JPS62259187A - Pattern measuring instrument - Google Patents

Abstract

PURPOSE:To speed up the data transfer processing without an expensive computer and to shorten time required for deciding a pattern by providing a ROM storing address information used for deciding a projection pattern image and a transfer processing means. CONSTITUTION:The ROM 16 stores the address information necessary for deciding the projection pattern image in a RAM 14. The transfer processing means 17 has a function to call photoelectric transfer information in the RAM 14 not through a microprocessor 15 based on the address information in the ROM 16. When a processor 15 inputs a transfer start command signal Ts to a read/ write control register 19, said register 19 calls the address information in the ROM 16. A control register 20 sequentially calls photoelectrical transfer information at an address corresponding to the address information in the ROM 16 based on the called address information, and transfers said transfer information to the RAM 18. Thus data transfer processing can be speed up without an expensive computer, and the time required for deciding the pattern can be shortened.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention is a method for photoelectrically converting a projected pattern image based on a pattern of a known shape projected through an object to be inspected using a photoelectric conversion element having a large number of pixels. , this photoelectric conversion element is scanned to extract photoelectric conversion information for each pixel, and the photoelectric conversion information is stored in each address of the random access memory, and the central processing unit calculates the photoelectric conversion information based on the photoelectric conversion information stored in each address of the random access memory. The present invention relates to an improvement in a pattern measuring device that determines the shape of a projected pattern image by performing calculations.

(Prior Art) Conventionally, as a pattern measuring device, a projected pattern image based on a pattern of a known shape projected through an object to be inspected is transferred to an area C as a photoelectric conversion element having a large number of pixels.
This area COD is formed on the pixel surface of the CD, and this area COD is scanned to take out photoelectric conversion information for each pixel and stored in each address of the random access memory.Then, the central processing unit stores the photoelectric conversion information in each address of the random access memory. It is known that the shape of the projected pattern image is determined by calling out stored photoelectric conversion information according to a predetermined program and performing predetermined calculations.

(Problem to be Solved by the Invention) However, the central processing unit i! retrieves the photoelectric conversion information as data from the random access memory one by one for each address. Because the number of pixels is large and the units that make up one word are, for example, 16 bits or 32 bits, it takes a lot of time to transfer the data to the microprocessor. During the transfer process, the central processing unit is occupied with the input/output task of transferring the data, and there is a problem in that it takes a lot of time to determine the pattern. Although this problem can be solved by using a computer with high processing speed, another problem arises in that the pattern measuring device becomes expensive.

(Purpose of the Invention) Therefore, the present invention aims to quickly perform data transfer processing without using an expensive computer with high processing speed, and to shorten the time required to determine the pattern compared to the conventional method. The object of the present invention is to provide a pattern measuring device that can measure the pattern. - (Means for Solving the Problems) The present invention provides that when a pattern of a known shape is projected to form a projected pattern image on a pixel surface of a photoelectric conversion element, the projected pattern image may have some distortion and size. Even if there is a change in the pattern, there is a certain relationship with the pattern of the known shape, and the projected pattern image can be created without performing calculation processing using all of the photoelectric conversion information as all data possessed by each pixel of the photoelectric conversion element. This invention was developed with a focus on accurate determination, and features of the present invention include a memory for storing address information necessary for determining a projection pattern image among each address of a random access memory, and a random access memory for storing address information necessary for determining a projection pattern image. A transfer processing means is provided for calling out the photoelectric conversion information stored at each address of the memory based on the address information stored in the memory without going through the central processing unit.

(Example) Hereinafter, an example of a pattern measuring device according to the present invention will be described with reference to the drawings.

1 to 5 are diagrams showing an embodiment in which a pattern measuring device according to the present invention is applied to a curvature radius measuring device for the cornea of an eye to be examined, and in FIG. 1, 1 is the cornea of the eye to be examined; is the cornea 1 using a known ring-shaped pattern as pattern projection light.
3 is a projected pattern image forming optical system, and Ω is the projected pattern image forming optical system 3.
is the main optical axis of The pattern projection optical system 2 is roughly composed of a light source 4 and a pattern forming plate 5. A ring-shaped pattern 6 is formed on the pattern forming plate 5, as shown in FIG.

