KR101228804B1 - Method and system for controlling light emitting driving, and visible light communication device - Google Patents

Abstract

In a configuration in which data is transmitted by simultaneous flashing from a plurality of light emitting elements, communication in visible light communication is suppressed while suppressing flickering and color variation as illumination by reducing variations in waveform characteristics in optical signals of each light emitting element. Improve distance or communication speed For a light emitting drive adjustment system having a plurality of light emitting elements and a light receiving element, each of the plurality of light emitting elements is adapted to match the waveform characteristics of each received signal based on the received signal by the light receiving element for each of the plurality of light emitting elements. Calculation means for calculating the delay time of the light emission control timing with respect to the light emission control timing and setting means for setting the light emission control timing for each light emitting element based on the calculated delay time.

Description

METHOD AND SYSTEM FOR CONTROLLING LIGHT EMITTING DRIVING, AND VISIBLE LIGHT COMMUNICATION DEVICE}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical communication device having a light source, for example, LED (Light Emitting Diode) lighting, and more particularly, to a light emission driving adjustment method and system and a visible light communication device.

In recent years, visible light communication using visible light as a communication medium has been known. In visible light communication, the same data may be transmitted using a plurality of LEDs, for example, as a light emitting element. In particular, in a visible light transmitting device which also serves as an illuminating device, the intensity of light may be increased in order to secure a constant brightness as illumination and to increase a communication distance. Therefore, a method of performing data transmission by emitting a plurality of light emitting elements at the same timing. Is employed.

In addition, as a visible light communication technology using one light emitting device, there is a desire to improve the communication speed by adjusting the modulation timing of the optical transmission signal in accordance with the rising and falling characteristics of the light output signal by the light emitting device in use ( See, for example, Patent Document 1).

As a countermeasure against deterioration and contamination of the light emitting element, there is a case where a current value or a voltage value flowing into the light emitting element is simply adjusted by using a D / A circuit (see Patent Document 2, for example).

In addition, in order to avoid the problem of heat generation while strengthening the light emission signal output from each one light emitting element, one light emitting element is emitted in order of time division so that each light emitting element does not emit light at the same time. (For example, refer patent document 3).

[Patent Document 1] Japanese Unexamined Patent Publication No. 2009-4841 [Patent Document 2] Japanese Patent Application Laid-Open No. 2000-68942 [Patent Document 3] Japanese Patent Application Laid-Open No. 8-186539

However, in the above prior art, it is considered that there are the following problems.

First, since a light emitting device that performs light output in the visible light region is mainly used as light that strikes the eyes of a person such as lighting, it focuses on the precision of chromaticity and illuminance felt by the human eye. The response characteristics in blinking are often not considered very much. For this reason, in the light emitting element which produces the light output of the visible light area mass-produced, the response characteristic in the blinking of a light emitting element will arise for every product. For this reason, in order to realize visible light communication using a plurality of light emitting elements simultaneously to be used as one data transmitter in order to increase the amount of light and improve the communication distance, there is a problem that the waveform characteristics of the light output are deteriorated and the communication quality is deteriorated.

In addition, in order to solve this problem, there is a method of performing adjustment while changing the resistance and capacitor values of each light emitting element or a peripheral circuit of the light emitting element, but the adjustment takes time and secures a surplus part for adjustment replacement. There was a problem that the cost cost and the manufacturing cost were increased due to the necessity.

In addition, there may be a method of easily adjusting the current value and the voltage value flowing into the light emitting element by using the D / A circuit to adjust the variation of the flashing response characteristic of the light emitting element. Since the adjustment of the variation of the response characteristic and the adjustment of the color tone and brightness of each light emitting device are tradeoffs, there is a problem that the flickering of the light emitting device as illumination light is increased. In addition, since the current value and the voltage value applied to each light emitting element are not constant, there is a problem that the electric load on the light emitting element is changed and the lifespan as a product is reduced.

Moreover, in order to suppress the fluctuation | variation of the response characteristic in the flashing of a light emitting element previously, there also exists a method of using a high precision light emitting element, but there existed a problem that the cost cost at the time of manufacture increases. Moreover, there also existed a problem of being unable to use the light emitting element currently prevalent as illumination in the present condition.

That is, in the above-mentioned general visible light communication device, in order to realize the structure which transmits the same data from a some light emitting element, there existed the following subjects.

The first problem is that even in a light emitting element such as an LED, variations in the response characteristics of the flashing element of the light emitting element exist even in parts of the same kind, and thus it is difficult to optimize the waveform characteristics of the optical signal to be transmitted, which can be realized. This is a reduction in the communication possible distance and a decrease in the communication speed at which communication is possible.

This problem is mainly focused on the precision of chromaticity and illuminance that a human eye feels, since the light emitting element that performs light output in the visible light region is considered to be mainly used as light that strikes the human eye such as lighting. There is a cause to work. In addition, when illumination is used as visible light communication, variations in the distance between the driving circuit for driving the light source and the plurality of light sources can also be caused. Moreover, when using LED as a light emitting element, there existed a possibility that the waveform characteristic of an optical output signal may change also according to environmental conditions used, such as the variation of response characteristic by environmental conditions, such as air temperature.

The second problem is that when the light emitting element components are replaced in order to suppress the variation in the response characteristics, a large number of surplus components cannot be used when the response characteristics are taken into consideration. In addition, if the capacitor or resistance of the peripheral circuit is changed to adjust the current value or the voltage value for the light emitting element, and the response characteristic is improved, there is a problem that the adjustment is very troublesome.

In addition, the above-mentioned patent document 1 determines a modulation timing according to a single light emitting element, and it was not considered even to use when adjusting the fluctuation | variation of the response characteristic in a some light emitting element.

In addition, the above-mentioned patent document 2 aims at adjustment of the brightness and illumination intensity with respect to a human eye, and was not considered even about improving the waveform characteristic of light output. In addition, if the waveform characteristics are to be improved by this method, there is a relationship between the adjustment of the brightness, illuminance and color tone as illumination and the trade-off, and there is a problem of flickering and color variation as illumination.

In addition, the above-mentioned Patent Document 3 is intended to adjust the timing at which each light emitting element is lighted in order by time division, and emits light with improved variation by using light emission signals output from a plurality of light emitting elements at the same timing. It wasn't considered until the realization.

