Abstract: In an exposure device having tiny light emitting elements aligned, a space required for drive circuits and wires is secured without affecting the size or alignment of the light emitting elements for arrangement and wiring of the drive circuits. In this exposure device, the drive circuits are separately arranged outside the column formed by the multiple organic EL elements, and, the length of the region occupied by the circuit exceeds one pitch in the alignment of the organic EL elements, and, the multiple drive circuits are arranged along the column.

Abstract: To provide an exposure device which is capable of controlling light intensity with high precision by improving reliability of light intensity detection, and an image forming apparatus using the same, an exposure device includes a light emitting device array having a plurality of organic electroluminescence devices 110 arranged on a substrate, a light detecting device 120 that detects light emitted from the organic electroluminescence devices 110, and a light intensity detecting circuit C that processes an output of the light detecting device 120. The light intensity detecting unit C includes a capacitive element 140 connected to the light detecting device 120 and a select transistor 130 that is connected to the capacitive element 140 and draws out charges accumulated in the capacitive element 140. The select transistor 130 and the light detecting device 120 are isolated from each other with the capacitive element 140 interposed therebetween.

Abstract: Providing an exposure unit using an organic electroluminescence element with a large emitted light quantity. The organic electroluminescence element has, on a substrate 31, an anode 32 acting as a hole injection electrode, a cathode 33 acting as an electron injection electrode, a first and second emission layers 34 and 35 each having a light emission region, and a charge generation layer 38 injecting electrons into the light emission layer 34 lying close to the anode 32 and injecting holes into the light emission layer 35 lying close to the cathode 33, these layers being arranged between the anode 32 and the cathode 33.

Abstract: In order to resolve the problem, an image forming apparatus of the invention is constructed by a constitution including exposing means including an exposure head comprising an organic electroluminescence element including at least an anode for injecting a hole, a luminescent layer having a luminescent region and a cathode for injecting an electron on a board, a photosensitive member formed with an electrostatic latent image by exposing light of the exposing means, developing means for forming a toner image on the photosensitive member by supplying a toner to the electrostatic latent image and cooling means for cooling the organic electroluminescence element. The organic electroluminescence element is cooled by the cooling means in this way and therefore, the temperature of the organic electroluminescence element can be controlled.

Abstract: An image forming apparatus includes an exposer including an organic electroluminescence element including at least an anode for injecting a hole, a luminescent layer having a luminescent region and a cathode for injecting an electron on a board. A photosensitive member is formed with an electrostatic latent image by exposing light of the exposer, a developer forms a toner image on the photosensitive member by supplying a toner to the electrostatic latent image, and a cooler cools the organic electroluminescence element such that the temperature of the organic electroluminescence element can be controlled.

Abstract: As for a light emitting array and an exposure head provided with a plurality of light emitting elements capable of emitting light by the supplying power respectively, the electrical stress is given only to the light emitting element selected based on the luminance of each light emitting element, whereby the luminance of the light emitting element is reduced. According to such configuration, it is possible to provide the light emitting array with the small light volume dispersion, and the exposure head, and the electrophotographic apparatus thereof.

Abstract: The invention has an object of providing an organic electroluminescence element with a large emitted light quantity, an exposure unit and an image-forming apparatus both using the element. The organic electroluminescence element in accordance with the invention has, on a substrate, an anode acting as a hole injection electrode, a cathode acting as an electron injection electrode, a plurality of light emission layers each having a light emission region and a charge generation layer injecting electrons into the light emission layer lying close to the anode and injecting holes into the light emission layer lying close to the cathode, these layers being arranged between the anode and the cathode, and is configured so that the work function of the charge generation layer is set higher than the ionization potential of the light emission layer lying close to the anode.

Abstract: An inkjet head driving circuit driving piezoelectric actuators 21 for ink ejection provided on an inkjet head H includes one D/A converter 62 that converts a digital signal into an analog voltage and outputs the analog voltage, and a waveform generating portion 64 into which an output voltage of the D/A converter 62 is input, and which generates a voltage rising waveform when the output voltage of the D/A converter 62 is larger than a predetermined potential that is midway between a maximum value and a minimum value of that output voltage, and generates a voltage rising waveform when the output voltage of the D/A converter 62 is smaller than the predetermined potential.

Abstract: A light source includes a light emitting unit including a light emitting layer for electrically emitting a light, and a waveguide for emitting a light irradiated from the light emitting unit into air through a light take-out surface formed on an end face, wherein an area of the light take-out surface of the waveguide is set to be smaller than that of the light emitting layer. Thus, the light irradiated from the light emitting layer is emitted through the light take-out surface of the waveguide. Therefore, it is possible to freely determine the size of the light source by the size of the light take-out surface of the waveguide. Consequently, it is possible to easily obtain a very small light source.

Abstract: In order to resolve the problem, an image forming apparatus of the invention is constructed by a constitution including exposing means including an exposure head comprising an organic electroluminescence element including at least an anode for injecting a hole, a luminescent layer having a luminescent region and a cathode for injecting an electron on a board, a photosensitive member formed with an electrostatic latent image by exposing light of the exposing means, developing means for forming a toner image on the photosensitive member by supplying a toner to the electrostatic latent image and cooling means for cooling the organic electroluminescence element. The organic electroluminescence element is cooled by the cooling means in this way and therefore, the temperature of the organic electroluminescence element can be controlled.

Abstract: An inkjet head driving circuit driving piezoelectric actuators 21 for ink ejection provided on an inkjet head H is provided with an analog switch 71 (72) whose input can be switched between the output voltage of a D/A converter 62 (63) and ground potential, and outputs either that output voltage or ground potential to a waveform generating portion 64. The analog switch 71 (72) is configured such that when a digital signal for generating a voltage rising waveform (voltage falling waveform) with the waveform generating portion 64 is input into the D/A converter 62 (63), the input into the analog switch 71 (72) is switched from ground potential to the output voltage of the D/A converter 62 (63).

Abstract: An inkjet head driving circuit driving piezoelectric actuators 21 for ink ejection provided on an inkjet head H includes one D/A converter 62 that converts a digital signal into an analog voltage and outputs the analog voltage, and a waveform generating portion 64 into which an output voltage of the D/A converter 62 is input, and which generates a voltage rising waveform when the output voltage of the D/A converter 62 is larger than a predetermined potential that is midway between a maximum value and a minimum value of that output voltage, and generates a voltage rising waveform when the output voltage of the D/A converter 62 is smaller than the predetermined potential.

Abstract: An inkjet head driving circuit driving piezoelectric actuators 21 for ink ejection provided on an inkjet head H is provided with an analog switch 71 (72) whose input can be switched between the output voltage of a D/A converter 62 (63) and ground potential, and outputs either that output voltage or ground potential to a waveform generating portion 64. The analog switch 71 (72) is configured such that when a digital signal for generating a voltage rising waveform (voltage falling waveform) with the waveform generating portion 64 is input into the D/A converter 62 (63), the input into the analog switch 71 (72) is switched from ground potential to the output voltage of the D/A converter 62 (63).