JP3830725B2 - Drive control system for in-vehicle hard disk drive - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present inventionDrive control system for in-vehicle hard disk driveAbout.
[0002]
[Prior art]
Hard disk devices (HDDs) have become widespread as external storage devices for personal computers. However, as the recording density has improved, the price has been reduced, and recently, home appliances with built-in HDDs have emerged. A considerable amount of video and music content can be stored in this HDD, and products using this are appearing one after another. It is expected to be installed in car audio products, and DVDs are currently the mainstream in car navigation systems.
[0003]
A basic structure of the HDD is shown in FIG. Here, a ramp loading type HDD is shown in which the magnetic head 51 disposed at the tip of the actuator 54 is mechanically levitated from the surface of the magnetic disk.
As shown in the figure, the magnetic head 51 attached to the actuator 54 is attached so as to be movable in the radial direction (arrow) of the magnetic disk 53. The magnetic head 51 is attached to the surface of the magnetic disk 53 by the elastic force of the suspension 57. However, the rotation of the magnetic disk 53 is controlled so that the distance from the disk surface of the magnetic disk 53 becomes several tens of μm by the aerodynamic levitation force acting on the magnetic head 51. Further, when not operating, the magnetic head 51 is in a retracted position in a state where the magnetic head 51 rides on a tapered portion 56 of a ramp 55 formed at one end of the housing frame 50.
[0004]
FIG. 10 is a sectional view showing the positional relationship between the magnetic head 51 and the ramp 55. As shown in the figure, the ramp 55 located in the vicinity of the outer peripheral portion of the magnetic disk 53 disk has a tapered portion 56 that is tapered in a direction away from the surface of the magnetic disk 56 disk gradually from the outer peripheral portion to the outer peripheral portion. Have The magnetic head 51 is positioned (position a) at an appropriate interval on the magnetic disk 53 disk when reading information from the magnetic disk 53 or writing information to the magnetic disk 53 (during operation). At the time of non-operation (unloading), as shown by the arrow in the figure, the vehicle gets over the tapered portion 56 and waits at the retracted position (position b).
[0005]
[Problems to be solved by the invention]
Incidentally, a function called emergency unload is added to the HDD. The emergency unload function is to forcibly move the head to the retracted position in order to prevent the magnetic disk 53 from being damaged by the head when both the power sources of the motor for driving the spindle 52 and the magnetic head 51 are down. It is a function. It is known that a power source is required to perform this emergency unloading, but when the power sources are both down as described above, the operation is performed using the counter electromotive force generated by inertial rotation of the spindle motor 52. It has been.
[0006]
When the above-mentioned HDD is applied to a vehicle such as a car audio product or a car navigation system, there is a possibility that a so-called instantaneous interruption may occur when the engine is started. Therefore, there is a high possibility that the emergency unloading described above occurs every time the engine is started. .
[0007]
FIG. 11 shows a power supply line of an on-vehicle audio product.
As shown in FIG. 11, a backup power source (always power source) line to which power is constantly supplied and an accessory (ACC) power source line to which power is supplied in conjunction with a key switch are connected to the in-vehicle audio product. ing.
[0008]
FIG. 12 shows a timing chart of the state of power supply when the engine of the in-vehicle power supply circuit supplied with power via both power lines is started. In this figure, (a) shows a state of power supply of a constant power supply, and (b) shows a state of power supply of ACC. The timings (I), (II), (III), and (IV) in the figure correspond to the position of the key switch of the engine key, respectively. For example, (II) indicates a case where the power is supplied to the power window or the like, and (II) indicates a case where the power is supplied to the power window or the like. The case where the power is supplied is in the “ST position”, and (IV) shows the case where the engine is started and the engine key is returned to the “ON position” again.
[0009]
In such operation, when the engine is started, the power supply voltage on the audio product side may drop (instantaneous interruption) due to the power supply voltage used for starting the engine (period (III) to (IV) in FIG. 12). .