SUMMARY OF THE INVENTION The present invention has been made in view of such a situation, and in a configuration in which data transmission by simultaneous flashing from a plurality of light emitting elements is performed, the flickering as illumination is reduced by reducing the variation in waveform characteristics in the optical signal of each light emitting element. It is an object of the present invention to provide a light emission drive adjustment system, a visible light receiver, a visible light transmitter, a light emission drive adjustment method, and a program of the device which can improve the communication distance and communication speed in visible light communication while suppressing color variations. .

In order to achieve this object, the light emission drive adjustment system according to the present invention comprises a plurality of light emitting elements, a light receiving element, and the respective received signals on the basis of the received signals by the light receiving elements for each of the plurality of light emitting elements. Calculating means for calculating a delay time of light emission control timing for each of the plurality of light emitting elements so as to match the waveform characteristic of the light emitting device; and setting means for setting light emission control timing for each light emitting element based on the calculated delay time. It is characterized by one.

In addition, the visible light receiving apparatus according to the present invention is a visible light receiving apparatus which is connected to a visible light transmitting apparatus having a plurality of light emitting elements and performs light emission adjustment of the visible light transmitting apparatus. And calculation means for calculating a delay time of light emission control timing for each of the plurality of light emitting elements so as to match the waveform characteristics of the respective received signals based on the received signal by the light receiving elements.

Moreover, the visible light transmitting apparatus which concerns on this invention is a visible light transmitting apparatus connected to the visible light receiving apparatus provided with a light receiving element, and adjusted by the said light receiving element with each of a plurality of light emitting elements, and each said plurality of light emitting elements. Based on the received signal, the light emission control timing for each light emitting element is determined by the delay time of the light emission control timing for each of the plurality of light emitting elements calculated by the visible light receiving device so as to match the waveform characteristics of the respective received signals. It is characterized by including setting means for setting.

Further, the light emission drive adjustment method according to the present invention is a light emission drive adjustment method in a system having a plurality of light emitting elements and a light receiving element, based on a received signal by the light receiving element for each of the plurality of light emitting elements. Calculating a delay time of light emission control timing for each of the plurality of light emitting elements so as to match the waveform characteristics of each of the received signals, and setting light emission control timing for each light emitting element based on the calculated delay time. It is characterized by including the setting step.

Moreover, the program of the visible light receiving apparatus which concerns on this invention is a program of the visible light receiving apparatus which is connected to the visible light transmitting apparatus provided with the some light emitting element, and performs the light emission adjustment of the visible light transmitting apparatus, The said visible light receiving apparatus is a light receiving element. And calculating a delay time of light emission control timing for each of the plurality of light emitting elements to match the waveform characteristics of the respective received signals based on the received signal by the light receiving element for each of the plurality of light emitting elements. The computer program of the visible light receiving device is characterized in that the procedure is executed.

As described above, according to the present invention, in the configuration in which data is transmitted by simultaneous flashing from a plurality of light emitting elements, variations in waveform characteristics in the optical signal from each light emitting element can be reduced less. For this reason, it is possible to improve the communication distance and communication speed in visible light communication while suppressing flickering and color variation as illumination.

BRIEF DESCRIPTION OF THE DRAWINGS The block diagram which shows the structural example of the light emission drive adjustment system as embodiment of this invention.
FIG. 2 is a diagram showing an example of the connection configuration between the visible light transmitting device 1 and the visible light receiving device 5; FIG.
3 is a diagram showing an example of a connection configuration between the visible light transmitting device 1 and another visible light receiving device 5;
4 is a flowchart for explaining the operation of the light emission drive adjustment system according to the present embodiment.
5 is a signal waveform diagram for explaining a comparative example of waveform characteristics by the signal comparison circuit 6;
6 is a table showing a storage example of a table area of the adjustment value storage / setting circuit 9;
Fig. 7 is a block diagram showing a configuration example in which the light emission drive adjustment system is realized by one device.
8 is a block diagram showing another configuration example in which the light emission drive adjustment system is realized by one device;

Next, an embodiment to which the light emission drive adjustment system, the visible light receiver, the visible light transmitter, the light emission drive adjustment method, and the program of the device according to the present invention are applied will be described in detail with reference to the drawings.

First, the main feature of this embodiment is demonstrated.

The light emission drive adjustment method of the visible light communication device according to the present embodiment is a visible light communication device that transmits by using a plurality of light emitting elements, depending on the response characteristics in the blinking of each light emitting element, the wiring delay or the temperature characteristic. Variation in the waveform timing of the generated light output can be reduced by using a simple adjustment method, and the improvement of the communication distance and the communication speed can be realized.

In addition, when the light output used as visible light communication is used as illumination light, this light emission drive adjustment method can be implemented, suppressing the flicker as illumination which a human eye feels.

In the light emission drive adjustment system according to the present embodiment, as shown in FIG. 1, the visible light receiving device 5 serving as the adjustment device is connected to the visible light transmitting device 1 to be adjusted.

The light emission drive adjustment system receives the light output signals 20 to 22 output from the light emitting elements 10 to 12 separately from the light receiving elements 13 to 15, and the received signals 24 to 26 are binarized. Optimizing the light emission drive signals 17 to 19 to the light emitting elements 10 to 12 by receiving the signal comparison circuit 6 for comparing the transmission signal 23 for transmission timing confirmation and the comparison result information 27. The adjustment value calculating circuit 7 which calculates the transmission timing, respectively, the adjustment value storage / setting circuit 9 which receives the determined transmission timing calculation value 28, and saves it as a transmission timing setting value, and a transmission timing setting value ( 29, an adjusting circuit 3 for generating light emission drive signals 17 to 19 at an optimum transmission timing for each light emitting element 10 to 12 is provided. Thereby, it has a function which automatically optimizes the waveform timing of the light output signals 20-22 output from each light emitting element 10-12.

In addition, the light emission drive adjustment system according to the present embodiment has means (storage means) for storing a plurality of transmission timing setting values in the adjustment value storage / setting circuit 9, so as to provide a usage environment such as a temperature sensor or a communication speed. By selecting the optimal setting value from the plurality of transmission timing setting values from the information such as the environmental sensor 30 to be sensed, and transmitting as the transmission timing setting value (control timing) 29, the optimum transmission timing according to the use environment is obtained. It has a function of performing adjustment.

Next, the structure of the light emission drive adjustment system which concerns on this embodiment is demonstrated in detail with reference to FIG.

