JPH07162586A - Light emitting device and contact image sensor unit using it - Google Patents
Light emitting device and contact image sensor unit using itInfo
- Publication number
- JPH07162586A JPH07162586A JP30644793A JP30644793A JPH07162586A JP H07162586 A JPH07162586 A JP H07162586A JP 30644793 A JP30644793 A JP 30644793A JP 30644793 A JP30644793 A JP 30644793A JP H07162586 A JPH07162586 A JP H07162586A
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- Prior art keywords
- light emitting
- light
- guide plate
- light guide
- emitting elements
- Prior art date
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Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、原稿情報を光学的に読
み取るための発光装置とそれを用いた密着型イメージセ
ンサユニットとに関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light emitting device for optically reading document information and a contact type image sensor unit using the same.
【０００２】[0002]
【従来の技術】近年においては密着型イメージセンサユ
ニットは小型ファクシミリやデジタル複写機等の読み取
り装置として汎用されるに至っている。以下、図６ない
し図９を参照しながら、上記した従来の発光装置の一例
とそれを原稿照明用光源として用いた密着型イメージセ
ンサユニットの一例について説明する。2. Description of the Related Art In recent years, a contact type image sensor unit has been widely used as a reading device for a small facsimile, a digital copying machine or the like. Hereinafter, an example of the above-described conventional light emitting device and an example of a contact image sensor unit using the same as a light source for document illumination will be described with reference to FIGS. 6 to 9.
【０００３】図６を参照して説明するように、前記原稿
照明用光源として用いられる従来の発光装置１は、回路
導体層を設けた基板２と、その基板１の表面上の所定の
位置に一列に実装された多数の発光素子３と、基板２の
端部に半田付けされた一対のリード線４とを備えるとと
もに、イメージセンサユニットの光源として原稿面を照
明するときはリード線４に直流の定格電圧が印加されて
前記回路導体層に電流を流すことによって発光素子３を
点灯させるようになっている。As will be described with reference to FIG. 6, a conventional light emitting device 1 used as a light source for illuminating a document has a substrate 2 provided with a circuit conductor layer and a predetermined position on the surface of the substrate 1. A large number of light emitting elements 3 mounted in a row and a pair of lead wires 4 soldered to the ends of the substrate 2 are provided, and when the document surface is illuminated as a light source of the image sensor unit, a DC voltage is applied to the lead wires 4. The rated voltage is applied and a current is passed through the circuit conductor layer to light the light emitting element 3.
【０００４】図７を参照して説明するように従来の密着
型イメージセンサユニット５は回路導体層付きの基台６
を備え、この基台６内部に原稿面を照明させるために図
６の発光装置１が装備されている。このような従来の密
着型イメージセンサユニット５の全体の概略構成につい
て詳しく説明すると、基台６の上面には光電変換素子７
が一列に配列されたガラス基板８が載置されている。基
台６の下部側は凹所９を備え、この凹所９内部に前記し
た発光装置１が斜め向きに配備される一方、ロッドレン
ズアレイ１０が垂直向きに配備される。この凹所９は原
稿１１に当接する原稿面ガラス板１２で閉鎖されてい
る。また、基台６には正立等倍結像系としてのロッドレ
ンズアレイ１０とガラス基板８上の光電変換素子７とが
対応する箇所にスリット１３が形成されている。As described with reference to FIG. 7, a conventional contact type image sensor unit 5 has a base 6 with a circuit conductor layer.
The light emitting device 1 of FIG. 6 is provided in order to illuminate the document surface inside the base 6. The overall schematic configuration of the conventional contact image sensor unit 5 will be described in detail. The photoelectric conversion element 7 is provided on the upper surface of the base 6.
The glass substrates 8 arranged in a line are placed. The lower side of the base 6 is provided with a recess 9, and inside the recess 9, the above-described light emitting device 1 is obliquely arranged, while the rod lens array 10 is arranged vertically. The recess 9 is closed by a document surface glass plate 12 that contacts the document 11. A slit 13 is formed on the base 6 at a position where the rod lens array 10 as an erecting equal-magnification imaging system and the photoelectric conversion element 7 on the glass substrate 8 correspond to each other.
【０００５】このような構成のイメージセンサユニット
５においては、発光装置１に定格電圧を印加して発光素
子３を点灯駆動させることでガラス板１２の下面に位置
する原稿１１の面を照明し、その反射光をロッドレンズ
アレイ１０によって集光させるとともに、スリット１３
を介して光電変換素子７で受光させ、ここで原稿上の文
字、図形などに対応した電気信号に変換していた。In the image sensor unit 5 having such a configuration, the rated voltage is applied to the light emitting device 1 to drive the light emitting element 3 to light up, thereby illuminating the surface of the original 11 located on the lower surface of the glass plate 12. The reflected light is condensed by the rod lens array 10, and the slit 13
The light is received by the photoelectric conversion element 7 via the, and converted into electric signals corresponding to characters, figures, etc. on the original document.
