Abstract:
A surround sound effect control device includes a plurality of sound signal sources each for producing a sound signal, a sound source selection signal generator for generating a sound source selection signal indicative of one sound sources, and a plurality of surround effect circuits for modifying the sound signal. A memory is provided for storing data identifying one surround effect circuit correspondingly to each of the sound sources. A first switching arrangement is provided for selecting one of the plurality of sound sources in response to the sound source selection signal, and a second switching arrangement is provided for selecting one surround effect circuit in response to the data read from the memory.

Description:
This application is a continuation of application Ser. No. 07/729,647 filed Jul. 15, 1991, now abandoned. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a surround sound effect control device for selecting one of a plurality of surround sound effect circuits and, more particularly, to a surround sound effect control device for use in a television set. 
     2. Description of the Prior Art 
     Conventionally, a surround sound effect control device is provided in the audio device to allow the user to vary the reproduced sound effect according to his desire. 
     An example of a conventional surround effect control device is shown in FIGS. 4. Reference numeral 1 is a sound signal source selection circuit for selecting a signal source from a plurality of signal sources TV, V1, V2, and V3 by a source switch SW1 in response to the sound signal selection signal SA. The selected signal S is transmitted through a line L1. The sound sources are, for example, a television set TV, a first video cassette recorder V1, a second video cassette recorder V2, and a third video cassette recorder V3. 
     Reference numeral 8 is a surround effect pattern selection circuit for selecting one of a plurality of surround sound effect patterns by surround switches SW2 and SW3 switched to one of surround effect circuits 3, 4, 5, 6, and 7 in response to a surround effect selection signal SS. Surround effect circuits 3, 4, 5, 6, and 7 can modify the sound signal S from line L1 to various signal patterns of surround sound effect, such as &#34;Dolby (Trade Mark) Surround&#34;, &#34;Movie Surround&#34;, &#34;Music Surround&#34;, &#34;Monaural Surround&#34;, and &#34;Surround-off&#34;. The modified sound signal S&#39; is output through a line L2. 
     Each of surround sound effect circuits 3, 4, 5, 6 and 7 is briefly described as follows. 
     The dolby surround circuit 3 reproduces a sound from a sound signal including a delay between left and right sound signals. 
     The movie surround circuit 4 reproduces a sound by the delay of a difference signal between left and right sound signals. 
     The music surround circuit 5 reproduces a sound in a manner similar to that of the movie surround circuit 4, but the amount of the delay is reduced. 
     The monaural surround circuit 6 generates the difference signal from the original sound signal and a delayed signal thereof. 
     In operation, when the sound selection signal SA is input to the sound source selection circuit 1, the selection switch SW1 turns to connect one of the sound signal sources TV, V1, V2, and V3 to line L1. For example, it is assumed that the switch SW1 is turned such that the sound source V1 is connected to line L1, as depicted in FIG. 4 by the input signal SA. 
     When the surround effect selection signal SS is input to a surround effect pattern selection circuit 8, the surround switches SW2 and SW3 are turned to connect line L1 to one of surround effect pattern circuits 3, 4, 5, 6, and 7 and further to line L2. For example, it is assumed that the switches SW2 and SW3 are turned such that lines L1 and L2 are connected through the movie surround circuit 4 by the surround effect selection signal SS. 
     In this case, the sound signal S from the first video cassette recorder V1 is input to the movie surround circuit 4 in which the original sound signal S is modified to signal S&#39;. The modified signal S&#39;, thus obtained, is further transmitted to a next stage through line L2. 
     However, according to the prior art surround sound effect control device, the selection of sound signal sources TV, V1, V2, and V3 and the selection of surround effect pattern circuits 3, 4, 5, 6, and 7 are performed individually, without any mutual relationship. Thus, it is necessary for the user to make two selections, one for the sound signal source and the other for surround sound effect pattern, every time when the viewing source is changed. For example, while watching a TV program which is usually served in a monaural sound, if a user switches to a video cassette recorder, associated with the sound signal source V1, it is necessary to further turn the switches SW2 and SW3 from the &#34;Monaural Surround&#34; to a position other than the &#34;Monaural Surround&#34; so that the stereo sound as usually served by the video cassette tape can be appreciated with its full performance. 
