UPS devices is a Universal Power Supply. The purpose of this device is to keep your equipment running briefly if there is a power outage. The laser printer should never be plugged into a UPS. The reason for this is due to the wiring in the UPS. It will not supply the appropriate power to the printer.
The same thought is with a power strip. With a power strip if you have multiple devices plugged in, it will share the power with all of the devices plugged in. Laser printers need a large amount of power to operate, and there could be issues because of the lack of power. It is recommended that you plug the laser printer directly into the wall socket.