JPH04120866A - Original reader - Google Patents

Abstract

PURPOSE:To obtain a high-accuracy picture signal by shielding stray light made incident through a space between a pedestal and a rod lens array into a photoelectric converting element. CONSTITUTION:Inside a pedestal 1, there is a space for housing a rod lens array 6. In this space, a space 7 is provided at a certain degree between the pedestal 1 and the rod lens array 6 so as to slightly move the rod lens array 6 vertically and horizontally, and a space 9 is provided between a shielding body 8 fitted to the pedestal 1 and the rod lens array 6. Then, a convex reflecting mirror 10 is provided at the space 9 for reflection. In this way, since the shielding body 8 and the reflecting mirror 10 are provided to shield the light beam passing through the space 9, the stray light incident from the space 9 is prevented from being made incident to a photoelectric converting element 2, and only the reflected light from an original 4 after passing through the rod lens array 6 is made incident to the photoelectric converting element 2. Thus, the high-accuracy picture signal can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a document reading device that optically reads document information.

2. Description of the Related Art A document reading device has a structure as shown in FIG.
A rod lens array 6 and a light emitting diode array 5 serving as a light source are mounted inside the base 15. 4, the reflected light is focused by the rod lens array 6, and the focused light passes through the base at the top of the rod lens array 6 or the attached translucent glass substrate 3, and is transmitted to the photoelectric conversion element 2. It receives light and converts it into an electrical signal.
Rod lens array 6 (photoelectric conversion element 2 and original 4
It is necessary to adjust the position relative to the This eight base 15
A gap 7 is provided beside the rod lens array 6, and the structure is such that it is fixed with a fixing screw 11 after adjustment.

Problems to be Solved by the Invention In the above-mentioned conventional configuration, there is a reflected light device that has the originally necessary image signal that is reflected by the original 4, focused by the rod lens array 6, and guided to the photoelectric conversion element 2.The base 15 and the rod. Because there is reflected light that enters the photoelectric conversion element 2 through the horizontal gap 7 of the lens array 6, unnecessary light (hereinafter referred to as
Since stray light (also known as stray light) is also added and photoelectrically converted, the output signal becomes a signal with low precision, causing a decrease in image resolution.To solve the above problem, Japanese Patent Application Laid-Open No. 2-89461 etc. , a structure has been proposed in which a light shielding body 8 is disposed on a base 14 to block continuous wires passing through the gap 7 as shown in FIG.

However, the force that is effective against the optical path 13 of the light beam reflecting off the original document 4 (for the optical path 12, it still becomes stray light due to multiple reflections, etc.).The present invention (which solves the above conventional problems) The purpose of this project is to provide a document reading device that can obtain high-precision image signals. Means To solve this object, a document reading device (
a base; a light source provided on the base to irradiate a document located at one end of the base; and a light source provided inside the base to collect light rays irradiated onto the document from the light source and reflected. a rod lens array that emits light; a photoelectric conversion element that is provided at the other end of the base and receives the light beam condensed by the rod lens array and converts it into an electrical signal; and the rod lens for the original document and the photoelectric conversion element. The structure has a gap between the base and the rod lens array necessary for adjusting the position of the array, and a light shield and a reflector to block the passage of light in this gap. .

Function: With this configuration, it is possible to block stray light that enters the photoelectric conversion element through the gap between the base and the rod lens array, and it is possible to obtain the originally required high-precision image signal.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to the drawings. FIG. 1 shows a document reading device according to an embodiment of the present invention. In FIGS. 3 to 2, the same parts as in FIG. 1 are given the same reference numerals. In FIG. 1, the base 1 is horizontally long, and a glass substrate 3 on which a photoelectric conversion element 2 is mounted and wired is attached to one side of the base 1, and a document is attached to the other side. A light emitting diode array 5 is attached for illuminating 4. There is a space inside the base 1 to accommodate the rod lens array 6. This space allows the rod lens array 6 to move slightly in the vertical and lateral directions. A gap 9 is provided between the rod lens arrays 6, and a concave reflecting mirror 10 is provided to reflect the light into the gap 9. Also, the rod lens array 6 whose position has been adjusted is fixed from the side of the base 1. The operation of the document reading device configured as described above will be explained below.The rod lens array 6 connects the surface of the document 4 and the glass substrate 3.
The rod lens array 6 is adjusted vertically so that it is in focus with the photoelectric conversion element 2 on the top of the lens, and the rod lens array 6 is fixed with the screw 11, and the rod lens array 6 is set almost in a straight line with the photoelectric conversion element 2 so that the light efficiently reaches the photoelectric conversion element 2. Make sure you reach it. By setting the originals 4 in the thus assembled and adjusted original reading device and operating the originals 4, the originals 4 can be sequentially read. The light beam emitted from the light emitting diode array 5 is applied to the document 4.
Reflected light is reflected from the original surface according to its density, and this reflected light is guided to the photoelectric conversion element 2 on the glass substrate 3 through the rod lens array 6. Original 4 guided by photoelectric conversion element 2
The reflected light is converted into an electrical signal according to the amount of light and output. However, this reflected light does not only pass through the rod lens array 6, but also enters the optical path 12 in the direction of the gap 9. Conventionally, this stray light reaches the photoelectric conversion element 2, causing a force that adversely affects the image signal. Invention (Yo)
The light entering from the gap 9 is reflected by the concave reflector 10.
As a result, the light guided to the photoelectric conversion element 2 on the glass substrate 3 is reflected by the surface of the document 4 and is reflected by the rod lens array 6. Only the reflected light that has passed is present, and the reflected light and stray light are not simultaneously converted into electrical signals by the photoelectric conversion element 2, and a high-resolution image signal can be obtained.

Effects of the Invention As described above, the document reading device of the present invention has a light shielding member and a reflector that block light passing through the gap between the rod lens array inside the base and the base. This prevents stray light from entering the photoelectric conversion element through the gap between the rod lens array and inputting only the reflected light from the document that has passed through the rod lens array to the photoelectric conversion element, producing a high-resolution, high-precision image signal. Obtainable. Moreover, such a structure can be easily realized using methods such as aluminum extrusion molding, and has great industrial value.

[Brief explanation of the drawing]

FIG. 1 is a side cross-sectional view of a document reading device according to an embodiment of the present invention. FIG. 3 is a side cross-sectional view of a conventional optical document reading device. 1... Base 2... Photoelectric conversion element, 3...
・Glass substrate, 4... Original 5... Light emitting diode array, 6... Rod lens array, 7
...Gap between the base and the rod lens array 8...
- Light shielding body 9... Gap between light shielding body and rod lens array 10... Reflector 11... Screw, 12...
・Name of the agent responsible for the reflection of the manuscript: Patent attorney Akira Okaji and 2 other people - Mimi.

Claims (1)

[Claims] a base; a light source provided on the base to irradiate a document located at one end of the base; and a light source provided inside the base to condense the light rays irradiated onto the document from the light source and reflected. a photoelectric conversion element provided at the other end of the base and configured to receive the light beam condensed by the rod lens array and convert it into an electrical signal; and the rod lens array for the original document and the photoelectric conversion element. A gap is provided between the base and the rod lens array necessary for adjusting the position of the rod lens array, and a light shielding member and a reflecting mirror are provided to block the passage of light rays in this gap. original reading device.