JP3257118B2 - Optical disk recording device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk recording apparatus suitable for application to, for example, an optical disk drive for storing a rewritable optical disk or an optical disk drive for storing a write-once optical disk.

[0002]

2. Description of the Related Art In a recordable optical disk such as a rewritable optical disk or a write-once optical disk (hereinafter simply referred to as a recordable optical disk), laser beams form appropriate pits on the disk surface.

In this case, it is necessary to control the shape of the formed pit so that a data reading error or the like is minimized.

In order to control the shape of the formed pits, it is necessary to continuously supply a stable recording power to the recordable optical disk. It is necessary to control the height and pulse width to constant values.

Conventionally, it has been known that the pulse height of the laser beam waveform greatly depends on the temperature. Therefore, a closed loop circuit for the pulse height is formed so that the pulse height is constant. Control, so-called AP
C (Automatic Power Control) control is adopted.

On the other hand, since the pulse width of the laser light waveform depends on the temperature characteristics of the circuit system for driving the laser light emitting element, the change is relatively small. Just managing the absolute value of each circuit element
In other words, if the pulse width is managed by selecting and using a circuit element whose absolute value is standardized with high precision,
It was sufficient for accuracy.

[0007]

In recent years, there has been a demand for higher frequencies and higher speeds in the recording / reproducing processing of an optical disk. Therefore, the recording frequency has become higher, such as the optical disk being rotated at a high speed. Inevitably, the pulse width of the waveform of the laser beam must be narrowed.

However, when the pulse width is reduced, there is a problem that it is difficult to accurately set the pulse width.

Further, when the pulse width is reduced, the pulse width changes due to a change in the temperature of the circuit system or the like. Even if a circuit element whose absolute value is standardized with high precision is selected and used, the laser power (pulse) is not changed. As a result, it becomes impossible to form a pit having a predetermined shape, and there is a problem that a data reading error becomes relatively large.

SUMMARY OF THE INVENTION The present invention has been made in view of such a problem, and has made it possible to accurately set a pulse width of a light beam waveform and to maintain the accurate pulse width. It is an object of the present invention to provide an optical disk recording device that performs the following.

[0011]

SUMMARY OF THE INVENTION The present invention relates to an optical disk recording apparatus for recording an information signal on a recordable optical disk by a recording light beam output from the light beam generating means, and supplying a pulse signal to the light beam generating means. The pulse signal supply means has a configuration of a closed loop circuit in which the pulse width of the pulse signal becomes a predetermined pulse width, and the pulse signal supply means converts the supplied recording pulse signal to a predetermined pulse width. Pulse width varying means for supplying a pulse signal having a pulse width to the light beam generating means,
A pulse width detecting means for detecting a pulse width of a pulse signal on an output side of the pulse width varying means and outputting a detection signal; and a pulse width setting means connected between the pulse width detecting means and the pulse width varying means. The pulse width setting means has a duty ratio of the pulse signal on the output side based on the value of the detection signal when the duty ratio of the pulse signal is 100% and the value of the detection signal when the duty ratio is 0%. An optical disk recording apparatus is configured to supply a setting signal for providing a duty ratio corresponding to a predetermined pulse width to a pulse width varying unit.

[0012]

According to the present invention, an information signal is recorded on a recordable optical disk by the recording light beam output from the light beam generating means, and a pulse signal is supplied from the pulse signal supplying means to the light beam generating means. The pulse signal supply means has a closed loop circuit configuration in which the pulse width of the pulse signal becomes a predetermined pulse width. In the pulse signal supply means, the recording pulse signal supplied by the pulse width variable means is converted into a pulse signal having a predetermined pulse width and supplied to the light beam generation means, and the output side of the pulse width variable means is supplied by the pulse width detection means. The pulse width setting means connected between the pulse width detecting means and the pulse width varying means detects when the duty ratio of the pulse signal is 100%. Based on the value of the signal and the value of the detection signal when the duty ratio is 0%, a setting signal such that the duty ratio of the pulse signal on the output side becomes a duty ratio corresponding to a predetermined pulse width is sent to the pulse width variable means. Supply.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments (Embodiments 1 to 4) of an optical disk recording apparatus according to the present invention will be described below with reference to the drawings.

(Embodiment 1)

FIG. 1 shows a configuration of a main part of an optical disk recording apparatus according to a first embodiment. In FIG. 1, reference numeral 2 denotes a pulse signal supply circuit as pulse signal supply means. The pulse signal supply circuit 2 includes a pulse width variable circuit 4 as a pulse width variable means and a pulse width setting means.
It has a CPU 6 composed of a one-chip microcomputer and a pulse width detecting circuit 8 as a pulse width detecting means, which are configured as a closed loop circuit.

