JPH01223896A - Acoustic diaphragm member - Google Patents

Abstract

PURPOSE:To obtain an acoustic diaphragm member excellent in external appearance and design by forming the member from a plate base having a horogram pattern face. CONSTITUTION:A film and an object 2 are arranged to a prescribed location and an optical system 6 such as a half mirror 5 splits a laser beam 4 from a laser light source 3 into an object light 7 radiated onto an object and a reference light 8 radiated onto the film at a prescribed angle. when the object light is radiated onto the object, the object light 7 is reflected and refracted by be object and the light is interfered with the reference light 8 and the interference fringe of wave front is recorded on the film face as a horogram pattern face with uneven or contrast. For example, the polypropylene continuous sheet plate base is formed in a cone shape in case of cone shape diaphragm, a photo resist is coated and the horogram is recorded in place of the film. Thus, excellent design performance is attained.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to an acoustic vibration member used in a speaker or the like.

BACKGROUND ART In general, a vibrating member for acoustic use is required to be lightweight, rigid, have an appropriate internal loss, and have a large ratio of Young's modulus E to density ρ. Paper, synthetic resin, metal, etc. have been used as conventional vibrating members.

A vibrating member made of paper material has a large internal loss and can obtain flat sound pressure frequency characteristics, but on the other hand, because of its low rigidity, it generates split vibration from the low frequency band and deteriorates transient characteristics, distortion characteristics, etc. Furthermore, a diaphragm made of paper material easily absorbs moisture, which causes changes in sound quality, and also tends to cause deterioration of sound quality over time.

Vibrating members made of metal materials have high rigidity but low internal loss, making it difficult to damp high-frequency resonances, so they are used for medium- and high-frequency vibrating members that can drive high-frequency resonances out of the audible frequency range. Even if it is possible, it is not suitable for use as a bass vibration member.

In vibrating members made of synthetic resin materials such as polymeric thermoplastic resins, unstable physical properties do not pose much of a problem during production because they do not absorb moisture and have large internal losses. Also,
Synthetic resin materials had the disadvantage of low rigidity, but recently carbon fiber, carbon graphite,
Products with increased rigidity have also been developed by adding powdered fillers such as mica and whiskers.

However, when these vibrating members containing fillers in synthetic resin are molded using a molding method such as injection molding, vacuum molding, or pressure molding, the surface gloss of the vibrating member may decrease, or the color tone or color may be reduced. There was a problem that some people couldn't get what they wanted. In addition, vibrating members with rich patterns, tones, and colors have been developed using coatings, film laminates, etc., but these have been unsatisfactory due to design constraints.

SUMMARY OF THE INVENTION An object of the present invention is to provide an acoustic vibrating member that supports various images, maintains surface gloss, and has a high degree of freedom in applying colors and the like.

The acoustic vibration member of the present invention is characterized by comprising a plate-like substrate having a hologram pattern surface.

Example Embodiments of the present invention will be described below with reference to the drawings.

(1) A composition containing a plate-like base polymer resin and a scale-like or fibrous filler can be formed into a sheet at a sheet-forming temperature (approximately 230 to 260°C), and can be rolled in several stages. By passing it through a cooling roll, a continuous sheet of plate-like substrate having an arbitrary thickness can be obtained. As the thermoplastic resin, a thermoplastic resin film such as PPXPVCXPET can be used.

(2) Formation of a hologram pattern surface Holography is a technology for recording and reproducing images of objects using holograms, and resin films having surfaces with rich tones and colors have been developed using holograms. A hologram is a recording of interference fringes created by adding a coherent reference beam to diffracted light from an object to cause interference. There are two types of holograms: transmissive and reflective.

Holography is outlined below. When recording a hologram, as shown in FIG. 1, a film 1 coated with photoresist in advance and a subject 2, that is, an object to be recorded, are prepared.

