JP4296489B2 - Recording medium recording and / or reproducing apparatus - Google Patents

Description

  The present invention relates to a novel recording medium recording and / or reproducing apparatus. Specifically, in a recording medium recording and / or reproducing apparatus including a recording medium such as a hard disk drive or an optical disk drive and a storage means having a reading means for reading a signal from the recording medium, the recording medium or the reading device can be detected by reliably detecting the fall. The present invention relates to a technique for preventing breakage of means.

  Semiconductor memories are frequently used in storage devices used for portable recording medium recording and / or playback devices, such as portable audio devices, mobile phones, digital video cameras, digital still cameras, etc. A 128 MB (megabyte) semiconductor memory is also commercially available.

  However, more capacity is required to carry music data for a longer time (multi-track) and to record higher-definition image data or moving images.

  On the other hand, miniaturization of hard disk drives, optical disk drives, and the like has progressed, and small hard disk drives and optical disk drives that use 1-2.5 inch size disks have appeared, and these are used for recording medium recording and / or playback devices. An attempt has been made.

  By the way, there is a problem that reading means such as a hard disk drive or an optical disk drive, which scans a recording medium in the vicinity of the recording medium and reads and writes a signal, for example, a storage means having a head, is generally vulnerable to shock. There is. For example, in a hard disk drive, in order to achieve a high recording density, a magnetic head as a reading means floats on the surface of a rotating magnetic disk at a very close interval of 20 to 50 nm (nanometers). The amount tends to decrease further.

  When an external impact is applied to a hard disk drive that reads or writes signals while the magnetic head is flying with the flying height as described above, the magnetic head collides with the magnetic disk, greatly damaging the recording surface of the magnetic disk. The recorded data will be destroyed, and the magnetic head may be damaged.

  And, in the recording medium recording and / or reproducing apparatus as described above, since it is often operated with a hand while walking, it is always next to the danger of falling.

  Thus, Patent Document 1 (see paragraph “0060”) discloses that acceleration is detected by an acceleration sensor and the magnetic head is retracted based on the detection result.

  In addition, although it is regarding an operator, the means for detecting a more reliable fall is shown by patent document 2. FIG.

JP 2002-251857 A

JP 2000-258453 A

  Although the details of the technique disclosed in Patent Document 1 are not clear, if a 3-axis acceleration sensor composed of three accelerometers that individually detect 3-axis accelerations that are orthogonal to each other is used, the fall can be reliably ensured. It is extremely difficult to detect.

  In a recording medium recording and / or reproducing apparatus, particularly in a portable recording medium recording and / or reproducing apparatus, the position where the above-described three-axis acceleration sensor is installed is very limited, and should be installed at the center of gravity. Is extremely difficult. Therefore, the combined vector of the outputs of the three accelerometers shows different values for free fall (fall without rotation) and for fall with rotation, that is, for rotary fall, and as a result, the fall is guaranteed. Therefore, it is difficult to take the evacuation operation.

  FIG. 8 and FIG. 9 show the output of each accelerometer at the time of free fall and rotary fall, and the resultant vector. Time is plotted on the horizontal axis, and acceleration (G) is plotted on the vertical axis. Of the three accelerometers Sx, Sy, Sz, it is assumed that it falls in the axial direction of Sx that is stationary and the axial direction is vertical. The vector is denoted by S.

  FIG. 8 shows the outputs of the accelerometers Sx, Sy, Sz and the combined vector S at the time of free fall respectively in (a), (b), (c), and (d). For example, in the state of being held still by hand (the time between time t0 and t1), the combined vector indicates 1G by receiving the earth's attractive force as it is. When the hand is released from that state (begins at t1 and is completely released from the hand at t2), it is released from the attractive force, so the combined vector becomes 0G. Then, a large acceleration is applied due to the impact that hits the ground at t3, and the bounce stops on the ground and converges to 1G while swinging to the plus side and the minus side by bouncing on the ground.

  In addition, if it falls from the height of 100 cm (centimeter), the time taken from t2 to t3 is 452 msec (millisecond). The time required for dropping 25 cm is 226 msec. Therefore, by providing a buffer mechanism in the recording medium recording and / or reproducing apparatus, the strength is set such that the head and the recording medium are not damaged even if the head is not retracted when dropped from a height of 25 cm. If the head is retracted in the interval (between t2 and t4 in FIG. 8), serious damage to the head and the recording medium can be avoided.

