JP2001092923A - Ic type number identifying method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an IC type number inspecting device capable of exactly identifying the type number of an IC in a short time. SOLUTION: It is estimated which font of character used by an IC maker is close to a specified character segmented from an input image and on the basis of the estimated font, the other character in the input image is identified as well.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a method for identifying a model number printed on an upper surface of an IC using an image recognition technique.

[0002]

2. Description of the Related Art For example, the difference between ICs mounted on a substrate,
An IC model number inspection device for inspecting reverse mounting, positional deviation, and the like identifies an IC model number as follows. That is, IC
The model number inspection apparatus has a configuration including a photographing unit, a storage unit, and a calculation unit, and preliminarily registers an image of each character of alphanumeric characters as a reference in the storage unit as a reference image. FIG. 5 is a diagram illustrating an example of the reference image. At the time of inspection, the IC model number inspection apparatus first photographs the model number printed on the upper surface of the IC by photographing means. An image photographed by the photographing means (hereinafter referred to as an input image) is as shown in FIG. Next, the IC model number inspection device cuts out characters from the input image, and performs pattern matching of the characters cut out from the input image and the reference image registered in the storage unit one by one to determine alphanumeric characters in the input image. Then, the determined alphanumeric group is arranged in order to identify the model number of the IC.

[0003] Thereafter, the IC model number inspection apparatus, the identified I
I to be mounted on the board registered in the model number and data of C
C is compared with a model number (hereinafter referred to as an inspection model number) to determine whether or not the identified IC model number is the same as the inspection model number.
The position coordinates of the model number of C and the position coordinates of the IC to be mounted on the board registered in the data (hereinafter referred to as component position coordinates)
To determine whether or not the identified IC is mounted according to the component coordinate position, thereby inspecting for reverse mounting and misalignment.

[0004]

By the way, the fonts and scales of IC models differ from manufacturer to manufacturer. For this reason, the IC model number inspection apparatus registers in advance as reference images indicating all types of expected fonts and alphanumeric models for each scale, and replaces all these reference images and characters cut out from the input image with one character. It is necessary to match one by one. FIG. 7 is a diagram showing the total number of models of the reference image. FIG.
Indicates that there are m types of fonts, and there are n types of models with different scales for each font, and the total number of these models is (n1 + n2 +... + Nm). The IC model number inspection apparatus needs to match all of these models. Therefore, it takes a lot of time to identify the model number of the IC. Note that the time at this time is specifically a value obtained by (pattern matching time per model × the number of English characters × the number of all models × the number of model numbers), and the number of English characters is 36 characters. If the pattern matching time is 2 ms, the type of font is 10, the number of models having different scales for each font is 3, and the number of characters of the model number is 8, 2 ms × 36
Character x 30 x 8 = 17280 msec.

In addition, the IC model number inspection apparatus uses a luminance projection method (a method of adding a luminance of light and shade in a horizontal direction and a vertical direction of an image, and determining a position where an added value of the luminance becomes a certain value or less as a character string, a character string and a character). Although the character is cut out by a method of cutting out a character string and a character as a character boundary), the character cutout may fail as shown in FIG. FIG. 8 is a diagram illustrating an example of a failure in character segmentation.
The character “74” indicates that the adjacent characters could not be separated, and the character “N” indicates that the character was split. The IC model number inspection device is liable to fail when the character line is thin or when adjacent characters overlap in the vertical direction. In such a case, the IC model number cannot be identified accurately, or the IC model number cannot be identified. Or it takes a lot of time to identify

[0006]

According to a first aspect of the present invention, there is provided an IC model number identification method using an IC model number identification device having a storage unit, a photographing unit, and a calculation unit. An alphanumeric reference image associated with each font used by the IC maker is registered, the photographing means photographs the model number of the top surface of the IC, and the arithmetic means is photographed by the photographing means. Characters are cut out from the image, the font of one or more cut out characters is estimated using the alphanumeric reference image in the storage means, and other characters are identified based on the estimated font.

According to a second aspect of the present invention, the arithmetic means according to the first aspect of the present invention is characterized in that the scale of the cut-out character matches the scale of the alphanumeric reference image, and then estimates the font of the cut-out character. I do.

[0008] A third invention is characterized in that the arithmetic means of the first or second invention first estimates the font of the first character, and subsequently identifies the second and subsequent characters. .

According to a fourth aspect of the present invention, there is provided an IC model number identifying method using an IC model number identifying device having an image sensing unit and an arithmetic unit. The image is thickened in the vertical direction or thinned in the horizontal direction to identify the position where the character should be cut out, and the character is cut out from the image captured by the image capturing means based on the identified position.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention estimates a specific character cut out from an input image to be close to a font of a character used by which IC maker, and determines a specific character in the input image based on the estimated result. Characters other than characters are also identified. As a result, the present invention can accurately identify the model number of the IC in a short time. The specific characters are, for example, as follows. In other words, the IC is printed on the upper surface with a marking corresponding to the type of the IC, for example, "74HC24OO" or "$ SN74OO". Among them, reference numeral 74 denotes a marking for indicating that the IC is a transistor / transistor logic (TTL), which is a specific character.

