JP2006179071A - Dvd recorder and video audio reproducing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To change the rotational speed of a fan based on the level of audio information without incurring increase in hardware. <P>SOLUTION: A video audio reproducing means 6 which reproduces video audio information recorded on a video audio recording medium 20 and extends and outputs audio information obtained by applying a prescribed process to the reproduced video audio information, a spectrum analysis section 17 which analyzes the spectrum of the audio information, a fan 13 which cools inside a casing and a fan control means 18 which changes the rotational speed of the fan based on the level of the sound volume of the audio information, are included, and a decoder section 15 and the spectrum analysis section 17 are formed so as to be integrated into a signal processing IC3, wherein the fan control means 18 assumes the level of the spectrum analyzed by the spectrum analysis section 17 as the level of the sound volume so as to change the rotational speed of the fan 13. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a DVD recorder and a video / audio reproduction device that control the rotation speed of a fan based on a volume level, and more particularly, a DVD recorder that determines a volume level based on a spectrum analysis result of reproduced audio information. The present invention also relates to a video / audio reproduction device.

  In an audio apparatus such as a DVD recorder, since heat tends to be trapped inside the housing, a configuration in which the inside is cooled using a fan is employed. However, the fan rotation sound becomes annoying, so when the DVD rotation stops, the fan rotation speed is slowed down, or the temperature inside the housing is detected, and the rotation speed is controlled according to the detected temperature. However, since it cannot be said that the control is optimal from the viewpoint of hearing, the following technique has been proposed (referred to as the first conventional technique). That is, in this technique, two types of modes, a silent mode and a normal mode, are prepared. In normal mode, the fan is always rotated. In silent mode, the fan is rotated or stopped based on the volume (adjusted volume) of the analog audio signal whose level is adjusted by the electronic volume. is doing.

  That is, when the silent mode is set, the volume of the analog audio signal set in advance (hereinafter referred to as the set volume) is compared with the adjusted volume. When the adjustment volume becomes larger than the set volume, the fan rotation sound does not become annoying, so the fan is rotated to cool the inside of the housing. However, when the adjustment volume is smaller than the moderation volume, the rotation sound of the fan tends to be annoying, so the rotation of the fan is stopped. Furthermore, providing a temperature sensor is also disclosed. When controlling the fan to rotate, the rotational speed of the fan is increased when the temperature detected by the temperature sensor is high, and the rotational speed of the fan is decreased when the detected temperature is low. (For example, refer to Patent Document 1).

Further, the following technique has been proposed (referred to as a second conventional technique). That is, this technology includes a mini-disc unit for reproducing a mini-disc and a compact disc unit for reproducing a CD, and a preamplifier unit attenuator using a central processing unit based on an instruction input by a user to an operator. This is applied to a car audio device that sets the sound volume to a user's desired value by controlling the attenuation rate of the sound. That is, the present invention is applied to a configuration in which the set value of the volume is always known to the central processing unit. The rotation speed of the fan that cools the apparatus is set to the highest speed when the set value of the sound volume exceeds a predetermined value, and is set to the medium speed when the set value of the sound volume is equal to or lower than the predetermined value. When both the mini disc unit and the compact disc unit are in a standby state where playback is stopped, the rotational speed of the fan is set to the slowest speed. Therefore, even when the sound is not output from the speaker and the standby state where the sound of the fan is most audible is entered, the rotating sound of the fan is prevented from becoming annoying. In addition, the reference value that serves as a reference for switching between a high speed and a medium speed of the fan differs depending on the type of sound source of the audio signal when different values are set according to the type of sound source. It has also been disclosed that the rotational speed of the fan can be controlled with higher accuracy corresponding to the average level (see, for example, Patent Document 2).
JP 2003-224990 A JP 2004-120268 A

  However, when the first prior art is used, the following problems occur. In other words, additional hardware is required to detect the volume of the analog audio signal whose level is adjusted by the electronic volume. That is, for example, as shown in FIG. 5, in order to amplify the level of the audio signal output to the outside of the apparatus main body and send it to the microcomputer 95, an amplifier circuit 94 having a low-pass characteristic is required. That is, four elements of the OP amplifier 93, the two resistors R8 and R9, and the capacitor C9 are required. Therefore, the scale of hardware is increased. Further, the audio characteristic may be deteriorated due to the influence of the amplifier circuit 94 connected to the output path of the amplifier 91. In the figure, reference numeral 92 denotes a pin jack for outputting an audio signal to the outside of the apparatus main body, and 91 denotes an amplifier for amplifying the audio signal. The audio signal is sent to the outside without being adjusted by an electronic volume. It has come to be.

