Method for fast checking a timer of a video cassette tape recorder and video cassette tape recorder for carrying out the method

Abstract: Method and apparatus for fast checking a timer of a video cassette tape recorder. A service menu picture of a service mode is displayed when the service mode is selected. A timer check menu picture is displayed if a timer check mode in the service menu picture is selected. A refresh operation of a television program information is locked if a fast clock operation mode in the timer check menu picture is selected. A timer with a fast clock is operated and a reservation recording is performed after a reservation setting of a television program is made. Then, the timer with a normal clock is operated when the reservation recording is finished and a refresh locking state of the television program information is unlocked.

Description: The present invention relates to a service mode of a video cassette tape recorder, and more particularly to a method and an apparatus for fast checking a timer of a video cassette tape recorder which can check a timer function such as a reservation recording in a relatively short time while carrying out the service mode. Generally, a video cassette tape recorder has a reservation recording function. Reservation recording is a function which automatically records a broadcast program from a selected channel at preset data and time if a user has input information including a channel, a data, and a start time of a desired television broadcast program. However, when there is a change in a start time of the broadcast program due to a plan of a broadcasting station, an undesired program may be recorded. Accordingly, techniques which can detect the start time by decoding a signal having a program start time information in a received television signal sent by the broadcasting station have been provided. As one of the above mentioned technique, there is a program delivery control (PDC) method used in Europe. The PDC method constructs date, start time, channel information in a data area which is not used during a data format of a teletext broadcasting and superposes the constructed program information onto a television broadcasting signal so as to send the same. The set decodes the PDC data from a received broadcasting signal at a time when a power of the set is turned off or at a predetermined time and refreshes a reservation recording information with the decoded program information, thereby synchronizing the reservation recording to an actual program broadcasting time of the broadcasting station. The timer function such as the reservation recording is checked at the service mode so that whether or not the reservation recording is correctly carried out at the preset reservation time is tested. However, the timer check at the service mode with a normal clock consumes a relatively long time and large effort. Accordingly, in a case where the test is carried out in a few minutes after a reservation setting for the test is done, there is a problem in setting the reservation. EP-A-0 725 541 discloses a video recorder with a PDC or VPS decoder. The present invention is intended to overcome the above described disadvantages. Therefore, it is an object of the present invention to provide a method and an apparatus for fast checking a timer of a video cassette tape recorder which can check a timer function of a set in a relatively short time. Also, it is an another object of the present invention to provide a method and an apparatus for fast checking a timer of a video cassette tape recorder which can avoid an erroneous manipulation of a reservation recording information due to a PDC operation during the fast timer check. In order to achieve the object of the present invention, there is provided a method for fast checking a timer of a video cassette tape recorder, which comprises the steps of: displaying a service menu picture of a service mode when the service mode is selected; displaying a timer check menu picture if a timer check mode in the service menu picture is selected; locking a refresh operation of a television program information and operating a timer with a fast clock if a fast clock operation mode in the timer check menu picture is selected; carrying out a reservation recording after a reservation setting of a television program is done; and operating the timer with a normal clock when the reservation recording is finished and unlocking a refresh locking state of the television program information. Also, in order to achieve the object of the present invention, there is provided a video cassette tape recorder, which comprises: a tuner section for outputting video and audio signals by decoding a television signal of a selected channel; a decoder for decoding a television program information superposed on the video signal, storing the decoded television program information and refreshing the stored television program information at least once a day; a video processing section for processing the video signal so as to record the video signal processed onto a video cassette tape loaded in a deck section; an input means for inputting a remote controller signal; an on-screen-display signal generating means for outputting an on-screen-display picture signal on a television after receiving an on-screen-display data; and a control section for displaying a service menu picture of a service mode through the on-screen-display signal generating means when the service mode is selected, displaying a timer check menu picture if a timer check mode in the service menu picture is selected, locking a refresh operation of a television program information of the decoder, operating a timer with a fast clock, carrying out a reservation setting of a television program by the input means, carrying out a reservation recording by controlling the video processing section and the deck section, operating the timer with a normal clock when the reservation recording is finished, and unlocking a refresh locking state of the television program information of the decoder. The present invention will become more apparent by describing in detail a preferred embodiment thereof with reference to the attached drawings in which: FIG. 1 is a block diagram illustrating a structure of a video cassette tape recorder having a fast timer check function according to the present invention; FIGs. 2A and 2B