Patent Description:
An endoscope disposed with alternating white light emitting parts and narrow band light emitting parts circumferentially has been disclosed (Patent Document <NUM>). The white light emitting parts are used for illumination upon a normal light observation. The narrow band light emitting parts are used for illumination upon a special light observation.

[Patent Document <NUM>] <CIT>
Further prior art documents are <CIT> showing an endoscope apparatus and adapter for endoscope and <CIT> showing a capsule endoscope.

A white light emitting parts is achieved by, for example, a combination of a blue light emitting element and a fluorescent substance that is excited by blue light to emit yellow light. In the case where light emitted from the narrow band light emitting part is applied to the fluorescent substance at the white light emitting part, a so-called cross talk occurs in which the white light emitting part emits light when it is to be in a non-light emitting state. The light emission by crosstalk affects the color tone of an endoscopic image.

In one aspect, an object is to provide an endoscope and an endoscope illumination substrate that prevent crosstalk between multiple light emitting parts.

An endoscope illumination substrate and an endoscope are defined by the respective claims.

In one aspect, it is possible to provide an endoscope or an endoscope illumination substrate that prevent crosstalk between multiple light emitting parts.

<FIG> illustrates the outer appearance of an endoscope <NUM>. An endoscope <NUM> according to the present embodiment is a flexible endoscope for a gastrointestinal tract. The endoscope <NUM> has an insertion part <NUM>, an operation part <NUM>, a universal cord <NUM> and a connector part <NUM>. The operation part <NUM> has a bend control knob <NUM> and a channel inlet <NUM>.

The insertion part <NUM> is long and has an end connected to the operation part <NUM> via a bending proof portion <NUM>. The insertion part <NUM> has, from the operation part <NUM> side, a flexible section <NUM>, a bending section <NUM> and a distal end section <NUM>. The bending section <NUM> bends in response to the operation of the bend control knob <NUM>.

Between the channel inlet <NUM> and the distal end section <NUM>, a channel <NUM> running through the insertion part <NUM> is provided. The channel inlet <NUM> is attached with a forceps plug <NUM> through which a treatment tool or the like is inserted.

In the following description, the longitudinal direction of the insertion part <NUM> will be referred to as an insertion direction. Likewise, along the insertion direction, the side closer to the operation part <NUM> will be referred to as an operation part side, whereas the side farther from the operation part <NUM> will be referred to as a distal end side.

The universal cord <NUM> is long, and has a first end connected to the operation part <NUM> and a second end connected to the connector part <NUM>. The connector part <NUM> is covered with a connector case <NUM> having a shape of a substantially rectangular parallelepiped. A scope connector <NUM> protrudes from one of the surfaces of the connector case <NUM>. The connector part <NUM> is connected to an endoscope processor or the like (not illustrated).

<FIG> is a drawing when viewed from the arrow direction II in <FIG>. <FIG> is a drawing when viewed from the arrow direction III in <FIG> shows a state in which the end face of the insertion part <NUM> is viewed from the front. <FIG> illustrates a side surface of the distal end section <NUM>.

As illustrated in <FIG>, an observation window <NUM> is disposed at a position shifted upward from the central axis of the insertion part <NUM> in <FIG>. As illustrated in <FIG>, the observation window <NUM> is dome-shaped. An annular illumination window <NUM> is disposed in such a manner as to surround the observation window <NUM>. The details of the illumination window <NUM> will be described later.

At the bottom right from the observation window <NUM> in <FIG>, an air/water supply nozzle <NUM> is disposed with an outgoing outlet facing the observation window <NUM>. At the bottom left from the observation window <NUM>, a channel outlet <NUM> and a distal end water delivery hole <NUM> are disposed.

Note that <FIG> is one example of the appearance of the end face of the distal end section <NUM>, and the arrangement of the respective parts is not limited to <FIG>. For example, an air supply nozzle and a water supply nozzle may separately be provided in place of the air/water supply nozzle <NUM>.

As illustrated in <FIG>, the distal end section <NUM> has a first frame <NUM> and a second frame <NUM> from the distal end side. The lower half of the first frame <NUM> in <FIG>, that is, the part where the air/water supply nozzle <NUM>, a channel outlet <NUM> and the distal end water delivery hole <NUM> are provided, has a substantially conical surface.

The first frame <NUM> has a projection portion <NUM> projecting toward the operation part side at the upper part in <FIG>. The part corresponding to the projection portion <NUM> at the edge of the second frame <NUM> on the distal end side is retracted toward the operation part side. The projection portion <NUM> is engaged with the recess of the second frame <NUM> to restrict the rotation angle between the first frame <NUM> and the second frame <NUM>.

The operation part side of the second frame <NUM> is secured with a fourth frame <NUM>. A bending piece <NUM> shown by a dot-dot-dash line in <FIG> is fit into the fourth frame <NUM> and secured there. The operation part side of the second frame <NUM> and the bending piece <NUM> are covered with a bend rubber <NUM>.

<FIG> is a partially sectional view of the endoscope <NUM> taken along the line IV-IV in <FIG>. <FIG> is a partially sectional view of the endoscope <NUM> taken along the line V-V in <FIG>. <FIG> is a partially sectional view of the endoscope <NUM> taken along the line VI-VI in <FIG>. <FIG> is a partially sectional view of the endoscope <NUM> taken along the line VII-VII in <FIG>. In <FIG> and <FIG>, the bending piece <NUM> and the bend rubber <NUM> are not illustrated.

The above-described first frame <NUM>, second frame <NUM> and fourth frame <NUM> are tubular. Inside the first frame <NUM> and the second frame <NUM>, a tubular third frame <NUM> is contained. The third frame <NUM> is a stepped drum being thick on the distal end side while being narrow on the operation part side. As illustrated in <FIG>, the third frame <NUM> has a circular cross section on the outer side and a rectangular cross section on the inner side. The dimension of the rectangular at the inner peripheral edge is substantially equal through the entire length of the third flame <NUM>.

At the end face on the distal end side of the third frame <NUM>, an annular endoscope illumination substrate <NUM> is disposed. At the peripheral edge of the surface on the distal end side of the endoscope illumination substrate <NUM>, first light-emitting elements <NUM> and second light-emitting elements <NUM> (see <FIG>) that emit illumination light are mounted. The details of the configuration of the endoscope illumination substrate <NUM> will be described later. Note that if there is no need to distinguish the first light-emitting element <NUM> from the second light-emitting element <NUM>, they are simply described as a light-emitting element <NUM> (see <FIG>).

The first frame <NUM> is made of a translucent resin permeable to light emitted from the light-emitting element <NUM>. As illustrated in <FIG>, a part of the inner surface of the first frame <NUM> facing the light-emitting element <NUM> is recessed in a U-shaped groove to form a concave lens. The advantages of the concave lens and a side surface of the light-emitting element <NUM> not being covered with a light-shielding body <NUM> allow light emitted from the light-emitting element <NUM> to illuminate a wide area ranging from the front to the sides as illustrated by a reference code A in <FIG>.

The part of the first frame <NUM> permeable to light emitted from the light-emitting element <NUM> serves as an illumination window <NUM>. The distal edge of the first frame <NUM> may be made of a translucent resin while the other part thereof may be made of a non-translucent resin. The distal edge of the first frame <NUM> may be made of any translucent material such as a translucent resin, a translucent ceramic or the like while the other part thereof may be made of any material such as a resin, metal, a ceramic or the like.

A tabular fifth frame <NUM> is inserted to the endoscope illumination substrate <NUM> and the third frame <NUM>. The outer peripheral edge of the cross section of the fifth frame <NUM> on the distal side is substantially D-shaped with the straight line portion of the D shape facing the channel outlet <NUM> side as illustrated in <FIG> while the outer peripheral edge of the cross section of the fifth frame <NUM> on the operation side is rectangular as illustrated in <FIG>. The hole that penetrates the fifth frame <NUM> in the longitudinal direction has a circular cross section with a uniform thickness.

As illustrated in <FIG>, two cable grooves <NUM> extending in the longitudinal direction of the fifth frame <NUM> are provided at the curved portion of the substantially D shape of the fifth frame <NUM>. The two cable grooves <NUM> are arranged substantially symmetrically. A bottom portion of the cable grooves <NUM> is substantially flush with the side surface of the short side of the rectangular cross-section as illustrated with reference to <FIG>.

