Advantages of High-Bright Color LCDs for PACS
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TOTOKU White Paper High-Bright Color Advantages of High-Bright Color LCDs for PACS

TOTOKU White Paper ADVANTAGES OF HIGH-BRIGHT COLOR LCDs FOR PACS 2. THE TREND OF COLOR IMAGING AND ADVANTAGES OF HIGH-BRIGHT COLOR LCD-------- 2 Copyright © 2005 TOTOKU ELECTRIC CO., LTD. All rights reserved.

1. PREFACE The Picture Archive and Communication System (PACS) introduced in the early 1990's, was a computer system designed to provide aid in diagnostic image reading and data management, in the world of conventional X-ray films. Initially, these systems were handling monochrome images generated from Ultrasound, CT and MRI. As the technology of diagnostic devices and IT advanced, the use of color images has become more prominent. This advance in technology is driving increased demand for PACS monitors capable of diagnostic color image reading. Commercially available color LCDs are not...

areas of nuclear medicine, ultrasound, and endoscopic images. At large hospitals, implementation of PACS is growing beyond the radiology departments and expanding to internal medicine, orthopedics, ophthalmology, and the dermatology departments. These new applications create more diversity and frequency of color images. In summary, this trend in medical color imaging is driving an increasing demand for color displays that are suitable for diagnostic reading and use as the primary monitor with workstations. To date, color displays have been mainly used as secondly monitors. Additionally,...

available LCDs; the number of JNDs is 20% higher in the entire 0-200 lux luminous range (See Figure 1). As mentioned above, the most important challenge in developing color monitors adequate for medical systems including PACS is achieving higher brightness. The next section describes the technical aspects of our high-bright color technology. 3. TECHNOLOGY BEHIND THE HIGH-BRIGHT COLOR LCD This chapter describes the technical background; how color LCDs work and why color LCD’s brightness is generally lower than the monochrome LCD, and tells how we overcame the challenge to develop our...

3.2.1 Optimizing the backlight and the circuit There are two types of LCD backlights. One is called an edge type that mounts the CCFL lamps both at the top and bottom of the panel edges. This type is effective in keeping the panels thinner, but is not able to accomplish higher brightness. The other is called the direct type, which has the CCFL lamps located directly behind the liquid crystal cells. This method is more effective in achieving higher brightness compared to the edge type. Using the direct type and increasing the output of individual CCFL lamps, we have achieved higher...

TOTOKU White Paper calibration table Built-in sensor driving circuit External brightness eensor Figure 5. Brightness detection feedback loop The brightness feedback system is optimized to measure the light transmitted through the liquid crystal cells by using the "sensor elements," the "micro current amplification circuit," and its "firmware," then realizes the high accurate brightness stability for the entire grayscale range from minimum to maximum luminance based on measured data by the sensor. 3.2.4 Light condensing lenses As mentioned in the previous section, the higher the resolution,...

TOTOKU White Paper Engineering Group Intelligent Devices & Solutions Company Copyright © 2005 TOTOKU ELECTRIC CO., LTD. All rights reserved.