JP2008064826A - Image processing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image processing apparatus which solves various problems that it takes time for an operation in case of conventional light control, light control algorithm is complicated since a light emission curve is not linear, and illumination light is guided, which can cause light loss or damage to a light guide, since such the image processing apparatus is desired. <P>SOLUTION: The image processing apparatus includes: a microscope that magnifies an object; an imaging section that images the object on the microscope; an image processing means that detects the level of at least luminance among video signals obtained from the imaging section; an illuminating device that irradiates the object with specific light; and an illuminating control means that controls the illumination level of the illuminating device. The illuminating device has an illumination characteristic that changes substantially linearly. The illuminating control means controls the illumination level of the illuminating device so that the luminance level detected by the image processing means reaches a predetermined target luminance level. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image processing apparatus, and more particularly to an image processing apparatus having an automatic light control function.

  Conventionally, a subject image is magnified using a microscope, the magnified subject image is captured by a television camera composed of a solid-state imaging device such as a CCD (Charge Coupled Device), and a video signal output from the television camera is image-processed. There are inspection devices or measuring devices that perform inspection and measurement. For example, a line width measuring device or a dimension measuring device is a film formation on an FPD (Flat Panel Display) substrate, for example, a TFT (Thin Film Transistor) formed on an LCD (Liquid Crystal Display) substrate or a semiconductor integrated circuit. For example, it is an apparatus for measuring the pattern width and pattern interval of a wiring mask. There are also defect inspection apparatuses for film formation on the FPD substrate itself and the FPD substrate, for example, defect inspection apparatuses for a phosphor coating layer or ribs applied to a TFT film on a LCD substrate or a PDP (Plasma Display Panel).

  Now, the line width measuring device or the dimension measuring device enlarges, for example, a pattern image obtained by irradiating a thin film pattern formed on a transparent glass substrate (hereinafter referred to as an object) with a microscope. A pattern image obtained by picking up the image with an image pickup apparatus such as a CCD camera is subjected to image processing, and the size is measured. Note that the image processing apparatus is generically referred to as a line width measuring apparatus, a dimension measuring apparatus, a line width inspection apparatus, a dimension inspection apparatus, a defect inspection apparatus, or the like.

  In the image processing apparatus described above, illumination light is irradiated on the object for measurement or inspection, but a video signal obtained from an imaging apparatus such as a CCD camera is used to reduce variations in measurement or inspection results. Is provided with a function of controlling illumination (hereinafter referred to as a function of automatic light control) so that the intensity (luminance) of the light source is substantially constant.

  A function of performing automatic light control of the conventional image processing apparatus will be described. FIG. 7 is a block diagram showing a schematic configuration of an example of a conventional image processing apparatus. In FIG. 7, 101 is an object, 102 is a microscope, and 103 is an objective lens. The objective lens 103 includes objective lenses having different magnifications in order to enlarge the optical image of the object 101. In FIG. 7, three objective lenses 103 are shown. Reference numeral 104 denotes an imaging unit such as a CCD camera, 105 denotes a video signal, 115 denotes an image processing unit, 116 denotes a display unit such as a monitor, 117 denotes a stage control unit, 118 denotes an XY axis stage, and 119 denotes Z An axis stage, 120 is an illumination control unit, 121 is a light emission control signal, 122 is an illumination device, for example, a light source for illumination, and in this example represents a halogen lamp. Reference numeral 123 denotes a light guide such as an optical fiber, 124 denotes an optical axis of the microscope 102, 125 denotes a beam splitter, 126 denotes a lens, 127 denotes a reflecting mirror, and 128 denotes an optical path of light from the light guide 123. The light from the illumination light source 122 is configured to irradiate the object 101 through the light guide 123, the lens 126, the reflecting mirror 127, and the half mirror 125. Reference numeral 130 denotes an operation unit that performs operation of the apparatus and various settings. The operation of this image processing apparatus will be briefly described.

