Patent Publication Number: US-8120713-B2

Title: Television apparatus

Description:
CROSS REFERENCES TO RELATED APPLICATIONS 
     The present invention contains subject matter related to Japanese Patent Application JP 2006-062689 filed in the Japan Patent Office on Mar. 8, 2006, the entire contents of which being incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a television apparatus. 
     2. Description of the Related Art 
     In recent years, there has been provided a television apparatus having a thin display panel including a liquid crystal display, a plasma display, or an organic electro-luminescence (organic EL) display, speakers for outputting sounds, and a housing accommodating therein the display panel and the speakers (see Japanese Patent Laid-open No. 2005-165350). 
     Since the speakers are incorporated in left, right, and lower sides of the display panel, however, the above television apparatus is subject to constraints on its design and limits on efforts to improve its design and aesthetic aspects. 
     SUMMARY OF THE INVENTION 
     The present applicant has proposed a television apparatus of novel design which gives the user an illusion of floating television display, as disclosed in Japanese Patent Laid-open No. 2005-333279. 
     The disclosed television apparatus includes a thin television display device, a first speaker disposed in the display device, a mount section placed in a site, a support mechanism projecting upwardly from the mount section and supporting the display device in an upper portion spaced from the mount section in a manner to allow the display device to change its attitude, and a second speaker disposed in the mount section. 
     The television apparatus allows the user to have an illusion of floating display device and supports the display device in a manner to allow the display device to change its attitude. If the display device is largely pulled forward of the mount section, then the distance from the ears of the user to the second speaker becomes greater than the distance from the ears of the user to the first speaker. 
     Therefore, the sound emitted from the first speaker reaches the ears of the user earlier than the sound emitted from the second speaker reaches the ears of the user, making the user feel uncomfortable and unnatural. 
     According to an embodiment of the present invention, it is desirable to provide a television apparatus which is effective to reproduce sounds of good quality. 
     According to an embodiment of the present invention there is provided a television apparatus including a thin display device, a mount section adapted to be placed in a site, a support mechanism projecting upwardly from the mount section and supporting the display device in an upper portion spaced from the mount section in a manner to allow the display device to change an attitude thereof, a first speaker mounted on the display device, a second speaker mounted on the mount section, a signal supply section for supplying a first audio signal to the first speaker and supplying a second audio signal to the second speaker, and a signal processor for adjusting the time difference between the timing of the first audio signal output from the signal supply section and the timing of the second audio signal output from the signal supply section. 
     The above and other features and advantages of the present invention will become apparent from the following description when taken in conjunction with the accompanying drawings which illustrate preferred embodiments of the present invention by way of example. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a television apparatus according to a first embodiment of the present invention; 
         FIG. 2  is an enlarged side elevational view showing a junction between a support post and arms; 
         FIG. 3  is a view as viewed in the direction of the arrow E in  FIG. 2 ; 
         FIG. 4  is a cross-sectional view taken along line F-F of  FIG. 3 ; 
         FIG. 5  is a cross-sectional view taken along line G-G of  FIG. 3 ; 
         FIG. 6  is a plan view of a display device; 
         FIG. 7  is a cross-sectional view of a vertical swing mechanism; 
         FIG. 8  is a block diagram of a signal box; 
         FIG. 9  is a detailed block diagram of an audio signal processing circuit; 
         FIG. 10  is a schematic view showing the relationship between sounds emitted from first and second speakers of the television apparatus and the user; 
         FIG. 11  is a schematic view showing angles detected by angle sensors of a television apparatus according to a second embodiment of the present invention; and 
         FIG. 12  is a schematic view showing the calculation of the distance between the first and second speakers based on the detected angles in the television apparatus according to the second embodiment. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Television apparatus according to the embodiments of the present invention will be described in detail below with reference to the drawings. 
     First Embodiment 
       FIG. 1  shows a perspective view of a television apparatus  10  according to a first embodiment of the present invention. 
     As shown in  FIG. 1 , the television apparatus  10  includes a display device  12 , a stand  20  supporting the display device  12 , a first speaker  50 , a second speaker  52 , and a distance detector  54 . 
     First, the display device  12  will be described below. 
     As shown in  FIG. 1 , the display device  12  includes a thin display device  1202 , a frame  1204 , and a display driver circuit  1210  (see  FIG. 8 ). 
