JP3331082B2 - Lighting control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image input apparatus having an electro-developing recording medium capable of holding an image as a visible image, and more particularly to an electro-developing recording medium for reading an image from the recording medium. The present invention relates to a control device for a light source that illuminates a light source.

[0002]

2. Description of the Related Art Conventionally, silver halide photographic materials have been widely used as materials for recording optical images. Silver halide photographic materials have features such as high light sensitivity and resolution, and are also economical, but not only are the development processes complicated,
There is also a disadvantage that a visible image cannot be obtained simultaneously with shooting. Although a dry development method has been developed to simplify the development processing, it is impossible to immediately develop the image, that is, obtain a visible image at the time of photographing, even with this development method.

On the other hand, as a non-silver salt photographic material, an electrophotographic material, a diazo photographic material, a free radical photographic material and the like are known. However, none of these photographic materials has characteristics such as silver halide photographic materials and can be developed immediately. Since electrophotographic materials can be dry-developed and an electrostatic latent image obtained by exposure can be immediately developed with toner or the like, they have been widely used mainly in copiers.

In recent years, in such an electrophotographic technique, a photographic material, such as a silver halide photographic material, in which a recording medium itself is directly electronically developed and the developed visible image is immediately obtained, has been developed. Is coming. Such an electronically developed recording medium is referred to as an electro-developing recording medium in this specification.

For example, JP-A-5-2280 discloses a recording medium in which an electrostatic information recording medium and a charge holding medium are combined. The electrostatic information recording medium comprises a photoconductive layer and an inorganic oxide layer. And the charge holding medium has a liquid crystal display element. With this configuration, when the electrostatic information recording medium is exposed while a voltage is applied to the electrostatic information recording medium and the charge holding medium, charges corresponding to the amount of incident light are generated on the electrostatic information recording medium. Since the strength of the electric field applied to the liquid crystal display element arranged opposite to the electrostatic information recording medium changes according to the generated charges, an image corresponding to the light amount distribution is displayed on the liquid crystal display element, that is, the image is developed. .

Japanese Patent Application Laid-Open No. 5-150251 discloses a dispersion type liquid crystal display element in which an image displayed on the liquid crystal display element is retained even when an electric field applied to the liquid crystal display element is removed.

An image held on such an electro-developing recording medium can be read out, for example, by sub-scanning a line sensor. For this reading, a light source is placed facing the front surface of the electro-developing recording medium. It is possible to arrange.

[0008]

When the light sources are arranged as described above, it is difficult to faithfully reproduce an image unless the light distribution characteristics of the light source are uniform along the optical sensor. There is a problem that the load increases and the processing time increases. An object of the present invention is to make it possible to faithfully reproduce an image even when the light distribution characteristics of a light source are non-uniform, and to reduce the burden of correction processing of an image read by an optical sensor as much as possible. I have.

[0009]

According to the present invention, there is provided an illumination control apparatus comprising: an electro-developing recording medium for electronically holding an image;
A light source for illuminating the electro-developing recording medium, an optical sensor for detecting light transmitted or reflected on the electro-developing recording medium by the illumination of the light source, and an optical sensor for reading the image by the optical sensor during an image reading operation. And light source control means for displacing in the main scanning direction.

[0010]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. FIG. 1 is an external view of a still video camera to which one embodiment of the present invention is applied.

When the camera body 11 is viewed from the front, an imaging optical system 12 having a photographing lens and the like is provided substantially at the center of the front surface, and a strobe 13 is provided at the upper right of the imaging optical system 12. A release switch 14 is provided on the opposite side of the flash 13. The finder 15 is provided at the center of the upper surface of the camera body 11, and operation switches such as the scan start switch 16 are provided on the side of the finder 15. In order to output an image signal obtained by the camera to an external recording device or the like, the camera body 11
An output terminal 17 is provided at a lower portion of the side surface of the.

FIG. 2 is a block diagram of a still video camera. The system control circuit 20 is a microcomputer, and controls the whole still video camera.

The imaging optical system 12 includes a plurality of lens groups,
An aperture 12a is provided. An electro-developing recording medium 30, which will be described later, is provided behind the imaging optical system 12, and a quick return mirror 21 is provided between the imaging optical system 12 and the electro-developing recording medium 30. A shutter 22 is provided between the electro-developing recording media 30.
Is provided. Above the quick return mirror 21, a focus plate 23a of the finder optical system 23 is provided.

