JPH10322720A - Method and apparatus for detecting transmission system of color image signal - Google Patents

Abstract

(57) [Summary] (With correction) [PROBLEMS] To detect whether a color image signal is a SECAM L system or a SECAM BG system when reproducing a color image signal recorded on a record carrier by a color under method. I do. SOLUTION: A reproduced color burst signal is multiplied by itself (2), and one color burst signal of two color burst signals is converted into a red color burst of a SECAM BG signal in a color under frequency mode. If the frequency is higher than the frequency of the signal, the phase is shifted by + 90 °, or if the frequency is lower than the frequency of the blue color burst signal, the phase is -90.
° The phase-shifted (4), low-pass filtered the multiplied product signal (6), rectified and inverted (7) in every other image line (7) and integrated (8) Signal and filtering The signal (11) obtained by directly integrating the obtained signal is coupled to the first capacitor 9 and the second capacitor 12 whose charge state indicates a color image signal according to the SECAM BG system or the L system.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for detecting a SECAM L and SECAM BG transmission system during reproduction of a color image signal recorded on a record carrier by a color under method.

[0002]

2. Description of the Related Art Recording devices for video signals, for example, VHS
In a video recorder according to the system, a color signal of a color image signal to be recorded is generally recorded by a so-called color under method. This means that the carrier frequency of the color signal should be converted to a lower frequency than the carrier frequency for recording the luminance signal of the color image signal. For example, originally 4.406 and 4.250M
The carrier frequency of the color burst signal of the SECAM BG signal having a frequency of Hz is 0.81 and 0.65.
It is down-converted (frequency down-converted) to a frequency of 4 MHz. This also applies to color image signals by other transmission methods.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to reproduce a color image signal recorded by the color under method when the reproduced color image signal is SECAM L.
Another object of the present invention is to provide a method and a circuit device for detecting whether the transmission is based on the SECAM BG transmission method.
The detection of such a transmission system must be performed before the frequency of the color burst signal is converted into a standard frequency, that is, in a color under frequency mode in which these signals are recorded.

[0004]

According to the present invention, in order to achieve the above object, according to the present invention, a color burst signal of a reproduced color under image signal is multiplied by itself, and a color burst signal of the two color burst signals is multiplied. One of the color burst signals is converted to SECA in color under frequency mode.
If the MBG signal has a frequency equal to or higher than the frequency of the red color burst signal, the phase is shifted by + 90 °, or the one of the two color burst signals is SECAM in a color under frequency mode.
If the BG signal has a frequency lower than the frequency of the blue color burst signal, the phase is shifted by -90 °, the multiplied product signal is low-pass filtered, rectified, and the polarity is inverted at every other image line. And integrating the integrated signal, coupling the integrated signal to a first capacitor whose charge state indicates a color image signal according to the SECAM BG transmission method, integrating the low-pass filtered signal, and integrating the integrated signal, The charging state is coupled to the second capacitor indicating a color image signal according to the SECAM L transmission method.

For example, a characteristic characteristic of a color under image signal recorded on a tape is that a color signal and a color burst signal included in the color signal have a carrier frequency lower than a carrier frequency of a luminance signal recorded on the tape. It is recorded in.

Therefore, in order to reproduce the color under image signal recorded in this way, the color burst signal of the image signal is multiplied by itself. In this case, one of the color burst signals is multiplied in its original phase relationship, and the other color burst signal is multiplied in a phase shifted phase relationship. One of the two signals is shifted in phase according to the frequency of the color burst signal. When the frequency of the reproduced color burst signal is higher than the frequency of the red color burst signal reproduced in the color under frequency mode of the SECAM BG signal, the former color burst signal is phase-shifted by + 90 °. However, when the frequency of the color burst signal of the reproduced color under image signal is lower than the frequency of the blue color burst signal of the reproduced color under image signal of SECAM BG, this signal is shifted by -90 °. Are combined. In principle, SECAM in color under frequency mode
The frequency of the BG color image signal is known. Color·
The frequencies of the red and blue color burst signals included in the SECAM BG color image signal in the case of the under frequency mode are also known. As described above, the reproduced color image signal in the color under frequency mode is shifted in phase according to the known frequency range and the frequency range of the reproduced color burst signal.

