JP2013076844A - Photographic lens unit for endoscope and camera module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To review dimensional accuracy of each component of a photographic lens unit for an endoscope and to improve a product yield.SOLUTION: A first lens movable frame 26 and a second lens movable frame 27 are engaged with a cam shaft 25, and first and second movable lenses 22 and 23 are individually moved in an optical axis direction by rotation of the cam shaft 25. A sliding guide surface 35a of a coupling hole is set to a metal processing surface. The cam shaft 25, the first and second lens movable frames 26 and 27, antireflection cylinders 36 and 37, lens frames 21a and 24a are subjected to black dye processing, and black layers 39 are formed on surfaces thereof. An inside of the minute coupling hole is not subjected to the black dye processing, and unevenness of the sliding guide surface 35a due to the black dye processing is eliminated. Even when sliding surfaces of the first and second lens movable frames 26 and 27 are subjected to the black dye processing, the sliding surfaces are outside surfaces, and, accordingly, dimensional accuracy thereof is maintained. The dimensional accuracy of both sliding surfaces is maintained. On account of this, smooth movement of the first and second movable lenses 22 and 23 can be also performed by wire drive, and, in addition, a product yield is improved.

Description

  The present invention relates to an endoscope photographing lens unit and a camera module.

  In the medical field, many diagnoses and treatments using an electronic endoscope are performed. The electronic endoscope includes a camera module at the distal end of the insertion portion, and can capture image light in the patient's body and display it on a monitor or the like.

  Some camera modules have a mechanism for changing the focal length of a photographing lens and can switch the focal length between normal observation and magnified observation (see, for example, Patent Documents 1 and 2). In such a camera module, the photographing lens unit and the camera unit are integrated. The taking lens unit has a drive unit for moving a part of the taking lens in the optical axis direction to change the focal length.

  The drive unit electrically controls a drive unit having a shape memory alloy as in Patent Document 2 or a cam shaft drive type in which the lens moving frame is displaced in the optical axis direction by rotational displacement of the cam shaft as in Patent Document 1. Accordingly, there is a direct drive type in which the lens moving frame is displaced in the optical axis direction. However, in the case of the direct drive type, the lens to be moved is limited to one, unlike the cam shaft type. On the other hand, the cam shaft type has an advantage that a plurality of lenses can be moved simultaneously by increasing the cam groove and the lens moving frame engaged therewith.

JP 2002-58635 A JP 2009-294540 A

  Regardless of which drive method is adopted, when manufacturing a small camera module having an outer diameter (vertical x horizontal x length) of about 7 mm x 4 mm x 15 mm, for example, the dimensional accuracy of each component is a problem. It becomes. In particular, in the cam shaft type, the lens moving frame slides in the direction of the photographing optical axis in the housing along the two cylindrical centers, so that the dimensional accuracy of the sliding portion becomes a problem. For example, if the gap between the lens moving frame and the sliding guide surface of the housing is small, the operability is lowered and the movement becomes worse. If a motor that transmits torque to the camshaft is at the distal end of the insertion section, the torque is sufficiently transmitted to the camshaft, and even if the gap with a little tight fitting accuracy is small, it does not matter so much. However, in the endoscope camera module, it is difficult to arrange a motor for rotating the cam shaft at the distal end of the insertion portion in response to a request for reducing the diameter of the endoscope insertion portion in consideration of the burden on the patient. Therefore, if a motor or the like is disposed in the hand control unit and torque is transmitted to the camshaft by a wire, sufficient torque cannot be transmitted to the camshaft, so the gap between the lens moving frame and the sliding guide surface If is small, there is a problem that the lens moving frame cannot be moved.

  On the other hand, if the gap between the lens moving frame and the sliding guide surface is increased in order to improve operability and ease of movement, the movable lens will shake during operation and image blurring may occur during zoom operation. Will occur. When the blur increases, the movement is performed in an inclined state, and driving with low torque becomes difficult. In the worst case, the lens moving frame cannot be moved.

