TW561455B - Low-inertia compact disk driving device - Google Patents

Abstract

The present invention relates to a low-inertia compact disk driving device (2). In the low-inertia compact disk driving device, the disk and laser pickup are kept still, and an optical device is provided as a media of optical path transmission of the laser pickup. A coarse tracking device converts the optical device position to convert the read/write position of the optical path projected on the disk. A precise tracking device controls the light spot to accurately fall in the disk track to be read/written. The precise tracking device includes: two fixing stands, two permanent magnets, a tracking moving block and a balance moving block. Each of the tracking moving block and balance moving block is wound by a focus coil and suspended between the two fixing stands by an elastic wire, and a steel string having an end connected to an optical device is passed through the center of each of the tracking moving block and balance moving block. Focus driving voltage obtained by converting the focus error caused by the laser beam transmitted through the optical device is applied to focus coil to produce magnetic field which interacts with the magnetic field of permanent magnet to make the focus coil produce tiny displacement in left and right directions, thereby driving the steel string and optical device to perform real-time an precise tracking while slightly moving in left and right directions, so that the laser beam precisely moves from the current track to the target track.

Description

561455 V. Description of the invention d) Description of the field of the invention: A% hair per month is related to a low-inertia optical disc drive device (b) 'especially the transmission medium and the recording head are stationary' and the optical member is used as the stray head light f. In the low-inertia optical disc drive device of B 装置 B, a tracking device that enables the light spot to be precisely traced on the disc. Description of the technical background: The existing read and write operation technology adopted by the existing optical disc drive device uses an If, M, and a linear reciprocating motion of the laser head. Frequently, the disc drive device consumes a lot of power during read and write operations, and produces shortcomings such as shock release and heat energy. The conventional low-speed optical disc drive mostly adopts the Constant Linear Velocity (CL ^) method. The current reading and writing technology has been converted to discs, and the local constant angular velocity (PCAV) or, constant Angular velocity, (c〇nstant AnguUr

Veloci ty (CAV for short), the motor rotates at the same speed when the laser head reads and writes data at any position on the disc. In terms of improving the speed of reading data, it is still a traditional practice to increase the speed of the motor. Some optical disc players and DVDR0Ms have already used "True X", "True X" Multi-beam Technology, "True χ" The technology can ensure that the optical disc device reads the disc at a relatively uniform speed over the entire range of the optical disc ', and it only changes the speed due to different disc quality and operating systems. Μ DVD reading technology is not currently Too consistent, the previous MDROM is

Page 5 561455 V. Description of the invention (2) Compatible with ordinary CDROM discs, mostly adopts double optical head technology to achieve double read. At present, single lens technology is generally used. In addition, the digital servo system can realize the automatic adjustment of the disc drive split servo mechanism, so that the accuracy of the data read by the optical disc drive can be improved; the dual dynamic anti-vibration suspension system μ (DDSS) technology can effectively reduce the optical disc drive when rotating at high speeds. ABS (Auto Balance System) automatic balance system keeps the disc always horizontally rotated, which improves the disc reading ability of the disc drive; artificial intelligence error correction (AIEC) can greatly increase the number of correct data read by the disc. The use of many new technologies mentioned above has continuously improved the performance of optical disc drive devices. However, at present, optical disc drive devices are still used to rotate discs at high speeds and lasers: the square of complex linear motion < due to the large rotational inertia of discs, the quality of laser heads is high. 'So the energy consumption of the existing optical disc drive device is high, and the vibration during the reading process: Second, it generates heat energy, which limits the use of the optical disc drive device. For example, the existing optical disc drive technology cannot be used in personal digital assistants (PDAs, functions, these functions Both: m, and the Internet must be low energy consumption and not implemented. The peripheral device of m must drive the device due to the thermal energy release of the disc, and the current optical disc achieves low energy Μο ^ # And the limitation of the mass of the laser head cannot be seen. Low contraction and low thermal energy release. The eccentricity of the contraction and the existence of compensation for expansion and clearance will cause the two centering errors of the channel and the shaft, plus the displacement in the direction of the bearing. In addition, the center of the circle, 'causes the channel in the radius bu' due to the shrinkage in all directions of the molded disc is not