After that, the signal of the reproduced color under mode burst signal having the original phase relationship and the shifted phase relationship is filtered by a low-pass filter and then rectified. Further, the polarity of the rectified signal is inverted every second image line. Thereafter, the signal whose polarity is inverted for every other line is integrated. This integration signal is coupled to a first capacitor. During the multiplication of the color burst signal of the color under image signal described above, various mixed product signals are generated according to the sign of the phase shift. When a color image signal is reproduced by the SECAMBG method, the above-described phase shift occurs alternately for every other line because the color burst signal has a different frequency in every other line.
Therefore, the sign of the product signal is alternated for each image line, that is, the product signal alternately exhibits positive and negative values for each image line. However, since the polarity of the product signal subjected to the low-pass filtering after the rectification is inverted for every other line, the sign of all the pulses becomes the same again during the subsequent integration. However, this is SECAM BG
It can only be said about the color image signal by the method.
When such a signal is generated, pulses of the same polarity are integrated, and the integrated signal charges the first capacitor, so that the charge of this capacitor increases and SECAM
It will indicate the presence of a BG signal.

[0008] This means that the color burst signal of the reproduced color under image signal exhibits the above-mentioned frequency at which the color burst signal alternately changes for each image line, and this frequency is SECAM.
Changes every other line in a range between a frequency equal to or higher than the frequency of the red color burst signal of the BG color under image signal and a frequency equal to or lower than the frequency of the blue color burst signal of the reproduced SECAM BG color under image signal. It only happens when you do. Only in this case, the first capacitor is charged by alternately inverting the sign of the reproduced color image signal, more precisely, the sign of the color burst signal. Done in This alternating frequency range does not occur for all other types of color image signals and the corresponding color under image signal, in which case the product signal of each image line is the same. It becomes a sign signal. To invert the sign of the color burst signal for each image line, the signal to be integrated will include a pulse whose sign changes from image line to image line. In this case, the capacitor is no longer charged to a significant extent. Therefore, the state of charge of the first capacitor clearly indicates whether the reproduced color under image signal is a signal according to the SECAM BG transmission method.

In order to detect a SECAM L color image signal reproduced in the color under frequency mode, a low-pass filtered signal which has not been inverted in a line-alternating manner is integrated and stored in a second capacitor. Join. The color burst signal of the SECAM L color image signal has a frequency of 1.1 MHz in the color under frequency mode. Thus, during the formation of the product signal, such signals are always phase shifted by 90 °, so that the pulses of the product signal due to the color burst signal always have the same polarity sign. In this case, the second capacitor is charged by a signal obtained by integrating the product signal when a signal according to the SECAM L system appears. However, when a signal according to the SECAM BG system appears, pulses of positive / negative signs appearing alternately for each image line appear at the output terminal of the mixer (multiplier), and these pulses cause the second capacitor after integration to a significant extent. Do not charge.

Therefore, by using the state of charge of the first and second capacitors, it is possible to detect the transmission system of the reproduced color image signal in the SECAM BG or SECAM L system obtained in the color under frequency mode. The detection of the transmission method can be performed directly by, for example, a video recorder, and the reproduced color image signal is directly processed without requiring the conventional standard frequency conversion.

In order to achieve the above-mentioned object, the present invention further provides SECAM L and SE during reproduction of a color image signal recorded on a record carrier by the color under method.
An apparatus for detecting a CAM BG transmission system, comprising: a multiplier having a first input terminal to which a reproduced color under image signal is supplied; and a second input terminal of the multiplier, wherein a color burst signal is combined. Having a resonance frequency between the frequency of the red color burst signal and the frequency of the blue color burst signal of the SECAM BG signal in the color-under-frequency mode, the resonance circuit comprising: A multiplier is coupled to the low pass filter, a rectifier / inverter for rectifying and inverting the rectified signal every other image line of the reproduced color image signal, and an output signal coupled to the first capacitor. The charge state of the first capacitor is followed by a SECAM BG transmission Shows a color image signal according to scheme, and the low-pass filter is followed by a second integrator, the output signal of the second integrator is coupled to the second capacitor, the charge state of the second capacitor SECAM L
The color image signal according to the transmission method is shown.