  In the camshaft system, a camshaft is provided in parallel with the photographic optical axis, and a lens moving frame needs to be engaged with the camshaft. The lens moving frame extends over the camshaft and the photographic optical axis. Be placed. The housing that holds the lens moving frame movably increases the sliding guide area where the lens moving frame contacts the inner surface of the housing, and the processing accuracy of the sliding guide surface must be maintained within the design value range. There is. However, for example, two cylindrical bodies of approximately 4 mmφ and 3.2 mmφ are arranged side by side in the horizontal direction and connected to a small housing having a length of about 15 mm, the taking lens storage hole and the camshaft storage In addition to the holes, it is necessary to cut out the gap between them, for example, to form a sliding space having an entrance opening height of 1 mm, an opening width of 1.5 mm, and a depth of less than 10 mm. Moreover, the sliding guide surface of the sliding space and the sliding surface of the lens moving frame have an area of, for example, a width (height) of 1 mm and a depth of 10 mm, and the flatness requires a dimensional accuracy of about ± 3 μm. Become. The dimensional accuracy of ± 3 μm is the limit accuracy that can be processed by normal cutting. For this reason, the finished housing and the lens moving frame are individually measured, a combination with a fitting accuracy within a predetermined range is found, and these are assembled and used. This was the cause of a decrease in (the number of products that passed completion / the total amount of manufactured products).

  In order to improve product yield, we reviewed the fitting accuracy and reviewed the processing accuracy of each part. As a result, each part was black-dyed to prevent flare, resulting in variations in processing accuracy. Turned out to be.

  The present invention has been made in view of the above problems, and can maintain the dimensional accuracy of each component with high accuracy, and can smoothly slide the movable lens of the photographic lens unit for an endoscope. It is an object to provide an imaging lens unit for an endoscope and a camera module that can also improve a yield rate.

  To achieve the above object, the present invention provides a photographic lens having a movable lens that is movable in the optical axis direction, a lens moving frame that holds the movable lens and moves it in the optical axis direction, and the photographic lens. A cam shaft provided in parallel to the optical axis and engaged with the lens moving frame, a photographing lens housing hole for housing the photographing lens, a cam shaft housing hole for housing the cam shaft, and connecting these housing holes, A housing having a sliding connection hole having a pair of sliding guide surfaces for slidingly guiding the lens moving frame when the lens moving frame is moved, and a black processed surface in which the surface of the lens moving frame is blackened; The sliding guide surface has a cut surface obtained by cutting.

  In addition, it is preferable that the said cam shaft has a wire connection part at one end, and is rotated by the wire connected via this wire connection part. The photographing lens includes a first fixed lens, a first movable lens, a second movable lens, and a second fixed lens that are sequentially arranged in the optical axis direction, and the lens moving frame holds the first movable lens. Each of the first lens moving frame and the second lens moving frame for holding the second movable lens. The cam shaft has first and second cam grooves, and the first cam groove has a first It is preferable that one lens moving frame is engaged and the second lens moving frame is engaged with the second cam groove. The housing is preferably black-dyed by masking the cut surface.

  The photographing lens housing hole is formed in a cylindrical shape having a slit in the optical axis direction through which the lens moving frame passes between the first fixed lens and the second fixed lens, and the surface is blackened. It is preferable to have an antireflection cylinder. The photographing lens housing hole is formed in a cylindrical shape having a slit in the optical axis direction through which the lens moving frame passes between the first fixed lens and the second fixed lens, and the surface thereof is blackened. A first anti-reflection cylinder and a second anti-reflection cylinder being processed, the first anti-reflection cylinder having an aperture plate at an end on the second anti-reflection cylinder side, and a lens of the first lens moving frame; Preferably, the second antireflection cylinder is disposed so as to surround the holding portion, and is disposed so as to surround the lens holding portion of the second lens moving frame.