The input terminal 10 of the variable pulse width circuit 4
Binary recording pulse signal P₁Is supplied. This recording pal
Signal P₁Is the channel clock period T_LWith pulse width
Is T _CKIt is. This channel clock period T_LAnd pa
Loose width T_CKIs the recording pulse signal P₁Is not shown
Clock generated from high-precision and high-stability oscillators such as vibrators
Since the signal is formed based on the signal,
Values do not change with changes in ambient temperature, etc.
be able to.

The recording pulse signal P ₁ is supplied to the inverter 1
2, the signal is supplied to the signal input terminal of the programmable delay line 14 and to one input terminal of the AND circuit 16 and the input contact 18b of the switch 18. The switch 18 has one movable contact 18a and three fixed contacts 1
This is a one-circuit, three-contact switch having 8b to 18c.

The recording pulse signal P ₂ delayed by the delay time τ ₁ by the programmable delay line 14 is supplied to the other input terminal of the AND circuit 16 through the fixed contact 18 c and the movable contact 18 a of the switch 18.

The recording pulse signal P ₃ output from the AND circuit 16 is supplied to a control terminal 20 c of the switch 20. The switch 20 has a movable contact 20a and a fixed contact 20b.
Has bets, the level of the recording pulse signal P ₃ which is supplied to the control terminal 20c is in the closed state (the state shown in the figure) at the high level and at a low level the open state.

The movable contact 20a side of the switch 20 is grounded through a variable current source circuit 22. The fixed contact 20b side of the switch 20 is connected to a power supply through a laser diode 24 as a light beam generating means.
The laser beam L emitted from the laser diode 24 from the variable current source circuit 22 in accordance with the drive current I _L is supplied,
A recording type optical disk 32, a part of which is supplied to a photodiode 28 as a light detecting means through an optical system 26 and the other part is rotated by a spindle motor 30.
Supplied to

The cathode side of the photodiode 28 is connected to a power supply, and the anode side is connected to a well-known APC circuit 34. The current I _L flowing through the variable current source circuit 22, that is, the value (pulse height) of the current I _L flowing through the laser diode 24 is determined by the output signal of the APC circuit 34 and is kept at a constant value.

On the other hand, the recording pulse signal P ₃ which is an output signal of the AND circuit 16 is converted into a DC signal P ₄ through a low-pass filter 34 and supplied to an A / D conversion circuit 36.

The A / D conversion circuit 36 outputs a DC signal P_FourN
Data detection signal D₁And supply it to CPU6.
You. The CPU 6 also operates as an arithmetic circuit, and detects this detection signal.
No. D ₁And a predetermined mathematical expression (to be described later)
Represents a programmable delay line based on a built-in program
The setting signal D, which is M-bit data,_TwoTo
Supply. The programmable delay line 14 uses this M bit
Data setting signal D_TwoDelay time τ based on₁Is determined
It is.

Next, the operation of the first embodiment will be described.

FIG. 2 is a waveform diagram for explaining the operation of the example of FIG. An input terminal 10 of the pulse signal supply circuit 2, the recording pulse signal P ₁ shown in FIG. 2A is supplied. The pulse width T _CK of the pulse signal P ₁ is the pulse width T _{OP of the} optimum recording.
And it is wider than it is necessary to narrow the pulse width T _CK to the pulse width T _OP optimum recording by a pulse width variable circuit 4. The pulse width T _OP optimum recording is a pulse width in the current I _L flowing actually into the laser diode 24 corresponds to the pulse width of the recording pulse signal P ₃ which is supplied to the control terminal 20c of the nearly switch 20.

Further, the switch 20, due to the high frequency and high speed transistors, for example, by using a current-mode transistor switch circuit, from the supply of the recording pulse signal P ₃ to the control terminal 20c until the switch 20 is actually open and close Time can be made negligibly small.

In place of the detection signal P ₃ supplied to the low-pass filter 34, for example, the variable current source circuit 22
A configuration may be adopted in which a relatively low-resistance resistor is connected in series between the ground and the ground, and a detection signal from the resistor is supplied to the low-pass filter 34. Further, the line driving current I _L flows, and insert the current probe utilizing such as a Hall element can be amplified from DC, may be supplied to the output of the current probe to the low-pass filter 34.

In this case, the pulse width of the waveform of the laser beam L can be accurately detected by taking the detection signal as close as possible to the laser diode 24 as an output element. Therefore, the photodiode 28
May be taken from the output.

