JP3966621B2 - Electronic level - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a surveying instrument, and more particularly to a surveying instrument capable of capturing a bar code image on a scale and reading a scale on the scale with high accuracy.
[0002]
[Prior art]
Conventionally, a barcode is printed on a scale, a barcode image is captured from a remote location with a CCD image sensor, the barcode is decoded, its value is calculated, further interpolation is performed, and a scale on the scale. Surveying instruments that read the data with high accuracy are known.
[0003]
This kind of electronic level bar code processing unit takes an image of the bar code of the scale with a CCD line sensor, amplifies the output of the CCD line sensor, converts it from analog to digital, and sends it to a microcomputer. In this microcomputer, it is displayed on a display unit as a scale by comparing with previously inputted bar code information and further performing interpolation calculation.
[0004]
In the microcomputer, the output from the CCD sensor is substantially constant by increasing / decreasing the charge time of the CCD sensor in the CCD drive unit depending on whether or not the bar code data sent after analog / digital conversion is at a constant output level. To be held.
[0005]
That is, when the measurement environment becomes dark, the signal level from the CCD line sensor decreases, and the signal level of the data input to the microcomputer also decreases accordingly, so that accurate calculation cannot be performed. Therefore, when the signal level of data input to the microcomputer decreases, the charge time of the CCD drive unit is lengthened so that the data has a sufficient signal level even in a dark environment.
[0006]
[Problems to be solved by the invention]
In general, the electronic lighting level used as a surveying instrument has a very wide range of conditions, from tunnels and dimly lit evenings to very bright areas such as direct sunlight or near white walls. Over. In order to capture an image of a wide dynamic range of this light with a CCD line sensor, it is difficult to process only with control of charge time. That is, the width of the light / dark difference is too large.
[0007]
For example, if it is attempted to cope with only the charge time, the charge time becomes several seconds (too long) and accurate measurement cannot be performed. More specifically, for example, a state in which a standard (barcode) image moves on the CCD line sensor due to, for example, fluctuations in the atmosphere, the CCD line sensor cannot accurately capture the standard (barcode).
[0008]
An object of the present invention is to provide an electronic level that can be used in a very wide range of brightness and darkness.
[0009]
[Means for Solving the Problems]
According to the electronic level of the present invention, the above-described problem is achieved by a CCD line sensor that images a scale with a bar code as a scale through optical means, an amplifier that amplifies the output of the CCD line sensor, and an amplifier that amplifies the output. A / D converter for analog / digital conversion of the output, and digital data output by the A / D converter are encoded and compared with the code of the bar code table data input in advance, and further inserted. a microcomputer for processing the scale data by calculating a display unit for displaying the scale data, an electronic level and a CCD driving unit for adjusting the charge time of the CCD line sensor, said optical means is arranged beam splitter, an image of the barcode leveling rod is dispersed by the Bimusupu splitter, whereas To eyepiece side as viewed mutatis mutandis, the other is intended to be guided to the CCD line sensor side, to set the spectral ratio of the beam splitter so that the light intensity of a CCD line sensor side to the eyepiece side is increased, the The microcomputer adjusts the charge time of the CCD line sensor and the gain of the amplifier so that the signal level of the digital data input from the A / D converter is constant regardless of the light and dark conditions of the measurement environment. Solved.
[0010]
At this time, the gain is adjusted such that a plurality of gains are obtained in an amplifier that amplifies the analog signal captured by the CCD line sensor, the analog signal is digitally converted, its value is determined, and output. It is preferable that the plurality of gains are switched according to the input signal level.
[0011]
Further, when L: illuminance, T: charge time, G: gain of amplifier, M: digital value obtained by analog / digital conversion, the microcomputer is set so that L × T × G / M = constant. Configure to adjust charge time and gain.
[0012]
Further, when the charge time exceeds a predetermined time, the gain is increased and the charge time is decreased. When the charge time is less than the predetermined time, the gain is decreased and the charge time is increased.
[ 0013 ]
DETAILED DESCRIPTION OF THE INVENTION
The electronic level S of the present invention includes an optical unit 10, an eyepiece unit 20, and a barcode data processing unit 30, and the light divided by the beam splitter 14 is received in the barcode data processing unit 30. The apparatus includes a CCD line sensor 31, an amplifier 32, an A / D converter 33, a microcomputer 34, and a CCD driving unit 35.
[ 0014 ]
The bar code data processing unit 30 first amplifies output data from the CCD line sensor 31 by an amplifier 32, and analog / digital converts the amplified output data by an A / D converter 33. The microcomputer 34 compares the digital value (output data) with the table data relating to the barcode input in advance, calculates which position of the barcode, and further performs interpolation calculation. As a result of this interpolation, a predetermined value is displayed on the display unit 40 as a scale.
