Mode changing of electronic apparatus

Abstract: A mode processing circuit for a multiple operational mode electronic apparatus such as a video tape recorder includes a mode stack having a plurality of stages in which an input command signal is stored as an operational mode of the electronic apparatus. The operational mode supplied to the mode stack is sequentially stored and optimized, and the optimized operational mode is read out from the mode stack in sequential order and then executed after the transition of the operational mode has ended.

Description: This invention relates to methods of and circuits for mode changing of electronic apparatus, which are particularly, but not exclusively, suitable for a multiple operational mode electronic apparatus such as a video tape recorder (VTR), a tape deck, a video disc player, or a compact disc (CD) player. Various operational modes, such as a playback mode and a rewind mode are available in a known VTR. To change these operational modes, it is necessary to switch the VTR, or to move its brake and pinch roller into and out of engagement. If a plunger solenoid is used to switch the mechanism, the operational mode can be changed substantially instanteously. The use of the plunger solenoid, however, causes a large current to flow upon its actuation. Also, in the normal operational mode, a current must flow continuously, requiring a large power supply circuit, which consumes a large amount of power. It has therefore been proposed to use a motor instead of the plunger solenoid. When a motor is used together with a gear mechanism, the necessary driving power to switch the mechanism can be generated even with a small motor. Moreover, the use of the motor can reduce the power consumption and allow the power supply circuit to be small in size. However, when a motor is used to switch the mechanism, the mode switching takes a relatively long time. For example, in a typical example, it takes about two seconds for the VTR to change from the stop mode (STOP) to the playback mode (PB); it takes about 1.5 seconds for the VTR to change from the playback mode (PB) to the stop mode (STOP); and it takes about 1.8 seconds for the VTR to change from the stop mode (STOP) to the recording mode (REC). Accordingly, when a user intends to press a second operation key after a first operation key has been pressed, the user must not press the second operation key until the VTR has finished changing to the mode commanded by the first operation key. This is very inconvenient for the user, so it has been proposed to stack input commands issued by pressing the operation keys. Let it now be assumed that as, for example, illustrated in Figure 1 of the accompanying drawings, the VTR is placed in the stop mode before time point t1 and that a recording key is pressed at time point t1. Then, the mode of the VTR begins to change from the stop mode to the recording mode at time point t1. If a stop key, for example, is pressed at time point t2 during this transition period, then because the stop key corresponds to a mode which is valid for command during the recording mode, the command instructing the stop mode after the mode transition is stacked in the mode stack. When the mode transition of the VTR ends at a time point t3, the VTR is then in the recording mode (REC). At that time, the stop mode command stacked in the mode stack at the time point t2 is read out and the processing of this command is executed. Accordingly, the VTR begins the transfer to the stop mode at time point t3 and is in the stop mode by time point t4. If a pause key is pressed at time point t5 in the stop mode, then, because the pause mode (PAUSE) is not valid for command during the stop mode, the command issued by pressing the pause key is not executed. Using such a mode stack system, it becomes possible to remove the cumbersome requirement that the user must not press the next operation key until the mode transition of the VTR has ended (because if the next key is pressed, the command will be ignored). However, the above-mentioned mode stack system has the following defect. If the stop key is pressed at time point t2 and the pause key is then pressed at time point ta as, for example, shown in Figure 2 of the accompanying drawings, since the pause mode is valid for command during the recording mode, which will be the mode after the current mode transition, then the mode stacked in the mode stack is changed again from the stop mode to the recording pause mode. Accordingly, the mode of the VTR is changed to the recording pause mode at time point t3, and the VTR is then placed in the recording pause mode at time point t4. Thus, even although the stop key and the pause key were pressed in the same sequential order as that of Figure 1, the VTR is placed in an operational mode different from that in Figure 1, because of the timing of the depression of the pause key vis-a-vis the actual mode shifting of the VTR. In other words, if a plurality of valid operation keys are pressed during the mode transition period, the mode stacked in the mode stack is renewed to the mode corresponding to the operation key that was last pressed by the user, and the modes commanded by the previously-pressed operation keys are all ignored. Accordingly, the operational mode of the VTR becomes different