Display device and information processing device

Abstract

To improve sound quality in a display unit that emits a sound from a display panel.SOLUTION: A display unit comprises: a plurality of electroacoustic conversion elements that include a first electroacoustic conversion element and a second electroacoustic conversion element; a display panel to which the plurality of electroacoustic conversion elements are connected; a storage unit that stores correction information calculated based on a first signal and a second signal acquired by receiving, with the second electroacoustic conversion element, a sound emitted from the first electroacoustic conversion element based on the first signal; and a correction unit that, when the plurality of electroacoustic conversion elements emit sounds, corrects the sound emitted from the second electroacoustic conversion element based on the correction information.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a display device and an information processing device. [Background technology]

[0002] Patent Document 1 discloses a display device including a display panel and an acoustic generator supported on the back surface of the display panel. The display device of Patent Document 1 can emit sound in front of the display panel by driving the acoustic generator to vibrate the display panel. Patent Document 1 also discloses a structure in which a partition is arranged to surround the acoustic generator in order to improve sound quality. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Korean Patent Publication No. 10-2018-0131248 Summary of the Invention [Problem to be solved by the invention]

[0004] There is a demand for improving sound quality using a method other than the method described in Patent Document 1, which involves providing a physical structure.

[0005] The present invention has been made in view of the above-mentioned problems, and has an object to improve sound quality in a display device that emits sound from a display panel. [Means for solving the problem]

[0006] According to one aspect of the present invention, there is provided a display device comprising: a plurality of electroacoustic conversion elements including a first electroacoustic conversion element and a second electroacoustic conversion element; a display panel to which the plurality of electroacoustic conversion elements are connected; a memory unit that stores correction information calculated based on a first signal and a second signal obtained by receiving sound emitted from the first electroacoustic conversion element based on the first signal with the second electroacoustic conversion element; and a correction unit that corrects the sound emitted from the second electroacoustic conversion element based on the correction information when sound is emitted from the plurality of electroacoustic conversion elements.

[0007] According to another aspect of the present invention, there is provided an information processing device comprising: a control unit that controls a plurality of electroacoustic conversion elements, each including a first electroacoustic conversion element and a second electroacoustic conversion element, each of which is provided on a display panel, the control unit controlling the plurality of electroacoustic conversion elements so that the first electroacoustic conversion element emits a sound based on a first signal and the second electroacoustic conversion element receives the sound to obtain a second signal; and a calculation unit that calculates correction information for correcting the sound emitted from the second electroacoustic conversion element based on the first signal and the second signal. [Effects of the Invention]

[0008] According to the present invention, it is an object to improve the sound quality in a display device that emits sound from a display panel. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a block diagram showing a schematic configuration of a display device according to a first embodiment. [Figure 2] FIG. 2 is a plan view showing the arrangement of piezoelectric elements according to the first embodiment. [Figure 3] FIG. 2 is a block diagram showing a hardware configuration of a first control device according to the first embodiment. [Figure 4] FIG. 2 is a functional block diagram of a first control device according to the first embodiment. [Figure 5]5 is a flowchart showing a process for generating a lookup table for resonance correction according to the first embodiment. [Figure 6] 10 is a table showing a specific example of the relationship between a critical band and a transfer function. [Figure 7] 10 is a table showing specific examples of correction functions calculated for each critical band. [Figure 8] 5 is a flowchart showing a resonance correction process according to the first embodiment. [Figure 9] FIG. 10 is a displacement distribution diagram showing an example of vibration distribution of a display panel. [Figure 10] FIG. 10 is a displacement distribution diagram schematically illustrating the principle of resonance correction. [Figure 11] FIG. 10 is a plan view showing the arrangement of piezoelectric elements according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Elements having common functions throughout the drawings will be designated by the same reference numerals, and duplicate descriptions may be omitted or simplified.

[0011] [First embodiment] 1 is a schematic diagram of a display device 1 according to a first embodiment. The display device 1 of this embodiment can be used, for example, as an image output device for a computer, a television receiver, a smartphone, a game console, etc., but is not particularly limited thereto.