Page 6 561455 V. Description of the invention (3) — = Light 2 will deform. Therefore, the main purpose of the radial tracking servo is to drive the 捭 /, s from the current orbit to the target orbit in the shortest time, and to avoid crosstalk between channels and decrease of signal potential at the center of the channel. In general, the information pattern on the optical disc drive is a spiral line, and due to factors such as concentricity of the disc spot, the beam of light irradiated during the reading and writing operation will continuously deviate from the information pattern. According to the analysis study 1 ^ system within ... incident to; read = data is correct. But in fact, due to the partial / two discs on the disc and the plate; Traditional optical heads detect radial error signals; two-beam method and push-pull method are used for suspension. In the full self light wind-push-pull method is generally used. However, the existing focusing coil has a large mass and frequently performs main f-line motion 'because it consumes a lot of power. The straight line is always fascinated by complex movements. The reason is that in view of the current optical drive rotation, the way the laser head performs a linear reciprocating motion. 2 The disc spinning laser head and the disc are in read and write operations. ^ Developed a low-inertia optical disc drive for writing disc data. Set while changing read

Architecture ΐSecond to the aforementioned low-inertia optical disc drive, a kind of fine tracking device that reads and writes data by laser master: J 561455 V. Description of the invention (4)

The front with a low moment of inertia can be accurately controlled by another current closed loop focus control ring of the present invention. The focus servo signal is pushed to the focus device to control the film. Lift down 'to move the focal point of the laser beam emitted by the laser head to the target. The purpose can be achieved by the following methods. The method of “spotting” uses the spot size detection method to detect the movement of the servo signal after phase and amplitude compensation and power amplification to focus the objective lens, so that the light spot accurately falls below the disc. Design and technical principles, a detailed description, and refer to the attached drawings, will further understand the characteristics of the present invention, of which: Detailed description of the present invention: The disc according to the present invention is a computer file storage Media, including ISO-9660 'J〇Het and Rome〇 file systems. The invention comprises: a disc fixing device 10 (as shown in FIG. 1), which is composed of a disc mounting upper pressing device 11 and a disc lower support 12; the disc 20 is placed on the lower support of the disc The disc 12 is mounted on the disc by an upper pressing device u and the disc 20 is pressed down on the disc lower support 12 to fix the disc 20 and ensure that the disc 20 cannot rotate. Ah, the displacement device controls the position of the beam emitted by the laser head on the disc, including: A rotation index 30 (as shown in Figures A and B), which is located below the read-write surface of the disc 20 ' There is a lateral groove 31 (please refer to Figure 8 first)

Page 8 561455 V. Description of the invention (5) And a hole 32 is provided in the center, and a bismuth π-point Ikon show integrated with a gray rotation indicator 30 is protruded below the hole 32. The center of the gear 33 is engaged with the rotation finger, and can rotate the rotation indicator 30 for rotation. The center of τ 〇 has two light-weight suspension wheels 34 at each end of the rotation indicator 30. The horizontal axis of the rotation indicator is ^ =; wheel 4 'This rotation movement, light-weight suspension wheel 3 4 平 柞 # ϋ Mosco U is in continuous contact with the inner 2 of the ring-shaped limiter 36 during the continuous internal rotation of the π. The% -shaped limiter 36 remains stationary to prevent = 2 excessive jitter during rotation. 'Control the rotation index at 3 ° at "The shortness of deformation is within the state. The state driving device 35 'is composed of a driving horse ^ combined with a gear 352, which is coupled to the aforementioned gear 33. The driving motor 351 directly drives the gear 35 2 is rotated, and the gear 33 is rotated, so that the rotation index 30 is continuously rotated with the central axis A-β as an axis. An optical component (refer to FIG. 3A and B together) is used as a laser head 70 The transmitting member that emits the light beam includes: a fixed reflector 40, which is fixed at the center of the rotation index 30 and is used to refract the laser beam to the movable mirror 41 or to the laser head. A movable mirror 41 is provided at an appropriate angle for gathering The focusing lens 42 for laser light is used to converge and radiate the laser beam transmitted from the fixed mirror 40 to the disc 20, or to transmit the beam reflected from the disc 20 to the fixed mirror 40. A balance block 43, It is located on the opposite side of the movable mirror 41 to maintain the balance of the rotation index 30. A coarse tracking device includes:

