TWI763418B - Light source system, display device, and brightness adjustment method - Google Patents

Abstract

The disclosure provides a light source system including a light source, a photoelectric sensor, and a controlling portion. The light source is configured to emit source light based on a driving signal. The photoelectric sensor is located on a light path of the source light to receive the source light. The photoelectric sensor is further configured to generate a sensing signal by photoelectric conversion according to the source light received. The controlling portion is electrically connected to the light source and the photoelectric sensor and is used for acquiring a first difference between the sensing signal and a first reference signal. The controlling portion is further configured to acquiring a second difference between the sensing signal and a second reference signal if the first difference is less than a first preset difference. The controlling portion is further configured to adjust the driving signal if the first difference is greater than a second preset difference, wherein the driving signal is configured to control a brightness of the source light. The disclosure further provides a display device and a brightness adjustment method.

Description

Light source system, display device and illumination adjustment method

The present application relates to the technical field of light sources, and in particular, to a light source system, a display device using the light source system, and an illuminance adjustment method applied to the light source system and the display device.

Lighting equipment, display equipment, etc. all include light sources, and the light sources may be incandescent lamps, tungsten halogen lamps, fluorescent lamps, and the like.

Excessive use of the light source or improper maintenance will cause the light source parameters to gradually deviate from the standard level. In the technical field with higher requirements on light source, the deviation of light source parameters from the standard level will bring great loss. Therefore, it is necessary to calibrate the parameters of the light source in real time. The traditional calibration method is to change the parameters of the light source (such as power) by manually adjusting the knob (such as the power regulator knob). However, the manual adjustment method will bring a large reading error; and it needs to be repeatedly confirmed and adjusted manually, and the adjustment efficiency is low.

An aspect of the present application provides a light source system, including: a light source for emitting light source light based on a driving signal; a photoelectric sensor, located on an optical path of the light source light, for receiving the light source light, and for receiving the light source light according to the received light The light source light is photoelectrically converted to generate a detection signal; and a control part is electrically connected to the light source and the photoelectric sensor, and the control part is used to obtain a first difference between the detection signal and a first reference signal value, and used to obtain the second difference between the detection signal and a second reference signal when it is determined that the first difference is less than a first preset difference, and is also used to determine the second difference When the value is greater than a second predetermined difference value, the value of the driving signal is adjusted, and the driving signal is used to control the luminous power of the light source to control the illuminance of the light of the light source.

Another aspect of the present application provides a display device, comprising: a light source for emitting light from the light source based on a driving signal; a photoelectric sensor, located on the optical path of the light source light, is used for receiving the light source light, and is used for photoelectric conversion according to the received light source light to generate a detection signal; the control part is electrically connected to the light source and the photoelectric A sensor, the control part is used to obtain a first difference between the detection signal and a first reference signal, and to obtain the first difference when it is judged that the first difference is smaller than a first preset difference The second difference between the detection signal and a second reference signal is also used to adjust the value of the driving signal when it is judged that the second difference is greater than a second predetermined difference. Controlling the luminous power of the light source to control the illuminance of the light source light; and a display panel, the display panel is located on the light path of the light source light, and is used for displaying an image according to the light source light.

Another aspect of the present application provides an illuminance adjustment method, comprising: emitting light source light based on a driving signal; receiving the light source light, and performing photoelectric conversion according to the received light source light to generate a detection signal; acquiring the detection signal and a first a first difference between reference signals, obtaining a second difference between the detection signal and a second reference signal when judging that the first difference is less than a first predetermined difference, and then judging the When the second difference is greater than a second predetermined difference, the value of the driving signal is adjusted, and the driving signal is used to control the illuminance of the light source.

The above-mentioned light source system, by acquiring the detection signal, can monitor whether the photoelectric sensor works normally in real time, so as to facilitate replacement or repair when the photoelectric sensor is abnormal; on the other hand, it can also monitor the illuminance of the light source light in real time. Whether it meets the expected illuminance (if the above-mentioned second difference is less than the second preset difference, it is considered to meet the expected illuminance), so as to adjust the size of the driving signal in time to adjust the illuminance of the light source when the expected illuminance is not met. meets the expected illuminance. The above-mentioned light source system, display device and illuminance adjustment method improve the problems of errors and time-consuming caused by manual monitoring, and are beneficial to improve monitoring efficiency and monitoring accuracy.