  An object 101 mounted on an object table (XY axis stage) 118 such as a sample of the microscope 102 is enlarged to a desired size by the objective lens 103 and projected onto the imaging unit 104 via the half mirror 125. The In the imaging unit 104, the projected image of the object is photoelectrically converted into a video signal, and input to the image processing unit 115 via the video signal transmission path 105. The image processing unit 115 extracts a luminance signal from the input video signal and supplies it to the illumination control unit 120. The illumination control unit 120 compares the supplied luminance signal with a predetermined target luminance level, outputs a light emission control signal 121 based on the comparison result, and controls the illumination level of the halogen lamp 122. Note that the predetermined target luminance level means brightness that provides a luminance signal level sufficient for performing measurement, inspection, and the like in the image processing unit 115 of the image processing apparatus. The predetermined target luminance level is experimentally set by irradiating the object 101 with illumination light in advance. The object platform 118 is driven by an XY-axis stage to position a desired portion of the object to be photographed, and the Z-axis stage 119 performs focusing of the objective lens 103. The XY axis stage 118 and the Z axis stage 119 are configured to be controlled by a stage control unit 117.

  Now, the automatic light control operation of the image processing apparatus will be described with reference to FIG. FIG. 8 is a diagram showing the relationship between the illumination level of the halogen lamp 122 and the luminance level of the video signal, for example. In FIG. 8, the horizontal axis indicates the illumination level of the halogen lamp 122, and corresponds to, for example, a light emission signal from the illumination control unit 120, for example, a control voltage. The vertical axis represents the luminance signal level extracted by the image processing unit 115 from the video signal from the imaging unit 104 and changes according to the change in the illumination level of the halogen lamp 122. When the illumination light is the halogen lamp 122, it becomes nonlinear as shown by a curve 801. Note that the luminance signal level in this case is set to the maximum luminance level in the video signal of one screen obtained from the imaging unit 104, for example. The curve 801 changes depending on the material of the object 101, the reflectance of the surface, or the type of the light source, but can be experimentally measured and created in advance.

  In FIG. 8, the illumination level L1 of the halogen lamp 122 corresponds to the luminance signal level B1 extracted by the image processing unit 115. Similarly, the illumination level L2 corresponds to the brightness level B2, the illumination level L3 corresponds to the brightness level B3, and the illumination level L4 corresponds to the brightness level B4. The luminance level B0 indicates a target luminance level (indicated by a one-dot chain line) for automatic light control of the image processing apparatus.

  Next, the light control operation by the illumination control unit 120 will be described with reference to FIG. First, the illumination level is as shown in (1) below from FIG.

Illumination level L1 <illumination level L2 <illumination level L3 <illumination level L4 (1)
In FIG. 8, when the luminance level B of the video signal detected by the image processing unit 115 is very close to the target luminance level B0, for example, when the detected luminance level B is within the non-dimming range S1, The lighting is judged to be sufficient and the lighting level is not changed. For example, since the detected luminance level B is the luminance level B4 and is within the non-dimming range S1, the illumination level L4 at that time does not need to be changed. Therefore, it can be understood that the image processing apparatus may be operated at the illumination level L4.

  Similarly, when the luminance level B of the video signal detected by the image processing unit 115 is within the fine adjustment range S2 or S3, it is slightly away from the target luminance level B0. adjust. For example, in FIG. 8, the detected luminance level B is the luminance level B3 and is within the fine adjustment range S3. Since the illumination level at that time is L3, the illumination level L of the halogen lamp 122 is increased by the light emission control signal 121 from the illumination control unit 120 and is controlled so as to approach the target luminance level B0. As a result, it is adjusted within the non-dimming range S1.

  When the luminance level B of the video signal detected by the image processing unit 115 is within the rough adjustment range S4 or S5, the illumination level L is coarsely adjusted because it is far from the target luminance level B0. . For example, in FIG. 8, the detected brightness level B is the brightness level B2 or B1, which is within the coarse adjustment range S5. Since the illumination level at that time is L2 or L1, the illumination level L of the halogen lamp 122 is largely changed by the light emission control signal 121 from the illumination control unit 120 and is controlled so as to approach the target luminance level B0. As a result, the illumination level is changed, and the brightness level detected after the change is adjusted within the non-dimming range S1, and the dimming ends.

  As described above, the image processing unit 115 outputs a control signal for changing the illumination level to the illumination control unit 120 so that the difference from the target luminance level B0 is small. The illumination control unit 120 outputs a light emission control signal 121 to the halogen lamp 122 so as to change the illumination level in response to the control signal, and performs automatic dimming by controlling the illumination level of the halogen lamp 122. The light emission control signal 121 is a voltage variable signal for changing the light emission voltage of the halogen lamp 122, for example.

