JPH033124A - Optical head device - Google Patents

Optical head device

Info

Publication number
JPH033124A
JPH033124A JP1138481A JP13848189A JPH033124A JP H033124 A JPH033124 A JP H033124A JP 1138481 A JP1138481 A JP 1138481A JP 13848189 A JP13848189 A JP 13848189A JP H033124 A JPH033124 A JP H033124A
Authority
JP
Japan
Prior art keywords
temperature
semiconductor laser
temperature control
control circuit
laser
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP1138481A
Other languages
Japanese (ja)
Inventor
Masato Tanaka
正人 田中
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Panasonic Holdings Corp
Original Assignee
Matsushita Electric Industrial Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Matsushita Electric Industrial Co Ltd filed Critical Matsushita Electric Industrial Co Ltd
Priority to JP1138481A priority Critical patent/JPH033124A/en
Publication of JPH033124A publication Critical patent/JPH033124A/en
Pending legal-status Critical Current

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  • Optical Head (AREA)

Abstract

PURPOSE:To prevent an optical axis to a recording medium from being deviated and a spot position from being changed by detecting the temperature of a semiconductor laser, controlling an electric current flowing to a temperature control element by means of a control circuit and maintaining the temperature of the semiconductor laser to be always constant. CONSTITUTION:The temperature of the semiconductor laser 1 is always detected by a temperature sensor 2. A temperature signal detected by the temperature sensor 2 is inputted to a temperature control circuit 3 and the electric current flowing to the temperature control element 4 is controlled by the temperature control circuit 3 based on the inputted temperature signal. As the result, the temperature of the semiconductor laser 1 is maintained to be always constant. Thus, laser light whose wavelength is constant is outputted from the semiconductor laser 1 and condensed on the recording medium 9 through a collimator lens 5, a beam shaping prism 6, a beam splitter 7 and an objective lens 8. Since the wavelength of the laser light outputted by the semiconductor laser 1 is not changed by the change of the circumferential temperature, the failure that the optical axis is deviated or the spot position is changed is eliminated.

Description

【発明の詳細な説明】 産業上の利用分野 本発明は光デイスク装置に使用する光学ヘッド装置に関
する。
DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an optical head device used in an optical disk device.

従来の技術 従来光デイスク装置に使用されている光学ヘッド装置は
第2図に示すように、半導体レーザ11より出力された
レーザ光をコリメートレンズ12により平行光に変換し
た後、ビーム整形プリズム13により強度分布が均一化
され、さらにビームスプリッタ14を通過したレーザ光
を対物レンズ15により記録媒体16上へ集光するよう
になっている。
2. Description of the Related Art As shown in FIG. 2, an optical head device used in a conventional optical disk device converts laser light outputted from a semiconductor laser 11 into parallel light using a collimating lens 12, and then converts it into parallel light using a beam shaping prism 13. The intensity distribution is made uniform, and the laser beam that has passed through the beam splitter 14 is focused onto the recording medium 16 by the objective lens 15.

また記録媒体16より反射された反射光は対物レンズ1
5により集光されてビームスプリッタ14により反射さ
れて信号検出器17へと入射され、この信号検出器17
により記録媒体16に記録された信号が検出されるよう
に構成されている。
Further, the reflected light reflected from the recording medium 16 is transmitted to the objective lens 1.
5, the beam is reflected by the beam splitter 14, and enters the signal detector 17.
It is configured such that the signal recorded on the recording medium 16 is detected.

発明が解決しようとする課趙 しかし半導体レーザ11は、温度が変化すると出力する
レーザ光の波長が変わるため、従来の光学ヘッド装置で
は、レーザ光の強度分布を均一にするビーム整形プリズ
ムの屈折角が変化して光軸がずれたり、対物レンズ15
の屈折率の波長依存性により集光されたレーザ光のスポ
ット位置が変って目的とするトラックの信号が検出でき
な(なるなどの不具合があった。
Issues to be Solved by the Invention However, in the semiconductor laser 11, the wavelength of the laser beam output changes when the temperature changes. may change, causing the optical axis to shift, or the objective lens 15
Due to the wavelength dependence of the refractive index of the laser beam, the spot position of the focused laser beam changes, making it impossible to detect the signal of the target track.

本発明は上記不具合を改善するものであり、光軸がずれ
たり、スポット位置が変化することを防止することがで
きる光学ヘッド装置を提供することを目的とする。
The present invention is intended to improve the above-mentioned problems, and an object of the present invention is to provide an optical head device that can prevent the optical axis from shifting and the spot position from changing.

