GB2227353A - Method of randomly searching for a desired picture portion on a video cassette tape - Google Patents

Abstract

A method of searching for a desired picture portion on a video cassette tape comprises the steps of setting a search counter for a random search mode together with a count value of a desired search portion, and selecting for the motor of a VCR system a rotational direction in a given mode by using a search key and other keys; driving said motor in the set rotational direction; and automatically performing the play mode of said system when the present counted value of a reel counter agrees with the value of said desired search portion. The apparatus comprises a microcomputer 1 having a plurality of flags for controlling the operation of the apparatus, a controller 7 for controlling a mechanism for driving the tape drive motor, and a key signal generating means 3 having various control keys for generating the signals to control the micom 1. <IMAGE>

Description

METHOD OF RANDOMLY SEARCHING FOR A DESIRED PICTURE PORTION ON A VIDEO CASSETTE TAPE The present invention concerns a method of searching for a desired picture portion on a video cassette tape.

In a conventional video cassette recorder (hereinafter referred to as VCR), the rewind key or fast forward key is used to search for a desired picture portion on a video cassette tape when the VCR is in a stop mode in which the tape is not already running. When the VCR is in a play mode, the fast forward picture search key or the rewind picture search key is used to search for a desired picture portion on the tape whilst viewing the screen.

However, such a conventional method for searching a desired picture portion on a tape has the disadvantage that the user has to keep on pushing the keys to search on a trial-and-error basis, until the desired picture portion is successfully found. Besides, as the forward and rewind motions are repeated frequently in order to reach the desired picture portion on the tape, the conventional method not only causes the user to waste time but also shortens the life span of the system.

Preferred embodiments of the present invention aim to provide a method for randomly searching a desired picture portion on a tape whereby the play mode is automatically performed when the value of a search counter set for the desired picture portion agrees with a counted value of a tape running counter.

Another aim is to provide a method for randomly searching a desired picture portion on a tape whereby a picture search mode is performed until a counted value of a tape running counter agrees with a value of a search counter set for the desired picture portion, and thereafter, the play mode is automatically performed.

According to a first aspect of the present invention, there is provided a method of searching for a desired picture portion on a video cassette tape using a system comprising a microcomputer (micom) having in a memory region thereof a plurality of flags for controlling the operation of said system according to key inputs, a controller for controlling a mechanism for driving said tape under the control of said micom, said controller providing said micom with reel pulses generated by rotation of a drive motor, which pulses are counted by a reel counter, and a key signal generating means having a search key, ten key and other keys for generating signals to control said micom, the method comprising the steps of:: (a) setting a search counter into a search mode, with a selected value of a desired search position, and setting the motor of said controller for a selected rotational direction in a selected system mode, using said search key and other keys; (b) driving said motor in the selected rotational direction when the search mode is set; and (c) automatically performing the play mode of said system when the present counted value of said reel counter agrees with the selected value of said desired search position.

Preferably, step (a) comprises: (i) setting a first flag (FSRCH) representing the search mode by the input of said search key before performing the next routine; (ii) searching for whether said first flag is set during the input of said ten key; (iii) setting a second flag (FTEN) representing the input of said ten key when said first flag (FSRCH) is set and storing the input number into said search counter (SRDATA), and then performing the next routine, or otherwise, directly performing the next routine when said first flag (FSRCH) is reset; (iv) searching for whether the second flag (FTEN) is set to check said ten key being presently input;; (v) setting a third flag (FGOGO) or fourth flag (FBACK) representing respectively the forward running or the backward running according to the input of a key selecting said rotational direction when the second flag (FTEN) is set, and then performing the next routine, or otherwise, directly performing the next routine when the second flag (FTEN) is reset; and (vi) resetting the flags set in the above (i) to (v) as well as clearing the data stored into said search counter when a key signal other than that of said search key, ten key, and rotational direction key is input.

Preferably, step (b) comprises: driving said motor in fast forward or rewind mode when search mode is selected when said system is initially in stop mode; or otherwise driving said motor in forward picture search mode or rewind picture search mode when search mode is selected when said system is initially in play mode.

