GB2186136A - Video recorder - Google Patents

Abstract

A control system for a videocassette recorder operates a check on each new set of instructions for a subsequent automatic recording, to determine if there is any overlap with other sets of instructions presently held in store 4. In order to achieve this, a day transition unit 7 notes if one recording extends over midnight, even-repetition detector 9 looks for daily repeats, and unit 10 checks for the start of one recording occurring during the other recording. If an overlap condition is noted, panel 2 provides a display either specifying an overlap or indicating that an error exists. <IMAGE>

Description

SPECIFICATION Video recorder The present invention relates to a video recorder.

Conventionally a videocassette recorder has a facility whereby it can be pre-programmed to automatically record a particular channel for a specified time interval. In order to programme the recorder, the user instructs the recorder as to the appropriate channel and time, the details of which are held in memory.

If the recorder is pre-programmed with two different sets of instructions which happen to overlap in time, then the recorder will operate initially according to the first one. However when initiation of the automatic recording for the later set of instructions becomes due, then operation of the recorder will switch to that appropriate to the second set. Thus, when the user plays back the recorded cassette in due course, it will become apparent that an overlap of instructions had occurred.

An object of the present invention is to avoid such an occurrence.

The present invention provides a video recorder having means to-control operation of the recorder, the control means comprising: means to instruct the automatic recording, at a specified subsequent time, of a video signal input to the recorder, the instructions means including storage means to hold information relating to instructions of forthcoming automatic-recordings, means to monitor each set of instructions for automatic-recordings to determine if the set overlaps temporally with any other automatic-recordings instructions; and means to provide an indication when the monitor means determines any such overlap.

In this way, the user is made aware of the occurrence of an overlap in the automatic recordings at an early opportunity thereby providing an opportunity to check the accuracy of the instructions and/or to take appropriate action to remedy any mistake.

Preferably, the monitor means comprises means to compare the start time of one set of instructions for an automatic-recording with the information corresponding to the automatic-recording instructions held in the storage means, thereby to determine if the start time of the one set of instructions is between the start time and the stop time of any other set of instructions held in the storage means. This arrangement provides a first monitoring operation and requires few steps in the procedure or components to implement them.

Preferably the monitor means, in use, effects the test for any overlap in relation to a set of instructions upon its input to the video recorder. In this way, as a user keys in a set of instructions for a subsequent automatic recording, then that set is checked for overlaps in relation to all those instructions held in store at that time.

Preferably, the monitor means comprises one stage to determine if the two sets of instructions correspond to the same day and a subsequent stage to determine if the two sets have any temporal overlap.

Preferably the monitor means comprises means to check whether at least one of the two sets of instructions is repetitive daily. In this way, if either set is due to be repeated daily, then the first of the two stages mentioned above could be circumvented.

Preferably, the recorder has means to provide an indication when the monitor means determines overlaps between more than two sets of instructions. In this way, the recorder can provide an indication of there being multiple overlaps, this being evidently different from the indication given for a single overlap.

Preferably, the indication means includes means to effect a display which specifies the relevant set(s) of instructions involved in the overlap(s). If the overlap test is done immediately after the procedure to input a set of instructions to the recorder, then the displayeffect means may specify only the other set concerned with a particular overlap condition.

If there are a number of separate overlap conditions, each involving only two sets in total, then there may be specified by the display one set with an indication that other overlap conditions exist; each such other overlap conditions may be specified by display in turn, when requested by the user.

According to another aspect of the present invention, a video recorder has a stand-by mode in which the clock-control display is fully-operational but has minimal display. Thus, this aspect of the present invention provides a video cassette recorder comprising means to display times and/or control information, the display means including a mode in which it is fully-energised but provides a minimal light output, and means to effect switching of the display means into and/or out of this mode by appropriate electronic signals input to the video cassette recorder.

