JPH0823355A - Transmitter-receiver - Google Patents

Abstract

PURPOSE:To attain a high rate of data transmission and to enhance the reliability of data discrimination in the transmitter-receiver employing infrared rays or the like. CONSTITUTION:A high level and a low level of a transmission signal in pairs form a unit bit while the waveform of the transmission signal is shaped. When a time length of each bit is T, a ''0'' of a binary signal is expressed and when a time length of each bit is 2T, a '1' of a binary signal is expressed. Furthermore, the time length of each bit is discriminated by measuring a period of a reference bit B0 and a 1st bit B1. Since the time length of the reference bit B0 is predetermined, the time length of the 1st bit B1 is discriminated. Then the period of the 1st bit B1 and a 2nd bit B2 is measured. Since the time length of the 1st bit is already discriminated, the time length of the 2nd bit is discriminated. Coding is made efficient by using each of the high level and the low level for a bit and the reliability of the discrimination is enhanced by discriminating the bit through the measurement of periods.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmitter / receiver used for transmitting / receiving a signal such as coordinate information from an input device for inputting coordinates to a main unit by wireless transmission such as infrared transmission, and particularly to a high-speed transmission / reception device. The present invention relates to a transmission / reception device that enables highly reliable signal transmission / reception.

[0002]

2. Description of the Related Art FIG. 11 shows an input device 3 capable of remotely inputting coordinate positions on a screen 1 provided in a device body such as a computer or a game device.
This device is the same as that described in the specification and drawings of Japanese Patent Application No. 5-317479. In FIG.
Reference numeral 1 is a CR of a device body such as a computer or an AV device
It is a T screen. A light emitting device 2 is fixed on the CRT screen 1, and the light emitting device 2 is provided with a light source 2a that emits reference light. At the tip of the input device 3, the detection unit 4 having the structure shown in FIG. 12 is provided. The detector 4 is provided with a light receiver 5, and in front of it a diaphragm 6 and a visible light cut filter 7 are provided.

When the optical axis orthogonal to the center of the aperture of the diaphragm 6 is the Z-axis, the Z-axis is the axis extending forward along the center of the input device 3. As shown in FIG. 13, the light receiving portion 5 is composed of a pin photodiode having four divided light receiving portions 5a, 5b, 5c and 5d. Taking the XY orthogonal coordinates orthogonal to the Z axis, 5a of the divided light receiving unit,
The set of 5b and the set of 5c and 5d are divided in the Y-axis direction, and
The group of b, 5d and the group of 5a, 5c are divided in the X-axis direction.

The aperture section 6 has a rectangular opening, and the infrared light emitted from the light source 2a is applied to the light receiving section 5 as rectangular spot light α. Each divided light receiving section 5
In a to 5d, the detection current based on the irradiation area of the spot light α is obtained. The detection output based on the irradiation area of the spot light α at each of the divided light receiving units 5a to 5d is Lu, R respectively.
Assuming u, Ld, and Rd, regarding the respective detection outputs, the difference between the light receiving output in the group of divided light receiving portions divided in the Y axis direction and the difference in the light receiving output in the group of divided light receiving portions divided in the X axis direction. By calculating the difference between the received light outputs, the inclination (θx, θy) of the Z axis extending in front of the input device 3 in the two-dimensional direction can be obtained. Thereby, the movement of the cursor mark 8 appearing on the screen 1 can be input. In this type of input device 3, it is necessary to transmit the coordinate information in the X direction and the coordinate information in the Y direction obtained by the above calculation to the device body having the screen 1. As the transmission means, that is, a transmission / reception device for transmission, one using infrared light emission can be considered.

FIG. 14 shows an example of a transmission signal adopted in an infrared remote control device used in a conventional household electric appliance. A signal having the waveform shown in FIG. 14 is emitted from the remote control device by infrared rays. The infrared rays are received by a device such as a household electric appliance, and the received light signal is waveform-shaped. Transmission data is discriminated from the rectangular wave signal whose waveform has been shaped. The transmission signal shown in FIG. 14 is a carrier signal of a predetermined frequency that is phase-modulated. At the head of this transmission signal, a signal 11 based on the transmission data follows the leader code 10 whose high level becomes the predetermined time length t1 and then becomes the low level at the predetermined time t2. Signal 1
1 represents the binary signals "1" and "0".
In the case of infrared transmission / reception, conventionally, as shown in FIG. 15 (A), when a high-level time length is a unit time T and a low-level time length that follows is a unit time T, a binary signal "0" is output. Expressed. As shown in FIG. 7B, when the high-level time length is the unit time T and the subsequent low-level time length is 3T, which is three times the unit time T, the binary signal "1" is expressed. Has been done.

[0006]

In the conventional transmitter / receiver using infrared rays, the binary signal "0" is represented by "2T" which is twice the unit time T, as shown in FIG. 15 (A). , A binary signal "1" is represented by "4T" which is four times the unit time. Therefore, "1"
Alternatively, the time length of a unit bit representing "0" is "2T" at the shortest and "4T" at the longest. Therefore, the time length for expressing 1 bit is "3T" on average.
Becomes In order to express 1 bit in this way, "3T"
Therefore, it takes a long time to transmit a certain data group. When the infrared transmitting device using the above-mentioned transmission data is used for the device body having the input device 3 and the screen 1 shown in FIGS. 11 to 13, the transmission rate of the coordinate input information from the input device 3 to the device body is It becomes too slow, and it becomes impossible to cope with high-speed movement of the cursor mark 8 on the screen 1.

