Abstract: A display device includes a multiple of light-emitting elements and a multiple of driving circuits. Each of the multiple of driving circuits is configured to generate a driving current flowing through one of the multiple of light-emitting elements. Each of the multiple of driving circuits includes a first transistor, a second transistor, a reset circuit, a first control circuit and a second control circuit. The driving current flows from a first system high voltage terminal through the first transistor, the second transistor and one of the multiple of light-emitting elements to a system low voltage terminal. The first control circuit is configured to control the first transistor to modulate pulse amplitude of the driving current. The second control circuit is configured to control the second transistor to modulate pulse width of the driving current.

Abstract: A heating sleeve for medical examination instruments includes an open circular band having a free end provided with a first engaging means and another free end provided with a second engaging means engageable with the first engaging means, a flexible heat emitting member affixed to an inner side of the open circular band, a power source mounted on an outer side of the open circular band, whereby the power source will heat the flexible heat emitting member thereby rapidly warning a contact member of a medical examination instrument and therefore preventing a patient from feeling uncomfortable to the cold contact member.