JPH0238932B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Description of Technical Field) The present invention relates to a negation logic operation device for calculating negation logic of an image.

(Background of the Invention) Logical operations on one image or between images are possible by using image processing technology using an electronic computer.

When you want to perform a logical operation, such as negation, on the information of a single image, you can divide the image information into pixels and perform a logical operation, such as negation, on each pixel. Logical operations can be performed.

Also, if you want to perform a logical operation between two images, for example to calculate a logical sum, you must similarly decompose each image into pixels and calculate the logical sum of the corresponding pixels to reconstruct the image. For example, it is possible to obtain the results of logical operations between images.

To perform such calculations, a television imaging device, a frame memory that stores image information pixel by pixel, a frame memory that stores calculation results pixel by pixel, and an arithmetic circuit for logical operations are usually required. Become.

Such a calculation process involves many serial processes, and as the number of pixels increases, a larger arithmetic processing device is required.

(Objective of the Invention) An object of the present invention is to provide a negative logic operation device that obtains logic with a novel configuration that is completely different from the image processing technology described above.

(Structure of the Invention) In order to achieve the above object, a first negative logic operation device for calculating negative logic of an image according to the present invention includes a photocathode, a first surface facing the photocathode, and a second surface facing the photocathode. an electro-optic crystal having a transparent electrode on its surface; a spatial light modulation tube comprising a mesh electrode provided between the photocathode and the electro-optic crystal plate; a laser light source device that irradiates with linearly polarized laser light from the second surface side of the crystal; a photocathode of the spatial light modulation tube;
a mesh electrode, a voltage generation circuit that supplies an operating voltage to the transparent electrode, an image optical device that forms an image to be calculated on a photocathode of the spatial light modulation tube, and a photocathode of the spatial light modulation tube. includes an irradiation optical device that uniformly irradiates light, and a polarizer into which light reflected by the first surface of the electro-optic crystal is incident; By applying a voltage equal to or close to an odd multiple of a half-wavelength voltage, applying a writing voltage to the photocathode, and uniformly irradiating the photocathode with the irradiation optical device, the first part of the electro-optic crystal is A uniform charge is formed on the surface of the photocathode, and the voltage generating circuit applies a voltage that is an even multiple of a half-wavelength voltage or close to it between the mesh electrode and the transparent electrode, and a writing voltage is applied to the photocathode. By forming an image of an image to be calculated on the photocathode using the optical device, a charge image corresponding to the image is formed on the first surface of the electro-optic crystal, and the laser light source device Accordingly, the electro-optic crystal is irradiated and the light transmitted through the polarizer is configured to obtain the negative logic of the image.

In order to achieve the above object, the second negative logic operation device for calculating the negative logic of an image according to the present invention includes a photocathode, a first surface facing the photocathode, and a transparent electrode on the second surface. an electro-optic crystal provided, a spatial light modulation tube consisting of a mesh electrode provided between the photocathode and the electro-optic crystal plate; a laser light source device that irradiates with linearly polarized laser light from the surface side of the spatial light modulation tube; and a photocathode of the spatial light modulation tube;
a mesh electrode, a write voltage generation circuit that supplies an operating voltage to the transparent electrode, an image optical device that forms an image of an image to be calculated on the photocathode of the spatial light modulation tube, and an electric current of the spatial light modulation tube. an electro-optic crystal for readout having the same characteristics as the electro-optic crystal of the spatial light modulation tube having transparent electrodes on first and second surfaces between the optical crystal and the laser light source device; and an electro-optic crystal for readout; a readout voltage generation circuit that applies a voltage to the crystal; and a polarizer into which light that is reflected by a first surface of the electro-optic crystal of the spatial light modulation tube and transmitted through the read-out electro-optic crystal is incident; The write voltage generation circuit applies a voltage that is or is an odd multiple of the half-wave voltage between the mesh electrode and the transparent electrode, and by applying the write voltage, the image optical device generates an image of the image to be calculated. was formed on the photocathode to form a charge image corresponding to the image on the first surface of the electro-optic crystal, and the electro-optic crystal was irradiated with the laser light source device and transmitted through the polarizer. The light is configured to obtain the negative logic of the image.

