JP7030012B2 - Backlight control system - Google Patents

Description

The present invention relates to a backlight control system.

A backlight that emits light uniformly over the entire surface of a liquid crystal panel by adjusting the amount of light of the light emitting element is known as a prior art. Examples of such a backlight include the backlight disclosed in Patent Document 1.

The backlight has a plurality of types of light emitting elements that emit light of different colors from each other, and is configured by combining a plurality of light source modules that emit light of a predetermined color by mixing the lights of each color. The light source module is a light receiving sensor that receives light emitted from a light emitting element and measures the intensity of the light, and a color that performs color correction by controlling the output of the light emitting element based on the measurement result of the light receiving sensor. It is equipped with a correction circuit.

Japanese Unexamined Patent Publication No. 2007-214053 (published on August 23, 2007)

In the backlight disclosed in Patent Document 1, when the liquid crystal panel is large, it is necessary to provide a plurality of light receiving elements. Therefore, since a plurality of wirings for transmitting the measurement result of the light receiving sensor to the color correction circuit are required, there is a problem that the wiring structure of the backlight becomes complicated and the manufacturing cost of the backlight increases.

One aspect of the present invention is to simplify the wiring structure of the backlight control system and reduce the manufacturing cost of the backlight control system.

In order to solve the above problems, the backlight control system according to one aspect of the present invention is a backlight control system that controls a backlight composed of a plurality of light emitting elements, and each of the plurality of light emitting elements is used. It is provided with a plurality of light emitting driving units that drive the light to emit light at a specified brightness, has a light receiving element that receives light emitted from each of the plurality of light emitting elements, and measures the brightness of the light. It is provided with a plurality of units, and has a configuration in which the output of the light emitting drive unit in the front stage is connected to the input of the light emitting drive unit in the rear stage between two adjacent light emitting drive units, and the plurality of said measurements are made. A control unit that controls the light emitting drive unit based on the brightness measured by each unit is further provided, and an enable signal indicating that the control unit can communicate with the measurement unit is carried by a wiring. It further comprises a configuration in which two adjacent measuring units are connected to each other .

According to one aspect of the present invention, the wiring structure of the backlight control system can be simplified and the manufacturing cost of the backlight control system can be reduced.

It is a figure which shows the internal structure of the backlight control system which concerns on Embodiment 1 of this invention. It is a figure which shows the internal structure of the measuring part of the backlight control system shown in FIG. It is a schematic diagram which looked at the backlight control system shown in FIG. 1 from the side where the liquid crystal panel is arranged. It is a figure which shows the internal structure of the backlight control system which concerns on Embodiment 2 of this invention. It is a figure which shows the internal structure of the backlight control system which concerns on Embodiment 3 of this invention. It is a figure which shows the internal structure of the backlight control system which concerns on Embodiment 4 of this invention. It is a figure which shows the internal structure of the backlight control system which concerns on Embodiment 5 of this invention. It is a figure which shows the internal structure of the modification of the backlight control system shown in FIG. 7.

[Embodiment 1]
(Internal configuration of backlight control system 1)
FIG. 1 is a diagram showing an internal configuration of the backlight control system 1 according to the first embodiment of the present invention. FIG. 2 is a diagram showing an internal configuration of the measurement unit 30 of the backlight control system 1 shown in FIG. FIG. 3 is a schematic view of the backlight control system 1 shown in FIG. 1 as viewed from the side where the liquid crystal panel (not shown) is arranged. As shown in FIG. 1, the backlight control system 1 includes a backlight 10, a plurality of light emitting drive units 20, a plurality of measurement units 30, a control unit 40, and a power supply 50. The backlight control system 1 is a system that controls the backlight 10.

The backlight 10 is composed of a plurality of light emitting elements 11. Examples of the light emitting element 11 include an LED (Light Emitting Diode). Each light emitting element 11 is connected to a power source 50 and is supplied with electric power from the power source 50. The backlight 10 is arranged on the back side of the liquid crystal panel (not shown), for example, and irradiates the liquid crystal panel with light from the back side.

The light emitting drive unit 20 is connected to a plurality of light emitting elements 11, and drives each of the plurality of light emitting elements 11 so as to emit light with a brightness designated by the control unit 40. Further, between two adjacent light emitting drive units 20, the output Dout of the light emitting drive unit 20 in the front stage is connected to the input Din of the light emitting driving unit 20 in the rear stage.

Specifically, as shown in FIG. 1, for example, between two adjacent light emitting drive units 20_1 and 20_2, the output Dout of the light emitting drive unit 20_1 in the front stage is connected to the input Din of the light emitting driving unit 20_1 in the rear stage. ing. That is, the connection between the two adjacent light emitting drive units 20 is a cascade connection. Cascade connection is the longitudinal connection of one output and the other input.

Further, the plurality of light emitting drive units 20 are connected to the wiring DD1 extending from the terminal DD of the control unit 40 and the wiring CLD1 extending from the terminal CLD of the control unit 40, respectively. The input Din of the light emitting drive unit 20_1 in the frontmost stage is connected to the terminal END of the control unit 40.

The measuring unit 30 has a light receiving element 31 that receives light emitted from each of the plurality of light emitting elements 11, and measures the brightness of the light. Examples of the light receiving element 31 include PD (Photo Diode). Further, between two adjacent measurement units 30, the output Pout of the measurement unit 30 in the front stage is connected to the input pin of the measurement unit 30 in the rear stage.