Aperture 12a, quick return mirror 21
And the shutter 22 are provided in the iris drive circuit 2 respectively.
4. Driven by a mirror drive circuit 25 and a shutter drive circuit 26, and these circuits 24, 25 and 26 are controlled by an exposure control circuit 27. The exposure control circuit 27 operates according to a command signal output from the system control circuit 20. That is, at the time of exposure control, the photometric sensor 2
The aperture of the aperture 12a is adjusted by the iris drive circuit 24 under the control of the exposure control circuit 27 based on the output signal from the iris 8. The quick return mirror 21 is normally set at the down position (in an inclined state shown by a solid line), and guides the light that has passed through the imaging optical system 12 to the finder optical system 23. Accordingly, the mirror is driven upward by the mirror driving circuit 25 and is set to the up position (horizontal state indicated by a broken line). Although the shutter 22 is normally closed,
According to the control of the exposure control circuit 27, the shutter drive circuit 2
6 is opened for a predetermined time.
The light passing through 2 is applied to the light receiving surface of the electro-developing recording medium 30.

A voltage is applied to the electro-developing recording medium 30 under the control of the recording medium drive circuit 41, and the electro-developing recording medium 30 is exposed during the application of the voltage to thereby be exposed.
As described later, the image formed by the imaging optical system 12 is developed as a visible image, as described later. The recording medium drive circuit 41 operates according to a command signal output from the system control circuit 20.

A sub-scanning mechanism 50 is provided near the electro-developing recording medium 30. The sub-scanning mechanism 50 supports a light source 42, a scanner optical system 43, and a line sensor 44, which move along the electro-developing recording medium 30 by sub-scanning by the sub-scanning mechanism 50.
As the line sensor 44, for example, a CCD one-dimensional sensor having 2000 pixels can be used. The light source 42 is movable along the front surface of the shutter 22, that is, the front surface of the electro-developing recording medium 30, and the line sensor 44 is movable along the back surface of the electro-developing recording medium 30. The scanner optical system 43 is provided between the light source 42 and the line sensor 44. In the sub-scanning by the sub-scanning mechanism 50, the light source 42 is
The image developed on the electro-developing recording medium 30 is illuminated by the light source 42 and the line sensor 4 is operated by the scanner optical system 43.
4 is formed on the light receiving surface. That is, the scanner optical system 43
Is provided in the middle of the path of light transmitted through the electro-developing recording medium 30, and the line sensor 44 is provided with a scanner optical system 43.
Move on the image plane of the image.

The on / off control of the light source 42 is performed by an illumination light source driving circuit 45, and the control such as the reading operation of the pixel signal generated in the line sensor 44 is performed by a line sensor driving circuit 47.
It is performed by The movement of the sub-scanning mechanism 50 is controlled by the scanner drive circuit 46. These circuits 45,
46 and 47 are controlled by the system control circuit 20.

The pixel signal read from the line sensor 44 is amplified by an amplifier 61 and converted into a digital signal by an A / D converter 62. The digital pixel signal is stored in the memory 64 under the control of the system control circuit 20, and is subjected to processing such as shading correction, dropout correction, and gamma correction in the image processing circuit 63, and then is processed as image data in the interface circuit 65 or It is input to the recording device control circuit 66.

The image data is subjected to predetermined processing such as format conversion in the interface circuit 65,
Output can be made to an external display device (not shown) via the output terminal 17. The image data is subjected to predetermined processing such as image compression or format conversion in a recording device control circuit 66, and can be recorded in a recording medium such as a hard disk or an IC memory card in the image recording device 67. Interface circuit 6
5 and the recording device control circuit 66 operate according to a command signal from the system control circuit 20.

A release switch 14 and a scan start switch 16 are connected to the system control circuit 20. According to the operation of these switches 14, 16,
An imaging operation, an image signal reading operation, and the like are performed.

The system control circuit 20 includes:
A display element 68 for displaying various setting states of the still video camera and the like, and a flash drive circuit 69 for controlling the light emission of the flash 13 are connected.

FIG. 3 is a perspective view showing the configuration of the sub-scanning mechanism 50 and its vicinity. The moving member 52 of the sub-scanning mechanism 50 is slidably supported by the pair of guide shafts 51 and has first and second legs 52a and 52b. The first leg 52a projects between the quick return mirror 21 and the shutter 22 (see FIG. 1), and the second leg 52a.
b protrudes to the back side of the electro-developing recording medium 30. The light source 42 is connected via a displacement mechanism 57 to a projection 52d extending downward from the tip of the first leg 52a. The scanner optical system 43 is supported via a connecting member (not shown) in front of the second leg 52b.
Is mounted in a frame formed on the second leg 52b. The rack 53 fixed to the moving member 52 is a pinion 5
4 and the pinion 54 meshes with a gear 56 provided on the output shaft of the scan drive motor 55.