depending on the timing at which the user presses the operation keys, depending on whether the VTR mode was in the process of being changed or was already changed when the keys were pressed. German patent specification DE-A1-30 29 689 discloses a mode processing circuit for electronic apparatus and including mode stack means for storing operational modes in sequence for subsequent execution in sequence. A demonstration of a video recorder ITT VR3946ST, serial number N242692 at Oral Proceedings on 11 April 1994 in respect of the present patent illustrated various operational mode changes. According to one aspect of the present invention, there is provided a method of changing the operational mode of a multiple operational mode electronic apparatus during a mode transition period in which the operational mode is transferring in a present operational mode, that is the next operational mode into which the apparatus is being shifted, and subsequently transferring to a final operational mode, that is the last operational mode in a sequence of operational modes corresponding to previously received, valid command signals and stored in an electronic memory device, the method comprising the steps of: receiving an input command signal; judging whether said input command signal is valid or not in view of the final operational mode; redetermining the final operational mode in accordance with said input command signal if valid and storing said redetermined final operational mode; determining a sequence of operational mode changes from said present operational mode to said redetermined final operational mode including optimizing the stored sequence of operational modes by comparison tests according to predetermined criteria between the stored operational modes and the redetermined final operational mode and between the stored operational modes and the present operational mode and eliminating operational modes found to be unnecessary as a result of said tests; and executing said sequence of operational mode changes until said present operational mode has been changed to said redetermined final operational mode. In accordance with another aspect of the invention there is provided a mode processing circuit for a multiple operational mode electronic apparatus, the circuit comprising: means for receiving an input command signal during a mode transition period in which the operational mode is transferring in a present operational mode, that is the next operational mode into which the apparatus is being shifted, and subsequently transferring to a final operational mode, that is the last operational mode in a sequence of operational modes corresponding to previously received valid command signals, judging whether said input command signal is valid or not in view of the final operating mode and redetermining the final operational mode of said electronic apparatus in accordance therewith; transition vector look-up table means for determining a new operational mode to which the operational mode of said electronic apparatus is to be shifted next in response to the redetermined final operational mode and a mode to which the operational mode of said electronic apparatus was shifted; and means for changing the operational mode of said electronic apparatus to said new operational mode thus determined, and for executing a sequence of mode changes thus determined until said redetermined final operational mode is achieved. The invention will now be described by way of example with reference to the accompanying drawings, throughout which like parts are referred to by like references, and in which: Figure 1 is a mode transition diagram used to explain a previously proposed mode stack system for a VTR; Figure 2 is another mode transition diagram used to explain the same previously proposed mode stack system for a VTR; Figure 3 is a block diagram of an embodiment of mode processing circuit according to the present invention, illustrating hardware relating to the mode transition operation of a VTR; Figure 4 is a mode transition diagram used to explain the embodiment; Figure 5 is a flow chart used to explain the mode transition operation in association with the mode transition diagram of Figure 4; Figure 6 is a table used to explain an algorithm of the mode transition and the change of data stacked in a mode stack; Figure 7 is a diagram used to explain the mode stack of the embodiment; Figures 8, 9, 10 and 11 are respectively diagrams used to explain the mode transition operation and the mode stack of the embodiment; Figure 12 is a mode transition table used to explain another embodiment of mode processing circuit according to the present invention for a multiple operational mode electronic apparatus; Figure 13 is a transition vector table used to explain the operation of the embodiment; Figure 14 is a mode transition diagram used to explain the operation of the embodiment; and Figure 15 is a flow chart used to explain the operation of the present invention. Figure 3 illustrates hardware relating to an embodiment of mode processing circuit for a VTR and according to the present invention. Referring to Figure 3, there is shown a mechanism (VTR) control section 1 which includes a loading motor 11 for loading or unloading a tape on or from the VTR, a control motor 12 for controlling the mode of the