In this way, a remote control unit associated with the videocassette can be used to switch it in, or switch it out of, this mode. Also, fast switching between this mode and a record mode can be achieved. Also the light output of the display means when in this mode will tend not to attract attention.

If an instant recording is instructed without there being a usuable cassette loaded in the videocassette recorder, then an appropriate indication is displayed. This situation might arise either because there is no cassette in the videocassette recorder, or because an unrecordable (i.e. protected against recording) cassette is in the videocassette recorder.

In order that the invention may more readily be understood, a description is now given, by way of example only, reference being made to the accompanying drawings in which: Figure 1 is a block diagram of part of a videocassette recorder embodying the present invention; Figure 2 and 3 are flow diagrams of a routine to operate the equipment of Fig. 1; Figure 4 is a flow diagram of an errorchecking procedure which includes the routine of Figs. 2 and 3; and Figures 5 to 8 are flow diagrams for additional routines which may be incorporated in the recorder.

Fig. 1 shows part of a videocassette recorder consisting of an instructions key-in pad 1, a display panel 2, and that section 3 of the videocassette recorder control system which is relevant to providing the overlap feature of the present invention. The control system section 3 has a memory store 4 to hold all the information on any pre-programmed automatic recordings which are keyed into the recorder via pad 1; each set of instructions for such a pre-programmed automatic recording would include, typically, the day, the frequency of occurrence (i.e. whether daily, weekly, or only a single occurrence), the start-time, the stoptime and the relevant channel. Store 4 has a capacity to hold many sets of such instructions and also information for use in relation to other facilities.The control system makes reference to any given day by indicating the count from the present day; thus store 4 refers to "day zero" when specifying "today", to "day one" when specifying "tomorrow", "day two" when specifying "the day after tomorrow", and so on. The videocassette recorder control system is able to accept, and operate, pre-programming instructions for automatic recordings up to fourteen days ahead.

In the following description of the operation of the overlap feature of the present invention, it is assumed that store 4 already holds five sets (namely A, B, C, D and E) of pre-programming instructions which have been checked, and cleared, for any overlap condition. The user now inputs, via pad 1, a further set, X, of pre-programming instructions which pass into store 4, duly actuating a switch unit 5 which passes a signal to the control system microprocessor control unit 6 to initiate the procedure for checking whether there is an overlap condition between X and any of the sets A, B, C, D and E already held in the store 4.Firstly, store 4 passes all the information held on instructions A along line L, to a day-transition detector unit 7 which determines if the recording corresponding to instructions A would extend over midnight and, if so, then an adder unit 8 is made to modify the stop-time information of A to increase it by 24.00 hours. Then, with the information for X passing along line L2, an event-repetition detector unit 9 checks the information for A and for X in order to determine if either set of instructions is repeated daily. If neither is a daily event, then A and X proceed towards an overlap detection unit 10 which has a first stage having a comparator 11 which determines if A and X correspond to the same day, and a second stage having a comparator 12 which determines whether the start-time of X is intermediate the start-time and the stoptime of A.A positive result from both comparators 11 and 12 causes display panel 2 to indicate that an overlap condition exists, whereas a negative result from either comparator causes termination of the overlap procedure in respect of A and X, and the initiation of the next overlap procedure in respect of B and X.

If event-repetition detector unit 9 determines that either A or X is repeated daily, then comparator 11 is by-passed, as in that case there will inevitably be co-incidence in respect of the day values for A and X.

Clearly at the end of the overlap procedure in respect of A and X, it may be necessary to adjust certain of the information for A and/or X in order to return it to the original state, for example to subtract 24.00 hours from the stop-time of A if day-transition detector unit 7 had activated adder unit 8.

In order to effect a comprehensive check for overlaps the procedure described above is repeated, with each of the sets B, C, D and E in turn replacing A, and then there is another series of check procedures in which X is now passed along line L1, while A, B, C, D and E are each passed along line L2 in turn. This second series is necessary in order to check whether any of the existing pre-programmed recordings begin during the proposed new recording.

