1: phase lock loop frequency synthesizer; 14-2: Power amplifier; 15: Antenna; 20: Wireless short-distance transmission system; 22: Controller; 22-1: Modulator; 24: Transmitter; 24-1: Phase-locked loop; 24-2: Power Amplifier; 24-3: Frequency selection pin; 24-4: Modulation pin; 30: Wireless short-distance transmission system; 34: Transmitter; 34-1: Quick lock phase lock circuit; 40: Wireless keyboard; 42: Controller; 44: transmitter; 46: memory; 50: wireless keyboard; 52: controller; t 1: time point; t 2: time point; t 3: time point; 111-115: steps.

Detailed ways

Reference will now be made in detail to the examples illustrated in the accompanying drawings of the invention. Wherever possible, the same reference numerals are used throughout the drawings to represent the same or similar parts. Please note that the drawings described are drawn in simplified form and are not drawn to exact scale.

FIG. 4 is a block diagram of a wireless short-distance transmission system 20 according to a first embodiment of the present invention. Referring to FIG. 4 , the wireless short-distance transmission system 20 may include a controller 22 , a crystal oscillator 13 , a transmitter 24 and an antenna 15 for transmitting radio frequency (RF) signals. The controller 22 may include a modulator 22-1, and the transmitter 24 may 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. The 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 an analog phase-locked loop frequency synthesizer.

In an example according to the present invention, the above-mentioned components of the system 20 may be integrated into a chip, and the system 20 may be in the form of an integrated circuit ("IC"). In another example, system 20 may be part of an IC. In addition, the 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 controller.

The controller 22 is coupled to the crystal oscillator 13 and the transmitter 24 . When the controller 22 receives a trigger to start the crystal oscillator 13 or transmit the modulated signal, the controller 22 can use an activation signal ACT1 to start the crystal oscillator 13, so that the crystal oscillator 13 generates a reference signal REF, and The reference signal REF is then transmitted to the transmitter 24 via the frequency selection pin 24-3. The controller 22 may be configured to determine whether the crystal oscillator 13 has stabilized by receiving a feedback signal (not shown) from the crystal oscillator 13 or having a counter (not shown) to count a predetermined period of time. The predetermined period of time is roughly the time required to stabilize the quartz oscillator 13, and the time can be determined through experiments. 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 method to generate a modulated signal. In addition, since the controller 22 is a digital circuit, it needs a pulse signal to operate. In one example, the controller 22 may include an internal oscillator (not shown) for generating the pulse signal. In addition, the controller 22 can receive the pulse signal from the external crystal oscillator 13 . Furthermore, in another embodiment, the transmitter 24 may include another frequency selection pin (not shown) to receive a signal from the controller 22 and transmit the received signal to the phase locked The loop 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 diagram illustrating the timing of 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. picture. First, at time point t1, the controller starts the quartz oscillator 13 to generate a reference signal REF, which is sent to the phase-locked loop frequency synthesizer 24-1 of the transmitter 24. Once the controller 22 determines that the crystal 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- through 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. The carrier signal is then sent to a power amplifier 24-2. As shown in FIG. 5, the phase locked loop frequency synthesizer 24-1 is activated at time point t2 and stabilized at time point t3. The time required to stabilize the phase locked loop frequency synthesizer 24-1 is approximately 100 microseconds (μs). The times can vary depending on the design of the phase locked loop frequency synthesizer. The controller 22 may count the number of times required for 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 (for example, 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, a rising edge and a falling edge of a second modulation signal MOD2 respectively, thereby based on the carrier wave The signal and the second modulating signal MOD2 generate a modulated signal. Therefore, as shown in FIG. 5 , the output of the power amplifier may have the same waveform as the second modulation signal MOD2.

In one example, the phase-locked loop frequency synthesizer 24- and the power amplifier 24-21 can be driven to be turned off by the falling edge of the second modulation signal MOD2. In another example, the phase locked loop frequency synthesizer 24-1 may 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 with the same frequency and amplitude but different phases. In an example according to the present invention, the transmitter 24 may include a phase delay circuit (not shown), which receives a single modulation signal from the controller 22, and generates the first modulation signal MOD1 and the second modulation signal Signal MOD2. For example, the phase delay circuit may include a buffer for delaying the received modulation signal, thereby generating a second modulation signal MOD2, wherein the phase of the second modulation signal MOD2 is different from The received modulated signal. In another example according to the present invention, the two modulation signals MOD1 and MOD2 are both generated by the modulator 22-1 and sent to the phase-locked loop frequency synthesizer 24-1 through different modulation pins 24-4 with power amplifier 24-2.

