Display device

Abstract

This display device, which vibrates a display for displaying an image and emits sound, comprises: an actuator unit that vibrates the display on the basis of a supplied acoustic signal; and an abnormality detection unit that detects the presence or absence of an abnormality in the image display on the display, wherein, when the abnormality in the image display is detected, the volume level of the emitted sound is reduced (S20, S21).

Description

[Technical field]

[0001] The present invention relates to a display device. [Background technology]

[0002] 2. Description of the Related Art There are display devices that emit sound (output sound) by vibrating a display that displays an image. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-186829 A [Patent Document 2] JP 2019-80099 A Summary of the Invention [Problem to be solved by the invention]

[0004] In this type of display device, when the magnitude of vibration is increased to increase the volume level, a large load is applied to the connection between the display and the block that supplies the video signal to the display, and the image may be distorted due to poor contact at the connection. Abnormalities in the video display should be suppressed. Also, checking whether the video is normal or abnormal in relation to the volume level is useful from the standpoint of distinguishing between good and defective products.

[0005] An object of the present invention is to provide a display device that contributes to suppressing abnormalities in image display or a display device that can check whether an image is normal or abnormal in relation to the volume level. [Means for solving the problem]

[0006] The display device of the present invention is a display device that emits sound by vibrating a display that displays an image, and is equipped with an actuator unit that vibrates the display based on a supplied acoustic signal, and an abnormality detection unit that detects whether or not there is an abnormality in the image display on the display, and is configured (first configuration) to reduce the volume level of the sound if an abnormality in the image display is detected.

[0007] The display device according to the first configuration may further include a volume level setting unit that sets the volume level of the sound emitted, and an acoustic signal of the set volume level by the volume level setting unit is supplied to the actuator unit, and the volume level setting unit may be configured to lower the volume level of the sound emitted by lowering the set volume level when an abnormality is detected in the image display (second configuration).

[0008] In the display device of the above second configuration, the volume level setting unit may be configured (third configuration) to set the volume level in accordance with user operation to the set volume level when no abnormality is detected in the image display, and to lower the set volume level below the volume level in accordance with the user operation when an abnormality is detected in the image display.

[0009] The display device according to the first configuration may further include an acoustic signal processing unit that generates an output acoustic signal, which is an acoustic signal that is supplied to the actuator unit, based on an input acoustic signal, and the acoustic signal processing unit may be configured to reduce the volume level of the sound output by setting an upper limit on the amplitude of the output acoustic signal in the process of generating the output acoustic signal from the input acoustic signal when an abnormality is detected in the video display (fourth configuration).

[0010] The display device according to the first configuration may further include an acoustic signal processing unit that generates an output acoustic signal, which is an acoustic signal that is supplied to the actuator unit, based on an input acoustic signal, and the acoustic signal processing unit may be configured to lower the volume level of the sound output by attenuating signal components in a predetermined band in the process of generating the output acoustic signal from the input acoustic signal when an abnormality is detected in the video display (fifth configuration).

[0011] Another display device according to the present invention is a display device that emits sound by vibrating a display that displays an image, and is configured (sixth configuration) to include an actuator unit that vibrates the display based on a supplied acoustic signal, an abnormality detection unit that detects whether or not there is an abnormality in the image displayed on the display, and a judgment unit that changes the volume level of the emitted sound and judges whether or not the abnormality has been detected by the abnormality detection unit after the change.

[0012] In the display device of the sixth configuration, the judgment unit may be configured to sequentially switch the volume level of the sound emission in a plurality of stages, and, during the switching process, when a state changes from a first state in which the abnormality is not detected to a second state in which the abnormality is detected, or when a state changes from the second state to the first state, store in a memory unit information corresponding to the volume level of the sound emission in the first state or information corresponding to the volume level of the sound emission in the second state (seventh configuration). Effect of the Invention

[0013] According to the present invention, it is possible to provide a display device that contributes to suppressing abnormalities in image display or a display device that can check whether an image is normal or abnormal in relation to the volume level. [Brief description of the drawings]

[0014] [Figure 1] 1 is an overall configuration diagram of a display device according to an embodiment of the present invention. [Diagram 2] FIG. 2 is an exploded perspective view of a display according to an embodiment of the present invention. [Diagram 3] FIG. 2 is a block diagram relating to volume setting according to an embodiment of the present invention. [Figure 4] FIG. 2 is a configuration diagram relating to an abnormality detection according to an embodiment of the present invention. [Diagram 5] 1A and 1B are diagrams showing an example of a configuration for detecting an abnormality in a video output according to an embodiment of the present invention. [Figure 6] 1 is a flowchart showing an operation of a display device related to setting a volume level, according to a first example belonging to an embodiment of the present invention. [Figure 7] 11 is a flowchart showing a modified operation of the display device related to setting a volume level, according to a first example of an embodiment of the present invention. [Figure 8] FIG. 11 is a diagram showing an internal configuration of a signal processing unit according to a second embodiment of the present invention. [Figure 9] FIG. 11 is a conceptual diagram of amplitude limiting processing according to a second embodiment of the present invention. [Figure 10] FIG. 11 is a diagram showing an internal configuration of a signal processing unit according to a third embodiment of the present invention. [Figure 11] FIG. 11 is a functional block diagram of a microcomputer according to a fourth embodiment of the present invention. [Figure 12] 13 is a flowchart of a shipping inspection process according to a fourth embodiment of the present invention. [Figure 13] 13 is another flowchart of the shipping inspection process according to the fourth embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, examples of the embodiments of the present invention will be described in detail with reference to the drawings. In each of the drawings, the same parts are given the same reference numerals, and duplicated explanations of the same parts are omitted as a rule. In this specification, for the sake of simplicity, a symbol or a code referring to information, a signal, a physical quantity, a member, etc. may be written, and the name of the information, signal, physical quantity, member, etc. corresponding to the symbol or code may be omitted or abbreviated. For example, the abnormal signal referred to by "ERR" described later (see FIG. 1) may be written as an abnormal signal ERR or abbreviated as a signal ERR, but they all refer to the same thing.

[0016] 1 is an overall configuration diagram of a display device 1 according to an embodiment of the present invention. The display device 1 includes a microcomputer 10, a video signal processing unit 20, an ASIC (Application Specific Integrated Circuit) 30, a driver 40, a display 50, an audio signal processing unit 60, and an actuator unit 70. The ASIC 30 is mounted on a driver substrate SUB having rigidity. The driver 40 is mounted on a flexible substrate FLX having flexibility. The driver substrate SUB and the flexible substrate FLX are also included as components of the display device 1.

[0017] The microcomputer 10 comprehensively controls the operation of each part of the display device 1. The microcomputer 10 includes a CPU (Central Processing Unit), a memory, and the like as hardware, and realizes various functions by executing predetermined programs using the hardware.