are a flowchart illustrating a method for fast checking a timer of the video cassette tape recorder according to a preferred embodiment of the present invention; and FIGs. 3 and 4 show error check display pictures according to the present invention; Hereinafter, a method and an apparatus for fast checking a timer of a video cassette tape recorder according to a preferred embodiment of the present invention will be explained in more detail with reference to the accompanying drawings. FIG. 1 is a block diagram illustrating a structure of a video cassette tape recorder according to the present invention. As shown in FIG. 1, a video cassette tape recorder includes a tuner section 10, a PDC decoder 15, a switching section 20, an on-screen-display signal generating section 30, a video processing section 40, a deck section 50, an input section 60, a display section 70, a power section 80 and a control section 90. Tuner section 10 tunes a broadcasting signal of a channel selected among television broadcasting signals received by an antenna, demodulate a tuned signal and outputs video and audio signals (not shown). Also, although it is not shown, tuner section 10 modulates inputted video and audio signals into a broadcasting signal of a specific channel so as to output a high frequency signal. The high frequency signal is provided as an antenna input of a television set. PDC decoder 15 decodes a PDC data from a video signal which is demodulated and outputted by tuner section 10 at the time when an operating power of a set is turned off or at a predetermined time of the day, for example at six o'clock p.m., and refreshes a reservation recording information with a decoded program information, thereby synchronizing to an actual program broadcasting time of a broadcasting station and accordingly, correctly carrying out the reservation recording. Switching section 20 switches the input/output of the video and audio signals according to an operation mode. A line-output of switching section 20 is line-inputted into the television set. On-screen-display signal generating section 30 transforms an inputted on-screen-display data into an RGB signal, transforms the RGB signal into a video signal and overlaps the video signal on a composite video signal so as to output the same. Video processing section 40 separates a signal reproduced from the video cassette tape into a luminance and a color signal, and signal-processes them respectively so as to output a composite video signal to on-screen-display signal generating section 30. Also, video processing section 40 separates a video signal provided from switching section 20 into a luminance and a color signal and signal-processes them respectively so as to provide a recorded video signal to a recording head. Deck section 50 reproduces a signal from a video cassette tape 52 by operating capstan and drum motors, and records a provided recorded signal onto video cassette tape 52. Input section 60 receives an optical signal of a remote controller 62 so as to generate a key signal in response to a pushing of a key pad of a front panel of the set. Display section 70 is generally an electron-ray indicator tube and displays a time information. Power section 80 receives a power-AC so as to generate an operating power V N and a standby power V S . Accordingly, during a standby mode, the standby power is applied to tuner section 10, PDC decoder 15, input section 60, display section 70 and control section 90 which are enclosed in a domain indicated as " 100". While, during an operating mode, the operating power is applied to an entire circuitry block including domains "100" and "200". Control section 90 is a microcomputer including a memory 82. Microcomputer executes an operating program stored in memory 82 so as to control the above described sections and to execute a timer fast check program. FIGs. 2A and 2B are a flowchart illustrating a method for fast checking a timer according to a preferred embodiment of the present invention. Repairmen execute a timer fast check mode in a state where the video cassette tape recorder is connected to the television set. As shown in FIG. 2A, a service mode program according to the present invention is accessible only by a combination of password keys known only to a specific worker such as a set developer, a test worker or a repairman. This prevents consumers from accessing the service mode. The worker pushes a menu key at first by remote controller 62 and sequentially push password keys such as number keys "4", "8" and "4". Input section 60 receives a key signal of remote controller 62 and transmits the same to control section 90. Control section 90 determines that a service mode is selected if the inputted key combination is identical to a preset key combination (step S202) and transmits on-screen-display data to on-screen-display signal generating section 30 so as to generate a video signal. The generated video signal is transmitted to the television set through switching section 20 so as to be displayed as an on-screen-display picture as shown in FIG. 3 (step S204). The service mode includes generally a repair mode, a timer check mode and an EEPROM data change mode. Thereafter, the worker pushes the number key "2" in order to select the timer check mode as shown in FIG. 3 by remote controller 62, and then the key signal is transmitted to control section 90 as above described. Control section 90 determines that the timer check mode is selected (step S206) and transmits on-screen-display data to on-screen-display signal generating section 30. Accordingly, on-screen-display signal generating section 30 generates a video signal. The generated video signal is transmitted to the television set through switching section 20 so as to be displayed as an on-screen-display picture as shown in FIG. 4 (step S208). The timer check mode includes a fast clock operation mode, an electron-ray indicator tube segment check mode. As shown in FIG. 4, when the worker pushes the number key "1" by remote controller 62 in order to select the fast clock operation mode, by the same operation described above, control section 90 determines that the fast clock operation mode is selected (step S210), and transmits a control signal to PDC decoder 15 through a serial data bus so as to lock a refresh operation of PDC decoder 15 (step S212). As shown in FIG. 2B, control section 90 operates an