【０００６】[0006]
【発明が解決しようとする課題】上記従来の発光装置１
においては、それに組み込まれる発光素子３が例えば発
光ダイオードである場合は、その発光ダイオードから原
稿面に照射される光は図８に示すような指向特性を有す
るために、本来、発光素子３が照射すべき方向以外にも
光が照射されてしまうから、発光素子３の実装数が少な
いと原稿面への照明効率に劣ってくるので照明効率を上
げるには多数の発光素子３を実装させる必要があり、そ
の実装に要するコストもかさんでくるという問題を有し
ていた。SUMMARY OF THE INVENTION The above conventional light emitting device 1
In the case where the light emitting element 3 incorporated therein is, for example, a light emitting diode, the light emitted from the light emitting diode to the document surface has the directivity characteristic as shown in FIG. Since light is emitted in a direction other than the desired direction, if the number of mounted light emitting elements 3 is small, the efficiency of illuminating the original surface is inferior. Therefore, it is necessary to mount a large number of light emitting elements 3 to increase the illumination efficiency. However, there was a problem that the cost required for its implementation would be too expensive.
【０００７】上記従来の密着型イメージセンサユニット
５においては、原稿１１へ照射する発光素子３の光線が
その発光素子が発光ダイオードである場合、これも前記
と同様に図８のような指向特性を有することから、読み
取るべき原稿１１の一ライン分へ照射される光というの
は発光素子３から発せられる光の一部分となってしま
い、このことも結果として原稿面を照明させるために多
数の発光素子が必要となる問題を有していた。In the conventional contact type image sensor unit 5 described above, when the light beam of the light emitting element 3 for irradiating the original 11 is a light emitting diode, this also has the directional characteristics as shown in FIG. Therefore, the light emitted to one line of the original 11 to be read is a part of the light emitted from the light emitting element 3, and as a result, many light emitting elements are used to illuminate the original surface. Had the problem that was needed.
【０００８】ここで、図９（ａ）および図９（ｂ）を参
照して発光装置１における基板２上の発光素子３の素子
数に対応して、その発光素子３による原稿１１上の面照
度と、有効照明長とを説明する。この場合、発光素子３
の素子数は図９（ａ）では一例として５個であり、図９
（ｂ）は一例として３個である。また、これらの図でΔ
ｘは原稿１１の面照度の偏差であり、ｍａｘは最大面照
度であり、ｍｉｎは最小面照度であり、ａｖｅは平均面
照度である。また、原稿１１の面上での照度偏差Δｘは
（最大原稿面照度ｍａｘ−最小原稿面照度ｍｉｎ）／
（最大原稿面照度ｍａｘ＋最小原稿面照度ｍｉｎ＊１０
０）で算出される。図９（ａ）の場合のように発光素子
数が多いときでは照度偏差Δｘも小さく、有効照明長も
長く、平均原稿面照度ａｖｅも明るくなって照明性能に
優れるが、図９（ａ）よりも発光素子３の素子数が少な
くなる図９（ｂ）の場合では原稿１１の面上での照度偏
差Δｘが大きく、平均原稿面照度ａｖｅも暗くなり、有
効照度長も極めて小さくなるという問題点を有してい
た。そのために、発光素子にはそれ固有の指向性からく
る問題と、図９を参照して説明したような問題があり、
素子数を多くするとコストがかさむなどの理由で発光素
子数を減少させるとしてもそれらの問題を解決する必要
があった。Here, referring to FIGS. 9A and 9B, the surface of the original 11 formed by the light emitting elements 3 corresponds to the number of the light emitting elements 3 on the substrate 2 in the light emitting device 1. Illuminance and effective illumination length will be described. In this case, the light emitting element 3
The number of elements in FIG. 9 is five in FIG. 9A as an example.
(B) is three pieces as an example. In these figures, Δ
x is the deviation of the surface illumination of the document 11, max is the maximum surface illumination, min is the minimum surface illumination, and ave is the average surface illumination. Further, the illuminance deviation Δx on the surface of the document 11 is (maximum document surface illuminance max−minimum document surface illuminance min) /
(Maximum document surface illuminance max + minimum document surface illuminance min * 10
0). When the number of light emitting elements is large as in the case of FIG. 9A, the illuminance deviation Δx is small, the effective illumination length is long, the average document surface illuminance ave is bright, and the illumination performance is excellent. 9B in which the number of light emitting elements 3 is small, the illuminance deviation Δx on the surface of the document 11 is large, the average document surface illuminance ave is dark, and the effective illuminance length is extremely small. Had. Therefore, the light emitting element has a problem caused by its own directivity and a problem described with reference to FIG.
Even if the number of light emitting elements is reduced for the reason that the cost is increased if the number of elements is increased, it is necessary to solve those problems.
【０００９】したがって、本発明は上記問題点に鑑みて
なされたものであって、発光素子をアレイ状に実装した
基板の短辺方向のみ該発光素子の指向特性を狭くするこ
とで従来分散していた基板の短辺方向の光を集光させ、
かつ基板の長辺方向の発光素子の指向特性を広くするこ
とで発光素子数を減らしたとしても従来の発光装置と同
等な照度偏差と有効照明長とを持つようにして原稿への
照明性能を十分に発揮でき、これによって前記課題を解
決し得た発光装置を提供するとともに、それを用いて低
コストのもので高性能な密着型イメージセンサユニット
を提供することを目的としている。Therefore, the present invention has been made in view of the above problems, and has been conventionally dispersed by narrowing the directional characteristics of the light emitting elements only in the short side direction of the substrate on which the light emitting elements are mounted in an array. The light from the short side of the substrate
Moreover, even if the number of light-emitting elements is reduced by widening the directional characteristics of the light-emitting elements in the long side direction of the substrate, the same illuminance deviation and effective illumination length as those of the conventional light-emitting device are provided to improve the illumination performance of the original. It is an object of the present invention to provide a light-emitting device which can be sufficiently exhibited and can solve the above problems, and to provide a low-cost and high-performance contact image sensor unit by using the light-emitting device.
