JPH02289929A - Semiconductor integrated circuit - Google Patents
Semiconductor integrated circuitInfo
- Publication number
- JPH02289929A JPH02289929A JP1111117A JP11111789A JPH02289929A JP H02289929 A JPH02289929 A JP H02289929A JP 1111117 A JP1111117 A JP 1111117A JP 11111789 A JP11111789 A JP 11111789A JP H02289929 A JPH02289929 A JP H02289929A
- Authority
- JP
- Japan
- Prior art keywords
- tracking
- circuit
- semiconductor integrated
- integrated circuit
- photodiodes
- 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
Links
Landscapes
- Optical Head (AREA)
- Light Receiving Elements (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
この発明は光ピックアップ用の半導体集積回路に関し、
例えばＣＤプレーヤーに用いられている１・ラソキング
用及びフ］一カス用のフォトダイオードが一つの半導体
基板上に形成されている半導体集積回路に関する。[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a semiconductor integrated circuit for an optical pickup.
For example, the present invention relates to a semiconductor integrated circuit in which photodiodes used in a CD player, for example, photodiodes for 1/2 and 1/2 are formed on one semiconductor substrate.
第２図は′３ビーム方式を採用しているＣＤブレヤーの
受光部の十導体集積回路を上面から見た図である。３ビ
ーム方式ではこの図に示すように一つの゛＋′．導体基
板上に６分割されたフオ１・ダイオドが設けられている
。１〜４はフォーカス用のフォｌ・ダイオード（以下Ｐ
Ｄと略す）、５及び６は１・ラソキング用のＰＤである
。３ビームのうち１つのレーザ光が主ビームＢ，（フォ
ーカス用）である。主ビームＢｉがディスク４二で反射
され、ＰＤ１〜４に照射され、ＰＤ１−〜４が発生ずる
光電流に応しフォーカス調整が行われる。３ビームのう
ち残りの２つのレーザ光か副ビームＢ２ （＋・ラッキ
ング用）である。副ビームＢ２かディスク」二で反射さ
れ、ＰＤ５．６に照射され、ＰＩ．）５６が発生ずる光
電流に応じて１・ラッキング調整（レーザ光かディスク
−１二のピッ１・列に適切に照射されるように位置決め
を行うこと）がｆｊわれる。FIG. 2 is a top view of a ten-conductor integrated circuit in the light receiving section of a CD player employing the '3 beam system. In the three-beam system, one ゛+′. A photo 1 diode divided into six is provided on a conductive substrate. 1 to 4 are focus diodes (hereinafter referred to as P
(abbreviated as D), 5 and 6 are PDs for 1. Laso king. One of the three laser beams is the main beam B (for focusing). The main beam Bi is reflected by the disk 42 and irradiated onto the PDs 1 to 4, and focus adjustment is performed in response to the photocurrent generated by the PDs 1 to 4. The remaining two laser beams among the three beams are the sub beam B2 (+ for racking). The sub beam B2 is reflected by the disk 2, irradiated onto PD5.6, and PI. ) 56 generates a photocurrent, 1. racking adjustment (positioning so that the laser beam is appropriately irradiated on the 1st column of the disk 12) is performed fj.
第３図は」二述した１・ラッキング用のＰＤ５．６の信
号処理回路の構成を示す回路図である。これらの信号処
理回路はＰＤＩ〜６とともにモノリシック′１テ導体集
積回路として形成される。図において、５及び６は６分
割されたフォ１・ダイオードの内の１・ラッキンク用の
ＰＤであり、照射される光の強度に応じた光電流を発生
する。Ａ，Ｂは各々ＰＤ５，６の発生した光電流を電圧
に変換する電流一電圧変換回路（以下■−■変換回路と
いう）である。Ｉ−Ｖ変換回路Ａ，Ｂは各々演算増幅器
７と抵抗８、演算増幅器１１と抵抗１ｏより成る。FIG. 3 is a circuit diagram showing the configuration of the signal processing circuit of the PD5.6 for racking described above. These signal processing circuits are formed together with PDI-6 as a monolithic conductor integrated circuit. In the figure, numerals 5 and 6 are PDs for one rack of the six divided photodiodes, which generate a photocurrent according to the intensity of the irradiated light. A and B are current-to-voltage conversion circuits (hereinafter referred to as ①-② conversion circuits) that convert photocurrents generated by the PDs 5 and 6 into voltages, respectively. The IV conversion circuits A and B each include an operational amplifier 7 and a resistor 8, and an operational amplifier 11 and a resistor 1o.
