JPS6379236A - Optical recording and reproducing device - Google Patents

Abstract

PURPOSE:To realize the prevention against the dissipation of data saved on a recording medium by using the artificial light gate signal outputting from a CPU during the process of a self-diagnosis and confirming the motion of a light protection function. CONSTITUTION:A CPU 28 makes a device in a reproducing mode with the command for self-diagnosis and outputs an artificial light gate (q) from an outport 2. The artificial light gate (q) comes in a delay circuit 24 via an OR circuit 33, a recording light power detection signal (o) is obtd., an AND circuit 26 is attained to an active H level and D-FF 27 is set. The Q output (p) of the FF 27 is then added to the interruption input of the CPU 28, the output of the artificial light gate of the outport 2 is suspended by detecting the light protection function having worked, a clear pulse (r) is outputted from an outport 1 to clear the D-FF 27 and it is returned to the initial state.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an optical recording and reproducing device for recording information on a disc-shaped recording medium (disc) capable of recording and reproducing information, and for reproducing the recorded information from this disc. .

BACKGROUND OF THE INVENTION In recent years, so-called write-once optical disks that users can write on have begun to be used as large-capacity file memories.

In this case, it is important to know whether information is being recorded reliably on the disc. To this end, it is required that the optical power from the optical head reaches the desired recording power when recording information on the disk. When the desired recording power is not reached, the recording operation is immediately stopped, the user is notified of this, and the abort process is performed to protect user data. The above-mentioned operation will be described below with reference to the drawings. FIG. 3 mainly shows the recording section of a conventional optical recording/reproducing device.

1 is an optical disk with a guide track formed in a spiral shape; 2 is a disk motor that rotates this optical disk at a specified speed; 3 is an optical head; this optical head 3
is linearly moved in the radial direction of the optical disc 1 by a stepping motor or a linear motor (not shown). 4 is a semiconductor laser that emits light in two directions, 6 is a condenser lens, 6 is a beam splitter, 7 is a tracking mirror, and 8 is an aperture lens.

The aperture lens 8 focuses the light from the semiconductor laser 4 onto the optical disk 1 into light having a diameter of about 1 μm. A first photodetector 9 detects reflected light from the optical disc 1 and converts it into an electrical signal. A second photodetector 10 converts monitor light output from the rear of the semiconductor laser 4 into an electrical signal. The optical head 3 is composed of the above components 4 to 10. A preamplifier 11 can output changes in the amount of reflected light from the optical disc as a reproduction signal. 12 is an integrating amplifier, and 13 is a differential amplifier that amplifies the difference between the output a of the integrating amplifier 12 and a reference voltage S preset by a variable resistor 14. The reference voltage S is a voltage for setting the oscillation output level during reproduction, for example, 1 mW. Reference numeral 16 denotes a sample and hold circuit that constantly samples the output g of the differential amplifier 13. The current supply circuit (1) 16 outputs a current according to this sampling value. Note that the sampling and holding circuit 15 is switched from a sampling state to a holding state in response to a write gate signal.

The current supply circuit (1) 1s drives the semiconductor laser 4 via the current adder 17. 2o uses a comparator to compare the monitor signal obtained by the integrating amplifier 12 according to the recording/reproduction and the level j set by the variable resistor 19, and determines the TTL "L" level Ov during recording and the TTL "L" level Ov during reproduction. This is a level detection circuit that outputs a signal d that becomes 6V, which is the "H" level. 18 is a variable resistor for setting the recording power to, for example, amW. 22 is a voltage C set by the variable resistor 18. 24 is a current supply circuit (If) that outputs a current i necessary for outputting recording power to the semiconductor laser 4. 24 is a signal f obtained by delaying the write gate signal e at the terminal 21 using a shift register. 25゜26 is a ND circuit.2
Reference numeral 7 denotes a D-type flip-flop (hereinafter abbreviated as I-FF) configured to operate at the rising edge of the output of the ND 26. 28 is a CPU that comprehensively controls this optical recording/reproducing apparatus. 29 is the write gate signal e I)
-F, is an AND circuit for controlling by the output of 7.27. 23 is an analog switch controlled by a gate signal m which is an output of an AND circuit 30 which inputs the data signal l of the terminal 31 and the write gate signal n controlled by the ND 29. That is, only during recording, the analog switch 23 is turned OFF according to the data signal.
N10 II F. The current adder 17 adds together the currents of the current supply circuits (1) 16° (U) 22 and i, and drives the semiconductor laser 4 by passing the added current.

Next, the operation of the optical information recording/reproducing apparatus configured as above will be explained with reference to FIG. 4.