VTR, and a servo circuit 13 for controlling a drum and a capstan of the VTR. A mode controller 2 is formed of a microcomputer whose output is supplied to the control section 1 to place the VTR in each operational mode. At the same time, a signal indicative of the state (mode) of the VTR is supplied from the control section 1 to the mode controller 2. Key input means 3 is provided with a plurality of operation keys (not shown). A receiving circuit 4 receives a signal supplied by the operation key of a remote controller (not shown) when the VTR is operated by the remote controller. The key input signals from the key input means 3 and the receiving circuit 4 are both supplied to the mode controller 2. Mode indicating means 5 visually indicates to the user, for example by a liquid crystal display, the mode in which the VTR is placed, on the basis of the output signal from the mode controller 2. The mode stack is provided within a random access memory (RAM) of the microcomputer which forms the mode controller 2. When the operation key of the key input means 3 or the operation key of the remote controller (not shown) is pressed, its command is processed by the mode controller 2, and the processed result or data is supplied to the control section 1, so that the control section 1 is operated so as to place the VTR in a predetermined operational mode. At the same time, the corresponding mode of the VTR is visually indicated by the mode indicating means 5. Figure 4 illustrates, by way of example, how the VTR mode and data stacked in the mode stack are changed by input command when the operation key is pressed at a certain time point. In the description below, 'present mode' and 'final mode' indicates the mode of the VTR at the certain time point and also indicates, during the mode transition period of the VTR, the next mode in which the VTR is to be placed; and the 'final mode' indicates the mode stored last in the mode controller 2 at that certain time point. The final mode becomes the same as the present mode when no mode data are stacked in the mode stack. The validity of the operation key pressed is judged depending upon whether the operation key pressed is valid for the final mode or not. The mode indicating means 5 visually indicates the final mode. In the illustrated example of Figure 4, since the VTR is placed in the stop mode before time point t1, the present mode is the stop mode. At the same time, no mode is stacked in the mode stack and the final mode and the visual indication thereof are the stop mode. When the recording key is pressed at the time point t1, this recording mode is valid for the final mode (stop mode), so that 'REC' (recording mode) is stacked in the first stage of the mode stack. However, since the VTR has not yet started changing its operational mode, the VTR immediately starts changing its mode from the stop mode to the recording mode, and 'REC' is indicated by the mode indicating means 5. Moreover, the 'REC' mode command stacked in the mode stack is removed. If the stop key is pressed at time point t2 while the VTR is changing its mode, the stop mode is valid for the final mode (recording mode), so that 'STOP' (stop mode) is stacked in the first stage of the mode stack and final mode and the visual indication thereof are made the stop mode. However, the VTR itself is changing its operation mode into the recording mode (present mode) which was designated by the key input at time point t1. When the pause key is pressed at time point t3, while the VTR is in the mode transition period, the pause mode is invalid for the final mode (stop mode), so that this key input is ignored, leaving the mode stack, the final mode and the visual indication unchanged. When the rewind key is pressed at time point t4, while the VTR is in the mode transition period, the rewind mode is valid for the final mode (stop mode), so that 'REW' (rewind mode) is stacked in the second stage of the mode stack and the final mode and the visual indication thereof are made the rewind mode. However, the VTR itself is still in the process of changing its operational mode into the recording mode (present mode) which was designated by the key input at time point t1. When the stop key is pressed at time point t5 while the VTR is in the mode transition period, the stop mode is valid for the final mode (rewind mode), so that 'STOP' (stop mode) is stacked in the third stage of the mode stack. At that time, since the same 'STOP' (stop mode) is also stacked in the first stage of the mode stack, 'STOP' and 'REW' stacked respectively in the first and second stages of the mode stack are removed and 'STOP' stacked in the third stage of the mode stack is transferred to the first stage of the mode stack. This processing is an example of what may be called 'optimization'. In that case, the final mode and the visual indication thereof are made the stop mode. When the playback key is pressed at time point t6, while the VTR is in the mode transition period, the playback mode is valid for the final mode (stop mode), so that 'PB' (playback mode) is stacked in the second stage of the mode stack and the final mode and the visual indication thereof are made the playback mode. When the fast forward key is pressed continuously from the time point t7 while the VTR is in the mode transition period, the fast