CN1251222C - Magnetic Test Method of Optical Disc Clamp - Google Patents

Abstract

The present invention discloses a method for testing the magnetic properties of a disc clamp, which is applicable to a tray-type optical drive. The method uses a DC motor input voltage control method to adjust the tray's ejection force so that when the ejection force is insufficient to complete the tray's ejection, an ejection test is performed on the tray. The ejection distance of the tray during the ejection test is measured as a basis for determining whether the clamp's magnetic properties are abnormal.

Description

Magnetic Test Method of Optical Disc Clamp

technical field

The invention relates to a clamp for a tray-type optical drive, in particular to a method for magnetic testing of a disc clamp applied to a tray-type optical drive.

Background of the invention

Due to the advent of the electronic information age, the demand for portable digital storage media with high capacity is also increasing day by day, and the storage capacity provided by the floppy disk (floppy disk) that was widely used in the early days is no longer sufficient. Therefore, optical storage media and storage devices with characteristics such as high storage capacity, high quality, portability, and easy storage are rapidly and widely used, such as CD-ROM drives and CD-R drives. etc.

Optical disc drives can generally be divided into tray type (tray) and slot-in (slot-in) optical drives by the way the disc is inserted and ejected. A known tray-type optical drive usually has a structure as shown in FIG. A motor 40 as a driving device. In FIG. 1 a , the optical read-write head 20 , the turntable 30 and the motor 40 are all arranged in a frame 50 , and the tray 10 is movably arranged on the frame 50 . There can be more than one set of motors 40 for driving the optical pickup 20 , the turntable 30 , and the gear belt set 52 on the frame 50 respectively. The tray 10 has a recessed bearing part 12 for carrying the optical disk, and the bottom of the tray 10 is provided with a rack, which can be engaged with the gear belt set 52, so that the tray 10 is driven by the gear belt set 52 to slide relative to the frame 50 . In addition, a support plate 26 is provided in the frame 50 to support the optical pick-up head 20 and the turntable 30, so that the turntable 30 can extend into the center hole of the optical disc to drive the optical disc to rotate, and the optical pick-up head 20 can move relative to the optical disc. slices to move. In addition, in order to control the relative position of the tray 10 and the frame 50 when sliding, a position detection device for the tray 10 is usually provided on the frame 50, for example, an inner limit switch 54 and an outer limit switch are arranged on the frame 50 of FIG. 1a 56, to detect the relative position of the tray 10 and the frame 50 when sliding.

In addition, in order to fix the optical disc to the turntable 30 for rotation, a clamper device is usually used to fix the optical disc to the turntable 30 . For example, FIG. 1b shows an example of a clamp device used in a conventional optical drive, wherein the clamp 60 is arranged on a swing arm, which can swing up and down relative to the rotating shaft 62, and fixes the optical disc 1 on the inserted optical disc. The turntable 30 in the center hole of the disc 1 enables the turntable 30 to stably drive the optical disc 1 to rotate. The fixing of the optical disc 1 by the clamp 60 can be carried out in various ways such as elastic clamping of an elastic body or magnetic attraction of an electromagnet according to different mechanism designs.

When the user intends to put the optical disk 1 into the tray-type optical drive to read and write, he must first withdraw the tray 30 so that the tray slides out of the optical drive so that the user can place the optical disk 1 on the loading portion of the tray 10. 12, and then put the tray 10 into the optical drive, so that the turntable 30 extends into the center hole of the optical disc 1. In this way, the optical disk 1 can be fixed on the turntable 30 by the clamp 60, the optical disk 1 is driven to rotate by the turntable 30, and then the optical pickup 20 writes data into the optical disk 1, or reads data from the optical disk 1. fetch data.

Generally speaking, in order to improve the operating efficiency of the tray-type optical drive, a DC motor (DC motor) is usually used as the motor 40 for controlling the sliding of the tray 10 and the clamping action of the clamp 60 . In this way, the output torque and power can be controlled by the input voltage of the DC motor, so that when the tray 10 is feeding or ejecting the optical disk 1, the clamp 60 can act synchronously, so as to save the tray 10 and the clamp 60 from operating separately. time.