Such a color image signal transmission system detecting device has a multiplier at its input terminal, and a color under image signal is supplied to a first input terminal of the multiplier in its original phase relationship. You. Color·
The under image signal is also coupled to a resonant circuit, which is coupled to a second input terminal of the multiplier. The resonance frequency of the resonance circuit is in a range between the frequency of the red color burst signal and the frequency of the blue color burst signal of the SECAMBG color image signal reproduced in the color under frequency mode. To this end, the resonant circuit shifts the phase of the signal supplied to it according to whether its frequency is above or below the resonance frequency inherent in the resonator. For example, SECAM in color under frequency mode
During the reproduction of the BG signal, the color burst signal of this signal is supplied to the second input terminal of the mixer with an alternate phase shift for each image line. However, the reproduced SECAM L signal will always receive the same + 90 ° phase shift.

In order to detect a signal according to the SECAM BG transmission system, a low-pass filter is provided to the multiplier,
A rectifier / inverter and a first integrator arranged in series follow. In the manner described above, the integrator generates a signal that is coupled to the first capacitor such that the state of charge of this capacitor indicates the presence of the reconstructed SECAM BG color image signal.

In order to detect a signal according to the SECAM L transmission scheme, a low pass filter is followed by a second integrator, and the output signal of this integrator is coupled to a second capacitor.

Depending on the characteristics of the resonant circuit coupled to the second input terminal of the multiplier, or more precisely, the resonance frequency of the resonant circuit, in the case of a signal according to the SECAM BG system, it is supplied to the second input terminal of the multiplier. Color burst signals undergo alternate phase shifting for each image line. A color burst signal of a color image signal by another transmission method does not undergo a phase shift every other line as described above. Due to such characteristics of the resonant circuit,
The output of the multiplier is either a pulse whose pulse code changes from image line to image line or a pulse whose pulse code remains the same. Therefore, since the first or second capacitor is charged alternately as described above, whether the color image signal reproduced in the color under frequency range is a signal according to the SECAM BG transmission method,
It is possible to detect whether the signal is based on the ECAM L transmission method.

In a preferred embodiment of the device according to the invention, claim 3
The configuration is as described above. In order to improve the detection accuracy, the voltage between the capacitors is compared with a reference voltage by a comparator. This detects whether the voltage between the capacitors is higher or lower than the reference voltage. The comparator is SEC
A corresponding output signal is provided which indicates the presence of a color image signal according to the AML or SECAM BG transmission scheme. By using the comparator in this way, the detection accuracy can be further improved.

A preferred embodiment of the device according to the present invention has a configuration as described in claim 4. By controlling the multiplier in this manner, the multiplier provides an output signal only if the color image signal supplied to it includes a color burst signal in a color under frequency mode. To this end, in effect the multiplier supplies only the product signal of the color burst signal which can be processed directly.

According to a further preferred embodiment of the present invention as set forth in claim 5, the second capacitor discharges in the case of the SECAM BG signal and the first capacitor discharges in the case of the SECAM L signal. Therefore, the detection accuracy can be further improved. As a result, when there is a color image signal of each of the other transmission methods, the capacitor is immediately discharged, so that the capacitor does not indicate an erroneous transmission method due to residual charge of the capacitor.

In another preferred embodiment of the present invention, claim 6
The configuration is as described above. In any case, many receivers or playback devices include a PAL identification circuit. If such a PAL identification circuit supplies a signal indicating the presence of a reproduced PAL signal in the color under frequency mode, both capacitors of the circuit arrangement according to the invention are discharged. The reason is that in this case, a signal according to the SECAM BG or SECAM L system cannot appear. In this case, the previously detected SECAM BG or SE
It is also possible to discharge both of the capacitors by immediately discharging the residual charges due to the CAM L signal.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Signal Vin is supplied to an input terminal of the device shown in the block diagram of FIG. This signal is a color image signal reproduced from a record carrier, which is obtained within the color under frequency range. Color image signals of any transmission scheme are generally converted to signals in such a frequency range before recording. The color image signal and the color burst signal contained therein are mixed down to a signal in a frequency range lower than the frequency range of the luminance signal to be recorded. Therefore, such a signal is called a color under signal.