An embodiment of the present invention will be described below with reference to the drawings. In addition, each figure is only schematically shown to the extent that the present invention can be understood. In each figure,
Elements that are common are assigned the same numbers, and descriptions thereof are omitted.

(First Embodiment) FIG. 1 shows an IC according to the present invention.
It is a block diagram of a model number inspection apparatus. In FIG. 1, reference numeral 1 denotes illumination, 2 denotes photographing means such as a camera or a video camera (hereinafter referred to as a camera), 3 denotes an image processing device, 4 denotes a personal computer (hereinafter referred to as a PC), 5 denotes a substrate, and 6 denotes an IC. It is.

The IC model number inspection apparatus uses the illumination 1 to
The camera 2 captures the model number of the IC 6 mounted on the substrate 5 with the camera 2 and outputs the captured image (hereinafter, referred to as an input image) to the image processing device 3.

In this image processing apparatus 3, table data of an alphanumeric reference image created as described below is registered in advance. That is, the creator of the reference image table data first classifies the alphanumeric images used for marking by each IC maker into fonts such as Mincho and Gothic fonts, and determines whether or not there is a splash. Classified by type based on differences due to shape, line thickness, etc. to obtain alphanumeric reference images, and the obtained reference images are used by each IC manufacturer centering on the specific characters mentioned above. A specific character and a character other than the specific character are associated with each other and converted into table data.

The image processing apparatus 3 performs character recognition as follows using the table data of the alphanumeric reference image. That is, when receiving the image from the camera 2, the image processing device 3 cuts out characters from the input image and extracts a specific character from the characters. Then, pattern matching is performed between the image of the specific character extracted from the input image and the specific character in the table data of the reference image, and the specific character extracted from the input image is close to which font used by which IC maker. Estimate. Thereafter, characters other than the specific character in the input image are also identified based on the estimated specific character font, and the character in the input image is determined. Then, data relating to the character identification (for example, the font of the character, the result of the character identification, the position of the character identified, etc.) is transmitted to the PC 4. If the character cut out from the input image is a font not stored in the image processing device 3, the image processing device 3 determines that the character cannot be identified. In this case, assuming that the character is a character of a new font, the operator newly registers the image of the character in the image processing apparatus 3 as a reference image. At this time, the operator checks which manufacturer's IC uses the character, and registers the reference image so as to correspond to the IC maker. Thereby, the image processing device 3 will thereafter
Characters in this font can be identified.

When the PC 4 receives data relating to character identification (eg, character font, character identification result, character position, etc.) from the image processing apparatus 3, the PC 4 identifies the IC model number. Then, the model number of the identified IC and the model number of the IC to be mounted on the board registered in the data (hereinafter, referred to as the model number)
(Referred to as an inspection model number) to determine whether or not the identified IC model number is the same as the inspection model number, thereby inspecting for physical differences or registering the identified IC model number in position coordinates and data. By comparing the position coordinates of the ICs to be mounted on the board (hereinafter, referred to as component position coordinates) to determine whether or not the identified IC is mounted according to the component coordinate positions, it is possible to perform reverse mounting, Inspect for misalignment.

FIG. 4 shows an IC model number identification method according to the present invention.
This will be described with reference to FIG. FIG. 4 is a diagram showing an IC model number inspection flow.

In step 1 (S 1), the IC model number inspection apparatus takes an image of the model number printed on the IC 6 on the substrate 5 with the camera 2 and inputs the captured image to the image processing apparatus 3.

At S2, the IC model number inspection apparatus
As shown in (1), character strings and characters are cut out by acquiring histograms of the input image in the vertical and horizontal directions by the luminance projection method and cutting out the input image at locations corresponding to the valleys of the histogram. FIG. 2 is a diagram illustrating an example of cutting out characters.

At this time, the IC model number inspection apparatus can prevent one character from being divided or adjacent characters from being merged and cut out by cutting out characters as described below. That is, the IC model number inspection device
The character is vertically bolded at a predetermined ratio, and the character is horizontally thinned at a predetermined ratio. The IC model number inspection device performs thickening in the vertical direction of the character at a predetermined ratio, so that the output of the luminance distribution at the portion where the character is drawn becomes high. The IC model number inspection apparatus identifies a position where a character is to be cut out in that state, and cuts out the character from the input image based on the position information, thereby preventing the character from being divided at a thin portion. In addition, the IC model number inspection apparatus can make an interval between adjacent characters by thinning the characters in the left-right direction at a predetermined ratio. The IC model number inspection apparatus identifies a position where a character is to be cut out in that state, and cuts out the character from the input image based on the position information, so that adjacent characters can be separated.