In FIG. 1, the movable contact 1 of the switch 18
Optical disk 32 with 8a connected to fixed contact 18c
When the delay time of the programmable delay line 14 is τ ₁ at the time of recording, the recording pulse signal P ₃
As shown in the figure, the pulse width is changed from the pulse width _TCK to the delay time τ ₁
Since the narrowed waveform to the pulse width tau ₂ corresponding to (FIG. 2B, the signal P reference _2), a delay where seemingly time tau ₁
And the pulse width τ ₂ are equal. Therefore, it is sufficient to set the delay time tau ₁ by a programmable delay line 14 to the optimum recording pulse width T _OP.

However, according to the specification of the program delay line 14, the setting signal D is required to obtain the pulse width _TOP of the optimum recording.
_When the setting signal D ₂ having the value Mx (M bit data) should be given as ₂ and the setting signal D ₂ = Mx is supplied from the CPU 6 to the control input terminal of the programmable delay line 14, the circuit the error (in particular errors of the programmable delay line 14) of the system, the waveform of the recording signal P _3, it is impossible to obtain the actual optimum recording pulse width T _OP.

That is, the set delay time τ ₁ and the recording signal P
_It does not match the pulse width τ ₂ in the waveform ₃ (τ ₁ ≠
τ ₂ ). In addition, even if the value of the setting signal D ₂ is held at a constant value D ₂ = Mx due to environmental conditions, particularly a change in ambient temperature, the circuit system (FIG.
In the example, when the inverter 12, the programmable delay line 14, the AND circuit 16, and the switch 18 are semiconductor switches such as a multiplexer, the input / output characteristics (transfer characteristics) of the switch 18, the low-pass filter 34, and the A / D converter 36 ) Fluctuates, so that even if τ ₁ = τ ₂ is initially met, τ ₁ ≠ τ _{2 due} to changes in ambient temperature.

Therefore, it is necessary to actually measure the pulse width τ ₂ on the waveform of the recording signal P _{3. In} the example of FIG. 1, the pulse width τ ₂ is converted by the low-pass filter 34 into the duty ratio R (R = τ ₂ / T _L ) for measurement. If the low-pass filter 34 is used, the pulse width τ ₂
Signal processing is facilitated because it can be measured into a DC signal P _4. Since the cycle T _{L of the} channel clock is a constant value as described above, the pulse width τ ₂ can be accurately measured by measuring the duty ratio R. That is, as shown in FIG. 4D, the value of the DC signal P ₄ becomes equal to the duty ratio R (R = τ ₂ / T _L ).

Next, as described above, the value of the DC signal P ₄ , in other words, the detection signal D obtained by converting the analog DC signal P ₄ into a digital signal by the A / D converter 36.
₁ value, by utilizing the fact that equal to the duty ratio R, the pulse signal P ₃ will be described technique to determine the value of the setting signal D ₂ to become optimum pulse width T _OP.

Firstly, all the recording pulse signal P ₁ and the high-level signal, and connects the movable contact 18a of the switch 18 to the fixed contact 18b. Thereby, the recording signal P
₃ is kept at a high level state, therefore, the value of the detection signal D ₁ of the time the duty ratio R is R = 100% of CPU
6 obtained. This value is assumed to be D ₁ = N ₁₀₀ (N bits). These values, that is, R = 100% and D ₁ = N ₁₀₀ are stored in the CPU 6 as a pair.

Next, the movable contact 18a of the switch 18 is connected to the fixed contact 18d, that is, to the ground. As a result, the recording signal P ₃ is held at the low level, and therefore, the detection signal D ₁ when the duty ratio R is R = 0%.
Is obtained by the CPU 6. This value is assumed to be D ₁ = N ₀ . These values are stored in the CPU 6 in pairs.

In FIG. 3, points P ₀ and P ₁₀₀ are
In FIG. 3 shows the data stored as a pair plotted on the XY coordinates. In the figure, X-coordinate is the duty ratio R, Y coordinates are detected signal D _1. If the relationship between the duty ratio R and the detection signal D ₁ is first-order approximated, the characteristic 4
It becomes 0. This characteristic represents the 40 equations, the duty ratio variable R, is expressed as shown in Equation 1 functions as a detection signal D _1.

[0037]

D ₁ = {(N ₁₀₀ −N ₀ ) / (1−0)} · R + N ₀ = (N ₁₀₀ −N ₀ ) · R + N ₀

Therefore, the pulse signal P ₃ has an optimum pulse width T _OP (assuming that the duty ratio is R _OP , R _OP = T _OP /
T _L can be calculated in advance by the CPU 6. )) To determine the value of the setting signal D ₂
The movable contact 18a of the switch 18 is connected to the fixed contact 18c, and the recording pulse signal P ₁ (see FIG.
Supply through.

