Abstract:
An information reproducing apparatus is disclosed which recovers a video signal and an audio signal from input information, displays the video signal on a display unit, and reproduces the audio signal by a loudspeaker. When restriction information extracted from a broadcast signal indicates restrictions on video display, reproduction restrictions based on the restriction information are imposed on video display by the display unit. When the restriction information indicates restrictions on audio reproduction, reproduction restrictions based on the restriction information are imposed on audio reproduction by the loudspeaker.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application is based upon and claims the benefit of priority from prior Japanese Patent Application No. 2004-194933, filed Jun. 30, 2004, the entire contents of which are incorporated herein by reference.  
       BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates to an information reproducing apparatus applicable to a portable broadcast receiving terminal by way of example and a control method therefor, and more particularly to improvements for use in facilities such as buildings, railroads, etc.  
         [0004]     2. Description of the Related Art  
         [0005]     In recent years, mobile phones have been subject to an increase in their functions and performance, and small-sized, lightweight and large-capacity recording media, such as mini disks (MDs), have been developed. Accordingly, portable information reproducing terminals adapted to reproduce information recorded on such recording media have come into wide spread use.  
         [0006]     At present, in addition to satellite digital broadcasting and terrestrial digital broadcasting, satellite-based mobile broadcasting is planned, the main candidates for services of which are mobiles such as portable broadcast receiving terminals. In terrestrial digital broadcasting as well, low-data-rate broadcasting (one-segment broadcasting) is planned, the main candidates for services of which are mobiles.  
         [0007]     Portable information reproducing apparatuses, exemplified by the aforementioned mobile phones, information reproducing terminals, and broadcast receiving terminals, are allowed for use in specific facilities, such as public buildings, railroads, etc., and therefore need to limit volume or the like for appropriate use in such facilities.  
         [0008]     However, when users limit the volume, the volume set varies from user to user; that is, at present, no unified volume control is performed. At present, in many cases, there is no indication of to which degree the volume is to be limited to in the facilities. In most cases, the users merely limit the volume according to their own judgment.  
         [0009]     For example, Japanese Unexamined Patent Publication No. 2002-123801 discloses a reproducing apparatus adapted to check the legality of reproducing contents or restrict reproduction according to conditions of reproducing equipment, date and time or term, area, etc. However, this reproducing apparatus employs condition information recorded on a recording medium to check the legality of reproducing content or restrict reproduction and is therefore difficult to meet conditions which vary from facility to facility.  
       BRIEF SUMMARY OF THE INVENTION  
       [0010]     According to an embodiment of the present invention, there is provided an information reproducing apparatus comprising: a receiving unit which receives a broadcast signal; an extraction unit which extracts restriction information from the broadcast signal received by the receiving unit; a processing unit which recovers a video signal and an audio signal from input information; a display unit which displays the video signal recovered by the processing unit; a loudspeaker which reproduces the audio signal recovered by the processing unit; and a control unit which, when the restriction information extracted by the extraction unit indicates restrictions on video display, imposes reproduction restrictions based on the restriction information on display of the video signal by the display unit, and, when the restriction information extracted by the extraction unit indicates restrictions on audio reproduction, imposes reproduction restrictions based on the restriction information on audio reproduction by the loudspeaker.  
         [0011]     According to another embodiment of the present invention, there is provided a method of controlling an information reproducing apparatus equipped with a processing unit which recovers a video signal and an audio signal from input information, a display unit which displays the video signal recovered by the processing unit, and a loudspeaker which reproduces the audio signal recovered by the processing unit, comprising the steps of: receiving a broadcast signal; extracting restriction information from the received broadcast signal; when the extracted restriction information indicates restrictions on video display, imposing reproduction restrictions based on the restriction information on display of the video signal by the display unit; and when the extracted restriction information indicates restrictions on audio reproduction, imposing reproduction restrictions based on the restriction information on audio reproduction by the loudspeaker. 
     
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING  
       [0012]     The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention, and together with the general description given above and the detailed description of the embodiments given below, serve to explain the principles of the invention.  
