Abstract: An image reading apparatus includes a platen, a frame for holding the platen, an installation device disposed to the frame so that the platen can be held in a substantially vertical state, and a scanning device for reading a document along the platen substantially vertically held. The reading of the document is carried out by elevating or lowering the scanning device.

Abstract: A switching power supply; wherein a voltage detector is provided at the output of a power supply circuit and connected to the negative input of an error amplifier to amplify the error between detected voltage and reference voltage, the output of said amplifier is connected to the negative input of a first comparator and to the negative input of a second comparator through split resistors, a filter circuit is connected between a control switch and synchronous switch and the output of said filter circuit is connected to a first comparator and a second comparator, wherein said configuration constitues a control means to control the amplitude of the triangular waveform obtained through said filter circuit to be between an input level of said first comparator and an input of said second comparator, whereby the stability of the switching power supply is ensured without lowering the frequency band of said amplified error signal and stable output ripple characteristics can be materialized.

Abstract: A switching power supply; wherein a voltage detector is provided at the output of a power supply circuit and connected to the negative input of an error amplifier to amplify the error between detected voltage and reference voltage, the output of said amplifier is connected to the negative input of a first comparator and to the negative input of a second comparator through split resistors, a filter circuit is connected between a control switch and synchronous switch and the output of said filter circuit is connected to a first comparator and a second comparator, wherein said configuration constitues a control means to control the amplitude of the triangular waveform obtained through said filter circuit to be between an input level of said first comparator and an input of said second comparator, whereby the stability of the switching power supply is ensured without lowering the frequency band of said amplified error signal and stable output ripple characteristics can be materialized.

Abstract: An image reading apparatus includes a platen, a frame for holding the platen, an installation device disposed to the frame so that the platen can be held in a substantially vertical state, and a scanning device for reading a document along the platen substantially vertically held. The reading of the document is carried out by elevating or lowering the scanning device.

Abstract: A document passage in an image reading device, which is defined between an upper frame having means for transporting a given document and a base frame having a document setting surface and means for optically reading an image on the given document, is open at its one side by supporting the upper frame above the base frame in a cantilever state, so that the document of any size such as a name card and envelope can be dealt with to be subjected to image processing regardless of the size of the document. The document transporting means brings about a laterally urging force to be imparted to the document being forwarded on the document setting surface, so that the document can be stably forwarded without causing wobbling widthwise, thus effecting automatic document feeding and image reading with a high accuracy.

Abstract: An image processing apparatus furnished with an overhead projector has an image projecting function and an image-forming function. The image processing apparatus is designed to detect the movement of an original support table or a reflection-type focusing plate during projecting of an original. The result is that the original support table is free from being heated by the focusing plate and also that the focusing plate is free from any deviation of its axis of light, thus preventing the reflected light from striking on the eyes of the operator.

Abstract: An image processing apparatus comprising: an input unit for inputting an image of an initial original; a support table on which the initial original is to be set, the support table being movably mounted along the input unit; a reflection-type focusing plate on which an OHP (overhead projector). original is to be set, the focusing plate being disposed along side the input unit; an image forming unit disposed under the focusing plate for forming on a sheet an image inputted from the input unit to provide an OHP original; and a projecting unit disposed above the focusing plate for projecting an image of the OHP original set on focusing plate.