JP2000339732A - Optical pickup device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical pickup device in which maintenance work is easily conducted. SOLUTION: In the optical pickup device, both terminals of normally closed switches 5 and 6 are respectively connected to the anode and the cathode of a laser diode 2. The switch 5 is made into an open condition by the input from a control terminal CNT connected to a flexible cable and the switch 6 is made into an open condition by the input from a power supply terminal VCC.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical pickup device used for a CD player or the like, and more particularly, to an optical pickup device which facilitates maintenance.

[0002]

2. Description of the Related Art FIG. 3 shows an example of a circuit of an optical pickup head 1 of a conventional optical pickup device. The cathodes of the laser diode 2 and the photodiode 3 shown in the figure are connected to a printed circuit board from a ground terminal GND by a flexible cable. The anode of the laser diode 2 is connected to the printed circuit board by a flexible cable from a laser diode terminal LD, and the laser diode 2 receives a forward bias and emits light.

The photodiode 3 is a laser diode 2
, And outputs a current corresponding to the amount of light received on the light receiving surface from the photodiode terminal PD to the printed circuit board via the flexible cable. The volume 4 has one terminal connected to a printed circuit board via a volume terminal VR and a flexible cable, and the other terminal connected to the anode of the photodiode 3.
The current output from the photodiode 3 is finely adjusted.

The anode and the cathode of the laser diode 2 are connected to short lands 7, 7, respectively. When removing the optical pickup head from the printed circuit board, the short lands 7, 7 are short-circuited by soldering to prevent electrostatic breakdown.

[0005]

In the above-mentioned conventional optical pickup device, when the soldering between the short lands 7 and 7 is repeated, the land portion causes metal fatigue due to the soldering, and the land surface is peeled off. There has been a problem that subsequent maintenance work becomes difficult.

Further, since the short lands 7, 7 are often provided on the back surface of the optical pickup head, it is difficult to remove the solder between the short lands 7, 7 after connecting the optical pickup head to the printed circuit board. There was a problem that maintenance work was difficult.

[0007] The present invention has been made in view of the above points, and an object of the present invention is to provide an optical pickup device capable of easily performing maintenance work.

[0008]

According to the optical pickup device of the present invention, both terminals of a normally closed switch are connected to an anode and a cathode of a laser diode, respectively, and the switch is connected to a control terminal or a flexible terminal. It is configured to be in an open state by an input from a power supply terminal.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An optical pickup device according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a circuit diagram showing an optical pickup head 1 of an optical pickup device according to a first embodiment of the present invention. In the figure, portions having the same functions as those shown in the conventional example are denoted by the same reference numerals, and detailed description thereof will be omitted.

In this example, the normally closed contact terminal of the one-contact switch 5 is connected to the anode and the cathode of the laser diode 2, respectively. The control terminal of the one-contact switch 5 is connected to the printed circuit board via the control terminal CNT and a flexible cable.

When the optical pickup head is detached from the printed board, or when a signal for closing the one-contact switch 5 is input from the control terminal CNT even when the optical pickup head is connected to the printed board, the one-contact switch 5 Is closed, and the anode and the cathode of the laser diode 2 become conductive.

An optical pickup head is connected to a printed circuit board, and a signal for opening a switch contact is input to a control terminal CNT to thereby control the laser diode 2.
Then, the space between the anode and the cathode is open, and the optical pickup is ready for use. In this way, when the optical pickup head is detached from the printed circuit board, the soldering of the short land is not required, and the maintenance is easy.

FIG. 2 is a circuit diagram showing an optical pickup head of an optical pickup device according to a second embodiment of the present invention. In this example, a two-contact switch 6 is used instead of the one-contact switch 5 of the first embodiment. That is,
The normally closed terminal and the two-contact switch 6 are connected to the ground and the anode of the laser diode 2, respectively.

The normally open terminal of the two-contact switch 6 is not connected to the circuit. One terminal of the coil of the two-contact switch 6 is connected to a printed circuit board via a power supply terminal VCC and a flexible cable, and the other terminal is connected to ground via a resistor.

If no power supply voltage is applied to the power supply terminal VCC, no magnetic field is generated by the coil, the terminals are opened, and the terminals are closed. That is,
When the optical pickup head is detached from the printed circuit board, soldering of the short land is not required, and maintenance is easy. When the optical pickup head is connected to the printed circuit board by a flexible cable, the anode and the cathode of the laser diode 2 are opened, and the optical pickup is ready for use.

Although the embodiment is constructed as described above, the invention is not limited to this. For example, if the switch has one or more contacts having a control terminal as a switch for short-circuiting the anode and cathode of the laser diode, an electronic switch, An analog switch, a digital switch, or the like can be used.

[0017]

According to the optical pickup device of the present invention, the soldering work for short-circuiting the anode and the cathode of the laser diode in the optical pickup head becomes unnecessary, and the maintenance work becomes easy. In addition, the metal fatigue due to the detachment of the solder is eliminated, and the safety is improved.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing an optical pickup head of an optical pickup device according to a first embodiment of the present invention.

FIG. 2 is a circuit diagram showing an optical pickup head of an optical pickup device according to a second embodiment of the present invention.

FIG. 3 is a circuit diagram showing an optical pickup head of a conventional optical pickup device.

[Explanation of symbols]

 Reference Signs List 1 optical pickup head 2 laser diode 3 photodiode 4 volume 5 1 contact switch 6 2 contact switch 7 short land GND ground terminal VR volume terminal PD photodiode terminal LD laser diode terminal CNT control terminal VCC power supply terminal

Claims (1)

[Claims] 1. Both terminals of a normally closed switch are connected to an anode and a cathode of a laser diode, respectively, and the switch is opened by an input from a control terminal or a power supply terminal connected by a flexible cable. Optical pickup device configured.