[0018] The video signal processing unit 20 is composed of a video IC (Integrated Circuit) suitable for video signal processing, and outputs a video signal VS1 to the ASIC 30. The video signal VS1 is generated in the video signal processing unit 20 based on a video signal provided to the video signal processing unit 20 from an external device (not shown in FIG. 1) of the display device 1. However, the video signal processing unit 20 itself may generate the video signal VS1 without relying on an external device of the display device 1. Alternatively, the video signal itself provided to the video signal processing unit 20 from the external device may become the video signal VS1. The video signal VS1 is transmitted from the video signal processing unit 20 to the ASIC 30 using, for example, LVDS (Low Voltage Differential Signaling). However, the method of transmitting the video signal VS1 is arbitrary.

[0019] The ASIC 30 generates a video signal VS2 based on the video signal VS1 by performing necessary signal processing on the video signal VS1, and outputs the video signal VS2 to the driver 40. One end of the flexible substrate FLX is connected to the driver substrate SUB, and the other end of the flexible substrate FLX is connected to the display 50. For this reason, the output signal (video signal VS2) of the ASIC 30 is transmitted to the driver 40 via a connection portion (for example, a connection connector not shown) between the substrates SUB and FLX.

[0020] The driver 40 includes a gate driver and a source driver for a display panel 51 in the display 50, and outputs to the display panel 51 a video signal VS3 based on the video signal VS2.

[0021] The display 50 includes a display panel 51 and a cover panel 52. The display panel 51 is made of organic EL (ElectroLuminescence) elements. The organic EL elements are electro-optical elements whose brightness is controlled by the current flowing through them. The display panel 51 is an organic EL panel formed by arranging pixel circuits, each of which includes an organic EL element, in a matrix. The organic EL elements of each pixel circuit emit or do not emit light based on a gate signal and a data signal included in the video signal VS3, so that an image based on the video signal VS3 is displayed on the display panel 51. The image based on the video signal VS3 is also an image based on the video signal VS2 and an image based on the video signal VS1. The gate signal for each pixel circuit is generated by a gate driver in the driver 40, and the data signal for each pixel circuit is generated by a source driver (in other words, a data driver) in the driver 40. The cover panel 52 is attached to the display panel 51 so as to cover the display surface of the display panel 51.

[0022] The acoustic signal processing unit 60 is made up of a DSP (digital signal processor) and outputs an acoustic signal AS1 to the actuator unit 70. The acoustic signal AS1 is generated in the acoustic signal processing unit 60 based on an acoustic signal provided to the acoustic signal processing unit 60 from an external device (not shown in FIG. 1) of the display device 1. However, the acoustic signal processing unit 60 itself may generate the acoustic signal AS1 without relying on an external device of the display device 1. Alternatively, the acoustic signal provided to the acoustic signal processing unit 60 from the external device may itself become the acoustic signal AS1.

[0023] The actuator section 70 includes a driving circuit 71 and an excitation element 72. Each acoustic signal handled by the acoustic signal processing section 60 is expressed in a digital signal format, and therefore an acoustic signal AS1 is supplied as a digital signal from the acoustic signal processing section 60 to the driving circuit 71. The driving circuit 71 includes a D / A converter (digital / analog converter) and an amplifier. The driving circuit 71 converts the digital acoustic signal AS1 into an analog acoustic signal AS1 in the D / A converter, amplifies the analog acoustic signal AS1 in the amplifier, and outputs the amplified analog acoustic signal AS1 to the excitation element 72 as a driving signal AS2. The excitation element 72 is composed of a piezo element or the like. The driving signal AS2 is applied to the excitation element 72 as a driving voltage for the excitation element 72. The excitation element 72 vibrates by expanding and contracting in response to the applied driving voltage. In other words, the excitation element 72 vibrates in response to the driving signal AS2. When the vibration of the excitation element 72 is transmitted to the display 50, the display 50 also vibrates, and the vibration of the display 50 causes sound based on the acoustic signal AS1 to be output (i.e., sound waves to be output). The output of sound (i.e., the output of sound waves) is also expressed as "sound emission." Hereinafter, when the term "sound emission" is used simply, it refers to the output of sound (sound wave output) from the display 50 due to the vibration of the display 50.

[0024] Bidirectional communication is possible between the microcomputer 10 and the ASIC 30 by SPI (Serial Peripheral Interface) communication or the like, and the signal COM in Fig. 1 represents a signal in the bidirectional communication. The ASIC 30 has an abnormality detection function, and outputs an abnormality signal ERR indicating the result of the abnormality detection by the abnormality detection function to the microcomputer. The technology related to the abnormality detection function will be described in detail later. In addition, a brightness control signal BCNT is output from the microcomputer 10 to the ASIC 30, and the ASIC 30 controls the brightness of the image displayed on the display panel 51 based on the brightness control signal BCNT.

[0025] The relationship between the display 50 and the excitation element 72 will be described with reference to FIG. 2. FIG. 2 is an exploded perspective view of the display 50 and the excitation element 72. An image is displayed on the display surface 51a of the display panel 51. A viewer is present at a position where the image displayed on the display panel 51 can be viewed. The viewer refers to the viewer of the display device 1 (the viewer of the image on the display 50). The cover panel 52, the display panel 51, and the excitation element 72 are arranged in this order from the front side to the rear side of the display 50. The viewer is located on the front side of the display 50, and the distance from the viewer increases as the viewer moves from the front side to the rear side of the display 50.

[0026] The display panel 51 is a glass organic EL panel having organic EL elements formed on a glass substrate, and has a roughly rectangular shape when viewed from the front of the display 50 (in other words, when viewed from the viewer). The cover panel 52 is disposed on the display surface 51a side of the display panel 51. The cover panel 52 is a rectangular panel having a size equal to or larger than that of the display panel 51 when viewed from the front of the display 50 (in other words, when viewed from the viewer), and covers the entire display surface 51a of the display panel 51. A touch panel may be formed on the cover panel 52.

[0027] The excitation element 72 is disposed on the rear side of the display panel 51. That is, the excitation element 72 is disposed on the surface (rear surface) of the display panel 51 opposite to the display surface 51a. In the example of FIG. 2, one excitation element 72 having an area smaller than that of the display panel 51 is disposed in the center of the rear surface of the display panel 51. However, the excitation element 72 may be disposed in a position other than the center of the rear surface of the display panel 51, or multiple excitation elements 72 may be disposed on the rear surface of the display panel 51.

[0028] 2, the cover panel 52, the display panel 51, and the excitation element 72 are shown separated from each other, but in reality, the cover panel 52 and the display panel 51 are bonded via an adhesive layer, and the display panel 51 and the excitation element 72 are bonded via another adhesive layer, so that the cover panel 52, the display panel 51, and the excitation element 72 are integrally formed. Therefore, the display 50 consisting of the cover panel 52 and the display panel 51 vibrates in accordance with the vibration of the excitation element 72, and sound is output from the display 50.

