JP2005268362A - Optical pickup device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical pickup device capable of utilizing a lead not functioning in a conventional light emitting element, and of improving the flexibility of a device design. <P>SOLUTION: An LD 110 for emitting an optical beam comprises a stem 112 having a first face 160 and a second face 161; a heatsink 113 joined to the first face 160; leads 114, 115, and 116 penetrating the first face 160 and the second face 161; and a chip 117 held on the heatsink 113 and conducted to the leads 114, 115, and 116. The leads 114, 115, and 116 include the two leads 115, 116 functioning as an electrically identical terminal, and include the one lead 114 functioning as an electrically different terminal from the two leads 115, 116 in the LD 110. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present application belongs to the technical field of an optical pickup device that irradiates an information recording medium with a light beam.

  2. Description of the Related Art Conventionally, as this type of optical pickup device, an apparatus including a light emitting element that emits a light beam and an optical member that irradiates the information recording medium with the emitted light beam is known (for example, see Patent Document 1).

Specifically, a conventional light emitting device includes a disc-shaped stem, a heat sink joined to the stem, a plurality of (for example, three) leads penetrating the stem, and a chip that is held by the heat sink and is electrically connected to the lead. And a cap for protecting the chip.
Japanese Unexamined Patent Publication No. 2004-5903 (page 6, FIG. 2)

  However, although the above-described conventional light emitting element has a plurality of (for example, three) leads, one lead is an anode terminal, one lead is a ground terminal, and one lead is There was a situation that the lead of is unused.

  Specifically, the unused lead is a back monitor terminal for controlling the light emission output. However, when a separate front monitor is provided, it remains as a non-functional lead, particularly in a recording light emitting device. ing.

  Therefore, the present application has been made in view of the above-described circumstances, and as an example of the problem, a lead that does not function in a conventional light emitting element can be used, and the degree of freedom in device design can be improved. An object of the present invention is to provide an optical pickup device that can be used.

  In order to solve the above-described problem, a light-emitting element according to claim 1 is a light-emitting element that emits a light beam, bonded to a base portion having a first surface and a second surface, and to the first surface. A plurality of leads penetrating the first surface and the second surface, and a chip held by the wall portion and conducting to the plurality of leads. And having two leads that function as the same terminal and one lead that functions as a terminal that is electrically different from the two leads. ing.

  The best mode for carrying out the present application will be described below with reference to the drawings. The embodiment described below shows an embodiment in which the optical pickup device according to the present application is applied to, for example, an information recording / reproducing device.

  Specifically, the information recording / reproducing apparatus in the present embodiment includes information such as a CD (Compact Disc), an MD (Mini Disc), an MO disc (Magneto Optical Disc), a DVD (Digital Versatile Disc), and other large-capacity discs. Information is recorded or reproduced by irradiating a recording medium (hereinafter simply referred to as “optical disk”) with a light beam.

  First, the configuration of the information recording / reproducing apparatus in the present embodiment will be described with reference to FIG. FIG. 1 is a perspective view of the information recording / reproducing apparatus in the present embodiment.

  As shown in FIG. 1, the information recording / reproducing apparatus 100 in this embodiment illustrates LDs (Laser Diodes) 110 and 111 as examples of light emitting elements that emit light beams, and light beams emitted from the LDs 110 and 111. The optical member 120 that irradiates the optical disk not to be received, PDs (Photo Detectors) 140 and 141 that receive the light beam incident through the optical member 120, and a frame 150 that supports each member are provided.

  For example, the LD 110 generates a laser with a short wavelength (for example, 650 nm) for DVD, and emits the generated light beam to the optical member 120. Thus, the light beam emitted from the LD 110 is used for recording or reproducing information. The configuration of the LD 110 will be described below.

  For example, the LD 111 generates a laser having a long wavelength (for example, 780 nm) for CD, and emits the generated light beam to the optical member 120. Thus, the light beam emitted from the LD 111 is used for recording or reproducing information.

  The optical member 120 includes gratings 121 and 122, a combining prism 123, a half prism 124, a liquid crystal plate 125, a collimator lens 126, a quarter wavelength plate 127, a rising mirror 128, an objective lens 129, And a multi lens 130, which is disposed along the optical axis of the LDs 110 and 111.

  The grating 121 diffracts the light beam incident from the LD 110 to divide the light beam into, for example, zero-order light and ± first-order light, and emit the divided light beam to the combining prism 123.

  The grating 122 divides the light beam incident from the LD 111 into, for example, 0th order light and ± 1st order light, and emits the divided light beam to the combining prism 123.

