CN103345907A - Automatic regulator of LED backlight optical parameters based on ambient light detection - Google Patents

Abstract

An automatic adjuster of optical parameters of LED backlight source based on ambient light detection. It includes I2C interface, illuminance calculation module, luminance comparator, luminance value register, data sending module and luminance value adjustment module; I2C interface is connected with illuminance calculation module; illuminance calculation module is connected with luminance comparator; luminance comparator is connected with luminance value register It is used to compare the ambient light intensity value with the backlight brightness value of the previous state saved in the current brightness value register; the brightness value register is connected with the data sending module; the data sending module is connected with the brightness comparator and the brightness value adjustment module; the brightness value adjustment The module is connected to a brightness comparator. In order to make better use of the advantages of LED backlight TVs in terms of picture quality and energy-saving lamps, the automatic adjuster of the present invention adjusts parameters according to the visual effects of the human eye, which has a certain protective effect on the eyesight of the viewer, and can also relieve Viewer visual fatigue.

Description

Automatic adjuster of optical parameters of LED backlight based on ambient light detection

technical field

The invention belongs to the technical field of display screen backlights, in particular to an automatic adjuster for optical parameters of LED backlight sources based on ambient light detection.

Background technique

In recent years, concepts such as environmental protection, energy saving, and low carbon have been deeply rooted in the hearts of the people. The country has also formulated LCD TV energy efficiency rating standards, prohibiting products that do not meet the standards from entering the market, and classifying the power consumption levels of LCD products. When choosing a product, you can understand its performance more comprehensively. This feature of energy saving alone makes LCD products that use LEDs as backlight sources continue to occupy the market. No matter in the field of lighting or display, the backlight source of liquid crystal display is constantly transitioning from CCFL backlight source to LED backlight source. Compared with CCFL, as a new type of light source, the photoelectric effect of LED has been greatly improved. It overcomes the shortcomings of CCFL such as narrow color gamut coverage, high voltage control, fragility, and mercury content, and has richer colors and higher dynamic contrast. The ordinary display has been greatly improved. While LED has the advantages of mercury-free environmental protection, low voltage control, wide color gamut coverage, and long life, due to its small size and high luminous efficiency, it has the characteristics of lightness, thinness, and low power consumption in structural design. , which also makes the market competitiveness of LED backlight display more prominent. However, the optical parameters of the LED backlight source on the currently commonly used LED backlight TV are fixed and cannot be automatically adjusted, and the eyesight of the viewer is different. have a certain detrimental effect.

Contents of the invention

In order to solve the above problems, the object of the present invention is to provide an automatic adjuster of optical parameters of LED backlight source based on ambient light detection.

In order to achieve the above object, the automatic adjuster of the optical parameters of LED backlight based on ambient light detection provided by the present invention includes: I2C interface, illuminance calculation module, brightness comparator, brightness value register, data transmission module and brightness value adjustment module; : The I2C interface is an I2C serial data transceiver interface circuit, which is connected with the illuminance calculation module, and is used to read the ambient light detection data collected by the ambient light detection module from the outside through the I2C bus, and transmit it to the illuminance calculation module ;

The illuminance calculation module is a digital operation module, which is connected with the brightness comparator, and is used to calculate the actual ambient illuminance value according to the data collected by the ambient light detection module, and transmit the value to the brightness comparator 3;

The brightness comparator and the brightness value register are used to compare the ambient light intensity value with the backlight brightness value of the previous state saved in the current brightness value register to judge whether the backlight brightness needs to be adjusted currently, if the judgment result is "Yes" , then the backlight brightness value is adjusted by the brightness value adjustment module to obtain the current backlight brightness value; otherwise, the original backlight brightness value remains unchanged;

The brightness value register is connected with the data sending module and is used to store the current backlight brightness value;

The data sending module is connected with the brightness comparator and the brightness value adjustment module, and is used to send the finally obtained current backlight brightness value to the LCD display, and save the current backlight brightness value in the brightness value register;

The brightness value adjusting module is connected with the brightness comparator, and is used for adjusting the brightness value of the backlight according to the comparison result of the brightness comparator.

The automatic adjuster of the optical parameters of the LED backlight source based on ambient light detection is realized by CPLD programmable logic device.

In order to make better use of the advantages of LED backlight TVs in image quality and energy-saving lamps, the automatic adjuster of optical parameters of LED backlight based on ambient light detection provided by the present invention is of great significance in terms of energy saving and environmental protection, because its parameter adjustment is based on The visual effect of the human eye is carried out, which has a certain protective effect on the eyesight of the viewer, and can also relieve the visual fatigue of the viewer.

Description of drawings

FIG. 1 is a schematic structural diagram of an automatic adjuster for optical parameters of an LED backlight source based on ambient light detection provided by the present invention.

