METHOD AND APPARATUS FOR PREPROGRAMMING A VIDEO CASSETTE RECORDER

Abstract: Disclosed herein is a timer preprogramming system of a video cassette recorder, which sets up a set of preprogramming information designating an initial recording tape speed, an initial recording channel, an initial recording start time and an initial recording end time and then updates the preprogramming information wherein the initial recording end time is determined by adding a predetermined period of time to the initial recording start time. The initial recording start time is updated to adjust it to an actual start time of a desired broadcast program. Simultaneously, the initial recording end time is updated to a time determined by adding the predetermined period of time to the updated start time. Further, the video cassette recorder has a rechargeable battery which serves to save the time information and the preprogramming information stored in a memory in case of a power failure.

Description: METHOD AND APPARATUS FOR PREPROGRAMMING A VIDEO CASSETTE RECORDER TECHNICAL FIELD OF THE INVENTION The present invention relates to a video cassette recorder ( "VCR") having a rechargeable battery for use in the event of a severance of electric power supply so as to enable the preprogramming information stored in the VCR to survive and further having a capability of performing timer- controlled preprogramming in a simple and efficient manner. BACKGROUND ART Nowadays, most VCRs are provided with the capability of recording a desired television broadcast program at a designated time for a certain duration under the control of a timer. In order to set up the VCR to record the desired TV broadcast program in advance, various preprogramming information must be inputted through a series of operations which may comprise: fixing time data in the order of month, day and year in the timer to designate when the recording of the desired program is to be carried out; setting a recording start time and a recording end time; selecting any one of tape running speeds, i.e., "SP(Standard Playback)", "LP(Long Playback)" and "EP(Extended Playback)"; selecting a TV channel through which the desired broadcast program is to b received; and then pressing a RECORD key on the VCR or remote control unit. If any of the operations is erroneously carried out, th desired broadcast program cannot be recorded correctly; and, the above series of complex operations makes the prior ar method rather vulnerable to such an error. In order to simplify and accurately perform the timer- controlled preprogramming, therefore, there are propose several techniques in the art, including the one disclosed i PCT/US89/05806 filed on December 16, 1989, wherein the tas of preprogramming is simplified through the use of encode information which is referred to as' a "G-code" made of, e.g., 7 digits. This method of preprogramming is accomplished b looking up a G-code printed in a TV program guide an entering the G-code instead of the channel, date, time an length (CDTL) data. When the G-code is entered, it is converted into the CDTL information by a G-code decode incorporated in the VCR. While the G-code method is capable of providing a shortened preprogramming precedure, it suffers from a lack of flexibility as its utility entirely depends on the availability and accuracy printed in the media. Furthermore, should there be a change in the printed television program, the given G-code cannot be used. On the other hand, the VCR may be subjected to a power failure, or may be deplugged or disconnected from the power source by the user. Against these situations, particularly in preparation for the power failure, most VCRs having a timer-controlled preprogramming feature are provided with means, e.g., a capacitor, for keeping alive the timer and the preprogramming information stored in a memory which can be erased at the time of power failure. However, since the duration of information compensation by the capacitor is confined to a short period of time, e.g., one or two hours, a discontinuation of power supply for a longer while than the compensation duration may result in the loss of the stored information. DISCLOSURE OF THE INVENTION It is, therefore, an object of the invention to provide an improved VCR having a back-up battery so as to save the preprogramming information stored in the VCR in case of a power failure. Another object of the invention is to provide an improved VCR capable of performing timer-controlled preprogramming in a simplified and flexible manner. In accordance with the present invention, there is provided an improved VCR having a rechargeable battery and a preprogramming apparatus capable of recording a desired TV broadcast program in a simplified fashion. Specifically, the preprogramming apparatus sets up a set of initial preprogramming information including a recording channel, a predetermined recording tape speed, a recording start time and a recording end time necessary to record the desired TV program, wherein the initial recording channel is set to a channel through which a broadcast program is currently received, the initial recording start time is set to a current time indicated on a timer, and the initial recording end time is set to a time determined