In a preferred arrangement, when said system is in the search mode, step (c) comprises: reading the present counted value of said reel counter to save it into the internal memory as well as reading the reel pulses according to the rotation of said motor; performing the main routine when said reel pulse is not in the logic state representing one complete rotation of the running motor, or otherwise, searching for whether there is set the third flag (FGOGO) representing the forward running when in the logic state representing one complete rotation; increasing or decreasing the present counted value of said reel counter when the third flag represents respectively the forward running or the backward running to search for whether the present counted value of said reel counter agrees with the value of said search counter; and stopping the search mode operation when said values agree with each other to perform the play mode.

The invention extends also to apparatus for carrying out the above mentioned methods, including the micom, controller, drive motor, reel pulse counter and key signal generating means, all constructed and arranged to carry out a method in accordance with the first aspect of the invention.

In a second aspect, the invention provides a method of searching for a desired location on a recording medium, comprising the steps of inputting a desired number indicating said desired location, causing a drive motor to drive the recording medium from a present location, incrementing or decreasing a current value of a counter in accordance with driving of said recording medium, and ceasing drive of the recording medium when the current value of said counter corresponds to said desired number.

Such a method may comprise any one or more of the additional steps recited in this specification, drawings, abstract or claims.

The invention also extends to apparatus constructed and arranged to carry out a method according to the second aspect of the invention.

For a better understanding of the invention and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying diagrammatic drawings, in which: Figure 1 is a block diagram of one example of a system for carrying out a method in accordance with the present invention; Figure 2 is a flow chart for setting a random search counting value; Figure 3 is a flow chart of performing a stop mode; Figure 4 is a flow chart of performing a play mode; Figure 5 is a flow chart of performing a fast forward/rewind mode; Figure 6 is a flow chart of performing a fast forward picture search/rewind picture search mode; and Figure 7 is a flow chart of performing a reel counting mode.

Referring to Figure 1, the system is controlled by a microcomputer (micom) 1 according to mode control signals. The micom 1 receives the mode control signals from a key matrix 3 having a plurality of keys. A mechanism control block (controller) 5 controls a mechanism for running a tape under the control of the micom 1, and provides the micom 1 with reel pulses generated according to running of the tape. A circuit controller 7 controls a servo for controlling the running of the tape under the control of the micom 1. The controlling actions of the micom 1 are displayed on a display 9. The mode control signals may be output as optical beams by a remote transmitter 11 having the same keys as the key matrix 3. A search key for carrying out a search is included in the key matrix 3 and the remote transmitter 11.

Figure 2 is a flow chart for setting the random search counting value, wherein the system is set for random mode, the search counting value to be displayed while randomly searching is set, and then play mode is set.

Figure 3 is a flow chart of performing the stop mode, wherein the system is set to the random search mode from a present stop mode.

Figure 4 is a flow chart of performing the play mode, wherein the system is set to the random search mode from a present play mode of the system.

Figure 5 is flow chart of performing the fast forward/rewind mode wherein the system checks the present mode during random search by the state of FFF (fast forward flag) and FREW (fast review) in the operational state of fast forward/rewind mode.

Figure 6 is a flow chart of performing the forward picture search/rewind picture search mode, wherein the system checks the present mode during random search by the state of FFPS (fast forward picture search) / FRPS (fast rewind picture search) in the operational state of forward/rewind mode.

Figure 7 is a flow chart of performing the reel counting mode, wherein the random search mode is performed by comparing the value of the search counter with the value of the running counter, and then the play mode is automatically performed when the two values agree with each other.

An example of operation of the above described system will now be given, with reference to the accompanying drawings.

At first, if the micom 1 is supplied with power, it is initialised and checks whether a key signal is input in the step 21 of Figure 2. If the key signal is not input because the key matrix 3 or the remote transmitter 11 is not operated, the system jumps to the next routine of the main program. If the key signal is input in the above step 21, the micom 1 checks in the step 23 whether the input key signal is the search key signal for carrying out the random search. If it is the search key signal, the micom 1 sets in the step 25 a flag FSRCH (random search mode flag) of the internal memory region, and performs the next routine. The next routine refers to a sub-routine of the main routine, and indicates the routine after carrying out the check mode routine for the random search mode of Figure 2.