A film 1 and a subject 2 are placed in a predetermined position, and a laser light 4 from a laser light source 3 is irradiated onto the object via an optical system 6 such as a half mirror 5, and an object light 7 is irradiated onto the film at a predetermined angle. Divide 8. The lens 9 in the optical system has a short focal length in order to spread the laser beam.

When the object light is illuminated on the object, the object light 7 is reflected and diffracted by the object and interferes with one of the reference beams 8, and the interference fringes of their wavefronts are recorded on the film surface as an uneven or light and shaded hologram pattern surface. Ru.

When reproducing a hologram, as shown in FIG. 2, when white light 10 is irradiated from the direction of incidence of the reference light during recording, a virtual image 12 or a real image of the subject is generated by the reproduction light 11 reflected by the Bragg beam by the hologram pattern surface of the film 1. A monochromatic image is reproduced (Li ppmann method)
.

In a film having such a hologram pattern surface = 5-, only interference fringes are captured, or when light is applied in this way, an image of the subject is obtained at the original location.

In this embodiment, the hologram is a cone-shaped, dome-shaped, or flat-plate-shaped diaphragm, and therefore, during recording, the reference beam of the laser beam is irradiated at various positions depending on the shape of the diaphragm. In the case of this embodiment, the diaphragm is a diaphragm processed with a hologram using a phase hologram. For example, in the case of a cone-shaped diaphragm, a plate-like substrate made of continuous polypropylene sheet is formed into a cone shape, and if necessary, the surface is cleaned by corona discharge treatment, and a photoresist is applied. It is sufficient to record a hologram (double-dashed line in Fig. 1). When a diaphragm having such a hologram pattern surface is incorporated into a speaker, the positions of the reference light source and the point light source of the reproduction light are set to be varied in consideration of the optimal listening position of the viewer. Normally, in the case of a white light source, about 10
It is better to play it by irradiating it from a range of angles.

The detection results detected in this way are shown in Fig. 2 (
1), and the processing circuit 15 adjusts the amount of change in the phase shifter 7 based on this detection result.
As shown in FIG. 2, the output sound pressure level of each frequency band 11 to f3 is adjusted to be flat. Speaker F is close to the listener, and it is easier to obtain a natural hearing sensation by changing the phase of speaker R than by changing the phase of speaker F. When the adjustment is completed in this way, switch S1 is turned on. By switching to the acoustic signal source 4 side, an acoustic signal whose phase has been changed by the phase shifter 7 in accordance with the acoustic characteristics of the vehicle interior 10 is reproduced from the speaker R.

In this way, even if the playback environment differs depending on the type of car, the number of passengers, etc., deviations in frequency characteristics can be eliminated without feeling the lack of low frequency range as described in connection with the conventional technology section. This allows for good sound reproduction.

Furthermore, as shown in FIG. 2 (3), the phase can be adjusted to obtain frequency characteristics that suit the listener's preferences. In this way, the sound reproducing device 1 according to the present invention can correspond to various acoustic characteristics of the vehicle interior 10, but it can be installed in a wide range of vehicles depending on the type of vehicle. Limited to genuine products that are incorporated at the manufacturing stage and are standard equipment, additional equipment can be added after manufacturing. Furthermore, as mentioned above, it is used in a so-called 3D system, which is limited to placing left and right channel speakers in the front and rear of the vehicle compartment 1o, and the same effect can be obtained even when the woofer phase is changed. Obtainable.