forward mode is valid for the final mode (playback mode). At the same time, upon the playback mode, the fast forward key is pressed in the cue mode, so that 'CUE' (cue mode) is stacked in the third stage of the mode stack and the final mode and the visual indication thereof are made the cue mode. At time point t8, when the VTR finishes changing its operational mode into the recording mode designated by the key input at time point t1, the mode stack is checked. In this case, since 'STOP' is stacked in the first stage of the mode stack, this 'STOP' is set to the present mode and the VTR therefore starts changing its operational mode to the stop mode at time point t9 (approximately the same as t8). When it is confirmed that the operational mode of the VTR is to be changed to the stop mode, 'PB' stacked in the second stage of the mode stack is transferred to the first stage thereof and 'CUE' stacked in the third stage of the mode stack is transferred to the second stage thereof, making the third stage of the mode stack empty. When the VTR has finished changing its operational mode to the stop mode at time point t10, the mode stack is checked. In this case, since 'PB' is stacked in the first stage of the mode stack, this 'PB' is set to the present mode, so that the VTR starts changing its operational mode to the playback mode at time point t11 (approximately the same as t10). After it is confirmed that the operational mode of the VTR has been changed to the playback mode, 'CUE' stacked in the second stage of the mode stack is transferred to the first stage thereof, thus making the second stage of the mode stack empty. When the VTR has finished changing its mode to the playback mode at time point t12, the mode stack is checked. Since 'CUE' is stacked in the first stage of the mode stack, this 'CUE' is set to the present mode, so that the VTR starts changing its operational mode into the cue mode at time point t13 (approximately the same as t12). After it has been confirmed that the operational mode of the VTR has been changed to the cue mode, the mode stack is made empty. In this way, the VTR is placed in the cue mode after time point t13. While the operational mode of the VTR and mode data stacked in the mode stack are changed as described above, this will also be explained with reference to a general algorithm which is represented in the form of a flow chart in Figure 5. This algorithm is exemplified in the flow chart (Figure 5) of the program that the microcomputer forming the mode controller 2 (Figure 3) executes. The presence or absence of the command (key input) supplied by the operation key is checked, as represented at decisional step 21 in Figure 5. If the command exists, the processing of the microcomputer (mode controller 2) goes from step 21 to decisional step 22. Then, it is checked, as represented at decisional step 22, whether or not the key input of which the presence was confirmed at step 21 is valid for the final mode. The validity of the key input relative to the final mode is checked on the basis of a mode transition look-up table which forms, for example, Figure 6. Such a look-up table can be stored within a read only memory (ROM) which forms the mode controller 2 (Figure 3). This mode transition look-up table of Figure 6 reads as follows. If the recording key ('REC') is pressed when the final mode is, for example, the playback ('PB') mode, it is judged that this recording key is invalid for the final mode, however, if the pause key is pressed instead, it is judged that this pause key is valid for the final mode and the final mode is renewed to 'PB PAUSE' (playback pause mode). If the key input is judged to be valid as represented at decisional step 22, the processing of the microcomputer goes from step 22 to step 23. As represented at step 23, the final mode and the visual indication thereof are renewed at time point t4 shown, for example, in Figure 4 and in Figure 7 (reference letters A to E throughout Figures 7 to 11 respectively designate operational modes) in accordance with the mode transition look-up table of Figure 6. Then, the operational mode renewed is stacked in the mode stack. The processing of the microcomputer goes from step 23 to the next decisional step 31. It is checked, as represented at decisional step 31, whether or not a mode which is the same as the renewed final mode is stacked in the mode stack. If not, the processing of the microcomputer goes from step 31 to decisional step 33. If on the other hand the same mode is stacked in the mode stack, as for example shown at time point t5 in Figure 4 and as illustrated in Figure 8, the processing of the microcomputer goes from step 31 to the next step 32. As represented at step 32, the modes, beginning from the mode (B mode in the second stage) which is the same as the final mode renewed in the mode stack up to the mode (D mode) just one stage before the final stage of the mode stack, are removed as unnecessary modes and the final mode renewed is shifted to the prior stage of the mode stack. This processing forms a part of 'optimization'. Then, the processing of the microcomputer goes from step 32 (or step 31) to decisional step 33 where it is checked whether or not a mode which can be changed directly the final mode is stacked in the mode stack, thereby omitting unnecessary