JP3444837B2 - Audio equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an audio device having an anti-heat protection device for protecting the device when the temperature inside the audio device rises above a predetermined temperature, and particularly to the inconvenience felt by the user due to the operation of the anti-heat protection device. The present invention relates to an audio device with less feeling or discomfort.

[0002]

2. Description of the Related Art In an audio apparatus such as an optical disk reproducing apparatus, heat generated from a heat generating section such as an output amplifier circuit affects the operation of the apparatus when the acoustic output is large, and in extreme cases, the audio apparatus itself is damaged. Sometimes. For example, the heat from the amplifier makes it impossible to guarantee the accurate operation of the signal processing IC and the control microprocessor (hereinafter also referred to as MPU), which makes the rotational drive of the spindle motor unstable and outputs the sound from the speaker. Sound may deteriorate. In particular, in an audio device mounted on a vehicle, the temperature of the environment in which the audio device is used is likely to be high due to the outside air or heat generated by the engine, and it is an important subject to protect the audio device from heat.

In order to solve the problems such as the destruction of semiconductor elements due to heat, the deterioration of signals, and the unstable rotation of a motor, in a conventional audio device, a temperature detecting element is provided in the audio device to detect the temperature. The "HEAT" state, which is a state in which the operation of the audio device is immediately stopped when the temperature rises above the allowable value (predetermined value), is set. Further, even when the detected temperature falls from the high temperature to the allowable value or less, the "HEAT" state is immediately released and the reproduction state is set.

In the above-described conventional heat protection device for an audio device, when the temperature inside the audio device becomes lower than the allowable value, the reproduction state is immediately set, and when the temperature becomes higher than the allowable value, immediately.
The problem that the operation of the audio device becomes unstable because the switching between the reproduction state and the "HEAT" state is frequently repeated near the allowable temperature because the HEAT "state, that is, the operating state of the heat protection device is entered. was there.

For this reason, even in the conventional anti-heat protection device for audio equipment, after the temperature exceeds a permissible value, a "HEAT" state (operating state of the anti-heat protection device) is set after a lapse of a predetermined time. Output is stopped, the reproduced sound can be output after a predetermined time elapses when the temperature in the audio device becomes equal to or lower than the allowable value (predetermined value), and the reproduction state and the "HEAT" state are prevented from being frequently repeated. Such technology has also been proposed.

[0006]

However, in the conventional heat protection device for an audio device, when the detected temperature detected in the audio device is equal to or higher than a permissible value, the "HEAT" state is set and the acoustic output is stopped to detect the detected temperature. When the temperature is below the allowable value, the "HEAT" state is released and the sound is output with the previous volume position. Therefore, the "HEA
In the T "state, you cannot listen to music at all,
The "HEAT" state is released from the silent state in the operation stop state at a point not intended by the user, and a loud sound is suddenly output from the speaker. As described above, while the anti-heat protection device is in operation, the user feels inconvenienced by the inconvenience that no sound is output and the sudden loud sound, which may cause an accident when the vehicle is being driven.

The present invention has been made in view of the above problems, and an object thereof is to provide an audio device in which the inconvenience or discomfort felt by the user due to the operation of the heat protection device is reduced.

[0008]

The digital television broadcast receiving apparatus of the present invention has been made to solve the above-mentioned problems. The first invention is an electronic device for controlling the amplification degree according to a control signal. In an audio device including an acoustic signal amplifier having a volume and an output amplifier circuit that amplifies an output of the acoustic signal amplifier and supplies the output to a speaker, the internal temperature of the audio device is detected, and the detected temperature is a predetermined value. The audio device is configured to reduce the amplification degree of the acoustic signal amplifier to a predetermined value larger than zero when the temperature is kept above the temperature for a first time.

According to the audio device of the present invention, when the temperature inside the device is kept above the predetermined temperature for a predetermined time and the anti-heat protection device is activated, the amplification degree of the acoustic signal amplifier is set to zero. By lowering the temperature to a large predetermined value and setting the protection state against heat, the protection state and the protection release state are frequently repeated in the vicinity of the predetermined temperature (allowable temperature), and the operation of the audio device becomes unstable. Can be prevented. Even when the heat protection device is activated, the amplification of the acoustic signal amplifier does not become zero and the acoustic output from the speaker is not stopped, so the user can continue to obtain acoustic information from the speaker. In addition, since the change in the sound output between the protected state and the unprotected state can be reduced, the shock to the user when switching between the two states can be reduced.