Returning to <FIG> and <FIG>, a lens unit <NUM> is inserted to the fifth frame <NUM> from the distal end side. The lens unit <NUM> has a lens frame <NUM> and multiple lenses secured in the lens frame <NUM>. The periphery of the lens located closest to the distal end side out of the lenses consisting of the lens unit <NUM> is disposed to merge smoothly with the periphery of the recess of the first frame <NUM>. The above-described observation window <NUM> corresponds to the outer surface of the lens arranged closest to the distal end side.

The lens unit <NUM> according to the present embodiment is a so-called super-wide angle lens with a viewing angle of <NUM> degrees or over. The lens unit <NUM> includes a lens with a large diameter on the distal end side and a lens with small diameter on the operation part side. The lens frame <NUM> has a cylindrical shape with a flange on the distal end side. The lens with a large diameter located at the distal end side is secured to the flange part of the lens frame <NUM> while the lens with a small diameter located at the operation part side is secured to the internal surface of the lens frame <NUM>.

At the operation part side of the lens unit <NUM>, an imaging unit <NUM> is disposed. The imaging unit <NUM> is a member including an imaging element <NUM> arranged at the end face on the distal end side, a driver circuit and a cable connected thereto that are solidified in a substantially rectangular parallelepiped shape. The imaging unit <NUM> includes an imaging cable <NUM> extending toward the operation part side. The imaging cable <NUM> is a bundle of multiple cables. The imaging cable <NUM> is connected to the endoscope processor via the operation part <NUM>, the universal cord <NUM> and the connector part <NUM>.

The positional relation between the lens unit <NUM> and the imaging unit <NUM> is adjusted so that light incident on the lens unit <NUM> forms an image on the imaging element <NUM>. The lens unit <NUM> and the imaging unit <NUM> form an observation optical system of the endoscope <NUM>.

The first frame <NUM> is provided with through holes respectively corresponding to the channel outlet <NUM>, the air/water supply nozzle <NUM> and the distal end water delivery hole <NUM>. As illustrated in <FIG>, the through hole corresponding to the channel outlet <NUM> is a stepped hole having a large inside diameter on the operation part side and is connected to a channel tube <NUM>.

Though not illustrated, the through hole corresponding to the distal end water delivery hole <NUM> is connected to a distal end water delivery tube. The through hole corresponding to the air/water supply nozzle <NUM> is attached with the air/water supply nozzle <NUM> on the distal end side while being attached with an air supply tube and a water supply tube on the operation part side.

<FIG> is a perspective view of the endoscope illumination substrate <NUM>. <FIG> is a front view of the endoscope illumination substrate <NUM>.

As described above, the endoscope illumination substrate <NUM> is annular. The endoscope illumination substrate <NUM> has a substantially D-shaped imaging hole <NUM> at its center portion. The outer periphery near the straight line portion of the imaging hole <NUM> of the endoscope illumination substrate <NUM>, a substantially arcuate channel concave portion <NUM> is provided.

The endoscope illumination substrate <NUM> has a laminated structure of a base substrate <NUM> and a light-shielding body <NUM>. The base substrate <NUM> is mounted with eight first light-emitting elements <NUM> and four second light-emitting elements <NUM>. The second light-emitting elements <NUM> each include a green light-emitting element <NUM> and a purple light-emitting element <NUM> adjacently arranged along the outer periphery of the endoscope illumination substrate <NUM>.

The first light-emitting elements <NUM> are dispersedly arranged at substantially equally spaced intervals along the circumference of the base substrate <NUM>. At the above-described channel concave portion <NUM> is disposed so as to be positioned between the two adjacent first light-emitting elements <NUM>.

The second light-emitting element <NUM> is arranged between the two adjacent first light-emitting elements <NUM> at every other space. The second light-emitting elements <NUM> are also dispersedly arranged at substantially equally spaced intervals along the circumference of the base substrate <NUM>.

The first light-emitting elements <NUM> and the second light-emitting elements <NUM> are spaced at a substantially equal distance from an optical axis of an observation optical system composed of the imaging unit <NUM> and the lens unit <NUM>.

Two groups of three wire lands <NUM> are respectively arranged at spaces having no second light-emitting element <NUM> interposed between the first light-emitting elements <NUM>. The two groups of the wire lands <NUM> are disposed to face each other across the central portion of the base substrate <NUM>. The wire lands <NUM> are one example of a cable connection part according to the present embodiment.

The light-shielding body <NUM> is stacked on the base substrate <NUM> except for the locations where the light-emitting elements <NUM> are mounted and their surrounding areas and the locations where the wire lands <NUM> are arranged and their surrounding areas. In the vicinity of the location where the first light-emitting element <NUM> is mounted, the end face of the light-shielding body <NUM> surrounds the first light-emitting element <NUM> to form a U-shaped light-shielding face <NUM> that opens toward the outer periphery of the endoscope illumination substrate <NUM>.

In the vicinity of the place where the second light-emitting element <NUM> is mounted as well, the end face of the light-shielding body <NUM> surrounds the green light-emitting element <NUM> and the purple light-emitting element <NUM> to form a U-shaped light-shielding face <NUM> that opens toward the outer periphery of the endoscope illumination substrate <NUM>.

In the vicinity of the location where the wire lands <NUM> are arranged, the end face of the light-shielding body <NUM> surrounds the three wire lands <NUM> to form a U-shaped connection part wall surface <NUM> that opens toward the inner periphery of the endoscope illumination substrate <NUM>.

As illustrated in <FIG>, the endoscope illumination substrate <NUM> is assembled in the endoscope <NUM> with the mounting surface on which the light-emitting elements <NUM> are mounted facing toward the distal end side.

<FIG> is a partially sectional view of the endoscope illumination substrate <NUM> taken along the line X-X in <FIG>. <FIG> is a partially sectional view of the endoscope illumination substrate <NUM> taken along the line XI-XI in <FIG>. <FIG> illustrates a cross section of the endoscope illumination substrate <NUM> taken along an arcuate curved line substantially parallel with the outer periphery of the endoscope illumination substrate <NUM>, including two first light-emitting elements <NUM> and a second light-emitting element <NUM> that is interposed between them. <FIG> illustrates a cross section of the endoscope illumination substrate <NUM> taken along a face passing through a single first light-emitting element <NUM> and extending in the radial direction. In <FIG> and <FIG>, the illustration of the internal structure of the light-emitting element <NUM> and the wiring pattern provided on the endoscope illumination substrate <NUM> are not made.

The surrounding area of the first light-emitting element <NUM> is filled with a fluorescent resin <NUM>. The details of the fluorescent resin <NUM> will be described later. The surrounding area of the second light-emitting element <NUM> is filled with a translucent resin <NUM>. The fluorescent resin <NUM> and the translucent resin <NUM> fill the space surrounded by the U-shaped light-shielding face <NUM>, the base substrate <NUM>, the outer peripheral surface of the endoscope illumination substrate <NUM> and the main surface of the endoscope illumination substrate <NUM> on the light-shielding body <NUM> side. The endoscope illumination substrate <NUM> is formed in a plate with uniform thickness except for the surrounding areas of the wire lands <NUM> by the filled resins.

The base substrate <NUM> is in the form of laminations of a wiring board <NUM> and a support plate <NUM>. The wiring board <NUM> is a so-called printed circuit board (PCB) having a laminated structure of an insulating layer and a wiring layer. The wiring board <NUM> may be a so-called hard substrate employing a hard material such as a glass epoxy substrate or the like for the insulating layer, or may be a so-called a flexible printed circuit (FPC) employing a polyimide sheet or the like for the insulating layer.

Though not illustrated, the base substrate <NUM> is a so-called multilayer circuit board, and formed with wiring for connecting the lands where the light-emitting elements <NUM> are mounted and the wire lands <NUM>.

The support plate <NUM> is a plate for supporting the wiring board <NUM> and preventing a breaking wire due to bending or the like of the wiring board <NUM>. The support plate <NUM> is a metal plate made of, for example, copper, aluminum, stainless steel or the like. The support plate <NUM> may be a ceramic plate or a resin plate. In the case where the support plate <NUM> is conductive, an insulating layer formed with no pattern is disposed on a side of the wiring board <NUM> that is in contact with the support plate <NUM>.

The light-shielding body <NUM> is a metal plate, for example, a copper plate, an aluminum plate or the like. The light-shielding body <NUM> may be a plate made of a ceramic or a resin having a light blocking effect. In the case where the light-shielding body <NUM> is conductive, an insulating layer formed with no pattern is disposed at a location of the wiring board <NUM> that is in contact with the light-shielding body <NUM>. The desirable thickness of the light-shielding body <NUM> will be described later.

The support plate <NUM> and the wiring board <NUM> as well as the wiring board <NUM> and the light-shielding body <NUM> are fixed by any method such as adherence, chemical bonding or the like.

Returning to <FIG>, an illumination cable <NUM> extends from the endoscope processor to the distal end section <NUM> via the connector part <NUM>, the universal cord <NUM> and the operation part <NUM>. The illumination cable <NUM> is a bundle of multiple cables. In <FIG>, the illumination cable <NUM> is disposed at the left from the fifth frame <NUM>.

The illumination cable <NUM> is separated into two bundles at the distal end section <NUM>. One of the bundles is drawn out to the vicinity of the left side wire land <NUM> after passing through the left side cable groove <NUM> in <FIG>. The other one of the bundles is drawn out to the vicinity of the right side wire land <NUM> after routed through a substantially U-shaped wire groove <NUM> provided in the third frame <NUM> and then passing through the right side cable groove <NUM> in <FIG>.

Each cable strand of the illumination cable <NUM> are connected to the wire lands <NUM> by any method such as soldering or the like. It is noted that the cable strands connected to the respective wire lands <NUM> are not illustrated in <FIG>. The light illumination of the light-emitting element <NUM> is controlled by the endoscope processor through the illumination cable <NUM>.

The fluorescent resin <NUM> will be described. In the present embodiment, the first light-emitting element <NUM> is a so-called light source for normal light observation while the second light-emitting element <NUM> is a so-called light source for special light observation. For the normal light observation, white light with a wide bandwidth is employed. However, a semiconductor light-emitting element such as light emitting diode (LED), for example, is a narrow band light emitting element for emitting narrow band light with a narrow band width.

A technique of obtaining white light has been developed by hitting narrow band light emitted from a semiconductor light-emitting element with a fluorescent substance to emit a mixed light of fluorescence radiated from the fluorescent substance and the light radiated from the semiconductor light-emitting element. For example, it has already been known that white light is obtained according to the combinations shown in Table <NUM>.

In the present embodiment, a case where the combination of No. <NUM> is employed for the first light-emitting element <NUM> will be described as an example. Namely, the fluorescent resin <NUM> according to the present embodiment is a resin obtained by mixing a translucent resin and a yellow fluorescent substance, and the first light-emitting element <NUM> is a blue LED. The first light-emitting element <NUM> and the fluorescent resin <NUM> constitute a first light-emitting part <NUM> according to the present embodiment.

It is noted that any combination capable of obtaining illumination light suitable for the normal light observation as well as the combination of No. <NUM> in Table <NUM> may be employed for the color of the light-emitting element and the color of the fluorescent substance.

A so-called white light-emitting element, which contains a semiconductor light-emitting element and a fluorescent substance sealed in a package, may be employed for the first light-emitting element <NUM>. In the case where the white light-emitting element is employed, there is no need to cover the first light-emitting element <NUM> with the fluorescent resin <NUM>. The thickness of the white light-emitting element may be substantially the same as that of the light-shielding body <NUM>. The white light-emitting element may be covered with a transparent resin not containing a fluorescent substance as in the second light-emitting element <NUM>.

Illumination light for special light observation emitted from the second light-emitting element <NUM> will be described. The special light observation is a technique for highlighting a blood vessel running through the deep region below a mucous membrane by using narrow-band illumination light. A method of utilizing the illumination light shown in Table <NUM> is proposed, for example.

It is desirable that the colors shown in Table <NUM> are each narrow band light with a narrow bandwidth. A semiconductor light-emitting element such as an LED, a semiconductor laser or the like may be employed for the second light-emitting element <NUM>. In the present embodiment, a case where employment of the combination of No. <NUM> will be described as an example, in which the green light-emitting element <NUM> and the purple light-emitting element <NUM> are used.

It is noted that filling the surrounding areas of the green light-emitting element <NUM> and the purple light-emitting element <NUM> with the translucent resin <NUM> prevents reduction in reliability due to water entering the endoscope illumination substrate <NUM>, for example. The green light-emitting element <NUM> and the purple light-emitting element <NUM> constitute a second light-emitting part <NUM> according to the present embodiment. The second light emitting part <NUM> does not necessarily include the translucent resin <NUM>.

Returning to <FIG>, the function of the light-shielding body <NUM> will be described. In the case where the normal light observation is performed, the first light-emitting element <NUM> is turned on while the second light-emitting element <NUM> is turned off. The light emitted from the first light-emitting element <NUM> is turned to white light by the action of the fluorescent substance in the fluorescent resin <NUM> to illuminate the front and sides through the illumination window <NUM>.

In the case where the special light observation is performed, the first light-emitting element <NUM> is turned off while the second light-emitting element <NUM> is turned on. The light emitted from the second light-emitting element <NUM> illuminates the front and sides through the illumination window <NUM>.

Assuming that the light emitted from the second light-emitting element <NUM> is incident on the fluorescent resin <NUM>, crosstalk occurs in which the fluorescent resin <NUM> emits light. In other words, though the special light observation is being performed, the first light-emitting part <NUM> becomes a pseudo light-emitting state.

The presence of the light-shielding body <NUM> prevents or reduces crosstalk in which light emitted from the second light-emitting element <NUM> enters the fluorescent resin <NUM>, which thereby emits light.

With reference to the surface of the base substrate <NUM>, the height H1 of the light-shielding body <NUM> is higher than the height H2 of the second light-emitting element <NUM>. The height H1 of the light-shielding body <NUM> is desirably at least two times greater than the height H2 of the second light-emitting element <NUM>. With reference to the surface of the base substrate <NUM>, the height H1 of the light-shielding body <NUM> is desirably at least two and a half times greater than the height H2 of the second light-emitting element <NUM>.

According to the present embodiment, the endoscope <NUM> that prevents crosstalk between multiple light-emitting parts can be provided. Since the white illumination light for the normal observation does not cause crosstalk due to the illumination light for the special light observation, image quality upon the special light observation is improved.

According to the present embodiment, since light emitted from the side surface of the light-emitting elements <NUM> disposed near the observation window <NUM> is not shut off, the endoscope <NUM> that illuminates even the sides of the insertion part <NUM> can be provided. Since the illumination light reaches up to the end of the observation visual field using the observation optical system with a wide angle, the endoscope <NUM> that is capable of observing a wide visual field can be provided.

It is noted that the light-shielding face <NUM> may be formed on a surface of high reflectivity by grinding or the like. The endoscope <NUM> that is capable of illuminating the sides of the insertion part <NUM> can be provided.

A material having high thermal conductivity such as metal or the like is employed for the support plate <NUM> and the light-shielding body <NUM>, whereby the endoscope <NUM> that is capable of promptly diffusing heat occurring in the light-emitting element <NUM> can be provided. The thermal diffusion is promptly performed within the endoscope illumination substrate <NUM>, and thus by disposing a heat dissipation sheet or a cooling element at any place of the endoscope illumination substrate <NUM>, the endoscope illumination substrate <NUM> can be protected from heat.

Since the first light-emitting elements <NUM> and the second light-emitting elements <NUM> are evenly arranged, the endoscope <NUM> that causes less variations in luminance can be provided. Since the green light-emitting elements <NUM> and the purple light-emitting elements <NUM> are respectively arranged adjacent to each other, the endoscope <NUM> that causes less color irregularities of illumination light for the special light observation can be provided.

By provision of the U-shaped concave lens formed in the internal surface of the first frame <NUM>, light emitted from the light-emitting element <NUM> is diffused. Thus, the endoscope <NUM> that is capable of illuminating the wide range can be provided.

It is noted that the shapes of the lenses formed in the internal surface of the first frame <NUM> may be different between the part facing the first light-emitting element <NUM> and the part facing the second light-emitting element <NUM>. For example, the lenses formed in the internal surface of the first frame <NUM> are formed such that light emitted from the first light-emitting element <NUM> is diffused in a wide range while light emitted from the second light-emitting element <NUM> is strongly emitted to the area ahead of the insertion part <NUM>.

In the case where the endoscope <NUM> with wide observation angle is used as in the present embodiment, illumination light for normal light observation needs to also illuminate the sides of the insertion part <NUM>. The user can find the part of a lesion while observing a wide range at the same time.

If conducting the special light observation during the endoscopy, the user operates the endoscope <NUM> such that the target region is positioned at the central portion of the visual field of the endoscope. Accordingly, it is desirable that the illumination light for the special light observation emitted from the second light-emitting element <NUM> mainly illuminates the central portion of the visual field. The central portion of the visual field can be brightly illuminated since the illumination light is not diffused to the periphery portion of the visual field.

The light emitted from the first light-emitting element <NUM> is diffused in a wide range while the light emitted from the second light-emitting element <NUM> is strongly emitted toward the area ahead of the insertion part <NUM>. This makes it possible to provide the endoscope <NUM> that illuminates ranges suitable for the normal light observation and the special light observation.

The channel concave portion <NUM> is provided at the outer periphery of the endoscope illumination substrate <NUM>, so that the observation window <NUM> and the channel outlet <NUM> can be disposed close to each other. This makes it possible to provide the endoscope <NUM> having the distal end section <NUM> with a thinner diameter.

The present embodiment relates to an endoscope <NUM> in which the light-shielding face <NUM> is a reflecting surface for reflecting light. Components common to those of Embodiment <NUM> are not described.

<FIG> is a partially sectional view of an endoscope illumination substrate <NUM> according to Embodiment <NUM>. <FIG> illustrates a cross section as in <FIG>. Though not illustrated, the light-shielding face <NUM> surrounding the second light-emitting element <NUM> also has a shape similar to that of the light-shielding face <NUM> surrounding the first light-emitting element <NUM>.

In the present embodiment, a reflecting surface shown by a bold line is formed on the surface of the light-shielding face <NUM>. The reflecting surface is a surface smoothed by grinding the light-shielding face <NUM>, for example. The reflecting surface may be formed by a reflecting film such as a nickel chrome plating film or the like formed on the surface of the light-shielding face <NUM>.

As illustrated by the arrows in <FIG>, light emitted from the first light-emitting element <NUM> and the fluorescent resin <NUM> impinges on and is reflected by the light-shielding face <NUM>, and the reflected light is emitted to the area ahead of the insertion part <NUM>. That is, the light emitted from the light-emitting element <NUM> can be utilized with efficiency.

According to the present embodiment, the endoscope <NUM> having high utilization efficiency of light reflected from the light-emitting element <NUM> can be provided.

The present embodiment relates to the endoscope <NUM> in which the light-shielding face <NUM> is partially formed in an inclined surface. Components common to those of Embodiment <NUM> are not described.

<FIG> is a partially sectional view of an endoscope illumination substrate <NUM> according to Embodiment <NUM>. <FIG> is a cross section as in <FIG>. In the present embodiment, a part closer to the center of the endoscope illumination substrate <NUM> of the light-shielding face <NUM> is so inclined that the distance from the center of the endoscope illumination substrate <NUM> is shorter as it is more separated from the base substrate <NUM>.

In the present embodiment, the cross section of the endoscope illumination substrate <NUM> taken along an arcuate curved line substantially parallel with the outer periphery of the endoscope illumination substrate <NUM> is as in <FIG>. In other words, the part of the light-shielding face <NUM> that is vertical to the circumferential direction is formed in a vertical surface. Though not illustrated, the light-shielding face <NUM> surrounding the second light-emitting element <NUM> also has a similar shape as the light-shielding face <NUM> surrounding the first light-emitting element <NUM>.

As illustrated by the arrows in <FIG>, the light emitted from the first light-emitting element <NUM> and the fluorescent resin <NUM> to the center of the insertion part <NUM> can be radiated without being shut off by the light-shielding body <NUM>.

The present embodiment relates to the endoscope <NUM> in which the light-shielding face <NUM> is entirely formed in an inclined surface. Components common to those of Embodiment <NUM> are not described.

<FIG> is a partially sectional view of an endoscope illumination substrate <NUM> according to Embodiment <NUM>. <FIG> shows the cross section of the endoscope illumination substrate <NUM> taken along an arcuate curved line substantially parallel with the outer periphery of the endoscope illumination substrate <NUM> as in <FIG>. The cross section in the radial direction of the endoscope illumination substrate <NUM> is as in <FIG>.

In the present embodiment, the light-shielding face <NUM> is entirely formed in an inclined surface that becomes wider as it is far away from the base substrate <NUM>. Though not illustrated, the light-shielding face <NUM> surrounding the second light-emitting element <NUM> also has a shape similar to the light-shielding face <NUM> surrounding the first light-emitting element <NUM>.

As illustrated by the arrows in <FIG> and <FIG>, light obliquely emitted from the first light-emitting element <NUM> and the fluorescent resin <NUM> is radiated without being shut off by the light-shielding body <NUM>.

The present embodiment relates to the endoscope <NUM> in which a part of the wiring board <NUM> is formed thicker. Components common to those of Embodiment <NUM> are not described.

<FIG> is a partially sectional view of an endoscope illumination substrate <NUM> according to Embodiment <NUM>. <FIG> is a cross section of the endoscope illumination substrate <NUM> taken along a face passing through a single green light-emitting element <NUM> and extending in the radial direction.

The wiring board <NUM> according to the present embodiment includes a first substrate layer <NUM> and a second substrate layer <NUM>. The first substrate layer <NUM> and the second substrate layer <NUM> are stacked with each other to form a single piece. The land mounted with the light-emitting element <NUM> such as the green light-emitting element <NUM> or the like is provided on the first substrate layer <NUM>. The end face of the second substrate layer <NUM> is flush with the light-shielding face <NUM>.

The wire lands <NUM> may be provided on the first substrate layer <NUM> or on the second substrate layer <NUM>.

With reference to the surface mounted with the light-emitting element <NUM>, i.e., the surface of the first substrate layer <NUM>, the height H3 of the light-shielding body <NUM> is higher than the height H2 of the second light-emitting element <NUM>. The height H3 of the light-shielding body <NUM> is desirably two times greater than the height H2 of the second light-emitting element <NUM>. With reference to the surface mounted with the light-emitting element <NUM>, the height H3 of the light-shielding body <NUM> is more desirably two and half times greater than the height H2 of the second light-emitting element <NUM>.

In the case where an insulating layer forming of the second substrate layer <NUM> has translucency, it is desirable that the height H4 of the second substrate layer <NUM> is equal to or less than the height H2 of the second light-emitting element <NUM>. This prevents crosstalk that causes the fluorescent resin <NUM> to emit light by the light transmitted through the insulating layer while being reflected by the wiring pattern provided inside the insulating layer.

According to the present embodiment, the thick wiring board <NUM> can be utilized while the total thickness of the endoscope illumination substrate <NUM> is the same as that in Embodiment <NUM>. Since the wiring board <NUM> is thinner at the location where the second light-emitting element <NUM> is mounted, a crosstalk prevention effect as in Embodiment <NUM> or the like can be produced.

Since a wiring pattern can be routed at the second substrate layer <NUM>, a necessary wiring pattern can be provided without increasing the outside diameter of the endoscope illumination substrate <NUM> even if the wiring between the wire lands <NUM> and the light-emitting element <NUM> is complicated.

Claim 1:
An endoscope illumination substrate (<NUM>), comprising:
an annular base substrate (<NUM>) having a mounting surface;
a plurality of first light-emitting parts (<NUM>) on the mounting surface;
a second-light emitting part (<NUM>) that is disposed between the first light-emitting parts (<NUM>) and being configured to emit light at a bandwidth different from a bandwidth of light the first light-emitting part (<NUM>) is configured to emit;
the first light-emitting parts (<NUM>) and the second light emitting part (<NUM>) include respective light-emitting elements (<NUM>);
characterized by
a light-shielding body (<NUM>) that is disposed between one of the first light-emitting parts (<NUM>) and the second-light emitting part (<NUM>); wherein
the light-shielding body (<NUM>) is stacked on a part of the base substrate (<NUM>) on which the first and second light-emitting elements (<NUM>) are not mounted;
the light-shielding body (<NUM>) has a light-shielding face (<NUM>) that surrounds the first and second light-emitting elements (<NUM>) in a U-shape that opens to an outer periphery of the endoscope illumination substrate (<NUM>).