DE3233730A1 - Method and circuit arrangement for checking recorded video cassettes - Google Patents

Abstract

A method for checking video cassettes recorded by copying on a video player and a circuit arrangement for carrying out this method, comprising a logic circuit (10), a frequency detector (12), a drop-out counter (14), a synchronisation pulse detector (16), a colour detector (18), and a clock generator (20). <IMAGE>

Description

Method and circuit arrangement for checking

of pre-recorded video cassettes The invention relates to a method for checking video cassettes recorded by dubbing on a video recorder and a corresponding circuit arrangement. With the automatic installation of Programs on video cassettes using a master copy often encounter errors, which are due to poor functioning of the recording device, poor tape quality on video or audio track, a breakdown of the device before the end of the program (due to incorrect operation, failure of the Mechanics or electronics or insufficient length of the video cassette, etc.) after the start of recording the beginning of the program due to a malfunction of the remote control or a recording of poor quality due to an error in the video cassette used are based.

Since about 100 video cassettes are often recorded at the same time, one automatic review of the recorded video cassettes desirable, so only error-free copies can be put on the market.

It is desirable that when found to be defective Videotapes the type of error can be determined so that the error of the Device can be fixed.

According to the invention, this object is achieved by the following process steps: On playing a first signal code at the beginning of the overplayed program; on playing a second signal code at the end of the dubbed program; Return matches the tape for a first period of time; Searching for the second signal code during the first time period; if the second signal code is not discovered after the first has expired Duration of ejection of the video cassette when the second signal code is detected during the first period of time further playing back for a second period of time; Play the Videocassette for a third period of time; Playing the videotape for a fourth Duration; on checking the video cassette for the presence during the fourth period of time of color signals and the presence of vertical synchronization pulses as Determining the number of defects in the video tape; in the absence of color signals, Missing of the vertical synchronization pulses or exceeding the established ones Defects (dropouts) after ejecting the video cassette a predetermined number, otherwise rewind the cassette until the beginning of the tape is detected; Play of the video tape over the first period of time; Searching for the first signal code during the first period; if the first signal code is not detected after the ejecting the video cassette for the first time upon detection of the first signal code during the first period, playing the video cassette for the fourth period; Check the videocassette for the presence during the fourth period of color signals and the presence of vertical synchronization pulses as well Determining the number of dropouts of the video tape; in the absence of Color signals, lack of vertical synchronization pulses or exceeding the detected defects (dropouts) over a specified number of ejecting the Video cassette, otherwise rewind the video recorder to the beginning of the tape, eject the video cassette.

In particular, a display of a specific one can be provided Number depending on the reason for the ejection of the video cassette, namely the end the test process if the cassette was found to be good, the second signal code is missing, Exceeding the specified number of arop-outs, lack of vertical synchronization pulses or lack of color signals.

It is advantageous that the first and the second signal code as in the Tonfregpenzbereich Lying signals of a certain duration shown on the audio track of the video cassette are; a special embodiment is characterized in that the first signal code relatively short and high-frequency, the second signal code relatively long and low-frequency is, and that the ratios of their durations and frequencies as or vice versa like the ratio of the playback and replay speeds of the video device used are set up. A circuit arrangement for implementing the invention Method is characterized by a logic circuit, a frequency detector, a drop-out counter, a sync pulse detector, a color detector and a Clock.

The logic circuit can consist of two programmable read-only memories, programmed to control the sequence of the test program, as well as a series consist of integrated circuits.

It is preferably provided that the clock generator at regular intervals a clock pulse, the drop-out counter the one supplied by the video recorder enumerates drop-out signals and, if a specified number is exceeded, an error signal, the synchronization pulse detector in the absence of synchronization pulses from the video recorder an error signal that Color detector in the absence of the video recorder incoming color pulses an error signal and the video recorder an end of tape signal supplies.

Clock pulses, error signals and end-of-line signals can be added to the logic circuit are fed.

According to the invention, the logic circuit can play, replay and Control rewind and ejection of the video cassette.

Further features and advantages of the invention emerge from the claims, the description and the drawing, in which an embodiment in detail is shown. 1 shows a flow chart of the method according to the invention; and FIG. 2 is a block diagram of the corresponding circuit arrangement.

In Fig. 1, the first two steps of the method according to the invention are namely the play on a first signal code S1 and the playing of a second Signal codes S2 not shown at the end of the dubbed program because the inventive Process for checking the presence of such signal codes requires.

The video tape is at the beginning of the method according to the invention at the end of the loaded program. The video cassette is inserted into a video player, which is connected to the test device via an interface. Then will the start pulse is given to trigger the method according to the invention. Thereupon the video player is via the logic circuit for a period of time T1 - for example 45 seconds - brought to the "play reverse" position, ie return matches. While During this time period T1, the signal code given at the end of the program is recorded on the sound track S2 sought (in order to reproduce the tone also in the r position "Play-Revers" enable, the mute function is interrupted in the video player).