課題を解決するための手段 本発明は上記目的を達成するために、半導体レーザの温
度を検出する温度センサを設け、半導体レーザの温度を
もとに温度制御回路が半導体レーザに設けられた温度制
御素子を流れる電流を制御して、半導体レーザの温度を
常に一定に維持するようにしたものである。
Means for Solving the Problems In order to achieve the above object, the present invention provides a temperature control system in which a temperature sensor for detecting the temperature of a semiconductor laser is provided, and a temperature control circuit is provided in the semiconductor laser based on the temperature of the semiconductor laser. The temperature of the semiconductor laser is always maintained constant by controlling the current flowing through the element.

作用 上記構成により、半導体レーザより出力されるレーザ光
の波長が変化することがないため、光軸がずれたり記録
媒体上でのスポット位置が変化するのを防止することが
できる。
Effect: With the above configuration, the wavelength of the laser light output from the semiconductor laser does not change, so it is possible to prevent the optical axis from shifting and the spot position on the recording medium from changing.

実施例 第1図は本発明の一実施例になる光学ヘッド装置を示す
もので、1は半導体レーザ、2は半導体レーザ1の温度
を検出する温度センサ、3は半導体レーザの温度を制御
する温度制御回路、4は上記温度制御回路3により制御
されて半導体レーザ1の温度を一定に保持する温度制御
素子、5は半導体レーザ1より出力されたレーザ光を平
行光に変換するコリメートレンズ、6はレーザ光の強度
分布を均一化するビーム整形プリズム、7はビームスプ
リッタ、8は対物レンズ、9は記録媒体、10は信号検
出器である。
Embodiment FIG. 1 shows an optical head device according to an embodiment of the present invention, in which 1 is a semiconductor laser, 2 is a temperature sensor that detects the temperature of the semiconductor laser 1, and 3 is a temperature sensor that controls the temperature of the semiconductor laser. A control circuit, 4 a temperature control element that is controlled by the temperature control circuit 3 to keep the temperature of the semiconductor laser 1 constant, 5 a collimating lens that converts the laser light output from the semiconductor laser 1 into parallel light, and 6 a temperature control element that keeps the temperature of the semiconductor laser 1 constant; 7 is a beam splitter, 8 is an objective lens, 9 is a recording medium, and 10 is a signal detector.

次に上記構成された光学ヘッド装置の作用を説明すると
、半導体レーザ1より出力されるレーザ光は半導体レー
ザ1の温度が変化すると波長が変化し、光軸がずれたり
、記録媒体9上におけるスポット位置が変わってしまう
が、半導体レーザ1の温度は温度センサ2により常時検
知されている。温度センサ2により検知された温度信号
は温度制御回路3へと入力され、温度制御回路3は温度
センサ2より入力される温度検出信号をもとに温度制御
素子4に流れる電流を制御して、半導体レーザ1の温度
を常に一定に維持する。
Next, to explain the operation of the optical head device configured as described above, the wavelength of the laser light output from the semiconductor laser 1 changes when the temperature of the semiconductor laser 1 changes, causing the optical axis to shift or spotting on the recording medium 9. Although the position changes, the temperature of the semiconductor laser 1 is constantly detected by the temperature sensor 2. The temperature signal detected by the temperature sensor 2 is input to the temperature control circuit 3, and the temperature control circuit 3 controls the current flowing to the temperature control element 4 based on the temperature detection signal input from the temperature sensor 2. The temperature of the semiconductor laser 1 is always maintained constant.

これによって半導体レーザ1からは波長の一定したレー
ザ光が出力されると共に、このレーザ光はコリメートレ
ンズ5により平行光線に変換された□後、ビーム整形プ
リズム6により強度分布が均一化される。
As a result, a laser beam with a constant wavelength is output from the semiconductor laser 1, and after this laser beam is converted into a parallel beam by the collimating lens 5, the intensity distribution is made uniform by the beam shaping prism 6.

