JP2012216905A - Display device and electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display device that is usable as a parametric speaker and allows directivity thereof to be changed.SOLUTION: A display device has a polarization member 120. The polarization member 120 includes a piezoelectric film 10, polarizer layers 22 and 24, and a plurality of first electrodes 12. The polarizer layers 22 and 24 are formed on the piezoelectric film 10. The first electrodes 12 are provided on a surface of the piezoelectric film 10, and are separated from one another. A vibrational region A of the piezoelectric film 10 changes depending on to which one of the first electrodes 12 a driving signal is input. When the vibrational region A changes, a resonance frequency changes. A carrier wave of a parametric speaker is often set at a resonance frequency of an oscillation source. Accordingly, the display device of the invention allows directivity of the parametric speaker to be changed depending on different occasions on which the parametric speaker is used.

Description

  The present invention relates to a display device and an electronic apparatus.

  One type of speaker is used as an oscillation source in which a piezoelectric element is fixed on a vibrating member. This type of speaker is characterized in that it is easy to miniaturize compared to an electrodynamic speaker using a voice coil and a magnet. Such a speaker may be incorporated in an electronic device having a display, such as a mobile communication terminal.

  Patent Document 1 describes that a piezoelectric film is incorporated in a polarizing assembly of a display, and this piezoelectric film is used as a speaker. In this polarizing assembly, a polarizing film is disposed on a piezoelectric film.

  Patent Document 2 describes that a piezoelectric film is incorporated in a touch panel and this piezoelectric film is used as a speaker.

JP 2007-28641 A JP 2007-66306 A

  One of the speakers using a piezoelectric element is a parametric speaker using ultrasonic waves as a carrier wave. Since ultrasonic waves are highly oriented, when a parametric speaker is used, a sound field can be formed only in a specific direction such as near the user.

  In consideration of mounting the parametric speaker in a portable electronic device, it is preferable that the directivity of the parametric speaker can be changed depending on the use scene. On the other hand, miniaturization is required for portable electronic devices. For this purpose, it is desirable to incorporate the parametric speaker into other parts.

  The objective of this invention is providing the display apparatus and electronic device which can be used as a parametric speaker and can change directivity.

According to the present invention, a piezoelectric film;
A polarizer layer formed on the piezoelectric film;
A plurality of electrodes provided on one surface of the piezoelectric film and separated from each other;
Provided is a display device having a polarizing member.

  According to the present invention, an electronic apparatus having the display device described above is provided.

  ADVANTAGE OF THE INVENTION According to this invention, the display apparatus and electronic device which can be used as a parametric speaker and can change directivity can be provided.

It is a top view which shows the structure of the display apparatus which concerns on 1st Embodiment. It is sectional drawing which shows the layer structure of the display apparatus shown in FIG. It is a figure explaining the effect of an embodiment. It is a figure which shows the case where the polarizing member shown in FIG.1 and FIG.2 is connected to the control part. It is a top view of the electronic device which has a polarizing member shown in FIG. It is sectional drawing which shows the layer structure of a display. It is a figure which shows the structure of the polarizing member used for the display display which concerns on 2nd Embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings, the same reference numerals are given to the same components, and the description will be omitted as appropriate.

(First embodiment)
FIG. 1 is a plan view showing the configuration of the display device according to the first embodiment. FIG. 2 is a cross-sectional view showing a layer structure of the display device shown in FIG. This display device has a polarizing member 120. The polarizing member 120 includes the piezoelectric film 10, the polarizer layers 22 and 24, and the plurality of first electrodes 12. The polarizer layers 22 and 24 are formed on the piezoelectric film 10. The plurality of first electrodes 12 are provided on one surface of the piezoelectric film 10 and are separated from each other.

  The directivity of the ultrasonic wave becomes better as the frequency is higher. For this reason, when the frequency of the carrier wave of the parametric speaker is increased, the directivity of the parametric speaker is increased. The carrier wave of the parametric speaker is often set to the resonance frequency of the oscillation source.

  In this embodiment, when a drive signal is input to the first electrode 12, the piezoelectric film 10 oscillates. And as shown to Fig.3 (a) and (b), the area | region A which vibrates among the piezoelectric films 10 changes with which drive signal is input into which 1st electrode 12. FIG. When the vibrating region A changes, the resonance frequency changes. Therefore, according to this embodiment, the directivity of the parametric speaker can be changed depending on the usage scene. Details will be described below.