  An endoscope camera module according to the present invention includes the above-described photographing lens unit and an imaging element unit, and the imaging element unit includes a prism holder that is fitted on the outer periphery of a housing near the photographing lens storage hole, and the prism holding A prism held by the fixture, an image sensor that receives light reflected from the photographic lens by the prism, a signal cable connected to the image sensor, and a protection tube of the signal cable and the prism holder It is preferable to include a cable reinforcing plate.

  According to the present invention, the surface of the lens moving frame among the sliding guide surface of the sliding connection hole formed in the housing and the sliding surface of the lens moving frame that is moved and guided in contact with the sliding guide surface. Is a black machined surface that has been black-dyed, and the sliding guide surface of the sliding connection hole is a machined machined surface. Since the inner surface is not black-dyed, the dimensional accuracy during cutting is maintained. Further, the sliding surface of the lens moving frame is a surface located on the outer side, and is formed with a substantially uniform thickness even when blackening is performed, so that the dimensional accuracy is kept constant. Moreover, since the lens moving frame is a black processed surface, the occurrence of flare can be suppressed. In addition, dimensional accuracy can be maintained, and the movable lens can be smoothly moved in the optical axis direction by rotation of the cam shaft.

It is a perspective view which decomposes | disassembles and shows the photographic lens unit of this invention. It is the perspective view which looked at the housing from front diagonally. It is sectional drawing which decomposes | disassembles and shows a photographic lens unit. It is principal part sectional drawing of the camera module of a standard position. It is principal part sectional drawing of the camera module of an expansion position. It is a table | surface which shows the difference and effect of a structure with each embodiment of this invention, and a prior art example. It is a perspective view which decomposes | disassembles and shows the camera module of this invention. It is a perspective view which shows the external appearance of the whole camera module. It is a perspective view which shows the structure of an electronic endoscope system. It is a perspective view which shows the front-end | tip part of an electronic endoscope.

  As shown in FIGS. 1 to 3, the photographing lens unit 11 of the present invention includes a housing 13, a photographing lens 14 housed in the housing 13, and a lens moving unit 15.

  The photographing lens 14 is configured by sequentially arranging a first fixed lens 21, a first movable lens 22, a second movable lens 23, and a second fixed lens 24 in the optical axis direction. Each of the fixed lenses 21 and 24 and each of the movable lenses 22 and 23 includes a lens frame 21a to 24a and one or a plurality of lens bodies 21b to 24b held by the lens frames 21a to 24a.

  The lens moving unit 15 includes a cam shaft 25, and a first lens moving frame 26 and a second lens moving frame 27 that slide on the cam shaft 25. The lens moving unit 15 moves the movable lenses 22 and 23 in the optical axis direction and changes the focal length of the photographing lens 14 to enable variable magnification photographing.

  The housing 13 is configured by arranging the first cylinder part 30 and the second cylinder part 31 in a direction orthogonal to the cylinder center direction and connecting them with a connecting part 32. As shown in FIG. 2, the outer diameter of the second cylindrical portion 31 is slightly smaller than the outer diameter of the first cylindrical portion 30, and has an 8-shape when viewed from the front. A photographing lens storage hole 33 is formed in the first tube portion 30, and the photographing lens 14 is stored in the hole 33. A lens moving part storage hole 34 is formed in the second cylinder part 31 to store the lens moving part 15. As shown in FIG. 3, a locking ring 34 a projects from the lens moving part storage hole 34. Further, a sliding hole 35 for connecting the taking lens storage hole 33 and the lens moving part storage hole 34 is formed in the connection part 32.