[0010]
As described above, when the HDD described above is applied to a vehicle, there is a possibility that a momentary interruption may occur when the engine is started. Therefore, there is a high possibility that the emergency unload described above occurs every time the engine is started. Emergency unloading uses the back electromotive force of the spindle motor to forcibly move the head as described above, so in the case of in-vehicle products, compared to the case of products such as personal computers that are not used for in-vehicle use. Thus, the chance that the magnetic head 51 collides with the tapered portion 56 of the ramp 55 increases until the magnetic head 51 reaches the standby position b of the ramp 55. That is, in the case of in-vehicle use, the possibility of a momentary disconnection increases every time the engine is started, so the durability due to a collision must be taken into consideration.
[0011]
The present invention has been made in view of the above circumstances, and in a vehicle-mounted HDD, a time measuring unit that performs a time measuring operation based on a predetermined signal related to a key switch of a vehicle is used, and a predetermined time is measured by the time measuring unit. By driving the HDD or flying head slider at the time, the number of occurrences of emergency unloading is reduced, thereby extending the life of the flying head slider and improving the reliability of the HDD. An object is to provide an information recording / reproducing apparatus.
[0012]
[Means for Solving the Problems]
  To solve the above issues,The present inventionFor one thing,A drive control system for an in-vehicle hard disk device, comprising: a head for reading or writing information to a loaded recording medium; and a head driving means for driving the head, and the head driving means is driven by a power supply voltage of the vehicle. A voltage monitoring means for monitoring a power supply voltage of the vehicle;,When the timing operation of the first set time is started based on a signal corresponding to the operation of the engine key of the vehicle, and the power supply voltage is below a set threshold when the first set time is measured And a time movement means for measuring the second set time, and a head movement permission means for allowing the head drive means to move the head after the time of the second set time.It is characterized by that.
[0014]
In addition, the present invention includes a head for reading or writing information on a loaded recording medium, and a head driving means for driving the head, and the head driving means is driven by a vehicle power supply voltage. A drive control system for a hard disk device, comprising: an engine start detection means for detecting engine start by monitoring a power supply voltage value of the vehicle; and a timed operation of a set time based on a signal corresponding to an operation of an engine key of the vehicle And a head movement permission means for permitting movement of the head by detection of the engine start when the engine start detection means is detected within the set time. To do.
[0015]
Further, according to the present invention, in addition to the above-described feature, the time measuring means can detect the second set time when the power supply voltage value is below a set threshold when the first set time is measured. Time measurement is performed, and the head movement permission means permits movement of the head by the head driving means after counting the second set time.
[0016]
According to each of the above configurations, even when the vehicle has no voltage drop at the time of engine start, the engine start can be detected by timer monitoring, and when the voltage drop has occurred, the start of the recording / reproducing apparatus can be accelerated. . By allowing the head to move after this detection time, it is possible to minimize or avoid the occurrence of emergency unload when starting the engine. Accordingly, the number of collisions between the head and the lamp due to a decrease in the chances of emergency unloading is reduced, thereby extending the life of the head and improving the reliability of the in-vehicle HDD.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a block diagram showing a system configuration of a car navigation system equipped with a recording / reproducing apparatus of the present invention. Here, an example is shown in which an HDD is used as a map information storage unit of a car navigation system in place of a DVD. The present invention is not limited to car navigation, and can be applied to all in-car audio products equipped with HDDs. However, as an example, the present invention will be described using car navigation. The recording / reproducing apparatus of the present invention has a host CPU 11 as a control center, ROM 12, RAM 13, timer LSI (14), hard disk device (HDD) 15, sensor unit 16, GPS receiving unit 17, interface 18, input device 19, and display 20. , A display control unit 21, a display memory 22, an audio processing circuit 23, a speaker 24, an in-vehicle power supply circuit 25, a hard disk controller (HDC) 26, and a backup RAM 27.
[0018]
The host CPU 11 performs overall navigation control such as destination search and route guidance based on programs stored in the ROM 12 and RAM 13, and each unit 12, 13, 14, 27, 19, 23 connected to the system bus 10. , 18, 26 and 21 are controlled. The timer LSI 14 has a time count value programmable by the host CPU 11, issues an interrupt when the time is up, and leaves the processing to the interrupt processing routine. Here, the drive timing of the HDD after engine start is specified.