  FIG. 9 shows the outputs of the accelerometers Sx, Sy, Sz and the combined vector S at the time of rotating and dropping, respectively, in (a), (b), (c), and (d). For example, in a state where the hand is stationary (time between time t0 and t1), similarly to the case of FIG. 8, a 1G composite vector is shown, and when an operation of moving away from the hand while giving rotation to t1 is started. Acceleration is increased by the centrifugal force accompanying the rotation, and while the rotation speed is increasing, that is, while the rotation is continuously applied by the hand (between t1 and t5), the acceleration is increased and released from the hand. From the moment, the composite vector decreases toward 0G, and eventually (t2) the rotational speed becomes stable and the composite vector also settles to a certain value. Then, a large acceleration is applied due to the impact that hits the ground at t3, and the bounce stops on the ground and converges to 1G while swinging to the plus side and the minus side by bouncing on the ground.

  As can be seen from the comparison between FIG. 8 and FIG. 9, the value of the combined vector is different between the free fall and the rotary drop even if the drop is the same. That is, it shows almost 0G at the time of free fall, but shows a combined vector of 0G + ΔS at the time of rotary fall.

  As shown in FIG. 10, for example, an angular velocity in the rotational direction is generated while a force is applied by a hand, and the center of rotation moves to the center of gravity c from the moment when the hand is released. This is because only the constant acceleration due to the centrifugal force (F = Ro · ωo) of rotation acts on the axial acceleration sensor S. Note that Ro is a distance between the rotation center c and the triaxial acceleration sensor S, and ωo is an angular velocity.

  As described above, when the triaxial acceleration sensor S is provided at a position away from the position of the center of gravity, the combined vector of the triaxial acceleration sensor S is obtained by the constant acceleration due to the centrifugal force acting on the triaxial acceleration sensor S when rotating and dropping. 1G or less, but not 0G.

  Therefore, if the combined vector indicated by the three-axis acceleration sensor S is 0G to almost 0G and the head is retracted and the head is retracted, the head is not retracted when the head is rotationally dropped.

  Therefore, considering that there is no index commonly seen in the combined vector of FIGS. 8 and 9, both of them show a substantially flat value between 0G and 1G between t2 and t3. is there. Therefore, it is conceivable that the head is retracted when the combined vector shows a flat value between 0G and 1G for a certain period of time (for example, a time obtained by subtracting the time required for retracting the head from 226 msec). . In this case, the head and the recording medium can be prevented from being damaged by reliably retracting the head regardless of whether it is free fall or rotational fall.

  Therefore, look at FIG. FIG. 11 shows a case where the user performs the operation of lifting the recording medium recording and / or reproducing device on the desk by hand, holding it at the same height for a certain period of time, lifting it from the desk, and placing it on the desk. The outputs of the accelerometers Sx, Sy, Sz and the combined vector S are respectively shown in (a), (b), (c), and (d). First, while being placed on the desk (t0 to t6), the combined vector S is 1G, but when lifted by hand (t6), the combined vector increases for a moment (t6 to t7) and has a constant speed. While it is being lifted up, it stabilizes at a constant level (0G + ΔSG) (t7 to t8). When the height is maintained at a certain height, the combined vector S returns to 1G for a moment (t8 to t9), and keeps 1G while maintaining the same height (t9 to t10). . Then, when it is lowered from the height to return it to the desktop, the combined vector S decreases for a moment (t10 to t11), and is kept at a constant level (t11 to t12). Stable at (1G−ΔSG). When placed on the desk (t13), the combined vector S becomes 1G for a moment (t12 to t13).

  As seen in FIG. 11, even when no fall occurs, the combined vector S may be stabilized at a constant level for a predetermined time. In particular, during the period from t11 to t12, the combined vector S is between 0G and 1G. It stabilizes for a certain time at a certain value. As described above, this is configured such that the head is retracted by reading the characteristic between t2 and t3 in FIG. 9 (the combined vector S is stabilized for a certain time at a constant value between 0G and 1G). In this case, the head is retracted even during the period from t11 to t12 in FIG.