Specifically, as shown in FIG. 1, for example, between two adjacent measuring units 30_1 and 30_2, the output Pout of the measuring unit 30_1 in the front stage is connected to the input pin of the measuring unit 30_2 in the rear stage. The input Pin of the measurement unit 30_1 in the earliest stage is connected to the terminal DPO of the control unit 40. That is, the connection between two adjacent measuring units 30 is a cascade connection.

Further, each of the plurality of measuring units 30 is connected to the wiring ENP1 extending from the terminal ENP of the control unit 40 and the wiring CLP1 extending from the terminal CLP of the control unit 40. The output Pout of the measurement unit 30 in the latter stage is connected to the terminal DPI of the control unit 40.

Further, as shown in FIG. 2, the measuring unit 30 includes a light receiving element 31, an AD (Analog-Digital) converter 32, an internal register 33, and a shift register 34. The light receiving element 31 receives light emitted from each of the plurality of light emitting elements 11 and converts the received light into an electric current.

The AD converter 32 converts the analog data output from the light receiving element 31 into digital data, and stores the converted digital data in the internal register 33. The digital data converted by the AD converter 32 is the brightness data of the light received by the light receiving element 31. That is, the luminance data is stored in the internal register 33. The shift register 34 is connected to the input Pin and the output Pout of the measuring unit 30.

(Configuration of the backlight control system 1 on the liquid crystal panel side)
The liquid crystal panel side of the backlight control system 1 is divided into m × n (m and n are natural numbers) regions. For example, as shown in FIG. 3, it is assumed that the liquid crystal panel side of the backlight control system 1 is divided into 4 × 6 regions. In one of the 4 × 6 regions, for example, three light emitting elements 11 that emit red (R), green (G), and blue (B) light are provided. It should be noted that one light emitting element 11 may be provided in one of the 4 × 6 regions.

Six light emitting driving units 20 may be provided in the entire 4 × 6 region. These six light emitting drive units 20 have (x, y) = (1 to 2, 1 to 2), (1 to 2, 3 to 4), (1 to 2, 5 to 6), and (3 to 4), respectively. It drives 12 light emitting elements 11 provided in the regions corresponding to 1 to 2), (3 to 4, 3 to 4), and (3 to 4, 5 to 6). “X” indicates a row in the entire 4 × 6 region, and y indicates a column in the entire 4 × 6 region. For example, one light emitting drive unit 20 drives 12 light emitting elements 11 provided in the region corresponding to (x, y) = (1 to 2, 1 to 2).

That is, the 4 × 6 region is divided into the 2 × 3 region by the light emitting driving unit 20. A light receiving element 31 is provided in the center of each of the 2 × 3 regions. As a result, the light receiving element 31 can receive light emitted from each of the 12 light emitting elements 11 provided in one of the 2 × 3 regions.

(Processing of control unit 40)
The control unit 40 includes terminals END, DD, CLD, DPO, ENP, CLP, and DPI, and controls the light emitting drive unit 20 based on the luminance measured by each of the plurality of measurement units 30. The processing contents of the control unit 40 will be described below.

The control unit 40 transmits a measurement start signal instructing the plurality of measurement units 30 to start measuring the luminance from the terminal DPO to the input pin of the measurement unit 30_1 in the earliest stage. The measurement start signal includes the contents of the operation setting (PD gain, etc.) of the light receiving element 31.

Further, for example, consider a case where the amount of data that can be stored in one shift register 34 included in the measuring unit 30 is 16 bits. In this case, for example, when the connection between the 10 measuring units 30 is a cascade connection, the control unit 40 transmits 160 bits of data as the measurement start signal to the 10 measuring units 30.

At this time, the data for 16 bits transmitted first by the control unit 40 is the data set in the measurement unit 30 in the rearmost stage, and the data for 16 bits transmitted last in the control unit 40 is the data for the measurement unit 30_1 in the earliest stage. It is the data to be set. Further, in the wiring between two adjacent measurement units 30, a signal including data stored in the shift register 34 of the measurement unit 30 at a stage after the wiring flows among the contents included in the measurement start signal.

After transmitting the measurement start signal, the control unit 40 transmits an enable signal S1 from the terminal ENP to each measurement unit 30 via the wiring ENP1. The enable signal S1 is a signal indicating that the control unit 40 can communicate with each measurement unit 30. When each measurement unit 30 receives the enable signal S1, each measurement unit 30 stores the content included in the measurement start signal in the shift register 34. After that, each measurement unit 30 stores the content included in the measurement start signal in the internal register 33.

After the control unit 40 transmits the enable signal S1 to each measurement unit 30, the control unit 40 sends the data stored in the shift register 34 of each measurement unit 30 from the terminal DPO to the input pin of the measurement unit 30_1. Send a signal. As a result, the data stored in the shift register 34 of each measurement unit 30 is sent out from the shift register 34 of each measurement unit 30.

After that, the control unit 40 retransmits the enable signal S1 from the terminal ENP to each measurement unit 30 via the wiring ENP 1, so that the measurement unit 40 measures the brightness data stored in the internal register 33 of the measurement unit 30. It is instructed to store in the shift register 34 of 30. When each measuring unit 30 receives the enable signal S1, each measuring unit 30 stores the luminance data stored in the internal register 33 in the shift register 34 of the measuring unit 30.