         [0013]      FIG. 1  is a perspective view of a broadcast receiving apparatus according to an embodiment of the present invention;  
         [0014]      FIG. 2  is a block diagram of a signal processing system used in the broadcast receiving apparatus of the embodiment;  
         [0015]      FIG. 3  is a flowchart illustrating a part of the main operation of the broadcast receiving apparatus of the embodiment;  
         [0016]      FIG. 4  is a flowchart illustrating the remainder of the main operation of the broadcast receiving apparatus of the embodiment;  
         [0017]      FIG. 5  shows a modification of the broadcast receiving apparatus of the embodiment;  
         [0018]      FIG. 6  is a flowchart illustrating a part of the main operation of the modification of the broadcast receiving apparatus of the embodiment;  
         [0019]      FIG. 7  is a flowchart illustrating the remainder of the main operation of the modification of the broadcast receiving apparatus of the embodiment; and  
         [0020]      FIG. 8  is a flowchart illustrating the operation of another modification of the broadcast receiving apparatus of the embodiment. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0021]     An embodiment of the present invention will be described in detail below with reference to the accompanying drawings.  FIG. 1  is an exterior view of a broadcast receiving apparatus  11  as an information reproducing apparatus according to this embodiment. The broadcast receiving apparatus  11  has a portable, thin box-like housing  12 .  
         [0022]     The housing  12  of the broadcast receiving apparatus  11  is provided on the front  12   a  with a display unit  13  and a control panel  14  and on one side  12   b  with a loudspeaker  15  and an audio-signal outputting connector  16  for connecting headphones or the like.  
         [0023]      FIG. 2  shows a signal processing system in the broadcast receiving apparatus  11 . Broadcast signals received by an antenna  17  built into the housing  12  are applied to a tuner  18  where a signal on a selected channel is selected.  
         [0024]     The broadcast signal selected by the tuner  18  is applied to a video and audio processing unit  19  where a demodulation process is carried out on the signal to recover a video signal and an audio signal. The video signal is then applied to a display control unit  20  where it is converted into a format displayable on the display unit  13 . The resulting video signal is applied to the display unit  13  and displayed.  
         [0025]     The audio signal recovered in the video and audio processing unit  19  is applied to an amplifier  21  where it is amplified. The amplified audio signal is then applied to the loudspeaker  15  to provide sound reproduction. The audio signal recovered in the video and audio processing unit  19  is also applied to the connector  16  for providing audio output to the outside.  
         [0026]     The broadcast receiving apparatus  11  has its all operations including the receiving operation described above controlled by a controller  22 . The controller  22  has a central processing unit (CPU) not shown built in and receives operation information from the control panel  14  to control each component so that the contents of operations are reflected.  
         [0027]     In this case, the controller  22  utilizes a memory unit  23 . The memory unit  23  includes a read-only memory (not shown) stored with a control program executed by the CPU in the controller  22 , a read/write memory (not shown) serving as a working area for the CPU, and a nonvolatile memory (not shown) stored with various pieces of setting information and control information.  
         [0028]     The broadcast receiving apparatus  11  has another antenna  24  built in to receive broadcast signals from various facilities, such as buildings, railroads, roads, etc., each of the broadcast signals containing information associated with corresponding facilities.  
         [0029]     A broadcast signal received by the antenna  24  is demodulated in a receiving unit  25  and then applied to a restriction information extraction unit  26 . The restriction information extraction unit  26  extracts restriction information indicating reproduction restrictions from the input signal and then outputs it to the controller  22 . Thereby, the controller  22  is allowed to control each component so as to meet restriction information transmitted from the corresponding facilities. Thus, reproduction restrictions which vary from facility to facility are realized.  
         [0030]      FIGS. 3 and 4  show a flowchart illustrating a reproduction restriction operation performed by the broadcast receiving apparatus  11  on the basis of a broadcast signal transmitted from facilities. The process is started in step S 1 . Upon receiving a broadcast signal from facilities, the controller  22  makes a determination of whether or not restriction information has been obtained from the restriction information extraction unit  26 .  
         [0031]     When the determination is that no restriction information is obtained (NO), the controller  22  makes a determination of whether or not a volume control operation is performed on the control panel  14 . When the determination is that no volume control operation is performed (NO), the process is completed (step S 6 ).  
         [0032]     If the determination in step S 4  is that the volume control operation has been performed (YES), the controller  22  controls, in step S 5 , the gain of the amplifier  21  to conform to the volume control operation and completes the process (step S 6 ).  
         [0033]     If the determination in step S 3  is that the restriction information has been obtained (YES), the controller  22  makes a determination, in step S 7 , of whether or not the restriction information allows video display. If the determination is that video display is allowed (YES), the controller  22  controls, in step S 8 , the display control unit  20  so as to allow the display unit  13  to make video display. Otherwise, the controller controls the display control unit  20  so as not to display the video signal on the display unit  13 , thereby stopping video display by the display unit  13 .  
