Claims
- 1. An interface unit comprising:a converting circuit for selectively connecting a first interface of a lower apparatus and a second interface of an upper apparatus; a first power monitoring circuit for monitoring the presence of power from said lower apparatus; and a second power monitoring circuit for monitoring the presence of power from said upper apparatus; wherein said converting circuit enables a connection between said upper apparatus and said lower apparatus when both of said first and second power monitoring circuits detect power.
- 2. The interface unit according to claim 1, further comprising:an AND circuit having first and second input ports connected to said first and second power monitoring circuit, respectively, and an output port connected to said converting circuit.
- 3. An interface unit comprising:a converting circuit for connecting a first interface of a lower apparatus and a second interface of an upper apparatus; and a switching circuit for enabling said converting unit when detecting the presence of power from both of said lower apparatus and said upper apparatus.
Priority Claims (2)
Number |
Date |
Country |
Kind |
8-124489 |
May 1996 |
JP |
|
9-103070 |
Apr 1997 |
JP |
|
Parent Case Info
This is a divisional of application Ser. No. 08/891,382, filed Jul. 11, 1997, now U.S. Pat. No. 6,295,569, which is a continuation-in-part of application Ser. No. 08/791,261, filed Jan. 30, 1997, now abandoned.
US Referenced Citations (20)
Foreign Referenced Citations (5)
Number |
Date |
Country |
6020244 |
Jan 1994 |
JP |
6139682 |
May 1994 |
JP |
7029299 |
Jan 1995 |
JP |
7093954 |
Apr 1995 |
JP |
7114770 |
May 1995 |
JP |
Continuation in Parts (1)
|
Number |
Date |
Country |
Parent |
08/791261 |
Jan 1997 |
US |
Child |
08/891382 |
|
US |