Referring to FIG. 1 c , the process of controlling the tray 10 and the clamp 60 by the DC motor 40 will be described by taking the ejection of the tray 10 of the tray-type optical drive as an example. When the user inputs an instruction to withdraw the tray from the optical drive (step S10), the DC motor 40 receives a front-stage input voltage, and simultaneously drives the clamp 60 and the gear belt assembly 52 (step S20), so that the clamp 60 releases the optical disc 1, And provide an exit force to the tray 10, ready to drive the tray 10 to exit outward. This stage is the front stage withdrawal action of the tray 30 . When the tray 10 starts to move and the inner limit switch 56 is driven, it indicates that the optical disk 1 has been out of position, and the front stage withdrawal action is completed (step S30); at this time, the DC motor 40 can stop the driving of the clamp 60, and continue to receive an input voltage, The tray 10 is driven outward by the drive gear belt set 52 with the withdrawal force (step S40 ). When the tray 10 slides to the outside of the optical drive and drives the outer limit switch 54 (step S50), it means that the tray 10 has retreated to the outside, and now the DC motor 40 can stop driving (step S60), so that the tray 10 stops sliding and the withdrawal action is completed. .

However, if the tray-type optical drive uses an electromagnet as the magnetic force clamp 60, because the clamp 60 may have magnetic anomalies due to manufacturing defects, or abnormal conditions in the assembly or operation of the optical drive, it cannot be used. The action of sucking and clamping the optical disc 1 is surely carried out. This may not only cause the problem that the optical disc 1 cannot be read normally, but also may cause the optical disc 1 to be scratched due to the poor adsorption of the clamp 60 when the tray 10 is fed into or withdrawn, which affects the feeding or ejection. Exit action.

In view of the above problems, although it is possible to measure the magnetic properties of the clamps during manufacture to reduce the failure rate of the magnetic properties of the clamps, however, measuring the magnetic properties of each clamp will increase the time and cost of the manufacturing process, which is not only time-consuming Laborious, and still unable to prevent the clamp from magnetic anomalies caused by improper assembly or handling of the optical drive.

Contents of the invention

In view of this, an object of the present invention is to propose a method for testing the magnetism of the disc clamp, using the voltage control of the DC motor to measure the parameters when the tray of the tray-type optical drive is withdrawn, as a method for judging whether the clamp is magnetic or not. In this way, it is possible to test whether the magnetism of the clamp is abnormal through the simple tray exit inspection action directly during the test of the optical drive assembly, without additional magnetic test of the clamp.

The invention discloses a method for testing the magnetism of a disc clamp, which is suitable for a tray-type optical drive. Firstly, a front-stage input voltage is provided to the DC motor of the tray-type optical drive to drive the tray and clamp of the tray-type optical drive to perform a front-stage ejection action. After the previous stage of ejection is completed, a test voltage that is smaller than the previous stage input voltage and not enough to complete the ejection of the tray is provided to the DC motor to drive the tray to perform an ejection test. When the withdrawal distance of the tray in the withdrawal test action is greater than a certain distance, it means that the magnetic adsorption force of the clamp is insufficient, so it is determined that the clamp is magnetically abnormal.

A method for testing the magnetism of a disc clamp provided by the present invention is suitable for a tray-type optical drive, and the method includes the following steps:

providing a front-stage input voltage to a DC motor of the tray-type optical drive to drive a tray and a magnetic clamp of the tray-type optical drive to perform a front-stage ejection action;

providing a test voltage to the DC motor which is smaller than the input voltage of the previous stage and not enough to complete the ejection action of the tray, so as to drive the tray to perform an ejection test action; and

When the withdrawal distance of the tray in the withdrawal test action is greater than a specific distance, it is determined that the magnetic clamp is magnetically abnormal.

Said front-stage withdrawing action includes the action of the magnetic clamp detaching from a disc and the action of the tray driving an inner limit switch.

The aforementioned front-stage input voltage and test voltage are determined according to the ratio of the input current to the output power of the DC motor.

The front-stage input voltage includes a first input voltage of 6 volts and a second input voltage of 3.4 volts.

The test voltage includes a DC voltage of 2.2 volts.

Since the magnetic testing method of the optical disk clamp of the present invention is to perform the magnetic test of the clamp after the tray type optical drive is assembled, it can ensure that the magnetic abnormality of the clamp will not occur due to improper assembly or operation of the optical drive.

Description of drawings

Figure 1a is a perspective view of a tray structure of a conventional tray-type optical drive;

FIG. 1b is a schematic diagram of a clamp structure of a conventional tray-type optical drive;

Fig. 1c is a flow chart of the ejection action of the tray-type optical drive;

FIG. 2 is a flow chart of a method for magnetically testing an optical disc clamp according to an embodiment of the present invention;

FIG. 3 is a graph showing the relationship between the input voltage and time of the DC motor in an embodiment of the present invention.

