JP2002057841A - Image reading system and method for reading the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image reading system and a method for reading the same capable of significantly decreasing time for reading and effectively recognizing images. SOLUTION: The image reading system reads images of electronic parts 6A, 6B, and 6C by a camera 8 having a line sensor with a plurality of pixels including serially arranged optical/electrical conversion element. The system outputs image signal by periodically choosing pixels one by one which will be an object of image signal set based on width data of image pickup area stored in a image pickup area storage section 10, monitors relative positional relation between an image pickup object and the line sensor with pulse of encoder 4a, and controls writing of image signal to a image storing section 15 based on length data of the image pickup area with storage operation control section 12. This eliminates useless output and storage of image signal from unnecessary area and can effectively read images.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image reading apparatus and an image reading method for reading an image to be imaged by a line sensor.

[0002]

2. Description of the Related Art A line sensor is known as an imaging means for performing position recognition of an electronic component by image processing in an electronic component mounting apparatus or the like. This line sensor is configured by linearly arranging a pixel having a photoelectric conversion element for storing an electric charge corresponding to the amount of received light and a transfer unit for receiving an electric charge from the pixel and outputting it as an electric signal. When an optical image of an object to be imaged is formed on a line sensor by an optical system, electric charges corresponding to the optical image of the object are stored in each pixel.

By receiving the charges of each pixel by the transfer unit and sequentially outputting them as electric signals, one-dimensional image data in the arrangement direction of the photoelectric conversion elements, that is, in the main scanning direction can be obtained. Then, desired two-dimensional image data is obtained by paralleling a plurality of one-dimensional image data obtained by relatively moving the electronic component in a sub-scanning method orthogonal to the main scanning direction. Conventionally, a CCD line sensor has been used as the line sensor.

[0004]

By the way, the types and sizes of electronic components are diverse, and a multi-function type electronic component mounting apparatus which targets various types of electronic components from small to large sizes has the same image reading capability. It is necessary to image electronic components of different sizes depending on the device. For this reason,
In general, an image reading apparatus using a line sensor often includes a line sensor having a scanning width corresponding to the size of the largest electronic component among the target components.

However, in the CCD line sensor used in the conventional image reading apparatus, it is necessary to transfer charges from all the pixels constituting the line sensor at the time of image reading, regardless of the size of the image reading target. For this reason, electric charges are transferred from pixels in an unnecessary range that do not contain any necessary information, so that extra time is required for image reading.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an image reading apparatus and an image reading method capable of greatly shortening an image reading time and improving image recognition efficiency.

[0007]

According to a first aspect of the present invention, there is provided an image reading apparatus for reading an image of an imaging target by forming an optical image of the imaging target on a photoelectric conversion element. A line sensor in which a plurality of pixels each including an element are arranged in series in an X direction; a pixel selection unit that outputs an image signal from a pixel selected by selecting one of the plurality of pixels; Relative movement mechanism for relatively moving the image pickup object at least in the Y direction crossing the X direction, and an imaging area storage for storing the X direction numerical value and the Y direction numerical value related to the size of the imaging area by the line sensor. Unit, an image storage unit that stores an image signal output from the line sensor, and control of selection of pixels by the pixel selection unit using the numerical value in the X direction. That the image output control section, with the Y-direction values and the storage operation control unit for controlling the writing of the image signal to the image storage unit based on the position information of the relative movement mechanism.

According to a second aspect of the present invention, in the image reading apparatus according to the first aspect, the imaging area can be set to a width smaller than a width of a maximum imaging area of the line sensor. .

According to a third aspect of the present invention, in the image reading apparatus according to the first aspect, the numerical value in the Y direction includes at least size data of the imaging area in the Y direction.

According to a fourth aspect of the present invention, in the image reading apparatus according to the first aspect, the storage operation control unit converts the numerical value in the Y direction into a coordinate system of the relative movement mechanism. A writing control unit that controls whether or not writing of an image signal to the image storage unit is possible based on the numerical value in the Y direction converted by the coordinate conversion unit and the position information.

According to a fifth aspect of the present invention, in the image reading apparatus according to the first aspect, the numerical value in the Y direction is a numerical value on a coordinate system of the relative movement mechanism.

According to a sixth aspect of the present invention, in the image reading apparatus according to the first aspect, the numerical value in the Y direction includes at least positional information of an imaging area on a coordinate system of the relative movement mechanism.