By checking whether the start-time of a set of instructions lies with another set and then cycling through the variations, the time to effect a comprehensive overlap check can be minimised.

When an overlap condition is noted, the display panel 2 can provide any appropriate form of display as required. In its simplest form, the panel 2 may provided a display, which is used to indicate generally that some form of error exists; then the user has to diagnose the fault and identify that the nature of the error is an overlap in the sets of instructions. In another form, the panel 2 provides a display which specifies that an overlap condition exists; in a variation, the panel 2 may provide one display to specify that there is a single overlap condition and a different display to specify that there are a number of separate overlap conditions. Additionally, the panel may be capable of indicating or specifying which sets of instructions are involved in the overlap condition(s); the display need not refer to the new set of instructions, as it would be evident that this is involved.

In a modification to the equipment as illus trated in Fig. 1, the switch unit 5 is omitted and the information (i.e. relevant day, times, channel) concerning the set of instructions for an automatic recording are input directly to store 4. The overlap check procedure is initiated by the last element of the set of instructions, which is the instruction to the microprocessor control unit 6 that the preceding data relates to an automatic recording and that the set of instructions should be handled accordingly.

The event-repetition detector unit 9 may also look for weekly repetitions and take appropriate action to check for an overlap condition.

There is shown in Fig. 2 a flow diagram for an overlap procedure, essentially as described in relation to the equipment of Fig. 1, in order to check whether the recording corresponding to instructions A would be interrupted by that of X. Fig. 3 shows a sub-routine incorporated within the routine of Fig. 2.

There is shown in Fig. 4 the general errorchecking routine for each set of instructions, Y, upon input to the recorder already with instructions W, which routine includes as one element the comprehensive overlap check based on the procedure of Figs. 2 and 3.

The 'error' indication for "instant recording" and "timer recording" modes provides a simple level of interactivity. Often when a user is entering details into pad 1, there is some doubt as to whether it has been carried out correctly. By putting additional data in the display the user can be told if it has been done correctly e.g. pertaining to a simple button press when deep in one of the timer programming modes. In the present case, the "timer" mode or "instant record" mode cannot be entered unless an unprotected cassette is in the recorder. If the condition is not met, on trying to enter either of these modes, the word 'CASS' is displayed which gives the interactivity. The user can then take necessary action.

The second stage of error reporting is during "timer" mode. Overlap indication has already been covered. The rest of the error routine is concerned with the complete/valid data entry for timer programming. The error-checking routine of Fig. 4 looks for: complete entry of the start and stop times; invalid start and stop times, e.g. if the start time equals the stop time; overlapping programmes; existence of one or more timer programmes.

Fig. 5 is a flow diagram showing the subroutine to achieve the electronic display-off feature whereby a control unit incorporating a microprocessor monitors the state of the "display-off" switch (which is operated by the user via the remote-control unit) and transmits either the normal data or a particular display with minimal light output, namely As the display is still being scanned and the heater voltage is still applied, the above mode enables an interactive 'Display On' in the case where an instant recording is requested or where the display needs to be switched on from a remote control. The operation routine of the control system has a procedure which displays "-:-" when "display off" is requested. Full display mode is re-instated when either the instant record routine is entered or the clock display is requested for the remote control.

Fig. 6 is a flow diagram showing the subroutine to achieve the feature relating to correct-day clocking. The programmed day is stored as an off-set number relative to the present day, which is designated "0". When the "day" button is first pressed, the present day is displayed. To programme a day N days hence, the button is pressed a further N times and thereafter the number is stored in the memory. With each day which elapses, each of the stored day numbers is decremented so that the present day is always "0".

