Abstract: Provided is a color-developing composition for recording materials having a superior heat resistance. The color-developing composition is a reaction composition containing a mixture of compounds represented by formula (III) obtained by reacting a dihydroxydiphenylsulfone derivative represented by formula (I) with a dihalide represented by formula (II) X—Y—X (II), wherein, in a composition where the content of a compound with n=1 in said reaction composition is from 5 to 80% by mass of the total solid content of the composition, at least 10% by mass of the compound with n=1 is a crystalline material.

Abstract: Provided is a color-developing composition for recording materials having a superior heat resistance. The color-developing composition is a reaction composition containing a mixture of compounds represented by formula (III) obtained by reacting a dihydroxydiphenylsulfone derivative represented by formula (I) with a dihalide represented by formula (II) X-Y-X (II), wherein, in a composition where the content of a compound with n=1 in said reaction composition is from 5 to 80% by mass of the total solid content of the composition, at least 10% by mass of the compound with n=1 is a crystalline material.

Abstract: An auto-loading system of disk playback apparatus includes a door open/close detecting device for detecting that a door is being closed when a disk is being ejected, and loads the disk into the disk playback apparatus by the detection signal therefrom. According to another aspect, the apparatus generates an alarm immediately when detection is made thereby that the door is being closed when the disk is being ejected.

Abstract: The present invention provides a naphthoquinone derivative represented by the general formula (I): ##STR1## wherein R.sup.1 and R.sup.2 are as defined in the specification. An electrophotosensitive material containing this naphthoquinone derivative as an electron transferring material has high sensitivity.

Abstract: This invention relates to an image forming apparatus in which a cleaning device is arranged above a photosensitive drum close thereto. The image forming apparatus has an image processing unit provided with the photosensitive drum. The photosensitive drum is constructed such that a gear portion formed in a flange member at one axial end of the photosensitive drum has a diameter not greater than an outer diameter of the photosensitive drum. The image processing unit is constructed such that a driving force from the image forming apparatus is transmitted to the photosensitive drum via the gear portion formed in the one flange member to rotate the photosensitive drum and is transmitted to at least one of image processor means via a gear portion formed in a flange member at the opposite axial end of the photosensitive drum. With this arrangement, a poor image formation due to a blocking phenomenon resulting from long stay of toner residues can be prevented and downsizing of the image forming apparatus is realized.

Abstract: The photosensitive material of the present invention is provided in contact with a developing roller and has a surface potential decay characteristic in which when the photosensitive material is charged to a surface potential of 800 V and is contacted with the developing roller to which a voltage (VR) is applied, the surface potential (VD) of the photosensitive material after contacting is represented by the formula (1):VD.gtoreq.800.times.EXP (0.00235.times.VR).By using this photosensitive material, a transverse black stripe in the tip of the transfer paper is prevented and it is possible to form an image having excellent image quality and image density.

Abstract: The present invention provides a naphthoquinone derivative represented by the general formula (I): ##STR1## wherein R.sup.1 and R.sup.2 are as defined in the specification. An electrophotosensitive material containing this naphthoquinone derivative as an electron transferring material has high sensitivity.

Abstract: The present invention provides a tryptoanthrinimine derivative represented by the general formula (Y): ##STR1## wherein R.sup.A to R.sup.M are as defined. Such a derivative of the general formula (Y) is superior in electron transferring capability. Accordingly, an electrophotosensitive material comprising a photosensitive layer containing this derivative (Y) is superior in sensitivity.

Abstract: The present invention provides a novel trinitrofluorenonimine derivative represented by the general formula (1): ##STR1## wherein R.sup.0 is an alkyl group; and R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 are the same or different and indicate a hydrogen atom, an alkyl, an alkoxy, an aryl, an aralkyl, a halogen atom or an alkyl halide. This derivative is superior in electron transferring capability and compatibility with binding resin. Accordingly, an electrophotosensitive material comprising this derivative as an electron transferring material is superior in sensitivity.

Abstract: According to the present invention, there is provided a novel tryptoanthorine derivative represented by the formula: ##STR1## wherein R.sup.1a, R.sup.1b, R.sup.1c, R.sup.1d, R.sup.2a, R.sup.2b, R.sup.2c, and R.sup.2d are the same or different and indicate a hydrogen atom, an alkyl group or a halogenated alkyl group; provided that R.sup.1a, R.sup.1b, R.sub.1c and R.sup.1d do not indicate a hydrogen atom, simultaneously. Tryptoanthorine and a derivative thereof are suitably used for an electrophotosensitive material because of their excellent electron transferring capability.

Abstract: An image-forming apparatus employing a reversal developing system and using a photosensitive material capable of being charged into both positive and negative polarities and further using a transfer roller made of an electrically conducting sponge rubber. The photosensitive material and the transfer roller are press-contacted to each other with a suitable force, and a DC voltage is applied to the transfer roller, the DC voltage having a polarity opposite to the polarity of the potential created by the main charger and having a value larger than a charge start voltage of the photosensitive material but being so set that the potential on the surface of the photosensitive material after discharged is not larger than 50 V in an absolute value. This apparatus permits a toner image formed on the surface of the photosensitive material to be transferred at a high efficiency and enables the photosensitive material to be uniformly charged in a next cycle of forming image.