intermediate modes. If not, the processing of the microcomputer goes from step 33 to decisional step 41. If on the other hand such a mode is stacked in the mode stack, the processing of the microcomputer goes from step 33 to step 34. At step 34, as shown in Figure 9, the modes between the mode (B mode), which can be changed to the final mode, and the final mode (E mode) are removed and the final mode (E mode) is shifted to the stage of the mode stack subsequent to the mode which can be changed to the final mode (B mode). This processing also forms a part of 'optimization'. The processing of the microcomputer goes from step 34 (or step 33) to the next decisional step 41. Also, if the absence of a key input is determined, as represented at decisional step 21, or if the key input is invalid for the final mode, as represented at decisional step 22, the processing of the microcomputer goes directly from step 21 or 22 to the decisional step 41. At decisional step 41 the microcomputer checks whether the VTR is now changing its operational mode or has finished its mode changing. If the VTR is changing its operational mode, the processing of the microcomputer goes from step 41 to the next decisional step 42 where the micrcocomputer checks whether a mode which is the same as the present mode exists in the mode stack or not. If not, the processing of the microcomputer goes from step 42 to decisional step 44. If the same mode exists in the mode stack as represented at decisional step 42, as shown, for example, in Figure 10, the processing of the microcomputer goes from step 42 to step 43. As represented at step 43, the modes from the mode (A mode) of the first stage to the mode (C mode) which is the same as the mode which is under transition, are removed and the next mode (D mode) is shifted forward (to the first stage of the mode stack). This processing also forms a part of 'optimization'. Subsequently, the processing of the microcomputer goes from step 43 (or step 42) to the next decisional step 44 where it is checked whether or not there is a mode in the mode stack to which the present mode of the VTR in its transition period can be directly shifted, as for example, shown in Figure 11 (mode A can be shifted to mode D). If not, the processing of the microcomputer returns from step 44 to the decisional step 21. If such a mode exists in the mode stack the processing goes from step 44 to step 45. At step 45 the modes from the mode in the first stage to the mode (C mode) which is located just before the transferrable mode are removed and the succeeding mode (D mode) is shifted forward in the mode stack, so that 'optimization' is carried out. Then, the processing of the microcomputer goes back to step 21. If it is determined, as represented at decisional step 41, that the VTR has already finished changing its operational mode, the processing of the microcomputer goes from step 41 to decisional step 51. It is then checked, as represented at decisional step 51, whether or not any mode command remains stacked in the mode stack. If no mode is stacked in the mode stack, the processing of the microcomputer goes back from step 51 to step 21. If, on the other hand, one or more modes remain stacked in the mode stack, the processing of the microcomputer goes from step 51 to step 52 where the present mode of the VTR begins to change into the mode of the first stage in the mode stack. If it is confirmed that the change of the operational mode of the VTR is started, the mode of the first stage in the mode stack is removed and the next mode is shifted forward. Subsequently, the processing of the microcomputer goes back from step 52 to step 21. Therefore, according to the above described processing routine, the operational mode of the VTR is changed as, for example, shown in Figure 4. Alternatively, the presence or absence of the key input can be checked by executing the condition determining command instead of using the mode transition look-up table, as represented at decisional step 21. Another embodiment of mode processing circuit according to the present invention will now be described. This embodiment is similar to that shown in Figure 3 but in this embodiment, a mode transition look-up table and a mode transition vector look-up table shown, for example, in Figures 12 and 13 are provided within a ROM which forms the mode controller 2 (Figure 3). When the operation key of the key input means 3 or the operation key of the remote controller (not shown) is pressed, the input data or command is similarly supplied to the mode controller 2, in which it is processed. The processed result or data therefrom is then supplied to the control section 1, whereby the control section 1 is so operated as to place, for example, the VTR in the predetermined operational mode and the operational mode in which the VTR is just placed is visually indicated by the mode indicating means 5 similar to the first embodiment. Figure 14 illustrates an example in which the operational mode of the VTR is changed with the command supplied by the operation key using this second embodiment. In the description below, 'present mode' and 'final mode' are respectively defined as follows: the 'present mode' indicates the mode in which the VTR is now placed at a certain time point and also indicates the next operation mode