  Further, when the second prior art is used, the following problems have occurred. That is, when reproducing a DVD, the level of the audio signal changes greatly from time to time. Therefore, even when the volume setting is high, that is, when the volume is set to increase, the volume actually output from the speaker may be low, or the volume may be set to decrease. In some cases, the volume output from the speaker may increase accordingly. For this reason, when the rotation speed of the fan is controlled based on the set value of the sound volume, the fan may be rotated at a high speed even when the sound volume output from the speaker is small. Was annoying.

  The present invention was devised to solve the above problems, and its purpose is to change the rotation speed of the fan based on the level of audio information reproduced from the DVD without increasing the hardware. The temperature inside the housing can also be reduced when the rotation speed of the fan is changed based on the level of audio information reproduced from the DVD to prevent the fan rotation sound from becoming annoying. Can be made sufficiently low, and even when the level of audio information continues to be low, an excessive rise in temperature inside the housing can be prevented, and the playback sound of a DVD can be reduced. Provided is a DVD recorder capable of preventing the generation of audible discomfort caused by switching of the rotation speed of a fan when a DVD is kept played when not being listened to. Lies in the fact.

  Another object of the present invention is to provide a rotational speed of the fan based on the spectrum level analyzed by the spectrum analysis unit when the decoder unit and the spectrum analysis unit are integrated in the signal processing IC. It is an object of the present invention to provide a video / audio reproduction device capable of changing the rotation speed of a fan based on the level of reproduced audio information without causing an increase in hardware.

  Another object of the present invention is to change the rotation speed of the fan based on the level of the spectrum in the frequency band in which the rotation sound generated by the fan is difficult to hear among the frequency band in which the spectrum is analyzed by the spectrum analysis unit. Provided is a video / audio reproduction device capable of making the temperature inside a housing sufficiently low even when preventing the rotation sound of the fan from becoming annoying by increasing the ratio of the period of rotation at high speed. There is.

  In addition to the above-mentioned purpose, when the temperature detected by the temperature sensor exceeds a preset temperature, the fan rotation speed is increased, so that the sound information level is maintained even when a low level of audio information continues. It is an object of the present invention to provide a video / audio reproducing apparatus capable of preventing an excessive increase in temperature.

  In order to solve the above problems, a DVD recorder according to the present invention reads information recorded on a DVD, and outputs a video / audio information obtained by performing predetermined processing on the information obtained by reading, , A decoder unit that expands audio information included in the video / audio information, a spectrum analysis unit that analyzes the spectrum of the audio information, a fan that cools the inside of the housing, a temperature sensor that detects the temperature inside the housing, and audio Fan control means for changing the rotation speed of the fan based on the volume level of the information is provided, and the decoder unit and the spectrum analysis unit are applied to a DVD recorder integrated in the signal processing IC. When the silent mode is selected from the two modes of the normal mode and the silent mode, the fan control means hears the rotating sound generated by the fan in the frequency band in which the spectrum is analyzed by the spectrum analysis unit. The rotational speed of the fan is changed by regarding the level of the spectrum of the frequency band to be difficult as the volume level, and when the temperature detected by the temperature sensor exceeds a preset temperature, the rotational speed of the fan is increased. When the normal mode is selected from the two modes, the rotational speed of the fan is changed based on the temperature detected by the temperature sensor.