In the light emission drive adjustment system according to the present embodiment, as shown in FIG. 1, the visible light receiving device 5 serving as the adjustment device is connected to the visible light transmitting device 1 to be adjusted. As a result, the waveform timing of the light output signals 20 to 22 can be adjusted to the visible light transmitting device 1 using the visible light receiving device 5.

The visible light transmitting device 1 to be adjusted includes a modulation circuit 2 for generating a transmission signal as an optical output, an adjustment circuit 3, light emitting elements 10 to 12 for outputting light, and an adjustment value storage. And a setting circuit 9 and an environmental sensor 30.

The modulation circuit 2 generates a transmission signal 16 by performing modulation for transmission as visible light communication. The adjustment circuit 3 is based on the transmission signal 16 received from the modulation circuit 2, and sets the transmission timing set values for each of the light emitting elements 10 to 12 transmitted from the adjustment value storage / setting circuit 9 ( 29, light emission drive signals 17 to 19 are generated. The light emitting elements 10-12 operate by the light emission drive signals 17-19 output from the adjustment circuit 3, and output the light output signals 20-22.

The adjustment value storage / setting circuit 9 sets a plurality of setting timing calculation values 28 for each of the light emitting elements 10 to 12 calculated by the visible light receiving device 5 and transmitted to the visible light transmitting device 1. It has the function to save. The adjustment value storage / setting circuit 9 selects an optimal one from among the plurality of transmission timing calculation values 28 stored according to the use environment information from the environmental sensor 30, and transmits the transmission timing setting value 29 Is transmitted to the adjustment circuit 3 as.

The environmental sensor 30 transmits to the adjustment value storage / setting circuit 9 information of the temperature of the environment where the visible light transmitting device 1 is used and the communication speed used as the visible light communication.

The visible light receiving device 5 serving as the adjustment device includes light receiving elements 13 to 15 that receive the light output signals 20 to 22 from the visible light transmitting device 1, a signal comparison circuit 6, and an adjustment operation. The circuit 7 is comprised.

The light receiving elements 13 to 15 are provided to correspond to each of the light emitting elements 10 to 12, and the light receiving element 13 receives the light output signal 20 from the light emitting element 10, and receives the light receiving element 14. Receives the light output signal 21 from the light emitting element 11 and receives the light output signal 22 from the light emitting element 12 at the light receiving element 15.

The signal comparison circuit 6 receives the output signals 20 to 22 in which the light output signals 20 to 22 are binarized, and the two to be notified by wire 4 by the cable 4 from the visible light transmitting device 1. The converted transmission confirmation signal (reference waveform) 23 is compared with respect to the rising and falling timing as a waveform signal, and the comparison result information 27 is transmitted to the adjustment calculation circuit 7.

The adjustment arithmetic circuit 7 is based on the comparison result information 27 transmitted from the signal comparison circuit 6, and the visible light transmission apparatus 1 is made to adjust the timing of the rise and fall in the reception signals 24-26. The transmission timings of the light emission drive signals 17-19. The adjustment calculation circuit 7 transmits the calculation result as the transmission timing calculation value 28 to the adjustment value storage / setting circuit 9 of the visible light transmission device 1 by wired communication by the cable 8. In addition, the adjustment calculation circuit 7 has a function of storing the comparison result information 27 for a plurality of times.

Next, a detailed connection configuration between the visible light transmitting device 1 serving as the adjustment target and the visible light receiving device 5 serving as the adjusting device will be described with reference to FIGS. 2 and 3.

2 shows an example of the configuration when the visible light receiving device 5 is connected to the visible light transmitting device 1 to be adjusted to perform transmission timing adjustment of the light emitting element. In the example of FIG. 2, one light receiving element 13 to 15 is associated with each of the light emitting elements 10 to 12 of the visible light transmitting device 1, and spaces for optical communication are respectively provided by the light shielding plates 41 to 44. Divided. That is, the light output signal 20 from the light emitting element 10 is received only by the light receiving element 13, and the light output signal 21 from the light emitting element 11 is received only by the light receiving element 14, The light output signal 22 from the light emitting element 12 is received only by the light receiving element 15. This makes it possible to simultaneously check the individual light output signals for each of the light emitting elements 10 to 12.

In addition, as shown in the example of FIG. 3, the individual light output signals for each of the light emitting elements 10 to 12 cannot be simultaneously checked, such as when the visible light receiving device 5 includes only one light receiving element 13. , Adjustment is possible. First, the light-emitting element 10 and the light-receiving element 13 correspond to each other, and the result of the comparison in the signal comparison circuit 6 is stored by the adjustment calculation circuit 7. Similarly, the light-emitting element 11 and the light-receiving element 13 ), The results of the light emitting element 12 and the light receiving element 13 are also stored. In this way, the adjustment arithmetic circuit 7 can store the comparison result in all the light emitting elements, and it is possible to perform transmission timing adjustment by matching the stored comparison result.

Next, operation | movement of the light emission drive adjustment system as this embodiment is demonstrated with reference to the flowchart of FIG.

First, when the visible light receiving device 5, which is the adjustment device, is connected to, for example, the visible light transmitting device 1 to be adjusted as shown in FIG. 2, and the adjustment of the transmission timing is started (step S1), the adjustment circuit 3 Receives the transmission signal 16 from the modulation circuit 2 and outputs the light emission driving signals 17 to 19 to the light emitting elements 10 to 12, respectively (step S2).

When outputting these light emission drive signals 17-19, the adjustment circuit 3 outputs the transmission signal 16 as light emission drive signals 17-19 as it is. As the control method, the transmission timing setting value 29 output from the adjustment value storage / setting circuit 9 to the adjustment circuit 3 in the initial state may be a value which does not perform transmission timing adjustment. The transmission timing setting value 29 may be ignored and the transmission signal 16 may be used as the light emission drive signals 17 to 19 only at the time of outputting the initial light emission drive signal. In this case, the signal pattern of the transmission signal 16 is a test waveform pattern according to a modulation method used for visible light communication.

The light output signals 20 to 22 outputted from the light emitting elements 10 to 12 by the drive signals 17 to 19 are received by the light receiving elements 13 to 15 of the visible light receiving device 5, respectively. The comparison circuit 6 acquires the binarized received signals 24 to 26 (step S3). In addition, the signal comparison circuit 6 directly receives the transmission signal 16 from the visible light transmitting device 1 as the transmission confirmation signal 23 through the cable 4. The signal comparison circuit 6 compares the transmission confirmation signal 23 with the reception signals 24 to 26 to obtain a comparison result as transmission timing information for each light emitting element (step S4).