of the VTR during the mode transition period; and the 'final mode' indicates the mode stored last in the mode controller 2 at that time point. The validity of the operation key pressed is determined depending upon whether the operation key pressed is valid for the final mode or not. The mode indicating means 5 visually indicates the final mode. The areas in which the present mode and the final mode are stored are formed within the RAM of the microcomputer forming the mode controller 2. In this embodiment, since the VTR is placed in the stop mode before time point t1, the present mode at time point t1 is the stop mode. Also, the final mode and the visual indication thereof are the stop mode. When the reproducing key is pressed at time point t1 in Figure 14, the mode transition table in Figure 12 is looked up by the microcomputer. This mode transition look-up table in Figure 12 indicates whether or not, when the operation key is pressed, the key input is valid for the final mode at that time point or if the key input is valid for the final mode, to which mode the mode is to be transferred. Since the final mode is the stop mode at time point t1 and the key input is the playback mode, it will be clear from the mode transition look-up table of Figure 12 that the operation mode of the VTR should be 'PB' (playback mode). Accordingly, the final mode and the visual indication thereof are made the playback mode from time point t1. Further, the VTR starts changing its operational mode from the stop mode into the playback mode and the present mode is made the playback mode. When the stop key is pressed at time point t2 while the VTR is in the mode transition period as shown in Figure 14, the mode transition look-up table of Figure 12 is looked up. Since this mode transition look-up table of Figure 12 indicates that the mode should be shifted to the stop mode, the final mode and the visual indication thereof are made the stop mode. However, during this period, the VTR itself continues changing its operation mode to the playback mode (present mode) which was designed by the key input at time point t1. Further, when the recording key is pressed at time point t3 during this mode transition period of the VTR, the same mode transition table (Figure 12) is looked up. This mode transition look-up table of Figure 12 indicates that the mode should be shifted to the recording mode. Thus, the final mode and the visual indication thereof are made the recording mode. However, during this period, the VTR itself continues changing its operational mode into the playback mode which was designated by the key input at time point t1. When at time point t4 the operational mode of the VTR has finally changed into the playback mode, the mode transition vector table forming Figure 13 is looked up. This mode transition vector look-up table of Figure 13 indicates whether or not at that time the VTR should further change its operational mode and the mode into which the VTR should change its operational mode. At that time (at time point t4 in Figure 14), since the present mode is the playback mode and the final mode is the recording mode, the mode transition vector look-up table of Figure 13 indicates that the mode of the VTR should be 'PB PAUSE' (playback pause mode). Accordingly, the VTR starts changing its operational mode to the playback pause mode from time point t4 and the present mode is also changed into the playback pause mode. When the mode transition to the playback pause mode has ended at time point t5, the same mode transition vector table of Figure 13 is looked up. At time point t5 in Figure 14, since the present mode is 'PB PAUSE' (playback pause mode) and the final mode is 'REC' (recording mode), it will be clear from the mode transition vector look-up table of Figure 13 that the mode should be 'REC PAUSE' (recording pause mode) next. Accordingly, the VTR starts changing its operational mode into the recording pause mode at time point t5 and the present mode is also made the recording pause mode. When the mode transition of the VTR to the recording pause mode is ended at time point t6 in Figure 14, the mode transition vector table of Figure 13 is looked up again. At time point t6 in Figure 14, since the present mode is the recording pause mode and the final mode is the recording mode, the mode transition vector look-up table of Figure 13 indicates that the next mode should be the recording mode. Accordingly, the VTR starts changing its operational mode into the recording mode at time point t6, and the present mode is also made the recording mode. When the mode transition to the recording mode is ended at time point t7, the mode transition vector table of Figure 13 is looked up. At time point t7 in Figure 14, since the present mode and the final mode are both the recording mode and equal to each other, the operational mode of the VTR is not changed any more. Accordingly, the VTR remains placed in the recording mode after time point t7. While the operational mode of the VTR is changed as described above, this mode changing operation of the VTR will be similarly explained by a general algorithm which is represented in a flow chart forming Figure 15. In other words, this algorithm forms the flow chart (Figure 15) of a program that the microcomputer forming the mode controller 2 (Figure 