The control unit 40 transmits a clock signal from the terminal CLP to each measurement unit 30 via the wiring CLP1. When each measurement unit 30 receives this clock signal, the luminance data stored in the shift register 34 of each measurement unit 30 is transmitted from the output Pout of the measurement unit 30 in the latter stage to the terminal DPI of the control unit 40. .. At this time, the 16-bit data first transmitted to the terminal DPI is the luminance data stored in the shift register 34 of the measurement unit 30 at the rearmost stage. Further, the data from the 145th bit to the 160th bit transmitted to the terminal DPI is the luminance data stored in the shift register 34 of the measurement unit 30_1 in the earliest stage.

As described above, the two adjacent measurement units 30 are connected by a wiring through which the measurement start signal flows. As a result, the control unit 40 instructs each measurement unit 30 to start measuring the luminance while reducing the number of wirings connecting the control unit 40 and the measurement unit 30 that transmit the measurement start signal to the measurement unit 30. Can be done.

Further, the control unit 40 designates the brightness (output) of the plurality of light emitting elements 11 driven by each light emission drive unit 20 based on the brightness data received from each measurement unit 30. Specifically, for example, in the control unit 40, the brightness of the light emitted from the plurality of light emitting elements 11 for each light emitting drive unit 20 is the same as the brightness of the light when the production of the backlight control system 1 is completed. In addition, the brightness of a plurality of light emitting elements 11 driven by each light emitting driving unit 20 may be specified.

That is, the brightness of the plurality of light emitting elements 11 is specified for each light emitting drive unit 20, and the brightness of each light emitting element 11 driven by one light emitting drive unit 20 is the brightness of the light when the production of the backlight control system 1 is completed. Will be the same as.

Further, when the production of the backlight control system 1 is completed, the brightness of the three types of light emitting elements 11 that emit red, green, and blue light is set in advance so that the desired white light is emitted from the backlight 10. adjust.

At this time, the light receiving sensitivities of the plurality of light receiving elements 31 vary. Therefore, when the production of the backlight control system 1 is completed, the brightness of each light emitting element 11 is adjusted so that the desired white light is emitted from the backlight 10 without using the light receiving element 31 included in the backlight control system 1. Adjust in advance. Further, since the deterioration of the light emitting element 11 also varies, the control unit 40 needs to specify the brightness of the light emitting element 11 for each light emitting driving unit 20.

As a result, even if the light emitting performance of the light emitting element 11 deteriorates due to the deterioration of the light emitting element 11, the brightness of the light emitted from each light emitting element 11 is set to the brightness of the light when the production of the backlight control system 1 is completed. Can be kept identical.

Further, the control unit 40 transmits the enable signal S2 from the terminal END to the input Din of the light emitting drive unit 20_1 in the earliest stage. The enable signal S2 is a signal indicating that the control unit 40 can communicate with each light emitting drive unit 20. By transmitting the enable signal S2 to the light emitting drive unit 20_1, the control unit 40 can communicate with only the light emitting drive unit 20_1 among the plurality of light emitting drive units 20.

The control unit 40 transmits a clock signal from the terminal CLD to the light emitting drive unit 20_1 via the wiring CLD1. When this clock signal is transmitted to the light emitting drive unit 20_1, the control unit 40 instructs the light emitting drive unit 20_1 to emit light of the light emitting element 11 with the brightness specified by the control unit 40 from the terminal DD via the wiring DD1. Sends a light emission control signal. The light emission control signal includes the luminance data of the light emitting element 11 designated by the control unit 40 and the contents of the operation setting of the light emitting element 11. The amount of data received by each light emitting drive unit 20 is fixed.

When the light emission driving unit 20_1 receives the light emission control signal from the control unit 40, the light emission driving unit 20_1 emits light from the light emitting element 11 with the brightness specified by the control unit 40. Next, the light emitting drive unit 20_1 transmits the enable signal S2 from the output Dout to the input Din of the light emitting driving unit 20_2 in the subsequent stage. That is, the enable signal S2 flows through the wiring between the light emitting drive unit 20_1 and the light emitting drive unit 20_2. When the light emitting drive unit 20_1 transmits the enable signal S2 to the light emitting drive unit 20_1, the control unit 40 can communicate with only the light emitting drive unit 20_2 among the plurality of light emitting drive units 20.

The control unit 40 transmits the light emission control signal to the light emission drive unit 20_1 as in the case of the light emission drive unit 20_1. When the light emission driving unit 20_2 receives the light emission control signal from the control unit 40, the light emission driving unit 20_2 emits light from the light emitting element 11 with the brightness specified by the control unit 40. Similarly, the subsequent light emitting drive unit 20 also emits light from the light emitting element 11 with the brightness specified by the control unit 40.

In this way, the two adjacent light emitting drive units 20 are connected by a wiring through which the enable signal S2 flows. As a result, the control unit 40 transmits the enable signal S2 to each light emitting drive unit 20 while reducing the number of wirings connecting the control unit 40 that transmits the enable signal S2 to the light emitting drive unit 20 and the light emitting drive unit 20. Can be done.

As described above, in the backlight control system 1, the output Pout of the measurement unit 30 in the front stage is connected to the input pin of the measurement unit 30 in the rear stage, and the output Dout of the light emission drive unit 20 in the front stage is the light emission drive unit in the rear stage. It is connected to 20 input bins.

