JPH03283799A - On-vehicle acoustic equipment - Google Patents

Abstract

PURPOSE:To obtain an optimum directivity in matching with number of passengers, their seat position or property of a music to be listened to by utilizing an acoustic diffraction device so as to adjust the directivity of a radiation sound from a speaker in matching with the number of passengers and their seat position in the cabin. CONSTITUTION:A position command section 9 gives an object position of a moving reflector 4 to a servo control section 8. Plural kinds of position combination patterns as to the moving reflector of left and right channel acoustic diffraction device are preset to the position command section 9. When a selector switch 10 selects any of preset reflector positions, a relevant object position signal is inputted from the position command section 9 to the servo control section 8, which applies servo control to a motor 6 so as to make the moving reflector 4 coincident with the object position. Thus, the optimum directivity is obtained in matching with number of passengers, their seat position and property of a music.

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to a vehicle audio device generally referred to as a car stereo, and in particular to a technology for adjusting the characteristics of a reproduced sound field by changing the directional characteristics of speakers. Regarding.

(Prior Art) The narrow space inside a car cannot be said to be a good quality sound field for reproducing music with a rich sense of presence and good sound quality.

In recent multi-speaker systems, a large number of speakers are installed in the front, sides, and rear of the vehicle interior, but because a large number of speakers and listeners are placed in a small space, the distance between them is very short,
The positional relationship with each speaker changes significantly depending on the position of the listener, that is, the seating position of the passenger. Furthermore, the propagation characteristics of sound in the vehicle interior change dramatically depending on whether there is one occupant or a large number of occupants.

(Problems to be Solved by the Invention) In conventional vehicle audio equipment, the volume ratio of each speaker in a multi-speaker system can be freely adjusted, and the frequency characteristics can be freely adjusted using an equalizer.
The sound field characteristics can be corrected by adjusting the sound field according to changes in the number of listeners and seating positions.

However, the conventional device does not have an adjustment mechanism for changing the directivity characteristics of the sound radiated from the speaker, and is extremely inadequate in that respect. For example, when a driver is listening alone, radiating sound from the rear speakers toward the front provides a stereophonic effect with better localization. However, if a person sits in the rear seat with these directivity characteristics intact, the sound from the rear speakers will directly reach the rear passenger's ears, making the noisy area louder. It is easier for passengers in the rear seats to hear the sound from the rear speakers if it is emitted upwards. In conventional devices, the placement of speakers is determined so that these characteristics are moderate.

This invention was made in view of the above-mentioned conventional problems, and its purpose is to use acoustic diffraction mechanisms such as acoustic reflectors and acoustic lenses to adjust the number of occupants in the vehicle and their seating positions. An object of the present invention is to provide a vehicle acoustic device that can adjust the directional characteristics of radiated sound.

(Means for Solving the Problems) A vehicle acoustic device according to the present invention includes an acoustic diffraction device that is installed in front of a speaker installed in a vehicle interior, and includes a movable part that changes the directional characteristics of sound radiated from the speaker. mechanism and
an actuator for driving and displacing the movable part of the acoustic diffraction mechanism; a control means for controlling the actuator to displace the movable part and positioning it at a desired position; Position command means is provided for commanding the control means to position the movable portion at a commanded position.

(Function) For example, when a switch or the like is operated to generate the selection input signal, a signal specifying a position is applied from the position command means to the control means, and in response, the control means controls the actuator. The movable part of the sound intervening mechanism is positioned at the commanded position.

(Embodiment) FIG. 1 shows the main structure of a vehicle acoustic device according to an embodiment of the present invention. In the figure, 2 is a speaker mounted on the rear tray 1 facing upward, and although only one is shown in the figure, two left and right channel speakers are mounted on the rear tray 1. A diffraction mechanism is attached.

Reference numeral 3 denotes a fixed reflector, and the speaker 2 is attached to the rear tray L with screws or the like at a slightly rearward position, and is installed at an angle to the front band, and has the effect of diffracting the sound radiated from the speaker 2 forward. Fulfill.

A movable reflector 4 is attached to the side end of the fixed reflector 3 via a hinge shaft 5 so as to be rotatable as shown by the arrow. This movable reflector 4 also has the function of diffracting the radiated sound from the speaker 2, but the direction of diffraction of the radiated sound changes depending on the rotational position of the movable reflector 4.

That is, by changing the angle of the movable reflector 4, the substantial directivity characteristics of the sound radiated from the speaker 2 can be changed.

The hinge shaft 5 is interlocked and connected to the motor 6 as the actuator via a reduction gear or the like, and the rotation of the motor 6 drives the movable reflector 4 through the hinge shaft 5 to rotationally displace it. .

