Abstract: The screen layout of a main screen and a subscreen is optimized, depending on the types of images to be displayed on the main screen and the subscreen. A video terminal, capable of displaying a subscreen within a main screen, is equipped with a signal control unit 15 as means for optimizing the main screen/subscreen layout, depending on the types of images to be displayed on the main screen and the subscreen. When the main screen is in a split composite screen mode, the signal control unit 15 allows a subscreen to be displayed on a screen of a television 11, with the subscreen occupying one section of the split composite screen. When the main screen is in a full screen mode, the signal control unit 15 allows a subscreen to be diminished.

Abstract: In this system, an instructor's device for teaching how to operate a personal computer is bidirectionally connected to a student's device for learning how to operate a personal computer, via a communication line of various types. The instructor's device has a personal computer as a lesson device, together with a TV monitor, a terminal, etc. for a videophone. The student's device 3 has a PC 1 as a lesson device, together with a TV monitor, a terminal 34, etc. for a videophone. The instructor and the student have a lesson on the personal computers, together with watching the TV monitors respectively.

Abstract: In this system, an instructor's device 1 for teaching how to operate a personal computer is bidirectionally connected to a student's device 3 for learning how to operate a personal computer, via a communication line N of various type. The instructor's device 1 has a PC 11 as a lesson device (a PC unit 11a, a monitor 11a1, a keyboard 11a2, and a mouse 11a3), together with a TV monitor 23, a terminal 20, etc. for the videophone. The student's terminal 1 has a PC 31 as a lesson device (a PC unit 31a, a monitor 31a1, a keyboard 31a2, and a mouse 31a3), together with a TV monitor 36, a terminal 34, etc. for the videophone. The instructor and the student have a lesson on the personal computer, with watching the TV monitors 23, 36, respectively.

Abstract: In the conversation skills testing system of this invention, the first examiner's videophone terminal 11 and the examinee's videophone terminal 26 are connected with each other via the circuit network 25. A test image is read out from the image/voice storage device 23, sent to the examinee's videophone terminal 26, and shown on the display screen of the examinee's videophone terminal 26. Based on an examinee's talk or conversation between the examiner and the examinee about contents of the test image, examinee's conversation skills are judged. Therefore, an examinee who may even live in a distant place can take a conversation skills test easily and at any time.

Abstract: A videophone device 1 for providing audio and video communication via a communication line, through operation of the remote controller 25. In the videophone device 1, a special button 23 having an answer button function is provided on a device body 31. When an incoming call from a remote telephone device is received, a press of the special button 23 allows the videophone device 1 to establish a communication line with the remote telephone device. Even if the remote controller is lost, the videophone device 1 enables minimum operations which would be required for the period until the remote controller is found.

Abstract: The present invention provides a teleconferencing system that can prevent connection errors between teleconferencing terminals and a communication control device and can optimize utilization of the communication control device, and can set and change the conference conditions with the teleconferencing terminal. The teleconferencing terminal is provided with information regarding a first connection destination number, and conference participants are provided with respective ID numbers and passwords. Information regarding a conference request, and the respective ID numbers and passwords of the conference participants are recorded in the receiving terminal at a time of reserving a conference. At the time of accepting a conference request, the teleconferencing terminals establish a connection to the receiving terminal via the communication lines with the first connection destination number and transmits information regarding the ID numbers and the passwords.

Abstract: The screen layout of a main screen and a subscreen is optimized, depending on the types of images to be displayed on the main screen and the subscreen. A video terminal, capable of displaying a subscreen within a main screen, is equipped with a signal control unit 15 as means for optimizing the main screen/subscreen layout, depending on the types of images to be displayed on the main screen and the subscreen. When the main screen is in a split composite screen mode, the signal control unit 15 allows a subscreen to be displayed on a screen of a television 11, with the subscreen occupying one section of the split composite screen. When the main screen is in a full screen mode, the signal control unit 15 allows a subscreen to be diminished.

Abstract: A logic circuit in which first and second transistors are connected in series between high and low potential power sources with the middle point of the series connection used as the output terminal; A same- and inverse-phase signal generating unit is provided connected between the high and low potential power sources in parallel with the first and second transistors for generating same- and inverse-phase signals based on the single input signal output from the logic circuit. A transient signal generating unit is provided for generating transient large current signals at the rise time of the inverse-phase signals and generating transient cut-off signals at the fall time of the inverse-phase signals. The series connected first transistor is driven and controlled based on the regular-phase signals, while the second transistor is driven and controlled based on the transient large current signal and transient cut-off signal, thus producing an inverse-phase output by a simple circuit construction.