  Now, in such an illuminating device such as a halogen lamp used in such a conventional image processing apparatus, the relationship between the luminance level B and the illumination level L is non-linear as shown by a curve 801 in FIG. Adjusting the lighting level for is complicated. Further, as described above, when the material or reflectance of the object to be measured changes, the curve 801 also needs to be changed. Furthermore, when the magnification of the objective lens 103 is changed, the curve 801 needs to be changed. For example, the relationship between the luminance level B with respect to the illumination level L of the illuminating device is non-linear, and complicated dimming is required.

  In particular, in the case of the above-described conventional dimming, when the illumination level of the illuminating device is changed, it takes several seconds to several minutes until the actual illumination intensity changes, and a waiting time corresponding to the characteristics of the illuminating device for each dimming Was necessary. Further, when the detected luminance level B is far from the target luminance level B0, several dimming operations are required, and it takes time for dimming. In addition, since the emission curve is non-linear, the dimming algorithm is complicated, and it is necessary to change parameters for each lens magnification. For example, if the parameters are not changed for each magnification of the microscope, there are problems that the light control time increases or hunts.

  Further, since the illumination light is guided from the illumination device using the light guide, light loss also occurs. In particular, when the object is large, the light guide becomes as long as several meters with an increase in the size of the image processing apparatus, but the loss of illumination light increases in proportion to the length of the light guide, for example, 40% to 70%. Decreases by about%. Further, when the microscope side is movable, the light guide may be damaged, and it is desired to realize an image processing apparatus that solves these problems.

JP 2000-28319 A JP 2005-283319 A

  In the case of conventional dimming, the operation takes time and the dimming algorithm is complicated because the emission curve is non-linear. Furthermore, since the illumination light is guided from the illumination device using the light guide, there is a case where the light loss or the light guide may be damaged, and realization of an image processing device that solves these problems is desired.

  An object of the present invention is to provide an image processing apparatus capable of dimming with a simple operation.

  Another object of the present invention is to provide an image processing apparatus using a light control means with good responsiveness and good linearity.

  Another object of the present invention is to provide an image processing apparatus that eliminates the need for a light guide.

  Still another object of the present invention is to provide an image processing apparatus capable of widening the dynamic range of dimming.

  The present invention relates to a microscope for enlarging an object, an imaging unit for imaging an object image of the microscope, an image processing means for detecting at least a luminance level among video signals obtained from the imaging unit, and the object A lighting device that irradiates predetermined light to the lighting device, and a lighting control unit that controls a lighting level of the lighting device, the lighting device has a lighting characteristic that changes substantially linearly, and the lighting control unit includes: The illumination level of the illumination device is controlled so that the brightness level detected by the image processing means becomes a predetermined target brightness level.

  Moreover, in the image processing apparatus of the present invention, the illumination device is composed of LEDs.

  In the image processing apparatus of the present invention, the image processing means includes a storage unit, and the storage unit stores an illumination level of the illumination device and a luminance level of the video signal corresponding to the illumination level. Configured to be.

  In the image processing apparatus according to the aspect of the invention, the microscope includes an objective lens having a plurality of different magnifications, and the illumination control unit is configured to illuminate the illumination device corresponding to the objective lenses having the different magnifications. It has a function of changing the level, and is configured to switch the illumination level of the illumination device in accordance with the switching of the objective lens.

  In the image processing apparatus of the present invention, the function of changing the illumination level of the illumination device is a function of changing the pulse width of the pulse current supplied to the illumination device.

  As described above, according to the present invention, it is possible to realize an image processing apparatus that is easy to operate and capable of automatic light control. In addition, since a light guide is not used, illumination efficiency is good and low power consumption can be achieved. In addition, since the lighting device has a long life and there is no light guide that is a consumable item, the running cost is low. In addition, since the light control device is simple, it can be incorporated into an image processing unit or an illumination control unit and unitized, so that the size of the device can be reduced. In addition, since the dimming algorithm is simple, it is not necessary to prepare parameters for each magnification of the microscope. In addition, when measuring at various magnifications, it is possible to realize an extremely excellent image processing apparatus, such as being able to obtain an appropriate dynamic range at each magnification.

