Display apparatus

Patent metadata

Field	Value
Publication number	US-12593379-B2
Application number	US-202418895335-A
Country	US
Kind code	B2
Filing date	Sep 24, 2024
Priority date	Apr 19, 2022
Publication date	Mar 31, 2026
Grant date	Mar 31, 2026

Abstract

Disclosed is a display apparatus. The display apparatus includes: a transformer, voltage conversion modules, a feedback module and a light string group. The light string group includes a first light string and a second light string; a first secondary coil and a second secondary coil of the transformer are coupled with a primary coil of the transformer; the first secondary coil is configured to output a first voltage according to a power received by the primary coil. The second secondary coil is configured to output a second voltage from both ends of the second secondary coil alternately according to the power received by the primary coil. The voltage conversion module is configured to generate an additional voltage according to the first voltage, and superimpose the additional voltage onto a corresponding second voltage at both ends of the second secondary coil to output a superimposed third voltage.

First claim

What is claimed is:

1 . A display apparatus, comprising: a transformer, a voltage conversion module, a feedback module, and a light string group;
wherein the voltage conversion module corresponds one-to-one with the light string group, and the light string group comprises a first light string and a second light string; a first secondary coil and a second secondary coil of the transformer are coupled with a primary coil of the transformer; the first secondary coil is configured to output a first voltage according to a power received by the primary coil; the second secondary coil is configured to output a second voltage from both ends of the second secondary coil alternately according to the power received by the primary coil; the second secondary coil corresponds one-to-one with the light string group; the voltage conversion module is configured to generate an additional voltage according to the first voltage, and superimpose the additional voltage onto a corresponding second voltage at both ends of the second secondary coil to output a superimposed third voltage; the feedback module is configured to generate a feedback signal based on an output current of the light string group and send the feedback signal to the voltage conversion module, wherein the feedback signal is configured to instruct the voltage conversion module to adjust the third voltage; the first light string is connected with one corresponding end of the second secondary coil, the second light string is connected with the other corresponding end of the second secondary coil, and both are configured to emit light based on the third voltage.

2 . The display apparatus according to claim 1 , wherein the voltage conversion module comprises: a voltage adjustment module and a voltage superimposition module;
the voltage adjustment module is connected with an output end of the first secondary coil and configured to generate the additional voltage based on the first voltage; the voltage superimposition module is configured to receive the additional voltage and is connected with both ends of the second secondary coil, and is configured to superimpose the additional voltage onto the corresponding second voltage at both ends of the second secondary coil and output the superimposed third voltage; wherein the feedback signal is configured to instruct the voltage adjustment module to adjust the third voltage by adjusting the additional voltage.

3 . The display apparatus according to claim 2 , wherein the voltage superimposition module comprises a first current equalization capacitor, a first rectifier diode, a second rectifier diode, a third rectifier diode, and a fourth rectifier diode;
one end of the first current equalization capacitor is connected with the one end of the second secondary coil, and the other end of the first current equalization capacitor is connected with a positive electrode of the first rectifier diode and a negative electrode of the second rectifier diode; a positive electrode of the second rectifier diode is provided with the additional voltage; a negative electrode of the first rectifier diode is connected with a positive electrode of the first light string, and a negative electrode of the first light string is grounded; a positive electrode of the third rectifier diode is connected with the other end of the second secondary coil and a negative electrode of the fourth rectifier diode; a positive electrode of the fourth rectifier diode is provided with the additional voltage; a negative electrode of the third rectifier diode is connected with a positive electrode of the second light string; and a negative electrode of the second light string is grounded.

4 . The display apparatus according to claim 2 , wherein the voltage adjustment module comprises: a second transistor, a third transistor, a second inductor, and a second capacitor;
one end of the second transistor is connected with an output end of the first secondary coil, and the other end of the second transistor is connected with one end of the third transistor and one end of the second inductor; the other end of the third transistor is grounded; the other end of the second inductor serves as an output end of the voltage adjustment module, outputting the additional voltage; one end of the second capacitor is connected with the other end of the second inductor; the other end of the second capacitor is grounded; control electrodes of the second transistor and the third transistor are both connected with the feedback module and are configured to adjust switching frequencies of the second transistor and the third transistor based on the feedback signal to adjust the additional voltage.

5 . The display apparatus according to claim 4 , wherein the voltage adjustment module further comprises a second diode;
a negative electrode of the second diode is connected to the one end of the second capacitor, and a positive electrode of the second diode is connected to the other end of the second capacitor.

6 . The display apparatus according to claim 1 , further comprising a first switching circuit and a first grounding resistor;
wherein the first switching circuit is located between the light string group and the first grounding resistor; one end of the first switching circuit is connected with a negative electrode of the first light string and a negative electrode of the second light string, and the other end of the first switching circuit is connected with one end of the first grounding resistor and an input end of the feedback module; the other end of the first grounding resistor is grounded; and the first switching circuit is configured to be turned on or off based on a duty cycle control signal.

7 . The display apparatus according to claim 1 , further comprising: a second switching circuit and a second grounding resistor;
wherein the second switching circuit is located between the light string group and the second grounding resistor; one end of the second switching circuit is connected with a negative electrode of the first light string and a negative electrode of the second light string, and the other end of the second switching circuit is connected with one end of the second grounding resistor; the other end of the second grounding resistor is grounded; and the second switching circuit is configured to change a loop current for analog dimming.

8 . The display apparatus according to claim 7 , wherein the second switching circuit comprises: a fifth transistor and a comparator;
one end of the fifth transistor is connected with the negative electrode of the first light string and the negative electrode of the second light string, and the other end of the fifth transistor is connected with the one end of the second grounding resistor and an inverting input end of the comparator; a non-inverting input end of the comparator is provided with a required voltage of the light string group, and an output end of the comparator is connected with a gate of the fifth transistor; wherein a resistance of the fifth transistor is configured to be adjusted to change the loop current for analog dimming.

9 . The display apparatus according to claim 1 , wherein a plurality of second secondary coils, a plurality of voltage conversion modules, and a plurality of light string groups are provided;
the display apparatus further comprises a plurality of current equalization inductors; wherein mutually-coupled current equalization inductors are provided between two adjacent ones of the plurality of second secondary coils.

10 . The display apparatus according to claim 1 , further comprising:
a backlight control module configured to control light emitting

Assignees

• Hisense Visual Tech Co Ltd

Inventors

• Pang Zhenhua

Classifications

• H05B45/385 Primary

  using flyback topology · CPC title

• H05B45/46

  having LEDs disposed in parallel lines · CPC title

• H05B45/382

  with galvanic isolation between input and output · CPC title

• H05B45/14 Primary

  using electrical feedback from LEDs or from LED modules · CPC title

• H02M3/335

  using semiconductor devices only · CPC title