等于个圈圈
clear jam，jam in output bin，指的是卡纸了，请清除。
Jam in output bin是提示出纸口处卡纸。建议您先查看一下打印机内是否有卡纸，然后重新启动一下打印机看是否可以就绪。如果打印机内无卡纸，每次打印标准A4纸均提示Jam in output bin，有可能是机器的硬件故障导致的。
打印机的维护
打印机在使用的过程中，相应的参数不要超过打印机可以承受的范围。打印机使用之前，工作人员应该仔细阅读打印机说明书，在进行打印的过程中，运行的读数一定不要超过设定的参数。
如果打印时出现设备温度过高、或者打印声音异常的情况，一定要关掉电源，及时检查打印机的问题。打印机一旦带病工作，很可能会产生更严重的问题，严重时很可能会导致打印机重要部件的破损。
淘淘7011
Gray CardWhat is a gray card?Camera light meters see reflected light, but it is often useful to know the incident light (the light hitting your subject). With an 18 percent gray card you can get a reflected light reading which is essentially the same as reading incident light. Our gray cards are made from mat board. They have been painted to give results similar to an 18 percent reflectance Kodak gray card. This is equivalent to zone V. In the zone system, V is the middle tone half way between black and white.