The phase-locked loop frequency synthesizer 24-1 may include a voltage-controlled oscillator (VCO) and a frequency divider, which are the most power-consuming components in 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 the controller 22, the VCO can generate a carrier signal for the power amplifier 24-2. The modulated signal can then be converted to a radio frequency signal and transmitted via the antenna 15 coupled to the transmitter 24 .

The phase-locked loop frequency synthesizer 24-1 of the first embodiment of the present invention shown in FIG. 4 is not continuously turned on (ON) during the entire period during which the modulated signal is being generated. The wireless short-distance transmission system 20 of the first example consumes very little power and is more energy-efficient than the wireless short-distance transmission system in conventional wireless keyboards. Specifically, it can again be assumed that information is transmitted at 1 kbps, that the bit times for logic high and logic low are the same (i.e., the duty cycle is 50%), that the voltages for logic high and logic low are 2V and 0V, respectively, and that the crystal oscillator 13 The currents of the phase-locked loop frequency synthesizer 24-1 and the power amplifier 24-2 are 500μA, 5mA and 5mA respectively. Additionally, the phase locked loop frequency synthesizer lock time is typically approximately 1/10 of a 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 lock time of the phase locked loop frequency synthesizer is negligible. In addition, when the signal transmitted by the transmitter 24 is logic low, the most energy-consuming component, the 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 about 11000 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 mentioned above. Furthermore, the present invention uses RF signals to transmit the modulated signals, which is more energy efficient than using IR signals to transmit the modulated signals, and the wireless keyboard according to the present invention does not require direct Operate by sight. Therefore, those skilled in the art will be able to understand that the first example of the present invention requires less energy to transmit information than conventional short-range wireless transmission systems.

FIG. 6 is a block diagram of a wireless short-distance transmission system 30 according to a second embodiment of the present invention. The second embodiment shown in FIG. 6 is similar to the first embodiment shown in FIG. 4, but the difference is that the second embodiment includes a transmitter 34; the transmitter 34 includes a fast locking phase locked loop frequency The synthesizer 34-1 is different from the phase locked loop frequency synthesizer 24-1 of the first embodiment. The fast-locking phase-locked-loop frequency synthesizer 34-1 has significantly shorter lock times than the phase-locked-loop frequency synthesizer 24-1, and may be a digital fast-locking phase-locked-loop frequency synthesizer or an analog fast-locking phase-locked-loop frequency synthesizer. The fast-locking PLL frequency synthesizer 34-1 can be, for example, an integer-N PLL integrated with additional components to reduce the locking time. For example, it has been proposed to add a digital discriminator aided phase detector ("DAPD") in an integer-N PLL to accelerate the loop to a steady state. Another example of the fast-locking PLL frequency synthesizer 34 - 1 may be a fractional-N PLL, which has a more complex structure than the integer-N PLL, but has a shorter locking time. When the lock time is shorter, the bit rate may be increased, thereby thereby increasing the energy efficiency of the wireless short-distance transmission system 30 as described below with reference to FIG. 7 . The operation method of the second embodiment is the same or similar to the operation method of the first embodiment.

Fig. 7 illustrates that after the controller 22 receives the trigger, the crystal oscillator 13 shown in Fig. Signal timing diagram. As shown in FIG. 7, the lock time of the fast lock phase locked loop frequency synthesizer 34-1 is about 10 μs, which is 10 times shorter than that of the phase locked loop frequency synthesizer 24-1. Therefore, the bit rate of the transmitter 34 of the second embodiment is 10 kbps, which is 10 times higher than the bit rate of the transmitter 24 of the first embodiment. Therefore, in the second embodiment according to the present invention, the average current for transmitting a "1" and a "0" bit is also 5500 μA, but because the bit rate is increased due to the shorter lock time 10 times, the energy efficiency of the second embodiment of the present invention is about 1100 nJ/bit, which is 10 times more than the energy efficiency of the first embodiment. In other words, the second embodiment of the present invention uses less energy to transmit information.

