Tohoku Pioneer Corporation

Pioneer Corporation

Katsuhiro Kanauchi

Shuichi Seki

Hiroki Tan

Akinori Hayafuji

Masaki Murakata

Shigehiro Umetsu

Nobuhiko Saegusa

Hideo Ochi

Shinsuke Tanaka

Takayoshi Yoshida

Noriaki Waki

A display device () includes a light-emitting device (), a reflective liquid crystal element (), and an optical member (). The light-emitting device () includes a plurality of light-emitting units () and a light-transmitting unit () located between the light-emitting units () adjacent to each other. The light-emitting device () is located between the reflective liquid crystal element () and the optical member (). The plurality of light-emitting units () emit light toward the reflective liquid crystal element (). The light emitted from the plurality of light-emitting units () is reflected by the reflective liquid crystal element (), transmitted through the light-emitting unit () of the light-emitting device (), and formed into an image by the optical member ().

Display device

A first luminous body is formed on a substrate and is linear. A second luminous body is also formed on the substrate and is linear. The second luminous body extends in parallel with the first luminous body. A first anode and a first cathode are formed on the substrate, and supply electric power to the first luminous body. A second anode and a second cathode are also formed on the substrate, and supply electric power to the second luminous body. The first anode and the first cathode extend in parallel with each other, and the second anode and the second cathode extend in parallel with each other. In a range overlapping with the first luminous body when seen in a plan view, the first anode is not connected to the second anode, and the first cathode is not connected to the second cathode.

Light emitting apparatus having first luminous body and second luminous body

A light-emitting device () includes a first light-emitting region () and a second light-emitting region (). The first light-emitting region () emits a light ray having a first color by making a first light-emitting layer group including at least two or more kinds of light-emitting layers emit light. In addition, the second light-emitting region () emits a light ray having the first color (for example, daylight color, natural white color, white color, warm white color, or incandescent color) by making a second light-emitting layer group including at least two or more kinds of light-emitting layers emit light. In addition, at least one kind of light-emitting layer included in the second light-emitting layer group emits a light ray having a different spectrum peak from all of the light-emitting layers included in the first light-emitting layer group. Therefore, the color-rendering properties of light emitted from the light-emitting device () are improved.

Light-emitting device

A light-emitting device () includes a first light-emitting region () and a second light-emitting region (). The first light-emitting region () emits a light ray having a first color by making a first light-emitting layer group including at least two or more kinds of light-emitting layers emit light. In addition, the second light-emitting region () emits alight ray having the first color (for example, daylight color, natural white color, white color, warm white color, or incandescent color) by making a second light-emitting layer group including at least two or more kinds of light-emitting layers emit light. In addition, at least one kind of light-emitting layer included in the second light-emitting layer group emits a light ray having a different spectrum peak from all of the light-emitting layers included in the first light-emitting layer group. Therefore, the color-rendering properties of light emitted from the light-emitting device () are improved.

A drive device for a light-emitting element that improves accuracy while driving the light-emitting element at small currents for which a comparatively simple configuration is provided. The drive device includes detecting means, comparing means, a driving voltage source, and offset means. The detecting means detects a voltage corresponding to a current flowing through a first resistor for current detection. The first resistor is coupled to a light-emitting element in series. The comparing means compares a magnitude of the detection voltage of the detecting unit with a comparison voltage. The driving voltage source applies a voltage corresponding to a comparison result by the comparing means to a series circuit of the light-emitting element and the first resistor. The offset means corrects the voltage corresponding to a current flowing through the first resistor by a correction voltage.

Drive device for light-emitting element

Treating light emitting elementsin all the display pixels in a light emitting display panel as objects, a maximum value of the forward voltages is drawn by a multi-input comparatorand a peak hold circuit. Based on the maximum value of the forward voltages, a voltage boost circuitswitching operates a power FET to supply a boosted output by this operation to a constant current circuitas the operational voltage VH. In the case where the maximum value of the forward voltages increases due to trouble or the like and based on this increment the operational voltage VH excessively increases, the operation of the voltage boost circuitis stopped by a control output from an analog comparatorwhich functions as voltage limiter.

Self light emitting type display device

Treating light emitting elementsin all the display pixels in a light emitting display panel as objects, a maximum value of the forward voltages is drawn by a multi-input comparatorand a peak hold circuit. Based on the maximum value of the forward voltages, a voltage boost circuitswitching operates a power FET to supply a boosted output by this operation to a constant current circuitas the operational voltage VH. In the case where the maximum value of the forward voltages increases due to trouble or the like and based on this increment the operational voltage VH excessively increases, the operation of the voltage boost circuitis stopped by a control output from an analog comparatorwhich functions as a voltage limiter.

A clock signal in synchronization with a data writing signal, every scanning line, which is supplied from a light-emitting control circuitto a scanning driver, is supplied to an oscillatorwhich generates a reference switching signal, according to a PWM method, in a DC-DC converter. Thereby, the timing at data writing every scanning line is in synchronization with the phase of a ripple component superimposed on a driving voltage Va from the DC-DC converter. Accordingly, a problem that there is caused a state in which light-emitting intensity is different every scanning line can be solved because the same voltage Vgs between a gate and a source is supplied every scanning line to a light-emitting driving transistor Trat any time even if the ripple component by switching of the DC-DC converter is superimposed on the driving voltage Va. Thereby, a problem that the display quality of images is remarkably reduced can be prevented in a light-emitting driving operation of a display panel, wherein the operation has a configuration in which an organic EL element with a light-emitting intensity characteristic of a current dependence type, for example, is used as a pixel.

Light emitting display device and driving control method therefor

In a drive device for an active type light emitting display panel which can apply a reverse bias voltage to an EL element, in order to be able to compensate deterioration in light-emitting efficiency of the EL element accompanied by applying of the reverse bias voltage and the like, one pixelis composed of a controlling TFT (Tr), the driving TFT (Tr), a capacitor Cand the EL element ESwitching switches SWSWmutually enables a supplying state of a forward current to the EL element Eand an applying state of the reverse bias voltage to be selected. In one control form according to the present invention, when the applying state of the reverse bias voltage shifts to the supplying state of the forward current, by switching one switch first, the anode and cathode of the EL element Eare made to the same electrical potential to allow electrical charges to be discharged. Thus, charge of the forward current for a parasitic capacitance of the EL element Ecan be performed rapidly, and rising of the lighting operation of the EL element can be advanced.

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Yonezawa, Japan

Katsuhiro Kanauchi