The light source 42 has a support frame 42a connected to a displacement mechanism 57 and a plurality of light emitting elements (LEDs) 42b. Each light emitting element 42b is arranged in the horizontal direction and faces the line sensor 44. ing. The displacement mechanism 57 has a solenoid in the present embodiment, and the support frame 42a is fixed to a plunger of the solenoid. The plunger can be displaced in the direction in which the light emitting elements 42a are arranged (the longitudinal direction of the line sensor 44, that is, the main scanning direction) according to a command signal output from the illumination light source drive circuit 45 (see FIG. 1). Note that the plurality of light emitting elements 42
Instead of the configuration in which b is provided, a continuous linear light emitting element may be provided.

At the time other than the photographing operation, the moving member 52 is located at a position off the optical path between the imaging optical system 12 and the electro-developing recording medium 30, for example, below the electro-developing recording medium 30. When the imaging operation is completed, the electro-developing recording medium 3
When the image is developed at 0, the scan drive motor 55 rotates, the moving member 52 rises and the sub-scan is performed by the line sensor 44, and the line sensor 44 is orthogonal to the longitudinal direction, as described later. Scan in the direction. During this sub scanning, the displacement mechanism 57 is controlled, and the light emitting element 42a is displaced in the direction of the arrow L1 or L2 as shown in FIG. Therefore, even if the light distribution characteristics of each light emitting element 42a are non-uniform as indicated by the curve C1, the distribution of the light applied to the electro-developing recording medium 30 is made uniform.

FIG. 5 is a diagram showing the structure of the electro-developing recording medium 30, which is the same as that disclosed in Japanese Patent Application Laid-Open No. 5-2280. That is, the electro-developing recording medium 3
0 denotes an electrostatic information recording medium 31, a charge holding medium 32, and a power supply 3
3 is provided. The electrostatic information recording medium 31 is
4, electrode layer 35, inorganic oxide layer 36, and photoconductive layer 37
And the photoconductive layer 37 is formed by polymerizing the charge generation layer 37a and the charge transport layer 37b. The charge holding medium 32 includes a liquid crystal 4 between the liquid crystal support 38 and the liquid crystal electrode layer 39.
0 is enclosed. The charge transport layer 37b of the electrostatic information recording medium 31 and the liquid crystal support 38 of the charge holding medium 32 face each other with a small gap.

The power supply 33 is turned on and off by a recording medium drive circuit 41. When the power supply 33 is on, the electrode layer 3 is turned on.
5 and the liquid crystal electrode layer 39, that is, the electrostatic information recording medium 3
1 and a voltage are applied to the charge holding medium 32. When the electrostatic information recording medium 31 is exposed in this voltage applied state, charges corresponding to an image are generated on the electrostatic information recording medium 31. Since the intensity of the electric field acting on the liquid crystal 40 changes according to the charge, the image is displayed on the liquid crystal 40 as a visible image, and the subject image is developed. The charge holding medium 32 is a dispersion type liquid crystal display element, and the developed visible image is held even when the electric field is removed. The dispersion type liquid crystal display element can erase the developed visible image by heating to a predetermined temperature using a heating device (not shown). In this case, the same recording medium can be repeatedly used. it can.

FIG. 6 is a timing chart showing an image pickup operation and an operation of reading a pixel signal from the line sensor 44.

When it is detected that the release switch 14 has been pressed (reference S11), an output signal from the photometric sensor 28, that is, a photometric value is detected. Exposure calculation is started based on the photometric value (reference S12). After a predetermined time has elapsed since the release switch 14 was pressed, a recording medium activation signal is output from the recording medium drive circuit 41 (reference S13), whereby the power supply 33 is turned on and the electrostatic information recording is performed. A voltage is applied to the medium 31 and the charge holding medium 32. Next, when it is confirmed that the exposure calculation is completed (reference S14), an imaging operation is performed according to the calculation result.