[0012] 1, the display device 1 includes a piezoelectric element array 10, a display panel 20, a connection member 30, a first control device 40, a second control device 50, a data drive circuit 60, and a gate drive circuit 70. The display device 1 displays an image on the display panel 20 based on input RGB data, etc., and generates sound based on input audio signals, etc.

[0013] The display panel 20 includes a plurality of pixels P arranged in a plurality of rows and a plurality of columns. The display device 1 may be, for example, an OLED display that uses organic light-emitting diodes (OLEDs) as light-emitting elements of the pixels P. If the display device 1 is capable of displaying color images, the pixels P may be sub-pixels that display any of a plurality of colors (e.g., RGB) that make up the color image.

[0014] The piezoelectric element array 10 includes a plurality of piezoelectric elements 11. The plurality of piezoelectric elements 11 are arranged in a matrix on a surface (rear surface of the display panel 20) facing the image display surface of the display panel 20.

[0015] The piezoelectric element 11 is an electroacoustic transducer that converts electricity and sound mutually by the piezoelectric effect (normal piezoelectric effect) and the inverse piezoelectric effect. The piezoelectric element 11 may be, for example, a bimorph, unimorph, or other element that undergoes flexural displacement in response to a voltage. When a voltage based on an input audio signal is applied to the piezoelectric element 11, the piezoelectric element 11 undergoes displacement due to the inverse piezoelectric effect. Since the input audio signal is usually an AC voltage, the piezoelectric element 11 vibrates in response to the input audio signal, and the voltage is converted into sound. Furthermore, when the piezoelectric element 11 vibrates in response to external sound, the voltage of the electrodes of the piezoelectric element 11 changes in accordance with the vibration frequency due to the piezoelectric effect, and the sound is converted into an AC voltage. In this way, the piezoelectric element 11 functions as both a speaker and a microphone. The state in which the piezoelectric element 11 functions as a speaker and the state in which it functions as a microphone can be switched under control of the first control device 40.

[0016] The connecting member 30 is a member that connects each of the plurality of piezoelectric elements 11 to the display panel 20. The connecting member 30 is made of an elastic material. The connecting member 30 is typically made of a material such as rubber that has a smaller elastic modulus than the piezoelectric elements 11 and the display panel 20. A portion of the piezoelectric elements 11 and a portion of the display panel 20 are connected by the connecting member 30. As a result, vibrations of the piezoelectric elements 11 are transmitted to the display panel 20, and the display panel 20 emits sound based on the input audio signal.

[0017] The host system 2 is a device or a system including multiple devices that controls the display device 1 by supplying image signals (e.g., RGB data), audio signals, and timing signals (vertical synchronization signal, horizontal synchronization signal, data enable signal, etc.). The host system 2 may be, for example, a television system, a set-top box, a navigation system, an optical disc player, a computer, a home theater system, a video telephone system, etc. The display device 1 and the host system 2 may be an integrated device or separate devices.

[0018] The first control device 40 supplies a voltage to each of the plurality of piezoelectric elements 11 based on the audio signal and timing signal input from the host system 2. The first control device 40 also performs a process of supplying a voltage based on a reference signal to the piezoelectric elements 11 and a process of measuring the voltage of the electrodes of the piezoelectric elements 11 to obtain a signal based on the sound received by the piezoelectric elements 11.

[0019] The second control device 50 controls the data drive circuit 60 and the gate drive circuit 70 based on image data and timing signals input from the host system 2. The data drive circuit 60 supplies data voltages and the like to the plurality of pixels P via drive lines 61 arranged for each column of the plurality of pixels P. The gate drive circuit 70 supplies control signals to the plurality of pixels P via drive lines 71 arranged for each row of the plurality of pixels P. Note that each of the drive lines 61 and the drive lines 71 may be configured with a plurality of wires.

[0020] Each of the first control device 40, the second control device 50, the data drive circuit 60, and the gate drive circuit 70 may be configured as one or more semiconductor integrated circuits. In addition, some or all of the first control device 40, the second control device 50, the data drive circuit 60, and the gate drive circuit 70 may be integrated into a single semiconductor integrated circuit.