According to a seventh aspect of the present invention, in the image reading apparatus according to the first aspect, the numerical value in the X direction includes at least size data of the imaging area in the X direction.

According to an eighth aspect of the present invention, there is provided the image reading apparatus according to the first aspect, wherein the image output control section sets a target pixel for image output based on the numerical value in the X direction. A setting unit; and a selection operation control unit that controls the pixel selection unit so as to periodically select the pixel that is the target of the image output.

According to a ninth aspect of the present invention, in the image reading apparatus according to the first aspect, the numerical value in the X direction includes at least the number of pixels corresponding to the size of the imaging area in the X direction.

According to a tenth aspect of the present invention, in the image reading method, a line sensor in which a plurality of pixels having photoelectric conversion elements are arranged in series in the X direction is relatively moved in the Y direction intersecting the X direction with respect to the imaging target. An image reading method for reading a pixel to be imaged, wherein: (1) a step of setting an imaging area; and (2) a plurality of pixels for outputting an image signal based on the set width of the imaging area in the X direction. (3) outputting an image signal by periodically selecting pixels one by one, and (4) monitoring the relative positional relationship between the imaging target and the line sensor in the Y direction. The method includes at least a step of controlling writing of the image signal to the image storage unit, and the step (3) is performed only on the plurality of pixels set in the step (2).

According to the present invention, when outputting an image signal from the line sensor, the image signal is selectively output only from the photoelectric conversion element corresponding to the imaging area set as the image signal output target within the imaging range. In addition, by monitoring the relative positional relationship between the imaging target and the line sensor and controlling the writing of the image signal, it is possible to eliminate the waste of outputting and storing the image signal from an unnecessary range, thereby improving the efficiency of image reading. Can do well.

[0018]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is a block diagram showing a configuration of an electronic component mounting apparatus according to an embodiment of the present invention, FIG. 2 is a block diagram showing a configuration of a camera of an image reading apparatus according to an embodiment of the present invention, and FIG. FIG. 4 is a configuration diagram of a line sensor of the image reading apparatus according to one embodiment of the present invention, FIG. 4 is a flowchart of an imaging area setting process of the image reading apparatus according to one embodiment of the present invention, and FIGS. FIG. 7 is a flowchart of an image reading method according to an embodiment of the present invention, and FIG. 8 is an explanatory diagram of an image reading method according to an embodiment of the present invention. is there.

First, an electronic component mounting apparatus incorporating an image reading apparatus will be described with reference to FIG. In FIG. 1, a component supply unit 1 supplies an electronic component to be mounted. The board positioning stage 2 holds and positions a board 3 on which electronic components are mounted. A transfer head 5 is disposed above the component supply unit 1 and the substrate positioning stage 2 so as to be horizontally movable in the Y direction by a transfer head moving mechanism 4. The transfer head moving mechanism 4 includes a position detection encoder 4 a, generates a pulse signal indicating the position of the transfer head 5, and transmits the pulse signal to the mechanism control unit 7.

The transfer head 5 is a multiple transfer head provided with three pickup heads 5a.
, Different kinds of electronic components 6 from the component supply unit 1 by the respective pickup heads 5a.
A, 6B, and 6C are taken out, transported to a position on the substrate positioning stage 2, and mounted on the substrate 3.

A camera 8 is provided on a moving path of the transfer head 5 between the component supply unit 1 and the substrate positioning stage 2. As will be described later, the camera 8 includes a line sensor in which a plurality of pixels each having a photoelectric conversion element are arranged in series in the X direction. Electronic component 6 held by transfer head 5
By positioning A, 6B and 6C on the camera 8,
Optical images of these electronic components to be imaged are formed on a photoelectric conversion element, and an image signal obtained by converting the optical image into an electric signal is always output to the recognition device 9.

The transfer head 5 is moved by the transfer head moving mechanism 4 with respect to the camera 8 in the Y direction.
By performing imaging of the electronic component, a scanned image of the electronic component to be recognized can be obtained. The transfer head moving mechanism 4 is a relative moving mechanism that relatively moves the line sensor of the camera 8 with respect to the imaging target in the Y direction intersecting the arrangement direction (X direction) of the line sensors.

