Optical line sensor, data processing device, and data processing method

Abstract

Provided are an optical line sensor, a data processing device, and a data processing method that make it possible to effectively remove a noise component produced by stray light. A light source 103 illuminates an object. A plurality of light reception elements 121 are arranged in a line along a principal scanning direction and receive light from the object as illuminated by the light source 103. An on / off processing unit 202 repeatedly performs processing that turns the light source 103 on and then off for exactly a prescribed on period and exactly a prescribed off period, respectively. A computation processing unit 205 performs processing that calculates a noise component for the on period by converting the amount of light received by the light reception elements 121 during the off period to an amount of light received were the light source 103 off during the on period and subtracts the noise component from the amount of light received by the light reception elements 121 during the on period.

Description

Optical line sensor, data processing device, and data processing method

[0001] The present invention relates to an optical line sensor that reads an object that is relatively moved in a sub-scanning direction with a reading line that extends in a main scanning direction, and to a data processing device and a data processing method used therefor.

[0002] A typical optical line sensor includes a light source that illuminates an object such as a paper sheet, and a plurality of light-receiving elements that receive light from the object illuminated by the light source. When reading an image of an object, the object is illuminated with light from the light source as it is transported along the sub-scanning direction, and the light from the object is received by the plurality of light-receiving elements along a reading line extending in the main scanning direction, thereby obtaining data for a plurality of lines as image data of the object.

[0003] When acquiring data for each line, the light source is turned on for a predetermined lighting time (exposure time) and then turned off for a predetermined lighting time. In other words, when acquiring data for multiple lines while transporting an object, the light source is repeatedly turned on and off for each line, and a signal based on the amount of light received by the light receiving element for each line is output. In this case, to prevent the influence of stray light entering the light receiving element during the light source off time, it has been proposed to not output a signal from the light receiving element during the light off time, and to output only the signal from the light receiving element during the light on time (see, for example, Patent Document 1 below).

[0004] Chinese Utility Model No. 207820026

[0005] However, while the above-described conventional technology can prevent the influence of stray light incident on the light receiving element while the light source is off, it cannot prevent the influence of stray light incident on the light receiving element while the light source is on. In other words, since stray light is incident on the light receiving element not only while the light source is off but also while it is on, it is not possible to completely prevent the influence of stray light unless the noise components due to this stray light are also removed.

[0006] The present invention has been made in consideration of the above-mentioned circumstances, and aims to provide an optical line sensor, a data processing device, and a data processing method that can effectively remove noise components caused by the influence of stray light.

[0007] (1) An optical line sensor according to the present invention is an optical line sensor that reads an object that moves relatively in a sub-scanning direction with a reading line extending in a main scanning direction, and includes a light source, multiple light receiving elements, an illumination processing unit, and a calculation processing unit. The light source illuminates the object. The multiple light receiving elements are arranged in a line along the main scanning direction and receive light from the object illuminated by the light source. The illumination processing unit repeatedly turns on the light source for a predetermined illumination time and then turns it off for a predetermined extinguishing time. The calculation processing unit converts the amount of light received by the light receiving elements during the extinguishing time into the amount of light received if the light source were extinguished during the illumination time, thereby calculating noise components during the illumination time, and subtracting the noise components from the amount of light received by the light receiving elements during the illumination time.

[0008] With this configuration, the amount of light received by the light receiving element during the off time can be converted to the amount of light received when the light source is off during the on time, thereby calculating the noise component during the on time. Then, by performing a process of subtracting the noise component from the amount of light received by the light receiving element during the on time, the noise component due to the influence of stray light can be effectively removed from the amount of light received by the light receiving element during the on time.

[0009] (2) The calculation processing unit may calculate the noise component by multiplying the amount of light received by the light receiving element during the off time by the ratio of the on time to the off time, and may perform a process of subtracting the noise component from the amount of light received by the light receiving element during the on time.