The second invention comprises an acoustic signal amplifier having an electronic volume for controlling the amplification degree according to a control signal, and an output amplifier circuit for amplifying the output of the acoustic signal amplifier and giving it to the speaker. In the audio device, the internal temperature of the audio device is detected, and when the detected temperature is equal to or higher than a predetermined temperature for a first time, the output of the output amplifier circuit is limited to a predetermined value larger than zero. After that, when the detected temperature is equal to or lower than the predetermined temperature for the second time, the audio device is configured to release the restriction.

According to the audio device of the present invention, the output of the output amplifier circuit is generated when the temperature inside the audio device is equal to or higher than the predetermined temperature for the first time and the thermal protection device is activated. To a predetermined value greater than zero,
When the detected temperature is equal to or lower than the predetermined temperature for the second time, the protection state and the protection release state are frequently repeated near the predetermined temperature (allowable temperature) by releasing the restriction. As a result, it is possible to prevent the operation of the audio device from becoming unstable. Even when the anti-heat protection device is activated, signals that do not contribute significantly to heat generation, that is, acoustic signals with small amplitude, are output without being affected by the anti-heat protection device, and only large-amplitude signal parts are output. Can be influenced, so that the user can continuously obtain sound information of a certain volume from the speaker, and the change in sound output between the protected state and the unprotected state can be reduced. Two
It is possible to reduce the shock received by the user when switching the state.

According to a third aspect of the present invention, in the audio device according to the first or second aspect, when the detected temperature is equal to or higher than a predetermined temperature for a first time, the electronic volume controls the When the amplification degree of the acoustic signal amplifier is lowered to a predetermined value larger than a predetermined zero value, and then the detected temperature is equal to or lower than the predetermined temperature for a second time, the amplification degree of the acoustic signal amplifier is changed to the original value. It is an audio device that is set back to the value.

In the audio device of the present invention, the position of the electronic volume, that is, the amplification degree of the acoustic signal amplifier, which is set during the operation of the heat protection device, is predetermined, and unless an abnormal acoustic signal is input, the device is controlled. The amplification degree is set so that the internal temperature is sufficiently lower than the allowable temperature. Then, when the operation of the heat protection device is released, the amplification degree is returned to the original level, so that the user does not need to readjust the amplification degree of the acoustic signal amplifier even after the operation of the heat protection device.

In a fourth aspect of the present invention, in the audio device of the first aspect, when the detected temperature is equal to or higher than a predetermined temperature for a first time, the electronic volume controls the amplification of the acoustic signal amplifier. Audio device that reduces the amplification degree of the acoustic signal amplifier to the predetermined value even after the detected temperature is lower than the predetermined temperature for a second time. Is.

According to the audio device of the present invention, if the signal sources input to the acoustic signal amplifier are the same, the temperature inside the audio device is maintained even after the thermal protection device has been activated and released. The effect is that the temperature is maintained within the allowable predetermined temperature.

In a fifth aspect of the present invention, in the audio device of the first or second aspect, when the detected temperature is equal to or higher than a predetermined temperature for a first time, the output amplifier circuit An audio device, wherein a dynamic range is limited to a predetermined value, and when the detected temperature is equal to or lower than the predetermined temperature for a second time, the dynamic range limitation is released.

According to the audio device of the present invention, even when the heat protection device is in the operating state, signals that do not significantly contribute to heat generation, that is, acoustic signals having a small amplitude, are affected by the heat protection device. Since the sound information is output without being supplied, the user can continuously obtain the sound information from the speaker, and the change in the sound output between the protected state and the unprotected state can be reduced, so that the user receives the information when switching between the two states. Shock can be reduced.

According to a sixth aspect of the invention, in the audio device of the fifth aspect, when the detected temperature is equal to or higher than a predetermined temperature for a first time, the average amplitude of the acoustic signal in the acoustic signal amplifier is increased. Is measured for a predetermined period, and within a range where the measured value is equal to or larger than the predetermined value, the amplification degree of the acoustic signal amplifier is reduced as the measured value increases.

According to the audio device of the present invention, when the heat protection device is in the operating state, the sound output is not affected by the heat protection device when the amplitude of the sound signal is within a predetermined value. , In the range where the amplitude of the acoustic signal is equal to or more than a predetermined value, the amplification degree of the acoustic signal amplifier is reduced and the acoustic output is reduced, but the signal waveform of the acoustic signal does not change, so distortion caused by the heat protection device occurs. The effect of not doing.