[0019]
The HDD 15 is provided with a measure for preventing emergency unloading according to the present invention, and is connected to the system bus 10 via the HDC 26. The HDC 26 controls the format of the magnetic disk disk loaded in the HDD 15, and also has functions as a host interface and an HDD interface.
The sensor unit 16 refers to sensors necessary for autonomous traveling as a car navigation system, and is, for example, a vehicle speed sensor, a gyro sensor, or the like, and is connected to the system bus 10 via an interface 18. In addition, the output of the GPS receiver 17 is also supplied to the interface 18 to perform hybrid traveling control by GPS positioning and autonomous traveling.
[0020]
The display 20 is composed of a liquid crystal monitor, and processing contents such as map information written in the display memory 22 by the host CPU 11 are read and displayed by the display control unit 21. In relation to the present invention, the map information indicating the position of the vehicle at the time of the previous engine stop, which is written in the backup RAM 27 until the HDD is started after the ACC power is supplied, is displayed. .
[0021]
The input device 19 is a remote controller or a console, and is used as a GUI used for inputting a command or having a conversation with the navigation system via the display 20. The voice processing circuit 23 functions as a GUI for interacting with the navigation system by issuing a voice guide or inputting voice. The voice guide is output via the speaker 24.
Reference numeral 25 denotes an in-vehicle power supply circuit, which is composed of the constant power supply line (a) and the ACC power supply line (b) as described above.
[0022]
  FIG. 2 includes a detailed configuration of the HDD 15 and the in-vehicle power supply circuit 25 in FIG. 1 and an engine start detection device 30 for detecting engine start.Drive control system for in-vehicle hard disk driveFIG. The HDD 15 has a host interface circuit 151, a program memory 153, a data memory 154, an HDD interface circuit 155, an R / W (read / write) circuit 156, a head drive control circuit 157, and a spindle motor control circuit 158 with the HDD built-in CPU 152 as the core. , A magnetic head 51, a voice coil motor (VCM) 160, and a spindle motor 161.
[0023]
The host interface 5, the HDD built-in CPU 152, the program memory 153, the data memory 154, and the HDD interface circuit 155 are commonly connected to the HDD system bus 150.
[0024]
The HDD built-in CPU 152 receives a command (Seek, Read / Write, etc.) from the host CPU 11 shown in FIG. 1 via the host interface circuit 151, and follows the program stored in the program memory 153 via the HDD interface circuit 155. The command is controlled. Data read / written to / from the magnetic disk disk via the magnetic head 51 is controlled by the R / W circuit 156, the drive of the VCM motor 160 is controlled by the head drive control circuit 157, and the spindle motor 161 is driven to rotate. Is controlled by a spindle motor control circuit 158. The spindle motor 161 supplies the head drive control circuit 157 with a back electromotive force generated by inertial rotation of the spindle motor when the power is turned off.
[0025]
The in-vehicle power supply circuit 25 has a backup power supply (always power supply a) that supplies power constantly and an accessory power supply (ACC power supply b) that supplies power in conjunction with the key switch. The engine start detection device 30 includes a voltage value monitoring circuit 301, a threshold setting circuit 302, an engine start detection circuit 303, and sensors 304. The voltage value monitoring circuit 301 monitors each voltage value in the power supply lines 251 and 252 supplied from the two power sources described above, and notifies the engine start detection circuit 303 of the value. A threshold value for detecting an instantaneous interruption is set in the threshold setting circuit 304, and the value is notified to the engine starting circuit. The engine start detection circuit 303 obtains voltage value data from the voltage value monitoring circuit 301 and the threshold value setting circuit 302, detects the engine start timing in accordance with a procedure described later, and supplies a start signal to the HDD.