そしてビームスプリッタ7を通過後対物レンズ8により
記録媒体9上へ集光されると共に、記録媒体9より反射
されたレーザ光は対物レンズ8により集光されてビーム
スプリッタ7により反射され、信号検出器10に入射さ
れ、この信号検出器10により記録媒体9に記録された
信号が検出される。
After passing through the beam splitter 7, the laser beam is focused onto the recording medium 9 by the objective lens 8, and the laser beam reflected from the recording medium 9 is focused by the objective lens 8 and reflected by the beam splitter 7, and the laser beam is detected by the signal detector. 10, and the signal recorded on the recording medium 9 is detected by the signal detector 10.

以上のように半導体レーザ1の温度が温度制御回路3と
温度制御素子4により常に一定に維持されるため、半導
体レーザ1より出力されるレーザ光の波長が温度により
変化するのを確実に防止することができる。
As described above, since the temperature of the semiconductor laser 1 is always maintained constant by the temperature control circuit 3 and the temperature control element 4, the wavelength of the laser light output from the semiconductor laser 1 is reliably prevented from changing due to temperature. be able to.

発明の効果 本発明は以上詳述したように、半導体レーザの湿度を検
出して、制御回路により温度制御素子を流れる電流を制
御することにより半導体レーザの1度を常に一定に維持
したことから、半導体レーザより出力されるレーザ光の
波長が周囲の温度変化により変わることがなく、これに
よってレーザ光の強度分布を均一にするビーム整形プリ
ズムの屈折率が変わって光軸がずれたり、対物レンズの
屈折率の波長依存性によりスポット位置が変わるなどの
不具合を解消することができる。
Effects of the Invention As detailed above, the present invention detects the humidity of the semiconductor laser and controls the current flowing through the temperature control element using the control circuit to maintain the temperature of the semiconductor laser at a constant temperature. The wavelength of the laser beam output from the semiconductor laser does not change due to changes in the surrounding temperature, and this changes the refractive index of the beam shaping prism that makes the intensity distribution of the laser beam uniform, causing the optical axis to shift or the objective lens to change. It is possible to eliminate problems such as the spot position changing due to the wavelength dependence of the refractive index.

【図面の簡単な説明】[Brief explanation of the drawing]

第1図は本発明の一実施例になる光学ヘッド装置の概略
図、第2図は従来の光学ヘッド装置の概略図である。 1・・・半導体レーザ、2・・・温度センサ、3・・・
温度制御回路、4・・・温度制御素子、6・・・ビーム
整形ブノズム、7・・・ビームスプリッタ、8・・・対
物レンズ、9・・・記録媒体、10・・・信号検出器。
FIG. 1 is a schematic diagram of an optical head device according to an embodiment of the present invention, and FIG. 2 is a schematic diagram of a conventional optical head device. 1... Semiconductor laser, 2... Temperature sensor, 3...
Temperature control circuit, 4... Temperature control element, 6... Beam shaping unit, 7... Beam splitter, 8... Objective lens, 9... Recording medium, 10... Signal detector.

Claims (1)

【特許請求の範囲】[Claims] レーザ光を出力する半導体レーザと、前記半導体レーザ
の温度を検出する温度センサと、前記半導体レーザの温
度を制御する温度制御素子と、前記温度センサにより検
出された温度により、前記半導体レーザの温度が一定に
なるように前記温度制御素子を制御する手段とを有する
光学ヘッド装置。
A semiconductor laser that outputs laser light, a temperature sensor that detects the temperature of the semiconductor laser, a temperature control element that controls the temperature of the semiconductor laser, and a temperature of the semiconductor laser that is controlled by the temperature detected by the temperature sensor. and means for controlling the temperature control element to maintain a constant temperature.
JP1138481A 1989-05-31 1989-05-31 Optical head device Pending JPH033124A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP1138481A JPH033124A (en) 1989-05-31 1989-05-31 Optical head device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP1138481A JPH033124A (en) 1989-05-31 1989-05-31 Optical head device

Publications (1)

Publication Number Publication Date
JPH033124A true JPH033124A (en) 1991-01-09

Family

ID=15223086

Family Applications (1)

Application Number Title Priority Date Filing Date
JP1138481A Pending JPH033124A (en) 1989-05-31 1989-05-31 Optical head device

Country Status (1)

Country Link
JP (1) JPH033124A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111386439A (en) * 2017-09-18 2020-07-07 安盟生技股份有限公司 Interference imaging device and application thereof

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111386439A (en) * 2017-09-18 2020-07-07 安盟生技股份有限公司 Interference imaging device and application thereof
CN111386439B (en) * 2017-09-18 2022-07-12 安盟生技股份有限公司 Interference imaging device and application thereof

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