The acquisition information of this transmission timing is demonstrated with reference to the signal waveform diagram of FIG. As an example, the example of the reception signal 24 will be described. The signal comparison circuit 6 includes delays A1 to An at the timing of rising of the waveform between the transmission confirmation signal 23 and the reception signal 24, and Delays AA1 to AAn at the falling timing are checked, and the adjustment value calculating circuit 7 is notified of the average value of each delay as the comparison result information 27 with respect to the reception signal 24. The average value of a rising delay and a falling delay is computed as follows.

Rising delay average value: A_av = (A1 + A2 +… + An) / n

Fall Delay Average: AA_av = (AA1 + AA2 +… + AAn) / n

When the acquisition of the delay timing information is completed, the signal comparison circuit 6 next confirms whether or not the result of comparing the received signals corresponding to all the light emitting elements has been acquired (step S5).

If all the comparison results have not been acquired, the signal comparison circuit 6 switches to the light emitting element that has not yet been acquired (step S6), and performs the same comparison operation (step S4). As a result, the comparison results are also calculated for the received signals 25 and 26 as follows.

Rising delay average value: B_av = (B1 + B2 +… + Bn) / n

Fall Delay Average Value: BB_av = (BB1 + BB2 +… + BBn) / n

Rising delay average value: C_av = (C1 + C2 +… + Cn) / n

Fall Delay Average Value: CC_av = (CC1 + CC2 +… + CCn) / n

In this way, when the comparison result information 27 for each of the reception signals 24 to 26 is notified to the adjustment value calculating circuit 7, the adjustment value calculating circuit 7 is executed for each of the received signals 24 to 26 (that is, It is confirmed how much fluctuations in the rising delay average value and the falling delay average value of each of the light emitting elements 10 to 12 (step S7).

In the determination of step S7, when the difference between the smallest value and the largest value among the average values of the rising / falling delays is not less than or equal to a predetermined threshold value (NO in step S7), the transmission timing is adjusted by the adjustment circuit 3. In order to perform the adjustment, the process shifts to the calculation of the adjustment value by the adjustment value calculating circuit 7. Moreover, when it is below a predetermined threshold (example of step S7), it is judged that the drive signals 17-19 of the phenomenon by the adjustment circuit 3 are appropriate, and adjustment is complete | finished (step S11).

This predetermined threshold value is a value that can be arbitrarily set, and is a value that the user adjusts while judging whether the operating frequency of the waveform in the transmission signal or how much accuracy is to be provided. As an example, 20% or less of the wavelength of the communication frequency used in the transmission signal is valid.

In this way, the calculation method in the case where the adjustment value calculation circuit 7 calculates the adjustment value will be described (step S8).

The adjustment value calculating circuit 7 adjusts the delay average value to the value having the largest delay in order to adjust the rising timing and the falling timing in all the reception signals 24 to 26 to be the same. In other words, the delay timing is adjusted so as to match the transmission timing of the light emission drive signals 17 to 19 to the largest delay average value so that the rising timing and the falling timing of the reception signals 24 to 26 are matched.

In this adjustment, if there is a difference between the values of the rising delay and the falling delay, the duty ratio of the ON / 0FF of the light emitting element changes, and the expected emission rate cannot be realized.

Therefore, when the rising delay setting values Da, Db and Dc, which are the delay setting values for adjusting the light emission drive signals 17 to 19, and the falling delay setting values are Daa, Dbb, and Dcc, the adjustment value calculating circuit ( 7) calculates the largest value among all values of the rising delay average values A_av, B_av and C_av and the falling delay average values AA_av, BB_av and CC_av as D_max and calculates the result by the following calculation formula.

Rise delay setting value in the light emission drive signal 17: Da = D_max-A_av

Falling delay setting value in the light emission drive signal 17: Daa = D_max-AA_av

Rise delay setting value in the light emission drive signal 18: Db = D_max-B_av

Falling delay setting value in the light emission drive signal 18: Daa = D_max-BB_av

Rise delay setting value in the light emission drive signal 19: Dc = D_max-C_av

Falling delay setting value in the light emission drive signal 19: Daa = D_max-CC_av

The adjustment value calculating circuit 7 adjusts the rising delay setting values Da to Dc and the falling delay setting values Daa to Dcc to the transmission timing calculation values 28 for adjusting the light emission drive signals 17 to 19. Is transmitted to the visible light transmitting device 1, and stored in the adjustment value storage / setting circuit 9 (step S9).

The adjustment value storage / setting circuit 9 outputs the transmission timing setting value 29 to the adjustment circuit 3 on the basis of the updated information in this way, and adjusts the transmission timing of the light emission drive signals 17 to 19. (Step S10). In the adjustment of the rising and falling of the transmission signal 16, the adjustment circuit 3 performs the output operation of the light emission drive signals 17 to 19 by the amount of the rising delay setting value and the falling delay setting value, respectively. It is realized by delay. This rise and fall delay has a function of changing a delay buffer in an integrated circuit such as a large scale integrated circuit (LSI) or a field programmable gate array (FPGA) according to the transmission timing set value 29, for example. By changing the transmission timing automatically, it is possible.

After this adjustment operation, the transmission / reception operation of the optical output signal similar to steps S3 to S6 described above is performed at the transmission timing after adjustment, and the signal comparison circuit 6 performs reception comparison confirmation on the transmission signal after adjustment. The adjustment value calculating circuit 7 confirms how much the fluctuations in the rising delay average value and the falling delay average value of each of the received reception signals 24 to 26 (that is, for each of the light emitting elements 10 to 12) after the adjustment (step S7). ).

In the judgment of this step S7, when the fluctuation was not equal to or less than the above-described predetermined threshold value (NO in step S7), the adjustment value calculating circuit 7 again determines the adjustment value delay value for performing the transmission timing adjustment. The calculation is performed. The calculation of the delay setting value for adjusting the second and subsequent light emission drive signals 17 to 19 is as follows. The number of calculations is the m-th (m≥2) rising delay setting values Da (m), Db (m) and Dc (m), and the falling delay setting values Daa (m), Dbb (m) and Dcc ( m), and the average of the mth rising delays is A_av (m), B_av (m), C_av (m), and the falling delay average values are AA_av (m), BB_av (m), CC_av (m), and the largest delay average values. When D is set to D_max (m), the delay set value is calculated by the following formula.

