JPH0265585A - Picture input device - Google Patents

Abstract

PURPOSE:To reduce time fetching a picture with less vibration by turning a filter unit at an equal speed, arranging color filters in order to an optical path reaching an image pickup means, excluding an optical signal inputted to an image pickup means at a period when a border of each color filter passes in the optical path and selecting a remaining signal. CONSTITUTION:A filter unit 13 is made as a disk shape and a red filter 14R, a green filter 14G and a blue filter 14B of the same shape are provided on the circumference at the same interval. The filter unit 13 is turned around at an equal speed by 9 periods of vertical synchronizing signals. Every time magnets 17, 18 cross a Hall IC 19 attended with the rotation, the Hall IC 19 generates an angular signal and an origin signal. A control circuit 40 detects the leading of each pulse of a filter switching signal and stores the data in an area corresponding to the memory 33. The filter unit 40 is driven by 40 deg. during that time and the border of each filter crosses the optical path reaching the CCD 12. Thus, the integrated value in this period is not stored in the memory 33.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to an image input device.

[Prior Art] Conventionally, this type of image input device has a structure as shown in FIG. In the figure, a solid-state image sensor (hereinafter referred to as COD) 53 is provided at a position where light from a subject 52 is imaged by a lens 51 attached to the front surface of the device 50, and on the optical path leading to the CCD 53, A filter unit 54 is attached. As shown in FIG. 5, this filter unit 54 includes red, green, and blue color filters 55R, 55G, and 55B, and a transparent filter 56. This filter unit 54 is
By rotating around the rotation axis 54C, each of the filters can be selectively placed on the optical path. A step motor 57 is attached to this rotating shaft 54C. The CCD 53 is connected to a memory 59 via a converter 58 for converting output data from analog to digital. Furthermore, a control circuit 60 is installed to collectively control each member.

In the apparatus configured as described above, brightness adjustment, focal length #adjustment, etc. are first performed with the transparent filter 56 placed on the optical path. Next, the step motor 57 rotates, and the red filter 55R is placed on the optical path. Then, only the red component of the subject image is formed on the CCD 53. C
The CD 53 receives light for a predetermined period under the control of the control device 60, and outputs data of the integrated value of the luminance of the light received during that period. This data is converted into digital data by a converter 58 and stored in a memory 59.

Next, the step motor 57 rotates every 90 degrees, and the green and blue filters 55G and 55B are sequentially arranged on the optical path, and the digital data of the green and blue components of the subject image are stored in the memory 59 in the same manner. Make me remember.

Further, as shown in FIG. 6, each input element 61 of the CCD 61
a for red, green, and blue small filters 62R, 6
By covering with 2G and 62B, it is also possible to capture a color image at -degree.

[Problems to be Solved by the Invention] However, in the former configuration, there are problems in that the filter needs to be rotated intermittently, vibrations occur frequently, and it takes a long time to capture one image. Furthermore, the latter configuration had the problem that the resolution was reduced to about one-third.

The present invention has been made to solve the above problems, and its purpose is to provide an image input device with less vibration, high resolution, and a sufficiently short time to capture one image. It is.

[Means for Solving the Problems] In order to achieve the above object, the present invention comprises a plurality of optical input elements arranged in the vertical and horizontal directions, and receives the luminance signal of the light inputted by each input element in field units. An imaging means that outputs an output in synchronization with a vertical synchronization signal, and at least two color filters arranged on a predetermined circumference centered on a rotation axis are sequentially connected to the imaging means as the rotation is made around the rotation axis. a filter unit disposed on an optical path; a filter driving means for rotating the filter unit at a constant speed; The present invention is characterized by comprising a selection means for excluding a signal of luminance of the output light.

[Operation] In the present invention having the above configuration, the filter unit rotates at a constant speed, and color filters are sequentially arranged on the optical path leading to the imaging means. The selection means excludes the light signals input to the imaging means in the period in which the boundary of each color filter passes through the optical path, and selects the remaining signals.