  The combining prism 123 reflects the light beam incident from the grating 121 and emits the reflected light beam to the half prism 124. The combining prism 123 transmits the light beam incident from the grating 122 and emits the transmitted light beam to the half prism 124.

  The half prism 124 transmits a part of the light beam incident from the combining prism 123 and emits the transmitted light beam to the liquid crystal plate 125. Further, the half prism 124 reflects a part of the light beam incident from the combining prism 123 and emits the reflected light beam to the PD 141.

  Further, the half prism 124 is reflected by the optical disk, reflects the light beam incident through the objective lens 129, the rising mirror 128, the quarter wavelength plate 127, the collimator lens 126, and the liquid crystal plate 125, and is reflected. The emitted light beam is emitted to the multi-lens 130.

  The liquid crystal plate 125 corrects wavefront aberration generated in the light beam by giving a phase difference to the light beam incident from the half prism 124, and emits the corrected light beam to the collimator lens 126. ing.

  The collimator lens 126 converts the light beam incident from the liquid crystal plate 125 from divergent light to parallel light, and emits the converted light beam to the quarter wavelength plate 127.

  The quarter wavelength plate 127 converts the light beam incident from the collimator lens 126 from linearly polarized light to circularly polarized light, and emits the converted light beam to the rising mirror 128.

  The raising mirror 128 reflects the light beam incident from the quarter-wave plate 127 and emits the reflected light beam to the objective lens 129.

  The objective lens 129 collects the light beam incident from the raising mirror 128 and irradiates the optical disk with the collected light beam.

  The multi lens 130 condenses the light beam incident from the half prism 124 and irradiates the PD 140 with the collected light beam.

  The PD 140 receives the light beam incident from the multi-lens 130, generates a light reception signal according to the received light beam, and outputs the generated light reception signal to a signal processing circuit (not shown). Yes. The signal processing circuit generates an error signal for executing the tracking servo and the focus servo based on the light reception signal input from the PD 140 and decodes information recorded on the optical disc.

  The PD 141 receives the light beam incident from the half prism 124, generates a light reception signal according to the received light beam, and outputs the generated light reception signal to an APC (Auto Power Control) circuit (not shown). It is like that. The APC circuit controls the light emission output of the LDs 110 and 111 based on the light reception signal input from the PD 141.

  The frame 150 includes holders 151 and 152 that hold the LD 110 from the back. The tilt of the LD 110 with respect to the frame 150 is adjusted by rotating the holder 151.

  Next, the structure of the light emitting element in this embodiment will be described with reference to FIGS. 2 and 3 are perspective views of the light emitting elements of the information recording / reproducing apparatus shown in FIG.

  As shown in FIG. 2, the LD 110 in this embodiment includes a stem 112 as an example of a base, a heat sink 113 as an example of a wall, a plurality of (for example, three) leads 114, 115, and 116, and a laser. A chip 117 to be generated and a cap 118 that protects the chip 117 are provided and supported by the frame 150 through holders 151 and 152.

  The stem 112 is made of a metal material formed in an I shape (I-cut), and has a first surface 160 and a second surface 161 as a back surface of the first surface 160.

  In the present embodiment, the stem 112 is formed in an I shape (I cut), but is not limited thereto, and may be formed in a D shape (D cut), a disc shape, or the like.

  The stem 112 is formed with a plurality of holes 162, 163, 164 (not shown) and a plurality of grooves 165, 166. The LD 110 is positioned with respect to the frame 150 by being attached to the holders 151 and 152 with the grooves 165 and 166 as a reference.

  The heat sink 113 is made of a metal material formed in a semicircular shape, and is bonded to the first surface 160 of the stem 112 so as to absorb heat generated in the chip 117.

  The leads 114, 115, 116 are made of a metal material formed in a rod shape and are inserted into holes 162, 163, 164 (not shown) of the stem 112, and the first surface 160 and the second surface 161 of the stem 112 are connected to each other. It penetrates. One end of the leads 114 and 115 protrudes in the vicinity of the chip 117, and one end of the lead 116 is joined to the heat sink 113.

  The leads 114, 115, and 116 are electrically identical terminals, for example, two leads 115 and 116 that function as ground terminals, and terminals that are electrically different from the two leads 115 and 116, for example, And one lead 114 functioning as an anode terminal.

  The chip 117 is held by the heat sink 113 so that the optical axis 101 of the emitted light beam coincides with the central axis 102 of the stem 112, and is conducted to the leads 114 and 115 via the wires 167 and 168, and the wire 169. In addition, the leads 116 are electrically connected to each other through the heat sink 113.

