1. Field of the Invention
The present invention relates generally to wireless information transmission systems including a wireless transmit device and a wireless receive device communicating information with each other, and particularly to wireless information transmission systems free of illegal operations if there is an interruption in transmission of information between the wireless transmit device and the wireless receive device.
2. Description of the Background Art
Information apparatus like computers can have a wireless system connecting a main unit of the computer with its peripherals such as a mouse or a keyboard. In such system, data input is transmitted from peripherals to the main unit by wireless.
For example, whenever a key is pressed or released on a keyboard, the code assigned to the key is transmitted to the main unit by wireless. After receiving the code, the main unit decodes it and provides a predetermined input/output operation.
A main unit of a computer can support an auto-repeat function to repeatedly input the data corresponding to a code received from a peripheral to an application program if the code from the peripheral is not followed by any codes that are received within a predetermined period of time. If the main unit with such auto-repeat function supported receives a code indicating that a key is pressed and thereafter fails to receive a code indicating that the key is released, unintended data will be continuously inputted until a code indicating that a next key is pressed is actually received. To overcome such disadvantage, a method is disclosed in Japanese Patent Publication No. 2766125.
Reference will now be made to FIG. 14 to describe one example of an operation according to the method disclosed in the publication. For example, when on a keyboard the xe2x80x9cAxe2x80x9d key is pressed, a main unit of a computer receives a Press code and thus recognizes that the xe2x80x9cAxe2x80x9d key is pressed and the main unit thus inputs a letter xe2x80x9caxe2x80x9d to an application program. When the xe2x80x9cAxe2x80x9d key is released on the keyboard, the main unit receives a Release code and thus recognizes that the xe2x80x9cAxe2x80x9d key is released and the main unit thus stops inputting the letter xe2x80x9ca.xe2x80x9d
When on the keyboard the xe2x80x9cBxe2x80x9d key is pressed, the main unit recognizes that the xe2x80x9cBxe2x80x9d key is pressed and thus inputs a letter xe2x80x9cbxe2x80x9d to the application program. However, if the main unit fails to receive a code indicating that the xe2x80x9cBxe2x80x9d key is released when the xe2x80x9cBxe2x80x9d key is released, then the letter xe2x80x9cbxe2x80x9d would be repeatedly inputted to the application program.
To overcome such disadvantage, the keyboard calculates the number of keys being pressed which is in turn transmitted as press-count information to the main unit. The main unit can refer to the press-count information consecutively to determine the condition of the keyboard and thus determine that the key has been released. When the keys of the keyboard are all released, data indicating a press count of zero is transmitted from the keyboard to the main unit. As such, if the main unit fails to receive a code indicating that the xe2x80x9cBxe2x80x9d key is released, it can check that any keys are not being pressed. Thus the main unit can stop repeatedly inputting the letter xe2x80x9cb.xe2x80x9d
This method is applicable to a toggle operation which, as with the Caps Lock key, switches between setting and canceling an input mode in response to a series of output codes indicating that a key is pressed or released. More specifically, if a main unit of a computer fails to receive a code indicating that the Caps Lock key is released, the main unit can refer to the press-count information consecutively to be informed that the Caps Lock key is released. Thus the toggle operation can be provided accurately and consistency between the condition of the keyboard and the condition of the main unit can be maintained.
In accordance with the above method, however, the exact key data indicating the press count of zero will not be transmitted when a failure occurs in a communication channel, e.g., when after a key is pressed the exact key data is still not transmitted for a period of time or transmitted at all. For example, the exact key data indicating the press count of zero will not be transmitted if a fatal error occurs in a keyboard""s wireless transmit portion or a main unit""s wireless receive portion. As such, as shown in FIG. 15, the auto-repeat condition is maintained until the communication channel recovers or until the key information including the initial-press count is communicated after the recovery of the communication channel. This means that if the keyboard suffers abnormal communication, the main unit in effect normally operating appears to operate illegally, and there also be incurred a possibility of delay of other applications or the entire system fault.
Furthermore, in the above method, even after a keyboard has its keys all released a Release code indicating that any key is not pressed is repeatedly transmitted at intervals as predetermined. This complements cancellation of a repeated input when data reception fails, by repeatedly transmitting a state indicating that any key is not pressed, and is also required for preventing the above-mentioned apparent illegal operations. On the other hand, the keyboard transmits a wireless signal in spite that there is not an event that a key is in effect passed. Therefore, this method has significantly bad effects for battery-driven wireless equipment and thus results in a wasteful power consumption.
The present invention has been made to overcome the above disadvantage.
The present invention contemplates a wireless information transmission system prevented from consecutive auto-repeat condition entered if a failure has occurred in a communication channel.
The present invention also contemplates a wireless information transmission system reducing wasteful power consumption.