[0021] FIG. 2 is a plan view showing the arrangement of piezoelectric elements 11 according to the first embodiment. FIG. 2 is a plan view of a display panel 20 as seen from the back side. The rectangular outer frame of the display panel 20 in FIG. 2 schematically shows the outer shape of the display panel 20. The piezoelectric element array 10 is connected near the center of the display panel 20. In FIG. 2, 36 piezoelectric elements 11 arranged in 6 rows and 6 columns are shown in the piezoelectric element array 10, but this is an example and the number of piezoelectric elements 11 can be adjusted as appropriate.

[0022] The piezoelectric element array 10 is divided into an area R1 including 16 piezoelectric elements 11 (first electroacoustic conversion elements) arranged in 4 rows and 4 columns near the center, and an area R2 including 20 piezoelectric elements 11 (second electroacoustic conversion elements) arranged in one row on the periphery of the area R1. The difference in usage between the piezoelectric elements 11 in the area R1 and the piezoelectric elements 11 in the area R2 will be described later.

[0023] 3 is a block diagram showing the hardware configuration of the first control device 40 according to the first embodiment. The first control device 40 has a processor 401, a memory 402, an interface 403, and a piezoelectric element drive circuit 404. The first control device 40 functions as an information processing device that performs information processing necessary for controlling the piezoelectric element array 10. The components within the first control device 40 are connected to each other via buses, wiring, drive devices, etc. (not shown).

[0024] The memory 402 is a storage medium including a ROM (Read Only Memory), a RAM (Random Access Memory), a flash memory, etc. The memory 402 stores programs and data for implementing information processing by the processor 401, and stores data input from the outside. The processor 401 is an integrated circuit that performs information processing and control based on the programs stored in the memory 402. The interface 403 is a circuit that inputs and outputs signals between the first control device 40 and an external device, and may include an amplifier circuit, an analog-to-digital conversion circuit, a digital-to-analog conversion circuit, etc.

[0025] The piezoelectric element driving circuit 404 includes a circuit that supplies a voltage for driving each of the plurality of piezoelectric elements 11 based on an input audio signal. The piezoelectric element driving circuit 404 also includes a circuit that has a function of acquiring an audio signal from a voltage generated by vibration of the plurality of piezoelectric elements 11. These two circuits can be switched by a switch or the like.

[0026] 3, the components constituting first control device 40 are illustrated as an integrated device, but some of these functions may be provided by external devices. For example, piezoelectric element drive circuit 404 may be an external device separate from the components constituting the functions of a computer including processor 401, etc.

[0027] 4 is a functional block diagram of the first control device 40 according to the first embodiment. The first control device 40 has a control unit 411, a calculation unit 412, a correction unit 413, a storage unit 414, and a drive unit 415. The processor 401 performs predetermined processing based on a program stored in the memory 402, thereby realizing the functions of the control unit 411, the calculation unit 412, and the correction unit 413. The processor 401 controls the memory 402 to store and read data, thereby realizing the function of the storage unit 414. The processor 401 controls the interface 403 and the piezoelectric element drive circuit 404 to input and output voltages to and from the plurality of piezoelectric elements 11, thereby realizing the function of the drive unit 415. The specific processing performed by each functional block will be described later.

[0028] When the vibration of the piezoelectric element array 10 is transmitted to the display panel 20 and the display panel 20 vibrates, a resonance phenomenon may cause the vibration within the plane of the display panel 20 to become uneven, resulting in deterioration of sound quality. In this embodiment, the first control device 40 has a function of correcting the deterioration of sound quality caused by the resonance phenomenon.

[0029] Fig. 5 is a flowchart showing a process for generating a lookup table for resonance correction according to the first embodiment. The process in Fig. 5 is performed in advance before a user views content using the display device 1. Typically, the process in Fig. 5 is performed before shipping the display device 1 or during calibration when changing settings of the display device 1, for example.

[0030] In step S11, the control unit 411 applies a voltage based on the test signal to the piezoelectric elements 11 in the region R1. This causes the piezoelectric elements 11 in the region R1 to emit a test sound. The characteristics (signal waveform, intensity, frequency spectrum, etc.) of the test signal used to generate this test sound are prepared in advance and stored in the storage unit 414.

