答案：1. Belyaev.
解析：文中第二段提到“The designer says he comes up with the idea...”，第四段提到“Belyaev says he recently introduced his creation...”，可知设计者是Belyaev。
2. Because he saw people trying to hide from the rain under street lamps and thought a canopy built into a street lamp would help.
解析：根据第二段“Once, I was driving on a central Saint Petersburg street and saw the street lamps lighting up people trying to hide from the rain. I thought it would be all right to have a canopy built into a street lamp”可知原因。
3. After three minutes.
解析：第四段明确提到“After three minutes of not being used the canopy is closed.”。
4. Several people.
解析：第五段“Each lampbrella would offer enough protection for several people.”表明可以保护几个人。
5. The passage introduces a new invention called lampbrella, including its designer, creation reason, functions and future prospects.
解析：文章围绕lampbrella展开，介绍了设计者、发明原因、功能（如感应下雨开合、运动传感器、安全措施等）以及目前无生产计划但有推广意向等，此句概括了主要内容。