【００１０】[0010]
【課題を解決するための手段】上記問題点を解決するた
めに本発明の発光装置は、列状に実装した複数の発光素
子と、その発光素子から出射された光を目標とする所定
の位置まで導くための導光板とを備え、前記発光素子
は、その発光面側を前記導光板の長辺側に当接するよう
に並べ実装し、前記導光板の短辺長は、前記実装発光素
子の実装ピッチ以上とした構成としている。In order to solve the above-mentioned problems, a light emitting device of the present invention has a plurality of light emitting elements mounted in a row and a predetermined position at which light emitted from the light emitting elements is targeted. A light guide plate for guiding up to, the light emitting element is mounted side by side so that its light emitting surface side abuts the long side of the light guide plate, and the short side length of the light guide plate is equal to that of the mounted light emitting element. It is configured to be mounted pitch or more.
【００１１】本発明の密着型イメージセンサユニット
は、基台と、読み取られるべき原稿の面に当接する光透
過板と、前記基台の内部に設けられ前記原稿面を照明す
るための発光装置と、照明された前記原稿からの反射光
を所定の結像系を通して受光して電気信号に変換する光
電変換素子とからなるものにおいて、前記発光装置は複
数の発光素子と、その発光素子から出射された光を前記
原稿まで導くための導光板とを備え、前記発光素子は、
その発光面側を導光板の長辺側に当接するように並べ実
装し、前記導光板の短辺長が前記発光素子の実装ピッチ
以上とした構成としている。The contact-type image sensor unit of the present invention includes a base, a light transmitting plate that comes into contact with the surface of the original to be read, and a light emitting device provided inside the base to illuminate the original surface. A photoelectric conversion element that receives the reflected light from the illuminated original through a predetermined image forming system and converts it into an electric signal, wherein the light emitting device emits light from a plurality of light emitting elements and the light emitting elements. And a light guide plate for guiding light to the original,
The light emitting surface side is mounted side by side so as to abut the long side of the light guide plate, and the short side length of the light guide plate is set to be equal to or greater than the mounting pitch of the light emitting elements.
【００１２】本発明の密着型イメージセンサユニットは
また、発光装置の導光板が、各々屈折率の異なる二枚以
上の導光板を発光素子からの光の進行方向に連ねるとと
もに、屈折率の大きい一方の導光板を発光素子から放射
される光の入射側に設け、屈折率の小さい他方の導光板
を前記一方の導光板からの光の出射側に設けてなる複合
体とした構成としている。In the contact-type image sensor unit of the present invention, the light guide plate of the light emitting device has two or more light guide plates each having a different refractive index connected in the traveling direction of the light from the light emitting element, and one having a large refractive index. The light guide plate is provided on the incident side of the light emitted from the light emitting element, and the other light guide plate having a small refractive index is provided on the exit side of the light from the one light guide plate.
【００１３】[0013]
【作用】本発明の発光装置は、上記した構成によって、
発光素子をアレイ状に実装した基板の短辺方向のみの指
向特性を狭くし、従来分散していた基板の短辺方向の光
を集光し、かつ基板の長辺方向の指向特性を広くするこ
とで、発光素子の素子数を減らしても従来の発光装置と
同等な照度偏差と有効照明長とを有する。The light emitting device of the present invention has the above-mentioned structure.
Narrow the directional characteristics only in the short side direction of the substrate on which the light-emitting elements are mounted in an array, collect the light in the short side direction of the substrate that was previously dispersed, and widen the directional characteristic in the long side direction of the substrate. Therefore, even if the number of light emitting elements is reduced, the illuminance deviation and the effective illumination length are the same as those of the conventional light emitting device.
【００１４】また、本発明の密着型イメージセンサユニ
ットは、前記発光装置を用いているから、安価で高性能
な密着型イメージセンサユニットとなる。Further, since the contact type image sensor unit of the present invention uses the light emitting device, the contact type image sensor unit is inexpensive and has high performance.
