JPS62222768A - Picture reader - Google Patents

Abstract

PURPOSE:To contrive thinning and miniaturization of an entire device by constituting an optical means with two reflection mirrors with a lens interposed therebetween. CONSTITUTION:The optical means 25 constituting a sensor unit 22 of a scanner unit 20 is integrally assembled on a part of a housing of a carriage 21 so as to hold a condenser lens 28 between the first reflection mirror 31 and the second reflection mirror 32. A substrate 23 on which an image sensor 24 is disposed is placed at a bottom surface side and the bottom plate of the sensor unit 2 is commonly used. thereby, the length L of an optical path can be shortened to contrive miniaturization of the entire device and the assembling and adjustment of the optical means 25 are simplified.

Description

DETAILED DESCRIPTION OF THE INVENTION (Objective of the Invention) (Industrial Application Field) The present invention relates to an image reading device used in an image forming apparatus such as a serial scanner printer.

(Prior Art) Conventionally, in this type of image forming apparatus, as shown in FIG.
Vj, place the document G8 on top.A scanner unit is guided and scanned along the document table 3 by a guide means to be described later.The scanner unit scans in the Y direction and moves in the X direction to read the document image. The printer unit 4 forms an image on recording paper (not shown) based on the information read by the printer.

The guide means of such a scanner unit 20 is
a first drive unit 8 for driving the guide shaft support block 5.5 in such a way that the guide shaft support block 5.5 can be guided and slid on the guide member 7.7 by means of a timing belt 6;
5. A second drive unit 11 that guides and scans a scanner unit 2o that is slidable along the guide shirts 1 to 9 horizontally suspended in the darkness in the Y direction by a timing belt 10, and this scanner unit 20 will be described later. A sensor unit is mounted on the main body 1 of the apparatus located on the opposite side of the document table 3.
It is designed to be slidably guided along the fixed face plate 1a of the.

As shown in FIGS. 5 and 6, the scanner unit 20 includes a carriage 21 that is attached so as to be able to guide and run along a guide shaft 9 that is a part of the guide means, and a carriage 21. The sensor unit 22 consists of a substrate 23 that forms an amplifier circuit as a light receiving means, and a photoelectric conversion element (COD image) installed on this substrate 23. The optical system means 25 comprises a sensor) 24 and an optical system means 25 that receives and displays an original image on the image sensor 24. an exposure lamp (light source) 26 that irradiates light to the image sensor 24; a reflection mirror 27 that reflects the reflected light from the exposure lamp 26; and a reflection mirror 27 that reflects the reflected light from the reflection mirror 27 to the image sensor 24. It consists of a condensing lens (optical element) 28 that condenses light.

(Problems to be Solved by the Invention) However, in the conventional scanner unit structure described above, the reflection mirror 27 reflects the reflected light from the document surface toward the image sensor 24 via the lens 28.
Since the image sensor 2 has a single-layer structure,
Not only does the optical path length between the 4th and 5th reflecting mirrors 27 become longer.

Board 2 with an image sensor 24 installed upright on a narrow side surface
3, the capacity for forming circuits on the board is small, and as a result, the weir plate surface is also required on other surfaces, and the contact surface is made to be able to slide freely on the fixed face plate 1a of the main body 1 of the device. Coupled with the adhesion of the two sliders, it not only becomes N-shaped, but also increases the overall size.Also, since the single reflecting mirror 27 and lens 28 are each mounted independently, it is extremely difficult to assemble and adjust the optical system. There was a problem that it was troublesome.

The present invention has been made under the above circumstances, and its purpose is to make it possible to achieve N-type design and miniaturization, and to easily adjust the assembly of the optical system. An object of the present invention is to provide an image reading device.

[Structure of the invention]

(Means for solving problems) One aspect of the present invention is to solve the above problems.

A document table on which a document is placed, a light source that irradiates light onto the document placed on the document table, an optical system that collects the light emitted by the light source and reflected by the document, and a light source that collects the light that is reflected by the document. A sensor unit comprising a light receiving means for receiving the emitted light, a guide means for guiding the lenser unit along the document table, and a carriage for taking the sensor unit as a part of the guide means. In the image reading device, the optical system of the sensor unit includes a condensing lens and a first sensor unit with the condensing lens interposed therebetween. B and a second reflecting mirror.