[0029] As shown in Fig. 3, the audio signal processing unit 60 is provided with a volume level setting unit 61 that sets the volume level of sound emitted from the display 50. The volume level of sound emission represents the intensity of the sound emitted. The intensity of the sound may be an amount measured in decibels (i.e., sound pressure level) or an amount measured in phons. In either case, the higher the volume level, the higher the sound intensity, and the lower the volume level, the lower the sound intensity.

[0030] The volume level setting section 61 has a set value VOL * is entered, and the set value VOL * Set the volume level of the sound based on the setting value VOL * may be input from the microcomputer 10. The operator of the display device 1 sets the set value VOL * The operator of the display device 1 typically coincides with the viewer of the display device 1, but the operator and the viewer may be different. Both the operator and the viewer belong to the user of the display device 1. For example, the operator inputs a predetermined volume setting operation to an operation unit (not shown), and the set value VOL * is determined. The form of the operation unit is arbitrary. For example, when a touch panel is formed on the cover panel 52, the touch panel may function as the operation unit. The operation unit may be realized by a remote controller or any terminal device connected to the display device 1 by wire or wirelessly.

[0031] The acoustic signal processing unit 60 is further provided with a signal processing unit 62, which performs necessary signal processing on the acoustic signal AS0 under the control of the volume level setting unit 61 to generate an acoustic signal AS1 to be supplied to the actuator unit 70 (see also FIG. 1). The acoustic signal AS0 is provided to the acoustic signal processing unit 60 from an external device (not shown in FIG. 1) of the display device 1. Therefore, the acoustic signal AS0 is an input acoustic signal to the acoustic signal processing unit 60 and the signal processing unit 62. However, the acoustic signal AS0 may be generated within the acoustic signal processing unit 60 without relying on an external device of the display device 1. The acoustic signal AS1 is an output acoustic signal from the acoustic signal processing unit 60 and the signal processing unit 62.

[0032] The signal processing unit 62 is capable of executing an amplitude adjustment process to adjust the amplitude of the acoustic signal AS0, and outputs the acoustic signal obtained by performing the amplitude adjustment process on the acoustic signal AS0 (i.e., the acoustic signal AS0 after the amplitude adjustment by the amplitude adjustment process) as the acoustic signal AS1.

[0033] Since the acoustic signal AS1 is an electrical signal representing the sound to be output from the display 50, the greater the amplitude of the acoustic signal AS1, the greater the volume level of the sound emitted by the display 50, and vice versa.

[0034] Here, the signal processing unit 62 adjusts the amplitude of the acoustic signal AS0 by k AMP The audio signal AS1 is generated by multiplying the volume by a set value VOL * Based on the coefficient k AMP Furthermore, the setting value VOL * is an integer between 1 and n, and the set value VOL * The larger the coefficient k AMP The value of VOL increases, where n is an arbitrary integer equal to or greater than 2 (e.g., 3). Therefore, assuming that the acoustic signal AS0 is constant, the set value VOL * The larger the value, the higher the volume level of the sound emitted based on the acoustic signal AS0 becomes.* The smaller the value, the smaller the volume level of the sound emitted based on the acoustic signal AS0.

[0035] That is, the volume level setting unit 61 sets the set value VOL * The volume level of the sound output is set based on the set value VOL. Hereinafter, the volume level of the sound output set by the volume level setting unit 61 may be referred to as the set volume level. * can be understood as a numerical representation of the set volume level.

[0036] 4, the functional block of the ASIC 30 includes an abnormality detection unit 31. The abnormality detection unit 31 may be realized by the ASIC 30 and other circuits mounted on the driver board SUB. The abnormality detection unit 31 detects the presence or absence of one or more types of abnormality that may occur in the display device 1, and outputs an abnormality signal ERR indicating the detection result to the microcomputer 10.

[0037] Abnormalities that the abnormality detection unit 31 can detect include at least a video output abnormality. A video output abnormality refers to an abnormality in the image displayed on the display panel 51. A state in which there is no abnormality in the image displayed on the display panel 51 is referred to as a normal image state, and a state in which there is an abnormality in the image displayed on the display panel 51 is referred to as an abnormal image state. Therefore, in a normal image state, the abnormality detection unit 31 determines and detects that there is no video output abnormality, and in an abnormal image state, the abnormality detection unit 31 determines and detects that there is a video output abnormality.

[0038] In the normal image state, the video signal VS2 based on the video signal VS1 is accurately transmitted to the driver 40, and the video signal VS3 based on the accurately transmitted video signal VS2 is accurately provided to the display panel 51, so that the image displayed on the display panel 51 is an image that correctly complies with the video signals VS1 and VS2. In contrast, in the abnormal image state, an image that complies with the video signals VS1 and VS2 is not displayed on the display panel 51. Even if a part of the image displayed on the display panel 51 complies with the video signals VS1 and VS2, a state in which the remaining part of the image displayed on the display panel 51 does not complies with the video signals VS1 and VS2 also belongs to the abnormal image state.

[0039] The abnormality detection unit 31 detects the presence or absence of an abnormality in the video output based on a feedback signal based on the video signal VS3, for example. That is, as shown in FIG. 5(a), a configuration can be adopted in which a feedback signal FB1 corresponding to the video signal VS3 output from the driver 40 to the display panel 51 is provided to the driver 40, and a feedback signal FB2 corresponding to the feedback signal FB1 is output from the driver 40 to the ASIC 30. The feedback signals FB1 and FB2 may be the same signal. Alternatively, as shown in FIG. 5(b), a configuration can be adopted in which the feedback signal FB1 is provided to the ASIC 30 without passing through the driver 40. Hereinafter, the feedback signal FB1 or FB2 provided to the ASIC 30 is referred to as the feedback signal FB.

[0040] The abnormality detection unit 31 in the ASIC 30 detects the presence or absence of a video output abnormality based on the feedback signal FB (FB2 or FB1). The abnormality detection unit 31 recognizes what kind of signal the feedback signal FB is in a normal video state, and when the actually received feedback signal FB satisfies a predetermined normality determination condition based on the recognition result, it determines that there is no video output abnormality, and when the actually received feedback signal FB does not satisfy the normality determination condition, it determines that there is a video output abnormality.

[0041] For example, the abnormality detection unit 31 may determine whether the feedback signal FB is a signal that accurately reflects the video signal VS2 based on the video signal VS2 that it generates and outputs. In this case, the normality determination condition is satisfied only when the feedback signal FB is a signal that accurately reflects the video signal VS2.

[0042] The video signal VS3 in the normal video state includes synchronizing signals (vertical synchronizing signal, horizontal synchronizing signal) necessary for correctly displaying the video based on the video signal VS3 on the display panel 51. In the normal video state, the feedback signal FB may be a signal including the synchronizing signal in the video signal VS3. In this case, if the feedback signal FB includes a predetermined synchronizing signal, the normal judgment condition is satisfied, and if not (for example, if the feedback signal FB does not include a synchronizing signal and the signal that should represent the synchronizing signal is fixed to a low level or a high level), the normal judgment condition is not satisfied.