If the signal code S2 is not found during the time period T1, then if the video cassette is ejected, a display - such as an LED display - the number 11111 is displayed.

On the other hand - as it will usually be the case - the signal code 2 is found, the video player is for a second period of time T2 - for example 10 seconds - held in "play lapel". Since the return leg speed is very much is greater than the playback speed - typically by a factor of 9 the video cassette is thus rewound in the example by a length that corresponds to a playing time of 90 seconds.

Then the control logic brings the video player to the "Play" position thus playing, un for a third period of time T3 - for example 5 seconds -.

This third period is used to review the video tape before it is checked to stabilize.

The video tape is then played over a fourth period of time T4 - for example 15 seconds -checked. The number of drop-outs is counted, with corresponding Signals from the video player. be delivered. If this number exceeds a predetermined number Number, the video cassette is ejected and the number "2" is displayed. Simultaneously it is examined whether the required vertical synchronization pulses are present are. These signals are also supplied by the video player. If these synchronization pulses are missing, so the video cassette is also ejected, indicating the number "3". It is also examined at the same time whether the color pulses are present. Missing this Color pulses, the cassette is ejected and the number "4" is displayed.

If the tape does not show any of the three faults just mentioned, it brings the control logic puts the video recorder in the "Rewind" position until the video player recognizes the beginning of the tape and stops rewinding. Then the video player will be in the "Play" position, ie playing, over a period of time of T1 - in our example so 45 seconds - brought. The signal code S1 is searched for during this period and in the event that this is not found, the video cassette under display the number 5 ejected.

On the other hand, it becomes the signal code recorded at the start of dubbing S is found, the video player remains in the Plan position, i.e. play, and for a period of T4, in the example 15 seconds. During this Period is - as just described - the presence of color and vertical Synchronization pulses are checked, the drop-outs are also counted and if exceeded a predetermined number and, in the absence of said pulses, the video cassette ejected showing the corresponding number. Then the video player into the "Rewind" position - that is, rewind - until the beginning of the tape is reached.

Now the video recorder ejects the video cassette, the number "O" is displayed.

It will have become clear that the number "O" indicates that the tape is OK, i.e. color pulses and vertical pulses in the areas tested Having synchronization pulses. It is also ensured that the audited Ranges the number of drop-outs that can be caused by tape errors, is below the tolerable number.

The first and the second signal code are according to the invention on the Soundtrack of the video cassette applied, so they are in the frequency range of the usual recorded tones. It is advantageous if the first signal code S1 is relatively short and high frequency, about a duration of 0.5 seconds for a Frequency of 4500 Hz and the second signal code relatively long and low-frequency, for example 4.5 seconds at 500 Hz. The ratio of the frequencies and the ratio of the The duration of these signal codes S1 and S2 corresponds to the ratio of the playback speed to the return speed of the video player, in the example 9.

2 shows a block diagram of the circuit arrangement according to the invention. The logic circuit 10, a frequency detector 12, a drop-out counter 14, a synchronization detector 16, a color detector 18 and clock generator 20 as well as the VCR 8.

The clock 20 is - in the example every 5 seconds - one Clock pulse to logic circuit 10.

This clock pulse corresponds to the duration T3 and represents a fraction of the time periods T1, T2, T3 and T4.

The control circuit receives 10 signals from the video player at the end of the tape, he in turn controls the video player according to the requirements of the program by he gives it the commands play, rewind, rewind and eject. One Display unit 6 displays the number indicating the cause of the ejection. This display is also determined by the logic circuit.

The video player transmits its audio signals to the frequency detector 12. By bridging the muting of the video player in the "play reverse" position ensures that the frequency generator generates sound signals even when playing backwards of the tape. The frequency detector 12 determines - with appropriate control through the logic circuit 10 - the occurrence of a signal code S1, S2 and gives a corresponding one Signal code signal to the control circuit 10, which, as shown above, either for Ejection of the cassette and a display of the number "1" or

"5", or leads to the continuation of the program.

The drop-out counter 14 receives drop-out signals from the video player. The video player provides the corresponding drop-out signals, since it has a circuit is equipped, which in case of a defective wall coating or worn or dirty video heads prevents the picture from being disturbed by in the noisy line component keyed in the image information of the previously written lines will. If the number of drop-outs identified exceeds a specified threshold During the time of the test, the drop-out counter 14 gives a corresponding one Error signal to the control circuit 10, resulting in the ejection of the video cassette and a Display of the number "2" leads. In the absence of the synchronization pulse detector 16 vertical synchronization pulses supplied by the video player 8 a corresponding one Error signal sent to the control circuit. The same applies if there are no color pulses, which the color detector 18 receives from the video player 8.