Then, the value of the setting signal D ₂ is varied and the value of the setting signal D ₂ when the optimum value N _OP of the setting signal D ₁ that satisfies the following equation 2 is obtained is changed to the optimum value M _OP It may be determined as The initial value at the time of changing the setting signal D ₂ is set to a nominal value of optimum pulse width T _OP in the specification of the programmable delay line 14 is obtained, detection signals D ₁
Calculate the difference between the value N ₁ and the optimum value N _OP, as the difference is within the zero value or + 1LSB, depending on the above difference bit by bit from the initial value (the nominal value) setting signal D ₂ Of course, by increasing or decreasing, the optimum value M _OP can be determined in a short time.

[0040]

## EQU2 ## N _OP = (N ₁₀₀ −N ₀ ) · T _OP / T _L + N ₀

If the above-described processing is automatically performed when the power is turned on (hereinafter, referred to as power-on reset processing), the recording operation can always be performed with the optimum pulse width _TOP .

The CPU 6 detects the detection signal D₁Monitor the value of
And the detection signal D₁Is, for example, a change in ambient temperature.
The optimum value N_OP(R_OP) Is detected.
In the case of a high-level controller (not shown)
Inform them of the situation and apply
Activating the closed loop circuit at an appropriate time and detecting the detection signal D ₁
Is the optimal value N_OPThat is, the pulse signal P_ThreePulse of
Width τ_TwoIs the optimal pulse width T_OP(Τ_Two= T_OP)
The above processing may be performed again. This process is required below
In response to this, it is called intermittent negative feedback processing.

A temperature sensor (not shown) as a temperature detecting means is provided and connected to the CPU 6, and when the temperature detected by the temperature sensor changes by a predetermined value or more, the upper controller is notified of the change. Just as you did,
The value of the detection signal D ₁ by operating the closed loop circuit at the appropriate time under the direction of the upper controller the optimum value N _OP
The above processing may be performed again.
This process is hereinafter referred to as a temperature-based negative feedback process as needed.

(Embodiment 2) In the equation (2), the cycle T _L of the channel clock is a substantially constant value determined by the crystal oscillator as described above.
Although it is sufficient to use, in the case of measuring accurately even this value may be measured and the time placed a timer between the pulse signals P ₃ and the CPU.

FIG. 4 shows a configuration using the timer 42. Reference numeral 43 denotes a pulse signal supply circuit of this example. In this case, since the optimum pulse width T _OP and the period T _L can be directly measured by the timer 42, there is no need to use Equation 2, and therefore the value N ₁₀₀ and the value N _It is not necessary to measure ₀ , and the optimum value M _OP can be determined in a shorter time. Note that the timer 42 is relatively expensive, and in terms of cost, the low-pass filter 34 and the A / D
The pulse signal supply circuit 43 using the converter 36 is excellent.

Also in this embodiment, the above-described power-on reset processing, intermittent negative feedback processing, and negative feedback processing based on temperature may be performed.

As described above, Embodiments 1 and 2 are described.
According to, since the pulse signal supply circuit 2, 43 for supplying a pulse signal P ₃ corresponding to the waveform of the drive current I _L supplied to the laser diode 24 and the configuration of the closed loop circuit, the pulse signal P ₃ pulse The width τ ₂ can be accurately set to the optimum value _TOP .

[0048] Further, it is possible to hold the pulse width tau ₂ of the pulse signal P ₃ to an optimum value T _OP by a negative feedback processing based on the intermittent negative feedback process or temperature.

(Embodiment 3)

In the third embodiment, the circuit shown in FIG. 1 can be used, and can be constituted by rewriting the contents of a program stored in a ROM (not shown) in the CPU 6. In Example 3, the circuit configuration circuit same as in example FIG, the optimum pulse width T _OP of the pulse signal P ₃ may be determined in a short time as compared to Example 1.

In FIG. 1, first, the recording pulse signal P ₁
Are all high level signals, and the movable contact 18a of the switch 18 is connected to the fixed contact 18b. Thereby, the recording signal P ₃ is kept at a high level state, therefore, the detection signal D of when the duty ratio R is R = 100%
The value of ₁ is obtained by the CPU 6. This value is D ₁ = N
It shall be ₁₀₀ (N bits). These values are
In the PU 6, the data is stored in pairs.

Next, the movable contact 18a of the switch 18 is connected to the fixed contact 18d, that is, to the ground. As a result, the recording signal P ₃ is held at the low level, and therefore, the detection signal D ₁ when the duty ratio R is R = 0%.
Is obtained by the CPU 6. This value is assumed to be D ₁ = N ₀ . These values are stored in the CPU 6 in pairs.

Next, the movable contact 18a of the switch 18 is switched to the fixed contact 18c side, and two appropriate values M ₁ and M ₂ are set from the CPU 6 while the recording pulse signal P ₁ is supplied. The value of the detection signal D ₁ at this time is stored in the CPU 6 as D ₁ = N ₁ , N ₂ .