3) executes. Firstly, the presence or absence of a command supplies by pressing an operation key is checked as represented at decisional step 121. If the presence of the command is confirmed at step 121, the processing of the microcomputer (mode controller 2) goes from step 121 to the next decisional step 122. It is checked as represented at decisional step 122 by the mode transition look-up table of Figure 12 whether or not the key input (command) whose existence was checked at step 121 is valid for the final mode. It is is judged as represented at decisional step 122 that the key input is valid for the final mode, the processing of the microcomputer goes from step 122 to step 123, in which the final mode and the mode visual indication thereof are renewed in accordance with the mode transition look-up table of Figure 12, as represented at time point t1 in Figure 14. Then, the processing of the microcomputer goes from step 123 to the next decisional step 131. Also, if the absence of the key input is confirmed as represented at decisional step 121 or it is judged as represented at decisional step 122 that the key input is invalid for the final mode, the processing of the microcomputer goes directly from steps 121 and 122 to the next decisional step 131. It is checked, as represented at decisional step 131, whether the mode of the VTR is still shifting or it has already finished. If the mode of the VTR is shifting, the processing of the microcomputer goes back from step 131 to step 121. Accordingly, the steps 121 to 123 and the step 131 are repeatedly executed during the period from the time point t1 to the time point t4. If on the other hand it is judged, as represented at decisional step 131, that the mode transition of the VTR has already ended, the processing of the microcomputer goes from step 131 to the next decisional step 132. There, it is checked whether or not the present mode is the same as the final mode. If they are not the same, the processing of the microcomputer goes from step 132 to step 133. As represented at step 133, the operation mode to which the mode of the VTR should be newly shifted is determined with reference to the mode transition vector look-up table of Figure 13, whereby the present mode is renewed to the new operation mode determined. Then, the processing of the micrcomputer goes from step 133 to step 134. The VTR starts changing its operation mode to the present mode, which was renewed as represented at step 133, as represented at step 134, and the processing of the microcomputer goes back from step 134 to step 121. Consequently, the steps 131 to 134 are executed at time points t4, t5 and t6 in the mode transition diagram forming Figure 14, respectively. If it is judged, as represented at decisional step 132, that the present mode and the final mode are the same, the processing of the microcomputer goes back from step 132 to step 121. Accordingly, this processing of the microcomputer is executed at time point t7. According to the processing routine in Figure 15 as described above, the operational mode of the VTR is changed as, for example, shown in the mode transition diagram of Figure 14. It will be appreciated that the presence or absence of the command supplied by the operation key can be checked by using a condition judging command instead of using the above mentioned mode transition look-up table, as represented at decisional step 122 in Figure 15. The present invention is not limited to a VTR as mentioned above, but can be applied to various kinds of multiple operational mode electronic apparatus such as a tape deck, a video disc player, or a CD player which take a significant time to change their operation modes. With embodiments of the present invention, since the transition mode to which the mode of the multiple operational mode electronic apparatus should be transferred is stacked in the mode stack and is optimized, the operational mode of the multiple operational mode electronic apparatus can be changed to the desired operational mode in the shortest period of time from the time point at which the operation key is pressed. If the key input is valid, the reception of the key input and the visual indication of the operational mode can be immediately executed and the transition of the operational mode of the electronic apparatus can be carried out in the shortest period of time, so that the user never feels that the electronic apparatus is taking a great deal of time to change its operational mode and thus, the apparent time required by such a mode transition can be removed. Moreover, the operational mode can be changed to the same final operational mode by pressing the operation key at any time. Furthermore, even if any number of operation keys are pressed, since the operational mode to which the mode of the electronic apparatus should be shifted can be made optimum in accordance with the mode transition vector look-up table, the operational mode can be changed to the desired mode in the minimum number of mode transitions at the time point at which the operation key is pressed. In addition, since the optimization is not required, the processing program to be executed by the mode controller 2 can be simplified and the execution of the program does not take a lot of time. Also, the mode stack area becomes unnecessary.