The opening of the aperture 12a changes from a fully opened state to a predetermined opening (reference S15), and the quick return mirror 21 changes from a down state to an up state (reference S).
16). Change of the mirror 21 to the up state and the aperture 12a
When it is confirmed that the opening adjustment of the shutter 2 is completed, the shutter 2
2 is released (reference S17). When the exposure period obtained by the exposure calculation has elapsed and the completion of the exposure is detected, the shutter 22 is closed (reference S18). With the completion of the closing operation of the shutter 22, the mirror 21 changes to the down state (reference S19), the aperture 12a opens to the fully open state (reference S20), and the output of the recording medium activation signal is stopped (reference S20). Symbol S21).

That is, the recording medium activation signal is output at least while the shutter 22 is open, and during this time, a predetermined voltage is applied to the electro-developing recording medium 30. By exposing in this state, the subject image is developed on the electro-developing recording medium 30 as a visible image. This visible image is retained even when the output of the recording medium activation signal is stopped.

Thereafter, when it is confirmed that the mirror 21 and the aperture 12a have returned to the initial state, the mirror 21 and the aperture 1
The driving of 2a is stopped, and this imaging operation ends.

Next, when the scan start switch 16 is pressed, the sub-scanning by the sub-scanning mechanism 50 starts, and the reading operation described below is performed.

When it is confirmed that the scanner drive command signal has been output (reference S31), the shutter 22 is opened (reference S32), and the light source 42 is turned on (reference S3).
3). Then, a scanner drive signal is output (reference S
34), the scan drive motor 55 rotates forward, and the moving member 52 of the sub-scanning mechanism 50 starts to rise (reference S35). At about the same time when the driving of the sub-scanning mechanism 50 is started, the line sensor driving power supply is turned on (reference S36).

When it is confirmed that the line sensor 44 is set at the reading start position, the output of the scanner drive signal is stopped (reference S37), and the scan drive motor 55 is stopped.
Is stopped (reference S38). Thus, the line sensor 44 is positioned at, for example, the lower end of the recording area of the electro-developing recording medium 30. Such a stop operation is controlled, for example, by counting pulse signals for driving the scan drive motor 55 to rotate.

Next, exposure to the line sensor 44 is started, and charge accumulation is performed (reference S39). When the predetermined time has elapsed and it is confirmed that the exposure of the line sensor 44 has been completed, the reading scan of the line sensor 44 is started, and the output of pixel signals for one horizontal scanning line is started (reference S40). Then, a scanner drive signal for rotating the scan drive motor 55 forward is output (reference S41), and the moving member 52 starts to further rise (reference S42). During this rising operation, the pixel signal is stored in the memory 64.

During the movement of the moving member 52, if it is confirmed that pixel signals for one horizontal scanning line have been read from the line sensor 44 and stored in the memory 64a, the reading scan is stopped ( Symbol S43). The end of the readout scanning is controlled by counting pulse signals for driving the line sensor 44 output from the line sensor drive circuit 47, for example.

When it is confirmed that the line sensor 44 is set at the position of the next horizontal scanning line, the output of the scanner drive signal is stopped (reference S44), and the scan drive motor 55 is stopped (reference S45). ). This stop operation is controlled by, for example, counting pulse signals for driving the scan drive motor 55 to rotate.

As described above, in this embodiment, the line sensor 4
4 scans the image forming surface by the scanner optical system 43 while repeating the stop of the predetermined time and the movement of the predetermined amount by the sub-scanning mechanism 50, so that the image signal developed by the electro-developing recording medium 30 is read. It is.

When the reading of all the horizontal scanning lines is completed in this manner (reference S51), the driving power supply of the line sensor 44 is switched off, and the light source 42 is turned off (reference S52). Then, the shutter 22 is closed (reference S53), a scanner drive signal for reversing the scan drive motor 55 is output (reference S54), and the moving member 52 starts to descend (reference S55).

During the lowering operation of the moving member 52, when it is confirmed that the line sensor 44 has returned to the initial position,
The output of the scanner drive signal is stopped (reference S56),
The scan drive motor 55 is stopped (reference S57).
The operation of detecting the initial position is performed based on, for example, a signal output when a part of the moving member 52 crosses a photo interrupter (not shown).

FIG. 7 shows two types of signals for driving the displacement mechanism 57 below the charge accumulation and output signals in the line sensor 44 shown in the timing chart of FIG.

In the first example, the displacement mechanism 5 is driven by the drive signal a.
7 is driven. The magnitude of the drive signal a linearly increases during the charge accumulation time in the line sensor 44 (reference S61), and after the completion of the charge accumulation, 1
While the pixel signals for the horizontal scanning lines are being output, they decrease linearly (reference S62). Thereafter, the drive signal a changes periodically.