The IC model number inspection device cuts out a character from an input image, and then estimates the scale of the character from the vertical length of the cut out character. In this embodiment, the vertical length of the character (that is, the length of the arrow in FIG. 2) is estimated as the model number scale.

In step S3, the IC model number inspection apparatus performs pattern matching between the histogram of the input image and the histogram of a specific character determined according to the IC model number for each cut-out character unit, and performs similarity from the input image. Search for the part to be extracted and extract the relevant part. That is, for example, when “74” is defined as a specific character as in the present embodiment, the IC model number inspection apparatus continuously displays histograms similar to the histograms of “7” and “4”. A part to be extracted is extracted from the input image.

Next, the IC model number inspection apparatus further resembles “7” from the corresponding portion extracted from the input image (ie, the portion where the histogram similar to the specific character “74” exists). The part where the histogram exists is extracted. Next, as shown in FIG. 3, the IC model number inspection device enlarges or reduces the reference image of each font so as to match the scale estimated in S2. FIG. 3 is a diagram showing the scale conversion of the reference image. And
The extracted portion (that is, the portion where a histogram similar to “7” exists) and the histogram of “7” of the reference image of each font enlarged or reduced to match the scale estimated in S2 are sequentially patterned. Match. Thereby, the font of a specific character is estimated. That is, the font of the reference image that matches the specific character is regarded as the font of the specific character.

In step S4, the IC type number inspection apparatus identifies a character other than the specific character in the input image based on the estimated specific character font, and determines the character in the input image.

In S5, the IC model number inspection device identifies the IC model number from the characters in the determined input image. Then, the model number of the identified IC is compared with the model number of the IC to be mounted on the board registered in the data (hereinafter referred to as an inspection model number), and it is determined whether or not the identified IC model number is the same as the inspection model number. I do. As a result, it is possible to inspect for a physical difference. Further, by comparing the position coordinates of the model number of the identified IC with the component position coordinates registered in the data, and determining whether or not the identified IC is mounted according to the component coordinate position, reverse mounting, The displacement can be inspected.

The time required to identify the model number of an IC according to the present invention is (pattern matching time per model × number of English characters × number of fonts + pattern matching time per model × number of English characters × model number The number of English characters is 36. The number of English characters is 36. If the pattern matching time per model is 2 ms, the type of font is 10, and the number of characters of the model number is 8,
2 ms x 36 characters x 10 + 2 ms x 36 x 7 = 12
This is 24 ms. Therefore, according to the present invention, character identification can be performed in a very short time as compared with the related art.

[0027]

The present invention described above has the following effects.

According to the first invention, the model number of an IC can be accurately identified in a short time.

According to the second invention, since it is not necessary to register a reference image for each scale, the capacity of the reference image to be stored can be reduced, and the number of times of matching the character cut out from the input image with the reference image is reduced. It is possible,
The model number of the IC can be accurately identified in a short time.

In the third invention, since the first character is often a specific character, the processing time can be reduced by identifying the character based on this character.

According to the fourth aspect of the present invention, characters can be correctly cut out from an input image, so that the model number of an IC can be correctly identified.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of an IC model number inspection apparatus according to the present invention.

FIG. 2 is a diagram showing an example of character cutout.

FIG. 3 is a diagram illustrating scale conversion of a reference image.

FIG. 4 is an IC model number inspection flow.

FIG. 5 is a diagram illustrating an example of an alphanumeric reference image.

FIG. 6 is a diagram illustrating an input image.

FIG. 7 is a diagram showing the total number of models of a reference image.

FIG. 8 is a diagram illustrating an example of a failure in character segmentation.

[Description of Signs] 1 lighting 2 camera 3 image processing device 4 personal computer 5 board 6 IC

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5B029 AA01 BB02 EE11 EE15 EE16 EE17 5B064 AA05 AB13 BA01 CA08 CA11 DA17 DA35 DC37

Claims (4)

[Claims] 1. An IC model number identification method using an IC model number identification device having a storage unit, a photographing unit, and a calculation unit, wherein the storage unit includes an alphanumeric character associated with each font used by an IC maker. A reference image is registered, the photographing unit photographs a model number of an upper surface of the IC, the calculating unit cuts out characters from the image photographed by the photographing unit, and stores the font of one or more cut out characters. An IC model number identification method characterized by estimating using an alphanumeric reference image of the means, and identifying other characters based on the estimated font. 2. The IC model number identification method according to claim 1, wherein said calculating means estimates the font of the cut out character after matching the scale of the cut out character with the scale of the alphanumeric reference image. . 3. The IC model number identification method according to claim 1, wherein said calculating means first estimates a font of a first character, and subsequently identifies a second character and a subsequent character. 4. An IC model number identification method using an IC model number identification device having a photographing means and a calculating means, wherein the photographing means photographs a model number on an upper surface of the IC, and the computing means vertically moves an image photographed by the photographing means. An IC model number identification method comprising: identifying a position where a character is to be cut out by bolding or thinning the line in the left-right direction, and cutting out the character from an image photographed by photographing means based on the identified position.