(Description of Embodiments) FIG. 1 is a block diagram showing the configuration of a basic part of a negation logic operation device for calculating negation logic between images according to the present invention.

A photocathode 31 is formed on the inner surface of the entrance window of the vacuum vessel 34 of the spatial light modulation tube 3 .

A first surface 33a of an electro-optic crystal 33 made of a 55° cut crystal of LiNbO ₃ is opposed to the photocathode, and a transparent electrode 33b is formed on the second surface.

A mesh electrode 32 is arranged in front of the first surface 33 a of the electro-optic crystal 33 .

The photocathode 31, the mesh electrode 32, and the transparent electrode 33b on the second surface of the electro-optic crystal 33 are connected to operating voltages from connection terminals 31c, 32c, and 33c, respectively.

The image I is supported on an image arrangement table 22 and illuminated by an incoherent light source 1, and the image of the image I is formed on the photocathode 31 of the spatial light modulation tube 3 by a lens 2.

The operating voltage is supplied from the terminals 31c, 32c, and 33c, and the voltage of the photocathode 31 is set to a lower voltage (writing voltage) than the voltage of the mesh electrode 32 and the transparent electrode 33b on the second surface of the electro-optic crystal 33. Within the above voltage range, the mesh electrode 32, the electro-optic crystal 3
By applying a voltage between the transparent electrodes 33b on the second surface of the electro-optic crystal 33, a positive or negative charge image corresponding to the image of electrons emitted by the photocathode 31 is formed on the first surface of the electro-optic crystal 33. Here, the secondary electron emission characteristics of the electro-optic crystal 33, as shown in FIG. 8 like many substances, are such that the emission ratio δ is smaller than 1 at a voltage E ₁ or less specific to the crystal (material), and the above E ₁ Similarly, the emission ratio δ is larger than 1 between the crystal-specific voltage E ₂ and the above
When E is larger than ₂ , the emission ratio δ becomes smaller than 1 again.

When the voltage of the mesh electrode 32 is set to approximately _E2 , the difference between the voltage of the photocathode 31 and the voltage of the transparent electrode 33b on the second surface of the electro-optic crystal 33 is shown in FIG.
When a voltage is applied to the transparent electrode 33b to be greater than E ₂ , electrons are attached to the first surface 33a of the electro-optic crystal 33 until the voltage becomes equal to the voltage of the mesh electrode 32 (δ <1) A negative charge image is formed. When the potential due to the negative charge becomes equal to the potential E ₂ of the mesh electrode 32, the charge will not change even if electrons fly in after that. The parts to which electrons do not come are in an uncharged state.

The difference between the voltage on the photocathode 31 and the voltage on the transparent electrode 33b on the second surface of the electro-optic crystal 33 is shown in FIG.
The transparent electrode 33b is located between E ₁ and E ₂ .
When a voltage is applied to the area, secondary electrons (δ>1) generated by electrons that reach the first surface 33a of the electro-optic crystal 33 are captured by the mesh electrode 32, resulting in A positive charge image is accumulated in .

The potential due to positive charges is the potential of the mesh electrode 32.
Equilibrium occurs when it becomes equal to E ₂ , and the charge does not change even if electrons come in after that.

The parts to which electrons do not come are kept uncharged.

If electrons are not incident, the charge on the surface of the electro-optic crystal 33 is preserved even if the voltage is changed.

The state of this electro-optic crystal 33 is read out by laser light from a laser light source device.

The laser light source device includes a laser oscillator 4, a polarizer 5, a lens 6, a pinhole 7, and a collimating lens 8.

The light from the laser oscillator 4 is polarized by the crystal x
It is converted into linearly polarized light in the direction of 45° from the axis (or y′ axis).

The light is then magnified by a lens 6 and excess diffracted light is removed by a pinhole 7.