[0031] The display panel 20 emits sound within the audible range. Therefore, it is desirable that the test sound contain frequency components within the audible range so that the transfer characteristics within the audible range can be calculated. Furthermore, it is desirable that the test sound be white noise at frequencies within the audible range (e.g., 20 Hz to 20 kHz). In this case, the test sound uniformly contains frequency components within the audible range emitted by the display device 1. Therefore, a white noise test sound is suitable for calculating the frequency dependency of the transfer function described below with high accuracy.

[0032] The test sound may also be pink noise (1 / f noise) at frequencies within the audible range. In this case, the energy of each octave of the test sound is uniform. Therefore, pink noise test sounds are suitable for calculating transfer functions at uneven intervals, such as logarithmic intervals, taking into account auditory characteristics, etc.

[0033] In step S12, the control unit 411 acquires a signal based on the test sound received by the piezoelectric elements 11 in region R2 by acquiring a voltage from the piezoelectric elements 11 in region R2. Hereinafter, the test signal used to generate the test sound emitted from the piezoelectric elements 11 in region R1 may be referred to as a first signal, and the signal based on the test sound received by the piezoelectric elements 11 in region R2 may be referred to as a second signal. The second signal differs from the first signal due to a change in waveform caused by the transfer characteristics when the test sound is transferred from region R1 to region R2. The second signal is stored in the storage unit 414.

[0034] In step S13, the calculation unit 412 calculates a transfer function based on the first signal prepared in advance and the second signal acquired in step S12. In step S14, the calculation unit 412 calculates an inverse function of the transfer function for each critical band as a correction function. In step S15, the storage unit 414 stores the correction function obtained for each critical band as a lookup table.

[0035] The processing from step S13 to step S15 will be described in more detail with reference to Fig. 6 and Fig. 7. Fig. 6 is a table showing a specific example of the relationship between critical bands and transfer functions. Fig. 7 is a table showing a specific example of the correction function calculated for each critical band.

[0036] The human inner ear is structured so that different parts of it sense vibrations for each frequency band. For this reason, it is said that human hearing has the ability to perceive sounds collectively for each frequency band. For example, when two sounds of similar frequencies reach the ear, a phenomenon known as masking occurs, in which one sound is less perceptible. The frequency bands that are perceived collectively are called the critical bands of hearing.

[0037] Considering the characteristics of human hearing, the resolution of two sounds within a critical band is low, so performing correction in a frequency band finer than the critical band does not contribute much to improving accuracy. Therefore, it is more efficient to perform the correction process in this embodiment for each critical band.

[0038] As shown in FIG. 6, in this embodiment, for the calculation process of the correction function, a transfer function is defined separately for each critical band (1 to N) (G1 to G N ) The frequencies (100 Hz, 200 Hz, 300 Hz, ...) shown in parentheses as arguments of the transfer function in Figure 6 indicate the center frequencies of the corresponding critical bands. The scale used to divide these critical bands is called the Bark scale. However, scales other than those shown in Figure 6, such as the mel scale or the Equivalent Rectangular Bandwidth scale, may also be used.

[0039] As shown in Figure 7, the correction functions (F1 to F N ) is calculated as separate data associated with each critical band (1 to N). That is, the same correction function is used within the same critical band. This reduces the amount of data to be prepared for correction. Also, reducing the amount of data for correction may result in a deterioration in correction accuracy. However, in this embodiment, the frequency intervals for which the same correction function is used are determined taking into account the critical bands based on auditory characteristics, thereby reducing the deterioration in correction accuracy. Also, since the correction functions are stored in advance in the storage unit 414 as a lookup table, there is no need to calculate inverse functions during correction, which reduces the amount of calculation required for correction and speeds up processing.

[0040] Fig. 8 is a flowchart showing the resonance correction process according to the first embodiment. The process in Fig. 8 is performed when an audio signal is input to the display device 1 and sound is emitted from the display device 1, that is, when a user watches or listens to content using the display device 1.

[0041] In step S21, the correction unit 413 reads the lookup table stored in the storage unit 414 in step S15.