If the step 23 does not identify the search key, the micom 1 checks whether the input key is a ten key (numeric key). If it is the ten key, the micom 1 checks in the step 29 whether the flag FSRCH is high, namely, is set. If the step 29 indicates that the flag FSRCH is high, the micom 1 recognizes the random search mode, sets the FTEN (ten key flag), thereby representing the completion of inputting the ten key signal in the step 31, and stores the ten key signal in the step 33 into the search register SRDATA of the internal memory. The term "ten key" herein refers to ten keys each representing respectively the numbers 0 to 9, and therefore, if the number 3 key is pushed on, the number 3 is stored into the search register SRDATA.

If the step 29 does not indicate that the flag FSRCH is set, the system jumps to the next routine to carry out the corresponding service of inputting a number. If the number keys "387" are input after the search key, by successively carrying out the steps 21, 23, 25, 27, 29, 31, 33, the number data 387 is stored into the register SRDATA for storing the data chosen by the user when randomly searching.

Thereafter, the channel-up key (+ key) of the key matrix 3 or the remote transmitter 11 being input and checked out in the step 35, the micom 1 checks in the step 37 whether the flag FTEN of the internal memory is set (high). If the step 37 indicates that the flag FTEN is reset (low), the system jumps to the next routine to serve the channel-up key input. On the other hand, if the flag FTEN is set, the flag FGOGO (motor forward flag) is set in the step 39 for forwardly driving the tape running motor when randomly searching, and the next routine is performed.

If in the step 35 the channel-up key is not checked out, the micom 1 checks in the step 41 whether the input key signal indicates the channel-down key (-key). The channel-down key being checked out in the step 41, the micom 1 checks out in the step 43 whether the flag FTEN is set (high), thereby checking out whether the ten key input has been input before the channel-down key. If the step 43 indicates the flag FTEN reset (low), the system jumps to the next routine of the main program to serve the channel-down key input. If the flag FTEN is set, the micom 1 sets in the step 45 the flag FBACK (motor back flag) for driving the tape running motor in reverse when randomly searching, and the next routine is performed.

If the step 41 does not check out the channeldown key, the flags FSRCM, FTEN, FGOGO, FBACK, etc. that are set durina random search are reset (cleared) in the step 47 and the system jumps to the routine for performing the input key and serves the corresponding key. Thus, if the search key, the number keys (ten key) 3, 8, 7, and the channel-up key are sequentially input, the flags FSRCH and FTEN in the micom are set, and the data 387 is stored into the register SRDATA, as shown in the flow chart of Figure 2. Further, the flag FGOGO is set for driving the motor forwardly when searching. If the finally input key is the channel-down key, the flag FBACK is set for driving the motor in reverse when searching.

If the random search check routine of Figure 2 is performed when the VCR is presently in the stop mode, the micom 1 checks in the step 49 of Figure 3 whether the flag FSRCH is set (high). If the step 49 indicates the flag FSRCH is set in logic high which is the random search mode, in the step 51 it is checked out whether the flag FGOGO is set (high). If the step 49 indicates the flag FSRCH is not set in logic high, the next routine is performed to carry out normal operation. The step 51 indicating forward tape motion, (namely, the flag FGOGO being set), the micom 1 sets in the step 53 the FFF (fast forward flag) of the internal memory and performs the FF fast forward) mode routine.

If the step 51 does not indicate the flag FGOGO set, the micom 1 checks in the step 55 whether the flag FBACK is set in logic high. If the step 55 checks the flag FBACK set, the micom 1 sets in the step 57 the flag FREW (flag rewind) of the internal memory region in logic high, and performs the rewind mode routine. If the step 55 checks the flag FBACK not being set, the next routine is performed. The flag FFF is for randomly searching in the FF mode, while the flag FREW for randomly searching in the REW mode.

In the procedures of Figure 3, if the flag FFF is set, the micom 1 performs the FF mode routine of Figure 5 to check in the step 69 whether the flag FFF is high, namely, the FF mode when randomly searching. The flag FFF being high, the micom 1 outputs the FF forward driving control signal of the tape running motor to the controller 5 so as to drive the motor forwardly and goes to the reel counting mode routine. If the flag FREW is set in Figure3, the micom 1 checks in the step 71 of Figure 5 whether the flag FREW is high. The flag FREW being high, the micom 1 outputs the REW control signal of the tape running motor to the controller 5 so as to drive the motor in reverse, and goes into the reel counting mode routine.

