| 摘要 |
<p>TITLE KEY TELEPHONE EXCLUSION CIRCUIT An exclusion circuit for use in a key telephone providing an exclusion release feature. Key telephones are excluded or prevented from accessing a busy line by the exclusion circuit The exclusion release feature, in a key telephone connected to a telephone line, is operated in response to operation of an exclusion release key or partial operation of a hold key, to allow an associated excluded key telephone to connect to a busy telephone line.</p> |