(Function) In other words, in the present invention, by having the above-described configuration, the optical system means is formed integrally with two first and second reflecting mirrors with a condensing lens interposed therebetween. Since the optical path length is shortened and the distance between the object and image can be increased, the overall thickness and size can be reduced, and the installation and adjustment of the optical system can be easily performed.

(Embodiment) The present invention will be described below with reference to an embodiment shown in FIGS. 1 to 2. In addition, in the illustrated embodiment of the present invention, The parts having the same structure as those of the conventional structure are designated by the same reference numerals, and the explanation thereof will be omitted.

That is, the present invention, as shown in FIGS. 1 to 3,
The optical system means 25 constituting the sensor unit 22 of the scanner unit 20 is integrated into a part of the housing of the carriage 21 with a first reflecting mirror 31 and a second reflecting mirror 32 sandwiching the condensing lens 28. The substrate 23, on which the image sensor 24 is placed in LΩ, is placed on the bottom side so that it also serves as the bottom plate of the sensor unit 2, thereby shortening the optical path length. The objective is to reduce the overall size by making it easier to attach and adjust the optical system means 25, and to reduce the dead space on the image sensor installation side of the substrate 23 at the bottom of the sensor unit 22. A sliding block 33 is slidably attached to the opposite side back surface 23a to improve the sliding property between the surfaces that come into contact with the fixed face plate 1a of the device main body 1, and at the same time, it is possible to reduce the thickness of the device. This is what happens.

It should be noted that the present invention is not limited to the above embodiments, and it goes without saying that various modifications can be made without departing from the gist of the present invention.

[Effects of the Invention] As is clear from the above description, according to the present invention, the optical system means is composed of two first and second reflecting mirrors with a lens interposed therebetween, which is different from the conventional method. The optical path length can be shortened compared to the conventional optical system, and the distance between the object and image can be increased, so the overall IW can be made smaller and smaller. It is possible to provide an image reading device that has an excellent effect of being easy to perform.

[Brief explanation of drawings]

FIG. 1 is a plan view of essential parts showing one embodiment of a scanner unit applied to an image reading device according to the present invention, FIG. 2 is a vertical front view, FIG. 3 is a vertical side view, and FIG.
The figure is a perspective view of a conventional image forming apparatus, FIG. 5 is a longitudinal sectional front view of the same conventional image reading apparatus, and FIG. 6 is a longitudinal sectional side view. DESCRIPTION OF SYMBOLS 1... Apparatus body, 3... Original table, 9-... Guide shaft, 20... Scanner unit, 21... Carriage, 22... Sensor unit, 23-... Board, 24...・Photoelectric conversion element, 25...-optical system means,
26... Light source, 28... Condensing lens, 31...-first reflecting mirror, 32... second reflecting mirror, G.-
- Original, L-... Optical path length. Figure 5 Figure 6

Claims (5)

[Claims] (1) A document table on which a document is placed, a light source that irradiates light onto the document placed on the document table, an optical system that collects light irradiated by this light source and reflected by the document, and this A sensor unit comprising a light receiving means for receiving light focused by an optical system, a guide means for guiding the sensor unit along the document table, and the sensor unit is attached to a part of the guide means. An image reading device comprising a carriage, wherein the optical system of the sensor unit includes a condensing lens, and first and second reflecting mirrors with the condensing lens interposed therebetween. Device. (2) The image reading device according to claim 1, wherein the light receiving means includes a photoelectric conversion element and a substrate on which the photoelectric conversion element is attached, and this substrate also serves as a bottom plate of the sensor unit. (3) The guide means includes a guide shaft to which the carriage is attached, and a fixing plate that slidably guides the sensor unit from the side opposite to the document table. Image reading device. (4) The light receiving means includes a photoelectric conversion element, a substrate to which the photoelectric conversion element is attached, and a block attached to the side of the substrate opposite to the photoelectric conversion element, and the guide means includes a guide shaft to which the carriage is attached, and a sensor. A fixed plate that slidably guides the unit from a side opposite to the document table, and the block is configured to slidably hold the sensor unit in contact with the fixed plate. The image reading device according to item 1. (5) The image reading device according to claim 1, wherein the carriage constitutes a part of a housing of the sensor unit.