KR100384461B1 - Optical receiver with photo diode divided ten - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an optical receiver having a ten-division photodiode (also called "PDIC"). The present invention relates to an optical receiver having a ten-division photodiode suitable for using a two-wavelength laser diode. A photodiode for a CD comprising two focusing photodiodes 31 and two tracking photodiodes 32a and 32b; Four DVD photodiodes 33 arranged in a square at a set distance from the focusing photodiode 31 on a line substantially perpendicular to the arrangement direction of the CD photodiodes 32a, 31, and 32b; A first adder (38a) for adding an output value of the focusing photodiode (31); A second adder 38b for adding an output value of the DVD photodiode 33; Comparator 39 for comparing the output of the first adder 38a and the output of the second adder 38b and providing the switching signal according to the comparison result to the input selector 36 and the output selector SW. ); An input selector 36 for selecting one of an output of the focusing photodiode 31 and an output of the DVD photodiode 33 in accordance with a switching signal; An output selector (SW) for selecting an output of the first adder and an output of the second adder according to a switching signal; It is provided.

Description

OPTICAL RECEIVER WITH PHOTO DIODE DIVIDED TEN}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical receiver (also called "PDIC") having a ten-divided photodiode, and in particular, to easily apply a two-wavelength laser diode (LD), The present invention relates to an optical receiver having a ten-segment photodiode, which enables to achieve a low cost and a small size of a light pick-up device.

In general, in an optical pickup device, a pit or hole is drilled in a digital shape on a surface of a CD or the like, and the optical pickup device detects a laser beam reflected after irradiating a laser light to the hole of the CD, thereby detecting a digital signal. It is a device that can detect. Here, the pit is an elongated shape having a width of 0.5 m and a length of 0.9 to 3.3 m, and the light source uses an infrared laser of 0.78 m (780 mm).

FIG. 1 is a schematic diagram of a general optical pickup device. Referring to FIG. 1, a general optical pickup device 10 includes a laser diode (LD) 11 for irradiating an infrared laser, and a laser of the laser diode 11 is a spectroscope. 12, the collimating lens 13 and the objective lens 14 are transmitted to the surface of the CD 1, and the laser reflected from the surface of the CD 1 is again the objective lens 14, the collimating lens 13 ), Through the spectrometer 12 and the lenses 15 and 16 to the photodiode on the optical receiver 17. The pickup device is composed of an LD unit for transmitting a laser, an optical unit (or an optical system) including a lens for transmitting a laser, and an optical receiver for receiving a laser.

In this way, in the optical receiver to which the optical receiver is applied, in order to read the data recorded on the CD, an optical unit including a corresponding LD unit, a lens for delivering the laser of the LD unit to a set path, and an oscillator transmitted through the optical unit may be used. It should include the receiving optical receiver, and LD, optical and optical receiver are closely related to each other in terms of function and structure.

FIG. 2 is a configuration diagram of a photodiode of a conventional optical receiver. Referring to FIG. 2, a photodiode of a conventional optical receiver includes a focusing photodiode 21 (A, B, C, D) and a focusing photodiode. Tracking photodiodes 22a and 22b (E, F) provided on both sides of the diode 21 are included.

FIG. 3 is a circuit diagram of a conventional optical receiver. Referring to FIG. 3, a circuit of a conventional optical receiver converts a detected current from the focusing photodiode 21 (A, B, C, D) into a voltage. A first I / V converter 24 for converting and a second, third I / V converter 25 for converting the detected current from the tracking photodiodes 22a, 22b (E, F) into voltage; 26, and an adder 27 for adding the detected currents from the focusing photodiodes 21 (A, B, C, D) to convert them into voltages.

The output voltage of the optical receiver 20 is provided to a signal processing device (not shown), and the signal processing device is based on the focus check based on the output voltage VA-VD of the first I / V converter 24. And detecting a tracking error based on the output voltages VE and VF of the second and third I / V converters 25 and 26, and outputting the output voltage VRF of the adder 27. Data is detected based on

Recently, as the spread of DVD has been expanded, the spread of computers using existing CDs and DVDs at the same time is increasing.

In order to simultaneously use a CD and a DVD using the conventional optical receiver shown in FIG. 3, the optical unit for the CD and the LD unit for the CD must be provided, as well as the optical unit for the DVD and the LD unit for the DVD. Therefore, a device for selecting two LD units and an optical unit should be additionally provided.

