Camera head

Abstract

To provide a small diameter camera head that can be used in applications, such as endoscopes, to allow access through smaller diameter orifices.SOLUTION: A video camera head comprises at least two rigid printed circuit boards (PCBs) arranged in parallel planes. The at least two PCBs are mechanically supported one above the other by pins made of an electricity conducting material. The pins conduct electrical power from the bottom PCB to electronic components or illumination means mounted on the other PCBs, and conduct, to the bottom PCB, signals from a solid-state sensor chip mounted on one of the other PCBs of the at least two PCBs.SELECTED DRAWING: Figure 1

Description

Technical Field

[0007] ,

[0001] The present invention relates to the field of video cameras. Specifically, the present invention relates to a small-diameter camera head for use in applications such as medical endoscopes, laparoscopes, and industrial endoscopes.

Background Art

[0002] Since the first use of medical endoscopes, laparoscopes, and industrial endoscopes, reducing the diameter of these instruments in order to be able to access through ever smaller diameter openings has continued to be a goal of instrument designers.

[0003] A method of achieving diameter reduction is described, for example, in Patent Document 1, in which the applicant of the present invention describes a camera head having an outer diameter of 1.4 mm or less.

[0004] Two of the obstacles in further reducing the diameter are generally the flexible PCB substrate to which the sensor and other components of the camera head are attached, and the internal wiring for electrically connecting various electronic components. A third obstacle associated with small-diameter camera heads such as those described in Patent Document 1 is that assembly (especially connection of internal wiring) is difficult and not suitable for mass production.

[0005] The fourth obstacle is related to the need to incorporate lighting into the above-described device and the difficulty of transmitting a sufficient amount of current while maintaining the extremely small dimensions of the camera-illumination assembly.

Prior Art Documents

Patent Documents

[0008] Further objectives and advantages of the present invention will become apparent as you continue reading the description. [Means for solving the problem]

[0009] In a first embodiment, the present invention is a video camera head comprising at least two rigid printed circuit boards (PCBs) arranged in parallel planes. These PCBs are mechanically supported vertically by pins made of a conductive material. The pins transmit power from the lower PCB to electronic components and / or lighting means mounted on another PCB of the at least two PCBs, and transmit signals from a sensor chip mounted on one of the other PCBs to the lower PCB.

[0010] In embodiments of the video camera head of the present invention, the illumination means comprises at least one LED (e.g., an annular array of LEDs).

[0011] An embodiment of the video camera head of the present invention includes an objective optical system.

[0012] In an embodiment of the video camera head of the present invention, three PCBs are provided, with a component that receives signals from a solid-state sensor and outputs video signals mounted on the lower PCB, a solid-state sensor chip mounted on the middle PCB, and an objective optical system and illumination means mounted on the upper PCB. Pins made of conductive material (a) mechanically support the middle PCB and upper PCB above the lower PCB, (b) transmit power from the lower PCB to the middle PCB and upper PCB, and (c) transmit signals from the sensor chip on the middle PCB to the lower PCB.

[0013] In an embodiment of the video camera head of the present invention, the head comprises two PCBs. An electronic component that receives signals from a solid-state sensor and outputs video signals is mounted on the lower surface of the lower PCB, a solid-state sensor chip is mounted on the upper surface of the lower PCB, and an objective optical system and illumination means are mounted on the upper PCB. Pins made of conductive material mechanically support the upper PCB above the lower PCB and transmit power from the lower PCB to the upper PCB. Through-vias are provided to transmit power from the lower surface to the upper surface of the lower PCB and to transmit signals from the sensor chip on the upper surface to the lower surface of the lower PCB.

[0014] In an embodiment of the video camera head of the present invention, four PCBs are provided, with electronic components that receive signals from a solid-state sensor and output video signals mounted on the first (lower) PCB and the second PCB, a solid-state sensor chip mounted on the third PCB, and an objective optical system and illumination means mounted on the fourth (upper) PCB. Pins made of conductive material (a) mechanically support the second, third, and fourth (upper) PCBs above the first PCB, (b) transmit power from the first PCB to the second, third, and fourth (upper) PCBs, and (c) transmit signals from the sensor chip on the third PCB to the first PCB.