[ 0015 ]
In the microcomputer 34 of this example, the charge time (accumulation time) of the CCD line sensor 31 is stored in the CCD drive unit 35 so that the output (digital value) data obtained from the A / D converter 33 always has a constant signal level. ) Is output for the purpose of lengthening or shortening.
[ 0016 ]
That is, as shown in FIG. 2, the amplifier 32 includes a preamplifier 32a and a main amplifier 32b. The main amplifier 32b is configured so that the gain can be selected between High and Low. The CCD drive unit 35 is configured to increase or decrease the charge time (accumulation time) of the CCD line sensor 31 according to instructions from the microcomputer 34. In the microcomputer 34, the charge time (accumulation time) of the CCD line sensor 31 is set so that the digital value M analog / digital converted by the A / D converter 33 becomes L × T × G / M = constant. ) And the gain of the amplifier 32 (where L = illuminance, T = charge time, G = amplifier gain, M = digital value).
[ 0017 ]
For example, in an example in which the gain is set in two stages of High Gain and Low Gain, when the measurement environment is bright, the gain is controlled to be Low, and the charge time (accumulation time) is further shortened. On the other hand, when the measurement environment is dark, control is performed such that the gain is set to High and the charge time (accumulation time) is further increased.
[ 0018 ]
As described above, by adjusting the gain of the amplifier that amplifies the output of the CCD line sensor in addition to the charge time of the CCD line sensor, the signal level that has been too weak or too high until now is set to an appropriate level. It is possible to provide an electronic level that can be measured from a small range of illuminance to a large range.
[ 0019 ]
As described above, it is possible to perform measurement under a very wide range of brightness in the measurement environment, which is difficult to use at the conventional electronic level, and is 20 lx (lux) to 16 × 10 ⁴ lx (lux). Since measurement under a very wide range of conditions is possible, it is possible to set the spectral ratio to the beam splitter so that the amount of light on the eyepiece side is larger than before, which makes collimation difficult in the past. Collimation is possible even under the dim conditions.
[ 0020 ]
【Example】
Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The members, arrangements, and the like shown in the following explanation examples do not limit the present invention, and it is needless to say that various modifications can be made within the scope of the gist of the present invention.
[ 0021 ]
FIG. 1 to FIG. 4 show an example of the present invention, FIG. 1 is a schematic configuration diagram showing one embodiment of an electronic level, and FIG. 2 is a block diagram illustrating one embodiment of a CCD drive unit and a data processing unit. 3 is a graph showing an embodiment in which gain is switched between illuminance and accumulation time, and FIG. 4 is a flowchart showing an embodiment.
[ 0022 ]
The electronic level S of this example includes the optical unit 10, the eyepiece unit 20, the barcode data processing unit 30, the display unit 40, and the input unit 50 as main components. In FIG. 1, symbol H is a bar code-equipped measure.
[ 0023 ]
The optical unit 10 of this example includes an objective lens 11, a focusing lens 12, an automatic tilt correction mechanism 13, and a beam splitter 14. The beam splitter 14 splits the image of the bar code-equipped measure H to the eyepiece 20 side and the CCD line sensor 31 side.
[ 0024 ]
The eyepiece unit 20 of this example includes a focusing mirror 21 and an eyepiece lens 22 through which one light divided by the beam splitter 14 is guided. In this example, the spectral ratio of the beam splitter 14 is configured so that the amount of light increases toward the eyepiece 20 compared to the conventional case.
[ 0025 ]
The bar code data processing unit 30 of this example is for guiding the other light divided by the beam splitter 14, and includes a CCD line sensor 31, an amplifier 32, an A / D converter 33, a microcomputer 34, And a CCD drive unit 35.
[ 0026 ]
The bar code data processing unit 30 first amplifies output data from the CCD line sensor 31 by an amplifier 32, and analog / digital converts the amplified output data by an A / D converter 33. The microcomputer 34 compares the digital value (output data) with the table data relating to the barcode input in advance, calculates which position of the barcode, and further performs interpolation calculation. As a result of this interpolation, a predetermined value is displayed on the display unit 40 as a scale.
[ 0027 ]
In the microcomputer 34 of this example, the charge time (accumulation time) of the CCD line sensor 31 is stored in the CCD drive unit 35 so that the output (digital value) data obtained from the A / D converter 33 always has a constant signal level. ) Is output for the purpose of lengthening or shortening.