In accordance with the present invention in one aspect a wireless information transmission system includes a wireless transmit device transmitting information by wireless signal and a wireless receive device receiving information by wireless signal from the wireless transmit device. The wireless transmit device includes an input portion for a user to input an instruction therethrough, a transmit portion transmitting information to the wireless receive device by wireless signal, and an information generation control portion connected to the input portion and the transmit portion of the transmit device, to transmit instructions at predetermined intervals while input continues from the input portion. The wireless receive device includes a receive portion receiving an instruction transmitted from the wireless transmit device by wireless, and an operation portion connected to the receive portion of the receive device to operate according to the instruction received by the receive portion on the receive device.
Since the wireless transmit device can transmit at predetermined intervals while an instruction input sustains from the input portion, the wireless transmit device can provide a transmission of the instruction minimized as required to achieve reduced power consumption and the instruction can also be used for detection of communication-channel failure.
The input portion may include equipment having a single or multiple keys, buttons, touch panels and the like for input, such as a mouse, a keyboard and a remote controller.
Preferably the wireless transmit device also includes a receive portion receiving information transmitted from the wireless receive device. The wireless receive device also includes a transmit portion by wireless signal to transmit information to the wireless transmit device.
Between the wireless transmit device and the wireless receive device there can be provided a bi-directional communication. As such, the wireless transmit device and the wireless receive device can exchange data, as appropriate, to provide an enhanced reliability of data transmission.
Still preferably, when the instruction from the wireless transmit device is not received for a period of time, the operation portion transmits a request to retransmit the instruction to the wireless transmit device via the transmit portion of the receive device. When the request to retransmit the instruction is received via the transmit device""s receive portion the information generation control portion retransmits the instruction via the transmit portion.
In case that a request to retransmit the instruction is made and the instruction is still not received, the wireless receive device can determine that a failure has occurred in a communication channel. As such, if with an instruction being transmitted a failure has occurred in a communication channel, the wireless receive device can independently cancel an auto-repeat condition of an input.
Still preferably if any instruction is not received from the wireless transmit device for a predetermined period of time the operation portion determines that the wireless transmit device completes providing an instruction.
The wireless receive device, with a decision made that the wireless transmit device completes providing the instruction, can provide a process such as canceling repeat function, without being affected by the failure in the communication channel.
Still preferably the wireless transmit device also includes a receive portion receiving information transmitted from the wireless receive device by wireless signal. The wireless receive device also includes a transmit portion transmitting information to the wireless transmit device by wireless signal. The information generation control portion responds to an information-transmission permitting signal received from the wireless receive device via the transmit device""s receive portion for transmitting the instruction from the input portion to the wireless receive device via the wireless transmit device""s transmit portion, and while the instruction continues from the input portion, for transmitting the instruction whenever the information-transmission permitting signal is received a first predetermined number of times. Whenever a predetermined process completes the operation portion transmits the information-transmission permitting signal via the wireless receive device""s transmit portion to the wireless transmit device.
In case that an instruction is inputted continuously from the input portion, the wireless transmit device transmits the instruction whenever it receives an instruction from the wireless receive device a first, predetermined number of times. Thus the wireless transmit device can provide a transmission of the instruction minimized as required to achieve reduced power consumption.
Still preferably, when in spite that the information-transmission permitting signal is received a second, predetermined number of times any instruction is still not received from the wireless transmit device, the operation portion determines that the wireless transmit device completes providing an instruction.
The wireless receive device, with a decision made that the wireless transmit device completes providing an instruction, can provide a process such as canceling a repeat function without being affected by the failure in the communication channel.
Still preferably, if a single instruction is continuously transmitted, for any transmission(s) of the single instruction subsequent to a first transmission thereof the information generation control portion transmits status information indicating that the same, single instruction as initially transmitted is transmitted.
When a single instruction continues, the instruction can be transmitted only once, thereafter status information can be transmitted. As such, the wireless transmit device can transmit a reduced amount of data to the wireless receive device, and as a result it can achieve a reduced power consumption.
In accordance with the present invention in another aspect a wireless transmit device is used in a wireless information transmission system including a wireless transmit device transmitting information by wireless signal and a wireless receive device receiving information transmitted from the wireless transmit device by wireless signal. The wireless transmit device includes an input portion for user to input an instruction therethrough, a transmit portion transmitting information to the wireless receive device by wireless signal, and an information generation control portion connected to the input portion and the transmit portion to transmit via the transmit portion at predetermined intervals while any instruction input continues from the input portion.
In accordance with the present invention in still another aspect, a wireless receive device is used in a wireless information transmission system including a wireless transmit device transmitting information by wireless signal and a wireless receive device receiving information transmitted from the wireless transmit device by wireless signal. The wireless receive device includes a receive portion receiving an instruction transmitted from the wireless transmit device by wireless signal, and an operation portion connected to the receive portion and operating according to an instruction received by the receive portion and determining that the wireless transmit device completes providing an instruction if any instruction is not received from the wireless transmit device for a predetermined period of time.
When in the wireless transmit device the information generation control portion detects that an event that a key is pressed has occurred, the information generation control portion changes a key status for the key to a Press state. The information generation control portion transmits key data for the pressed key to the wireless receive device via the transmit device""s transmit portion.