561455 V. Description of the invention (6) A moving plate 50 'is used as the base of the movable mirror 41 and the balance block 43. A set of shaft sleeves 51 at the rotation index 30 is extended at the bottom, and are respectively socketed. At the appropriate positions on both sides of the rotation indicator 30, a rack 52, 53 is respectively extended on the sides to be placed on the sides of the movable mirror 41 and the weight 43. A hollow transmission member 54 is fixedly disposed on the inner edge of the aforementioned hole 31, and a gear 54i, 54 2 is provided at the upper and lower ends; the upper gear 541 is connected to the two racks 52 and 53; a servo motor 55, It is combined with a gear 551, which is connected to the lower gear 54 2 of the lower end of the hollow transmission member 54 and is used to drive the movable mirror 41 and the balance weight 43 to reciprocate in a straight line. The servo motor 55 drives the gear 551 to drive the lower gear 542 of the hollow transmission member 54 to rotate, so that the upper gear 54 of the hollow transmission member 54 moves to the racks 52 and 53 to change the racks 52 and 53 to move in a straight line. Thus, the movable mirror 41, the focusing lens 42 and the balance weight are driven synchronously in opposite directions in the direction of ^, that is, the movement direction of the balance weight 43 is opposite to that of the movable reflection mirror 41, so that the rotation index 3 is always maintained. The balance of 〇 enables the rotation indicator 30 to maintain the dynamics of the entire rotation device during high-speed rotation; while the fixed reflector 40 is fixed at the center of the rotation indicator 30, it will only perform high-speed rotation movement with the rotation indicator 30 to maintain The relative angle of the mirror 41 does not change. The auxiliary tracking device (as shown in Figures 5 to 8) drives the aforementioned mirror 41, focusing lens 42 and balance block to move left and right slightly. The light spot can accurately fall on the target track of the disc 20, including: two permanent magnets 60, which are vertically arranged relative to the center through the connecting member 61

Page 10 561455 V. Description of the invention (7) Inside the rotation index 30 at the empty transmission member 54. The two fixing frames 62 are vertically arranged through the connecting member 63 inside the rotating index 30 outside the two permanent magnets 60 at 4 positions relative to the hollow transmission member. A tracking moving block 64 is provided with a through hole 641, and a tracking coil 65 is wound on the outside, which is suspended between two permanent magnets 60 and a hollow transmission member 54 through a plurality of elastic wires 66 (4 in the preferred embodiment). On one side, under the action of force, the tracking moving block 64 can move up and down or left and right. A balance moving block 67 is provided with a through hole 671, and a tracking coil 65 is wound on the outside, and is suspended between the permanent magnets 60 and the hollow transmission member 54 through a number of elastic wires 66 (4 in the preferred embodiment). On the other side, under the action of force, the 'balance movement block 67 can move up and down or left and right. The two steel wires 6 8 ′ have excellent rigidity. One end of each of the steel wires 6 8 is folded up to a 90-degree angle. One of the steel wires 68 passes through the through hole 641 of the track moving block 64 ′ and is bent at 90 degrees. The end of the angle is connected to the aforementioned movable mirror 41, and the other wire 68 is passed through the through hole 67m of the balance moving block 67. The end of the angle of 90 degrees is connected to the foregoing balance block 43. The elastic wire 66, which is also mentioned, also serves as the lead wire of the tracking coil 65. When the current is passed in the tracking coil 65, the tracking moving block 64 may be; the left π (in the FG direction of the fifth middle) moves, and the wire 68 In the magnetic field through hole 641 generated by the tracking coil, the wire 68 will move slightly with the tracking moving block. "When no current is passed in the tracking coil 65, the wire 68 can slide freely in the through hole 6 4 1 Similarly, the balance moving block 67 can move in the opposite direction to the tracking movement block 64 when the current is opposite. The ten-balance moving block 67 can move in the left and right directions (Figure

