Slide đa phương tiện chương 4 multimedia devices

Email: tienpv-fet@mail.hut.edu.vn C9-411 Dai Co Viet str 1, Hanoi c om Pham Van Tien, Dr rer nat , Embedded Networking Research Group Faculty of Elec and Telecom, Hanoi University of Science and Technology ng th an co ng Multimedia Devices cu u du o Tien Pham Van, Dr rer nat Hanoi University of Science and Technology CuuDuongThanCong.com https://fb.com/tailieudientucntt Pham Van Tien, Dr rer nat , Embedded Networking Research Group Faculty of Elec and Telecom, Hanoi University of Science and Technology Email: tienpv-fet@mail.hut.edu.vn C9-411 Dai Co Viet str 1, Hanoi c om Agenda cu u du o ng th an co ng • Capturing/recording/Sensing devices • Rendering/Recontruction/Actuator devices CuuDuongThanCong.com https://fb.com/tailieudientucntt Pham Van Tien, Dr rer nat , Embedded Networking Research Group Faculty of Elec and Telecom, Hanoi University of Science and Technology Email: tienpv-fet@mail.hut.edu.vn C9-411 Dai Co Viet str 1, Hanoi c om Microphones cu u du o ng th an co ng • Microphones are sound sensors (really - transient pressure sensors) • Speakers are sound actuators • The first microphones and speakers (or earphones) were devised and patented for use in telephones • Alexander Graham Bell patented the first variable resistance microphone in 1876 CuuDuongThanCong.com https://fb.com/tailieudientucntt Pham Van Tien, Dr rer nat , Embedded Networking Research Group Faculty of Elec and Telecom, Hanoi University of Science and Technology Email: tienpv-fet@mail.hut.edu.vn C9-411 Dai Co Viet str 1, Hanoi cu u du o ng th an co ng c om Bell’s Microphone CuuDuongThanCong.com https://fb.com/tailieudientucntt Pham Van Tien, Dr rer nat , Embedded Networking Research Group Faculty of Elec and Telecom, Hanoi University of Science and Technology Email: tienpv-fet@mail.hut.edu.vn C9-411 Dai Co Viet str 1, Hanoi cu u du o ng th an co ng c om The carbon microphone (Edison) CuuDuongThanCong.com https://fb.com/tailieudientucntt Pham Van Tien, Dr rer nat , Embedded Networking Research Group Faculty of Elec and Telecom, Hanoi University of Science and Technology Email: tienpv-fet@mail.hut.edu.vn C9-411 Dai Co Viet str 1, Hanoi cu u du o ng th an co ng c om The carbon microphone CuuDuongThanCong.com https://fb.com/tailieudientucntt Pham Van Tien, Dr rer nat , Embedded Networking Research Group Faculty of Elec and Telecom, Hanoi University of Science and Technology Email: tienpv-fet@mail.hut.edu.vn C9-411 Dai Co Viet str 1, Hanoi cu u du o ng th an co ng c om The magnetic microphone CuuDuongThanCong.com https://fb.com/tailieudientucntt Pham Van Tien, Dr rer nat , Embedded Networking Research Group Faculty of Elec and Telecom, Hanoi University of Science and Technology Email: tienpv-fet@mail.hut.edu.vn C9-411 Dai Co Viet str 1, Hanoi cu u du o ng th an co ng c om Dynamic microphone CuuDuongThanCong.com https://fb.com/tailieudientucntt Pham Van Tien, Dr rer nat , Embedded Networking Research Group Faculty of Elec and Telecom, Hanoi University of Science and Technology Email: tienpv-fet@mail.hut.edu.vn C9-411 Dai Co Viet str 1, Hanoi Capacitive microphones u du o ng th an co ng c om Also called “condenser” microphones Idea is trivially simple: Allow sound to move a plate in a capacitor Sense the change in capacitance cu • • • • CuuDuongThanCong.com https://fb.com/tailieudientucntt Pham Van Tien, Dr rer nat , Embedded Networking Research Group Faculty of Elec and Telecom, Hanoi University of Science and Technology Email: tienpv-fet@mail.hut.edu.vn C9-411 Dai Co Viet str 1, Hanoi The electret microphone cu u du o ng th an co ng c om • The electret microphone is a capacitive microphone • Made of two conducting