FIG. 5 is a diagram plotting each value stored in the CPU 6 in this manner.

In FIG. 5, each axis is an axis whose value increases on the right and left sides of the X axis and above the Y axis with respect to the origin O. On the right side of the X axis, the detection signal D
₁ , the setting signal D ₂ is on the left side, and the duty ratio R is on the Y axis.

In this case, the characteristic 48 is
The relationship is an inverse function of the characteristic 40 shown in FIG. Property 50
Is a representation of the relationship between the setting signal D ₂ duty ratio R.

Equation 3 is obtained from the characteristic 50 of FIG. 5, and Equation 3 can be transformed into Equation 4. Further, it can be seen that T ₁ and T ₂ in Equation 4 are obtained as Equation 5 from the characteristic 48.

[0058]

[Equation 3] {(T _OP / T _L ) − (T ₁ / T _L )} / {(T ₂ / T _L ) − (T ₁ / T _L )} = (M _OP −M ₁ ) / (M ₂ -M ₁₎

[0059]

## EQU4 ## M _OP = M ₁ + (M ₂ −M ₁ ) × (T _OP −T ₁ ) / (T ₂ −T ₁ )

[0060]

T ₂ / T _L = (N ₂ −N ₀ ) / (N ₁₀₀ −N ₀ ) T ₁ / T _L = (N ₁ −N ₀ ) / (N ₁₀₀ −N ₀ )

As described above, according to the third embodiment, the two setting signals D ₂ = M ₁ , M _2
2 and the detection signal D when the duty ratio R is 0% and 100%
₁ = N ₁ , N ₂ , N ₁₀₀ , N ₀ and the optimum pulse width T _OP
, The optimum value M _OP of the setting signal D ₁ for obtaining the above can be uniquely determined. Therefore, the optimum value M _OP can be determined in a shorter time than in the first embodiment.

In the third embodiment, the optimum value M _{OP is set} to 2
Although it is obtained by linear approximation in relation to the _two set values M ₁ and M ₂ , measured values are obtained in relation to a larger number of set values according to the degree of linearity of the characteristic 50 and the characteristic 48, and those values are obtained. By obtaining the optimum value M _OP from, the setting error can be reduced.

(Embodiment 4)

FIG. 6 shows a circuit configuration having a pulse signal supply circuit 50 according to the fourth embodiment. FIG. 7 is a waveform chart for explaining the operation. In this embodiment 4,
Instead of the pulse width variable circuit 4 including the inverter 12, the programmable delay line 14, and the AND circuit 16 in the example of FIG. 1, a pulse width variable circuit 51 including a D / A conversion circuit 52, a comparison circuit 54, and a sweep circuit 56 is used. I have. In FIGS. 6 and 7, those corresponding to FIGS. 1 and 2 are denoted by the same reference numerals, and detailed description thereof will be omitted. The resolution of the D / A conversion circuit 52 is not limited to M bits, but may be set to the same resolution as the A / D converter 36, ie, N bits.

[0065] recording pulse signal P ₁ repeatedly sawtooth signal P ₅ (see FIG. 7A) is sweep circuit 56 (FIG. 7B
) And supplied to the non-inverting input terminal of the comparison circuit 54.

The M-bit setting signal D ₂ is converted to a corresponding DC signal P ₆ (see FIG. 7B) and supplied to the inverting input terminal of the comparing circuit 54 as a threshold value.

Therefore, the pulse signal P ₃ output from the comparison circuit 54 is as shown in FIG. 7C. That is,
The pulse width τ ₂ of the pulse signal P ₃ is equal to the setting signal D ₂ (P ₆ )
Will be changed accordingly.

The pulse signal P ₃ is supplied to the low-pass filter 34,
The details of the signal processing performed by the A / D conversion circuit 36 and the CPU 6 are the same as those in the first to third embodiments.

According to the example of FIG. 6, the programmable delay line 1
Since 4 is replaced by the sweep circuit 56 or the like, the circuit can be configured at low cost. Further, since the resolution of the D / A conversion circuit 52 can be made larger than M bits simply and inexpensively as compared with the case where the resolution of the programmable delay line 14 is made large, the D / A conversion circuit 52 has a higher resolution than the example shown in FIG. Accuracy is easy.

As described above, Embodiments 1 to 4
According to the above, the pulse signal P_ThreeProvide
The pulse signal supply circuits 2, 43, 50 for supplying
No. P _ThreePulse width τ_TwoIs the optimal pulse width T_OPBecome a closed loop
The pulse signal P_ThreePulse width τ
_TwoExactly the optimal pulse width T_OPCan be set to
Exact pulse width T_OPThe effect that can be held
Is obtained.