Detailed ways

The automatic adjuster of the optical parameters of the LED backlight source based on ambient light detection provided by the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

As shown in Figure 1, the automatic regulator of the optical parameters of the LED backlight based on ambient light detection provided by the present invention includes: I2C interface 1, illuminance calculation module 2, brightness comparator 3, brightness value register 4, data transmission module 5 and Brightness value adjustment module 6; wherein: I2C interface 1 is an I2C serial data transceiver interface circuit, which is connected with the illuminance calculation module 2, and is used to read the ambient light detection collected by the ambient light detection module 7 from the outside through the I2C bus data, and send it to the illuminance calculation module 2;

The illuminance calculation module 2 is a digital operation module, which is connected with the brightness comparator 3, and is used to calculate the actual ambient illuminance value according to the data collected by the ambient light detection module 7, and transmit the value to the brightness comparator 3;

The brightness comparator 3 and the brightness value register 4 are used to compare the ambient light intensity value with the previous state backlight brightness value saved in the current brightness value register 4, so as to judge whether the backlight brightness needs to be adjusted currently, if the judgment result is "Yes", then the backlight brightness value is adjusted by the brightness value adjustment module 6 to obtain the current backlight brightness value; otherwise, the original backlight brightness value remains unchanged;

The brightness value register 4 is connected with the data sending module 5, and is used for storing the current backlight brightness value;

The data sending module 5 is connected with the brightness comparator 3 and the brightness value adjustment module 6, and is used to send the finally obtained current backlight brightness value to the LCD display 8, and save the current backlight brightness value in the brightness value register 4;

The brightness value adjustment module 6 is connected with the brightness comparator 3 and used for adjusting the brightness value of the backlight according to the comparison result of the brightness comparator 3 .

The automatic adjuster of the optical parameters of the LED backlight source based on ambient light detection is realized by CPLD programmable logic device.

The working process of the internal function module of this regulator is as follows:

The ambient light intensity signal detected by the ambient light detection module 7 is read into the regulator through the I2C bus interface, and then the corresponding ambient light intensity is calculated according to the illuminance calculation formula, and then the relationship between the ambient light and the backlight brightness is used to calculate The backlight brightness and PWM duty cycle that need to be adjusted are compared with the current brightness value of the LCD display to determine whether the backlight intensity should be changed. Range comparison determines the brightness level to be adjusted, thereby changing the duty cycle of the PWM signal input to the LED driver chip to change the brightness of the LED, thereby adapting to the current external brightness and realizing automatic adjustment of the brightness of the LCD display.

The regulator reads the data in the ADC register of the ambient light detection module 7 through the I2C bus interface, outputs the current light condition after calculation and processing, and then inputs its value into a comparator to compare with the current screen brightness to determine whether adjustment is required brightness. The brightness adjustment value calculation module calculates the LCD brightness adjustment value according to another output of the comparator—the current external brightness value and the current LCD brightness value, and adjusts the brightness of the LCD display 8 through the data sending module.

The ambient light detection module 7 is an ambient light sensor TSL2550T, which provides an SMBus interface, and communicates with the regulator through SMBData signals. In order to ensure the synchronization of the system, the clock of TSL2550 can be provided by this regulator. This regulator reads data from TSL2550T every once in a while. It takes a total of 800ms for TSL2550T to complete the conversion of two channels. Therefore, in the timing control, a start condition is generated every second, so as to avoid excessive brightness of the LED backlight. The adjuster judges the brightness that needs to be adjusted according to the read data. When the adjustment value is quite different from the current brightness, in order not to make the viewer notice it visually, select the middle value between the current brightness and the theoretical brightness.

The automatic adjuster of the optical parameters of the LED backlight based on ambient light detection provided by the present invention transmits the output of the ambient light detection module to the adjuster through detection, parameter adjustment, and LED driving, and then according to the current brightness and brightness adjustment principles, Input the PWM signal to the LED driver, and finally achieve the purpose of automatically adjusting the brightness of the LED, making the brightness of the display more suitable for human eyes and more energy-saving.

Claims (2)

1. the automatic regulator of a LED-backlit source optical parametric of surveying based on surround lighting, it is characterized in that: described automatic regulator comprises: I2C interface (1), illuminance are calculated module (2), brightness comparer (3), brightness value register (4), data transmission blocks (5) and brightness value adjustment module (6); Wherein: I2C interface (1) is I2C serial data transmitting-receiving interface circuit, it calculates module (2) with illuminance and is connected, be used for reading the surround lighting detection data that surround lighting detection module (7) collects from the outside by the I2C bus, and send it to illuminance calculating module (2);

It is digital operation module that illuminance is calculated module (2), and it is connected with brightness comparer (3), is used for going out actual ambient light value according to the data computation that surround lighting detection module (7) is gathered, and sends this value to brightness comparer (3);

Brightness comparer (3) and brightness value register (4), be used for the backlight brightness values of ambient light value with the previous state of current brightness value register (4) preservation compared, to judge that current whether the needs adjust backlight illumination, if judged result is "Yes", then by brightness value adjustment module (6) backlight brightness values is adjusted, tried to achieve current backlight brightness values; Otherwise keep former backlight brightness values constant;

Brightness value register (4) is connected with data transmission blocks 5, is used for the current backlight brightness values of storage;

Data transmission blocks (5) is connected with brightness value adjustment module (6) with brightness comparer (3), the current backlight brightness value that is used for finally obtaining sends to LCD display (8), and current backlight brightness values is kept among the brightness value register (4);

Brightness value adjustment module (6) is connected with brightness comparer (3), is used for the comparing result according to brightness comparer (3), and backlight brightness values is adjusted.

2. automatic regulator according to claim 1 is characterized in that: the automatic regulator of the described LED-backlit source optical parametric of surveying based on surround lighting adopts the CPLD programmable logic device (PLD) to realize.

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