[0026]
In addition, various sensors 304 are connected to the engine start detection circuit 303 as an option. In this case, a signal serving as a trigger for detecting the engine start timing is received without being monitored by the above-described voltage value monitoring. Judgment by the program is required. Therefore, monitoring and control are performed by program logic using a microcomputer or the like. In this case, as the sensors 304, in addition to the sensor 16 provided as a car navigation system, a tachometer, a vibration sensor, a cell motor, a generator, and the like are conceivable. Details will be described later.
[0027]
The timer LSI (14) has its time count value set by the host CPU (11) in a programmable manner, issues an interrupt when the time is up, and leaves the processing to its interrupt processing routine. Here, the drive timing of the HDD after engine start is specified.
[0028]
Next, the HDD activation timing of the present invention will be described in detail. In this embodiment, when the engine is started, the activation of the HDD is controlled after a predetermined time is counted by a timer, so that the number of occurrences of emergency unloading is reduced.
FIG. 3 is a timing chart quoted for explaining the timing of HDD activation by the timer. 3A shows a voltage waveform in the constant power supply line 251, and FIG. 3B shows a voltage waveform in the ACC power supply line 252. SL (threshold value) indicates a predetermined voltage value, and is, for example, 9 V in this embodiment. This is set so that the voltage value at the time of the instantaneous interruption is lower than this SL when the instantaneous interruption of the vehicle occurs.
[0029]
The driver first inserts the engine key into the LOCK position, releases the LOCK, and turns to the ACC position (I). As a result, the ACC power supply rises and reaches, for example, 12V, and further, the cell starts by turning to the START position (II) via the ON position (II), and the voltages of the constant power supply line 251 and the ACC power supply line 252 are started. Fall together. After a predetermined time has elapsed, the engine is started (IV), and the ACC power supply line 252 and the constant power supply line 251 rise to the original voltage value of 12 V and return to the steady state. Note that the time from the ACC position to the cell start and engine start is random.
[0030]
The driver first inserts the engine key into the LOCK position, releases the LOCK, and turns to the ACC position. As a result, the ACC power supply starts up. Here, timing by the timer LSI 14 is started. Further, the cell starts by turning to the START position via the ON position, and the voltages of the power supply line 251 and the ACC power supply line 252 both fall. After the cell rotates and a predetermined time elapses, the ACC power supply line 252 and the constant power supply line 251 rise in this order and return to a steady state. The time from the ACCON position to the cell start and engine start is random.
[0031]
In the embodiment of the present invention, the timer LSI (14) is pre-programmed with a time count of 5 seconds (time count). The timer LSI (14) starts timing from the ACC position, and from the host CPU 11 when it has counted 5 seconds. An instruction for permitting the HDD 15 to move the magnetic head 51 is issued. That is, in the present embodiment, since there is a possibility that the predetermined threshold value (SL) may not be dropped at the instantaneous interruption portion (A) in the figure, a timer is used to minimize the number of occurrences of emergency unloading.
[0032]
The HDD 15 receives the command signal by the HDD built-in CPU 152, and then controls the magnetic head 51 to be allowed to move according to an instruction from the HDD built-in CPU 152.
[0033]
In the above-described embodiment, a control method that allows movement of the magnetic head 51 after a predetermined time is measured by a timer is employed. However, the HDD is not turned on until the engine is started. It is also possible to configure so that the HDD is turned on after the engine start is detected by the above means.
[0034]
FIG. 4 is a timing chart according to another embodiment cited for explaining the timing of HDD activation by the timer. In this figure, members denoted by the same reference numerals as those in FIG. 2 perform the same operation, and therefore, in the present embodiment, the description thereof is omitted to avoid redundant explanation.
[0035]
Here, when a predetermined time of 5 seconds elapses, the voltage value of the power supply line 251 or the ACC power supply line 252 is constantly monitored, and when the voltage is still below the threshold value (SL), the timer is restarted. The HDD is started after waiting for a predetermined time of 3 seconds.
[0036]
Thus, even if the predetermined time of 5 seconds elapses, if the vehicle engine is not yet started, the HDD 15 is started again after the predetermined time of 3 seconds elapses. It may take time. This operation may be repeated a plurality of times.