Thus, in order to use CD and DVD at the same time, the conventional pickup apparatus, which must be equipped with CD optical section, CD LD section, DVD optical section, DVD LD section and selectors, is not only very complicated, but also, There were various problems such as rising production prices.

Accordingly, research and development are being conducted to simplify the optical pickup device, and as one method for this, in the present invention, an improved optical that can simplify the optical pickup device and accordingly, make the optical pickup device cheaper Suggest a receiver.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and therefore, an object of the present invention is to make it easy to apply a two-wavelength laser diode, so that the cost and size of the optical pickup device can be achieved. An optical receiver having a ten-segment photodiode is provided.

1 is a schematic diagram of a general optical pickup device.

2 is a diagram illustrating a photodiode of a conventional optical receiver.

3 is a circuit configuration diagram of a conventional optical receiver.

4 is a photodiode configuration diagram of an optical receiver according to the present invention.

5 is a circuit diagram of an optical receiver according to the present invention.

Explanation of symbols on the main parts of the drawings

30: optical receiver 31,32a, 32b: photodiode for CD

33: Photodiode for DVD 34: First I / V Converter

35: second I / V converter 36: input selector

37: power amplifier 36-1 to 36-4: first to fourth switches

38a: first adder 38b: second adder

39: comparator SW: output selector

As a technical means for achieving the above object of the present invention, the optical receiver of the present invention is an optical receiver having a ten-segment photodiode suitable for using a two-wavelength laser diode, comprising four focusing photodiodes and two A photodiode for a CD comprising two tracking photodiodes; Four DVD photodiodes arranged in a square at a predetermined distance from the focusing photodiode on a line substantially perpendicular to an arrangement direction of the CD photodiodes; A first adder for adding an output value of the focusing photodiode; A second adder for adding an output value of the photodiode for DVD; A comparison unit comparing the output of the first adder with the output of the second adder and providing a switching signal according to the comparison result to the input selector and the output selector; An input selector for selecting one of an output of the focusing photodiode and an output of the DVD photodiode according to a switching signal; An output selector configured to select an output of the first adder and an output of the second adder according to a switching signal; Characterized in having a.

Hereinafter, an optical receiver according to the present invention will be described in detail with reference to the accompanying drawings. In the drawings referred to in the present invention, components having substantially the same configuration and function will use the same reference numerals.

According to the present invention, an optical receiver comprises a photodiode for CD and a photodiode for DVD, so that the optical receiver is suitable for use with a laser having a wavelength of CD and a laser having a wavelength of DVD. The circuit includes a circuit for selecting and processing the detected signal based on the magnitude of the detected signal, thereby eliminating the need for a separate LD unit and an optical unit for each wavelength as in the prior art. That is, the present invention proposes an optical receiver having a two-wavelength LD unit and a ten-segment photodiode so that CD and DVD can be simultaneously used as one optical unit.

FIG. 4 is a photodiode configuration diagram of an optical receiver according to the present invention. Referring to FIG. 4, an optical receiver having a ten-division photodiode suitable for using a two-wavelength laser diode according to the present invention is used for detecting a focusing error. Four focusing photodiodes 31 arranged in a square and two arranged on the left and right sides of the focusing photodiode 31 at a set distance from the focusing photodiode 31 for tracking error detection. A CD photodiode having tracking photodiodes 32a and 32b, and a set distance from the focusing photodiode 31 on a line substantially perpendicular to the arrangement direction of the CD photodiodes 32a, 31, and 32b. Four photodiodes 33 for DVD are arranged in a square.

Focusing photodiodes 31 of the photodiode for CD, that is, four A, B, C and D photodiodes are arranged in a quadrangular pattern adjacent to each other on a substrate to detect focusing error, and the photodiode for CD Tracking photodiodes 32a and 32b, i.e., two E and F photodiodes, are arranged on the left side of the focusing photodiode 31 at a set distance from the focusing photodiode 31 for tracking error detection. , One is arranged on the right side. Since the arrangement and function of such a photodiode for CD are already known contents, detailed description thereof will be omitted.