plates with a layer of an electret material under the upper plate CuuDuongThanCong.com https://fb.com/tailieudientucntt Pham Van Tien, Dr rer nat , Embedded Networking Research Group Faculty of Elec and Telecom, Hanoi University of Science and Technology Email: tienpv-fet@mail.hut.edu.vn C9-411 Dai Co Viet str 1, Hanoi c om Touch Screen Technology u du o ng th an Resistive Capacitive Surface Acoustic Wave (SAW) Infrared LED or Optical cu • • • • co ng • Four different technologies used to make touch screens today: CuuDuongThanCong.com https://fb.com/tailieudientucntt Pham Van Tien, Dr rer nat , Embedded Networking Research Group Faculty of Elec and Telecom, Hanoi University of Science and Technology Email: tienpv-fet@mail.hut.edu.vn C9-411 Dai Co Viet str 1, Hanoi co cu u du o ng th an • Two layers of conductive material • Touch creates contact between resistive layers completing circuit ng c om Resistive Touch Screens CuuDuongThanCong.com https://fb.com/tailieudientucntt Pham Van Tien, Dr rer nat , Embedded Networking Research Group Faculty of Elec and Telecom, Hanoi University of Science and Technology Email: tienpv-fet@mail.hut.edu.vn C9-411 Dai Co Viet str 1, Hanoi ng cu u du o ng th an co • Voltage in circuit changes based on position • Controller determines location based on voltages • Any material can trigger sensors c om Resistive Touch Screens CuuDuongThanCong.com [2] https://fb.com/tailieudientucntt Pham Van Tien, Dr rer nat , Embedded Networking Research Group Faculty of Elec and Telecom, Hanoi University of Science and Technology Email: tienpv-fet@mail.hut.edu.vn C9-411 Dai Co Viet str 1, Hanoi ng cu u du o ng th an co • Glass panel with conductive layer (Indium Tin Oxide) • Small amount of voltage applied to four corners of touch screen c om Capacitive Touch Screens CuuDuongThanCong.com https://fb.com/tailieudientucntt Pham Van Tien, Dr rer nat , Embedded Networking Research Group Faculty of Elec and Telecom, Hanoi University of Science and Technology Email: tienpv-fet@mail.hut.edu.vn C9-411 Dai Co Viet str 1, Hanoi ng co cu u du o ng th an • Touch draws minute amount of current creating voltage drop • Coordinates of point of contact calculated by controller c om Capacitive Touch Screens CuuDuongThanCong.com https://fb.com/tailieudientucntt Pham Van Tien, Dr rer nat , Embedded Networking Research Group Faculty of Elec and Telecom, Hanoi University of Science and Technology Email: tienpv-fet@mail.hut.edu.vn C9-411 Dai Co Viet str 1, Hanoi Why Capacitive? c om • Advantages: ng th an co ng – Durable surface material – High endurance (~255 million touches) – Very accurate – Good optical quality du o • Disadvantages: cu u – Triggered only by bare finger or active stylus CuuDuongThanCong.com https://fb.com/tailieudientucntt Pham Van Tien, Dr rer nat , Embedded Networking Research Group Faculty of Elec and Telecom, Hanoi University of Science and Technology Email: tienpv-fet@mail.hut.edu.vn C9-411 Dai Co Viet str 1, Hanoi cu u du o ng th an co ng c om Surface Acoustic Wave Touch Screens • Surface consists of glass overlay with transmitting and receiving transducers CuuDuongThanCong.com https://fb.com/tailieudientucntt Pham Van Tien, Dr rer nat , Embedded Networking Research Group Faculty of Elec and Telecom, Hanoi University of Science and Technology Email: tienpv-fet@mail.hut.edu.vn C9-411 Dai Co Viet str 1, Hanoi ng th an co ng c om Surface Acoustic Wave Touch Screens cu u du o • Electrical signals sent to the transmitting transducers converts to ultrasonic waves • Waves are directed across screen by reflectors then directed to receiving transducers CuuDuongThanCong.com https://fb.com/tailieudientucntt Pham Van Tien, Dr