If the random search check routine of Figure 2 is performed whilst the VCR is presently in the play mode, the micom 1 checks in the step 59 of Figure 4 whether the flag FSRCH is set (high). If the step 59 indicates the flag FSRCH set in logic high, which is the random search mode, the micom 1 checks in the step 61 whether the flag FGOGO is set (high). If the step 59 indicates the flag FSRCH is not set, the micom 1 performs the next routine to carry out normal operation. The step 61 indicating forward drive, namely, the flag FGOGO being set, the micom 1 sets in the step 63 the flag FFPS (fast forward picture search flag), and performs the FPS (forward picture search) mode routine. If the step 61 checks the flag FGOGO not set, the micom 1 checks in the step 65 whether the flag FBACK is set in logic high. If the step 65 checks the flag FBACK being set, the micom 1 sets in the step 67 the flag FRPS of the internal memory region into logic high, and performs the RPS (rewind picture search) mode routine. The step 65 checking the flag FBACK not being set, the next routine is performed.

Here, the flag FFPS is for randomly searching in the FPS mode, while the flag FRPS is for randomly searching in the RPS mode.

If the flag FFPS is set in the procedures of Figure 4, the micom 1 goes into the FPS mode routine of Figure 6, and in the step 73 checks whether the flag FFPS is in logic high, namely, the FPS mode when randomly searching. The flag FFPS being high, the micom 1 outputs the tape forward driving control signal to the controller 5 so as to drive the motor in the FPS mode, and goes into the reel counting mode routine. If the flag FRPS is set in Figure 4, the micom 1 checks in the step 75 of Figure 6 whether the flag FRPS is in logic high. The flag FRPS being high, the micom 1 outputs the RPS control signal of the tape running motor to the controller 5 so as to drive the motor, and goes into the reel counting mode routine.

The micom 1 performing the reel counting routine of the procedures as shown in Figure 5 or 6 checks in the step 77 of Figure 7 whether the flag FRSCH of the internal memory is in logic high, and thus, whether the present system mode is in the random search mode. If the step 77 does not indicate the random search mode, the next routine is performed to serve the main program. If the flag FSRCH is set in logic high, the present value of the reel counter that is output from the controller 5 according to the rotation of the tape running motor is read in the step 79, and saved in the internal memory.

The controller 5 outputs the counting value representing the amount of rotation of the tape running motor, and the reel pulses are generated according to the rotation of the motor. The micom 1 which stores the reel counting value generated by the controller 5 according to the tape running in the step 79 reads the reel pulses generated in the step 81 by the controller 5 according to the rotation of the tape running motor.

The micom 1 checks in the step 83 whether the reel pulses are in logic high. If the reel pulses are in logic high, the micom 1 sets in the step 85 the flag FGOGO, and checks whether the random search mode is set in the forward set mode. The reason that the step 83 checks whether the reel pulses are logic high is that every time the motor in the controller 5 makes one rotation, a respective one pulse is generated. The reason that the step checks the flag FGOGO is that the present value of the reel counter increases or decreases according to the search mode. If the step 85 checks the flag FGOGO of the memory being set (high), which indicates the forward running of the motor, the present value of the reel counter is increased by one in the step 87.If the step 85 checks the flag FGOGO being reset (low), which indicates the backward running of the motor, the present value of the reel counter is decreased by one in the step 89. After increasing or decreasing the present value of the reel counter stored into the internal memory in the step 87 or 89, the micom 1 checks in the step 91 whether the present value of the reel counter agrees with the counting value of the search counter stored in the register SRDATA. If the step 91 indicates the two values are different from each other, the next routine of the main program is performed so that the motor keeps running in the forward or backward direction by the above described procedures.

However, if the present value of the reel counter agrees with the counting value of the search counter stored into the register SRDATA, namely, the desired portion of the tape is reached by the tape drive, the micom 1 clears in the step 93 not only the flags FSRCH, FFF, FREW, FGOGO, FBACK, FFPS, FRPS, FTEN used for the random search, but also the search counting value stored into the register. After performing the step 93, the micom 1 goes into the normal play mode. Thus, if the counting value of the search counter stored into the register which is set by the user agrees with the present counted value of the reel counter which varies according to the motor running, and therefore, the desired portion of the tape is reached, the search mode is automatically stopped and the play mode is performed.