演算増幅器７の反転入カはＰＤ５のカソードに、非反転
入力は基準電圧Ｖ に各々接続され、出ｖｅｒ
力は抵抗８を介し反転入刀に帰還されている。演算増幅
器１１の反転入カはＰＤ６のカソードに、非反転入力は
基準電圧Ｖ に各々接続され、出ｒｅｒ
力は抵抗１０を介し反転入刀に帰還されている。The inverting input of the operational amplifier 7 is connected to the cathode of the PD 5, the non-inverting input is connected to the reference voltage V, and the output is fed back to the inverting input via the resistor 8. The inverting input of the operational amplifier 11 is connected to the cathode of the PD 6, the non-inverting input is connected to the reference voltage V, and the output power is fed back to the inverting input via the resistor 10.
１−Ｖ変換回路Ａ，Ｂの出カは差動増幅回路Ｘに与えら
れる。差動増幅回路Ｘは、差動増幅用の演算増幅器１２
，差動増幅用抵抗１３〜１６より成る。演算増幅器１２
の反転入力は抵抗１３を介し１−Ｖ変換回路Ａの出力に
接続され、非反転入カは抵抗１５を介しＩ−Ｖ変換回路
Ｂの出カに接続されるとともに抵抗１６を介し基準電圧
Ｖｒｅｆにも接続されている。また、出力は抵抗］４を
介し反転入力に帰還されるとともに、出力端子ＯＵＴに
も接続されている。The outputs of the 1-V conversion circuits A and B are given to a differential amplifier circuit X. The differential amplifier circuit X includes an operational amplifier 12 for differential amplification.
, differential amplification resistors 13 to 16. Operational amplifier 12
The inverting input of is connected to the output of the 1-V conversion circuit A through a resistor 13, and the non-inverting input is connected to the output of the I-V conversion circuit B through a resistor 15, and the reference voltage Vref is connected through a resistor 16. is also connected. Further, the output is fed back to the inverting input via the resistor]4, and is also connected to the output terminal OUT.
次に動作について説明する。抵抗８と１０、１３と１５
、］４と１６の抵抗値を各々Ｒ，Ｒ２Ｒ とし、基準電
圧Ｖ の電位を接地電位とず３
ｒｅｆ
る。光源から発せられたレーザ光はコンバク１・ディス
ク上で反射され、トラッキング用のＰＤ５６に照射され
る。ＰＤ５．６は照射されるレーザ光の強度に応じた光
電流１ ，Ｉ６を発生ずる。Next, the operation will be explained. Resistors 8 and 10, 13 and 15
, ]4 and 16 are R and R2R, respectively, and the potential of the reference voltage V is the ground potential and Z3
ref. The laser beam emitted from the light source is reflected on the convex disk 1 and irradiated onto the tracking PD 56. PD5.6 generates photocurrents 1 and I6 according to the intensity of the irradiated laser light.
ｒ−ｖ変換回路Ａ，Ｂの出力電圧は各々Ｉ５Ｒ，Ｉ−Ｒ
１となり、この出力電圧が差動増ｌ６
幅器Ｘに与えられる。差動増幅器Ｘはこれらの出力電圧
の差を増幅して、出力端子ＯＵＴに！ｊえる。The output voltages of r-v conversion circuits A and B are I5R and I-R, respectively.
1, and this output voltage is applied to the differential amplifier I6. Differential amplifier X amplifies the difference between these output voltages and outputs it to output terminal OUT! I can do it.
差動増幅回路Ｘの出力電圧をＶ。１とすると、となる。The output voltage of the differential amplifier circuit X is V. When it is set to 1, it becomes.
出力電圧Ｖ を用いトラッキングのサーボ制御（レーザ
光がディスク上のピット列に適切に照射されるように位
置決めを行うこと）が行われる。Tracking servo control (positioning so that laser light is appropriately irradiated onto pit rows on the disk) is performed using the output voltage V 2 .
従来の光ピックアップ用半導体集積回路においては、ト
ラッキング用のＰＤ５．６の信号処理は以上のように構
成されており、演算増幅器が３個必要であるので、回路
構成が複雑になるとともに高価になるという問題点があ
った。In conventional semiconductor integrated circuits for optical pickups, the signal processing of PD5.6 for tracking is configured as described above, and three operational amplifiers are required, making the circuit configuration complex and expensive. There was a problem.
