Chochin(提灯) is a traditional Japanese lantern which is originally made of bamboo or wood and Japanese washi paper. Characteristic part of chochin is telescoping, you can fold the main part of the lantern and extend when using.
Traditional chochin used candles and people used as portable lighting source as same as flash light when moving in dark or placed outside in the evening, next to the entrance of the stores or restaurant. Today, modern chochin is made of plastics and uses electricity for the light source , then not used as a flash light anymore.
However, you still can see it mostly at the authentic Japanese restaurants throughout Japan. Restaurant staff turns on chochin upon opening the restaurant and turns it off when closing. Therefore if you see the light is off during evening, it means that the restaurant is already closed.