Here, for example, consider the case where the control unit 40 and the light emitting drive unit 20 are connected, and the control unit 40 and the measurement unit 30 are connected. In this case, in the configuration of the backlight control system 1, the number of wirings can be reduced as compared with the case where the control unit 40 and each light emitting drive unit 20 and the control unit 40 and each measurement unit 30 are connected by wiring. can.

Further, since the number of wirings can be reduced, it is not necessary to make the substrate (not shown) provided with the light emitting drive unit 20 and the measurement unit 30 into a multilayer board. Further, since the number of terminals of the control unit 40 can be reduced, the size of the control unit 40 can be reduced. Therefore, the wiring structure of the backlight control system 1 can be simplified, and the manufacturing cost of the backlight control system 1 can be reduced.

[Embodiment 2]
FIG. 4 is a diagram showing an internal configuration of the backlight control system 2 according to the second embodiment of the present invention. For convenience of explanation, the same reference numerals are given to the members having the same functions as the members described in the above-described embodiment, and the description thereof will not be repeated.

As shown in FIG. 4, in the backlight control system 2, the control unit 40 is changed to the control unit 40a as compared with the backlight control system 1, and the connection relationship between each measurement unit 30 and the control unit 40a. Is different. Here, regarding the connection relationship between each measurement unit 30 and the control unit 40a, only the part where the backlight control system 2 is different from the backlight control system 1 will be described.

The control unit 40a is different from the control unit 40 in that it does not have a terminal DPO. Further, the input Pin of the measurement unit 30_1 in the earliest stage is connected to the terminal ENP of the control unit 40a. Each of the plurality of measuring units 30 is connected to the wiring DPI 1 extending from the terminal DPI of the control unit 40a. The control unit 40a transmits the above-mentioned enable signal S1 from the terminal ENP to the input pin of the measurement unit 30_1. By transmitting the enable signal S1 to the measurement unit 30_1, the control unit 40a can communicate with only the measurement unit 30_1 among the plurality of measurement units 30.

The control unit 40a transmits a measurement start signal instructing the measurement unit 30_1 to start measuring the luminance from the terminal DPI to the measurement unit 30_1. Upon receiving the measurement start signal, the measurement unit 30_1 stores the contents included in the measurement start signal in the shift register 34.

Next, the control unit 40a transmits a clock signal from the terminal CLP to the measurement unit 30_1 via the wiring CLP1. When the measuring unit 30_1 receives this clock signal, the content included in the measurement start signal stored in the shift register 34 of the measuring unit 30_1 is stored in the internal register 33 of the measuring unit 30_1. Then, the luminance data stored in the internal register 33 of the measuring unit 30_1 is stored in the shift register 34 of the measuring unit 30_1. The luminance data stored in the shift register 34 of the measuring unit 30_1 is input to the terminal DPI via the wiring DPI1.

After the measuring unit 30_1 transmits the luminance data to the control unit 40a, the measuring unit 30_1 transmits the enable signal S1 to the measuring unit 30_1. At this time, the enable signal S1 flows through the wiring between the measuring unit 30_1 and the measuring unit 30_2. When the measuring unit 30_1 transmits the enable signal S1 to the measuring unit 30_2, the control unit 40a can communicate with only the measuring unit 30_2 among the plurality of measuring units 30. The control unit 40a transmits a measurement start signal instructing the measurement unit 30_2 to start measuring the luminance from the terminal DPI to the measurement unit 30_2.

Similarly, the luminance data stored in the shift register 34 of the measuring unit 30_2 is input to the terminal DPI via the wiring DPI1. Similarly, for the measurement unit 30 in the subsequent stage from the measurement unit 30_2, the luminance data stored in the shift register 34 of the measurement unit 30 is input to the terminal DPI via the wiring DPI1.

As described above, the two adjacent measuring units 30 are connected by a wiring through which the enable signal S1 flows. As a result, the control unit 40a can instruct each measurement unit 30 to start measuring the luminance while reducing the number of wirings connecting the control unit 40a that transmits the enable signal S1 to the measurement unit 30 and the measurement unit 30. Can be done.

[Embodiment 3]
FIG. 5 is a diagram showing an internal configuration of the backlight control system 3 according to the third embodiment of the present invention. For convenience of explanation, the same reference numerals are given to the members having the same functions as the members described in the above-described embodiment, and the description thereof will not be repeated.

As shown in FIG. 5, the backlight control system 3 differs from the backlight control system 2 in that the measurement unit 30 and the control unit 40a are changed to the measurement unit 30a and the control unit 40b, respectively. Further, the backlight control system 3 is different from the backlight control system 2 in the connection relationship between each light emitting drive unit 20, each measurement unit 30a, and the control unit 40b. Here, regarding the connection relationship between each light emission driving unit 20, each measuring unit 30a, and the control unit 40b, only the part where the backlight control system 3 is different from the backlight control system 2 will be described.

The measurement unit 30a is different from the measurement unit 30 in that it does not have an output Pout, and the control unit 40b is different from the control unit 40a in that it does not have a terminal ENP. Further, the input Pin of the measurement unit 30a_1 in the earliest stage is connected to the terminal END of the control unit 40b, and the wiring branched from the wiring END1 connecting the terminal END and the input Bin of the light emitting drive unit 20_1 in the earliest stage. It is connected to B1. The input Pin of each measuring unit 30a is connected to the wiring B1 branched from the wiring END1 connecting between the two adjacent light emitting driving units 20. An enable signal S3, which will be described later, flows through the wiring END1.