[0010] According to this configuration, the noise component can be easily calculated by a calculation using the ratio of the on time to the off time.

[0011] (3) The optical line sensor may further include a clock pulse generating unit that generates clock pulses at a constant cycle. In this case, the arithmetic processing unit may calculate the noise component by multiplying the amount of light received by the light-receiving element during the off-time by a ratio of the number of clock pulses during the on-time to the number of clock pulses during the off-time, and may perform processing to subtract the noise component from the amount of light received by the light-receiving element during the on-time.

[0012] According to this configuration, the noise component can be easily calculated by a calculation using the ratio of the number of clock pulses during the light-on time to the number of clock pulses during the light-off time.

[0013] (4) The optical line sensor may further include a plurality of light receiving lenses respectively corresponding to the plurality of light receiving elements. In this case, the plurality of light receiving elements may receive light from the object that has passed through each of the light receiving lenses.

[0014] With this configuration, light from the object that has passed through multiple light-receiving lenses is received by multiple corresponding light-receiving elements, and noise components due to the influence of stray light can be effectively removed from the amount of light received by each light-receiving element.

[0015] (5) A plurality of the light sources may be provided corresponding to the plurality of light receiving elements, respectively. In this case, the plurality of light receiving elements may receive light from the object illuminated by each of the light sources.

[0016] With this configuration, light from an object illuminated by multiple light sources is received by multiple corresponding light receiving elements, and noise components due to the influence of stray light can be effectively removed from the amount of light received by each light receiving element.

[0017] (6) A data processing device according to the present invention is a data processing device that processes data obtained based on the amount of light received from the object by a plurality of light receiving elements by repeatedly performing a process of illuminating an object by turning on a light source for a predetermined lighting time, and then turning off the light source for a predetermined lighting time. The data processing device converts the amount of light received by the light receiving elements during the lighting time into the amount of light that would be received if the light source were turned off during the lighting time, thereby calculating the noise component during the lighting time and subtracting the noise component from the amount of light received by the light receiving elements during the lighting time.

[0018] With this configuration, the amount of light received by the light receiving element during the off time can be converted to the amount of light received when the light source is off during the on time, thereby calculating the noise component during the on time. Then, by performing a process of subtracting the noise component from the amount of light received by the light receiving element during the on time, the noise component due to the influence of stray light can be effectively removed from the amount of light received by the light receiving element during the on time.

[0019] (7) A data processing method according to the present invention processes data obtained based on the amount of light received from the object by a plurality of light receiving elements by repeatedly performing a process of illuminating the object by turning on a light source for a predetermined lighting time, and then turning off the light source for a predetermined lighting time. The method converts the amount of light received by the light receiving elements during the lighting time into the amount of light received if the light source were turned off during the lighting time, thereby calculating the noise component during the lighting time and subtracting the noise component from the amount of light received by the light receiving elements during the lighting time.

[0020] With this configuration, the amount of light received by the light receiving element during the off time can be converted to the amount of light received when the light source is off during the on time, thereby calculating the noise component during the on time. Then, by performing a process of subtracting the noise component from the amount of light received by the light receiving element during the on time, the noise component due to the influence of stray light can be effectively removed from the amount of light received by the light receiving element during the on time.

[0021] According to the present invention, it is possible to calculate the noise component during the lighting time, and by performing a process of subtracting the noise component from the amount of light received by the light receiving element during the lighting time, it is possible to effectively remove the noise component due to the influence of stray light from the amount of light received by the light receiving element during the lighting time.

[0022] Fig. 2 is a cross-sectional view showing an example of the configuration of an optical line sensor according to one embodiment of the present invention. Fig. 3 is an exploded perspective view showing an example of the configuration of an illumination optical system in the optical line sensor of Fig. 1. Fig. 4 is a schematic diagram showing the configuration of a portion of the optical line sensor of Fig. 1. Fig. 5 is a block diagram showing an example of the electrical configuration of the optical line sensor of Fig. 1. Fig. 6 is a timing chart for explaining the operation of the optical line sensor of Fig. 1. Fig. 7 is a schematic diagram showing the configuration of a portion of an optical line sensor according to another embodiment of the present invention.