When the pattern projection light is projected onto the cornea 1, a virtual image 11 of the ring-shaped pattern 6 is formed. This virtual image 11 is
The image is distorted due to astigmatism in the cornea 1. The projection pattern imaging optical system 3 includes an objective lens 7 and an aperture 8
, and a relay lens 9, and the reflected light forming the virtual image 11 as a ring-shaped projection pattern image is transmitted as projection pattern light to an area as a photoelectric conversion element via an objective lens 7, an aperture 8, and a relay lens 9. The light is guided to C0DIO, and an image is formed on the pixel surface 10a. Note that the aperture 8 functions as a telecentric aperture.

Area CCDl0 has a large number of pixels G as shown in FIG.
LJ (i=1,2....1m, j=1.2....
, n), and an elliptical image 11 is formed as a projected pattern image on this pixel surface 10a, as shown by the solid line in FIG. The area CCDl0 is scanned by a known driving means 12, and each pixel GLj (1=1.2, . . . , m,
The photoelectric conversion information of j=1.2, . The data is transferred and temporarily stored at each address of this random access memory (RAM) 14. Note that this random access memory (RAM) 14 is one that is used in known video devices.

The pattern measuring device here includes a microprocessor 15 as a central processing unit and a read-only memory (R
16, a transfer processing means 17, and a random access memory (RAM) 18. A read-only memory (ROM) 16 stores address information necessary for determining a projection pattern image in the random access memory (RAM) 14. Here, the address information corresponding to the address of the pixel GLJ existing on the arrow lines A, B, and C shown in FIGS. 3 and 4 is stored in the read-only memory (RO).
M) 16. This read-only memory (ROM) 16 also stores information other than address 1 information, but since it is not directly related to the present invention, its explanation will be omitted here.

The transfer processing means 1f has a read/write control register 19 and a control register 20. This transfer processing means 1
7 has a function of calling up the photoelectric conversion information stored at each address of the random access memory (RAM) 14 without going through the microprocessor 15 based on the address information stored in the read only memory (ROM) 16. When the transfer start command signal Ts is input from the microprocessor 15 to the read/write control register 19 via the control bus, the read/write control register 19 transfers to the read-only memory (R) via the address bus.
OM) 16, and based on the address information, the address information stored in the random access memory (RAM) is called.
Among the photoelectric conversion information stored in each address of the read-only memory (ROM) 16, the photoelectric conversion information of the address corresponding to the address information of the read-only memory (ROM) 16 is sequentially called into the control register 20. (RAM) Transfer processing is performed to 18.

During this transfer process, the microprocessor 15 is executing other program processes and the read-only memory (
A random access memory (RAM) of photoelectric conversion information stored at each address of the random access memory (RAM) 14 based on the address information stored in the ROM 16.
AM) When the transfer process to 18 is completed, the read/write control register 19 outputs a transfer end signal Te to the microprocessor 15.Then, the microprocessor 15 transfers the random access memory (RAM) 1 to the microprocessor 15.
The arithmetic processing for determining the elliptical image 11 is performed based on the photoelectric conversion information temporarily stored in the elliptical image 11, the details of which will be described later.

In this way, the random access memory (RAM) 14 temporarily stores and holds the minimum photoelectric conversion information necessary for determining the elliptical image 11. For example, if we extract the photoelectric conversion information of the address corresponding to each pixel GLJ existing on the line in the direction of arrow line A, the photoelectric conversion information will be
The result will be as shown in FIG. In this Figure 5,
The horizontal axis corresponds to each address where photoelectric conversion information is stored, and the vertical axis corresponds to brightness level information V. Also,
L is the slice level. The microprocessor 15 uses a counter (not shown) to first perform processing to determine at which address position the peak of luminance is located, as processing for determining an ellipse.

The address position of the brightness peak is determined by determining the address existing at the boundary of the slice level L based on the slice level L. That is, based on the slice level L, a counter counts the addresses existing on the boundary, and the microprocessor 1 counts the addresses existing on the boundary as virtual address information.
Output to 5.

Let the virtual address information be abl, C1md1.

This virtual address information abl, C□, d□ corresponds to the intersection points a2, bl, C, d□ between the boundary line Q2 of the projected pattern image 11 shown in FIG. 4 and the arrow line A. There is.

Therefore, the virtual address information a1. b, average and C
By averaging the values d and d, virtual address information corresponding to the peak brightness can be obtained.

The virtual address information corresponding to the peak of brightness (X-=
Yl) −CX2= Yl). Here, the code or the X-axis direction is shown, and the code Y is the Y-axis direction, and the virtual address information corresponding to the peak of the brightness is determined as the position from the origin 0. Virtual address information corresponding to the peak of luminance is obtained in the same manner for the directions of arrow lines B and C. In this way, virtual address information (x 1.Yz ), (
x z −y z ), (X 3 , Y 3 ),
(x,,y,), (x,,ys).