[0043] Additionally, the abnormality detection unit 31 may detect the presence or absence of an abnormality in the video output by using any method including known abnormality detection methods.

[0044] The abnormality detection unit 31 may be capable of detecting an abnormality of a different kind from the video output abnormality. For example, the abnormality detection unit 31 may be capable of detecting a low voltage abnormality in which the power supply voltage supplied to the driver board SUB or to the ASIC 30 is excessively low, an overvoltage abnormality in which the power supply voltage is excessively high, a temperature abnormality in which the temperature at a predetermined location in the display device 1 (for example, the temperature of the ASIC 30) is abnormally high, and the like. In the following, it is assumed that the abnormality detection unit 31 is capable of detecting the presence or absence of a plurality of types of abnormalities, and that one of the plurality of types of abnormalities includes a video output abnormality.

[0045] When the abnormality detection unit 31 detects any of the above-mentioned multiple types of abnormalities (i.e., when it is determined that there is some abnormality), it sets the abnormality signal ERR to active, and when it detects no abnormality (i.e., when it is determined that there is no abnormality at all), it sets the abnormality signal ERR to non-active. The abnormality signal ERR may be a 1-bit signal that takes either a low level or a high level signal level, and for example, a low level abnormality signal ERR can be associated with active and a high level abnormality signal ERR can be associated with non-active (the correspondence relationship may be reversed).

[0046] When the abnormality signal ERR becomes active, the microcomputer 10 uses two-way communication by the signal COM to transmit a command signal inquiring about the details of the detected abnormality to the ASIC 30. When the ASIC 30 receives the command signal, it transmits abnormality information indicating the details of the abnormality detected by the abnormality detection unit 31 to the microcomputer 10 by using two-way communication by the signal COM. As a result, the microcomputer 10 acquires the abnormality information.

[0047] The microcomputer 10 can determine whether or not there is an abnormality in the video output based on the abnormality information, and can perform a characteristic operation when an abnormality in the video output is detected. Note that it is also possible to configure the abnormality signal ERR to be latched in the active state after it becomes active once. However, in the following, it is assumed that after the abnormality signal ERR becomes active, when the microcomputer 10 obtains abnormality information through communication by the signal COM, the abnormality signal ERR is returned to non-active and the abnormality information in the ASIC 30 is discarded (cleared).

[0048] In the following, specific operation examples, application techniques, modified techniques, etc. related to video output abnormalities will be described in several examples. The matters described above in this embodiment are applied to each of the following examples unless otherwise specified and unless there is a contradiction. In the cases where there are matters in each example that contradict the matters described above, the description in each example may take precedence. Furthermore, unless there is a contradiction, matters described in any of the following examples can also be applied to any of the other examples (i.e., any two or more of the multiple examples can also be combined).

[0049] <<First Example>> A first embodiment will be described. In order to realize a normal image state, it is necessary to transmit an accurate image signal to the display panel 51. However, vibration of the display 50 can be a factor that impedes accurate transmission of the image signal. That is, depending on the degree of vibration of the display 50, a large load is applied to the connection between the ASIC 30 and the driver 40 or the connection between the driver 40 and the display panel 51. As a result, the electrical connection state becomes unstable, and the image signal VS2 may not be transmitted correctly to the driver 40, or the image signal VS3 may not be transmitted correctly to the display panel 51. In these cases, an image output abnormality occurs. Concerns regarding the image output abnormality are particularly noticeable when the display panel 51 is formed of a glass organic EL panel having rigidity.

[0050] When an image output abnormality occurs due to vibration of the display 50, it is expected that the image output abnormality can be resolved by reducing the magnitude of the vibration of the display 50. On the other hand, a reduction in the magnitude of the vibration of the display 50 can be achieved by lowering the volume level of the emitted sound. Taking this into consideration, in the display device 1 according to the first embodiment, when an image output abnormality is detected, the volume level of the emitted sound is lowered, thereby resolving the image output abnormality.

[0051] A specific example of the implementation method will be described below. For the sake of concreteness, unless otherwise specified, the set value VOL * Assume that the upper limit n of the volume control signal satisfies "n=3", and the set value VOL* Consider a situation where the setting value VOL is changed from 1 to 2 and then to 3. FIG. 6 is a flow chart showing the operation of the display device 1 in relation to the volume level setting under this situation. The operation of the display device 1 in relation to the volume level setting will be described with reference to the flow chart in FIG. * Although a volume setting operation for instructing a decrease in the set value VOL * In this figure, the flow of operations performed when a volume setting operation is input to instruct a decrease in the volume is omitted. Also, when an arbitrary audio signal AS1 is supplied to the actuator section 70, the video signal VS1 is always supplied to the ASIC 30 (this also applies to other embodiments described later).

[0052] First, in step S11, the set value VOL * Assume that the initial value of is set to 1. After step S11, the process proceeds to step S12.

[0053] In step S12, the “VOL * .=1”, the microcomputer 10 judges whether the abnormality detection unit 31 has detected that there is an abnormality in the video output based on the signals ERR and COM.

[0054] “VOL * If an abnormality in the video output is detected in the “VOL * If no abnormality in the video output is detected in the “VOL * If a video output abnormality is detected in the state of "video output abnormality=1", the process may not immediately proceed from step S12 to step S19, but may proceed from step S12 to step S19 only if the occurrence of a video output abnormality is repeatedly detected multiple times within a certain period of time.

[0055] In step S13, the set value VOL *The microcomputer 10 judges whether or not a volume setting operation instructing to increase the volume has been input to the operation unit. If the volume setting operation has been input, the process proceeds from step S13 to step S14 (Y in step S13), whereas if the volume setting operation has not been input, the process returns from step S13 to step S12 (N in step S13).

[0056] In step S14, the microcomputer 10 sets the set value VOL * The setting value VOL is increased from "1" to "2". * As the coefficient k increases, AMP As the volume level of the emitted sound also increases (see FIG. 3), the process proceeds to step S15.

[0057] In step S15, “VOL * In the state of "=2", the microcomputer 10 judges whether the abnormality detection unit 31 has detected that there is an abnormality in the video output based on the signals ERR and COM.

[0058] “VOL * If an abnormality in the video output is detected in the “VOL=2” state (Y in step S15), the process proceeds from step S15 to step S20. * If no video output abnormality is detected in the "VOL=2" state (N in step S15), the process proceeds from step S15 to step S16. * If a video output abnormality is detected in the state of "video output abnormality=2", the process may not immediately proceed from step S15 to step S20, but may proceed from step S15 to step S20 only if the occurrence of a video output abnormality is repeatedly detected multiple times within a certain period of time.

[0059] In step S16, the set value VOL *The microcomputer 10 judges whether or not a volume setting operation instructing to increase the volume has been input to the operation unit. If the volume setting operation has been input, the process proceeds from step S16 to step S17 (Y in step S16), whereas if the volume setting operation has not been input, the process returns from step S16 to step S15 (N in step S16).