Therefore, it is possible to accurately set and hold a narrow pulse width, and it is possible to obtain an effect that a high-frequency and high-speed recording / reproducing process for the optical disk 32 can be realized.

Further, since the configuration of the closed loop circuit is employed, it is possible to use a low-precision circuit element such as the program delay line 14 and the like, and therefore, an inexpensive element. IC conversion is also possible at low cost.

Further, when the present invention is applied to, for example, a high-rotation type disk drive, the fluctuation of the recording laser power is reduced, so that the production yield can be improved. The stability of the disk drive in the market
Reliability is improved.

It should be noted that the present invention is not limited to the above-described embodiment, but can adopt various configurations without departing from the gist of the present invention.

[0075]

According to the first aspect of the present invention, in an optical disc recording apparatus for recording an information signal on a recordable optical disc with a recording light beam output from a light beam generating means, a pulse signal is applied to the light beam generating means. The pulse signal supply means is configured to have a closed loop circuit in which the pulse width of the pulse signal becomes a predetermined pulse width, and the pulse signal supply means supplies the supplied recording pulse signal. Pulse width means for supplying a pulse signal having a predetermined pulse width to the light beam generating means, and a pulse width detection means for detecting the pulse width of the pulse signal on the output side of the pulse width variable means and outputting a detection signal And a pulse width setting means connected between the pulse width detection means and the pulse width variable means, wherein the pulse width setting means has a duty cycle of the pulse signal. Based on the value of the detection signal when the ratio is 100% and the value of the detection signal when the duty ratio is 0%, the duty ratio of the pulse signal on the output side becomes a duty ratio corresponding to a predetermined pulse width. Since the setting signal is supplied to the pulse width varying means, the pulse width of the above-described pulse signal can be set accurately, and the accurate pulse width can be maintained. The setting and the holding thereof can be performed, so that it is possible to obtain an optical disc recording apparatus capable of realizing high-frequency and high-speed recording processing on the optical disc.
According to a second aspect of the present invention, there is provided an optical disc recording apparatus for recording an information signal on a recordable optical disc by a recording light beam output from a light beam generating means, comprising a temperature detecting means, and a pulse detecting means for the light beam generating means. A pulse signal supply unit for supplying a signal; the pulse signal supply unit is configured as a closed loop circuit that stabilizes a pulse width of the pulse signal when a temperature change is detected by a temperature detection device; The signal supply means converts the supplied recording pulse signal into a pulse signal having a predetermined pulse width, and supplies the pulse signal to the light beam generating means. The signal supply means detects the pulse width of the pulse signal on the output side of the pulse width variable means. And a pulse width setting means for outputting a detection signal, and a pulse width setting means connected between the pulse width detection means and the pulse width variable means, The pulse width setting means sets the duty ratio of the pulse signal on the output side to a predetermined pulse based on the value of the detection signal when the duty ratio of the pulse signal is 100% and the value of the detection signal when the duty ratio is 0%. Since a setting signal that provides a duty ratio corresponding to the width is supplied to the pulse width variable means, the pulse width of the above-described pulse signal can be accurately set regardless of a temperature change, and the accurate pulse width can be adjusted. The pulse width can be maintained, and therefore, a narrow pulse width can be set accurately regardless of a temperature change, and the accurate pulse width can be maintained, thereby realizing higher frequency and higher speed of the recording process for the optical disc. An optical disk recording device capable of performing the above operation can be obtained.