  The technique of Patent Document 2 is intended to reliably detect a rotating drop, but for that purpose, it requires a complicated configuration in which many means such as a posture angle calculating means and a vertical acceleration detecting means are introduced, I cannot help getting expensive. Since this technology is human life related, the cost may be secondary, but it is too expensive for consumer products.

  In view of this, the present invention devised the installation position of the three-axis acceleration sensor to reliably read the fall state with an inexpensive configuration and to retract the reading means when necessary and only when necessary. The challenge is to make it.

In order to solve the above-described problems , the present invention is detected by a reading unit that reads a signal from a recording medium, an acceleration sensor that detects a combined vector of accelerations in three orthogonal directions at the center of gravity, and the acceleration sensor. recording medium recording the value of the resultant vector that is a control means for controlling the reading means so as to avoid contact with the reading means and the recording medium when a state equal to or less than a predetermined value continues for a predetermined time or more And / or a playback device comprising two triaxial acceleration sensors and an arithmetic means for calculating a combined vector at the center of gravity position from the outputs of the two triaxial acceleration sensors, the two triaxial acceleration sensors However, the axes of three orthogonal accelerometers constituting each of the three-axis acceleration sensors are oriented in the same direction and separated in the three axial directions. The additional device is configured to be detachable, and the calculation means performs a calculation according to a change in a distance in each axial direction between the center-of-gravity position changed by the mounting of the additional device and each of the three-axis acceleration sensors. The composite vector at the new center of gravity position is calculated .

  In the recording medium recording and / or reproducing apparatus of the present invention, the acceleration sensor detects the combined vector of accelerations in the three-axis directions at the center of gravity of the recording medium recording and / or reproducing apparatus. At any time, it can be determined that the camera is falling by detecting a composite vector at the same level.

The present invention provides a reading unit that reads a signal from a recording medium , an acceleration sensor that detects a combined vector of accelerations in three orthogonal directions at the center of gravity, and a value of a combined vector detected by the acceleration sensor is a predetermined value or less. A recording medium recording and / or reproducing apparatus comprising a control means for controlling the reading means so as to avoid contact between the reading means and the recording medium when the state becomes a predetermined time or longer , Two triaxial acceleration sensors, and calculation means for calculating a combined vector at the position of the center of gravity from the outputs of the two triaxial acceleration sensors, and the two triaxial acceleration sensors have their respective triaxial acceleration sensors The three axes of the three accelerometers that are orthogonal to each other are oriented in the same direction and are separated in the three axis directions so that the additional device can be attached and detached. The calculation means performs calculation according to the change in the distance in the direction of each axis between the center of gravity position changed by the attachment of the additional device and each of the three-axis acceleration sensors, and the combined vector at the new center of gravity position Is calculated .

Therefore, in the recording medium recording and / or reproducing apparatus of the present invention, the fall state is determined by detecting the combined vector of accelerations in the three orthogonal directions at the center of gravity, so that the centrifugal force in the case of a rotary drop is determined. It is possible to detect the fall state reliably regardless of whether it is free fall or rotational fall. Therefore, it is possible to force the reading unit not to contact the recording medium when necessary and only when necessary by an inexpensive configuration. In addition, two triaxial acceleration sensors and an arithmetic means for calculating a combined vector at the center of gravity position from outputs of the two triaxial acceleration sensors are provided. Since the three axes of the three accelerometers that are orthogonal to each other are oriented in the same direction and are separated in the three axial directions, even if the three-axis acceleration sensor cannot be arranged at the center of gravity, By arranging three triaxial acceleration sensors, it is possible to virtually derive a combined vector of accelerations in the orthogonal triaxial directions at the center of gravity position by calculation from the outputs of the triaxial acceleration sensors. Further, the additional device is configured to be detachable, and the calculation means performs a calculation according to a change in the distance in each axial direction between the center of gravity position changed by the mounting of the additional device and each three-axis acceleration sensor. Since the combined vector at the new center of gravity is calculated, the fall state can be reliably detected even when the additional device is attached.

