Touch switch screen and touch delay circuit of electronic blackboard

Abstract

The invention discloses a touch switch screen and a touch delay circuit of an electronic blackboard, comprises a capacitive screen touch switch, + 5V sockets JP1-JP2, a correction copper foil socket JP3, relays J1-J2, transistors Q1-Q5, resistors R0-R7, capacitors C1-C2, a USB socket of an OPS computer, a USB socket of a PC, a digital selector and a USB socket of a touch control board. The invention pre-corrects the grounding of the power supply of the touch pad, Subsequently, the power supply time of the touch pad is delayed about 1.5 seconds, and the touch pad is supplied with power througha USB socket, so that the touch pad can carry out real-time data detection after the power supply of the backlight is stable, and the touch control threshold value under the new environment is determined, so as to avoid the influence of the large current supplied by the backlight, and realize stable and accurate touch control.

Description

technical field [0001] The invention belongs to the technical field of electronic blackboards, and relates to a touch switch screen and a touch delay circuit of the electronic blackboard. Background technique [0002] With the advancement of teaching modernization and the advancement of large-screen display and touch control technology, electronic blackboards are more and more widely used in all walks of life, especially in the field of education. [0003] The electronic blackboard needs the function of turning off the screen with one key (turning off the backlight) in actual use. In order to avoid misoperation during the writing process, the power supply to the touch panel is also cut off when the backlight is turned off. The following two problems may occur when turning on the screen again. [0004] One is that when the screen needs to be turned on, the current circuit starts the backlight power supply and the touchpad power supply at the same time. At this time, the larg...

AI Technical Summary

Problems solved by technology

[0004] One is that when the screen needs to be turned on, the current circuit starts the backlight power supply and the touchpad power supply at the same time. At this time, the large current of the backlight power supply may affect the real-time data detection after the touchpad is powered, thus causing the problem of touch failure.

[0005] Second, during the use of the blackboard, due to changes in temperature, humidity and structure, the touch may become unstable. Generally speaking, as long as the blackboard is turned off and then turned on again, the touchpad can re-adapt to the new environment and return to normal. At this time, the large current of the backlight power supply may also affect the real-time data detection.

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