     SUMMARY OF THE INVENTION 
     The present invention has been developed with a view to substantially solving the above described disadvantages and has for its essential object to provide an improved surround sound effect control device. 
     In order to achieve the aforementioned objective, a surround sound effect control device comprises a plurality of sound signal sources each for producing a sound signal, a sound source selection signal generating means for generating a sound source selection signal indicative of one of the plurality of sound sources, and a plurality of sound signal modifying means for modifying the sound signal. The surround sound effect control device further comprises a memory means for storing data identifying one of the plurality of sound signal modifying means correspondingly to each of the sound sources, a first switching means for selecting one of the plurality of sound sources in response to the sound source selection signal, and a second switching means for selecting one of the plurality of sound signal modifying means in response to data read from the memory means. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     These and other objects and features of the present invention will become clear from the following description taken in conjunction with the preferred embodiment thereof with reference to the accompanying drawings throughout which like parts are designated by like reference numerals, and in which: 
     FIG. 1 is a block diagram of a surround sound effect control device according to a preferred embodiment of the present invention; 
     FIG. 2 is a table showing a relationship between a sound signal source, and a surround sound effect pattern stored in a memory device provided in the surround sound effect control device of FIG. 1; 
     FIG. 3 is a flow chart showing an operation of the surround sound effect device of FIG. 1; and 
     FIG. 4 is a block diagram of a conventional surround sound effect control device. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIG. 1, a surround sound effect control device according to an embodiment of the present invention is shown. 
     In FIG. 1, reference numeral 1 is a sound signal source selection circuit for selecting a signal source from a plurality of signal sources TV, V1, V2, and V3 by a source switch SW1 in response to the sound signal selection signal SA. The selected signal S is transmitted through a line L1. The sound sources are, for example, a television set TV, a first video cassette recorder V1, a second video cassette recorder V2, and a third video cassette recorder V3. 
     Reference numeral 8 is a surround effect pattern selection circuit for selecting one of a plurality of surround sound effect patterns by surround switches SW2 and SW3 switched to one of surround effect circuits 3, 4, 5, 6, and 7. Surround effect circuits 3, 4, 5, 6, and 7 can modify the sound signal S from line L1 to various signal patterns of surround sound effect, such as &#34;Dolby (Trade Mark) Surround&#34;, &#34;Movie Surround&#34;, &#34;Music Surround&#34;, &#34;Monaural Surround&#34;, and &#34;Surround-off&#34;. The modified sound signal S&#39; is output through a line L2. 
     The surround sound effect control device according to the embodiment of the present invention further comprises a memory 11 for storing a table carrying a number of different sound sources and corresponding pattern numbers identifying different surround sound effect. 
     Referring to FIG. 2, an example such a table stored in memory 11 is shown. In the table of FIG. 2, the sound signal sources are shown in the left column and the surround sound effect patterns with surround circuit numbers are shown in the right column. The sound signal sources and the surround sound effect patterns are stored in pairs to set desired combinations, and such combinations can be set by the user. For example, for the sound signal source TV, &#34;MONAURAL SURROUND&#34; is paired, and thus the surround circuit number &#34;6&#34; is assigned. 
     Referring back to FIG. 1, the memory 11 is coupled with a sound selection signal generator 12 and a surround selection signal generator 13. The sound selection signal generator 12 repeatedly or continuously generates the sound selection signal SA identifying the sound source which the user selects. For example, when the sound signal source TV is selected by a suitable selection key, such as provided in a remote controller (not shown), a sound selection signal SA representing the TV is produced not only at the time when the selection is made, but during the entire period while the sound signal source TV is selected. 
     The surround selection signal generator 13, on the other hand, generates one shot of a surround selection signal SS in response to each selection of surround sound effect pattern by a suitable selection key (not shown). 