100: Display device

10: Light source system

11: Light source

111: Carrier substrate

112: LEDs

113: Luminous area

12: Photoelectric sensor

13: Control Department

131: Driver chip

132: Controller

14: Light guide plate

15: Homogenizing plate

20: Display panel

S1, S2, S3, S4, S51, S52: Steps

FIG. 1 is a schematic block diagram of a display device according to an embodiment of the present application.

FIG. 2 is a schematic block diagram of the light source system in FIG. 1 .

FIG. 3 is a schematic structural diagram of the light source system in FIG. 1 .

FIG. 4 is a schematic flowchart of a method for adjusting illuminance according to an embodiment of the present application.

FIG. 5 is a schematic structural diagram of a light source in a modified embodiment.

FIG. 1 shows a light source system 10 of this embodiment for emitting light source light. The light source light may be visible light of any wavelength, and the light source light may include visible light of various wavelengths. The light source 11 can be applied to various equipments requiring light sources, such as display devices (such as outdoor electronic screens, mobile phones, etc.), lighting devices (such as incandescent lamps, tungsten halogen lamps, fluorescent lamps, etc. as lighting devices as light-emitting elements).

In this embodiment, the light source light includes visible light of a single wavelength, and the light source system 10 is applied to the display device 100 for illustration. The display device 100 includes a light source system 10 and a display panel 20 . The display panel 20 is located on the light path of the light source light, and is used for receiving the light source light and modulating the light source light to display an image. In this embodiment, the display panel is, for example, a liquid crystal display panel, a light emitting diode display panel, or the like.

Referring to FIG. 2 , the light source system 10 includes a light source 11 , a photoelectric sensor 12 , and a control unit 13 electrically connected to the light source 11 and the photoelectric sensor 12 , respectively.

The light source 11 emits light source light with a certain power under the driving of the driving signal. The photoelectric sensor 12 is located on the optical path of the light source light, and is used for receiving the light source light and performing photoelectric conversion to generate a detection signal corresponding to the light source light. The control unit 13 is used for receiving the detection signal and outputting a driving signal according to the detection signal. The control unit 13 is further configured to adjust the value of the drive signal output by the control unit 13 for driving the light source 11 to emit light according to the received detection signal. By adjusting the value of the driving signal, the illuminance of the light source light emitted by the light source 11 can be adjusted.

The light source 11 includes at least one light-emitting element, such as a light-emitting diode (Light Emit Diode, LED), an incandescent lamp, and the like. Referring to FIG. 3 , in this embodiment, the light source 11 includes a carrier substrate 111 and a plurality of LEDs 112 disposed on the same surface of the carrier substrate 111 . The carrier substrate 111 can be provided with a circuit structure to be electrically connected to the plurality of LEDs 112 to output driving signals to each of the LEDs 112 . Each LED 112 can emit light independently according to the received driving signal. In this embodiment, the driving signal is a current signal. The illuminance of the light source light emitted by the LED 112 varies with the value of the driving signal. The greater the value of the driving signal, the greater the illuminance of the light source emitted by the LED 112 . That is, there is a corresponding relationship between the value of the driving signal and the illuminance of the light source light. During the operation of the light source 11 , the value of the driving signal output to each LED 112 can be determined according to the illuminance of the light source light that the LED 112 needs to emit.

The light source system 10 of the present embodiment further includes a light guide plate 14 and a light homogenizing plate 15 arranged in parallel with the carrier substrate 111 . The light guide plate 14 is located between the carrier substrate 111 and the light homogenizing plate 15 . After the light source light is emitted from the light source 11 , the illuminance of the light source can be uniformized by the light guide plate 14 and the light homogenizing plate 15 .