  As shown in FIGS. 1 and 3, the cam shaft 25 has two cam grooves 25a and 25b on the outer peripheral surface, and is engaged with the wire connecting hole 25c along the axis at the rear end and on the outer peripheral surface of the rear end portion. It has a flange 25d. As shown in FIG. 4, the tip end of the wire 18 for rotational driving is fixed in the wire connecting hole 25c. The wire 18 is put in the protective tube 19 and connected to a motor 80 (see FIG. 9) in the hand operating section 67. The motor 80 is driven and controlled by a controller (not shown) so as to rotate forward or reverse by operation of the seesaw switch 79 of the hand operation unit 67.

  As shown in FIGS. 1 and 3, a fixing ring 29 is attached to the tip of the cam shaft 25. As shown in FIG. 4, the fixing ring 29 allows the cam shaft 25 to rotate smoothly without tilting in the lens moving portion accommodation hole 34. Further, since the locking flange 25d on the rear end side of the cam shaft 25 is locked to the locking ring 34a, the cam shaft 25 does not come out of the lens moving part storage hole 34.

  As shown in FIGS. 1 and 3, the first lens moving frame 26 includes a guide tube 26a, a lens frame 22a, and an arm 26b that connects them, and these are integrally formed. Similarly, the second lens moving frame 27 has a guide tube 27a, a lens frame 23a, and an arm 27b, and is integrally formed. A first engagement pin 28a is attached to the guide tube 26a of the first lens moving frame 26, and the tip of the engagement pin 28a enters the first cam groove 25a. An engagement pin 28b is attached to the guide tube 27a of the second lens moving frame 27, and the second engagement pin 28b enters the second cam groove 25b.

  When the camshaft 25 is rotated forward or reversely by the motor 80 (see FIG. 9), the camshaft 25 is rotationally displaced in accordance with the amount of rotation, and the rotational displacement causes the first and second via the engagement pins 28a and 28b. The second lens moving frames 26 and 27 move in the optical axis direction within the housing 13.

  4 and 5 illustrate switching of the focal length of the photographing lens. FIG. 4 shows a standard position and FIG. 5 shows an enlarged position. In the enlarged position, the first lens moving frame 26 moves to the front side from the standard position, and the second lens moving frame 27 moves to the rear side from the standard position.

  In the present embodiment, the arms 26b and 27b of the first and second lens moving frames 26 and 27 are moved so that the first and second lens moving frames 26 and 27 move smoothly in the optical axis direction by the rotation of the cam shaft 25. These parts are measured and combined in a gap of 3 ± 3 μm so that the gap when fitting the thickness t1 of the sliding hole and the distance L1 between the sliding guide surfaces of the sliding holes is, for example, 3 ± 3 μm. And use these as a set.

  As shown in FIG. 3, the photographing lens storage hole 33 has a first storage portion 33 a for storing the first fixed lens 21 and the first movable lens 22 in order from the front end to the rear end of the housing 13, and a second movable lens. A second storage portion 33b for storing the second storage lens 23 and a third storage portion 33c for storing the second fixed lens 24 are formed. A ring protrusion 33d serving as a partition is formed between the second storage portion 33b and the third storage portion 33c. The second storage portion 33b is formed slightly smaller than the inner diameter of the first storage portion 33a, and the second storage portion 33b and the third storage portion 33c are formed with the same inner diameter.

  A second antireflection cylinder 37 is accommodated in the second accommodating portion 33b. The second antireflection cylinder 37 is formed in a cylindrical shape, and has a slit 37a in the optical axis direction. The arm 27b of the second lens moving frame 27 enters the slit 37a, and the lens frame 23a of the second lens moving frame 27 enters the cylinder. The cylinder inner diameter is formed slightly larger than the outer diameter of the lens frame 23a, and the lens frame 23a does not contact the inner peripheral surface of the cylinder portion when the lens frame 23a moves in the cylinder portion.