[0015] In a second embodiment, the present invention is a video camera head comprising at least two rigid printed circuit boards (PCBs) arranged in parallel planes. In this embodiment of the camera head, an objective optical system and illumination means are mounted on the distal end of the housing of the camera head, a solid-state sensor chip is mounted on a PCB below the objective optical system, an electronic component that receives signals from the solid-state sensor and outputs video signals is mounted on at least one of the PCBs, at least two PCBs are mechanically supported vertically by conductive pins, and the illumination means supported at the distal end of the camera housing is an output coupler of an optical fiber or the distal end of a light guide.

[0016] The light source for the illumination means of the video camera head in a second embodiment of the present invention can be any conventional light source used in endoscope systems. In these embodiments, light from an LED is transmitted to the distal end of the camera head housing through a hollow light guide.

[0017] In an embodiment of a video camera head according to a second aspect of the present invention, the light source is an LED mounted on one of the PCBs in the camera head, or mounted proximal to the camera head. The LED can be mounted on the PCB together with a solid sensor chip. In another embodiment, the LED is mounted on a PCB below the PCB on which the solid sensor chip is mounted.

[0018] In an embodiment of a video camera head according to a second aspect of the present invention, the light source is located far from the camera head, and the light is transmitted directly from the light source to an output coupler at the distal end of the camera housing, or to one of the PCBs, and incident on a hollow light guide on that PCB.

[0019] In embodiments of the video camera head of the present invention, the pins can be either rigid or flexible.

[0020] In an embodiment of the video camera head of the present invention, the PCB can have any shape that is not circular, either symmetric or asymmetric.

[0021] In an embodiment of the video camera head of the present invention, some or all of the PCBs in the camera head can be different in shape and size from another PCB in the camera head.

[0022] In an embodiment of the video camera head of the present invention, some or all of the components of the objective optical system can be attached to the housing of the camera head.

[0023] Hereinafter, embodiments of the present invention will be described through examples with reference to the accompanying drawings (however, the present invention is not limited by the following description). The above and all other features and advantages of the present invention will be further understood through the following description.

Brief Description of the Drawings

[0024] [Figure 1] Schematically shows the structure of an embodiment of the camera head of the present invention. [Figure 2] Schematically shows a second embodiment of the camera head of the present invention. [Figure 3] Schematically shows a second embodiment of the camera head of the present invention.

Modes for Carrying Out the Invention

[0025] Figure 1 schematically shows the structure of one embodiment of the camera head (10) of the present invention. This embodiment of the camera head of the present invention comprises three rigid PCBs (12a, 12b, 12c). These three PCBs are arranged vertically relative to each other in three parallel planes. (For convenience, the camera head is described assuming that its central axis is perpendicular. This defines the relative directions such as upper and lower as used herein.)

[0026] The intermediate PCB (12b) is mechanically supported above the lower PCB (12c) by six short pins (14), and the upper PCB (12a) is mechanically supported above the lower PCB (12c) by two long pins (16) passing through the through-passage in PCB (12b). Note that the embodiment of the camera head (10) may have more or fewer than six pins (14) and more than two pins (16).

[0027] A metallization coating (18) is formed on the surface of the lower PCB (12c), and an electronic component (20) that receives signals from a solid-state image sensor (e.g., CMOS) and outputs video signals is electrically connected to this metallization coating. A camera cable (30) that transmits power to the camera head and transmits video signals from the camera head to a remote signal processor is connected to the metallization pattern on the upper surface of the PCB (12c) by passing through a through-passage.

[0028] The intermediate PCB (12b) supports the solid sensor chip (22).

[0029] The upper PCB (12a) supports the objective optical system (24) inside the housing (26) and the illumination means (e.g., at least one LED (28) surrounding the housing (26), or an annular array of LEDs (28)).

[0030] Pins (14) and (16) are made of conductive material. Therefore, these pins serve two purposes: to mechanically support the two upper PCBs, and to transmit power to the sensor chip (22), transmit signals from the sensor chip (22), and transmit power to the LED 28.

[0031] Therefore, the internal structure of the camera head (10) addresses all four obstacles described in the background art section of this application. Firstly, by using a rigid PCB instead of a flexible PCB, the bending radius of the flexible PCB, which would normally increase the diameter of the camera head, is eliminated. Secondly, by using conductive pins, a sufficient amount of current for the illumination source can be transmitted. Thirdly and fourthly, by using electrically connected pins, most of the difficulties in forming internal wiring connections are eliminated, and the assembly process is greatly simplified, making the camera head (10) a device that is highly suitable for mass production.