It goes without saying that the control circuit 10 takes the necessary time Controls of the frequency detector 12, the drop-out counter 14, the synchronization pulse detector 16 and the color detector 18 takes over.

The in the above description, the drawings and in the Features of the invention disclosed claims can both individually and in any combination for the implementation of the invention in its various Embodiments are essential.

REFERENCE CHARACTERISTICS LIST first signal code S second signal code T1 first Duration T1 T2 second duration T2 T3 third duration T3 T4 fourth duration T4 1 1 2 4 4 5 5 6 Display unit 6 7 8 Video recorder 8 9 10 Logic circuit 10 11 11 12 Frequency detector 12 13 13 14 drop-out counter 14 15 15 16 synchronous satellite detector 16 17 17 18 color detector 18 19 19 20 clock generator 20 21 21 22 clock pulse 22 23 23 24 drop-out signals 24 25 26 error signal 26 27 27 28 error signal 28 29 29 30 error signal 30 31 31 32 end of tape 33 33 34 34 35 35 36 36 37 37 38 38 39 39 40 40 41 41 42 42 43 43 44 44 45 45 46 46 47 47 48 48 49 49 50 50 51 51 52 52 53 53 54 54 55 55 56 56 57 57 58 58 59 59 60 60 61 61 62 62 63 64 64 65 65 Read more e

Claims (9)

DEMANDING PROCEDURES FOR REVIEWING RECORDED Video cassettes on a video player, characterized by a) playing a first Signal codes at the beginning of the transferred program, b) playing a second signal code at the end of the copied program, c) playing back the tape for a first period of time, d) searching for the second signal code during the first period of time, e) if it is not discovered ejecting the second signal code after the first period of time has elapsed, upon discovering the second m) if the first signal code is not detected after the first period of time, eject the video cassette, if the first signal codes during the first period of time playing the video cassette for the fourth time period, n) checking the video cassette during the fourth time period for the presence of color signals and the presence of vertical synchronization pulses and determining the number of faults in the video tape, o) in the absence of Color signals, lack of vertical synchronization pulses or exceeding the detected flaws by ejecting the video cassette a specified number of times, otherwise p) rewind the video recorder to the beginning of the tape, q) eject the Videotape. 2. A method for checking video cassettes according to claim 1, characterized by displaying a certain number depending on the reason for the ejection the video cassette, namely Signal codes during the first period further playback for a second period of time, f) playing the video cassette for a third period of time, g) playing the video cassette for a fourth period of time, h) Checking the video cassette for the presence during the fourth period of color signals and the presence of vertical synchronization pulses as well Determination of the number of faults in the video tape, i) in the absence of color signals, Missing of the vertical synchronization pulses or exceeding the established ones Defects after ejecting the video cassette a predetermined number, otherwise j) rewind the cassette until the beginning of the tape is detected; k) Playing the video tape over the first period, 1) searching for the first signal code during the first period, (O) End of the test process if the cassette is found to be good, (1) the second signal code is missing, (2) Exceeding the specified number of drop-outs, (3) Lack of vertical ones Synchronization pulses, or (4) lack of color signals. 3. A method for checking video cassettes according to claim 1 or 2, characterized in that the first and the second signal code as in the audio frequency range Lying signals of a certain duration shown on the audio track of the video cassette are. 4. A method for checking video cassettes according to claim 3, characterized characterized in that the first signal code is relatively short and high frequency, the second Signal code is relatively long and low-frequency, and that the ratios of their Duration and frequencies like or vice versa like the ratio of playback and return speeds of the video device being used. 5. Circuit arrangement for checking on recorded by dubbing Videotapes on one Video recorder, indicated by a Logic circuit (10) a frequency detector (12), a drop-out counter (14), a synchronization pulse detector (16), a color detector (18), and a clock (20). 6. Circuit arrangement according to claim 5, characterized in that the logic circuit of two programmable pest value memories, which are used to control the Sequence of the test program are programmed, as well as a number of built-in Circuits. 7. Circuit arrangement according to claim 5 or 6, characterized in that that the clock (20) at regular intervals a clock pulse (22), the drop-out counter (24) enumerates the drop-out signals (24) supplied to him by the video player (8) and if a predetermined number is exceeded, an error signal (26) the Synchronization pulse detector (16) in the absence of synchronization pulses from the video player an error signal (28) from the color detector (18) - in the absence of the one coming from the video recorder Color pulses an error signal (30) and the video player an end of tape signal (32) supplies. 8. Circuit arrangement according to claim 7, characterized in that Clock pulses (22), error signals (24, 26, 28, 30) and tape end signals (32) to the logic circuit (10) are supplied. 9. Circuitry for checking video cassettes for one or more of the preceding claims, characterized in that the logic circuit (10) playing, rewinding, rewinding and ejecting the video cassette controls.