by adding a predetermined period of time to the recording start time. In acorrdance with the present invention, when necessary, it is possible to update the recording start time to the actual start time of the desired program,- the recording end time, the recording tape speed, and the recording channel. Further, the back-up battery serves to save the time data set up in the timer and the preprogramming information stored in the memory in case of an electricity failure. BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects and features of the present invention will become apparent from the following description of preferred embodiments with reference to the accompanying drawings, in which: Fig. 1 is a schematic block diagram of a VCR capable of performing timer preprogramming in accordance with the present invention; Figs. 2 is a plan view of a remote control unit whic produces operation signals to the system controller shown i Fig. 1; Figs. 3, 4, 5 and 6 are flow charts illustrating the operation of the system controller shown in Fig. 1, respectively; and Figs. 7A, 7B and 7C are display patterns developed on screen during the timer preprogramming. MODES OF CARRYING OUT THE INVENTION Referring to Fig. 1, there is* shown a VCR having basic components required to carry out timer-controlled preprogramming in accordance with the present invention. They are: a system controller 10, a timer 15, a tuner 20, a recording/playback circuit 25, an OSD(on screen display) generator 35, a key matrix 55 and a receiver 60. The system controller 10, which may be implemented with a microcomputer, includes a microprocessor 11, a read only memory(ROM) 12 in which various programs are stored, a random access memory (RAM) 13 to store data and preprogramming information that may be changed or updated during the operation of the microprocessor 11, and an input/output port(not shown). The timer 15 includes a real time clock which is normally provided in the VCR to offer time and date information. The tuner 20 is provided with necessary circuits for receiving a TV broadcast program in a known manner. Under the control of the system controller 10, any one of the broadcast programs selected by the tuner 20 can be reserved or preset for preprogrammed recording. The recording/playback apparatus 25 connected to the system controller 10 employs a mechanism which performs various mechanical functions for the VCR. The mechanical functions may include loading and unloading of a videotape, recording of video signals on the tape, reproduction of the video signals recorded on the videotape and the like. The OSD generator 35 generates"display patterns for the display of preprogramming information on a television screen (not shown) which may be conventionally connected to the VCR in accordance with a display algorithm which prompts the user to enter the preprogramming data through the operation of the keys on the remote control unit 50 or on the key matrix 55. The key matrix 55 built in the VCR may have a number of keys which may be the same as those in the remote control unit 50 which will be fully discussed hereinafter. The tape speed selector 60, which may be a capstan motor for controlling the tape speed, serves to select any one mode of the available tape running speeds such as SP', LP and EP modes under a control of the system controller 10. Connected to the system controller 10 is a receiver 65 which receives a command signal transmitted from the remote control unit 50 and converts it to an electrical signal for the system controller 10. In accordance with the present invention, built in the VCR is an auxiliary voltage supply 40, which is coupled to a main power supply (for the sake of simplicity, the main power supply is omitted in Fig. 1), for use to compensate an interruption of power supply in the event of, e.g., a power failure. The auxiliary voltage supply 40 includes a rectifier 42 to rectify an AC input to the VCR, a reverse current blocking diode Dl connected to the rectifier 42, a rechargeable battery 46 and an overcharge prevention resistor Rl for the rechargeable battery 46. 'The rechargeable battery 46, which may be of a nikel-cadmium(NiCd) battery, is actuated at a time when the AC input is interrupted due to the power failure or disconnection and maintains the timer 15 and the system controller 10 to save the time data in the timer 15 and the preprogramming information stored in the RAM 13. As clearly shown in Fig. 2, the remote control unit 50 has a reservation key 52, a channel selection key 54, a tape speed selection key 56 and updating keys including a recording start time increment(+) and decrement(-) keys 62 and 64 and a recording end time increment(+) and decrement(-) keys 66 and 68 together with a plurality of such other keys as numeric keys 72 and operation keys 74. The reservation key 52 functions to generate a signal indicative of the recording commencement or completion when it is pressed. In response to the recording commencement signal generated when the reservation key 52 is operated, the system controller 10 simultaneously sets up or "initializes" the preprogramming information including a recording channel, a tape speed, a recording start time and a recording end time, as follows: the