[0042] In step S22, the correction unit 413 decomposes the input audio signal into multiple audio signals having the same frequency range as the critical band of the lookup table. This processing can be realized by digital signal processing such as applying a band-pass filter having one critical band as its pass band to the audio signal.

[0043] In step S23, the correction unit 413 applies the correction function of the corresponding critical band to the audio signal decomposed for each critical band to generate a corrected signal for each critical band. In step S24, the correction unit 413 combines the corrected signals for each critical band to generate a corrected signal for the entire band.

[0044] In step S25, the driving unit 415 applies a voltage to the piezoelectric elements 11 in the piezoelectric element array 10, controlling them to emit sound. Here, the driving unit 415 applies a voltage based on the original audio signal to the piezoelectric elements 11 in region R1, and applies a voltage based on the corrected signal to the piezoelectric elements 11 in region R2. As a result, the piezoelectric elements 11 in region R1 emit sound based on the original audio signal, and the piezoelectric elements 11 in region R2 emit sound based on the corrected signal. As a result, the display panel 20 emits a sound that is a mixture of sound based on the original audio signal and sound based on the corrected signal.

[0045] The effects obtained by performing the above-described correction will be described with reference to Figs. 9 and 10. Fig. 9 is a displacement distribution diagram showing an example of vibration distribution of the display panel 20. Fig. 9 shows, by gray shading and deformation of grid lines, the two-dimensional distribution of displacement of the display panel 20 that occurs when a sound of a certain frequency is emitted from the piezoelectric elements 11 in the piezoelectric element array 10. The vibration distribution shown in Fig. 9 can be obtained, for example, by simulation using the finite element method or a vibration distribution meter such as a scanning laser vibrometer.

[0046] 9, the vibrations on the surface of the display panel 20 are not uniform, with many peaks and dips occurring locally. This is thought to be due to the interference between the sound emitted by the piezoelectric element array 10 and the sound reflected from the edge of the display panel 20, causing resonance at specific locations on the surface of the display panel 20. Such uneven vibration distribution can be a cause of deterioration in sound quality.

[0047] 10(a), 10(b), and 10(c) are displacement distribution diagrams that schematically illustrate the principle of resonance correction. The vertical axes of Fig. 10(a), 10(b), and 10(c) represent displacement, and the horizontal axes represent position in one direction (e.g., the horizontal direction) on the surface of the display panel 20. R1 and R2 in the diagrams indicate positions corresponding to regions R1 and R2.

[0048] 10(a) shows an example of the displacement distribution when sound based on the original audio signal is emitted from the piezoelectric element 11 in region R1. As described in the explanation of FIG. 9, wavy displacement occurs not only within region R1 where the piezoelectric element 11 emitting the sound is located, but also outside region R1 where the piezoelectric element 11 is located, and peaks and dips indicating resonance exist.

[0049] 10(b) shows an example of the displacement distribution when a sound based on the corrected signal is emitted from the piezoelectric element 11 in region R2. It can be seen that the vibration spreads from region R2, which is the vibration source, at the center.

[0050] Figure 10(c) shows an example of the displacement distribution when sound based on the original audio signal is emitted from the piezoelectric element 11 in region R1 and sound based on the corrected signal is emitted from the piezoelectric element 11 in region R2. In other words, this is the displacement distribution obtained by superimposing Figures 10(a) and 10(b). It can be seen that the peaks and dips indicating resonance outside region R1 are canceled out.

[0051] The correction signal is calculated from the inverse function of the transfer function when sound is transmitted from region R1 to region R2. Therefore, when sound based on this correction signal is emitted from region R2, the sound component transmitted from region R1 to region R2 is canceled in region R2. This results in the cancellation of resonance as shown in Figure 10(c) above.

[0052] As described above, in this embodiment, the test sound emitted from the piezoelectric elements 11 in region R1 is received by the piezoelectric elements 11 in region R2, and is acquired using this to generate correction information. Then, when sound is emitted from the piezoelectric element array 10, the sound emitted from the piezoelectric elements 11 in region R2 is corrected based on the correction information. This makes it possible to correct at least part of the effects of resonance in the display panel 20, thereby improving sound quality.

