Instruction: Parse the product information to locate the target attribute, and then provide the extracted value of the target attribute and its source in the output, specifying None if the attribute is not present.

Input:
Product title: 19" Norcent LT-1931 720p Widescreen LCD HDTV (Black/Silver)
Product description: This Norcent LT-1931 HDTV boasts a breathtaking picture quality on the 19-inch widescreen LCD display, 1440 x 900 resolution and 800:1 contrast ratio! Digital and Analog TV reception is provided by the built-in ATSC/Clear-QAM/NTSC tuner. The HDMI input delivers uncompressed crystal clear digital video and audio via a single cable! Other features include S-Video, component and composite video inputs, 2D digital combo for accurate color processing, 300 cd/m2 brightness, tri-lingual on screen menu and favorite channel selection! The Norcent LT-1931 features a stylish black and silver cabinet and includes a table stand that easily removes for wall mounting application! Order today!
Product feature: Norcent LT-1931 19-inch Widescreen LCD HDTV General Features: Black and Silver design, 19-inch widescreen LCD display 16:10 aspect ratio ATSC/Clear-QAM/NTSC TV Tuner, 480i, 480p, 720p, 1080i signal compatibility 1440 x 900 panel resolution, 0.285 x 0.285 mm pixel pitch 300 cd/m2 brightness 800:1 contrast ratio 16.2 million colors, 160-degree H/V viewing angle
Product brand: Norcent
Target attributes: Display Type
Answer: attribute: display type
value: lcd
source: product description
attribute: display type
value: lcd
source: product feature
attribute: display type
value: lcd
source: product title