この発明は上記のような問題点を解決するためになされ
たもので、回路構成が簡単で安価な光ピックアップ用の
半導体集積回路を得ることを目的とする。The present invention was made to solve the above-mentioned problems, and an object of the present invention is to obtain a semiconductor integrated circuit for an optical pickup that has a simple circuit configuration and is inexpensive.
この発明に係る半導体集積回路は、トラッキング用及び
フォーカス用のフォトダイオードが一つの半導体基板上
に形成された光ピックアップ用の半導体集積回路におい
て、トラッキング用のフォトダイオードを直列に接続し
ている。A semiconductor integrated circuit according to the present invention is a semiconductor integrated circuit for an optical pickup in which tracking and focusing photodiodes are formed on one semiconductor substrate, and the tracking photodiodes are connected in series.
この発明においては、トラッキング用のフォ１・ダイオ
ードを直列に接続しているので、トラッキング用のフォ
トダイオードが発生する光電流の差の電流が直接に得ら
れる。In this invention, since the tracking photodiodes are connected in series, a current corresponding to the difference in photocurrent generated by the tracking photodiodes can be directly obtained.
第１図はこの発明に係る半導体集積回路の一実施例を示
す回路図である。図において、５，６はトラッキング用
のＰＤであり、これらのＰＤ５．６は互いに直列に接続
されている。ＰＤ５のアノドとＰＤ６のカソードが接続
され、ＰＤ５のカソードが電源電圧Ｖ。０に接続され、
ＰＤ６のアノードが接地されている。ＰＤ５のアノード
とＰＤ６のカソードの共通接続点にはこの共通接続点か
らの電流を電圧に変換するためのＩ−■変換回路Ｃが接
続されている。Ｉ−Ｖ変換回路Ｃは、演算増幅器２０と
抵抗２］より成る。演算増幅器２０は、反転入力がＰＤ
５のアノードとＰＤ６のカソドの共通接続点に、非反転
入力が基’ｌ圧源ｖｒｅｆ’に各々接続され、出力が抵
抗２］を介し非反転入力に帰還されるとともに出力端Ｔ
−ＯＵＴにも接続されている。FIG. 1 is a circuit diagram showing an embodiment of a semiconductor integrated circuit according to the present invention. In the figure, 5 and 6 are PDs for tracking, and these PDs 5 and 6 are connected to each other in series. The anode of PD5 and the cathode of PD6 are connected, and the cathode of PD5 is connected to the power supply voltage V. connected to 0,
The anode of PD6 is grounded. An I-■ conversion circuit C is connected to a common connection point between the anode of PD5 and the cathode of PD6 for converting the current from this common connection point into voltage. The IV conversion circuit C consists of an operational amplifier 20 and a resistor 2. The operational amplifier 20 has an inverting input as PD.
The non-inverting inputs are connected to the base voltage source vref at the common connection point between the anode of 5 and the cathode of PD 6, and the output is fed back to the non-inverting input via the resistor 2 and output terminal T.
- Also connected to OUT.
次に動作について説明する。今、抵抗２］の抵抗値をＲ
４とする。光源から発せられたレーザー光（主ビーム，
副ビーム）はコンパクトディスク」二で反射され、この
うちの副ビームがトラッキング用のＰＤ５．６に照射さ
れる。ＰＤ５．６は照射されるレーザ光の強度に応じた
光′屯流Ｉ５，Ｉ６を発生ずる。■−■変換回路Ｃには
光電流Ｉ とＩ６の差電流（１５−１６）がＪｊえられ
る。Next, the operation will be explained. Now, the resistance value of resistor 2 is R
Set it to 4. Laser light emitted from a light source (main beam,
The sub-beam) is reflected by the compact disk 2, and the sub-beam is irradiated onto a tracking PD 5.6. PD5.6 generates light streams I5 and I6 corresponding to the intensity of the laser beam irradiated. The difference current (15-16) between the photocurrents I and I6 is obtained by the (1)-(2) conversion circuit C.
