JPH114328A - Image sensor driving device and image reading device using the same - Google Patents

Abstract

(57) [Problem] To stably drive an image pickup device without distortion. SOLUTION: A plurality of pixels for reading a certain color component are arranged one-dimensionally, and an image pickup device 12 for converting an image of a formed document 2 into an electric signal, and the image pickup device 12 is arranged in a pixel arrangement direction. An image sensor driving device is composed of a vibration unit 13 that vibrates in a sinusoidal manner with an amplitude of one half of the width of the pixel and a signal processing unit 17 that performs a predetermined process on an electric signal output from the image sensor 12. I do. According to this, the image sensor 1
2 is oscillated in a sinusoidal manner, so that it is driven stably without distortion.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image pickup device driving device for reading an original while vibrating image pickup devices arranged one-dimensionally in the pixel column direction, and an image reading device using the same.

[0002]

2. Description of the Related Art Conventionally, an image reading apparatus has been used as an image input device such as a scanner, a facsimile, a copying machine, or the like. Recently, there has been an increasing demand for higher resolution of the image reading apparatus.

Here, as a means for realizing high resolution, there is a technique of increasing the number of pixels of an image sensor. But,
As the number of pixels increases, the image sensor becomes expensive.As a means for obtaining a high-resolution image at a lower cost, one-dimensionally arrayed image sensors are vibrated in the pixel direction to obtain information on a plurality of image forming positions. Then, there is a technique (swing method) of combining and reading them.

Hereinafter, an image pickup device driving device using the swing method will be described. FIG. 7 is a schematic diagram showing a configuration of a conventional image sensor driving device and its related parts.

[0005] The illustrated apparatus has a light source 102 for irradiating an original 101. An image sensor 104 on which an image of the document 101 is formed by the imaging lens 103 is disposed on the optical path of the light reflected from the document 101. The image sensor 104 is oscillated by the vibration means 105 in the direction in which the pixels are arranged at an amplitude of １ ／ of the width of the pixels. Then, the vibration unit 105 is driven by the driving unit 107 according to the trapezoidal wave generated by the trapezoidal wave generation unit 106.

According to such an apparatus, when the document 101 is irradiated by the light source 102, the reflected light from the document 101 is imaged on the image sensor 104 by the imaging lens 103. The image pickup device 104 is a vibrating unit 1 driven by a driving unit 107.
Due to the trapezoidal vibration 05 in the pixel column direction, reading is performed within a period in which the waveform does not fluctuate.

FIG. 8 shows the relationship between the drive waveform of the vibration means 105 for vibrating the image sensor 104 and the reading area.

[0008] A trapezoidal drive waveform 108 shown in FIG.
The image sensor 104 is vibrated at an amplitude of の of the pixel width as described above in accordance with the driving waveform of (1). Then, an area indicated by a solid line in FIG. 8B is read in the period A of the driving waveform 108, and an area indicated by a broken line in FIG. In FIG. 8B, the area to be read in each of the periods A and B is represented for each pixel.

The number of pixels of the image sensor 104 is N
And the original 101 in the length direction of the image sensor 104
Is the width of D [inch], the original 101 is the sum of the number N of pixels read by the image sensor 104 in the period A and the number N of pixels read in the period B, that is, 2N pixels D [inch] is read with the number of pixels of. The reading resolution at this time is 2N / D [dpi], which is twice as high as that obtained when no vibration is applied.

[0010]

However, in the above-described conventional apparatus, when the vibration frequency of the trapezoidal wave increases and the amount of movement of the image sensor increases, or the mass of the image sensor increases, as shown in FIG. In this case, distortion occurs in the vibration waveform of the image sensor.

Then, the driving of the image sensor becomes unstable,
There is a problem that the reading speed cannot be increased.

Accordingly, an object of the present invention is to provide a driving technique capable of stably driving an image sensor without causing distortion in its vibration waveform.

[0013]

In order to solve this problem, an image pickup device driving apparatus according to the present invention comprises: a plurality of pixels for reading a predetermined color component arranged one-dimensionally; An image sensor that converts the image of the image into an electric signal, vibrating means for vibrating the image sensor in a pixel arrangement direction with an amplitude of half the width of the pixel and in a sine wave shape, and an electric signal output from the image sensor. Signal processing means for performing predetermined processing on the signal, whereby the imaging element is driven stably without causing distortion in the vibration waveform.

