JPH0618334Y2 - Imaging device - Google Patents

Description

[Detailed Description of the Invention] [Outline] The present invention relates to an imaging device that detects a light beam from an object and visualizes the object according to its intensity, and enables measurement without contact with a small and simple structure. A deflecting optical system for sequentially performing optical scanning of a scanning plane divided into a plurality of parallel plane regions in a two-dimensional scanning region set for an object for the purpose of providing an image pickup apparatus capable of performing the same, and the deflecting optical system. And a condensing optical system for condensing a light beam from the two-dimensional scanning region onto an optical sensor via a tilting angle which makes each of the plurality of mirrors with respect to the rotation axis by the deflection optical system. Is a rotary polygon mirror arranged in an array shifted by a predetermined angle, the optical sensor is a multi-element infrared linear sensor, the condensing optical system is made of an optical material that transmits infrared rays, each of the plurality of parallel plane regions The vertical direction of the area The number of pixels corresponding to the number of elements of the child infrared linear sensor is arranged, and the light rays from each of the pixels in one column arranged in the vertical direction are transmitted through the deflection optical system and the condensing optical system. The present invention is configured by an image pickup device that simultaneously collects light on corresponding elements of a multi-element infrared linear sensor.

(a) Technical Field of the Invention The present invention relates to a structure of an image pickup device, and more particularly to a device applicable to an infrared image pickup device capable of pattern measurement as a surface without contacting the temperature of an object.

(b) Background of technology In recent years, fields requiring optical imaging technology have been developed in various fields, and the technology related thereto has been remarkably advanced.

In particular, in addition to the usual optical image pickup device, an infrared ray image pickup device and a video device thereof are widely used.

In such an image pickup apparatus, when an optical sensor having a small number of elements is used, optical scanning in the horizontal direction and the vertical parallel is necessary to obtain a two-dimensional screen. These horizontal / vertical scanning optical systems consist of two independent scanning optical systems that move in synchronization with the horizontal and vertical signals of the video signal, and the image pickup apparatus becomes complicated and large in size. Mechanism and miniaturization are demanded.

(c) Conventional Technique and Problems FIG. 1 is a diagram for explaining a conventional device.

Reference numeral 1 denotes a scanning surface, and in order to scan the scanning surface, an optical system is used in which a lens 2 of the optical system collects light at a viewing angle of 25 degrees both vertically and horizontally.

Reference numeral 3 denotes a horizontal scanning mirror, which performs optical deflection for horizontally scanning the scanning surface, and this horizontal scanning mirror is constantly constant during the imaging operation so that the projected optical path deflects and scans in the horizontal direction. It reciprocates horizontally in a cycle of.

Reference numeral 4 denotes a vertical scanning mirror, which performs optical deflection so as to vertically scan the scanning surface. This vertical scanning always deflects and scans the projected optical path in the vertical direction. The structure is such that it reciprocally vibrates in the vertical direction while synchronizing with.

Reference numeral 5 is a sensor, which has some elements, but when the number of elements is small, it is necessary to optically scan the scanning surface.

In this way, the light beam condensed by the optical system is optically input to the sensor, the change in the intensity of the optical input is converted into the detection current and input to the amplifier 6, and then the video signal 7 separately sent. At the same time, it is input to the video display device 8 and displayed on the display device.

In such an image pickup apparatus, two sets of optical mirrors for mechanical reciprocating scanning are required, and synchronization is required, so that the apparatus becomes mechanically complicated, and the entire apparatus becomes large.

(d) Purpose of the Invention In view of the above-mentioned conventional drawbacks, the present invention uses a multi-faceted optical mirror with one deflecting optical system, which has conventionally used two deflection optical systems, and tilts each optical mirror. To provide an image pickup device capable of high-speed scanning by using an array of different angles so that both horizontal and vertical scanning can be performed by rotation of a polygonal optical mirror and an optical sensor having multiple elements. With the goal.