Rise delay setting value (m-th) in the light emission drive signal 17:

Da (m) = {Da (m-1) + D_max (m) -A_av (m)} / 2

Falling delay setting value (mth time) in the light emission drive signal 17:

Daa (m) = {Daa (m-1) + D_max (m) -AA_av (m)} / 2

Rise delay setting value (m-th time) in the light emission drive signal 18:

Db (m) = {Db (m-1) + D_max (m) -B_av (m)} / 2

Falling delay setting value (mth time) in the light emission drive signal 18:

Dbb (m) = {Dbb (m-1) + D_max (m) -BB_av (m)} / 2

Rise delay setting value (m-th time) in the light emission drive signal 19:

Dc (m) = {Dc (m-1) + D_max (m) -C_av (m)} / 2

Falling delay setting value (mth time) in the light emission drive signal 19:

Dcc (m) = {Dcc (m-1) + D_max (m) -CC_av (m)} / 2

That is, the delay setting value after the 2nd time (m time) is computed by the average of the delay setting value of the last time and this time delay setting value computed by the same formula as the first time. The adjustment value calculation circuit 7 calculates the rising delay setting values {Da (m) to Dc (m)} and the falling delay setting values {Daa (m) to Dcc (m)} calculated in this way. It transmits to the visible light transmission device 1 as the transmission timing calculation value 28 for adjusting ˜19), and stores it in the adjustment value storage / setting circuit 9 (step S9). Thereby, similarly to the operation of step S10 described above, the transmission timing setting value 29 for the adjustment circuit 3 is updated from the adjustment value storage / setting circuit 9 to transmit the light emission drive signals 17 to 19. The timing is adjusted.

As described above, in the adjustment operation after the second time (the m time), the operations of steps S3 to S10 are continuously repeated as described above until the variation of the delay becomes equal to or less than the predetermined threshold value. Thereby, adjustment for improving the waveform characteristic of an optical output can be implement | achieved automatically.

Next, the operation using the environmental sensor 30 shown in FIG. 1 will be described with reference to the configuration of FIG. 1 and the table of FIG. 6.

In the adjustment value storage / setting circuit 9, a table area for storing a combination of a plurality of rising / falling delay setting values T4 and T5 is set in advance for each of the optical transmission units T1. When performing the transmission timing adjustment operation shown in FIG. 4 step S3-S10 mentioned above, adjustment is made about each environmental condition, changing environmental conditions, such as communication speed T2 and temperature T3, The combination of the rising and falling delay set values T4 and T5 as the adjustment result is stored.

In the example shown in FIG. 6, as the table area of the adjustment value storage / setting circuit 9, the low and high speed environmental condition divisions are set with respect to the environmental conditions of the communication speed T2, and the environmental conditions of the temperature T3. The case where the low temperature and high temperature environmental condition division is set, and the combination of the rising / falling delay setting values T4 and T5 is stored for each environmental condition division is shown.

When the visible light transmitting device 1 is operating after this adjustment operation, the adjustment value storage / setting circuit 9 enters the table area in accordance with environmental condition values such as temperature information and communication speed information by the environmental sensor 30. The optimal combination is selected from the rising / falling delay setting values T4 and T5 for each stored environmental condition. The transmission timing adjustment according to the environmental conditions at the time of use can be realized by outputting the selected rising / falling delay setting values T4 and T5 as the transmission timing setting values 29 to the adjustment circuit 3.

As mentioned above, according to embodiment mentioned above, the following effects are acquired.

The 1st effect can adjust the response characteristic in ON / OFF of a visible light transmission part (light emitting element), without replacing parts, and can improve the waveform characteristic of an optical output signal at low cost.

The second effect is that the response characteristic at ON / OFF of the visible light transmitting unit can be automatically confirmed, and the adjustment value can be set, so that the waveform characteristic of the light output signal can be easily improved.

The third effect is that the response characteristics of the visible light transmitting unit can be automatically changed in accordance with the use environment, so that the waveform characteristics of the light output signal can be provided optimally in accordance with the change of the environment in use.

Since the fourth effect can adjust the response characteristics at the ON / OFF of the visible light transmission unit without changing the luminous intensity or illuminance of the light emitting element, visible light or the like should be used to suppress the flicker of brightness visible to the human eye. It is easy to apply the communication.

As described above, in the above-described embodiment, the driving timing of the LEDs is finely adjusted so that one LEDs emit light at the same time in order to make the light emission signals output from the one LEDs at the same timing. In this way, by making fine adjustments to alleviate the variation in the response characteristics for each LED, a light emission signal without variation for each LED can be realized, so that the communication distance can be increased while realizing high-speed communication.

As described above, in the above-described embodiment, by finely adjusting the slight difference in the response characteristics according to the absence of the light emitting element, it is possible to simply generate an optical signal that realizes clean simultaneous light emission using a plurality of light emitting elements.

In addition, in the above-described embodiment, a function of using a binarized digital received signal is provided in performing waveform characteristic adjustment of a transmission signal.

Moreover, it is provided with the function which can change the setting of a signal transmission part according to a use environment, such as temperature.

As described above, in the above embodiment, in the configuration in which the same data is transmitted from the plurality of light emitting elements, the waveform characteristics of the optical output signal synthesized as the output from the plurality of light emitting elements can be improved. As a result, fluctuations in waveform characteristics in the optical signals of the respective light emitting elements can be reduced, and communication distances and communication speeds in visible light communication can be improved while suppressing flickering and color fluctuations as illumination.

As described above, according to the above-described embodiment, in the visible light communication in which the same data is transmitted from the plurality of light emitting elements, it is possible to improve the fluctuations in the waveform characteristics of the respective light outputs while suppressing the flicker of light to the human eye. It can provide an easy way.

In addition, each embodiment mentioned above is preferable embodiment of this invention, This invention is not limited to this, It is possible to perform various modifications based on the technical idea of this invention.

For example, in the above-described embodiment, in the table area of the adjustment value storage / setting circuit 9 with respect to the environmental conditions measured by the environmental sensor 30, two types (high speed / low speed, Although the storage area is prepared only for each of the high temperature / low temperature), it is not limited to this, for example, the structure which memorize | stores the combination by temperature and communication speed more finely may be sufficient.