Page 11 561455 V. Description of the invention (8) == Hj direction), the wire 68 is generated by the tracking coil 1 towel, the steel paste is slightly moved by the scale 67 while the 1 lock block is 6 ", but it is balanced; The moving direction of the moving block 67 is exactly opposite to that of the tracking moving block 64, and the amplitude of the micro-movement is the same. 杪 勤 ΐ 杪 U ί Hanging the number of evaluation wires 66 of the tracking moving block 64 and the balance moving block 67 will not affect the hollow Rotating movement of transmission member 54. Figure 4 shows the structural diagram of the present invention. Disc MF f disc: the upper part of the lower bracket 12 and the upper part are pressed down. The disc 20 is locked and locked. Please do not rotate. When the optical disc player starts to work, the rotating finger = 〇3 is driven by the red rotation driving device 35, so that the gear 33 and the gear and the gear I and I are rotated at high speed using the central axis A_B of the gear 33 as an axis. At Rotating: = 0 at the same day temple that rotates at high speed, the optical components and translation device will perform high-speed rotational movement together with the rotation ΐίϋ. The fine tracking device inside the rotation index 30 will also rotate synchronously; at the same time, the movable mirror 41 With the balance weight, the left and right directions on the rotation indicator 30 ( C_D direction) for linear reciprocating motion, at this time, the entire rotating mechanism maintains a balanced state; the fixed mirror 40 performs a high-speed rotational movement in synchronization with the rotation index 30 to keep the relative angle with the movable mirror 41 unchanged, so that the laser The light beam emitted by the head 70 is first reflected by the fixed mirror 40 to the movable mirror 41, and is converged to a track on the disc 20 through the focusing lens, and the f beams reflected from the reflection layer of the disc 20 are in turn. Received by the laser head 70 after passing through the focusing lens 42, the movable mirror 41, and the fixed mirror 40, that is, the mirror 41, the focusing lens 42, and the balance weight 43 which are rotated and moved at a high speed at a rotation index of 30, make a straight line When reciprocating, the light beam emitted by the laser head 70 is incident on the surface of the fixed mirror 40.

561455

The angle of incidence will remain the same. Similarly, the angle of incidence of the fixed mirror 40 and the incident angle of the movable lens 41 will also remain unchanged. The @@ beam reflected by the reflective layer of the disc 20 will also be reflected by the laser head along the same optical path. 70 receives, and transmits to the control circuit board 80 for processing via the asset line 81. In addition, on the same day that the gears 33, 3 52 drive the rotation index 30 at high speed, it does not affect the hollow transmission member 54 installed concentrically with the gear 33, because the gear 33 and the gear 352 play a clearance fit, and the friction between the two is sufficiently small. Therefore, when the gear 54i drives the movable mirror 41 and the balance weight 43, the rotation of the gear 33 is not affected. The light suspension wheel 34 provided at both ends of the rotation indicator 30 uses C_D as an axis to perform continuous rotary motion. During the continuous rotation motion, the outer edge of the light suspension wheel 34 is in contact with the inner wall of the annular limit device 36 Its function is to prevent the rotation index 30 from generating excessive jitter and excessive deflection deformation during high-speed rotation. At the same time, the rotation index 30, the movable mirror 41, the fixed mirror 40, and the balance weight 43 are all streamlined in appearance, in order to reduce the air resistance they receive during high-speed rotation. When the optical disc drive is performing read and write operations, the coarse tracking process is that the servo motor 55 drives the movable mirror 4 丨 to move in the left and right direction to change the read and write execution, that is, the diameter of the disc 20. The process of moving up. The linear reciprocating motion of the movable mirror 41 and the balance weight 43 is driven by the coarse tracking device. The servo motor 55 drives the gears 541 and 542 and the racks 52 and 53 via the gear 551 to convert the rotation of the servo motor 55 to The synchronous linear reciprocating movement of the movable mirror 41 and the balance block 43 is performed while the movable mirror 41 is moved, and the balance block 43 is also adjusted in real time in the opposite direction so as to start

