JPH07192275A - Optical information recording and reproducing device - Google Patents

Abstract

PURPOSE:To surely pull in focus servo by sufficiently obtaining the braking force of an objective lens by pulling in the focus servo at prescribed timing from the peak value of a focus error signal to a comparative level. CONSTITUTION:When pulling in the focus servo, at a CPU 4, the peak detection mode of an error signal (FE) is processed, and the focus error signal of an error signal generator 2 is fetched from an A/D converter 3 to the CPU 4. The CPU 4 stores a value fetched at that time in an internal memory and drives the objective lens through a focus actuator later. Then, the CPU 4 fetches the FE in a fixed cycle, when that peak value is detected, a value lower than the peak value just at a prescribed level is stored as the comparative level, and the next pull-in mode is started. Afterwards, when the FE is gradually lowered from the peak value and reaches the comparative level, a focus servo loop is turned on, and the focus servo is surely pulled in.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical information recording / reproducing apparatus for optically recording / reproducing information on / from an information recording medium, and more particularly to improvement of a focus servo pull-in apparatus for pulling in a focus servo.

[0002]

2. Description of the Related Art FIG. 10 is a block diagram showing a focus servo loop and a tracking servo loop of a conventional optical information recording / reproducing apparatus. In the figure, reference numeral 1 denotes an optical sensor for detecting light reflected from a recording medium such as an optical disk, and 2 denotes a focus error signal, a tracking error signal and a sum signal based on the detection signal of the optical sensor 1. It is an error signal generator. Usually, the optical sensor 1 uses a multi-divided photo sensor divided into a plurality of parts, and the error signal generator 2 combines the signals of the detection pieces of the multi-divided photo sensor to generate a focus error signal, a tracking error signal and a sum signal. To be done. The astigmatism method, the knife edge method, the beam size method and the like are available as methods for detecting the focus error signal, and the bush pull method, the heterodyne method and the three-beam method are available as methods for detecting the tracking error signal.

Reference numeral 10 is a focus phase compensation circuit, 11 is a switch for opening and closing a focus servo loop, and 6 is a driver for driving a focus actuator 7. A focus servo loop is configured by the components from the optical sensor 1 to the focus actuator 7, and the focus actuator 7 is controlled based on the focus error signal to displace the objective lens (not shown) in the focus direction to record a light spot. Focus control is performed so as to focus on the medium surface. Further, 12 is a tracking phase compensation circuit, 13 is a switch for opening and closing the tracking servo loop, and 8 is a driver for driving the tracking actuator 9. A tracking servo loop is configured by the components from the optical sensor 1 to the tracking actuator 9, and the tracking actuator 9 is controlled based on the tracking error signal to displace the objective lens in the tracking direction, so that the light spot becomes an information track. Tracking control is performed so as to follow.

Reference numeral 14 is a zero-cross comparator for detecting the zero-cross point of the focus error signal, and reference numeral 15 is a level comparator for comparing the sum signal with a predetermined slice level to generate a window pulse. Reference numeral 16 is a controller such as a CPU, and 17 is a focus search circuit for applying a search voltage to the driver 6 based on an instruction from the controller 16. A focus servo pull-in circuit is configured by the above two comparators 14 and 15, the controller 16 and the focus search circuit 17.

Next, the focus pull-in operation of the focus servo pull-in circuit will be described with reference to FIG. First, when pulling in the focus servo, the controller 1
The switches 11 and 13 are turned off by the instruction of 6. In this state, the controller 16 outputs a control signal to the focus search circuit 17 so as to supply the search voltage to the driver 6. As a result, the search voltage is applied from the focus search circuit 17 to the driver 6, and the focus actuator 7 is driven in the direction perpendicular to the surface of the recording medium. FIG. 11A shows a focus error signal obtained by the error signal generator 2 when the search voltage is supplied, and FIG. 11B shows a sum signal. Note that FIG.
1 (a) shows three focus error signals, of which (a) is a normal focus error signal.