In addition, although the above-mentioned embodiment demonstrated the environmental conditions measured by the environmental sensor 30 only by the communication speed and temperature, it is not limited to this, It combines the various sensors which sense the environmental conditions at the time of use, Even if 30) is configured, the above-described embodiments can be realized in a similar manner.

Moreover, in the structural example shown in FIG. 1, although the number of light emitting elements is three, it is not limited to this number, Two or more arbitrary numbers may be sufficient.

The present embodiment can be similarly applied not only to visible light such as fluorescent lamps and LEDs, but also to communication devices using infrared light emitting elements.

In addition, the "system" in this specification is logical collection of a plurality of functional units (functional modules or devices for realizing specific functions), and each device or each functional module is included in any one of a plurality of cases, It is in a single case or not particularly a problem.

Another configuration example of such a case configuration will be described with reference to FIGS. 7 and 8.

7 and 8 show a configuration example in which the basic configuration is the same as the light emission drive adjustment system according to the above embodiment, but the light emission drive adjustment system is realized by one device.

In the structural example shown in FIG. 7, the visible light transmitting device 101 itself is provided with the light receiving element 103 for reception confirmation, and the adjustment circuit 102 includes the adjustment circuit 3 in the structural example of FIG. 1. In addition to the function of, the signal comparison circuit 6, the adjustment value calculating circuit 7, and the adjustment value storage setting circuit 9 each have functions. When the visible light transmitting device 101 operates, first, the light emitting elements 104 to 105 separately flash sequentially as a preparation operation, and the light receiving element 103 performs acknowledgment and based on the result, the above-described transmission is performed. The timing of the transmission in the light emitting elements 104 to 105 is adjusted by the timing adjustment method, and the adjustment proceeds to the normal light emission operation. Thereby, the visible light communication device provided with the reception confirmation function for adjusting the drive signal of the optical transmission unit at the time of operation can be realized.

In addition, in the structural example shown in FIG. 8, instead of the light receiving element 103 in the structural example of FIG. 7, the light receiving elements 106-107 corresponding to each of the light emitting elements 104-105 of the visible light transmitting apparatus 101 are shown. ), And the light shielding plates 108 to 109 are provided so that only light signals from corresponding light receiving elements enter. For this reason, the light output signal for every light emitting element can be confirmed by each light receiving element also during operation | movement by normal light emission operation. For this reason, the transmission timing adjustment of the light emitting elements 104-105 can be performed during operation by a normal light emission operation, and the feedback control which always obtains the waveform characteristic of the optimal light output can be implement | achieved.

In the configuration example shown in FIG. 8, the transmission timing adjustment according to the above-described embodiment can be performed between the preparation operation immediately before the operation start and the normal light emission operation during operation, so that the visible light transmission device 101 is actually operated. It is possible to provide the waveform characteristics of the optimum light output signal according to the environment.

For this reason, according to the above-described embodiment, as illustrated in FIGS. 2 and 3, the transmission signal may be adjusted during manufacturing evaluation, and the adjustment value may be stored and set. In addition, as illustrated in FIGS. 7 and 8, each time the transmission device is used, the transmission signal may be adjusted to update the setting.

Furthermore, by recording the processing procedure for realizing the light emission drive adjustment system, the visible light receiving device, and the visible light transmitting device as the above-described embodiments in a recording medium as a program, the above-described functions according to each embodiment of the present invention can be obtained. The program supplied from the recording medium can cause the CPU of the computer constituting the system to perform the processing.

In this case, the present invention is applied even when an information group including a program is supplied to the output device by the above recording medium or from an external recording medium via a network.

That is, the program code itself read out from the recording medium realizes the novel function of the present invention, and the recording medium storing the program code and the signal read out from the recording medium constitute the present invention.

As this recording medium, for example, a hard disk, an optical disk, a magneto-optical disk, a floppy (registered trademark) disk, a magnetic tape, a nonvolatile memory card, a ROM, or the like may be used.

According to this program according to the present invention, the devices controlled by the program can realize the respective functions in the above-described embodiments.

〔bookkeeping〕

Although some or all of said embodiment can be described also as the following bookkeeping, it is not limited to the following.

[Book 1]

A plurality of light emitting elements,

A light receiving element,

Calculation means for calculating a delay time of light emission control timing for each of the plurality of light emitting elements so as to match the waveform characteristics of the respective received signals based on the received signal by the light receiving element for each of the plurality of light emitting elements;

And setting means for setting light emission control timings for the respective light emitting elements based on the calculated delay time.

[Supplementary Note 2]

The calculating means calculates a delay time of the rise and fall control timings for each of the plurality of light emitting elements so as to match the rise and fall with respect to each of the received signals as waveform characteristics of the respective received signals,

The setting means sets the control timing of rising and falling for each of the light emitting elements. The light emitting drive adjustment system according to Appendix 1.

[Appendix 3]

Comparison means for comparing a waveform characteristic of a received signal by the light receiving element to each of the plurality of light emitting elements with respect to a reference waveform used for light emission control of the plurality of light emitting elements,

The calculation means calculates a delay time of the light emission control timing based on a comparison result by the comparison means, wherein the light emission drive adjustment system according to Appendix 1 or 2.

[Appendix 4]

The comparison means, as a waveform characteristic of each of the received signals, compares the rise of each of the received signals with the rise of the reference waveform, and the fall of each of the received signals with the fall of the reference waveform. The light emission drive adjustment system of the appendix 3 characterized by the above-mentioned.

[Appendix 5]

Environmental condition measurement means for measuring which of the predetermined environmental condition values are included in the predetermined environmental condition value;

Storage means for storing the delay time calculated by the calculation means for each of the environmental condition classifications,

The setting means sets the light emission control timing for each of the light emitting elements based on the delay time corresponding to the environmental condition classification measured by the environmental condition measuring means among the delay time stored in the storage means. The light emission drive adjustment system in any one of notes 1-4.

[Supplementary Note 6]

The light receiving element is provided so as to be one to one for each of the plurality of light emitting elements,

The light emission drive adjustment system includes light shielding means for shielding only the light signal from the light emitting element associated with each one of the light receiving elements so as to enter each of the light receiving elements,

The light emission drive adjustment system according to any one of notes 1 to 5, wherein calculation by the calculating means and setting by the setting means are performed for each predetermined instrument.