The light transmitted through the pinhole 7 is converted into parallel light by a collimating lens 8, and is made incident on the crystal from the second surface of the electro-optic crystal through a half mirror 9. The electro-optic crystal (LiNbO ₃ ) is cut into a wafer shape as shown in FIG.

Due to the surface charge of the LiNbO ₃ electro-optic crystal 33, the electric field in the thickness direction of the crystal changes and
The refractive index in the y′ direction changes as shown in the following equation.

nx＝nx ₀ −rx・E……(1) ny′=ny′ ₀ −ry′・E……(2) Here, nx ₀ , ny′ ₀ : x direction when no charge exists, y′ Refractive index in the direction E: electric field generated in the crystal due to the presence of charges rx, ry': electro-optic constant x-direction component of light incident on the electro-optic crystal 33,
Since the speed of the y' direction component is different (because the refractive index of the crystal is different in the x and y' directions), the x direction component and the y' direction component of the light reflected from the crystal surface and returning have a position as shown in the following equation. A phase difference occurs, and the light is generally output as elliptically polarized light.

Γ=(2π/λ)・(El)・2(ry'−rx) ...(3) Here, λ: Wavelength of light output from laser oscillator 4 l: Thickness of crystal 33 This output light is polarized. When the light beam passes through the element 10, only one polarization direction component is extracted, and a coherent optical image modulated by the input image I is obtained as an output. At this time, the output light intensity I ₀ is given by the following formula.

I ₀ = A sin ₂ Γ/2 = A sin ₂ (π/2)・(V/Vπ
)...(4) Here, V: Voltage equivalent to charge σVπ: Voltage equivalent to charge σπ (half-wave voltage) Figure 2 shows a curve based on equation (4).

As shown in FIG. 2, the electric field within the electro-optic crystal 33 changes due to surface charges, thereby changing the intensity of the reflected light.

The following can be understood from Figure 2.

When the surface charge of the electro-optic crystal is 0, that is, when there is no incidence of photoelectrons (hereinafter referred to as state a),
It enters the electro-optic crystal 33 via the half mirror 9, is reflected by the first surface, is reflected by the half mirror 9,
The intensity of the laser beam that has passed through the polarizer 10 is zero. When the surface charge is -σπ (hereinafter referred to as state b) and when the surface charge is σπ (hereinafter referred to as state c), the transmitted light is at a maximum.

When the surface charge is -σπ/2 (hereinafter referred to as d state)
and when the surface charge is σπ/2 (state e below)
Then, the transmitted light is 1/2 of the maximum light.

Generally speaking, when a voltage that is an odd multiple of the half-wave voltage is applied between the mesh electrode 32 and the electro-optic crystal 33, if a write voltage that lowers the voltage of the photocathode 31 is applied, it is sufficient to A charge of -σπ or an odd multiple of σπ is accumulated in the area where the photoelectrons have arrived.

Furthermore, when a voltage that is an even number multiple of the half-wavelength voltage is applied between the mesh electrode 32 and the electro-optic crystal 33, if a write voltage that lowers the voltage of the photocathode 31 is applied, sufficient photoelectrons will fly. If there is-
Charges of σπ or even multiples of σπ are accumulated.

FIG. 3 is a block diagram showing an embodiment of the first configuration of a negative logic operation device for calculating negative logic of an image according to the present invention.

The configurations of the spatial light modulation tube 3 and the laser light source device are the same as those described with reference to FIG.

Electrodes at various parts of the spatial light modulation tube 3 are connected to a voltage generation circuit 11.

An output terminal a of the voltage generating circuit 11 generates an image writing voltage Va. Va is normally +3kV (write prohibited state), and when it is 0, it is a write state. The mesh electrode 32 is connected to the voltage Vb from the output terminal b of the voltage generation circuit 11, and the transparent electrode 33b on the second surface of the electro-optic crystal 33 is connected to the voltage Vc from the output terminal c of the voltage generation circuit 11. . These voltages are usually positive voltages, and when Vb-Vc<0, writing is performed on the first surface 33a of the electro-optic crystal 33 using negative charges, and when Vb-Vc>0, writing is performed using positive charges. .

