JP3792478B2

JP3792478B2 - Vehicle periphery visual recognition device

Info

Publication number: JP3792478B2
Application number: JP2000139754A
Authority: JP
Inventors: 政善井本
Original assignee: Sumitomo Wiring Systems Ltd; AutoNetworks Technologies Ltd; Sumitomo Electric Industries Ltd
Current assignee: Sumitomo Wiring Systems Ltd; AutoNetworks Technologies Ltd; Sumitomo Electric Industries Ltd
Priority date: 2000-05-12
Filing date: 2000-05-12
Publication date: 2006-07-05
Anticipated expiration: 2020-05-12
Also published as: JP2001318398A

Description

【０００１】
【発明の属する技術分野】
本発明は、見通しの悪い状況で、運転者の死角となる車両前方又は後方の、左右又は前後の周辺景色を撮影して運転者に表示する車両周辺視認装置に関する。
【０００２】
【従来の技術】
図５に従来の車両周辺視認装置の構成図を示す。この車両周辺視認装置１は、車両外部に配設されて車両周辺の互いに反対方向の２方向の景色を撮像する撮像装置１１と、この撮像装置１１から供給される画像信号を鏡像反転処理する鏡像反転処理部１２と、車室内に配設されて鏡像反転処理部１２から得られる画像信号を表示する表示部１５とを備えて構成される。
【０００３】
撮像装置１１は、その両側に透明ガラス等から構成された左右一対の透過窓部２Ｌ，２Ｒが設けられた遮光性のケース３を有し、このケース３内に、断面二等辺三角形のプリズム４がその頂角５をケースの前部（図ではケース３の上部）に向け、且つその二等辺三角形の二等辺に対応する左右のプリズム側面８Ｌ，８Ｒをそれぞれ左右の透過窓部２Ｌ，２Ｒ側に向けた姿勢で収納配設されると共に、プリズム側面８Ｌ，８Ｒから入射してプリズム４内で光路変換して所定の結像レンズ９を介して撮像面上に案内される光線１８Ｌ，１８Ｒを画像信号に変換する撮像素子１０がプリズム４の後側に収納配設される。
【０００４】
かかる撮像装置１１は、図２に示すように、例えば撮像装置１１の前部（ケース３の前部）を車両１６の前方に向け、且つ透過窓部２Ｒ，２Ｌをそれぞれ左右側に向けるようにしてフロントバンパ１７に取り付けられる。この状態で、左側景色に対応する光線１８Ｌは、図５に示すように、透過窓部２Ｌおよびプリズム側面８Ｌを透過し直接にプリズム側面８Ｒに入射し、プリズム側面８Ｒで内面反射した後、プリズム後面８Ｂから射出して結像レンズ９で結像されて撮像素子１０の撮像面の左半面１０Ｌに案内される。対称的に考えることで、右側景色に対応する光線１８Ｒについても同様に、撮像素子１０の撮像面の右半面１０Ｒに案内される。そして、ともに撮像素子１０で画像信号に変換される。
【０００５】
このようにして左側及び右側景色が撮像され、撮像された画像信号は、図５に示すように、鏡像反転処理部１２で鏡像反転処理されて表示部１５に供給される。表示部１５においては、透過窓部２Ｌから取り込まれた左側景色が左半画像として左半画面１５Ｌに表示され、透過窓部２Ｒから取り込まれた右側景色が右半画像として右半画面１５Ｒに表示される。
【０００６】
【発明が解決しようとする課題】
しかしながら、かかる車両周辺視認装置１では、例えば夜間にヘッドライト２１を点灯した対向車両が前方Ａ方向から接近した状況で、そのヘッドライト２１の発した光線２１ａが透過窓部２Ｒおよびプリズム側面８Ｒを透過して直接にプリズム後面８Ｂへ入射し、プリズム後面８Ｂで全反射した場合には、その光線２１ａは、プリズム側面８Ｌを射出して透過窓部２Ｌへ入射する。その際、透過窓部２Ｌに入射した光線２１ａの殆ど（９６．１％）は透過窓部２Ｌを透過して外部へ射出されるが、その残り（３．２％）は反射光２１ｂとしてプリズム側面８Ｌへ入射する。
【０００７】
その反射光２１ｂは、プリズム側面８Ｌを透過して直接にプリズム側面８Ｒへ入射し、プリズム側面８Ｒで内面反射した後、プリズム後面８Ｂから射出して結像レンズ９を介して撮像素子１０の撮像面の左半面１０Ｌに案内される。その結果、その反射光２１ｂは、撮像素子１０の左半面において、左側景色に対応する光線１８Ｌと合成されて画像処理される。
【０００８】
そのような場合、表示部１５には、その左半画面１５Ｌに、透過窓部２Ｌから取り込んだ左側景色の画像２２Ｌ上に、透過窓部２Ｒから入り込んだヘッドライト２１の光線２１ａの透過窓部２Ｌでの反射光２１ｂの画像２１Ｂが重ねられて誤表示される。
【０００９】
このように、従来の車両周辺視認装置１では、一方側の透過窓部２Ｌ，２Ｒから取り込まれる景色の一部が表示部１５の他方側の画面１５Ｒ，１５Ｌに映り込んで誤表示されて運転者の視認性を悪化させる問題があった。
【００１０】
そこで、この発明の課題は、一方側の透過窓部から取り込まれる景色の一部が表示部１５の他方側の画面に映り込んで誤表示されることを防止した車両周辺視認装置を提供することにある。
【００１１】
【課題を解決するための手段】
上記課題を解決するためには、請求項１に記載された発明は、車両外部に配設されてその両側に左右一対の透過窓部が設けられたケースを有し、このケース内に、断面二等辺三角形のプリズムがその頂角を前記ケースの前部に向け且つその二等辺三角形の二等辺に対応する左右のプリズム側面をそれぞれ前記左右の透過窓部側に向けた姿勢で収納配設されると共に、前記左右のプリズム側面の一方から前記プリズム内に入射し、他方の前記プリズム側面で内面反射して前記プリズムのプリズム後面より射出する光線を所定の結像レンズを介し撮像面上に集光させて画像信号に変換する撮像素子が前記プリズムの後方位置に収納配設された撮像装置を備え、それぞれ前記左右の透過窓部および前記左右のプリズム側面を順に透過して前記プリズム後面の内面で全反射した後、反対側の前記左右のプリズム側面を透過して同側の前記左右の透過窓部で反射した反射光が、前記撮像面上に結像することを防止する防止手段を備え、前記防止手段は、前記左右の透過窓部で反射した前記各反射光がそれぞれ、同側の前記左右のプリズム側面を透過した後、前記プリズム後面の内面で全反射して反対側の前記左右のプリズム側面および前記左右の透過窓部を透過して外部へ放出されるように、前記左右の透過窓部の前記プリズム後面に対する角度が設定されてなる車両周辺視認装置である。