     The display device  1202  has a display surface on one side and a rear surface on the other side. One side of the display device  1202  is referred to as a front side, and the other side thereof as a rear side. 
     The frame  1204  is in the form of a thin plate covering the rear surface of the display device  1202  thereby to support the display device  1202 . 
     In the present embodiment, the display device  1202  includes an organic EL display. However, the display device  1202  may include a plasma display or a liquid crystal display. 
     The stand  20  will be described below. 
     As shown in  FIG. 1 , the stand  20  includes a base  22 , a support post  24 , arms  26 , and a counterweight  28 . In the present embodiment, the base  22  serves as a mount section placed in a site. 
     The support post  24  projects upwardly from the base  22 , and the arms  26  have longitudinally intermediate portions supported on the upper distal end of the support post  24 . The display device  12  is supported on front ends of the arms  26 , and the counterweight  28  is coupled to rear ends of the arms  26 . 
     The base  22  includes a frame and a cover  2202  covering the frame. 
     A semispherical support  30  is disposed on an upper portion of the frame for turning adjusting movement about a vertical axis and swinging adjusting movement in vertical directions. The support  30  is exposed upwardly from an upper surface of the cover  2202 . The support post  24  projects from the support  30 . In the present embodiment, the support post  24  includes two rods  2402  extending parallel to each other. 
     A turning mechanism and a vertical swinging mechanism in related art, are provided between the frame and the support  30 . A friction mechanism is also provided in association with the turning mechanism and the vertical swinging mechanism to keep the support  30  in a certain turned and vertically swung state. When the user turns or vertically swings the display device  12  or the support post  24  to a desired attitude, and then the user releases the display device  12  or the support post  24 , the support post  24  remains angularly displaced with respect to the frame. 
       FIG. 2  is an enlarged side elevational view showing a junction between the support post  24  and the arms  26 ,  FIG. 3  is a view as viewed in the direction of the arrow E in  FIG. 2 ,  FIG. 4  is a cross-sectional view taken along line F-F of  FIG. 3 , and  FIG. 5  is a cross-sectional view taken along line G-G of  FIG. 3 . 
     As shown in  FIGS. 4 and 5 , the support post  24  and the arms  26  are joined to each other at a junction incorporating a vertical swing mechanism  33  by which the arms  26  are vertically swingably supported on the support post  24 , a torsion coil spring  32 , and a friction mechanism  34  for maintaining the arms  26  in a vertically swung state with respect to the support post  24  under frictional forces. 
     The torsion coil spring  32  serves to hold in balance a rotational moment which acts on the support post  24  based on the weight of the display device  12  and a rotational moment which acts on the support post  24  based on the weight of the counterweight  28 . At the junction between the support post  24  and the arms  26 , a rotational moment generated by the resiliency of the torsion coil spring  32  in cooperation with the rotational moment generated by the weight of the counterweight  28  counteracts the rotational moment generated by the weight of the display device  12  and the weight of the arms  26 . 
     As shown in  FIGS. 2 through 5 , brackets  2404 ,  2406  are positioned in facing relation of the distal ends of the two rods  2402 . A male screw member  2408  extends between and through the brackets  2404 ,  2406 . A tubular member  2602  made of a material having a large coefficient of friction, which projects from the intermediate portions of the arms  26 , is sandwiched between the brackets  2404 ,  2406  and rotatably supported on the shank of the male screw member  2408 , providing the vertical swing mechanism  33 . 
     The tubular member  2602  has an inner tube section  2604  through which the shank of the male screw member  2408  extends, and an outer tube section  2606  disposed radially outwardly of and joined to the inner tube section  2604 . The outer tube section  2606  has an outside diameter which is substantially the same as the outside diameter of the brackets  2404 ,  2406 . 
     The torsion coil spring  32  is disposed in an annular space between the inner tube section  2604  and the outer tube section  2606 . The torsion coil spring  32  has an end  3202  engaging a wall surface  2410  of the bracket  2404  and another end  3204  displaced against the bias of the torsion coil spring  32  as indicated by the dotted-line arrow in  FIG. 4  and engaging a wall surface  2610  of the tubular member  2602 . The torsion coil spring  32  applies its resilient forces acting between the support post  24  and the arms  26  in the circumferential direction of the male screw member  2408 . 
     When the male screw member  2408  is loosened or tightened, the force tending to tighten the tubular member  2602  between the brackets  2404 ,  2406  is adjusted, i.e., the frictional force generated between the brackets  2404 ,  2406  and the tubular member  2602  is adjusted. The friction mechanism  34  for maintaining the arms  26  in a vertically swung state with respect to the support post  24  is thus provided. 