[Example] An example embodying the present invention will be described below with reference to the drawings.

The image input device of this embodiment uses a CCD 12 and peripheral equipment set to perform interlaced scanning and output even and odd field data every cycle of the vertical synchronization signal. In other words, the CCD 12 of this device outputs monochrome image data for one screen (one frame) in two cycles of the vertical synchronization signal.

In FIG. 1 showing the configuration of the image input device of this embodiment,
Behind the lens mechanism 11 attached to the front of this device is a C
CD12 is installed. This lens mechanism 11 is composed of a plurality of lenses, and by adjusting the position of each lens, a subject 13 located at an arbitrary distance can be photographed.
It is possible to form a real image on the CCD 12.

A filter unit 13 is attached between the lens mechanism 11 and the CCD 12. As shown in FIG. 2, this filter unit 13 has a disk shape, with a red filter 14R and a green filter 1 having the same shape on the same circumference.
4G and blue filters 14B are provided at the same interval. This filter unit 15 is rotatably supported around a rotating shaft 13C provided in the center, and each color filter 14R, 14G, 14B can be inserted into the optical path according to the rotation. This rotating shaft 13C is the DC motor 1
It is connected to the output shaft of 6.

The optical path is surrounded by a black light shielding wall (not shown), and the color filters 14R, 14G, and 14B can cover the cross section of the optical path without any gaps. The position and size ratio between this filter unit 13 and the cross section 37 of the optical path leading to the CCD 12 is as shown in FIG. As shown in the figure, the filter unit 13 has a filter unit 13 whose boundary between each color filter enters the cross section 37 of the optical path due to the rotation of the filter unit 13, and then passes through the cross section 37.
In addition, three magnets 1 for detecting the rotation angle are installed at the boundary positions between the color filters of the filter unit 13.
7.18 is provided. Of these three magnets, the magnet 18 provided between the red filter 14R and the blue filter 14B is longer than the other two, and also serves to detect the origin. A Hall IC (integrated circuit) 19 constituted by a Hall element is attached at a position where the magnets 17 and 18 cross as the filter unit 13 rotates about the rotation axis 13C. This Hall IC 19 is connected to the magnet 17. A pulse is generated every time the fill crosses between the Hall ICs 19. This pulse train is hereinafter referred to as an angle signal. Further, the magnet 18 for detecting the origin is located at the hole I.
A pulse is generated from another terminal each time it crosses between C and C. This pulse train is hereinafter referred to as the origin signal.

The Hall IC 19 is connected to a phase comparator 21, and the angle signal is input to one input terminal of the phase comparator 21.

The vertical synchronization signal is also connected to a frequency divider circuit 34, which divides the frequency of the vertical synchronization signal by three and outputs the divided signals in the same phase. This vertical synchronization signal frequency-divided by three is called a filter switching signal. This filter switching signal is input to the other input terminal of the phase comparator 21. This phase comparator 21 compares the phase difference at the rise of each pulse of the filter switching signal and the angle signal input to both input terminals, and outputs a positive or negative voltage corresponding to the phase difference. The output terminal of this phase comparator 21 is connected to a low-pass filter 22 having integral characteristics. This low-pass filter 22 integrates the voltage output from the phase comparator 21 and smooths the waveform. A pulse width modulator 23 is connected to the output terminal of this low-pass filter 22.
is installed. The pulse width modulator 23 pulse width modulates the voltage output from the power supply 24 in relation to the voltage output from the low-pass filter 22 and supplies the modulated voltage to the DC motor 16 .

The CCD 12 includes a variable gain amplifier 31 and an analog
Digital converter (hereinafter referred to as A/D converter) 3
2 to the memory 33.

This memory 33 has areas for storing even and odd field data for each color.