In this example, the half-wave voltage Vπ mentioned above is
It is 1.0kV.

Images for which negative logic is required are placed on image placement stand 2 in Figure 3.
2 and is irradiated by an incoherent light source 1 via a half mirror 16.

The image is formed on the photocathode 31 of the spatial light modulation tube 3 via the half mirror 17 and the lens 2.

incoherent light source 1, half mirror 16,
The total reflection mirror 14, the shutter 13, the total reflection mirror 15, and the half mirror 17 are the photocathode 3 of the spatial light modulation tube 3.
1 is formed as an irradiation optical system that uniformly irradiates the light.

The shutter 13 is opened and closed by a shutter drive circuit 18, and even when an image is supported on the image arrangement table 22, by opening the shutter 13, the photocathode 31 of the spatial light modulation tube 3 can be uniformly irradiated.

Next, an example of determining the negative logic of the image Ix shown in FIG. 5A will be explained in detail.

The shutter drive circuit 18 opens the shutter 13 and uniformly illuminates the photocathode of the spatial light modulation tube 3. In this state, from the voltage generation circuit 11, Vb=
2kV and Vc=3kV, mesh electrode 32
From the voltage of the transparent electrode of the electro-optic crystal 33,
Lower it by Vπ (Vb-Vc=-1.0kV=-Vπ).

Then, the voltage Va of the photocathode 31 is changed from +3kV to 0.
change to Since photoelectrons uniformly fly to the first surface of the electro-optic crystal 33, charges of -σπ are uniformly accumulated on the first surface of the electro-optic crystal 33.

At this time, the electro-optic crystal 33 is in the state of point b in FIG.

The voltage Va is changed from 0 to +3 kV to complete writing of the entire surface.

Next, from the voltage generation circuit 11, Vb=2kV and Vc
=2kV, and write voltage Va from +3kV to 0
change to

Electro-optic crystal 3 corresponding to the background part of image Ix
Since no photoelectrons fly to the first surface of 3, the charge -σπ of that part does not change.

Secondary electrons (δ>1) caused by photoelectrons incident from the white circle part of the image Ix are captured by the mesh electrode 32, and as a result, the negative charge in that part decreases and the charge becomes 0 and is balanced.

Image Ix by changing voltage Va from 0 to +3kV
Finish writing.

Electro-optic crystal 33 written in this way
When reading light from the laser oscillator 4 of the laser light source device is applied to the surface of the electro-optic crystal 33, the plane of polarization changes by 90° because an electric field is formed in the crystal due to the half-wave voltage at the charge −σπ portion on the surface of the electro-optic crystal 33. When the light passes through the polarizer 10, it is observed brightly. As a result, the data is read out as shown in FIG. 4B.

FIG. 4 is a block diagram showing an embodiment of a second configuration of a negative logic operation device for calculating negative logic of an image according to the present invention.

The configurations of the spatial light modulation tube 3 and the laser light source device are the same as those described with reference to FIG.

Electrodes at various parts of the spatial light modulation tube 3 are connected to a voltage generation circuit 11.

In this embodiment, an electro-optic crystal 12 for reading is arranged between an electro-optic crystal 33 of the spatial light modulation tube 3 and the laser light source device.

This readout electro-optic crystal 12 is the first
Transparent electrodes 12a and 12b are provided on the second surface. As the crystal, a 55° cut LiNbO ₃ crystal having the same characteristics as the electro-optic crystal 33 of the spatial light modulation tube 3 is used.

A read voltage is connected between the transparent electrodes 12a and 12b from an output terminal d of a read voltage generation circuit 11 provided integrally with the write voltage generation circuit 11.