The level comparator 15 is shown in FIG.
As shown in (1), the sum signal is compared with the slice level, and when the sum signal is higher than a predetermined level, a pulse signal having a low level is generated and output to the controller 16.
Further, the zero-cross comparator 14 compares the focus error signal with the zero level, and outputs a zero-cross detection signal which is inverted to the low level at the zero-cross point as shown in FIG. 11 (d). The pulse signal of the level comparator 15 is monitored by the controller 16, and the zero-cross comparator 14 is monitored while this pulse signal is at the low level.
When a zero-cross detection signal is output from, the supply of the voltage for search is stopped, and at the same time, the switch 11 is turned on to pull in the focus servo. That is, since the normal focus error signal is at a low level as shown in FIG. 11A, the sum signal is binarized to generate the window pulse,
The focus servo pull-in is performed only when the zero cross is detected within the low level period of the pulse signal.

[0007]

By the way, when the focus error signal is detected, a normal focus error signal is not always obtained as shown in (a) of FIG. 11 (a). ), The positive / negative balance of the focus error signal is out of order as shown in (b),
As shown in (c), the focus error signal may have an offset. However, in such a case, in the conventional focus servo pull-in circuit, the pull-in of the focus servo may fail because the braking force of the objective lens is not sufficiently obtained after the focus servo is turned on. That is, when pulling in the focus servo, the focus servo is turned on at the zero-cross point of the focus error signal to start the position control of the objective lens. At this time, from the zero level of the focus error signal to the negative peak value. Signal is applied to bring the objective lens back to the focal position. Therefore,
If the focus error signal has an offset or the positive and negative balance is out of balance as in 1 (a), (b) and (c), the braking force for returning the objective lens to the focal position is insufficient, so the focal position shifts. There was a case where it failed to pull in the focus servo.

The present invention has been made in view of the above conventional problems, and its purpose is to always obtain a sufficient braking force of the objective lens irrespective of the signal waveform of the focus error signal and to reliably perform the focus servo. Another object of the present invention is to provide an optical information recording / reproducing apparatus capable of pulling in.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to provide an objective lens for irradiating an optical information recording medium with a light beam emitted from a light source into a minute light spot, and the recording medium for the light spot. An optical sensor for detecting the reflected light from the optical sensor, an error signal generator for generating a focus error signal based on the detection signal of the optical sensor, and a recording of the light spot based on the focus error signal. In an optical information recording / reproducing apparatus having a focus servo loop for controlling focus on a medium surface, means for driving the objective lens in a focus direction to detect a peak value of the focus error signal, and detecting the peak value of the focus error signal. Means for setting a target level of the focus servo loop to a predetermined level based on the peak value thus obtained, The focus servo is pulled in at a predetermined timing from when the peak value reaches the peak value to the predetermined level, and after the focus servo loop becomes stable, the target level of the focus servo loop is gradually decreased from the predetermined level to 0 level. This is achieved by an optical information recording / reproducing device characterized in that

[0010]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a block diagram showing the overall configuration of a focus and tracking control device of an optical information recording / reproducing device according to the present invention. In FIG. 1, reference numeral 1 is an optical sensor that detects light reflected from a recording medium such as an optical disk, and 2 is an error signal generator that generates a focus error signal and a tracking error signal based on the detection signal of the optical sensor 1. is there. All of these are the same as those shown in FIG. However, since the sum signal is not used in this embodiment, the error signal generator 2 generates only the focus error signal and the tracking error signal.

Optical elements such as a semiconductor laser which is a light source for recording / reproducing, an objective lens which focuses a light beam of the semiconductor laser into a minute light spot and irradiates the recording medium, and an optical sensor 1 which detects reflected light from the recording medium Is provided in the optical head, and information is recorded and reproduced by irradiating a recording medium with a light beam from the optical head. Reference numeral 3 denotes an A / D converter for digitizing the focus error signal and the tracking error signal, respectively. The focus error signal and the tracking error signal are A / D converters 3, respectively.
Are digitized at a constant cycle by and are taken into the CPU 4. The CPU 4 is a processor circuit for controlling the pull-in of focus servo, focus servo, tracking servo, and the like by digital signal processing. The pull-in operation of the focus servo will be described later in detail.