In order to further increase the transmission rate in infrared transmission / reception using the transmission formats shown in FIGS. 14 and 15, the frequency of the carrier signal is increased and the pulse width (the unit time length T) is extremely increased. It needs to be shortened. However, in order to increase the frequency of the carrier signal, it is necessary to make the transmitter on the input device 3 side highly accurate, which is different from the conventional one. Further, in order to discriminate a short pulse width, it is necessary to increase the discrimination accuracy of the receiving device on the apparatus main body side, and the cost of the entire device becomes high.

The present invention is to solve the above-mentioned conventional problems, and an object thereof is to provide a transmitting / receiving apparatus capable of transmitting a transmission signal from a transmitting apparatus to a receiving apparatus at high speed and with high reliability. I am trying.

[0009]

SUMMARY OF THE INVENTION The present invention is directed to a transmitter for transmitting a phase-modulated signal, a waveform shaping section for shaping the received signal, and a high level time and low level of the waveform shaped signal. Binary signal "1""0" from time
In the transmitting / receiving device including a receiving device having a discriminating unit for discriminating the time, in the discriminating unit, a time when the waveform-shaped rectangular wave signal is at a high level and a time when the waveform is rectangular are a unit time T It is characterized in that it is measured as an integer multiple of the time T, and a binary signal of "1" or "0" is discriminated for each bit with each of the high level time and the low level time being a unit bit. Is.

Further, according to the present invention, there are provided a transmitting device for transmitting a phase-modulated signal, a waveform shaping section for shaping the waveform of the received signal, and a high level time and a low level time of the waveform shaped signal. In a transmission / reception device including a reception device having a discrimination unit for discriminating between "1" and "0" of a binary signal, the signal forms a unit bit at a high level and at a low level, and each bit forms a unit bit. The binary signal "1" or "0" is expressed depending on whether it is the unit time T or an integral multiple of the unit time T, and the discriminator determines a continuous high level and a low level or a continuous low level and a high level. The period of the bit of 2 units of the level is measured, and the type of the binary signal of the bit of the preceding stage within this period and the type of the binary signal of the bit of the subsequent stage within the period are determined from the above period. Features A.

In both of the above means, the transmission signal is transmitted from, for example, an infrared light emitting element provided in the transmitting device, and in the receiving device, a light receiving portion for receiving the infrared signal emitted from the light emitting element, and a waveform of this light receiving output. A waveform shaping section for shaping is provided. The discriminating unit for measuring the high-level time and the low-level time for the waveform-shaped signal has a self-timer or a clock oscillating unit, and measures the time based on the count of the timer or the clock signal. For example, it is a digital operation unit mainly composed of a CPU of a microcomputer.

In the second means, the time length of the reference bit provided at a predetermined position of the signal and the type of the binary signal are determined, and the cycle is measured with the starting position of the reference bit as the starting point. Determines the type of the binary signal of the first bit following the reference bit, and then determines the type of the binary signal of the second bit by measuring the period starting from the start position of the first bit. It is preferable that the type of binary signal of each bit is determined by repeating this.

The reference bit is, for example, a low-level bit of the reader code, and the time length of this bit is 2T or 4T, for example.

An integer multiple of the unit time T is, for example, twice, and when the time length of each bit is T, a binary signal "0" is given.
Is expressed and the time length is "2T (means twice T)".
When, the binary signal "1" is expressed.

Further, a parity bit is provided in one group of signals, and whether the parity bit is a binary signal type "1" of each high-level bit of the rectangular wave signal is an even number or an odd number, Alternatively, it is preferable to express whether the binary signal type “1” of each low-level bit is an even number or an odd number. In this case, only one of the parity bit corresponding to each high level bit and the parity bit corresponding to each low level bit may be provided.
It is preferable to have both parity bits in a group of signals. This parity bit is the same as each signal, and is "1" or "0" depending on whether the high-level or low-level time length is the unit time T or an integral multiple of the unit time T (for example, "2T"). Will be expressed.

In each of the above means, it is preferable that the number of bits in each of the high level and the low level of a group of signals is an odd number. However, the first bit of the signals of the first group is a high level bit, and the last bit is also a high level bit.

[0017]

In the above means, in the rectangular wave obtained by waveform-shaping the signal received by the receiving device, the unit bit is formed when the rectangular wave is at the high level and when it is at the low level. Each bit is a binary signal "1" or "0" depending on whether the high-level bit and the low-level bit are the unit time T or an integer multiple of the unit time T.
Is determined. "1" is twice the unit time T "2"
When expressed by "T", the maximum bit length is "2".
The shortest is “T”. Therefore, the average time length in which 1 bit is expressed is “1.5T”. In the conventional example shown in FIG. 15, since the average time length for expressing 1 bit is “3T”, the above means has twice the encoding efficiency of the conventional example shown in FIG. Therefore, even when the same resolution as the conventional infrared transmitter / receiver to which the signal format shown in FIG. 15 is applied is used, the present invention can realize a double transmission rate.