[0023] 1. Overall Configuration of Optical Line Sensor Fig. 1 is a cross-sectional view showing an example of the configuration of an optical line sensor according to one embodiment of the present invention. Fig. 1 shows a cross-sectional view of the optical line sensor near the longitudinal center. Fig. 2 is an exploded perspective view showing an example of the configuration of an illumination optical system in the optical line sensor of Fig. 1. Fig. 3 is a schematic diagram showing the configuration of a portion of the optical line sensor of Fig. 1. In Figs. 1 to 3, the X direction is the main scanning direction, and the Y direction is the sub-scanning direction. The Z direction is perpendicular to the X and Y directions.

[0024] This optical line sensor is a contact image sensor (CIS) that irradiates light onto a thin object, such as a sheet of paper or film, mainly printed matter, and receives the reflected light or transmitted light from the object with a light receiving element array 12. As shown in Fig. 3, the light receiving element array 12 has a plurality of light receiving elements 121 arranged in a line along the X direction, and receives light from the illuminated object with each light receiving element 121 on a reading line L extending in the X direction.

[0025] In the optical line sensor shown in FIG. 1 , two housings 16 are arranged opposite each other with a focal plane 20 interposed therebetween. Each housing 16 is provided with a linear light source unit 10 for illuminating an object on the focal plane 20. One housing 16 is provided with a light-receiving lens array 11 and a light-receiving element array 12, and light from the illuminated object is guided to the light-receiving element array 12 via the light-receiving lens array 11. The light-receiving lens array 11 forms an image of the light from the object on the light-receiving surface 12A of each light-receiving element 121 of the light-receiving element array 12. In the optical line sensor shown in FIG. 1 , one of the two light source units 10 is arranged on the light-receiving element array 12 side, and the other is arranged on the opposite side from the light-receiving element array 12 side, with respect to the focal plane 20. In addition, a protective glass 14 is installed in the opening of each housing 16 on the focal plane 20 side.

[0026] The light-receiving lens array 11 may be, for example, a rod lens array such as a SELFOC lens array (registered trademark: Nippon Sheet Glass). Specifically, as shown in Fig. 3, the light-receiving lens array 11 includes a plurality of light-receiving lenses 111, each of which is associated with a light-receiving element 121. Therefore, light from an object that passes through each light-receiving lens 111 is received by the corresponding light-receiving element 121. However, the configuration is not limited to one including a plurality of light-receiving lenses 111, and a configuration in which light from an object is imaged on the light-receiving surface 12A of each light-receiving element 121 by a single light-receiving lens may also be used.

[0027] The light-receiving element array 12 is mounted on a substrate 13 fixed to one of the housings 16. Light passing through the light-receiving lens array 11 is received by the light-receiving surface 12A of each light-receiving element 121 of the light-receiving element array 12, and a signal corresponding to the amount of received light is output from each light-receiving element 121. As the object is transported in the Y direction along the focal plane 20, light from the object is continuously received by the light-receiving element array 12, and an image of the object is obtained based on the output signal from the light-receiving element array 12. In this way, the object transported in the Y direction is read by the light-receiving element array 12 extending in the X direction, along a reading line L formed by the light-receiving surface 12A of the light-receiving element array 12.

[0028] An ultraviolet light blocking filter (UV cut filter) 15 that blocks ultraviolet light from entering the light receiving element array 12 may be provided at any position between the focal plane 20 and the light receiving element array 12. In addition, a color filter 18 that passes visible light in a specific wavelength range may be provided between the light receiving element array 12 and the ultraviolet light blocking filter 15.