According to the third aspect of the present invention, there is provided an optical disc recording apparatus for recording an information signal on a recordable optical disc by using a recording light beam output from a light beam generating means.
The pulse signal supply unit includes a pulse signal supply unit that supplies a pulse signal to the light beam generation unit. The pulse signal supply unit is configured as a closed loop circuit in which the pulse width of the pulse signal becomes a predetermined pulse width. A pulse width varying means for converting the supplied recording pulse signal into a pulse signal having a predetermined pulse width and supplying the pulse signal to the light beam generating means, and detecting the pulse width of the pulse signal on the output side of the pulse width varying means, And a pulse width setting means connected between the pulse width detection means and the pulse width variable means, wherein the pulse width setting means has a pulse signal suitable for the pulse width variable means. The duty ratio value is M ₁ ,
While supplying the first and second setting signals of M ₂ , the first and second detection signals corresponding to the first and second setting signals are received from the pulse width detecting means, and the first and second setting signals are received. duty ratio of the detection signal value N _1, N ₂ and the pulse signal is 1
Based on the value N ₁₀₀ of the detection signal at the time of 00% and the value N ₀ of the detection signal when the duty ratio of the pulse signal is 0%,
When trying to set the pulse width of the pulse signal on the output side to _TOP , the value M _{OP of the} setting signal is set as follows: M _OP = M ₁ + (M ₂ −M ₁ ) × (T _OP −T ₁ ) / (T ₂₋ T ₁ ) where T ₂ = T _L × (N ₂ −N ₀ ) / (N ₁₀₀ −N ₀ ) T ₁ = T _L × (N ₁ −N ₀ ) / (N ₁₀₀ −N ₀ ) T _L : Since the pulse signal period is set as follows, the value M _{OP of the} setting signal can be determined in a short time, and the pulse width of the above-mentioned pulse signal can be set accurately, and the accurate pulse width can be determined. Therefore, it is possible to accurately set a narrow pulse width and hold the narrow pulse width, thereby obtaining an optical disc recording apparatus capable of realizing a higher frequency and a higher speed of a recording process for an optical disc. it can. According to the fourth invention, in an optical disc recording apparatus for recording an information signal on a recordable optical disc by a recording light beam output from a light beam generating means, the apparatus has a temperature detecting means and transmits a pulse signal to the light beam generating means. A pulse signal supply means for supplying the pulse signal, wherein the pulse signal supply means has a configuration of a closed loop circuit for stabilizing the pulse width of the pulse signal when a temperature change is detected by the temperature detection device, and Means for changing the supplied recording pulse signal into a pulse signal having a predetermined pulse width, supplying the pulse signal to the light beam generating means, and detecting the pulse width of the pulse signal on the output side of the pulse width variable means. A pulse width detection unit that outputs a detection signal; and a pulse width setting unit that is connected between the pulse width detection unit and the pulse width variable unit. Width setting means, the values which the pulse signal is appropriate duty ratio to the pulse width varying means is M _1, first and second M ₂
And the pulse width detection means
First and second detection signals corresponding to the first and second setting signals are received, and the values N ₁ , N of the first and second detection signals are received.
The duty ratio of the value N ₁₀₀ and the pulse signal of the detection signal when the duty ratio of ₂ and the pulse signal of 100% based on the values N ₀ of the detection signal when the 0%, the pulse width of the output side of the pulse signal when to be set to T _OP, the value M _OP setting _{signal, M OP = M 1 + (} M 2 -M 1) × (T OP -T 1) / (T 2 -T 1) , however, T ₂ = T _L × (N ₂ −N ₀ ) / (N ₁₀₀ −N ₀ ) T ₁ = T _L × (N ₁ −N ₀ ) / (N ₁₀₀ −N ₀ ) T _L : like the period of the pulse signal Since the setting is performed, the value M _{OP of the} setting signal can be determined in a short time, and the pulse width of the above-described pulse signal can be set accurately regardless of a temperature change, and the accurate pulse width is maintained. Therefore, a narrow pulse width can be set accurately regardless of a temperature change, and the accurate pulse width can be maintained. Further, it is possible to obtain an optical disk recording apparatus capable of realizing higher frequency and higher speed of a recording process for an optical disk.

[Brief description of the drawings]

FIG. 1 shows an optical disc recording apparatus according to a first embodiment of the present invention.
FIG. 14 is a block diagram showing a configuration of a main part of a third embodiment.

FIG. 2 is a waveform chart used for describing the operation of the example in FIG. 1 (Example 1).

FIG. 3 is a diagram used to explain the operation of the example in FIG. 1 (Example 1);

FIG. 4 is a block diagram showing a main configuration of an optical disc recording apparatus according to a second embodiment of the present invention.

FIG. 5 is a diagram used for describing the operation of the example in FIG. 1 (third embodiment);

FIG. 6 is a block diagram illustrating a configuration of a main part of an optical disc recording apparatus according to a fourth embodiment of the present invention.

FIG. 7 is a waveform chart used for describing the operation of the example in FIG. 6 (Example 4).

[Explanation of symbols]

 2 pulse signal supply circuit 4 pulse width variable circuit 6 CPU 8 pulse width detection circuit 24 laser diode 32 optical disk

Claims (4)