(e) Constitution of device According to the present invention, a deflection optical system for sequentially performing optical scanning of a scanning plane divided into a plurality of parallel plane regions in a two-dimensional scanning region set for an object, A condensing optical system for condensing a light beam from the two-dimensional scanning region onto an optical sensor via a deflection optical system, wherein the deflection optical system causes each of a plurality of mirrors to rotate about an axis of rotation. A rotary polygon mirror in which the tilt angles formed are shifted by a predetermined angle, and the optical sensor is a multi-element infrared linear sensor, and the condensing optical system is an optical material that transmits infrared rays. The number of pixels corresponding to the number of elements of the multi-element infrared linear sensor is arranged in the vertical direction of each area of the area, and the light beam from each row of pixels arranged in the vertical direction is the deflection optical system. And through the condensing optical system It is achieved by providing an image pickup device characterized in that the respective elements of the multi-element infrared linear sensor are simultaneously focused.

Provided are a plurality of AC-coupling type low noise amplifiers each connected to each element of the multi-element infrared linear sensor, a multiplexer for outputting the output signal of each element as a serial signal, and a timing circuit for controlling the timing of the multiplexer. As a result, the light rays from each pixel area corresponding to the multi-element infrared linear sensor in each scanning area are condensed by the condensing optical system to each element corresponding to the multi-element infrared linear sensor to be optically input and The change in intensity is converted into a detection current corresponding to the amount of incident light, amplified by an AC coupling type low noise amplifier, and parallel output signals from each element are output as serial video signals by a multiplexer controlled by a timing circuit. Projected on a video device (to clarify the positional relationship by mixing with the video signal sent separately) It is the can.

It is possible to perform time-delayed integral scanning by causing the scanning area to perform overlap scanning for each horizontal scanning.

(f) Embodiment of the Invention [Embodiment 1] FIG. 2 shows a first embodiment of the invention.

The rotary polygon mirror and the optical sensor, which are the features of the present invention,
A case where a polyhedral rotating mirror having an eight-sided mirror and a multi-element infrared linear sensor as shown in FIG. 2 are used will be described.

Reference numeral 10 denotes a two-dimensional scanning area set for the object, which is divided into eight parallel surfaces, and the optical scanning is sequentially performed.

11 is an incident optical system that transmits infrared rays, 12 is a rotating polygonal mirror having an eight-sided mirror, 13 is a condensing optical system that transmits infrared rays made of germanium Ge, and 14 is a photoconductive infrared sensor. A multi-element infrared linear sensor, 15 is an AC-coupled low-noise amplifier that is prominent in each element of the multi-element, 16
Is a timing circuit, and 17 is a multiplexer for converting the output signal of each element into a serial video signal, from which a video signal 18 is output.

The operation of the image pickup apparatus of the present invention will be described as the rotary polygon mirror 12 rotates clockwise as shown in the figure.
Each of the surface-rotating polygon mirrors scans from the left end to the right end of the scanning surface 1. Each element of the linear sensor 14 outputs a signal corresponding to the amount of incident light at each scanning position. This output is A
After being amplified by the C-coupled low noise amplifier 15, the signal is multiplexed by the multiplexer 17 and output as a video signal.

In FIG. 2, regarding the operation of the rotary polygon mirror, it is assumed that the mirror surface 12-5, which is one of the rotary polygon mirrors, scans the scanning region 10-5.

The mirror surface 12-4, which is one front in the rotation direction, is inclined inward by an angle θ with respect to the mirror surface 12-5, and the viewing angle of the optical system is 2θ.
Only the upper side, that is, the area of 10-4 is horizontally scanned.

The scanning surface is divided into eight areas as viewed from the optical system, and is sequentially scanned by 10-1 to 10-8, and the corresponding mirror surfaces 12-1 to 12-8. Go up again 12
To return to -1, the mirror surfaces of 12-1 and 12-8 are angled in the opposite direction by 8θ.

Further, each area is configured by the number of pixels corresponding to the number of linear sensors. For example, if a 10-element linear sensor is used, each scanning area is configured by 10 pixels, and one scanning surface is configured by 80 pixels in the vertical direction. Will be.

