Display device and method for driving the same

Patent metadata

Field	Value
Publication number	US-11249716-B2
Application number	US-201916677936-A
Country	US
Kind code	B2
Filing date	Nov 8, 2019
Priority date	Dec 11, 2018
Publication date	Feb 15, 2022
Grant date	Feb 15, 2022

Abstract

A display device includes a display panel which includes a first substrate, a second substrate, and a light emitting element layer disposed between the first substrate and the second substrate and outputting light to the second substrate, a first sound generator which is disposed on a surface of the first substrate and outputs sound by vibrating the display panel, and a first buffer member which is disposed on the surface of the first substrate, where a height of the first buffer member is smaller than that of the first sound generator.

First claim

What is claimed is:

1. A display device comprising:
a display panel comprising a first substrate;
a first sound generator which is disposed on a surface of the first substrate and vibrates the display panel according to a first sound signal to output a first sound;
a second sound generator which is disposed on the surface of the first substrate and vibrates the display panel according to a second sound signal to generate a second sound in a higher frequency range than the first sound; and
a sound driver circuit which generates the first sound signal and the second sound signal from a first stereo signal and outputs the first sound signal to the first sound generator and the second sound signal to the second sound generator,
wherein a sound pressure level of a fundamental tone of the first sound is lower than a sound pressure level of a first harmonic tone of the first sound.

2. The display device of claim 1 , wherein the first sound comprises k harmonic tones, wherein k is a positive integer, and wherein the sound pressure level of the fundamental tone of the first sound is less than a sound pressure level of a k th harmonic tone of the first sound.

3. The display device of claim 1 , further comprising:
a third sound generator which is disposed on the surface of the first substrate and vibrates the display panel according to a third sound signal to generate a third sound in a higher frequency range than the first sound, wherein the sound driver circuit generates the third sound signal from a second stereo signal to output the third sound signal to the third sound generator.

4. The display device of claim 3 , wherein the sound driver circuit comprises:
a digital signal processor which reproduces a first high-frequency signal from the first stereo signal, reproduces a second high-frequency signal from the second stereo signal, generates a mono signal from the first stereo signal and the second stereo signal, and generates a modulated low-frequency signal by modulating a low-frequency signal reproduced from the mono signal;
a digital-to-analog converter which converts the modulated low-frequency signal into the first sound signal, converts the first high-frequency signal into the second sound signal and converts the second high-frequency signal into the third sound signal; and
an amplifier which amplifies the first sound signal, the second sound signal and the third sound signal to output them.

5. The display device of claim 4 , wherein the digital signal processor comprises:
a first high-pass filter which filters a sound signal in a first high-frequency range from the first stereo signal to output the first high-frequency signal; and
a second high-pass filter which filters a sound signal in the first high-frequency range from the second stereo signal to output the second high-frequency signal.

6. The display device of claim 5 , wherein the digital signal processor further comprises:
a mono signal generator which generates the mono signal from the first stereo signal and the second stereo signal;
a low-pass filter which filters a sound signal in a low-frequency range to output the low-frequency signal;
a low-frequency signal modulator which modulates the low-frequency signal so that a harmonic tone of the k harmonic tones is generated based on a fundamental tone of the low-frequency signal to generate the modulated low-frequency signal;
a third high-pass filter which filters a sound signal in the first high-frequency range from the modulated low-frequency signal; and
a gain multiplier which applies a gain value to the modulated low-frequency signal filtered by the third high-pass filter and outputs a gained modulated low-frequency signal.

7. The display device of claim 6 , wherein the first high-frequency range is above a first threshold frequency, and the low-frequency range is below the first threshold frequency.

8. The display device of claim 3 , wherein the first sound generator vibrates the display panel by generating a magnetic force using a voice coil, and
wherein each of the second sound generator and the third sound generator vibrates the display panel by a piezoelectric material which contracts or expands depending on a voltage applied thereto.

9. The display device of claim 3 , wherein the first sound generator comprises:
a bobbin disposed on the surface of the first substrate;
a voice coil wound around the bobbin; and
a magnet disposed on the bobbin and spaced apart from the bobbin.

10. The display device of claim 3 , wherein each of the second sound generator and the third sound generator comprises
a first electrode to which a first driving voltage is applied,
a second electrode to which a second driving voltage is applied, and
a vibration layer disposed between the first electrode and the second electrode and having a piezoelectric material which contracts or expands depending on the first driving voltage applied to the first electrode and the second driving voltage applied to the second electrode.

11. The display device of claim 8 , wherein the second sound generator is disposed closer to one side of the display panel than the third sound generator is, and the third sound generator is disposed closer to an opposite side of the display panel than the second sound generator is.

12. The display device of claim 11 , wherein the first sound generator is disposed closer to a center of the display panel than the second sound generator and the third sound generator are.

13. The display device of claim 3 , further comprising:
a fourth sound generator which is disposed on the surface of the first substrate and vibrates the display panel according to a fourth sound signal to generate a fourth sound,
wherein the sound driver circuit generates the fourth sound signal from the second stereo signal to output the fourth sound signal to the fourth sound generator.

14. The display device of claim 13 , wherein a sound pressure level of a fundamental tone of the fourth sound is less than a sound pressure level of a first harmonic tone of the fourth sound.

15. The display device of claim 13 , wherein the sound driver circuit comprises:
a digital signal processor which reproduces a first high-frequency signal and a first low-frequency signal from the first stereo signal, reproduce a second high-frequency signal and a second low-frequency signal from the second stereo signal, generate a mono signal from the first stereo signal and the second stereo signal, generate a modulated low-frequency signal by modulating a low-frequency signal reproduced from the mono signal, generate a first modulated low-frequency signal by adding the modulated low-frequency signal to the first low-frequency signal, and generate a second modulated low-frequency signal by applying the modulated low-frequency signal to the second low-frequency signal;
a digital-to-analog converter which converts the first modulated low-frequency signal into the first sound signal, converts the first high-frequency signal into the second sound signal, converts the second high-frequency signal into the third sound signal and converts the second modulated low-frequency into the fourth sound signal; and
an amplifier which amplifies the first sound signal, the second sound signal, the third sound signal and the fourth sound signal and outputs amplified first to fourth sound signals.

16. The display device of claim 4 , wherein digital signal processor comprises:
a first high-pass filter which filters a sound signal in a first high-frequency range from the first stereo signal to output the first high-frequency signal;

Assignees

• Samsung Display Co Ltd

Inventors

• Ahn Yi Joon
• Kim Ga Na
• Won Byeong Hee
• Lee Jae Been
• Im Jae Woo

Classifications

• H04R1/28 Primary

  Transducer mountings or enclosures modified by provision of mechanical or acoustic impedances, e.g. resonator, damping means {(combinations of transducers with horns, i.e. front-loaded horns H04R1/30)} · CPC title

• H04R2499/15

  Transducers incorporated in visual displaying devices, e.g. televisions, computer displays, laptops · CPC title

• G10K11/17853

  of the filter · CPC title

• G06F3/16 Primary

  Sound input; Sound output (speech processing G10L) · CPC title

• H04R7/10 Primary

  comprising superposed layers in contact · CPC title