Wobulation is a term which refers to the known variation (or wobble) in a characteristic. Examples of where the term is used, include to describe advanced radar waveform modulations - where the repetition rate or centre frequency of a signals is changed in a repetitive fashion to reduce the probability of intercept of a signal. Such techniques can also have some beneficial effects to a received radar signal. It can be used to reduce clutter, making side-lobe powers decorrelate by a proportion and make second time around signal decorrelate when used as an anti-Fruiting measure (FRUIT means: False Returns Uncorrelated In Time).

In large-screen television technology, wobulation is Hewlett-Packard's term for a form of interlacing designed for use with fixed pixel displays. The term is loosely derived from the word 'wobble' and was inspired by HP's work with the overlap of printing ink. Wobulation reduces the cost and complexity of components required for the creation of high resolution displays. Large-screen television technology developed rapidly in the late 1990’s and 2000’s, and currently the most popular technologies are liquid crystal display (LCD), plasma display, and projection television. ... The Hewlett-Packard Company (NYSE: HPQ), commonly known as HP, is a very large, global company headquartered in Palo Alto, California, United States. ... Interlacing is a method of displaying images on a raster-scanned display device, such as a cathode ray tube (CRT). ... Fixed pixel displays are display technologies such as LCD and plasma that use an unfluctuating matrix of pixels with a set number of pixels in each row and column. ...

Wobulation works by overlapping pixels. It does so by generating multiple sub-frames of data while an optical image shifting mechanism (e.g. the mirror of a digital micromirror device) then displaces the projected image of each sub-frame by a fraction of a pixel (e.g. one-half or one-third). The sub-frames are then projected in rapid succession, and appear to the human eye as if they are being projected simultaneously and superimposed. For example, a high-resolution HDTV video frame is divided into two sub-frames, A and B. Sub-frame A is projected, and then the miniature mirror on a digital micromirror device switches and displaces sub-frame B one half pixel length as it is projected. When projected in rapid succession, the sub-frames superimpose, and create to the human eye a complete and seamless TV image. If the video sub-frames are aligned so that the corners of the pixels in the second sub-frame are projected at the centers of the first, the illusion of double the resolution is achieved, like in an interlaced CRT display. Thus a lower resolution fixed pixel device using wobulation can emulate the picture of higher resolution fixed device, at a reduced cost. This example shows an image with a portion greatly enlarged, in which the individual pixels are rendered as little squares and can easily be seen. ... A Digital Micromirror Device, or DMD is an optical semiconductor that is the core of DLP projection technology, and was invented by Dr. Larry Hornbeck and Dr. William E. Ed Nelson of Texas Instruments (TI) in 1987. ... Cathode ray tube employing electromagnetic focus and deflection Cutaway rendering of a color CRT: 1. ...

While wobulation can in theory be used in many types of display devices, it is currently primarily used in displays using Digital Light Processing (DLP). DLP is a Texas Instruments (TI) technology which relies on a Digital Micromirror Device (DMD) chip. TI calls its implementation of wobulation 'SmoothPicture'. Horizontal wobulation used in current TI products allows a DMD chip with a 960x1080 mirror array to produce a 1920x1080 pixel picture. Also, the image overlap inherent in the use of wobulation eliminates the 'screen door' effect common on other fixed pixel displays such as plasma and LCD, but may in some implementations also create some reduction in sharpness. Wobulation is used by a number of TV manufacturers, including Hewlett-Packard, Mitsubishi, RCA, Samsung, and Toshiba. For political parties using this acronym, see Democratic Labour Party. ... Texas Instruments (NYSE: TXN), better known in the electronics industry (and popularly) as TI, is an American company based in Dallas, Texas, USA, renowned for developing and commercializing semiconductor and computer technology. ... Planar Systems plasma display Composition of plasma display panel A plasma display panel (PDP) is a type of flat panel display now commonly used for large TV displays (typically above 37-inch or 940 mm). ... LCD redirects here. ... The Hewlett-Packard Company (NYSE: HPQ), commonly known as HP, is a very large, global company headquartered in Palo Alto, California, United States. ... Mitsubishi Logo The Mitsubishi Group ), Mitsubishi Group of Companies, or Mitsubishi Companies, all refer to a large grouping of independently operated Japanese companies which share the Mitsubishi brand name. ... RCA, formerly an acronym for the Radio Corporation of America, is now a trademark owned by Thomson SA through RCA Trademark Management S.A., a company owned by Thomson. ... Samsung Group is one of the largest South Korean business groupings. ... Toshiba Corporations headquarters (Center) in Hamamatsucho, Tokyo Toshiba Corporation sales by division for year ending March 31, 2005 Toshiba Corporation ) (TYO: 6502 ) is a Japanese multinational conglomerate manufacturing company, headquartered in Tokyo, Japan. ...

In its current implementation Wobulation is used only to double the horizontal resolution of a display. However, Wobulation is currently capable of doubling the vertical and horizontal resolution of an image (2x wobulation). HP has 4x wobulation, or quadrupling in the horizontal and vertical directions, planned for the future.

References

U.S. Patents 6,078,038; 7,030,894 and 7,034,811.

External links

• Hewlett-Packard Wobulation
• Diagram at Sound & Vision Magazine
• Explanation at Popular Science