In this case, a predetermined range including the peak of the sine wave can be converted into an electric signal by the image pickup device. Further, it is possible to perform processing by the signal processing means only on the electric signals in a predetermined range including the peak of the sine wave.

Further, the image reading apparatus of the present invention uses such an image sensor driving device.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS According to the first aspect of the present invention, a plurality of pixels for reading a predetermined color component are arranged one-dimensionally, and a formed image of the object is converted into an electric signal. Image sensor, vibrating means for vibrating the image sensor in a sine wave shape with an amplitude of half the width of the pixel in the pixel arrangement direction, and performing predetermined processing on the electric signal output from the image sensor An image sensor driving device having a signal processing unit,
The image pickup device is always in a state of being continuously moved, so that the vibration waveform is not distorted and has an effect of being driven stably.

Further, the invention according to claim 2 of the present invention provides
According to the first aspect of the present invention, there is provided an image pickup device driving device in which a predetermined range including a peak of a sine wave is converted into an electric signal by an image pickup device, and the influence of movement of the image pickup device during a reading period is reduced. Has the effect that a high-resolution image with less blur can be obtained.

According to a third aspect of the present invention, there is provided the imaging apparatus according to the second aspect, wherein only the electric signal in a predetermined range including the peak of the sine wave is processed by the signal processing means. This is an element driving device, and has an effect that the device can be configured with a simpler circuit configuration, and the reading speed can be increased.

According to a fourth aspect of the present invention, there is provided an image reading apparatus using the image pickup device driving device according to the first, second, or third aspect, wherein the image reading apparatus is provided with high reliability. This has the effect that image quality can be improved.

FIG. 1 shows an embodiment of the present invention.
This will be described with reference to FIG. In these drawings, the same members are denoted by the same reference numerals, and duplicate description is omitted.

FIG. 1 is a schematic diagram showing an image reading apparatus using an image pickup device driving apparatus according to an embodiment of the present invention. FIG. 2 is an image pickup apparatus driving apparatus according to an embodiment of the present invention and its related parts. 3, FIG. 3 is a plan view showing the image sensor of FIG. 2, FIG. 4 is a block diagram showing the internal configuration of the signal processing unit of FIG. 2, FIG. 5 is a driving waveform, a reading period by the image sensor, and a signal processing unit. And FIG. 6 is a timing chart showing signal processing in the signal processing means.

In FIG. 1, an original glass 3 on which an original (object to be imaged) 2 is loaded is fitted on the upper surface of the apparatus main body 1. A document pressing plate 4 is attached to the document glass 3 so as to be openable and closable in order to press the loaded document 2 against the document glass 3.

A carriage frame 5 is provided inside the apparatus main body 1 so as to be movable in the scanning direction of the original 2 shown by an arrow A. An illumination unit 6 for irradiating the original 2 is attached to an upper portion of the carriage frame 5. Reflection mirrors 7, 8, 9, and 10 are appropriately arranged on the optical path of the reflected light emitted from the illumination unit 6 and reflected by the document 2. Then, these reflection mirrors 7, 8, 9, 10
Thereby, the reflected light is guided to the imaging lens 11 which changes the magnification of the reflected light to a predetermined magnification. Behind the imaging lens 11 on the optical path,
An image sensor 12 for converting an image of the document 2 formed by the imaging lens 11 into an electric signal is provided.

FIG. 2 shows the image pickup device driving device and its related parts. As described above, the image sensor 12 is disposed behind the imaging lens 11 on the optical path of the light reflected by the document 2 from the light source 6a of the illumination unit. The image sensor 12 is vibrated by vibrating means 13 composed of, for example, a piezoelectric element or a voice coil, and is vibrated in the direction in which the pixels are arranged at an amplitude of の the width of the pixels. The vibrating means 13 drives the driving means 1 in accordance with the sine wave generated by the sine generating means 15 composed of, for example, a digital / analog converter and an LUT.
4.

Further, in order to perform reading at a predetermined timing in the sine wave generated by the sine generating means 15, a timing generating means 16 is connected to the image sensor 12, and the reading timing is controlled. Further, in order to perform predetermined processing on the electric signal output from the image sensor 12,
Signal processing means 17 is connected to the image sensor 12.

Here, the structure of the image pickup device 12 is shown in detail in FIG. In the case of the embodiment of the present invention, the image sensor 12 includes red (hereinafter, referred to as “R”), green (hereinafter, referred to as “G”), and blue (hereinafter, referred to as “B”).
That. ) Have pixel rows 18R, 18G, and 18B in which pixels for reading respective color components are one-dimensionally arranged. Each pixel column is composed of N pixels, and the interval between the pixel columns is represented by the number of lines and L lines are provided. For example, L is 4 lines.