In the apparatus shown in FIG. 1, whether the reproduced color image signal is based on the SECAM BG system or whether
It is intended to detect whether or not the method is based on the color under frequency mode. Strictly speaking, the reproduction signal is not based on the SECAM BG or SECAM L transmission scheme, but represents a color under signal in which a color burst signal is converted into a signal in a color under frequency range. However, certain characteristics of the transmission scheme remain in this frequency range,
The reproduced signal in the color under frequency mode is SECA
Whether it is from a signal in the MBG system or SECAM L
It is possible to detect whether or not the signal is derived from the method.

The signal Vin is supplied to the first input terminal 1 of the multiplier 2. In addition, this signal is coupled to coupling capacitor 3
Is also coupled to the parallel resonance circuit 4 via a capacitor, a resistor, and an inductor.
The parallel resonance circuit 4 is coupled to the second input terminal 5 of the multiplier 2. The blanking signal B is supplied to the multiplier 2.
K, which is also the color under image signal Vin
Generated when a color burst signal occurs.

Behind the multiplier 2, there is arranged a low-pass filter 6 for filtering the product signal supplied thereby.

In order to detect a signal according to the SECAM BG system, a rectifier / inverter 7 is connected to the low-pass filter 6.
Followed by The rectifier / inverter 7 first rectifies the signal supplied thereto. Thereafter, the polarity of the rectified signal is inverted every other image line, that is, the polarity of the rectified signal is changed every second image line. For this purpose, a signal fH / 2 is supplied to the rectifier / inverter 7, which is preferably a clock signal dependent on the line frequency.

The rectifier / inverter 7 is followed by a first integrator 8 whose output signal is coupled to a first capacitor 9. The voltage across the capacitor 9 is also supplied to a comparator 10 which compares the voltage across the capacitor 9 with a reference voltage Vref. In this case, the comparator 10 supplies the output signal VsecBG.

Color and color data by the SECAM L transmission system
To detect a color image signal in the under-frequency mode, a low pass filter 6 is followed by a second integrator 11 and the output signal of this integrator is coupled to a second capacitor 12. The voltage between the capacitors 12 is also compared with the reference voltage Vref by the second comparator 13. In this case, the second comparator 13 supplies the output signal VsecL. The state of charge of the two capacitors 9 and 12 indicates the presence of a SECAM BG or SECAM L color image signal in the color under frequency mode.

In order to improve the detection accuracy, the capacitors 9 and 12 are discharged via the switches 14 and 16 as necessary.

For this purpose, the first capacitor is connected to a resistor 1
5 coupled to a switch 14, which discharges the capacitor 9 as required. Switch 1
4 can be activated either when the comparator 13 supplies the output signal Vsec L or when an external PAL identification circuit (not shown) detects the presence of a signal according to the PAL scheme. In each of these cases, the capacitor 9
Can be made to flow to the ground by the switch 14.

Similarly, the second capacitor 12 is connected to the comparator 10
Supplies an output signal Vsec BG or an external PAL
When the identification circuit detects the presence of a signal by the PAL method, it can be discharged by the second switch 16 via the resistor 17.

Therefore, in short, the two capacitors 9 and 12 can also output signals according to the SECAM BG system to the SECA BG system.
Discharge occurs when a signal based on the PAL system is detected without reproducing a signal based on the ML system. In addition, these capacitors are alternately discharged by switches 14 and 16 respectively when signals of other transmission schemes are detected. Thus, the previously detected SECAM BG
Alternatively, the residual charge of the SECAM L signal is removed.

Next, the operation of the apparatus shown in FIG. 1 will be described with reference to FIGS. FIG. 2 shows waveforms of some signals appearing in the circuit device of FIG. 1 when the signal Vin is a signal according to the SECAM BG system that appears in the color under frequency mode.

Such an input signal Vin is shown as a waveform A in FIG. S appears in color under frequency mode
In the ECAM BG system, fOR 'and fO
The red and blue color burst signals called B 'are 654k.
Hz and 810 kHz, respectively. The input signal is supplied unchanged to the first input terminal of the multiplier 2 in the device shown in FIG. This signal is also coupled to the parallel resonance circuit 4. The resonance frequency of this parallel resonance circuit is a frequency in the range of 654 kHz, preferably a center frequency between these two frequencies. Therefore, the SECAM BG appearing in the color under frequency mode and supplied to the second input terminal 5 of the multiplier 2
The signal according to the method is + 90 ° or −90 ° depending on whether the frequency of the signal is equal to or higher than the resonance frequency of the resonance circuit 4.
Phase shifted. Multiplier 2 is controlled such that it provides an output signal only during the time interval in which the color burst signal appears in signal A or in the phase shifted signal. Therefore, only the color burst signal of the signals supplied to the multiplier is processed.