[0029] 1 and 2 , the light source unit 10 includes a transparent light guide 101 extending along the longitudinal direction (X direction), a light source 103 provided near one end face in the longitudinal direction, and a cover member 102 for holding each side face of the light guide 101. After entering the light guide 101, light emitted from the light source 103 is appropriately reflected by the light diffusion pattern P while propagating through the light guide 101, and is emitted from the light exit surface in the direction of the arrow in Fig. 2, becoming a line-shaped illumination light that illuminates an object.

[0030] Although two light source units 10 are shown in FIG. 1 , one of the light source units 10 may be omitted. For example, by omitting the light source unit 10 arranged on the opposite side from the light receiving element array 12, only reflected light from the object may be received by the light receiving element array 12 using the light source unit 10 arranged on the light receiving element array 12 side. In this case, the other housing 16 arranged opposite the one housing 16 on which the light receiving element array 12 is provided across the focal plane 20 may be omitted. On the other hand, by omitting the light source unit 10 arranged on the light receiving element array 12 side, only transmitted light from the object may be received by the light receiving element array 12 using the light source unit 10 arranged on the opposite side from the light receiving element array 12 side.

[0031] Furthermore, the number of light source units 10 arranged on the light receiving element array 12 side is not limited to one, but may be multiple. That is, light may be emitted from multiple light source units 10 at different angles to the same position on the focal plane 20. Similarly, the number of light source units 10 arranged on the opposite side from the light receiving element array 12 side is not limited to one, but may be multiple.

[0032] Furthermore, instead of conveying the object in the Y direction, sub-scanning along the Y direction may be achieved by moving the optical line sensor relative to a stationary object. In other words, it is sufficient that the object is configured to move relative to the optical line sensor in the Y direction.

[0033] 2. Electrical Configuration of Optical Line Sensor Figure 4 is a block diagram showing an example of the electrical configuration of the optical line sensor of Figure 1. The operation of the optical line sensor according to this embodiment is controlled by a control unit 200. The functions of the control unit 200 can be realized by a processor such as a CPU (Central Processing Unit) mounted on the substrate 13. When the CPU executes a program, the control unit 200 functions as a clock pulse generating unit 201, a lighting processing unit 202, a light receiving processing unit 203, an A / D conversion processing unit 204, an arithmetic processing unit 205, and the like.

[0034] The clock pulse generating unit 201 generates clock pulses at regular intervals. These clock pulses are reference clocks that serve as a timing reference for controlling the operation of the optical line sensor, and each part of the optical line sensor can be controlled at a timing according to the count number of clock pulses.

[0035] The lighting processing unit 202 controls the turning on and off of the light source 103. Specifically, the lighting processing unit 202 starts turning on the light source 103 using a pulse signal from an encoder (not shown) as a start pulse, and counts clock pulses based on an input signal from a clock pulse generating unit. The lighting processing unit 202 then turns off the light source 103 when a predetermined number of clock pulses has been counted, and turns the light source 103 on again when the next start pulse is input. In this way, the processing by the lighting processing unit 202 of turning on the light source 103 for a predetermined lighting time and then turning it off for a predetermined lighting time is repeated for each line.

[0036] The light receiving processing unit 203 controls light reception by each light receiving element 121 of the light receiving element array 12. Specifically, when the light source 103 starts to be turned on, the light receiving processing unit 203 starts accumulating charge in each light receiving element 121. Then, when the light source 103 is turned off (when a predetermined number of clock pulses have been counted), the light receiving processing unit 203 causes the light receiving element array 12 to output an analog charge signal corresponding to the amount of light received by each light receiving element 121 during the lighting time.

[0037] The accumulation of charge in each light receiving element 121 continues even after the light source 103 is turned off. Then, when the next start pulse is input and the light source 103 is turned on again, the light receiving processing unit 203 causes the light receiving element array 12 to output an analog charge signal corresponding to the amount of light received by each light receiving element 121 during the off time. In this way, while the light source 103 is repeatedly turned on and off for each line, analog charge signals corresponding to the amount of light received by each light receiving element 121 during the on time and the off time for each line are alternately output from the light receiving element array 12.