[0037]
FIG. 5 and FIG. 6 are embodiments for monitoring the timer and the voltage value of the power supply voltage of the vehicle, and starting the HDD when a predetermined condition is met.
In the embodiment shown in FIG. 5, the power supply voltage is monitored by monitoring both the constant power supply line 251 and the ACC power supply line 252 together. First, the driver inserts an engine key into the LOCK position to release LOCK. Then, the ACC power supply rises at the time of turning to the ACC position (timing I), and monitoring of the voltage value by the voltage value monitoring circuit 301 and timing by the timer LSI 14 are started.
[0038]
Next, when the engine key is turned to the ST position (III), the cell is started, and the voltage of the constant power supply line 251 and the ACC power supply line 252 rises by the above-described instantaneous interruption operation, and the voltage value is set to a predetermined threshold value. When the voltage falls below the level SL, the voltage value monitoring circuit 301 can detect that the monitored voltage has fallen below the predetermined threshold level SL. Thus, during the period from (III) to (IV), when the voltage values of the constant power supply line 251 and the ACC power supply line 252 due to the instantaneous interruption are below the predetermined threshold level SL, these voltages are thereafter When the value again exceeds the predetermined threshold level SL, the engine start can be detected. In this case, the HDD is started from the engine start timing (IV). Therefore, in this case, the HDD is not started by monitoring the timer.
[0039]
On the other hand, during the periods (III) to (IV), the voltage values of the constant power supply line 251 and the ACC power supply line 252 due to instantaneous interruption may not fall below a predetermined threshold level SL (indicated by a one-dot chain line). In this case, since the engine start of the vehicle cannot be detected even if the voltage value of the power supply voltage is monitored, the HDD is started by the timer as shown in FIG.
[0040]
Then, when the engine start is detected or when the timer has elapsed for 5 seconds, the host CPU 11 issues an instruction to permit the HDD 15 to move the magnetic head 51.
[0041]
As described above, in the present embodiment, the HDD activation timing is changed according to the voltage level at the momentary interruption, and the voltage value at the momentary interruption is larger than a predetermined threshold level (for example, (( In the case of the voltage value of A), the start of the HDD is controlled at the time when the engine start by the voltage value is detected (timing IV). On the other hand, when the voltage value at the momentary interruption is smaller than the predetermined threshold level SL When the timer LSI (14) measures a predetermined time, the activation of the HDD is controlled. In this way, the movement of the magnetic head 51 is controlled to avoid emergency unloading.
[0042]
In the embodiment shown in FIG. 6, when the engine of the vehicle has not been started even after a predetermined time of 5 seconds has elapsed since the timer LSI (14) was started, that is, the constant power line 251 or the ACC power line 252. If the voltage value is still below the threshold value (SL), the timer is restarted, and after waiting for a predetermined time of 3 seconds, the HDD is started. In this way, the movement of the head is controlled, and emergency unloading is avoided.
[0043]
Next, a description will be given of an embodiment for starting an HDD using a method of detecting engine start using a power line connected to a key switch and a method of detecting engine start using a timer.
[0044]
FIG. 7 is a diagram in which each power line connected to the key switch 40 is added to the block diagram of FIG. In this figure, since members having the same reference numerals as those in FIG. 2 perform the same operation, the description thereof is omitted in this embodiment in order to avoid redundant explanation.
[0045]
As shown in FIG. 7, the key switch 40 includes a constant power line 251 indicating a voltage value when the engine key is at the LOCK position, an ACC power line 252 indicating a voltage value when the engine key is at the ACC position, and an IG A power supply line 253 indicating a voltage value when the engine is in the position and a power supply line 254 indicating a voltage value when the engine is started are connected.
[0046]
FIG. 8 is a timing chart showing an embodiment for starting an HDD by performing both monitoring by a timer and monitoring of a voltage value of a power supply line connected to a key switch. In the figure, (a) shows the voltage waveform in the constant power supply line 251, (b) shows the ACC power supply line 252, (c) shows the IG power supply line 253, and (d) shows the voltage waveform in the ST power supply line 254. SL (threshold value) indicates a predetermined voltage value, and is, for example, 9 V in the present embodiment.