The motor 6 is attached with a position detector 7 such as a contact mechanism for position detection or a rotary encoder. The servo control unit 8 controls the rotation of the motor 6 using the output signal of the position detector 7 as a position feedback signal, and positions the movable reflector 4 at an arbitrary position.

A position command section 9 gives a command signal for the target position of the movable reflector 4 to the servo control section 8 . In the position command unit 9, a plurality of types of position combination patterns are preset for the movable reflectors of the acoustic diffraction mechanisms of the left and right channels. In other words, the position of the movable reflector 4 for a single driver, the position of the reflector for the passenger seat, the position of the reflector for the second row passenger, the position of the reflector for the passenger of the third row, or for reproducing a sound field with sharp localization. There are preset settings such as the position of the flap lever and the position of the flap flap for playing a soft mood sound field. When any one of these preset or flapper positions is selected with the selection switch 10, the corresponding target position signal is sent from the position command section 9 to the servo control section 8.
is input, and the servo control section 8 servo-controls the motor 6 to align the movable reflector 4 with the target position.

Next, the configuration of a second embodiment of the present invention will be described.

In the embodiment described above, the configuration is such that the flapper position is preset by the selection switch 1o or manually selected.

In the second embodiment, for example, in a car with 3 rows of seats p and a capacity of 7 people, detectors are provided to detect whether or not a person is sitting in the seating position of each seat, and these detectors can be used to determine the number of occupants in the vehicle interior. and detect the seating position. The number of occupants in the vehicle interior and their seating positions are classified in advance into several patterns, and the pattern classification information is configured to act on the position command section 9 in the same manner as the selection switch 10. In other words, the target position of the reflector is automatically determined according to the number of occupants in the vehicle interior and the seating position pattern, and the target position is input from the position command unit 9 to the servo control unit 8, and the movable reflector 4 is moved to that position. Positioned. In this way, the movable reflector 4 is automatically adjusted to an appropriate reflector position in accordance with the number of occupants and their seating positions, without the occupants being aware of the adjustment operation of the movable reflector 4 at all.

For example, in the case of only front seat occupants, the angle between the fixed reflector 3 and the movable reflector 4 on the front side is made small. This spreads the sound uniformly only in the direction of the left and right passengers in the front seats, reduces the propagation to the door glass, etc., and eliminates unnecessary interference due to glass reflection. Furthermore, since the main sound path lengths of the left and right speakers are approximately equal for front seat occupants, sound image localization with a stereo effect is possible.

Furthermore, if there are passengers in the rear seats, the angle formed by the front sides of both reflectors is increased. Then, the right speaker will strongly diffuse the sound to the left, and the left speaker will strongly diffuse the sound to the right.
Not only does the rear passenger feel less noisy due to direct sound from the speakers, but the left and right sound levels are approximately equal.

(Effects of the Invention) As explained in detail above, according to the present invention, the characteristics of the sound field in a narrow space inside a car can be adjusted by changing the directional characteristics of the sound radiated from the speakers, and the number of occupants can be adjusted. You can obtain the optimal directional characteristics according to your listening position, seating position, or the nature of the music you are listening to. Furthermore, since the acoustic diffraction mechanism for changing the directivity characteristics is remotely controlled, operation is extremely simple. In addition, by presetting several combinations of the positions of the acoustic diffraction mechanisms for the left and right speakers, and selecting one, appropriate adjustments can be easily made.

[Brief explanation of drawings]

FIG. 1 is a block diagram of the main parts of a vehicle audio system according to an embodiment of the present invention. 1... Rear tray 3... Fixed reflector 5... Hinge shaft 7... Position detector 9... Position command unit 2... ... Speaker 4 ... Movable reflector 6 ... Motor 8 ... Servo control section 10 ... Selection switch

Claims (2)

[Claims] (1) An acoustic diffraction mechanism that is installed on the front side of a speaker installed in the vehicle interior and includes a movable part that changes the directional characteristics of the sound radiated from the speaker, and a displacement by driving the movable part of this acoustic diffraction mechanism. an actuator that controls the actuator to displace the movable part and position it at an arbitrary position; and a control means that controls the actuator to displace the movable part and position it at a desired position, and a command signal corresponding to a selection input signal is given to the control means to move the movable part to the commanded position. A vehicle acoustic device comprising: a position command means for positioning the vehicle; (2) The vehicle includes means for detecting the number of occupants and their seating positions in the vehicle, and the selection input signal is automatically generated in response to information detected by the means. vehicle sound equipment.