The optical head 3 is moved to a predetermined position on the optical disc 1,
A beam light from a semiconductor laser 4 is outputted, and a beam spot is narrowed to a diameter of 1 μm or less on the optical disk 1 via a condenser lens 6 and an aperture lens 8. At this time, the optical disc 1 is rotated at a predetermined speed by the disc motor 2, and the beam light performs tracking control along the guide track while detecting the guide track of the optical disc 1.

The information recorded on the guide track of the optical disc 1 is applied as a change in reflectance to the first photodetector 9, converted into an electrical signal, and then passed through the preamplifier 11 to obtain a reproduced signal. Next, the time of reproduction will be explained. Semiconductor laser 4
The monitor light from behind is converted into an electrical signal by the second photodetector 10 and amplified by the integrating amplifier 12, resulting in the R part of the signal a shown in FIG. This output is supplied to the differential amplifier 13, which amplifies the difference between the signal & and the reference voltage signal S set by the variable resistor 14, and sends the signal g corresponding to the difference to the sample-and-hold circuit 15. supply to. During this playback, the write gate signal n of the AND29 output is "0"
level, and the sample hold circuit 16 is in a sampling state. The sample hold circuit 16 then supplies the sampled value of the output signal g of the differential amplifier 13 to the current supply circuit (T) 16 as it is.

Current supply circuit (1) 1e is the input differential amplifier 13
A driving current corresponding to the R' portion of the output signal g is supplied to the semiconductor laser 4 via the current adder 17. Since the analog switch 23 is OFF during playback, the drive current i of the other current supply circuit (n) 22 is not applied to the current adder 17, and the semiconductor laser 4 is driven only by the drive current of the current supply circuit (1) 1e. do. K in FIG. 4 shows the drive current waveform of the semiconductor laser 4.

By such an operation, the output level of the beam light during reproduction is controlled to a constant value according to the reference voltage.

That is, during reproduction, control is performed to stabilize the oscillation output of the semiconductor laser 4.

Next, the operation during recording will be explained. M Nl) Circuit 29
When the output write gate signal n is at the "1" level, the sample and hold circuit 16 stores the input signal level of the immediately preceding output signal C of the differential amplifier 13, uJ, and enters a hold state. This held signal level R'.

is supplied to the current supply circuit (I 2 ) 1e to generate a current hl for driving the semiconductor laser just before it enters the hold state, and to add it to the current adder. On the other hand, in order to record information, a data signal l with a frequency of about 1 MHz to 2 MH2 is sent to the terminal 31 via the ND circuit 3o to the analog switch 23.
Switch to ON10FF. That is, when the data signal l is at the "1" level, the analog switch 23 is turned on, and when the data signal l is at the "0" level, the analog switch 23 is turned off.The analog switch 23 is turned on by the data signal e. As a result, whether the output current i of the current supply circuit (n) 22 is applied to the current adder 17 or not, the current driving the semiconductor laser 4 becomes h8 as shown by K in FIG. or h11+i. Therefore, the optical disc 1
Data bits corresponding to the data signal l are formed on the guide track. At this time, monitor light corresponding to the recording beam light is input to the second photodetector 10. At this time, the output signal a of the integrating amplifier 12 becomes a high level as shown at section W in FIG. 4.

Next, the output a of the integrating amplifier 12 is compared with the voltage j set by the variable resistor 19 in the level detection circuit 20, and as shown in FIG.

On the other hand, write gate 0 is delayed by a delay circuit 24 consisting of a shift register, and outputs signals 0 and f to obtain f in FIG.
By adding it to the D circuit 26, as shown in FIG. 4, a recording light power detection period signal for monitoring the recording power delayed from the original write gate e of the terminal 21 can be obtained.

During this detection period, the output of the level detection circuit 20 is
As shown in , since it is Ov at the “L” level of TTL, MuN
The output of the D circuit 2e is always at the tt L” level D −
F, F, 27 are not set and Q output p is ゞゞH''
The output n of the ND circuit 29 becomes equal to the write gate signal e at the terminal 21, depending on the level.

Then, the output n of this NI circuit 29 is applied as a write gate to the ND circuit 3o to control the laser drive circuit.

Next, if the output d of the level detection circuit 20 does not reach the recording light power during the recording light power detection period of the output O of the mu ND circuit 26 due to damage to the semiconductor laser or abnormality in the semiconductor laser drive circuit, the integrating amplifier 12 The output a is the fourth
As shown in figure a', the output d of the level detection circuit 20 is therefore
Also, as shown in Figure 4 d', the TTL is "H" even during recording.
“The level is +6v.At this time, D −F, 7.2
7 is set, and the output p of Q becomes ++L" level after the recording power becomes abnormal, and the original write gate e of the terminal 21 is forcibly closed by the AND circuit 29, as shown in FIG. 4, n'. In other words, this is the write fault function.Then, the delay circuit 24 and the AND circuit 2ei
, 26, 29 and D-FJ, 27 constitute a write protect circuit 32. When the write protect function is activated, the Q output p' of D-F, F, 27 is added to the interconnected input, which is the input port of the CPU 25S, and the
recognizes this abnormal condition. The CPU 28 then performs abort processing, and during this processing reports via the ink 7 ace that a write fault has occurred in the host. Finally, the CPU 28 clears D-F, 7.27 by outvoting the CPU 2B, and the series of processing ends.