【００１５】さらに、本発明の密着型イメージセンサユ
ニットは、前記導光板を、各々屈折率の異なる二枚以上
の導光板を発光素子からの光の進行方向に連ねるととも
に、屈折率の大きい一方の導光板を発光素子から放射さ
れる光の入射側に設け、屈折率の小さい他方の導光板を
前記一方の導光板からの光の出射側に設けてなる複合体
とした構成により屈折率の大きい導光板から屈折率の小
さい導光板に光が進入する際に両導光板の境界で光がそ
の横方向の指向特性を広げられるから、導光板の短辺長
を発光素子のピッチ長とは無関係に短縮可能となり発光
装置の小型化が可能となり、これを用いたイメージセン
サユニットは上述のように安価で高性能にできるうえに
その小型化がより促進される。Further, in the contact type image sensor unit of the present invention, the light guide plate is formed by connecting two or more light guide plates each having a different refractive index in the traveling direction of light from the light emitting element, and the one having a large refractive index. The light guide plate is provided on the incident side of the light emitted from the light emitting element, and the other light guide plate having a small refractive index is provided on the emission side of the light from the one light guiding plate to form a composite structure having a large refractive index. When the light enters from the light guide plate to the light guide plate with a small refractive index, the light can spread the directional characteristics in the lateral direction at the boundary of both light guide plates, so the short side length of the light guide plate is independent of the pitch length of the light emitting element. Therefore, the light emitting device can be downsized, and the image sensor unit using the light emitting device can be inexpensive and high-performance as described above, and the downsizing can be further promoted.
【００１６】[0016]
【実施例】以下本発明の実施例１ないし３を図面を参照
しながら説明する。Embodiments 1 to 3 of the present invention will be described below with reference to the drawings.
【００１７】実施例１ 図１および図２は本発明の実施例１に係る発光装置の構
成を示す図であって、図１はその斜視図であって、図２
はその側面断面図である。これらの図において、図６と
対応する部分には同一の符号を付し、その同一の符号に
係る部分についての詳しい説明は省略する。図１におい
て、符号２０は実施例１の発光装置の全体を示してい
る。この発光装置２０は、従来例と同様に基板２と、複
数の発光素子３と、一対のリード線４とを基本構成とし
て備えている。 Embodiment 1 FIGS. 1 and 2 are views showing the structure of a light emitting device according to Embodiment 1 of the present invention, and FIG. 1 is a perspective view thereof.
FIG. In these figures, the portions corresponding to those in FIG. 6 are designated by the same reference numerals, and detailed description of the portions having the same reference numerals is omitted. In FIG. 1, reference numeral 20 indicates the entire light emitting device of the first embodiment. This light emitting device 20 includes a substrate 2, a plurality of light emitting elements 3, and a pair of lead wires 4 as a basic configuration, as in the conventional example.
【００１８】本実施例１の発光装置２０は、上記基本構
成に加えて、基板２上にアレイ状に実装された発光素子
３の発光面側でかつ発光素子３の放射光軸上に長辺を合
わせられた矩形状導光板２１を設置したことに特徴を有
している。この導光板２１はその短辺長ｐ１が発光素子
３の実装ピッチｐ２よりも長くされており、図示してい
ない適宜の固定手段で固定配備されている。なお、この
導光板２１は光を導光させるうえでは透明体で構成され
ることが好ましいが、必ずしも透明体で構成される必要
はなく光を導くことのできるものであればよい。In addition to the above basic structure, the light emitting device 20 of the first embodiment has a long side on the light emitting surface side of the light emitting elements 3 mounted in an array on the substrate 2 and on the emission optical axis of the light emitting elements 3. It is characterized in that a rectangular light guide plate 21 which is aligned is installed. The short side length p1 of the light guide plate 21 is longer than the mounting pitch p2 of the light emitting elements 3, and the light guide plate 21 is fixedly arranged by an appropriate fixing means (not shown). The light guide plate 21 is preferably formed of a transparent body in order to guide light, but it does not necessarily have to be formed of a transparent body as long as it can guide light.
【００１９】図２および図３を参照して本実施例１の発
光装置２０に搭載された発光素子３からの光２２が導光
板２１に進入する進路について説明する。なお、図２に
おいて、θ１は光２２の屈折角、θ２は光２２の入射角
である。また、図３において、本実施例１にる発光装置
２０による原稿面照度と有効照明長とを説明するために
基板２を上に、導光板２１を下に向けた状態での発光装
置２０と、この発光装置２０の導光板２１を介して照明
される原稿１１の面と、その発光装置２０により照明さ
れる原稿１１上の面上の照度のグラフとが示されてい
る。The path along which the light 22 from the light emitting element 3 mounted on the light emitting device 20 of the first embodiment enters the light guide plate 21 will be described with reference to FIGS. 2 and 3. In FIG. 2, θ1 is the refraction angle of the light 22, and θ2 is the incident angle of the light 22. Further, in FIG. 3, in order to explain the illuminance on the document surface and the effective illumination length by the light emitting device 20 according to the first embodiment, the light emitting device 20 with the substrate 2 facing upward and the light guide plate 21 facing downward. A surface of the document 11 illuminated through the light guide plate 21 of the light emitting device 20 and a graph of illuminance on the surface of the document 11 illuminated by the light emitting device 20 are shown.
【００２０】まず、リード線３に直流の定格電圧を印加
すると、回路導体層に電流が流れ発光素子３が点灯し、
この発光素子３で放射された光２２が図２のように導光
板２１の一方の端面へ入射する。こうして、導光板２１
の一方の端面に入射した光２２は導光板２１の内部と外
部の境界とで屈折角をもって屈折し外部へ放射されるの
であるが、この屈折角θ１が９０°以上になるような角
度、例えば入射角θ２で入った光２２は導光板２１の内
部を全反射して進み、導光板２１の他方の端面から放射
される。したがって、アレイ状に実装した発光素子３の
発光面側で、かつ発光素子３の放射する光２２の光軸上
に導光板２１を設置したことにより、少なくとも屈折角
θ１が９０°以上になるような角度、つまり入射角θ２
で入った光は、すべて導光板２１の内部を全反射して進
み、この導光板２１の他方の端面から放射されることに
なり、結果として発光素子３をアレイ状に実装した基板
２の短辺方向（図２で左右方向）の指向特性が狭くな
り、従来分散していた光を集光し、導光板２１の内部に
光を閉じこめ、ほとんど損失なしに導光板２１の出射面
である他方の端面から光２２を出射することができ、あ
たかも導光板２１の光の出射側に発光素子３があること
と同等の動作をする。また、原稿１１の面上での照度偏
差Δｘは実際に位置している発光素子３と原稿面との距
離で決定するので、導光板２１の出射面から原稿面まで
の距離を従来のものと等しくすれば、図９（ａ）と図３
とを比較すれば明らかなように本実施例１では発光素子
３の素子数が図３の例では３個であっても、図９（ａ）
のようにその素子数が５個の場合とそれほど変わらない
照度偏差Δｘとなる。すなわち、従来の発光装置では発
光素子３を間引いて発光素子３の数を減らせば、図９
（ｂ）のように原稿面の照度が減少し、照度偏差Δｘは
大きくなってしまう一方で、原稿面照度を発光素子３を
間引かない状態と同等とするために原稿面に近づけて行
けばさらに照度偏差Δｘが大きくなり、また照度偏差Δ
ｘを発光素子３を間引かない状態と同等とするために原
稿面から遠ざけてやると原稿面照度が暗くなるという相
反した問題があったが、本実施例１では、発光素子３の
実装ピッチｐ２以上の短辺長ｐ１を持った導光板２１が
設けられていることによって、その素子数が少なくても
平均原稿面照度ａｖｅおよび照度偏差Δｘを従来の発光
素子の素子数が多い場合と同等とすることができる。First, when a DC rated voltage is applied to the lead wire 3, a current flows through the circuit conductor layer to turn on the light emitting element 3,
The light 22 emitted from the light emitting element 3 is incident on one end surface of the light guide plate 21 as shown in FIG. Thus, the light guide plate 21
The light 22 that has entered one end face is refracted with a refraction angle at the boundary between the inside and the outside of the light guide plate 21 and is emitted to the outside. For example, an angle at which the refraction angle θ1 is 90 ° or more, for example, The light 22 entering at the incident angle θ2 travels by being totally reflected inside the light guide plate 21, and is emitted from the other end surface of the light guide plate 21. Therefore, by disposing the light guide plate 21 on the light emitting surface side of the light emitting elements 3 mounted in an array and on the optical axis of the light 22 emitted by the light emitting elements 3, at least the refraction angle θ1 becomes 90 ° or more. Angle, that is, incident angle θ2
All the light that enters in the light guide plate 21 is totally reflected inside the light guide plate 21 and travels, and is emitted from the other end face of the light guide plate 21. As a result, the short length of the substrate 2 on which the light emitting elements 3 are mounted in an array form. The directional characteristic in the side direction (left and right direction in FIG. 2) becomes narrower, the light that was dispersed in the past is condensed, the light is confined inside the light guide plate 21, and the other is the emission surface of the light guide plate 21 with almost no loss. The light 22 can be emitted from the end surface of the light emitting element, and the operation is equivalent to that the light emitting element 3 is provided on the light emitting side of the light guide plate 21. Further, since the illuminance deviation Δx on the surface of the document 11 is determined by the distance between the light emitting element 3 which is actually located and the document surface, the distance from the exit surface of the light guide plate 21 to the document surface is different from the conventional one. If they are the same, FIG. 9 (a) and FIG.
As is clear from a comparison of the above, even if the number of light emitting elements 3 in the first embodiment is three in the example of FIG.
As described above, the illuminance deviation Δx is not so different from the case where the number of elements is 5. That is, in the conventional light emitting device, if the number of the light emitting elements 3 is reduced by thinning out the light emitting elements 3, FIG.
As shown in (b), the illuminance on the document surface decreases and the illuminance deviation Δx increases. On the other hand, in order to make the illuminance on the document surface equivalent to the state in which the light emitting elements 3 are not thinned out, it is necessary to bring the document surface closer to the document surface. Further, the illuminance deviation Δx becomes larger, and the illuminance deviation Δx
There is a contradictory problem that the illuminance of the document surface becomes darker if it is moved away from the document surface in order to make x equivalent to the state in which the light emitting elements 3 are not thinned out. Since the light guide plate 21 having a short side length p1 of p2 or more is provided, even if the number of elements is small, the average document surface illuminance ave and the illuminance deviation Δx are equivalent to those when the number of conventional light emitting elements is large. Can be
【００２１】実施例２ 図４（ａ）は本発明の実施例２に係る発光装置２３を示
しており、図４（ｂ）は図４（ａ）の要部を拡大したも
のである。本実施例２の発光装置２３が実施例１の発光
装置２０と異なっている構成は、実施例１では導光板２
１が１枚で構成されていたのに、本実施例２では導光板
２１がｎ1なる屈折率を持つ導光板２１ａと、ｎ2（＜ｎ
１）なる屈折率を持つ導光板２１ｂとの２枚構成になっ
ていることである。この実施例２においても実施例１と
同様にこの導光板２１ａ，２１ｂは透明体であるのが好
ましいが、必ずしも透明体である必要はなく光を導くこ
とのできるものであればよい。 Example 2 FIG. 4 (a) shows a light emitting device 23 according to Example 2 of the present invention, and FIG. 4 (b) is an enlarged view of the main part of FIG. 4 (a). The light emitting device 23 of the second embodiment is different from the light emitting device 20 of the first embodiment in that the light guide plate 2 in the first embodiment is different.
In the second embodiment, the light guide plate 21 has a refractive index of n1 and n2 (<n.
The light guide plate 21b having the refractive index 1) has a two-layer structure. Also in the second embodiment, it is preferable that the light guide plates 21a and 21b are transparent bodies as in the first embodiment, but it is not always necessary that the light guide plates 21a and 21b are transparent bodies as long as they can guide light.
【００２２】上記構成の本実施例２では、まず、発光素
子３から放射された光２２はｎ1なる屈折率を持つ導光
板２１ａに入射角Ф１で入射するとともに、ｎ2なる屈
折率を持つ導光板２１ｂに屈折角Φ2で進入して外部へ
放射される。つまり導光板２１ａ、２１ｂの境界で入射
角Ф1がｃｏｓ-1（ｎ2／ｎ1）よりも大きい角度で進入
してくる光は導光板２１ｂでさらに横方向の指向特性を
広げ、導光板２１ｂの出射放面から放射される。このよ
うに屈折率がｎ1＞ｎ2なる材料によって導光板２１を２
枚構成とすることにより、導光板２１の短辺ｐ１の長さ
は発光素子３の実装ピッチに関係なく短くすることがで
き発光装置全体の小型化の促進が実現される。In the second embodiment having the above-described structure, first, the light 22 emitted from the light emitting element 3 is incident on the light guide plate 21a having a refractive index of n1 at an incident angle Φ1 and has a refractive index of n2. It enters 21b with a refraction angle of Φ2 and is emitted to the outside. That is, light entering at an angle of incidence Φ1 greater than cos-1 (n2 / n1) at the boundary between the light guide plates 21a and 21b further expands the lateral directional characteristics at the light guide plate 21b and is emitted from the light guide plate 21b. Emitted from the surface. As described above, the light guide plate 21 is made of a material having a refractive index of n1> n2.
With the single-piece configuration, the length of the short side p1 of the light guide plate 21 can be shortened regardless of the mounting pitch of the light emitting elements 3, and the miniaturization of the entire light emitting device can be promoted.
【００２３】実施例３ 図５は本発明の実施例３に係る密着型イメージセンサユ
ニットの断面の概略化構造図であって、図７と対応する
部分には同一の符号を付し、同一の符号に係る部分につ
いての詳しい説明は省略する。本実施例３においては従
来の発光装置の替えてそれには実施例１または２の発光
装置２０または２３が装備されていることである。な
お、原稿面にはガラス板１２が当接するが、このガラス
板１２に替えて透明性のプラスチックなどの他の光透過
性の板体であればよい。また、ロッドレンズアレイ１０
は正立等倍結像系を構成するが、他の結像系であっても
よい。 Embodiment 3 FIG. 5 is a schematic structural view of a cross section of a contact type image sensor unit according to Embodiment 3 of the present invention, in which parts corresponding to those in FIG. Detailed description of the parts related to the reference numerals is omitted. In the third embodiment, the conventional light emitting device is replaced by the light emitting device 20 or 23 of the first or second embodiment. The glass plate 12 is in contact with the surface of the original, but instead of the glass plate 12, any other transparent plate such as transparent plastic may be used. In addition, the rod lens array 10
Constitutes an erecting equal-magnification imaging system, but may be another imaging system.
【００２４】すなわち、本実施例の密着型イメージセン
サユニット２４は、上記のように発光装置２０または２
３を装備したから、発光装置２０の発光素子３から放射
される光は、上記実施例１、および実施例２において説
明したように導光板２１の端面から放射され、ガラス板
１２の下面に位置する原稿１１の面を照射し、その反射
光をロッドレンズアレイ１０によって集光し、次いでス
リット１３を通り光電変換素子７で受光し電気信号に変
換する。That is, the contact-type image sensor unit 24 of this embodiment has the light emitting device 20 or 2 as described above.
3, the light emitted from the light emitting element 3 of the light emitting device 20 is emitted from the end surface of the light guide plate 21 as described in the first and second embodiments, and is located on the lower surface of the glass plate 12. The surface of the original 11 is illuminated, the reflected light thereof is condensed by the rod lens array 10, and then passes through the slit 13 to be received by the photoelectric conversion element 7 and converted into an electric signal.
【００２５】このようにして本実施例３のイメージセン
サユニット２４によれば実施例１および実施例２で説明
した発光装置を光源とすることにより発光素子３を間引
いてその素子数を削減しても図３で示したような原稿面
照度および照度偏差を維持することができ、安価で高性
能な密着型イメージセンサユニットを得ることができ
る。As described above, according to the image sensor unit 24 of the third embodiment, the light emitting device described in the first and second embodiments is used as a light source to thin out the light emitting elements 3 and reduce the number of the elements. 3 can maintain the illuminance and the illuminance deviation as shown in FIG. 3, and an inexpensive and high-performance contact image sensor unit can be obtained.
【００２６】[0026]
【発明の効果】以上のように本発明の発光装置は、列状
に実装した複数の発光素子と、その発光素子から出射さ
れた光を目標とする所定の位置まで導くための導光板と
を備え、前記発光素子はその発光面側を導光板の長辺側
に当接するように並べて実装し、前記導光板の短辺長は
前記発光素子の実装ピッチ以上とした構成により、発光
素子を実装した基板の短辺方向のみを発光素子からの光
の指向特性を狭くしてその光を集光させかつ基板の長辺
の長辺方向の指向特性を広くすることができ、結果とし
て、発光素子の素子数を減少させても原稿面に対しての
十分な照度偏差と有効照明長とを得ることができる。As described above, the light emitting device of the present invention comprises a plurality of light emitting elements mounted in a row and a light guide plate for guiding the light emitted from the light emitting elements to a predetermined target position. The light emitting elements are mounted side by side so that their light emitting surfaces are in contact with the long side of the light guide plate, and the short side length of the light guide plate is equal to or greater than the mounting pitch of the light emitting elements. The directivity of the light from the light emitting element can be narrowed only in the short side direction of the substrate and the light can be condensed and the directivity of the long side of the substrate in the long side direction can be widened. Even if the number of elements is reduced, it is possible to obtain a sufficient illuminance deviation with respect to the document surface and an effective illumination length.
【００２７】また、本発明の密着型イメージセンサユニ
ットは、前記発光装置を備えたから、必要な発光素子の
素子数の少ない、したがって、安価なものとなる。さら
にまた、本発明の密着型イメージセンサユニットは、導
光板を各々屈折率の異なる２枚以上の導光板を発光素子
からの光の進行方向に連ね、屈折率の大きい一方の導光
板は発光素子から放射される光の入射側に設け、屈折率
の小さい他方の導光板は前記一方の導光板からの光の出
射側に設けた複合体の構成としたから、導光板の短辺長
を発光素子の実装ピッチとは無関係に短くできることに
なる結果、さらに小型のものを実現できる。Further, since the contact image sensor unit of the present invention includes the light emitting device, the number of necessary light emitting elements is small, and hence the cost is low. Furthermore, in the contact type image sensor unit of the present invention, two or more light guide plates each having a different refractive index are connected in a traveling direction of light from the light emitting element, and one light guide plate having a large refractive index is a light emitting element. Since the light guide plate provided on the incident side of the light emitted from the light guide plate and the other light guide plate having a small refractive index is provided on the output side of the light from the one light guide plate, the light guide plate emits light with the short side length. As a result of being able to shorten the length irrespective of the mounting pitch of the elements, it is possible to realize a smaller size.
【図１】本発明の実施例１に係る発光装置の斜視図であ
る。FIG. 1 is a perspective view of a light emitting device according to a first embodiment of the invention.
【図２】実施例１の発光装置の側面断面図である。FIG. 2 is a side sectional view of the light emitting device of the first embodiment.
【図３】実施例１における動作説明のための発光装置と
それに対応する原稿面照度と有効照明長との関係を示す
図である。FIG. 3 is a diagram showing a relationship between a light-emitting device for explaining the operation in Embodiment 1 and the corresponding document surface illuminance and effective illumination length.
【図４】本発明の実施例２に係る発光装置の正面を
（ａ）に、それの拡大要部を（ｂ）に示す図である。FIG. 4 is a diagram showing a front surface of a light emitting device according to a second embodiment of the invention in (a) and an enlarged main portion thereof in (b).
【図５】本発明の実施例３に係る密着型イメージセンサ
ユニットの正面断面概略図である。FIG. 5 is a schematic front sectional view of a contact image sensor unit according to Embodiment 3 of the present invention.
【図６】従来の発光装置の構成図である。FIG. 6 is a configuration diagram of a conventional light emitting device.
【図７】従来の密着型イメージセンサユニットの正面断
面概略図である。FIG. 7 is a schematic front sectional view of a conventional contact image sensor unit.
【図８】発光素子の指向特性を示す図である。FIG. 8 is a diagram showing directional characteristics of a light emitting element.
【図９】発光素子の素子数が多い場合を（ａ）で少ない
場合を（ｂ）でそれぞれ示す従来例の発光装置の構成図
である。FIG. 9 is a configuration diagram of a conventional light emitting device, in which (a) shows a case where the number of light emitting elements is large and (b) shows a case where the number is small.
２ 基板 ３ 発光素子 ４ リード線 ２０，２３ 発光装置 ２１ 導光板 ２４ 密着型イメージセンサユニット 2 substrate 3 light emitting element 4 lead wires 20, 23 light emitting device 21 light guide plate 24 contact image sensor unit
Claims (3)
発光素子から出射された光を目標とする所定の位置まで
導くための導光板とを備え、前記発光素子は、その発光
面側を前記導光板の長辺側に当接するように並べ実装
し、前記導光板の短辺長は、前記発光素子の実装ピッチ
以上であることを特徴とする発光装置。1. A plurality of light emitting elements mounted in a row, and a light guide plate for guiding light emitted from the light emitting elements to a target predetermined position, wherein the light emitting element has a light emitting surface side. Are arranged side by side so as to abut on the long side of the light guide plate, and the short side length of the light guide plate is equal to or greater than the mounting pitch of the light emitting elements.