Further, since the time taken for the rotary scanning mirror to make 360 ° / 8 rotations is one horizontal scanning time, the time taken for one rotation is one frame time.

In FIG. 2, the light beam from the pixel 10-5-i in the scanning area 10-5 passes through the incident optical system 11, the rotating polygon mirror 12, and the condensing optical system 13 and is passed through the pixel 10-5 of the multi-element infrared linear sensor. The condensed light is input to the element 14-i corresponding to -i.

FIG. 3 (a) is a diagram schematically showing the relationship between the light emitting position and the light incident position, According to the formula used for the general lens system of
Rays from pixel 10-in are multi-element infrared ria sensor
It is focused on 14 corresponding elements 14-n. The light from pixel 10-i-1 is the corresponding element of multi-element infrared linear sensor 14.
It is focused on 14-1.

In FIG. 3 (a), the reflection by the mirror of the rotary polygon mirror is omitted for simplification, but FIG. 3 (b) shows the case where the reflection by the mirror 12 of the rotary polygon mirror is performed.

[Embodiment 2] FIG. 4 is a view for explaining a second embodiment of the present invention, in which an eight-sided polygon scanning mirror 12 is used as a rotary polygon mirror, and HgCdTe (mercury cadmite is used as a multi-element infrared linear sensor. ), An infrared detector 14 of 16 elements, a condensing lens 13 made of Si (silicon) as a condensing optical system, Si (silicon) as an infrared window 19, an infrared detector 14, an amplifier 15, 1 shows the configuration of an infrared camera including a condenser lens 13, a polygon scanning mirror 12, and the like.

In the case of FIG. 4, each element of the 16-element infrared detector 14 made of HgCdTe has a size of about 50 μm ^□ ,
Further, since there is a space between each element, the detected scanning area has a comb shape, and the scanning area corresponding to the space between each element and not detected has different tilt angles of the rotary polygon mirror. It is detected by scanning with a mirror. The size of the infrared detector 14 is 16 × 2 × 50 μm × 50 μm = 1.6 mm × 50 μm when one element is 50 μm ^□ , assuming that the size of each element and each space are provided at equal intervals.
Becomes

In the present invention, the tilt angle (θ) when scanning a block
About settings.

If the number of pixels of the multi-element sensor is n, the pixel pitch is d (when there is no space between elements), and the focal length of the condenser lens is f, Therefore, the tilt angle (θ) of the mirror when scanning blocks
Is Becomes

In addition, in order to detect infrared rays, which are extremely weak light (electromagnetic waves), in order to suppress the thermal noise of the infrared detector, it is necessary to measure by cooling to about -60 ° C or liquid nitrogen temperature by an electronic cooling method or the like. preferable. An infrared detector made of InSb may be used as the multi-element infrared linear sensor.

As the optical material that transmits infrared rays, Ge that transmits light (electromagnetic waves) in the wavelength range of 3 to 5 μm and 8 to 12 μm, which has been raised in the examples; Si that transmits light in the wavelength range of 3 to 5 μm, or the like is used. sell.

FIG. 5 is a schematic explanatory view of a configuration in which the incident optical system 11 is not provided between the scanning region 10 and the rotary polygon mirror 12 as in FIG. The light flux from each pixel in the scanning area is deflected by each mirror 12-1 to 12-n of the rotary polygon mirror 12, is condensed by the condensing optical system 13, and corresponds to the pixel of the multi-element infrared linear sensor 14. It is focused on the element.

In FIG. 5, for simplicity, the correspondence relationship from each pixel to each corresponding element is omitted. In the schematic view of FIG.
, Each scanning area AB, BC, CD, D of the scanning surface 10
E is scanned by each of the mirrors 12-1 to 12-n of the rotary polygon mirror.

When the scanning surface is at the 10 'position, overlap scanning can be performed on the scanning area every horizontal scanning. Although the tilt angle is enlarged in FIG. 5, the tilt angle of the mirror of the actual rotating polyhedral mirror is small.