[0053] As shown in Figure 2, it is desirable that region R2 be located further outward than region R1. This is because when sound spreads outward from region R1, the sound emitted in region R2 is superimposed, improving the effect of resonance compensation. In addition, to further enhance this effect, it is more desirable that region R2 be located so as to surround region R1, as shown in Figure 2.

[0054] [Second embodiment] In this embodiment, a modified example of the arrangement of the piezoelectric element 11 according to the first embodiment will be described. The basic configuration of the display device 1, the structure of the piezoelectric element 11, the algorithm for resonance correction, etc. are the same as those in the first embodiment, so the description will be omitted.

[0055] FIG. 11 is a plan view showing the arrangement of piezoelectric elements 11 according to the first embodiment. In this embodiment, two piezoelectric element arrays 10 are provided on a display panel 20. The structure of each of the two piezoelectric element arrays 10 is the same as that of the first embodiment. The two piezoelectric element arrays 10 are arranged side by side in the long side direction of the display panel 20. Two-channel audio signals of a stereophonic sound source are input to the two piezoelectric element arrays 10, respectively. This allows the display device 1 to function as a stereo speaker capable of reproducing a stereophonic sound source.

[0056] The number of piezoelectric element arrays 10 provided on the display panel 20 may be three or more. By providing three or more piezoelectric element arrays 10, it becomes possible to reproduce a sound source of three or more channels, that is, a so-called surround sound source.

[0057] In this embodiment, sound quality can be improved in the same way as in the first embodiment, and by providing a plurality of piezoelectric element arrays 10 (electroacoustic conversion element arrays), it becomes possible to accommodate a multi-channel sound source.

[0058] [Other embodiments] The above-described embodiments merely exemplify some aspects to which the present invention can be applied, and the technical scope of the present invention should not be interpreted as being limited by the above-described embodiments. Furthermore, the present invention can be implemented in various aspects by making appropriate modifications and variations without departing from the spirit of the present invention. For example, it should be understood that embodiments in which part of the configuration of any embodiment is added to or replaced with part of the configuration of another embodiment are also embodiments to which the present invention can be applied.

[0059] In the above-described embodiment, the device configuration of the display device 1 and the like is merely an example and is not limited to that shown in the drawings. For example, the display device 1 may be a liquid crystal display, a CRT display, or the like, instead of an OLED display. However, since it is desirable for the display device 1 to be able to efficiently transmit vibrations from the piezoelectric element 11 to the display panel 20, it is particularly desirable for the display device 1 to be an OLED display with few cavities.

[0060] Furthermore, in the above-described embodiment, the piezoelectric element 11 is used as an example of an electroacoustic conversion element, but the present invention is not limited to this. For example, the piezoelectric element 11 may be replaced with a magnet-type electroacoustic conversion element using a magnet and a coil. However, in a configuration in which an electroacoustic conversion element is provided in the display panel 20 as in the present embodiment, it is often necessary to achieve both a low profile and high sound pressure, and therefore a configuration using the piezoelectric element 11 that can achieve both of these is particularly desirable.

[0061] The scope of each embodiment also includes a processing method in which a program that operates the device of the above-described embodiment to realize the functions described in the above-described embodiments is recorded on a storage medium, the program recorded on the storage medium is read as code, and the program is executed on a computer. That is, a non-transitory computer-readable storage medium is also included in the scope of each embodiment. Furthermore, not only the storage medium on which the above-described program is recorded, but also the program itself is included in the scope of each embodiment. Furthermore, one or more components included in the above-described embodiments may be circuits such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array) configured to realize the functions of each component.

[0062] In addition, the scope of each embodiment is not limited to programs that execute processing by themselves recorded on a storage medium, but also includes programs that execute processing by operating on an OS (Operating System) in cooperation with other software and the functions of an expansion board. [Explanation of symbols]

[0063] 1 Display device 11 Piezoelectric element 20 Display panel 40 First control device 411 Control Unit 412 Arithmetic section 413 Correction Unit 414 Storage section 415 Drive unit

Claims

1. a display panel including a first region and a second region surrounding the first region; a first electroacoustic transducer configured to vibrate the first region; a second electroacoustic transducer configured to vibrate the second region; a driver for controlling the first electroacoustic transducer and the second electroacoustic transducer, the first electroacoustic transducer and the second electroacoustic transducer generate different sounds from each other by the driving unit; The second electroacoustic transducer element acquires the sound emitted by the first electroacoustic transducer element.