[0060] In step S17, the microcomputer 10 sets the set value VOL * The setting value VOL is increased from “2” to “3”. * As the coefficient k increases, AMP (See FIG. 3), the volume level of the emitted sound also increases. After step S17, the process proceeds to step S18.

[0061] In step S18, the “VOL * In the state of "0", the microcomputer 10 judges whether the abnormality detection unit 31 has detected that there is an abnormality in the video output based on the signals ERR and COM.

[0062] “VOL * If a video output abnormality is detected in the “VOL = 3” state (Y in step S18), the process proceeds from step S18 to step S21. * If no abnormality in the video output is detected in the "VOL=3" state (N in step S18), the process of step S18 is repeated. * If a video output abnormality is detected in the state of "video output abnormality=3", the process may not immediately proceed from step S18 to step S21, but may proceed from step S18 to step S21 only if the occurrence of a video output abnormality is repeatedly detected multiple times within a certain period of time.

[0063] In step S19, the microcomputer 10 executes a predetermined error process. In the error process, the following video stop process and log recording process may be executed. In the video stop process, the microcomputer 10 stops the display of the video on the display panel 51. To achieve this, for example, the microcomputer 10 may control the video signal processor 20 to stop the transmission of the video signal VS1 to the ASIC 30, or may control the ASIC 30 to stop the transmission of the video signal VS2 to the driver 40. The microcomputer 10 records log information indicating that a video output abnormality has been detected in the log recording process in a non-volatile memory (not shown) provided in the display device 1. The log information is used for repairs of the display device 1, etc.

[0064] In step S20, the microcomputer 10 sets the set value VOL * Decrease the setting value VOL from “2” to “1”. * With the decrease in the coefficient k AMP As a result, the volume level of the sound emitted decreases (see FIG. 3), and it is expected that the abnormal state of the image will be resolved thereafter. * After the setting value VOL * Even if a volume setting operation to increase the volume is input to the operation section, * 6 may be modified to the operation flowchart of FIG. 7, and the set value VOL * After the set value VOL is decreased from "2" to "1", the process may return to step S13. * The volume setting operation, which indicates an increase in the set value VOL * is allowed to go back to “2” again.

[0065] In step S21, the microcomputer 10 sets the set value VOL * Decrease the setting value VOL from “3” to “2”. * With the decrease in the coefficient k AMPAs a result, the volume level of the sound emitted decreases (see FIG. 3), and it is expected that the abnormal state of the image will be resolved thereafter. * After the setting value VOL * Even if a volume setting operation to increase the volume is input to the operation section, * 6 may be modified to the operation flowchart of FIG. 7, and the set value VOL * After the set value VOL is decreased from "3" to "2", the process may return to step S16. * The volume setting operation, which indicates an increase in the set value VOL * is allowed to revert back to "3."

[0066] In this way, in the display device 1 of the first embodiment, when an abnormality in the image display is detected (i.e., when an abnormality in the image output is detected, or more specifically, when an abnormality in the image output is detected), the volume level of the sound is reduced (step S20 or S21).

[0067] This reduces the volume level, but also reduces the magnitude of vibration of the display 50, thereby eliminating the video output abnormality (it is expected that image distortion due to the video output abnormality will be eliminated).

[0068] Specifically, a volume level setting unit 61 is provided to set the volume level of the emitted sound, and an acoustic signal of the set volume level by the volume level setting unit 61 is supplied to the actuator unit 70 (see Figs. 1 and 3). The acoustic signal of the set volume level refers to an acoustic signal having an amplitude corresponding to the set volume level, and corresponds to the acoustic signal AS1. When an abnormality in the video display is detected, the volume level setting unit 61 lowers the set volume level, thereby lowering the volume level of the emitted sound.

[0069] More specifically, when no abnormality in the image display is detected, the volume level setting unit 61 sets the volume level according to the user operation (the volume setting operation input to the operation unit) as the set volume level. In other words, when no abnormality in the image display is detected, the set value VOL * For example, in step S17, the set volume level is determined by the volume level according to the user operation, that is, "VOL * =3”. However, even if an abnormality in the image display is detected, the volume level setting unit 61 lowers the set volume level below the volume level according to the user operation. For example, in step S21, the set volume level is set to the volume level according to the user operation, that is, “VOL * =3” to the volume level corresponding to “VOL * =2”.

[0070] <<Second Example>> A second embodiment will be described. It is assumed that the amplitude of the acoustic signal AS0 changes from moment to moment, and when the amplitude of the acoustic signal AS0 becomes relatively large, the vibration of the display 50 increases, and image distortion is likely to occur. For this reason, when an abnormality in the image output occurs, it is also useful to set an upper limit on the amplitude of the acoustic signal. Below, an example of a configuration for realizing this will be described.

[0071] Fig. 8 shows the configuration of a signal processing unit 62a according to the second embodiment. The signal processing unit 62a can be used as the signal processing unit 62 in Fig. 3. The signal processing unit 62a includes an amplitude adjustment unit 62a_1, an amplitude limiting unit 62a_2, and a switch 62a_3.

[0072] The amplitude adjustment unit 62a_1 performs the above-mentioned amplitude adjustment process. In detail, the amplitude adjustment unit 62a_1 adjusts the amplitude of the acoustic signal AS0 by k AMP As described above, the set value VOL * Based on the coefficient k AMP The value of is specified.

[0073] The amplitude limiting unit 62a_2 performs amplitude limiting processing on the audio signal ASa_1 to generate an audio signal ASa_2. FIG. 9 is a conceptual diagram of the amplitude limiting processing. In any section of interest, the amplitude limiting unit 62a_2 determines whether or not there is a restriction target section in which the amplitude of the audio signal ASa_1 exceeds a predetermined upper limit amplitude value, and when there is a restriction target section, reduces the amplitude of the audio signal ASa_1 in the restriction target section so that the amplitude of the audio signal ASa_1 in the restriction target section is equal to or less than the upper limit amplitude value, and outputs the audio signal ASa_1 after the amplitude reduction as the audio signal ASa_2. If there is no restriction target section in any section of interest, the amplitude reduction by the amplitude limiting processing is not performed, and the audio signal ASa_2 is the same as the audio signal ASa_1.