initial recording channel is set to the channel of a broadcast program currently received by the tuner 20, the initial tape speed is set to any one of the available tape speeds such as SP, LP and EP modes, and the initial recording start time is set to a current time indicated on the timer 15. And the initial recording end time is set to a time that is defined by adding a predetermined duration of recording to the recording start time. While the initialization is carried out by simply pressing the reservation key 52 once, it may be necessary to individually fit or adjust the initial recording start time and the initial recording end time to the actual broadcast schedule of a desired broadcast program for recording. The recording start time and the recording end time can be updated or adjusted through the use of the start time increment(+)/ decrement(-) keys 62 and 64 and the end time increment(+) / decrement(-) keys 66 and 68, respectively. The start time increment(+) key 62 is used to delay the recording start time from the current time, while the start time decrement(-) key 64 is used to step up the delayed recording start time. That is, the start time decrement(-) key 64 may be used to reverse or correct the start time erroneously delayed by the operation of the start time increment(+) key 62. Thereafter, the recording end time will be automatically adjusted or updated to a new end time defined by the predetermined duration of recording (Tl) added to the updated start time. Or, the end time adjustment keys including the end time increment(+) and decrement(-) keys 66 and 68 may be employed to further adjust the recording end time to an actual end time of the desired broadcast program. Further, in accordance with the present invention, it is possible to update the recording channel and the tape speed through the use of the ' channel selection key 54 and the tape speed selection key 56 as well known in the art, respectively. After updating the recording start time, end time, channel and tape speed, the reservation key 52 is pressed once again so as to signify the completion of the preprogramming process in accordance with the present invention. The simplified recording operation described above will now be explained in further details with reference to Figs. 3 to 6. As shown in Fig. 3, the simplified recording process in accordance with the invention directly begins by simply pressing the reservation key 52. When the reservation key 52 is pressed in step SI, " the process proceeds to step S2 where the system controller 10 "initializes" the preprogramming information including the recording channel, the tape speed and the recording start time. The initial recording channel will be a channel through which a TV program is being currently received by the tuner 20, the initial recording tape speed will be any one of the tape speeds, for example, LP mode, and the initial recording start time will be the current time which is read from the timer 15. And then, the process proceeds to step S3, wherein the system controller 10 sets the recording end time by adding the predetermined duration of recording(Tl ) to the initial start time. The predetermined duration of recording(Tl) may correspond to a program length, e.g., two hours. As described above, it should be appreciated that the initialization of the preprogramming information is automatically done by simply pressing the reservation key 52 once. The above procedure helps to save the time needed to input four or more pieces of preprogramming information as is done in other types of VCR systems . Since it is not possible to record a desired program to be broadcast in a future with the recording start time set to the current time, the initial preprogramming information in such case is, therefore, updated in accordance with the following procedure. In step S4, it is determined whether the start time increment(+) ' key 62 is to be pressed. If positive, the process goes to step S5. In step S5, the start time is incremented by a time interval(T2) each time the start time increment(+) key 62 is pressed until it reaches the desired start time. After adjusting the start time in step S5, the process returns to step S3 where the updated end time is determind by adding the predetermined duration of recording (Tl) to the updated start time. In step S4, if it is determined that the start tim increment (+) key 62 is not to 'be pressed, the proces proceeds to step S6. "In step S6, the system controller 1 determines whether the reservation key 52 is to be pressed o not. If positive, the process proceeds to step S7. If it i not to be pressed, the proceess passes to step S8 through tab A. In step S7, in response to the preprogramming completio signal generated by the operation of the reservation key 52 second time, the system controller 10 stores th preprogramming information including the updated start time, the updated end time, the channel and the tape speed in th RAM 13. Consequently, the preprogrammed recording procedur in accordance with the present invention is economicall accomplished with only the three steps of operation b pressing the reservation key 52, the start time updating ke 62, and again the reservation key 52, in that order. As described above, the