  Embodiments according to the present invention will be described with reference to FIGS. FIG. 1 is a block diagram of a schematic configuration of an embodiment of the present invention. 106 is a video distributor, 107 and 108 are video signals, 109 is a dimming control signal, 110 is an automatic dimming unit, 111 is an illumination control signal, 112 is an illumination control unit, and 113 is a light emission signal. 114 are illumination devices. In addition, the same code | symbol is attached | subjected to the same thing as FIG. Next, the operation of this image processing apparatus will be described.

  In FIG. 1, the video signal 105 from the imaging unit 104 is supplied to the video distributor 106. The video distributor 106 distributes the video signal 105 to the automatic light control unit 110 and the image processing unit 115. The automatic light control unit 110 calculates a predetermined luminance level from the input video signal and outputs an illumination control signal 111 to the illumination control unit 112. Here, the automatic light control unit 110 is also referred to as an image processing unit. The automatic light control unit 110 will be described later. The illumination control unit 112 keeps the current value constant from the illumination control signal 111, makes a pulse signal with a variable pulse width of high-frequency lighting described later, and outputs this as a light emission signal 113 to the illumination device 114. Thereby, the illumination device 114 is automatically dimmed. Note that the illumination device 114 in this case changes the illumination level substantially linearly, as will be described later, for example, PWM (Pulse Width Modulation) that illuminates an LED (Light Emitting Diode) at high frequency and variably controls the pulse width. A lighting device is used.

  FIG. 2 shows an illuminance characteristic diagram of an illuminating device in which the illumination level changes substantially linearly, such as an LED used in the present invention. In FIG. 2, the horizontal axis represents the illumination level of the lighting device, and the vertical axis represents the luminance level detected from the video signal. And in the illuminating device where the illumination level changes almost linearly, such as an LED, the illumination level and the luminance level change almost linearly like a straight line 201. Note that since the inclination of the straight line 201 changes depending on the material or reflectance of the object 101, the object 101 is irradiated with illumination light from the illumination device 114 in advance before the image processing apparatus is operated. This can be determined experimentally in advance. Further, the target luminance level means the brightness at which a luminance signal level sufficient for performing measurement, inspection, etc. in the image processing unit 115 of the image processing apparatus is obtained as in the case described above. For example, the luminance level is about 0.7 V to 0.3 V when the level of the video signal is 1 Vpp (peak to peak). The predetermined target luminance level is experimentally set by irradiating the object 101 with illumination light in advance. These data are stored in the storage unit in advance.

  In this way, when the illumination level is L1 from FIG. 2, the detected luminance level B is B1, and therefore the illumination level L for obtaining the target luminance level B0 can be obtained by the following equation.

Illumination level L = (L1 / B1) × target luminance level B0 (2)
Next, the automatic light control unit 110 and the illumination control unit 112 will be described in detail. FIG. 3 is a block diagram illustrating specific configurations of the automatic light control unit 110 and the illumination control unit 112. In FIG. 3, the video signal 108 from the video distributor 106 is supplied to the input terminal 301. The dimming control signal 109 from the image processing unit 115 is supplied to the input terminal 302. The video input unit 303 of the automatic light control unit 110 detects the luminance level B, for example, the luminance level B 1 from the video signal 108 and supplies the detected luminance level B to the arithmetic unit 305. In the memory unit (storage unit) 304, a predetermined target luminance level B0 is supplied and stored as the dimming control signal 109 from the image processing unit 115 in advance. The predetermined target brightness level B0 can be set by the operation unit 130, for example. Further, the current illumination level L, for example, the illumination level L1 is input from the output of the calculation unit 305 and stored. The illumination level L1 is supplied to the calculation unit 305. The calculation unit 305 calculates the illumination level L from the luminance level B1, the illumination level L1, and the target luminance level B0 based on Expression (2), and supplies the illumination control signal 111 to the illumination control unit 112. Note that if the memory unit 304 stores the illumination level L1 and the luminance level B1 corresponding to the illumination level L1, the luminance level B with respect to the illumination level L is calculated by the arithmetic unit 305 according to equation (2) Can be calculated. However, the illuminance characteristics shown in FIG. 2 can be stored as data in the memory unit 304 and the luminance level B can be output for a predetermined illumination level L. Here, the illumination control signal 111 is supplied to the illumination control unit 112 as, for example, a digital signal having a pulse width of 8 bits.