The photoelectric sensor 12 is disposed on the surface of the light homogenizing plate 15 facing the light guide plate 14 . In this embodiment, the photoelectric sensor 12 is a photoresistor. The light source system 10 may include a complex number of photo sensors 12 . In other embodiments, the photoelectric sensor 12 can also be a photodiode, a photomultiplier tube, a phototransistor, an infrared sensor or an optical fiber sensor. This application does not limit the specific type of the photoelectric sensor 12, and it is sufficient to convert the optical signal (light source light) into an electrical signal (detection signal). In this embodiment, the detection signal generated by the photoelectric sensor 12 according to the light of the light source is a current signal. In other embodiments, the detection signal can also be an electrical signal in other forms, such as a voltage signal or a resistance signal.

The control unit 13 includes a drive chip 131 and a controller 132 electrically connected to the drive chip 131 . In this embodiment, the controller 132 may be a control chip inside the display device 100 . In other embodiments, the controller 132 may be a terminal external to the device to which the light source system 10 is applied. The controller 132 is electrically connected to the photoelectric sensor 12 for receiving the detection signal generated by the photoelectric sensor 12 and outputting a command to the driving chip 131 according to the detection signal, so as to control the driving chip 131 to output the driving signal to drive each LED 112 Emit light from the light source.

This embodiment also provides a method for adjusting the illuminance, and the method for adjusting the illuminance is applied to the above-mentioned display device 100 and the light source system 10 .

Referring to FIG. 4 , a method for adjusting the illuminance of an embodiment includes: step S1, emitting light source light based on a driving signal; step S2, receiving the light source light, and performing photoelectric conversion according to the received light source light to generate a detection signal; step S3 , obtain the first difference between the detection signal and a first reference signal, and determine whether the first difference is less than a first preset difference; if it is determined to be yes in step S3, step S4 is performed: Acquire a second difference between the detection signal and a second reference signal, and determine whether the second difference is greater than a second predetermined difference; if the determination in step S4 is yes, then execute step S51 : adjust The size of the driving signal; if the determination in step S4 is no, then step S52 is executed: the size of the driving signal is not adjusted.

In step S1, the driving chip 131 outputs a driving signal having an initial value to each LED 112 according to the required illuminance of the light source light.

In step S2, the photoelectric sensor 12 receives the light source light from the light source 11, and generates a detection signal (current signal) through photoelectric conversion. When the photoelectric sensor 12 is working normally, there is a one-to-one correspondence between the illuminance of the light source light it receives and the value of the detection signal it generates. That is, different illuminances The light of the light source is incident on the photoelectric sensor 12, and the generated detection signals have different values. If the photoelectric sensor 12 works abnormally, the corresponding relationship between the illuminance of the light source light it receives and the value of the detection signal it generates will change. Smaller changes are permissible, but larger changes indicate that the photoelectric sensor 12 has been damaged and needs to be repaired or replaced in time.

In this embodiment, a comparison table between the illuminance of the light source corresponding to the photoelectric sensor 12 during normal operation and the electrical signal generated by the photoelectric sensor 12 can be pre-recorded. When the light source of a certain illuminance is received, a unique electrical signal can be found according to the comparison table, and the found electrical signal is defined as the first reference signal. A first difference is preset.

In step S3, the controller 132 obtains the detection signal currently generated by the photoelectric sensor 12, calculates the difference between the detection signal and the first reference signal, and determines whether the difference between the detection signal and the first reference signal is less than the first difference. If it is judged that the difference between the detection signal and the first reference signal is smaller than the first difference, it is considered that the difference between the detection signal and the first reference signal found in the comparison table is within an acceptable fluctuation range. If the detector 12 is working normally, step S4 can be executed. If it is determined in step S3 that the difference between the detection signal and the first reference signal is greater than or equal to the first difference, it is considered that the difference between the detection signal and the first reference signal found in the comparison table has exceeded an acceptable fluctuation In the range, the photoelectric sensor 12 is in abnormal operation, and an error needs to be reported at this time, so as to facilitate repair or replacement of the photoelectric sensor 12.