FIG. 4 shows the internal structure of the signal processing means 17. As shown in the figure, the signal processing means 17 includes pixel rows 18R, 18G, 18B of the image sensor 12 respectively.
An analog / digital conversion unit (hereinafter, “A”) that receives an electric signal corresponding to each of R, G, and B components of the original image output from FIG. 3 and converts it into a digital signal
D conversion means ". ) 19R, 19G and 19B are provided.

At the subsequent stage of the A / D converters 19R, 19G, and 19B, selection units 20R, 20G, and 20B that pick up only data in a predetermined range including the sine wave vertices from the outputs of the A / D converters 19R, 19G, and 19B. 20
B is provided. At the subsequent stage of the selection means 20R, 20G, the outputs from the selection means 20R, 20G are temporarily stored, and the memories 21R, 21R, which take timing so that the electric signal of the same pixel as the selection means 20B are output, are provided.
21G is provided. Then, the memories 21R, 21
At the subsequent stage of G and the selection means 20B, there is provided an image processing means 22 for performing predetermined processing such as color processing, resolution conversion, etc. from the output of the same pixel data.

As described above, the pixel rows 18R, 18G, 1
8B are arranged at intervals of L lines. Therefore, each of the pixel rows 18R, 18G, and 18B simultaneously reads a position separated by L lines. Therefore, the outputs of the selection units 20R and 20G are temporarily stored in the memories 21R and 21G, respectively, and are delayed by the distance of the separated lines and output at the same timing as the output of the selection unit 20B, so that the data of the same pixel is obtained. At the same time, it is input to the image processing means 22.

According to such an image reading apparatus, when the document 2 is irradiated by the light source 6a, the image is
Imaged on top. Then, reading is performed by the imaging element 12 vibrated in the pixel column direction by the vibration means 13 driven by the driving means 14. At this time, as described above, since the image pickup device 12 is vibrated in a sine wave shape, the image pickup device 12 is maintained in a state in which the image pickup device 12 is constantly moving instead of repeating movement and stopping like the trapezoidal wave vibration. As a result, the image sensor 12 is driven stably without causing distortion in its vibration waveform.

Here, the pixel size W × L of the image sensor 12
Is set to, for example, 10 μm × 10 μm, and the moving distance of the image sensor 12 is set to 5 μm, which is の of the pixel size.

FIGS. 5A, 5B and 5C show a sine wave which is a driving waveform of the image pickup device 12, a reading period of the image pickup device 12 driven by the sine wave, and a signal processing means for the reading period. The respective relationships of the selection timings by the selection means 20R, 20G, and 20B are shown.

As shown in the figure, the image sensor 12 reads eight times during one cycle of the drive waveform (see FIGS. 5A and 5B). The eight reading data output from the image pickup device 12 to the signal processing means 17 are output to the AD conversion means 19R, 19G, and 19B.
After being converted into a digital signal by the selection means 20
Only the third and seventh read data in the range including the peak of the sine wave are selected by R, 20G, and 20B (see FIGS. 5B and 5C). Therefore, the image data used for the subsequent processing is only the third and seventh read data.

This is for the following reason. That is, the image sensor 12 integrates and outputs the input over a certain period, not at a certain moment. Therefore, if the amount of movement of the imaging element 12 during the reading period is large, a wider image is read, and as a result, the image quality is reduced. Therefore, during the reading period, it is desirable that the movement of the imaging element 12 is small. For example, FIG.
In the case of the first reading in, the distance that the image sensor 12 moves during the reading period is 1.91 μm. However, the distance that the image sensor 12 moves during the third and seventh reading periods, which is the range including the peak of the sine wave, is
0.38 μm. As described above, in the predetermined range including the peak of the sine wave, the influence of the movement of the imaging element 12 during the reading period becomes smaller.

It should be noted that here, the sine wave 1 which is the drive waveform
An example is described in which eight readings are performed during a cycle. However, even when reading is performed at other times during one cycle, only the read data within the range including the peak of the sine wave is selected. do it. However, as the number of times of reading increases, the moving distance of the image sensor 12 including the peak of the sine wave becomes shorter, so that a high-resolution image with less blur can be obtained.