[0047]
The driver first inserts the engine key into the LOCK position, releases the LOCK, and turns to the ACC position (I). As a result, the ACC power supply rises and reaches, for example, 12V. At the same time, the timer LSI (14) starts timing.
[0048]
Next, when the engine key is turned to the ON position (II), the IG power supply rises, and for example, a power supply voltage is supplied to a power window or the like. Note that the timer LSI (14) may start counting from the time point (II). Then, when the engine key is turned to the ST position (III), the cell starts, the voltages of the constant power supply line 251 and the ACC power supply line 252 both fall due to instantaneous interruption, and the ST power supply rises. At this time, the voltage value monitoring circuit 301 detects an instantaneous interruption because the monitoring voltage falls below a predetermined threshold level SL. After a predetermined time has elapsed, the engine starts (IV), the ACC power supply line 252 and the constant power supply line 251 rise to their original voltage values, the ST power supply falls, and return to a steady state. By detecting the voltage value in the steady state, the engine start can be detected. At this time, the host CPU 11 issues an instruction for permitting the HDD 15 to move the magnetic head 51.
[0049]
On the other hand, during the periods (III) to (IV), the voltage values of the constant power supply line 251 and the ACC power supply line 252 due to instantaneous interruption may not fall below a predetermined threshold level SL (indicated by a one-dot chain line). In this case, since the engine start of the vehicle cannot be detected even if the voltage value of the power supply voltage is monitored, the HDD is started by the timer as shown in FIG.
[0050]
When the engine start is detected or when the timer has elapsed for 5 seconds, the host CPU 11 issues an instruction to permit the HDD 15 to move the magnetic head 51.
[0051]
Further, whether or not the power supply voltage is supplied to start the engine can be determined from the voltage value of the ST power supply line 254. That is, since the ST power line 254 rises only when a power supply voltage is supplied to start the engine, the voltage value may be monitored. That is, since the engine start can be detected when the voltage value of the ST power line 254 exceeds a predetermined threshold level (SL) and then the voltage value falls below the predetermined threshold value, the HDD is started thereafter. On the other hand, if the voltage value of the ST power line 254 at the moment of interruption does not exceed a predetermined threshold level (SL), the HDD may be activated after 5 seconds have elapsed due to timer timing.
[0052]
Then, when the engine start is detected or when the timer has elapsed for 5 seconds, the host CPU 11 issues an instruction to permit the HDD 15 to move the magnetic head 51.
[0053]
As described above, in the present embodiment, the engine is started by monitoring the voltage values of the four power supply lines of the constant power supply line 251, the ACC power supply line 252, the IG power supply line 253, and the ST power supply line 254. The detection is surely performed, and then the movement of the magnetic head 51 of the HDD 15 is allowed. Alternatively, the time is monitored by the timer LSI (14), and when either one of the conditions is met, the host CPU 11 issues an instruction for permitting the HDD 15 to move the magnetic head 51.
[0054]
Therefore, emergency unload due to a momentary interruption that occurs when the engine is started can be avoided, and a collision between the magnetic head 51 and the ramp 55 when the engine is started can be avoided. In the embodiment described above, a control method that allows the movement of the magnetic head 51 after the engine is started is adopted. However, the HDD is not turned on until the engine is started. By the above means, the HDD can be configured to be turned on after the engine start is detected.
[0055]
As described above, in this embodiment, since the HDD is started after the vehicle engine is started, occurrence of emergency unloading at the time of engine start can be surely prevented. However, until the HDD is activated, for example, in the navigation system, since map data is not displayed on the monitor screen, there is a possibility that the user may be worried. Therefore, during the period from ACCON to engine start, it is preferable to perform control so that the vehicle position map display at the time of the previous engine stop saved in advance in the backup RAM 27 is performed. In addition to the navigation system, the on-vehicle HDD-mounted music information reproducing apparatus controls the backup RAM 27 to display specific information (table of contents information, etc.) related to music information at the time of the previous engine stop that has been saved in advance. Is good.
