JPH104341A - Data transmission method - Google Patents

Abstract

(57) [Problem] To provide a data transmission method capable of significantly reducing current consumption in a light emitting element. When transmitting binary data indicating a count value n represented by a plurality of bits, a transmission carrier is turned on for a predetermined time τ at the start of transmission; a fixed delay time t
And a time Tn obtained by adding a time corresponding to the count value n,
Turn off the transmission carrier;
During this time, data transmission is performed by turning on. The time Tn for turning off the transmission carrier is Tn = t + na.
(Where a is a constant time).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a data transmission method, and more particularly, to a method of transmitting binary data indicating a count value represented by a plurality of bits from a wireless pointing device used as an input device of a personal computer.

[0002]

2. Description of the Related Art As is well known, in a personal computer, a pointing device is used as an input device used to designate a position on a screen of a display device such as a CRT display or to designate coordinate data. Such pointing devices use graphical user interfaces (GUIs) like Macintosh and Windows.
It is a standard input device for personal computers that employ.

[0003] Pointing devices include a mouse and a track ball which indicate a position on coordinates according to a moving direction and a moving amount. In recent notebook personal computers, a new type of pointing device, such as a “touch pad”, has replaced the conventional track ball.

[0004] A mouse is a small input device, such as a cigarette box, with a rotating ball on the back, as is well known.
The ball is rotated by moving the mouse on the desk, and the data is input as data of the moving direction and the moving distance.
The name of the connection cable that connects to a personal computer is long because it looks like a mouse. A relative coordinate point input device such as a mouse displays a symbol called a mouse cursor on a screen of a display device by using X and X orthogonal to each other.
It is necessary to move in the direction (horizontal direction on the screen) and the Y direction (vertical direction on the screen). On a desk or the like, the X direction is the left-right direction, and the Y direction is the front-back direction. Therefore, the relative coordinate point input device includes an X encoder that holds an X count value indicating the amount of movement in the X direction, and a Y encoder that indicates the amount of movement in the Y direction.
A Y encoder for holding a count value, and a switch button pressed to determine a position. The count values such as the X count value and the Y count value are represented by binary data represented by a plurality of bits. In addition, the relative coordinate point input device, in addition to the count value indicating the movement amount,
A value indicating the moving direction (a bit indicating positive or negative in the X direction and Y
(A bit indicating the sign of the direction). Therefore, the count value takes zero or a positive value.

Recently, a wireless mouse using infrared rays instead of a connection cable for connecting to a personal computer has appeared. A pointing device that uses infrared light, such as a wireless mouse, is collectively referred to as a wireless pointing device. The wireless pointing device transmits (emits) the binary data indicating the count value represented by the plurality of bits to the receiving unit (light receiving unit) of the personal computer using infrared rays. Work as The transmission of the binary data indicating the count value is as follows.
This is performed when a count value other than “0” is detected and when the state of the switch button changes.

[0006] Conventionally, in a wireless pointing device, data transmission is performed using a transmission format (transmission line code) similar to that used in a remote controller or the like. This transmission format is
The logic "0" and the logic "1" constituting the binary data are defined in advance, and the binary data is transmitted using the logic. Generally, logic "0" and logic "1" are distinguished by the time at which the transmission carrier is turned on. That is, pulse duration modulation (pulse duration modulation) for converting logic “0” and logic “1” into a pulse length as a transmission line code.
ion) method.

[0007] When transmitting binary data using infrared rays, a pulse representing information of logic "0" and logic "1" is determined in advance, and a pulse is transmitted to the transmitting unit using the pulse. Data is exchanged with the receiving unit. The pulse for transmitting the predefined logic "0" is called a logic "0" pulse, the pulse for transmitting the logic "1" is called a logic "1" pulse, and these are collectively called a logic format. .

FIG. 7 shows transmission line codes of logic "0" and logic "1". As is clear from FIG. 7, the time (pulse width) τ ₀ for turning on the transmission carrier in the logical “0” pulse transmitting the logical “0” is determined by the transmission in the logical “1” pulse transmitting the logical “1”. It is shorter than the time (pulse width) τ ₁ for turning on the carrier (τ ₀ <τ ₁ ). In FIG. 7, T is a pulse repetition period.