  That is, in most types of signal processing ICs in which the decoder unit is integrated, the spectrum analysis unit is also integrated. Therefore, spectrum analysis can be performed without adding hardware. The analyzed spectrum level indicates the level of reproduced audio information. In addition, when the fan rotation speed is increased when the level of the sound in the band where the fan rotation sound is difficult to hear exceeds a predetermined value, the rotation sound of the fan rotating at high speed is the sound output from the speaker. It is efficiently masked by and does not become harsh. For this reason, the reference level for determining whether or not to perform high-speed rotation can be lowered, and the ratio of the period during which the fan rotates at high speed becomes high. In addition, since the state where the level of audio information is low continues, if the state where the fan rotates at a low speed becomes longer and the temperature inside the housing rises, the fan rotation speed is increased and the inside of the housing is cooled. The In the normal mode, the fan rotation speed does not change even when the level of reproduced audio information changes.

  The video / audio reproduction device according to the present invention has a decoder unit for expanding audio information, and reproduces the video / audio information recorded on the video / audio recording medium, and is obtained by performing predetermined processing on the reproduced video / audio information. Audio / video playback means that decompresses and outputs the audio information, a spectrum analysis unit that analyzes the spectrum of the audio information, a fan that cools the inside of the housing, and the rotation speed of the fan changes based on the volume level of the audio information This is applied to a video / audio reproduction device that includes a fan control unit that integrates a decoder unit and a spectrum analysis unit in a signal processing IC. The fan control means considers the level of the spectrum analyzed by the spectrum analysis unit as the volume level and changes the rotation speed of the fan.

  That is, in most types of signal processing ICs in which the decoder unit is integrated, the spectrum analysis unit is also integrated. Therefore, spectrum analysis can be performed without adding hardware. The analyzed spectrum level indicates the level of reproduced audio information.

  The video / audio reproduction apparatus according to the present invention reproduces the video / audio information recorded on the video / audio recording medium, and expands and outputs the audio information obtained by performing predetermined processing on the reproduced video / audio information. The present invention is applied to a video / audio reproduction device including reproduction means, a fan for cooling the inside of the housing, and fan control means for changing the rotation speed of the fan based on the volume level of audio information. The fan control means includes a spectrum analysis unit that analyzes a spectrum of audio information, and the fan control unit is configured to detect a level of a spectrum in a frequency band that makes it difficult to hear a rotating sound generated by the fan in the frequency band in which the spectrum is analyzed by the spectrum analysis unit. Is considered as the volume level, and the rotational speed of the fan is changed.

  In other words, when the total level of all the frequency bands of voice information exceeds a predetermined value, the control to increase the rotation speed of the fan, even when the level of the frequency band that makes it difficult to hear the sound of the fan is small, A situation occurs in which the fan rotates at a high speed. Therefore, even when the level of the frequency band that makes it difficult to hear the rotation sound of the fan is low, in order to prevent the rotation sound of the fan from being annoying, a level that is a criterion for determining whether to rotate at high speed is set high. Must be set to level. However, when the level of the sound in the frequency band in which the rotation sound of the fan is difficult to hear exceeds a predetermined value, when the rotation speed of the fan is increased, the rotation sound of the fan rotating at high speed is output from the speaker. It is efficiently masked by voice and does not become harsh. For this reason, the reference level for determining whether or not to perform high-speed rotation can be reduced, and the ratio of the period during which the fan rotates at high speed becomes high.

  In addition to the above configuration, a temperature sensor for detecting the temperature inside the housing is provided, and the fan control means increases the rotation speed of the fan when the temperature detected by the temperature sensor exceeds a preset temperature. It has become. That is, since the state where the level of audio information is low continues, if the state where the fan rotates at a low speed becomes long and the temperature inside the casing rises, the rotation speed of the fan is increased and the inside of the casing is cooled. The