When a voltage is applied between the transparent electrodes of the electro-optic crystal 12, the same electro-optic characteristics as when uniform charges are accumulated on the first surface of the electro-optic crystal 33 are exhibited. For example, when a half-wavelength voltage Vπ is applied, electro-optical characteristics similar to those obtained when a uniform charge −σπ or σπ is applied to the surface are exhibited.

Next, using the embodiment apparatus, the image shown in FIG. 5A is
An example of finding the negative logic of Ix will be explained in detail.

The image Ix is supported by the image arrangement stand 22. The image Ix is illuminated by the incoherent light source 1, and an image of the white circle portion is formed on the photocathode of the spatial light modulation tube 3.

In this state, Vb=
2kV, Vc = 3kV to the transparent electrode of electro-optic crystal 33
Apply. A negative half-wavelength voltage -Vπ is applied at Vb-Vc=-1.0kV.

By changing the photocathode voltage Va from +3kV to 0,
Form a write state.

Electrons do not fly to the surface of the electro-optic crystal 33, which corresponds to the background part (black part) of the image Ix.

Therefore, the charge accumulated in that portion is 0, and the charge that causes a potential difference between the transparent electrodes 33c on the back surface is not accumulated.

The characteristics of that part correspond to the position shown in Figure 2a.

The signal part (white circle part) of image Ix accumulates the incoming charge, and - between it and the transparent electrode 33c on the back side.
A charge −σπ giving a potential difference of Vπ is accumulated. The characteristics of this part correspond to FIG. 2b. The voltage Va of the photocathode is changed from 0 to +3 kV to complete writing of the image Ix.

The charges written in the above manner are the voltage Va,
It is saved even if Vb is set to 0.

Next, the voltage π/2 is applied from the d terminal of the voltage generating circuit 11.
is applied to the electro-optic crystal 12 for reading.

When reading light from the laser oscillator 4 of the laser light source device is applied, the light traveling back and forth through the crystal 12 uniformly undergoes a phase change corresponding to Vπ. Therefore,
The light from the portion of charge −σπ on the surface of the electro-optic crystal 33 that has passed through the polarizer 10 moves from point b to a in FIG.
In the part where there is no charge, the intensity appears to be large as point a moves to point c, as shown in FIG. 5B.

In the embodiment described above, writing was performed by changing the write voltage Va with an image irradiated onto the photocathode, but writing was performed by keeping Va in the writing state and controlling the image on the photocathode with an optical shutter. can be made to perform an action.

Various modifications can be made to the embodiments described in detail above within the scope of the present invention.

As shown in FIG. 6, if the microchannel plate 35 is inserted into the spatial light modulation tube,
This is useful when calculating the logical sum of weak images.

As an example, a 55° cut crystal of LiNbO ₃ is used as the electro-optic crystal of the spatial light modulation tube, but single crystals such as KDP and BSO can be similarly used.

(Description of Effects) As explained above, the device according to the present invention can obtain the negative logic of an image by writing an image on the surface of an electro-optic crystal using electric charges.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of the main part of a negative logic operation device for calculating negative logic of an image according to the present invention. FIG. 2 is a graph showing the characteristics of the electro-optic crystal of the spatial light modulation tube and the characteristics of the electro-optic crystal for readout of the negative logic operation device for calculating the negative logic of an image according to the present invention. FIG. 3 is a block diagram showing an embodiment of the first configuration of a negative logic operation device for calculating negative logic of an image according to the present invention. Fourth
The figure is a block diagram showing an embodiment of a second configuration of a negative logic operation device for calculating negative logic of an image according to the present invention. FIG. 5 is an explanatory diagram showing an image that is the object of a logical operation and the result of the logical operation. FIG. 6 is a sectional view showing another embodiment of the spatial light modulation tube. FIG. 7 is a schematic diagram for explaining the direction of the crystal axis of an electro-optic crystal. FIG. 8 is a graph showing the relationship between secondary electron energy and secondary electron emission ratio. 1...Incoherent light source, 2...Lens,
3... Spatial light modulation tube, 31... Photocathode, 32...
mesh electrode, 33...electro-optic crystal, 34...vacuum container, 35...microchannel plate,
4... Laser oscillator, 5... Polarizer, 6... Lens, 7... Pinhole, 8... Collimating lens, 9... Half mirror, 10... Polarizer,
11... Voltage generating circuit, 12... Electro-optic crystal for readout, 13... Shutter, 14, 15... Total reflection mirror, 16, 17... Half mirror, 18
... Shutter drive circuit, 20 ... Reproduction image surface, 22
...Image arrangement table.