     The friction mechanism  34  is not limited to the above structure, but may be of any of various structures. In the present embodiment, the male screw member  2408 , the brackets  2404 ,  2406 , and the tubular member  2602  of the friction mechanism  34  also serve as components of the vertical swing mechanism  33 . 
     When the user grips the arms  26  or the display device  12 , swings the arms  26  or the display device  12  to bring the display device  12  into a desired position with respect to the support post  24 , and releases the arms  26  or the display device  12 , the angle of the arms  26  with respect to the support post  24  is maintained by the torsion coil spring  32 , the counterweight  28 , and the friction mechanism  34 . 
       FIG. 6  is a plan view of the display device  12 , and  FIG. 7  is a cross-sectional view of a vertical swing mechanism  36 . 
     As shown in  FIG. 6 , the vertical swing mechanism  36  and a friction mechanism  38  are disposed in a junction between the distal ends of the arms  26  and the display device  12 . The display device  12  is vertically swingably coupled to the distal ends of the arms  26  by the vertical swing mechanism  36 , and the display device  12  is maintained in a swung attitude by the friction mechanism  38 . 
     As shown in  FIG. 7 , the vertical swing mechanism  36  includes a pair of first members  36 A attached to the rear surface of the display device  12 , an externally threaded screw  3606  extending between and through the first members  36 A, and a second member  36 B vertically swingably coupled to the externally threaded screw  3606 . The second member  36 B is mounted on the distal end of the stand  20  (the arms  26 ). 
     When the externally threaded screw  3606  is loosened or tightened, the force tending to tighten the second member  36 B with the first members  36 A is adjusted, i.e., the frictional force generated between the first members  36 A and the second member  36 B is adjusted. The display device  12  is thus maintained in a vertically swung state with respect to the arms  26 . 
     The vertical swinging mechanism  36  is not limited to the above structure, but may be of any of various structures. In the present embodiment, the first members  36 A, the second member  36 B, and the externally threaded screw  3606  of the friction mechanism  38  also serve as components of the vertical swing mechanism  36 . 
     When the user grips the arms  26  or the display device  12 , swings the arms  26  or the display device  12  to bring the display device  12  into a desired position with respect to the display device  12  or the arms  26 , and releases the arms  26  or the display device  12 , the angle of the display device  12  with respect to the arms  26  is maintained by the friction mechanism  38 . 
     In the present embodiment, a support mechanism supports the display device  12  in a position projecting upwardly from the mount section and spaced from the mount section in a manner to allow the display device  12  to change its attitude. The support mechanism includes the support  30 , the support post  24 , the arms  26 , the torsion coil spring  32 , the counterweight  28 , and the friction mechanisms  34 ,  38 . 
     As shown in  FIG. 1 , a signal box  40  is disposed in the cover  2202 . 
     The signal box  40  controls the display device  1202  to display images and also controls the first and second speakers  50 ,  52  to output sounds based on radio waves received from broadcasting stations or image and audio signals supplied from an external device. 
       FIG. 8  shows details of the signal box  40  in block form. 
     As shown in  FIG. 8 , the signal box  40  includes a reception circuit  4002 , a switching circuit  4004 , an image signal processing circuit  4006 , an audio signal processing circuit  4008 , a remote control signal reception circuit  4010 , and a control circuit  4012 . The signal box  40  is connected to a control section  42  and an external input terminal  44  which are separate from the signal box  40 . 
     The control section  42  can be operated by the user to make various operations and settings for viewing broadcasts on the television apparatus  10 . The control section  42  includes, for example, a channel selecting button, a volume adjusting button, a tone adjusting button, and an input selecting button, and is mounted on an outer surface of the cover  2202 , for example. 
     In the present embodiment, the control section  42  includes a timing controller  4202  (see  FIG. 9 ) for manually setting the time difference between sounds output from the first and second speakers  50 ,  52 . The timing controller  4202  includes a control button or knob and is mounted on an outer surface of the cover  2202 . 
     The external input terminal  44  is a terminal for receiving image and audio signals supplied from an external device such as a DVD player, a video deck, or the like, and is mounted on an outer surface of the cover  2202 . 
