The Disney Channel logo has undergone numerous changes over the years.
The original Disney Channel logo was rectangular with the edges rounded off, had lines cutting through it, and the classic Mickey Mouse silhouette in the middle. At times, the logo was made to look like glass. This logo was often seen in similarly-themed station identifications accompanied by light piano music.
The channel during this time had some stop motion cartoons, seen in a first person view from either Mickey or Donald, which ultimately and in a comical fashion resulted in the creation of the Disney logo.
The Zoog EraEdit
When The Disney Channel went public (having been a PBS-like station for many years), the logo and channel were themed in a more cartoony fashion, and featured a TV-shaped Mickey silhouette. This reflected the new target audience of kids rather than families (alongside the Disney/ABC merger). This logo was more bouncy and later had Disney cartoon characters on it.
The Disney logo became only a partial Mickey silhouette, often transparent so as to not be invasive. For awhile, Disney stars would draw the logo with a magic wand (the logo itself thus becoming sparkly). The network eventually dropped the article and became simply "Disney Channel".
Today's Disney Channel logo is the classic Disney signature with "CHANNEL" written below it in comic sans with the Mickey silhouette forming the dot of the I in the word "Disney".