2. each of the first electroacoustic transducer and the second electroacoustic transducer includes a plurality of piezoelectric elements; The sound generating device according to claim 1 , wherein the number of the piezoelectric elements included in the second electroacoustic conversion element is different from the number of the piezoelectric elements included in the first electroacoustic conversion element.

3. The sound generating device of claim 2 , wherein the first electroacoustic transducer element includes more piezoelectric elements than the second electroacoustic transducer element.

4. The sound generating device according to claim 2 , wherein the plurality of piezoelectric elements included in the first electroacoustic conversion element and the second electroacoustic conversion element are arranged in a matrix on the display panel.

5. The sound generating device according to claim 2 , further comprising a connection member between each of the plurality of piezoelectric elements and the display panel.

6. The sound generating device according to claim 5 , wherein a portion of each of the plurality of piezoelectric elements and a portion of the display panel are connected by the connecting member.

7. The sound generating device according to claim 5 , wherein the connecting member is made of an elastic material.

8. The sound generating device according to claim 5 , wherein the connecting member has a modulus of elasticity smaller than those of the plurality of piezoelectric elements and the display panel.

9. The sound generating device according to claim 5 , wherein the connecting member comprises a rubber material.

10. The sound generating device according to claim 2 , wherein the plurality of piezoelectric elements are configured to undergo bending displacement in response to a voltage of a bimorph or unimorph.

11. The sound generating device according to claim 1 , wherein the driving section applies a first signal to the first electroacoustic transducer and applies a second signal, different from the first signal, to the second electroacoustic transducer.

12. The sound generating device according to claim 11 , wherein the driver generates the first signal based on an original sound signal and generates the second signal based on the first signal.

13. The drive unit is a storage unit that stores correction information calculated based on a predetermined signal and a third signal obtained by acquiring, with the second electroacoustic conversion element, a sound emitted from the first electroacoustic conversion element based on the predetermined signal; The sound generating device according to claim 11 , further comprising: a correction unit that corrects the sound emitted from the second electroacoustic conversion element based on the correction information.

14. The sound generating device according to claim 13 , wherein the correction information includes data associated with the frequency of the sound emitted from the second electroacoustic transducer.

15. The sound generating device according to claim 14 , wherein the correction information is stored in the storage unit as a lookup table configured with a plurality of frequency bands and a plurality of data items associated with the plurality of frequency bands.

16. the correction information includes data based on an inverse function of a transfer function when the predetermined signal is used as an input and the third signal is used as an output.

16. The sound generating device according to any one of claims 13 to 15.

17. The sound generating device according to claim 13 , wherein when sounds are generated from the first and second electroacoustic conversion elements, the first signal is not corrected based on the correction information.

18. The sound generating device according to claim 1 , wherein the second electroacoustic transducer is switchable between a state in which it functions as a speaker and a state in which it functions as a microphone in response to external control.

19. 18. The sound generating device according to claim 13, wherein the predetermined signal is a signal containing frequency components within an audible range.

20. 18. The sound generating device according to any one of claims 13 to 17, wherein the predetermined signal is white noise or pink noise at a frequency within the audible range.

21. 18. The acoustic generating device of claim 11, further comprising a control unit that controls the first electroacoustic conversion element and the second electroacoustic conversion element so that sound based on the first signal is emitted from the first electroacoustic conversion element and sound based on the first signal is received by the second electroacoustic conversion element.

22. 22. The sound generating device of any one of claims 1 to 21, wherein the display panel includes organic light-emitting diodes (OLEDs).

23. a plurality of electroacoustic transducer arrays connected to the display panel; The sound generating device according to claim 1 , wherein each of the plurality of electroacoustic transducers includes the first electroacoustic transducer and the second electroacoustic transducer.

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