Page 13 561455 V. Description of the invention (10) Final hold rotation refers to the control circuit that maintains the whole set of rotation for coarse tracking. The control circuit of the coarse tracking tester detects the packets and compares them to reflect the algorithm. The back-off power is amplified after the field and the two permanent magnets are moved in the left and right directions, and the drive is movable to achieve the same mark as the servo horse circuit of the device with real-time mark 30. The end of the process includes the tracking error. Of the movement, and the trace of the movement. Balance, maintain dynamic balance up to 55 by the electric current technology, no need to be heavy, the tracking coil is driven by the well-focused tracking of the complex error signal of the It error 6 5 the magnetic fields are mutually locked and the steel mirror 41 proves the rotation state; Control the tracking voltage of the newly opened transmitter head 70 in the 80, and the tracking voltage of the signal processing circuit. When the switch is on, the wire 68 and the indicator 30 are moved at high control. The laser head 70 and the tracking error in the new control circuit are moved. “After the error with the tracking”, the signal is errored, and then the tracking coil 65 is used to make the tracking move in conjunction with the steel wire 6 8 Lens 42 — The reflection mirror 41 is completed at the speed of rotation. The value is amplified, and then the magnetic block 64 generated by the transfer circuit generates left and right, left and right, and at the same time, the tracking coil 65 wound around the balanced moving block 67 passes a current in the opposite direction to the tracking coil 65 of the cumulative moving block 64. , Make the balance moving block 67 produce a fine movement in the opposite direction of the tracking moving block 64, and lock the wire 68 to move the wire 68 to the left and right, and adjust the left and right fine movement of the balance block 43 to ensure the entire set of rotating parts Balancing. '' The circuit and chip for controlling the tracking signal are the same as those used in the existing optical disc drive technology to control the tracking lens of the laser head 70 focus lens, and there is no need to redevelop a new chip and processing circuit. In addition, the control circuit board 80 used in the present invention is the same as the prior art.

561455 V. Description of the invention (11) ----- Consistent. The circuit that controls the rotation of the disc 2 in the original circuit board is used to control the rotation of the rotation index 30. The circuit that controls the linear reciprocation of the laser head 70 and its accessories in the original circuit board is used to control the rotation of the index 30. The linear movement of the movable mirror 41 and the balance weight 43 makes it unnecessary to develop a new control circuit and a new control chip, which reduces the manufacturing cost. In summary, the low-inertia optical disc drive device (1) provided by the present invention is characterized in that the disc and the stray head are stationary, the optical component is used as the medium for the laser head optical path transmission, and the precise tracking device is accurate in real time. In addition, it has the advantages of small actuator components, easy control, simple structure, and low cost. It provides effective solutions and countermeasures for the lack of inertia, high energy consumption, and high heat generated by traditional optical disc drive devices. The unprecedented design has indeed met the application requirements for invention patents. We sincerely ask the Bureau to examine it in detail and grant the patent in order to benefit the people and benefit the country and the people. Only the methods, techniques, diagrams, programs, or controls described above are just one of the preferred embodiments of the present invention; for example, all the equivalent changes or modifications or extraction of some functions made according to the patented technology of the present invention are similarly made. 'All should still be within the scope covered by the patent right of the present invention; when the scope of implementation of the present invention cannot be limited accordingly.

Page 15 561455 Brief description of the drawings Description of the drawings: Figure 1 is a schematic diagram of the disc installation device of the present invention; Figure 2A is a schematic side view of the rotation index structure of the present invention; Figure 2B is a rotation index of the present invention Top view of the structure; Figure 3A is a schematic side view of the coarse tracking mechanism of the present invention; Figure 3B is a schematic top view of the coarse tracking mechanism of the present invention; Figure 4 is a specific embodiment of the present invention; It is a three-dimensional enlarged schematic view of the fine tracking actuator of the present invention; FIG. 6 is a schematic diagram of the spatial configuration of the fine tracking mechanism of the present invention; FIG. 7 is a plan view of FIG. 6; and FIG. 8 is an enlarged view of the A-B section of FIG. Description of drawing number: 10 disc fixing device 11 disc installation upper pressing device 12 disc lower support 20 disc 30 rotation index 31 transverse groove 32 hole 3 3 gear 34 light suspension wheel 3 5 rotary drive device 3 5 1 drive motor

Page 16 561455 Brief description of the drawings 352 Gear 3 6 Ring stop device 40 Fixed mirror 41 Movable mirror 42 Focusing lens 43 Balance block 50 Moving plate 51 Bushing 5 2 Rack 53 Rack 54 Hollow transmission 5 4 1 Upper gear 542 Lower gear 5 5 Servo motor 5 5 1 Gear 6 0 Permanent magnet 61 connector 62 holder 63 connector 6 4 Tracking moving block 641 Through hole 65 Tracking coil 6 6 Elastic wire 67 Balanced moving block

Page 17 561455 Simple illustration of the drawing 6 7 1 through hole 68 steel wire 70 laser head 8 0 control circuit board 81 data line

Page 18

Claims (1)