  According to a second aspect of the present invention, the acceleration sensor is a three-axis acceleration sensor including three accelerometers that individually detect three-axis accelerations orthogonal to each other, and the three-axis acceleration sensor is located at the center of gravity position. Alternatively, since it is arranged in the vicinity of the center of gravity position, the combined vector of the accelerations in the three-axis directions orthogonal to each other at the center of gravity position can be detected by one three-axis acceleration sensor, so that it can be configured at low cost.

  The best mode for carrying out the recording medium recording and / or reproducing apparatus of the present invention will be described below with reference to the accompanying drawings.

  The best mode of the recording medium recording and / or reproducing apparatus of the present invention includes a reading means for reading a signal from the recording medium, an acceleration sensor for detecting a combined vector of accelerations in three orthogonal directions at the center of gravity, and Control means for controlling the reading means so as to avoid contact between the reading means and the recording medium when a state in which the value of the combined vector detected by the acceleration sensor is not more than a predetermined value continues for a certain time or longer. It is to prepare. .

  It is particularly important to provide an acceleration sensor that detects a combined vector of accelerations in three orthogonal directions at the center of gravity. That is, in the state where the rotation in the case of the rotation drop is stable, the rotation is performed around the position of the center of gravity, so that the constant acceleration due to the centrifugal force of rotation (F = Ro · ωo) is not applied at the position of the center of gravity. Therefore, the combined vector of accelerations in the three-axis directions has the same value as that during free fall. Therefore, as in the case of free fall, it can be determined that the combined vector is falling when the combined vector indicates 0G or a value in the vicinity of 0G for a certain period of time or longer.

  If the triaxial acceleration sensor can be arranged at or near the centroid position of the recording medium recording and / or reproducing apparatus, it is only necessary to arrange one triaxial acceleration sensor, and the centroid position can be obtained by the triaxial acceleration sensor. Since it is possible to detect a combined vector of accelerations in three orthogonal directions, there is little problem in a recording medium recording and / or reproducing apparatus, and in many cases the center of gravity is It is difficult to arrange the triaxial acceleration sensor near the position or the center of gravity position.

  Therefore, the best embodiment in the case where the three-axis acceleration sensor cannot be arranged at the gravity center position or in the vicinity of the gravity center position will be described below.

  First, an outline of a recording medium recording and / or reproducing apparatus will be described with reference to FIGS. In the illustrated embodiment, the present invention is applied to a portable video player 10. The video player 10 includes, for example, a display unit 20 including a display unit such as a liquid crystal display panel on the front surface of the housing 30, and extracts and displays image information stored in a hard disk drive 40 mounted in the housing 30. This is displayed on the unit 20. Note that the recording medium recording and / or reproducing apparatus to which the present invention is applied is not limited to a video player, but various recording medium recording and / or reproducing such as an audio player, a digital video camera, a digital still camera, a mobile phone, and the like. Can be widely applied to the device. In addition, the storage means included in the recording medium recording and / or reproducing apparatus is not limited to the hard disk drive, and the optical disk drive such as a DVD (Digital Versatile Disk) drive or the like reads a signal from the recording medium and the recording medium. Any storage means having a reading means can be widely applied.

  FIG. 2 shows details of the hard disk drive 40. The hard disk drive 40 includes a magnetic disk 41 as a recording medium, and the magnetic disk 41 is rotated by a spindle motor 42. Reference numeral 43 denotes a rotation type actuator, which is a linear motor type drive unit 43a, an arm 43b rotated by the drive unit 43a, a magnetic head 43c supported by a gimbal mechanism (not shown) at a position near the tip of the arm 43b, A load plate 43d protruding from the tip of 43b is provided. A ramp 44 is provided so as to be positioned on the movement locus of the magnetic head 43 c at a position adjacent to the magnetic disk 41. The ramp 44 has a trapezoidal shape, and has an inclined portion 44a that is inclined so that the upper surface thereof is lowered toward the magnetic disk 41, and a rest portion 44b that is continuous with the opposite side of the inclined portion 44a to the magnetic disk 41, and the inclined portion 44a. The height of the end on the magnetic disk 41 side is substantially the same as or slightly lower than the recording surface 41a of the magnetic disk 41, and the rest portion 44b has the magnetic disk 41 except for the end 44 on the inclined portion 44a side. Is located at a position parallel to the recording surface 41a and higher than the recording surface 41a, and slightly lower than the end of the inclined portion 44a opposite to the end on the magnetic disk 41 side. The end portion 44c on the inclined portion 44a side of the ramp portion 44b continues to the inclined portion 44a in a state of being gently curved in a concave shape.

