Technical Details for Hitachi CP SX5600

Hitachi CP SX5600 ... XGA models. Class leading video performance comes from LCOS's high contrast ratio and high response speed, to which are added Hitachi's motion adaptive progressive scan, black level enhancement and noise reduction. The CP-SX5600 takes flexibility and ease of use to new levels with multiple computer and video inputs including DVI and component video, plus great new features like horizontal keystone correction and convenient control panel input selection.

In a conventional (transmissive) LCD panel, the light passing through each element is obstructed by the connections to that pixel element. These control circuits block the light passing through the LCD panel and as resolution is increased so the aperture ratio is further reduced. In Hitachi's LCOS panel, light is reflected back through the liquid crystal by the mirrored surface of a silicon substrate containing the control circuits. Without the control circuits between them the liquid crystal elements can be placed very close together producing a smooth, natural image on screen and yielding an aperture ratio of 92% compared with 40,60% for transmissive panels. This results in higher contrast ratio and the ability to manufacture more compact panels that achieve similar resolution and brightness. The secret of Hitachi's original LCOS technology is the use of very narrow spacing between the plates allowing the thickness of the liquid crystal to be halved, greatly reducing response time - the thinner the liquid crystal the faster it can change state in response to control signals. This is particularly important for video with moving content where a slow response time leads to image smearing.

A number of new facilities are incorporated in the CP-SX5600 to make it easy to use and to achieve highly professional presentations. Setting up is made easier and more flexible by integrated horizontal and vertical keystone correction. With this feature image distortion can be removed even when the projector is set off to the side of the square-on position. Keystone adjustment is simply achieved using buttons on the top of the unit. In the same convenient location are input selection buttons and a display giving an instant view of which input is selected.

The CP-SX5600 offers virtually every input connection required to accommodate today's media sources. Video inputs cater for composite, S-video and component video formats, all with stereo audio. On the computer side there are two analogue RGB inputs and a digital visual interface (DVI-D), again with stereo audio. Each input can be simultaneously connected and easily selected from the projector's control panel while the image freeze feature avoids any transient on screen noise during switching. Other connectors include RGB out for a monitor display, RS232C for control by a PC and USB for remote mouse operation.

The CP-SX5600's native SXGA+ resolution (1365 x 1024) allows the true 1: 1 display of SXGA images that are ideal for detailed high-resolution images from presentation applications and especially for subjects involving drawings or diagrams. In addition, the 4: 3 aspect ratio of SXGA+ gives the CP-SX5600 the ability to display other 4: 3 formats such as UXGA (1600 x 1200) and XGA (1024 x 768) without the distortion involved in resizing to fit the 5: 4 aspect ratio of SXGA.

A TV picture comprises two fields, displayed one after the other, containing the even or odd lines of the image. This only works because CRT phosphors have a persistence that causes them to glow for a short time after the signal is removed. Projection screens, white boards and office walls have no persistence so a video projector must create a full frame image to replace every field. Many projectors achieve this by repeating the lines of each field, "line doubling", but this reduces resolution and causes line flicker. The CP-SX5600 overcomes these problems by combining the two fields in a memory buffer which is projected twice - progressive scanning. Even progressive scanning can't prevent the alternate lines of a rapidly moving object shifting between the odd and even fields causing a broken up appearance. This problem affects normal TV displays as well as projectors. The CP-SX5600 uses sophisticated image processing techniques to isolate a moving object. Its field lines are aligned and combined, and the object shown in its correct position in each frame - Motion Adaptive Progressive Scanning.

In most video images the darkest areas of the picture are not fully black. By forcing these areas to black the perceived quality of the projected image can often be improved. Normally, black enhancement is a linear adjustment, which proportionately darkens all areas of the picture causing an unwelcome reduction in midrange brightness. Hitachi's advanced black enhancement method avoids this by applying a measured adjustment to the darker areas but leaving the brighter areas unaffected. The CP-SX5600 also uses digital image processing to reduce excessive image noise. By continually comparing the value of each pixel over successive fields, any abrupt or isolated change can be identified and suppressed resulting in a cleaner sharper image.