Fullscreen HTML5Med Res (??MB)HTML4

Sanyo's big screen video projector + Yamaha's surround sound system= 4 S ILICON CHI P This photo shows the dramatic sweep of the picture available from the Sanyo liquid crystal video projector. For best results, the room should be completely darkened. Would you like to bring the large screen & big sound of a cinema into your home? Now you can, as we found when we reviewed the combination of Sanyo's PLC-200PP liquid crystal video projector and Yamaha's RX-V1050 stereo receiver with Dolby Pro-Logic surround sound. By LEO SIMPSON No matter how much you may enjoy movies and documentaries on your TV set at home, their impact is but a pale shadow of what you see when you visit your local cinema. Big screen and big sound is what you get at the cinema and these are sadly lacking when you watch the same programs at home. Even if you have one of the later model TV sets with screen sizes up to 80cm diagonal, they are still small relative to what you see in a cinema. And while you may have quite a respectable sound system, it is out of place with a small screen. The only remedy has been to obtain a video projection system but these have been large, unwieldy and expensive. Up until about 12 months ago, video projectors have all been based on three high power CRTs which produce separate red, blue and green beams which must be carefully converged and focused onto a fixed screen. Now there is a new type of video projector with 'just a single lens system. It is simple to set up, takes only a moment to focus and can be zoomed up or down to give the picture size you want. Th ere are no bulky CRTs (cathode ray tubes). How do you produce a full colour video picture if you do not employ one or three CRTs? The answer is to use a completely new technology based on liquid crystal panels. But these panels are far removed from the everyday liquid crystal displays used in watches, digital M A RCH 1993 5 This photo of the projector shows the flip-up lid which conceals the controls, although all functions can also be accessed by the remote control. The real magic is in the liquid crystal panels concealed inside the chassis. multimeters and a host of consumer appliances. Most LCDs are reflective but some are backlit so that they can be seen at night. The liquid crystal devices used in the Sanyo video projector are transmissive which means that they work in a similar way to a backlit LCD but that is where the -comparison ends. The diagram of Fig. l shows the general principle used. Inside the projector is a 160 watt metal halide discharge lamp which is the sole light source for the projector. It is fitted with a dichroic reflector and its light output is directed through filters which remove ultraviolet and infrared (heat). The focused beam then passes through a dichroic mirror (DMl) which splits off (reflects) the red light while allowing green and blue light to pass through. The green and blue light is then split in another dichroic mirror (DMZ) so that now we have three separate beams. Each of the three beams is passed through a liquid crystal panel which has 110,450 pixels (picture elements) and these individual picture elements modulate the beam to make up the picture. The modulated red, green and blue beams are then combined into a single beam by two further dichroic mirrors (DM3 and DM4) and then passed through the 67mm zoom lens system to project onto the screen. The above description is highly sim6 SILICON CHIP plified and encompasses new technology which is breathtaking in its scope. Just think of it: hundreds of thousands of liquid crystal picture elem ents being turned on and off with refresh rates of 25 or 30Hz. Moreover, the pixels are being constantly modulated so that they can provide a contrast range of 100:1. In essence, it is a completely new technology for projecting a moving colour image onto a screen and it has arrived at this advanced stage of development with almost no fanfare at all. Projector features Sanyo's PLC-200PP can be used in virtually any room and can produce a picture which ranges from 63cm diagonal to 7.6 metres diagonal. The smallest projection distance it will allow is 2.3 metres from the lens to the screen and since the zoom range is 2:1 the picture size can range from 63q:n to 114cm diagonal. !Ii a larger room, where the projection distance might be say, 6 metres, the maximum · picture size would be 3.4 metres diagonal. That might not seem all that big until you realise that the picture would be about 2. 