A seventh aspect of the invention is the audio device according to the first or second aspect of the invention, wherein when the detected temperature is equal to or higher than a predetermined temperature for a first time, the electronic volume controls the The amplification degree of the acoustic signal amplifier is reduced to a predetermined value larger than a predetermined zero, and the dynamic range in the acoustic signal amplifier is limited to a predetermined value, and then the detected temperature is equal to or lower than the predetermined temperature. In the audio device, the amplification degree is maintained at the predetermined value when the second time is continued, and the dynamic range limitation is released.

According to the audio device of the present invention, once the thermal protection device is activated and deactivated, the limitation of the dynamic range is released and the amplification degree of the acoustic signal amplifier is kept lowered. Thus, while the sound that does not suppress the dynamic range is output, the position of the electronic volume, that is, the amplification degree of the acoustic signal amplifier can be set to the amplification degree that is unlikely to activate the heat protection device again.

An eighth aspect of the present invention is the audio apparatus of the first aspect, wherein when the detected temperature is equal to or higher than a predetermined temperature for a first time, the amplification degree of the acoustic signal amplifier is set to zero. The audio apparatus is capable of setting the amplification degree of the acoustic signal amplifier to be set between zero and the predetermined value after the value is lowered to a large predetermined value.

According to the audio device of the present invention, it is possible to adjust the volume of the speaker output even while the heat protection device is operating.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION The audio device of the present invention controls the amplification degree of the acoustic signal amplifier when the internal temperature of the audio device is equal to or higher than a predetermined temperature (allowable temperature) for a first time. An audio device that activates the thermal protection device by lowering it to a predetermined value greater than zero. The position of the electronic volume that determines the amplification degree of the acoustic signal amplifier in the operating state of the heat protection device is predetermined, and unless the abnormal acoustic signal is input, the temperature inside the device is sufficiently lower than the allowable temperature. The amplification degree is set as follows. However, the sound output from the speaker continues without being stopped even while the heat protection device is operating.

Further, in the audio device of the present invention, when the temperature inside the audio device is equal to or higher than a predetermined temperature (allowable temperature) for the first time, the output of the output amplifier circuit is set to a predetermined value. The audio device is restricted, and thereafter, when the detected temperature is equal to or lower than the predetermined temperature for a second time, the restriction is released. As a method of limiting the output of the output amplifier circuit by a predetermined value, a method of reducing the amplification degree of the acoustic signal amplifier to reduce the amplitude of the acoustic signal, and a method of limiting the output of the acoustic signal with a large amplitude to obtain a dynamic range (Hereafter, D
(Also referred to as range) and a method of mixing the above two methods.

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of an audio device of the present invention. In FIG. 1, the reproducing means 17 is, for example, a reproducing means for reproducing an optical disc, and its output is amplified by the acoustic signal amplifier 19. The acoustic signal amplifier 19 has an electronic volume for controlling the amplification degree of the acoustic signal amplifier by a control signal. The acoustic signal amplified by the acoustic signal amplifier 19 is power-amplified by the output amplifier circuit 21, and the output of the output amplifier circuit 21 drives the speaker 23.

Reference numeral 15 denotes a microprocessor (MPU) for controlling the audio device 10 as a whole, which is composed of a CPU, an input port, an output port, a RAM, a ROM and the like. The MPU 15 has an A timer and a B timer configured by a CPU or the like. The A timer is an audio device 1
The elapsed time after the time when the temperature inside 0 reaches the predetermined temperature (permissible temperature) or more is measured, and the B timer elapses after the time when the temperature inside the audio device 10 reaches the predetermined temperature or below. Time is measured. The measurement by the A timer continues until a predetermined time elapses if the temperature inside the audio device 10 is equal to or higher than a predetermined temperature, and the B timer elapses a predetermined time when the temperature inside the audio device 10 is equal to or lower than a predetermined predetermined temperature. Will continue until.

A command is input to the MPU 15 from the user via the input device 11 or a menu is selected. The temperature detector 13 measures the internal temperature of the audio device 10 and gives the result to the MPU 15. Display 2
Reference numeral 5 is a display device for displaying the operating state of the audio device 10. Based on the display information given from the MPU 15, "HEAT" is displayed to inform the user that the heat protection device is operating. Inform. The MPU 15 gives a control signal P to the reproducing means 17 to control reproduction of the reproducing means 17. The position of the electronic volume 29 that determines the amplification degree of the acoustic signal amplifier 19 is controlled by the MPU 15.