  According to the present invention, spectrum analysis can be performed without adding hardware, and the analyzed spectrum level indicates the level of reproduced audio information. In addition, when the fan rotation speed is increased when the level of the sound in the band where the fan rotation sound is difficult to hear exceeds a predetermined value, the rotation sound of the fan rotating at high speed is the sound output from the speaker. It is efficiently masked by and does not become harsh. For this reason, the level used as a criterion for determining whether to perform high-speed rotation can be lowered, and the ratio of the period during which the fan rotates at high speed becomes high. In addition, since the state where the level of audio information is low continues, if the state where the fan rotates at a low speed becomes longer and the temperature inside the housing rises, the fan rotation speed is increased and the inside of the housing is cooled. The In the normal mode, the fan rotation speed does not change even when the level of reproduced audio information changes. Therefore, the rotation speed of the fan can be changed based on the level of audio information reproduced from the DVD without causing an increase in hardware, and the fan can be changed based on the level of audio information reproduced from the DVD. By changing the rotation speed of the fan, the temperature inside the housing can be made sufficiently low and the level of the sound information is low even when the rotation sound of the fan is prevented from becoming annoying When the DVD continues to play, it is possible to prevent an excessive increase in the temperature inside the housing and to keep the DVD playing when not listening to the DVD playback sound. Occurrence of audible discomfort caused by the switching of can be prevented.

  Further, according to the present invention, spectrum analysis can be performed without adding hardware. The analyzed spectrum level indicates the level of reproduced audio information. For this reason, the rotational speed of the fan can be changed based on the level of the audio information without causing an increase in hardware.

  In addition, according to the present invention, when the sound level in a band in which the fan rotation sound is difficult to hear exceeds a predetermined value, the fan rotation speed is increased. Therefore, the rotating sound of the fan rotating at high speed is efficiently masked by the sound output from the speaker, and does not become harsh. As a result, the reference level for determining whether to rotate at high speed can be lowered, so that the ratio of the period during which the fan rotates at high speed becomes high. For this reason, also when preventing the rotation sound of the fan from becoming annoying, the temperature inside the housing can be made sufficiently low.

  Furthermore, since the state where the level of the audio information is low continues, when the state where the fan rotates at a low speed becomes longer and the temperature inside the casing rises, the rotation speed of the fan is increased and the inside of the casing is Since it is cooled, it is possible to prevent an excessive increase in the temperature inside the housing even when the state where the level of audio information is low continues.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram showing an electrical configuration of an embodiment of a disc reproducing apparatus according to the present invention, and specifically shows a DVD recorder.

  In the figure, a tuner unit 1 receives a commercial broadcast of a channel designated by a microcomputer (hereinafter referred to as a microcomputer) 7 and receives an analog video signal (including an analog audio signal) obtained by the reception as A. Output to the / D converter 2. The A / D conversion unit 2 converts the video signal output from the tuner unit 1 into a digital video signal (including a digital audio signal) and outputs it to the signal processing IC 3.

  The disk drive unit 5 includes a pickup, an encoding circuit, a demodulation circuit (not shown), and the like, converts the video / audio information output from the signal processing IC 3 into information for recording, and converts it into a DVD (video / audio recording). Medium) 20. In addition, the information recorded on the DVD 20 is read, and video / audio information obtained by performing predetermined processing on the read information is output to the signal processing IC 3.

  The D / A conversion unit 4 outputs an analog video signal obtained by D / A converting the digital video signal output from the signal processing IC 3 to a television receiver 14 provided outside. Further, an analog audio signal obtained by D / A converting the digital audio signal output from the signal processing IC 3 is output to the television receiver 14.

  The signal processing IC 3 uses the decoder unit 15 to decompress the video information included in the video / audio information output from the disk drive unit 5 using the MPEG2 method. Then, the digital video signal obtained by the decompression process is output to the D / A converter 4. Further, by using the decoder unit 15, the audio information included in the video / audio information is decompressed by the AC3 method. Then, the digital audio signal obtained by the decompression process is output to the D / A converter 4.

  The signal processing IC 3 uses the encoder unit 16 to compress the digital video signal output from the A / D conversion unit 2 using the MPEG2 method (for digital audio signals using the AC3 method), and then perform a predetermined process. The video / audio information is converted into a format and sent to the disk drive unit 5.

  The spectrum analysis unit 17 is a block integrated together with the decoder unit 15 and the encoder unit 16 in the signal processing IC 3. That is, in the signal processing IC 3 in which the decoder unit 15 and the encoder unit 16 are integrated together, in many types, the spectrum analysis unit 17 is also integrated. That is, the spectrum analysis unit 17 is a block that does not need to be additionally provided. Therefore, when the spectrum analysis unit 17 is used to analyze the spectrum of audio information, the number of elements constituting the hardware is not increased as compared with the case where the spectrum analysis is not performed. It is like that.