         [0034]     In step S 10  subsequent to step S 8  or step S 9 , the controller  22  makes a determination of whether or not the restriction information allows audio reproduction by the loudspeaker  15 . If the determination is that audio reproduction is allowed (YES), the controller  22  controls, in step S 1 , the amplifier  21  so as to allow audio reproduction by the loudspeaker  15 .  
         [0035]     If the determination in step S 10  that audio reproduction is not allowed (NO), the controller  22  controls the amplifier  21  so as not to cause the loudspeaker  15  to reproduce audio and then completes the process (step S 6 ). In that case, since an audio signal is output from the connector  16 , audio reproduction through headphones is allowed.  
         [0036]     In step S 13  subsequent to step S 11 , the controller  22  makes a determination of whether or not volume is limited. If the determination is that the volume is limited (YES), the controller  22  controls, in step S 14 , the amplifier  21  so as to keep the volume to within a specified range and then completes the process (step S 6 ).  
         [0037]     Specifically, even if a volume control operation is performed on the control panel  14 , the controller  22  controls the amplifier  21  so that the volume is kept to within the specified range. Thereby, even if the currently set volume is beyond the specified range, it is automatically kept to within the specified range. In this case, it is possible to hold the volume set prior to restriction and automatically restore that volume when the restriction is removed.  
         [0038]     If the determination in step S 13  is that the volume is not limited (NO), the controller  22  controls, in step S 15 , the gain of the amplifier  21  so that the volume becomes the one set by the volume control operation on the control panel  14  and then completes the process (step S 6 ).  
         [0039]     Thereby, if the volume has been limited, the volume is automatically restored to the level before it is limited.  
         [0040]     According to the embodiment described above, since the reproduction of video or audio is automatically restricted on the basis of restriction information contained in a broadcast signal from facilities, information reproduction can be made to automatically conform to reproduction conditions which vary from facility to facility. Therefore, the broadcast receiving apparatus can be made much easier to handle.  
         [0041]     If the user leaves facilities that disable receiving a broadcast signal, the reproduction restrictions are automatically removed. Even in this respect, the broadcast receiving apparatus can be made much easier to handle.  
         [0042]     If, when video display is allowed and audio reproduction by the loudspeaker  15  is prohibited, character information is contained in a received broadcast signal, a character on-screen display can be displayed on the display unit  13 .  
         [0043]     If an upper limiting value for volume is set in restriction information, then the volume can be kept below the upper limiting value even if a volume control operation is performed.  
         [0044]     Moreover, if restriction information contains a video signal displaying a message indicating its contents, the message can be displayed on the display unit  13  with superimposition upon a video signal obtained from a broadcast signal. It is also possible to cause the controller  22  to produce a video signal corresponding to a message indicating the contents of restriction information and display the message on the display unit  13  with superimposition upon a video signal obtained from a broadcast signal.  
         [0045]     If, when restriction information prohibits both video display and audio reproduction by the loudspeaker  15 , a message to the effect that video display and audio reproduction cannot be made according to the restriction information, the user will not mistake such a situation for a failure.  
         [0046]     When restriction information contains information indicating a recommended broadcast channel in facilities, it is also possible to automatically select that broadcast channel. In that case, by displaying the presence of a recommended broadcast channel and its channel number on the display unit  13  prior to selection of the broadcast channel, it becomes possible to prompt the user to select that broadcast channel.  
         [0047]     When restriction information contains information to prohibit the use of the broadcast receiving apparatus  11  in facilities, the power to the broadcast receiving apparatus may be turned off.  
         [0048]     If restriction information contains information to identify facilities, the number of times the user visited the facilities can be stored by counting the number of times reproduction restrictions were removed. In addition, the dates and times of visit to the facilities can also be stored. In this way, the user will be allowed to receive service the facilities offer on the basis of the number of visits during a certain period.  
         [0049]     It is also possible to allow restriction information to contain time information and carry out reproduction restrictions only during a particular period of time. Furthermore, it is also possible to carry out reproduction restrictions the contents of which vary from period to period.  
         [0050]     A modification of the embodiment described above will be described next. As shown in  FIG. 5 , two oscillators  28  and  29  are placed along the direction of people coming and going indicated by arrows A and B at a doorway  27   a  of a building  27 . The oscillators  28  and  29  produce signals of different frequencies. In this case, the oscillator  28  is located in the proximity of the doorway  27   a,  while the oscillator  29  is located distant from the doorway.  
