Camera head

Abstract

This invention relates to small-diameter camera heads for medical endoscopes, laparoscopes, industrial endoscopes, etc. One obstacle to reducing the diameter is the flexible PCB board on which the camera head's sensors and other components are mounted, and the internal wiring that electrically connects the various electronic components, which are difficult to assemble and not suitable for mass production. The present invention provides a camera head that addresses the above-mentioned obstacles. The video camera head includes at least two rigid printed circuit boards (PCBs) arranged in parallel planes, the at least two PCBs mechanically supported above and below each other by pins made of conductive material that carry power from the lower PCB to electronic components or lighting means mounted on another PCB, and that carry signals to the lower PCB from a solid-state sensor chip mounted on one of the other PCBs.

Description

Technical Field

[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 to enable access through ever-smaller diameter openings has continued to be a goal of instrument designers.

[0003] A method for 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 to further reducing the diameter are generally the flexible PCB board 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

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] Accordingly, an object of the present invention is to provide a camera head that addresses the above-described drawbacks.

[0008] Further objects and advantages of the present invention will become apparent as the description proceeds.

Means for Solving the Problems

[0009] In a first aspect, 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 from each other by pins made of a conductive material. The pins transmit power from the lower PCB to electronic components and / or lighting means attached to another PCB among at least two PCBs, and transmit signals from a sensor chip attached to one of the other PCBs among at least two PCBs to the lower PCB.

[0010] In an embodiment of the video camera head of the present invention, the lighting means comprises at least one LED (for example, an annular array of LEDs).

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

[0012] In an embodiment of the video camera head of the present invention, it comprises three PCBs, and a component that receives signals from a solid-state sensor and outputs a video signal is attached to the lower PCB, the solid-state sensor chip is attached to the intermediate PCB, and the objective optical system and the lighting means are attached to the upper PCB. The pins made of a conductive material (a) mechanically support the intermediate PCB and the upper PCB above the lower PCB, (b) transmit power from the lower PCB to the intermediate PCB and the upper PCB, and (c) transmit signals from the sensor chip on the intermediate PCB to the lower PCB.

[0013] In an embodiment of the video camera head of the present invention, there are two PCBs, and electronic components that receive signals from the solid-state sensor and output video signals are attached to the lower surface of the lower PCB. The solid-state sensor chip is attached to the upper surface of the lower PCB, and the objective optical system and the illumination means are attached to the upper PCB. Pins made of a 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, there are four PCBs, and electronic components that receive signals from the solid-state sensor and output video signals are attached to the first (lower) PCB and the second PCB. The solid-state sensor chip is attached to the third PCB, and the objective optical system and the illumination means are attached to the fourth (upper) PCB. Pins made of a conductive material (a) mechanically support the second PCB, the third PCB, and the fourth (upper) PCB above the first PCB, (b) transmit power from the first PCB to the second PCB, the third PCB, and the fourth (upper) PCB, and (c) transmit signals from the sensor chip on the third PCB to the first PCB.

[0015] In a second aspect, the invention is a video camera head comprising at least two rigid printed circuit boards (PCBs) arranged in parallel planes. In the camera head of this aspect, the objective optical system and the illumination means are attached to the distal end of the camera head housing, the solid state sensor chip is attached to the PCB below the objective optical system, and the electronic components that receive signals from the solid state sensor and output video signals are attached to at least one of the PCBs. At least two PCBs are mechanically supported vertically with respect to each other by conductive pins, and the illumination means supported at the distal end of the camera housing is the 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 according to the second aspect of the invention can be any conventional light source used in an endoscope system. In these embodiments, light from an LED is transmitted through a hollow light guide to the distal end of the camera head housing.

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

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

[0019] In an embodiment of the video camera head of the 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, 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 from the shape and dimensions of 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

Figure 2

Figure 3

Modes for Carrying Out the Invention

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

[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-holes in the PCB (12b). Note that it should be noted that the embodiment of the camera head (10) may include more than six or less than six pins (14) and more than two pins (16).

[0027] A metal coating (18) (metallization) is formed on the surface of the lower PCB (12c), and an electronic component (20) that receives signals from a solid-state imaging device (e.g., CMOS) and outputs video signals is electrically connected to this metal 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 metal coating pattern on the upper surface of the PCB (12c) by passing through the through-holes.

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

[0029] The upper PCB (12a) supports an objective optical system (24) inside the housing (26) and lighting 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. Thus, these pins serve two purposes: mechanically supporting the upper two PCBs and transmitting power to the sensor chip (22), transmitting signals from the sensor chip (22), and transmitting power to the LED 28.

[0031] Thus, the internal structure of the camera head (10) addresses all four obstacles described in the background art section of this application. First, by using rigid PCBs instead of flexible PCBs, the bending radius of the flexible PCB, which would normally increase the diameter of the camera head, is eliminated. Second, by using conductive pins, a sufficient amount of current can be transmitted for the illumination source. Third and fourth, by using pins for electrical connection, most of the difficulties in forming internal wiring connections are eliminated, thus greatly simplifying the assembly process, which in turn makes the camera head (10) a device highly suitable for mass production.