The control unit 40b transmits the enable signal S3 from the terminal END to the light emitting drive unit 20 and the measurement unit 30a. The enable signal S3 is a signal indicating that the control unit 40b can communicate with each light emission driving unit 20 and each measuring unit 30a.

Here, the operation when the light emitting drive unit 20 receives the enable signal S3 is the same as the operation when the light emitting drive unit 20 receives the enable signal S2 in the backlight control system 1. Further, the operation when the measuring unit 30a receives the enable signal S3 is the same as the operation when the measuring unit 30 receives the enable signal S1 in the backlight control system 2. However, when the measurement unit 30a in the subsequent stage from the measurement unit 30a_1 receives the enable signal S3, the measurement unit 30a in the stage after the measurement unit 30a_1 receives the enable signal S3 from the light emitting drive unit 20.

As described above, the two adjacent light emitting drive units 20 are connected by the wiring END1 through which the enable signal S3 flows, and the measurement unit 30a is connected to the wiring B1 branching from the wiring END1 through which the enable signal S3 flows. Thereby, for example, the control unit 40b that transmits the enable signal to the light emitting drive unit 20 can communicate only with the measurement unit 30a that has received the enable signal S3 without managing the measurement unit 30a for each identification number. ..

Further, between two adjacent measuring units 30a, the number of terminals of the measuring unit 30a can be reduced as compared with the case where the output Pout of the measuring unit 30a in the front stage is connected to the input pin of the measuring unit 30a in the rear stage. can. Further, since it is not necessary to connect the control unit 40b and each measurement unit 30a, the number of wirings can be reduced. The same effect as that of the measuring unit 30a can be obtained in the light emitting driving unit 20.

[Embodiment 4]
FIG. 6 is a diagram showing an internal configuration of the backlight control system 4 according to the fourth embodiment of the present invention. For convenience of explanation, the same reference numerals are given to the members having the same functions as the members described in the above-described embodiment, and the description thereof will not be repeated.

As shown in FIG. 6, in the backlight control system 4, the measurement unit 30a is changed to the measurement unit 30b as compared with the backlight control system 3, and each light emitting drive unit 20, each measurement unit 30b, and a control unit are used. The connection relationship between 40b is different. Here, regarding the connection relationship between each light emission driving unit 20, each measuring unit 30b, and the control unit 40b, only the part where the backlight control system 4 is different from the backlight control system 3 will be described.

The measuring unit 30b is different from the measuring unit 30a in that it does not have an input pin. Although FIG. 6 shows that the measuring unit 30b is provided with the power supply terminal VDD and the terminal GND, the above-mentioned measuring units 30 and 30a are also provided with the power supply terminal VDD and the terminal GND. In FIGS. 1, 4, and 5, the power supply terminal VDD and the terminal GND are omitted.

Further, the power supply terminal VDD of the earliest measurement unit 30b_1 is connected to the terminal END of the control unit 40b, and branches from the wiring END1 connecting the terminal END and the input Din of the light emission drive unit 20_1 of the earliest stage. It is connected to the wiring B2. The power supply terminal VDD of each measurement unit 30b is connected to the wiring B2 branched from the wiring END1 connecting between the two adjacent light emitting drive units 20. The enable signal S3 described above flows through the wiring END1.

The control unit 40b transmits the enable signal S3 from the terminal END to the power supply terminal VDD of the light emitting drive unit 20 and the measurement unit 30b. That is, the electric power of the measuring unit 30b is supplied by the wiring B2 branched from the wiring END1. Here, the operation when the measuring unit 30b receives the enable signal S3 at the power supply terminal VDD is the same as the operation when the measuring unit 30a receives the enable signal S3 in the backlight control system 3. The terminal GND of the measuring unit 30b is connected to the ground.

Therefore, the measuring unit 30b receives the enable signal S3 at the terminal for supplying electric power instead of the terminal for receiving the enable signal S3. Therefore, the backlight control system 4 can be manufactured by using the measurement unit 30b that does not have a terminal for receiving the enable signal S3.

[Embodiment 5]
FIG. 7 is a diagram showing an internal configuration of the backlight control system 5 according to the fifth embodiment of the present invention. For convenience of explanation, the same reference numerals are given to the members having the same functions as the members described in the above-described embodiment, and the description thereof will not be repeated.

As shown in FIG. 7, in the backlight control system 5, the light emitting drive unit 20, the measuring unit 30, and the control unit 40 have the light emitting driving unit 20a, the measuring unit 30c, and the control, respectively, as compared with the backlight control system 1. The difference is that it is changed to the part 40c. Further, the backlight control system 5 has a different connection relationship between each light emitting drive unit 20a, each measurement unit 30c, and the control unit 40c as compared with the backlight control system 1.

Here, regarding the connection relationship between each light emission driving unit 20a, each measuring unit 30c, and the control unit 40c, only the part where the backlight control system 5 is different from the backlight control system 1 will be described.

As shown in FIG. 7, the light emitting drive unit 20a includes a drive circuit 21, a reception circuit 22, and an interface unit 23. The drive circuit 21 is connected to a plurality of light emitting elements 11 and an interface unit 23, and drives the plurality of light emitting elements 11. The receiving circuit 22 is connected to the measuring unit 30c and receives data from the measuring unit 30c.