  The first antireflection cylinder 36 is stored in the first storage portion 33a. The first antireflection tube 36 is also formed in the same manner as the second antireflection tube 37, and has a slit 36a. The difference from the second antireflection cylinder 37 is that a diaphragm plate 38 is integrally formed at the rear end. The rear end surface of the first antireflection tube 36 is locked by the step surface 33e between the first storage portion 33a and the second storage portion 33b, and is positioned when stored. In the first antireflection cylinder 36, the lens frame 22a of the first lens moving frame 26 moves.

  As shown in FIG. 6, in the first embodiment, in order to prevent the occurrence of flare, the first lens movement integrally including the lens frame 21a of the first fixed lens 21 and the lens frame 22a of the first movable lens 22 is integrated. The frame 26, the second lens moving frame 27 having the lens frame 23 a of the second movable lens 23, the lens frame 24 a of the second fixed lens 24, and the cam shaft 25 are black-dyed, and a black layer 39 is formed on the surface thereof. Is formed. Since these parts are basically cylindrical with both ends open and the appearance is not complicated, the black layer 39 is formed almost uniformly even after black processing. Is almost maintained. Any of the known methods may be used for the black dyeing process. For example, the black layer 39 is formed by chemical treatment using a black dyeing treatment liquid. In FIG. 3, hatching is added to illustrate the black layer 39 formed on the inner peripheral surfaces of the antireflection cylinders 36 and 37. The other black-treated parts 21a, 26, 27, and 24a also have a black layer 39 on the surface, but since they appear as a slightly thick cross-section, they are not shown with thickness. Further, since the cam shaft 25 is located in a portion far from the optical path, the black dyeing process may be omitted.

  On the other hand, the housing 13 has a complicated shape in which two cylindrical portions 30 and 31 are connected side by side, and a bag-like sliding hole 35 is formed inside the connecting portion 32, and the outer diameter is small. It is a minute part of about 7 mm x 4 mm x 15 mm. Therefore, when the black dyeing process is performed, the inner surface of the housing 13, particularly the sliding guide surfaces 35 a on both sides of the sliding hole 35, do not smoothly circulate the processing liquid and the like during the black dyeing process. The layer 39 is not formed, or even if it is formed, the layer 39 is slightly formed, or on the contrary, the layer 39 is formed thick, so that the thickness of the entire sliding guide surface 35a becomes non-uniform. Therefore, even if dimensional accuracy is obtained by cutting, variation in dimensional accuracy is caused by this black processing. Due to this variation in dimensional accuracy, there is a problem that the number of pairs created by combining those whose processing accuracy is within a certain range is reduced, resulting in a decrease in product yield.

  For this reason, in the first embodiment, the housing 13 is assembled in the state of the cut surface without blackening. In the conventional case, since the inner surface of the housing 13 is also black-dyed, the dimension between the first and second lens moving frames 26 and 27 and the sliding guide surface 35a that holds and slides these frames. It was difficult to obtain accuracy. In the first embodiment, the sliding guide surface 35a (hatched portion) of one housing 13 is in a state of a cutting surface, and the other lens moving frames 26 and 27 are easily subjected to the outside black dyeing process. The black layer 39 is formed almost uniformly. In this way, since the dimensional accuracy of both is maintained, the first and second lens moving frames 26 and 27 can smoothly slide on the sliding guide surface 35 a, and the cam shaft is connected by the connection of the wire 18. Even when the rotation is applied with a low torque as in the case of the 25 rotational drive, the lens moving frames 26 and 27 can be reliably moved in the optical axis direction. Moreover, since the blackening process is not performed on the housing 13 itself, the processing accuracy of the housing 13 is maintained accordingly, so that the number of sets within the acceptable range can be increased, and the product yield rate is lowered. There is no.

  In the first embodiment, the housing 13 is not black-dyed, and the sliding guide surface is used as a cutting surface to maintain the accuracy of the finished dimensions. As in the second embodiment, the housing 13 may also be black dyed. In this case, for example, a rubber masking member (not shown) that fits into the sliding hole 35 is disposed, for example, so that the black dyeing liquid does not contact the sliding guide surface 35a. The processing accuracy of the moving guide surface 35a is maintained. The sliding hole 35 may be masked by any method that can mask the sliding guide surface 35a, or may be masked by other methods. In this case, since the black layer is also formed on the housing 13, the antireflection cylinders 36 and 37 are not necessary, and the configuration is simplified and the assembly is facilitated.