Next, the configuration of the recognition device 9 will be described. The recognition device 9 processes an image signal output from the camera 8 to perform recognition processing of the electronic component. As shown in FIG.
Includes an imaging area setting unit 11, an imaging area storage unit 10, a storage operation control unit 12, an image storage unit 15, and an image processing unit 16. The storage operation control unit 12 includes a coordinate conversion unit 13 and a writing control unit 14.

The imaging area setting section 11 has a function of inputting a numerical value in the X direction and a numerical value in the Y direction relating to the imaging area set when the recognition target is imaged by the line sensor. These numerical values include size data defining the width (size in the X direction) and length (size in the Y direction) of the imaging area, a reference position in the X direction of the imaging area, and a position in the Y direction (scanning area). (The imaging start position at the time).

These numerical values are input on a display screen as described later, and are input as numerical values on an image coordinate system of an image processing unit that performs display processing of the screen. The maximum width size of the imaging area set here is the width size of the maximum imaging area of the line sensor (the pixel array width of the line sensor). If the size is smaller than this, an arbitrary width size can be set. I have.

The input numerical value relating to the imaging area is stored in the imaging area storage unit 10. Imaging area storage unit 1
Of the numerical values relating to the imaging area stored in 0, the numerical value in the X direction of the imaging area is output to the camera 8 and the numerical value in the Y direction is output to the coordinate conversion unit 13 of the storage operation control unit 12.

The above-described numerical value in the Y direction, that is, the numerical value indicating the size (length) in the Y direction of the imaging area and the imaging start position represented by the numerical value on the image coordinate system is transferred by the coordinate conversion unit 13 to the transfer head movement. It is converted into a numerical value on the machine coordinate system of the mechanism 4 and transmitted to the writing control unit 14. The writing control unit 14 sends a write permission signal for writing an image signal to the image storage unit 15 based on the numerical value in the Y direction converted by the coordinate conversion unit 13 and the position information transmitted from the transfer head moving mechanism 4. Output.

That is, by outputting to the image storage unit 15 a write enable signal indicating that it is a timing at which the image signal constantly output from the line sensor of the camera 8 is allowed to be written to the image memory. Only the image signal output from the camera 8 at the set predetermined timing is written to the image memory of the image storage unit 15, and the writing control of the image signal for inhibiting the writing of the image signal output at another timing is performed.

This write control monitors the position information of the transfer head 5 sent from the transfer head moving mechanism 4 via the mechanism control unit 7, and controls the position of the image pickup area stored in the image pickup area storage unit 10 in the Y direction. This is performed by detecting the imaging start position in comparison with a numerical value. That is, the storage operation control unit 1
Reference numeral 2 controls whether an image signal can be written to the image storage unit 15 based on the numerical value of the imaging area in the Y direction and the position information of the transfer head moving mechanism 4. Thereby, the transfer head 5
The relative position of the camera 8 with respect to the imaging target among the image signals output from the camera 8 while each electronic component to be imaged is moving in the Y direction is set in a predetermined imaging area set for each electronic component. Only the image signal output at the corresponding position is written into the image storage unit 15.

The written image signals are read by the image processing unit 16, and the images are processed to recognize the electronic components 6A, 6B, and 6C.
The recognition result is sent to the mechanism control unit 7 and used for mounting operation control when these electronic components are mounted on the board 3, and is output to the display monitor 17 as necessary, and a predetermined screen display is performed. . Various operations of the recognition device 9 and inputs necessary for input are performed via the operation unit 18.

Next, the configuration of the camera 8 used for imaging will be described with reference to FIGS. 2, the camera 8 includes a line sensor 8a, an image output control unit 26, and a signal processing unit 30. The line sensor 8a includes a reset drain 20 and a second shift gate 2 described below.
1, a photoelectric conversion unit 22, a first shift gate 23, and a sample hold unit 24.

In the photoelectric conversion section 22, a plurality of photoelectric conversion elements 22a are arranged in a lattice. The photoelectric conversion unit 22 is provided with a first shift gate 23 and a second shift gate 21, and each photoelectric conversion element 22 a of the photoelectric conversion unit 22 is provided.
Are the first shift gate 23 and the second shift gate 23 as shown in FIG.
Each gate element 23a, 21 of the shift gate 21
a. Each gate element 21a of the second shift gate 21 is connected to the reset drain 20, and each gate element 23a of the first shift gate 23 is connected to each power storage element 24a of the sample and hold unit 24.