     The reception circuit  4002  selects a channel based on a command from the control circuit  4012 , demodulates a television signal received from an antenna  4001 , separates the television signal into an image signal and an audio signal, and outputs the image signal and the audio signal. 
     The switching circuit  4004  selects either image and audio signals supplied from the reception circuit  4002  or image and audio signals supplied from the external device through the external input terminal  44 , and supplies the selected image and audio signals to the image signal processing circuit  4006  and the audio signal processing circuit  4008 . 
     The image signal processing circuit  4006  processes the image signal to generate a drive signal for driving the display device  12 , and supplies the drive signal to the display device  12 . 
     The audio signal processing circuit  4008  processes and amplifies the audio signal, and supplies the processed and amplified audio signal to the first speaker  50  and the second speaker  52 . The first speaker  50  and the second speaker  52  output sounds based on the supplied audio signal. 
     The remote control signal reception circuit  4010  receives a wireless signal (infrared signal) representing control commands for various operations including channel selection, volume adjustment, and input selection, sent from a remote control signal transmitter  46  separate from the television apparatus  10 . The remote control signal reception circuit  4010  supplies the received control commands to the control circuit  4012 . 
     Based on operations on the control section  42  or the control commands supplied from the remote control signal reception circuit  4010 , the control circuit  4012  controls the reception circuit  4002  to select a channel, controls the switching circuit  4004  to switch between an image signal or an audio signal, and also controls the image signal processing circuit  4006  and the audio signal processing circuit  4008 . 
     The display driver circuit  1210  of the display device  12  drives the display device  1202  to display an image on its display surface based on the drive signal supplied from the image signal processing circuit  4006 . 
     The first and second speakers  50 ,  52  will be described below. 
     The first and second speakers  50 ,  52  are disposed in separate positions. 
     In the present embodiment, as shown in  FIG. 1 , the first speaker  50  is mounted on the display device  12 , and the second speaker  52  is mounted on the base  22 . 
     More specifically, the first speaker  50  is disposed in left and right positions on a lower portion of the frame  1204  of the display device  12 , and faces forwardly. 
     The first speaker  50  includes a left-channel speaker section  50 A and a right-channel speaker section  50 B. The first speaker  50  produces sounds in a high-frequency range. 
     The second speaker  52  is disposed in left and right positions on a front surface  2202 A of the cover  2202  of the base  22 . 
     The second speaker  52  includes a left-channel speaker section  52 A and a right-channel speaker section  52 B. The second speaker  52  produces sounds in medium- and low-frequency ranges. 
     The distance detector  54  will be described below. 
     As shown in  FIG. 1 , the distance detector  54  detects the distance between the first speaker  50  and the second speaker  52 . 
     According to the present embodiment, the distance detector  54  includes an infrared transmitter  5402  mounted on the frame  1204  near the first speaker  50  and an infrared receiver  5404  disposed on the cover  2202  near the second speaker  52 . The infrared transmitter  5402  transmits an infrared signal, and the infrared receiver  5404  receives the infrared signal transmitted from the infrared transmitter  5402 , detects the distance between the infrared transmitter  5402  and the infrared receiver  5404  as the distance between the first speaker  50  and the second speaker  52 , and generates a detected distance signal. 
     The distance detector  54  may be of any of various other designs in related art, such as an ultrasonic distance detector, rather than the infrared distance detector described above. 
       FIG. 9  shows in detailed block form the audio signal processing circuit  4008 . 
     As shown in  FIG. 9 , the audio signal processing circuit  4008  includes a microcomputer  56 , an A/D converter  58 , a signal processing block  60 , two D/A converters  62 H,  62 L, and two amplifiers  64 H,  64 L. 
     The microcomputer  56  generates a delay control signal based on the detected distance signal supplied from the distance detector  54  and a control signal supplied from the timing controller  4202 . 
     The A/D converter  58  converts left- and right-channel analog audio signals supplied from the switching circuit  4004  into digital signals. 
     The signal processing block  60  includes a delay adjuster  6002  and a tone corrector  6004 . 
     The tone corrector  6004  separates the audio signals supplied from the A/D converter  58  into an audio signal in a medium-to-low frequency range and an audio signal in a high frequency range, and increases or decreases the output levels of the separated audio signals thereby to adjust the tone of the sounds, i.e., to adjust the frequency characteristics. The tone corrector  6004  adjusts the tone of the sounds when the tone adjusting button of the control section  42  is pressed. 