  Further, instead of masking the sliding guide surface 35a of the housing 13 and performing black dyeing processing, the housing 13 is subjected to black dyeing processing without masking as in the third embodiment shown in FIG. The sliding guide surface 35a requiring dimensional accuracy may be cut again. In this case, although the re-cutting process is increased, it can be finished by cutting, so that it can be finished with high accuracy and the product yield rate can be improved in the same manner as described above, and the movable lenses 22 and 23 can be reliably secured with low torque. Can be moved.

  FIG. 6 is a table comparing the first to third embodiments and the conventional example. In both the first to third embodiments, the yield rate was improved as compared with the conventional one. In addition, the lens can be moved smoothly by the rotation transmission by the wire, while the conventional one does not move smoothly.

  As shown in FIG. 3, the second cylindrical portion 31 is formed longer than the first cylindrical portion 30 in order to accommodate the cam shaft 25. The leading ends of the second cylindrical portions 31 are aligned with each other, and the rear ends of the second cylindrical portions 31 are formed so as to protrude rearward from the rear ends of the first cylindrical portions 30. A space is generated on the rear end side of the first cylindrical portion 30 due to the step difference between the two cylindrical portions 30 and 31. Using this space, as shown in FIG. 7, a CCD unit (imaging device unit) 12 is attached to the photographing lens unit 11 to constitute a camera module 10.

  For this reason, the rear half 30a of the outer peripheral surface of the first cylindrical portion 30 of the housing 13 is formed to have a slightly smaller outer diameter than the front half 30b of the outer peripheral surface, and between the front half 30b and the rear half 30a. A step surface 30c is formed. An attachment cylinder portion 40a of the prism holder 40 of the CCD unit 12 is externally fitted and attached to the rear half 30a of the outer peripheral surface. Thus, by arranging the prism 41 in the space on the rear end side of the first tube portion 30, the camera module 10 can be configured compactly as a whole.

  The CCD unit 12 includes a prism holder 40, a prism 41, a CCD (CCD type image sensor) 42, a circuit board 43, a transmission cable 44, a cable connector 45, and a sealing agent (not shown) for sealing wiring. Have The hole 48 formed in the housing 13 is for injecting adhesive and inserting screws when the antireflection tubes 36 and 37 and the second fixed lens 24 are fixed in the photographing lens storage hole 33. Provided as needed.

  The prism holder 40 includes a mounting cylinder portion 40a and a prism mounting frame 40b. As shown in FIG. 5, the prism 41 is composed of a right-angle prism having five surfaces, that is, an incident surface 41a and an output surface 41b intersecting at right angles, a reflecting surface 41c formed of an inclined surface, and both side surfaces 41d. The prism mounting frame 40b has an opening 40c through which incident light from the photographic lens 14 passes, and first and second prism mounting position restricting pieces 40d and 40e (see FIGS. 4 and 8) on the rear end surface. As shown in FIG. 8, the first position restricting piece 40d abuts on the side surface 41d of the prism 41, and the second position restricting piece 40e abuts on a ridge line 41f where the incident surface 41a and the exit surface 41b are orthogonal to each other. The prism 41 can be positioned on the prism mounting frame 40b by the side surface 41d and the ridge line 41f of the prism 41 coming into contact with the two position restricting pieces 40d and 40e.

  A CCD 42 is attached to the emission surface 41 b of the prism 41, and a circuit board 43 for driving the CCD 42 is attached to the slope of the prism 41 with an adhesive. The CCD 42 and the circuit board 43 are connected to a connection or a flexible wiring circuit board. The connection of the transmission cable 44 is connected to the circuit board 43. The transmission cable 44 is formed by covering a signal line with a shield line, and the shield line is covered with a covering cord. The circuit board 43 may be divided and arranged at an appropriate position.