Next, in the signal format of the conventional infrared transmitter / receiver shown in FIG. 15, the unit time T is 0.
Although it was about 5 msec, in the present invention, the unit time T can be shortened to about 0.2 msec to further increase the transmission rate. Unit time T is 0.2 mse
When shortened to c or the like, for example, when a conventional infrared transmitting / receiving unit is used, a bit discrimination error may occur.

In order to deal with this case, according to the present invention, the high level and the subsequent low level cycle, or the low level and the subsequent high level cycle are time-measured for each cycle,
By previously recognizing "1" and "0" of the preceding bit in the same cycle, it is possible to determine the type of the binary signal of the subsequent bit in the cycle based on the measurement of the time length of one cycle. ing. For example, the low-level signal of the reader code is used as the reference bit, and its time length is set to, for example, "2T". The time length of the reference bit is known in advance by measuring the time of one cycle of the reference bit and the subsequent first bit with the start position of the reference bit as the starting point. Therefore, the binary signal of the first bit The type can be determined. Repeat this,
Measure the time length for each cycle and set 2 for each bit.
The type of the progress signal is determined.

When a signal using infrared rays is received and waveform-shaped, the time length of the signal is judged to be high level rather than individually measuring the high level time length and the low level time length. The measurement accuracy is higher when the time length of one cycle of low level or low level and high level is measured. Therefore, the discrimination error rate can be reduced by discriminating the type of the binary signal of each bit by measuring the time length for each cycle. Further, since the reliability of the bit determination based on the measurement of the time length for each cycle is high, even if the time length of the unit time T is shortened to, for example, about 0.2 msec, the bit determination accuracy does not significantly decrease. .

Further, according to the present invention, whether the parity bit expressing whether the number of "1" of the high level bit is an even number or the odd number or the number of "1" of the low level bit is an even number. Of the parity bit that represents whether it is an odd number,
By including either one or both parity bits in one group of signals, the reliability of signal discrimination is further improved.

Since the transmission signal of the present invention uses both high level and low level as unit bits, if the first bit of a group of signals is set to high level and the total number of bits is odd, The bit always becomes a high level bit and the group of signals ends. In the conventional signal formats shown in FIG. 14 and FIG. 15, the high level and the low level form a set to form a bit, so that the last signal of a group of signals always ends at the low level. Therefore, FIG.
As shown in FIG. 4, the stop bit 12 must be provided at the final position of the signal of the first group. However, in the present invention,
Since the final bit is always at a high level by making the number of bits odd, the final bit is unnecessary. Therefore, the signal format can be simplified.

[0023]

Embodiments of the present invention will be described below with reference to the drawings. The transmission / reception device of this embodiment is used for transmitting information (data) from the input device 3 to the device body having the screen 1 as shown in FIGS. 11 to 13, for example. The screen 1 shown in FIGS.
The pulse-modulated reference light is emitted from the light source 2a on the main body side of the device, and this is detected by the four-division light receiving parts 5a, 5b, 5c, 5d of the light receiving part 5 provided in the input device 3. In the input device 3, a detection current based on the amount of light received by each divided light receiving unit is converted into a voltage, and based on this detection voltage, {(Ru + Rd)-(Lu + Ld)} / (Ru + Lu +
Rd + Ld) operation and {(Ru + Lu) − (Rd
+ Ld)} / (Ru + Lu + Rd + Ld) is calculated, whereby the angles θx and θy of the Z axis extending vertically from the front surface of the input device 3 with respect to the screen 1 are detected, and the XY coordinates with respect to the screen 1 are detected.

The input device 3 calculates the XY coordinates on the screen at the position where the Z axis hits the screen, and the transmitting / receiving device of this embodiment calculates information (coordinate data) about the XY coordinates.
Are transmitted to the apparatus body having the screen 1 at regular time intervals. On the device body side, the X- transmitted from the input device 3
Based on the Y coordinate information, for example, the cursor mark 8 displayed on the screen 1 is moved. That is, Z of the input device 3
When the directions of the axes (angles θx and θy) are changed with respect to the screen 1, the cursor mark 8 on the screen 1 moves according to the change in the direction. Thereby, it is possible to draw on the screen 1 or to align the cursor mark 8 with an arbitrary position displayed on the screen 1. Further, the input device 3 is provided with a click switch and other operation switches (operation members), and the operation information (operation signal or operation data) of each switch is also transmitted to the apparatus body. With this, for example, the cursor mark 8 is aligned with an arbitrary position on the screen 1,
At that time, by operating the switch of the input device 3, it becomes possible to input ON or OFF to the switch mark displayed on the screen 1.