[0038] The A / D conversion processing unit 204 converts the analog charge signals output from the light receiving element array 12 into digital data. The digital data after A / D conversion by the A / D conversion processing unit 204 is stored in the memory 300. Specifically, digital data corresponding to the amount of light received by each light receiving element 121 during the light-on time is stored in the first memory 301 as a light-on gain G, and digital data corresponding to the amount of light received by each light receiving element 121 during the light-off time is stored in the second memory 302 as a light-off gain G'. That is, the light-on gain G for each line is stored in the first memory 301, and the light-off gain G' for each line is stored in the second memory 302.

[0039] The calculation processing unit 205 performs calculation processing based on the light-on gain G and the light-off gain G' stored in the memory 300. The processing by the calculation processing unit 205 will be described later. The data obtained by calculation is called post-calculation data G ｎｅｔ are stored in the third memory 303 as

[0040] The memory 300 is a storage unit capable of storing various data, and examples thereof include, but are not limited to, a random access memory (RAM), a hard disk drive (HDD), or a solid state drive (SSD). In the example of Fig. 4, the storage areas of the memory 300 are allocated to a first memory 301, a second memory 302, and a third memory 303, but this configuration is not limiting, and at least one of the first memory 301, the second memory 302, and the third memory 303 may be configured as a separate memory.

[0041] 3. Processing by the Arithmetic Processing Unit Fig. 5 is a timing chart for explaining the operation of the optical line sensor of Fig. 1. First, with reference to Fig. 5, the relationship between the clock pulse (reference clock) generated by the clock pulse generating unit 201, the timing of turning on and off the light source 103 by the lighting processing unit 202, and the timing of data output from the light receiving element array 12 will be explained.

[0042] When a pulse signal from an encoder (not shown) is used as a start pulse and the light source 103 starts to light up (light-on 1) at the timing of the generation of a subsequent clock pulse, charge is accumulated in each light-receiving element 121 for a time (light-on time t1) until a predetermined number of clock pulses are counted and the light source 103 is turned off (light-off 1). Then, during a time (light-off time t1') until the next start pulse is input and the light source 103 resumes lighting (light-on 2), an analog charge signal during the lighting time t1 is output from the light-receiving element array 12. The analog charge signal output at this time during the lighting time t1 is A / D converted to digital data, which is stored in the memory 300 as the lighting gain G1 for the first line.

[0043] Charge is also accumulated in each light receiving element 121 during the lights-out time t1', and when the next start pulse is input and the light source 103 is turned on again (light-on 2), the analog charge signal during the lights-out time t1' is output from the light receiving element array 12. The analog charge signal output during the lights-out time t1' is A / D converted to digital data, which is stored in the memory 300 as the lights-out gain G1' for the first line.

[0044] Based on the light-on gain G1 and the light-off gain G1' for the first line stored in the memory 300 as described above, the calculation processing unit 205 performs calculation using the following formula (1): G1 ｎｅｔ =G1-G1'×t1 / t1'...(1)

[0045] Similarly, during the time (light-on time t2) from when the next start pulse is input and the light source 103 is turned on again (light-on 2) until a predetermined number of clock pulses are counted and the light source 103 is turned off (light-off 2), electric charge is accumulated in each light-receiving element 121. Then, during the time (light-off time t2') from when the next start pulse is input and the light source 103 is turned on again (light-on 3), an analog charge signal during the light-on time t2 is output from the light-receiving element array 12, and digital data obtained by A / D converting this analog charge signal during the light-on time t2 is stored in the memory 300 as the light-on gain G2 for the second line.

[0046] Furthermore, when the next start pulse is input and the light source 103 is turned on again (lighting 3), the analog charge signal during the off time t2' is output from the photodetector array 12, and the digital data obtained by A / D converting this analog charge signal during the off time t2' is stored in the memory 300 as the off-time gain G2' for the second line.