operation clock which is sixty times faster than a normal clock in such a manner that one minute of an inner timer lasts one second (step S214). In the fast clock operation mode, if the worker selects a reservation mode by remote controller 62 (step S216), control section 90 switches the system to the reservation mode in response to the selection of the worker (step S218). Thereafter, control section 90 controls power section 80 so as to turn off the operating power so that the system is switched to a standby mode (step S220). Accordingly, while in the conventional case, when the operating power is turned off, PDC decoder 15 carries out the refresh operation so as to refresh the program information with an actual program information of the broadcasting station, however, according to the present invention, since the refresh operation is locked in step 212, the refresh operation is not carried out. That is, without the refresh lock, there is a possibility that PDC decoder 15 would refresh the program information in response to the fast clock which is sixty times faster than the normal clock, thereby inducing an error. In the standby mode, control section 90 checks whether or not the reservation time set in step S218 comes by checking a time of the timer operated sixty times faster by the fast clock (step S222). If the time of the timer is identical to the reservation time while the fast clock is operated, control section 90 switches the system from the standby mode to the operating mode so as to carry out the reservation recording operation (step S224). Control section 90 checks whether the reservation recording operation is finished (step S226), and if so, then stops the fast clock operation mode (step S228), unlocks the PDC refresh locking mode (step S230) and returns the display to the menu picture of the timer check mode. As above described, in the method and apparatus for fast checking a timer according to the present invention, since one hour in the normal clock is equal to one minute in the fast clock, the preset reservation time is fast checked and whether or not the reservation operation is being correctly carried out is fast checked. In addition, in the method and apparatus for fast checking a timer according to the present invention, there can be no error in the program due to the PDC operation when the power is turned off or when it is six o'clock p.m. while carrying out the fast clock operation mode since the refresh operation is locked. Although the preferred embodiment of the invention has been described, it is understood that the present invention should not be limited to this preferred embodiment, but various changes and modifications can be made by one skilled in the art within the scope of the invention as hereinafter claimed.

Claims: A method for fast checking a timer of a video cassette tape recorder, said method characterized by comprising the steps of: (i) displaying (S204) a service menu picture (Fig.3) of a service mode when the service mode is selected; (ii) displaying (S208) a timer check menu picture (Fig.4) if a timer check mode in the service menu picture is selected; (iii) locking (S212) a refresh operation of a television program information and operating a timer with a fast clock if a fast clock operation mode in the timer check menu picture is selected; (iv) carrying out (S218) a reservation recording after a reservation setting of a television program is done; and (v) operating (S228) the timer with a normal clock when the reservation recording is finished and unlocking a refresh locking state of the television program information. The method for fast checking a timer of a video cassette tape recorder recited in claim 1, wherein in step (i), the service mode is selected by a combination of at least three remote controller inputs. The method for fast checking a timer of a video cassette tape recorder recited in claim 1, wherein in step (iii), the fast clock is sixty times faster than the normal clock. The method for fast checking a timer of a video cassette tape recorder recited in claim 1, wherein the television program information is a program delivery control information. The method for fast checking a timer of a video cassette tape recorder recited in claim 4, wherein the program delivery control information is refreshed at least once a day. The method for fast checking a timer of a video cassette tape recorder recited in claim 5, wherein the program delivery control information is refreshed when an operating power is turned off or at a predetermined time. The method for fast checking a timer of a video cassette tape recorder recited in claim 6, wherein the predetermined time is six o'clock p.m.. A video cassette tape recorder, which comprises: a tuner section (10) for outputting video and audio signals by decoding a television signal of a selected channel; a decoder (15) for decoding a television program information superposed on the video signal, storing the decoded television program information and refreshing a stored television program information at least once a day; a video processing section (40) for processing the video signal so as to record the video signal processed onto a video cassette tape loaded in a deck section; an input means (60) for inputting a remote controller signal; an on-screen-display signal generating means (30) for outputting an on-screen-display picture signal on a television after receiving on-screen-display data; characterised by a control section (90) for displaying a service menu picture of a service mode through the on-screen-display signal generating means when the service mode is selected, displaying a timer check menu picture if a timer check mode in the service menu picture is selected, locking a refresh operation of a television program information of the decoder, operating a timer with a fast clock, carrying out a reservation setting of a television program by the input means, carrying out a reservation recording by controlling the video processing section and the deck section, operating the timer with a normal clock when the reservation recording is finished, and unlocking a refresh locking state of the television program information of the decoder.

Inventors: JEONG BYOUNG-CHUL, JEONG, BYOUNG-CHUL
Applicants: DAEWOO ELECTRONICS CO LTD, DAEWOO ELECTRONICS CO., LTD
Application year: 1998
Main classification: G11B15
IPC codes: G11B15