Further, each storage element 24 a of the sample and hold section 24 is connected to each gate element 25 a of the pixel selection section 25. In FIG. 3, the photoelectric conversion element 22a, the gate elements 21a and 23a, and the power storage element 24a, which are shown in a broken-line frame,
Constitutes one pixel 19 of a plurality of pixels arranged in series with the line sensor 8a. The image signal from each pixel 19 of the line sensor 8a is selected and output for each pixel by the pixel selection unit 25.

The image output control section 26 comprises a timing signal generation section 27, a target pixel setting section 28, and a selection operation control section 29. The timing signal generator 27 generates an internal clock signal, and generates a first
Control signals Csg1 and Csg2 for controlling the opening and closing of the shift gate 23 and the second shift gate 21 and a control signal Csh for controlling the reset operation of the sample and hold unit 24 are generated at predetermined timing.

By forming an optical image on the photoelectric conversion section 22, the photoelectric conversion element 22a is exposed to light and accumulates electric charges. When the control signal Csg1 is transmitted to the first shift gate 23, each of the photoelectric conversion elements 2 of the photoelectric conversion unit 22 is transmitted.
2a is stored in each storage element 24 of the sample and hold unit 24.
a. The transferred charge is held as a voltage value corresponding to the amount of charge. By transmitting the control signal Csh to the sample and hold unit 24 before new charge is transferred, the held voltage value is reset. When the control signal Csg 2 is transmitted to the second shift gate 21, the charge of each photoelectric conversion element 22 a of the photoelectric conversion unit 22 is discharged to the reset drain 20.
Thereby, the potential of each photoelectric conversion element 22a of the photoelectric conversion unit 22 is initialized.

The pixel selector 25 selects one of the plurality of pixels of the line sensor 8a to output an image signal from the selected pixel. That is, the voltage value is output as the image signal Vout only from the storage element 24a specified by the selection operation control unit 29 among the storage elements of the sample hold unit 24. This pixel selection operation is performed by the image output control unit 26.

The photoelectric conversion element 22 of the photoelectric conversion unit 22
a (refer to the leftmost black photoelectric conversion element 22a) is a reference element for setting a black reference level on an image, and is based on electric charges transferred from this reference element. The reference potential Vbl corresponding to the black reference level
ack is output.

The target pixel setting unit 28 specifies a pixel to be an image signal output based on the width data (numeric value in the X direction) of the imaging area read from the imaging area storage unit 10. That is, by converting the numerical value (the numerical value on the image coordinate system) regarding the width of the imaging area into the number of pixels in the line sensor 8a, the pixel selected as the target of the image signal output at the time of imaging by the line sensor 8a is determined. Data to be specified is obtained, and these data are sent to the selection operation control unit 29.

The selection operation control section 29 periodically selects, one by one, the pixels from which the image signal is to be output based on the data specifying these pixels, that is, a predetermined time interval from these specified pixels. Controls the pixel selection unit 25 so as to sequentially output image signals. Therefore, the selection operation control unit 29 of the image output control unit 26 controls the selection of the pixel to be the target of the image signal output by the pixel selection unit 25 using the numerical value of the imaging area in the X direction. This allows
Image signals are sequentially output only from the pixels corresponding to the imaging area among the pixels of the line sensor 8a.

Note that the width data of the imaging area received by the target pixel setting unit 28 is already represented based on the number of pixels in the line sensor 8a as described later, and the position of the pixel serving as a reference of the imaging position and the width of the imaging area Is provided as it is, the function of the target pixel setting unit 28 is not required, and these data are transmitted to the selection operation control unit 29 as they are.

An image signal output from each pixel of the line sensor 8a via the pixel selector 25 is sent to the signal processor 30. The signal processing unit 30 includes a correction coefficient storage unit 31 and D
An A / A converter 32 and an image signal corrector 34 are provided, where the image signal is corrected. In this correction processing, the digital correction data stored in the correction coefficient storage unit 31 is converted into an analog signal by the D / A conversion unit 32, and the analog signal is converted by the image signal correction unit 34 into an image from the pixel selection unit 25. This is done by adding to the signal. Here, Black33a, Coffset
Four kinds of correction coefficients 33b, Coeffin 33c, and Gain 33d are used.