Thus, there is provided an effortless method for randomly searching a desired picture portion in a video cassette tape.

Although specific constructions and procedures of the present invention have been illustrated and described herein, it is not intended that the invention be limitted to the elements, constructions, and procedures disclosed above. One skilled in the art will easily recognize that the particular elements or subconstructions may be used without departing from the scope and spirit of the invention.

The reader's attention is directed to all papers and documents which are filed concurrently with or previous to this specification and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

Each feature disclosed in this specification (including any accompanying claims, abstract and drawings), may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims (9)

CLAIMS:

1. A method of searching for a desired picture portion on a video cassette tape using a system comprising a microcomputer (micom) having in a memory region thereof a plurality of flags for controlling the operation of said system according to key inputs, a controller for controlling a mechanism for driving said tape under the control of said micom, said controller providing said micom with reel pulses generated by rotation of a drive motor, which pulses are counted by a reel counter, and a key signal generating means having a search key, ten key and other keys for generating signals to control said micom, the method comprising the steps of:: (a) setting a search counter into a search mode, with a selected value of a desired search position, and setting the motor of said controller for a selected rotational direction in a selected system mode, using said search key and other keys; (b) driving said motor in the selected rotational direction when the search mode is set; and (c) automatically performing the play mode of said system when the present counted value of said reel counter agrees with the selected value of said desired search position.

2. A method as claimed in claim 1, wherein step (a) comprises: (i) setting a first flag (FSRCH) representing the search mode by the input of said search key before performing the next routine; (ii) searching for whether said first flag is set during the input of said ten key; (iii) setting a second flag (FTEN) representing the input of said ten key when said first flag (FSRCH) is set and storing the input number into said search counter (SRDATA), and then performing the next routine, or otherwise, directly performing the next routine when said first flag (FSRCH) is reset; (iv) searching for whether the second flag (FTEN) is set to check said ten key being presently input;; (v) setting a third flag (FGOGO) or fourth flag (FBACK) representing respectively the forward running or the backward running according to the input of a key selecting said rotational direction when the second flag (FTEN) is set, and then performing the next routine, or otherwise, directly performing the next routine when the second flag (FTEN) is reset; and (vi) resetting the flags set in the above (i) to (v) as well as clearing the data stored into said search counter when a key signal other than that of said search key, ten key, and rotational direction key is input.

3. A method as claimed in Claim 1 or 2, wherein step (b) comprises: driving said motor in fast forward or rewind mode when search mode is selected when said system is initially in stop mode; or otherwise driving said motor in forward picture search mode or rewind picture search mode when search mode is selected when said system is initially in play mode.

4. A method as claimed in Claim 2 or Claims 2 and 3, wherein step (c), when said system is in the search mode, comprises: reading the present counted value of said reel counter to save it into the internal memory as well as reading the reel pulses according to the rotation of said motor; performing the main routine when said reel pulse is not in the logic state representing one complete rotation of the running motor, or otherwise, searching for whether there is set the third flag (FGOGO) representing the forward running when in the logic state representing one complete rotation; increasing or decreasing the present counted value of said reel counter when the third flag represents respectively the forward running or the backward running to search for whether the present counted value of said reel counter agrees with the value of said search counter; and stopping the search mode operation when said values agree with each other to perform the play mode.

5. A method of searching for a desired picture portion on a video cassette tape, the method being substantially as hereinbefore described with reference to the accompanying drawings.

6. Apparatus for carrying out a method according to any of the preceding claims, including the micom, controller, drive motor, reel pulse counter and key signal generating means, all constructed and arranged to carry out said method.

7. A method of searching for a desired location on a recording medium, comprising the steps of inputting a desired number indicating said desired location, causing a drive motor to drive the recording medium from a present location, incrementing or decreasing a current value of a counter in accordance with driving of said recording medium, and ceasing drive of the recording medium when the current value of said counter corresponds to said desired number.

8. A method according to Claim 8, comprising any one or more of the additional steps recited in this specification, drawings, abstract or preceding claims.

9. Apparatus constructed and arranged to carry out a method according to Claim 7 or 8.