         [0051]     When the user with the broadcast receiving apparatus  11  enters the building  27  through the doorway  27   a  as indicated by arrow B, the broadcast receiving apparatus will first receive a signal from the oscillator  28  and then receive a signal from the oscillator  29 .  
         [0052]     When the user goes out of the building  27  through the doorway  27   a  as indicated by arrow A, the broadcast receiving apparatus will first receive the signal from the oscillator  29  and then receive the signal from the oscillator  28 .  
         [0053]     The signals from the oscillators  28  and  29  are received by the antenna  24  and then applied through the receiving unit  25  to the restriction information extraction unit  26  where their frequencies are discriminated. The result of discrimination is sent to the controller  22 . Thus, the controller  22  is allowed to judge from which of the oscillators  28  and  29  the signal is being received at present.  
         [0054]     Upon judging that the signal from the oscillator  28  was first received and then the signal from the oscillator  29  was received, the controller  22  judges that the user has entered the building  27  and is subject to reproduction restrictions through restriction information which is broadcast in the facilities.  
         [0055]      FIG. 6  is a flowchart illustrating the operation when the broadcast receiving apparatus is subject to reproduction restrictions after judging that the user has entered the building  27 . When the process is started (step S 16 ), the controller  22  makes, in step S 17 , a determination of whether or not the signal from the oscillator  28  has been received. If the determination is that the signal has not been received (NO), the process is completed (step S 20 ).  
         [0056]     If the determination is that the signal from the oscillator  28  has been received (YES), the controller  22  makes, in step S 18 , a determination of whether the signal from the oscillator  29  has been received. If the determination is that the signal has not been received (NO), the process is completed (step S 20 ).  
         [0057]     If, on the other hand, the determination in step S 18  is that the signal from the oscillator  29  has been received (YES), the controller  22 , in step S 19 , starts reproduction restrictions associated with the facilities and then completes the process (step S 20 ).  
         [0058]     Upon judging that the signal from the oscillator  29  was first received and then the signal from the oscillator  28  was received, the controller  22  judges that the user has gone out of the building  27  and then removes the reproduction restrictions based on restriction information which is broadcast in the facilities.  
         [0059]      FIG. 7  is a flowchart illustrating the operation when the broadcast receiving apparatus removes the reproduction restrictions after judging that the user has gone out of the building  27 . When the process is started (step S 21 ), the controller  22  makes, in step S 22 , a determination of whether or not the signal from the oscillator  29  has been received. If the determination is that the signal has not been received (NO), the process is completed (step S 25 ).  
         [0060]     If the determination is that the signal from the oscillator  29  has been received (YES), the controller  22  makes, in step S 23 , a determination of whether the signal from the oscillator  28  has been received. If the determination is that the signal has not been received (NO), the process is completed (step S 25 ).  
         [0061]     If, on the other hand, the determination in step S 23  is that the signal from the oscillator  28  has been received (YES), the controller  22  removes the reproduction restriction associated with the facilities and then completes the process (step S 25 ).  
         [0062]     According to the above operation, the broadcast receiving apparatus carries out reproduction restrictions associated with facilities by detecting that the user has entered the building  27  and removes the reproduction restriction by detecting that the user has gone out of the building, thus allowing reliable reproduction restriction to be carried out. For example, it becomes possible to prevent a malfunction such that reproduction restrictions are carried out as a result of receiving leakage restriction information though the user is outside the building  27 .  
         [0063]      FIG. 8  shows another modification of the embodiment described above. In  FIG. 8 , the corresponding steps to those in  FIG. 6  are denoted by like reference numerals. The controller  22  makes, in step S 26 , a determination of whether or not a certain period has lapsed after the start of reproduction restrictions in step S 19 . If the determination is that the certain period has lapsed (YES), the controller  22  removes the reproduction restrictions in step S 27  and then completes the process (step S 20 ). Thereby, the reproduction restrictions are allowed only for a certain period after the user has entered the building  27 .  
         [0064]     Although the embodiment and modifications have been described in terms of a broadcast receiving apparatus, the invention can be widely applied to mobile phones, recording and reproducing equipment, etc.  
         [0065]     The present invention is not limited to the embodiments described above. At the stage of practice of the invention, constituent elements can be embodied in modified forms without departing from the scope thereof. The constituent elements disclosed in the above embodiments can be combined appropriately to form various inventions. For example, some elements may be removed from all the constituent elements shown in the embodiments. In addition, the constituent elements in the difference embodiments may be combined appropriately.  
         [0066]     Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.