7 m etres wide and 2 metres high. That's about as big as would be practical in most homes, given the standard ceiling height of 2.4 metres. If you want a larger image, you will need a much larger room and then you tend to run out of brightness. Even with smaller pictures, the most impact is obtained with the room in complete darkness - the same as in a cinema. Setting the unit up is dead simple and you don't even need a screen - a blank wall is ideal and it doesn't even have to be white; a pastel colour will do. You can use any PAL, SECAM or NTSC video source and that includes TV tuners, camcorders, VCRs and laser disc players. All you do is set the projector up on a table or bench square to the wall and turn it on. The lamp takes 30 seconds to come up to full brilliance and during this time it projects a blue image with the message "A MOMENT/UN MOMENTO" together with a countdown in seconds to zero. After that, the video signal can be seen on screen. The projector has adjustable feet at the front and a click-out foot at the back so that it can be set up to project down or up by 5°. With any normal projector, whether film or video, this leads to an image which is trapezoidal rather than rectangular. However, the Sanyo projector has electronic "keystone" correction so that the image can be "squared up " simply by pushing a recessed button on the remote control. By the way, pushing any button on the remote control or the equivalent button on the projector brings up a message on the screen. For example, pushing one of the Focus buttons on the remote control brings up "FOCUS" on the screen and you can then precisely focus on that text. Similarly, pushing one of the Zoom buttons brings up "ZOOM" on the screen and you can then adjust the picture to size as required. Each onscreen message disappears after eight seconds. Remote control features While all of the features of the projector can be operated by buttons which are-underneath a flip-up cover on the machine, it is far more convenient to use the remote control. This can be used as a conventional infrared remote control or as a wired remote with a cable. While the wired remote is tethered to the machine, you don't have to worry about aiming it in the general direction of the unit. Since the Sanyo video projector performs best in completely darkened Sanyo's top of the range VHR-290 hifi stereo video recorder is an ideal program source for the video projector. It is a very fast machine which means that you don't spend any time waiting for it to put the picture on the screen. rooms, it follows that a normal remote control is pretty useless because you can't see the buttons. Sanyo has recognised this by providing a remote where all the buttons light up. Just press the "Light Up" bar on the remote and all the buttons light up for a period of five seconds. Also on the remote control are buttons to turn the projector on and off, select the video source, select the video standard (auto, PAL, SECAM, NTSC, adjust the sound level, mute the sound, picture adjust (contrast, sharpness, brightness, tint and colour saturation), normalisation (restores picture and sound to standard settings) and expand. This last button allows the central portion of the image to be blown up to twice size which may be useful in some circumstances. All your settings are stored in memory, so there is no need to go through the set-up procedure each time you turn on the projector unless, of course, you have moved it to a different position. There is also an S-video socket and a 21-pin SCART socket. The projector has an internal speaker and 3 watt amplifier (mono sound) and the remote control can be used to adjust the sound, as noted above. Interestingly, the remote control has no effect on the sound level if an external amplifier and loudspeakers are used. Styling of the unit is definitely low key. While it is robustly built inside, as it needs to be to maintain all those mirrors and liquid crystal panels in alignment, its outer plastic case is Picture reversal One feature which is not available on the remote control but accessible on the projector itself is picture reversal. This allows the machine to be used in a rear projection set up. On the rear of the projector are a number of sockets for video and audio connections. There are three RCA sockets for video plus audio left and right inputs and a further two RCA sockets for audio left and right connections to an external amplifier. The rear of the video projector has sockets for audio & video connections, including S-video. The unit also has an internal loudspeaker but using external amplifiers & speakers gives a much better result. very subdued, finished in matt grey. In fact, it looks a lot smaller than its overall dimensions suggest. It measures 572mm from the lens cap to the rear, 268mm wide and 253mm high. It is also fairly heavy at 13kg but it is quite comfortable to carry. Lamp life Metal halide lamps do not last as long as CRTs but they are much longer lived than conventional slide or movie projector lamps. Sanyo recommends lamp replacement at 2000 hours and there is a LED which comes on when this time has been reached. Picture quality Ah, now this is where we come to the nub of the matter. In the past, it has been accepted, by most people who bothered to think about the subject, that for optimum picture presentation, you should sit far away enough from your TV set so that the line structure is not readily apparent. Clearly, a