  The spectrum analysis unit 17 analyzes the spectrum level in each of seven (which may be other numbers) frequency bands for the audio information included in the video / audio information. That is, the spectrum level is analyzed for each of the seven frequency bands divided by the stream separation unit (not shown) for the audio information separated from the video / audio information. The analysis result is stored in a register provided for each frequency band and readable from the microcomputer 7.

  The seven frequency bands in the spectrum analysis unit 17 are specifically the bands shown in FIG. Further, as shown in FIG. 3, the level of each band is analyzed as to which level is divided among the 32 levels.

  The input circuit unit 8 includes a key switch such as a power key provided on the front panel of the apparatus main body (not shown), a light receiving unit that receives an infrared signal transmitted from a remote controller (hereinafter referred to as a remote controller) 9, and the like. An instruction from the user is input. Further, the input instruction from the user is output to the microcomputer 7.

  The temperature sensor 11 is a sensor that detects the internal temperature of the housing, and its output is amplified by the amplifier circuit 10 and then input to the microcomputer 7. The fan 13 cools the inside of the housing by blowing the air inside the housing to the outside. The drive circuit 12 drives the fan 13 with a voltage instructed from the microcomputer 7.

  The microcomputer 7 controls main operations as a DVD recorder. That is, the channel received by the tuner unit 1 is controlled in accordance with a user instruction input to the remote controller 9 or the like. Further, the program received by the tuner unit 1 is recorded on the DVD 20 by controlling the signal processing IC 3 and the disk drive unit 5. Further, by controlling the disk drive unit 5 and the signal processing IC 3, information (information indicating video and audio) recorded on the DVD 20 is reproduced and displayed on the television receiver 14.

  The microcomputer 7 constitutes the fan control means 18 by a part of its functions. The fan control means 18 changes the rotation speed of the fan 13 based on the volume level of the audio information in order to prevent the rotation sound of the fan 13 from becoming annoying when the volume output from the speaker is low. . That is, the rotational speed of the fan 13 is changed assuming that the level of the spectrum analyzed by the spectrum analysis unit 17 corresponds to the volume level of the sound output from the speaker.

  Further, when the fan control means 18 indicates that the temperature detected by the temperature sensor 11 has exceeded a predetermined temperature when the fan 13 is rotating at a low speed, the fan control means 18 is due to the high temperature inside the housing. In order to prevent damage to the apparatus, the rotation speed of the fan 13 is increased to lower the temperature inside the housing.

  In the present embodiment, in the initial setting, one of the two modes, the normal mode and the silent mode, can be selected according to preference. When the silent mode is selected, the fan control means 18 controls the rotational speed of the fan 13 by the method described above. However, when the normal mode is selected, the fan control means 18 controls the rotational speed of the fan 13 in accordance with only the temperature detected by the temperature sensor 11 regardless of the volume level.

  As a supplementary explanation, the block 6 including the disk drive unit 5 and the decoder unit 15 is the video / audio reproduction means described in the claims.

  FIG. 4 is a flowchart showing the main operation of the embodiment when the rotational speed of the fan is controlled. The operation of the embodiment will be described with reference to FIG.

  The fan control means 18 rotates the fan 13 at a low speed when the power is turned on. Then, it is checked whether or not the DVD 20 is in a playback state (step S1). When it is in the reproduction state, it is checked whether the mode selected in the initial setting is the silent mode or the normal mode (step S2). When the silent mode is selected, the volume level of the voice information is calculated from the level of the spectrum analyzed by the spectrum analysis unit 17 (step S3). Then, it is checked whether or not the calculated volume level exceeds a predetermined value (step S4).

  When the calculated volume level exceeds a predetermined value, the rotational speed of the fan 13 is increased so that the rotational sound of the fan 13 is less likely to be annoying (steps S5 and S6). On the other hand, when the calculated volume level does not exceed the predetermined value, the rotation speed of the fan 13 is changed to high speed, and then it is checked whether or not a predetermined period (for example, 10 seconds) has elapsed (steps S5 and S11). . When the predetermined period has not elapsed, the rotation speed of the fan 13 is maintained at a high speed in order to suppress excessive switching of the rotation speed of the fan 13 (steps S12 and S6).