[0047] Based on the light-on gain G2 and the light-off gain G2' for the second line stored in the memory 300 as described above, the calculation processing unit 205 performs calculation using the following formula (2): G2 ｎｅｔ =G2-G2'×t2 / t2'...(2)

[0048] In this way, the calculation processing unit 205 performs calculation processing based on the light-on gain G and the light-off gain G' using the light-on time t and the light-off time t' for each line according to the following formula (3), and obtains the calculated data G ｎｅｔ is stored in the memory 300. ｎｅｔ =GG'×t / t'...(3)

[0049] That is, the calculation processing unit 205 calculates the noise component by multiplying the amount of light received by each light receiving element 121 during the off time t' (light-off gain G') by the ratio t / t' of the on time t to the off time t', and subtracts the noise component from the amount of light received by each light receiving element 121 during the on time t (light-on gain G'), thereby obtaining the calculated data G ｎｅｔ In other words, the calculation processing unit 205 converts the amount of light received by each light receiving element 121 during the off time t' (light-off gain G') into the amount of light received when the light source 103 is off during the on time t (G' x t / t'), thereby calculating the noise component during the on time t, and performs processing to subtract the noise component from the amount of light received by each light receiving element 121 during the on time t (light-on gain G). This makes it possible to effectively remove noise components due to the influence of stray light from the amount of light received by each light receiving element 121 during the on time t.

[0050] In the above formula (3), the calculation processing unit 205 performs calculation processing using the on-time t and off-time t' for each line. However, the present invention is not limited to this configuration, and calculation processing may be performed using other formulas as long as noise components due to the influence of stray light can be removed from the amount of light received by each light-receiving element 121 during the on-time t.

[0051] For example, as shown in FIG. 5, the number of clock pulses N during the lighting time t ｃ and the number of clock pulses during the off time t', N ｃ The ratio of the number of clock pulses N during the lighting time t corresponds to the ratio of the lighting time t to the lighting time t'. ｃ and the number of clock pulses during the off time t', N ｃ ' can also be used to perform arithmetic processing.

[0052] Specifically, the calculation processing unit 205 calculates the number of clock pulses N during the lighting time t for each line. ｃ and the number of clock pulses during the off time t', N ｃ Using the gain G′, calculation processing can be performed based on the light-on gain G and the light-off gain G′ using the following equation (4): ｎｅｔ = G-G' x N ｃ / N ｃ ´ ... (4)

[0053] That is, the calculation processing unit 205 multiplies the amount of light received by each light receiving element 121 during the light-off time t' (light-off gain G') by the number of clock pulses N during the light-off time t'. ｃ The number of clock pulses N during the lighting time t for ｃ Ratio N ｃ / N ｃ The noise component is calculated by multiplying the gain G by ', and the noise component is subtracted from the amount of light received by each light receiving element 121 during the lighting time t (lighting gain G), thereby obtaining the calculated data G ｎｅｔ may be calculated.

[0054] 5. Alternative Embodiment Figure 6 is a schematic diagram showing a partial configuration of an optical line sensor according to another embodiment of the present invention. In the above embodiment, as shown in Figure 3, a case has been described in which an object is illuminated with light emitted from a single light source unit 10. However, this configuration is not limited to this, and a configuration may also be used in which multiple light sources 103 are provided in the light source unit 10 and the object is illuminated with light emitted from each light source 103, as shown in Figure 6. The number of light sources 103 may be the same as the number of light receiving elements 121, and each light source 103 may be in one-to-one correspondence with each light receiving element 121. Each light source 103 may emit laser light.

[0055] In this case, the lighting processing unit 202 may sequentially turn on and off each light source 103, and the light receiving processing unit 203 may perform control so that light from the object illuminated by each light source 103 is sequentially received by the light receiving elements 121 corresponding to each light source 103. In other words, the process by the lighting processing unit 202 of turning on and off each light source 103 and the process by the light receiving processing unit 203 of receiving light from the object by the light receiving elements 121 corresponding to each light source 103 may be synchronized.