However, this does not mean that the user must work out the number of days in advance that he wishes the timer recording to commence. It does mean that the majority of the recordings, i.e. usually one to two days hence will require a reduced number of key presses; the day of the week is still indicated. As the current day passes midnight, each of the stored timer programme days are decremented so that the current day remains the reference i.e. zero. Fig. 6 includes the procedure for the current day referencing. 'Timer B' runs the real-time clock with special regard to decrementing the timer programme days when midnight is passed. The data for timer programming once entered is subjected to the routine continually and the programme is executed when the day equals zero, and the start time equals the current time.In this way the procedure can handle any timer programme on any day, up to the limits imposed by the individual storage capacity for the day number.

Figs. 7 and 8 are flow diagrams showing the sub-routine to achieve the incomplete-recording indication. The microprocessor control unit monitors operation of the videocassette recorder and sets a "record" flag when the machine is recording and resets when the recording stops. In the "instant-record" and "timer-record" modes, an "end-flag" is set and remains set until the programmed time has elapsed. When the "record flag" is reset, the "end-flag" is examined and if it is still in the set state the "end" message is applied to the display to indicate that the recording is incomplete.

The 'end' indication is used to provide the consumer with extra information on the instant recording or the timer recording. In the past it was not known if a recording had been completed. Now, in the case of the tape running out before the finish of the execution of the "instant record" or "timer record" modes, the word 'end' is shown in the display.

The timer/display processor communicates with another processor which has overall control of the mechanical transport of the video tape. It is possible to decode the data from the mechanical transport (subsequently referred to as "mech") microprocessor and therefore know when the tape is ended. Fig. 7 is concerned with reading this data. A check is then made for the "instant record" instruction followed by a check for timer mode. Only in these modes is it possible to detect for 'End' because only during "instant record" and "timer record" modes is there a definitive record stop time. In Fig. 7 if the VCR is in record, the mech record flag is "1", (as decoded from the bus). The record status is then set and compared with the mech record flag. If the mech flag changes while the record status and end request flags are set the 'End' message is put into the display. Before the sub-routine is exited the mech eject request and the 'instant record' flag are reset. (On 'End' the tape is ejected). Fig. 6 shows the main 'End' program loop.

Clearly, the instructions key-in pad 1 need not be on the body of the recorder, but could, for example, be part of a remote control unit for the recorder.

Claims (9)

1. A video recorder having means to control operation of the recorder, the control means comprising: means to instruct the automatic recording, at a specified subsequent time, of a video signal input to the recorder, the instruction means including storage means to hold information relating to instructions of forthcoming automatic-recordings, means to monitor each set of instructions for automatic-recordings to determine if the set overlaps temporally with any other automatic-recordings instructions; and means to provide an indication when the monitor means determines any such overlap.

2. A video recorder according to Claim 1, wherein the monitor means comprises means to compare the start time of one set of instructions for an automatic recording with the information corresponding to the automatic-recording instructions held in the storage means, thereby to determine if the start time of the one set of instructions is between the start time and the stop time of any other set of instructions held in the storage means.

3. A video recorder according to Claim 1 or Claim 2, wherein the monitor means, in use, effects the test for any overlap in relation to a set of instructions upon its input to the video recorder.

4. A video {recorder according to any one of the preceding Claims wherein the monitor means comprises one stage to determine if the two sets of instructions correspond to the same day, and a subsequent stage to determine if the two sets have any temporal overlap.

5. A video recorder according to anyone of the preceding Claims, wherein the monitor means comprises means to check whether at least one of the two sets of instructions is repetitive daily.

6. A video recorder according to anyone of the preceding Claims, comprising means to provide an indication when the monitor means determines overlaps between more than two sets of instructions.

7. A video recorder according to anyone of the preceding Claims, wherein the indication means includes means to effect a display stating that one or more overlaps exists.

8. A video recorder according to anyone of the preceding Claims, wherein the indication means includes means to effect a display which specifies the relevant set,(s) of instructions involved in the overlap(s).

9. A video recorder substantially as hereinbefore described with reference to and as illustrated in Fig. 1 alone, or in Figs. 1 to 3, or in Figs. 1 to 3 and any one or more of Figs.

4 to 8, of the accompanying drawings.