  The illumination control unit 112 includes a pulse current generation unit 306 and a storage unit 307. The pulse current generation unit 306 receives the illumination control signal 111 and generates a pulse current (or pulse voltage) that causes the illumination device 114, for example, an LED, to emit light at a predetermined illumination level. In the present embodiment, for example, a rectangular pulse having a lighting pulse width W is generated by a high frequency pulse of 1 KHz as described later. The storage unit 307 stores a predetermined lighting pulse width W or a duty ratio D, which will be described later.

  FIG. 4 is a diagram for explaining the operation of the illumination control unit 112, and also shows the relationship with the video signal. The horizontal axis represents time. First, FIG. 4A shows one frame period of the video signal, for example, (1/30) second. S represents a vertical synchronization signal. In the present embodiment, progressive type scanning will be described in units of frames, but interlaced scanning and in units of fields are the same. FIG. 4B shows a blanking period T1 and a video period T2 in one frame period.

  FIG. 4C shows the exposure time T3 and the video signal V. In FIG. 4C, an exposure time T3 is a period during which the camera unit 104 exposes the object 101 for imaging, and is determined as appropriate. The charge exposed in the previous frame is read out in the video period T2 of the next frame. This exposure and readout operation is a conventional CCD operation and is well known. Omitted. The video signal V is a schematic representation of the video signal V output from the imaging unit 104, and in this embodiment, the maximum luminance level B is detected from the video signal V by the video input unit 303.

  FIG. 4D shows the timing calculated by the calculation unit 305 of the automatic light control unit 110. In the present embodiment, the calculation time T4 in the calculation unit 305 is allocated to a portion immediately before the end of the video period T2, for example, a horizontal scanning period of several texts.

  FIG. 4E shows a method of causing the illumination device 114, for example, an LED, to emit light with the illumination level L obtained by the arithmetic unit 305. Note that the time axis of FIG. 4E is shown in an enlarged manner, and is different from the time axes of FIG. 4A to FIG. 4D. In the present embodiment, the light emission of the LED 114 is controlled based on the illumination control signal 111 supplied from the calculation unit 305 of the automatic light control unit 110. This method will be described with reference to FIG. In FIG. 4E, the horizontal axis represents time, and the vertical axis represents the current value supplied to the LED 114. T represents the light emission period of the LED 114, and W1 and W2 represent lighting periods. Accordingly, the lighting method of the LED 114 of this embodiment is high-frequency lighting, and the illumination level L employs a control method in which the widths W1 and W2 of the lighting pulses are variable. In this case, the duty ratio D of the pulse is expressed by the following equation, where T is the light emission period of the LED 114 and W is the width of the lighting pulse.

D = W / T (3)
Here, when the current value supplied to the LED 114 is constant and the lighting cycle is also constant, for example, 1 KHz, the light emission level L of the LED 114 is changed by varying the duty ratio D, that is, the width W of the lighting pulse. Can be changed. Therefore, it is very easy to control the light emission level. For example, as shown in FIG. 4, when the lighting pulse width W is W1, the current illumination level L is L1, and when the luminance level B at that time is B1, in order to obtain the target luminance level B0, It is necessary to change the illumination level from L1 to L2.

  In view of this, in the calculation unit 305, as shown in FIG. 4D, when the video signal V ends, from the target luminance level B0, the current luminance level B1, and the current illumination level L1 based on the equation (2). The lighting level L, that is, L2 is calculated, and the lighting control signal 111 is output to the lighting control unit 112 at the next falling timing of the vertical synchronization signal S. In the illumination control unit 112, the pulse width setting is immediately changed to W2, and the LED 114 emits light with the light emission signal 113 changed from the next lighting cycle T to the pulse width W2. By repeating this, real-time dimming can be realized. In the above embodiment, the lighting device 114 is described as an LED. However, the present invention is not limited to this, and the luminance level B is almost equal to the change in the lighting level L as shown in the illuminance characteristic diagram shown in FIG. Any lighting device that changes to a straight line can be used. In the above embodiment, the video distribution unit 106 and the automatic light control unit 110 are used. However, since the automatic light control unit 110 has a simple configuration as shown in FIG. 3, the image processing unit 115 (image It is also possible to form a single unit. Further, in FIG. 4E, the lighting device has been described as emitting light over the entire frame at a constant period. However, for example, the lighting device may be configured to emit light according to the exposure time.