  In the hard disk drive 40, signals are written to and read from the magnetic disk 41 so that the magnetic head 43c moves slightly above the recording surface 41a of the magnetic disk 41 rotated by the spindle motor 42. This is performed while the arm 43b is rotated by 43a (see FIG. 2A). When the signal is not written to or read from the magnetic disk 41, the load plate 43d at the tip of the arm 43b is placed on the rest 44b of the ramp 44 (FIGS. 2B and 2C). reference).

  When the fall is detected by the three-axis acceleration sensor, the magnetic head 43c is forcibly prevented from coming into contact with the recording surface 41a of the magnetic disk 41, that is, retracted. It may be in the state shown in (b). That is, when a fall is detected during operation (when in the state of FIG. 2A), the arm 43b is quickly rotated to the position of FIG. Then, the load plate 43d at the tip of the arm 43b slides up the inclined portion 44a of the ramp 44 and is placed on the rest portion 44b beyond the uppermost portion of the inclined portion 44a. Since the rest portion 44b is located outside the magnetic disk 41 and is sufficiently higher than the recording surface 41a of the magnetic disk 41, even if the arm 43b is bent by a strong impact, the magnetic head 43c is magnetically There is no collision with the recording surface 41a of the disk 41. Further, since the drive unit 43a is a linear motor type, if the arm 43b is electromagnetically locked to the position shown in FIG. 2B by a large electric power during retraction, the arm 43b can be inclined even if there is a strong impact. The last part of the disk is not crossed and the magnetic disk 41 is not returned. When operating again, by rotating the arm 43b, the load plate 43d slides up the concave curved portion 44c of the rest portion 44b, and further moves toward the magnetic disk 41 through the inclined portion 44a. .

  The retraction of the magnetic head 43c is not limited to moving the arm 43b to the position shown in FIG. 2B as described above. For example, there are various means such as forcing the position so as not to go to the magnetic disk 41 while keeping the position of the arm 43b during operation, or to slightly move away from the magnetic disk 41. Conceivable.

  Further, as a means for retracting the magnetic head, it is conceivable to place a contact blocking means between the magnetic head and the magnetic disk. For example, when an engaging portion is provided on a magnetic head or an arm that supports the magnetic head, and the state where the value of the combined vector is not more than a predetermined value continues for a certain time or longer, the engaged portion protrudes as a contact blocking means. The contact between the magnetic head and the magnetic disk can be avoided by engaging the engaged portion with the engaging portion.

  When the triaxial acceleration sensor cannot be arranged at the gravity center position of the video player 10 or in the vicinity of the gravity center position, two triaxial acceleration sensors are arranged so as to have a predetermined relationship, and the triaxial direction at the gravity center position is calculated. Find the resultant acceleration vector.

  The arrangement of the two triaxial acceleration sensors S1 and S2 will be described with reference to FIGS. Each of the three-axis acceleration sensors S1 and S2 includes three accelerometers X1, Y1, Z1, X2, Y2, and Z2 that detect accelerations in the directions of three axes (x, y, and z) orthogonal to each other. Thus, the axial directions of the accelerometers X1 and X2, Y1 and Y2, and Z1 and Z2 are the same.

  The two three-axis acceleration sensors S1 and S2 are the axes of three accelerometers X1, Y1, Z1, X2, Y2, and Z2 that are orthogonal to each other (in FIG. 3 and FIG. 4, each axis is an acceleration). Are indicated in the same direction and are separated in the three axial directions. In other words, the three-axis acceleration sensors S1 and S2 have a volume (see the hatched portion in FIG. 3 and FIG. 4) having a volume inside the intersection of lines extending from the axes of the accelerometers.

  When the two triaxial acceleration sensors S1 and S2 are arranged so as to have the above-described relationship, a combined vector of triaxial acceleration at the center of gravity position c can be calculated by calculation. This will be described with reference to FIG.