  The piezoelectric film 10 is made of a resin material that exhibits piezoelectricity. This resin material is, for example, polyvinylidene fluoride. However, the piezoelectric film 10 may be formed of other resin materials such as polyvinyl chloride and polytrifluoroethylene.

  In the present embodiment, the first electrode 12 is formed on one surface of the piezoelectric film 10, and the second electrode 14 is formed on the opposite surface of the piezoelectric film 10. The second electrode 14 has the same shape as the first electrode 12 and is disposed in the same portion as the first electrode 12 in plan view. Note that the second electrode 14 may not be divided and may be a so-called solid electrode.

  Each of the plurality of first electrodes 12 has the same planar shape, for example, a rectangular shape. The first electrodes 12 are two-dimensionally arranged at equal intervals.

  On the piezoelectric film 10, the protective layer 32, the polarizer layer 22, the protective layer 34, the polarizer layer 24, and the protective layer 36 are laminated in this order. The protective layers 32, 34, and 36 are, for example, triacetyl cellulose. The polarizer layers 22 and 24 are, for example, polyvinyl alcohol. However, the material which comprises these layers is not limited to these.

  FIG. 4 is a diagram illustrating a case where the polarizing member 120 illustrated in FIGS. 1 and 2 is connected to the control unit 50. The control unit 50 modulates audio data input from the outside to generate modulation data for a parametric speaker, generates a drive signal based on the data, and generates the first electrode 12 and the second electrode 14 of the piezoelectric film 10. To enter. In the present embodiment, the control unit 50 inputs drive signals to the plurality of first electrodes 12 and the second electrodes 14 independently of each other. Which of the first electrode 12 and the second electrode 14 the drive signal is input to by the control unit 50 can be arbitrarily set.

  FIG. 5 is a plan view of an electronic apparatus having the polarizing member 120 shown in FIG. The polarizing member 120 is incorporated in the display display 100. In the present embodiment, the electronic device is a portable electronic device, such as a portable communication terminal or a portable game device. When this electronic device is a mobile communication terminal, the electronic device may be configured by a single housing. In this case, the display 100 also has a touch panel function. Note that the electronic device may include a first housing having the display 100 and a second housing having an input key. In this case, the electronic device may be a folding type or a sliding type.

  FIG. 6 is a cross-sectional view showing the layer structure of the display 100. The display 100 has a structure in which a light source 110, a polarizing member 120, and a liquid crystal panel 130 are stacked. The light source 110 may be a light emitting diode.

  As described above, according to the present embodiment, the directivity of the parametric speaker can be changed depending on which first electrode 12 the drive signal is input to.

(Second Embodiment)
FIG. 7 is a diagram illustrating a configuration of the polarizing member 120 used in the display 100 according to the second embodiment. In the polarizing member 120 according to the present embodiment, the planar shapes of at least two first electrodes 12 are different from each other.

  Also according to this embodiment, the same effect as that of the first embodiment can be obtained.

  As mentioned above, although embodiment of this invention was described with reference to drawings, these are the illustrations of this invention, Various structures other than the above are also employable.

DESCRIPTION OF SYMBOLS 10 Piezoelectric film 12 1st electrode 14 2nd electrode 22 Polarizer layer 24 Polarizer layer 32 Protective layer 34 Protective layer 36 Protective layer 50 Control part 100 Display 110 Light source 120 Polarizing member 130 Liquid crystal panel

Claims (6)

Piezoelectric film,
A polarizer layer formed on the piezoelectric film;
A plurality of electrodes provided on one surface of the piezoelectric film and separated from each other;
The display apparatus which has a polarizing member which has. The display device according to claim 1,
A display device further comprising control means for independently inputting drive signals for vibrating the piezoelectric film to the plurality of electrodes. The display device according to claim 1 or 2,
The display device in which the plurality of electrodes have the same planar shape and are two-dimensionally arranged at equal intervals. The display device according to claim 1 or 2,
The display device in which at least two of the electrodes have different planar shapes. In the display device according to any one of claims 1 to 4,
A display device further comprising a liquid crystal panel provided on the polarizing member. The electronic device which has a display apparatus as described in any one of Claims 1-5.

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