Reference numeral 5 is a D / A converter for converting the command value of the CPU 4 into an analog signal, 6 is a driver for driving the focus actuator 7, and 8 is a driver for driving the tracking actuator 9. The drivers 6 and 8, the focus actuator 7, and the tracking actuator 9 are the same as those in FIG. The focus actuator 7 and the tracking actuator 9 are provided in the optical head. In the focus servo loop and the tracking servo loop, the focus actuator 7 and the tracking actuator 9 are based on the focus error signal and the tracking error signal of the error signal generator 2. Control the objective lens to focus direction,
Focus control and tracking control are performed by displacing in the tracking direction.

Next, a first embodiment of the present invention will be described with reference to FIGS.
It will be described based on. FIG. 2 is a flowchart showing the focus servo pull-in operation, and FIG. 3 is a diagram showing the focus error signal and the focus servo pull-in timing when the focus servo is pulled in. In FIG. 2, first, when pulling in the focus servo, the CPU 4
Then, the peak detection mode processing for detecting the peak value of the focus error signal is performed. When detecting the peak value,
First, the focus error signal of the error signal generator 2 is taken into the CPU 4 from the A / D converter 3 (S1), and the CPU
In 4, the value is compared with the previous value (previously fetched value) to determine whether the current value is larger than the previous value (S2). Since the value initially fetched is of course 0, the value fetched at that time is stored in the internal memory (S3), and then the drive voltage for search is output to the D / A converter 5 (S4). As a result, the drive voltage is applied to the driver 6 to drive the focus actuator 7, and the objective lens (not shown) is driven in the focus direction.

In this way, the CPU 4 takes in the focus error signal at a constant cycle and compares it with the previous value each time, thereby performing the process of detecting the peak value of the focus error signal. When the search D / A value is output to the D / A converter 5, the D / A output value is gradually increased and output so that the focus actuator 7 approaches the surface of the recording medium at a constant speed. Therefore, by repeating the processing of S1 to S4, the focus error signal (the signal indicated by the solid line) increases as shown in FIG. 3A, and eventually the value of the focus error signal becomes larger than the previous value in S2. If it is determined that the focus error signal has reached the peak value. When the peak value is detected, the CPU 4 stores a value lower than the peak value by a predetermined level X in the internal memory as a comparison level (S5), and shifts to the next focus servo pull-in mode. The focus error signal shown by the broken line in FIG. 3A is a signal when the focus servo loop is kept off.

In the pull-in mode, first, the A / D value of the focus error signal is fetched (S6), and it is judged whether the value is equal to or lower than the previously stored comparison level (S7). Initially, the value of the focus error signal is close to the peak value, so S7 is NO. Therefore, at this time, after the search value is output to the D / A converter 5 (S8), the process returns to S6 and the value of the focus error signal is fetched. In this way, the CPU 4 fetches the value of the focus error signal at a constant cycle and repeats the processing of S6 to S8. At this time, the focus error signal is as shown in FIG.
When the level gradually decreases from the peak value and reaches the comparison level as shown in (a), it is determined in S7 that the focus error signal has reached the comparison level, and the focus servo is pulled in. That is, when the level of the focus error signal reaches the comparison level, the focus servo loop is turned on and the focus servo is pulled in as shown in FIG. 3B.

When the focus servo is turned on, the CPU 4
Then, processing in the focus servo mode is performed. In the focus servo mode, the CPU 4 first sets the previous comparison level as the target level of the focus servo (S9). That is, the target level of the focus servo is set so as to focus at the position of the comparison level of the focus error signal. Next, the value of the focus error signal is fetched (S10), and then it is determined whether the target level is 0 (S11). Here, since the target level is the comparison level, S11 is NO. Therefore,
At this time, the target level (comparison level) is subtracted from the value of the focus error signal fetched in S10 (S1
2) Since the target level has been set to the comparison level previously, a process of subtracting that amount as an offset is performed. Next, the CPU 4 performs a process of determining whether the focus servo loop is stable (S13). This stability determination will be described later in detail, and the description will continue assuming that it is determined to be unstable.

If the focus servo loop is not stable, the CPU 4 proceeds to S15 to perform the arithmetic processing of the phase compensation filter of the focus servo loop, and the arithmetic result is output to the D / A converter 5 (S16). And
The focus error signal is captured again in the next cycle, and the focus control of the light beam is performed so that the focus of the light beam reaches the target level (comparison level) by repeating the processing of S10 to S16. As a result, the focus error signal has the comparison level as the target level as shown in FIG. 3A, and thus gradually converges to the comparison level while repeating vibration around the comparison level, and gradually stabilizes. The period in which the focus error signal converges in this way is shown as the target level converging period in FIG.