The DVD photodiodes 33, i.e., four A ', B', C 'and D' photodiodes are arranged in the arrangement direction of the CD photodiodes 32a, 31 and 32b, i.e., in the transverse direction in FIG. On a line perpendicular to the focusing photodiode 31, the photodiode 31 is arranged in a square at a predetermined distance from the focusing photodiode 31. The arrangement of the four A ', B', C 'and D' photodiodes is The arrangement of the focusing photodiode 31 of the CD photodiode is the same, and the distance from the focusing photodiode 31 is the distance between two laser emitters having different wavelengths of the two wavelength laser diode, and the optical receiver. And the distance from the LD unit and the structure of the optical unit.

FIG. 5 is a circuit diagram of an optical receiver according to the present invention. Referring to FIG. 5, the optical receiver circuit includes a plurality of circuits for converting respective detection currents of the CD photodiodes 31, 32a, and 32b into voltages. A first I / V converter 34 including an I / V converter, and a second I / V converter including a plurality of I / V converters for converting each detected current of the plurality of DVD photodiodes 33 into voltage. A first adder 38a for adding output voltages of the / V converter 35 and the plurality of I / V converters connected to the focusing photodiode 31 of the first I / V converter 34; The second adder 38b that adds a plurality of output voltages of the second I / V converter 35 and the output of the first adder 38a and the output of the second adder 38b are compared and compared. Comparator 39 for providing a switching signal according to the result to the input selector 36 and the output selector SW, and a focusing element of the first I / V converter 34 according to the switching signal. An input selector 36 for selecting one of an output of the plurality of I / V converters connected to the diode 31 and an output of the first I / V converter 34, and an input selector 36 of the input selector 36 A power amplifier 37 for amplifying the power of the output voltage, and an output selector SW for selecting the output of the first adder 38a and the output of the second adder 38b according to the switching signal.

The first I / V converter 34 includes a plurality of I / V converters connected one-to-one to each of the photodiodes A, B, C, and DEF of the photodiode for CD, and the second I / V. The conversion unit 35 includes a plurality of I / V converters connected one-to-one to each of the photodiodes A ', B', C ', and D' of the photodiode 33 for DVD.

If the output of the first adder 38a is greater than the output of the second adder 38b, the comparison unit provides a switching signal for selecting the output of the first I / V converter 34 to the input selector 36. At the same time, a switching signal for selecting the output of the first adder 38a is provided to the output selector SW, and the output of the first adder 38a is smaller than the output of the second adder 38b. In addition, a switching signal for selecting the output of the second I / V converter 35 is provided to the input selector 36, and a switching signal for selecting the output of the second adder 38b is output to the output selector ( SW).

That is, the comparator selects the detection signal by the photodiode for CD when the output of the first adder 38a is greater than the output of the second adder 38b, and the output of the first adder 38a is the second adder. If smaller than the output of 38b, a switching signal for selecting a detection signal by the photodiode for DVD is provided.

The input selector 36 selects one of an output of the photodiodes A, B, C, and D and an output of the photodiodes A ', B', C ', and D'. A first switch 36-1 for selecting one of the output of the diode A and the photodiode A ', and a second for selecting one of the output of the photodiode B and the photodiode B' A switch 36-2, a third switch 36-3 for selecting one of an output of the photodiode C and a photodiode C ', an output of the photodiode D and a photodiode ( And a fourth switch 36-4 that selects one of D '). These switches 36-1 to 36-4 are electrical, electronic devices or switching circuits such as relays and transistors that switch by the switching signal of the comparator 39, for example, and are specifically limited to the switches. It doesn't work.

The power amplifier 37 includes a plurality of power amplifiers PA1-PA4 connected one-to-one to outputs of the plurality of switches 36-1 to 36-4, and the output selector SW The switching signal of the comparator 39 is synchronized with the switching operation of the input selector 36 to select one of the output of the first adder 38a and the output of the second adder 38b. That is, one of the CD side detection signal or the DVD side detection signal is selected.

Such an optical receiver according to the present invention includes six photodiodes for CD, four photodiodes for DVD, and a total of ten photodiodes. As the circuit is implemented as an integrated circuit, the optical receiver according to the present invention is provided. Is also called a 10-division (10-division) photodiode integrated circuit, that is, a 10-division PDIC.

Operation according to the present invention configured as described above will be described in detail below based on the accompanying drawings.

The present invention relates to an optical receiver capable of achieving a simple and inexpensive optical pickup device. Hereinafter, a detailed description of the already known two-wavelength LD unit and one optical unit will be omitted, and the main technical features of the present invention will be omitted. The optical receiver including the content is explained mainly.

Referring to FIGS. 4 and 5, the operation of the optical receiver according to the present invention will be described. First, a two-wavelength laser emitted from a two-wavelength laser diode LD, that is, an infrared laser of 780 mm wavelength for CD or 650 mm wavelength for DVD, is described. The visible light laser may be selectively provided, and the laser is reflected after reaching the CD or DVD through the optical unit including the lens (LEN) and then reaches the photodiode of the optical receiver according to the present invention.

Here, the two-wavelength laser diode (LD) applied to the present invention is a position that emits an infrared laser of 780mm wavelength for CD, and the position that emits a visible light laser of 650mm wavelength for DVD is a predetermined interval, for example, about 115um Spaced apart, the laser transmitted through one optic will reach different locations on the CD / DVD surface and the optical receiver.

At this time, if the two-wavelength laser diode LD emits an 780mm wavelength infrared laser, the CD photodiodes 31, 32a, and 32b of the optical receiver of the present invention detect the 780mm wavelength infrared laser, Each current detected by the plurality of photodiodes A, B, C, D, E, and F of the photodiodes 31, 32a, and 32b for CD is converted to each I of the first I / V converter 34. Converted to a voltage at the / V converter.

On the other hand, if the two-wavelength laser diode LD emits a visible light laser having a wavelength of 650 mm, the photodiode for DVD of the optical receiver of the present invention detects a visible light laser having a wavelength of 650 mm, and the photodiode for DVD (33) Each current detected by the plurality of photodiodes A ', B', C ', and D' is converted into voltage at each I / V converter of the second I / V converter 35.

The first adder 38a adds the output of the I / V converter connected to the focusing photodiode 31 of the I / V converter of the first I / V converter 34 and compares the added voltage. The second adder 38b adds the output voltage of the I / V converter of the second I / V converter 35 to the comparing unit 39. to provide.

The comparison unit 39 compares the output voltage of the first adder 38a with the output voltage of the second adder 38b so that the output voltage of the first adder 38a is equal to the output voltage of the second adder 38b. If higher, a switching signal for selecting an output voltage of the first adder 38a is provided, while if the output voltage of the first adder 38a is lower than the output voltage of the second adder 38b, A switching signal for selecting the output voltage of the adder 38b is provided.

Referring to FIG. 5, in the exemplary embodiment of the present invention, when the output voltage of the first adder 38a is higher than the output voltage of the second adder 38b, a high level switching signal is provided. When the output voltage of the adder 38a is lower than the output voltage of the second adder 38b, a low level switching signal is provided.

In fact, in a device such as a computer using a CD and a DVD simultaneously, only one operation of a CD lead or a DVD lead operation is performed at a predetermined time, so that a detection voltage is actually output from the first I / V conversion unit 34, or Alternatively, the detection voltage is output from the second I / V converter 35, and the input selector 36 selects an actual valid detection voltage of the CD or DVD according to the switching signal of the comparator 39. Done.

The input selector 36 switches according to a switching signal to select an output of the first I / V converter 34 or an output of the second I / V converter 35. For example, when the switching signal is a switching signal for selecting the output voltage of the first adder 38a, that is, a high level, the common terminal c of the switch is always connected to the open contact a so that the first I When the output of each I / V converter of the / V converter 34 is selected, while the switching signal is a switching signal for selecting the output voltage of the second adder 38b, that is, a low level, the common terminal of the switch. (c) is always connected to the close contact b so that the output of each I / V converter of the second I / V converter 35 is selected.

The selected detection voltage is amplified by the power set in each of the power amplifiers PA1-PA4 of the rear stage power amplifier 37, and the power amplified voltages V1-V4 are transmitted to a signal processor or a controller (not shown). Here, the current detected by the tracking photodiodes 32a and 32b among the CD photodiodes is converted into voltages VE and VF by the first I / V converter 34 and then not shown. Is sent to.

In addition, the operation of the output selection unit SW will be described in detail. When the comparison view 39 switching signal is at a high level, the common terminal c of the switch is always connected to the open contact a so that When the output of the first adder 38a is selected, while the switching signal is at the low level, the common terminal c of the switch is always connected to the close contact b so that the output of the second adder 38b is The output voltage VRF is transmitted to a signal processor or controller, not shown.

As described above, the optical receiver of the present invention automatically selects a detection signal having a relatively high level of the detection signal based on the signal level detected by itself.