Symbol Description

1～CD;

10～trays;

12～carrying part;

20～optical reading head;

26 ~ support plate;

30 ~ turntable;

40～motor;

50 ~ frame;

52～gear belt set;

54 ~ inner limit switch;

56 ~ outer limit switch;

60 ~ clamp;

62 ~ rotating shaft;

110～front input voltage;

112～the first input voltage;

114～the second input voltage;

120 ~ test voltage.

Detailed ways

As described in the prior art, in the tray-type optical drive, the clamp may have magnetic abnormalities due to manufacturing defects, or abnormal conditions in the assembly or operation of the optical drive, and cannot reliably absorb and hold the optical disc. At this time, if the ejection action of the tray is performed on the tray-type optical disc drive with the magnetically abnormal clamp, it may also be affected jointly, and the tray cannot be ejected normally.

Therefore, the method for testing the magnetism of the disc clamp proposed by the present invention aims at the characteristics that the abnormality of the clamp’s magnetism will affect the withdrawal action of the tray, and uses the method of controlling the input voltage of the DC motor to adjust the withdrawal force of the tray so that the withdrawal force is insufficient. Perform an exit test on the tray under the condition that the tray completes the exit action, and measure the distance when the tray exits during the exit test action as a basis for judging whether the magnetism of the clamp is abnormal. In this way, during the manufacturing process of the tray-type optical drive, the manufacturer does not need to perform an additional magnetic test of the clamps, and can test whether the magnetic properties of the clamps are abnormal by simply performing a simple tray withdrawal inspection action during the assembly test of the optical drive.

Referring to FIG. 2 and FIG. 3 , an embodiment of the magnetic testing method of the disc clamp of the present invention will be described in detail.

The magnetic testing method of the optical disk clamp of the present invention is improved by withdrawing the action of the tray, and is suitable for a tray-type optical drive, such as the tray-type optical drive shown in Figure 1a and Figure 1b, wherein the clamp 60 uses the magnetic force of the electromagnet Adhesive magnetic clamp.

When the manufacturer of the tray-type optical drive intends to carry out the clamp magnetic test on an assembled tray-type optical drive, it must first input an exit test command (step S110). At this time, a front-end input voltage will be sent to the tray-type optical drive The DC motor 40 is used to drive the tray 10 and the magnetic clamp 60 of the tray-type optical drive to perform the front-stage withdrawing action (step S120 ). Specifically, this front-stage exit action is exactly the same as the front-stage exit action in the general tray exit action, that is, as described in steps S20 and S30 of FIG. 1c, the DC motor 40 simultaneously drives the magnetic clamp 60 and The gear belt set 52 enables the magnetic clamp 60 to release the optical disk 1, and provides an exit force to the tray 10, ready to drive the tray 10 to slide out until the inner limit switch 56 is driven when the tray 10 starts to move, indicating that the optical disk 1 It has been out of position, so the previous exit action is completed.

As described in step S20 of FIG. 1c, when performing the withdrawal action at the front stage, the DC motor 40 simultaneously drives the magnetic clamp 60 and the gear belt set 52, so that the magnetic clamp 60 releases the optical disc 1, and provides an withdrawal force to the tray 10, ready to Drive the tray 10 to slide out outward. At this time, if the magnetic adsorption force of the magnetic clamp 60 is normal, the action of releasing the optical disc 1 from the magnetic clamp 60 will consume a part of the power provided by the DC motor 40, thus limiting the ejection force of the tray 10 to a certain range. However, if the magnetism of the magnetic gripper 60 is abnormal, the power consumption provided by the DC motor 40 in the magnetic gripper 60 will be reduced, thereby relatively increasing the withdrawing force of the tray 10 . Therefore, the lower the magnetic adsorption force of the magnetic clamp 60 , the greater the withdrawal force of the tray 10 will be, thus affecting the subsequent withdrawal action of the tray 10 .