The stability determination of the focus servo loop in S13 will be described. The CPU 4 is stable when the level of the focus error signal is within a predetermined range centered on the comparison level, and is out of the predetermined range when it is out of the predetermined range. It is determined to be unstable. Therefore, after the focus servo is pulled in in FIG. 3A, when the vibration amplitude of the focus error signal is large, it is determined to be unstable, and the focus error signal gradually converges to the comparison level, and then the comparison level is changed. If it is within the predetermined range at the center, it is determined in S13 that the focus servo loop is stable.

When the focus servo loop is stable, the CPU 4 determines whether the target level is one level lower by subtracting 1 from the comparison level previously set as the target level after determining the stability in S13 and proceeding to S14. It Next, the calculation process of the phase compensation filter (S15), D / A
The output (S16) is performed, and then the focus error signal is captured in the next cycle (S10). In this way, when the focus servo loop becomes stable, the processing of S10 to S16 is repeated, and at this time, the target level is decremented by 1 for each control cycle so that the focus servo target level becomes the original 0 level. Shift processing is performed. As a result, as shown in FIG. 3A, the focus error signal gradually decreases and approaches the 0 level.
The decrease period of the focus error signal is shown as the target level decrease period in FIG.

When the target level gradually decreases to 0 in this way, the target level is determined to be 0 in S11 (YES in S11), and thereafter, S10, S11 to S15, S1.
By repeating the process of 6, normal focus servo control is performed. That is, the focus error signal is fetched at a constant cycle, the calculation of the phase compensation filter is performed based on the focus error signal, and the calculation result is output to the D / A converter 5 repeatedly. Focus control is performed so as to focus on.

In this embodiment, the peak value of the focus error signal is detected, a value lower than the peak value by a predetermined value is set as the comparison level, and the focus servo is pulled in when the focus error signal reaches the comparison level. A sufficient braking force of the objective lens can be obtained, and the focus servo can be reliably pulled in. That is, when the focus servo is pulled in, the objective lens is braked from the comparison level of the focus error signal, so that a sufficient braking force should be secured as compared with the conventional control from the 0 level of the focus error signal. You can
Therefore, even if the positive / negative balance of the focus error signal is out of balance or the focus error signal has an offset, the braking force is not insufficient, and the focus servo can be reliably pulled in.

Further, after the focus servo is pulled in at the comparison level, the target value of the focus servo is gradually approached to 0 level after waiting for the focus servo to stabilize, whereby the normal focus control can be restored. it can. Further, since a level comparator for binarizing the sum signal is unnecessary, the structure can be simplified accordingly. When detecting the peak value of the focus error signal, if the lower limit value is set for the peak value and the peak value below that value is ignored as a pseudo peak value, the disk surface is erroneously focused. It is possible to prevent it from being pulled in.

Next, a second embodiment of the present invention will be described with reference to FIGS. FIG. 4 is a flowchart showing the focus servo pull-in operation, and FIG. 5 is a view showing the focus error signal and the focus servo pull-in timing when the focus servo is pulled in. This example
This is an example of setting the comparison level at a predetermined ratio Y% (Y is 100% or less) from the peak value of the focus error signal when setting the comparison level. Others are the same as in the previous embodiment. In FIG. 4, first, the CPU 4 detects the peak value of the focus error signal (S1 to S4).
Up to this point, the process is the same as in FIG. Next, the CPU 4 stores a value obtained by multiplying the detected peak value by a predetermined ratio Y% (Y <100%) in the memory and sets the comparison level as shown in FIG. 5A (S5). After setting the comparison level, it is exactly the same as in FIG.

That is, when the focus servo pull-in mode is entered and the focus error signal reaches the comparison level in S6 to S8, the focus servo is turned on to pull in the focus servo as shown in FIG. 5B. Be seen.
When the focus servo is turned on, S9 to S13,
In S15 to S16, the focus servo is performed with the comparison level as the target level, and the focus error signal is shown in FIG.
The focus servo loop gradually stabilizes. Then, when the focus servo loop becomes stable, the target level is gradually brought closer to the 0 level from the comparison level, and the normal focus control is resumed.