lot of people don't bother with this and sit quite close to their TV sets. With the very large picture presented by the Sanyo projector, the line structure is clearly apparent. And depending on how close you are to the screen and how keen your sight is, the individual pixels of the image can also be seen. Nor.is the picture quality really anything to write home about, if you are judging it on a purely objective basis. As you can imagine, if you blow up a standard PAL picture by many times, the limited video bandwidth is readily apparent in the relatively soft focus. It is certainly not high definition TV and it is a long way short of the best 35mm film images. On the other MARCH 1993 7 Sanyo's flicker free video - how it works There are many aspects of Sanyo's PLC-200PP video projector which beggar the imagination. For example, most people who have any knowledge of liquid crystal displays know that are they digital in nature, either fully on or fully off. But Sanyo's 110,450 pixel liquid crystal panels produce the full range of colours expected from a standard colour TV set and with a contrast range (bright to dark) of 100:1. Just how does Sanyo manage that? And the projector copes with any standard video source whether it is PAL, NTSC or SECAM (or S-video). The normal method of doing a full video standards conversion would be to incorporate a "frame store". This would also enable the field rate to be doubled (to 10OHz) and thus avoid flicker which is otherwise very troublesome on large screen sets. But the Sanyo projector does not have a field store for standards conversion and nor does it double the vertical scan rate . And yet, that large and dramatic screen is completely free of flicker, in spite of being scanned at the normal 50Hz rate for PAL sources. Let's consider how the liquid crystal panels are driven first. Each of the pixels is controlled by its own thin film transistor (TFT) which is on the pixel itself (ie, the light passes through it. Each TFT is essentially a Mosfet which naturally has a fairly substantial gate capacitance and this provides a sample-and-hold facility. The gate of each TFT is supplied with a sample of the video signal and this signal is analog which means that the transistor does not have to be either on or off, it can also be anywhere in between and hence the "twisted nematic" fluid of the pixel can be anywhere between fully transmissive and opaque. hand, in view of the poorly fo cused images you see in man y cinemas, th e Sanyo projector stands up pretty well by comparison. So on a purely objective assessment, concerned with line and pixel structure and video bandwid th, the picture quality is pretty ordinary. However, that is not the end of the matter by a long shot. The strong point of the Sanyo video projector is that it produces such a large and bright picture and furth ermore, it is completely fli cker-free. The simple fac t is that, after watching that dramatically' large picture for a few minutes, line and pixel structure becomes unimportant. You become so engrossed in the program that you just don 't notice the line structure. 8 SILICO N CHJ P Sample & hold But why doesn't the picture flicker? The answer is because of that "sample and hold" facility on the gate of each TFT. In a normal television picture tube, the image is created line by line, with the electron beam scanning rapidly over the picture tube. In the 625-line PAL system, the image is scanned at 50Hz, alternating between odd and even lines which build up a complete frame in 1125th of a second. After the electron beam has passed over a particular spot on the tube, the phosphors will continue to emit light for a brief period of time but the system also depends on persistence of vision so that we see a constant image on the screen. However, while the screen may be Sound quality Sound quality is a most important factor. While the Sanyo projector does have an inbuilt speaker, its mono output quality is no more than could be expected and it also has to compete with the noise of the internal cooling fans. To do justice to the system , you need good quality stereo sound at the very least. That means that any video source you are using shoul d provide stereo sound. For the purpose of our review, we used a Sanyo VHR 290 video recorder with hifi stereo sound. This VCR is the flagship of Sanyo's range and has scanned at 50Hz (the field rate), the complete image is updated at 25Hz and this leads to residual flicker which can be very noticeable on bright parts , of the screen. In the Sanyo projector, the pixels are split between odd and even lines and they build up the picture in the same way as in a cathode ray tube. The difference is that whereas the image from a picture tube depends on phosphor spots which are excited very briefly every 1125th of a second, each pixel TFT is fed a sample of video signal every 1125th of a second and its stays turned on to that value until it receives the next video sample. Thus, most of the