[0032] Note that one embodiment of the camera head of the present invention can include two PCBs. In that case, it should be noted that 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 the illumination source are located on the upper PCB. Another embodiment can include more than three PCBs, for example four PCBs. In that case, the lower two PCBs support the electronic components, the third PCB supports the sensor chip, and the upper PCB supports the objective optical system and the illumination means. In all embodiments, the conductive pins serve two purposes: mechanically supporting the PCBs apart and transmitting power and video signals between the PCBs.

[0033] In another embodiment of the present invention, the lighting means supported on the uppermost PCB is the output coupler of an optical fiber or a 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 plurality of 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 FIG. 2, the camera head comprises three PCBs that are mechanically supported vertically with respect to each other 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 imaging device 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 attached at its lower end towards the PCB 12a) or by a structure attached to the camera housing 34 surrounding the internal components of the camera head. Further, the camera head also comprises vertical tubular light guides 32 that transmit light from the LEDs 28 up to the height of the objective lens 24 at the distal end 36 of the camera housing 34 facing the object to be imaged. The light guide 32 is supported above the LEDs 28, for example, by being attached to the PCB 12a at its lower end or by a support attached inside 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 of the electronic components can be located on PCB 12a, whereby this embodiment of the camera head can comprise 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 a variation 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 in some variations also 12b), the LED 28 is on PCB 12c, and the light guide 32 conveys the light from the LED 28 up to the height of the objective lens 24 at the distal end 36 of the camera housing 34 facing the object to be imaged.

[0037] In another embodiment, the light source can be located far from the camera head and the light is conveyed directly to the output coupler at the distal end 36 of the camera housing 34 from the light source or, alternatively, as shown in Figures 2 and 3, to one of the PCBs and enters a hollow light guide in that PCB.

[0038] Although the embodiments of the present invention have been described by way of example so far, it should be understood that the present invention can be implemented with numerous changes, modifications, adaptations, etc., without departing from the scope of the claims, for example as follows. a) The pins can be rigid or flexible. b) The shape of the PCB can be other than circular, and can be any symmetric shape (e.g., square or rectangular) or an asymmetric shape. c) The shape and dimensions of some or all of the PCBs in the camera head can be different from the shape and dimensions of another PCB in the camera head. d) In an embodiment of the camera head, some or all of the components of the objective optical system can be attached to the housing of the camera head.

Claims

1. A video camera head comprising at least three rigid printed circuit boards (PCBs) arranged in a parallel plane, a) the video camera head includes a solid-state sensor chip, an objective lens system, lighting 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 apart sufficiently to provide space for the electronic components of the video camera head supported thereon, The video camera head, i) all of the at least three PCBs other than the lower PCB are mechanically supported vertically above each other by pins on the upper side of the lower PCB, ii) the pins are made of a conductive material, iii) at least some of the pins conduct power from the lower PCB to electronic components or lighting means attached to another PCB among the at least three PCBs, iv) some of the pins conduct signals from a solid-state sensor chip attached to one of the other PCBs among the at least three PCBs to the lower PCB, v) all of the pins are arranged in the respective planes of the PCBs and pass through through-holes formed in the PCBs, vi) at least some of the pins are short and are located between two adjacent PCBs, Video camera head.

2. The video camera head according to claim 1, wherein the lighting means comprises at least one LED.

3. The video camera head according to claim 2, wherein the lighting means comprises an annular array of LEDs.

4. Comprising three PCBs, an electronic component that receives a signal from a solid-state sensor chip and outputs a video signal is attached to the lower PCB, the solid-state sensor chip is attached to the intermediate PCB, the objective optical system and the lighting means are attached to the upper PCB, and pins made of a conductive material (a) mechanically support the intermediate PCB and the upper PCB above the lower PCB, (b) conduct power from the lower PCB to the intermediate PCB and the upper PCB, and (c) conduct a signal from the solid-state sensor chip on the intermediate PCB to the lower PCB. The video camera head according to claim 1.

5. An electronic component that receives a signal from a solid-state sensor chip and outputs a video signal is attached to the lower surface of the lower PCB, the solid-state sensor chip is attached to the upper surface of the lower PCB, and an objective optical system and illumination means are attached to the upper PCB. Pins made of a conductive material mechanically support the upper PCB above the lower PCB and transmit power from the lower PCB to the upper PCB. A through passage is used to transmit power from the lower surface to the upper surface of the lower PCB and to transmit a signal from the solid-state sensor chip on the upper surface to the lower surface of the lower PCB. The video camera head according to claim 1.

6. The video camera head according to claim 1, comprising four PCBs, wherein an electronic component that receives a signal from a solid-state sensor chip and outputs a video signal is attached to a first (lower) PCB and a second PCB, the solid-state sensor chip is attached to a third PCB, an objective optical system and illumination means are attached to a fourth (upper) PCB, and pins made of a conductive material (a) mechanically support the second PCB, the third PCB, and the fourth PCB above the first PCB, (b) transmit power from the first PCB to the second PCB, the third PCB, and the fourth PCB, and (c) transmit a signal from the solid-state sensor chip on the third PCB to the first PCB.

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