The measuring unit 30c is different from the measuring unit 30 in that it does not have the shift register 34 and that it is provided with only two terminals. Further, each measuring unit 30c is connected to each light emitting driving unit 20a. As a result, it is not necessary to directly connect the control unit 40c and the measurement unit 30c. Therefore, the number of wirings can be reduced.

The control unit 40c is different from the control unit 40 in that it does not have the terminals DPO, ENP, CLP, and DPI. Further, the control unit 40c transmits the above-mentioned enable signal S2 from the terminal END to the input Din of the light emitting drive unit 20a_1 at the earliest stage. After the control unit 40c transmits the enable signal S2 to the light emitting drive unit 20a_1, the control unit 40c transmits a clock signal from the terminal CLD to the light emitting drive unit 20a_1 via the wiring CLD1. When this clock signal is transmitted to the light emitting drive unit 20a_1, the control unit 40c transmits a control signal from the terminal DD to the light emitting drive unit 20a_1 via the wiring DD1. The control signal is a signal instructing the light emitting drive unit 20a to emit light from the light emitting element 11 and to start measuring the luminance measured by the measuring unit 30c.

When the light emitting drive unit 20a_1 receives the control signal, the interface unit 23 instructs the drive circuit 21 to drive a plurality of light emitting elements 11, and instructs the reception circuit 22 to receive data from the measurement unit 30c. do. When the drive circuit 21 is instructed by the interface unit 23 to drive the light emitting element 11, the drive circuit 21 drives a plurality of light emitting elements 11. When the receiving circuit 22 is instructed by the interface unit 23 to receive the data from the measuring unit 30c, the receiving circuit 22 receives the luminance data stored in the internal register 33 of the measuring unit 30c from the measuring unit 30c. ..

Next, the control unit 40c retransmits the clock signal from the terminal CLD to the light emitting drive unit 20a_1 via the wiring CLD1. When this clock signal is transmitted to the light emitting drive unit 20a_1, the luminance data is input to the terminal DD via the wiring DD1. That is, the luminance data is transmitted to the control unit 40c via the light emission driving unit 20a_1. As a result, the luminance data can be transmitted to the control unit 40c without directly connecting the control unit 40c and the measurement unit 30c. The control unit 40c designates the brightness of the plurality of light emitting elements 11 driven by the light emitting drive unit 20a_1 based on the brightness data received from the light emitting drive unit 20a_1.

After designating the luminance of the plurality of light emitting elements 11 driven by the light emitting drive unit 20a_1, the control unit 40c again transmits the clock signal from the terminal CLD to the light emitting drive unit 20a_1 via the wiring CLD1. When this clock signal is transmitted to the light emitting drive unit 20a_1, the control unit 40c instructs the light emitting drive unit 20a_1 to drive the plurality of light emitting elements 11 with the brightness specified by the control unit 40c.

When the light emitting drive unit 20a_1 is instructed to drive the plurality of light emitting elements 11 with the brightness specified by the control unit 40c, the interface unit 23 causes the drive circuit 21 to emit a plurality of light sources with the brightness specified by the control unit 40c. Instruct to drive the element 11. When the drive circuit 21 is instructed by the interface unit 23 to drive the light emitting element 11 with the brightness specified by the control unit 40c, the drive circuit 21 drives the plurality of light emitting elements 11 with the brightness specified by the control unit 40c.

Next, the light emitting drive unit 20a_1 transmits the enable signal S2 from the output Dout to the input Din of the light emitting drive unit 20a_2 in the subsequent stage. When the light emitting drive unit 20a_1 transmits the enable signal S2 to the light emitting drive unit 20a_2, the control unit 40c can communicate with only the light emitting drive unit 20a_2 among the plurality of light emitting drive units 20a. Similar to the light emitting drive unit 20a_1, the subsequent light emitting drive unit 20a also performs the same processing.

As described above, the light emitting drive unit 20a has a receiving circuit 22 for receiving data from the measuring unit 30c, and the backlight control system 5 causes the light emitting driving unit 20a to start measuring the light emission and the luminance of the light emitting element 11. A control unit 40c for transmitting a control signal to be instructed is provided. This makes it possible to instruct the measuring unit 30c to start measuring the luminance without directly connecting the control unit 40c and the measuring unit 30c. Therefore, since wiring for connecting the control unit 40c and the measurement unit 30c is not required, the number of wirings can be reduced.

(Modification example)
FIG. 8 is a diagram showing an internal configuration of the backlight control system 6. The backlight control system 6 is a modification of the backlight control system 5 shown in FIG. 7. The backlight control system 6 is different from the backlight control system 5 in that the measuring unit 30c is changed to the light receiving element 31 and the light emitting driving unit 20a is changed to the light emitting driving unit 20b.

The light emitting drive unit 20b is different from the light emitting driving unit 20a in that it does not include the receiving circuit 22 and that it includes the AD converter 24. The AD converter 24 is the same as the AD converter 32 described above. The AD converter 24 converts the analog data output from the light receiving element 31 into digital data, and transmits the converted digital data to the interface unit 23.

The light receiving element 31 is connected to the AD converter 24 of the light emitting driving unit 20b and the power supply 50. The light receiving element 31 is supplied with electric power from the power source 50. Further, by changing the measuring unit 30c to the light receiving element 31, the number of terminals of the measuring unit 30c can be reduced.

Further, the light receiving element 31 may not be connected to all the light emitting driving units 20b. That is, there may be a light emitting drive unit 20b that is not connected to the light receiving element 31. The plurality of light emitting elements 11 and the light receiving element 31 connected to one light emitting drive unit 20b may be packaged in one package.