Also in this embodiment, the braking force of the objective lens can be sufficiently obtained, and the focus servo can be reliably pulled in, just as in the first embodiment. Further, in the present embodiment, since the comparison level is set at a certain ratio from the peak value, the comparison level can be set according to the amplitude value of the focus error signal. That is, since the comparison level is set to a level of a certain ratio from the peak value regardless of the amplitude of the focus error signal, when the amplitude of the focus error signal is small, the comparison level is set close to 0 level. Conversely, when the amplitude of the focus error signal is large, the comparison level is not set near the peak value, and the comparison level can be set according to the amplitude value. Also in this embodiment, it is preferable to set the lower limit value to the peak value when detecting the peak value of the focus error signal as in the first embodiment.

Next, a third embodiment of the present invention will be described with reference to FIGS. FIG. 6 is a flowchart showing the focus servo pull-in operation, and FIG. 7 is a view showing the focus error signal and the focus servo pull-in timing when the focus servo is pulled in. In the first and second embodiments, the focus servo is pulled in when the focus error signal reaches a predetermined comparison level. In this embodiment, however, the focus servo is pulled in when the peak value of the focus error signal is detected. Is to do. Further, in this embodiment, after the focus servo is pulled in, the focus servo is performed by setting the target level to a value lower than the peak value by a predetermined value as in the first embodiment.

In FIG. 6, first, the peak value of the focus error signal is detected in S1 to S4 as in the first and second embodiments (see FIG. 7A). When the peak value is detected,
In S5, a value lower than the peak value by the predetermined value X is stored in the memory as the target level (S5), and the target level of the focus servo loop is set. At the same time, FIG. 7 (b)
As shown in, the focus servo loop is turned on to pull in the focus servo. The operation after pulling in the focus servo is exactly the same as in the first and second embodiments. That is, as shown in FIG. 7A, the focus servo is performed at the previously set target level and waits for the focus servo loop to stabilize, after which the target level is gradually reduced to 0 level to achieve normal focus. Servo operation is performed.

As described above, in this embodiment, the focus servo is pulled in at the peak value of the focus error signal, so that the braking force of the objective lens can be sufficiently obtained in exactly the same manner as in the first and second embodiments. The focus servo can be pulled into. Also in this embodiment, when detecting the peak value of the focus error signal, it is desirable to set the lower limit value to the peak value so that the focus servo is not pulled in on the disk surface.

Next is a fourth embodiment. FIG. 8 is a flowchart showing the operation of the fourth embodiment, and FIG. 9 is a diagram showing the focus error signal and the focus servo pull-in timing. In this embodiment, like the third embodiment, the focus servo is pulled in at the time when the peak value of the focus error signal is detected, and the target level is set at a certain ratio from the peak value as in the second embodiment. To do.

In FIG. 8, first, when the peak value of the focus error signal is detected in S1 to S4, a value of a certain percentage Y% (Y is 100% or less) from the peak value is stored in the memory as a target level ( S5). The setting of the target level is the same as in the second embodiment. At the same time, as shown in FIG. 9B, the focus servo loop is turned on at the timing when the peak value is detected, and the focus servo is pulled in. The operation after this is the same as in the previous embodiment, and waits for the focus servo loop to stabilize as shown in FIG. 9A, after which the target level is gradually decreased and normal focus control is resumed.

Also in this embodiment, since the focus servo is pulled in at the peak value of the focus error signal, the braking force of the objective lens will not be insufficient and the focus servo can be pulled in reliably. Moreover, since the target level is set at a certain ratio from the peak value, the target level can be set according to the amplitude level of the focus error signal. Further, also in this embodiment, when the peak value of the focus error signal is detected, the lower limit value of the peak value may be set and the peak values below it may be ignored.

In the above embodiments, the focus servo is pulled in when the focus error signal reaches the peak value or when it reaches the comparison level, but if it is between the target level and the comparison level, It may be any timing. That is, the pull-in timing is not particularly limited as long as the level of the focus error signal at that time is a level at which the braking force of the objective lens can be sufficiently secured. Further, although the comparison level is set to a value lower than the peak value of the focus error signal by a predetermined value or at a fixed ratio, the point is that the braking force of the objective lens can be secured, so the comparison level is also set in the embodiment. It is not limited to

[0033]

As described above, according to the present invention, the braking force of the objective lens can be sufficiently obtained by pulling in the focus servo at a predetermined timing from the peak value of the focus error signal to the comparison level. Even if the positive / negative balance of the focus error signal is out of balance or the focus error signal has an offset, the braking force is not insufficient, and the focus servo can be reliably pulled in.