Abstract: The present invention relates to a benzidine derivative represented by the general formula (1): ##STR1## wherein R.sup.1 to R.sup.6, m and n are as defined in the present specification. The benzidine derivative improves durability and heat resistance of a membrane containing the same while maintaining high hole transferring capability. Therefore, an electrophotosensitive material, which comprises a photosensitive layer containing the benzidine derivative, has high sensitivity and is superior in durability and heat resistance.

Abstract: A reversal developing system using a photosensitive material that can be electrically charged into both a positive polarity and a negative polarity, and a DC voltage applied to the transfer roller has a polarity opposite to and more than 1.5 times as great than that of the charge start potential by the primary charger, and is so set that the potential on the surface of the photosensitive material after discharge is 50 V or smaller in absolute value. Therefore, the discharging is effectively carried out after the image has been formed, the photosensitive material is uniformly and effectively charged by the main charger even in the subsequent cycle of forming image, a good image is formed without image spots, and the toner image formed on the photosensitive material is transferred maintaining a high transfer efficiency. The transfer roller is arranged to have a gap between the transfer roller and photosensitive surface between 0.3 to 0.7 mm.

Abstract: The present invention provides an electrophotosensitive material having an improved sensitivity in comparison with a conventional one, obtained by combining a trinitrofluorenoneimine derivative represented by the formula (1): ##STR1## wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 are the same or different and indicate a hydrogen atom, an alkyl group, an alkoxy group, an aryl group which may contain a substituent, an aralkyl group which may contain a substituent, or a halogen atom! as an electron transferring material with a prescribed electric charge generating material or hole transferring material.

Abstract: The present invention relates to a novel phenylenediamine derivative of the general formula (1): ##STR1## wherein R.sup.1 R.sup.2 R.sup.3 and R.sup.4 are selected from the group consisting of: alkyl groups, alkoxy groups, halogen atoms and aryl groups; and m, n, p and q are integers in the range of 0 to 3, andan electrophotosensitive material using the same as an electric charge transferring material.The phenylenediamine derivative is excellent in not only compatibility with binding resin but also electric charge transferring capability, particularly hole transferring capability. Therefore, a photosensitive material using the above derivative as an electric charge transferring material exhibits a higher sensitivity.

Abstract: An electrophotographic photoconductor includes: a conductive substrate and a photosensitive layer formed on the conductive substrate, wherein the photosensitive layer includes charge generating particles, a charge transporting material, and a binder resin, and the charge generating particles are made of a composition including a charge generating material dispersed in a binding medium.

Abstract: Disclosed is an organic photosensitive material for electrophotography which is characterized by containing a specific diphenoquinone derivative in an organic photosensitive layer of the material. The diphenoquinone derivative is a compound represented by the following general formula: ##STR1## wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are alkyl groups, alkoxy groups, aryl groups or aralkyl groups, and at least one of R.sub.1, R.sub.2, R.sub.3 and R.sub.4 is an aryl group or an aralkyl group, and at least 2 of the remaining R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are alkyl groups or alkoxy groups,the organic photosensitive material mentioned above has excellent sensitivity and residual potential.

Abstract: The image forming apparatus in this invention uses a positive corona discharger as a main charger. A photosensitive material having a charge accepting ability per run-off current of at least 40 V/.mu.A from a corona discharger (measured by using a discharge length of 230 mm and by taking the peripheral speed of the photosensitive material as 48 mm/sec) is used, and a DC voltage is impressed on the positive corona discharger so that the average ozone concentration of an atmosphere of the photosensitive material 2 ppm or less and the ozone concentration immediately below the corona discharger becomes 5 ppm or less to perform main charging. According to this apparatus, the amount generated of ozone can be decreased, and charging unevenness can be prevented to form a good image.

Abstract: An image carrier of an organic photosensitive material containing a charge-generating agent and a charge-transporting agent, and a transfer roller using an electrically conducting polyurethane rubber composition which is so cured as to exhibit a rubber hardness of higher than 50.degree. (JIS A), are disposed being spaced apart maintaining a small gap which is greater than the thickness of the transfer material enabling the toner to be transferred onto the transfer material. This makes it possible to prevent the occurrence of image defects such as white spots and the like, to form transferred image favorably and stably over an extended period of time maintaining a high density without fogging and consuming a small transfer current.

Abstract: The organic photosensitive material for electrophotography in accordance with this invention is characterized in that a non-symmetrically substituted diphenoquinone derivative represented by the following formulae ##STR1## wherein each of R.sub.1 and R.sub.2 represents an alkyl or aryl group, R.sub.2 having larger carbon atoms than R.sub.1, is used as an electron transporting agent. This photosensitive material has a residual potential limited to a low level, and shows excellent sensitivity in both positive charging and negative charging.