As described above, in the audio device 10, the temperature detector 13 detects the temperature inside the device and supplies the detected temperature to the MPU 15 via the input port. In the MPU 15, the CPU operates according to the program stored in the ROM, controls the operation specified by the key data signal input from the input device 11, and sends the display data to the display 25 through the output port. Then, for example, a display showing a "HEAT" state for notifying an error situation is performed. The CPU stores various data such as a temperature signal given through the input port in the RAM, performs processing according to a processing procedure described later, and then reproduces the data through the output port.
A control signal P is sent to control the start and stop of reproduction of the reproducing means 17, and the control signal V controls the electronic volume 29 to adjust the output of the speaker 23 to an appropriate volume.

FIG. 2 is a flow chart showing a processing procedure for heat protection in the embodiment of the present invention. In the heat protection process shown in FIG. 2, is voice output in operation in step S11? Is asked. In this case, if the output amplifier circuit 21 is in operation, the determination result is Yes, and the process proceeds to step S13 and N
If it is o, the process returns to step S11. In step S13, is the protection flag 1? Is asked. Here, the protection flag is set to 0 at the start of the regenerating operation, and is set to 1 when heat protection is required due to temperature rise. If Yes in step S13, step S
If No, the process proceeds to step S41. In step S41, is the temperature inside the device higher than a predetermined value? If Yes, the process proceeds to step S45, and if No, the process proceeds to step S43. In step S43, the timer A is cleared and the process returns to step S41.

In step S45, is the A timer already counting? If Yes, step S4
If No, the process proceeds to step S47. In step S47, the time counting by the timer A is started, and
Proceed to 49. In step S49, has a predetermined time (for example, 1 minute) elapsed since the timer A started counting? , Yes, the process proceeds to step S51, and if No, the process returns to step S41. In step S51, the MPU sets the electronic volume to a predetermined position, that is, the amplification degree of the acoustic signal amplifier to a predetermined value, and the process proceeds to step S53. In step S53, the dynamic range (D
Range) is limited to a predetermined value or less, and the process proceeds to step S55. In step S55, "HEAT" is displayed on the display 25, and the process proceeds to step S57. In step S57, the protection flag is set to 1 and the process returns to step S13.

At step S15, is the temperature inside the apparatus lower than a predetermined value (allowable temperature)? If Yes, the process proceeds to step S19, and if No, the process proceeds to step S17. In step S17, the B timer is cleared and the process returns to step S15.

In step S19, is the B timer already counting? If Yes, step S2
If No, the process proceeds to step S21. In step S21, time counting by the B timer is started, and then step S
Proceed to 23. In step S23, has a predetermined time (for example, 1 minute) elapsed since the B timer started counting? , Yes, the process proceeds to step S25, and if No, the process returns to step S15. In step S25, the limitation of the D range in the output amplifier circuit 21 is released to restore the original D range, and the process proceeds to step S27. At this time, the position of the electronic volume is not changed.

In step S27, the display 25 displays
The display "HEAT" is erased and the process proceeds to step S29. In step S29, the protection flag is set to 0 and the process proceeds to step S31. In step S31, the B timer is cleared, and the process returns to step S11. In the step S51, a transition is made to the heat protection operation state,
The position of the electronic volume is lowered to a predetermined position in order to reduce the amplification degree of the acoustic signal amplifier 19 to a predetermined amplification degree, and thereafter, the user sets the amplification degree of the acoustic signal amplifier 19 between zero and the predetermined value. , Can be adjusted. Accordingly, the user can adjust the acoustic output output from the speaker 23 even when the heat protection device is in operation.

An example of the D range limiting device in step S53 will be described with reference to FIG. FIG. 3 shows a block diagram of an embodiment in which the D range is within a predetermined value. Elements having the same functions and functions in FIG. 3 and FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted. The audio device 20 shown in FIG. 3 is different from the audio device 10 shown in FIG. 1 in that an amplitude measuring means 27 is provided. The amplitude measuring means 27 measures the amplitude of the output of the acoustic signal amplifier 19 for a predetermined time, and the measurement result is measured directly or by the electronic volume 29.
To the MPU 15 via. The MPU 15 gives a control signal V to the electronic volume 29 so that the maximum amplitude of the output of the acoustic signal amplifier 19 is within a predetermined value.

When the amplification degree of the acoustic signal amplifier 19 suddenly changes, the acoustic signal output from the speaker 23 becomes unnatural, so the MPU gradually changes the position of the electronic volume 29. Although the limitation of the D range can be realized by limiting the maximum amplitude of the acoustic signal applied to the output amplification circuit 21 as described above, the acoustic signal amplifier 1
The amplification degree of 9 may be controlled according to the output of the amplitude measuring means 27.