The information generation control portion transmits the key data and also holds the pressed key""s status until the key is released, and determines the status whenever a defined period of time elapses. As shown in FIG. 1, if a held status does not change or a key is kept pressed, the key data which is identical to that previously transmitted is transmitted to the wireless receive device.
As such, with a key being pressed, wireless data is transmitted whenever the defined period of time elapses. If a key status is held in the Press state, the wireless receive device expects that the wireless transmit device should transmit the same data at least once whenever the defined period of time elapses.
If the same data is not received from the wireless transmit device within the defined period of time, then the operation portion determines that a failure has occurred in a communication channel, and the operation portion, with an auto-repeat condition entered, cancels such state and, without the auto-repeat condition entered, prevents the state from being entered.
A description will now be provided of a wireless information transmission system with a wireless transmit device and a wireless receive device each having a transmit portion and a receive portion. When an event that a key is pressed has occurred, the information generation control portion of the wireless transmit device, as well as that of the previously mentioned wireless information transmission system, changes the key""s status to a Press state and transmits key data to the wireless receive device via the transmit device""s transmit portion.
The information generation control portion, until a pressed key is released, transmits the same data as previously transmitted key data or status information indicating the same input provided via a key, to the wireless receive device repeatedly at predetermined intervals.
With any key held in the Press state, the wireless receive device expects that it should receive the same data from the wireless transmit device at least once whenever a predetermined period of time elapses. However, if within the predetermined period of time the wireless receive device does not receive from the wireless transmit device the same data or a status indicating the same input provided via a key, then the wireless receive device""s operation portion determines a failure has occurred in a communication channel. Then to check such failure the wireless receive device transmits control data (a request to retransmit data) to the wireless transmit device. The wireless transmit device receives the control data from the wireless receive device and thus retransmits the key code.
The wireless receive device after the control data is transmitted determines whether data reception is achieved and a content of received data. If the same data or status information indicating the same input provided via a key is not received and the auto-repeat condition is also entered, the wireless receive device performs a process to cancel the auto-repeat condition. If the auto-repeat condition is not entered, then the wireless receive device performs a process to prevent the auto-repeat condition from being entered.
Furthermore, when the wireless receive device""s operation portion recognizes that in a communication channel a failure has occurred, the operation portion transmits control data to the wireless transmit device. Simultaneously the operation portion, with the auto-repeat condition entered, performs a process to cancel such state and, without the auto-repeat condition entered, performs a process to prevent the auto-repeat condition from being entered.
A description will now be provided of a wireless information transmission system wherein a wireless receive device""s operation portion provides to a wireless transmit device a permission to transmit information and according such permission the wireless transmit device transmits information.
When an event that a key is pressed has occurred, the wireless transmit device""s information generation control portion, as well as the previously mentioned wireless transmit device""s information generation control portion, changes a status for the key to the Press state, the information generation control portion generates key data to be transmitted to the wireless receive device and then waits for a permission to transmit information that is provided from the wireless receive device. It is not until such permission is received from the wireless receive device that the information generation control portion transmits the key data to the wireless receive device.
Also, until the key is released, the wireless transmit device repeatedly transmits to the wireless receive device the same data as previously transmitted key data or status information indicating the same input provided via a key whenever it receives from the wireless receive device a permission to transmit information a first, predetermined number of times.
With a specific key held in the Press state, the wireless receive device expects that it should receive data from the wireless transmit device at least once whenever it transmits a permission to transmit information a second, predetermined number of times. It should be noted that the second, predetermined number of times is larger in value than the first, predetermined number of times.
However, if within the second, predetermined number of times the wireless receive device does not receive from the wireless transmit device the same data or a status indicating the same input provided via a key, the wireless receive device""s operation portion determines a failure has occurred in a communication channel. To check such failure the wireless receive device may transmit control data to the wireless transmit device. The wireless transmit device receives the control data from the wireless receive device and thus retransmits the key code.
The wireless receive device""s operation portion after the control data is transmitted determines whether data reception is achieved and a content of received data. If the same data or status information indicating the same input via a key is not received and the auto-repeat condition is also entered, the operation portion performs a process to cancel the auto-repeat condition. If the auto-repeat condition is not entered, then the operation portion performs a process to prevent the auto-repeat condition from being entered.
The wireless transmit device""s input portion may be configured of a plurality of components. For example, it may be a keyboard with a plurality of keys together with a pointing device such as a trackball mounted.
In such apparatus as configured above, there exist in parallel a portion which processes signals input via the pointing device and a portion which processes signals input via the keyboard. As such, the information generation control portion may deal with such input signals collectively. More specifically, if there are a plurality of input portions, the information generation control portion directly controlling the transmit portion of the transmit device can eliminate the necessity of providing for each input portion a mechanism exclusively using the transmit portion. From an event independently occurring from each input portion the information generation control portion generates data to be transmitted and transmits the data via the transmit portion to the wireless receive device.
In preparation for events simultaneously occurring from multiple input portions, a predetermined format may be provided to allow multiple events to be transmitted in single data. This allows the information generation control portion to notify the wireless receive device of multiple events in single data.
The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.