  One end of the cable connector 45 is fixed to the covering cord of the transmission cable 44 with an adhesive. Further, the other end of the cable connector 45 is formed with a locking claw 45a bent, and this locking claw 45a is locked in a locking hole 47 formed in the second position regulating piece 40e. In order to protect the cable connector 45, the connection covered by the CCD 42, and the circuit board 43, a sealing agent (not shown) is injected into these gaps as necessary and solidified. The cable connector 45 may have a frame shape in addition to the plate shape.

  The camera module 10 configured as described above is attached to the distal end portion of the endoscope 60 as shown in FIG. The electronic endoscope system 59 includes an electronic endoscope 60, a processor device 61, and a light source device 62. The electronic endoscope 60 includes a flexible insertion portion 66 that is inserted into a body cavity of a patient, a hand operation portion 67 that is connected to a proximal end portion of the insertion portion 66, a processor device 61, and a light source device 62. It has a connector 69a to be connected, a hand operating section 67, and a universal cord 69 that connects the connectors 69a.

  The insertion portion 66 includes a distal end portion 66a, a bending portion 66b, and a flexible portion 66c in order from the distal end. The tip portion 66a is configured by covering a tip portion body made of a hard resin with a tip cap made of a soft resin, and covering the tip portion body and a metal tip tube of the curved portion 66b following the tip portion body with a tube. The curved portion 66b has a unit in which each node ring is pin-coupled, and the whole is curved. The bending portion 66b is bent at an arbitrary angle in the vertical and horizontal directions by the rotation operation of the angle knob 70 of the hand operation portion 67. Thereby, the observation part in a body cavity can be imaged with the camera module 10 with the front-end | tip part 66a facing the desired direction in a body cavity. The soft portion 66c is a portion that connects the hand operating portion 67 and the bending portion 66b in a narrow shape with a long diameter, and has flexibility.

  As shown in FIG. 10, in addition to the forceps outlet 72, an observation window 73, illumination windows 74a and 74b, and an air / water supply nozzle 75 are provided on the distal end surface of the distal end portion 66a. In addition, a water jet outlet and other nozzles are provided as necessary.

  The hand operation unit 67 includes various operation members such as an angle knob 70, an air / water supply button 76, a suction button 77, a release button 78, and a seesaw switch 79 for zoom operation. The angle knob 70 bends the distal end portion 66a of the insertion portion 66 in the vertical and horizontal directions by a rotation operation. The air / water supply button 76 ejects air or water from the air / water supply nozzle 75 by a pressing operation. The suction button 77 sucks a suction target such as a liquid or tissue in the body from the forceps outlet 72 by a pressing operation. The release button 78 records an observation image as a still image by the camera module 10 by a pressing operation. The seesaw switch 79 rotates the motor 80 forward or backward and transmits this rotation to the camshaft 25 via the wire 18 to switch the photographing lens 14 between standard and magnified photographing.

  The processor device 61 is electrically connected to the light source device 62 and comprehensively controls the operation of the electronic endoscope system 59. The processor device 61 supplies power to the electronic endoscope 60 through the universal cord 69 and the transmission cable 44 inserted into the insertion portion 66, and controls the driving of the camera module 10 at the distal end portion 66a. Further, the processor device 61 receives a signal from the camera module 10 via the transmission cable 44 and performs various processes to generate image data. A monitor 81 is connected to the processor device 61. The monitor 81 displays an observation image based on the image data from the processor device 61.