Therefore, by making the tilt angle of the polyhedral mirror smaller than the above-mentioned θ, it becomes possible to perform overlap scanning in each scanning operation for each horizontal operation, and to realize time-delay integration scanning.

(g) Effect of the invention As described in detail above, by using the rotating mirror using the polyhedral mirror with different tilt angles of the present invention,
An optical system with a single rotating mirror is realized, and the configuration is simplified. Also, by using a multi-element infrared linear sensor as an optical sensor, each pixel in each scanning area can be made to correspond to each element of the multi-element infrared linear sensor, and by a synergistic effect with a rotating polygon mirror that rotates at high speed, High-speed scanning of the two-dimensional scanning area (scanning surface, screen) becomes possible. By using an infrared detector made of a ternary semiconductor of HgCdTe as a multi-element infrared linear sensor,
By detecting the infrared rays radiated from the object to be measured with the imaging device of the present invention, the temperature distribution and the like can be measured as the surface information of the object without contacting the object.

[Brief description of drawings]

FIG. 1 is a conventional image pickup device, FIG. 2 is an image pickup device of the present invention,
FIGS. 3 (a) and 3 (b) are views for explaining the correspondence of condensed light rays between each pixel in the scanning region of the apparatus shown in FIG. 2 and each corresponding element of the multi-element infrared linear sensor, and FIG. 4 is the present invention. FIG. 5 is a schematic explanatory view of the relationship between the tilt angle of the rotary polygon mirror and each scanning region in the case where the incident optical system is not provided. In the figure, 1 is a scanning plane, 2 is an optical system lens, 3 is a horizontal scanning mirror, 4 is a vertical scanning mirror, 5 is a sensor, 6 is an amplifier, 7 is a video signal, 8 is a video display device, and 10 is a two-dimensional device. Scanning area, 11 is an incident optical system, 12 is a rotary polygon mirror consisting of 8 surfaces, 13
Is a condensing optical system, 14 is a multi-element infrared linear sensor, 15 is an AC coupled low noise amplifier, 16 is a timing circuit, 17 is a multiplexer, 18 is a video output, and 19 is an infrared window.

Claims (5)

[Scope of utility model registration request] 1. A deflection optical system (12) for sequentially performing optical scanning of a scanning surface (1) divided into a plurality of parallel plane areas in a two-dimensional scanning area set for an object, and the deflection optical system ( An image pickup device having a condensing optical system (13) for condensing a light beam from the two-dimensional scanning region to an optical sensor (14) via the deflecting optical system (12) having a plurality of mirrors. Each of the above is a rotary polygonal mirror in which the tilt angle formed with respect to the rotation axis is shifted by a predetermined angle, the optical sensor (14) is a multi-element infrared linear sensor, and the condensing optical system (13) is It is made of an optical material that transmits infrared rays, and in the vertical direction of each area of the plurality of parallel plane areas, there is an arrangement relationship in which a number of pixels corresponding to the number of elements of the multi-element infrared linear sensor (14) is arranged in the vertical direction. Rays from each of the pixels arranged in a row are transmitted through the deflection optical system (12) and the condensing optical system (13). Te, imaging apparatus characterized by each is focused simultaneously in each corresponding element of the multi element infrared linear sensor (14). 2. A plurality of AC-coupled low noise amplifiers (15) each connected to each element of the multi-element infrared linear sensor (14).
And a multiplexer (17) for outputting the output signal of each element as a serial signal, and a timing circuit (16) for controlling the timing of the multiplexer (17). The image pickup apparatus according to the first section. 3. An incident optical system (1) made of an optical material for transmitting infrared rays between the scanning surface (1) and the deflection optical system (12).
The image pickup device according to claim 1, characterized in that 1) is provided. 4. The rotating polygon mirror (12) for overlapping scanning in a scanning region for each horizontal scanning so that time-delay integration scanning is possible.
The imaging device according to claims 1 and 2, wherein the tilt angle is set. 5. The utility model registration claim 1, wherein the rotary polygon mirror (12) is a rotary polygon mirror having eight faces.
The imaging device according to items 2 and 4.