SINGER Alan Tam Wing-lun yesterday succeeded in preventing a rival music company from using his name and picture on a karaoke laser disc. Giving judgement in favour of Mr Tam, Mr Justice Mayo held that there was ample evidence to prove Lex Video Production Ltd and Universe Laser and Video Co Ltd had been guilty of passing off a disc they produced and distributed as one the artist's fans had been waiting for. The judge also said that had Mr Tam not obtained an interim injunction, the sale of the disc would no doubt have had a severely detrimental effect on the sales of his own disc. Also named as plaintiffs with Mr Tam were Magic Key International Ltd, Polygram Records Ltd and Entertainment Impact Ltd. They were seeking damages and an injunction to restrain Lex, which put out Alan Tam's Classic Golden Hits, and distributor Universe, from passing off laser video discs not made by the plaintiffs as their own. The amount of damages sought - believed to be in the region of $250,000 - will be assessed at a later date. During the hearing, Mr Tam had given evidence, and counsel for the plaintiffs, Mr Anthony Rogers QC, called singers Anita Mui Yim-fong and George Lam Chi-cheung to testify. Mr Tam had told the court that he first conceived the idea of producing a karaoke laser disc when undertaking a series of concerts at the Hongkong Coliseum in the summer of 1989. He gave 38 solo performances. During an interlude in the concerts, he visited Phuket to find suitable locations to make videos for the disc. He had given interviews about the planned disc. It was decided to launch it as near as possible to August 23, 1990, his birthday. Mr Tam said that his fans generally knew about the karaoke disc and awaited its introduction with ''eager anticipation''. However, on July 31, 1990, Lex brought out a karaoke disc which contained exclusively songs which had been made popular by Mr Tam. Mr Tam's name appeared together with a sketch bearing a resemblance to him on the sleeve. It was the plaintiffs' case that Lex and Universe had been guilty of passing off their work as being the work of Mr Tam, who was not impressed with the quality of the defendants' disc and feared it might have an adverse impact on the sale of his own recording. However, Lex and Universe, represented by Mr Andrew Liao QC, contended that since February that year, Polygram had been fully aware of their plan to release the disc. The songs did not use Mr Tam's vocals and the singer's only connection with the songs was that he first made them hits. The use of the name and image of Mr Tam was not calculated to deceive and would not lead to the belief that the disc was endorsed or approved of by the plaintiffs, the defence pleaded. In his reserved judgement, delivered yesterday, Mr Justice Mayo said he was satisfied that Mr Tam was very well known. His image was clearly a major hallmark for himself, his work, his products and his concerts, he said. He accepted that it was general knowledge among Mr Tam's fans that he would be releasing his own solo karaoke disc in August 1990. The release of Lex's disc at least created confusion and the evidence indicated a deliberate attempt to pass it off as being the genuine solo disc of Mr Tam, said the judge. He said the packaging of the disc produced and distributed by Lex and Universe gave potential buyers every reason to suppose that the disc was the one they were awaiting. There was ample evidence to prove the plaintiffs' claim that the defendants had been guilty of misrepresentation, said Mr Justice Mayo.