start time is updated with th operation of the start time increment(+) key 62. However, i case where the updated start time is past the time to commenc the recording of the desired broadcast program, it will b required to reverse the late start time. Fig. 4 is a flow chart illustrating the procedure t restore or reverse the late start time. In step S8, the system controller 10 determines whethe the start time decrement(-) key 64 is to be pressed or not If not, the process proceeds to step S12 in Fig. 5 through tab C. However, if the' start time decrement(-) key 64 need b pressed, the process proceeds to step S9 to back up or revers the start time by a time interval(T3) each time the start tim decrement (-) key 64 is pressed. It may be desirable t program the time intervals(T2 and T3) to be several minutes for example, 5 and 3 minutes respectively, for the purpose o a quick adjustment. However, in case where the reversed start time in ste S9 is earlier than the current time indicated on the timer 15 the preprogrammed recording cannot be accomplished Therefore, the start time should be set on or after th current time read from- the timer 15. Accordingly, in step S10, it is checked whether th reversed start time is earlier than the current time. If not the process returns to " step S3 through the tap B. Otherwise the process proceeds to step Sll where the system controlle 10 sets the current time indicated on the timer 15 as th recording start time and then the process returns to step S through the tab B. If necessary, it is also possible in step 11 to set th start time to the updated start time as in step S5. On the other hand, as described in step S3, there i always the predetermined duration of recording (Tl) betwee the recording start time and the recording end time. Thus there is no problem if the predetermined duration of recordin (Tl) is equal to the length of the desired broadcast program However, if the predetermined duration of recording (Tl is different from the length of the desired broadcast program the end time increment(+) and decrement(-) keys 66 and 68 ar used to adjust the recording end time to an actual end time o the desired broadcast program. A flow chart for th adjustment of the recording end time is shown in Fig. 5. In step Ξ12, the system controller 10 checks whether th end time increment(+) key 66 or decrement(-) key 68 is to b pressed or not. If the increment (+) key 66 or decrement (- key 68 need be pressed, the process proceeds to step S13; otherwise, the process -flows to step S14 through a tab D. I step S13, the end time is increased or decreased by a tim interval (T4) upon the pressing of the end time increment (+ key 66 or the end time decrement(-) key 68. In accordanc with a preferred embodiment of the present invention, it i desirable to program the time interval (T2 or T3) used t adjust the recording start time to be more precise or fine than the time interval (T4) used to adjust the recoring en time. Turning now to Fig. 6, there is shown a flow chart fo updating the channel and the tape speed. In step S14, th system controller 10 checks whether the channel selection ke 54 is to be pressed. When pressed, the system controller 1 causes the tuner 20 to change the recording channel to anothe in step S15. Alternatively, the numeric key 72 may be used t directly select the recording channel as well known in th art. In step S14, if the key 54 need not be pressed, th process proceeds to step S16 and the system controller 1 checks whether the tape speed selection key 56 is to b pressed or not. In step S16, if the speed selection key 56 is required t be pressed, the process proceeds to step S17 and the syste controller 10 causes the tape speed selector 60 to change th tape speed to another. If the speed selection key 56 need no be pressed, the process returns to step S6 through the tab B and the entire procedure for timer-controlled preprogrammin becomes completed by pressing the reservation key 52 once again. At the same time, all of the newly update preprogramming information is stored in the RAM 13; and the VCR enters into a stand-by mode until the recording starts . Fig. 7 exemplifies display patterns which may b displayed on the television screen by the OSD generator 35. The system controller 10 controls the OSD generator 35 t generate an OSD signal corresponding to an original displa pattern including such letters as TIMER RESERVATION, CHANNEL, TAPE SPEED, DATE, START TIME and END TIME in the order show in Fig. 7A when the reservation key 52 is pressed as in ste Sl(see Fig. 3) . Fig. 7B shows an exemplary display pattern generated whe the start time increment(+) key 62 is pressed as in step S4, indicating that the date, the recording start time and the en time are changed. Fig. 7C illustrates a representative display patter generated when the keys 66, 54 and 56 are pressed, respectively, as in steps S12, S14 and S16, indicating tha the recording end time, the channel and the tape speed ar further changed from the information displayed in Fig. 7 respectively. While the present invention has been described with respect to the particular embodiments, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the spirit and the scope of the invention as defined in the claims.