[0074] More specifically, for example, the amplitude limiting unit 62a_2 can divide an arbitrary section of interest into a plurality of unit sections each having a length of a unit time (for example, 1 second), and perform amplitude limiting processing for each unit section. At this time, the amplitude limiting unit 62a_2 calculates an average value AVE of the amplitude of the audio signal ASa_1 for each unit section. The average value AVE calculated here corresponds to a time average value of the intensity of the sound (volume level of the sound output) output from the display 50 when the audio signal ASa_1 is supplied to the actuator unit 70 as the audio signal AS1. Therefore, when the average value AVE calculated for a certain unit section exceeds a predetermined value REF corresponding to the above-mentioned upper limit amplitude value, the certain unit section is included in the section to be restricted. When a certain unit section is included in the section to be restricted, the amplitude limiting unit 62a_2 reduces the amplitude of the audio signal ASa_1 in the certain unit section by (REF / AVE) times, and sets the reduced audio signal ASa_1 as the audio signal ASa_2 of the certain unit section. When a certain unit section is not included in the section to be limited, the amplitude limiting unit 62a_2 sets the sound signal ASa_1 in the certain unit section as the sound signal ASa_2 in the certain unit section as it is. Such processing may be performed for each unit section.

[0075] The switch 62a_3 selects the audio signal ASa_1 or ASa_2 as the audio signal AS1 based on the presence or absence of a video output abnormality and outputs it to the actuator section 70 (FIG. 8 shows the state in which the audio signal ASa_2 is selected). Specifically, when no video output abnormality is detected, the switch 62a_3 outputs the audio signal ASa_1 as the audio signal AS1 to the actuator section 70 under the control of the microcomputer 10. On the other hand, when a video output abnormality is detected, the switch 62a_3 outputs the audio signal ASa_2 as the audio signal AS1 to the actuator section 70 under the control of the microcomputer 10. Once a video output abnormality is detected, the switch 62a_3 may thereafter continuously output the audio signal ASa_2 as the audio signal AS1 to the actuator section 70.

[0076] In this way, when an abnormality in the image display is detected (i.e., when an abnormality in the image output is detected, more specifically, when an abnormality in the image output is detected), an upper limit is set on the amplitude of the output audio signal by the amplitude limiting process in the process of generating the output audio signal (AS1) from the input audio signal (AS0). The audio signal ASa_2 corresponds to an audio signal whose amplitude is limited to the upper limit. When an abnormality in the image display is detected, the volume level of the sound output is reduced (partially reduced) by such amplitude limiting process compared to when no abnormality in the image display is detected. As a result, the magnitude of vibration of the display 50 is limited, and it is expected that the image abnormality state is resolved. When an abnormality in the image display is not detected (i.e., when an abnormality in the image output is not detected, more specifically, when an abnormality in the image output is not detected), the audio signal (ASa_1) to which the amplitude control process has not been applied is used as the output audio signal (AS1).

[0077] It is also possible to combine the method shown in the second embodiment with the method shown in the first embodiment. That is, when none of steps S19, S20, and S21 in Fig. 6 (or Fig. 7) is reached, the acoustic signal ASa_1 is output as the acoustic signal AS1, and when step S19, S20, or S21 in Fig. 6 (or Fig. 7) is reached, the processing of step S19, S20, or S21 is executed and thereafter the acoustic signal ASa_2 is output as the acoustic signal AS1.

[0078] <<Third Example>> A third embodiment will be described. The load applied to the connection between the ASIC 30 and the driver 40 or the connection between the driver 40 and the display panel 51 is larger when the frequency of the vibration of the display 50 is relatively low than when the frequency of the vibration of the display 50 is relatively high, and image distortion is likely to occur when a large vibration is applied in the low-frequency range. For this reason, when an abnormality in the image output occurs, it is also useful to reduce the low-frequency components of the audio signal. An example of a configuration for realizing this will be described below.

[0079] Fig. 10 shows the configuration of a signal processing unit 62b according to the third embodiment. The signal processing unit 62b can be used as the signal processing unit 62 in Fig. 3. The signal processing unit 62b includes an amplitude adjustment unit 62b_1, a band attenuation unit 62b_2, and a switch 62b_3.

[0080] The amplitude adjustment unit 62b_1 performs the above-mentioned amplitude adjustment process. In detail, the amplitude adjustment unit 62b_1 adjusts the amplitude of the acoustic signal AS0 by k AMP As described above, the set value VOL * Based on the coefficient k AMP The value of is specified.

[0081] The band attenuation unit 62b_2 generates an audio signal ASb_2 by performing an attenuation process on the audio signal ASb_1. In the attenuation process, the band attenuation unit 62b_2 attenuates signal components of a predetermined band among the signal components of the audio signal ASb_1, and outputs the attenuated audio signal ASb_1 as the audio signal ASb_2. The predetermined band is assumed to be the entire band below a predetermined frequency (e.g., 100 Hz), in which case the band attenuation unit 62b_2 may be a high-pass filter. However, the predetermined band may also be a band from a predetermined first frequency to a predetermined second frequency higher than the first frequency, in which case the band attenuation unit 62b_2 may be a band-pass filter. The predetermined band may be set in consideration of the frequency band of vibrations that are likely to cause abnormalities in the video output.

[0082] The switch 62b_3 selects the audio signal ASb_1 or ASb_2 as the audio signal AS1 based on the presence or absence of a video output abnormality and outputs it to the actuator section 70 (FIG. 10 shows that the audio signal ASb_2 is selected). Specifically, when no video output abnormality is detected, the switch 62b_3 outputs the audio signal ASb_1 as the audio signal AS1 to the actuator section 70 under the control of the microcomputer 10. On the other hand, when a video output abnormality is detected, the switch 62b_3 outputs the audio signal ASb_2 as the audio signal AS1 to the actuator section 70 under the control of the microcomputer 10. Once a video output abnormality is detected, the switch 62b_3 may continuously output the audio signal ASb_2 as the audio signal AS1 to the actuator section 70.

[0083] In this way, when an abnormality in the video display is detected (i.e. when an abnormality in the video output is detected, more specifically when an abnormality in the video output is detected), an attenuation process is performed to reduce signal components in a predetermined band in the process of generating an output audio signal (AS1) from an input audio signal (AS0). With this attenuation process, when an abnormality in the video display is detected, the volume level of the emitted sound is lower (reduced in a predetermined band) compared to when no abnormality in the video display is detected. As a result, it is expected that video output abnormalities will be less likely to occur. When no abnormality in the video display is detected (i.e. when no abnormality in the video output is detected, more specifically when no abnormality in the video output is detected), an audio signal (ASb_1) to which no attenuation process has been applied is used as the output audio signal (AS1).

[0084] It is also possible to combine the method shown in the third embodiment with the method shown in the first embodiment. That is, when none of steps S19, S20, and S21 in Fig. 6 (or Fig. 7) is reached, the acoustic signal ASb_1 is output as the acoustic signal AS1, and when step S19, S20, or S21 in Fig. 6 (or Fig. 7) is reached, the processing of step S19, S20, or S21 is executed and thereafter the acoustic signal ASb_2 is output as the acoustic signal AS1.

[0085] Furthermore, it is possible to combine the second and third embodiments. In this case, when an abnormality in the image display is detected, both the amplitude limiting process of the second embodiment and the attenuation process of the third embodiment are applied to the audio signal ASa_1 in Fig. 8, and the audio signal ASa_1 after the amplitude limiting process and the attenuation process are regarded as the audio signal ASa_2 (otherwise, it is the same as described in the second embodiment). It is also possible to combine all of the first to third embodiments.