Black 33a, Coffset 33b
Is a correction coefficient for setting a reference potential serving as a reference for the black level of the image. Black 33a corrects the black level of the entire image, and Coffset 33b corrects the black level of each pixel constituting the image. Also Coe
fin33c and Gain33d are correction coefficients for setting the sensitivity. Gain33d corrects the sensitivity of the entire image, and Coefffin33c corrects the sensitivity of each pixel. The processing by the signal processing unit 30 is performed by the image output control unit 26.
This is performed based on the timing signal output from.

The analog image signal after the correction processing is A / D
The data is sent to the conversion unit 35. The A / D converter 35 performs A / D conversion on the analog image signal based on the timing signal from the image output controller 26. The digital image data after the A / D conversion is output via the digital buffer 37. The analog image signal is output as it is as image data for display via the analog buffer 36 as it is.

Next, the imaging area setting processing will be described. As described above, unlike the conventional CCD line sensor, the line sensor 8a of the camera 8 according to the present embodiment differs from the conventional CCD line sensor in that a plurality of pixels 19 constituting the line sensor 8a can be used to start an image from any specified pixel. A signal can be output. Therefore, when taking an image with the line sensor 8a, it is necessary to specify a pixel as an image signal output target according to the imaging target.

An image signal is always output from the line sensor 8a. To obtain a scanned image of an object to be imaged, a timing corresponding to a set imaging area of the image signal constantly output during scanning is used. Only the image signal output in step (1) need be written in the image memory. That is, in the imaging area setting processing, data input for setting the timing at which an image signal is to be written is performed while specifying the output target pixel of the line sensor 8a. Hereinafter, the imaging area setting process will be described with reference to FIG. 5 along the flowchart of FIG.

In the flowchart of FIG. 4, first, the imaging area is set to the maximum (ST1). That is, the width of the imaging area read by the target pixel setting unit 28 is set to the maximum. Thus, when the pixel selection unit 25 is controlled by the selection operation control unit 29, image signals are output from all the pixels 19 arranged in the line sensor 8a. Further, the write control unit 14 outputs a write permission signal to the image storage unit 15 so that the output image signal is written continuously without interruption.

Then, under these set conditions, an electronic component to be recognized is imaged (ST2). That is, as shown in FIG. 5A, while the transfer head 5 holding the electronic components 6A, 6B, 6C is horizontally moved at a predetermined scanning speed, the held electronic components are imaged by the camera 8, and the image signal is continuously output. In the image storage unit 15. Then, the image data is read by the image processing unit 16 and displayed on the screen of the display monitor 17 (ST3). As a result, as shown in FIG. 5B, images of the electronic components 6A, 6B, and 6C held in the three nozzles of the transfer head 5, respectively,
It appears on one screen at intervals corresponding to the nozzle pitch.

In this state, the apparatus waits for data input for setting the imaging area (ST4).
An imaging area is set on the screen. Since image information other than the area including the electronic component to be recognized is not necessary for the recognition of the electronic component, in setting this imaging area, as shown in FIG. 6B, 6
Areas A, B, and C including C are set as imaging areas. This setting operation is performed by designating and inputting an area frame with a pointer or the like on the display screen of the display unit 17 using the operation unit 18.

Thus, numerical values (W1, L1) and (W2, L) indicating the size (width, length) of each of the imaging areas A, B, C are obtained.
2), (W3, L3) and numerical values Y1S, Y2S, Y3S indicating the imaging start position of each imaging area A, B, C are obtained by the imaging area setting unit 11 as numerical values of the image coordinate system of the image processing unit 16. Can be

Regarding the width data (numerical value in the X direction) of the imaging area, in addition to W1, W2, and W3, data of the reference position, that is, which pixel in the pixel array of the line sensor 8a is used as a reference. Data indicating whether it is set as a position is required. However, normally, as shown in FIG. 5C, the center of the imaging areas A, B, and C is often set so as to coincide with the center line of the imaging visual field, and in this case, the input of the reference position is unnecessary. Thus, only the numerical values W1, W2, and W3 simply indicating the imaging area width are input. Then, as shown in FIG. 6, the imaging areas A ′,
When B ′ and C ′ are set off the center of the imaging field of view, in addition to the numerical values W1, W2, and W3 indicating the imaging area width, numerical values X1S and X1S indicating the X direction reference position of the imaging area
X2S and X3S are input together.