【００１２】
請求項２に記載された発明は、車両外部に配設されてその両側に左右一対の透過窓部が設けられたケースを有し、このケース内に、断面二等辺三角形のプリズムがその頂角を前記ケースの前部に向け且つその二等辺三角形の二等辺に対応する左右のプリズム側面をそれぞれ前記左右の透過窓部側に向けた姿勢で収納配設されると共に、前記左右のプリズム側面の一方から前記プリズム内に入射し、他方の前記プリズム側面で内面反射して前記プリズムのプリズム後面より射出する光線を所定の結像レンズを介し撮像面上に集光させて画像信号に変換する撮像素子が前記プリズムの後方位置に収納配設された撮像装置を備え、それぞれ前記左右の透過窓部および前記左右のプリズム側面を順に透過して前記プリズム後面の内面で全反射した後、反対側の前記左右のプリズム側面を透過して同側の前記左右の透過窓部で反射した反射光が、前記撮像面上に結像することを防止する防止手段を備え、前記防止手段は、前記左右の透過窓部で反射される前記反射光のうち前記左右のプリズム側面から前記プリズム内へ再度入射して反対側の前記左右のプリズム側面で内面反射した後、前記プリズム後面を射出して前記撮像素子へ入射することとなる光線に対して、その光経路を遮るようにして前記左右のプリズム側面の後部領域上に遮光部材を設けてなる車両周辺視認装置である。
【００１３】
請求項３に記載された発明は、車両外部に配設されてその両側に左右一対の透過窓部が設けられたケースを有し、このケース内に、断面二等辺三角形のプリズムがその頂角を前記ケースの前部に向け且つその二等辺三角形の二等辺に対応する左右のプリズム側面をそれぞれ前記左右の透過窓部側に向けた姿勢で収納配設されると共に、前記左右のプリズム側面の一方から前記プリズム内に入射し、他方の前記プリズム側面で内面反射して前記プリズムのプリズム後面より射出する光線を所定の結像レンズを介し撮像面上に集光させて画像信号に変換する撮像素子が前記プリズムの後方位置に収納配設された撮像装置を備え、前記左右の透過窓部が同側の前記左右のプリズム側面に対して傾斜されて設けられ、それぞれ前記左右の透過窓部および前記左右のプリズム側面を順に透過して前記プリズム後面の内面で全反射した後、反対側の前記左右のプリズム側面を透過して同側の前記左右の透過窓部で反射した反射光が、前記撮像面上に結像することを防止する防止手段を備え、前記防止手段は、前記各透過窓部の内面側および前記各プリズム側面のうち少なくとも前記各透明窓部の内面側に反射防止膜を配設してなる車両周辺視認装置である。
【００１５】
【発明の実施の形態】
＜第１実施形態＞
以下、本発明の第１実施形態を図１および図２に基づいて説明する。図１は、本発明の第１実施形態に係る車両周辺視認装置の概略図であり、図２は、その車両周辺視認装置を構成する撮像装置が車両に配設された状態の一例を示す図である。
【００１６】
この実施形態に係る車両周辺視認装置１Ａは、図１および図２に示すように、車両１６における例えばフロントバンパー１７の下方に設置される撮像装置１１Ａと、撮像装置１１Ａで撮像された車両周辺の画像を表示すべく、車室内のインストルメントパネル等の運転者が視認しやすい位置に設けられたＬＣＤまたはＣＲＴ等からなる表示部１５と、撮像装置１１Ａで撮像された画像信号を鏡像反転処理して表示部１５に供給する鏡像反転処理部１２とを備えて構成される。
【００１７】
撮像装置１１Ａは、両側面前部（図１では上部）が平面視山形に形成された遮光性のケース３Ａと、ケース３Ａの両側面前部に位置してそれぞれに形成された開口に装着された左右一対の透過窓部２Ｒ，２Ｌと、ケース３Ａ内に配置された例えばＣＣＤカメラなどの撮像素子１０と、結像レンズ９と、各透過窓部２Ｌ，２Ｒから進入した光線１８Ｌ，１８Ｒを光路変換して結像レンズ９を介して撮像素子１０の撮像面に案内するプリズム４とを備える。
【００１８】
ここで、結像レンズ９と撮像素子１０は撮像カメラを構成しており、一例として焦点距離ｆ＝４．６ｍｍ、水平画角α＝４５°、Ｆ（エフナンバー）＝２．８に設定されている。
【００１９】
また、プリズム４は、頂角５が例えば６４°の断面二等辺三角形の角柱体に形成されており、その二等辺三角形の頂角５をケース３Ａの前部（図ではケース３Ａの上部）に向け、且つその二等辺三角形の二等辺に対応するプリズム側面８Ｌ，８Ｒをそれぞれケース３Ａの透過窓部２Ｌ，２Ｒに向けた姿勢で配設されている。そして、結像レンズ９は、このプリズム４の後方（図１では下方）において、その結像レンズ９の光軸２５が、プリズム４の断面二等辺三角形の頂角５の２分線に一致するようにレンズホルダ２６によって固定されている。
【００２０】
透過窓部２Ｒ，２Ｌは、硝材として例えば屈折率１．１５１７のＢＫ７が用いられて平板状に形成されている。
【００２１】
そして、透過窓部２Ｌは、図１に示すように、光線２１ａのように外部より透過窓部２Ｒおよびプリズム側面８Ｒを順に透過してプリズム後面８Ｂに直接に入射し、プリズム後面８Ｂで全反射した後、プリズム側面８Ｌから射出して透過窓部２Ｌへ入射する光線に対して、透過窓部２Ｌでのその反射光２１ｂが、プリズム側面８Ｌを透過して直接にプリズム後面８Ｂへ入射してプリズム後面８Ｂで全反射した後、プリズム側面８Ｒおよび透過窓部２Ｒを順に透過して外部へ放出されるように、プリズム４の後面８Ｂに対する角度が設定されている。この角度としては、この実施形態では、例えば４０°の角度が配設される。透過窓部２Ｒについても、同様に、プリズム４の後面８Ｂに対して同様の角度（例えば４０°）でケース３Ａに配設される。
【００２２】
このように構成された撮像装置１１Ａでは、図１に示すように、右側景色に対応する光線１８Ｒについては、外部より透過窓部２Ｒおよびプリズム側面８Ｒを順に透過して直接にプリズム側面８Ｌへ入射し、プリズム側面８Ｌで内面反射した後、プリズム後面８Ｂを射出して結像レンズ９を介して撮像素子１０の撮像面の右半面１０Ｒに入射させる一方で、光線２１ａのように外部より透過窓部２Ｒおよびプリズム側面８Ｒを透過して直接にプリズム後面８Ｂに入射し、プリズム後面８Ｂで全反射した後、プリズム側面８Ｌから射出して透過窓部２Ｌへ入射する光線に対しては、透過窓部２Ｌでのその反射光２１ｂが、プリズム側面８Ｌを透過して直接にプリズム後面８Ｂへ入射し、プリズム後面８Ｂで全反射した後、プリズム側面８Ｒおよび透過窓部２Ｒを順に透過して外部へ放出するように図られている。これにより、反射光２１ｂが撮像素子１０の撮像面に入射することが防止される。同様に、外部から透過窓部２Ｌへ進入する光線に対しても、左右対称的に同様の現象が実現されている。詳細な説明は省略する。
【００２３】
そして、撮像素子１０に入射した光線１８Ｒ，１８Ｌは、画像信号に変換され、鏡像反転処理部１２にて鏡像反転処理されて表示部１５に供給され、表示部１５の左半画面１５Ｌに透過窓部２Ｌを通じて撮像された左側景色が左半画像として表示され、表示部１５の右半画面１５Ｒに透過窓部２Ｒを通じて撮像された右側景色が右半画像として表示される。
【００２４】
以上のように構成された車両周辺視認装置１Ａによれば、上記の角度に設定された透過窓部２Ｌ，２Ｒにより、例えば、外部から透過窓部２Ｒへ進入する光線について言えば、右側景色に対応する光線１８Ｒに対しては、透過窓部２Ｒおよびプリズム側面８Ｒを透過し直接にプリズム側面８Ｌに入射させ、プリズム側面８Ｌで内面反射させた後、プリズム後面８Ｂから射出させて、結像レンズ９で結像して撮像素子１０の撮像面の右半面１０Ｒに入射させる一方で、光線２１ａのように外部より透過窓部２Ｒおよびプリズム側面８Ｒを透過して直接にプリズム後面８Ｂに入射し、プリズム後面８Ｂで全反射した後、プリズム側面８Ｌから射出して透過窓部２Ｌへ入射する光線に対しては、透過窓部２Ｌでの反射光２１ｂが、プリズム側面８Ｌを透過して直接にプリズム後面８Ｂへ入射してプリズム後面８Ｂで全反射し、プリズム側面８Ｒおよび透過窓部２Ｒを順に透過して外部へ放出され、同様の現象が外部から透過窓部２Ｌへ進入する光線についても実現されているため、透過窓部２Ｌから取り込まれる景色の一部が表示部１５の右半画面１５Ｒに映り込んで誤表示されたり、右の透過窓部２Ｒから取り込まれる景色の一部が表示部１５の左半画面１５Ｌに映り込んで誤表示されることが防止されて、視認性の良い車両周辺画像を運転者に提供できる。
【００２５】
更に、透過窓部２Ｌ，２Ｒのプリズム後面８Ｂに対する角度は、実際には従来装置における透過窓部２Ｌ，２Ｒの角度よりも小さい角度となるため、ケース３Ａの両側面前部の山形が、従来装置のケース３の山形よりも、低く平らに形成でき、これによりケース３Ａとプリズム４の間隔を短くすることができて撮像装置１１Ａの小型化を図ることができる。
【００２６】
なお、この実施形態では、撮像装置１１Ａを車両１６のフロントバンパ１７に配設して車両前方の左右側景色を撮像する場合で説明したが、リアバンパに配設して車両後方の左右側景色を撮像するようにしても構わない。もちろん、車両前後の景色を撮像するようにしてもよい。
【００２７】
＜第２実施形態＞
以下、本発明の第２実施形態を図３および図４に基づいて説明する。図３は、第２実施形態において遮光する光線を説明する図であり、図４は、その光線を遮光する手段を説明する図である。なお、各図において第１の実施形態と同一部分には同一符号を付してその部分の説明を省略し、第１の実施形態と異なる部分のみのを以下において説明をする。
【００２８】
この実施形態における撮像装置１１Ｂは、図４に示すように、第１実施形態における撮像装置１１Ａ（図１参照）とは、透過窓部２Ｌ，２Ｒの角度と、後述する遮光部材２７Ｌ，２７Ｒがプリズム４の表面に設けられる点で相違する以外はほぼ同一に構成される。
【００２９】
この実施形態における透過窓部２Ｌ，２Ｒは、上記第１実施形態における透過窓部２Ｌ，２Ｒを、より左右方向に向くようにプリズム後面８Ｂに対する角度を大きく設定してケース３Ａに配設したものに相当し、図４に示すように、ここでは、例えばプルズム後面８Ｂに対して７５°の角度でケース３Ｂに配設される。
【００３０】
このように透過窓部２Ｌ，２Ｒの角度を設定した場合は、図３に示すように、図１の光線２１ａと同じ角度で透過窓部２Ｒより進入した光線に対して、即ち、透過窓部２Ｒおよびプリズム側面８Ｒを順に透過してプリズム後面８Ｂに直接に入射し、プリズム後面８Ｂで全反射した後、プリズム側面８Ｌから射出して透過窓部２Ｌへ入射する光線２１ＲＡに対して、透過窓部２Ｌでのその反射光２１ｂが、上記第１実施形態の場合のように、プリズム側面８Ｌを透過して直接にプリズム後面８Ｂへ入射してプリズム後面８Ｂで全反射し、プリズム側面８Ｒおよび透過窓部２Ｒを順に透過して外部へ放出される経路を必ずしも取るとは限らない。
【００３１】
例えば、図３においては、光線２１ＲＡの前側領域に含まれる光線２１Ｒａについては、第１実施形態の場合と同様に、透過窓部２Ｌでのその反射光２１ｂａは、プリズム側面８Ｌを透過して直接にプリズム後面８Ｂに入射し、プリズム後面８Ｂで全反射した後、プリズム側面８Ｒおよび透過窓部２Ｒを順に透過して外部へ放出される。しかし、光線２１ＲＡの後側領域に含まれる光線２１Ｒｄについては、透過窓部２Ｌでのその反射光２１ｂｄは、プリズム側面８Ｌを透過してプリズム後面８Ｂではなく直接にプリズム側面８Ｒに入射し、プリズム側面８Ｒで全反射した後、プリズム後面８Ｂから射出して結像レンズ９を介して撮像素子１０の撮像面の左半面１０Ｌへ入射し、誤表示の虞が生じる。なお、図３において、光線２１ＲＡの入射角は、一例として矢示Ｐ方向（光軸２５に並行な方向）を基準に時計回りに５８°〜６６°に設定されている。
【００３２】
遮光部材２７Ｒは、上記光経路による誤表示を防止するために設定されるもので、図４に示すように、上述の光線２１Ｒｄ、即ち透過窓部２Ｌでのその反射光２１ｂｄがプリズム側面８Ｒで内面反射されて撮像素子１０へ入射することとなる光線が、同経路を通って撮像素子１０に入射することのないように、その経路上、例えばプリズム側面８Ｒの例えば後部領域（図では下部領域）に配設される。その際、遮光部材２７Ｒは、右側景色に対応する正規の光線１８Ｒに対しては、できるだけ遮光しないように配設される。遮光部材２７Ｌについても、遮光部材２７Ｒと左右対称となるようにして、例えばプリズム側面８Ｌの後部領域（図では下部領域）に配設される。
【００３３】
以上のように構成された車両周辺視認装置１Ｂによれば、図４に示すように、プリズム側面８Ｌ，８Ｒの後部領域に遮光部材２７Ｒ，２７Ｌを設けることにより、例えば外部から透過窓部２Ｒへ進入する光線について言えば、右側景色に対応する光線１８Ｒについては、第１実施形態の場合と同様に、撮像素子１０の撮像面の右半面１０Ｒに入射させる一方で、光線２１Ｒｄ即ち透過窓部２Ｌでのその反射光２１ｂｄが撮像素子１０へ入射することとなる光線については、遮光部材２７Ｒで遮光されて、反射光２１ｂｄが発生しないように構成されているため、第１実施形態における車両周辺視認装置１Ａと同様に、右の透過窓部２Ｒから取り込まれる景色の一部が表示部１５の左半画面１５Ｌに映り込んで誤表示されたり、同様に左の透過窓部２Ｌから取り込まれる景色の一部が表示部１５の右半画面１５ＬＲ映り込んで誤表示されることが防止されて、視認性の良い車両周辺画像を運転者に提供できる。
【００３４】
更に、透過窓部２Ｒ，２Ｌは、第１実施形態における透過窓部２Ｒ，２Ｌよりも、より左右方向を向いて配設されているため、車両の進行中に正面からの砂ぼこりや泥を受け難くくなる。従って、泥や砂ぼこりにより透過窓部２Ｒ，２Ｌが汚れて視認性が低下することを防止することができる。
【００３５】
なお、この実施形態の車両周辺視認装置１Ｂは、透過窓部２Ｌで反射した全ての反射光２１ｂａ，２１ｂｄがプリズム側面８Ｒで内面反射して撮像素子１０へ入射されるように透過窓部２Ｌ，２Ｒの角度を更に大きく設定した場合に対しても適用することができる。その場合は、例えば図４に示すように、光線２１ＲＡの後側領域の光線２１Ｒｄについては、この実施形態と同様に、外部より透過窓部２Ｒを透過してプリズム側面８Ｒへ入射した際に、プリズム側面８Ｒ上の遮光部材２７Ｒで遮光する。また、光線２１ＲＡの前側領域の光線２１Ｒａについては、外部より透過窓部２Ｒおよびプリズム側面８Ｒを透過して直接にプリズム後面８Ｂへ入射し、プリズム後面８Ｂで全反射した後、プリズム側面８Ｌから射出する際に、プリズム側面８Ｌ上の遮光部材２７Ｌで遮光するようにしてもよい。
【００３６】
なお、この実施形態の車両周辺視認装置１Ｂは、遮光部材２７Ｌ，２７Ｒをプリズム４の表面に配設することで、上述の反射光２１ｂｄによる誤表示を防止するものであるが、遮光部材２７Ｌ，２７Ｒをプリズム４の表面に配設する代わりに、透過窓部２Ｌ，２Ｒの内側面およびプリズム側面８Ｌ，８Ｒの少なくともいずれかに反射防止膜を配設してもよい。その場合は、反射防止膜の作用により、撮像素子１０において、例えば光線２１ｂｄの光の強度を、相対的に左側景色に対応する光線１８Ｌ，１８Ｒの光の強度と比べて無視できる程度に小さくすることができ、これにより実質的に反射光２１ｂｄによる誤表示を防止することができる。例えば、反射防止膜が施されない場合は、通常４％（硝材ＢＫ７、波長５００ｎｍ、入射角０°の場合）の反射率が、反射防止膜としてＭｇＦ₂ をコーティングすると０．５％程度となる。
【００３７】
【発明の効果】
請求項１ないし請求項３に記載の発明によれば、それぞれ左右の透過窓部および左右のプリズム側面を順に透過してプリズム後面で全反射した後、反対側の左右のプリズム側面を透過して左右の透過窓部で反射した反射光が、撮像面上に結像することを防止する防止手段を備えるため、当該反射光が撮像素子の撮像面に案内されて、ケースの左右の透過窓部より取り込まれて撮像素子の撮像面に案内された左右側景色に対応する光線と合成されて画像処理されることが実質的に防止される。従って、その画像処理された画像信号を所定の表示部に表示した際に、左の透過窓部より取り込まれた景色の一部が表示部の右半画面に映り込んで誤表示されたり、同様に右の透過窓部から取り込まれた景色の一部が表示部の左半画面に映り込んで誤表示されることが防止されて、視認性の良い車両周辺画像を運転者に提供できる。
【００３８】
特に請求項２および請求項３に記載の発明によれば、透過窓部２Ｒ，２Ｌのプリズム後面に対する角度をある程度大きな角度に設定した場合に、撮像素子へ入射するような当該反射光が生じても、請求項２の場合では、その反射光はプリズム側面に設けられた遮光部材により遮光されて撮像素子へ入射することが防止され、また請求項３の場合では、反射防止膜の作用により、その反射光が撮像素子へ入射したときには、その反射光の光の強度は、相対的に左右側景色に対応する光線の光の強度と比べて無視できる。従って両方の場合とも、実質的にその反射光による誤表示が防止されるため、透過窓部２Ｒ，２Ｌの向きを、より左右方向へ向けてケースに配設することでき、これにより、左右の透過窓部は、車両の進行中に正面からの砂ぼこりや泥を受け難くくなり、その泥や砂ぼこりにより視認性が低下することを防止できる。
【図面の簡単な説明】
【図１】この発明の第１実施形態に係る車両周辺視認装置を説明する図である。
【図２】この発明の第１実施形態に係る車両周辺視認装置を構成する撮像装置が車両に取り付けられた状態の一例を示す図である。
【図３】この発明の第２実施形態に係る車両周辺視認装置を構成する撮像装置を説明する断面図である。
【図４】この発明の第２実施形態に係る車両周辺視認装置を説明する図である。
【図５】従来の車両周辺視認装置をを説明する図である。
【符号の説明】
１Ａ，１Ｂ車両周辺視認装置
２Ｒ，２Ｌ透過窓部
３Ａ，３Ｂケース
４プリズム
５頂角
８Ｌ，８Ｒプリズム側面
８Ｂプリズム後面
９結像レンズ
１０撮像素子
１０Ｒ撮像面の右半面
１０Ｌ撮像面の左半面
１１Ａ，１１Ｂ撮像装置
１２鏡像反転処理部
１５Ｌ左半画面
１５Ｒ右半画面
１６車両
１７フロントバンパ
１８Ｒ，１８Ｌ，２１ａ，２１Ｒａ，２１Ｒｄ光線
２１ｂ，２１ｂｄ，２１ｂａ反射光
２７Ｌ，２７Ｒ遮光部材[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vehicle periphery visual recognition device that captures and displays to the driver a left-right or front-rear surrounding landscape in front of or behind the vehicle that becomes a blind spot of the driver in a situation with poor visibility.
[0002]
[Prior art]
FIG. 5 shows a configuration diagram of a conventional vehicle periphery visual recognition device. The vehicle periphery visual recognition device 1 is disposed outside the vehicle and captures an image of a landscape in two opposite directions around the vehicle, and a mirror image that performs mirror image inversion processing on an image signal supplied from the image pickup device 11. The inversion processing unit 12 and a display unit 15 that is disposed in the vehicle interior and displays an image signal obtained from the mirror image inversion processing unit 12 are configured.
[0003]
The imaging device 11 has a light-shielding case 3 provided with a pair of left and right transmission window portions 2L and 2R made of transparent glass or the like on both sides thereof. In this case 3, a prism 4 having an isosceles triangle section. The apex angle 5 is directed to the front part of the case (the upper part of the case 3 in the figure), and the left and right prism side surfaces 8L and 8R corresponding to the isosceles sides of the isosceles triangle are arranged on the left and right transmission window portions 2L and 2R sides, respectively. The light rays 18L and 18R incident on the prism side surfaces 8L and 8R, converted into an optical path in the prism 4 and guided to the imaging surface through a predetermined imaging lens 9 are stored. An image sensor 10 for converting to an image signal is housed and disposed on the rear side of the prism 4.
[0004]
As shown in FIG. 2, the imaging device 11 has, for example, the front portion of the imaging device 11 (the front portion of the case 3) facing the front of the vehicle 16 and the transmission window portions 2R and 2L facing the left and right sides, respectively. To the front bumper 17. In this state, as shown in FIG. 5, the light ray 18L corresponding to the left-side view passes through the transmission window 2L and the prism side surface 8L, directly enters the prism side surface 8R, and is internally reflected by the prism side surface 8R. The light is emitted from the rear surface 8B, imaged by the imaging lens 9, and guided to the left half surface 10L of the imaging surface of the imaging device 10. By thinking symmetrically, the light ray 18R corresponding to the right scene is similarly guided to the right half surface 10R of the imaging surface of the imaging device 10. Both are converted into image signals by the image sensor 10.
[0005]
The left and right scenes are imaged in this way, and the captured image signals are subjected to mirror image inversion processing by the mirror image inversion processing unit 12 and supplied to the display unit 15 as shown in FIG. In the display unit 15, the left side view captured from the transmissive window unit 2L is displayed as a left half image on the left half screen 15L, and the right side view captured from the transmissive window unit 2R is displayed as a right half image on the right half screen 15R. Is done.
[0006]
[Problems to be solved by the invention]
However, in such a vehicle periphery visual recognition device 1, for example, in a situation where an oncoming vehicle that lights up the headlight 21 at night approaches from the front A direction, the light beam 21 a emitted by the headlight 21 passes through the transmission window portion 2 </ b> R and the prism side surface 8 </ b> R. When transmitted and directly incident on the prism rear surface 8B and totally reflected by the prism rear surface 8B, the light beam 21a exits the prism side surface 8L and enters the transmission window 2L. At that time, most (96.1%) of the light beam 21a incident on the transmission window portion 2L is transmitted through the transmission window portion 2L and emitted to the outside, but the rest (3.2%) is converted into the reflected light 21b as a prism. Incident on the side surface 8L.
[0007]
The reflected light 21b passes through the prism side surface 8L and directly enters the prism side surface 8R, is internally reflected by the prism side surface 8R, then exits from the prism rear surface 8B, and is imaged by the image sensor 10 via the imaging lens 9. Guided to the left half 10L of the surface. As a result, the reflected light 21b is combined with the light beam 18L corresponding to the left-hand scene on the left half surface of the image sensor 10 and subjected to image processing.
[0008]
In such a case, the display unit 15 has a transmission window portion of the light beam 21a of the headlight 21 that has entered from the transmission window portion 2R on the left half screen 15L on the left-side view image 22L captured from the transmission window portion 2L. The image 21B of the reflected light 21b at 2L is superimposed and erroneously displayed.
[0009]
Thus, in the conventional vehicle periphery visual recognition apparatus 1, a part of the scenery taken in from the transmission window portions 2L, 2R on one side is reflected on the screens 15R, 15L on the other side of the display unit 15 and erroneously displayed. There was a problem of worsening the visibility of the person.
[0010]
Accordingly, an object of the present invention is to provide a vehicle periphery visual recognition device that prevents a part of the scenery taken in from the transmission window portion on one side from being erroneously displayed on the screen on the other side of the display unit 15. It is in.
[0011]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the invention described in claim 1 has a case provided outside the vehicle and provided with a pair of left and right transmission windows on both sides thereof. The isosceles triangle prism is housed and disposed in such a posture that the apex angle is directed to the front part of the case and the left and right prism side surfaces corresponding to the isosceles triangle isosceles are directed to the left and right transmission window portions. Rutotomoni, enters into the prism from one prism side surface of the right and left, condensing on the imaging surface through the other of said prism sides by internal reflection to a predetermined imaging lens ray emerging from the prism rear surface of said prism An image pickup device that converts light into an image signal is housed and disposed at a rear position of the prism, and sequentially passes through the left and right transmission window portions and the left and right prism side surfaces, respectively. After total reflection at the inner surface of the rear surface, preventing the opposite side of the left and right of the reflected light reflected by the transparent window portion of the left and right prism side passes through the ipsilateral prevents the imaging on the imaging surface And the prevention means reflects each of the reflected light reflected by the left and right transmission window portions through the left and right prism side surfaces on the same side, and then totally reflects on the inner surface of the prism rear surface to the opposite side. The vehicle periphery visual recognition device is configured such that the angle of the left and right transmission window portions with respect to the rear surface of the prism is set so as to pass through the left and right prism side surfaces and the left and right transmission window portions.
[0012]
The invention described in claim 2 has a case disposed outside the vehicle and provided with a pair of left and right transmission windows on both sides thereof. In this case, a prism having an isosceles triangle section has an apex angle. With the right and left prism side faces corresponding to the isosceles sides of the isosceles triangles facing the left and right transmission window parts, respectively. Imaging in which light entering the prism from one side, reflected internally by the side of the other prism and exiting from the prism rear surface of the prism is condensed on the imaging surface via a predetermined imaging lens and converted into an image signal The element includes an imaging device housed and disposed at a rear position of the prism, and sequentially transmits through the left and right transmission window portions and the left and right prism side surfaces and totally reflects on the inner surface of the prism rear surface, The prevention means for preventing the reflected light that is transmitted through the opposite side surfaces of the left and right prisms and reflected by the left and right transmission window portions on the same side from forming an image on the imaging surface, Of the reflected light reflected by the left and right transmissive window portions, the light enters the prism again from the left and right prism side surfaces, and is internally reflected by the opposite left and right prism side surfaces, and then exits the prism rear surface. It is a vehicle periphery visual recognition apparatus which provides the light-shielding member on the rear area | region of the right-and-left prism side surface so that the optical path may be interrupted | blocked with respect to the light ray which injects into the said image pick-up element .
[0013]
The invention described in claim 3 has a case disposed outside the vehicle and provided with a pair of left and right transmission windows on both sides thereof. In this case, a prism having an isosceles triangle section has an apex angle. With the right and left prism side faces corresponding to the isosceles sides of the isosceles triangles facing the left and right transmission window parts, respectively. Imaging in which light entering the prism from one side, reflected internally by the side of the other prism and exiting from the prism rear surface of the prism is condensed on the imaging surface via a predetermined imaging lens and converted into an image signal The imaging device includes an element housed in a rear position of the prism, and the left and right transmission window portions are provided to be inclined with respect to the left and right prism side surfaces on the same side. Yo The reflected light that is transmitted through the left and right prism side surfaces in order and totally reflected by the inner surface of the rear surface of the prism, and then transmitted through the opposite left and right prism side surfaces and reflected by the left and right transmission window portions on the same side, And an antireflection film provided on the inner surface side of each of the transmission window portions and the inner surface side of each of the prism side surfaces. It is a vehicle periphery visual recognition device formed.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
<First Embodiment>
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a schematic diagram of a vehicle periphery visual recognition device according to a first embodiment of the present invention, and FIG. 2 is a diagram illustrating an example of a state in which an imaging device constituting the vehicle periphery visual recognition device is disposed in a vehicle. It is.
[0016]
As shown in FIGS. 1 and 2, the vehicle periphery visual recognition apparatus 1A according to this embodiment includes an imaging device 11A installed below the front bumper 17 in the vehicle 16, and an image of the vehicle periphery captured by the imaging device 11A. Is displayed on the display unit 15 such as an LCD or CRT provided at a position that is easily visible to the driver, such as an instrument panel in the vehicle interior, and the image signal captured by the imaging device 11A is mirror-inverted. A mirror image inversion processing unit 12 supplied to the display unit 15 is provided.
[0017]
The image pickup apparatus 11A includes a light-shielding case 3A in which front portions on both sides (upper part in FIG. 1) are formed in a mountain shape in plan view, and left and right attached to openings formed in the front portions on both sides of the case 3A. Optical path conversion of the pair of transmission window portions 2R and 2L, the image pickup device 10 such as a CCD camera disposed in the case 3A, the imaging lens 9, and the light beams 18L and 18R entering from the transmission window portions 2L and 2R And a prism 4 that guides the imaging surface of the imaging device 10 through the imaging lens 9.
[0018]
Here, the imaging lens 9 and the imaging device 10 constitute an imaging camera. For example, the focal length f = 4.6 mm, the horizontal angle of view α = 45 °, and F (F number) = 2.8 are set. ing.
[0019]
Further, the prism 4 is formed in a prismatic body having an isosceles triangle section having an apex angle 5 of, for example, 64 °, and the apex angle 5 of the isosceles triangle is formed at the front part of the case 3A (in the figure, at the upper part of the case 3A). And the prism side surfaces 8L and 8R corresponding to the isosceles sides of the isosceles triangle are disposed so as to face the transmission window portions 2L and 2R of the case 3A, respectively. In the imaging lens 9, the optical axis 25 of the imaging lens 9 coincides with the bisector of the apex angle 5 of the isosceles section of the prism 4 behind the prism 4 (downward in FIG. 1). In this way, the lens holder 26 is fixed.
[0020]
The transmission window portions 2R and 2L are formed in a flat plate shape using, for example, BK7 having a refractive index of 1.1517 as a glass material.
[0021]
As shown in FIG. 1, the transmissive window portion 2L passes through the transmissive window portion 2R and the prism side surface 8R sequentially from the outside like the light beam 21a and directly enters the prism rear surface 8B, and is totally reflected by the prism rear surface 8B. After that, with respect to the light beam that emerges from the prism side surface 8L and enters the transmission window portion 2L, the reflected light 21b at the transmission window portion 2L passes through the prism side surface 8L and directly enters the prism rear surface 8B. The angle with respect to the rear surface 8B of the prism 4 is set so that the light is totally reflected by the rear surface 8B of the prism, and then sequentially transmitted through the prism side surface 8R and the transmission window portion 2R to be emitted to the outside. In this embodiment, for example, an angle of 40 ° is disposed as this angle. Similarly, the transmission window portion 2R is disposed in the case 3A at the same angle (for example, 40 °) with respect to the rear surface 8B of the prism 4.
[0022]
In the imaging apparatus 11A configured as described above, as shown in FIG. 1, the light ray 18R corresponding to the right scene is sequentially transmitted from the outside through the transmission window portion 2R and the prism side surface 8R and directly enters the prism side surface 8L. Then, after being internally reflected by the prism side surface 8L, the prism rear surface 8B exits and enters the right half surface 10R of the imaging surface of the imaging device 10 via the imaging lens 9, while transmitting from the outside like the light beam 21a. The light is transmitted through the portion 2R and the prism side surface 8R, directly incident on the prism rear surface 8B, totally reflected by the prism rear surface 8B, and then emitted from the prism side surface 8L and incident on the transmission window portion 2L. The reflected light 21b from the portion 2L passes through the prism side surface 8L and directly enters the prism rear surface 8B and is totally reflected by the prism rear surface 8B. It is achieved so as to emit to the outside through the transparent window portion 2R in order. Thereby, the reflected light 21b is prevented from entering the imaging surface of the imaging device 10. Similarly, the same phenomenon is realized symmetrically with respect to a light ray entering the transmission window portion 2L from the outside. Detailed description is omitted.
[0023]
The light rays 18R and 18L incident on the image pickup device 10 are converted into image signals, subjected to mirror image inversion processing by the mirror image inversion processing unit 12, supplied to the display unit 15, and transmitted to the left half screen 15L of the display unit 15. The left side image captured through the part 2L is displayed as a left half image, and the right side image captured through the transmission window unit 2R is displayed as a right half image on the right half screen 15R of the display unit 15.
[0024]
According to the vehicle periphery visual recognition apparatus 1A configured as described above, for example, the light entering the transmissive window portion 2R from the outside by the transmissive window portions 2L and 2R set at the above-described angle, The corresponding light ray 18R is transmitted through the transmission window portion 2R and the prism side surface 8R, directly incident on the prism side surface 8L, reflected internally by the prism side surface 8L, and then emitted from the prism rear surface 8B. 9, the light is incident on the right half surface 10R of the imaging surface of the image sensor 10, while being transmitted from the outside through the transmission window portion 2R and the prism side surface 8R like the light beam 21a and directly incident on the prism rear surface 8B. For light rays that have been totally reflected by the prism rear surface 8B and then exit from the prism side surface 8L and enter the transmission window portion 2L, the reflected light 21b from the transmission window portion 2L is reflected by the prism side surface 8L. The light passes through and directly enters the prism rear surface 8B, is totally reflected by the prism rear surface 8B, is sequentially transmitted through the prism side surface 8R and the transmission window portion 2R, and is emitted to the outside. A similar phenomenon enters the transmission window portion 2L from the outside. Since the light beam is also realized, a part of the scenery captured from the transmission window portion 2L is erroneously displayed on the right half screen 15R of the display section 15, or the scenery captured from the right transmission window section 2R is displayed. A part of the image is displayed on the left half screen 15 </ b> L of the display unit 15 and is prevented from being erroneously displayed, so that a vehicle periphery image with high visibility can be provided to the driver.
[0025]
Furthermore, since the angle of the transmission window portions 2L and 2R with respect to the prism rear surface 8B is actually smaller than the angle of the transmission window portions 2L and 2R in the conventional device, the chevron at the front portions on both sides of the case 3A is the conventional device. Therefore, the distance between the case 3A and the prism 4 can be shortened, and the image pickup apparatus 11A can be reduced in size.
[0026]
In this embodiment, the imaging device 11A is disposed on the front bumper 17 of the vehicle 16 to capture the left and right scenery in front of the vehicle. However, the imaging device 11A is disposed on the rear bumper to obtain the left and right scenery behind the vehicle. You may make it image. Of course, you may make it image the scenery before and behind a vehicle.
[0027]
Second Embodiment
Hereinafter, a second embodiment of the present invention will be described with reference to FIGS. 3 and 4. FIG. 3 is a diagram for explaining light rays to be shielded in the second embodiment, and FIG. 4 is a diagram for explaining means for shielding the light rays. In addition, in each figure, the same code | symbol is attached | subjected to the same part as 1st Embodiment, the description of the part is abbreviate | omitted, and only a different part from 1st Embodiment is demonstrated below.
[0028]
As shown in FIG. 4, the imaging device 11B in this embodiment is different from the imaging device 11A in the first embodiment (see FIG. 1) in that the angles of the transmission window portions 2L and 2R and light shielding members 27L and 27R described later are provided. The configuration is almost the same except that the prism 4 is provided on the surface.
[0029]
The transmission window portions 2L and 2R in this embodiment are arranged in the case 3A with a large angle with respect to the prism rear surface 8B so that the transmission window portions 2L and 2R in the first embodiment are directed in the left-right direction. As shown in FIG. 4, here, for example, it is disposed in the case 3B at an angle of 75 ° with respect to the back surface 8B of the Prism.
[0030]
When the angles of the transmission window portions 2L and 2R are set in this way, as shown in FIG. 3, the light beams that have entered from the transmission window portion 2R at the same angle as the light beam 21a in FIG. 2R and the prism side surface 8R are sequentially transmitted and directly incident on the prism rear surface 8B. After being totally reflected by the prism rear surface 8B, the transmission window for the light beam 21RA which exits from the prism side surface 8L and enters the transmission window portion 2L. The reflected light 21b at the portion 2L is transmitted through the prism side surface 8L and directly incident on the prism rear surface 8B and totally reflected by the prism rear surface 8B, as in the first embodiment, and is transmitted through the prism side surface 8R. A path that sequentially passes through the window 2R and is discharged to the outside is not necessarily taken.
[0031]
For example, in FIG. 3, as for the light ray 21Ra included in the front region of the light ray 21RA, the reflected light 21ba at the transmission window portion 2L is directly transmitted through the prism side surface 8L as in the case of the first embodiment. Is incident on the prism rear surface 8B, totally reflected by the prism rear surface 8B, and then sequentially transmitted through the prism side surface 8R and the transmission window portion 2R to be emitted to the outside. However, for the light beam 21Rd included in the rear region of the light beam 21RA, the reflected light 21bd at the transmission window portion 2L passes through the prism side surface 8L and directly enters the prism side surface 8R instead of the prism rear surface 8B. After total reflection at the side surface 8R, the light exits from the rear surface 8B of the prism and enters the left half surface 10L of the image pickup surface of the image pickup device 10 via the imaging lens 9, which may cause erroneous display. In FIG. 3, the incident angle of the light beam 21RA is set to 58 ° to 66 ° clockwise with reference to the arrow P direction (direction parallel to the optical axis 25) as an example.
[0032]
The light shielding member 27R is set to prevent erroneous display due to the light path. As shown in FIG. 4, the light beam 21Rd, that is, the reflected light 21bd at the transmission window portion 2L is reflected on the prism side surface 8R. For example, a rear region (a lower region in the figure) of the prism side surface 8R on the path so that a light beam that is internally reflected and enters the image sensor 10 does not enter the image sensor 10 through the same path. ). At this time, the light shielding member 27R is disposed so as not to shield as much as possible the regular light ray 18R corresponding to the right scenery. The light shielding member 27L is also disposed in the rear region (lower region in the drawing) of the prism side surface 8L, for example, so as to be symmetrical with the light shielding member 27R.
[0033]
According to the vehicle periphery visual recognition apparatus 1B configured as described above, as shown in FIG. 4, by providing the light shielding members 27R and 27L in the rear regions of the prism side surfaces 8L and 8R, for example, from the outside to the transmission window portion 2R. Speaking of the incoming light ray, the light ray 18R corresponding to the right scene is made incident on the right half surface 10R of the image pickup surface of the image pickup device 10 as in the case of the first embodiment, while the light ray 21Rd, that is, the transmission window portion 2L. In the first embodiment, the light that the reflected light 21bd of the light enters the image sensor 10 is blocked by the light shielding member 27R so that the reflected light 21bd is not generated. Similar to the device 1A, a part of the scenery taken in from the right transparent window 2R is reflected on the left half screen 15L of the display unit 15 and is erroneously displayed. Partial view taken in from section 2L is prevented from being displayed erroneously crowded reflected right half screen 15LR of the display unit 15, can provide a good vehicle periphery image visibility to the driver.
[0034]
Furthermore, since the transmission window portions 2R and 2L are arranged in the left-right direction more than the transmission window portions 2R and 2L in the first embodiment, they receive sand dust and mud from the front while the vehicle is traveling. It becomes difficult. Therefore, it is possible to prevent the visibility of the transmission window portions 2R and 2L from becoming dirty due to mud or dust.
[0035]
In addition, the vehicle periphery visual recognition device 1B of this embodiment has the transmission window portion 2L, so that all the reflected lights 21ba, 21bd reflected by the transmission window portion 2L are internally reflected by the prism side surface 8R and are incident on the imaging device 10. The present invention can also be applied to the case where the angle of 2R is set larger. In this case, for example, as shown in FIG. 4, the light ray 21Rd in the rear region of the light ray 21RA is transmitted through the transmission window 2R from the outside and incident on the prism side surface 8R, as in this embodiment. The light is shielded by the light shielding member 27R on the prism side surface 8R. Further, the light ray 21Ra in the front region of the light ray 21RA is transmitted from the outside through the transmission window portion 2R and the prism side surface 8R, directly incident on the prism rear surface 8B, totally reflected by the prism rear surface 8B, and then emitted from the prism side surface 8L. In this case, the light shielding member 27L on the prism side surface 8L may shield the light.
[0036]
The vehicle periphery visual recognition device 1B of this embodiment prevents the erroneous display by the reflected light 21bd described above by disposing the light shielding members 27L and 27R on the surface of the prism 4. Instead of disposing 27R on the surface of the prism 4, an antireflection film may be disposed on at least one of the inner side surfaces of the transmission window portions 2L and 2R and the prism side surfaces 8L and 8R. In that case, due to the action of the antireflection film, for example, the light intensity of the light beam 21bd is made relatively small in the image sensor 10 to a level that can be ignored as compared with the light intensity of the light beams 18L and 18R corresponding to the left scenery. Accordingly, erroneous display due to the reflected light 21bd can be substantially prevented. For example, when the antireflection film is not applied, the reflectance of 4% (in the case of glass material BK7, wavelength 500 nm, incident angle 0 °) is usually about 0.5% when MgF ₂ is coated as the antireflection film.
[0037]
【The invention's effect】
According to the first to third aspects of the invention, the left and right transmission window portions and the left and right prism side surfaces are sequentially transmitted and totally reflected by the prism rear surface, and then transmitted through the opposite left and right prism side surfaces. In order to prevent the reflected light reflected by the left and right transmissive window portions from forming an image on the imaging surface, the reflected light is guided to the imaging surface of the image sensor and the left and right transmissive window portions of the case It is substantially prevented that the image processing is performed by combining with the light beam corresponding to the left and right side scenery guided by the image pickup surface of the image pickup device. Therefore, when the processed image signal is displayed on a predetermined display unit, a part of the landscape captured from the left transparent window unit is reflected on the right half screen of the display unit, or displayed in the same way. In addition, it is possible to prevent a part of the scenery taken in from the right transmission window part from being reflected on the left half screen of the display part and being erroneously displayed, and to provide a driver with a highly visible vehicle surrounding image.
[0038]
In particular, according to the invention described in claim 2 and claim 3, when the angle of the transmission window portions 2R, 2L with respect to the rear surface of the prism is set to a certain large angle, the reflected light that enters the image sensor is generated. However, in the case of claim 2 , the reflected light is shielded by the light shielding member provided on the side surface of the prism and is prevented from entering the image pickup device. In the case of claim 3 , the action of the antireflection film When the reflected light is incident on the image sensor, the intensity of the reflected light is relatively negligible compared to the intensity of the light corresponding to the left and right side scenery. Therefore, in both cases, erroneous display due to the reflected light is substantially prevented, so that the direction of the transmission window portions 2R and 2L can be arranged in the case in the left-right direction. The transmission window portion is less likely to receive sand dust and mud from the front during traveling of the vehicle, and visibility can be prevented from being reduced due to the mud and sand dust.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a vehicle periphery visual recognition device according to a first embodiment of the present invention.
FIG. 2 is a diagram showing an example of a state in which the imaging device constituting the vehicle periphery visual recognition device according to the first embodiment of the present invention is attached to the vehicle.
FIG. 3 is a cross-sectional view illustrating an image pickup apparatus that constitutes a vehicle periphery visual recognition apparatus according to a second embodiment of the present invention.
FIG. 4 is a diagram illustrating a vehicle periphery visual recognition apparatus according to a second embodiment of the present invention.
FIG. 5 is a diagram for explaining a conventional vehicle periphery visual recognition device.
[Explanation of symbols]
1A, 1B Vehicle periphery visual recognition device 2R, 2L Transmission window portions 3A, 3B Case 4 Prism 5 Vertical angle 8L, 8R Prism side surface 8B Prism rear surface 9 Imaging lens 10 Imaging element 10R Right half surface 10L of imaging surface Left half surface 11A of imaging surface , 11B Imaging device 12 Mirror image reversal processing unit 15L Left half screen 15R Right half screen 16 Vehicle 17 Front bumpers 18R, 18L, 21a, 21Ra, 21Rd Rays 21b, 21bd, 21ba Reflected light 27L, 27R Light shielding member

Claims

A case disposed outside the vehicle and provided with a pair of left and right transmission windows on both sides thereof, and in this case, a prism with an isosceles triangle cross section faces its apex angle toward the front of the case and while it is respectively accommodated arranged in a posture toward the transmission window portion of the left and right left and right prism side surfaces corresponding to the isosceles equilateral triangle, enters into the prism from one prism side surface of the left and right, the other An image sensor that condenses the light reflected from the prism side surface and exits from the prism rear surface of the prism onto the image pickup surface via a predetermined imaging lens and converts it into an image signal is accommodated in the rear position of the prism. Provided with an imaging device,
The left and right transmission window portions and the left and right prism side surfaces are sequentially transmitted and totally reflected by the inner surface of the prism rear surface , and then transmitted through the opposite left and right prism side surfaces and the left and right transmission window portions on the same side. A preventive means for preventing the reflected light reflected by the image forming on the imaging surface;
The preventing means reflects the reflected light reflected by the left and right transmission windows through the left and right prism side surfaces on the same side, and then totally reflects on the inner surface of the prism rear surface to cause the left and right prisms on the opposite side to be totally reflected. An apparatus for visually recognizing a vehicle periphery , wherein angles of the left and right transmissive window portions with respect to the rear surface of the prism are set so as to be transmitted through the prism side surfaces and the left and right transmissive window portions .

A case disposed outside the vehicle and provided with a pair of left and right transmission windows on both sides thereof, and in this case, a prism with an isosceles triangle cross section faces its apex angle toward the front of the case and The left and right prism side surfaces corresponding to the isosceles sides of the isosceles triangle are stored and arranged in a posture toward the left and right transmission window portions, respectively, and enter the prism from one of the left and right prism side surfaces, An image sensor that condenses the light reflected from the prism side surface and exits from the prism rear surface of the prism onto the image pickup surface via a predetermined imaging lens and converts it into an image signal is accommodated in the rear position of the prism. Provided with an imaging device,
The left and right transmission window portions and the left and right prism side surfaces are sequentially transmitted and totally reflected by the inner surface of the prism rear surface, and then transmitted through the opposite left and right prism side surfaces and the left and right transmission window portions on the same side. A preventive means for preventing the reflected light reflected by the image forming on the imaging surface;
The prevention means re-enters the prism from the left and right prism side surfaces of the reflected light reflected by the left and right transmission window portions, and internally reflects on the opposite left and right prism side surfaces, then the prism A vehicle periphery characterized in that a light shielding member is provided on a rear area of the side surfaces of the left and right prisms so as to block a light path with respect to a light beam that exits from the rear surface and enters the image pickup device. Visual device.

A case disposed outside the vehicle and provided with a pair of left and right transmission windows on both sides thereof, and in this case, a prism with an isosceles triangle cross section faces its apex angle toward the front of the case and The left and right prism side surfaces corresponding to the isosceles sides of the isosceles triangle are stored and arranged in a posture toward the left and right transmission window portions, respectively, and enter the prism from one of the left and right prism side surfaces, An image sensor that condenses the light reflected from the prism side surface and exits from the prism rear surface of the prism onto the image pickup surface via a predetermined imaging lens and converts it into an image signal is accommodated in the rear position of the prism. Provided with an imaging device,
The left and right transmission window portions are provided to be inclined with respect to the left and right prism side surfaces on the same side,
The left and right transmission window portions and the left and right prism side surfaces are sequentially transmitted and totally reflected by the inner surface of the prism rear surface, and then transmitted through the opposite left and right prism side surfaces and the left and right transmission window portions on the same side. A preventive means for preventing the reflected light reflected by the image forming on the imaging surface;
The vehicle periphery visual recognition device , wherein the prevention means includes an antireflection film disposed on at least an inner surface side of each transparent window portion among an inner surface side of each transmission window portion and each prism side surface .