rer nat , Embedded Networking Research Group Faculty of Elec and Telecom, Hanoi University of Science and Technology Email: tienpv-fet@mail.hut.edu.vn C9-411 Dai Co Viet str 1, Hanoi th an co ng c om Surface Acoustic Wave Touch Screens cu u du o ng • When finger touches screen it absorbs waves • Received values are compared to stored digital maps to calculate x and y coordinates CuuDuongThanCong.com https://fb.com/tailieudientucntt Pham Van Tien, Dr rer nat , Embedded Networking Research Group Faculty of Elec and Telecom, Hanoi University of Science and Technology Email: tienpv-fet@mail.hut.edu.vn C9-411 Dai Co Viet str 1, Hanoi Why SAW? c om • Advantages: ng • Disadvantages: th an co ng – Best optical quality – High surface durability and seal – Activated by multiple sources cu u du o – Expensive – Contaminates on screen can cause false-touches CuuDuongThanCong.com https://fb.com/tailieudientucntt Pham Van Tien, Dr rer nat , Embedded Networking Research Group Faculty of Elec and Telecom, Hanoi University of Science and Technology Email: tienpv-fet@mail.hut.edu.vn C9-411 Dai Co Viet str 1, Hanoi c om Surface Acoustic Wave Summary cu u du o ng th an co ng • We were not able to find prices for individual screens • Any object can be used to activate the screen • Able to register multiple touches • ~100% of light is transferred through CuuDuongThanCong.com https://fb.com/tailieudientucntt Pham Van Tien, Dr rer nat , Embedded Networking Research Group Faculty of Elec and Telecom, Hanoi University of Science and Technology [2] du o ng th an co ng c om Infrared/Optical Touch Screens Email: tienpv-fet@mail.hut.edu.vn C9-411 Dai Co Viet str 1, Hanoi cu u • Uses infrared LEDs and matching photodetectors • Touching screen interrupts LEDs CuuDuongThanCong.com https://fb.com/tailieudientucntt Pham Van Tien, Dr rer nat , Embedded Networking Research Group Faculty of Elec and Telecom, Hanoi University of Science and Technology Email: tienpv-fet@mail.hut.edu.vn C9-411 Dai Co Viet str 1, Hanoi u du o ng th an co ng c om Infrared/Optical Touch Screens cu • Cameras detect reflected LED caused by touch • Controller able to calculate coordinates from camera data CuuDuongThanCong.com https://fb.com/tailieudientucntt Pham Van Tien, Dr rer nat , Embedded Networking Research Group Faculty of Elec and Telecom, Hanoi University of Science and Technology Email: tienpv-fet@mail.hut.edu.vn C9-411 Dai Co Viet str 1, Hanoi c om Infrared/Optical Touch Screens co an ng th High optical clarity Durable surface Supports multi-touch Can scale to large sizes du o • • • • ng – Advantages: – Disadvantages: cu u • Expensive • Cameras can get out of alignment CuuDuongThanCong.com https://fb.com/tailieudientucntt Pham Van Tien, Dr rer nat , Embedded Networking Research Group Faculty of Elec and Telecom, Hanoi University of Science and Technology Email: tienpv-fet@mail.hut.edu.vn C9-411 Dai Co Viet str 1, Hanoi c om Further readings cu u du o ng th an co ng • LED back-lighted LCD • Storage media: flash, bluray… CuuDuongThanCong.com https://fb.com/tailieudientucntt ... tienpv-fet@mail.hut.edu.vn C9 -41 1 Dai Co Viet str 1, Hanoi c om Agenda cu u du o ng th an co ng • Capturing/recording/Sensing devices • Rendering/Recontruction/Actuator devices CuuDuongThanCong.com... University of Science and Technology Email: tienpv-fet@mail.hut.edu.vn C9 -41 1 Dai Co Viet str 1, Hanoi Piezoelectric devices ng th Qx = d11 Fx an co ng c om • A piezoelectric device is built... tienpv-fet@mail.hut.edu.vn C9 -41 1 Dai Co Viet str 1, Hanoi cu u du o ng th an co ng c om Piezoelectric buzzer CuuDuongThanCong.com https://fb.com/tailieudientucntt Email: tienpv-fet@mail.hut.edu.vn C9 -41 1 Dai Co