Claims: What is claimed is: 1. An improved video cassette recorder having a tuner fo receiving a television broadcast program through a pluralit of receiving channels, a real time clock for indicating tim information, a recording speed selector for selecting a tap running speed and a power supply for supplying electric powe to the video cassette recorder, wherein the improvemen comprises a timer-controlled preprogramming apparatus fo recording a desired broadcast program, the apparatu including: means for generating a signal indicative of preprogramming commencement mode or a preprogrammin completion mode when it is operated; means, in response to the preprogramming commencemen signal, for initializing a set of preprogramming informatio designating an initial recording channel, an initial recordin tape speed, an initial recording start time and an initia recording end time wherein the initial recording end time i automatically determined by adding a predetermined duration o recording to the initial recording start time; means for adjusting the initial recording start time t an actual start time of the desired broadcast program; means for adjusting the recording end time when th length of the desired broadcast program is different from th predetermined duration of recording; means, in response to the preprogramming completio signal, for storing the preprogramming information and settin the video cassette recorder in a stand-by mode fo preprogrammed recording; and a rechargeable battery coupled to the power supply fo supplying a battery power to the real time clock and th timer-controlled preprogramming apparatus in case of a powe failure. 2. The video cassette recorder of claim 1, wherein th apparatus further includes : means for adjusting the initial recording channel t another channel; and means for adjusting the initial recording tape speed t another speed. 3. A method for timer-controlled preprogramming of a vide cassette recorder having a tuner for receiving a televisio broadcast program through a plurality of receiving channels a real time clock for indicating time information, and rechargeable battery for use in the event of a severance o electric power supply so as to enable the preprogrammin information stored in the video cassette recorder and the tim information to survive, the method comprising the steps of: generating a signal indicative of preprogrammin commencement mode; initializing, in response to the preprogramming commencement signal, a set of preprogramming information designating an initial recording channel, an initial recording tape speed, an initial recording start time and an initial recording end time wherein the initial recording end time is automatically determined by adding a predetermined duration of recording to the initail recording start time; and adjusting the initial recording start time to an actual start time of the desired broadcast program; adjusting the initial recording end time when the length of the desired broadcast program is different from the predetermined duration of recording; generating a signal indicative of preprogramming completion mode; and storing, in response to the timer preprogramming completion signal, the preprogramming information and setting the video cassette recorder in a stand-by mode for preprogrammed recording. 4. The method for timer-controlled preprogramming of a video cassette recorder of claim 3, further comprising the step of adjusting the initial recording channel to another channel. 5. The method for timer-controlled preprogramming of a video cassette recorder of claim 3, further comprising the step of adjusting the initial recording tape speed to another speed.

Inventors: CHEON BYEONG HOO, KIM JAE KEY, PARK KEUN, CHEON, BYEONG, HOO, KIM, JAE, KEY, PARK, KEUN
Applicants: DAEWOO ELECTRONICS CO LTD, DAEWOO ELECTRONICS CO., LTD.
Application year: 1993
Main classification: H04N5
IPC codes: G04G15, G11B15, G11B27, H04N5