[Brief description of drawings]

FIG. 1 is a block diagram showing an example of the overall configuration of a servo control device of an optical information recording / reproducing device according to the present invention.

FIG. 2 is a flowchart showing a first embodiment of the optical information recording / reproducing apparatus according to the present invention.

FIG. 3 is a diagram showing a focus error signal and a focus servo pull-in timing at the time of pulling in the focus servo in the embodiment of FIG.

FIG. 4 is a flowchart showing a second embodiment of the present invention.

5 is a diagram showing a focus error signal and a focus servo pull-in timing at the time of pulling in the focus servo in the embodiment of FIG.

FIG. 6 is a flowchart showing a third embodiment of the present invention.

FIG. 7 is a diagram showing a focus error signal and a focus servo pull-in timing at the time of pulling in the focus servo according to the embodiment of FIG. 6;

FIG. 8 is a flowchart showing a fourth embodiment of the present invention.

9 is a diagram showing a focus error signal and a focus servo pull-in timing at the time of pulling in the focus servo in the embodiment of FIG.

FIG. 10 is a configuration diagram showing a focus servo loop and a tracking servo loop of a conventional optical information recording / reproducing apparatus.

11 is a time chart showing the focus servo pull-in operation of the recording / reproducing apparatus of FIG.

[Explanation of symbols]

 1 Optical Sensor 2 Error Signal Generator 3 A / D Converter 4 CPU 5 D / A Converter 6, 8 Driver 7 Focus Actuator 9 Tracking Actuator

[Procedure amendment]

[Submission date] March 31, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0014

[Correction method] Change

[Correction content]

In this way, the CPU 4 takes in the focus error signal at a constant cycle and compares it with the previous value each time, thereby performing the process of detecting the peak value of the focus error signal. When the search D / A value is output to the D / A converter 5, the D / A output value is gradually increased and output so that the focus actuator 7 approaches the surface of the recording medium at a constant speed. Therefore, by repeating the processing of S1 to S4, the focus error signal (the signal indicated by the solid line) increases as shown in FIG. 3A, and eventually the value of the focus error signal becomes smaller than the previous value in S2. If it is determined that the focus error signal has reached the peak value. When the peak value is detected, the CPU 4 stores a value lower than the peak value by a predetermined level X in the internal memory as a comparison level (S5), and shifts to the next focus servo pull-in mode. The focus error signal shown by the broken line in FIG. 3A is a signal when the focus servo loop is kept off.

Claims (4)

[Claims] 1. An objective lens for irradiating an optical information recording medium with a light beam emitted from a light source by focusing on a minute light spot, and light for detecting reflected light of the light spot from the recording medium. A sensor, an error signal generator for generating a focus error signal based on the detection signal of the optical sensor, and a focus for controlling the focus of the light spot on the recording medium surface based on the focus error signal. In an optical information recording / reproducing apparatus having a servo loop, a detecting means for driving the objective lens in a focus direction to detect a peak value of the focus error signal, and a focus servo based on the detected peak value. And a means for setting a target level of the loop to a predetermined level, wherein the focus error signal has a peak value, Optical information, wherein the focus servo is pulled in at a predetermined timing until reaching a predetermined level, and after the focus servo loop is stabilized, the target level of the focus servo loop is gradually decreased from the predetermined level to 0 level. Recording / playback device. 2. The optical information recording / reproducing apparatus according to claim 1, wherein the target level setting means sets the target level to a value lower than the peak value of the focus error signal by a predetermined value. 3. The optical information recording / reproducing apparatus according to claim 1, wherein the target level setting means sets the target level at a predetermined ratio from the peak value of the focus error signal. 4. The peak value detecting means, when the peak value of the focus error signal is less than or equal to a preset lower limit value, ignores the peak value as a pseudo peak value. 1. Optical information recording / reproducing apparatus 1.