[Example of implementation by software]
The control blocks (particularly the control units 40, 40a, 40b, 40c) of the backlight control systems 1 to 6 may be realized by a logic circuit (hardware) formed in an integrated circuit (IC chip) or the like, or software. May be realized by.

In the latter case, the backlight control systems 1 to 6 include a computer that executes a program instruction, which is software that realizes each function. This computer includes, for example, at least one processor (control device) and at least one computer-readable recording medium in which the program is stored. Then, in the computer, the processor reads the program from the recording medium and executes the program, thereby achieving the object of the present invention. As the processor, for example, a CPU (Central Processing Unit) can be used. As the recording medium, a "non-temporary tangible medium", for example, a ROM (Read Only Memory) or the like, a tape, a disk, a card, a semiconductor memory, a programmable logic circuit, or the like can be used. Further, a RAM (Random Access Memory) for expanding the above program may be further provided. Further, the program may be supplied to the computer via any transmission medium (communication network, broadcast wave, etc.) capable of transmitting the program. It should be noted that one aspect of the present invention can also be realized in the form of a data signal embedded in a carrier wave, in which the above program is embodied by electronic transmission.

〔summary〕
The backlight control system (1 to 5) according to the first aspect of the present invention is a backlight control system that controls a backlight (10) composed of a plurality of light emitting elements (11), and the plurality of the light emitting elements. Each of the above is provided with a plurality of light emitting drive units (20.20a) that are driven to emit light at a specified luminance, and has a light receiving element (31) that receives light emitted from each of the plurality of light emitting elements. However, a plurality of measuring units (30, 30a, 30b, 30c) for measuring the brightness of the light are provided, and the output of the measuring unit in the front stage is the output of the measuring unit in the rear stage between the two adjacent measuring units. It has a configuration connected to the input of.

According to the above configuration, the output of the measurement unit in the front stage is connected to the input of the measurement unit in the rear stage. Here, for example, consider a case where a control unit that controls a light emitting drive unit and a measurement unit are connected based on the luminance measured by each of the plurality of measurement units. In this case, in the above configuration, the number of wirings can be reduced as compared with the case where the control unit and each measurement unit are connected by wiring. Therefore, the wiring structure of the backlight control system can be simplified, and the manufacturing cost of the backlight control system can be reduced.

The backlight control system (2) according to the second aspect of the present invention controls the light emitting driving unit (20) based on the brightness measured by each of the plurality of measuring units (30) in the first aspect. A configuration in which a control unit (40a) is further provided, and two adjacent measurement units are connected to each other by a wiring through which an enable signal indicating that the control unit can communicate with the measurement unit is provided. Further, it is preferable to provide.

According to the above configuration, two adjacent measuring units are connected by a wiring through which an enable signal flows. This allows, for example, to reduce the number of wires connecting the control unit that transmits the enable signal to the measurement unit and the measurement unit, while allowing the control unit to instruct each measurement unit to start measuring the luminance. Can be done.

The backlight control system (1 to 5) according to the third aspect of the present invention is a backlight control system that controls a backlight (10) composed of a plurality of light emitting elements (11), and the plurality of the light emitting elements. Each of the above is provided with a plurality of light emitting drive units (20.20a) that are driven to emit light at a specified brightness, and has a light receiving element (31) that receives light emitted from each of the plurality of light emitting elements. However, a plurality of measuring units (30, 30a, 30b, 30c) for measuring the brightness of the light are provided, and the output of the light emitting drive unit in the front stage is the output of the light emitting drive unit in the rear stage between the two adjacent light emitting drive units. It has a configuration connected to the input of the light emitting drive unit.

According to the above configuration, the output of the light emitting drive unit in the front stage is connected to the input of the light emitting drive unit in the rear stage. Here, for example, consider a case where a control unit that controls a light emitting drive unit and a light emitting drive unit are connected based on the brightness measured by each of the plurality of measuring units. In this case, in the above configuration, the number of wirings can be reduced as compared with the case where the control unit and each light emitting drive unit are connected by wiring. Therefore, the wiring structure of the backlight control system can be simplified, and the manufacturing cost of the backlight control system can be reduced.

The backlight control system (3.4) according to the fourth aspect of the present invention has the light emitting driving unit (20) based on the brightness measured by each of the plurality of measuring units (30a and 30b) in the third aspect. A control unit (40b) for controlling It is preferable that the measuring unit is further provided with a configuration in which the measuring unit is connected to the wiring (B1 and B2) branched from the wiring (END1) through which the enable signal flows.

According to the above configuration, the two adjacent light emitting drive units are connected by a wiring through which the enable signal flows, and the measuring unit is connected to the wiring branching from the wiring through which the enable signal flows. Thereby, for example, the control unit that transmits the enable signal to the light emitting drive unit can communicate only with the measurement unit that has received the enable signal without managing the measurement unit for each identification number.

Further, it is possible to reduce the number of terminals of the light emitting drive unit between the two adjacent light emitting drive units as compared with the case where the output of the light emitting drive unit in the front stage is connected to the input of the light emitting drive unit in the rear stage. Further, since it is not necessary to connect the control unit and each measurement unit, the number of wirings can be reduced.