[Appendix 7]

And the comparing means compares the waveform characteristics obtained by binarizing the received signal by the light receiving element to each of the plurality of light emitting elements with respect to the binarized reference waveform used for light emission control of the plurality of light emitting elements. The light emission drive adjustment system of appendix 3 or 4.

[Appendix 8]

A visible light receiving device which is connected to a visible light transmitting device having a plurality of light emitting elements and performs light emission adjustment of the visible light transmitting device,

A light receiving element,

And calculating means for calculating a delay time of light emission control timing for each of the plurality of light emitting elements to match the waveform characteristics of the respective received signals based on the received signal by the light receiving elements for each of the plurality of light emitting elements. Visible light receiving device characterized in that.

[Appendix 9]

The calculation means calculates a delay time of the rise and fall control timings for each of the plurality of light emitting elements so as to match the rise and fall of each of the received signals as waveform characteristics of the respective received signals. The visible light receiving device according to 8.

[Appendix 10]

A comparison means for comparing waveform characteristics of a received signal by the light receiving element to each of the plurality of light emitting elements with respect to reference waveforms used for light emission control of the plurality of light emitting elements in the visible light transmitting apparatus;

The calculation unit calculates a delay time of the light emission control timing based on a comparison result by the comparison unit, wherein the visible light receiving device according to Appendix 8 or 9.

[Appendix 11]

The comparison means, as a waveform characteristic of each of the received signals, compares the rise of each of the received signals with the rise of the reference waveform, and the fall of each of the received signals with the fall of the reference waveform. The visible light receiving device according to Supplementary note 10.

[Appendix 12]

The light receiving element is provided so as to be one to one for each of the plurality of light emitting elements,

The visible light receiving apparatus includes light shielding means for shielding only the light signal from the light emitting element corresponding to each one of the light receiving elements so as to enter each of the light receiving elements. The visible light receiving device according to claim.

[Appendix 13]

And the comparing means compares the waveform characteristics obtained by binarizing the received signal by the light receiving element to each of the plurality of light emitting elements with respect to the binarized reference waveform used for light emission control of the plurality of light emitting elements. The visible light receiving device according to supplementary note 10 or 11.

[Appendix 14]

A visible light transmitting device connected to a visible light receiving device having a light receiving element and subjected to adjustment,

A plurality of light emitting elements,

Delay time of light emission control timing for each of the plurality of light emitting elements calculated on the visible light receiving device to match the waveform characteristics of the respective received signals based on the received signals by the light receiving elements for each of the plurality of light emitting elements. And setting means for setting light emission control timings for the respective light emitting elements.

(Supplementary Note 15)

Environmental condition measurement means for measuring which of the predetermined environmental condition values are included in the predetermined environmental condition value;

Storage means for storing the delay time calculated by the visible light receiving apparatus for each of the environmental conditions;

The setting means sets the light emission control timing for each of the light emitting elements based on the delay time corresponding to the environmental condition classification measured by the environmental condition measuring means among the delay time stored in the storage means. The visible light transmitting device according to Appendix 14.

(Supplementary Note 16)

As a light emission drive adjustment method in the system provided with the some light emitting element and the light receiving element,

A calculation step of calculating a delay time of light emission control timing for each of the plurality of light emitting elements so as to match the waveform characteristics of the respective received signals based on the received signal by the light receiving element for each of the plurality of light emitting elements;

And a setting step of setting a light emission control timing for each light emitting element based on the calculated delay time.

[Appendix 17]

In the calculation step, a delay time of rise and fall control timings for each of the plurality of light emitting elements is calculated so as to match rising and falling with respect to each of the received signals as waveform characteristics of each of the received signals,

The setting step WHEREIN: The light emission drive adjustment method as described in Appendix 16 characterized by setting the control timing of rise and fall with respect to each said light emitting element.

(Supplementary Note 18)

A comparison step of comparing waveform characteristics of a received signal by the light receiving element to each of the plurality of light emitting elements with respect to a reference waveform used for light emission control of the plurality of light emitting elements;

In the said calculation process, the delay time of the said light emission control timing is calculated based on the comparison result by the said comparison process, The light emission drive adjustment method as described in Appendix 16 or 17 characterized by the above-mentioned.

[Supplementary Note 19]

In the comparison step, as a waveform characteristic of each of the received signals, a rise for each of the received signals is compared with a rise in the reference waveform, and a drop for each of the received signals is compared with a fall in the reference waveform. The light emission drive adjustment method of Appendix 18 characterized by the above-mentioned.

(Book 20)

An environmental condition measuring step of measuring which of the predetermined environmental condition values is included in the predetermined environmental condition value,

A storage step of storing the delay time calculated by the calculation step for each of the environmental conditions;

In the setting step, the light emission control timing for each of the light emitting elements is set based on the delay time corresponding to the environmental condition classification measured by the environmental condition measurement step among the delay time stored by the storage step. The light emission drive adjustment method in any one of notes 16-19.

(Supplementary Note 21)

The light receiving element is provided so as to be one to one for each of the plurality of light emitting elements,

The system includes light shielding means for shielding only the light signal from the light emitting element corresponding to each one of the light receiving elements so as to enter each of the light receiving elements,

The light emission drive adjustment method according to any one of notes 16 to 20, wherein the calculation by the calculation step and the setting by the setting step are performed for each predetermined instrument.

(Supplementary Note 22)

In the comparison step, the waveform characteristic obtained by binarizing the received signal by the light receiving element for each of the plurality of light emitting elements is compared with the binarized reference waveform used for light emission control of the plurality of light emitting elements. The light emission drive adjustment method according to appendix 18 or 19.

(Supplementary Note 23)

A program of a visible light receiving device which is connected to a visible light transmitting device having a plurality of light emitting elements and performs light emission adjustment of the visible light transmitting device,

The visible light receiving device includes a light receiving element,

Based on the received signal by the light receiving element for each of the plurality of light emitting elements, the calculation procedure for calculating the delay time of the light emission control timing for each of the plurality of light emitting elements is adapted so as to match the waveform characteristics of the respective received signals. A program of a visible light receiving device, which is executed by a computer of the visible light receiving device.