As mentioned above, when the LED 112 is driven by a driving signal of a certain value, the light source light emitted by the LED 112 has a corresponding illuminance. However, in an actual product, due to various reasons such as process error or component performance degradation, when the LED 112 is driven with a certain value of the driving signal, there may be a deviation between the illuminance of the light source light actually emitted by the LED 112 and the expected illuminance (such as deviation). large or small). The light source system 10 , the display device 100 and the illuminance adjustment method of the present embodiment are used to monitor in real time whether there is a deviation between the illuminance of the light source light actually emitted by the LED 112 and the expected illuminance, and to adjust the driving signal in time when there is a large deviation. Adjusts the illuminance of the light source light.

In this embodiment, determining whether there is a deviation between the illuminance of the light source light actually emitted by the LED 112 and the expected illuminance is determined by detecting the value of the detection signal generated by the photoelectric sensor 12 .

Since there is a one-to-one correspondence between the driving signal and the illuminance of the light source, and there is a one-to-one correspondence between the illuminance of the light source and the electrical signal generated by the photoelectric sensor 12, the driving signal and the electrical signal generated by the photoelectric sensor 12 have a one-to-one correspondence. There is also a one-to-one correspondence between them. In this embodiment, a comparison table between the driving signal and the electrical signal generated by the photoelectric sensor 12 is pre-recorded. When driving LED112 with a certain driving signal When , a unique electrical signal can be found according to the comparison table, and the found electrical signal is defined as the second reference signal. A second preset difference is preset.

In step S4, the controller 132 calculates a second difference between the currently received detection signal and the second reference signal, and determines whether the second difference is greater than the second predetermined difference. If the determination in step S4 is yes, indicating that the illuminance of the light source light deviates greatly from the expected illuminance at this time, step S51 is executed to adjust the magnitude of the driving signal. Specifically, when the detection signal is larger than the second reference signal, the driving signal is reduced; when the detection signal is smaller than the second reference signal, the driving signal is increased. If the judgment in step S4 is no, it means that the difference between the illuminance of the light source light and the expected illuminance is within an acceptable range, then step S52 is executed, and the driving signal at the previous moment is continued without adjusting the magnitude of the driving signal. The LED 112 is driven to emit light.

In the light source system 10 , the display device 100 and the illuminance adjustment method of the present embodiment, by acquiring the detection signal, on the one hand, it is possible to monitor whether the photoelectric sensor 12 works normally in real time, so as to facilitate replacement or repair when the photoelectric sensor 12 is abnormal On the other hand, it is also possible to monitor in real time whether the illuminance of the light source meets the expected illuminance (if the above-mentioned second difference is less than the second preset difference, it is considered to meet the expected illuminance), so as to facilitate when the expected illuminance does not meet the expected illuminance. Adjust the size of the driving signal in time to adjust the illuminance of the light source to meet the expected illuminance. The above-mentioned light source system 10 , display device 100 and illuminance adjustment method improve the problems of errors and time-consuming caused by manual monitoring, and are beneficial to improve monitoring efficiency and monitoring accuracy.

In a modified embodiment, not only the illuminance of the light source light emitted from the light source 11 is required to meet expectations, but also the illuminance distribution of the light source light emitted from each region of the light source 11 is required to be uniform.

Referring to FIG. 5 , in this modified embodiment, the light source 11 can be divided into a plurality of light emitting regions 113 , each light emitting region 113 can include a plurality of LEDs 112 , and each light emitting region 113 receives driving signals independently to emit light. The plurality of photoelectric sensors 12 respectively receive the light source light emitted from each light-emitting area 113 and generate detection signals corresponding to each light-emitting area 113 . According to the detection signal corresponding to each light-emitting region 113 , it is determined whether the light source light emitted by each light-emitting region 113 meets the expectation, and if it does not meet the expectation, the driving signal corresponding to each light-emitting region 113 is adjusted. In this modified embodiment, the driving signals corresponding to each light emitting area 113 are adjusted to the same value, so that the light source illuminance emitted by each light emitting area 113 is the same, and the light source illuminance distribution of the light source 11 as a whole is uniform.