In the backlight control system (4) according to the fifth aspect of the present invention, in the fourth aspect, the power of the measuring unit (30b) is supplied by the wiring (B2) branched from the wiring (END1) through which the enable signal flows. It is preferable to further provide such a configuration.

According to the above configuration, the power of the measuring unit is supplied by the wiring branched from the wiring through which the enable signal flows. As a result, the measuring unit receives the enable signal at the terminal for supplying power instead of the terminal for receiving the enable signal. Therefore, it is possible to manufacture a backlight control system using a measuring unit that does not have a terminal for receiving an enable signal.

In the backlight control system (5) according to the sixth aspect of the present invention, in the third aspect, the light emitting drive unit (20a) has a drive circuit (21) for driving the light emitting element (11) and the measurement. It further comprises a configuration having a receiving circuit (22) for receiving data from the unit (30c), and the light emitting driving unit is used to emit light from the light emitting element and to start measuring the brightness measured by the measuring unit. It is preferable to further include a control unit (40c) for transmitting an instruction control signal.

According to the above configuration, the light emitting drive unit has a receiving circuit for receiving data from the measuring unit, and the backlight control system controls the light emitting driving unit to instruct the light emitting drive unit to start measuring the light emission and the luminance of the light emitting element. A control unit for transmitting a signal is provided. As a result, it is possible to instruct the measuring unit to start measuring the luminance without directly connecting the control unit and the measuring unit. Therefore, since wiring for connecting the control unit and the measurement unit is not required, the number of wirings can be reduced.

In the backlight control system (5) according to the seventh aspect of the present invention, the luminance data measured by the measuring unit (30c) in the sixth aspect is the control unit (20a) via the light emitting driving unit (20a). It is preferable to further include the configuration transmitted in 40c).

According to the above configuration, the luminance data measured by the measuring unit is transmitted to the control unit via the light emitting driving unit. As a result, the luminance data can be transmitted to the control unit without directly connecting the control unit and the measurement unit.

It is preferable that the backlight control system (5) according to the eighth aspect of the present invention further includes the configuration in which the light emitting driving unit (20a) is connected to the measuring unit (30c) in the above aspect 7.

According to the above configuration, the light emitting driving unit is connected to the measuring unit. This eliminates the need to directly connect the control unit and the measurement unit. Therefore, the number of wirings can be reduced.

The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims, and the embodiments obtained by appropriately combining the technical means disclosed in the different embodiments. Is also included in the technical scope of the present invention. Further, by combining the technical means disclosed in each embodiment, new technical features can be formed.

1 to 6 Backlight control system 10 Backlight 11 Light emitting element 20, 20a Light emitting drive unit 21 Drive circuit 22 Reception circuit 23 Interface unit 24 AD converter 30, 30a, 30b, 30c Measuring unit 31 Light receiving element 32 AD converter 33 Inside Register 34 Shift register 40, 40a, 40b, 40c Control unit 50 Power supply B1, B2, CLD1, CLP1, DD1, DPI1, END1, ENP1 Wiring Din, Pin input Dout, Pout output CLD, CLP, DD, DPI, DPO, END , ENP terminal ADC terminal S1, S2, S3 Enable signal VDD Power terminal

Claims (6)

A backlight control system that controls a backlight composed of multiple light emitting elements.
Each of the plurality of light emitting elements is provided with a plurality of light emitting driving units that drive the light emitting elements to emit light at a specified brightness.
It has a light receiving element that receives light emitted from each of the plurality of light emitting elements, and has a plurality of measuring units for measuring the brightness of the light.
A configuration is provided in which the output of the measurement unit in the front stage is connected to the input of the measurement unit in the rear stage between two adjacent measurement units.
Further, a control unit for controlling the light emission driving unit is provided based on the luminance measured by each of the plurality of measuring units.
The back is further provided with a configuration in which two adjacent measurement units are connected by a wiring through which an enable signal indicating that the control unit can communicate with the measurement unit is carried. Light control system. A backlight control system that controls a backlight composed of multiple light emitting elements.
Each of the plurality of light emitting elements is provided with a plurality of light emitting driving units that drive the light emitting elements to emit light at a specified brightness.
It has a light receiving element that receives light emitted from each of the plurality of light emitting elements, and has a plurality of measuring units for measuring the brightness of the light.
Between the two adjacent light emitting drive units, the output of the light emitting drive unit in the front stage is connected to the input of the light emitting drive unit in the rear stage .
Further, a control unit for controlling the light emission driving unit is provided based on the luminance measured by each of the plurality of measuring units.
The two adjacent light emitting drive units are connected by a wiring through which an enable signal indicating that the control unit can communicate with the light emitting driving unit flows.
The backlight control system further comprises a configuration in which the measuring unit is connected to a wiring branched from a wiring through which the enable signal flows . The backlight control system according to claim 2 , further comprising a configuration in which the electric power of the measuring unit is supplied by a wiring branched from the wiring through which the enable signal flows. The light emitting drive unit further includes a configuration including a drive circuit for driving the light emitting element and a receiving circuit for receiving data from the measuring unit.
The backlight control according to claim 2 , further comprising a control unit for transmitting a light emission of the light emitting element and a control signal instructing the start of measurement of the luminance measured by the measurement unit. system. The backlight control system according to claim 4 , further comprising a configuration in which the luminance data measured by the measuring unit is further transmitted to the control unit via the light emitting driving unit. The backlight control system according to claim 5 , wherein the light emitting driving unit further includes a configuration connected to the measuring unit.

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