     The tone corrector  6004  supplies the audio signal in the high frequency range to the delay adjuster  6002 , and supplies the audio signal in the medium-to-low frequency range to one of the D/A converters  62 L. 
     The delay adjuster  6002  delays the audio signal in the high-frequency range supplied from the tone corrector  6004  by a delay time determined based on the delay control signal supplied from the microcomputer  56 , and supplies the delayed audio signal to the other D/A converter  62 H. 
     The delay adjuster  6002  includes, for example, a RAM  6002 A and a controller  6002 B for controlling the reading of data from and the writing of data into the RAM  6002 A. After the controller  6002 B writes the data of the audio signal in the high-frequency range into the RAM  6002 A, the controller  6002 B reads the data from the RAM  6002 A thereby to delay the audio signal in the high-frequency range by the delay time. 
     D/A converter  62 H converts the digital audio signal in the high-frequency range (a first audio signal in this embodiment) supplied from the delay adjuster  6002  into an analog audio signal, and supplies the analog audio signal to one of the amplifiers  64 H. 
     The D/A converter  62 L converts the digital audio signal in the medium-to-low frequency range (a second audio signal in this embodiment) supplied from the tone corrector  6004  into analog audio signal, and supplies the analog audio signal to the other amplifiers  64 L. 
     The amplifier  64 H amplifies the audio signal in the high frequency range supplied from the D/A converter  62 H, and supplies the amplified audio signal to the first speaker  50 , i.e., the speaker sections  50 A,  50 B. 
     The amplifier  64 L amplifies the audio signal in the medium-to-low frequency range supplied from the D/A converter  62 L, and supplies the amplified audio signal to the second speaker  52 , i.e., the speaker sections  52 A,  52 B. 
     Therefore, the timing of the sound output from the first speaker  50  lags behind the timing of the sound output from the second speaker  52  by the delay time. 
     The audio signal processing circuit  4008  includes a signal supply section for supplying the audio signals to the first speaker  50  and the second speaker  52 . 
     The audio signal processing circuit  4008  also provides a signal processor for adjusting the time difference between the timing of the audio signal in the high frequency range (first audio signal) output from the signal supply section and the timing of the audio signal in the medium-to-low frequency range (second audio signal) output from the signal supply section. 
     Operation and advantages of the television apparatus  10  will be described below. 
       FIG. 10  schematically shows the relationship between sounds emitted from the first and second speakers  50 ,  52  of the television apparatus  10  and the user P. 
     As shown in  FIG. 10 , the display device  12  is largely pulled forward of the base  22 . 
     At this time, the distance L 2  from the ears of the user P positioned forward of the display device  1202  to the second speaker  52  is greater than the distance L 1  from the ears of the user P to the first speaker  50  by the difference (L 2 -L 1 ). 
     Therefore, the sound in the high frequency range emitted from the first speaker  50  reaches the ears of the user P earlier than the sound in the medium-to-low frequency range emitted from the second speaker  52  reaches the ears of the user P. 
     The time difference Δt between the time when the sound in the high frequency range reaches the ears of the user P and the time when the sound in the medium-to-low frequency range reaches the ears of the user P is expressed as:
 
Δ t =( L 2− L 1)/ Vs  
 
     where Vs represents the velocity of sound. 
     Depending on the magnitude of the time difference Δt, the user P may feel uncomfortable and unnatural about the sounds which the user P hears. 
     According to the present embodiment, the distance detector  54  detects the distance ΔL between the first and second speakers  50 ,  52  as (L 2 -L 1 ). The timing of the sound in the high frequency range is delayed by the time which is required for the sound to travel the distance ΔL, and the delayed in the high frequency range is output from the first speaker  50 . 
     Specifically, the microcomputer  56  generates a delay control signal for eliminating the time difference Δt and supplies the generated delay control signal to the delay adjuster  6002 . Stated otherwise, the microcomputer  56  adjusts the sound in the high frequency range such that the sound output from the first speaker  50  and the sound output from the second speaker  52  reaches the position forward of the television apparatus  10 , i.e., the ears of the user P, with the same timing. 
     Consequently, the user P is prevented from feeling uncomfortable and unnatural due to the time difference Δt, and can hear sounds of good tone. 
     Strictly, the distance ΔL between the first and second speakers  50 ,  52  and the difference (L 2 -L 1 ) are not the same as each other. However, in view of the positional relationship and the distance between the user P and the television apparatus  10  in actual use, any effect that the difference between the distance ΔL between the first and second speakers  50 ,  52  and the difference (L 2 −L 1 ) has on the adjustment of the timing of the sound is negligible. 