(57) [Claims] 1. An optical disk recording apparatus for recording an information signal on a recordable optical disk by a recording light beam output from a light beam generating means, comprising a pulse signal supplying means for supplying a pulse signal to the light beam generating means. The pulse signal supply means has a closed loop circuit configuration in which the pulse width of the pulse signal becomes a predetermined pulse width, and the pulse signal supply means converts the supplied recording pulse signal into a predetermined pulse width. A pulse width varying means for supplying a pulse signal to the light beam generating means, a pulse width detecting means for detecting a pulse width of a pulse signal on an output side of the pulse width varying means and outputting a detection signal, and the pulse Pulse width setting means connected between the width detection means and the pulse width variable means, wherein the pulse width setting means The duty ratio of the pulse signal on the output side corresponds to the predetermined pulse width based on the value of the detection signal when the duty ratio of the signal is 100% and the value of the detection signal when the duty ratio is 0%. An optical disk recording apparatus characterized in that a setting signal for providing a duty ratio is supplied to said pulse width varying means. 2. An optical disc recording apparatus for recording an information signal on a recordable optical disc by a recording light beam output from a light beam generating means, comprising a temperature detecting means and supplying a pulse signal to said light beam generating means. A pulse signal supply unit, wherein the pulse signal supply unit is configured as a closed loop circuit for stabilizing a pulse width of the pulse signal when a temperature change is detected by the temperature detection device; A signal supply unit configured to convert the supplied recording pulse signal into a pulse signal having a predetermined pulse width and to supply the pulse signal to the light beam generation unit; and a pulse width of the pulse signal on the output side of the pulse width variable unit. And a pulse width detecting means for detecting and outputting a detection signal, and connected between the pulse width detecting means and the pulse width varying means. A pulse width setting unit, wherein the pulse width setting unit is configured to determine, based on a value of the detection signal when the duty ratio of the pulse signal is 100% and a value of the detection signal when the duty ratio is 0%, An optical disk recording apparatus, wherein a setting signal is supplied to the pulse width varying means so that the duty ratio of the pulse signal on the output side becomes a duty ratio corresponding to the predetermined pulse width. 3. An optical disk recording apparatus for recording an information signal on a recordable optical disk by a recording light beam output from a light beam generating means, comprising a pulse signal supplying means for supplying a pulse signal to the light beam generating means. The pulse signal supply means has a closed loop circuit configuration in which the pulse width of the pulse signal becomes a predetermined pulse width, and the pulse signal supply means converts the supplied recording pulse signal into a predetermined pulse width. A pulse width varying means for supplying a pulse signal to the light beam generating means, a pulse width detecting means for detecting a pulse width of a pulse signal on an output side of the pulse width varying means and outputting a detection signal, and the pulse Pulse width setting means connected between the width detection means and the pulse width variable means, wherein the pulse width setting means With a value of the pulse signal is appropriate duty ratio is supplied to the first and second setting signals M _1, M ₂ in the width varying means, from said pulse width detecting means, said first and second setting signals , And the value N _{100 of the} detection signal when the duty ratio of the pulse signal is 100% with the values N ₁ and N _{2 of the first} and _second detection signals. And the value N of the detection signal when the duty ratio of the pulse signal is 0%
₀ , the pulse width of the pulse signal on the output side is set to T
_When setting to _OP , the value M _{OP of the} setting signal is set as follows: M _OP = M ₁ + (M ₂ −M ₁ ) × (T _OP −T ₁ ) / (T ₂ −T ₁ ) where T ₂ = T _L × (N ₂ −N ₀ ) / (N ₁₀₀ −N ₀ ) T ₁ = T _L × (N ₁ −N ₀ ) / (N ₁₀₀ −N ₀ ) T _L : like the period of the above pulse signal An optical disc recording apparatus, wherein the setting is made to: 4. An optical disc recording apparatus for recording an information signal on a recordable optical disc by a recording light beam output from a light beam generating means, comprising a temperature detecting means and supplying a pulse signal to said light beam generating means. A pulse signal supply unit, wherein the pulse signal supply unit is configured as a closed loop circuit for stabilizing a pulse width of the pulse signal when a temperature change is detected by the temperature detection device; A signal supply unit configured to convert the supplied recording pulse signal into a pulse signal having a predetermined pulse width and to supply the pulse signal to the light beam generation unit; and a pulse width of the pulse signal on the output side of the pulse width variable unit. And a pulse width detecting means for detecting and outputting a detection signal, and connected between the pulse width detecting means and the pulse width varying means. And a pulse width setting means, the pulse width setting means, the value of the pulse signal to the pulse width varying means is appropriate duty ratio for supplying the first and second setting signals M _1, M ₂ At the same time, the first and second detection signals corresponding to the first and second setting signals are received from the pulse width detection means, and the values N ₁ and N _{2 of the} first and second detection signals and the value N of the detection signal when the duty ratio of the detection signal value N ₁₀₀ and the pulse signal when the duty ratio of the pulse signal is 100% 0%
₀ , the pulse width of the pulse signal on the output side is set to T
_When setting to _OP , the value M _{OP of the} setting signal is set as follows: M _OP = M ₁ + (M ₂ −M ₁ ) × (T _OP −T ₁ ) / (T ₂ −T ₁ ) where T ₂ = T _L × (N ₂ −N ₀ ) / (N ₁₀₀ −N ₀ ) T ₁ = T _L × (N ₁ −N ₀ ) / (N ₁₀₀ −N ₀ ) T _L : like the period of the above pulse signal An optical disc recording apparatus, wherein the setting is made to: