JP6504970B2 - Prism dustproof structure of optical equipment - Google Patents

Description

  The present invention relates to a prism dustproof structure of an optical device that holds a prism that bends an optical path of display light.

  Conventionally, in optical devices such as single-lens reflex cameras and digital single-lens reflex cameras, for example, it is known that display light for displaying information in a finder is emitted from a display element and the optical path of the display light is bent by a bending prism. ing. Patent Document 1 discloses a configuration for improving the dust resistance of a prism that bends display light in this type of optical device. In this configuration, the dustproof packing is provided in a portion of the optical path bending prism where the display light is not reflected (not used optically), thereby preventing dust from being mixed in the housing.

JP, 2009-157290, A

  However, the prior art described in Patent Document 1 has the following problems. First, an elastic dustproof member such as a packing has an elastic force. Therefore, depending on the arrangement of the dustproof member with respect to the prism, not only the relationship between the relative position and posture of the prism and the housing may be disturbed, but also the prism itself may be deformed. That is, in the state where the prism is assembled to the housing, the prism may fall down due to the deformation of the dustproof member, or the prism may be distorted due to the uneven stress generated. If the prism falls or is deformed by the elastic force of the dustproof member unintentionally, the positional deviation of the display light and the appearance of the display change, which affects the quality of the optical image.

  On the other hand, it is conceivable to seal the space between the prism and the housing with an adhesive or the like instead of the dustproof member to achieve dustproof, but then it becomes difficult to disassemble the prism from the housing after bonding.

  An object of the present invention is to provide a prism dust-proof structure of an optical device capable of providing a dust-proof function as well as having a structure in which distortion of a prism hardly occurs.

  In order to achieve the above object, according to the present invention, a display unit for emitting display light for displaying information, an incident surface on which the display light emitted by the display unit is incident, and light incident on the incident surface are reflected. A prism having at least two reflecting surfaces, an emitting surface for emitting light reflected by the at least two reflecting surfaces, and a mounting surface, and a holding member for holding the prism, the mounting surface of the prism It is a prism dustproof structure of an optical device in which the prism is held by the holding member by being fixed to the holding member, and the prism is substantially parallel to the mounting surface and separately from the mounting surface. It has a first surface and a second surface which are two planes different in distance from each other in a direction orthogonal to the mounting surface, and the first surface and the second surface of the prism In a state where the elastic member interposed elastically deformed between the holding member, wherein the mounting surface is characterized in that it is fixed to the holding member.

  According to the present invention, it is possible to provide a dustproof function as well as a structure in which distortion of the prism hardly occurs.

It is a schematic diagram of an optical instrument to which a prism dustproof structure is applied. It is a perspective view of a prism dustproof structure. It is an exploded perspective view of a prism dustproof structure. It is a perspective view (figure (a)), a top view (figure (b)), a longitudinal section (figure (c)), and a side view (figure (d)) of a prism. They are a longitudinal cross-sectional view (figure (a)) of the prism dustproof structure in the state where the prism was fixed to the pentaholder, and an enlarged view (figure (b)) of an important section.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic view of an optical apparatus to which a prism dustproof structure according to an embodiment of the present invention is applied. This optical device is configured as a digital single-lens reflex camera 100 using a solid-state imaging device such as a CCD or CMOS type. The present invention is also applicable to a single-lens reflex still camera using a silver halide film. Alternatively, the present invention can be applied to an optical apparatus having a function of displaying an image or video through a prism, even if it is other than a camera.

  The camera body 1 of the camera 100 has various components necessary for photographing, such as a shutter 4 and a photosensitive member 5 described later. The taking lens 2 connected to the camera body 1 is indicated by two lenses for the sake of convenience, but in actuality, it is composed of a larger number of lenses. The camera body 1 includes a main mirror 3, a shutter 4, and a photosensitive member 5. The main mirror 3 is provided obliquely to the imaging light path or retracted from the imaging light path according to the observation state and the imaging state. The photosensitive member 5 is an imaging device such as a CCD or CMOS type. In a single-lens reflex still camera using a silver halide film, the photosensitive member 5 corresponds to a silver halide film.

  In the camera body 1, a focusing screen 6 is disposed on a planned imaging surface of the photographing lens 2. The imaging light from the imaging lens 2 is reflected by the main mirror 3 and is primarily formed on the focusing screen 6. The penta-dach prism 7 is a penta-dach prism for changing the finder optical path. The penta-dha prism 7 restores an image formed primarily in a state of left-right inverted on the focusing screen 6 into an erected image by left-right inversion and up-down inversion by the roof surface, and further up-down inversion by the second reflection surface. Lead to the eyepiece system. The camera body 1 has a so-called TTL optical finder configuration. That is, the photographer can view the object scene image that has passed the photographing lens 2 through the penta-dach prism 7 and the eyepiece lens 8.

  A configuration including a photometric lens 9a, 9b which is an optical member for photometry, a photometric sensor 10 which is a light receiving element for photometry, and a holding member (not shown) for holding these components is a photometric unit. The photometric lenses 9a and 9b cause the image primarily formed on the focusing screen 6 to form a secondary image on the photometric sensor 10 through the pentagonal prism 7. In this embodiment, the photometric lenses 9a and 9b are composed of two sheets, and an optical system which guides an image primarily formed on the focusing screen 6 to the upper side by the photometric lens 9a and forms an image on the photometric sensor 10 by the photometric lens 9b. It has become. Thus, the mechanical structure around the photometric optical system can be miniaturized. The photometric sensor 10 is, for example, a light receiving element such as a CCD or a CMOS, and detects the field brightness, the position of the subject, and the like from the information of the image formed by the photometric lenses 9a and 9b. From the result, exposure control of the camera, luminance modulation of information display, assistance of focus detection, etc. are performed.

  The camera body 1 further includes an in-finder information display device 11 (hereinafter sometimes abbreviated as "display device 11") and an optical path bending prism 12 (hereinafter sometimes abbreviated as "prism 12"). Be As the display device 11, a self-light emitting display element such as a TN liquid crystal element or an organic light emitting diode (OLED) is used. The TN liquid crystal element is an element utilizing a twisted nematic mode, which allows only a selected segment area to transmit light. OLED is a light emitting diode using organic EL (Organic Electro Luminescence). The display device 11 is a display unit that emits display light for displaying information. The prism 12 is a light guiding member which bends the optical path of the display light emitted by the display device 11 and guides it to the photographer.

  Subsequently, a prism dustproof structure for sealing and dustproofing between the prism 12 and the pentaholder 18 (which will be described later in FIG. 2) which is a holding member for holding the prism 12 will be described with reference to FIGS. .

  FIG. 2 is a perspective view of the prism dustproof structure. FIG. 3 is an exploded perspective view of the prism dustproof structure.

  As shown in FIG. 3, the display device 11 is held by the OLED holder 14. The OLED holder 14 is covered with the OLED cover 15 via the OLED fixing elastic member 16. Positioning portions 14 a, 14 b, 14 c are provided on the peripheral wall of the recess formed in the OLED holder 14. The display device 11 is adhesively fixed to the bottom of the recess of the OLED holder 14 by the double-sided tape 13. At that time, the edge of the display device 11 abuts on three positions of the positioning portions 14a, 14b and 14c, and the positioning is performed with high accuracy.

  Next, the claws 14 d formed at two places of the OLED holder 14 are locked to the corresponding hooks 15 a of the OLED cover 15, whereby the elastic member 16 for fixing the OLED is made of the display device 11 and the OLED cover 15. It is compressed and held between. This prevents the display device 11 from being peeled off from the double-sided tape 13 due to an impact or the like. After that, the OLED holder 14 is fitted to the prism 12 with the two positioning holes 12a formed in the prism 12 and the positioning pins 14e (only one is shown) corresponding to them and provided in the OLED holder 14 so as to project. It is positioned with high accuracy. The prism 12 and the OLED holder 14 are fixed by a clip spring 17.

  Thus, the OLED cover 15, the display device 11, the OLED holder 14, the prism 12 and the like are integrated. Then, this integrated one is fixed to the penta holder 18. The pentaholder 18 has a dustproof member affixing surface 18a (18ah, 18ai, 18aj). Hereinafter, the dustproof member affixing surface 18 a may be abbreviated as “affixing surface 18 a”. The prism 12 is attached to the pentaholder 18 in a state in which the dustproof member 19 which is an elastic member is elastically deformed and interposed. The detailed configuration of the prism 12 and the pentaholder 18 will be described.

  FIGS. 4A, 4 B, 4 C, and 4 D are a perspective view, a top view, a longitudinal sectional view, and a side view of the prism 12.

  As shown in FIG. 4C and the like, the prism 12 has an entrance surface 12c, an exit surface 12d, a first reflection surface 12e, and a second reflection surface 12f. Display light from the display device 11 is incident on the incident surface 12c. The light incident from the incident surface 12c is sequentially reflected by the first reflection surface 12e and the second reflection surface 12f, and the light reflected by the second reflection surface 12f is emitted from the emission surface 12d and enters the penta roof prism 7 Be done. The number of reflecting surfaces on the light path from the incident surface 12c to the exit surface 12d is two, but it is sufficient if there are at least two, and the number is not limited.

  The prism 12 has two mounting surfaces 12g for being attached to the pentaholder 18, and the positioning pins 12b are provided so as to protrude from the mounting surface 12g (FIGS. 4A and 4B). The prism 12 further has a first pressing surface 12 h (first surface) and a second pressing surface 12 i (a first pressing surface) as surfaces for pressing the dustproof member 19 at the time of fixing to the pentaholder 18 separately from the mounting surface 12 g. 2) and a connecting surface 12j. The connecting surface 12j is a slope connecting the pressing surfaces 12h and 12i to connect them. The pressing surfaces 12h and 12i and the connecting surface 12j have a generally continuous, substantially U-shaped annular shape as viewed from the mounting direction (the direction orthogonal to the mounting surface 12g).

  The dustproof member 19 is formed in an annular shape corresponding to the annular shape exhibited by the pressing surfaces 12h and 12i and the connecting surface 12j (FIG. 3). The pressing surfaces 12h and 12i are planes substantially parallel to the mounting surface 12g and different in distance in the direction orthogonal to the mounting surface 12g. The pressing surfaces 12 h and 12 i and the connecting surface 12 j face the bonding surfaces 18 ah, 18 ai and 18 aj of the pentaholder 18 with the dustproof member 19 interposed therebetween. The pressing surfaces 12h and 12i and the connecting surface 12j are connected to the mounting surface 12g by ribs 12k (FIGS. 4A and 4B). The rib 12k is a wall substantially orthogonal to the pressing surfaces 12h and 12i. That is, the thickness direction of the rib 12k is substantially orthogonal to the pressing surfaces 12h and 12i.

  As shown in FIG. 3, in the pentaholder 18, two contact surfaces 18 e are formed corresponding to the mounting surface 12 g, with which the mounting surface 12 g is oppositely contacted when the prism 12 is mounted. Positioning holes 18b are formed in each contact surface 18e. Each abutment surface 18 e is also formed with a screw hole into which the screw 20 is screwed.

  An adhesive is attached to one side of the dustproof member 19 opposite to the affixing surface 18 a of the pentaholder 18. When fixing an integrated structure of the OLED cover 15, the display device 11, the OLED holder 14 and the prism 12 to the pentaholder 18, the worker first attaches the adhesive of the dustproof member 19 to the affixing surface 18a. Paste the face of the other side. Next, the operator fits the positioning pin 12b of the mounting surface 12g into the positioning hole 18b of the contact surface 18e and brings the mounting surface 12g of the prism 12 into contact with the contact surface 18e of the pentaholder 18. The fitting of the positioning pin 12b and the positioning hole 18b allows the prism 12 to be accurately positioned. Further, the prism 12 is fixed to the pentaholder 18 by screwing with a screw 20.

  FIG. 5A is a vertical cross-sectional view of the prism dustproof structure in a state where the prism 12 is fixed to the pentaholder 18. FIG.5 (b) is an enlarged view of the principal part of the same prism dustproof structure.

  As described above, the prism 12 integrated with the OLED cover 15 or the like is fixed to the pentaholder 18. The dustproof member 19 is compressed between the first pressing surface 12h and the second pressing surface 12i and the contact surface 18e by a fastening force in which the mounting surface 12g is fastened to the contact surface 18e of the pentaholder 18 with a screw 20. It is pinched. The dustproof member 19 is held across the entire area with a substantially constant amount of elastic deformation without a gap, and the bonding surfaces 18ah, 18ai, 18aj and the pressing surfaces 12h, 12i, 12j maintain a constant distance. Thereby, the space between the prism 12 and the pentaholder 18 is sealed.

  By the way, the upper opening 18c (FIG. 2) of the pentaholder 18 is sealed without a gap by the penta-dach prism 7 and a dustproof member (not shown). Further, the lower opening 18 d (FIG. 2) of the pentaholder 18 is sealed by receiving and fixing the outer peripheral portion of the optical surface of the condenser lens (not shown) without a gap. As a result, the internal space of the pentaholder 18 becomes a sealed space, and the ingress of dust and the like from the outside is eliminated. Therefore, the adhesion can be secured by a simple operation.

  Here, since the pressing surfaces 12h and 12i are substantially parallel to the mounting surface 12g, the rotational moment applied to the prism 12 by the repulsive force of the dustproof member 19 is reduced, and a configuration in which the prism is not easily inclined to the mounting surface 12g can be secured. The pressing surfaces 12h and 12i and the connecting surface 12j are connected to the mounting surface 12g by ribs 12k substantially orthogonal to the pressing surfaces 12h and 12i. Thereby, the rigidity of the annular surface for pressing the dustproof member 19 exhibited by the pressing surfaces 12h and 12i and the connecting surface 12j is enhanced. Also in this case, distortion of the prism 12 due to the repulsive force of the dustproof member 19 is unlikely to occur.

  As shown in FIG. 4C, the first pressing surface 12h is closer to the exit surface 12d than the entrance surface 12c between the entrance surface 12c and the exit surface 12d in the direction orthogonal to the mounting surface 12g. Located in As a result, the arrangement of the display devices 11 can be made closer to the emission surface 12 d, and the enlargement of the unit itself can be avoided. It is also advantageous to secure the incident area and the display area. From these viewpoints, it is desirable that the first pressing surface 12h be disposed as close as possible to the exit surface 12d between the entrance surface 12c and the exit surface 12d in the direction orthogonal to the mounting surface 12g.

  The second pressing surface 12i is located closer to the second reflecting surface 12f than the first reflecting surface 12e between the first reflecting surface 12e and the second reflecting surface 12f. Thereby, the area | region of the 1st reflective surface 12e and the 2nd reflective surface 12f can be used effectively to the maximum. From this point of view, it is desirable that the second pressing surface 12i be disposed as close as possible to the second reflecting surface 12f between the first reflecting surface 12e and the second reflecting surface 12f.

  According to the present embodiment, the mounting surface 12g is fixed to the pentaholder 18 with the dustproof member 19 interposed between the pressing surfaces 12h and 12i of the prism 12 and the affixing surface 18 of the pentaholder 18 due to elastic deformation. Ru. The pressing surfaces 12h and 12i are substantially parallel to the mounting surface 12g, and the distances in the direction orthogonal to the mounting surface 12g are different from each other. As a result, it is possible to provide a dustproof function as well as a structure in which distortion of the prism 12 is less likely to occur. In particular, the dustproof member 19 is formed in an annular shape corresponding to the annular shape exhibited by the pressing surfaces 12h and 12i and the connecting surface 12j, and since the space between the pentaholder 18 and the prism 12 is sealed, a reliable dustproof function can be achieved. .

  Further, since the pressing surfaces 12h and 12i and the connecting surface 12j are connected to the mounting surface 12g by the ribs 12k substantially orthogonal to these, reinforcement of the pressing surfaces 12h and 12i and the connecting surface 12j is intended to enhance rigidity. , Contributes to suppression of distortion of the prism 12.

  Further, since the prism 12 and the pentaholder 18 are fastened by the screws 20, it is easy to disassemble both afterward. An adhesive was provided on one side of the dustproof member 19. However, since the dustproof member 19 is compressed and held by the fastening force of the screw 20, it is not essential to provide an adhesive.

  In addition, since the dustproof member 19 which is a separate member from the prism 12 and the pentaholder 18 is interposed between the prism 12 and the pentaholder 18 for the purpose of dustproofing, the improvement of the assemblability by the elimination of the post-process such as silicon coating can be expected. Here, from the viewpoint of the dustproof function, the dustproof member 19 is only required to have an elastic force and be able to be minutely deformed to fill the gap, for example, a urethane foam having a fine cell structure, or a foam It is desirable to be composed of a double-sided tape or the like of the substrate.

  In the present embodiment, the dustproof member 19 is configured as an independent part separate from the prism 12 and the penta holder 18, but may be integrated with either the prism 12 or the penta holder 18. For example, a foam material may be applied to the pressing surfaces 12 h and 12 i and the connecting surface 12 j or the mounting surface 12 g. Alternatively, an elastic member such as an elastomer may be integrally molded with the prism 12 or the pentaholder 18 by two-color molding.

  Although the present invention has been described in detail based on its preferred embodiments, the present invention is not limited to these specific embodiments, and various embodiments within the scope of the present invention are also included in the present invention. included.

11 Device for displaying information in the finder 12 Optical path bending prism 12c Incident surface 12d Emitting surface 12g Mounting surface 12h First pressing surface 12i Second pressing surface 18 Penta holder 19 Dustproof member

Claims (7)

A display unit that emits display light for displaying information;
An incident surface on which the display light emitted by the display unit is incident, at least two reflecting surfaces for reflecting the light incident on the incident surface, an emitting surface for emitting the light reflected by the at least two reflecting surfaces, and a mounting surface A prism having
And a holding member for holding the prism.
The prism dustproof structure of an optical device in which the prism is held by the holding member by fixing the mounting surface of the prism to the holding member,
The prism has a first surface and a second surface which are two planes which are substantially parallel to the mounting surface and different in distance in a direction orthogonal to the mounting surface, separately from the mounting surface,
The mounting surface is fixed to the holding member in a state in which an elastic member is elastically deformed and interposed between the first surface and the second surface of the prism and the holding member. Dustproof structure of optical equipment to be used. The prism has a connecting surface which is connected to the first surface and the second surface to connect the two, and has an annular shape on the first surface, the second surface and the connecting surface.
The elastic member has an annular shape corresponding to an annular shape exhibited by the first surface, the second surface, and the connecting surface.
The elastic member is interposed between the first surface and the second surface and the holding member, so that the space between the holding member and the prism is sealed. The prismatic dustproof structure of the described optical instrument.   The first surface is located closer to the exit surface than the incident surface between the incident surface and the exit surface in a direction orthogonal to the attachment surface. Or the prism dust-proof structure of the optical instrument as described in 2. The at least two reflective surfaces include a first reflective surface that reflects light incident on the incident surface, and a second reflective surface that reflects light reflected by the first reflective surface and guides the light to the exit surface. And contains
The second surface is located closer to the second reflective surface than the first reflective surface between the first reflective surface and the second reflective surface. The prism dustproof structure of the optical instrument as described in any one of claim | item 1 -3.   The first surface and the second surface are connected to the mounting surface by ribs substantially orthogonal to the first surface and the second surface. The prism dustproof structure of the optical instrument according to any one of 4.   The first surface, the second surface, and the connecting surface are connected to the mounting surface by ribs substantially orthogonal to the first surface and the second surface. The prism dustproof structure of the optical instrument according to claim 2. The elastic member is compressed and held between the first surface and the second surface and the holding member by a fastening force in which the mounting surface is fastened to the holding member. The prism dustproof structure of the optical instrument as described in any one of 1-6.