[ 0028 ]
That is, as shown in FIG. 2, the amplifier 32 includes a preamplifier 32a and a main amplifier 32b. The main amplifier 32b is configured so that the gain can be selected between High and Low. The CCD drive unit 35 is configured to increase or decrease the charge time (accumulation time) of the CCD line sensor 31 according to instructions from the microcomputer 34. In the microcomputer 34, the charge time (accumulation time) of the CCD line sensor 31 is set so that the digital value M analog / digital converted by the A / D converter 33 becomes L × T × G / M = constant. ) And the gain of the amplifier 32 (where L = illuminance, T = charge time, G = amplifier gain, M = digital value).
[ 0029 ]
Although the display unit 40 of this example is a liquid crystal display unit of an electronic level S, various means such as a plasma display unit can be used in addition to the means using liquid crystals. The input unit 50 in this example includes a key input unit 51 and a data I / O 52. The key input unit 51 is configured to allow various key inputs such as numeric keys, function keys, alphanumeric character keys, and character keys. Further, the data I / O 52 is information from the storage medium such as FD (floppy disk), MO (magneto-optical disk), optical disk, DVD, exchangeable card type ROM or RAM to the electronic level S side or the electronic level. It is configured to be able to transfer from S to the storage medium side.
[ 0030 ]
For example, in an example in which the gain is two stages of High Gain (8 times Low Gain) and Low Gain, when the measurement environment is bright, the gain is set to Low, and the charge time (accumulation time) is further shortened. Control to go. On the other hand, when the measurement environment is dark, control is performed such that the gain is set to High and the charge time (accumulation time) is further increased.
[ 0031 ]
More specifically, the microcomputer 34 controls the analog / digital converted value to be a constant value (for example, a digital value such as 200). As shown in FIG. When the number is less than one hundred lx, the gain of the amplifier 32 is set to High (8 times as low Gain), and the accumulation time of the CCD line sensor 31 is lengthened or shortened. When the illuminance is 1,000 to several hundred lx and ten thousand to lx, the gain of the amplifier 32 is set to High or Low, and the accumulation time of the CCD line sensor 31 is lengthened or shortened for control.
[ 0032 ]
When the gain is low and the illuminance drops to a state of several thousand lx, the gain is set to 8 times high, and the charge time (accumulation time) of the CCD line sensor 31 is lengthened and controlled. . By switching the gain between Low and High in this way, and simultaneously increasing or decreasing the charge time (accumulation time) of the CCD line sensor 31, the environment for measuring the electronic level S can be used in a very wide range of light and dark. it can.
[ 0033 ]
In other words, when the charge time (accumulation time) exceeds the predetermined time, the gain is increased (increased) and the charge time (accumulation time) is decreased. When the charge time (accumulation time) becomes less than the predetermined time, The charge time (accumulation time) is increased with the gain being lowered (lowered). Using this method, it is possible to measure the brightness of a bar code-equipped measure from 20 lx to 16 × 10 ^{4 in} this embodiment.
[ 0034 ]
Next, an embodiment having the above configuration will be described based on the flowchart of FIG. First, when the power of the electronic level S is turned on, initial values of charge time (accumulation time) and gain set in advance in step S1 are set. If the initial value is not set, the initial value is set. The initial value setting can be performed by the key input unit 51, but can also be performed by fetching data through the data I / O unit 52.
[ 0035 ]
Next, in step S2, an image obtained by separating the image of the bar code measure H by the beam splitter 14 of the optical unit is read by the CCD line sensor 31, amplified by an amplifier, and further subjected to an analog / digital converted output value. Do. Then, it is determined whether or not the output value satisfies a predetermined measurement condition (step S3). When the measurement condition is satisfied (that is, when the measurement condition is satisfied) (step S3: Yes), a measurement process is performed (step S4).
[ 0036 ]
When the measurement condition is not satisfied (that is, the measurement condition is not satisfied) (step S3: No), the next accumulation time (charge time) is calculated in step S5. After calculating the accumulation time (charge time), it is determined whether the current gain is High or Low (step S6).
[ 0037 ]
When the current gain is High (S6: High), it is determined whether or not the accumulation time (charge time) is shorter than the threshold value 1 in Step S7. If the accumulation time is shorter than the threshold value 1 (S7: Yes), the gain is changed from the current High to Low in step S8, and the accumulation time is calculated at the same time. Then, after the process of step S8, the process from step S2 is performed.
[ 0038 ]
On the other hand, if the accumulation time is not shorter than the threshold value 1 in step S7 (S7: No), it is determined in step S9 whether the dark limit is exceeded. If the darkness limit is not exceeded (S9: No), the processing from step S2 is performed again. If the darkness limit is exceeded (S9: Yes), an error is determined (step S10). For this error, various means such as an error display by characters and colors, a warning sound, etc. can be adopted.