According to the present invention as described above, by making it easy to apply a two-wavelength laser diode (hereinafter referred to as "two-wavelength LD"), one two-wavelength LD can be applied, one The optical part can be used, which in turn has a special effect of making it possible to achieve a reduction in cost and miniaturization of a light pick-up device.

The above description is only a description of one embodiment of the present invention, the present invention is capable of various changes and modifications within the scope of the configuration.

Claims (7)

In an optical receiver having a ten-segment photodiode suitable for use with a two-wavelength laser diode, A photodiode for CD including four focusing photodiodes 31 and two tracking photodiodes 32a and 32b; Four DVD photodiodes 33 arranged in a square at a set distance from the focusing photodiode 31 on a line substantially perpendicular to the arrangement direction of the CD photodiodes 32a, 31, and 32b; A first adder (38a) for adding an output value of the focusing photodiode (31); A second adder 38b for adding an output value of the DVD photodiode 33; Comparator 39 for comparing the output of the first adder 38a and the output of the second adder 38b and providing a switching signal according to the comparison result to the input selector 36 and the output selector SW. ); An input selector 36 for selecting one of an output of the focusing photodiode 31 and an output of the DVD photodiode 33 in accordance with a switching signal; And an output selector (SW) for selecting the output of the first adder and the output of the second adder according to a switching signal. The method of claim 1, wherein the optical receiver A first I / V converter 34 including a plurality of I / V converters for converting each detected current of the CD photodiodes 31, 32a, and 32b into voltages and providing them to the input selector 36; ; A second I / V converter (35) including a plurality of I / V converters for converting each detected current of the plurality of DVD photodiodes (33) into voltages and providing them to the input selector (36); And a power amplifier (37) for amplifying the power of the output voltage of the input selector (36). The method of claim 2, wherein the comparison unit If the output of the first adder 38a is greater than the output of the second adder 38b, the detection signal by the photodiode for CD is selected, And an optical receiver having a split-port photodiode, provided that the output signal of the first adder 38a is smaller than the output of the second adder 38b. . In an optical receiver having a ten-segment photodiode suitable for use with a two-wavelength laser diode, Four focusing photodiodes 31 arranged in a square for detection of focusing errors, and a focusing distance between the focusing photodiodes 31 and the left and right sides of the focusing photodiode 31 at a set distance for tracking error detection. A photodiode for a CD including two tracking photodiodes 32a and 32b disposed respectively; Four DVD photodiodes 33 arranged in a square at a set distance from the focusing photodiode 31 on a line substantially perpendicular to the arrangement direction of the CD photodiodes 32a, 31, and 32b; A first I / V conversion section 34 including a plurality of I / V converters for converting respective detection currents of the CD photodiodes 31, 32a, and 32b into voltages; A second I / V conversion section 35 including a plurality of I / V converters for converting respective detection currents of the plurality of DVD photodiodes 33 into voltages; A first adder (38a) for adding output voltages of a plurality of I / V converters connected to a focusing photodiode (31) of the first I / V converters (34); A second adder (38b) for adding a plurality of output voltages of the second I / V converter (35); Comparator 39 for comparing the output of the first adder 38a and the output of the second adder 38b and providing a switching signal according to the comparison result to the input selector 36 and the output selector SW. ); An input selector 36 for selecting one of an output of a plurality of I / V converters connected to the focusing photodiode 31 and an output of the first I / V converter 34 in accordance with a switching signal; A power amplifier 37 for amplifying the power of the output voltage of the input selector 36; And an output selector configured to select an output of the first adder and an output of the second adder according to a switching signal. The method of claim 4, wherein the comparison unit When the output of the first adder 38a is greater than the output of the second adder 38b, a switching signal for selecting the output of the first I / V converter 34 is provided to the input selector 36, And a switching signal for selecting an output of the first adder (38a) to an output selection unit (SW). The method of claim 5, wherein the comparison unit When the output of the first adder 38a is smaller than the output of the second adder 38b, a switching signal for selecting the output of the second I / V converter 35 is provided to the input selector 36. And a switching signal for selecting an output of the second adder (38b) to an output selection unit (SW). The method of claim 4, wherein the comparison unit If the output of the first adder 38a is greater than the output of the second adder 38b, the detection signal by the photodiode for CD is selected, And an optical receiver having a split-port photodiode, provided that the output signal of the first adder 38a is smaller than the output of the second adder 38b. .