FIG. 8 is a block diagram showing the configuration of the transmission device 20 provided on the input device 3 side. The transmitter 20 is provided with a signal generator 21 that generates a transmission signal. Based on the light receiving signals of the divided light receiving sections 5a, 5b, 5c, 5d, the calculation section in the input device 3 calculates.
Information about the XY coordinates of the screen 1 is generated, and the signal generator formats the transmission data based on this information. The carrier signal generation unit 22 has an oscillation circuit, a frequency divider circuit, and the like, and generates a carrier signal having a constant frequency. The phase modulator 23 modulates the carrier signal with transmission data to generate a phase-modulated transmission signal. The infrared light emitting element 25 is driven by the light emission drive section 24 based on this transmission signal, and the infrared transmission signal is transmitted toward the apparatus main body.

FIG. 9 is a block diagram showing the configuration of the receiving device 30 provided on the device main body side having the screen 1. The receiving device 30 includes a light receiving element 31 that receives a transmission signal emitted from the transmitting device 20 by infrared rays, and a current / voltage conversion unit 32 that converts the detected current photoelectrically converted by the light receiving element 31 into a voltage. And an amplification unit 3 for amplifying the voltage
3, a detection unit 34 for removing the component of the carrier signal from the voltage, and an amplification unit 3 based on the detection output of the detection unit 34.
AGC (automatic gain control) unit 35 for controlling the amplification gain of 3
have. The voltage waveform detected by the detection unit 34 is shaped by the waveform shaping unit 36, and the determination unit 37
Sent to

The discriminator 37 is a CP of a microcomputer.
Mainly used by U and the like, the high-level time and low-level time or cycle of a rectangular wave whose waveform is shaped is measured with reference to the cycle of a clock signal from a built-in or separately provided clock generator. To be done. Then, the discriminating section discriminates the types of the binary signals “1” and “0” based on the measured values. FIG. 5 shows a carrier signal (carrier wave) generated by the carrier signal generation unit 22. The carrier signal is the same as that used in the infrared transmission / reception unit used in the conventional home electric appliances, for example, the frequency fc = 38.46 kHz,
The duty ratio is 0.31.

The coding of the transmission signal in this embodiment will be described. As shown in FIG. 6, the transmission signal has unit bits when the phase-modulated signal is at a high level (H) and when it is at a low level (L).
Then, 4 units of bit B by the continuation of high level and low level
a to Bd are formed. Each bit represents a binary signal “1” or “0”. The time length of each of the high level and low level bits is the unit time T.
, The binary signal represented by the bit is “0”, and when the time length is “2T” which is twice the unit time T, the binary signal represented by the bit is “1”. . The time length expressing "1" is not limited to "2T", and may be "3T""4T" as long as it is an integral multiple of the unit time T.

In the embodiment shown in FIG. 6, the binary signal "1" is "2".
It is represented by "T". Therefore, the shortest time length of each bit is "T", the longest time length is "2T", and the average time length required to represent one bit is "1.5T". In the conventional infrared transmission encoding shown in FIG.
The average time length for expressing 1 bit is “3T”. Therefore, assuming that the unit time T has the same length in FIG. 6 and FIG. 15, the coding efficiency shown in FIG. 6 can be doubled as compared with the coding shown in FIG. , The data (signal) transmission rate can be doubled.

As the most basic embodiment of the present invention, the signal transmitted from the transmitter 20 of FIG. 8 based on the encoding shown in FIG. 6 is received by the receiver 30 shown in FIG. When the determination unit 37 determines a rectangular wave whose waveform has been shaped by removing the carrier wave from the signal, the determination unit 37 clocks the time length of the high-level bit and the time length of the low-level bit of the rectangular wave. It may be measured based on each.
When the time length of each bit (Ba, Bb, ... In FIG. 6) is T, it can be recognized that the bit represents “0” of the binary signal, and the time length of each bit is 2T. , It can be recognized that the bit represents "1" of the binary signal. Further, in this embodiment, the unit time T in encoding the transmission signal is shortened to 0.2 msec. In the conventional infrared transmission / reception shown in FIG. 15, the unit time T
Is about 0.5 msec, but in the present embodiment, the unit time T is shortened to further increase the signal transmission rate. When the unit time T of the transmission signal is shortened, the probability of occurrence of a discrimination error for each bit increases due to the discrimination ability of the receiving device 30. However, in the present embodiment, the probability of occurrence of a discrimination error is reduced by further measuring the time length for each cycle as follows.

That is, in the discriminating section 37 of the receiving apparatus 30 shown in FIG. 9, the high level of the rectangular-wave shaped reception signal of which the waveform is shaped and the 2-level cycle of the low level following the high level, and the low level and the high level following the low level. The time length of the 2-bit cycle of the level is measured. The measurement operation will be described with reference to FIG. As shown in FIG. 7, the reference bit B0 located at a predetermined position in the group of signals is set to a time length of "2T" representing "1" of the binary signal. FIG. 2 shows a group of signals (a group of signals) S transmitted from the transmitter 20. At the head of the group of signals S, high-level and low-level reader codes CH and CL are provided. . The low-level portion CL of this leader code is the reference bit B0.
And the time length is set to 2T.