  However, in the determination of step S12, when the predetermined period has elapsed, that is, when the period during which the volume level is lower than the predetermined value continues for 10 seconds, the operation proceeds from step S12 to step S13, and the temperature sensor 11 It is checked whether the temperature detected by (1) exceeds a predetermined value. That is, even if the rotation speed of the fan 13 is reduced, it is checked whether the temperature inside the housing is a temperature that does not cause damage to the apparatus. When the detected temperature does not exceed the predetermined value, the rotation speed of the fan 13 is reduced (steps S14 and S15). However, if it exceeds, if the rotation speed of the fan 13 is reduced, the apparatus may be damaged, and the rotation speed of the fan 13 is increased (steps S14 and S6).

  If it is determined in step S1 that the reproduction state is not established, the fan control means 18 checks whether or not the temperature detected by the temperature sensor 11 exceeds a predetermined value (step S21). When the detected temperature exceeds a predetermined value, the rotation speed of the fan 13 is increased to reduce the temperature inside the housing (steps S22 and S23). However, when the detected temperature does not exceed the predetermined value, the rotation speed of the fan 13 is reduced (steps S22 and S24).

  If it is determined in step S2 that the normal mode is set, the fan control means 18 checks whether or not the temperature detected by the temperature sensor 11 exceeds a predetermined value (step S21). When the detected temperature exceeds a predetermined value, the rotation speed of the fan 13 is increased to reduce the temperature inside the housing (steps S22 and S23). However, when the detected temperature does not exceed the predetermined value, the rotation speed of the fan 13 is reduced (steps S22 and S24).

  Therefore, when the normal mode is selected, the audio reproduced from the DVD 20 can be played even if the television 20 is used in the television receiver 14 while a commercial broadcast is viewed or other devices are used while the DVD 20 is in the reproduction state. Occurrence of a situation in which the rotation speed of the fan 13 is switched corresponding to the volume level of the information (voice information that has not been heard) is avoided. Therefore, it is possible to prevent an unpleasant sensation that the rotating sound of the fan 13 becomes louder or quieter according to the playback sound of the DVD that has not been heard.

  Below, the calculation method of the volume level in step S3 is demonstrated.

  The first calculation method is a method of calculating the sound volume level by equalizing the weights of all levels in the seven frequency bands. Therefore, when this calculation method is used, the calculated volume level indicates the level of the analog audio signal output from the decoder unit 15.

  The second calculation method has a level of a frequency band (for example, band “5” shown in FIG. 2) that makes it difficult to hear the rotation sound of the fan 13 when the fan 13 is rotated at a high speed among the seven frequency bands. This is a method of calculating the volume level by increasing the weighting and decreasing the weighting of the level of the frequency band that has little effect of masking the rotating sound of the fan 13.

  That is, in the control for increasing the rotational speed of the fan 13 (control using the first calculation method) when the total level of all frequency bands of the voice information exceeds a predetermined value, it is difficult to hear the rotational sound of the fan 13. Even when the level of the frequency band to be used is small, a situation occurs in which the fan 13 rotates at a high speed. Therefore, even when the level of the frequency band that makes it difficult to hear the rotation sound of the fan 13 is low, in order to prevent the rotation sound of the fan 13 from becoming annoying, a level serving as a criterion for determining whether to perform high-speed rotation is: Must be set to a high level.

  However, when the sound level of the band in which the rotation sound of the fan 13 is difficult to hear exceeds a predetermined value, when the rotation speed of the fan 13 is increased, the rotation sound of the fan rotating at high speed is output from the speaker. It is efficiently masked by the sound and does not become harsh. For this reason, it is possible to reduce the level serving as a criterion for determining whether to perform high-speed rotation. Therefore, the ratio of the period during which the fan is rotated at a high speed becomes high. For this reason, also when preventing the rotation sound of the fan 13 from becoming annoying, the effect that the temperature inside a housing | casing can be made low enough is acquired.