Further, a ternary counter is connected to the frequency divider circuit 34, and counts the filter switching signal at the rising edge of each pulse. The origin signal is input as a reset signal to the ternary counter 35, and the count value is forcibly reset to 0 at the rising edge of the pulse. A delay circuit 36 is connected to the ternary counter 35, which delays the count value data output from the ternary counter by one period of the vertical synchronizing signal. This delayed data (0 to 2) indicates the color of the data output by the CCD 12; 0 means red, 1 means green,
2 represents blue. This data is input to a control circuit 40 provided to collectively control the variable gain amplifier 31 and each member.

The operation of this device configured as above will be explained below.

First, control of rotation of the filter unit 13 will be explained. Electric power is supplied from the power supply 24 to the DC motor 16, and its rotating shaft 13C rotates. Along with this rotation, the filter unit 13 rotates. With this rotation, the magnet 17.
Each time 18 crosses Hall IC 19, Hall IC 19 generates an angle signal and an origin signal. This angle signal is input to one input terminal of the phase comparator 21. This phase comparator 21 compares the phase of this pulse train with the phase of the filter switching signal shown in FIG. 3 inputted to the other input terminal, and outputs a voltage related to the phase difference.

The absolute value of this voltage increases as the phase difference and frequency difference between the two inputs increases, and its polarity is positive if the phase of the pulse train is delayed or low in frequency compared to the filter switching signal, and negative if the opposite is the case. Become. The output of this phase comparator 21 is input to the low-pass filter 22. This low-pass filter 22 transmits the voltage output from this phase comparator 21 with a predetermined transmission characteristic having an integral characteristic. The pulse width modulator 23 pulse width modulates the current supplied to the DC motor 16 according to the voltage output from the low-pass filter 22, and linearly changes the duty of the pulse of the current. Therefore, if the phase of the pulse train output from the VH IC 19 is delayed or the frequency is low relative to the vertical synchronization signal, the duty of the current pulses input to the DC motor 16 becomes high, and the rotation speed becomes high. Conversely, if the phase is advanced or the frequency is high, the duty will be low and the rotation speed will be low. Therefore, as shown in Figure 3,
The phase difference between the pulse train of the angle signal and the filter switching signal becomes zero and converges. Therefore, the filter unit 13 rotates once every nine cycles of the vertical synchronization signal at a constant speed. In addition, when a pulse of the filter switching signal is generated, each of the color filters 14R
, 14G, and 14B are located at the lowest point in the rotational direction in the cross section 37 of the optical path, as shown in FIG. In this way, the filter unit 13 rotates, and each color filter 14R, 114G, 14B crosses the optical path one after another, and the CCD
Images of each color are formed on 12.

The CCD 12 integrates the luminance of incident light at each input element for each period of the vertical synchronization signal, and transfers the integrated value all at once to a built-in buffer at the rise of the next pulse of the vertical synchronization signal. Then, during one period after the rise of the pulse, data of each integral value in this buffer is serially outputted, and at the same time, integration for the next field is started.

Serial data output from the CCD 12 is input to a variable gain amplifier 31. The variable gain amplifier 31 transmits this data signal (analog signal) to the CCD according to the color signal.
12 and the sensitivity characteristics of the filter for each color. This amplified data is transferred to the A/D converter 3
Digitized by 2.

The control circuit 40 detects the rising edge of each pulse of the filter switching signal, and from that point on, the A/R is controlled during one period of the vertical synchronizing signal.
It is determined whether the data digitized by the D converter 32 is even field data or odd field data, and a color signal is inputted to know the color. Then, the data is stored in the corresponding area of the memory 33. During this time, the filter unit rotates 40'', and the boundary of each filter crosses the optical path to the CCD 12.

Therefore, the value integrated in this cycle, ie, the data output in the next cycle of the vertical synchronization signal, indicates the brightness of light in which two colors are mixed. Therefore, data output in the next cycle of the vertical synchronization signal is not stored in the memory 33.

The data output in the next cycle of the vertical synchronization signal is stored in the memory 33 in the same way as in the first cycle.