The numerical value input by setting the imaging area in this way is stored in the imaging area storage unit 10 (ST5). When this setting input is confirmed, the setting operation is completed, and the imaging area setting process ends (ST
6).

In the above description, an example has been described in which the numerical data on the image coordinate system of the image processing unit 16 is stored as it is when the numerical data is stored in the imaging area storage unit 10, but in this embodiment. Alternatively, the image data can be stored in the imaging area storage unit 10 in a numerical data format described below. That is, when storing the data of the imaging area,
Instead of storing as a numerical value on the image coordinate system, a numerical value based on the number of pixels in the line sensor 8a for the X direction, and a numerical value on the machine coordinate system for the Y direction,
A format for storing the data of the imaging area can be selected.

In this case, the numerical values in the X direction of the imaging area, that is, the numerical values W1, W2, W3 indicating the width and the numerical values X1S, X2S, X3S indicating the reference position are obtained from the numerical values on the image coordinate system by the line sensor. The number of pixels in the pixel array 8a and the numerical value indicating the position of the pixel are stored after being converted. Numerical values in the Y direction, that is, L1 and L
2, L3 and numerical values Y1S, Y2S, Y3S indicating the imaging start position of each imaging area are stored after being converted from numerical values on the image coordinate system into numerical values on the mechanical coordinate system of the transfer head moving mechanism 4. .

That is, in this format, the numerical value in the X direction is a numerical value including the number of pixels corresponding to the size in the X direction of the imaging area. The numerical value in the Y direction is a numerical value of the transfer head moving mechanism 4 on the mechanical coordinate system, and includes position information (Y1S, Y2S, Y3S) of the imaging area as a position on the mechanical coordinate system. When this data storage format is used, the processing performed by the target pixel setting unit 28 becomes unnecessary, and there is no need to perform data conversion by the coordinate conversion unit 13 each time an image is captured.

Next, an image reading process will be described with reference to FIGS. Prior to the image reading, the setting of the imaging area according to the recognition target is performed as described above. FIG. 8 shows numerical values in the X and Y directions set for the imaging areas A, B, and C set for the electronic components 6A, 6B, and 6C, and the actual electronic components 6A, 6B, and 6C.
Shows the relative positional relationship between the two. X1S, X2S, X
3S is a numerical value based on the number of pixels in the pixel array of the line sensor 8a, and Y1S, Y2S, and Y3S are numerical values on the mechanical coordinate system of the transfer head moving mechanism 4 that moves the transfer head 5 (for example, from the encoder 4a). (Number of output pulses).

Further, (X1E-X1S), (X2E-X
2S) and (X3E-X3S) correspond to W1, W2, and W3 shown in FIG. 5C, respectively, and (Y1E-Y1S),
(Y2E-Y2S) and (Y3E-Y3S) are L
1, L2 and L3. YC1, YC2, and YC3 set on the Y axis indicate shift positions corresponding to timings at which the transfer head 5 shifts relative movement speed with respect to the line sensor 8a.

That is, each numerical value (YC1, YC2, Y1S, Y1E,..., Y3E, Y3) in the Y direction shown on the Y axis in FIG.
YC3) corresponds to a specific relative positional relationship between the line sensor 8a and the transfer head 5 in the Y direction.
It is possible to determine what kind of positional relationship is established.
For example, if the position information (pulse signal) from the encoder 4a of the transfer head moving mechanism 4 matches the numerical value YC1, the transfer head 5 reaches the deceleration position set to realize a stable scanning speed. It is shown that. YC2 is a numerical value corresponding to the speed setting position at which the deceleration is completed and the scanning speed becomes constant.

Y1S and Y1E are numerical values corresponding to the imaging start position and the imaging end position of the imaging area A set for the electronic component 6A held by the transfer head 5, and are respectively imaged immediately above the line sensor 8a. Start position,
A numerical value indicating that the imaging end position has been reached. Y2
Similarly, S, Y2E, Y3S, and Y3E also have imaging areas B,
Numerical values respectively correspond to the imaging start position and the imaging end position of C.