[0086] <<Fourth Example>> A fourth embodiment will now be described. Fig. 11 shows a determination unit 11 and a storage unit 12 that are particularly involved in the operation of the fourth embodiment among the functional blocks of the microcomputer 10. The determination unit 11 may be realized by a program executed by the microcomputer 10. The storage unit 12 is a non-volatile memory provided in the microcomputer 10. However, the storage unit 12 may also be a non-volatile memory provided outside the microcomputer 10 and within the display device 1.

[0087] The determination unit 11 changes the volume level of the sound emitted by the display 50, and determines whether or not the abnormality detection unit 31 detects an abnormality in the video output after the change (in other words, determines whether the video display is normal based on the detection result of the abnormality detection unit 31). * The volume level of the sound output increases or decreases with an increase or decrease in the set value VOL * At this time, the determination unit 11 changes the volume level of the sound by changing the set value VOL * For example, when a test program is executed in the microcomputer 10, a predetermined test operation is executed, and the determination unit 11 determines the set value VOL * By using such a test operation, it is possible to determine the presence or absence of an abnormality in the video output according to the volume level of the emitted sound at any timing, such as during a shipping inspection process of the display device 1.

[0088] As a typical example, the flow of operations for making the determination unit 11 function in the shipping inspection process of the display device 1 will be described below. In the shipping inspection process of the display device 1, a test program is executed in the microcomputer 10. In the test operation by executing the test program, the determination unit 11 sequentially switches the volume level of the emitted sound among multiple stages. As described above, for the sake of concrete explanation, three stages are assumed here (i.e., it is assumed that "n=3"). The determination unit 11 determines the volume level of the emitted sound among multiple stages based on a set value VOL * can be switched between ascending and descending order.

[0089] FIG. 12 shows a flow chart of a first operation example of the shipping inspection process. In the first operation example, the set value VOL * The first operation example is made up of the processes of steps S61 to S71. The test operation is executed in steps S61 to S71. First, in step S61, input of a predetermined test acoustic signal to the acoustic signal processing unit 60 is started, and thereafter, input of the test acoustic signal is continued until any of steps S68 to S71 described later is reached. The test acoustic signal is input to the acoustic signal processing unit 60 as an acoustic signal AS0 (see FIG. 3). After step S61, the process proceeds to step S62. In the following, "VOL * The volume level of the sound emitted when the “VOL * The volume level of the sound emitted in the "VOL =2" state is sometimes called the second volume level, and * The volume level of the sound emitted in the "=3" state is sometimes referred to as the third volume level.

[0090] In step S62, the determination unit 11 determines whether the set value VOL * In the next step S63, the determination unit 11 assigns "1" to "VOL * =1”, it is determined based on the signals ERR and COM whether the abnormality detection unit 31 has detected an abnormality in the video output. *If it is detected that there is an abnormality in the video output in the state of "0x000000001" (Y in step S63), the process proceeds to step S69, and if not (N in step S63), the process proceeds to step S64.

[0091] In step S64, the determination unit 11 determines whether the set value VOL * In the next step S65, the determination unit 11 assigns "2" to "VOL * =2”, it is determined based on the signals ERR and COM whether the abnormality detection unit 31 has detected an abnormality in the video output. * If it is detected that there is a video output abnormality in the state of ".times. ...

[0092] In step S66, the determination unit 11 determines whether the set value VOL * In the next step S67, the determination unit 11 assigns "3" to "VOL * =3”, it is judged based on the signals ERR and COM. * If it is detected that there is a video output abnormality in the state of "0x0 ...

[0093] In step S68, the judgment unit 11 executes a pass / fail process. The pass / fail process includes a process of storing the information GOOD in the storage unit 12 as pass / fail judgment information. The information GOOD is stored in the storage unit 12 at the third volume level ("VOL * =3”) no video output abnormality occurred.

[0094] In step S69, the determination unit 11 executes a first failure process. The first failure process includes a process of storing information NG1 in the storage unit 12 as pass / fail determination information. The information NG1 is a first volume level ("VOL *= 1”) indicates that a video output abnormality has occurred.

[0095] In step S70, the determination unit 11 executes a second failure process. The second failure process includes a process of storing information NG2 in the storage unit 12 as pass / fail determination information. The information NG2 is a first volume level ("VOL * =1”), no video output abnormality occurs, but the second volume level (“VOL * =2”) indicates that an error has occurred in the video output.

[0096] In step S71, the determination unit 11 executes a third failure process. The third failure process includes a process of storing information NG3 in the storage unit 12 as pass / fail determination information. The information NG3 is a second volume level ("VOL * =2”), no video output abnormality occurs, but the third volume level (“VOL * =3”) indicates that an error has occurred in the video output.

[0097] In addition, the pass / fail judgment information may be, for example, information having a value of 0, 1, 2, or 3. In this case, the value of "0" is assigned to the information GOOD, and the values ​​of "1", "2", and "3" are assigned to the information NG1, NG2, and NG3, respectively.

[0098] FIG. 13 shows a flow chart of a second operation example of the shipping inspection process. In the second operation example, the set value VOL * are switched in descending order. The second operation example comprises the processes of steps S81 to S91. In steps S81 to S91, the test operation is executed. First, in step S81, input of a predetermined test acoustic signal to the acoustic signal processing unit 60 is started, and thereafter, input of the test acoustic signal is continued until any of steps S88 to S91 described later is reached. The test acoustic signal is input to the acoustic signal processing unit 60 as an acoustic signal AS0 (see FIG. 3). After step S81, the process proceeds to step S82.

[0099] In step S82, the determination unit 11 determines whether the set value VOL *In the next step S83, the determination unit 11 assigns "3" to "VOL * =3”, it is judged based on the signals ERR and COM. * If it is detected that there is a video output abnormality in the state of ".epsilon.=3" (Y in step S83), the process proceeds to step S84, and if not (N in step S83), the process proceeds to step S89.

[0100] In step S84, the determination unit 11 determines whether the set value VOL * In the next step S85, the determination unit 11 assigns "2" to "VOL * =2”, it is determined based on the signals ERR and COM whether the abnormality detection unit 31 has detected an abnormality in the video output. * If it is detected that there is a video output abnormality in the state of "=2" (Y in step S85), the process proceeds to step S86, and if not (N in step S85), the process proceeds to step S90.

[0101] In step S86, the determination unit 11 determines whether the set value VOL * In the next step S87, the determination unit 11 assigns "1" to "VOL * =1”, it is determined based on the signals ERR and COM whether the abnormality detection unit 31 has detected an abnormality in the video output. * If it is detected that there is an abnormality in the video output in the state of "0x000000001" (Y in step S87), the process proceeds to step S88, and if not (N in step S87), the process proceeds to step S91.