Claims (1)

[Claims] 1. A photocathode, an electro-optic crystal having a first surface facing the photocathode and a transparent electrode provided on a second surface, and a combination of the photocathode and the electro-optic crystal plate. a spatial light modulation tube comprising a mesh electrode provided between the spatial light modulation tubes; a laser light source device that irradiates the second surface of the electro-optic crystal with linearly polarized laser light from outside the spatial light modulation tube; a voltage generation circuit that supplies an operating voltage to the photocathode, the mesh electrode, and the transparent electrode of the spatial light modulation tube; and an image optical device that forms an image of an image to be calculated on the photocathode of the spatial light modulation tube. , an irradiation optical device that uniformly irradiates the photocathode of the spatial light modulation tube, and a first irradiation optical device of the electro-optic crystal.
a polarizer onto which the light reflected on the surface is incident, and the voltage generating circuit causes the mesh electrode to
By applying a voltage equal to or close to an odd multiple of a half-wavelength voltage between the transparent electrodes, applying a writing voltage to the photocathode, and uniformly irradiating the photocathode with the irradiation optical device, A uniform charge is formed on the first surface of the optical crystal, and a voltage that is an even multiple of the half-wavelength voltage or close to it is applied between the mesh electrode and the transparent electrode by the voltage generating circuit, and the voltage is applied to the photocathode. A charge image corresponding to the image is formed on the first surface of the electro-optic crystal by applying a write voltage and forming an image of an image to be calculated by the optical device on the photocathode. ,
A negation logic arithmetic device for obtaining negation logic of an image, configured to obtain negation logic of the image from light that is irradiated with the electro-optic crystal by the laser light source device and transmitted through the polarizer. 2. The negative logic operation device for determining the negative logic of an image according to claim 1, wherein the electro-optic crystal is a 55° cut crystal of LiNbO ₃ . 3. The negative logic operation device for determining the negative logic of an image according to claim 1, wherein the spatial light modulation tube has a microchannel plate disposed between the photocathode and the mesh electrode. 4. A photocathode, an electro-optic crystal having a first surface facing the photocathode and a transparent electrode provided on a second surface, a mesh provided between the photocathode and the electro-optic crystal plate. a spatial light modulation tube including a shaped electrode; a laser light source device for irradiating linearly polarized laser light from outside the spatial light modulation tube from the second surface side of the electro-optic crystal; a photocathode, a mesh electrode, a write voltage generation circuit that supplies an operating voltage to the transparent electrode, an image optical device that forms an image of an image to be calculated on the photocathode of the spatial light modulation tube, and the spatial light modulation tube. between the electro-optic crystal of the tube and the laser light source device;
a readout electro-optic crystal having the same characteristics as the electro-optic crystal of the spatial light modulation tube having a transparent electrode on a surface thereof; a readout voltage generation circuit for applying a voltage to the readout electro-optic crystal; and the spatial light modulation tube. a polarizer on which light reflected by a first surface of the electro-optic crystal of the tube and transmitted through the read-out electro-optic crystal is incident, and the write voltage generating circuit causes a polarizer to enter the polarizer between the mesh electrode and the transparent electrode. of the electro-optic crystal by applying a voltage that is an odd multiple of the half-wavelength voltage or close to it, and applying a write voltage to form an image of the image to be calculated by the image optical device on the photocathode. Negation of the image configured to form a charge image corresponding to the image on a first surface, irradiate the electro-optic crystal with the laser light source device, and obtain negation logic of the image in light transmitted through the polarizer. Negative logic operation device for finding logic.