出力端子ＯＵＴを出力電圧Ｖ。２は、
Ｖ ＝Ｒ （１ −Ｉ５） ・・（２
）となる。■−■変換回路Ｃの出力電圧■。２は（２）
式に示すように光電流Ｉ５と１６の差に比例する電圧と
なっており、このことは（１）式に示した出力電圧■。The output voltage V is applied to the output terminal OUT. 2 is V = R (1 - I5)...(2
). ■−■Output voltage of conversion circuit C■. 2 is (2)
As shown in the equation, the voltage is proportional to the difference between the photocurrents I5 and I16, and this means the output voltage ■ shown in equation (1).
１の場合と同じである。つまり、演算増幅器を１つ用い
て、従来と同様の出力電圧を得ることができる。そして
、出力電圧■。２を用い１・ラッキングのザーボ制御か
行われる。This is the same as in case 1. In other words, the same output voltage as the conventional one can be obtained using one operational amplifier. And the output voltage ■. 2 is used to perform 1. racking servo control.
なお、」二記実施例では、ＰＤ５．６の直列回路体を電
源電圧Ｖ。Ｃと接地間に接続しているが、その他の電圧
をｌｊえてもよい。In addition, in the second embodiment, the series circuit of PD5.6 is connected to the power supply voltage V. Although it is connected between C and ground, other voltages may be applied.
以上のように、この発明によれば、１・ラソギング用の
フォｌ・ダイオー１・を直列に接続し、１・ラッキング
用のＰＤが発生する光電流の差の電流を直接に得ること
ができるようにしたので、演算増幅器の数が減少し、そ
の結果、回路構成か簡甲で安価な光ピックアップ用の半
導体集積回路を得ることができるという効果がある。As described above, according to the present invention, it is possible to connect the FOL diodes 1 for lasogging in series and directly obtain the current that is the difference between the photocurrents generated by the PD for racking 1. As a result, the number of operational amplifiers is reduced, and as a result, it is possible to obtain a semiconductor integrated circuit for an optical pickup that has a simple circuit configuration and is inexpensive.
第１−図はこの発明に係る才導体集積回路の一丈施例を
示す回路図、第２図はＣＤプレーヤーの光ピックアップ
用の半導体集積回路を上面から見た図、第３図は従来の
半導体集積回路の回路構成を示す図である。
図において、５及び６は１・ラッキング用のフォトダイ
オードである。
なお、各図中同一符号は同一または相当部分を示す。
一２６８Fig. 1 is a circuit diagram showing an example of a semiconductor integrated circuit according to the present invention, Fig. 2 is a top view of a semiconductor integrated circuit for an optical pickup of a CD player, and Fig. 3 is a circuit diagram of a conventional semiconductor integrated circuit. 1 is a diagram showing a circuit configuration of a semiconductor integrated circuit. In the figure, 5 and 6 are photodiodes for 1/racking. Note that the same reference numerals in each figure indicate the same or corresponding parts. 1268
Claims (1)
ードが一つの半導体基板上に形成された光ピックアップ
用の半導体集積回路において、前記トラッキング用のフ
ォトダイオードを直列に接続したことを特徴とする半導
体集積回路。(1) A semiconductor integrated circuit for an optical pickup in which tracking and focusing photodiodes are formed on one semiconductor substrate, characterized in that the tracking photodiodes are connected in series.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1111117A JPH02289929A (en) | 1989-04-28 | 1989-04-28 | Semiconductor integrated circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1111117A JPH02289929A (en) | 1989-04-28 | 1989-04-28 | Semiconductor integrated circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH02289929A true JPH02289929A (en) | 1990-11-29 |
Family
ID=14552853
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1111117A Pending JPH02289929A (en) | 1989-04-28 | 1989-04-28 | Semiconductor integrated circuit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH02289929A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008209556A (en) * | 2007-02-26 | 2008-09-11 | Epson Imaging Devices Corp | Electro-optical device, semiconductor device, display device and electronic equipment having the same |
| NL2000789C2 (en) * | 2007-07-30 | 2009-02-02 | Univ Delft Tech | Sensor for position determination. |
-
1989
- 1989-04-28 JP JP1111117A patent/JPH02289929A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008209556A (en) * | 2007-02-26 | 2008-09-11 | Epson Imaging Devices Corp | Electro-optical device, semiconductor device, display device and electronic equipment having the same |
| NL2000789C2 (en) * | 2007-07-30 | 2009-02-02 | Univ Delft Tech | Sensor for position determination. |
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