[0056]
【The invention's effect】
As described above, according to the present invention, in the recording / reproducing apparatus that is driven and controlled using the power supply voltage of the vehicle, the engine start can be detected by the timer monitoring even in the case of a vehicle type in which the voltage does not drop when the engine starts. In addition, when there is a voltage drop, the start of the recording / reproducing apparatus can be accelerated, and the occurrence of emergency unloading at the time of engine start is avoided by allowing the head to move after this detection time. Can do. Accordingly, the number of collisions between the head and the lamp due to a decrease in the chances of emergency unloading is reduced, thereby extending the life of the head and improving the reliability of the in-vehicle HDD.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a system configuration of a car navigation system equipped with an in-vehicle information recording / reproducing apparatus of the present invention.
2 is a block diagram showing a detailed configuration around an HDD and an in-vehicle power supply circuit in FIG. 1. FIG.
FIG. 3 is a timing chart cited to explain the timing of HDD activation by a timer.
FIG. 4 is a timing chart according to another embodiment cited for explaining the timing of HDD activation by a timer.
FIG. 5 is a timing chart according to still another embodiment cited for explaining the timing of HDD activation by a timer.
FIG. 6 is a timing chart according to still another embodiment cited for explaining the timing of HDD activation by a timer.
7 is a block diagram showing an embodiment in which each power line connected to the IG switch is added to the embodiment shown in FIG.
FIG. 8 is a timing chart cited for explaining the operation of the engine start detection device in FIG. 7;
FIG. 9 is a plan view of a basic structure of a ramp load type HDD.
FIG. 10 is a diagram cited for explaining the positional relationship between the lamp and the head in FIG. 10;
FIG. 11 is a diagram showing a power supply line of an in-vehicle audio product.
FIG. 12 is a timing chart quoted for explaining an operation sequence at the time of engine start of the in-vehicle power supply circuit.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 11 ... Host CPU, 15 ... Hard disk drive (HDD), 16 ... Sensor, 25 ... In-vehicle power supply device, 27 ... Backup RAM, 30 ... Engine start detection device, 152 ... CPU with built-in HDD, 157 ... Head drive control circuit, 161 ... Spindle motor, 251 ... always power supply line, 252 ... accessory (ACC) power supply line, 253 ... ignition (IG) power supply line, 254 ... starter (ST) power supply line, 301 ... voltage value detection circuit, 302 ... threshold value Setting circuit 303 ... Engine start detection circuit 304 ... Various sensors

Claims (3)

A drive control system for an in-vehicle hard disk device, comprising: a head for reading or writing information to a loaded recording medium; and a head driving means for driving the head, and the head driving means is driven by a power supply voltage of the vehicle. Because
Voltage monitoring means for monitoring the power supply voltage of the vehicle ;
When the timing operation of the first set time is started based on a signal corresponding to the operation of the engine key of the vehicle, and the power supply voltage is below a set threshold when the first set time is measured A time measuring means for measuring the second set time,
Head movement permission means for permitting movement of the head by the head driving means after counting the second set time;
A drive control system for an in-vehicle hard disk device. A drive control system for an in-vehicle hard disk device, comprising: a head for reading or writing information to a loaded recording medium; and a head driving means for driving the head, and the head driving means is driven by a power supply voltage of the vehicle. Because
  Engine start detecting means for detecting engine start by monitoring a power supply voltage value of the vehicle;
Clocking means for starting a clocking operation of a set time based on a signal corresponding to the operation of the engine key of the vehicle;
  A head movement permission means for permitting movement of the head by detection of the engine start when the engine start detection means is detected by the engine start detection means within the set time;
  A drive control system for an in-vehicle hard disk device. The time measuring means measures the second set time when the power supply voltage value is below a set threshold when the first set time is measured, and the head movement permission means 3. The drive control system for a vehicle-mounted hard disk device according to claim 2, wherein the movement of the head by the head drive unit is permitted after the set time of 2 is counted.

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