[0102] The judgment unit 11 executes a non-defective product process in step S89, a first defective product process in step S88, a second defective product process in step S91, and a third defective product process in step S90. The contents of the non-defective product process and the first to third defective product processes are the same as those described above in relation to the first operation example of FIG.

[0103] In this manner, the volume level of the sound output is changed, and the determination unit 11 determines whether or not the abnormality detection unit 31 detects an abnormality in the video output after the change (in other words, it is determined whether or not the video display is normal based on the detection result of the abnormality detection unit 31). This makes it possible to check whether or not an abnormality in the video output occurs due to vibration of the display 50 during a shipping inspection process of the display device 1, and makes it possible to take measures such as excluding defective products from the list of products to be shipped (i.e., the reliability of the display device 1 as a product can be improved). As a typical example of operation, it is preferable to ship only the display device 1 that has been subjected to the non-defective product process as a non-defective product, and to exclude the display device 1 that has been subjected to the first, second, or third defective product process as a defective product and not to be shipped.

[0104] In the first operation example of FIG. 12, the volume level of sound emission is switched in ascending order in a plurality of stages, and during the switching process, the volume level may change from a first state in which no video output abnormality is detected to a second state in which a video output abnormality is detected. When such a change occurs, information NG2 or NG3 is stored in the storage unit 12 as information corresponding to the volume level of sound emission in the first state or the second state. In the second operation example of FIG. 13, the volume level of sound emission is switched in descending order in a plurality of stages, and during the switching process, the volume level may change from a second state in which a video output abnormality is detected to a first state in which a video output abnormality is not detected. When such a change occurs, information NG2 or NG3 is stored in the storage unit 12 as information corresponding to the volume level of sound emission in the first state or the second state.

[0105] For example, the first state and the second state for the information NG2 are states corresponding to a first volume level ("VOL *=1”), and the state corresponding to the second volume level (“VOL * As described above, the information NG2 is the first volume level ("VOL * =1”), no video output abnormality occurs, but the second volume level (“VOL * =2”) indicates that an error has occurred in the video output, so turn off the first volume level (VOL * =1), or information corresponding to the second volume level (VOL * =2). Similarly, the first and second states for information NG3 are states corresponding to the second volume level ("VOL * =2” state), and the state corresponding to the third volume level (“VOL * As described above, the information NG3 is the second volume level ("VOL * =2”), no video output abnormality occurs, but the third volume level (“VOL * =3”) indicates that an error has occurred in the video output, so turn off the second volume level (VOL * =2), or it can be said that it is information corresponding to the third volume level (VOL * =3).

[0106] By storing such information, it becomes possible to easily check at what volume level an image output abnormality occurs, or at what volume level an image output abnormality does not occur. This is thought to be of great benefit in facilitating defect investigations, etc.

[0107] In some cases, it is possible to include the display device 1 on which the third defect process has been performed in the shipment. However, in the display device 1 on which the third defect process has been performed, the “VOL * Alternatively, in the display device 1 on which the third defect process has been executed, the microcomputer 10 may be configured to prohibit the setting of "VOL = 3" based on the information NG3 stored in the storage unit 12 during actual use by a user.* =3” while allowing “VOL * In the state of "=3", the audio signal ASa_2 or ASb_2 (see FIG. 8 or FIG. 10) may always be used as the audio signal AS1.

[0108] It is also possible to execute the process according to the fourth embodiment in a process other than the shipping inspection process. For example, when a predetermined test command signal is input to the microcomputer 10 at any timing after the shipment of the display device 1, the microcomputer 10 may execute a test program to execute the process shown in FIG. 12 or FIG. 13.

[0109] <<Fifth Example>> A fifth embodiment will now be described.

[0110] The display device 1 can be used, for example, as a display device for the backseat of an automobile. The display device for the backseat is provided for viewing by passengers sitting in the backseat of the automobile. In this case, a video signal that is the source of the video signal VS1 and an audio signal that is the source of the audio signal AS1 (for example, the above-mentioned audio signal AS0) may be transmitted to the display device 1 by wire or wirelessly from an in-vehicle device (for example, an electronic device constituting a car navigation system) installed in the front seat of the automobile.

[0111] However, the display device 1 is not limited to in-vehicle applications and may be used in any type of display device. That is, the display device 1 may be mounted on any device that requires a display device, such as a personal computer, an information terminal (e.g., a tablet or a smartphone), a game device, or a television receiver.

[0112] Although it is assumed that the driver 40 is mounted on the flexible substrate FLX, it is not essential that the driver 40 is mounted on the flexible substrate FLX, and the driver 40 may be mounted on the driver substrate SUB or may be provided within the display 50.

[0113] Although it has been assumed that the display panel 51 is an organic EL panel formed of organic EL elements, the display panel 51 may be formed using electro-optical elements other than organic EL elements (for example, liquid crystal display elements).

[0114] The embodiments of the present invention can be modified in various ways as appropriate within the scope of the technical ideas set forth in the claims. The above embodiments are merely examples of the present invention, and the meanings of the terms of the present invention and each component are not limited to those described in the above embodiments. The specific numerical values ​​shown in the above description are merely examples, and can be changed to various numerical values ​​as a matter of course. [Explanation of symbols]

[0115] 1 Display device 10. Microcomputers 20 Video signal processing section 30 ASIC 31 Abnormality detection section 40 Drivers 50 Display 51 Display Panel 52 Cover Panel 60 Acoustic signal processing section 61 Volume level setting section 62 Signal processing section 70 Actuator section 71 Drive circuit 72 Drive element

Claims

1. In a display device that emits sound by vibrating a display that displays an image, an actuator unit that vibrates the display based on a supplied acoustic signal; an abnormality detection unit that detects whether or not there is an abnormality in the image display on the display; A volume level setting unit that sets a volume level of the sound emitted, an acoustic signal of a set volume level by the volume level setting unit is supplied to the actuator unit; the volume level setting unit sets a volume level according to a user operation as the set volume level when no abnormality is detected in the video display, When the set volume level is a first volume level and no abnormality in the image display is detected, and thereafter, when the set volume level is a second volume level that is higher than the first volume level and follows the user operation, the volume level setting unit lowers the set volume level to the first volume level. , display device.

2. When the set volume level is the minimum volume level within an adjustment range of the set volume level and an abnormality in the image display is detected, the image display on the display is stopped. The display device according to claim 1 .

3. An acoustic signal processing unit that generates an output acoustic signal based on an input acoustic signal, The actuator unit vibrates the display based on the output acoustic signal; The acoustic signal processing unit has a signal processing unit, When an abnormality in the image display is detected, the signal processing unit attenuates a signal component in a predetermined band among signal components of the input audio signal in a process of generating the output audio signal from the input audio signal. The display device according to claim 1 .

4. When an abnormality in the image display is detected, the signal processing unit attenuates signal components in the predetermined band among signal components of the input audio signal by using a high-pass filter or a band-pass filter. The display device according to claim 3 .

Images