561455 VI. Scope of patent application 1: A kind of low inertia optical disc drive equipped with a displacement device, including the right batch of soil 1 1), including the optical component as a straight line ^ Fu Jiang 2 component rotation index and control shot The coarse tracking device that emits the light beam from the head on the disc is used to convert the optical component of radium. It is set on the rotating finger beam transmission member. Π is used as the light tracking device emitted by the laser head. Transform to the dish ... the micro-displacement of the standard component 'makes the stray beam fine 2. As for the scope of patent application! Item mentioned above), wherein the rotation indicator is a moving device (two horizontal grooves and a one at the center of the plate); :::: 'It is provided with a record of -cheng-body. It is convexly arranged below the hole Rich money indicator with low-inertia optical disc drive device (2) as described in the scope of patent application (2), wherein two ends of the rotation indicator are respectively provided with a lightweight suspension wheel which rotates the indicator horizontally. The central axis is a shaft that can be rotated continuously. 4. The low-inertia optical disc drive device (2) as described in item 3 of the scope of patent application, wherein the suspension wheel is rotated on a ring-shaped limit device and contacted to prevent it The rotation index is within the range of excessive jitter during high-speed rotation and controlled deflection. '5. The low-inertia optical disc drive device (2) as described in item 1 of the patent application range, wherein the rotation index is driven by a rotation The device controls the rotation. The rotation driving device is composed of a driving motor combined with a gear, which is combined with the gear integrated with the rotation index as described in item 2. Page 19 561455 6. The low-inertia optical disc drive device described in item 1 of the scope of patent application (2) 'wherein the optical component includes: a fixed reflector' fixed at the center of the rotation index to refract the laser beam to Removable mirror or refracted to laser head. A movable mirror is set on one side of the rotating index, and a convex lens for condensing laser light is provided at an appropriate angle ax to converge the laser beam transmitted from the fixed mirror to the disc, or The beam reflected by the disc is transmitted to the fixed mirror; a balance block is placed on the opposite side of the movable mirror to maintain the balance of the rotation index. 7. The low-inertia optical disc drive device (2) as described in item 丨 of the patent application scope, wherein the coarse tracking device includes two moving plates, which are mounting bases for movable mirrors and weights A set of shaft sleeves is provided on the bottom of the rotation indicator, and is respectively connected to the appropriate positions on both sides of the rotation indicator. A rack is provided on the side, which is respectively placed on the side of the movable mirror and the balance weight. A hollow transmission is fixed on the inner edge of the hole, and a gear is arranged at the upper and lower ends, wherein the upper gear is connected to the two racks; a servo motor is combined with a gear, and the gear is connected to The gear that fits at the lower end of the hollow transmission part is used to drive the movable mirror and the balance block to make a straight line 8 · The low-inertia optical disc drive device described in item 丨 of the patent application scope), where the fine tracking device includes: Tracking moving block one by one, which is provided with a through hole. Page 20 561455 6. The scope of the patent application: The elastic wire is suspended between two permanent magnets and one side of the hollow transmission member. Under the action of force, the tracking moving block can move up and down or left and right; a balanced moving block is provided with a consistent A hole is wound with a tracking coil externally. It is suspended between permanent magnets and the other side of the hollow transmission member through a plurality of elastic wires. Under the action of force, the balance moving block can move up and down or left and right; Excellent rigidity, one end of each wire is folded up to a 90 degree angle, one of the wires is passed through the through hole of the track moving block, and the end of the f-folded 90 degree angle is connected to the aforementioned movable The other wire of the mirror is passed through the through hole of the balance weight, and the end bent at a 90-degree angle is connected to the balance weight. 9. The low-inertia optical disc drive device (2) according to item 8 of the scope of the patent application, wherein the elastic wire is used as a lead wire of a tracking coil. 10. The low-inertia optical disc drive device (2) according to item 8 of the scope of the patent application, wherein when the tracking coil is energized, a magnetic field will be generated to act on the two permanent magnets to drive the tracking moving block and the balancing moving block. Micro-movement in left and right directions 11 · The low inertia optical disc drive device described in item 10 of the patent application scope (2), wherein the current of the tracking coil by winding the balance moving block and the current of the tracking coil by winding the balance moving block The equal directions are opposite, so that the micro movement direction of the tracking movement block and the balance movement block is opposite, and the micro movement amplitude is the same.