FIG. 8 is a block diagram of a wireless keyboard 40 according to a third embodiment of the present invention. The wireless keyboard 40 includes a wireless short-distance transmission system similar or identical to the wireless short-distance 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 group of keys (not shown) connected to the key matrix 11 . The controller 42 is configured to scan the key matrix 11 to find out one or more signals representing "one or more keys are being pressed". If one or more signals representing "one or more keys are being pressed" are received by the controller 42, the controller 42 can make the wireless short-distance transmission system operate in a manner similar to or identical to that according to the first and second embodiments. A method for generating and transmitting modulated signals in an example wireless short-distance transmission system.

The fourth embodiment of the present invention is a wireless keyboard having the same components as the wireless keyboard 40, and the difference is that the transmitter 44 of the fourth embodiment may be the same as or similar to the transmitter 14 shown in FIG. 1 , such as One of the conveyor 24 shown in FIG. 4 or the conveyor 34 shown in FIG. 6 . The operation method of the fourth embodiment is the same as or similar to that of the third embodiment, except that the controller 42 of the fourth embodiment is configured to start 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 matrix example may be configured to determine whether the received one or more signals correspond to one or more of the first or second types of keys , and thus determine whether to activate the crystal oscillator 13 and the transmitter 44 to transmit information. The first type of keys each of which is associated with its own function. Keys of the first type include, for example, text keys, function keys (F1, F2, etc.), lock keys, navigation keys (up, down, etc.), and edit keys (delete, enter, etc.), usually arranged in a QWERTY style. wait). A second type of key is a modifier key, which only functions when pressed at the same time as other keys. Examples of the second type of keys include Ctrl, Alt, and Shift.

If the received signal corresponds to one of the keys of the first form, the controller 42 will trigger the quartz oscillator 13 and the transmitter in the same or similar manner to the first and second embodiments. 44. However, if the received signal corresponds to only one of the keys of the second type, the controller 42 will not transmit any signal to activate the crystal oscillator 13 or the transmitter 44 . In contrast, the controller 42 will wait for a subsequent signal from the key matrix 11 in the manner adopted. While the controller 42 is waiting for a subsequent signal, the controller 42 may completely power off itself, or turn off some of its components. In an alternative example of the fourth embodiment, when a signal representing that a key has been pressed is received by the controller 42, the quartz oscillator 13 is first activated, and in the subsequent operation, the transmitter 44 is only The one or more signals received are determined to correspond to one or more of the first or second types of keys, and are activated.

Fig. 9 is a flow chart of a method, has shown in the figure: after digital controller 42 has received one or more signals representing that one or more keys are being pressed from key matrix 11, controller 42 can execute and judge whether 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 whether two or more keys are being pressed. If two or more keys are being pressed, the controller 42 proceeds to step 113 to determine whether 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 keycode "A", however, the combination of "Alt" and "Shift" may not correspond to any keycode. If there is a key code corresponding to the combination of the two or more pressed keys, the controller 42 proceeds to start the quartz oscillator 13 and the transmitter 44, or when the quartz oscillator 13 has been started, then Only the transmitter 44 is activated and data is transmitted via the transmitter 44 in step 115 . The controller 42 can activate the quartz oscillator 13 and the transmitter 44, and transmit via the transmitter 44 according to any one of the methods described above with respect to the first and second examples shown in FIGS. 4 to 7 . The key code corresponding to the combination of the two or more pressed keys. On the other hand, if the controller 42 determines in step 113 that there is not any key code corresponding to the combination of the two or more pressed keys, the controller 42 will not activate the transmitter 44 .

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

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

The circuit system of the wireless keyboard 40 usually includes a printed circuit board ("PCB") and an IC chip. Fabrication of the wireless keyboard 40 generally includes the following steps: fabricating the IC on a wafer in a fab; testing the wafer; packaging the IC; and soldering the IC to a PCB. The PCB board is usually designed according to the application of the PCB board. FIG. 11 illustrates a procedure for manufacturing a wireless keyboard 40 according to an example of the present invention. When the IC is being designed, pins with a first number are assigned to be associated with a first type of key and pins with a second number are assigned to be associated with a second type of key. Then, according to the design concept of the IC, the IC is manufactured in a fab. Based on pin assignments from the foundry, customers can design a low power keyboard or keypad with keys at desired locations on a printed circuit board (PCB). The customer's PCB can then be fabricated accordingly. Therefore, the controller 42 in the wireless keyboard 40 manufactured according to the above-mentioned method will be able to determine whether the signal received from the key matrix 11 represents the first type of key or the second type of key, and according to the above-mentioned relationship in FIG. 9 to determine whether to transmit the signal via the transmitter 44.