After filtering by the filter 6, the signal indicated by B in FIG. 2 appears. Due to the above-described phase shift generated by the parallel resonance circuit 4, the polarity is changed for each image line, and the pulse due to the change in the frequency of the color burst signal is changed by the multiplier 2. And the output terminal of the low-pass filter 6.

A signal waveform C shown in FIG. 2 shows an output signal of the rectifier / inverter 7 in the device shown in FIG. Signal C indicates that, besides being rectified, the signal is inverted during each second image line. As a result, the negative pulse generated in the signal B has a positive polarity during each second image line. Therefore,
The signal C consists only of positive pulses, which are integrated by the integrator 8 and coupled to the first capacitor 9.

The signal D shown in FIG. 2 indicates the voltage between the capacitors 9. S in color under frequency mode
When a signal according to the ECAM BG system appears, the capacitor 9 is charged by the integration pulse of the signal C.
However, this capacitor 9 is charged only in SECA
For the switching frequency of the color burst signal of the color under signal by the MBG system, the multiplier 2
Has a corresponding phase shift in the output signal of
This is only the case when the polarity of the output of. In practice, such a change in the polarity is eliminated by the rectifier / inverter 7 every other line due to the polarity inversion, and the output signal of the rectifier / inverter 7 is SECAM.
When a signal based on the BG method exists, the signal is a signal of only a positive pulse.

For example, in the case of a signal according to the SECAM L system in which the color burst signal has a constant frequency of 1.1 MHz in each image line in the color under frequency mode, the output signal of the multiplier is a positive pulse. Since these pulses are inverted every other image line by the rectifier / inverter 7, the signal C is a signal in which positive and negative pulses alternate. 9 cannot be fully charged. Therefore, the state of charge of the capacitor 9 does not indicate the presence of the SECAM BG color image signal. The detection accuracy can be improved by comparing the state of charge of the capacitor 9 with the reference voltage Vref by the comparator 10 as shown in FIG. in this case,
The comparator 10 supplies a signal Vsec BG indicating the presence of a color image signal according to the SECAM BG system reproduced in the color under frequency mode.

FIG. 3 also shows some signal waveforms, and the signal A is the multiplier 2 in the circuit device shown in FIG.
2 shows an input signal Vin supplied to the first input terminal 1 of FIG. In the example shown in FIG. 3, this input signal is a signal according to the SECAM L system reproduced in the color under frequency mode. The color burst signal of this signal has a constant frequency of 1.1 MHz in the color under frequency mode.

The parallel resonance circuit 4 of the device shown in FIG.
Since it has a resonance frequency in the range of 4 kHz to 810 kHz, the signal A will be supplied to the second input terminal 5 of the multiplier 2 with a constant phase shift of + 90 °, and thus the signal A of FIG. As is evident from waveform B, the multiplier provides only positive pulses during the time when the color burst signal appears in the color image signal.

In the apparatus shown in FIG. 1, the positive pulse signal is supplied to the second integrator 11 after being filtered by the low-pass filter 6. The output signal of this integrator is coupled to a second capacitor 12 which indicates the state of charge of this capacitor in FIG.
The waveform E is shown in FIG.

In the case of the color image signal of the SECAM L system reproduced in the color under frequency mode, only positive pulses appear at the output terminal of the multiplier 2 for the above-mentioned reason, and these pulses are low-passed. After the filtering process, the direct integration is performed and the second capacitor 1 is integrated.
2 can be charged, and this charging state is SECAML
This shows the presence of a reproduced signal according to the method.

On the other hand, when a signal according to the SECAM BG system is reproduced, the signal shown in FIG. 2B appears at the output of the low-pass filter 6, and the polarity of this signal changes for each image line. Therefore, these signals are converted to the integrator 11
Since the capacitor 12 is not sufficiently charged even when the integration is performed, the state of charge of the capacitor 12 remains low during the period in which such a signal exists, and a signal according to the SECAM L system is not detected.