pixels of the screen stay on all the time, constantly transmitting light at whatever the required value is and only changing if the signal changes. This means that there is no apparent flicker in the picture at all. Standards conversion So how does Sanyo manage video standards conversion without resorting to a frame store? In essence, the projector is designed to the American NTSC standard as far as line scan rate is concerned. This means that the picture is essentially 525 lines with a field rate of 60Hz for just about every feature you could want. If you want a first class video signal with stereo sound, whether "off air" via its inbuilt tuner or from tape, it is the ideal source to team with the Sanyo PLC-200PP video projector. With the program source catered for, we still had the problem of the amplifier and loudspeaker system. To do the Sanyo projector full justice, you really should settle for nothing less than a system which can produce full surround sound. To obtain that from pre-recorded video tapes , that means you need an amplifier system which has Dolby's Pro-Logic decoder. Anything less is just short-changing the system . Sanyo do not have a surround sound Red panel Projection lens Dichroic reflector LCD panel Condenser lens Fig.1: the Sanyo projector uses four dichroic mirrors to first split the light beam from the metal halide lamp & then to recombine the red,• green & blue beams after they have been modulated by the liquid crystal panels. Ultraviolet filter NTSC program material and 50Hz for PAL material. To convert 625-line PAL pictures to 525 lines, the projector could do it by simply omitting one line in every six but this wou ld lead to jagged diagonal lines on the screen . Instead, the conversion is done by means of a "line store" (much simpler than a frame store) and a complex averaging scheme is used. For example, the first PAL line becomes the first NTSC line. The second NTSC line is a combination of 4/5ths of the 2nd PAL line and 115th of the 3rd PAL line. The third NTSC line becomes 3/5ths of the 3rd PAL line and 2/5ths of the 4th PAL line. The 4th PAL line becomes 2/5ths of the 4th PAL line and 3/5ths of the 5th PAL line. Finally, the 5th NTSC line becomes 115th of the 5th PAL and 4/5ths of the 6th PAL line. The process then repeats. Get the picture? When you thin k about it, while the Sanyo projector does not use a frame store to do the standards conversion , the LCD panels themselves are effectively a frame store. After all , they hold the video signal constant between each update, which happens every 1125th of a second. amplifier so we turned tOYamaha and arranged for the loan of their RXV1050 AM/FM stereo A/V receiver. If ever a product was made to complement the Sanyo projector, this Yamaha stereo receiver is it. It not only incorporates Dolby Pro-Logic decoding but also has has digital sound fi eld processing, as pion eered in the Yamaha DSP-1 a few years ago. With five amplifie r ch annels to drive front , rear and middle speakers, the DSP system can imitate the reverberation times of large and small concert halls. Not only that but the RXV1050 is also designed to switch video program sources so that it can handle video and audio signals from three sources; it even has S-video inputs. This makes it ideal as the program selector for the Sanyo projector. We set u p the San yo projector and Yam aha surround sound amplifi er combination with Dynaudio Image 4s as the main lou dspeakers (to be reviewed in a future issue), together with Yamaha NS-A102s as the rear speakers an d a Yamaha NS-Cl 10 as the centre effect speaker. Also hooked into the system was a Yamaha CD player. All of this equipment was set up in the reviewer's home, in a room measuring about 4.8 x 3.6 metres. This room is normally used as a music listening room and so is ideal fo r a "h ome cinema" . Th e final essential ingredients were a number of video Dichroic mirrors As Fig .1 shows, the Sanyo projector uses four dichroic mirrors to first split the light beam from the metal halide lamp and then to recombine the red, green and blue beams after they have been modulated by the liquid crystal panels. However, some readers may wonder why the lamp reflector is also labelled as being dichroic. How and why should a simple lamp reflector be dichroic? Should it not reflect all light equally well? The answer is that a dichroic mirror reflects some light and passes through the remainder. In the case of the lamp reflector, it reflects all light up into the ultraviolet range but most of the infrared (ie, heat) passes through it. This needs to be the case because the liquid crystal panels cannot stand very much heat. That is why there are also UV and infrared filters in front of the lamp. In fact , the liquid crystal panels can only withstand a maximum temperature of 80°C. Contrast that with the bulb temperature of the metal halide lamp which normally runs at 1000°C. No wander the projector has two fans to keep the interior cool. tapes