Claims: A method of changing the operational mode of a multiple operational mode electronic apparatus (1) during a mode transition period in which the operational mode is transferring in a present operational mode, that is the next operational mode into which the apparatus is being shifted, and subsequently transferring to a final operational mode, that is the last operational mode in a sequence of operational modes corresponding to previously received, valid command signals and stored in an electronic memory device (2), the method comprising the steps of: receiving an input command signal; judging whether said input command signal is valid or not in view of the final operational mode; redetermining the final operational mode in accordance with said input command signal if valid and storing said redetermined final operational mode; determining a sequence of operational mode changes from said present operational mode to said redetermined final operational mode including optimizing the stored sequence of operational modes by comparison tests according to predetermined criteria between the stored operational modes and the redetermined final operational mode and between the stored operational modes and the present operational mode and eliminating operational modes found to be unnecessary as a result of said tests; and executing said sequence of operational mode changes until said present operational mode has been changed to said redetermined final operational mode. A method according to claim 1 wherein said steps of determining and executing are performed by electronically accessing a transition vector look-up table stored in an electronic memory device (2). A method according to claim 1 wherein said step of judging the validity of the input command signal comprises determining that the following input commands are invalid with respect to the following corresponding final modes: Final Mode Input Mode STOP STOP FAST FORWARD FAST FWD, PAUSE, REC REWIND REW, PAUSE, REC PLAYBACK FAST FWD, REW, PB, REC PLAYBACK PAUSE FAST FWD, REW RECORD FAST FWD, REW, PB, REC RECORD PAUSE FAST FWD, REW, PB, REC A mode processing circuit for a multiple operational mode electronic apparatus (1), the circuit comprising: means (2) for receiving an input command signal during a mode transition period in which the operational mode is transferring in a present operational mode, that is the next operational mode into which the apparatus is being shifted, and subsequently transferring to a final operational mode, that is the last operational mode in a sequence of operational modes corresponding to previously received valid command signals, judging whether said input command signal is valid or not in view of the final operating mode and redetermining the final operational mode of said electronic apparatus (1) in accordance therewith; transition vector look-up table means (2) for determining a new operational mode to which the operational mode of said electronic apparatus (1) is to be shifted next in response to the redetermined final operational mode and a mode to which the operational mode of said electronic apparatus (1) was shifted; and means (2) for changing the operational mode of said electronic apparatus (1) to said new operational mode thus determined, and for executing a sequence of mode changes thus determined until said redetermined final operational mode is achieved. A mode processing circuit according to claim 4 wherein said transition vector look-up table means (2) comprises an electronic memory (2) which stores the following transition mode commands: Present Mode Final Mode Transition Command STOP PB PAUSE STOP TO PB FAST FORWARD PB PAUSE FAST FWD TO PB FAST FORWARD REC FAST FWD TO STOP FAST FORWARD REC PAUSE FAST FWD TO STOP REWIND PB PAUSE REC TO PB REWIND REC REW TO STOP REWIND REC PAUSE REW TO STOP PLAYBACK REC PB TO PB PAUSE PLAYBACK REC PAUSE PB TO PB PAUSE PLAYBACK PAUSE FAST FWD PB PAUSE TO STOP PLAYBACK PAUSE REW PB PAUSE TO STOP PLAYBACK PAUSE REC PB PAUSE TO REC PAUSE PLAYBACK PAUSE REC PAUSE PB PAUSE TO REC PAUSE A mode processing circuit according to claim 4 or claim 5 wherein said transition vector look-up table means (2) comprises an electronic memory (2) which stores the following transition mode commands: Present Mode Final Mode Transition Command RECORD REW REC TO STOP RECORD FAST FWD REC TO STOP RECORD PB REC TO STOP RECORD PB PAUSE REC TO STOP RECORD PAUSE REW REC PAUSE TO STOP RECORD PAUSE FAST FWD REC PAUSE TO STOP RECORD PAUSE PB REC PAUSE TO STOP RECORD PAUSE PB PAUSE REC PAUSE TO STOP

Inventors: ITO KENICHI, ITO RYO, IWAMOTO KOJI, KISHITAKA YURIKO, MATSUNO KATSUMI, MIURA TORU, SHIMADA KEIICHIRO, ITO, KENICHI, ITO, RYO, IWAMOTO, KOJI, KISHITAKA, YURIKO, MATSUNO, KATSUMI, MIURA, TORU, SHIMADA, KEIICHIRO, ITO, KENICHI C/O PATENTS DIVISION, ITO, RYO C/O PATENTS DIVISION, IWAMOTO, KOJI C/O PATENTS DIVISION, KISHITAKA, YURIKO C/O PATENTS DIVISION, MATSUNO, KATSUMI C/O PATENTS DIVISION, MIURA, TORU C/O PATENTS DIVISION, SHIMADA, KEIICHIRO C/O PATENTS DIVISION
Applicants: SONY CORP, SONY CORPORATION
Application year: 1987
Main classification: G11B15
IPC codes: G11B15