Problems to be Solved by the Invention However, in the conventional configuration as described above, if the write protection does not function for some reason, the data that the user attempts to save in the recording/playback device may be lost. had.

In view of this, an object of the present invention is to provide an optical recording/reproducing device that can confirm that this function is operating reliably during self-diagnosis processing.

Means for Solving Problems The present invention provides means for monitoring optical power, write protection means for forcibly prohibiting recording when an optical monitor signal is not detected as a recording state during recording, and pseudo protection means for self-diagnosis. Light gate signal to.

This is an optical recording and reproducing apparatus that includes means for generating write protection and means for checking whether write protection has been activated.

According to the above-described configuration, the present invention performs a self-diagnosis when the optical power is regenerated, and when the detection signal of the optical power monitor means is in the regenerated state, the CPU, which is the pseudo write gate signal generation means, generates a pseudo write gate signal. When this signal is output, the write protect means functions, and the CPU confirms that the write protect means has functioned.

Embodiment An embodiment of the present invention is shown in FIG. In FIG. 1, the write protect circuit section 32 shown in FIG. 3 is mainly shown.

The operation of the present invention will be explained below with reference to FIGS. 1 and 2.

When the optical recording/reproducing apparatus is powered on or in response to a self-diagnosis command from the host, the CPU 28 of the optical recording/reproducing apparatus executes the following procedure. Step 1 is to put the optical recording/reproducing device into a reproduction mode. At this time, the terminal 21 is connected to the light
is not added. And the output d of the level detection circuit 20
is TTL "H" L/Af) + 5 V. Then, in step 2, the CPU 28
From t2, the signal q in FIG. 2 is output as a pseudo write gate. At the time of recording in q, the TTL "H" level is present. The pseudo write gate q is applied to the delay circuit 24 via the OR circuit 33, and the recording light power detection interval signal 0 is obtained as explained in the section of the prior art. When this 0 becomes active, the output d of the level detection circuit 2o is at the +11 (47) level, so the ND circuit 26 goes to the active H'' level and fi, D-F, F, and 27 are set. Then, the Q output p of D-F, F, 27 is added to the interlaced input of the CPU 28. In step 3, the CPU 28 detects that the write protect function has been activated by inputting the interconnected signal, and activates the pseudo write gate of out port 2. Stop outputting.

As step 4, the CPU 28 outputs a clear pulse r from the out portl to clear D-F, 7.27, and return to the initial state.

The above steps complete the self-diagnosis to check the write protect function. Note that even if a write gate signal is generated in a pseudo manner, it is simply added to the drive protect section, so the optical power does not become write power.

Effects of the Invention The present invention allows self-diagnosis of the write protect function by adding simple hardware and software. Therefore, when a user is writing data to a recording medium, if the recording power is not generated due to an abnormality in the semiconductor laser or semiconductor laser drive circuit, etc., and the user is unable to write the user data to the recording medium, It can be confirmed in advance that the function of reporting the occurrence of this write fault state to the user will work reliably. Therefore, the user is guaranteed not to lose the data he or she tries to save on the recording medium at this time, and the user can use the optical recording/reproducing device as an external storage device with peace of mind.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram showing an embodiment of the present invention, Fig. 2 is a signal diagram explaining the operation of the same embodiment, Fig. 3 is a configuration diagram of a conventional optical recording/reproducing device, and Fig. 4 is a conventional example. FIG. 1... Optical disk, 4... Semiconductor laser, 1°... Second photodetector, 12...
・Integrator amplifier, 20...Level detector, 23・
...Analog switch, 24...Delay circuit, 2B, 26, 29.30...AND circuit,
27... Latch circuit, 28... CPU
(microprocessor), 32... write protection circuit, 33... OR circuit. Name of agent: Patent attorney Toshio Nakao and 1 other person 2nd
Figure 4

Claims (1)

[Claims] an optical power detection means for monitoring optical power when recording and reproducing information on an optical disc; and a write protection means for forcibly prohibiting recording when the optical power is not a recording power based on a detection signal obtained by the optical power detection means during recording. ,
A pseudo write gate generating means for generating a pseudo write gate signal and adding it to the write protection means during self-diagnosis, and means for confirming that the write protection means operates normally during self-diagnosis. An optical recording and reproducing device.