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This study introduces an X-ray imager that uses TlBr detectors and demonstrates its potential for X-ray imaging applications. Although TlBr detectors are suitable for X-ray imaging applications because of the associated large attenuation coefficients and direct conversion behavior, realizing a flat-panel detector with TlBr involves developing processes. The proposed imager is constructed utilizing a combination of existing technologies; it comprises a plate electrode containing thallium metal to suppress the polarization phenomenon, pixelated silver electrodes with $80~\mu \text{m}$ pitch, and a photon-counting-type readout integrated circuit (ROIC) that can work in the hole as well as electron collection modes. The modulation transfer function (MTF) of the imager is calculated based on the imaging results of an X-ray test chart, and the result corresponds to $180~\mu \text{m}$ sampling. Even though the imager is not designed specifically for TlBr detectors, the measured high-MTF shows the immense potential of TlBr detectors for X-ray imaging applications. In addition, the polarization phenomenon and its recovery effect through bias switching are confirmed to be similar to conventional detectors with large electrodes. The results of this study can motivate the development of flat-panel-detector processes optimized for TlBr detectors.

This study demonstrates a result of polarization effect of an X-ray imager that uses TlBr detectors with silver small electrodes. Although TlBr detectors are suitable for X-ray imaging applications because of the associated large attenuation coefficients and direct conversion behavior, realizing a flat-panel detector with TlBr involves developing processes. The demonstrated imager is constructed utilizing a combination of existing technologies; it comprises a plate electrode containing thallium metal to suppress the polarization phenomenon, pixelated silver electrodes with 80 µm pitch, and a photon-counting-type readout integrated circuit that can work in the hole as well as electron collection modes. As a result, it was reconfirmed that the polarization phenomenon is a serious problem for small electrodes as well as for large electrodes. In addition, the polarization could have accelerated by high X-rays flux. This result can motivate the development of polarization-tolerant small electrodes for TlBr detectors.

We have reported CdTe FPDs with high resolution imaging and energy distinguish for multi energy spectral CT X-ray imaging, and it can acquire high amount of information. This study developed a system that aggregates and 3DCT-Xray data with boundary extraction function for high speed data communication. In the medical and industrial field, it is necessary to narrow down the desired information and confirm it quickly for mobile devices. The developed system enables to divide high volume information imaging data into multiple low data 3D object data by surface rendering technique. The imaged data were rendered only by host PC and selectively transferred to client device such as smartphone so that user want to check.

Augmented Reality (AR) is a new form of human-machine interaction that superimposes digital information on the real-world environment. AR technology has the ability to organize much of the digital information from X-ray CT imaging. This paper proposes a new system that user can project 3D-Xray AR CT image on the screen of the device such as smartphone and tablets. In the future, the system will be combined with pseudo 3D color display technology by photon counting X-ray CT imaging.

A new photon counting X-ray imager with a 4-sided buttable structure is proposed. The imager consists of a stacked structure of a semiconductor detector such as Cadmium Telluride detector and a Si-based Read-Out Integrated Circuit (ROIC). The imager can be arranged in two dimensions with small gaps of less than 100 μm, because input/output pads of the ROIC are located on the back using through silicon via technology. In addition, daisy-chaining between imagers extends the number of tilings without increasing the number of external connections. This allows to connect small imagers to achieve a larger imaging area.

A direct charge conversion LSI for photon counting X-ray imager has been fabricated by TSMC 0.18um CMOS process. This LSI is designed to prove a behavior of the direct charge conversion architecture based on charge injection [1] for photon counting with energy information. The LSI has charge-to-digital convertors (QDC) used to read out a charge generated by an X-ray detector such as CdTe and digitize energy information of the source X-ray photon. The QDC realizes 15 energy windows within 200 keV and the LSI provides two 12-bit memories to output two images with differential energy information simultaneously. The LSI has 1600 QDCs and its pixel pitch is 80um. Analogue behaviors of the QDC, characteristics of energy discrimination and a capability to take X-ray/gamma-ray images have been tested. As the results, a desired gain and good linearity are equipped on the QDC, spectra of 241Am and 57Co can be discriminated, and differences between with and without a material have been shown as image.

CdTe photon-counting X-ray image sensor with charge-counting readout IC was developed for high quality X-ray imaging. CdTe is one of the good material for X-ray imaging, because it has i) high sensitivity for X-rays by high atomic number (Average 50), ii) room temperature operation with low thermal noise by large band-gap (1.44eV) , and iii) direct conversion from X-ray photon to electron-hole pair (charge). CdTe also has electron mobility (1,100cm2/V/s) and large ut. It is very good properties for X-ray sensor, and it can be processed by using laser processes and some semiconductor post processes. It is very difficult to make integrated circuit on CdTe wafer, however, we shold stack Si-readout IC and CdTe multi-pixel sensor chip. In this paper, we use sliver paste based bumping for this stack connection. We developed new readout IC, and report in this paper. A direct charge conversion LSI (Si readout IC) for photon counting X-ray imaging sensor has been fabricated by TSMC 0.18um CMOS process. This LSI is designed to prove a behavior of the direct charge conversion architecture based on charge injection [1] for photon counting with energy information. The LSI has charge-to-digital convertors (QDC) used to read out a charge generated by an X-ray detector such as CdTe and digitize energy information of the source X-ray photon. The QDC realizes 15 energy windows within 200 keV and the LSI provides two 12-bit memories to output two images with differential energy information simultaneously. The LSI has 1600 QDCs and its pixel pitch is 80um. Analogue behaviors of the QDC, characteristics of energy discrimination and a capability to take X-ray/gamma-ray images have been tested. As the results, a desired gain and good linearity are equipped on the QDC, spectra of 241Am and 57Co can be discriminated, and differences between with and without a material have been shown as image. We demonstrate X-ray penetrate image and report in this paper. References: [1] K. Takagi, et al., Sensors and Materials, Vol. 30, No. 7 (2018) 1611–1616 Fig.1. Direct charge conversion LSI with pixilated CdTe detector. Figure 1