The wireless keyboard 40 according to the present invention can be operated in at least one of the following two modes: an active mode, which is when the user is using the wireless keyboard 40 to transmit information; and a standby mode, which is when the user is not using the wireless keyboard 40 hour. When the wireless keyboard 40 is operating in the startup mode, the controller 42 repeatedly executes the method described in FIG. any signal. After the predetermined period has elapsed, the wireless keyboard 40 switches to the standby mode. When the wireless keyboard 40 is in standby mode, all of the components in the wireless keyboard may be powered off. When it is in the standby mode, the controller 42 receives a signal from the key matrix 11, and the controller 42 switches to the start-up mode and starts the procedure described in FIG. 9 .

FIG. 12 is a block diagram of a wireless keyboard 50 according to 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, but the difference is that the wireless keyboard 50 further includes a memory 46, in which some information has been pre-stored, which is related to the relative keys relative to the corresponding keys. Mapping information of addresses of the memory, and information indicating whether each key is a first type key or a second type key. The controller 52 is configured to, based on the one or more signals received from the key matrix 11 and information pre-stored in the memory 46, to determine whether the one or more signals received correspond to the first one or more of the first type of key or a second type of key.

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 an 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, a "0" could represent a first type of key and a "1" could represent a second type of key.

FIG. 14 illustrates a procedure for manufacturing a wireless keyboard 50 according to an example of the present invention. In the design stage, the position of each key on the PCB board is determined by the customer or the application method, and the PCB board is manufactured according to the position determined above. Due to the winding of each key according to the type of each key at the stage of designing the PCB board, it will become complicated and affected due to the complicated structure of the winding and the complicated structure of the winding. limit; therefore, when an IC is being designed, all keys are designed to be capable of transmitting signals. And, according to the conception of the IC design, the manufacturing of the IC is performed in a fab. Information about the location and type of each key may be recorded into memory 46 during wafer testing, during IC packaging, or after the IC is soldered onto the PCB. By manufacturing the wireless keyboard according to the above procedure, the keyboard can be customized according to the application and customer's needs. For example, a keyboard for a palmtop device may be wired differently than a desktop or laptop computer. Therefore, the positions of the equal keys can be different on each keyboard. Through the above procedure, the IC can be specially designed so that all the keys can transmit signals. Once the customer or application of the keypad has been determined, the non-transmitting characteristics of the second type of keys can be determined by adding Information recording is realized in the memory. Therefore, it is possible to provide energy-efficient wireless keyboards with different sizes.

In describing representative examples of the invention, the specification has presented the methods and/or procedures for operating the invention as a specific sequence of steps. However, to the extent the described methods or procedures do not rely on the specific order of steps set forth herein, the described methods or procedures should not be limited to the specific order of steps described. Other sequences of steps are also possible, as will be appreciated by those skilled in the art. Therefore, the specific order of steps presented in this specification should not be considered as limiting the scope of claims. Furthermore, claims relating to the methods and/or procedures of the present invention should not be limited to the performance of the steps in the order presented, as one skilled in the art will immediately appreciate that such order can be altered and still remain within the spirit of the invention and within range.

Claims (10)