  As described above, according to the present invention, automatic light control can be performed with a simple operation, and since no light guide is used, the light source is small, has high illumination efficiency, and low power consumption. Furthermore, LEDs and the like have the advantages of longer life and lower running costs than conventional halogen lamps.

  Next, another embodiment of the present invention will be described with reference to FIGS. In the image processing apparatus to which the present invention is applied, there is a case where the magnification of the microscope is changed depending on the size of the object. For example, in the embodiment shown in FIG. 1, three objective lenses 103 are shown. Depending on the size of the object, for example, an alignment mark on the semiconductor substrate of the object 101 is detected by an objective lens having a magnification of 2.5 times. In some cases, the measurement of a fine pattern is performed using an objective lens with a magnification of 20 or 50 times. In such a case, in order to perform appropriate automatic light control at each magnification, it is necessary to make the resolution of the illumination level fine and to have a sufficient number of gradations in order to increase the dynamic range of light control of the lighting device. is there. Here, the resolution of the illumination level means, for example, the lighting width W shown in FIG. 4, but if the lighting width W is made fine, light emission is caused by the influence of the rise and fall of the light emission signal 113 and the like. The intensity may become unstable and the linearity of the illumination intensity may be lost. Further, when the number of gradations is increased, the number of data of the illumination control signal 111 is increased, and the system configuration is complicated.

  In order to solve this problem, in another embodiment of the present invention, a method in which two control means of illumination level (voltage or current) control and pulse width control are combined will be described. FIG. 5 is a diagram illustrating the relationship between the illumination level and the illuminance characteristics when the lens magnification is changed. In FIG. 5, the horizontal axis indicates the illumination level L, and the vertical axis indicates the luminance level B. Reference numeral 501 denotes a target luminance level B0, 502 denotes a maximum luminance level Bm, and an area 503 denotes a saturated area. A curve 504 is a lighting pulse width W and a lens magnification of 50 times. A curve 505 is a lighting pulse width W and a lens magnification of 20 times. A curve 506 is a lighting pulse width W and a lens magnification of 10 times. A curve 507 is a lighting pulse width W and a lens magnification of 2.5 times.

  As is apparent from the illuminance characteristics of FIG. 5, for example, when the maximum magnification, that is, the lens magnification of 50 times is used as a reference and the lighting pulse width is W, the illuminance characteristics are as shown by a curve 504. At this time, the maximum luminance level is set to Bm, and the illumination level is set with the target luminance level B0 being about 70% of the maximum luminance level Bm. Next, if the one-step bright magnification, for example, the lens magnification is changed to 20 times, at the same pulse width W, the illumination level is greatly increased as shown by the curve 505, and the luminance level is saturated. Therefore, in order to adjust the illuminance characteristic curve 505 to the illuminance characteristic curve 504, the lighting pulse width W is adjusted. For example, this can be achieved by adjusting the lighting pulse width to 3W / 4. Similarly, if the magnification is increased by one step, for example, the lens magnification is changed to 10 times, at the same pulse width W, the illumination level is significantly increased as shown by the curve 506 and the luminance level is saturated. Therefore, in order to adjust the illuminance characteristic curve 506 to the illuminance characteristic curve 504, the lighting pulse width W is adjusted. For example, this can be achieved by adjusting the lighting pulse width to W / 2.

  Similarly, if the magnification is increased by one step, for example, the lens magnification is changed to 2.5 times, the illumination level is greatly increased and the luminance level is saturated as indicated by a curve 507 at the same pulse width W. Therefore, in order to adjust the illuminance characteristic curve 507 to the illuminance characteristic curve 504, the lighting pulse width W is adjusted. For example, this can be achieved by adjusting the lighting pulse width to W / 4. That is, even if the lens magnification is changed, if there is a relationship as shown in Table 1 between the lens magnification F and the lighting width W, the relationship between the illumination level and the luminance level is always constant even if the magnification is changed. It is possible.