  In the above-described embodiment, an example in which two movable lenses 22 and 23 are used as the photographing lens unit 11 has been described. Further, the present invention may be applied to a case where the lens frame is moved by focusing control in addition to the scaling process. In addition, although the cam shaft 25 is driven to rotate by the wire 18, in the case of a type in which a motor may be housed at the distal end of the insertion portion, the cam shaft 25 may be directly driven by the motor instead of the wire drive. Further, although an example using a CCD as an image sensor has been described, a CMOS image sensor may be used as the image sensor. Moreover, although the said embodiment demonstrated the example which applies this invention to a medical endoscope, you may apply this invention to an industrial endoscope.

DESCRIPTION OF SYMBOLS 10 Camera module 11 Shooting lens unit 12 CCD unit 13 Housing 14 Shooting lens 15 Lens moving part 21 First fixed lens 22 First movable lens 23 Second movable lens 24 Second fixed lens 25 Cam shaft 26 First lens moving frame 27 First Two-lens moving frames 28a, 28b Engaging pins 30, 31 Tube portion 32 Connecting portion 35 Slide hole 35a Slide guide surface 37, 38 Antireflection tube 39 Black layer 40 Prism holder 41 Prism 42 CCD (CCD type image sensor)
44 Transmission cable 45 Cable connector 59 Electronic endoscope system 60 Endoscope 66 Insertion section 67 Hand operation section

Claims (7)

A photographic lens having a movable lens movable in the direction of the optical axis;
A lens moving frame that holds the movable lens and moves it in the optical axis direction;
A cam shaft provided parallel to the optical axis of the photographing lens and engaged with the lens moving frame;
A pair of slides for slidingly guiding the lens moving frame when the lens moving frame is moved by connecting the receiving hole, a shooting lens storing hole for storing the shooting lens, a cam shaft receiving hole for storing the cam shaft, A housing with a sliding connection hole having a guide surface;
A black processed surface in which the surface of the lens moving frame is black-dyed;
An endoscope photographing lens unit, wherein the sliding guide surface has a cut surface obtained by cutting.   2. The photographic lens unit for an endoscope according to claim 1, wherein the cam shaft has a wire connecting portion at one end and is rotated by a wire connected through the wire connecting portion. The photographing lens has a first fixed lens, a first movable lens, a second movable lens, and a second fixed lens arranged in this order in the optical axis direction,
The lens moving frame individually has a first lens moving frame that holds the first movable lens and a second lens moving frame that holds the second movable lens,
The cam shaft has first and second cam grooves, and a first lens moving frame is engaged with the first cam groove, and a second lens moving frame is engaged with the second cam groove. The photographic lens unit for an endoscope according to claim 1 or 2.   The imaging lens unit for an endoscope according to any one of claims 1 to 3, wherein the housing has a surface that is blackened by masking the cut surface.   The photographing lens housing hole is formed in a cylindrical shape having a slit in the optical axis direction through which the lens moving frame passes between the first fixed lens and the second fixed lens, and the surface is blackened. The photographic lens unit for an endoscope according to any one of claims 1 to 3, further comprising an antireflection tube. The photographing lens housing hole is formed in a cylindrical shape having a slit in the optical axis direction through which the lens moving frame passes between the first fixed lens and the second fixed lens, and the surface is blackened. A first antireflection tube and a second antireflection tube,
The first antireflection cylinder has a diaphragm plate at an end on the second antireflection cylinder side, and is arranged so as to surround the lens holding portion of the first lens moving frame,
4. The photographic lens unit for an endoscope according to claim 1, wherein the second antireflection tube is disposed so as to surround a lens holding portion of the second lens moving frame. 5. An imaging lens unit for an endoscope according to any one of claims 1 to 6,
A prism holder externally fitted to the outer periphery of the housing near the photographing lens storage hole;
A prism held by the prism holder,
An image sensor for receiving light reflected from the prism by the prism;
A signal cable connected to the imaging unit;
An endoscope camera module, comprising: an imaging element unit including a cable reinforcing plate that connects a protective tube of the signal cable and the prism holder.

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