  In addition, even if there is no volume inside the intersection of the extended lines of the accelerometers of the triaxial acceleration sensors S1 and S2, it is possible to calculate a virtual composite vector at the center of gravity exceptionally. There are cases. That is, this is a case where the two three-axis acceleration sensors S1 and S2 are in the positional relationship shown in FIG. This is because the area inside the intersection of the lines extending in the two axial directions that are not separated in one axial direction (z-axis direction in the case of FIG. 8) in the three axial directions (FIG. 8A). And the center-of-gravity position c exists in the plane of the area.

  The distance from the center of gravity in each axial direction of each triaxial acceleration sensor S1, S2 is x1, y1, z1, x2, y2, z2, and the output of each accelerometer X1, Y1, Z1 of the triaxial acceleration sensor S1. Is Sx1, Sy1, Sz1, and the outputs of the accelerometers X2, Y2, Z2 of the triaxial acceleration sensor S2 are Sx2, Sy2, Sz2, the virtual accelerations Sxc, Syc, Szc at the center of gravity position c are expressed by the following equations (1) ), (2), (3).

Sxc = {x2 / (x1 + x2)} Sx1 + {x1 / (x1 + x2)} Sx2 (1)
Syc = {y2 / (y1 + y2)} Sy1 + {y1 / (y1 + y2)} Sy2 (2)
Szc = {z2 / (z1 + z2)} Sz1 + {z1 / (z1 + z2)} Sz2 (3)

  Therefore, if the square root of the square sum of the virtual accelerations Sxc, Syc, and Szc in the respective axis directions at the above-described center of gravity position is obtained, the virtual combined vector Sc of the accelerations of the respective axes can be obtained. That is, it is obtained by the following equation (1).

  In the above description, the square root of the square sum of the virtual accelerations Sxc, Syc, and Szc in each axis direction at the center of gravity position is obtained and used for the determination. However, the square sum is not obtained without obtaining the square root. Even if it is used for the determination as it is, there is no practical problem.

  FIG. 6 shows a block diagram of the main components of the recording medium recording and / or reproducing apparatus of the present invention.

  The outputs of the accelerometers X1, Y1, Z1, X2, Y2, and Z2 of the triaxial acceleration sensors S1 and S2 are input to the calculation means 50. The calculation means 50 includes a calculation unit 51 that calculates a combined vector of accelerations in the three-axis directions at the center of gravity position c, and a table 52 that the calculation unit 51 refers to. The table 52 is specifically a memory, and is a numerical value to be referred to when the calculation unit 51 calculates, for example, distances x1, y1, z1, x2 from the center of gravity in each axial direction of each of the three-axis acceleration sensors S1, S2. , Y2, z2, etc. are stored. The virtual combined vector Sc at the center of gravity position c calculated by the calculation unit 51 based on the outputs of the accelerometers X1, Y1, Z1, X2, Y2, and Z2 is output to the determination means 60.

  The determination unit 60 determines whether or not the video player 10 is in the fall state from the virtual composite vector Sc given from the calculation unit 50. That is, the virtual composite vector Sc is a value close to 0G or 0G, and it is determined whether or not the value has continued for a predetermined time or more. Output to forcing means 70. If NO (NO), it is determined that the vehicle is not in a fall state, and no drop signal is output to the forcing means 70.

  The forcing means 70 that has received the fall signal from the determination means 60 outputs a save command to the hard disk drive 40. Then, the hard disk drive 40 that has received the evacuation command performs the evacuation operation of the magnetic head 43c as described above.

  The determination means 60 and the forcing means 70 allow the magnetic head 43c to avoid contact between the magnetic head 43c and the magnetic disk 41 when the state where the value of the combined vector is not more than a predetermined value continues for a certain time or longer. Control means is configured to control

  A battery is used as a drive source of the recording medium recording and / or reproducing apparatus, and a secondary battery that can be repeatedly used is often used in consideration of economy. However, a battery holder may be used as an additional device for using a primary battery as a supplement when used for a long time in the field where charging is not possible. In addition, various adapters may be attached and used. In such a case, the position of the center of gravity moves by attaching the adapter. In such a case, if the determination is based on the virtual composite vector calculated based on the position of the center of gravity before the adapter is attached, an error due to the movement of the position of the center of gravity occurs in the case of a rotating drop, and correct determination cannot be performed.

  Therefore, when the adapter 80 is attached, the sensor 90 detects it and sends a signal to that effect to the computing means 50.