Effects of the Invention As described above, according to the present invention, the output of the noise generation circuit that generates at least 5 bass frequencies is given to the speakers that are not divided into two groups, the first and second groups, and the reproduction is performed. The sound is collected by a microphone placed at the listening position,
Since the phase of the acoustic signal reproduced from the speaker of the second croup is changed and adjusted according to the level of the bass range, it is possible to adjust the phase of the acoustic signal reproduced from the speaker of the second croup.
Mutual interference between the sounds reproduced by the speakers can be suppressed, and deviations in the frequency characteristics of the reproduction environment can be suppressed, or the frequency characteristics desired by the listener can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a sound reproduction device 1 according to an embodiment of the present invention, and FIG. 2 is a graph showing the frequency characteristics of the sound pressure level in the vehicle interior 10 due to phase changes. 1 sound reproduction device, 4... acoustic signal source, 5..., noise generation circuit, 6, 8 power amplifier, 7 phase shifter, 10
Cabin, 11 Driver's seat, 12-・Micro Bonn, 14...
- Band pass filter, 15... processing circuit, F. R.Speaker, Sl Changeover Switch Agent Patent Attorney Number of Strokes Table 1 It can be seen that compared to Comparative Examples 1 and 2 in Table 1, Example Works to 3 show almost no deterioration in physical properties. In addition, looking at what was molded on the diaphragm and center cap, Examples 1 to 3 had hologram processing, so
An image that could be mistaken for the real thing was obtained. Furthermore, it was found that by applying light and by vibrating the diaphragm and center cap, the image of the creature changes slightly. Also, by using any subject,
I was able to obtain various images. From the above, this example has
It is possible to obtain an acoustic vibrating member that does not deteriorate its physical properties and has an unprecedented appearance and design. Next, using the diaphragm and center cap of Example 1, an electrodynamic cone-shaped speaker (woofer) having an 8-inch diameter as shown in the cross-sectional view of FIG. 4, which is an electroacoustic transducer, was manufactured. In this electrodynamic speaker, the back plate 2
A pole piece 22 is placed on the center of the pole piece 1, and a magnet 23 is placed on the periphery of the pole piece 22. plate 24
is placed on the magnet 23 and forms a magnetic gap with the pole piece 22. A voice coil bobbin 26 having a voice coil 25 wound thereon is inserted into the magnetic gap so as to be able to freely vibrate, and the voice coil bobbin 26 is supported by a damper 27. A cone-shaped diaphragm 28 is coupled to the voice coil bobbin 27 at its center, and a center cap 2 is attached to the end of the cone-shaped diaphragm 28.
9 is crowned. The periphery of the opening of the diaphragm 28 is supported by a frame 31 via an edge 30. Edge 3
0 is further fixed to the frame 31 by a gasket 32. Note that the lead wire of the voice coil 25 is connected to a terminal 34 provided on the side surface of the frame 31 via a tinsel wire 33. The speaker assembled using the diaphragm of this example had a sound pressure frequency characteristic that had no peaks, had a wide band, and was flat, as shown in FIG. Effects of the Invention According to the present invention, by performing hologram processing, it is possible to make any three-dimensional image, laminated image, or planar image appear on a flat surface as it is, and by molding it into an acoustic vibration member, the appearance and design can be improved. An excellent acoustic vibration member never seen before can be obtained. 3 is a partially enlarged sectional view of a diaphragm according to the present invention; FIG. 4 is a sectional view of a speaker using a diaphragm according to the present invention; FIG. 1 is a frequency characteristic diagram of a speaker using a diaphragm according to the present invention. Explanation of symbols of main parts 1 - Synthetic resin 2... Filler 21 - Back plate 22... Pole piece 23... Magnet 24... Plate 25... Voice coil 26 ... Voice coil bobbin 27 ... Damper 28 ... Cone-shaped diaphragm 29 ... Center cap 30 ... Edge 31 ... Frame 32 ... ... Gasket 33 ... Tinsel wire applicant Pioneer Corporation

Claims (4)

[Claims] (1) An acoustic vibration member comprising a plate-like substrate having a hologram pattern surface. (2) The acoustic vibration member according to claim 1, wherein the plate-like substrate is made of a polymeric resin. (3) The acoustic vibration member according to claim 2, wherein solid particles having a fine shape are filled in the polymer resin. (4) The vibrating member according to any one of claims 1 to 3, wherein the plate-like base has a thickness of 20 μm to 100 mm.