1. A wireless keyboard, characterized in that it comprises: a plurality of keys, wherein the plurality of keys comprises a set of first keys and a set of second keys, each of the plurality of first keys is associated with one of a plurality of predetermined functions; a transmitter comprising a phase locked loop frequency synthesizer and a power amplifier; an antenna; and a controller coupled to the plurality of keys and the transmitter, wherein the controller is configured to: receiving a first signal from the plurality of keys, the first signal indicating that at least one of the plurality of keys has been selected, determining whether at least one selected among the plurality of keys is one of the plurality of keys of the first type based on the first signal, If at least one selected among the plurality of keys is one of the plurality of first keys, the transmitter is activated to transmit a second signal via the antenna, wherein the second signal bears the same value as the plurality of keys. information about one of the plurality of predetermined functions associated with at least one selected one of the plurality of keys; determining whether the selected at least one of the plurality of keys is one of the plurality of second keys based on the first signal, and If one of the plurality of keys is selected as one of the plurality of second keys, the controller turns off the power amplifier so that the power amplifier stops transmitting signals, or the controller turns off The phase-locked loop frequency synthesizer stops transmitting signals from the phase-locked loop frequency synthesizer. 2. The wireless keyboard according to claim 1, wherein the controller is further configured to: determining whether the selected at least one of the plurality of keys contains two or more keys, and If the selected at least one of the plurality of keys includes two or more keys, the controller is further configured to determine whether a combination of the two or more keys corresponds to one of the plurality of predetermined functions one, and if the combination of the two or more keys corresponds to one of the plurality of predetermined functions, activating the transmitter to transmit a third signal via the antenna, wherein the third signal carries the same information about one of the plurality of predetermined functions associated with the combination of the two or more keys. 3. The wireless keyboard according to claim 2, wherein each of said plurality of second keys is only activated when each of said plurality of second keys is in contact with at least one other of said plurality of keys is associated with one of the plurality of predetermined functions when received by the controller. 4. The wireless keyboard according to claim 3, characterized in that, The first set of keys includes at least one of letters, numbers, symbols, punctuation keys, enter, abdicate, tab and caps lock, and the second set of keys includes at least one of control, shift, and shift keys one. 5. The wireless keyboard according to claim 1, further comprising: a memory coupled to the controller, wherein the memory is configured to store predetermined information indicating each of the plurality of keys as one of the plurality of first keys or the plurality of keys one of the second keys, and where The memory includes a plurality of memory locations each identified by a memory address, the memory configured to store predetermined mapping information associated with the plurality of keys and the plurality of memory locations , each of said plurality of memory locations stores a flag indicating a corresponding key of said plurality of keys as said first type of key or said second type of key, and The controller determines whether at least one selected among the plurality of keys is one of the plurality of first-type keys based on the predetermined information. 6. The wireless keyboard according to claim 1, further comprising: a first oscillator; and in, The phase-locked loop frequency synthesizer is used to receive a reference signal from the first oscillator and a first modulation signal from the controller, wherein the phase-locked loop frequency synthesizer is configured to be controlled by the first a modulation signal is turned on to generate a carrier signal based on the reference signal; and The power amplifier is configured to receive the carrier signal and a second modulation signal from the phase-locked loop frequency synthesizer, wherein the power amplifier is configured to be turned on and off by the second modulation signal, and whereby the second signal is generated based on the carrier signal, wherein the power amplifier is turned on after the phase locked loop frequency synthesizer is stable, and the phase locked loop frequency synthesizer is turned off with the power amplifier, Or turn off after the power amplifier has been turned off. 7. The wireless keyboard according to claim 6, wherein the transmitter further comprises a frequency selection pin and at least one modulation pin; The phase locked loop frequency synthesizer receives the reference frequency signal from the first oscillator via the frequency selection pin, and receives the first modulation signal from the controller via the at least one modulation pin. change signal; the power amplifier receives the second modulation signal from the controller via the at least one modulation pin; and The controller includes one of an amplitude key shift and an on-off key modulator for generating the first modulation signal and the second modulation signal, wherein the first modulation signal and the The frequency and amplitude of the second modulated signal are the same, but the phase is different. 8. The wireless keyboard according to claim 7, wherein the controller is configured to: sending a third signal to the first oscillator to activate the first oscillator; transmitting the first modulation signal to the at least one modulation pin to activate the phase locked loop frequency synthesizer at one of the following conditions: (i) when the controller receives a first feedback signal from the first oscillator indicating that the first oscillator has stabilized, and (ii) after a first predetermined period, the first predetermined period being the time to stabilize the first oscillator; and transmitting the second modulated signal to the power amplifier at one of the following conditions: (i) when the controller receives a second feedback signal from the phase locked loop frequency synthesizer indicating that the phase locked loop has stabilized, and (ii) After a second predetermined period, the second predetermined period is the time to stabilize the phase locked loop frequency synthesizer. 9. The wireless keyboard according to claim 7, further comprising a key array, wherein The controller is configured to receive the first signal indicating that at least one key of the wireless keyboard is being pressed from the plurality of keys via the key array. 10. The wireless keyboard according to claim 6, characterized in that, The controller includes one of a microprocessor and a microcontroller; The phase-locked loop frequency synthesizer includes one of a digital phase-locked loop frequency synthesizer, an analog phase-locked loop frequency synthesizer, a digital fast-lock phase-lock loop and an analog fast-lock phase-lock loop, wherein the phase locked loop frequency synthesizer further includes a second oscillator, and the phase locked loop frequency synthesizer is turned on or off by turning on or off the second oscillator; and The modulated signal is converted into a radio frequency signal for transmission.