For example, when the amplitude of the input signal of the acoustic signal amplifier 19 is equal to or larger than a predetermined value, the acoustic signal is given with a characteristic of a logarithmic function such that the output is log (X) with respect to the input X. It is also possible to configure the amplifier 19.
In this case, when the amplitude of the acoustic signal becomes large, the speaker 2
Although the sound output from No. 3 has distortion, it has a characteristic that it is hardly affected by a signal with a small amplitude. The limitation of the D range described above is automatically released when the operation of the heat protection device is released.

The temperature inside the audio device is detected by
For example, it may be carried out by detecting an element having a particularly large temperature rise such as an output transistor, or by detecting the temperature in the vicinity of the element, or particularly by detecting the temperature in the vicinity of the element which is weak to heat, or in this case,
Since the rise and fall of temperature can be detected at high speed, a safer heat protection device can be constructed.

As described above in detail, according to the audio device of the present invention, even if the protection device against heat is activated after the temperature inside the device rises to the allowable temperature, the protection state and the protection release state are frequently repeated. It is possible to prevent the operation of the audio device from becoming unstable. Further, even in the heat protection (heat protection) state, the operation of the output amplifier circuit 21 is not stopped and the amplitude of the acoustic signal is reduced to lower the temperature in the audio device. Even when switching between the two states of release and release, the volume does not change rapidly, and the shock that the user receives due to the rapid change in volume can be reduced. When the user is driving the vehicle, the risk of driving mistakes associated with the shock is reduced.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of an audio device of the present invention.

FIG. 2 is a flowchart showing a processing procedure of heat protection in the embodiment of the present invention.

FIG. 3 is a block diagram of an embodiment in which a D range is within a predetermined value.

[Explanation of symbols]

11 Input device 13 Temperature detector 15 Microprocessor (MPU) 17 Playback means 19 Acoustic signal amplifier 21 Output amplifier circuit 23 speakers 25 indicator 27 Amplitude measuring means 29 electronic volume

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Claims (4)

(57) [Claims] 1. An audio device comprising an acoustic signal amplifier having an electronic volume for controlling an amplification degree according to a control signal, and an output amplifier circuit for amplifying an output of the acoustic signal amplifier and supplying the amplified speaker to a speaker. When the internal temperature of the audio device is detected and the detected temperature is equal to or higher than a predetermined temperature for a first time, the amplification degree of the acoustic signal amplifier is decreased to a predetermined value larger than zero, and When the detected temperature is equal to or higher than a predetermined temperature and continues for a first time, the dynamic range of the output amplifier circuit is limited to a predetermined value, and then the detected temperature is equal to or lower than the predetermined temperature. Some state is second
The audio device, wherein the limitation of the dynamic range is released when the time continues. 2. An audio device comprising an acoustic signal amplifier having an electronic volume for controlling an amplification degree according to a control signal, and an output amplification circuit for amplifying an output of the acoustic signal amplifier and supplying the amplified speaker to a speaker. When the internal temperature of the audio device is detected, and the detected temperature is equal to or higher than a predetermined temperature for a first time, the output of the output amplifier circuit is limited to a predetermined value larger than zero, and thereafter. , when the state wherein the detected temperature is equal to or less than the predetermined temperature continues for the second time, to release the restriction, 且
One, when the state wherein the detected temperature is preset predetermined temperature or higher was continued first time, restricted with predetermined value of the dynamic range of the output amplifier circuit, then the detected temperature is the predetermined temperature An audio device, wherein the dynamic range limitation is released when the following state continues for a second time. 3. The average amplitude of the acoustic signal in the acoustic signal amplifier is measured for a predetermined period when the detected temperature is equal to or higher than a predetermined temperature for a first time, and the measured value is equal to or higher than a predetermined value. 3. The audio device according to claim 1, wherein the amplification degree of the acoustic signal amplifier is reduced as the measured value increases in the range. 4. An audio device comprising: an acoustic signal amplifier having an electronic volume for controlling the amplification degree according to a control signal; and an output amplifier circuit for amplifying the output of the acoustic signal amplifier and giving it to a speaker. When the internal temperature of the audio device is detected, and the detected temperature is equal to or higher than a predetermined temperature for a first time, the amplification of the acoustic signal amplifier is larger than a predetermined zero by the electronic volume. When the state in which the detected temperature is equal to or lower than the predetermined temperature continues for a second time after the dynamic range of the acoustic signal amplifier is reduced to a predetermined value and the dynamic range in the acoustic signal amplifier is limited to a predetermined value. An audio device, wherein the restriction of the dynamic range is released with a predetermined value.