In the second example, the displacement mechanism 5 is driven by the drive signal b.
7 is driven, and the magnitude of the drive signal b increases linearly during the charge accumulation time in the line sensor 44 (reference S63).
While the pixel signals for the horizontal scanning lines are being output, they are held at a constant value (reference S64). Then, when the next exposure is performed in the line sensor 44, the magnitude of the drive signal b decreases linearly from the start of the exposure (reference S65), and while the pixel signals for one horizontal scanning line are being output, It is held at a constant value (reference S66). Thereafter, the drive signal b changes periodically.

In this embodiment, when the values of the drive signals a and b increase, the plunger of the displacement mechanism 57 projects and the light source 4
When the second support frame 42a is displaced rightward in FIG. 3 and the values of the drive signals a and b are reduced, the plunger is retracted and the support frame 42a is displaced leftward in FIG. In the first example, the light source 42 is constantly displaced in the same direction while the line sensor 44 is performing the charge accumulation operation, and the light source 4 is not moving when the line sensor 44 is performing the charge accumulation operation.
2 is displaced in the opposite direction. On the other hand, in the second example, focusing on the state where the line sensor 44 is performing the charge accumulation operation, the light source 44 is displaced in the opposite direction every other time, and the line sensor 44 is not performing the charge accumulation operation. At this time, the light source 44 is stopped.

The displacement of the light source 42 is, for example, 2
This is the distance between the two light emitting elements 42b, or a half of the distance, thereby making it possible to compensate for the non-uniform light distribution of the light source 42. Therefore, according to the present embodiment, even if the light distribution characteristics of the light source 42 are not uniform in the longitudinal direction of the line sensor 44, it is possible to alleviate the uneven illuminance on the light receiving surface of the line sensor 44. As a result, the burden of post-processing such as shading correction in the image processing circuit 63 can be reduced, the processing time can be shortened, and the accuracy in image reproduction can be increased.

Note that the electro-developing recording medium 30 is not limited to the above-described configuration, and may have another configuration as long as the image is developed electronically.

The line sensor 44 may be provided to detect light reflected on the electro-developing recording medium 30.

[0048]

As described above, according to the present invention, it is possible to faithfully reproduce an image even when the light distribution characteristics of the light source are not uniform, and to correct the image read by the optical sensor. Can be reduced as much as possible.

[Brief description of the drawings]

FIG. 1 is an external view of a still video camera to which an embodiment of the present invention has been applied.

FIG. 2 is a block diagram showing a circuit configuration of the still video camera of FIG. 1;

FIG. 3 is a diagram illustrating a configuration of a sub-scanning mechanism and its vicinity.

FIG. 4 is a diagram showing an arrangement of light emitting elements in a light source.

FIG. 5 is a diagram illustrating a configuration of an electro-developing recording medium.

FIG. 6 is a timing chart illustrating an imaging operation and an operation of reading a pixel signal from a line sensor.

FIG. 7 is a timing chart showing a drive signal of a light source.

[Explanation of symbols]

 Reference Signs List 30 electro-developing recording medium 42 light source 42a support frame 42b light emitting element 44 line sensor 57 displacement mechanism

Claims (7)

(57) [Claims] 1. An electro-developing recording medium for electronically storing an image, a light source for illuminating the electro-developing recording medium, and a light transmitted or reflected by the electro-developing recording medium by the light source. An illumination control device comprising: an optical sensor that reads an image by an optical sensor; and light source control means that displaces the light source in a main scanning direction of the optical sensor during an operation of reading the image by the optical sensor. 2. The optical sensor is a line sensor,
An illumination control device, wherein the light source is disposed so as to face the line sensor. 3. The illumination control device according to claim 1, wherein the light source control means displaces the light source in accordance with a charge accumulation time of the optical sensor. 4. The light source control means displaces the light source in a first direction while the optical sensor is performing a charge storage operation, and when the optical sensor is not performing a charge storage operation, the light source controls the light source. The illumination control device according to claim 1, wherein the control unit is displaced in a direction opposite to the first direction. 5. The light source control means displaces the light source in a first direction or a second direction opposite to this direction while the optical sensor performs a charge accumulation operation, and The lighting control device according to claim 1, wherein the light source is stopped when the charge accumulation operation is not performed. 6. An electro-information recording medium according to claim 1, wherein said electro-developing recording medium comprises: an electrostatic information recording medium on which an electric charge is generated according to an image; The lighting control device according to claim 1, further comprising a medium. 7. The illumination control device according to claim 6, wherein the charge holding medium is a dispersion type liquid crystal display device.