The discriminator 37 measures the period from the rising edge of the start position of the rectangular wave bit to the next rising edge and the period from the falling edge of the bit start position to the next falling edge as the time length. To be done. As shown in FIG. 7, first from the start position (falling edge) of the reference bit B0, the first bit B1 following this
The time of one cycle to the end position (falling edge) of is measured. If this cycle is 3T, the reference bit B0 in the previous stage of the cycle is determined to be 2T,
It can be determined that the first bit B1 at the subsequent stage in the cycle has a time length T and is a binary signal "0". The first bit B
The period from the start position of 1 (rising edge) to the end position of the second bit (rising edge) is measured. If the period is 3T, it is already determined that the time length of the first bit B1 is T, and therefore the second bit B2 expresses "1" of the binary signal with the time length 2T. Can be identified. Next, the cycle of the bit B2 and the third bit B3 is measured. If this cycle is 4T, bit B2
Since it is already known that the time length of is 3T,
It can be determined that the time length of the bit B3 of 2 is 2T and the binary signal is "1". By repeating this, the time length of each bit can be accurately determined.

Table 1 below shows a combination of the length of one cycle between rising edges or falling edges and the time length of the preceding bit and the succeeding bit within the cycle. (1) and (0) in Table 1 mean the code of "1" and the code of "0" of the binary signal, respectively.

[0034]

[Table 1]

As shown in Table 1 above, the binary signal "1"
Is represented by "2T", the length of one cycle is 2
T, 3T, and 4T, and the combination of the time length of the preceding bit and the time length of the following bit in the cycle is 4
Limited to the street. Therefore, it is not difficult for the discriminating unit 37 to measure the period and to discriminate the time length of each bit based on the period, and when the measurement and the discrimination are performed by the CPU, the software is also simple. Further, the time length for expressing "1" of a binary signal is not 2T, but is 3
Even if it is T, the easiness of the discrimination is the same. When the time length of "1" of the binary signal is "3T", 2T in Table 1
Is replaced with 3T, and the length of one cycle is replaced with 2T, 4T, 4T, 6T from the top to the bottom.

While the time lengths of the high level and low level bits are individually discriminated, it is easier to discriminate the time length of each cycle and the discrimination accuracy is higher. About this point, FIG. 10 (A) (B) (C)
Will be described with reference to. In the receiving device 30 shown in FIG. 9, a signal photoelectrically converted by the light receiving element 31 and converted into a voltage by the current / voltage conversion unit 32 is amplified by the amplification unit 33 and detected by the detection unit 34 to generate a carrier signal component. To be removed. The detected signal is almost a sine wave as shown in FIG. This sine wave is shaped by the waveform shaping unit 36. In this waveform shaping method, a comparator is generally provided and this comparator compares the voltage with a threshold (threshold level) SL voltage. As a result,
The rectangular wave shown in (B) is obtained. However, it is predicted that the level of the received signal is not constant but fluctuates.
The AGC unit 35 is provided to reduce the fluctuation range. However, for example, a signal is not received by the light receiving element 31 for a period of time, and at a certain point, the light receiving element 31 rapidly
When the transmission signal is received, the voltage detected by the detection unit 34 suddenly rises, which may cause a phenomenon in which the amplification gain of the amplification unit 33 is suddenly suppressed by the AGC unit 35. In this case, the threshold voltage apparently changes to SL 'with respect to the level of the received signal.

When the threshold value is located at the normal level SL with respect to the level of the received signal of the sine wave detected in FIG. 10A, the waveform-shaped rectangular wave output is as shown in FIG.
In this case, the time length of each of the high level bit and the low level bit is 2T, T, T, T, 2T,
It becomes possible to discriminate the type of binary signal of each bit from the time length of each bit. However,
If the threshold value apparently changes to the level of SL 'for this same received signal, that is, if the level of the received signal fluctuates, a rectangular wave whose waveform is shaped with reference to the threshold value SL' is shown in FIG. 10 (C). In FIG. 10C, when the time length of each of the high level and low level bits is measured, an error occurs in the identification of the bit time length. For example, in FIG. 10B, the bits Bb, Bc,
The time length of Bd is T, while in FIG.
In (C), the bits Bb and Bd each have a time length of 2T.

However, focusing on one cycle of consecutive high-level and low-level bits Ba and Bb, FIG.
Both (B) and FIG. 10 (C) can be measured as the same “3T”. Similarly, one cycle of bits Bb and Bc is shown in FIG.
In both 0 (B) and FIG. 10 (C), "2
It can be measured as "T". That is, when the levels of the threshold value and the received signal are relatively changed, the time lengths of the individual bits of the high level and the low level are changed, but the high level and the low level or the low level and the high level are continuously changed. Bit one
The variation in the length of the cycle is very small. Therefore, 1
The determination of the bit type based on the measurement of the time length of the cycle can be maintained with extremely high accuracy even if the received signal varies. Therefore, in the discriminating method of the present embodiment, it is not necessary to dare to use an expensive and highly accurate unit as a unit composed of each circuit from the light receiving element 31 on the receiving device side to the waveform shaping section 36, and shown in FIG. Sufficient code discrimination (signal discrimination) is possible even if the receiving unit used in the conventional remote control device for household electric appliances that is transmitted and received in the signal format is used. Further, even if the unit time length T is shortened to about 0.2 msec, the receiving device 30 using this conventional receiving unit can perform highly accurate code discrimination.