[0056] In such a configuration, by performing the above-described calculation processing by the calculation processing unit 205, light from an object illuminated by a plurality of light sources 103 is received by a corresponding plurality of light receiving elements 121, and noise components due to the influence of stray light can be effectively removed from the amount of light received by each light receiving element 121.

[0057] In the above embodiment, a configuration in which the control unit 200 is provided in the optical line sensor has been described, but a configuration in which a data processing device that processes data from the optical line sensor is provided separately and the data processing device performs the same processing as the control unit 200 may also be used. In this case, a personal computer or the like connected to the optical line sensor may function as the data processing device.

[0058] REFERENCE SIGNS LIST 10 light source unit 11 light receiving lens array 12 light receiving element array 103 light source 111 light receiving lens 121 light receiving element 200 control unit 201 clock pulse generating unit 202 lighting processing unit 203 light receiving processing unit 204 A / D conversion processing unit 205 arithmetic processing unit 300 memory

Claims

1. An optical line sensor that reads an object that is moved relatively in the sub-scanning direction with a reading line that extends in the main scanning direction, comprising: a light source that illuminates the object; a plurality of light receiving elements that are arranged in a line along the main scanning direction and receive light from the object illuminated by the light source; an illumination processing unit that repeatedly performs a process of turning on the light source for a predetermined illumination time and then turning it off for a predetermined extinguishing time; and an arithmetic processing unit that converts the amount of light received by the light receiving elements during the extinguishing time into the amount of light received if the light source were extinguished during the illumination time, calculates noise components during the illumination time, and performs a process of subtracting the noise components from the amount of light received by the light receiving elements during the illumination time.

2. The optical line sensor of claim 1, wherein the calculation processing unit calculates the noise component by multiplying the amount of light received by the light receiving element during the off time by the ratio of the on time to the off time, and performs processing to subtract the noise component from the amount of light received by the light receiving element during the on time.

3. An optical line sensor as described in claim 1, further comprising a clock pulse generating unit that generates clock pulses at a constant cycle, wherein the calculation processing unit calculates the noise component by multiplying the amount of light received by the light receiving element during the off time by the ratio of the number of clock pulses during the on time to the number of clock pulses during the off time, and performs processing to subtract the noise component from the amount of light received by the light receiving element during the on time.

4. The optical line sensor according to claim 1, further comprising a plurality of light receiving lenses respectively associated with the plurality of light receiving elements, wherein the plurality of light receiving elements each receive light from the object that has passed through each light receiving lens.

5. The optical line sensor according to claim 1, wherein the light source is provided in a plurality of light receiving elements each corresponding to a corresponding one of the light receiving elements, and the plurality of light receiving elements each receive light from the object illuminated by the light source.

6. A data processing device that processes data obtained based on the amount of light received from an object by a plurality of light receiving elements by repeatedly performing a process of illuminating the object by turning on a light source for a predetermined lighting time and then turning off the light source for a predetermined lighting time, wherein the data processing device converts the amount of light received by the light receiving elements during the lighting time to the amount of light received if the light source were turned off during the lighting time, calculates the noise component during the lighting time, and performs a process of subtracting the noise component from the amount of light received by the light receiving elements during the lighting time.

7. A data processing method for processing data obtained based on the amount of light received from an object by a plurality of light receiving elements by repeatedly performing a process of illuminating the object by turning on a light source for a predetermined lighting time and then turning off the light source for a predetermined lighting time, wherein the data processing method converts the amount of light received by the light receiving elements during the lighting time into the amount of light received if the light source were turned off during the lighting time, calculates the noise component during the lighting time, and subtracts the noise component from the amount of light received by the light receiving elements during the lighting time.

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