US 2010/0245940 A1Published application

U-shape optical path image scanning method and scanning module thereof

AssigneeE-Pin Optical Industry Co., Ltd.

InventorsAI-LIEN LAI, CHING-YUAN LIN, SAN-WOEI SHYU

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Abstract

The present invention discloses a U-shape optical path image scanning method and a scanning module thereof, in which an image of a document is reflected by a plurality of reflection mirrors to form image beams, and the image beams which enter the scanning module and the image beams which enter the pickup lens form a U-shape optical path. Optical axis of the pickup lens and the scanning module are parallel to the image of the document so as to prevent scattered beams from entering the pickup lens or forming a ghost image. Accordingly, the depth of field not only can be increased by increasing the length of the optical path in a limited space, but the pickup lens and the image sensor also can be easily adjusted in manufacture or assembly to reduce the assembly complexity and improve the mass production rate.

Claims7

Dependent claims

A U-shape optical path image scanning method for a scanning module, the scanning module having at least one light source, a plurality of reflection mirrors, a pickup lens and an image sensor, and the method comprising the steps of:

emitting a light by said light source to be incident to a document to be scanned such that the light reflected from the document to be scanned forms an image beam Li, wherein said image beam Li injected into the scanning module leads in a +Z-axis direction;
disposing a plurality of reflection mirrors such that said plurality of reflection mirrors reflect the image beam Li to form an image beam Lo incident to said pickup lens, wherein the image beam Li and image beam Lo are in opposite directions and the optical path is U-shaped;
adjusting an included angle φ between the image beam Lo and the image beam Li on a X-Z plane to satisfy the condition of:
-
1
≤
cos

(
π
-
φ
)
=
L
→
o
·
k
→

L
→
o

≤
-
0.707
;
where φ is an included angle between the image beam Lo and an axial line parallel to the Z-axis, and {right arrow over (k)} is a unit vector in the +Z-axis direction, and |{right arrow over (L)}o| is the length of the image beam Lo;
and
calibrating optical axis of said pickup lens and said image sensor such that the optical axis are coincide with the image beam Lo.

29 more elements

A scanning module, comprising:

at least one light source, a plurality of reflection mirrors, a pickup lens, and an image sensor and a frame;
wherein,
said light source emits a light incident to a document to be scanned to produce an image beam Li reflected from the document to be scanned to the scanning module;
said plurality of reflection mirrors are provided for reflecting the image beam Li to form an image beam Lo incident to the pickup lens, where the image beam Li and image beam Lo are in opposite directions and the optical path is U-shaped on the X-Z plane;
said pickup lens are used for focusing the incident image beam Lo on the surface of said image sensor,
said frame is provided for containing the light source, the plurality of reflection mirrors, the pickup lens and the image sensor;
the optical path satisfies the condition of:
-
1
≤
cos

(
π
-
φ
)
=
L
→
o
·
k
→

L
→
o

≤
-
0.707
;
where φ is an included angle between the image beam Lo and an axial line parallel to the Z-axis, and {right arrow over (k)} is a unit vector in the +Z-axis direction, and |{right arrow over (L)}o| is the length of the image beam Lo.

31 more elements

Dependencies are inferred from the claim text.

Facts

Application: 12/635,198Filed 10 Dec 2009
Priority: TW 09811076331 Mar 2009
Published: 30 Sep 2010
Term ends: Not estimatedThe source records don’t support an estimate.

Classification6 codes

H04N 1/03
For picture information pick-up: with photodetectors arranged in a substantially linear array
H04N 1/0305
Using a bent optical path between the scanned line and the photodetector array, e.g. a folded optical path: with multiple folds of the optical path
H04N 1/1017
With sub-scanning by translatory movement of at least a part of the main-scanning components: the main-scanning components remaining positionally…
H04N 1/193
Simultaneously or substantially simultaneously scanning picture elements on one main scanning line: using electrically scanned linear arrays ,…