In order to improve the detection accuracy of the signal according to the SECAM L system, the charge state of the second capacitor 12 is also compared with the reference signal Vref by the second comparator 13 and
A corresponding output signal Vsec L indicating the presence of a signal according to the SECAM L system is generated.

Therefore, according to the apparatus shown in FIG. 1, whether the color image signal reproduced in the color under frequency mode is a signal according to the SECAM BG system,
The signals Vsec BG and V
This can be reliably indicated by sec L.

[Brief description of the drawings]

FIG. 1 shows SECAM L and SECAM according to the present invention.
It is a block diagram of the apparatus for BG transmission system detection.

FIG. 2 is a waveform diagram of some signals appearing in the apparatus of FIG. 1 when a SECAM BG color image signal is present.

FIG. 3 is a waveform diagram of some signals appearing in the apparatus of FIG. 1 when a SECAM L color image signal is present.

[Explanation of symbols]

 2 Multiplier 4 Parallel resonance circuit 6 Low-pass filter 7 Rectifier / inverter 8 First integrator 9 First capacitor 10 First comparator 11 Second integrator 12 Second capacitor 13 Second comparator 14, 16 Switch 15, 17 Resistance

Claims (6)

[Claims] 1. A method for detecting a SECAM L and SECAM BG transmission system during reproduction of a color image signal recorded on a record carrier by a color under method, comprising the steps of: Multiplies by itself and shifts one of the two color burst signals by + 90 ° if it has a frequency equal to or higher than the frequency of the red color burst signal of the SECAM BG signal in the color under frequency mode. Or if one of the two color burst signals has a frequency less than or equal to the frequency of the blue color burst signal of the SECAM BG signal in the color under frequency mode.
Phase-shifted by 90 °, low-pass filtered the multiplied product signal, rectified, inverted and integrated in every other image line, and the integrated signal was charged in SECAM BG transmission system. And integrates the low-pass filtered signal and couples the integrated signal to a second capacitor whose charge state indicates a color image signal according to the SECAM L transmission method. A SECAM L and SECAM BG transmission method detection method, characterized in that: 2. An apparatus for detecting a SECAM L and SECAM BG transmission system during reproduction of a color image signal recorded on a record carrier by a color under method, wherein the detection device is supplied with a reproduced color under image signal. Multiplier (2) having a first input terminal (1)
And a resonant circuit (4) coupled with the color burst signal and coupled to the second input terminal (5) of the multiplier (2), the resonant circuit (4) being in a color under frequency mode. The multiplier (2) has a resonance frequency between the frequency of the red color burst signal and the frequency of the blue color burst signal of the SECAM BG signal, wherein the multiplier (2) is a low-pass filter (6).
A rectifier / inverter (7) that performs a rectifying operation and inverts the polarity of this rectified signal every other image line of the reproduced color image signal, and a second capacitor connected to the first capacitor (9). 1 followed by a series circuit with an integrator (8), wherein the state of charge of the first capacitor is SEC
A low-pass filter (6) indicating a color image signal according to an AMBG transmission system;
SECAM, wherein the output signal of the second integrator is coupled to a second capacitor (12) such that the state of charge of the second capacitor is indicative of a color image signal according to the SECAM L transmission scheme. L and SE
CAM BG transmission system detection device. 3. The comparator (10; 13) compares each voltage between the capacitors (9; 12) with a reference voltage, and each of the comparators (10; 13) uses a SECAM L or SECAM BG method. 3. An output signal indicating a color image signal is supplied.
An apparatus according to claim 1. 4. The blanking signal for controlling the multiplier so that the multiplier (2) supplies an output signal only during a time interval in which a color burst signal appears in a color image signal supplied thereto. 3. The apparatus according to claim 2, wherein the apparatus is supplied to a multiplier. 5. The first capacitor (9) is discharged when a color image signal according to the SECAM L method is detected, and the second capacitor (9) is discharged when a color image signal according to the SECAM L method is detected. Device according to claim 2, characterized in that the device (13) is discharged. 6. When the PAL identification circuit indicates that the reproduced color image signal is a color image signal according to the PAL system, the capacitors (9, 13) are connected via the switches (14, 16). 3. The device according to claim 2, wherein the discharge is performed.