     It is known in the art that according to the human aural characteristics, sounds in the high frequency range are heard earlier than sounds in the medium-to-low frequency range, and if sounds in the high frequency range are heard later than sounds in the medium-to-low frequency range, then the sounds are perceived mildly (softly). 
     Therefore, if the sounds in the high frequency range are heard too loud, then it is preferable to adjust the sounds such that the sounds in the high frequency range are heard later than the sounds in the medium-to-low frequency range. Conversely, if the sounds are heard as lacking clarity, then it is preferable to adjust the sounds such that the sounds in the high frequency range are heard earlier than the sounds in the medium-to-low frequency range. 
     According to the present embodiment, when the control signal generated by the timing controller  4202  is supplied to the microcomputer  56 , the microcomputer  56  supplies a delay control signal to the delay adjuster  6002  to advance or delay the timing of the sound in the high frequency range output from the first speaker  50  with respect to the timing of the sound in the medium-to-low frequency range output from the second speaker  52 , for thereby freely adjusting the clarity or softness of the sounds. Consequently, the television apparatus  10  is advantageous in that it can provide sounds depending on the preference of the user P. 
     In some television apparatus, the entire frequency range is divided into a plurality of frequency ranges, e.g., a high frequency range and a low frequency range, and the output sound level of each of the frequency ranges is adjusted. According to the present embodiment, however, the balance between the output sound levels in the frequency ranges is not changed at all, but is kept constant, and the clarity or softness of the sounds is freely adjusted. Consequently, the television apparatus  10  is advantageous in that it can provide good-quality sounds to the user P. 
     According to the present embodiment, furthermore, the delay control signal supplied from the microcomputer  56  to the delay adjuster  6002  is based on the delay control signal generated depending on the distance ΔL according to the detected distance signal supplied from the distance detector  54  and the delay control signal generated depending on the control signal supplied from the timing controller  4202 . 
     Therefore, even if the display device  12  is moved forward or rearward after the sound clarity or softness has been adjusted to a desired level by the timing controller  4202 , since the distance detector  54  detects a change in the distance ΔL and the microcomputer  56  adjusts the delay control signal depending on the detected change in the distance ΔL, the sound clarity or softness remains at the level achieved before the display device  12  is moved forward or rearward. Consequently, even when the display device  12  changes its position in the forward or rearward direction, the timing controller  4202  does not need to be adjusted again. Therefore, the television apparatus  10  is advantageous in that it can be operated simply and is easy to use. 
     Stated otherwise, the timing controller  4202  sets a time difference, and the sound output from the first speaker  50  and the sound output from the second speaker  52  reaches the user P in front of the television apparatus  10  with a certain time difference. At this time, if the distance detector  54  detects a change in the distance ΔL=(L 2 −L 1 ) between the first speaker  50  and the second speaker  52 , then the audio signal processing circuit  4008  (signal processor) adjusts the time difference such that the sound output from the first speaker  50  and the sound output from the second speaker  52  reaches the user P with the certain time difference. 
     Second Embodiment 
     A television apparatus according to a second embodiment of the present invention will be described below. 
     The television apparatus according to the second embodiment differs from the television apparatus according to the first embodiment in that the distance detector includes an angle sensor in related art, and are identical to the television apparatus according to the first embodiment as to other details. 
       FIG. 11  schematically shows angles θ 1 , θ 2  detected by respective angle sensors  5410 ,  5412 , and  FIG. 12  schematically shows the calculation of the distance ΔL between the first and second speakers  50 ,  52  based on the detected angles θ 1 , θ 2 . 
     Those parts of the television apparatus according to the second embodiment which are identical to those of the television apparatus according to the first embodiment are denoted by identical reference characters. 
     As shown in  FIG. 11 , the television apparatus  10  according to the second embodiment has a first angle sensor  5410  and a second angle sensor  5412 . 
     The first angle sensor  5410  is disposed in the junction between the support post  24  and the arms  26  for detecting the angle θ 1  formed between the arms  26  and the horizontal axis. 
     If the angle θ 1  is present above the horizontal axis, it has a positive value, and if the angle θ 1  is present below the horizontal axis, it has a negative value. 
