JPS59134975A - Photoelectric converting reader - Google Patents

Abstract

PURPOSE:To make a device compact, and also, to simplify the wiring by constituting so that a laser light is made incient into an optical medium for propagating a longitudinal wave of an ultrasonic wave, irradiating an original by curving said laser light by the longitudinal wave of the ultrasonic wave in said optical medium, and photodetecting reflected light from the original by a photoelectric converting element. CONSTITUTION:A laser light source 32 is placed on the end face of an optical medium 35 provided with an electrode on both ends, and a laser light emitted from its laser light source 32 is curved in the direction of an original 31 by a longitudinal wave 36 of an ultrasonic wave. Said curved laser light is reflected to the optical medium by a light intensity corresponding to a reflection factor (density) of the original 31. Subsequently, its reflected laser light is curved by the longitudinal wave 36 of the ultrasonic wave again, and made incident to a photoelectric converting element 33 provided on the end face of the optical medium 35, by which said reflected light is converted to an electric signal. Scanning of the direction (usually, a right angle direction) crossing the direction of the optical medium 35 is executed by moving a read system consisting of the original 31 or the optical medium 35, the laser light source 32 and the photoelectric onverting element 33, in said direction.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a photoelectric conversion/reading device, and more particularly to a photoelectric conversion/reading device that can be applied to facsimiles, digital copiers, barcode reading, etc.

Conventionally, in a document reading system such as a facsimile machine, a document 11 is uniformly illuminated by an illumination light source 12 such as a fluorescent lamp, and the reflected light is reflected by a lens 13 or the like, as shown in the schematic overall perspective view of FIG. An optical system is used to form an image on the photoelectric conversion element 14 to obtain a time-series electric signal. Assuming that the photoelectric conversion element 14 used here is a chip with a size of about 20II11 manufactured by IC technology such as MOS or COD, the original 11 is A4 size (210 m
mX297 gu+), the lens 13
Therefore, it is necessary to reduce the original 11 to about one tenth. Therefore, when a small-sized photoelectric conversion element is used for a document, the distance from the document to the photoelectric conversion element must be considerably increased in order to reduce the size of the document. For this reason,
Problems have arisen in that the device becomes larger, and because the document is reduced in size by the lens system, lens aberrations such as distortion of the document occur. Furthermore, if an attempt is made to manufacture a device that solves the above problems, it will require the use of expensive lenses, and the adjustment of the optical system will become difficult, resulting in problems in terms of cost.

As a means to solve the above-mentioned problems, for example, a long photoelectric conversion element and a CellHock lens array (5eHac
It has been proposed that the document and the photoelectric conversion element correspond to the tit using the 1 ens arry. This is a configuration as shown in the schematic overall perspective view of FIG. In FIG. 2, 21 is a document, 22 is a cell-hock lens array, and 23 is a photoelectric conversion element. Although such an apparatus is advantageous in eliminating lens aberrations and making the reading system more compact, it does not solve the problem of high cost because it uses a cell-hoc lens array. Also, since a Cell-Hock lens array is used in the optical system, the thickness of the entire reading system depends on the length of the Cell-Hock lens.
There remains the problem that there is a limit to how thin the reading system can be made in the thickness direction.

An object of the present invention is to provide a thin contact type photoelectric conversion/reading device that does not use an optical system (imaging lens) that causes the above-mentioned problems.

The photoelectric conversion/reading device of the present invention injects a laser beam into an optical medium that propagates a longitudinal ultrasonic wave, bends the laser beam by the longitudinal ultrasonic wave in the optical medium, and irradiates the original. It is characterized by a structure in which the reflected light of is received by a photoelectric conversion element.

In the above, a manuscript refers not only to what is normally called a manuscript in which characters or images are recorded on a recording material such as a sheet of paper, but also to what is called a barcode reading or a recording material. It goes without saying that documents such as OCR, mark sheets, etc. are generally not called original documents, but include any document whose characters, images, symbols, etc. can be read by photoelectric conversion.

Hereinafter, the present invention will be explained using figures.

FIG. 3 is a schematic overall perspective view showing one preferred embodiment of the present invention. In the figure, 31 is a document, 32 is a laser light source, 33 is a photoelectric conversion element, 34 and 34' are electrodes, 35 is an optical medium, and 36 is a schematically drawn ultrasonic longitudinal wave. In addition, in this embodiment example, 34.34'
The electrode was a comb-shaped electrode.

The present invention utilizes the following phenomenon.

Ultrasonic longitudinal waves are propagated from the outside into an optical medium such as glass, and at the same time, laser light is incident in a fixed direction relative to the traveling direction of the longitudinal waves. Then, the laser beam has a wavefront of the longitudinal wave of the ultrasonic wave.

Since it acts as a diffraction grating for goo light, it undergoes a diffraction effect. This method takes advantage of the phenomenon in which laser light in an optical medium is bent by the longitudinal waves of ultrasonic waves.

As shown in the figure, an embodiment of the present invention that utilizes the phenomenon described in item 2 is such that a laser light source 32 is disposed on the end face of an optical medium 35 provided with electrodes at both ends, and a laser light source 32 is emitted from the laser light source 32. The laser beam is bent in the direction of the document 31 by the ultrasonic longitudinal wave 36. The zero-bend laser beam is reflected by the optical medium with a light intensity corresponding to the reflectance (density) of the document 31. Then, the reflected laser light is again bent by the ultrasonic longitudinal wave 36 and made incident on the photoelectric conversion element 33 provided on the end face of the optical medium 35, thereby converting the reflected light into an electrical signal. Scanning in the direction of the optical medium 35 and in the irradiation direction of the clogged laser beam is performed by the timing of the ultrasonic longitudinal wave 36 and the laser beam,
Scanning in a direction crossing the direction of the optical medium 35 (usually perpendicular direction) is performed using the original 31 or the optical medium 35. This is carried out by moving a reading system consisting of a laser light source 32 and a photoelectric conversion element 33 in the above direction.

In the manner described above, in this embodiment, a document or the like is read.

According to the present invention, not only a compact device can be obtained compared to a conventional photoelectric conversion/reading device using a lens, etc., but also wiring can be greatly simplified because a long photoelectric conversion element is not used. Furthermore, a photoelectric conversion reader with a large reading width can be obtained.

[Brief explanation of drawings]

1 and 2 are schematic overall perspective views for explaining a conventional photoelectric conversion/reading device, respectively, and FIG. 3 is a tree. FIG. 1 is a schematic overall perspective view for explaining an embodiment of the invention. 11.21.31---1 original, 12---1 illumination light source, 13--lens, 14, 23.33----1 photoelectric conversion element, 22----Selfoc lens array, 32 -----Laser light source, 34, 34'--
-One electrode. 35 - - - Optical medium, 36 - - Schematically drawn longitudinal waves of ultrasonic wave - Heriga Wholesale 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Co., Ltd. 0 Inventor Mitsunobu Nakazawa Tokyo 734- Canon Co., Ltd., 3-30-2 Shimomaruko, Ota-ku, Tokyo

Claims (1)

[Claims] A laser beam is incident on an optical medium that propagates longitudinal ultrasonic waves, the laser beam is bent by the longitudinal waves of ultrasonic waves in the optical medium, and the original is irradiated, and the reflected light from the original is converted into a photoelectric conversion element. A photoelectric conversion/reading device characterized by being configured to receive light.