The 8-bit binary data “01010111” whose count value is “83 (D)” in decimal.
In this case, in the conventional data transmission method, the transmission carrier needs to be turned on eight times as shown in FIG. 8. In the wireless pointing device, as described above, Since it is necessary to transmit binary data indicating the X count value and the Y count value,
Assuming that each count value is represented by 8 bits, it is necessary to turn on the transmission carrier a total of 16 times, 8 times each for the X count value and the Y count value.

[0010]

As described above, in the conventional data transmission method, in order to transmit binary data, it is necessary to turn on the transmission carrier a number of times corresponding to the number of bits constituting the binary data. There is. For this reason, the conventional data transmission method has a disadvantage that the number of times that the transmission carrier is turned on is greatly increased, and accordingly, the current consumed by the light emitting element that emits infrared light is also increased.

Accordingly, an object of the present invention is to provide a data transmission method capable of greatly reducing current consumption in a light emitting element in view of the above-mentioned conventional problems.

[0012]

According to a first aspect of the present invention, in a method for transmitting binary data indicating a count value n represented by a plurality of bits, a transmission carrier is set at a predetermined time for a predetermined time. Turning on the transmission carrier for a predetermined delay time t plus a time corresponding to the count value n for turning off the transmission carrier; turning on the transmission carrier for the predetermined time. And a data transmission method characterized by including the following.

In the data transmission method according to the first aspect, the time Tn during which the transmission carrier is turned off is represented by, for example, Tn = t + na (where a is a constant time).

According to a second aspect of the present invention, there is provided a method for transmitting binary data indicating an X count value n (X) and a Y count value n (Y) each represented by a plurality of bits. At the start, the transmission carrier is
ON; X count value n at a fixed delay time t
The transmission carrier is turned off for a time Tn (X) obtained by adding a time corresponding to (X); the transmission carrier is turned on for the predetermined time; and the Y count value is added to the predetermined delay time t. Time Tn obtained by adding time corresponding to n (Y)
(Y) turning off the transmission carrier; turning on the transmission carrier for the predetermined time period.

In the data transmission method according to the second aspect, the times Tn (X) and Tn (Y) for turning off the transmission carrier are, for example, Tn (X) = t, respectively.
+ N (X) · a and Tn (Y) = t + n (Y) · a
(Where a is a constant time).

[0016]

Embodiments of the present invention will be described below in detail with reference to the drawings.

Referring to FIG. 1, a data transmission method according to the first embodiment of the present invention will be described. This data transmission method is a method of transmitting binary data indicating a count value n represented by a plurality of bits. In FIG. 1, (a)
Shows carrier transmission when the count value is "0" in decimal, (b) shows carrier transmission when the count value is "1", and (c) shows "carrier" when the count value is decimal. 2 "indicates carrier transmission, and (d) indicates carrier transmission when the count value is" n "in decimal.

The data transmission method according to the first embodiment is as follows.
At the start of transmission, the transmission carrier is turned on for a predetermined time τ, the transmission carrier is turned off for a time Tn obtained by adding a time corresponding to the count value n to a fixed delay time t, and the transmission carrier is turned off for a predetermined time τ During this time, it is turned on.

Therefore, when the count value is "0",
As shown in FIG. 1A, the time T0 for turning off the transmission carrier is equal to T0 = t. When the count value is "1", as shown in FIG. 1B, the time T1 for turning off the transmission carrier is equal to T1 = t + a (where a is a constant time). Similarly, when the count value is "2", as shown in FIG. 1C, the time T2 for turning off the transmission carrier is equal to T2 = t + 2a. Generally, when the count value is “n”, as shown in FIG. 1D, the time Tn during which the transmission carrier is turned off is represented by Tn = t + na.

A data transmission method according to a second embodiment of the present invention will be described with reference to FIG. This data transmission method uses an X count value n represented by a plurality of bits.
This is a method of transmitting binary data indicating (X) and Y count value n (Y).

In the transmission method according to the second embodiment, the transmission carrier is turned on for a predetermined time τ at the start of transmission, and a time obtained by adding a time corresponding to the X count value n (X) to a fixed delay time t. The transmission carrier is turned off during Tn (X), the transmission carrier is turned on for a predetermined time τ, and a time Tn (Y obtained by adding a time corresponding to the Y count value n (Y) to a fixed delay time t. ), Turn off the transmit carrier,
The transmission carrier is turned on for a predetermined time τ.

