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Author

Jun Koyama

Bio: Jun Koyama is an academic researcher from Toshiba. The author has contributed to research in topics: Thin-film transistor & Display device. The author has an hindex of 46, co-authored 355 publications receiving 9020 citations.


Papers
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Journal ArticleDOI
01 Jun 2009
TL;DR: This work designed, prototyped, and evaluated LCD integrated with a gate driver and a source driver using amorphous In‐Ga‐Zn‐Oxide TFTs having bottom‐gate bottom‐contact structure, thereby obtaining T FTs with superior characteristics.
Abstract: We designed, prototyped, and evaluated LCD integrated with a gate driver and a source driver using amorphous In-Ga-Zn-Oxide TFTs having bottom-gate bottom-contact structure, thereby obtaining TFTs with superior characteristics Then, we prototyped the world's first 4-inch QVGA LCD and integrated the gate driver and source driver on the display panel

984 citations

Patent
13 Feb 2001
TL;DR: In this article, an electro-optical device having a plurality of pixels, including a majority of EL elements, provides a gray-scale display by controlling a period of time at which the plurality of the EL elements emit light in one frame period, and a polarity of an EL driving voltage, which is a difference between the potentials applied to the first and second electrodes, is inverted for each one-frame period.
Abstract: An electro-optical device having a plurality of pixels including a plurality of EL elements, wherein the electro-optical device provides a gray scale display by controlling a period of time at which the plurality of the EL elements emit light in one frame period; the plurality of the EL elements have a first electrode and a second electrode; the first electrode is held at a constant potential; and a potential of the second electrode changes in such a manner that a polarity of an EL driving voltage, which is a difference between the potentials applied to the first and second electrodes, is inverted for each one frame period.

370 citations

Patent
16 Sep 1997
TL;DR: Linearly patterned or dot-patterned impurity regions are formed in a channel forming region 103 so as to be generally parallel with the channel direction as discussed by the authors, which suppress expansion of a drain-side depletion layer, so that the punch-through phenomenon can be prevented.
Abstract: A fine semiconductor device having a short channel length while suppressing a short channel effect. Linearly patterned or dot-patterned impurity regions 104 are formed in a channel forming region 103 so as to be generally parallel with the channel direction. The impurity regions 104 are effective in suppressing the short channel effects. More specifically, the impurity regions 104 suppress expansion of a drain-side depletion layer, so that the punch-through phenomenon can be prevented. Further, the impurity regions cause a narrow channel effect, so that reduction in threshold voltage can be lessened.

241 citations

Patent
02 Jun 2000
TL;DR: In this article, a multi-gate structure was proposed to prevent hot carrier injection and reduce the OFF current value of the EL display, where the LDD region of the current control TFT 202 is formed so as to overlap a portion of the gate electrode 35 to make a structure which imposes importance on prevention of hot-carrier injection and reduction of OFF current values.
Abstract: An object of the present invention is to provide an EL display device having a high operation performance and reliability. The switching TFT 201 formed within a pixel has a multi-gate structure, which is a structure which imposes an importance on reduction of OFF current value. Further, the current control TFT 202 has a channel width wider than that of the switching TFT to make a structure appropriate for flowing electric current. Morever, the LDD region 33 of the current control TFT 202 is formed so as to overlap a portion of the gate electrode 35 to make a structure which imposes importance on prevention of hot carrier injection and reduction of OFF current value.

195 citations

Journal ArticleDOI
01 Jun 2012
TL;DR: Kimizuka et al. as discussed by the authors found crystalline IGZO having c-axis alignment and have studied its application to displays, memories, processors, etc., which is expected to be used in a variety of applications.
Abstract: The study of IGZO was started by Kimizuka et al. in 1985. IGZO is developed as a material for displays. We found crystalline IGZO having c-axis alignment and have studied its application to displays, memories, processors, etc. Crystalline IGZO is expected to be used in a variety of applications.

188 citations


Cited by
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Patent
01 Aug 2008
TL;DR: In this article, the oxide semiconductor film has at least a crystallized region in a channel region, which is defined as a region of interest (ROI) for a semiconductor device.
Abstract: An object is to provide a semiconductor device of which a manufacturing process is not complicated and by which cost can be suppressed, by forming a thin film transistor using an oxide semiconductor film typified by zinc oxide, and a manufacturing method thereof. For the semiconductor device, a gate electrode is formed over a substrate; a gate insulating film is formed covering the gate electrode; an oxide semiconductor film is formed over the gate insulating film; and a first conductive film and a second conductive film are formed over the oxide semiconductor film. The oxide semiconductor film has at least a crystallized region in a channel region.

1,501 citations

Patent
13 Aug 2014
TL;DR: In this paper, the authors presented a heterocyclic compound and an organic light-emitting device including the HOC compound, which have high efficiency, low driving voltage, high luminance and long lifespan.
Abstract: The present invention provides a heterocyclic compound and an organic light-emitting device including the heterocyclic compound. The organic light-emitting devices using the heterocyclic compounds have high-efficiency, low driving voltage, high luminance and long lifespan.

1,346 citations

Patent
25 Sep 2013
TL;DR: In this paper, a connection terminal portion is provided with a plurality of connection pads which are part of the connection terminal, each of which includes a first connection pad and a second connection pad having a line width different from that of the first one.
Abstract: An object of the present invention is to decrease the resistance of a power supply line, to suppress a voltage drop in the power supply line, and to prevent defective display. A connection terminal portion includes a plurality of connection terminals. The plurality of connection terminals is provided with a plurality of connection pads which is part of the connection terminal. The plurality of connection pads includes a first connection pad and a second connection pad having a line width different from that of the first connection pad. Pitches between the plurality of connection pads are equal to each other.

1,136 citations

Patent
08 Jun 2007
TL;DR: In this paper, liquid-crystal display (LCD) touch screens that integrate the touch sensing elements with the display circuitry are discussed. But the integration may take a variety of forms.
Abstract: Disclosed herein are liquid-crystal display (LCD) touch screens that integrate the touch sensing elements with the display circuitry. The integration may take a variety of forms. Touch sensing elements can be completely implemented within the LCD stackup but outside the not between the color filter plate and the array plate. Alternatively, some touch sensing elements can be between the color filter and array plates with other touch sensing elements not between the plates. In another alternative, all touch sensing elements can be between the color filter and array plates. The latter alternative can include both conventional and in-plane-switching (IPS) LCDs. In some forms, one or more display structures can also have a touch sensing function. Techniques for manufacturing and operating such displays, as well as various devices embodying such displays are also disclosed.

1,083 citations

Patent
17 Jan 2006
TL;DR: In this article, the authors propose a technique by which a pattern of wirings or the like which is partially constitutes a semiconductor device or a display device can be formed with a desired shape with controllability.
Abstract: To provide a semiconductor device and a display device which can be manufactured through a simplified process and the manufacturing technique. Another object is to provide a technique by which a pattern of wirings or the like which is partially constitutes a semiconductor device or a display device can be formed with a desired shape with controllability.

1,043 citations