     When the surround selection signal SS carrying an information of surround sound effect pattern which is newly selected by the user is input to the memory 11, the surround sound effect patterns for the current sound source stored in the memory 11 is rewritten by the newly selected surround sound effect pattern. When the data in the table is renewed, the surround switches SW2 and SW3 turn to connect the lines L1 and L2 to the newly selected surround circuit. 
     For example, it is assumed that the sound signal source V2 is currently selected, the sound selection signal generator 12 continuously generates the sound selection signal SA which identifies the second video recorder V2. The sound selection signal SA is input to the sound signal selection circuit 1 which thereupon turns and holds the sound switch S1 to connect the line 1 to the sound source V2. In the mean time, the sound selection signal SA is also input to the memory 11 for reading the data paired with the received sound selection signal SA, which is &#34;Music Surround (2)&#34; according to the table in FIG. 2. 
     Then, when the user newly selects one of surround effect patterns such as &#34;Dolby Surround (3)&#34; through a suitable key (not shown), the surround selection signal generator 13 generates a surround selection signal SS identifying &#34;Dolby Surround (3)&#34;. The surround selection signal SS is then applied to the memory 11 and is rewritten in the memory 11. Thus the data in memory 11 at the area corresponding to the presently selected signal source is rewritten, e.g. from &#34;Music Surround (2)&#34; to &#34;Dolby Surround (3)&#34; in the above example. Thus obtained data identifying &#34;Dolby Surround (3)&#34; is applied to the surround selection circuit 8, which then drives the surround switches SW2 and SW3 to connect the lines L1 and L2 to the dolby surround 3. 
     As described above, according to the present invention, a desired surround sound effect pattern for each sound source can be stored in the memory 11 through a simple operation. 
     Referring to FIG. 3, a flow chart of operation executed in the surround sound effect control device according to the present invention is shown. 
     As shown at step #1, the system including memory 11 is set in a condition ready to receive from source selection signal generator 12 a sound signal selection signal SA which represents one of signal sources TV, V1, V2 and V3. 
     At step #2, the presence of the sound signal selection signal SA is detected. When the sound selection signal SA is not present, the operation returns to step #1. When the sound selection signal SA is present, the operation goes to step #3. 
     At step #3, in response to the detection of the sound signal selection signal SA, the sound signal selection circuit 1 is activated so that the source switch SW1 is turned to connect one of signal sources TV, V1, V2, and V3 to the line L1. 
     At step #4, the sound selection signal SA is input to the memory 11 to designate a particular area in the memory 11 at which the surround sound effect pattern, such as the surround circuit number, is stored, and in turn, the data in the designated area is read out. 
     At step #5, the surround switches SW2 and SW3 are turned by the surround selection circuit 8 to connect one of surround circuits 3, 4, 5, 6, and 7 to the lines L1 and L2 in response to the surround circuit number read out from the memory 11. 
     At step #6, the system is set in a condition ready to receive from the surround selection signal generate 13 the surround selection signal SS which represents one of surround sound effect pattern selected by the user. 
     At step #7, the presence of the surround selection signal SS is detected. When the surround selection signal SS is not present, the operation returns to step #1. When the sound selection signal SS is present, the operation goes to step #8. 
     At step #8, the surround selection signal SS is input to the memory 11 and is used for overwriting the surround sound effect pattern data at the area corresponding to the currently selected sound signal source. 
     Thereafter, the operation returns to step #4 and follows steps #5, #6, and #7, and further to step #1, provided that no more surround selection signal SS is present. 
     From the above, it is clear that surround sound effect pattern is automatically selected based on the data stored in the memory 11, every time when the user changes the sound signal source. 
     Thus, the surround sound effect control device according to the present invention can release the user from such a bothersome task to re-select a favorable surround effect pattern for each of the sound sources. Furthermore, when the user desires to change the surround effect set to the current sound source, the user can easily change the same to a new surround effect pattern.