That is, the position information from the encoder 4a is monitored, and if this position information matches each of the above numerical values, it is detected that a specific relative positional relationship corresponding to each numerical value has been realized. In accordance with the detection result, various operation controls, for example, operation control of the transfer head 5,
The writing control of the image signal, the updating of the setting of the image signal output target pixel of the line sensor 8a and the like are performed.

The operation will be described below with reference to the flowchart of FIG.
When reading of an image of an imaging target is started, data of imaging areas A, B, and C set in advance are read from the imaging area storage unit 10 (ST11). That is, each numerical value shown in FIG. 8 is read. Then, based on the read data, first, the target pixel setting unit 28 sets a pixel to be an image signal output target in capturing an image of the imaging area A where the image is first captured (ST12). As a result, of the pixels of the line sensor 8a of the camera 8, FIG.
Are set as the output targets.

Then, an image signal is constantly output from the set pixel (ST13). When the reading operation is started and the transfer head 5 holding the electronic component to be imaged starts moving, the pulse output from the encoder 4a of the transfer head moving mechanism 4 is transmitted as position information via the mechanism control unit 7 as position information. It is sent to the writing control unit 14 and the image output control unit 26 of the camera 8. The writing control unit 14 monitors this position information (ST14).

When the position information coincides with the deceleration position YC1, the movement of the transfer head 5 starts to decelerate, and the scanning speed is set to a stable value by YC2. If the position information matches the YIS corresponding to the imaging start position of the imaging area A (ST15), the writing control unit 14 sets the image storage unit 15
, And outputs a write enable signal (ST16). That is, storage of the image signal output from the pixel between X1S and X1E is started. After that, the writing is continued, and if the position information matches the YIE corresponding to the imaging end position of the imaging area A (ST15), the writing control unit 14 stops the writing permission signal to the image storage unit 15 and performs writing. Is prohibited (ST17). Thus, the storage of the image of the imaging area A by the image storage unit 15 ends.

Then, the presence or absence of the next imaging area is determined (ST18). If it is determined that there is, the imaging of the subsequent imaging area is performed in the same manner. At this time, the image output control unit 26 identifies the next imaging area based on the position information from the mechanism control unit 7, and sets the setting of the image output target pixel by the target pixel setting unit 28 to the width size of the imaging area. Update processing is performed accordingly. After the image reading is completed for all the imaging areas in this manner, when the transfer head 5 reaches the speed return position YC3, the transfer head 5 returns at a high speed and moves toward the substrate positioning stage 2.

That is, as described in the flowchart, the image reading method according to the present embodiment moves the line sensor 8a in which a plurality of pixels are arranged in series in the X direction relative to the imaging target in the Y direction. In this image reading, (1) an imaging area is first set, and (2) the line sensor 8a is set based on the set width of the imaging area in the X direction.
A plurality of pixels that output an image signal are set among the pixels of (3). In the imaging, (3) an image signal is output from the pixel by periodically selecting one pixel at a time, and (4) an imaging target and a line are output. By monitoring positional information indicating a relative positional relationship with the sensor 8a in the Y direction, writing of an image signal to the image storage unit 15 is controlled. The image signal output of (3) is performed only for the plurality of pixels set in the setting of the image output target pixel of (2).

In this image reading, when the image signal is output from the line sensor 8a, the image signal is selectively output only from the range corresponding to the imaging region set as the image reading target in the imaging range. Therefore, it is possible to eliminate the useless time for outputting the image signal from the unnecessary range and shorten the image reading time.

After the recognition of these electronic components 6A, 6B, 6C is completed, the transfer head 5 moves onto the substrate positioning stage 2. When mounting the electronic components on the substrate 3 by moving the transfer head 5 onto the substrate positioning stage 2,
Each electronic component is mounted on the board 3 after correcting the detected position shift based on the recognition result. In this mounting operation, the image reading time is greatly reduced as described above, so that high-speed image recognition is realized and mounting efficiency can be improved.