That is, by forming the bits at each of the high level and the low level of the signal, the efficiency of the encoding can be doubled as compared with the conventional example of FIG. 15, and the time length (pulse width) of the unit time T is increased. By shortening, the transmission rate of data (information) can be further increased. Therefore,
Even if a transmitting / receiving unit with the same accuracy as the conventional one is used, the transmission rate can be made extremely high, and the input device 3 as shown in FIG.
Can be sufficiently put into practical use as a transmission / reception device that transmits information on X-Y coordinates. Further, in this embodiment, as shown in FIG.
The reliability of signal reception is improved by providing two parity bits in the first group of signals (signal group) S shown in FIG.

In the signal group S shown in FIGS. 2 and 3, B2 and B
3 is a parity bit. The parity bit B2 relates to all the bits (B4, B6, ...) Determined by the low-level time length of the signal among the subsequent bits. If there is an even number of low-level bits expressing a binary signal "1", the parity bit B
2 is a binary signal "0". In the case of an odd number, the parity bit B2 is "1". In the example of FIGS. 2 and 3,
Since the time length of the parity bit B2 is 2T and is “1”, the number of bits “1” represented by the low level is an odd number among the following bits.

The parity bit B3 is a bit (B
5, B7, ...) When the number of bits that become “1” is an even number, it is set to “0”. In the case of an odd number, the parity bit B3 is "1". In the examples of FIGS. 2 and 3, since the time length of the parity bit B3 is 2T and is “1”, the number of subsequent “1” of high-level bits is an odd number. By using the parity bits B2 and B3 in the discriminator 37 to check the error of the read signal, the reliability of discriminating the received signal can be further increased.

Further, in the signal group S of one group shown in FIG. 2, the total number of high level bits and low level bits is odd. If the bit B1 following the leader codes CH and CL is the first bit and Bn is the last bit,
n is an odd number. When CH and CL of the leader code are each considered to be 1 bit, all the numbers of bits from the high level leader code CH to the final bit Bn are odd. In this embodiment, the high-level signal and the low-level signal are unit bits. Therefore, if the total number of bits is an odd number, the first bit and the last bit are always high level bits, and it is not necessary to provide the stop bit 12 as shown in FIG.
By not providing the stop bit 12, the transmission time is shortened,
The reception determination can be simplified.

Here, the format (signal content) of one signal group S shown in FIG. 2 will be described. The high level and low level CH and CL are reader codes, which are codes for causing the receiving device 30 to recognize that the signal is transmitted. Bit B1 is an inversion bit that distinguishes whether this signal group is due to an inversion signal or a non-inversion signal, B2 and B3 are the above-mentioned parity bits,
Each bit from B4 to Bn is transmission information (transmission data)
Is meant. The signal group S shown in FIG. 2 shows a case where XY coordinate information (coordinate data) is mainly transmitted, and the total number of bits from B6 to Bn is 16 bits, and 8 bits of them indicate the X coordinate position. The remaining 8 bits mean the Y coordinate position. Further, B4 and B5 are bits indicating the operation state of a switch used together with coordinate data, such as a mouse click switch.

The inverted bit B1 is shown in FIG.
As shown in FIG. 3, when the time length of the inversion bit B1 is T and the binary signal is "0", the binary signal "1""0" represented by each subsequent bit is It means recognizing without inverting. The time length of the inversion bit B1 is 2
When the binary signal is "1" at T, it means that the binary signal represented by the following bits is the inverse of "1" and "0". There is. When the inverted bit B1 is "1", the discrimination unit 37 of the receiving device 30 shown in FIG. 9 calculates the exclusive OR of the binary signals represented by the subsequent bits in the signal group S. Calculate,
The binary signal expressions "1" and "0" are restored by inverting each other. As shown in FIG. 1, signals (signal groups) S1, S2, S forming a group from the transmitter 20 to the receiver 30.
, 3, ... Are transmitted intermittently with a predetermined time t3 (for example, 4 msec) open, but the representation of the binary signal of each bit after the inversion bit B1 of each signal group is non-inversion in S1, S
Inversion is performed in S2, non-inversion is performed in S3, and inversion is performed in S4. Inversion and non-inversion are alternately repeated for each signal group.

As a result, it becomes possible to shorten the data transmission time for a set of a plurality of signal groups. For example, bit B
If all of the 18 bits from 4 to Bn are all “0” of the binary signal with the time length T, the time length of the entire signal group S is the shortest, but if all the bits are the time length. When the binary signal is “1” at 2T, the time length of the entire signal group S becomes the longest. For example, assuming that the signal group of the longest time is intermittently transmitted with the time t3 opened, the time of data processing in the transmitting device 20 and the receiving device 30, especially the data processing in the receiving device 30 is set to the longest. It is necessary to secure a long time margin for the data processing in accordance with the time length of. However, as described above, the signal groups S1, S2, S that are continuously and intermittently transmitted.
When the binary signal represented by each bit of 3, ... Is repeated for each signal group such as inversion and non-inversion, the coordinate information in which all the bits are “1” is set as S1, S2, S3 ,. In the case of transmission, in the inverted signal group, the bit of the transmission signal becomes “0” of the binary signal, and the time length T of all bits becomes short. Therefore, the longest one and the shortest one are alternately transmitted for each signal group, and considering a set of a predetermined number of signal groups, the processing time of the entire set can be shortened.