[ 0039 ]
In step S6, it is determined whether the current gain is high or low. If the current gain is low (S6: Low), it is determined whether the accumulation time is longer than the threshold value 2 in step S11. If the accumulation time is longer than the threshold 2 (S11: Yes), the gain is changed from the current Low to High in step S12, and the accumulation time is calculated at the same time. Then, after the process of step S12, the process from step S2 is performed.
[ 0040 ]
On the other hand, if the accumulation time is not longer than the threshold value 2 in step S11 (S11: No), it is determined whether or not the brightness limit is exceeded in step S13. If the brightness limit is not exceeded (S13: No), the processing from step S2 is performed again. If the brightness limit is exceeded (S13: Yes), an error is determined (step S10). As in the case of this error, various means such as an error display by characters and colors and a warning sound can be adopted.
[ 0041 ]
In the above-described embodiment, an example in which the gain is set to two stages of High and Low has been described. However, the gain can be configured to be switched not only to such two stages but also to several stages, and further to be switched steplessly. It may be.
[ 0042 ]
Further, although the CCD sensor is described as an example of the image sensor in the above description example, various types such as a CCD area sensor and a MOS type image sensor can be used.
[ 0043 ]
In order to measure the darkness at the time of High Gain at Low Gain and within the charge time variable range as shown in FIG. 3, it is necessary to change the spectral ratio of the beam splitter and to input a large amount of light. However, in this case, the amount of light to the eyepiece is reduced and collimation becomes difficult. Therefore, by amplifying a small signal with High Gain, it is possible to measure even if the amount of light incident on the CCD is small, and the amount of light to the eyepiece is increased even in a dark environment, which was difficult to measure in the past. The practical value is extremely large. In the present invention, the CCD and the eyepiece are distributed at a spectral ratio of 3: 7.
[ 0044 ]
【The invention's effect】
As described above, according to the present invention, it is possible to perform measurement under conditions in which the brightness range of the measurement environment is extremely wide, which is difficult to use at the conventional electronic level.
[ 0045 ]
In addition, since measurement can be performed under a very wide range of conditions from 20 lx (lux) to 16 × 10 ⁴ lx (lux), the spectral ratio to the beam splitter is adjusted so that the amount of light on the eyepiece side is larger than before. This makes it possible to collimate even under dim conditions, which was difficult to collimate in the past.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing an embodiment of an electronic level according to the present invention.
FIG. 2 is a block diagram illustrating one embodiment of a CCD drive unit.
FIG. 3 is a graph showing an embodiment in which gain is switched between illuminance and accumulation time.
FIG. 4 is a flowchart showing an embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Optical part 11 Objective lens 12 Focusing lens 13 Automatic inclination correction mechanism 14 Beam splitter 20 Eyepiece part 21 Focusing mirror 22 Eyepiece 30 Barcode data processing part 31 CCD line sensor 32 Amplifier 32a Preamplifier 32b Main amplifier 33 A / D conversion Device 34 Microcomputer 35 CCD drive unit 40 Display unit 50 Input unit 51 Key input unit 52 Data I / O
H Bar code with gauge S Electronic level

Claims (4)

CCD line sensor for imaging a scale with bar code as a scale via optical means, an amplifier for amplifying the output of the CCD line sensor, and an A / D converter for analog / digital conversion of the output amplified by the amplifier And a microcomputer that encodes the digital data output by the A / D converter, compares it with a bar code table data code that has been input in advance, and further performs interpolation processing to calculate scale data. An electronic level comprising a display unit for displaying the scale data and a CCD driving unit for adjusting the charge time of the CCD line sensor,
The optical means is provided with a beam splitter, and the image of the bar code scale is split by the beam splitter, one is guided to the eyepiece side for collimation and the other is guided to the CCD line sensor side And setting the spectral ratio of the beam splitter so that the amount of light from the CCD line sensor side to the eyepiece lens side is increased,
The microcomputer adjusts the charge time of the CCD line sensor and the gain of the amplifier so that the signal level of the digital data input from the A / D converter is constant regardless of the light / dark state of the measurement environment. An electronic level characterized.   The gain adjustment is performed so that a plurality of gains can be obtained in an amplifier that amplifies the analog signal captured by the CCD line sensor, the analog signal is digitally converted, and the value is determined and output or input. 2. The electronic level according to claim 1, wherein the plurality of gains are switched according to a signal level.   L: Illuminance, T: Charge time, G: Amplifier gain, M: Analog / digital converted digital value, the microcomputer has a charge time so that L × T × G / M = constant. The electronic level according to claim 1, wherein the gain is adjusted.   2. The electronic level according to claim 1, wherein when the charge time exceeds a predetermined time, the gain is increased and the charge time is decreased, and when the charge time is less than the predetermined time, the gain is decreased and the charge time is increased.

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