According to the above-mentioned principle, after the previous stage of withdrawing action is completed, a test voltage that is smaller than the input voltage of the previous stage and not sufficient to enable the tray 10 to complete the withdrawing action can be provided to the DC motor 40 to drive the tray 10 to perform an exiting test action (step S130 ). Since the test voltage is set to be insufficient to enable the tray 10 to complete the ejection action, the tray 10 cannot be completely ejected to the exception. At this time, the ejection distance of the tray 10 is related to the ejection force received by the tray in the previous stage ejection action. If the withdrawing force of the tray 10 in the previous withdrawing action is greater, the withdrawing distance of the tray 10 is farther; In other words, when the withdrawing distance of the tray 10 is longer, it means that the withdrawing force of the tray 10 in the previous withdrawing action is greater, that is, the magnetic adsorption force of the magnetic clamp 60 is smaller.

After the exit test action, the exit distance of the tray 10 in the exit test action can be measured (step S140 ), and it is determined whether the exit distance of the tray 10 is greater than a specific distance (step S150 ). This specific distance can be obtained through experiments. When the withdrawal distance of the tray 10 is greater than this specific distance, it means that the magnetic adsorption force of the magnetic clamp 60 is insufficient, so it can be determined that the magnetic clamp 60 is magnetically abnormal (step S160) and must be replaced; and when the withdrawal of the tray 10 When the distance is not greater than the specified distance, it means that the magnetic adsorption force of the magnetic clamp 60 is normal, so it can be determined that the magnetic clamp 60 meets the standard (step S170 ).

FIG. 3 shows the relationship between the input voltage of the DC motor 40 and time during the magnetic test of the disc clamp of the present embodiment. In Fig. 3, the front stage input voltage 110 adopts the first input voltage 112 of 6 volts and the second input voltage 114 of 3.4 volts, so that the DC motor 40 can smoothly drive the magnetic clamp 60 and the gear belt set 52 simultaneously, so that the magnetic The clamp 60 releases the optical disc 1 and provides an ejection force to slide the tray 10 outward. In the exit test action, the test voltage 120 adopts a DC voltage of 2.2 volts, which is significantly lower than the second input voltage 114 , so that the tray 10 is not enough to complete the exit action, and the exit test action can be performed.

It must be noted here that the input voltage 110 and the test voltage 120 of the present invention are related to the input current and output power ratio of the DC motor 40 used in the tray-type optical drive. Therefore, for the structure of different tray-type optical drives, reference can be made to the DC motor 40, the appropriate values of the front-end input voltage 110 and the test voltage 120 are obtained through experiments.

With the magnetic testing method of the disc clamp of the present invention, the manufacturer of the tray-type optical drive does not need to perform an additional magnetic test of the clamp during the manufacturing process of the tray-type optical drive, and only needs to use the simple tray directly when the optical drive is assembled and tested. Exit the inspection action to test whether the magnetism of the clamp is abnormal, so that the probability of magnetic abnormality of the clamp can be ensured without adding additional time cost.

In addition, since the method for testing the magnetism of the disc clamp of the present invention is to perform the magnetic test of the clamp after the tray-type optical drive is assembled, it can be ensured that the clamp will not produce magnetic abnormalities due to improper assembly or operation of the optical drive. question.

Although the present invention has been disclosed above with specific preferred embodiments, it is not intended to limit the present invention. Anyone skilled in this art can still make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be defined by the scope of the appended patent application.

Claims (5)

1. A method for magnetic testing of disc clamps, suitable for a tray-type optical drive, characterized in that the method comprises the following steps: Provide a front-stage input voltage to a DC motor of the tray-type optical drive to drive a tray and a magnetic clamp of the tray-type optical drive to perform a front-stage exit action, the front-stage exit action includes the action of a clamp detached from an optical disc and the Tray exit action; providing a test voltage to the DC motor which is smaller than the input voltage of the previous stage and not enough to complete the ejection action of the tray, so as to drive the tray to perform an ejection test action; and When the withdrawal distance of the tray in the withdrawal test action is greater than a specific distance, it is determined that the magnetic clamp is magnetically abnormal. 2. The method for testing the magnetism of a disc clamp as claimed in claim 1, wherein the front-stage withdrawing action further includes an action in which the tray drives an inner limit switch. 3. The method for magnetically testing the disc clamp as claimed in claim 1, wherein the front-end input voltage and the test voltage are determined according to the ratio of the input current to the output power of the DC motor. 4. The method for magnetic testing of disc clamps as claimed in claim 1, wherein the front-stage input voltage includes a first input voltage of 6 volts and a second input voltage of 3.4 volts. 5. The method for testing the magnetism of an optical disc clamp as claimed in claim 4, wherein the test voltage comprises a DC voltage of 2.2 volts.

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