  Note that the present invention is not limited to the above-described embodiment, and the spectrum analysis unit 17 has been described as being configured to analyze the spectrum by dividing the spectrum into seven frequency bands, but any other number of frequency bands In this case, the spectrum can be analyzed. Further, the number of stages for detecting the level of the spectrum is not limited to 32 stages, but may be other stages.

  Further, the case where the video / audio recording medium is applied to the DVD 20 has been described, but the present invention can be similarly applied to other media such as a hard disk drive (in this case, the disk drive unit 5). Is changed to a hard disk drive).

  Further, the rotation speed of the fan 13 has been described as being configured to switch between two speeds of high speed and low speed, but can be configured to switch to an arbitrary number of speeds such as three speeds.

It is a block diagram which shows the electric constitution of one Embodiment (DVD recorder) of the video / audio reproduction device based on this invention. It is explanatory drawing of the frequency band in which a spectrum is analyzed by a spectrum analysis part. It is explanatory drawing which shows the level division of the spectrum analyzed by a spectrum analysis part. It is a flowchart which shows the main operation | movement of embodiment which controls the rotational speed of a fan. It is explanatory drawing which shows the circuit used for the level detection of the audio | voice signal in a prior art.

Explanation of symbols

3 Signal processing IC
5 Disc drive unit 6 Video / audio reproduction means 11 Temperature sensor 13 Fan 15 Decoder unit 17 Spectrum analysis unit 18 Fan control means 20 DVD (video / audio recording medium)

Claims (4)

A disc drive unit that reads information recorded on a DVD and outputs video and audio information obtained by performing predetermined processing on the information obtained by reading;
A decoder unit for expanding audio information included in the video / audio information;
A spectrum analyzer that analyzes the spectrum of audio information;
A fan that cools the inside of the housing,
A temperature sensor that detects the temperature inside the housing;
Fan control means for changing the rotational speed of the fan based on the volume level of the audio information,
In a DVD recorder in which a decoder unit and a spectrum analysis unit are integrated in a signal processing IC,
The fan control means makes it difficult to hear the rotating sound generated by the fan in the frequency band in which the spectrum is analyzed by the spectrum analysis unit when the silent mode is selected from the two modes of the normal mode and the silent mode. The frequency of the spectrum in the frequency band is regarded as the volume level, and the rotation speed of the fan is changed. When the temperature detected by the temperature sensor exceeds a preset temperature, the rotation speed of the fan is increased, and the two modes A DVD recorder characterized in that when the normal mode is selected, the rotational speed of the fan is changed based on the temperature detected by the temperature sensor. A video / audio unit having a decoder unit for expanding audio information, reproducing the video / audio information recorded on the video / audio recording medium, and expanding and outputting the audio information obtained by predetermined processing of the reproduced video / audio information Reproduction means;
A spectrum analyzer that analyzes the spectrum of audio information;
A fan that cools the inside of the housing,
Fan control means for changing the rotational speed of the fan based on the volume level of the audio information,
In a video / audio reproduction device in which a decoder unit and a spectrum analysis unit are integrated in a signal processing IC,
The fan control means considers the level of the spectrum analyzed by the spectrum analysis unit as the volume level and changes the rotation speed of the fan. Video and audio reproduction means for reproducing the video and audio information recorded on the video and audio recording medium, and expanding and outputting the audio information obtained by performing predetermined processing on the reproduced video and audio information;
A fan that cools the inside of the housing,
In a video / audio reproduction device comprising fan control means for changing the rotational speed of a fan based on a volume level of audio information,
It has a spectrum analyzer that analyzes the spectrum of audio information,
The fan control means changes the rotation speed of the fan by regarding the level of the spectrum in the frequency band that makes it difficult to hear the rotation sound generated by the fan out of the frequency band in which the spectrum is analyzed by the spectrum analysis unit as the volume level. A video / audio reproduction device characterized by the above. It has a temperature sensor that detects the temperature inside the housing,
4. The video / audio reproduction device according to claim 2, wherein the fan control means increases the rotational speed of the fan when the temperature detected by the temperature sensor exceeds a preset temperature.

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