More specifically, when transmitting the information (data) of the XY coordinates from the input device 3 as shown in FIG. 11 to the main body of the device, the 16-bit data representing the XY coordinates at a certain coordinate position. Of the signals, the binary signal “0” may be increased and the time length of the signal group S may be shortened. At a certain coordinate position, the binary signal “1” of the 16-bit signal expressing the XY coordinate is displayed. May increase and the time length of the signal group S may increase. However, if the binary signal expressing the XY coordinates is repeated for each signal group S so as to be inverted and non-inverted as in the above embodiment, a predetermined number of signals are generated at each XY coordinate position. When viewed as a set of groups, the time length of the entire set is averaged. Therefore, the receiving device 3
In the determination unit 37 of 0, or another arithmetic processing unit in the main body of the apparatus, since the signal group having the longest time length is not continuously transmitted, it is not necessary to take a long time margin. . Further, since the time lengths of a predetermined number of aggregates of signal groups that are sequentially transmitted while the Z axis of the input device 3 moves are averaged, data processing can be efficiently performed.

The advantage of performing the inversion and the non-inversion is not limited to the case where each of the high level and the low level of the signal is used as a unit bit as in the above embodiment, and the conventional code as shown in FIG. 15 is used. It is similarly effective in transmitting and receiving a signal in the encoded format. Further, in the signal group S shown in FIG. 2 and FIG. 3, the bit B6 to the final bit Bn are 16 bits, so that the position information of the XY coordinates is given. Input device 3 is included in these 16 bits.
The operation signals when the various switches are operated are not included. Signal groups S1, S2, S sequentially transmitted in this manner
By including only coordinate data in 3, ..., the time length of each signal group unit can be shortened, and the resolution of transmission / reception of coordinate data that changes sequentially when the Z axis of the input device 3 is moved can be increased. .

However, it is necessary to send information such as switch operation from the input device 3 to the main body of the device. Therefore, in this embodiment, when any one of the operation switches and other operation members of the input device 3 is operated, a signal group Sa including data related to operation information (operation signal) is sent. That is, when the Z axis of the input device 3 is being moved, the signal group in which the bits B6 to Bn are 16-bit XY coordinate data is S1, S2, S3.
However, when the operation member of the input device 3 is operated at this time, the signal group Sa including data related to the operation information intervenes between the signal groups S1, S2 and S3 and has the same time interval. It is transmitted after opening t3. At this time, the ratio of the signal group related to the coordinate data and the signal group related to the operation information data may be such that both signal groups may be transmitted alternately, or the operation signal may be transmitted to two or three groups of the coordinate data signal group. The signal group Sa relating to data may be transmitted at a rate of one group.

Here, the contents of the signals of the signal group Sa including the data of the operation signal are substantially the same as those of the signal group S shown in FIG. 2, and the inversion bit B1 and the parity bits B2, B are included.
3 and further, 16 bits from B6 to Bn are replaced with data relating to operation signals instead of coordinate data. However, on the receiving device 30 and the device main body side, whether the transmitted signal group relates to coordinate data,
It is necessary to recognize whether it is related to the operation signal. As shown in FIG. 2 and FIG. 3, when the identification is a signal group for transmitting data regarding XY coordinates, the time length of the high level CH of the reader code is set to 4T and the time length of the low level CL is set. 2T. Further, as shown in FIG. 4, in the case of the signal group Sa including the data related to the operation signal, the time length of the high level CH of the reader code is 4T and the time length of the low level CL is 4T. In the discriminating unit 37 of the receiving device 30 or the arithmetic processing unit of the main body of the device, depending on whether the time length of the low level CL of the reader code is 2T or 4T, a signal group relating to coordinate data or a signal group relating to operation signals. Identify which is.

When the discriminating unit 37 measures and discriminates the time length of one cycle of the high level and the low level as described above, the discriminating unit 37 determines 1 of the leader code consisting of CH and CL. Measure the time length of the cycle. In both the coordinate data signal group and the operation signal signal group, the time length of the high level CH of the leader code is 4T. Therefore CH and C
Measure the period of L and if this is 6T, CL is 2T
If it is 8T and CL is 8T, CL is determined to be 4T. In the signal group Sa related to the operation signal shown in FIG. 4, the time length of CL is recognized as 4T, and the cycle of this CL and the next bit B1 is measured to determine the bit B
You can know the time length of 1. That is, in this case as well, C
L becomes the reference bit B0 for period measurement.

The signal group S (S
1, S2, S3, ...) In 16 bits from B6 to Bn other than B4 and B5 (or by increasing this bit number), operation of the operating device of the input device 3 which is frequently used together with coordinate data A bit for a signal is further included so that a frequently used operation signal can be transmitted together with the coordinate data, and when an infrequently used operation member is operated, the operation signal is transmitted by a separate signal group Sa shown in FIG. You may do it. The transmission / reception device of the present invention is not limited to the transmission / reception of coordinate data and operation data from the input device 3 shown in FIG. 11 and the like to the device body, and can also be used as a transmission / reception device for remote control of other equipment. .
Further, the transmission and reception may be optical communication other than infrared rays or radio wave communication.