[Bookkeeping 24]

In the arithmetic procedure, a delay time of the rise and fall control timings for each of the plurality of light emitting elements is calculated so as to match the rise and fall of each of the received signals as waveform characteristics of the respective received signals. The program of the visible light receiving apparatus of 23.

[Bookkeeping 25]

The comparison procedure of comparing the waveform characteristics of the received signal by the light receiving element with respect to each of the plurality of light emitting elements with respect to the reference waveform used in the light emission control of the plurality of light emitting elements in the visible light transmitting apparatus is performed. Run it on your computer,

In the calculation procedure, the delay time of the light emission control timing is calculated based on the comparison result according to the comparison procedure. The program according to Appendix 23 or 24, wherein the visible light receiving device.

(Supplementary Note 26)

In the comparison procedure, as a waveform characteristic of each of the received signals, a rise for each of the received signals is compared with a rise in the reference waveform, and a drop for each of the received signals is compared with a fall in the reference waveform. A program of the visible light receiving device according to Supplementary note 25.

[Supplementary Note 27]

In the comparison procedure, the waveform characteristic obtained by binarizing the received signal by the light receiving element for each of the plurality of light emitting elements is compared with the binarized reference waveform used for light emission control of the plurality of light emitting elements. The program of the visible light receiving device according to Appendix 25 or 26.

(Supplementary Note 28)

A program of a visible light transmitting device which is connected to a visible light receiving device having a light receiving element and is adjusted,

The visible light transmitting device includes a plurality of light emitting elements,

Delay time of the light emission control timing for each of the plurality of light emitting elements calculated by the visible light receiving device to match the waveform characteristics of the respective received signals based on the received signals by the light receiving elements for each of the plurality of light emitting elements. The computer program of the visible light transmitting device executes a setting procedure for setting the light emission control timing for each of the light emitting elements.

[Supplementary Note 29]

An environmental condition measurement procedure of measuring which of the predetermined environmental condition values is included in the predetermined environmental condition value,

Executing a storage procedure for storing the delay time calculated by the visible light receiving apparatus for each of the environmental conditions, in the computer of the visible light transmitting apparatus;

In the setting procedure, the light emission control timing for each of the light emitting elements is set based on the delay time corresponding to the division of the environmental conditions measured by the environmental condition measurement procedure among the delay time stored in the storage procedure. The program of the visible light transmitting device according to Appendix 28.

INDUSTRIAL APPLICABILITY The present invention can be used for all kinds of visible light communication devices that transmit the same signal using a plurality of light emitting elements.

1: visible light transmission equipment
2: modulation circuit
3: adjusting circuit
5: visible light receiving device
6: signal comparison circuit
7: Adjustment value calculation circuit
9: Adjustment value storage and setting circuit
10 to 12 light emitting element
13-15: light receiving element
17-19: light emission drive signal
20 to 22: light output signal
23: transmission signal
24 to 26: reception signal

Claims (10)

A plurality of light emitting elements,
A light receiving element,
Computing means for calculating a delay time of the rise and fall control timings for each of the plurality of light emitting elements so as to match the rise and fall of each of the received signals by the light receiving elements for each of the plurality of light emitting elements;
Setting means for setting light emission control timings for the respective light emitting elements based on the calculated delay time
The light emission drive adjustment system characterized by the above-mentioned. The method of claim 1,
And said setting means sets the control timing of rising and falling for each said light emitting element. The method according to claim 1 or 2,
Comparison means for comparing a waveform characteristic of a received signal by the light receiving element to each of the plurality of light emitting elements with respect to a reference waveform used for light emission control of the plurality of light emitting elements,
And said calculating means calculates a delay time of said light emission control timing based on a comparison result by said comparing means. The method of claim 3,
The comparison means, as a waveform characteristic of each of the received signals, compares the rise of each of the received signals with the rise of the reference waveform, and the fall of each of the received signals with the fall of the reference waveform. The light emission drive adjustment system characterized by the above-mentioned. The method according to claim 1 or 2,
Environmental condition measurement means for measuring which of the predetermined environmental condition values are included in the predetermined environmental condition value;
Storage means for storing the delay time calculated by the calculation means for each of the environmental condition classifications,
The setting means sets the light emission control timing for each of the light emitting elements based on the delay time corresponding to the environmental condition classification measured by the environmental condition measuring means among the delay time stored in the storage means. Luminous drive adjustment system. The method according to claim 1 or 2,
The light receiving element is provided so as to be one to one for each of the plurality of light emitting elements,
The light emission drive adjustment system includes light shielding means for shielding only the light signal from the light emitting element associated with each one of the light receiving elements so as to enter each of the light receiving elements,
A light emission drive adjustment system for performing calculation by the calculating means and setting by the setting means for each predetermined instrument. A visible light receiving device which is connected to a visible light transmitting device having a plurality of light emitting elements and performs light emission adjustment of the visible light transmitting device,
A light receiving element,
Calculation means for calculating a delay time of the rise and fall control timings for each of the plurality of light emitting elements so as to match the rise and fall of each of the received signals by the light receiving elements for each of the plurality of light emitting elements.
Visible light receiving device characterized in that it comprises a. A visible light transmitting device connected to a visible light receiving device having a light receiving element and subjected to adjustment,
A plurality of light emitting elements,
Setting means for calculating and setting a delay time of the rise and fall control timings for each of the plurality of light emitting elements so as to match the rise and fall of each of the received signals by the light receiving elements for each of the plurality of light emitting elements.
Visible light transmission device comprising a. As a light emission drive adjustment method in the system provided with the some light emitting element and the light receiving element,
A calculation step of calculating delay times of rise and fall control timings for each of the plurality of light emitting elements so as to match rising and falling of each of the received signals by the light receiving elements for each of the plurality of light emitting elements;
A setting step of setting light emission control timings for the respective light emitting elements based on the calculated delay time
The light emission drive adjustment method characterized by the above-mentioned. A computer-readable recording medium which records a program of a visible light receiving device connected to a visible light transmitting device having a plurality of light emitting elements and adjusting light emission of the visible light transmitting device.
The visible light receiving device includes a light receiving element,
The visible light receiving operation is performed to calculate a delay time of the rise and fall control timings for each of the plurality of light emitting elements, so as to match the rise and fall of each of the received signals by the light receiving elements for each of the plurality of light emitting elements. A computer-readable recording medium having recorded thereon a program of a visible light receiving apparatus, which is executed by a computer of the apparatus.

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