In the transmission method according to the second embodiment,
The time Tn (X) and T for turning off the transmission carrier
n (Y) is Tn (X) = t + n (X) · a
And Tn (Y) = t + n (Y) .a (where a is a constant time).

A personal computer to which the data transmission method according to the second embodiment is applied will be described with reference to FIG. The personal computer includes a personal computer main body 10 and a CRT display 20.
, A wireless keyboard 30 and a wireless mouse 40. Wireless keyboard 30
Has a wireless pointing device 50. The personal computer body 10 is a wireless
A receiving unit (light receiving unit) 60 for receiving (receiving) infrared light transmitted (emitted) from the mouse 40 or the wireless keyboard 30 is provided.

FIG. 4 shows the wireless mouse 40 and the receiving unit 6.
0 is shown. The wireless pointing device 50 has the same configuration as the wireless mouse 40.

The wireless mouse 40 has an X encoder 41 for holding an X count value indicating the amount of movement in the X direction,
It includes a Y encoder 42 for holding a Y count value indicating the amount of movement in the Y direction, a switch button 43 pressed to determine a position, a main CPU 44, a sub CPU 45, and a light emitting element 46 that emits infrared light. . Main C
The PU 44 performs sampling of the X encoder 41, the Y encoder 42, and the switch button 43 as described later. The sub CPU 45 drives the light emitting element 46 to perform carrier transmission, as described later. The wireless mouse 40 uses the transmission method according to the above-described second embodiment to use an infrared ray to transmit X represented by a plurality of bits.
The binary data indicating the count value n (X) and the Y count value n (Y) is transmitted to the receiving unit 60.

The receiving section 60 has a light receiving element 61 for receiving infrared rays, a light receiving module 62, and a microcomputer 63. The microcomputer 63 reproduces binary data from the electric signal from the light receiving element 61 via the light receiving module 62.

Next, referring to FIG.
Will be described.

First, after clearing an operation flag (not shown) (step S1), the main CPU 44 sequentially samples the X encoder 41, the Y encoder 42 and the switch button 43 (steps S2, S3, S4).
Next, the main CPU 44 determines whether or not the X encoder 41 has counted in the X direction (step S5). X
If there is a count in the direction, the main CPU 44 stores an X count value n (X) in an X count register (not shown).
Is set (step S6), an operation flag is set (step S7), and the process proceeds to step S8. On the other hand, when there is no count in the X direction, the X count value n (X) is set to “0” (step S9), and the process proceeds to step S8.

In step S8, the main CPU 44
It is determined whether or not the Y encoder 42 has counted in the Y direction. If there is a count in the Y direction, the main CPU
44 sets a Y count value n (Y) in a Y count register (not shown) (step S10), sets an operation flag (step S11), and proceeds to step S12. On the other hand, when there is no count in the Y direction, the Y count value n (Y) is set to “0” (step S13), and the process proceeds to step S12.

In step S12, the main CPU 44
Determines whether the state of the switch button 43 has changed. If there is a change in the state of the switch button 43, the main CPU 44 updates the contents of a switch register (not shown) that holds the state of the switch button 43 (step S14), and sets an operation flag (step S14). S15) and proceed to step S16. On the other hand, when there is no change in the state of the switch button 43, the main CPU 44
Proceeds to step S16 while keeping the state of the switch button 43 (step S17).

In step S16, the main CPU 44 determines whether or not the operation flag has been set. If the operation flag has not been set, the main CPU 44 directly returns to step S2. On the other hand, if the operation flag has been set, the main CPU 44 activates the sub CPU 45 to perform carrier transmission (step S18), clears the operation flag (step S19), and proceeds to step S19.
Return to 2.

Next, the operation of carrier transmission performed by the sub CPU 45 will be described with reference to FIG. 6 in addition to FIG.

First, the sub CPU 45 turns on the transmission carrier (step S21), delays for a predetermined time τ (step S22), and turns off the transmission carrier (step S23). Subsequently, the sub CPU 45
X of the main CPU 44 is stored in a loop counter (not shown).
X count value n (X) held in count register
Is set (step S24). This set operation requires a certain delay time t.

Next, the sub CPU 45 determines whether or not the count value of the loop counter is "0" (step S25). The count value of the loop counter is "0"
If not, the sub CPU 45 decreases the count value of the loop counter by 1 (step S26), and
After a delay (step S27), the process returns to step S25. If the count value of the loop counter is "0" in step S25, the sub CPU 45 turns on the transmission carrier (step S28). Therefore, the time Tn (X) for turning off the transmission carrier is Tn (X)
= T + n (X) · a.

