Method and apparatus for image readout

• US 20040086204A1
• Filed: 10/28/2003
• Published: 05/06/2004
• Est. Priority Date: 10/28/2002
• Status: Abandoned Application

• Current Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Original Assignee: Fuji Photo Film Co Limited (Fujifilm Holdings Corporation)
• Inventors: Shoji, Takashi
• Application Number:
  US10/694,296
• Publication Number:
  US 20040086204A1
• Time in Patent Office: Days
• US Class Current: 382/312
• CPC Class Codes: H04N 1/00249 with a photographic apparatus, e.g. a photographic printer or a projector photographic apparatus per se G03B, G03D
• CPC Class Codes: H04N 1/00257 with an electro-developing recording medium, e.g. generating image signals by reading such a medium in a still camera
• CPC Class Codes: H04N 1/0402 Scanning different formats; Scanning with different densities of dots per unit length, e.g. different numbers of dots per inch (dpi); Conversion of scanning standards H04N1/00283 takes precedence; picture signal circuits for modification of image resolution H04N1/3935, H04N1/40068
• CPC Class Codes: H04N 1/0408 Different densities of dots per unit length
• CPC Class Codes: H04N 1/0411 in the main scanning direction
• CPC Class Codes: H04N 1/0443 Varying the scanning velocity or position
• CPC Class Codes: H04N 1/0455 using a single set of scanning elements, e.g. the whole of and a part of an array respectively for different formats
• CPC Class Codes: H04N 1/193 using electrically scanned linear arrays , e.g. linear CCD arrays
• CPC Class Codes: H04N 2201/04768 Controlling the frequency of the signals
• CPC Class Codes: H04N 2201/04789 in the main-scan direction
• CPC Class Codes: H04N 25/00 Circuitry of solid-state image sensors [SSIS]; Control thereof
• CPC Class Codes: H04N 5/30 Transforming light or analogous information into electric information scanning details H04N3/00; cameras or camera modules comprising electronic image sensors, or control thereof H04N23/00; circuitry of solid-state image sensors [SSIS] or control thereof H04N25/00

Abstract

Changing pixel density in the longitudinal direction of stripe electrodes (a sub-scanning direction) is enabled in a method and apparatus for reading out images from an optical readout type solid state detector equipped with stripe electrodes. A sampling rate of an image signal obtaining means is kept fixed. A readout light scanning means irradiates readout light onto the solid state detector. A pixel density changing means changes a scanning speed of the readout light in the longitudinal direction of the stripe electrodes (the sub-scanning direction), corresponding to the pixel density to be read out.

Claims

1. An image readout method comprising the steps of:

scanning a solid state detector comprising;

a first conductive layer;

at least one photoconductive layer; and

a second electrode layer having stripe electrodes formed by a plurality of linear electrodes, stacked in the order listed, which records image data as an electrostatic latent image when irradiated with recording light bearing the image data, and generates electric current corresponding to the electrostatic latent image when scanned with readout light, with the readout light;

detecting the electric current output from the linear electrodes by the scanning; and

obtaining an image signal by sampling the detected electric current at a predetermined sampling rate;

wherein

a pixel density of an image formed by the image signal, in the longitudinal direction of the linear electrodes, is changed by changing the scanning speed of the readout light and/or the sampling rate.

2. An image readout method as defined in claim 1, wherein:

a beam width of the readout light, in the longitudinal direction of the linear electrodes, is changed according to the pixel density in the longitudinal direction of the linear electrodes.

3. An image readout method as defined in claim 1, wherein:

a pixel density of the image, in a direction perpendicular to the longitudinal direction of the linear electrodes, is changed by adding the electric current detected for each of the linear electrodes in an analog manner, according to the pixel density in the longitudinal direction of the linear electrodes.

4. An image readout method as defined in claim 2, wherein:

a pixel density of the image, in a direction perpendicular to the longitudinal direction of the linear electrodes, is changed by adding the electric current detected for each of the linear electrodes in an analog manner, according to the pixel density in the longitudinal direction of the linear electrodes.

5. An image readout method comprising the steps of:

scanning a solid state detector comprising;

a first conductive layer which is transmissive with respect to recording light;

a recording light photoconductive layer which exhibits photoconductivity when irradiated with the recording light;

a charge accumulating layer that stores image data borne by the recording light as an electrostatic latent image;

a readout light photoconductive layer formed from an amorphous substance which exhibits photoconductivity when irradiated with readout light; and

a second conductive layer having stripe electrodes formed by a plurality of linear electrodes, stacked in the order listed, which generates electric current corresponding to the electrostatic latent image when scanned with the readout light, with the readout light;

detecting the electric current output from each of the linear electrodes with a current detecting means; and

obtaining an image signal by sampling the electric current, detected by the current detecting means, at a predetermined sampling rate;

wherein

a frequency band of the current detecting means is changed according to a readout speed of the electrostatic latent image, in the case that the readout speed is changed by changing a scanning speed of the readout light and the sampling rate in proportion with each other.

6. An image readout apparatus comprising:

a solid state detector comprising;

a first conductive layer;

at least one photoconductive layer; and

a second electrode layer having stripe electrodes formed by a plurality of linear electrodes, stacked in the order listed, which records image data as an electrostatic latent image when irradiated with recording light bearing the image data, and generates electric current corresponding to the electrostatic latent image when scanned with readout light, with the readout light;

a readout light scanning means for scanning the solid state detector with the readout light;

a current detecting means for detecting the electric current output from each of the linear electrodes by the scanning with the readout light;

an image signal obtaining means for obtaining an image signal by sampling the detected electric current at a predetermined sampling rate; and

a pixel density changing means for changing a pixel density of an image formed by the image signal, in the longitudinal direction of the linear electrodes, by changing the scanning speed of the readout light and/or the sampling rate.

7. An image readout apparatus as defined in claim 6, further comprising:

a beam width changing means for changing a beam width of the readout light in the longitudinal direction of the linear electrodes.

8. An image readout apparatus as defined in claim 6, further comprising:

an adding means for adding the electric current detected from each of the linear electrodes in an analog manner.

9. An image readout apparatus as defined in claim 7, further comprising:

an adding means for adding the electric current detected from each of the linear electrodes in an analog manner.

10. An image readout apparatus comprising:

a solid state detector comprising;

a first conductive layer which is transmissive with respect to recording light;

a recording light photoconductive layer which exhibits photoconductivity when irradiated with the recording light;

a charge accumulating layer that stores image data borne by the recording light as an electrostatic latent image;

a readout light photoconductive layer formed from an amorphous substance which exhibits photoconductivity when irradiated with readout light; and

a second conductive layer having stripe electrodes formed by a plurality of linear electrodes, stacked in the order listed, which generates electric current corresponding to the electrostatic latent image when scanned with the readout light, with the readout light;

a readout light scanning means for scanning the solid state detector with the readout light;

a current detecting means for detecting the electric current output from each of the linear electrodes by the scanning with the readout light;

is an image signal obtaining means for obtaining an image signal by sampling the electric current, detected by the current detecting means, at a predetermined sampling rate; and

a readout speed changing means for changing the readout speed of the electrostatic latent image by changing the scanning speed of the readout light scanning means and the sampling rate in proportion with each other.

11. An image readout apparatus as defined in claim 10, further comprising:

a frequency band changing means for changing a frequency band of the current detecting means.