Therefore, in the light source system 10 , the display device 100 and the illuminance adjustment method in this modified embodiment, by monitoring the illuminance of the light source light in real time and adjusting the magnitude of the driving signal in real time, it is also beneficial to keep the illuminance distribution of the light source emitted by the light source 11 uniform.

Those skilled in the art should realize that the above embodiments are only used to illustrate the present invention, but not to limit the present invention, as long as the above embodiments are appropriately made within the spirit and scope of the present invention Changes and changes all fall within the scope of the claimed invention.

S1, S2, S3, S4, S51, S52: Steps

Claims (10)

A light source system, which is improved by comprising: a light source for emitting light source light based on a driving signal; a photoelectric sensor located on an optical path of the light source light for receiving the light source light and for receiving the light source light according to the received light source photoelectric conversion of light to generate a detection signal; and a control unit, electrically connected to the light source and the photoelectric sensor, the control unit is used for obtaining a first difference between the detection signal and a first reference signal , and is used to obtain a second difference between the detection signal and a second reference signal when the first difference is determined to be less than a first predetermined difference, and is also used to determine the second difference When it is greater than a second predetermined difference, the value of the driving signal is adjusted, and the driving signal is used to control the luminous power of the light source to control the illuminance of the light of the light source. The light source system of claim 1, wherein the detection signal, the first reference signal and the second reference signal are current signals, the first difference, the second difference, the Both the first preset difference and the second preset difference are current differences. The light source system according to claim 1, wherein the photoelectric sensor is a photoresistor, a photodiode, a photomultiplier tube, a phototransistor, an infrared sensor or an optical fiber sensor. The light source system according to claim 1, wherein the light source includes a plurality of light-emitting areas, each light-emitting area is used to emit the light source light independently of each other according to the driving signal; the control unit adjusts each light-emitting area by adjusting The driving current of the area controls the illumination of the light source light emitted by each light-emitting area to be the same. A display device is improved by comprising: a light source for emitting light from a light source based on a driving signal; a photoelectric sensor located on an optical path of the light from the light source for receiving the light from the light source and for receiving the light from the light source according to the received light source The light is photoelectrically converted to generate a detection signal; the control unit is electrically connected to the light source and the photoelectric sensor, and the control unit is used to obtain a first difference between the detection signal and a first reference signal, and is used to obtain a second difference between the detection signal and a second reference signal when the first difference is determined to be less than a first preset difference, and is also used to determine that the second difference is greater than A second preset difference is used to adjust the value of the driving signal, the driving signal is used to control the luminous power of the light source to control the illuminance of the light source light; and a display panel, located on the optical path of the light source light , for displaying an image according to the light source light. The display device according to claim 5, wherein the photoelectric sensor is a photoresistor, a photodiode, a photomultiplier tube, a phototransistor, an infrared sensor or an optical fiber sensor. An illuminance adjustment method, which is improved by: emitting light source light based on a driving signal; receiving the light source light, and performing photoelectric conversion according to the received light source light to generate a detection signal; acquiring the detection signal and a first reference signal the first difference between the two, when judging that the first difference is less than a first predetermined difference, obtain a second difference between the detection signal and a second reference signal, and when judging the second difference When the difference value is greater than a second predetermined difference value, the value of the driving signal is adjusted, and the driving signal is used to control the illuminance of the light source light. The illumination adjustment method according to claim 7, wherein the detection signal, the first reference signal and the second reference signal are current signals, the first difference, the second difference, the The first predetermined difference and the second predetermined difference are both current differences. The illuminance adjustment method according to claim 7, wherein the step of emitting light source light based on driving signals is specifically: emitting multiple beams of light source light based on complex driving signals, and each driving signal is used to control a unique beam of light source light The step of performing photoelectric conversion according to the received light source light to generate a detection signal is specifically: performing photoelectric conversion according to the received multiple beams of light source light to generate a complex detection signal; the acquiring the detection signal and The step of a second difference between the second reference signals is specifically: acquiring a second difference between each detection signal and the second reference signal. The illuminance adjustment method according to claim 9, wherein the step of adjusting the value of the driving signal is specifically: adjusting each driving signal to the same value.

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