Next, the sub CPU 45 turns off the transmission carrier after a delay for a predetermined time τ (step S29) (step S30). Subsequently, the sub CPU 45
The main CPU 44 stores a loop counter (not shown)
Count value n held in the Y count register
(X) is set (step S31). This set operation requires a certain delay time t.

Next, the sub CPU 45 determines whether or not the count value of the loop counter is "0" (step S32). The count value of the loop counter is "0"
If not, the sub CPU 45 decreases the count value of the loop counter by 1 (step S33), and
After a delay (step S34), the process returns to step S32. If the count value of the loop counter is "0" in step S32, the sub CPU 45 turns on the transmission carrier (step S35). Therefore, the time Tn (Y) for turning off the transmission carrier is Tn (Y)
= T + n (Y) · a.

Next, after a delay of a predetermined time τ (step S36), the sub CPU 45 turns off the transmission carrier (step S37) and returns control to the main CPU 44.

Therefore, the binary data indicating the X count value n (X) and the Y count value n (Y) is received by the receiving unit 60.
It is only necessary to turn on the transmission carrier three times to transmit to. Therefore, current consumption in the light emitting element 46 can be significantly reduced. Thereby, it is possible to realize the wireless mouse 40 and the wireless pointing device 50 of the low current consumption type.

The present invention is not limited to the above-described embodiment, and it is needless to say that various changes and modifications can be made without departing from the spirit of the present invention.

[0040]

As is apparent from the above description, according to the present invention, when transmitting binary data indicating the count value, the off period of the transmission carrier interposed between the binary data and the time corresponding to the count value is determined. Since the transmission is performed only by turning on the two transmission carriers, the current consumption in the light emitting element can be significantly reduced.

[Brief description of the drawings]

FIG. 1 is a time chart illustrating a data transmission method according to a first embodiment of the present invention.

FIG. 2 is a time chart illustrating a data transmission method according to a second embodiment of the present invention.

FIG. 3 is a block diagram showing a personal computer to which the data transmission method shown in FIG. 2 is applied.

4 is a block diagram showing a configuration of a wireless mouse and a receiving unit in the personal computer shown in FIG.

FIG. 5 shows a main C in the wireless mouse shown in FIG. 4;
5 is a flowchart for explaining the operation of the PU.

FIG. 6 shows a sub CP in the wireless mouse shown in FIG.
6 is a flowchart for describing an operation of carrier transmission performed in U.

FIG. 7 is a diagram showing transmission line codes (transmission formats) of logic “0” and logic “1” in a conventional transmission method.

FIG. 8 is a time chart showing a conventional data transmission method.

[Explanation of symbols]

T0, T1, T2, Tn Time for turning off the transmission carrier Tn (X), Tn (Y) Time for turning off the transmission carrier τ Time for turning on the transmission carrier t Constant delay time a Constant time

Continued on the front page (51) Int.Cl. ⁶ Identification number Reference number in the agency FI Technical display location H04L 27/02 H04Q 9/00 361

Claims (4)

[Claims] 1. A method for transmitting binary data indicating a count value n represented by a plurality of bits, wherein a transmission carrier is turned on for a predetermined time at the start of transmission, and the count value n is set to a predetermined delay time t. A data transmission method, comprising: turning off the transmission carrier for a time Tn obtained by adding a time corresponding to the above, and turning on the transmission carrier for the predetermined time. 2. A time Tn for turning off the transmission carrier.
The data transmission method according to claim 1, wherein is represented by Tn = t + na (where a is a constant time). 3. A method for transmitting binary data indicating an X count value n (X) and a Y count value n (Y) each represented by a plurality of bits, comprising: The transmission carrier is turned off for a time Tn (X) obtained by adding a time corresponding to the X count value n (X) to a fixed delay time t. The transmission carrier is turned off for a time Tn (Y) obtained by adding a time corresponding to the Y count value n (Y) to the fixed delay time t, and the transmission carrier is turned off for the predetermined time. , Turning on the data. 4. A time Tn for turning off the transmission carrier.
(X) and Tn (Y) are represented by Tn (X) = t + n (X) · a Tn (Y) = t + n (Y) · a (where a is a constant time). 4. The data transmission method according to claim 3, wherein: