JPH0812382B2 - Image reader - Google Patents
Image readerInfo
- Publication number
- JPH0812382B2 JPH0812382B2 JP1167908A JP16790889A JPH0812382B2 JP H0812382 B2 JPH0812382 B2 JP H0812382B2 JP 1167908 A JP1167908 A JP 1167908A JP 16790889 A JP16790889 A JP 16790889A JP H0812382 B2 JPH0812382 B2 JP H0812382B2
- Authority
- JP
- Japan
- Prior art keywords
- read
- image reading
- reflectance
- document table
- diffusing member
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Landscapes
- Optical Systems Of Projection Type Copiers (AREA)
- Facsimile Scanning Arrangements (AREA)
Description
【発明の詳細な説明】 （産業上の利用分野） 本発明は画像読取装置に関し、特に被読取部として通
常のシート上の原稿の他に、例えば金属光沢性のある反
射率の高い反射型の原稿や立体物等を読取画像として投
影レンズによりCCD等から成る画像読取手段面上に投影
し、該投影画像を読取る際に好適な画像読取装置に関す
るものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading device, and in particular, as a read portion, in addition to an ordinary document on a sheet, for example, a reflection type having metallic gloss and high reflectance is used. The present invention relates to an image reading apparatus suitable for reading an original image, a three-dimensional object, or the like as a read image on an image reading means surface such as a CCD by a projection lens and reading the projected image.
（従来の技術） 従来より原稿台面上に載置され照明手段で照明された
反射型の画像を投影レンズによりCCD等の画像読取手段
面上に投影し、該投影された画像を読取るようにした画
像読取装置が種々と提案されている。(Prior Art) Conventionally, a reflection type image placed on an original table surface and illuminated by an illumination means is projected onto an image reading means surface such as a CCD by a projection lens, and the projected image is read. Various image reading devices have been proposed.
第５図は従来のこの種の画像読取装置の要部断面概略
図である。FIG. 5 is a schematic cross-sectional view of a main part of a conventional image reading apparatus of this type.
同図において52は被読取部であり、例えば金属光沢性
のある原稿や反射率の高い立体物等であり原稿台51面上
に載置されている。54は凹面鏡であり光源53からの光束
を集光し、照明効率を上げて原稿台51面上に載置した被
読取部52を照明している。In the figure, reference numeral 52 denotes a read portion, which is, for example, a document having a metallic gloss or a three-dimensional object having a high reflectance, and is placed on the surface of the document table 51. Reference numeral 54 denotes a concave mirror, which collects the light flux from the light source 53 to increase the illumination efficiency and illuminates the read portion 52 placed on the surface of the document table 51.
55は投影レンズであり被読取部52をCCD等から成る画
像読取手段56面上に投影している。57は画像読取手段56
から得られる被読取部52の画像情報に基づく出力信号で
ある。Reference numeral 55 denotes a projection lens, which projects the portion to be read 52 onto the surface of the image reading means 56 including a CCD or the like. 57 is an image reading means 56
It is an output signal based on the image information of the read section 52 obtained from FIG.
（発明が解決しようとする問題点） 従来の画像読取装置は被読取部として最も多く用いら
れているシート状の原稿の反射率が比較的低い為に照明
手段により、原稿台面上に載置した被読取部をなるべく
効率良く照明するようにしている。(Problems to be Solved by the Invention) In the conventional image reading apparatus, since the reflectance of the sheet-like document which is most often used as the read portion is relatively low, the document is placed on the document table surface by the illumination means. The read section is illuminated as efficiently as possible.
この為、例えば金属光沢性のある被読取部、例えばア
クセサリー等の貴金属を読取るような場合には照明手段
からの光束が正反射して多くの光量が画像読取手段面上
に入射するようになる。この為、画像読取手段の光電変
換素子が飽和レベルを越えてブルーミング現象を起こし
画像信号をホワイトノイズにしてしまうという問題点が
あった。For this reason, for example, when reading a read part having a metallic luster, for example, a noble metal such as an accessory, the light flux from the illumination means is specularly reflected and a large amount of light is incident on the surface of the image reading means. . Therefore, there is a problem that the photoelectric conversion element of the image reading means exceeds the saturation level to cause a blooming phenomenon and the image signal becomes white noise.
これに対して照明手段の照明効率を落として、例えば
原稿を40度以上の入射角で照明して正反射が生じないよ
うにする方法も考えられるが、この方法は所定の光量を
確保する為に投影レンズのＦナンバーを明るくしなけれ
ばならずレンズ構成が複雑化してくるという問題点があ
った。On the other hand, it is conceivable to reduce the illumination efficiency of the illuminating means and illuminate the original at an incident angle of 40 degrees or more to prevent specular reflection, but this method is for securing a predetermined amount of light. In addition, the F number of the projection lens must be brightened, and the lens structure becomes complicated.
この他光電変換素子としての例えばCCDの使用レベル
を例えば飽和出力の３割以下とし、７割分を高い反射率
の被読取部を用いたときの正反射光に対するマージンと
してとる方法も考えられるが、この方法は、最も多い通
常の原稿を読取る場合には出力信号が少なくなりすぎS/
N比が低下してくるという問題点がある。In addition, a method of using a CCD, for example, as a photoelectric conversion element at a level of 30% or less of a saturated output and 70% as a margin for specularly reflected light when a read portion having a high reflectance is used may be considered. In this method, the output signal becomes too small when scanning the most ordinary documents, and S /
There is a problem that the N ratio decreases.
本発明は反射率の低い原稿であっても、又金属光沢性
のある反射率の高い原稿であっても所定の光路中に拡散
部材を挿脱可能に配置することによりどのような画像情
報であっても常に精度良く画像情報を読取ることのでき
る画像読取装置の提供を目的とする。According to the present invention, even if the original document has a low reflectance or the original document has a metallic gloss and a high reflectance, it is possible to obtain any kind of image information by arranging the diffusing member in the predetermined optical path in a removable manner. An object is to provide an image reading device that can always read image information with high accuracy.
（問題点を解決するための手段） 本発明の画像読取装置は原稿台面上に載置した被読取
部を照明手段により斜め下方から照明し、該被読取部を
投影レンズにより画像読取手段面上に投影して読取る
際、該被読取部の反射率が高いときは該被読取部と該原
稿台面との間に拡散部材を挿入し、該拡散部材を介して
該被読取部を照明及び読取るようにしたことを特徴とし
ている。(Means for Solving the Problems) In the image reading apparatus of the present invention, the reading portion placed on the original table surface is illuminated obliquely from below by the illumination means, and the reading portion is placed on the image reading means surface by the projection lens. When projecting and reading the image onto the reading target portion, if the reflectance of the reading target portion is high, a diffusion member is inserted between the reading target portion and the document table surface, and the reading target portion is illuminated and read through the diffusion member. It is characterized by doing so.
特に本発明では前記照明手段は前記被読取部を該原稿
台に対して40度以下の入射角で照明しており、又前記拡
散部材は80％以上の透過率を有した部材より構成されて
いることを特徴としている。Particularly in the present invention, the illuminating means illuminates the read part at an incident angle of 40 degrees or less with respect to the document table, and the diffusing member is composed of a member having a transmittance of 80% or more. It is characterized by being.
（実施例） 第１図は本発明の画像読取装置の一実施例の要部概略
図である。(Embodiment) FIG. 1 is a schematic view of a main part of an embodiment of an image reading apparatus of the present invention.
同図において６は被読取部（原稿）であり反射率の高
い原稿として同図では金属光沢性を有したアクセサリー
等の立体的な貴金属の場合を示している。In the figure, reference numeral 6 denotes a portion to be read (original), which is a high-reflecting original, and in the same figure, a case of a three-dimensional noble metal such as an accessory having metallic luster is shown.
８は原稿台であり被読取部６を載置しており、矢印8a
方向に移動可能となっている。７は拡散部材であり被読
取部６と原稿台８との間に挿脱可能となるように配置さ
れている。２は凹面鏡であり光源１からの光束を集光
し、原稿台８面上に載置した被読取部６を原稿台８面に
対して入射角40度以下となる下方向から照明している。
３は投影レンズであり原稿台８面上の被読取部６を所定
の倍率で画像読取手段４面上に投影している。Reference numeral 8 denotes a document table on which the section to be read 6 is placed, and an arrow 8a
It can be moved in any direction. Reference numeral 7 denotes a diffusing member, which is arranged so that it can be inserted and removed between the read portion 6 and the document table 8. Reference numeral 2 denotes a concave mirror that collects the light flux from the light source 1 and illuminates the read portion 6 placed on the surface of the document table 8 from below with the incident angle of 40 degrees or less with respect to the surface of the document table 8. .
Reference numeral 3 denotes a projection lens, which projects the read portion 6 on the surface of the document table 8 on the surface of the image reading means 4 at a predetermined magnification.
画像読取手段４は複数の素子を１次元的に配置したCC
D等の光電変換素子より成っており、原稿台８の移動に
より被読取部６面上の画像情報を順次走査し読取ってい
る。尚、画像読取手段４を２次元のCCDより構成しても
良く、このときは原稿台８は固定のままで良い。The image reading means 4 is a CC in which a plurality of elements are arranged one-dimensionally.
It is composed of a photoelectric conversion element such as D, and the image information on the surface of the read portion 6 is sequentially scanned and read by the movement of the document table 8. The image reading means 4 may be composed of a two-dimensional CCD, and at this time, the original table 8 may be fixed.
９は反射率検出手段であり、必要に応じて原稿台８近
傍に設けられており、投光部と受光部とを有しており、
原稿台８面上に載置した被読取部６の反射率を測定して
いる。Reference numeral 9 denotes a reflectance detecting means, which is provided near the document table 8 as necessary and has a light projecting portion and a light receiving portion.
The reflectance of the read portion 6 placed on the surface of the document table 8 is measured.
本実施例では反射率の高い被読取部６を読取るときに
は反射率検出手段９からの出力信号に基づいて自動的に
又は不図示の外部入力手段からの入力信号に基づいて拡
散部材７を被読取部６と原稿台８との間に挿入する。In the present embodiment, when the read portion 6 having a high reflectance is read, the diffusion member 7 is read automatically based on an output signal from the reflectance detecting means 9 or based on an input signal from an external input means (not shown). It is inserted between the section 6 and the document table 8.
尚、第２図はこのときの原稿台８と被読取部６（不図
示）との間に挿入された拡散部材７を示している。Incidentally, FIG. 2 shows the diffusing member 7 inserted between the document table 8 and the read portion 6 (not shown) at this time.
そして被読取部６を拡散光で照明し照明効率を積極的
に低下させている。これにより投影レンズ３により画像
読取手段４面上に入射する光量を少なくし、光電変換素
子のブルーミングを防止している。Then, the reading portion 6 is illuminated with diffused light to actively reduce the illumination efficiency. As a result, the amount of light incident on the surface of the image reading means 4 is reduced by the projection lens 3, and blooming of the photoelectric conversion element is prevented.
又、本実施例では光源１からの光束の被読取部６への
入射角が40度以下となるようにして被読取部６からの正
反射光が画像読取手段４に入射しないようにして読取り
精度を高めている。Further, in this embodiment, the light beam from the light source 1 is read so that the incident angle of the light beam to the read portion 6 is 40 degrees or less so that the specularly reflected light from the read portion 6 does not enter the image reading means 4. The accuracy is improved.
本実施例では被読取部６が通常のシート状の原稿等の
反射率が低いときは反射率検出手段９からの出力信号に
基づいて自動的に又は外部入力手段からの入力信号に基
づいて拡散部材７を被読取部６と原稿台８との間から抜
脱している。これにより光源１からの光束で効率良く被
読取部６を照明するようにしている。In the present embodiment, when the read portion 6 has a low reflectance of a normal sheet-like document, the reading portion 6 diffuses automatically based on an output signal from the reflectance detecting means 9 or based on an input signal from an external input means. The member 7 is removed from between the read portion 6 and the document table 8. Thus, the light beam from the light source 1 efficiently illuminates the read portion 6.
本実施例ではこのように被読取部の反射率の大小に応
じて拡散部材を光路中から挿脱させることにより被読取
部がどのような反射率を有した原稿であっても精度良く
読取ることができるようにしている。In this embodiment, by thus inserting / removing the diffusing member in the optical path according to the reflectance of the read portion, it is possible to accurately read an original having any reflectance. I am able to
尚、このとき本実施例では画像読取手段４をCCDより
構成し、原稿台８面上に白色原稿（一般のシート状の原
稿）を載置したときに読取信号が飽和レベルの３割以上
となるように各要素を設定し、光電変換素子のブルーミ
ング現象が生じないようにして高精度の画像読取りが行
なえるようにしている。At this time, in this embodiment, the image reading means 4 is composed of a CCD, and when a white original (general sheet-like original) is placed on the surface of the original table 8, the read signal is 30% or more of the saturation level. Each element is set so that the blooming phenomenon of the photoelectric conversion element does not occur so that highly accurate image reading can be performed.
本実施例において拡散部材は透過率が80％以上の部材
を用い、原稿の浮きに対してボケ量が少なく精度良く読
取りが出来るようにしている。In this embodiment, the diffusing member is made of a material having a transmittance of 80% or more, so that the amount of blurring with respect to the floating of the original is small and the reading can be performed accurately.
拡散部材は被読取部６と原稿台８との間に限らず原稿
台８の下方等光路中の任意の位置に配置しても良い。The diffusing member is not limited to be provided between the read section 6 and the document table 8, and may be disposed at any position in the optical path such as below the document table 8.
又、第３図に示すように拡散部材７を原稿台８の一部
に設け、拡散部31と非拡散部32とを形成し、原稿台８を
移動可能とし、被読取部の反射率に応じて駆動させ選択
的に用いるようにしても良い。Further, as shown in FIG. 3, a diffusing member 7 is provided on a part of the document table 8 to form a diffusing section 31 and a non-diffusing section 32 so that the document table 8 can be moved and the reflectance of the read portion can be improved. It may be driven accordingly and selectively used.
原稿台８への照明方法としているこの他第４図に示す
ように２つの凹面鏡2a、2bを用いて光源１からの光束の
原稿台８への入射角が共に40度以下となるように双方か
ら照明するようにしても良い。In addition to the method of illuminating the document table 8, two concave mirrors 2a and 2b are used so that the incident angles of the light flux from the light source 1 on the document table 8 are both 40 degrees or less, as shown in FIG. You may make it illuminate from.
（発明の効果） 本発明によればどのような反射率を有した被読取部で
あっても、反射率の大小に応じて光路中に挿脱可能とな
るように配置した拡散部材を用いることにより光電変換
素子のブルーミング現象を防止し、高精度な画像読取り
が可能な画像読取装置を達成することできる。(Effects of the Invention) According to the present invention, it is possible to use a diffusing member that is arranged so that it can be inserted into and removed from the optical path according to the magnitude of the reflectance, regardless of the reflectance of the read portion. Thus, the blooming phenomenon of the photoelectric conversion element can be prevented, and an image reading device capable of highly accurate image reading can be achieved.
第１図は本発明の一実施例の要部概略図、第２図は第１
図の一部分の説明図、第３図は第１図の原稿台近傍の他
の一実施例の概略図、第４図は本発明の他の一実施例の
要部概略図、第５図は従来の画像読取装置の概略図であ
る。 図中１は光源、２は凹面鏡、３は投影レンズ、４は画像
読取手段、６は被読取部、７は拡散部材、８は原稿台、
９は反射率検出手段、である。FIG. 1 is a schematic view of an essential part of an embodiment of the present invention, and FIG.
FIG. 3 is a schematic view of a part of the drawing, FIG. 3 is a schematic view of another embodiment near the document table of FIG. 1, FIG. 4 is a schematic view of a main part of another embodiment of the present invention, and FIG. It is a schematic diagram of the conventional image reading device. In the figure, 1 is a light source, 2 is a concave mirror, 3 is a projection lens, 4 is image reading means, 6 is a portion to be read, 7 is a diffusing member, 8 is a document table,
Reference numeral 9 is a reflectance detecting means.
Claims (5)
により斜め下方から照射し、該被読取部を投影レンズに
より画像読取手段面上に投影して読取る際、該被読取部
の反射率が高いときは該被読取部と該原稿台面との間に
拡散部材を挿入し、該拡散部材を介して該被読取部を照
明及び読取るようにしたことを特徴とする画像読取装
置。1. A reading part placed on a document table surface is illuminated obliquely from below by an illuminating means, and when the reading part is projected onto a surface of the image reading means by a projection lens and is read, the reading part is read. When the reflectance is high, an image reading apparatus is characterized in that a diffusing member is inserted between the read section and the document table surface, and the read section is illuminated and read through the diffusing member.
読取部の反射率を検出する反射率検出手段からの信号に
基づいて又は外部入力手段からの信号に基づいて挿脱可
能に構成したことを特徴とする請求項１記載の画像読取
装置。2. A structure in which the diffusing member can be inserted and removed based on a signal from a reflectance detecting means for detecting the reflectance of a portion to be read which is provided in the vicinity of the platen or based on a signal from an external input means. The image reading device according to claim 1, wherein
対して40度以下の入射角で照明していることを特徴とす
る請求項１記載の画像読取装置。3. The image reading apparatus according to claim 1, wherein the illuminating means illuminates the read portion with respect to the original table at an incident angle of 40 degrees or less.
部材より構成されていることを特徴とする請求項１記載
の画像読取装置。4. The image reading apparatus according to claim 1, wherein the diffusing member is made of a member having a transmittance of 80% or more.
取部が白色原稿であるとき読取信号が飽和レベルの３割
以上となるように各要素を設定したことを特徴とする請
求項１記載の画像読取装置。5. The image reading means is composed of a CCD, and each element is set so that the read signal is 30% or more of the saturation level when the read portion is a white original. The image reading device described.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1167908A JPH0812382B2 (en) | 1989-06-28 | 1989-06-28 | Image reader |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1167908A JPH0812382B2 (en) | 1989-06-28 | 1989-06-28 | Image reader |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0331839A JPH0331839A (en) | 1991-02-12 |
| JPH0812382B2 true JPH0812382B2 (en) | 1996-02-07 |
Family
ID=15858280
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1167908A Expired - Fee Related JPH0812382B2 (en) | 1989-06-28 | 1989-06-28 | Image reader |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0812382B2 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5084662B2 (en) * | 2008-08-05 | 2012-11-28 | キヤノン株式会社 | Image reading apparatus and image reading and recording apparatus |
| US8243349B2 (en) | 2008-08-05 | 2012-08-14 | Canon Kabushiki Kaisha | Image reading method and image reading apparatus |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS59144280A (en) * | 1983-02-07 | 1984-08-18 | Canon Inc | Image pickup device |
| JPS63155135A (en) * | 1986-12-19 | 1988-06-28 | Fuji Photo Film Co Ltd | Slit exposure device |
-
1989
- 1989-06-28 JP JP1167908A patent/JPH0812382B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0331839A (en) | 1991-02-12 |
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