  The table 52 is provided with numerical values corresponding to the adapter to be attached, and the calculation means 50 that has received a signal indicating that the adapter 80 has been attached performs a calculation with reference to the table prepared for the adapter 80. . For example, if the gravity center position is moved to c ′ in FIG. 5 by mounting the adapter 80, the distances x′1, y′1 in the respective axial directions from the new gravity center position c ′ of the three-axis acceleration sensors S1, S2 , Z ′ 1, x ′ 2, y ′ 2, z ′ 2 are calculated to calculate a virtual composite vector of accelerations in the three-axis directions at the new center-of-gravity position c ′.

  In the above description, the calculation means 50, the determination means 60, and the forcing means 70 have been described as being separated from each other. However, this may be functionally necessary for each function. It does not have to be physically present. For example, there are cases where the functions of the respective means are performed in a CPU (Central Processing Unit) of the computer.

  The present invention can be widely applied to various recording medium recording and / or reproducing apparatuses, and contributes to avoiding serious damage due to dropping.

2 to 7 show an embodiment of the recording medium recording and / or reproducing apparatus of the present invention, and this figure is a schematic front view. It is a top view which shows the outline | summary of a hard disk drive, (a) shows an operation state, (b) shows a retracted state, (c) is a C arrow directional view of FIG. (B). It is a figure which shows the example of arrangement | positioning of two 3-axis acceleration sensors, (a) shows a front view, (b) shows a side view. It is a figure which shows another example of arrangement | positioning of two 3-axis acceleration sensors, (a) is a front view, (b) shows a side view. It is a figure for calculating | requiring the virtual acceleration of a triaxial direction in a gravity center position, (a) shows a front view, (b) shows a side view. It is a block diagram of the main components. It is a figure which shows another example of the example of arrangement | positioning of two 3-axis acceleration sensors, (a) shows a front view, (b) shows a side view. It is a graph which shows the output of each accelerometer of a 3-axis acceleration sensor at the time of free fall, and a 3-axis synthetic vector. It is a graph which shows the output of each accelerometer at the time of rotation fall, and a 3 axis synthetic vector when a 3 axis acceleration sensor is not in a gravity center position. It is a figure explaining that the constant acceleration by centrifugal force arises. It is a graph which shows the output of each accelerometer when a 3 axis | shaft acceleration sensor is not in a gravity center position, and it lifts further from a desk, and also lowers, and a 3 axis | shaft synthetic vector.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Video player (recording medium recording and / or reproducing | regenerating apparatus), 41 ... Magnetic disk (recording medium), 43c ... Magnetic head (reading means), 50 ... Calculation means, 60 ... Determination means, 70 ... Force means, 60. 70 ... Control means, 80 ... Adapter (additional device), c ... Center of gravity position, c '... Fluctuated center of gravity position, S1 ... Triaxial acceleration sensor, S2 ... Triaxial acceleration sensor

Claims (2)

Reading means for reading a signal from a recording medium;
An acceleration sensor that detects a combined vector of accelerations in three orthogonal directions at the center of gravity;
Control means for controlling the reading means so as to avoid contact between the reading means and the recording medium when a state in which the value of the combined vector detected by the acceleration sensor is not more than a predetermined value continues for a certain period of time; A recording medium recording and / or reproducing device comprising:
Two 3-axis acceleration sensors;
Computing means for calculating a combined vector at the position of the center of gravity from the outputs of the two three-axis acceleration sensors,
In the two triaxial acceleration sensors, the axes of three orthogonal accelerometers constituting the respective triaxial acceleration sensors are oriented in the same direction and separated in the three axial directions,
The additional device is configured to be detachable,
The calculation means calculates according to a change in the distance in the direction of each axis between the position of the center of gravity changed by the attachment of the additional device and each of the three-axis acceleration sensors, and obtains a composite vector at the new position of the center of gravity. A recording medium recording and / or reproducing apparatus characterized by calculating . The acceleration sensor is a three-axis acceleration sensor comprising three accelerometers that individually detect three-axis accelerations orthogonal to each other, and the three-axis acceleration sensor is arranged at or near the center of gravity. The recording medium recording and / or reproducing apparatus according to claim 1.

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