  The cap 118 is joined to the first surface 160 of the stem 112 so that the central axis 103 of the cap 118 and the central axis 102 of the stem 112 coincide with each other, and accommodates the heat sink 113, the leads 114 and 115, and the chip 117. It has become. The chip 117 emits a light beam through an opening 170 formed in the cap 118.

  Further, as shown in FIG. 3, the leads 114, 115, and 116 extend to the back of the LD 110, the lead 114 is held by the stem 112 via an insulating material 171, and the lead 115 is made of a metal material 172. The lead 116 is held by the stem 112 via the metal material 173.

  In the LD 110 configured as described above, the heat absorbed by the heat sink 113 is conducted to the leads 115 and 116 via the stem 112 and the metal materials 172 and 173. Thereby, the leads 115 and 116 release heat generated in the chip 117 to the outside.

  As described above, in this embodiment, the LD 110 includes the stem 112 having the first surface 160 and the second surface 161 and the heat sink joined to the first surface 160 in the LD 110 that emits a light beam. 113, a plurality of leads 114, 115, 116 that penetrate the first surface 160 and the second surface 161, and a chip 117 that is held by the heat sink 113 and is electrically connected to the plurality of leads 114, 115, 116. The leads 114, 115, 116 are electrically connected to the two leads 115, 116 that function as the same terminal, and the one lead 114, which functions as a terminal electrically different from the two leads 115, 116. It has the structure characterized by including.

  With this configuration, in this embodiment, the plurality of leads 114, 115, 116 are electrically different from the two leads 115, 116 that function as the same terminal and the two leads 115, 116. Since it is configured to include one lead 114 that functions as a terminal, it is possible to use a lead 115 that does not function in a conventional LD, and to improve the degree of freedom in device design, for example, LD The wiring, the shape of the holder, the arrangement of the holder, etc. can be selected as appropriate. Further, conventional LD parts can be used, and production facilities can be shared. Therefore, parts such as stems, heat sinks, leads, chips, caps, and production equipment used in conventional LDs with multiple (for example, three) leads can be used as they are. Become.

  In the present embodiment, the two leads 115 and 116 function as ground terminals.

  With this configuration, in the present embodiment, since the two leads 115 and 116 are independently wired to the chip 117, the electrical impedance of the ground of the chip 117 can be reduced. Can be increased, unnecessary radiation can be suppressed, and the influence of external noise can be reduced.

  In the present embodiment, the two leads 115 and 116 are held by the stem 112 via the metal materials 172 and 173, and the heat generated in the chip 117 is released to the outside. ing.

  With this configuration, in the present embodiment, the two leads 115 and 116 release the heat generated in the chip 117 to the outside, so that the heat dissipation effect of the chip 117 can be improved, and the LD 110 has a high output and a long life. Can be

  In this embodiment, the information recording / reproducing apparatus 100 includes the above-described LD 110 and an optical member 120 that irradiates the optical disk with the emitted light beam.

  In the present embodiment, the two leads 115 and 116 function as ground terminals. However, the present invention is not limited to this, and the two leads 114 and 115 function as anode terminals. Good.

  With this configuration, in this embodiment, the two leads 114 and 115 are independently wired to the chip 117, whereby the electrical impedance of the anode of the chip 117 can be reduced. Can be increased, unnecessary radiation can be suppressed, and the influence of external noise can be reduced.

It is a perspective view of the information recording / reproducing apparatus in one Embodiment of this application. It is a perspective view of the light emitting element of the information recording / reproducing apparatus shown in FIG. It is a perspective view of the light emitting element of the information recording / reproducing apparatus shown in FIG.

Explanation of symbols

100 Information recording / reproducing apparatus 101 Optical axis 110, 111 LD
112 Stem 113 Heat sink 114, 115, 116 Lead 117 Chip 118 Cap 120 Optical member 140, 141 PD
150 Frame 151, 152 Holder 160 First surface 161 Second surface 171 Insulating material 172, 173 Metal material

Claims (4)

In a light emitting element that emits a light beam,
A base portion having a first surface and a second surface; a wall portion joined to the first surface; a plurality of leads penetrating the first surface and the second surface; and the wall portion. A chip that is held by and is electrically connected to the plurality of leads,
The plurality of leads are configured to include two leads that function as electrically identical terminals and one lead that functions as a terminal that is electrically different from the two leads. A light emitting device characterized. The light emitting device according to claim 1,
The light emitting element, wherein the two leads function as a ground terminal. The light emitting device according to claim 2,
The two leads are held by the base through a metal material and emit heat generated in the chip to the outside.   An optical pickup device comprising: the light-emitting element according to claim 1; and an optical member that irradiates an information recording medium with the emitted light beam.

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