接する光透過板と、前記基台の内部に設けられ前記原稿
面を照明するための発光装置と、照明された前記原稿か
らの反射光を所定の結像系を通して受光して電気信号に
変換する光電変換素子とからなる密着型イメージセンサ
ユニットにおいて、前記発光装置は複数の発光素子と、
その発光素子から出射された光を前記原稿まで導くため
の導光板とを備え、前記発光素子は、その発光面側を導
光板の長辺側に当接するように並べ実装し、前記導光板
の短辺長が前記発光素子の実装ピッチ以上であることを
特徴とする密着型イメージセンサユニット。2. A base, a light transmitting plate that abuts the surface of the original to be read, a light-emitting device provided inside the base for illuminating the surface of the original, and a light emitting device for illuminating the original. In a contact image sensor unit including a photoelectric conversion element that receives reflected light through a predetermined imaging system and converts it into an electric signal, the light emitting device includes a plurality of light emitting elements.
A light guide plate for guiding the light emitted from the light emitting element to the original, and the light emitting elements are mounted side by side so that their light emitting surfaces are in contact with the long sides of the light guide plate. A contact-type image sensor unit, wherein a short side length is equal to or larger than a mounting pitch of the light emitting element.
る二枚以上の導光板を発光素子からの光の進行方向に連
ねるとともに、屈折率の大きい一方の導光板を発光素子
から放射される光の入射側に設け、屈折率の小さい他方
の導光板を前記一方の導光板からの光の出射側に設けて
なる複合体であることを特徴とする前記請求項２に記載
の密着型イメージセンサユニット。3. A light guide plate of a light emitting device, wherein two or more light guide plates each having a different refractive index are connected in a traveling direction of light from the light emitting element, and one light guide plate having a large refractive index is emitted from the light emitting element. 3. The close contact type according to claim 2, wherein the light guide plate is a composite body that is provided on the light incident side and the other light guide plate having a small refractive index is provided on the light output side from the one light guide plate. Image sensor unit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP30644793A JPH07162586A (en) | 1993-12-07 | 1993-12-07 | Light emitting device and contact image sensor unit using it |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP30644793A JPH07162586A (en) | 1993-12-07 | 1993-12-07 | Light emitting device and contact image sensor unit using it |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH07162586A true JPH07162586A (en) | 1995-06-23 |
Family
ID=17957115
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP30644793A Pending JPH07162586A (en) | 1993-12-07 | 1993-12-07 | Light emitting device and contact image sensor unit using it |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH07162586A (en) |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6476369B1 (en) | 1999-10-07 | 2002-11-05 | Mitsubishi Denki Kabushiki Kaisha | Linear light source with increased light efficiency and uniform exposure, and image sensor using the linear light source |
| EP1615418A1 (en) * | 2004-07-09 | 2006-01-11 | Ricoh Company, Ltd. | Image reading apparatus and image forming apparatus |
| JP2006017951A (en) * | 2004-06-30 | 2006-01-19 | Ricoh Co Ltd | Document illuminating device, image reading unit, and image forming apparatus |
| JP2006017952A (en) * | 2004-06-30 | 2006-01-19 | Ricoh Co Ltd | Document illuminating device, image reading unit, and image forming apparatus |
| JP2006067551A (en) * | 2004-07-29 | 2006-03-09 | Ricoh Co Ltd | Original lighting system, image scanner, and image forming apparatus |
| EP1699224A1 (en) * | 2005-03-02 | 2006-09-06 | Ricoh Company, Ltd. | Illumination device, image reading device, and image forming apparatus |
| JP2011135585A (en) * | 2011-01-14 | 2011-07-07 | Ricoh Co Ltd | Original lighting system, image reader, and image forming apparatus |
| JP2012142847A (en) * | 2011-01-05 | 2012-07-26 | Ricoh Co Ltd | Line illumination optical system, and image reader |
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-
1993
- 1993-12-07 JP JP30644793A patent/JPH07162586A/en active Pending
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6476369B1 (en) | 1999-10-07 | 2002-11-05 | Mitsubishi Denki Kabushiki Kaisha | Linear light source with increased light efficiency and uniform exposure, and image sensor using the linear light source |
| JP2006017952A (en) * | 2004-06-30 | 2006-01-19 | Ricoh Co Ltd | Document illuminating device, image reading unit, and image forming apparatus |
| JP2006017951A (en) * | 2004-06-30 | 2006-01-19 | Ricoh Co Ltd | Document illuminating device, image reading unit, and image forming apparatus |
| US7495682B2 (en) | 2004-07-09 | 2009-02-24 | Ricoh Company, Ltd. | Image reading apparatus and image forming apparatus |
| EP1615418A1 (en) * | 2004-07-09 | 2006-01-11 | Ricoh Company, Ltd. | Image reading apparatus and image forming apparatus |
| EP2242246A2 (en) | 2004-07-09 | 2010-10-20 | Ricoh Company, Ltd. | Image reading apparatus and image forming apparatus |
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