     The second angle sensor  5412  is disposed in the junction between the frame of the base  22  and the support  30  for detecting the angle θ 2  formed between the support post  24  and the vertical axis. 
     If the angle θ 2  is present leftward of the vertical axis, it has a positive value, and if the angle θ 2  is present rightward of the vertical axis, it has a negative value. 
     Detected angle signals generated by angle sensors  5410 ,  5412  as representing the detected angles θ 1 , θ 2  are supplied to the microcomputer  56  (see  FIG. 9 ). 
     As shown in  FIG. 12 , it is assumed that the horizontal axis is given as an X-axis of a coordinate system, the vertical axis is given as a Y-axis of the coordinate system, the junction between the frame and the support  30  is located has coordinates at the origin P 0 ( 0 ,  0 ) of the coordinate system, the junction between the arms  26  and the display device  12  (the vertical swing mechanism  36 ) has first coordinates P 1 (x 1 , y 1 ), the junction between the arms  26  and the support post  24  (the friction mechanism  34 ) has second coordinates P 2  (x 2 , y 2 ), the distance from the first coordinates P 1 (x 1 , y 1 ) to the second coordinates P 2 (x 2 , y 2 ) is represented by LA 1 , and the distance from the second coordinates P 2 (x 2 , y 2 ) to the origin is represented by LA 2 . 
     The first coordinates P 1 (x 1 , y 1 ) are expressed by the following equation (1): 
     
       
         
           
             
               
                 
                   
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     According to the present embodiment, the first coordinates P 1 (x 1 , y 1 ) are positioned near the first speaker  50 , and the origin P 0 ( 0 ,  0 ) is positioned near the second speaker  52 . 
     Therefore, the distance from the origin to the first coordinates P 1 (x 1 , y 1 ), i.e., the distance ΔL=Lpanel between the first and second speakers  50 ,  52 , is expressed by the following equation (2), using the first coordinates P  1  (x  1 , y 1 ) according to the equation (1):
 
 L panel=( x 1 2   +y 1 2 ) 1/2   (2)
 
     Based on the above equations (1), (2), the microcomputer  56  calculates the distance ΔL between the first and second speakers  50 ,  52 . 
     According to the present embodiment of the present invention, distance detector includes the first angle sensor  5410 , the second angle sensor  5412 , and the microcomputer  56 . 
     The other components are same as mentioned in the first embodiment. 
     The television apparatus according to the second embodiment offers the same advantages as those of the television apparatus according to the first embodiment. According to the first embodiment, the infrared or ultrasonic distance detector needs to have their transmitter and receiver exposed to view. According to the second embodiment, however, since the first angle sensor  5410  and the second angle sensor  5412  may be located in unexposed positions, the television apparatus  10  according to the second embodiment is of a better appearance. 
     In the illustrated embodiments, the television apparatus  10  adjust the timing of the sound depending on the distance ΔL detected by the distance detector  54 . However, the distance detector  54  may be dispensed with, and the user may manually set the timing of the sound using the timing controller  4202 . The television apparatus  10 , according to the embodiment, which adjusts the timing of the sound depending on the distance ΔL detected by the distance detector  54  is easier to use because the user does not need to operate the timing controller  4202  depending on the changed position of the display device  12 . 
     In the illustrated embodiments, the frequency range of the sound output from the first speaker  50  is higher than the frequency range of the sound output from the second speaker  52 . The present invention is also applicable to a television apparatus wherein the first and second speakers  50 ,  52  have the same frequency range. 
     Even if the first and second speakers  50 ,  52  have the same frequency range, the television apparatus can provide good quality of the sound by adjusting the timing of the sound output from one of the speakers and arriving at the user P and the timing of the sound output from the other speaker and arriving at the user P. 
     Even if the first and second speakers  50 ,  52  have the same frequency range, the television apparatus can achieve the tone adjustment by adjusting the time difference between the timing of the sound output from one of the speakers and arriving at the user P and the timing of the sound output from the other speaker and arriving at the user P. 
     In the illustrated embodiments, the first speaker  50  is mounted on the display device  12 , and the second speaker  52  is mounted on the base  22 . However, insofar as the first and second speakers  50 ,  52  are separate from each other, one or both of the first and second speakers  50 ,  52  may be spaced from the display device  12  or the base  22 . 
     Although certain preferred embodiments of the present invention have been shown and described in detail, it should be understood that various changes and modifications may be made therein without departing from the scope of the appended claims.