of current action movies with lots of special effects and featuring Dolby Surround Sound. Audio/video integration With all of these factors brought together, the system really comes to life and is capable of providing an entertainment experience every bit as dram atic as that experienced in any picture theatre. The large screen is good, for all the reasons we have listed above, but it really needs a full range surround sound system for maximum impact. Once you sat down in the darkened room and pressed the play button on the VCR remote control to start the program you were then immersed in a MARCH 1993 9 Yamaha's RX-V1050 stereo receiver offers full Dolby Pro-Logic decoding & DSP to give a variety of surround sound environments. It has five amplifiers with a total power output of 390 watts into 8 ohms. It also has 40 preset AM/ FM stations & a comprehensive remote control with "learning" facilities. complete cinema experience. The larger than life-size images combined with spectacular surround sound make it all happen. Switching on the lights at the end of the program is just like emerging from a theatre and coming back to everyday reality - it's that good. In fact, with this combination of the Sanyo video projector and the YamahaRX-V1050 stereo receiver, we finally have achieved the "audio/ video integration" that the Japanese manufacturers have been talking about for years. Sound simulation Yamaha's RX-V1050 could be the subject of a complete review just by itself as it has so many features. With Dolby Surround Sound, the dialogue comes from the front speakers (in stereo) while music and sound effects come from the front, rear and centre channels to give dramatic reinforcement to the visual happenings. Yamaha has also added Enhanced Dolby mode which, as the name suggests, beefs up the sound effects. As well, there is Concert Video, Mono Movie, Rock Concert and Concert Hall effects. Concert Video is intended for movie soundtracks with stereo but without Dolby. Mono Movie is good for ordinary VCR tapes with mono sound - it gives a good simulated stereo spread. Rock Concert and Concert Hall are, as the names suggest, mainly intended for listening to music rather than as accompaniment to video but there is 10 SILICON CHIP no reason why they could not be used to provide the sound field for music videos, both rock and classical. And if you want to dispense with any enhancement, you can always listen to your music in unadorned stereo. be written the programmed functions. Naturally, it could be used to control both the Sanyo projector and VCR. Now if we had remote controlled room lighting as well, we would have total bliss! Juggling the remotes Closing thoughts And now to a few practicalities. Ever had the feeling that your remote controls were conspiring against you? They have the habit of hiding underneath the couch, underneath papers on the coffee table or even sliding behind cushions so that you go through enormous frustration when you suddenly need them. Well, home theatre is like that only worse. Each piece of equipment used in the above setup has its own remote control and only the one for the Sanyo projector has buttons which light up. In a darkened room, you then have the added complication of not being able to see which buttons to press, as well as the problem of finding the right remote control in the first place. The remote control for the Yamaha stereo receiver is a partial solution. As well as controlling its own extensive range of features, it can be used to control a Yamaha CD player and cassette deck so that meant I was not forced to use the remote control for my CD player. Still, you can't see the buttons in the dark. Furthermore, the Yamaha receiver's remote control has learning functions so that it can also be programmed to control other appliances. It comes with paper templates on which can So what is the overall picture? In our opinion, the Sanyo video projector will find a ready market both in teaching and training institutions, as well as in the home. In teaching applications, the internal speaker in the projector is adequate although a modest stereo setup with speakers either side of the screen is a big improvement. In the home, you really need to go for the full Sanyo and Yamaha combination. Going for one without the other would be a waste of money and even then, it is a choice which will only be available to the well-off. The recommended retail price of the Sanyo PLC200PP is $7499 while the RRP of the Sanyo-290R hifi stereo VCR is $899.00. The Yamaha RX-V1050 stereo receiver is $1399. To those figures must be added the cost of main and surround sound loudspeakers. For further information on the Sanyo video projector and hifi stereo VCR, contact Sanyo Australia Pty Ltd, PO Box 401 , Homebush, NSW 2140. Phone (02) 763 3822. For further information on the range of Yamaha surround sound equipment, contact Yamaha Music Australia Pty Ltd, 1733 Market Street, South Melbourne Vic 3205. Phone (03) 699 2388. SC