上述のようにレンズ倍率を変更しても、表１に示すようにパルス幅を適宜設定することにより図６に示されるように同じ対象物１０１に対して同様の照度特性曲線６０１を得ることが可能となる。従って、上記表１に示すテーブルを記憶部３０７に記憶し、レンズ倍率を変更した場合、表１に示すテーブルから所望のパルス幅（またはデューテイ比Ｄ）を読出し、照明制御部１１２を駆動すれば、容易に必要な調光を行うことができる。従って、倍率毎の調光パラメータを持つ必要が無くなり、１つの倍率、例えば、倍率５０倍の調光パラメータを設定するだけで、全ての倍率の調光を行える利点がある。

Even if the lens magnification is changed as described above, the same illuminance characteristic curve 601 can be obtained for the same object 101 as shown in FIG. 6 by appropriately setting the pulse width as shown in Table 1. It becomes possible. Therefore, when the table shown in Table 1 is stored in the storage unit 307 and the lens magnification is changed, a desired pulse width (or duty ratio D) is read from the table shown in Table 1 and the illumination control unit 112 is driven. The required dimming can be easily performed. Therefore, there is no need to have a dimming parameter for each magnification, and there is an advantage that dimming can be performed at all magnifications by setting a dimming parameter of one magnification, for example, 50 times magnification.

  Further, even when the lens magnification configuration of the image processing apparatus is changed, dimming can be performed by simply setting the pulse width in the same manner as in Table 1 and rewriting the contents. In the above-described embodiment, the case where the pulse width for each magnification is set while actually capturing an object has been described. However, if the brightness ratio for each magnification is known in advance, each magnification with respect to the reference magnification It is also possible to set the reciprocal of the ratio to the pulse width.

  Although the present invention has been described in detail above, the present invention is not limited to the embodiments of the image processing apparatus described herein, and can be widely applied to image processing apparatuses other than those described above. Needless to say.

The block diagram of schematic structure of one Example of this invention is shown. It is a figure which shows the illumination intensity characteristic of the illuminating device of this invention. The block diagram of the concrete structure of the automatic light control part and illumination control part of one Example of this invention shown by FIG. 1 is shown. It is a figure for demonstrating operation | movement of this invention. It is a figure which shows the illuminance characteristic of the illuminating device for describing another Example of this invention. It is a figure which shows the illuminance characteristic of the illuminating device used by other one Example of this invention. The block diagram of schematic structure of an example of the conventional image processing apparatus is shown. It is a figure which shows the illumination intensity characteristic of the conventional illuminating device.

Explanation of symbols

  101: Object, 102: Microscope, 103: Objective lens, 104: Imaging unit, 105: Video signal, 106: Video distributor, 107, 108: Video signal, 109: Dimming control signal, 110: Automatic dimming unit 111: Illumination control signal 112, 120: Illumination control unit 113: Light emission signal 114: Illumination device 115: Image processing unit 116: Display unit 117: Stage control unit 118: XY axis stage 119: Z-axis stage, 121: emission signal transmission path, 122: illumination light source, 123: light guide, 124: optical axis, 125: beam splitter, 126: lens, 127: reflector, 128: optical path of light, 130: operation Unit 301, 302: input terminal, 303: video input unit, 304: memory unit, 305: calculation unit, 306: pulse current generation unit, 307: storage unit.

Claims (2)

  A microscope for enlarging an object, an imaging unit for imaging an object image of the microscope, an image processing means for detecting at least a luminance level in a video signal obtained from the imaging unit, and predetermined light on the object And an illumination control means for controlling the illumination level of the illumination apparatus, the illumination apparatus has illumination characteristics that change substantially linearly, and the illumination control means includes the image processing means. An image processing apparatus that controls the illumination level of the illumination apparatus so that the brightness level detected in step 1 becomes a predetermined target brightness level.   2. The image processing apparatus according to claim 1, wherein the microscope includes an objective lens having a plurality of different magnifications, and the illumination control unit illuminates the illumination device corresponding to the objective lenses having the plurality of different magnifications. An image processing apparatus having a function of changing a level, wherein the illumination level of the illumination apparatus is switched according to switching of the objective lens.

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