[0052]

As described above, according to the present invention, the high level and the low level of the signal are set as unit bits, and the type of the binary signal is expressed by the time length thereof. If the binary signal "1" has a time length of 2T, the transmission rate can be doubled as compared with the conventional infrared transmission / reception.

Further, by determining the high-level and low-level periods of the signal and discriminating the type of the binary signal of each bit, it is possible to discriminate the bit with high accuracy.

Further, by providing a parity bit corresponding to each low level bit and each high level bit, the reliability of signal discrimination can be improved.

Further, it is not necessary to provide a stop bit by making the total number of bits represented by the high level and the low level of the signal group of one group odd.

[Brief description of drawings]

FIG. 1 is a waveform diagram showing a plurality of groups of signals transmitted by a transceiver of the present invention,

FIG. 2 is a waveform diagram showing the data content of one signal group including coordinate data,

FIG. 3 is an enlarged waveform diagram showing an enlarged part of the waveform of FIG.

FIG. 4 is an enlarged waveform diagram showing a part of a signal group transmitted including data regarding an operation signal;

FIG. 5 is a waveform diagram of a carrier signal,

FIG. 6 is a waveform diagram illustrating encoding of each bit,

FIG. 7 is a waveform diagram showing the principle of determining the type of binary signal of each bit by measuring the time length for each cycle.

FIG. 8 is a block diagram showing a configuration of a transmission device,

FIG. 9 is a block diagram showing a configuration of a receiving device,

FIG. 10A is a waveform diagram showing a received signal after detection,
(B) and (C) are waveform diagrams showing rectangular waves whose waveforms have been shaped,

FIG. 11 is a perspective view showing an input device capable of inputting coordinates as an example of a device to which the transmitting / receiving device of the present invention is applied;

12 is a sectional view showing a part of the input device shown in FIG.

FIG. 13 is a front view showing a four-division light receiving section of the input device,

FIG. 14 is a waveform diagram showing a signal format in a conventional infrared transmitter / receiver device;

15A and 15B are waveform diagrams showing encoding used in conventional infrared transmission / reception,

[Explanation of symbols]

 1 screen 3 input device 5a to 5d 4 split light receiving unit 20 transmitting device 21 signal generating unit 22 carrier signal generating unit 23 phase modulating unit 24 light emitting driving unit 25 light emitting element 30 receiving device 31 light receiving element 32 current / voltage converting unit 33 amplifying unit 34 detection section 36 waveform shaping section 37 discrimination section B0 reference bit B1 first bit B2 second bit

Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location H04B 10/26 10/14 10/04 10/06

Claims (6)

[Claims] 1. A transmission device for transmitting a phase-modulated signal, a waveform shaping section for shaping the waveform of the received signal, and a binary signal "from a high level time and a low level time of the waveform shaped signal". In a transmitting / receiving device including a receiving device having a discriminating unit for discriminating 1 "and" 0 ", in the discriminating unit, the time when the waveform-shaped rectangular wave signal is at high level and the time when it is at low level are unit time. Whether it is T or an integral multiple of the unit time T is measured, and a binary signal "1" or "0" is discriminated for each bit with each of the high level time and the low level time being a unit bit. A transmitter / receiver characterized by. 2. A transmission device for transmitting a phase-modulated signal, a waveform shaping section for shaping the waveform of the received signal, and a binary signal "from a high level time and a low level time of the waveform shaped signal". In a transmission / reception device including a reception device having a discrimination unit for discriminating 1 "and" 0 ", the signal forms a unit bit at a high level and at a low level, and each bit forms a unit time T or The binary signal "1" or "0" is expressed depending on whether it is an integral multiple of the unit time T. In the discrimination unit, two units of continuous high level and low level or continuous low level and high level are shown. The bit transmission cycle is measured, and the type of the binary signal of the bit in the preceding stage within this period and the type of the binary signal of the bit in the succeeding stage within the period are determined from the period. apparatus. 3. The time length of a reference bit provided at a predetermined position of a signal and the type of a binary signal are determined, and the period is measured starting from the start position of the reference bit and is followed by the reference bit. The type of the binary signal of the first bit is determined, and then the type of the binary signal of the second bit is determined by measuring the period starting from the start position of the first bit, and this is repeated. The transmitter / receiver according to claim 2, wherein the type of the binary signal of each bit is discriminated by. 4. The transmission / reception device according to claim 1, wherein an integral multiple of the unit time T is twice. 5. A parity bit is provided in the signal of one group, and the parity bit is whether the binary signal type “1” of each high level bit of the rectangular wave signal is an even number or an odd number, 4. The transmitter / receiver according to claim 1, wherein the type "1" of the binary signal of each low-level bit is an even number or an odd number. 6. The transmitter / receiver according to claim 1, wherein the number of bits in each of the high level and the low level of one group of signals is an odd number.