[0032] It should be noted that one embodiment of the camera head of the present invention may have two PCBs, in which case the electronic components are located on the lower surface of the lower PCB, the sensor chip is located on the upper surface of the lower PCB, and the objective lens system and illumination source are located on the upper PCB. Another embodiment may have more than three PCBs, for example four PCBs, in which case the two lower PCBs support the electronic components, the third PCB supports the sensor chip, and the upper PCB supports the objective optical system and illumination means. In all embodiments, conductive pins serve two purposes: to mechanically support the PCBs apart and to transmit power and video signals between the PCBs.

[0033] In another embodiment of the present invention, the illumination means supported on the uppermost PCB is an output coupler of an optical fiber or light guide. In these embodiments, the light source can be any conventional light source used in an endoscope system (e.g., an LED mounted on one of the lower PCBs in the camera head, or proximal to the camera head). In some embodiments, conductive pins can be combined with a hollow light guide.

[0034] In one embodiment schematically shown in Figure 2, the camera head comprises three PCBs mechanically supported vertically by conductive pins 14, 16. The two lower PCBs 12b, 12c support electronic components (not shown in the figure) that receive signals from the solid-state image sensor 22 and output video signals. The uppermost PCB 12a supports the solid-state sensor 22 and one or more LEDs 28 (e.g., a circular array) surrounding the sensor. In this embodiment, the objective lens system 24, enclosed in its own housing 26, is held in a predetermined position above the sensor 22 by a support structure (e.g., a hollow tube mounted toward PCB 12a at its lower end) or by a structure attached to the camera housing 34 surrounding the internal components of the camera head. Furthermore, the camera head also includes vertical tubular light guides 32, which transmit light from the LED 28 to the height of the objective lens 24 at the distal end 36 of the camera housing 34 facing the target object being imaged. The light guides 32 are supported above the LED 28, for example, by being attached to the PCB 12a at their lower ends, or by supports attached to the inside of the camera housing 34.

[0035] The electronic components located on PCBs 12a and 12b can be redistributed to only one of the PCBs, and / or some electronic components can be located on PCB 12a, thereby allowing this embodiment of the camera head to have only two PCBs. In all embodiments, the camera cable 30 is connected to the electronic components on the lower PCB.

[0036] Figure 3 schematically shows variations of the embodiment shown in Figure 2. In the camera head shown in Figure 3, electronic components (not shown) are located on PCBs 12a, 12c (and 12b in some variations), the LED 28 is on PCB 12c, and the light guide 32 transmits the light from the LED 28 to the height of the objective lens 24 at the distal end 36 of the camera housing 34 facing the target object to be imaged.

[0037] In another embodiment, the light source can be positioned far from the camera head, and the light is transmitted directly from the light source to an output coupler at the distal end 36 of the camera housing 34, or alternatively, as shown in Figures 2 and 3, to one of the PCBs, where it is incident on a hollow light guide.

[0038] While embodiments of the present invention have been described as examples up to this point, it should be understood that the present invention can be implemented with numerous changes, modifications, and adaptations without departing from the scope of the claims, for example, as follows. a) The pin can be rigid or flexible. b) The PCB shape is not circular, but can be any symmetrical shape (e.g., square or rectangle) or asymmetrical shape. c) The shape and dimensions of some or all of the PCBs in the camera head may differ from the shape and dimensions of other PCBs in the camera head. d) In embodiments of the camera head, some or all of the components of the objective optical system can be mounted in the housing of the camera head.

Claims

[Claim 1] An endoscope having a video camera head comprising at least three rigid printed circuit boards (PCBs) arranged in parallel planes, a) The video camera head includes a solid image sensor chip, an objective lens system, illumination means, and electronic components, all of which are supported on the at least three rigid printed circuit boards. b) The at least three rigid printed circuit boards are spaced far enough apart to provide sufficient space for the electronic components of the video camera head supported thereon. The aforementioned video camera head is i) All of the three PCBs other than the lower PCB are mechanically supported vertically above the lower PCB by pins, ii) The pin is made of a conductive material, iii) At least some of the pins transmit power from the lower PCB to an electronic component or lighting means mounted on another PCB among the at least three PCBs. iv) Some of the pins transmit signals from a solid image sensor chip mounted on one of the other PCBs among the at least three PCBs to the lower PCB. v) All of the pins are located within the respective planes of the PCB and pass through through passages formed in the PCB. Endoscope.

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