Further, in the embodiment of the present invention, the range including the peak of the sine wave is selected by the selecting means 20R, 20G, 20B. However, a memory is provided to control the read timing and to perform AD conversion. Means 19R, 19
The range may be selected by controlling G, 19B.

In this way, the selection means 20R, 20G,
The image data selected in 20B is stored in the memory 21
R, 21G and the image processing means 22.

Here, referring to FIG. 6, the memories 21R, 2R
The operation of 1G will be described. In FIG. 6, (a) shows a selection timing of the selection means 20R, 20G, 20B, (b) shows a pixel position of data input to the memory 21R, (c) shows a pixel position of data output from the memory 21R, d)
Is the pixel position of the data input to the memory 21G, (e)
Is the pixel position of the data output from the memory 21G,
(F) is the pixel position of the data output from the selection means 20B.

As shown in FIG. 6, the memories 21R and 21G
, The image processing means 2
2, the data of the same pixel is input simultaneously. As described above, since only the image data in the range including the sine wave vertex is selected, the memory 21R stores
It suffices that the memory 21G has a capacity for 16 lines for the line. When all the image data are processed without selecting only the necessary lines by the selection units 20R, 20G, and 20B, the memory 21R requires a capacity of 32 lines and the memory 21G requires a capacity of 64 lines. The choice will greatly reduce the amount of memory. Then, since the amount of data to be handled thereafter is reduced, the imaging device driving device can be configured with a simpler circuit configuration, and the reading speed can be increased.

The data of the same pixel output in this way is sent to the image processing means 22, where the data is subjected to predetermined processing such as color processing and resolution conversion and output.

[0041]

As described above, according to the present invention, since the image pickup device is vibrated in a sine wave shape, the image pickup device is constantly moving, and the vibration waveform is distorted. Therefore, an effective effect of stable driving can be obtained.

As a result, an effective effect that the reading speed of the image sensor can be increased can be obtained.

Also, by converting a predetermined range including the peak of the sine wave into an electric signal by the image sensor, the influence of the movement of the image sensor during the reading period is reduced, so that a high-resolution image with less blur can be obtained. An effective effect is obtained.

Further, by processing only the electric signals in a predetermined range including the peak of the sine wave by the signal processing means, the amount of subsequent data to be processed is reduced.
An advantageous effect is obtained in that the imaging device driving device can be configured with a simpler circuit configuration. Further, an effective effect that the reading speed can be increased is obtained.

According to the image reading apparatus of the present invention, since such an image pickup device driving apparatus is used, it is possible to effectively improve the image quality with high reliability. Is obtained.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an image reading device using an image sensor driving device according to an embodiment of the present invention;

FIG. 2 is a perspective view showing an image sensor driving device according to an embodiment of the present invention and its related parts.

FIG. 3 is a plan view showing the image sensor of FIG. 2;

FIG. 4 is a block diagram showing the internal configuration of the signal processing means of FIG. 2;

FIG. 5 is an explanatory diagram showing a correlation between a driving waveform, a reading period by an image sensor, and a selection timing by a signal processing unit.

FIG. 6 is a timing chart showing a state of signal processing in the signal processing means.

FIG. 7 is a schematic diagram showing a configuration of a conventional image sensor driving device and its related parts.

FIG. 8 is an explanatory diagram showing a relationship between a driving waveform of a vibrating means for vibrating an image sensor in a conventional image sensor driving device and a reading area.

FIG. 9 is an explanatory diagram showing a vibration waveform of an image sensor in a conventional image sensor driving device.

[Explanation of symbols]

 2 Document (object to be imaged) 12 Image sensor 13 Vibration means 17 Signal processing means

Claims (4)

[Claims] 1. An image pickup device in which a plurality of pixels for reading a predetermined color component are arranged in a one-dimensional manner, the image pickup device converting an image of an imaged object into an electric signal, and the image pickup device is arranged in an arrangement direction of the pixels. 2 of the width of the pixel
An image pickup device driving device comprising: a vibration unit that vibrates in a sinusoidal shape with an amplitude of one-half, and a signal processing unit that performs predetermined processing on the electric signal output from the image pickup device. 2. The image pickup device driving device according to claim 1, wherein said image pickup device converts a predetermined range including a vertex of a sine wave into said electric signal. 3. The image pickup device driving device according to claim 2, wherein said signal processing means processes only said electric signal in a predetermined range including a peak of a sine wave. 4. An image reading apparatus using the image pickup device driving device according to claim 1, 2 or 3.