JP2588417Y2 - Contact image sensor - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION This invention relates to an image input device such as a facsimile.

[0002]

2. Description of the Related Art FIG. 2 is a cross-sectional view showing a conventional contact type image sensor. In the figure, reference numeral 1 denotes a document to be read, 2 denotes a transparent plate for determining the position of 1, 3 denotes a light source, and 4 denotes a light source. A lens 5 for condensing the irradiated one reflected light, a photoelectric conversion element 5 for converting the optical information condensed by 4 into an electric signal, 6
Is a frame holding 2 to 5.

[0003] The reflected light from the document 1 illuminated by the light source 3 is condensed on the photoelectric conversion element 5 by the lens 4, and the optical information from the document 1 is extracted to the outside as an electric signal. In this optical system, the light source 3 is illuminated obliquely downward from the original reading position at about 45 °, and the illuminating light passing through the transparent plate 2 is reflected by the original 1, passes through the transparent plate 2 again, and is condensed. The light is focused on the light receiving element 5 by the lens 4.

[0004]

Since the conventional contact type image sensor is configured as described above, there is an optical path length (about 10 mm) between the light source and the original (and the transparent plate). Since there is a loss and the light source is provided beside the lens, this causes the unit outer shape (frame and transparent plate) to be large and expensive. Also, in this optical system, the unread portion of the document is also illuminated by the light source, and is affected by the peripheral portion of the document position to be read due to unnecessary reflected light from this portion,
There are drawbacks such as the inability to read accurately.

The present invention has been made to solve the above-mentioned problems, and has as its object to obtain a small and inexpensive contact type image sensor. It is an object of the present invention to improve the reading accuracy by eliminating the influence from other parts.

[0006]

A contact type image sensor according to the present invention contacts a frame and an original to be read.
And a transparent member facing each other at a predetermined interval
Light-emitting sections arranged in a
Fixed to the frame so that it is near the picking position
A surface-emitting light source, and fixed to the inner surface of the frame
Reflection of a surface-emitting light source from a document passing through the above-mentioned predetermined interval
A focusing lens for focusing light, and a focusing lens
The focused light focused by the focusing lens is converted into an electrical signal.
And a photoelectric conversion element for conversion .

[0007]

The surface emitting light source in this invention is read
And a transparent member in contact with the original
Because it has a light-emitting part, the light-emitting part must be
Can be placed closer to each other, and the optical path length of the reflected light from the original
Can be extremely short.

[0008]

[Embodiment 1] An embodiment of the present invention will be described below with reference to the drawings. FIG.
Is a cross-sectional view of a contact type image sensor according to the invention, 1 is the read object, transparent glass <br/> lath plate 2 determines the position of the 1, LED array (light source 3 is embedded in the 2 ),
4 is a lens for condensing the one reflected light emitted by 3;
Reference numeral 5 denotes a photoelectric conversion element that converts the optical information collected by 4 into an electric signal, and 6 denotes a frame that holds 2 to 5.

The reflected light from the document 1 illuminated by the light source 3 is condensed on the photoelectric conversion element 5 by the lens 4 and is extracted as an electric signal to the outside. At this time, since the light source 3 is embedded inside the glass plate 2, the position of the light source for illuminating the document is set to an ideal position where the amount of light is the largest and which contributes to downsizing of the unit. In this case, the light source 3 (LED array) uses the same object in two rows, and a necessary and sufficient slit ( about 1 mm width ) is formed by the two light sources immediately below the document reading position. For this reason, reflected light from the peripheral document surface unnecessary for reading is blocked.

Embodiment 2 FIG. In the above embodiment, an example was shown in which an LED array was used as a light source and this was embedded in a glass plate, but a fluorescent lamp or a cold cathode tube may be used as the light source.
Further, as a substitute for the glass plate in which the light source is embedded in the above embodiment, a flat light emitting type light source (for example, EL (electroluminescence)) having a slit provided immediately below the reading position may be used instead.

[0011]

[Effects of the Invention] As described above, the close contact type I according to the present invention is used.
The image sensor includes a transparent member in contact with a document to be read and a transparent member.
Surface emitting light having a light emitting portion arranged on a transparent member
Light source, so that the light-emitting part
The optical path length of the reflected light from the original
Can be extremely short, reducing light loss and improving lighting efficiency.
Can be further improved, the number of parts can be reduced, and
It has the effect of being able to reduce its own size.
You.

[Brief description of the drawings]

FIG. 1 is a sectional view illustrating a contact type image sensor according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a conventional contact image sensor.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Original 2 Transparent plate 3 Light source (LED array etc.) 4 Lens (rod lens array etc.) 5 Photoelectric conversion element (photodiode, phototransistor, CCD etc.) 6 Frame (housing)

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H04N 1/04-1/207

Claims (1)

(57) [Scope of request for utility model registration] 1. A frame and a document to be read are contacted
The transparent member and the transparent member are opposed to each other at a predetermined interval.
Light-emitting sections arranged in a row
Surface fixed to the frame so that it is near the mounting position
A light-emitting light source and the surface fixed to the inner surface of the frame
Reflected light from a document that has passed the above-mentioned predetermined interval of the light emitting type light source
A focusing lens that focuses on the
Contact image sensor comprising the photoelectric conversion element for converting the focused light focused by the focusing lens into an electrical signal.