(XieYi), and based on this virtual address information, the ellipse 11 as a projected pattern image is
Determine. The microprocessor 15 outputs the processing results to a display section 21 such as a television monitor.

6 to 8 show embodiments in which the pattern measuring device according to the present invention is applied to an autolensmeter.
In the figure, 25 is a measurement optical system, and this measurement optical system 25 includes a measurement light source 26, a collimator lens 27,
It is roughly composed of a pattern forming plate 28 and an area CCD 29, and is a non-imaging optical system. Reference numeral 30 denotes a lens to be tested, and a slit 32 for forming a square pattern 31 is formed in the pattern forming plate 28, as shown in FIG. This pattern 3
1 is projected onto the area CCD 29 through the test lens 30, a pattern image 33 as shown in FIG. 8 is formed on the pixel surface of the area CCD 29. The autolensmeter measures the refractive characteristics of the lens to be tested based on this pattern image 33. The lens to be tested 3
The refractive power of 0 is measured by a known method, and is measured at the intersections P, Q, and V of the virtual straight lines P-P4 shown in FIG.
, W by obtaining the movement amount. The amount of movement of these intersection points P, Q, V, and W can be obtained by finding the intersection points P', Q', V', and W' of the virtual straight lines P/1 to 24' of the projected pattern image 33. Intersection P', Q
', v', and w' can be found when the virtual straight lines P'□ to P,' are found.

This virtual direct, mp 'z~p, ni' can be determined by knowing at least two points, so read only memo
The address information necessary to determine the straight line is stored in advance. Here, in the read-only memory 16, the pixels GL existing on the arrow line □ to 9 are
Address information corresponding to address J is stored. The photoelectric conversion information of the pixel GLJ existing on the arrow line is transferred to the microprocessor 1 by the processing means 17.
Since the calling to the random access memory 18 without going through 5 is the same as in the previous embodiment, the explanation thereof will be omitted.

(Effects of the Invention) As explained above, the pattern measuring device according to the present invention includes a memory for storing address information necessary for determining a projected pattern image among each address of a random access memory (RAM), and a random access memory for storing address information necessary for determining a projected pattern image. A transfer processing means is provided to call the photoelectric conversion information stored at each address of the memory (RAM) based on the address information stored in the memory without going through the central processing unit, so the processing speed is fast. The present invention has the advantage that data transfer processing can be performed quickly without using an expensive computer, and the time required to determine the pattern can be shortened compared to the conventional method.

[Brief explanation of drawings]

1 to 5 are diagrams for explaining an embodiment in which a pattern measuring device according to the present invention is applied to a measuring device for an eye to be examined. Figure 2 shows the ring-shaped pattern, and Figure 3 shows the area CO.
4 and 5 are explanatory diagrams for explaining the process for determining the shape of the projection pattern, and FIGS. 6 to 8 are patterns according to the present invention. FIG. 6 is a diagram illustrating an embodiment in which the measuring device is applied to an autolensmeter for measuring a lens to be tested, and FIG. 6 is a diagram showing the configuration of its main parts, and FIG. 7 is a diagram showing its square pattern. FIG. 8 is a diagram showing an example of the projected pattern image. 10...Area CCD. 15...Microprocessor 14.18...Random access memory 16...Read only memory. 17...Transfer processing means 19...Read/write control register 20...Control register Fig. 2 Fig. 3 Fig. 4 Fig. 5

Claims (1)

[Claims] (1) A projected pattern image based on a pattern of a known shape projected through a test object is photoelectrically converted by a photoelectric conversion element having a large number of pixels, and the photoelectric conversion element is scanned to perform photoelectric conversion for each pixel. The information is extracted and stored in each address of the random access memory, and the shape of the projected pattern image is determined by causing the central processing unit to perform calculations based on the photoelectric conversion information stored in each address of the random access memory. In the pattern measuring device, a memory stores address information necessary for determining the projected pattern image among the addresses of the random access memory, and a memory stores address information necessary for determining the projected pattern image among the addresses of the random access memory, and a memory stores the photoelectric conversion information stored at each address of the random access memory. A pattern measuring device comprising: a transfer processing means for calling without going through a central processing unit based on the address information stored in a memory.