Finally, the process of reading one screen worth of images in this apparatus will be explained.

In Figure 3, when the pulse of the origin signal occurs, the integration of the blue field has already been completed, and its value changes when the pulse of the filter switching signal occurs (at the same time as the pulse of the origin signal occurs). transferred to the buffer.

Assume that this field is even.

Then, an even field in the blue image is stored in the memory 33 during one period (first period) of the vertical synchronizing signal immediately after the pulse of the origin signal is generated. This period (1
In the third period), the red filter 14R enters the optical path instead of the blue filter 14B. Therefore, this period (
The light input to the CCD 12 in the first period) is both blue light and red light. Therefore, the next period (2
The data output from the CCDI 2 in the third period) is not stored in the memory 33. However, the data output at this time is odd data. And this 2
During the period, only red light is irradiated to the CCD 12,
In the third cycle, the CCD 12 outputs even fields in the red image.

As described above, data is sequentially stored in the memory 33 in the order shown in FIG.

When outputting image data from this device, the data stored in the memory 33 is saved at the time of generation of the next angle signal pulse after generation of an arbitrary origin signal pulse, and the data is converted into a predetermined format. Output with .

Furthermore, if monochrome image data is required, the data is obtained by adding the data of each color.

In this embodiment, since a type of COD that performs interlaced scanning is used, the filter unit is rotated once during nine periods of the vertical synchronization signal, but a COD of a type that does not perform interlaced scanning
If a CD is used, the image reading speed can be increased by rotating the CD once every six cycles.

[Effects of the Invention] As detailed above, according to the present invention, an image can be read in a short time without reducing resolution. Furthermore, there is no need to rotate the filter unit intermittently, so there is less vibration.
It has excellent effects such as easy control.

[Brief explanation of the drawing]

1 to 3 are for explaining one embodiment of the present invention. FIG. 1 is a diagram showing the configuration of the device of this embodiment, FIG. 2 is a diagram showing a filter unit, and FIG. 5 is a timing chart showing the operation of the device. Furthermore, FIGS. 4 to 6 are diagrams for explaining the prior art, and FIG. 4 is a diagram showing its configuration, and FIG. 5 is a diagram of a filter unit.
FIG. 6 is a diagram showing another configuration. In the figure, 12 is a CCD corresponding to the imaging means, 13 is a filter unit, 14R, 14G, and 14B are color filters, and 1
6 is a DC motor corresponding to the filter driving means, 19 is a Hall IC corresponding to the signal generating means, 21 is a phase comparator corresponding to the phase difference signal generating means, 22 is a low-pass filter corresponding to the transmission system, and 31 is a variable gain An amplifier 40 is a control circuit corresponding to the selection means.

Claims (1)

[Claims] 1. Imaging means comprising a plurality of optical input elements arranged in the vertical and horizontal directions, and outputting the luminance signal of the light input by each input element field by field in synchronization with a vertical synchronizing signal. and a filter unit in which at least two color filters arranged at equal intervals on a predetermined circumference around a rotation axis are sequentially arranged on an optical path leading to the imaging means as the filter rotates around the rotation axis. , a filter driving means for rotating the filter unit at a constant speed, and a signal of the luminance of light that is imaged while at least a boundary portion of each color filter in the filter unit enters the optical path and is output from the imaging means. An image input device comprising: selection means for excluding. 2. The image input device according to claim 1, further comprising a signal generating means for generating a number of pulses corresponding to the number of color filters at equal intervals during one rotation of the filter unit; phase difference signal generating means for generating a signal corresponding to the difference between the phase of the pulse and the phase of the vertical synchronization signal; a transmission system including a transmission system, and the filter driving means controls rotation of the filter unit based on the output from the transmission system, thereby always keeping the phase difference between the two signals constant. Characteristic image input device. 3. The image input device according to claim 1 or 2, further comprising a variable gain amplifier whose gain changes depending on the color of the color filter arranged in the optical path.