[0067]

According to the present invention, when an image signal is output from a line sensor, an image signal is selectively output only from a photoelectric conversion element corresponding to an imaging area set as an image signal output target within the imaging range. In addition to monitoring the relative positional relationship between the imaging target and the line sensor and controlling the writing of the image signal, eliminating the waste of outputting and storing the image signal from the unnecessary range,
Image reading can be performed efficiently.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an electronic component mounting apparatus according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a camera of the image reading device according to the embodiment of the present invention;

FIG. 3 is a configuration diagram of a line sensor of the image reading apparatus according to the embodiment of the present invention;

FIG. 4 is a flowchart of an imaging area setting process of the image reading apparatus according to the embodiment of the present invention;

FIG. 5 is an explanatory diagram of an imaging area setting of the image reading apparatus according to the embodiment of the present invention;

FIG. 6 is an explanatory diagram of an imaging area setting of the image reading apparatus according to the embodiment of the present invention;

FIG. 7 is a flowchart of an image reading method according to an embodiment of the present invention.

FIG. 8 is an explanatory diagram of an image reading method according to an embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 4 Transfer head moving mechanism 8 Camera 8a Line sensor 9 Recognition device 10 Imaging area storage unit 11 Imaging area setting unit 12 Storage operation control unit 13 Coordinate conversion unit 14 Write control unit 15 Image storage unit 19 Pixel 22 Photoelectric conversion unit 22a Photoelectric conversion Element 25 Pixel selection unit 26 Image output control unit 28 Target pixel setting unit 29 Selection operation control unit

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5B047 AA01 BB02 BC16 CA11 CB09 DC13 EA02 EB12 5C051 AA01 BA03 DA03 DB01 DC07 DE12 5C073 BA01 BB03 CE10

Claims (10)

[Claims] 1. An image reading apparatus for reading an image of an imaging target by forming an optical image of the imaging target on a photoelectric conversion element, wherein a plurality of pixels including the photoelectric conversion element are arranged in series in the X direction. A line sensor, a pixel selection unit that outputs an image signal from the selected pixel by selecting one of the plurality of pixels, and a Y that intersects the line sensor at least in the X direction with respect to the imaging target. A relative movement mechanism for relatively moving in the direction, an imaging area storage unit for storing a numerical value in the X direction and a numerical value in the Y direction regarding the size of the imaging area by the line sensor, and storing an image signal output from the line sensor. An image storage unit, an image output control unit that controls selection of a pixel by the pixel selection unit using the numerical value in the X direction, and a numerical value in the Y direction and the relative value. Image reading apparatus characterized by having a storage operation control unit for controlling the writing of the image signal to the image storage unit based on the position information of the moving mechanism. 2. An image reading apparatus according to claim 1, wherein said image pickup area can be set to a width smaller than a width of a maximum image pickup area of said line sensor. 3. The image reading apparatus according to claim 1, wherein the numerical value in the Y direction includes at least size data of the imaging area in the Y direction. 4. A coordinate conversion unit for converting the numerical value in the Y direction into a coordinate system of the relative movement mechanism,
2. A writing control unit for controlling whether or not an image signal can be written into the image storage unit based on the numerical value in the Y direction converted by the coordinate conversion unit and the position information. The image reading device according to any one of the preceding claims. 5. The image reading apparatus according to claim 1, wherein the numerical value in the Y direction is a numerical value on a coordinate system of the relative moving mechanism. 6. The image reading apparatus according to claim 1, wherein the numerical value in the Y direction includes at least positional information of an imaging area on a coordinate system of the relative movement mechanism. 7. The image reading apparatus according to claim 1, wherein the numerical value in the X direction includes at least size data of the imaging area in the X direction. 8. An image output control section for setting a target pixel for image output based on the numerical value in the X direction, and periodically selecting the target pixel for image output. 2. The image reading device according to claim 1, further comprising a selection operation control unit that controls the pixel selection unit. 9. The image reading apparatus according to claim 1, wherein the numerical value in the X direction includes at least the number of pixels corresponding to the size of the imaging area in the X direction. 10. A line sensor in which a plurality of pixels each having a photoelectric conversion element are arranged in series in the X direction is read while moving the line sensor relative to the object in a Y direction intersecting the X direction. An image reading method,
(1) a step of setting an imaging area; (2) a step of setting a plurality of pixels for outputting an image signal based on the set width of the imaging area in the X direction; and (3) a cycle of one pixel at a time. Outputting an image signal by selectively selecting;
(4) At least a step of controlling the writing of the image signal to the image storage unit by monitoring a relative positional relationship between the imaging target and the line sensor in the Y direction, and the step of (3) includes: An image reading method, which is performed only for a plurality of pixels set in the step (2).